428 results on '"Shapley, A"'
Search Results
2. The role of the psychologist in the inpatient pain service: development and initial outcomes
- Author
-
Chandran Jepegnanam, Tecla Makaka, Zoey Malpus, Jo Cooper, Maureen Booth, Eleanor Bull, Sujesh Bansal, Gemma Shapley, David McCarthy, Jill Probert, and Elizabeth Purser
- Subjects
National health ,Service (business) ,medicine.medical_specialty ,business.industry ,Psychological therapy ,Psychological distress ,Articles ,Anesthesiology and Pain Medicine ,North west ,Medicine ,Anxiety ,medicine.symptom ,business ,Psychiatry ,Depression (differential diagnoses) ,Service development - Abstract
Aim: This article describes the development and initial evaluation of introducing a psychologist role within an adult inpatient pain service (IPS) in a large North West of England National Health Service (NHS) trust. Background: The role of a psychologist in the management of outpatient chronic pain has been well documented, but their role within the IPS is less well described and rarely evaluated. We describe the development of a psychologist role within the team and initial service evaluation outcomes. Methods: Following an initial needs assessment, a band 8c psychologist joined the IPS one day per week offering brief one-to-one psychological interventions to people struggling with acute or chronic pain in hospital referred by inpatient pain team. The psychologist had an indirect role offering training, supervision and support to members of the inpatient pain team. Regarding direct patient work, following psychometric screening for pain-related disability and distress, a cognitive behavioural therapy (CBT) approach was applied including identifying unhelpful beliefs about pain, psychoeducation about acute and persistent pain, developing and sharing formulations, skills training including breathing and relaxation exercises and where appropriate, signposting onto an outpatient chronic pain services for further pain self-management advice (e.g. pain management programme. To explore the impact of this direct intervention, a prospective service evaluation with a controlled before and after design was conducted. This compared (a) number of admissions and (b) length-of-stay outcomes in the 12 months following psychometric screening for patients who received psychological input (n = 34, the treatment group) and a sample who did not receive input because of discharge before intervention or non-availability of the psychologist, for example, annual leave (n = 30, control group). Demographic information and summaries of psychometric questionnaires were also analysed. Results: Of the sample of 64 patients, 50 were women, ages ranged from 18–80 years, 72% reported being currently unemployed or off sick from work and on screening and 39% and 48% met criteria for severe depression and pain-related anxiety, respectively. Hospital admissions in the intervention group reduced significantly (by 60%) in the 12 months following screening but increased (by 7%) for the control group (F(1,62) = 7.21, p = .009). Days of stay in hospital reduced significantly more (by 84%) in the intervention group than in the control group (by 41%) (F(1,62) = 8.90, p = .004). Illustrated case studies of brief psychological intervention with three people struggling with pain-related distress are presented. Conclusions: The psychologist became a valuable member of the multi-disciplinary IPS team, offering brief direct and indirect psychological interventions. While a relatively small sample, our prospective service evaluation data suggest brief psychological intervention may contribute to reduced length of stay and hospital admissions for people experiencing pain-related distress in hospital.
- Published
- 2020
- Full Text
- View/download PDF
3. Cortical double-opponent cells and human color perception
- Author
-
Robert Shapley, Valerie Nunez, and James Gordon
- Subjects
Color vision ,Cognitive Neuroscience ,media_common.quotation_subject ,050105 experimental psychology ,03 medical and health sciences ,Behavioral Neuroscience ,0302 clinical medicine ,medicine ,Contrast (vision) ,0501 psychology and cognitive sciences ,Color contrast ,media_common ,Physics ,Spatial contextual awareness ,business.industry ,05 social sciences ,Pattern recognition ,Psychiatry and Mental health ,Near threshold ,Visual cortex ,medicine.anatomical_structure ,Colored ,High color ,Artificial intelligence ,business ,030217 neurology & neurosurgery - Abstract
Human color perception’s dependence on the spatial pattern of color is a function of color contrast. At low color contrast, the visual system acts as a spatial integrator of color signals. Therefore, near threshold, the optimum color pattern is a large, uniformly colored region. But the system changes at high color contrast, becoming more sensitive to changes in the spatial context of color especially color boundaries with surrounding regions. We offer a mechanistic explanation of these phenomena in terms of the contrast dependencies of single-opponent and double-opponent neurons in the primary visual cortex, V1.
- Published
- 2019
- Full Text
- View/download PDF
4. Giving voice to the end-user: input on multipurpose prevention technologies from the perspectives of young women in Kenya and South Africa
- Author
-
Alexandra M. Minnis, Emily Krogstad, Mary Kate Shapley-Quinn, Kawango Agot, Khatija Ahmed, L. Danielle Wagner, Ariane van der Straten, and on behalf of the TRIO Study Team
- Subjects
medicine.medical_specialty ,Stigma (botany) ,HIV Infections ,end-user ,South Africa ,Nursing ,Pregnancy ,medicine ,Humans ,Product (category theory) ,multipurpose prevention technologies (MPTs) ,HIV and pregnancy ,Biomedical technology ,Reproductive health ,HQ1-2044 ,young women ,Cross-Over Studies ,End user ,business.industry ,Public health ,Obstetrics and Gynecology ,contraceptive preferences ,Focus group ,Kenya ,Diseases of the genitourinary system. Urology ,Contraception ,Reproductive Medicine ,The family. Marriage. Woman ,Female ,RC870-923 ,Psychology ,business ,Research Article - Abstract
Unintended pregnancy and unmet need for modern contraception contribute substantially to reproductive health disparities globally. In sub-Saharan Africa they occur in contexts of disproportionately high rates of HIV infection. Multipurpose prevention technologies (MPTs) can address HIV and pregnancy prevention needs in a single “2-in-1” product; however, few studies have solicited end-user views to inform design of new MPTs. We conducted the Tablets, Ring, Injections as Options (TRIO) study with young women aged 18−30 in Kenya and South Africa (N = 277) to examine preferences and acceptability of future MPTs. In a randomised clinical cross-over study in which women used three placebo delivery forms, we complemented quantitative acceptability assessments with in-depth interviews and focus group discussions (N = 88 participants). We examined anticipated enablers and barriers to adoption and use of future MPTs and synthesised novel product design recommendations. Participants expressed high interest in MPTs. Anticipated side effects constituted a primary concern; however, many expected barriers were not dosage form-specific, but addressed contextual factors instead, such as fears regarding use of new biomedical technologies, misunderstandings and stigma regarding use, and navigating partner disclosure and engagement. Women preferred MPTs that offered discreetness and long-duration protection to minimise user-burden, did not interfere with their relationships, and conferred protection for unanticipated situations. End-user research to identify and pre-emptively address potential barriers while underscoring benefits to a new MPT product is vital. Attention to cultural contexts in implementation of new MPTs is important to communicating perceived benefits, achieving acceptability and maximising public health benefits.
- Published
- 2021
5. 'I felt like a TRIO champion': end-user perspectives on their role as co-designers of multi-purpose technologies
- Author
-
Alexandra Lutnick, Khatija Ahmed, Mary Kate Shapley-Quinn, Ariane van der Straten, Kawango Agot, and Timothy Okello
- Subjects
media_common.quotation_subject ,Population ,HIV prevention ,Medicine (miscellaneous) ,Qualitative property ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Altruism ,03 medical and health sciences ,0302 clinical medicine ,Immunology and Microbiology (miscellaneous) ,Co-designer ,Reciprocity (social psychology) ,Agency (sociology) ,030212 general & internal medicine ,education ,media_common ,education.field_of_study ,030505 public health ,business.industry ,End user ,Health Policy ,Public Health, Environmental and Occupational Health ,Champion ,Articles ,Public relations ,Focus group ,PrEP ,contraception ,multipurpose technologies ,Africa ,end-users ,women ,0305 other medical science ,business ,Psychology ,Research Article - Abstract
Background: The likelihood that research will be relevant to and accepted by end-users and their communities is enhanced when the perspectives of both the “researchers” and the “researched” are considered. The Tablets, Ring, Injections as Options (TRIO) Study, conducted with young women in Kenya and South Africa, assessed the acceptability and preferences of three placebo-only multi-purpose technology (MPT) forms for prevention of HIV and unintended pregnancy. The objective of this analysis was to assess whether, and if so how, the women participating in the TRIO Study perceived themselves as co-designers of the three MPT products. Methods: We conducted 55 in-depth interviews, 6 focus group discussions, and 5 dissemination workshops with TRIO Study participants. Woven throughout these activities were questions and opportunities for participants to reflect on their role in the study, and to what extent they identified with their role as a co-designer. Qualitative data from these activities were analyzed thematically. Results: The analysis revealed four key themes about what resulted in the women’s views as co-designers: altruism, respectful treatment, agency, and reciprocity. The women were aware of their role in determining what end-users would and would not prefer and were motivated by a desire to help themselves and others. They recognized their role as co-designers and cited being treated well by study staff, being given a chance to make choices during the study period, and being recognized as equal partners of the researchers as the main reasons. Conclusions: If prevention products are going to be successfully developed, end-users and researchers must work hand in hand. Engaging participants meaningfully as co-designers in product development research can be a powerful tool in the effort to ensure new prevention products brought to market are acceptable to the population of interest.
- Published
- 2020
6. Abstract Supplement Oral Abstracts from the 23rd International AIDS Conference, 6‐10 July 2020
- Author
-
Mary Kate Shapley-Quinn, Yusnelkis Milanés Guisado, Alexandra Minnis, Miriam Hartmann, Sarah Moreheart, Ellen Luecke, Roberto Maximiliano Carrasco Navarro, John Oliver Corciega, GIOVANNI FRANCESCO PELLICANO', Elizabeth Montgomery, Patrick Eustaquio, Ariane Van der Straten, and Nsika Sithole
- Subjects
Infectious Diseases ,Nursing ,End user ,business.industry ,Public Health, Environmental and Occupational Health ,Human immunodeficiency virus (HIV) ,medicine ,Implant ,medicine.disease_cause ,business ,Abstract ,Unintended pregnancy - Published
- 2020
- Full Text
- View/download PDF
7. Mobile Phone Waste and the Circular Economy
- Author
-
Matthew Shapley, Christine Cole, and Tim Cooper
- Subjects
business.industry ,Mobile phone ,Circular economy ,Business ,Reuse ,Telecommunications ,Product lifetime ,Durability - Abstract
The need to progress toward the circular, low-carbon economies that are necessary for sustainable development demands a substantial reduction in the generation of waste. Although the amount of waste arising from the disposal of mobile phones is relatively insubstantial compared to other waste streams, it is problematic, partly due to the complexity of its composition: mobile phones contain many types of material in small quantities. Like other small electrical and electronic items, they have proven hard to recover and recycle cost-effectively. They are often stored for long periods and eventually discarded as residual waste rather than separated for recycling. Most have unduly short active lifetimes because they have not been designed for longevity and their potential for durability, repair, refurbishment, and reuse is not realized. This chapter discusses issues relating to e-waste from discarded mobile phones and explores the prospect of alternative approaches to their production and consumption, exemplified by the case of Fairphone.
- Published
- 2020
- Full Text
- View/download PDF
8. Spatial patterns of pharmaceuticals and wastewater tracers in the Hudson River Estuary
- Author
-
Carol Knudson, Daniel Shapley, Julia C. Sullivan, Mark G. Cantwell, David R. Katz, Jennifer L. Epstein, Andrew R. Juhl, Gregory D. O'Mullan, and John Lipscomb
- Subjects
Sucrose ,Environmental Engineering ,New York ,0211 other engineering and technologies ,Sewage ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,Waste Disposal, Fluid ,01 natural sciences ,Article ,Rivers ,Tributary ,Humans ,Transect ,Weather ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Hydrology ,021110 strategic, defence & security studies ,geography ,geography.geographical_feature_category ,business.industry ,Ecological Modeling ,Outfall ,Estuary ,Pollution ,Pharmaceutical Preparations ,Spatial ecology ,Environmental science ,Sewage treatment ,Estuaries ,business ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
The widespread use of pharmaceuticals by human populations results in their sustained discharge to surface waters via wastewater treatment plants (WWTPs). In this study, 16 highly prescribed pharmaceuticals were quantified along a 250 km transect of the Hudson River Estuary and New York Harbor to describe their sources and spatial patterns. Sampling was conducted over two dry weather periods in May and July 2016, at 72 sites which included mid-channel and nearshore sites, as well as locations influenced by tributaries and WWTP outfalls. The detection frequency of the study pharmaceuticals was almost identical between the May and July sampling periods at 55% and 52%, respectively. Six pharmaceuticals were measurable at 92% or more of the sites during both sampling periods, illustrating their ubiquitous presence throughout the study area. Individual pharmaceutical concentrations were highly variable spatially, ranging from non-detect to 3810 ng/L during the study. Major factors controlling concentrations were proximity and magnitude of WWTP discharges, inputs from tributaries and tidal mixing. Two compounds, sucralose and caffeine, were evaluated as tracers to identify wastewater sources and assess pharmaceutical behavior. Sucralose was useful in identifying wastewater inputs to the river and concentrations showed excellent correlations with numerous pharmaceuticals in the study. Caffeine-sucralose ratios showed potential in identifying discharges of untreated wastewater occurring during a combined sewage overflow event. Many of the study pharmaceuticals were present throughout the Hudson River Estuary as a consequence of sustained wastewater discharge. Whereas some concentrations were above published effects levels, a more complete risk assessment is needed to understand the potential for ecological impacts due to pharmaceuticals in the Hudson River Estuary.
- Published
- 2018
- Full Text
- View/download PDF
9. Favoring 'Peace of Mind': A Qualitative Study of African Women's HIV Prevention Product Formulation Preferences from the MTN-020/ASPIRE Trial
- Author
-
Palanee-PhillipsThesla, WoeberKubashni, ReddyKrishnaveni, MusaraPetina, EtimaJuliane, van der StratenAriane, M BaetenJared, ChengHelen, Shapley-QuinnMary Kate, and T MontgomeryElizabeth
- Subjects
0301 basic medicine ,Gynecology ,medicine.medical_specialty ,business.industry ,Public Health, Environmental and Occupational Health ,Vaginal gel ,Human immunodeficiency virus (HIV) ,medicine.disease_cause ,030112 virology ,Vaginal ring ,Preference ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,Behavioral and Psychosocial Research ,Family medicine ,Oral tablets ,Medicine ,030212 general & internal medicine ,Product (category theory) ,business ,Qualitative research - Abstract
Several formulations of HIV pre-exposure prophylaxis (PrEP) have shown varying levels of effectiveness in women. Little information is known about preference across formulations, especially among product experienced women. Seventy-one women (48% married; median age 26; range 18–45) who were participating in a vaginal ring trial for HIV prevention in Malawi, South Africa, Uganda, and Zimbabwe underwent an in-depth interview at their last study visit, during which they were presented with pictures and descriptions of nine possible product formulations (male and female condoms, oral tablets, injectables, implants, and a vaginal gel, ring, insert, and film). Each formulation was discussed, highlighting salient attribute(s) and contextual factors that may have informed stated preferences. Participants expressed most interest for long-acting PrEP formulations (rings, 94%; implants, 39%; injections, 34%), which were generally favored over short-acting ones. Participants appreciated the continuous protection offered, discreet usage, and the advantage of “peace of mind” imparted by simplified use and infrequent dosing, alleviating worries around forgetting doses. Preferred attributes of short-acting formulations included reversibility, user control, ease of administration, and low toxicity. Participants were least interested in the oral tablets (due to the daily dosing, difficulty swallowing pills, and HIV-related stigma), and the vaginal gel and film (due to vaginal insertion, coital dosing, effect on sex. and unfamiliarity with the method). Dislike for vaginally administered products was more pronounced among young women. Multiple factors played into potential users' considerations for preferred formulations, emphasizing how a suite of options for prevention might best respond to women's needs and wants.
- Published
- 2017
- Full Text
- View/download PDF
10. Chaplaincy Visitation and Spiritual Care after Intracerebral Hemorrhage
- Author
-
Anand Viswanathan, M. Edip Gurol, Steven M. Greenberg, Jonathan Rosand, Joshua N. Goldstein, Christopher D. Anderson, Melissa L. Howell, Kristin Schwab, Dean Shapley, and Alison M. Ayres
- Subjects
Male ,medicine.medical_specialty ,Health (social science) ,Critical Care ,Chaplaincy Service, Hospital ,Pastoral Care ,03 medical and health sciences ,0302 clinical medicine ,Pastoral care ,Humans ,Medicine ,Prospective Studies ,030212 general & internal medicine ,Prospective cohort study ,Stroke ,Aged ,Cerebral Hemorrhage ,Retrospective Studies ,Aged, 80 and over ,Intracerebral hemorrhage ,business.industry ,Critically ill ,Religious studies ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Clinical Psychology ,Family medicine ,Fatal disease ,Female ,Medical emergency ,Spiritual care ,business ,030217 neurology & neurosurgery - Abstract
To better understand factors influencing spiritual care during critical illness, we examined the use of spiritual care in patients hospitalized with intracerebral hemorrhage (ICH), a frequently disabling and fatal disease. Specifically, the study was designed to examine which demographic and clinical characteristics were associated with chaplain visits to critically ill patients. The charts of consecutive adults (>18) with spontaneous ICH presenting to a single academic medical center between January 2014 and September 2015 were reviewed. Chaplains visited 86 (32%) of the 266 patients. Family requests initiated the majority of visits (57%). Visits were disproportionately to Catholic patients and those with more severe injury. Even among Catholics, 28% of those who died had no chaplaincy visit. Standardized chaplaincy screening methods and note templates may help maximize access to spiritual care and delineate the religious and spiritual preferences of patients and families.
- Published
- 2017
- Full Text
- View/download PDF
11. Veiled Superheroes
- Author
-
Sarah Shapley
- Subjects
Battle ,History ,business.industry ,media_common.quotation_subject ,Subject (philosophy) ,Agency (philosophy) ,Popular culture ,Islam ,General Medicine ,Comics ,Feminism ,Narrative ,Religious studies ,business ,media_common - Abstract
Sophia Rose Arjana’s book Veiled Superheroes: Islam, Feminism, and PopularCulture raises a timely and critical discussion. The interdisciplinarynature of the book provides insight into various subjects, including women’sstudies, theology, and popular culture. Arjana, with Kim Fox, focuseson Muslim female (Muslima) superheroes. In a world where so oftenwomen (and in particular, Muslim women) are politicized, Arjana offers analternate exploration of how Muslima superheroes are poised to battle bothWestern and Islamic misogyny.Chapter 1, “Muslim Women in Popular Culture,” gives an overview ofthe discourse around Muslim women. The chapter explores how Orientalismhas influenced the presentation of Muslim women, particularly notinghow Muslim women lose agency in all discussions. Arjana looks specificallyat how the comic and cartoons have been subject to this thinking.She addresses how Muslims fall into the villain or the rescue narrative andthen turns to the problematic representation of some Muslima superheroes.Comics are just the starting point, for such representations are found incartoons and film as well. While this chapter provides a great basis for therest of the book and an essential introduction to the narrative that has oftensurrounded Muslim women, it does at times jump quickly from one discussionto the next (as continues through much of the book) ...
- Published
- 2018
- Full Text
- View/download PDF
12. First Impressions Matter: How Initial Worries Influence Adherence to the Dapivirine Vaginal Ring
- Author
-
Ariane van der Straten, Mary Kate Shapley-Quinn, Mtn, Elizabeth R. Brown, Krishnaveni Reddy, Barbara S. Mensch, Rachel Scheckter, Lydia Soto-Torres, Erica N Browne, Jared M. Baeten, Aspire Study Team, and Thesla Palanee-Phillips
- Subjects
Adult ,medicine.medical_specialty ,Adolescent ,Anti-HIV Agents ,Dapivirine ,HIV Infections ,Anxiety ,Article ,law.invention ,Young Adult ,Randomized controlled trial ,Double-Blind Method ,law ,Internal medicine ,Medicine ,Humans ,Pharmacology (medical) ,Young adult ,Africa South of the Sahara ,business.industry ,Extramural ,Contraceptive Devices, Female ,Middle Aged ,Vaginal ring ,Clinical trial ,Infectious Diseases ,Pyrimidines ,Multicenter study ,Patient Compliance ,Female ,business - Abstract
In MTN-020/ASPIRE, a dapivirine vaginal ring effectiveness trial in sub-Saharan Africa, we assessed whether worries about ring use changed over time and were associated with adherence.Participants (N = 2585) were surveyed at baseline and follow-up about worries regarding daily ring use. First, they answered a question about general worries and then responded to 15 items covering specific worries. From a nested qualitative component (N = 214), we extracted themes related to ring worries and adherence. Seven months into the trial, aggregate adherence data were shared with study sites as part of an intervention that included counseling and social support. Nonadherence was defined as dapivirine plasma levels of ≤95 pg/mL. Mixed-effect logistic regression models were used to assess changes in ring worries and nonadherence from baseline to month 3 and later.Worry about wearing the ring decreased from 29% at baseline to 4% at month 3 (P0.001), while having a specific worry decreased from 47% to 16% (P0.001). Among those enrolled before intervention, 29% with baseline worries were nonadherent at month 3 (95% confidence interval: 19% to 39%) compared to 14% without worries (95% confidence interval: 9% to 19%; P = 0.005); the difference persisted through month 6. There was no difference in nonadherence by baseline worry for those enrolled after intervention (P = 0.40). In the qualitative subset, initial ring anxieties reportedly subsided with self-experimentation and practice and the beneficial influence of the intervention.Although worries may be an initial deterrent to correct ring use, intervening early by leveraging social influences from peers and clinicians should facilitate successful adoption and correct ring use.
- Published
- 2019
13. Evaluating approaches to resource management in consumer product sectors - an overview of global practices
- Author
-
Tim Cooper, Christine Cole, Alex Gnanapragasam, Matthew Shapley, and Jagdeep Singh
- Subjects
Product design ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Strategy and Management ,Circular economy ,05 social sciences ,Resource efficiency ,02 engineering and technology ,Environmental economics ,Business model ,Natural resource ,Industrial and Manufacturing Engineering ,Sustainability ,050501 criminology ,0202 electrical engineering, electronic engineering, information engineering ,Resource management ,Business ,Product (category theory) ,0505 law ,General Environmental Science - Abstract
Addressing global sustainability challenges associated with natural resource security and climate change requires new perspective on waste and resource management. Sustainability-driven business model innovations have a crucial role in transforming current, unsustainable, production and consumption patterns by slowing product replacement and closing material cycles. This study identifies best practice across a range of consumer product sectors. The study developed a novel methodology to identify and evaluate practical approaches to resource efficiency and the circular economy in order to reduce energy and material demand in these product sectors. These approaches include durable product design, enhanced repair and upgrade services, and product take-back. The study analysed 519 products and identified a total 145 examples of best practice within their respective product sectors that provide important insights into planning more circular business models in a range of product sectors. The paper highlights major barriers to, and opportunities, for wider implementation of these practices.
- Published
- 2019
14. Individual and collective wage bargaining
- Author
-
Levy, Anat and Shapley, Lloyd S.
- Subjects
Collective bargaining -- Models ,Compensation management -- Models ,Game theory -- Models ,Business ,Business, international ,Economics - Abstract
Wage negotiation is modeled as an oceanic game. The employer and unions (if any) are atomic players, interacting with an 'ocean' of infinitesimal individual, unorganized workers. All workers are equally productive inside the firm, but may differ in their outside opportunities. The 'worth' of a coalition is its achievable surplus, and the Shapley value of the c - f game thereby defined provides a plausible, equitable wage settlement. Several different levels of unionization are investigated. It is noteworthy that this approach does not introduce specific bargaining procedures; instead (like the core) it builds on cooperative possibilities present in the economic situation itself.
- Published
- 1997
15. Fictitious play property for games with identical interests
- Author
-
Monderer, Dov and Shapley, Lloyd S.
- Subjects
Game theory -- Research ,Business ,Economics - Abstract
Fictitious play property (FPP), which is characterized by initial moves that are randomly selected and absence of tie-breaking rules, is considered present in games with similar payoff functions for every participants. The process attains equilibrium only if mixed strategies remains close to a pre-determined set of equilibrium after undergoing several phases of the game. It is concluded that the presence of FPP is still applicable despite some modified definitions in the game environment.
- Published
- 1996
16. Good Clinical Practice Training: Identifying Key Elements and Strategies for Increasing Training Efficiency
- Author
-
Gretchen Wild, Stephanie Shapley, Jonathan Seltzer, Colleen Gorman, Bridget Foltz, Jaime Arango, Tina Chuck, Susan S. Ellenberg, Susan McHale, Kunal Merchant, and Heidi Hinrichs
- Subjects
Government ,Medical education ,020205 medical informatics ,business.industry ,International standard ,education ,Public Health, Environmental and Occupational Health ,02 engineering and technology ,Audit ,Public relations ,16. Peace & justice ,Project team ,3. Good health ,Clinical trial ,03 medical and health sciences ,0302 clinical medicine ,Good clinical practice ,Credibility ,0202 electrical engineering, electronic engineering, information engineering ,Medicine ,Pharmacology (medical) ,Confidentiality ,030212 general & internal medicine ,business ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) - Abstract
Good Clinical Practice (GCP) is an international standard for the design, conduct, performance, monitoring, auditing, recording, analyses, and reporting of clinical trials. The goal of GCP is to ensure the protection of the rights, integrity, and confidentiality of clinical trial participants and to ensure the credibility and accuracy of data and reported results. In the United States, trial sponsors generally require investigators to complete GCP training prior to participating in each clinical trial to foster GCP and as a method to meet regulatory expectations (ie, sponsor's responsibility to select qualified investigators per 21 CFR 312.50 and 312.53(a) for drugs and biologics and 21 CFR 812.40 and 812.43(a) for medical devices). This training requirement is often extended to investigative site staff, as deemed relevant by the sponsor, institution, or investigator. Those who participate in multiple clinical trials are often required by sponsors to complete repeated GCP training, which is unnecessarily burdensome. The Clinical Trials Transformation Initiative convened a multidisciplinary project team involving partners from academia, industry, other researchers and research staff, and government to develop recommendations for streamlining current GCP training practices. Recommendations drafted by the project team, including the minimum key training elements, frequency, format, and evidence of training completion, were presented to a broad group of experts to foster discussion of the current issues and to seek consensus on proposed solutions.
- Published
- 2016
- Full Text
- View/download PDF
17. Center for Drug Evaluation and Research Perspective on Quality in Clinical Trials
- Author
-
Jacqueline O’Shaughnessy, Janet Woodcock, and Stephanie Shapley
- Subjects
medicine.medical_specialty ,business.industry ,media_common.quotation_subject ,Perspective (graphical) ,Public Health, Environmental and Occupational Health ,Alternative medicine ,Pharmacy ,Pharmacology ,030226 pharmacology & pharmacy ,01 natural sciences ,Clinical trial ,010104 statistics & probability ,03 medical and health sciences ,0302 clinical medicine ,Drug development ,Good clinical practice ,medicine ,Pharmacology (medical) ,Medical physics ,Quality (business) ,0101 mathematics ,business ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) ,media_common ,Agile software development - Abstract
Clinical trial quality is essential to bringing effective treatments to patients as quickly as possible. Clinical trials that answer important questions, yield meaningful data, and protect trial participants can provide data that support both regulatory and clinical decision making. The Food and Drug Administration's (FDA's) Center for Drug Evaluation and Research (CDER) encourages stakeholders to improve clinical trial quality and efficiency. CDER believes that a systematic approach to clinical trial quality-one that builds in quality up front and focuses on the most critical aspects of study conduct-contributes to successful trials. Beyond FDA's regulatory requirements for clinical trial quality, CDER is an active participant in multiple efforts to advance clinical trial quality, including the addendum to ICH E6 (Good Clinical Practice) and the Clinical Trials Transformation Initiative project on quality-by-design for clinical trials. These efforts aim to move clinical drug development to a desired state that centers on efficient and agile clinical development programs that reliably produce high-quality data and adhere to important ethical standards.
- Published
- 2017
- Full Text
- View/download PDF
18. Perspectives of South African youth in the development of an implant for <scp>HIV</scp> prevention
- Author
-
Tsholofelo Malapane, Kgahlisho Manenzhe, Alexandra M. Minnis, Millicent Atujuna, Emily A Krogstad, Mary Kate Shapley-Quinn, Elizabeth T. Montgomery, Linda-Gail Bekker, Sheily Ndwayana, and Ariane van der Straten
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,Adolescent ,implant ,Anti-HIV Agents ,Human immunodeficiency virus (HIV) ,Black People ,HIV Infections ,medicine.disease_cause ,South Africa ,Young Adult ,03 medical and health sciences ,Pre-exposure prophylaxis ,0302 clinical medicine ,Pregnancy ,medicine ,Humans ,030212 general & internal medicine ,product development ,Research Articles ,pre‐exposure prophylaxis ,Drug Implants ,business.industry ,Biodegradable implants ,Implant design ,Public Health, Environmental and Occupational Health ,Focus Groups ,030112 virology ,Focus group ,3. Good health ,High uptake ,Infectious Diseases ,Family medicine ,Female ,Pre-Exposure Prophylaxis ,Implant ,Contraceptive implant ,business ,Research Article - Abstract
Introduction Implants are a new dosage form in development for HIV pre‐exposure prophylaxis (PrEP) with potential for high adherence given that they are provider‐administered and are intended for long‐acting protection. Integrating end‐user preference into early stage product development may further overcome challenges with future product uptake and adherence. Hence, we sought to optimize the design of a PrEP implant in early‐stage development by gathering opinions about implant attributes from potential end‐users in South Africa. Methods We conducted 14 focus group discussions (FGDs) with young women and men aged 18 to 24 in Cape Town and Soshanguve, South Africa, inviting participants into discussion as co‐designers. FGDs were homogenous by gender and previous implant experience. During FGDs, we showed prototype devices and followed a semi‐structured guide with questions on history of contraceptive implant use, preferences for physical characteristics of an implant, implant biodegradability, insertion process, participant‐driven ideas for implant design, and social adoption considerations. FGDs were facilitated in English, isiXhosa, Tswana, isiZulu, or Tsonga, audio‐recorded, transcribed into English, and qualitatively coded and analysed. Results In this qualitative sample of 105 youth (68 women and 37 men), 58 participants were from Soshanguve and 47 from Cape Town, and 23% had previously used contraceptive implants. Participants expressed preferences for several implant design features; specifically, longer duration (≥6 months) was more important to most participants than the size or number of devices implanted. A majority preferred a flexible versus stiff implant to minimize palpability, thereby increasing discreetness and comfort. Nearly all participants favoured a biodegradable implant to avoid removal and thus reduce clinic visits. Concerns about the implant centred on its possible side effects and the “plastic” look of the prototype displayed for demonstration. Conclusions This study offers preliminary insights into an implant for HIV prevention that provides long‐lasting protection may be well received among young South Africans. Additionally, flexibility, discreetness, and biodegradability may increase acceptability of the implant. Such end–user feedback is being incorporated into current implant designs in the hope of creating an effective long‐acting PrEP product that is likely to achieve high uptake and adherence in target populations.
- Published
- 2018
- Full Text
- View/download PDF
19. Human Sound Localization Depends on Sound Intensity: Implications for Sensory Coding
- Author
-
Nima Alamatsaz, Robert Shapley, and Antje Ihlefeld
- Subjects
Sound localization ,Computer science ,business.industry ,media_common.quotation_subject ,Sensory system ,Pattern recognition ,Sound intensity ,Stimulus modality ,Perception ,Sensory coding ,Spatial cues ,Contrast (vision) ,Visual depth perception ,Artificial intelligence ,business ,media_common - Abstract
A fundamental question of human perception is how we perceive target locations in space. Through our eyes and skin, the activation patterns of sensory organs provide rich spatial cues. However, for other sensory dimensions, including sound localization and visual depth perception, spatial locations must be computed by the brain. For instance, interaural time differences (ITDs) of the sounds reaching the ears allow listeners to localize sound in the horizontal plane. Our experiments tested two prevalent theories on how ITDs affect human sound localization: 1) the labelled-line model, encoding space through tuned representations of spatial location; versus 2) the hemispheric-difference model, representing space through spike-rate distances relative to a perceptual anchor. Unlike the labelled-line model, the hemispheric-difference model predicts that with decreasing intensity, sound localization should collapse toward midline reference, and this is what we observed behaviorally. These findings cast doubt on models of human sound localization that rely on a spatially tuned map. Moreover, analogous experimental results in vision indicate that perceived depth depends upon the contrast of the target. Based on our findings, we propose that the brain uses a canonical computation of location across sensory modalities: perceived location is encoded through population spike rate relative to baseline.
- Published
- 2018
- Full Text
- View/download PDF
20. The historically enduring gap in death penalty support: Re-examining the role of context in the recent history of the black-white divide
- Author
-
Emory Morrison, Jeremy R. Porter, Derrick Shapley, and Sriram Chintakrindi
- Subjects
racial‑ecological theories ,public opinion ,death penalty support ,geo‑coded data ,White (horse) ,business.industry ,Context (language use) ,Sociology ,Criminology ,Public opinion ,business - Abstract
This paper evaluates four racial‑ecological theories regarding the historically enduring racial divide in public opinion regarding death penalty support. Using geo‑coded data from the 20th century, this research examines the relative representation of African Americans, the level of black‑white economic inequality, and the extent of racial residential segregation on race‑spe‑ cific odds of supporting the death penalty. The research finds support for aspects of racial social context accounting for a portion of the black-white gap in death penalty support at the time. We find differential effects, by race, of representation and segregation as mediators of public opinion regarding the death penalty.
- Published
- 2018
21. A Retrospective Review of the Clinical Characteristics and Blood Glucose Data from Cellnovo System Users using Data Collected from the Cellnovo Online Platform
- Author
-
Olivia Hautier-Suply, Julian Shapley, and Yasmin Friedmann
- Subjects
Type 1 diabetes ,Retrospective review ,Endocrine and Autonomic Systems ,business.industry ,Endocrinology, Diabetes and Metabolism ,030209 endocrinology & metabolism ,Cloud computing ,Patient data ,medicine.disease ,03 medical and health sciences ,Regimen ,Upload ,0302 clinical medicine ,Endocrinology ,Diabetes management ,medicine ,030212 general & internal medicine ,Medical emergency ,business ,Carbohydrate intake - Abstract
Technological advances have led to innovative insulin delivery systems for patients with type 1 diabetes mellitus. In particular, the combination of miniature engineering and software algorithms contained in continuous subcutaneous insulin infusion (CSII) system pumps provide the user and the healthcare practitioner with an opportunity to review and adjust blood glucose (BG) levels according to system feedback, and to modify or programme their regimen according to their needs. While CSII pumps record a number of data parameters such as BG level, carbohydrate intake, activity and insulin delivered, these data are generally ‘locked in’ and can only be accessed by uploading to a cloud-based system, thus information is not contemporaneous. The Cellnovo Diabetes Management System (Cellnovo, Bridgend, UK) allows data to be transmitted securely and wirelessly in real time to a secure server, which is then retrieved by an online platform, the Cellnovo Online platform, enabling continuous access by the user and by clinicians. In this article, the authors describe a retrospective review of the patient data automatically uploaded to the Cellnovo Online platform. Baseline clinical and demographic characteristics collected at the start of pump therapy are shown for all patients, and BG data from a sub-cohort of patients who have been using the system for at least 6 months and who take and record an average of three BG level tests per day are presented to demonstrate glycaemic data over time.
- Published
- 2017
22. Critical items for assessing risk of lung and colorectal cancer in primary care: a Delphi study
- Author
-
Daniëlle A W M van der Windt, Mark Shapley, Gemma Mansell, Paul Little, and Tom Sanders
- Subjects
Adult ,Male ,medicine.medical_specialty ,Lung Neoplasms ,Referral ,referral and consultation ,Delphi Technique ,Colorectal cancer ,Delphi method ,neoplasms ,Risk Assessment ,Clinical Protocols ,Predictive Value of Tests ,Medicine ,Humans ,Prospective cohort study ,Lung cancer ,Intensive care medicine ,Early Detection of Cancer ,Gynecology ,Lung ,Primary Health Care ,business.industry ,Research ,Cancer ,A300 ,Middle Aged ,medicine.disease ,Prognosis ,United Kingdom ,medicine.anatomical_structure ,Systematic review ,Female ,Family Practice ,business ,Colorectal Neoplasms - Abstract
Background: Patients with lung or colorectal cancer often present late and have a poor prognosis. Identifying diagnostic indicators to optimally assess the risk of these cancers in primary care would support early identification and timely referral for patients at increased risk.\ud \ud Aim: To obtain consensus regarding potential diagnostic indicators that are important for assessing the risk of lung or colorectal cancer in primary care consulters presenting with lung or abdominal symptoms.\ud \ud Design and setting: A Delphi study was conducted with 28 participants from primary and secondary care and academic settings in the UK and Europe.\ud \ud Method: Indicators were obtained from systematic reviews, recent primary studies and consultation with experts prior to the Delphi study being conducted. Over three rounds, participants rated each diagnostic indicator in terms of its importance, ranked them in order of importance, and rated each item as crucial or not crucial to assess during a GP consultation.\ud \ud Results: The final round resulted in 25 items remaining for each type of cancer, including established cancer symptoms such as rectal bleeding for colorectal cancer and haemoptysis for lung cancer, but also less frequently used indicators such as patients’ concerns about cancer.\ud \ud Conclusion: This study highlights the items clinicians feel would be most crucial to include in the clinical assessment of primary care patients, a number of which have rarely been noted in the previous literature. Their importance in assessing the risk of lung or colorectal cancer will be tested as part of a large prospective cohort study (CANDID).
- Published
- 2014
23. Concussion Education for High School Football Players
- Author
-
Kathy L. Shapley and Nancy J. Manasse-Cohick
- Subjects
Linguistics and Language ,medicine.medical_specialty ,biology ,Athletes ,business.industry ,Knowledge level ,Poison control ,Human factors and ergonomics ,medicine.disease ,biology.organism_classification ,Suicide prevention ,Occupational safety and health ,Speech and Hearing ,Concussion ,Injury prevention ,Physical therapy ,medicine ,business ,Clinical psychology - Abstract
This survey study compared high school football players’ knowledge and attitudes about concussion before and after receiving concussion education. There were no significant changes in the Concussion Attitude Index. Results revealed a statistically significant difference in the athletes’ scores for the Concussion Knowledge Index, t(244) = 8.49, p = .000, and Cohen’s d = 1.05. Concussion education can help football players learn signs, symptoms, and negative effects of mild brain injuries.
- Published
- 2013
- Full Text
- View/download PDF
24. The spontaneous resolution of heavy menstrual bleeding in the perimenopausal years
- Author
-
Kelvin P. Jordan, Mark Shapley, Peter Croft, and Milisa Blagojevic
- Subjects
Adult ,medicine.medical_specialty ,Time Factors ,Epidemiology ,Remission, Spontaneous ,menopause ,Spontaneous remission ,Menstrual symptoms ,Recurrence ,menorrhagia ,Humans ,Medicine ,reproductive and urinary physiology ,Gynecology ,business.industry ,Obstetrics and Gynecology ,Middle Aged ,Patient Acceptance of Health Care ,medicine.disease ,Perimenopause ,heavy menstrual bleeding ,Menopause ,Women's Health Services ,Menstrual bleeding ,England ,Female ,Epidemiologic Methods ,business - Abstract
Objective To obtain estimates of the rate of spontaneous resolution of heavy menstrual bleeding and to explore any association with specific menstrual symptoms. Design Two-year prospective cohort study. Setting Seven general practices, with 67 100 registered patients. Population All women aged 40–54 years on the practices age–sex registers. Methods Baseline postal questionnaire, with follow-up questionnaires sent to naturally menstruating respondents at 6, 12, 18 and 24 months. Main outcome measures Rate of spontaneous resolution of heavy menstrual bleeding in naturally menstruating women. Results A total of 7121 baseline questionnaires were sent out, with an initial response rate of 63%. We recruited 2051 naturally menstruating women for the prospective cohort study. The spontaneous rate of resolution of heavy menstrual bleeding varied from 8.1% (95% CI 5.3–12%) in women aged 45–49 years, who had resolution without recurrence for 24 months, to 35% (95% CI 30–41%) in women aged 50–54 years, who had resolution without recurrence for 6 months. Rates were lower in those who reported interference with life from heavy menstrual bleeding. There was a strong association between the spontaneous resolution of heavy menstrual bleeding and skipped periods in women aged over 45 years. The association with ‘cycle too variable to say’ was significant, but weaker. Conclusion There is a high prevalence, incidence and significant spontaneous rate of resolution of heavy menstrual bleeding in naturally menstruating women during the perimenopausal years. The rates have potential use for individual women, clinical decisions, devising and implementing interventions and planning the care of populations. Please cite this paper as: Shapley M, Blagojevic M, Jordan K, Croft P. The spontaneous resolution of heavy menstrual bleeding in the perimenopausal years. BJOG 2012;119:545–553.
- Published
- 2012
- Full Text
- View/download PDF
25. Review of sunscreen and the emergence of non-conventional absorbers and their applications in ultraviolet protection
- Author
-
Kenneth Morabito, Kristin G. Steeley, Nina C. Shapley, and Anubhav Tripathi
- Subjects
Uv protection ,Aging ,Future studies ,Materials science ,business.industry ,Ultraviolet protection ,Pharmaceutical Science ,Nanotechnology ,Sunscreening Agents ,Dermatology ,medicine.disease_cause ,Organic molecules ,Colloid and Surface Chemistry ,Optics ,Chemistry (miscellaneous) ,Drug Discovery ,Solid lipid nanoparticle ,medicine ,Organic component ,business ,Ultraviolet - Abstract
Protection against ultraviolet (UV) radiation is the major function of sunscreen lotions and UV-protective coatings for vehicles, homes, equipment and clothing. Sunscreen formulations have been optimized to become protective over a broader spectrum of UV radiation and maintain greater photostability. They are comprised of organic and inorganic components that act as chemical and physical UV protectors, respectively. Some of the organic components are limited by their spectrum of protection and photostability. Studies using solid lipid nanoparticles, recently explored organic molecules, inorganic components and antioxidants attempt to further optimize UV protection. In this review, we examine traditional and emerging nanoparticle components and highlight novel ideas in UV protection which may provide pathways for future studies.
- Published
- 2011
- Full Text
- View/download PDF
26. Dimensions of Care Model and Pediatric Audiology
- Author
-
Nannette Nicholson, Kathy Shapley, and Patti F. Martin
- Subjects
Speech and Hearing ,medicine.medical_specialty ,business.industry ,media_common.quotation_subject ,Medicine ,Quality (business) ,Audiology ,business ,media_common - Published
- 2010
- Full Text
- View/download PDF
27. The Cape crusaders
- Author
-
Shapley, David
- Subjects
Capespan International -- Management ,Fruit industry -- South Africa ,Export marketing -- Management ,Business ,Business, international ,Food and beverage industries - Abstract
The South African citrus industry employs 100,000 people directly and 600,000 other South Africans work in citrus exporting. It exports around 50 million cartons of fruit, with Western Europe accounting for 52% of the export market. The export function has been deregulated since Jan 1998 and former Outspan sales division Capespan International now deals with around 80% of exports. Analysts forecast that South African citrus exports will increase by 50% by 2003 and that growth markets will be North America and Eastern Europe., Capespan is confident of keeping its grip on most citrus export despite deregulation. David Shapley reports South Africa has enjoyed a reputation as one of the best and most consistent [...]
- Published
- 1998
28. A Dynamic Nonlinearity and Spatial Phase Specificity in Macaque V1 Neurons
- Author
-
Patrick E. Williams and Robert Shapley
- Subjects
Time Factors ,Action Potentials ,Simple cell ,Grating ,Stimulus (physiology) ,Macaque ,Step response ,biology.animal ,medicine ,Animals ,Visual Cortex ,Neurons ,Physics ,Communication ,biology ,business.industry ,General Neuroscience ,Articles ,Macaca fascicularis ,Nonlinear system ,medicine.anatomical_structure ,Visual cortex ,Nonlinear Dynamics ,Cascade ,Space Perception ,Biological system ,business ,Photic Stimulation - Abstract
While studying the visual response dynamics of neurons in the macaque primary visual cortex (V1), we found a nonlinearity of temporal response that influences the visual functions of V1 neurons. Simple cells were recorded in all layers of V1; the nonlinearity was strongest in neurons located in layer 2/3. We recorded the spike responses to optimal sinusoidal gratings that were displayed for 100 ms, a temporal step response. The step responses were measured at many spatial phases of the grating stimulus. To judge whether simple cell behavior was consistent with linear temporal integration, the decay of the 100 ms step response at the preferred spatial phase was used to predict the step response at the opposite spatial phase. Responses in layers 4B and 4C were mostly consistent with a linear-plus-static-nonlinearity cascade model. However, this was not true in layer 2/3 where most cells had little or no step responses at the opposite spatial phase. Many layer 2/3 cells had transient preferred-phase responses but did not respond at the offset of the opposite-phase stimuli, indicating a dynamic nonlinearity. A different stimulus sequence, rapidly presented random sinusoids, also produced the same effect, with layer 2/3 simple cells exhibiting elevated spike rates in response to stimuli at one spatial phase but not 180° away. The presence of a dynamic nonlinearity in the responses of V1 simple cells indicates that first-order analyses often capture only a fraction of neuronal behavior. The visual implication of our results is that simple cells in layer 2/3 are spatial phase-sensitive detectors that respond to contrast boundaries of one sign but not the opposite.
- Published
- 2007
- Full Text
- View/download PDF
29. Representation of Color Surfaces in V1: Edge Enhancement and Unfilled Holes
- Author
-
Shay Zweig, Guy Zurawel, Robert Shapley, and Hamutal Slovin
- Subjects
Male ,Visual perception ,Time Factors ,genetic structures ,Color vision ,Population ,Geometry ,Visual system ,Luminance ,law.invention ,Contrast Sensitivity ,law ,medicine ,Animals ,Visual Pathways ,Chromatic scale ,education ,Visual Cortex ,Physics ,Communication ,education.field_of_study ,Brain Mapping ,business.industry ,General Neuroscience ,Articles ,Voltage-Sensitive Dye Imaging ,Macaca fascicularis ,Visual cortex ,medicine.anatomical_structure ,Pattern Recognition, Visual ,Achromatic lens ,Visual Fields ,business ,Color Perception ,Photic Stimulation - Abstract
The neuronal mechanism underlying the representation of color surfaces in primary visual cortex (V1) is not well understood. We tested on color surfaces the previously proposed hypothesis that visual perception of uniform surfaces is mediated by an isomorphic, filled-in representation in V1. We used voltage-sensitive-dye imaging in fixating macaque monkeys to measure V1 population responses to spatially uniform chromatic (red, green, or blue) and achromatic (black or white) squares of different sizes (0.5°–8°) presented for 300 ms. Responses to both color and luminance squares early after stimulus onset were similarly edge-enhanced: for squares 1° and larger, regions corresponding to edges were activated much more than those corresponding to the center. At later times after stimulus onset, responses to achromatic squares' centers increased, partially “filling-in” the V1 representation of the center. The rising phase of the center response was slower for larger squares. Surprisingly, the responses to color squares behaved differently. For color squares of all sizes, responses remained edge-enhanced throughout the stimulus. There was no filling-in of the center. Our results imply that uniform filled-in representations of surfaces in V1 are not required for the perception of uniform surfaces and that chromatic and achromatic squares are represented differently in V1.SIGNIFICANCE STATEMENTWe used voltage-sensitive dye imaging from V1 of behaving monkeys to test the hypothesis that visual perception of uniform surfaces is mediated by an isomorphic, filled-in representation. We found that the early population responses to chromatic and achromatic surfaces are edge enhanced, emphasizing the importance of edges in surface processing. Next, we show for color surfaces that responses remained edge-enhanced throughout the stimulus presentation whereas response to luminance surfaces showed a slow neuronal ‘filling-in’ of the center. Our results suggest that isomorphic representation is not a general code for uniform surfaces in V1.
- Published
- 2015
30. Familial Risk in Low-Income Children With Chronic Illness Exposed to Passive Smoke
- Author
-
Rajalakshmi Cheerla, Angie Kyzer, Leanne Whiteside-Mansell, Taren Swindle, and Kathy L. Shapley
- Subjects
Adult ,Male ,Parents ,Family Conflict ,Risk Factors ,Environmental health ,medicine ,Early Intervention, Educational ,Humans ,Poverty ,Depression (differential diagnoses) ,Depressive Disorder ,business.industry ,Mental Disorders ,Resilience, Psychological ,Anxiety Disorders ,United States ,Passive Smoke Exposure ,Head start ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Chronic Disease ,Anxiety ,Marital status ,Residence ,Female ,Tobacco Smoke Pollution ,medicine.symptom ,Basic needs ,business ,Stress, Psychological - Abstract
Background. This study highlights the family characteristics of a child living in a state of triple risk: chronically ill, exposed to passive smoke, and residing in a low-income household. Methods. Head Start families were divided into 4 groups based on passive smoke exposure and child chronic illness status. Analyses of covariance controlling for parent education, parent employment, marital status, and residence were conducted to identify group differences in the Family Map risk areas. Results. Families of chronically ill, passive smoke–exposed children demonstrated the highest levels of risks across a range of areas including: meeting basic needs, family conflict, parenting stress, and parental depression and anxiety. Conclusions. Children living in poverty with a chronic illness who are exposed to smoke are likely to face many challenges in addition to their illness. Healthcare professionals can identify family risks and provide targeted educate and support to potentially reduce risk factors for children.
- Published
- 2015
31. LFP Power Spectra in V1 Cortex: The Graded Effect of Stimulus Contrast
- Author
-
Robert Shapley and J. Andrew Henrie
- Subjects
genetic structures ,Physiology ,Action Potentials ,Local field potential ,Stimulus (physiology) ,Macaque ,Spectral line ,biology.animal ,medicine ,Animals ,Visual Cortex ,Neurons ,Physics ,Communication ,biology ,business.industry ,Spectrum Analysis ,General Neuroscience ,Dose-Response Relationship, Radiation ,Electroencephalography ,Macaca fascicularis ,Visual cortex ,medicine.anatomical_structure ,Visual Perception ,Evoked Potentials, Visual ,business ,Neuroscience ,Photic Stimulation - Abstract
We recorded local field potentials (LFPs) and single-unit activity simultaneously in the macaque primary visual cortex (V1) and studied their responses to drifting sinusoidal gratings that were chosen to be “optimal” for the single units. Over all stimulus conditions, the LFP spectra have much greater power in the low-frequency band (≤10 Hz) than higher frequencies and can be described as “1/f.” Analysis of the total power limited to the low, gamma (25–90 Hz), or broad (8–240 Hz) frequency bands of the LFP as a function of stimulus contrast indicates that the LFP power gradually increases with stimulus strength across a wide band in a manner roughly comparable to the increase in the simultaneously recorded spike activity. However, the low-frequency band power remains approximately constant across all stimulus contrasts. More specifically the gamma-band LFP power increases differentially more with respect to baseline than either higher or lower bands as stimulus contrast increases. At the highest stimulus contrasts, we report as others have previously, that the power spectrum of the LFP typically contains an obvious peak in the gamma-frequency band. The gamma-band peak emerges from the overall broadband enhancement in LFP power at stimulus contrasts where most single units' responses have begun to saturate. The temporal/spectral structures of the LFP located in the gamma band—which become most evident at the highest contrasts—provide additional constraints on potential mechanisms underlying the stimulus response properties of spiking neurons in V1.
- Published
- 2005
- Full Text
- View/download PDF
32. Magnetic resonance imaging (MRI): a technique to study flow an microstructure of concentrated emulsions
- Author
-
Nina C. Shapley, S. R. Dungan, Ronald J. Phillips, Marcos Akira d’Ávila, Jeffrey H. Walton, and Robert L. Powell
- Subjects
Materials science ,Opacity ,medicine.diagnostic_test ,business.industry ,General Chemical Engineering ,lcsh:TP155-156 ,Magnetic resonance imaging ,Concentration distribution ,Microstructure ,Optics ,Nuclear magnetic resonance ,Flow (mathematics) ,Concentric cylinder ,Dispersion (optics) ,medicine ,Experimental methods ,Spatial homogeneity ,lcsh:Chemical engineering ,business ,Velocity profiles ,Droplet size distribution ,Concentrated emulsions - Abstract
Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) have recently been recognized as important techniques for R&D of products and processes, as is attested by several successful applications in different areas of chemical engineering in recent years. In this article we present new experimental methods based on MRI to study flow and microstructure of concentrated emulsions. The objective is to present the unique features of this noninvasive technique to accurately measure different properties of flowing particulate opaque systems. Experimental results of velocity profiles, spatial distribution of droplet sizes and spatial homogeneity of an oil-in-water dispersion in a horizontal, concentric cylinder geometry using different pulse sequences are presented. The application of these techniques allowed probing important information on flow and microstructure of multiphase systems of interest in chemical engineering and food science.
- Published
- 2005
33. From the Leaders of Our Nation: Prime Ministers' Records at the National Archives
- Author
-
Maggie Shapley
- Subjects
Prime minister ,Engineering ,business.industry ,National archives ,Library services ,Library science ,Library automation ,Library and Information Sciences ,business ,Prime (order theory) ,Management ,Library materials - Abstract
The National Archives of Australia holds the papers of many of Australia's Prime Ministers, including Bruce, Lyons, Curtin, Chifley, Holt, Whitlam, Fraser, Hawke, Keating and Howard. From 2000 it undertook a four-year Prime Ministers' Papers Project to locate the records of all 25 men who have held the position of Prime Minister of Australia. The Australia's Prime Ministers portal website was launched in 2002 and the Archives is also producing a series of guides to the archives of Prime Ministers.
- Published
- 2005
- Full Text
- View/download PDF
34. Entrainment to Video Displays in Primary Visual Cortex of Macaque and Humans
- Author
-
Patrick E. Williams, Ferenc Mechler, James Gordon, Robert Shapley, and Michael J. Hawken
- Subjects
Adult ,Male ,Time Factors ,Visual perception ,Cathode ray tube ,Action Potentials ,Behavioral/Systems/Cognitive ,Flicker fusion threshold ,Luminance ,Macaque ,law.invention ,Contrast Sensitivity ,Flicker Fusion ,law ,biology.animal ,medicine ,Animals ,Humans ,Computer vision ,Visual Cortex ,Communication ,biology ,business.industry ,General Neuroscience ,Flicker ,Geniculate Bodies ,Electroencephalography ,Signal Processing, Computer-Assisted ,Refresh rate ,Macaca fascicularis ,Visual cortex ,medicine.anatomical_structure ,Computer Terminals ,Evoked Potentials, Visual ,Female ,Artificial intelligence ,Psychology ,business ,Microelectrodes ,Photic Stimulation - Abstract
Cathode ray tubes (CRTs) display images refreshed at high frequency, and the temporal waveform of each pixel is a luminance impulse only a few milliseconds long. Although humans are perceptually oblivious to this flicker, we show in V1 in macaque monkeys and in humans that extracellularly recorded action potentials (spikes) and visual-evoked potentials (VEPs) align with the video impulses, particularly when high-contrast stimuli are viewed. Of 91 single units analyzed in macaque with a 60 Hz video refresh, 29 cells (32%) significantly locked their firing to a uniform luminance display, but their number increased to 75 (82%) when high-contrast stimuli were shown. Of 92 cells exposed to a 100 Hz refresh, 21 (23%) significantly phase locked to high-contrast stimuli. Phase locking occurred in both input and output layers of V1 for simple and complex cells, regardless of preferred temporal frequency. VEPs recorded in humans showed significant phase locking to the video refresh in all seven observers. Like the monkey neurons, human VEPs more typically phase locked to stimuli containing spatial contrast than to spatially uniform stimuli. Phase locking decreased when the refresh rate was increased. Thus in humans and macaques phase locking to the high strobe frequency of a CRT is enhanced by a salient spatial pattern, although the perceptual impact is uncertain. We note that a billion people worldwide manage to watch TV without obvious distortion of their visual perception despite extraordinary phase locking of their V1s to a 50 or 60 Hz signal.
- Published
- 2004
- Full Text
- View/download PDF
35. Correlation of local and global orientation and spatial frequency tuning in macaque V1
- Author
-
Robert Shapley, Dajun Xing, Michael J. Hawken, and Dario L. Ringach
- Subjects
Physics ,Communication ,genetic structures ,Quantitative Biology::Neurons and Cognition ,biology ,Physiology ,business.industry ,Bandwidth (signal processing) ,Sharpening ,Stimulus (physiology) ,Sinusoidal grating ,Macaque ,Correlation ,Visual cortex ,medicine.anatomical_structure ,biology.animal ,medicine ,Spatial frequency ,Biological system ,business - Abstract
Visual cortical neurones display a variety of visual properties. Among those that emerge in the primary visual cortex V1 are sharpening of selectivity for spatial frequency and for orientation. The selectivity for these stimulus attributes can be measured around the peak of the tuning function, usually as bandwidth. Other selectivity measures take into account the response across a broader range of stimulus values. An example of such a global measure is the circular variance of orientation tuning. Here we introduce a similar measure in the spatial frequency domain that takes into account the shape of the tuning curve at frequencies lower than the peak, called the low-spatial frequency variance. Our recent studies with dynamic stimuli suggest that the selectivity for spatial frequency and orientation is strongly correlated with the degree of suppression at low spatial frequencies and off-axis orientations. Here we extend the study of the global tuning to stimulus conditions that measure the response of cells to the presentation of drifting sinusoidal grating stimuli for periods of a few seconds. We find that under such steady-state stimulus conditions there is a strong correlation between the global selectivity measures, orientation circular variance and low spatial frequency variance. Consistent with previous studies, there is a weaker correlation between the local tuning measures, orientation and spatial frequency bandwidth. These results support the idea that there are multiple factors that contribute to tuning and that suppression observed in dynamic experiments is also likely to contribute to the global selectivity for steady-state stimuli.
- Published
- 2004
- Full Text
- View/download PDF
36. Patterns of Consent in Epidemiologic Research: Evidence from Over 25,000 Responders
- Author
-
Rosie J. Lacey, Kate M. Dunn, Mark Shapley, Clare Jinks, and Kelvin P. Jordan
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Epidemiology ,media_common.quotation_subject ,Population ,Bias ,Informed consent ,medicine ,Humans ,Longitudinal Studies ,education ,Psychiatry ,media_common ,Selection bias ,education.field_of_study ,Informed Consent ,business.industry ,Research ,Public health ,Medical record ,Odds ratio ,Middle Aged ,United Kingdom ,Confidence interval ,Epidemiologic Studies ,Logistic Models ,Family medicine ,Female ,business - Abstract
Ethical guidelines in the United Kingdom require written consent from participants in epidemiologic studies for follow-up or review of medical records. This may cause bias in samples used for follow-up or medical record review. The authors analyzed data from seven general population surveys conducted in the United Kingdom (1996-2002), to which over 25,000 people responded. Associations of age, gender, and symptom under investigation with consent to follow-up and consent to review of medical records were examined. Consent to follow-up was approximately 75-95% among survey responders under age 50 years but fell among older people, particularly females. Consent to follow-up was also higher among responders who had the symptom under investigation (pooled odds ratio = 1.61, 95% confidence interval: 1.36, 1.92). Consent to review of medical records followed a similar pattern. Patterns of consent were relatively consistent and represented a high proportion of responders. Males, younger people, and subjects reporting the symptom under investigation were more likely to give consent, and these groups may be overrepresented in follow-up samples or reviews of medical records. Although consent is high among responders, the additive effect of nonresponse and nonconsent can substantially reduce sample size and should be taken into account in epidemiologic study planning.
- Published
- 2004
- Full Text
- View/download PDF
37. Effects of contrast and size on orientation discrimination
- Author
-
Robert Shapley and Isabelle Mareschal
- Subjects
Fovea Centralis ,media_common.quotation_subject ,Differential Threshold ,Stimulus (physiology) ,Summation ,050105 experimental psychology ,Contrast Sensitivity ,03 medical and health sciences ,0302 clinical medicine ,Optics ,Orientation ,Perception ,Sensory threshold ,Psychophysics ,Humans ,0501 psychology and cognitive sciences ,Size Perception ,media_common ,business.industry ,05 social sciences ,Contrast (statistics) ,Sensory Systems ,Ophthalmology ,Receptive field ,Sensory Thresholds ,Visual Fields ,Psychology ,business ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Motivated by the recent physiological finding that a neuron’s receptive field can increase in size by a factor of 2–4-fold at low contrast [Nat. Neurosci. 2 (1999) 733, Proc. Natl. Acad. Sci. USA 96 (1999) 12073], we sought to examine whether a psychophysical task might reflect the contrast dependent changes in the size/structure of a receptive field. We postulate that since spatial summation is not contrast invariant, a task that relies on the spatial structure of a receptive field, such as orientation discrimination, should also be affected by changes in contrast. Previously, orientation discrimination thresholds have been reported to be roughly independent of the contrast of a stimulus for most of the visible range of contrasts [i.e. J. Neurophysiol. 57 (1987) 773, J. Opt. Soc. Am. 6 (1989) 713, Vis. Res. 30 (1990) 449, Vis. Res. 39 (1999) 1631]. Here, we found large improvements in orientation discrimination with contrast that were dependent on stimulus area. Furthermore, the apparent constancy of orientation discrimination for large area stimuli is possibly a result of a floor effect on the threshold. Therefore we conclude that there is not strong evidence for contrast invariant orientation discrimination. We interpret these results in the context of recent neurophysiological results about the expansion of cortical cells’ receptive fields at low contrast.
- Published
- 2004
- Full Text
- View/download PDF
38. On authority distributions in organizations: controls
- Author
-
Xingwei Hu and Lloyd S. Shapley
- Subjects
Economics and Econometrics ,Property (philosophy) ,business.industry ,media_common.quotation_subject ,Public relations ,Democracy ,Power (social and political) ,Power over ,Boss ,Sovereignty ,Private property ,Economics ,Common property ,business ,Finance ,media_common ,Law and economics - Abstract
A member's command game gives the direct boss and approval relations between him and other members in his organization. In a complicated organization, “commands” can be passed or implemented through command channels. This implies a global authority topology in the organization. This paper will investigate three related forms of command channels and their contexts. In the stricter form, a coalition has the complete power over a player. This form can be found in the military, a slavery as well as private property right. The other two equivalent forms analyze the sharing power over commonly-owned property. They can explain such issues as the controlling power, responsibility, democracy in instituting governments (e.g., one-person-one-vote principle), sharing sovereign and indivisible common property.
- Published
- 2003
- Full Text
- View/download PDF
39. Increased vaginal bleeding and psychological distress: a longitudinal study of their relationship in the community
- Author
-
Peter Croft, Kelvin P. Jordan, and Mark Shapley
- Subjects
Response rate (survey) ,Gynecology ,medicine.medical_specialty ,education.field_of_study ,Longitudinal study ,Obstetrics ,business.industry ,Population ,Obstetrics and Gynecology ,Odds ratio ,Distress ,medicine ,Vaginal bleeding ,medicine.symptom ,Prospective cohort study ,business ,education ,Cohort study - Abstract
Objective To explore the temporal relationship between the development of self-reported symptoms of vaginal bleeding and the development of psychological distress among women in the community. Design Prospective cohort study using postal surveys at baseline and at 6 and 12 months. Setting An urban four-partner general practice with 10,000 registered patients. Population All women aged 18–54 years on the practice age–sex register. Methods Baseline postal questionnaire with follow up questionnaires sent at 6 and 12 months. Main outcome measures The associations between the development of heavy periods and psychological distress. Results Two thousand and four hundred and thirty-five baseline questionnaires were sent out with an initial response rate of 76%. One thousand and five hundred and thirteen women (62%) responded to all three questionnaires. Women with psychological distress at baseline were more likely to develop heavy periods 6 months later than women without distress (adjusted odds ratio 1.87, 95% CI 1.15, 3.02). Women with heavy periods at baseline were no more likely to develop psychological distress 6 months later than women with non-heavy periods (adjusted odds ratio 1.09, 95% CI 0.73, 1.63). Similar findings existed with respect to intermenstrual bleeding and postcoital bleeding. Results of the 12-month analysis were similar. Conclusion In the community, psychological distress appears to influence the future self-reporting of heavy periods and other symptoms of vaginal bleeding.
- Published
- 2003
- Full Text
- View/download PDF
40. A psychophysical correlate of contrast dependent changes in receptive field properties
- Author
-
J. Andrew Henrie, Isabelle Mareschal, and Robert Shapley
- Subjects
media_common.quotation_subject ,Stimulus (physiology) ,Grating ,Summation ,Luminance ,050105 experimental psychology ,Contrast Sensitivity ,03 medical and health sciences ,0302 clinical medicine ,Optics ,Perception ,Psychophysics ,Humans ,0501 psychology and cognitive sciences ,media_common ,Physics ,business.industry ,05 social sciences ,Sensory Systems ,Ophthalmology ,Receptive field ,Sensory Thresholds ,Spatial frequency ,Visual Fields ,business ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Recent physiological investigations have demonstrated that a neuron's area of spatial summation can vary depending on stimulus contrast. Specifically, when the same stimulus is presented to a neuron at a low contrast, the area of summation (or neuron's receptive field) can increase by at least a factor of two, compared to that estimated with a high contrast stimulus. We sought to examine this phenomenon psychophysically by using an orientation discrimination task carried out in the presence of contextual stimuli. We have found previously that orientation discrimination thresholds for a sine-wave grating are elevated by the presence of a surround pattern of similar orientation (with an offset) and spatial frequency. However, when these patterns were separated by a gap of mean luminance exceeding roughly 1 deg, thresholds dropped to the level measured using the center pattern alone. Here, we examined the surround pattern's effect on orientation thresholds as a function of the contrast of the center and surround. We find that when both are presented at a low contrast, the detrimental influence of the surround on orientation thresholds is maintained over larger gap separations. We also find that the spatial frequency and orientation selectivity of the surround's masking effect on orientation thresholds is broader at low contrast than at high contrast. Although the results support the idea of a spatial reorganization of the mechanisms involved in the task at low contrast, these changes are insufficient, in and of themselves, to account for the data. We suggest that additional influences possibly reflecting image segmentation also affect performance.
- Published
- 2002
- Full Text
- View/download PDF
41. Suppression of Neural Responses to Nonoptimal Stimuli Correlates With Tuning Selectivity in Macaque V1
- Author
-
Dario L. Ringach, Robert Shapley, C. E. Bredfeldt, and Michael J. Hawken
- Subjects
Physiology ,Photic Stimulation ,Conditioning, Classical ,Models, Neurological ,Neural Inhibition ,Brain mapping ,Macaque ,Orientation ,biology.animal ,medicine ,Animals ,Computer Simulation ,Visual Cortex ,Feedback, Physiological ,Neurons ,Brain Mapping ,Communication ,Fourier Analysis ,biology ,business.industry ,General Neuroscience ,Macaca fascicularis ,Visual cortex ,medicine.anatomical_structure ,Spatial frequency ,Selectivity ,business ,Psychology ,Neuroscience - Abstract
Neural responses in primary visual cortex (area V1) are selective for the orientation and spatial frequency of luminance-modulated sinusoidal gratings. Selectivity could arise from enhancement of the cell's response by preferred stimuli, suppression by nonoptimal stimuli, or both. Here, we report that the majority of V1 neurons do not only elevate their activity in response to preferred stimuli, but their firing rates are also suppressed by nonoptimal stimuli. The magnitude of suppression is similar to that of enhancement. There is a tendency for net response suppression to peak at orientations near orthogonal to the optimal for the cell, but cases where suppression peaks at oblique orientations are observed as well. Interestingly, selectivity and suppression correlate in V1: orientation and spatial frequency selectivity are higher for neurons that are suppressed by nonoptimal stimuli than for cells that are not. This finding is consistent with the idea that suppression plays an important role in the generation of sharp cortical selectivity. We show that nonlinear suppression is required to account for the data. However, the precise structure of the neural circuitry generating the suppressive signal remains unresolved. Our results are consistent with both feedback and (nonlinear) feed-forward inhibition.
- Published
- 2002
- Full Text
- View/download PDF
42. Nonlinear dynamics of cortical responses to color in the human cVEP
- Author
-
Robert Shapley, James Gordon, and Valerie Nunez
- Subjects
Adult ,Male ,genetic structures ,cortical dynamics ,cVEP ,Lateral geniculate nucleus ,Article ,050105 experimental psychology ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Optics ,Cortex (anatomy) ,medicine ,Electrode array ,Humans ,Waveform ,human color vision ,0501 psychology and cognitive sciences ,Chromatic scale ,Evoked potential ,Visual Cortex ,Physics ,V1 ,business.industry ,05 social sciences ,Geniculate Bodies ,Middle Aged ,Sensory Systems ,Ophthalmology ,Visual cortex ,medicine.anatomical_structure ,Checkerboard ,Retinal Cone Photoreceptor Cells ,Evoked Potentials, Visual ,Female ,business ,Neuroscience ,Color Perception ,Photic Stimulation ,030217 neurology & neurosurgery - Abstract
The main finding of this paper is that the human visual cortex responds in a very nonlinear manner to the color contrast of pure color patterns. We examined human cortical responses to color checkerboard patterns at many color contrasts, measuring the chromatic visual evoked potential (cVEP) with a dense electrode array. Cortical topography of the cVEPs showed that they were localized near the posterior electrode at position Oz, indicating that the primary cortex (V1) was the major source of responses. The choice of fine spatial patterns as stimuli caused the cVEP response to be driven by double-opponent neurons in V1. The cVEP waveform revealed nonlinear color signal processing in the V1 cortex. The cVEP time-to-peak decreased and the waveform's shape was markedly narrower with increasing cone contrast. Comparison of the linear dynamics of retinal and lateral geniculate nucleus responses with the nonlinear dynamics of the cortical cVEP indicated that the nonlinear dynamics originated in the V1 cortex. The nature of the nonlinearity is a kind of automatic gain control that adjusts cortical dynamics to be faster when color contrast is greater.
- Published
- 2017
- Full Text
- View/download PDF
43. A contrast and surface code explains complex responses to black and white stimuli in V1
- Author
-
Hamutal Slovin, Robert Shapley, Shay Zweig, Inbal Ayzenshtat, and Guy Zurawel
- Subjects
Male ,Visual perception ,Surround suppression ,media_common.quotation_subject ,Population ,Astrophysics ,Relative strength ,Luminance ,Macaque ,Contrast Sensitivity ,Random Allocation ,biology.animal ,medicine ,Reaction Time ,Contrast (vision) ,Animals ,education ,media_common ,Visual Cortex ,Physics ,education.field_of_study ,Communication ,biology ,business.industry ,General Neuroscience ,Articles ,Macaca fascicularis ,Visual cortex ,medicine.anatomical_structure ,Visual Perception ,business ,Photic Stimulation ,Psychomotor Performance - Abstract
We investigated the cortical mechanisms underlying the visual perception of luminance-defined surfaces and the preference for black over white stimuli in the macaque primary visual cortex, V1. We measured V1 population responses with voltage-sensitive dye imaging in fixating monkeys that were presented with white or black squares of equal contrast around a mid-gray. Regions corresponding to the squares' edges exhibited higher activity than those corresponding to the center. Responses to black were higher than to white, surprisingly to a much greater extent in the representation of the square's center. Additionally, the square-evoked activation patterns exhibited spatial modulations along the edges and corners. A model comprised of neural mechanisms that compute local contrast, local luminance temporal modulations in the black and white directions, and cortical center-surround interactions, could explain the observed population activity patterns in detail. The model captured the weaker contribution of V1 neurons that respond to positive (white) and negative (black) luminance surfaces, and the stronger contribution of V1 neurons that respond to edge contrast. Also, the model demonstrated how the response preference for black could be explained in terms of stronger surface-related activation to negative luminance modulation. The spatial modulations along the edges were accounted for by surround suppression. Overall the results reveal the relative strength of edge contrast and surface signals in the V1 response to visual objects.
- Published
- 2014
44. Testicular swelling due to lymphatic filariasis after brief travel to Haiti
- Author
-
Nathan P. Shapley, Mark E. Eberhard, Jonathan I. Epstein, Luis A. Marcos, Thomas B. Nutman, Alan J. Magill, and Le Anne M. Fox
- Subjects
Adult ,Male ,Testicular swelling ,Physiology ,Testicular pain ,medicine.disease_cause ,Elephantiasis, Filarial ,Virology ,Biopsy ,parasitic diseases ,Testis ,medicine ,Animals ,Humans ,Wuchereria bancrofti ,Lymphatic filariasis ,Travel ,medicine.diagnostic_test ,business.industry ,Articles ,medicine.disease ,Haiti ,Infectious Diseases ,Immunology ,Parasitology ,Filarial parasite ,medicine.symptom ,business ,human activities - Abstract
After 6 months of a trip to Haiti, a 25-year-old healthy man presented with a 6-week history of a very slow progressive intermittent bilateral testicular pain and swelling. The biopsies in both testicles revealed the presence of a dead filarial parasite. Polymerase chain reaction products of the DNA from the biopsy were shown to have a 100% identity to Wuchereria bancrofti. Despite being uncommon in travelers, this presentation of W. bancrofti highlights the possibility of acquiring W. bancrofti during short-term trips to highly endemic regions of the world (i.e., Haiti).
- Published
- 2014
45. The relatively small decline in orientation acuity as stimulus size decreases
- Author
-
J. Andrew Henrie and Robert Shapley
- Subjects
Adult ,Male ,Visual acuity ,Psychometrics ,Bayesian decision theory ,genetic structures ,Sinusoidal gratings ,media_common.quotation_subject ,Visual Acuity ,Differential Threshold ,Stimulus (physiology) ,Bayes' theorem ,Discrimination, Psychological ,Optics ,Gabor filter ,Orientation ,Perception ,Statistics ,medicine ,Humans ,Orientation acuity ,Size Perception ,Visual Cortex ,media_common ,Bayes estimator ,business.industry ,Bayes Theorem ,Middle Aged ,Sensory Systems ,Ophthalmology ,Logistic Models ,Visual cortex ,medicine.anatomical_structure ,medicine.symptom ,business ,Psychology - Abstract
Orientation acuity was measured with circular patches of sinusoidal gratings of various sizes. Threshold estimates were lowest (acuity highest) for the largest size patch, and increased as the stimulus size was reduced, consistent with the results of many researchers using line stimuli. These results are compared with the predictions of a simple and widely accepted model of spatial vision whereby the output of independent feed-forward filters are combined to produce threshold estimates. Specifically, the rectified output of a number of independent filters (i.e. Gabors) spanning the stimulus space (i.e. orientation) are combined via Bayesian decision theory. This model cannot account quantitatively for the relatively low thresholds estimated for the small sized stimuli when compared to the thresholds measured with larger patches. Application of a comparable analysis, with preliminary measurements of neuronal responses from primary visual cortex replacing the response rectified Gabor filter's responses, provides a more reasonable account of behavioral acuity. This indicates a fundamental inadequacy of the feed-forward filter model in accounting for V1 neurons' role in perception.
- Published
- 2001
- Full Text
- View/download PDF
46. Visual Spatial Characterization of Macaque V1 Neurons
- Author
-
Michael P. Sceniak, Robert Shapley, and Michael J. Hawken
- Subjects
Difference of Gaussians ,Physiology ,Surround suppression ,media_common.quotation_subject ,Models, Neurological ,Population ,Normal Distribution ,Summation ,Macaque ,Contrast Sensitivity ,Vision, Monocular ,biology.animal ,medicine ,Animals ,Contrast (vision) ,education ,Spatial organization ,Visual Cortex ,media_common ,Neurons ,Physics ,Brain Mapping ,education.field_of_study ,Communication ,biology ,business.industry ,General Neuroscience ,Macaca fascicularis ,Visual cortex ,medicine.anatomical_structure ,Biological system ,business - Abstract
This study characterizes the spatial organization of excitation and inhibition that influences the visual responses of neurons in macaque monkey's primary visual cortex (V1). To understand the spatial extent of excitatory and inhibitory influences on V1 neurons, we performed area-summation experiments with suprathreshold contrast stimulation. The extent of spatial summation and the magnitude of surround suppression were estimated quantitatively by analyzing the spatial summation experiments with a difference of Gaussians (DOG) model. The average extent of spatial summation is approximately the same across layers except for layer 6 cells, which tend to sum more extensively than cells in the other layers. On average, the extent of length and width summation is approximately equal. Across the population, surround suppression is greatest in layer 4B and weakest in layer 6. Estimates of summation and suppression are compared for the DOG (subtractive) model and a normalization (divisive) model. The two models yield quantitatively similar estimates of the extent of excitation and inhibition. However, the normalization (divisive) model predicts weaker surround strength than the DOG model.
- Published
- 2001
- Full Text
- View/download PDF
47. The introduction of a routine monitoring system in primary care for patients with a first episode of cardiovascular disease
- Author
-
Mark Shapley, R McCarney, Peter Croft, and Rosemarie Goodwin
- Subjects
Adult ,Male ,medicine.medical_specialty ,Audit ,Disease ,Patient Education as Topic ,Health care ,Secondary Prevention ,Humans ,Medicine ,Stroke ,General Nursing ,Aged ,Aged, 80 and over ,First episode ,Primary Health Care ,business.industry ,Process Assessment, Health Care ,Middle Aged ,Community Health Nursing ,medicine.disease ,Checklist ,Health promotion ,England ,Cardiovascular Diseases ,Family medicine ,Female ,Medical emergency ,business ,Patient education - Abstract
The introduction of a routine monitoring system in primary care for patients with a first episode of cardiovascular disease A study at a group general practice in the English midlands found that health promotion advice had not been routinely provided to some patients with cardiovascular disease and stroke. The purpose of this project therefore was to introduce a monitoring system to ensure that health promotion issues were covered systematically with patients following a first episode of cardiovascular disease. Patients with a first episode of a relevant condition would be identified by an automated search on the practice database, and contacted by the health visitor. A checklist would ensure that all appropriate issues were covered. The system was easily introduced at the practice and no difficulties were experienced with its administration. A total of 62 patients were seen during the year. A substantial number of secondary prevention issues were addressed through advice and information leaflets. The project was felt to be a useful addition to care by the workers involved. Although some of the issues may have been addressed in routine care, early organized nurse contact ensures systematic coverage and early referrals where necessary, as well as potential psychological benefit to patients.
- Published
- 2000
- Full Text
- View/download PDF
48. [Untitled]
- Author
-
Robert Shapley, Dario L. Ringach, Michael Shelley, and M. C. Pugh
- Subjects
Computer science ,Orientation (computer vision) ,business.industry ,Cognitive Neuroscience ,Feed forward ,Filter (signal processing) ,Sensory Systems ,Cellular and Molecular Neuroscience ,Visual cortex ,medicine.anatomical_structure ,Receptive field ,Simple (abstract algebra) ,Theory of computation ,medicine ,Computer vision ,Artificial intelligence ,business ,Biological system ,Generator (mathematics) - Abstract
In the primate visual pathway, orientation tuning of neurons is first observed in the primary visual cortex. The LGN cells that comprise the thalamic input to V1 are not orientation tuned, but some V1 neurons are quite selective. Two main classes of theoretical models have been offered to explain orientation selectivity: feedforward models, in which inputs from spatially aligned LGN cells are summed together by one cortical neuron; and feedback models, in which an initial weak orientation bias due to convergent LGN input is sharpened and amplified by intracortical feedback. Recent data on the dynamics of orientation tuning, obtained by a cross-correlation technique, may help to distinguish between these classes of models. To test this possibility, we simulated the measurement of orientation tuning dynamics on various receptive field models, including a simple Hubel-Wiesel type feedforward model: a linear spatiotemporal filter followed by an integrate-and-fire spike generator. The computational study reveals that simple feedforward models may account for some aspects of the experimental data but fail to explain many salient features of orientation tuning dynamics in V1 cells. A simple feedback model of interacting cells is also considered. This model is successful in explaining the appearance of Mexican-hat orientation profiles, but other features of the data continue to be unexplained.
- Published
- 2000
- Full Text
- View/download PDF
49. Gene therapy in colour
- Author
-
Robert Shapley
- Subjects
Multidisciplinary ,Optics ,genetic structures ,business.industry ,Genetic enhancement ,Colour Vision ,Normal colour ,macromolecular substances ,Biology ,business ,Neuroscience ,eye diseases - Abstract
Replacing a missing gene in adult colour-blind monkeys restores normal colour vision. How the new photoreceptor cells produced by this therapy lead to colour vision is a fascinating question.
- Published
- 2009
- Full Text
- View/download PDF
50. Illusory Contour Perception and Amodal Boundary Completion: Evidence of a Dissociation Following Callosotomy
- Author
-
Robert Shapley, Paul M. Corballis, Michael S. Gazzaniga, and Robert Fendrich
- Subjects
Adult ,Male ,Communication ,Epilepsy ,Dissociation (neuropsychology) ,Optical Illusions ,business.industry ,Cognitive Neuroscience ,media_common.quotation_subject ,Amodal perception ,Middle Aged ,Corpus Callosum ,Form Perception ,Form perception ,Perception ,Illusory contours ,Humans ,Regression Analysis ,Female ,Percept ,Right hemisphere ,Psychology ,business ,media_common ,Cognitive psychology - Abstract
A fundamental problem in form perception is how the visual system can link together spatially separated contour fragments to form the percept of a unitary shape. Illusory contours and amodal completion are two phenomena that demonstrate this linking process. In the present study we investigate these phenomena in the divided hemispheres of two callosotomy (“split-brain”) patients. The data suggest that dissociable neural mechanisms are responsible for the generation of illusory contours and amodal completion. Although both cerebral hemispheres appear to be equally capable of perceiving illusory contours, amodal completion is more readily utilized by the right hemisphere. These results suggest that illusory contours may be attributable to low-level visual processes common to both hemispheres, whereas amodal completion reflects a higher-level, lateralized process.
- Published
- 1999
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.