89 results on '"L. Seguin"'
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2. Activity, heart rate, and energy expenditure of a cold-climate mesocarnivore, the Canada lynx (Lynx canadensis)
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Allyson K. Menzies, Emily K. Studd, Jacob L. Seguin, Rachael E. Derbyshire, Dennis L. Murray, Stan Boutin, and Murray M. Humphries
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Animal Science and Zoology ,Ecology, Evolution, Behavior and Systematics - Abstract
The energetic consequences of body size, behaviour, and fine-scale environmental variation remain understudied, particularly among free-ranging carnivores, due to logistical and methodological challenges of studying them in the field. Here, we present novel activity, heart rate, and metabolic data on free-ranging Canada lynx (Lynx canadensis Kerr, 1792) to (i) investigate intraspecific patterns of energy expenditure, particularly how they relate to body size, environmental conditions, and activity variation, and (ii) position lynx — a cold-climate, mesocarnivore — within interspecific allometries of carnivore energetics. Lynx demonstrated limited behavioural and metabolic responses to environmental conditions, despite extreme cold and moderate snow depths during our study, but marked body size patterns with larger lynx having higher activity and lower resting heart rate than smaller lynx. Compared with similar-sized carnivores, lynx were less active and had lower heart rate, likely due to their ambush hunting style, but higher energy expenditure, likely due to their cold-climate existence and access to abundant prey. Overall, lynx were more similar to other ambush hunters than to sympatric cold-climate species and mesocarnivores. Our data provide insight into the relative importance of abiotic and biotic drivers of carnivore energetics and the ways in which predators maintain energy balance in variable environments.
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- 2022
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3. Prevalence, determinants and outcomes of traditional, complementary and alternative medicine use for hypertension among low-income households in Malaysia and the Philippines
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Lia M. Palileo-Villanueva, Benjamin Palafox, Arianna Maever L. Amit, Veincent Christian F. Pepito, Fadhlina Ab-Majid, Farnaza Ariffin, Dina Balabanova, Mohamad-Rodi Isa, Nafiza Mat-Nasir, Mazapuspavina My, Alicia Renedo, Maureen L. Seguin, Khalid Yusoff, Antonio L. Dans, and Martin Mckee
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Adult ,Complementary Therapies ,Cross-Sectional Studies ,Complementary and alternative medicine ,Philippines ,Hypertension ,Malaysia ,Prevalence ,Humans - Abstract
Background Traditional, complementary and alternative medicine (TCAM) is used to treat a broad range of conditions. In low- and middle-income countries (LMICs), TCAM use is particularly common among those with low socio-economic status. To better understand the patterns and impact of TCAM use on the management of non-communicable diseases in these populations, this study examines the prevalence and characteristics of TCAM use for hypertension, its determinants, and its association with hypertension management outcomes and wellbeing among low-income adults in two Southeast Asian countries at different levels of economic and health system development, Malaysia and the Philippines. Methods We analysed cross-sectional data from 946 randomly selected adults diagnosed with hypertension from low-income rural and urban communities in Malaysia (n = 495) and the Philippines (n = 451). We compared the prevalence, characteristics and household expenditure on TCAM use between countries and used multi-level, mixed-effects regression to estimate associations between TCAM use and its determinants, and five hypertension management outcomes and wellbeing. Results The prevalence of TCAM use to manage hypertension was higher in the Philippines than in Malaysia (18.8% vs 8.8%, p Conclusions A small, but significant, proportion of individuals living in low-income communities in Malaysia and the Philippines use TCAM to manage their hypertension, despite a general lack of evidence on efficacy and safety of commonly used TCAM modalities. Recognising that their patients may be using TCAM to manage hypertension will enable health care providers to deliver safer, more patient-centred care.
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- 2022
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4. 2020 North America Annual Meeting for SMDM
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Kenneth A. Freedberg, Carolina Barbosa, Jagpreet Chhatwal, Sarah E. Wakeman, Gary A. Zarkin, Qiushi Chen, Anna P. Lietz, Marc R. Larochelle, Mohammad S. Jalali, Madeline Adee, Pari V. Pandharipande, Amy B. Knudsen, Claudia L. Seguin, and Peter R. Mueller
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medicine.medical_specialty ,business.industry ,Health Policy ,Emergency medicine ,medicine ,Opioid overdose ,Opioid use disorder ,medicine.disease ,business - Published
- 2021
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5. 'Something Fun to Look Forward to': Lessons From Implementing the
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Carly A, Joseph and Michelle L, Seguin
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Fruit and vegetable (FV) prescription programs are an increasingly popular community-based approach to addressing food insecurity and improving nutrition by connecting local health care and food systems. The Prescription for Health farmers' market FV prescription program was piloted in a rural, low-access low-income Michigan community in 2017. The program enrolled 33 adult participants with chronic disease and provided weekly farmers' market FV vouchers, educational nutrition handouts, and seasonal healthy recipes over 10 weeks. Weight, blood pressure, and the following self-rated variables were assessed pre- and post program: dietary habits, food literacy, physical health, and mental health. While most metrics remained generally unchanged, one of the strongest findings from our data included significant improvement in quality of life. Increased social interaction as a result of the attending the farmers' market was a prominent theme from informal open-ended participant feedback. Given the ongoing public health crisis of loneliness and social isolation, this finding led us to consider the farmers' market as an avenue for creating opportunities for meaningful social connection among participants and farmers. To this end, we discuss health outcomes of the Prescription for Health pilot program, reflect on unique aspects of implementing this program in a rural area, and explore future opportunities for farmers' market prescription programs as an innovative form of nature-based social prescribing.
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- 2022
6. Cascade testing of first-degree relatives of patients with pancreatic cancer with confirmed germline genetic mutations: A simulation modeling study
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Mary Linton Bounetheau Peters, Barak Davidi, Claudia L. Seguin, Andrew Eckel, and Pari Pandharipande
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Cancer Research ,Oncology - Abstract
10513 Background: Universal germline genetic testing is recommended for all patients with pancreatic ductal adenocarcinoma (PDAC). In addition to treatment implications for the patient, it is valuable for family members of the PDAC patient to undertake germline testing to understand their familial cancer risk. We evaluated the potential effectiveness of cascade testing of first-degree relatives (FDRs) of PDAC patients to guide MRI-based screening for PDAC. Methods: We used a microsimulation model of PDAC to estimate the potential life expectancy (LE) benefit of cascade genetic testing of FDRs of PDAC patients. Analysis was performed for eight mutations of interest (ATM, BRCA1, BRCA2, PALB2, Lynch, TP53, CDKN2A, STK11) with relative risk of PDAC ranging from 1.6 – 24. FDRs were defined by their sex, age, and information state (not informed, informed but not tested, test negative, or test positive). Family size and composition, communication of genetic testing results, and uptake of cascade testing were based on published studies. For each FDR group, we simulated multiple MRI-based screening strategies, defined by starting age (FDR age at patient diagnosis to age 75) and frequency (once or annual until age 75), and identified the strategy that resulted in the highest LE. Results: Each PDAC patient would have an average of 4.35 living FDRs. 1.32 of these living FDRs would be informed of the patient’s test results but not undergo testing themselves, and 1.03 would test positive for the mutation of interest. For lower risk mutations (ATM, BRCA2, PALB2), FDRs would only undergo screening if they test positive. For Lynch syndrome, not tested FDRs would undergo screening starting at age 65 or 70, whereas FDRs who test positive would start at 50 or 55. For STK11, the highest risk mutation, FDRs would start screening annually as soon as they are informed of the patient’s test results. The total LE gain for cascade testing of FDRs ranged from 0 (BRCA1) to 1.05 years (STK11). Conclusions: For each PDAC patient identified to have a germline genetic mutation, cascade testing of FDRs could add up to a year life expectancy for the family, in addition to the value of the germline information to the PDAC patient’s care. [Table: see text]
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- 2022
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7. Benefits, harms, and burden of colorectal cancer screening among childhood cancer survivors previously treated with abdominal-pelvic radiation
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Jennifer M Yeh, Claudia L. Seguin, Jillian Whitton, Wendy M. Leisenring, Gregory T. Armstrong, Tara O. Henderson, Melissa M. Hudson, Paul C. Nathan, Joseph Philip Neglia, Kevin C. Oeffinger, Lisa Diller, and Amy B Knudsen
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Cancer Research ,Oncology - Abstract
10015 Background: Survivors of childhood cancer treated with abdominal-pelvic radiation are at increased risk for colorectal cancer (CRC). The Children’s Oncology Group recommends early initiation of CRC screening at age 30, yet the benefits and burden are unknown. Methods: We used incidence and mortality data from the Childhood Cancer Survivor Study to modify the SimCRC model from the Cancer Intervention and Surveillance Modeling Network (CISNET) to reflect high CRC and competing mortality risks among survivors, assuming the elevated cancer risk arises from higher adenoma onset. Strategies evaluated varied by modality (no screening, colonoscopy, multitarget stool DNA [mtsDNA] testing, fecal immunochemical testing [FIT]), screening start age (25, 30, 35, 40, 45) and screening interval (every 3, 5 or 10 yrs for colonoscopy; every 1, 2 or 3 yrs for mtsDNA and FIT). Abnormal stool test results were followed up with colonoscopy. Screening performance and complication rates were based on published studies. Analyses assumed full uptake and adherence to all screening and follow-up procedures. To identify the optimal strategy for each modality, we estimated the number of colonoscopies required per additional life-year gained and compared it to benchmarks for screening strategies recommended by the US Preventive Services Task Force for average-risk individuals. Results: Among a simulated cohort of 20-yr-old 5-yr survivors with a history of abdominal-pelvic radiation, the cumulative CRC risk at age 50 was 0.8%, approximately twice that predicted among general population average-risk individuals (0.4%). In the absence of screening, 73 per 1000 survivors would be diagnosed with CRC in their lifetime and 29 would die from the disease. All screening strategies evaluated were estimated to yield substantial reductions in the lifetime number of CRC cases (45-71 cases averted per 1000) and deaths (23-28 deaths averted per 1000). The estimated lifetime number of colonoscopies ranged from 1781 to 14,625 per 1000. The lifetime number of colonoscopy complications was relatively low at 9 to 20 per 1000. Based on the burden-to-benefit ratios, colonoscopy every 10 yrs starting at age 30, mtsDNA every 3 yrs starting at age 30, or FIT every 3 yrs starting at age 25 were the optimal screening strategies identified (Table). Conclusions: Early initiation of screening may substantially reduce CRC mortality among high-risk childhood cancer survivors. These estimates of the balance of screening benefits and burden can inform follow-up care guidelines. [Table: see text]
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- 2022
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8. The Optimal Age to Stop Endoscopic Surveillance of Patients With Barrett's Esophagus Based on Sex and Comorbidity: A Comparative Cost-Effectiveness Analysis
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Chun Yin Kong, Brianna N. Lauren, Minyi Lee, Chin Hur, Steffie K. Naber, Ellen Richmond, Joel H. Rubenstein, Iris Lansdorp-Vogelaar, Georg Luebeck, William D. Hazelton, Ayman Ali, Amir-Houshang Omidvari, Claudia L. Seguin, John M. Inadomi, and Public Health
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0301 basic medicine ,Male ,Pediatrics ,Time Factors ,Stop Age ,Esophageal Neoplasms ,Cost-Benefit Analysis ,Comorbidity ,CEA ,0302 clinical medicine ,Risk Factors ,Medicine ,EAC ,Early Detection of Cancer ,Aged, 80 and over ,Gastroenterology ,Age Factors ,Cost-effectiveness analysis ,Health Care Costs ,Esophageal cancer ,Middle Aged ,Prognosis ,Surveillance endoscopy ,030211 gastroenterology & hepatology ,Female ,Esophagoscopy ,Quality-Adjusted Life Years ,Incremental cost-effectiveness ratio ,medicine.medical_specialty ,Esophageal Cancer ,Clinical Decision-Making ,Adenocarcinoma ,Risk Assessment ,Article ,Decision Support Techniques ,03 medical and health sciences ,Barrett Esophagus ,Sex Factors ,Predictive Value of Tests ,Humans ,In patient ,Computer Simulation ,Aged ,Hepatology ,business.industry ,medicine.disease ,Quality-adjusted life year ,030104 developmental biology ,Barrett's esophagus ,Quality of Life ,business - Abstract
Background and Aims: Current guidelines recommend surveillance for patients with nondysplastic Barrett's esophagus (NDBE) but do not include a recommended age for discontinuing surveillance. This study aimed to determine the optimal age for last surveillance of NDBE patients stratified by sex and level of comorbidity. Methods: We used 3 independently developed models to simulate patients diagnosed with NDBE, varying in age, sex, and comorbidity level (no, mild, moderate, and severe). All patients had received regular surveillance until their current age. We calculated incremental costs and quality-adjusted life-years (QALYs) gained from 1 additional endoscopic surveillance at the current age versus not performing surveillance at that age. We determined the optimal age to end surveillance as the age at which incremental cost-effectiveness ratio of 1 more surveillance was just less than the willingness-to-pay threshold of $100,000/QALY. Results: The benefit of having 1 more surveillance endoscopy strongly depended on age, sex, and comorbidity. For men with NDBE and severe comorbidity, 1 additional surveillance at age 80 years provided 4 more QALYs per 1000 patients with BE at an additional cost of $1.2 million, whereas for women with severe comorbidity the benefit at that age was 7 QALYs at a cost of $1.3 million. For men with no, mild, moderate, and severe comorbidity, the optimal ages of last surveillance were 81, 80, 77, and 73 years, respectively. For women, these ages were younger: 75, 73, 73, and 69 years, respectively. Conclusions: Our comparative modeling analysis illustrates the importance of considering comorbidity status and sex when deciding on the age to discontinue surveillance in patients with NDBE.
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- 2020
9. Surveillance in Older Women With Incidental Ovarian Cysts: Maximal Projected Benefits by Age and Comorbidity Level
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Amy B. Knudsen, Jason D. Wright, Anna P. Lietz, Pari V. Pandharipande, Claudia L. Seguin, and Alexi A. Wright
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Diagnostic Imaging ,Pediatrics ,medicine.medical_specialty ,Comorbidity ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Life Expectancy ,Patient age ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,In patient ,Aged ,Aged, 80 and over ,Ovarian Neoplasms ,Average risk ,Postmenopausal women ,business.industry ,medicine.disease ,Ovarian Cysts ,030220 oncology & carcinogenesis ,Cohort ,Life expectancy ,Female ,Ovarian cancer ,business - Abstract
Purpose The aim of this study was to estimate effects on life expectancy (LE) of imaging-based ovarian surveillance after detection of incidental postmenopausal ovarian cysts, under different assumptions of patient age, comorbidity level, and cancer risk and detection. Methods A decision-analytic Markov model was developed to estimate LE benefits. Hypothetical cohorts of postmenopausal women with simple ovarian cysts were evaluated, with varied age (66-80 years) and comorbidity level (none, mild, moderate, severe). For each cohort, imaging “follow-up” (2 years) and “no-follow-up” strategies were compared. Consistent with current evidence, increased cancer risk in patients with cysts was not assumed; however, incident ovarian cancers could be detected during follow-up. To estimate theoretical maximal LE gains from follow-up, perfect ovarian cancer detection and treatment during follow-up were assumed. This and other key assumptions were varied in sensitivity analysis. Results Projected LE gains from follow-up were limited. For 66-, 70-, 75-, and 80-year-old women with no comorbidities, LE gains were 5.1, 5.1, 4.5, and 3.7 days; with severe comorbidities, they were 3.5, 3.2, 2.7, and 2.1 days. With sensitivity of 50% for cancer detection, they were 3.7 days for 66-year-old women with no comorbidities and 1.3 days for 80-year-old women with severe comorbidities. When cancer risk for women with cysts was assumed to be elevated (1.1 times average risk), LE gains increased only modestly (5.6 and 2.3 days for analogous cohorts). Conclusions Even in the circumstance of perfect ovarian cancer detection and treatment, surveillance of postmenopausal women (≥66 years of age) with simple cysts affords limited benefits, particularly in women with advanced age and comorbidities.
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- 2020
10. New Breeding Record for Merlin (Falco columbarius) in Southwestern Yukon
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Jacob L. Seguin, Melanie R. Boudreau, and Ryan P. Lamoureux
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Geography ,biology ,Range (biology) ,Ecology ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics ,Falco columbarius - Abstract
On 3 May 2016, we observed two Merlins (Falco columbarius) copulating near Hungry Lake in southwestern Yukon. We recorded Merlins frequently from May until the beginning of July and observed them defending the area from Common Ravens (Corvus corax) on two occasions, an activity indicative of a nesting pair. This is the first breeding record for Merlins in southern Yukon, as previous records have documented the breeding range only in central and northern parts of the territory. Here, we summarize historical sightings and breeding reports throughout southern Yukon since 1975 and fill a gap in the breeding range of this species.
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- 2018
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11. The Recovery Illusion: What Is Delaying the Rescue of Imperiled Species?
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Jason Rae, Jacob L. Seguin, Dennis L. Murray, Deborah A. Jenkins, Catarina Ferreira, Cristen Watt, Cayla Austin, Melanie R. Boudreau, Yasmine N. Majchrzak, Jessica N. Longhi, Morgan Wehtje, Josée-Anne Otis, Thomas J. Hossie, Spencer Walker, Morgan A. Hrynyk, Shawn MacFarlane, Kevin Chan, Michael J. L. Peers, and Amy Clement
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0106 biological sciences ,Geography ,010604 marine biology & hydrobiology ,media_common.quotation_subject ,Illusion ,General Agricultural and Biological Sciences ,010603 evolutionary biology ,01 natural sciences ,Cognitive psychology ,media_common - Abstract
With unprecedented losses in biodiversity, the need for stronger environmental policy has emerged as a conservation priority. Yet recovery planning for imperiled species remains a cumbersome, slow legislative process. In the present article, we examine features of recovery planning for species listed under Canada's Species at Risk Act to determine those influencing recovery planning duration. We found that the time to completion of recovery strategies increases with the number of jurisdictions concurrently listing the species, greater land tenure diversity, species population size, and road density. Species at risk in Canada with no listing status in the United States also suffered longer delays. To achieve a more efficient, timely, and defensible implementation of recovery planning, we recommend that governments prioritize recovery planning on the basis of risk level, promote transjurisdictional collaboration among listing agencies, anticipate and mitigate conservation challenges associated with multitenured and developed landscapes, and adopt procedures that enhance compliance with legislated timelines for recovery planning.
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- 2019
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12. Use of Acceleration and Acoustics to Classify Behavior, Generate Time Budgets, and Evaluate Responses to Moonlight in Free-Ranging Snowshoe Hares
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Michael J. L. Peers, Yasmine N. Majchrzak, Dennis L. Murray, Melanie R. Boudreau, Allyson K. Menzies, Sophia G. Lavergne, Stan Boutin, Rudy Boonstra, Jacob L. Seguin, Murray M. Humphries, and Emily K. Studd
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0106 biological sciences ,0301 basic medicine ,Moonlight ,environmental acoustics ,Environmental acoustics ,Foraging ,lcsh:Evolution ,Winter time ,Nocturnal ,Biology ,010603 evolutionary biology ,01 natural sciences ,lunar phases ,03 medical and health sciences ,Acceleration ,biologging ,lcsh:QH540-549.5 ,Lepus americanus ,lcsh:QH359-425 ,boreal forest ,Ecology, Evolution, Behavior and Systematics ,Ecology ,Free ranging ,Snowshoe hare ,biology.organism_classification ,accelerometer ,030104 developmental biology ,lcsh:Ecology ,Physical geography - Abstract
Technological miniaturization is driving a biologging revolution that is producing detailed and sophisticated techniques of assessing individual behavioral responses to environmental conditions. Among the many advancements this revolution has brought is an ability to record behavioral responses of nocturnal, free-ranging species. Here, we combine captive validations of acceleration signatures with acoustic recordings from free-ranging individuals to classify behavior at two resolutions. Combining these classifications with ~2 month-long recordings, we describe winter time budgets, and responses of free-ranging snowshoe hares to changing moonlight. We successfully classified snowshoe hare behavior into four categories (not moving, foraging, hopping, and sprinting) using low frequency accelerometry, with an overall model accuracy of 88%, and acoustic recordings to three categories (silence, hopping, and chewing) with an accuracy of 94%. Broad-scale accelerometer-classified categories were composed of multiple fine-scale behavioral states with the composition varying between individuals and across the day. Time budgets revealed that hares spent ~50% of their time foraging and ~50% not moving, with most foraging and feeding occurring at night. We found that hares adjusted timing of activity in response to moon phase, with a 6% reduction in foraging and 30% reduction in travelling during the night when the moon was full. Hares compensated for this lost foraging time by extending foraging into the morning hours of the following day. Using two biologging technologies to identify behavior, we demonstrate the possibility of combining multiple devices when documenting behavior of cryptic species.
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- 2019
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13. Obstructive Sleep Apnea Syndrome (OSAS) Severity and Cardiac Arrythmias During Peri-Operative Time in Patients Undergoing General Anesthesia: The 3A Study
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J L Pépin, J.-F. Payen, S. Doutreleau, L. Seguin, M. Destors, P. Albaladejo, Rita Guzun, and R Tamisier
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Obstructive sleep apnea ,business.industry ,Anesthesia ,Medicine ,In patient ,Perioperative ,business ,medicine.disease - Published
- 2019
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14. Identifying Barriers to Building a Diverse Physician Workforce: A National Survey of the ACR Membership
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Nathaniel D. Mercaldo, Anna P. Lietz, Chrishanae D. Neal, Gelareh Sadigh, Karen Donelan, Claudia L. Seguin, Jan Cox, Swati Bansal, Katarzyna J. Macura, Jay R. Parikh, Katherine E. Maturen, Pari V. Pandharipande, Curtiland Deville, and Karla A. Sepulveda
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Male ,Attitude of Health Personnel ,Ethnic group ,Logistic regression ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Race (biology) ,0302 clinical medicine ,Underrepresented Minority ,Surveys and Questionnaires ,Radiologists ,Humans ,Radiology, Nuclear Medicine and imaging ,Minority Groups ,Societies, Medical ,Response rate (survey) ,Racial Groups ,Odds ratio ,Cultural Diversity ,Confidence interval ,United States ,030220 oncology & carcinogenesis ,Workforce ,Female ,Psychology ,Demography - Abstract
The aim of this study was to identify potential barriers to building a diverse workforce in radiology and radiation oncology by conducting a national survey of physicians in these fields and studying their reported career experiences.An electronic survey of ACR members (February 27, 2018, to April 26, 2018) was conducted in which physicians' attitudes about their work environment, relationships, and culture were queried. The aim was to determine if responses differed by gender or race/ethnicity. In total, 900 invitations were issued; women were oversampled with the goal of equal representation. Descriptive summaries (proportions of yes or no responses) were calculated per item, per subgroup of interest. Logistic regression analysis was used to identify significant associations between gender- and item-specific responses; it was not used in the race/ethnicity analysis because of the small sizes of many subgroups.The response rate was 51.2% (461 of 900). In total, 51.0% of respondents identified as women (235 of 461); the 9.5% (44 of 461) who identified as black or African American, Hispanic, or American Indian or Alaska Native were considered underrepresented minorities. Respondents' mean age was 40.2 ± 10.4 years. Subgroups varied most in their reporting of unfair or disrespectful treatment. Women were significantly more likely than men to report such treatment attributable to gender (50.6% versus 5.4%; odds ratio, 18.00; 95% confidence interval, 9.29-34.86; P.001), and 27.9% of underrepresented minorities compared with 2.6% of white non-Hispanic respondents reported such treatment attributable to race/ethnicity.Women and underrepresented minorities disproportionately experience unfair or disrespectful treatment in the workplace. Addressing this problem is likely to be critically important for improving workforce diversity.
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- 2019
15. Please come again: attractive bait augments recapture rates of capture-naïve snowshoe hares
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Lee Scholl, Melanie R. Boudreau, Samuel Sonnega, Jacob L. Seguin, Sophia G. Lavergne, Charles J. Krebs, and Alice J. Kenney
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010601 ecology ,0106 biological sciences ,Ecology ,Zoology ,Sampling (statistics) ,Context (language use) ,Population demographics ,Management, Monitoring, Policy and Law ,Biology ,010603 evolutionary biology ,01 natural sciences ,Ecology, Evolution, Behavior and Systematics ,Sampling bias - Abstract
Abstract ContextCapture–recapture sampling is one of the most commonly used methods for monitoring population demographics and is needed in a wide variety of studies where repeat sampling of individuals is desired. Although studies employing capture–recapture methods often assume unbiased sampling, it is well established that inherent capture biases can occur with these methods, including those related to baits. Reducing sources of sampling bias and augmenting recapture reliability is necessary for capture-dependent studies. However, few studies have examined the efficacy of baits on individuals with variable capture experience. AimsTo investigate the use of an attractant-augmented bait in enhancing capture–recapture probabilities for snowshoe hares (Lepus americanus). MethodsTo examine the efficacy of different attractant-augmented bait types, a variety of baits were created, with bait preference tested on a captive hare. Because a strawberry jam-based bait was preferentially consumed (in comparison with other tested baits), the effectiveness of this attractant in enhancing capture–recapture rates was subsequently examined in wild hares, using paired live-trapping field trials (n=6 trials). ResultsLive-trapping trials showed that although overall hare capture rates were not affected by the use of a jam-based bait, recaptures were 33.1% higher in capture-naïve individuals exposed to our attractant. This was not the case for hares with prior capture experience; such hares had an equal likelihood of being recaptured regardless of the bait type used. ConclusionsThe tested attractant improved recapture rates of capture-naïve hares. ImplicationsStudies relying on high recapture rates should use methods that maximise recapture rates wherever possible, including the use of baits that may augment recaptures in capture-naïve animals.
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- 2020
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16. Experimental increase in predation risk causes a cascading stress response in free-ranging snowshoe hares
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Charles J. Krebs, Rudy Boonstra, Dennis L. Murray, Stan Boutin, Melanie R. Boudreau, Rupert Palme, and Jacob L. Seguin
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0106 biological sciences ,Free ranging ,Hydrocortisone ,010604 marine biology & hydrobiology ,Stressor ,Foraging ,Zoology ,Biology ,Affect (psychology) ,Hares ,010603 evolutionary biology ,01 natural sciences ,Predation ,Fight-or-flight response ,13. Climate action ,Stress, Physiological ,Predatory Behavior ,Animals ,Stress measures ,Seasons ,Predator ,Ecology, Evolution, Behavior and Systematics - Abstract
Extensive research confirms that environmental stressors like predation risk can profoundly affect animal condition and physiology. However, there is a lack of experimental research assessing the suite of physiological responses to risk that may arise under realistic field conditions, leaving a fragmented picture of risk-related physiological change and potential downstream consequences on individuals. We increased predation risk in free-ranging snowshoe hares (Lepus americanus) during two consecutive summers by simulating natural chases using a model predator and monitored hares intensively via radio-telemetry and physiological assays, including measures designed to assess changes in stress physiology and overall condition. Compared to controls, risk-augmented hares had 25.8% higher free plasma cortisol, 15.9% lower cortisol-binding capacity, a greater neutrophil:lymphocyte skew, and a 10.4% increase in glucose. Despite these changes, intra-annual changes in two distinct condition indices, were unaffected by risk exposure. We infer risk-augmented hares compensated for changes in their stress physiology through either compensatory foraging and/or metabolic changes, which allowed them to have comparable condition to controls. Although differences between controls and risk-augmented hares were consistent each year, both groups had heightened stress measures during the second summer, likely reflecting an increase in natural stressors (i.e., predators) in the environment. We show that increased predation risk in free-ranging animals can profoundly alter stress physiology and that compensatory responses may contribute to limiting effects of such changes on condition. Ultimately, our results also highlight the importance of biologically relevant experimental risk manipulations in the wild as a means of assessing physiological responses to natural stressors.
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- 2018
17. Sequencing of VDJ genes in Lepus americanus confirms a correlation between VHn expression and the leporid species continent of origin
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Jacob L. Seguin, Dennis K. Lanning, Tereza Almeida, Melanie R. Boudreau, Ana Acacia S. Pinheiro, Patrícia de Sousa-Pereira, Josée-Anne Otis, Catarina Ferreira, and Pedro J. Esteves
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0301 basic medicine ,Lineage (evolution) ,Immunology ,03 medical and health sciences ,0302 clinical medicine ,Polymorphism (computer science) ,biology.domesticated_animal ,Animals ,Cell Lineage ,Amino Acid Sequence ,Molecular Biology ,Gene ,VDJ Recombinases ,Alleles ,Phylogeny ,Gene Rearrangement ,Polymorphism, Genetic ,biology ,Repertoire ,Hares ,Vh genes ,030104 developmental biology ,Evolutionary biology ,Adaptive selection ,Rabbits ,European rabbit ,Adaptation ,030215 immunology - Abstract
Leporid VH genes used in the generation of their primary antibody repertoire exhibit highly divergent lineages. For the European rabbit (Oryctolagus cuniculus) four VHa lineages have been described, the a1, a2, a3 and a4. Hares (Lepus spp.) and cottontail (Sylvilagus floridanus) express one VHa lineage each, the a2L and the a5, respectively, along with a more ancient lineage, the Lepus spp. sL and S. floridanus sS. Both the European rabbit and the Lepus europaeus use a third lineage, VHn, in a low proportion of their VDJ rearrangements. The VHn genes are a conserved ancestral polymorphism that is being maintained in the leporid genome.Their usage in a low proportion of VDJ rearrangements by both European rabbit and L. europaeus but not S. floridanus has been argued to be a remnant of an ancient European leporid immunologic response to pathogens. To address this hypothesis, in this study we sequenced VDJ rearranged genes for another North American leporid, L. americanus. Our results show that L. americanus expressed these genes less frequently and in a highly modified fashion compared to the European Lepus species. Our results suggest that the American leporid species use a different VH repertoire than the European species which may be related with an immune adaptation to different environmental conditions, such as different pathogenic agents.
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- 2018
18. Theta-gamma cross-frequency coupling during rapid-eye-movement sleep is associated with declarative memory retention and with working memory performance in seniors but not young adults
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J. O'Byrne, I. Mameri-Arab, N.E. Cross, O.M. Weiner, A. Krixian Colada, A. Ercolanese, E. Lachapelle, S. Williams, L. Seguin, M. Likoudis, Thien Thanh Dang-Vu, and S. Baillet
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medicine.medical_specialty ,Cross frequency coupling ,Working memory ,medicine ,Rapid eye movement sleep ,General Medicine ,Audiology ,Young adult ,Psychology ,Declarative memory - Published
- 2019
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19. The evolution of peer review as a basis for scientific publication: directional selection towards a robust discipline?
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Michael J. L. Peers, Amanda M. Bennett, Adrian Borlestean, Dennis L. Murray, Josée-Anne Otis, Adrian Forsythe, Morgan Wehtje, Melanie R. Boudreau, E. Hance Ellington, Cayla Austin, Guillaume Bastille-Rousseau, Catarina Ferreira, Kristen N. Landolt, Jacob L. Seguin, Jason Rae, Cristen Watt, Christine V. Terwissen, Jessica N. Longhi, Kevin Chan, and Thomas J. Hossie
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0301 basic medicine ,Process (engineering) ,business.industry ,Computer science ,media_common.quotation_subject ,Control (management) ,Cultural lag ,Context (language use) ,General Biochemistry, Genetics and Molecular Biology ,Rigour ,03 medical and health sciences ,030104 developmental biology ,Publishing ,Engineering ethics ,Quality (business) ,General Agricultural and Biological Sciences ,business ,media_common - Abstract
Peer review is pivotal to science and academia, as it represents a widely accepted strategy for ensuring quality control in scientific research. Yet, the peer-review system is poorly adapted to recent changes in the discipline and current societal needs. We provide historical context for the cultural lag that governs peer review that has eventually led to the system's current structural weaknesses (voluntary review, unstandardized review criteria, decentralized process). We argue that some current attempts to upgrade or otherwise modify the peer-review system are merely sticking-plaster solutions to these fundamental flaws, and therefore are unlikely to resolve them in the long term. We claim that for peer review to be relevant, effective, and contemporary with today's publishing demands across scientific disciplines, its main components need to be redesigned. We propose directional changes that are likely to improve the quality, rigour, and timeliness of peer review, and thereby ensure that this critical process serves the community it was created for.
- Published
- 2015
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20. Évolution du syndrome d’apnées obstructives du sommeil (SAOS) et impact sur les arythmies cardiaques après anesthésie générale
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J.L. Pépin, Renaud Tamisier, Marie Destors, Stéphane Doutreleau, P. Albaladejo, Rita Guzun, Jean-François Payen, and L. Seguin
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Behavioral Neuroscience ,Neuropsychology and Physiological Psychology ,Neurology ,Cognitive Neuroscience ,Neurology (clinical) - Abstract
Objectif Le sous diagnostic du SAOS est responsable d’une morbidite per-operatoire et son aggravation est potentiellement un facteur d’arythmies cardiaques post-operatoires. Etudier l’impact du SAOS sur les evenements cardiaques rythmiques apres chirurgie sous anesthesie generale (AG). Methodes Etude monocentrique cas temoins prospective non randomisee (juin 2015–juillet 2018). Les patients adresses en consultation d’anesthesie pour une chirurgie digestive ou urologique sous AG suivie d’hospitalisation ≥ 2 jours, âges ≥ 40 ans, avec questionnaire STOP-BANG ≥ 3 effectuaient une polygraphie ventilatoire couplee a un holter-ECG, nuit N0 (pre-operatoire) puis a N1 et N3 en post-chirurgie. Le « SAOS » etait defini par un IDO > 10 et/ou un IAH > 15, les patients presentant un IDO > 40/h etaient exclus. Resultats Cent vingt patients avec STOP-BANG ≥ 3 etaient inclus, 62 avec SAOS et 29 non SAOS, 13 patients (11 %) etaient exclus pour SAOS severe et 16 patients (13 %) sortis d’etude. Les anomalies rythmiques associees aux episodes hypoxiques augmentaient significativement en N3 par rapport a N0 sur la population totale (1 [0 ; 4] vs 0 [0 ; 2], p = 0,04), dans le groupe SAOS (1 [0 ; 4] vs 1 [0 ; 2], p = 0,02) mais pas dans le groupe non SAOS (0 [0 ; 5,5] vs 0 [0 ; 2,5], p = 0,84). Il n’existait pas d’aggravation significative de l’IAH et de l’IDO en post-operatoire. Conclusion Les arythmies cardiaques associees aux episodes hypoxiques se majorent lors de la 3e nuit post-operatoire chez les patients SAOS, demontrant la necessite d’un depistage du SAOS en pre-operatoire.
- Published
- 2019
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21. Identification of micro-scale calorimetric devices
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V. Torra, F. Martorell, C. Auguet, F. Moll, Johannes Lerchner, and J. L. Seguin
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Systematic error ,Chemistry ,Drop (liquid) ,Analytical chemistry ,Gas detector ,Calorimetry ,Mechanics ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Shape factor ,Thermal analysis ,Silicon based ,Volume rate - Abstract
An improved accuracy is researched in flat and silicon based nano-calorimeters related to fluid reaction via drop-to-drop 'reaction' or via a steady state in continuous injection of two reactants inside a working chamber. Two types of the experimental aspects of the sensitivity changes, related to 3-D effects, are described: drop effects and volume rate effects. To increase the accuracy, well-controlled joule measurements are dissipated in the manufacturer resistance and in several resistances in carefully controlled experiments. The shape factor (SF) values reduce the manufacturer's joule sensitivity up to fifty per cent. a working methodology is proposed: the results are compared with the standard TRIS reaction. The results suggest that the systematic error can be reduced to ±5%.
- Published
- 2006
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22. Crystal structure of a new form of Cs[B5O6(OH)4].2H2O and thermal behavior of M[B5O6(OH)4].2H2O (M=Cs, Rb, Tl)
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Guy Nowogrocki, L. Seguin, B. Gerand, Marcel Touboul, and Nicolas Penin
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Chemistry ,Mechanical Engineering ,Metals and Alloys ,Mineralogy ,Space group ,Crystal structure ,law.invention ,Crystallography ,Mechanics of Materials ,law ,X-ray crystallography ,Materials Chemistry ,Crystallization ,Hydrate ,Single crystal ,Powder diffraction ,Monoclinic crystal system - Abstract
The crystal structure of a new synthetic borate, β-Cs[B 5 O 6 (OH) 4 ].2H 2 O, was determined from single crystal X-ray diffraction data. The compound is monoclinic, space group C2/c ; the unit cell parameters are a =8.160(2) A, b =12.140(2) A, c =11.860(2) A, β =93.00(3)°; Z =4. The crystal structure was resolved from 1188 reflections until R 1 =0.0408; it contains isolated [B 5 O 6 (OH) 4 ] − polyanions separated by free water molecules and Cs + cations. The cohesion of the structure comes from the hydrogen bonds existing between the water molecules and the polyborate anions. The dehydration of three M [B 5 O 6 (OH) 4 ].2H 2 O borates ( M =Cs, Rb, Tl) and the transitions of anhydrous M B 5 O 8 compounds ( M =Cs, Rb, Tl) were investigated by temperature-resolved X-ray diffraction and thermal analysis. Whatever M + ions ( M =Cs, Rb, Tl), the thermal behavior of M [B 5 O 6 (OH) 4 ].2H 2 O compounds can be summarized in two steps. The first step corresponds to a loss of four water molecules and leads to an amorphous phase due to the collapsing of the hydrated pentaborate structure. In a second step, the amorphous phase crystallizes and transforms into two ( M =Tl), three ( M =Rb) or four ( M =Cs) anhydrous phases. All these phases are characterized by X-ray powder diffraction; unit cell parameters were determined for almost all of them.
- Published
- 2002
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23. A new cesium borate Cs3B13O21
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Guy Nowogrocki, L. Seguin, Marcel Touboul, and Nicolas Penin
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Incongruent melting ,Chemistry ,Resolution (electron density) ,chemistry.chemical_element ,Nanotechnology ,General Chemistry ,Crystal structure ,Condensed Matter Physics ,Ion ,Crystallography ,General Materials Science ,Binary system ,Boron ,Phase diagram ,Monoclinic crystal system - Abstract
Single crystals of Cs3B13O21 (B/Cs = 4.33) were obtained by heating, melting and cooling a powder of β-Cs[B5O6 (OH)4]·2H2O; its formula has been determined by the resolution of the structure from single-crystal X-ray diffraction data. The compound is monoclinic, space group C2/c; the unit cell parameters are a=23.064(5) A, b=13.367(5) A, c=24.464(5) A, β=90.281(4); Z=16 . The crystal structure was solved from 4763 reflections until R1=0.0540. It exhibits a two-dimensional framework built up from four B3O7 units linked by four BO3 triangles bound to a chain of two B5O10 units; this leads to a complex structure forming corrugated layers; the shorthand notation of this new polyborate ion is: 26:∞ 2 [2×(5:4▵+ T )+4×(3:2▵+ T )+4(▵)] . Cesium cations are located in the channels existing in the structure and between the layers. Comparisons were made between compounds of almost the same composition M2B8O13 (M = Na, Ag; B/M = 4) and M′5B19O31 (M′ = K, Rb; B/M′=3.8). Cs3B13O21 belongs to the Cs2OB2O3 binary system instead of Cs2B8O13; it presents an incongruent melting at 663 °C.
- Published
- 2002
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24. Laboratory and clinical findings in patients treated with carbomycin
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A H, KUTSCHER, J D, PIRO, E V, ZEGARELLI, S L, LANE, and L, SEGUIN
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Laboratories ,Leucomycins - Published
- 2014
25. Growth inhibiting properties of phenoxy-ethyl-dimethyl-dodecyl-ammonium bromide (PDDB) (bradosol) against Candida albicans in vitro; preliminary report
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A H, KUTSCHER, L, SEGUIN, S, LEWIS, J D, PIRO, and E V, ZEGARELLI
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Bromides ,Quaternary Ammonium Compounds ,Ammonium Compounds ,Candida albicans ,Anti-Infective Agents, Local ,Humans ,In Vitro Techniques ,Candida - Published
- 2014
26. Fungicidal properties of phenoxy-ethyl-dimethyl-dodecyl-ammonium bromide (PDDB) against Candida albicans in vitro. II
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A H, KUTSCHER, L, SEGUIN, S, LEWIS, J D, PIRO, and E V, ZEGARELLI
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Bromides ,Quaternary Ammonium Compounds ,Ammonium Compounds ,Candida albicans ,Anti-Infective Agents, Local ,Humans ,In Vitro Techniques ,Candida - Published
- 2014
27. Thiostrepton, a new antibiotic; disc sensitivity studies
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A H, KUTSCHER, L, SEGUIN, R M, RANKOW, and J D, PIRO
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Humans ,Dermatologic Agents ,Antibiotics, Antitubercular ,Thiostrepton ,Anti-Bacterial Agents - Published
- 2014
28. Cross-correlation of bacterial sensitivity to carbomycin and erythromycin compared with other antibiotics
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A H, KUTSCHER, L, SEGUIN, S, LEWIS, J D, PIRO, E V, ZEGARELLI, R, RANKOW, and R, SEGALL
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Bacteria ,Drug Resistance, Microbial ,Bacterial Infections ,Microbial Sensitivity Tests ,Antibiotics, Antitubercular ,Leucomycins ,Anti-Bacterial Agents ,Erythromycin - Published
- 2014
29. Synthesis and crystal structure of three MM′B9O15 borates (M=Ba, Sr and M′=Li; M=Ba and M′=Na)
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L. Seguin, Guy Nowogrocki, Nicolas Penin, and Marcel Touboul
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Alkaline earth metal ,Crystallography ,chemistry ,Group (periodic table) ,Inorganic chemistry ,Materials Chemistry ,Tetrahedron ,chemistry.chemical_element ,Lithium ,Crystal structure ,Boron ,Single crystal ,Ion - Abstract
The compounds BaLiB9O15 (BaLi), BaNaB9O15 (BaNa) and SrLiB9O15 (SrLi) have been synthesised, and their structure determined by single crystal X-ray diffraction methods. Each borate crystallises with six formula units in the R3c non-centrosymmetric space group. Cell parameters are: a=11.0223(19) A, c=17.106(4) A, and V=1799.8(6) A3 for the (BaLi) compound; a=11.0933(15) A, c=17.392(3) A, and V=1853.5(5) A3 for the (BaNa) compound; a=10.6129(9) A, c=17.555(2) A, and V=1712.4(3) A3 for (SrLi) compound. The borate anion is characterised by a three-dimensional framework built up from [B3O7] rings; its shorthand notation is 3: ∞3 (2△+T), where △ is a BO3 triangle and T is a BO4 tetrahedron. In these three compounds, the alkaline earth (Ba, Sr) and the alkaline (Li, Na) ions occupy alternate sites in the channels along the c axis; however, their oxygenated environment is different. In (BaNa) and (SrLi), the [BaO9] and [SrO9] form tricapped trigonal prisms and [NaO6] and [LiO6] trigonal antiprisms whereas in (BaLi), [BaO12] forms an irregular icosahedron and there are only three oxygen atoms in the neighboring of lithium ion.
- Published
- 2001
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30. Crystal Structures of Three MB5O8 (M=Cs, Rb) Borates (α-CsB5O8, γ-CsB5O8, and β-RbB5O8)
- Author
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Nicolas Penin, Marcel Touboul, Guy Nowogrocki, and L. Seguin
- Subjects
Chemistry ,Stereochemistry ,Beta phase ,chemistry.chemical_element ,Crystal structure ,Condensed Matter Physics ,Boron atom ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Crystallography ,Materials Chemistry ,Ceramics and Composites ,Physical and Theoretical Chemistry ,Isostructural ,Boron ,Monoclinic crystal system - Abstract
Crystal structures of α -CsB 5 O 8 , γ CsB 5 O 8 , and β -RbB 5 O 8 have been determined from single-crystal X-ray diffraction data. α -CsB 5 O 8 crystallizes in the monoclinic space group P 2 1 / n with the following parameters: a =7.117(2) A, b =9.634(3) A, c =10.391(4) A, β =101.160(4)°; Z =4; the structure was refined from 1392 reflections until R 1 =0.0489. γ -CsB 5 O 8 and β -RbB 5 O 8 have been found to be isostructural with α -KB 5 O 8 and β -KB 5 O 8 (and TlB 5 O 8 ), respectively. They crystallize with eight formula units in the Pbca space group. Unit cell parameters are a =8.697(3) A, b =8.431(2) A, c =21.410(6) A for γ -CsB 5 O 8 and a =7.553(2) A, b =11.857(3) A, c =14.813(4) A for β -RbB 5 O 8 ; their structures were refined from 1085 reflections until R 1 =0.0712, and from 1271 reflections until R 1 =0.0290, respectively. The structures of these compounds can be described on the basis of a new two- ( α -CsB 5 O 8 ) and three-dimensional ( γ -CsB 5 O 8 , β -RbB 5 O 8 ) network of pentaborate units [B 5 O 8 ] − ; these units are formed by two B 3 O 3 cycles linked by a boron atom, which contain two groups of two BO 3 triangles (Δ) on each side of a BO 4 tetrahedron (T); their shorthand notations are 5:∞ 2 (4Δ+T) for α -CsB 5 O 8 and 5:∞ 3 (4Δ+T) for γ -CsB 5 O 8 and β -RbB 5 O 8 . Distortions of the [B 5 O 8 ]− units found in these compounds are presented.
- Published
- 2001
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31. Morphology, Electrical Conductivity, and Reactivity of Mixed Conductor CuBr Films: Development of a New Ammonia Gas Detector
- Author
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† and J.-L. Seguin, M. Bendahan, C. Jacolin, P. Lauque, and Philippe Knauth
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Materials science ,Morphology (linguistics) ,Inorganic chemistry ,Detector ,Electrolyte ,Microstructure ,Decomposition ,Surfaces, Coatings and Films ,Mixed conductor ,Chemical engineering ,Electrical resistivity and conductivity ,Materials Chemistry ,Reactivity (chemistry) ,Physical and Theoretical Chemistry - Abstract
The microstructure, electrical properties, aging, and electrolytic decomposition of sputtered CuBr films are described and discussed with respect to the defect chemistry of this mixed Cu+ ion−elect...
- Published
- 2001
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32. β-Tl2B4O7:Compound Containing a New Three-Dimensional Borate Anion
- Author
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Nicolas Penin, Marcel Touboul, B. Gerand, Guy Nowogrocki, and L. Seguin
- Subjects
Stereochemistry ,chemistry.chemical_element ,Crystal structure ,Triclinic crystal system ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Ion ,Inorganic Chemistry ,Crystallography ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Thallium ,Physical and Theoretical Chemistry ,Boron ,Lone pair ,Phase diagram - Abstract
Single crystals of synthetic β -Tl 2 B 4 O 7 or Tl 6 B 12 O 21 were obtained by heating its hydrated precursor Tl 2 [B 4 O 6 (OH) 2 ]·2H 2 O. The compound is triclinic, space group P -1; the unit cell parameters are a =6.742(1) A, b =13.225(2) A, c =13.389(2) A, α =119.093(3)°, β =92.288(3)°, γ =91.012(3)°; Z =6. The crystal structure was solved from 2893 reflections until R =0.0312. It exhibits a three-dimensional framework containing a new complex borate anion (B 12 O 21 ) 6− formed by six BO 3 triangles (Δ) and six BO 4 tetrahedra (T), which are disposed on two and three B 3 O 3 rings; this leads to an anion with the shorthand notation: 12: 3 ∞ [(5: 2Δ+3T)+(7: 4Δ+3T)]. This new anion is different from those described in alkaline tetraborates M 2 B 4 O 7 , and especially K 2 B 4 O 7 and Rb 2 B 4 O 7 where the M + cations have a size close to that of Tl + . This difference may be due to the stereochemical role of the 6 s 2 lone pairs of Tl + cations, which has been pointed out. Upon heating at around 500°C, β -Tl 2 B 4 O 7 transforms into a second form of thallium tetraborate, α -Tl 2 B 4 O 7 .
- Published
- 2001
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33. In Situ Structural and Electrochemical Study of Ni1−xCoxO2 Metastable Oxides Prepared by Soft Chemistry
- Author
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Gavin Vaughan, Y. Chabre, Jean-Marie Tarascon, L. Seguin, Pierre Strobel, Glenn G. Amatucci, and Michel Anne
- Subjects
Intercalation (chemistry) ,Non-blocking I/O ,Oxide ,chemistry.chemical_element ,Mineralogy ,Condensed Matter Physics ,Soft chemistry ,Electronic, Optical and Magnetic Materials ,Electrochemical cell ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,chemistry ,X-ray crystallography ,Materials Chemistry ,Ceramics and Composites ,Lithium ,Thermal stability ,Physical and Theoretical Chemistry - Abstract
Metastable Ni 1− x Co x O 2 phases were obtained from the electrochemical deintercalation of lithium from the precursor phases, LiNi 1− x Co x O 2 ( x =0, 0.3, and 1), using plastic electrochemical cells. The structural changes induced during Li removal, together with the thermal stability of the end members Ni 1− x Co x O 2 , were determined by in situ X-ray measurements using a high-resolution synchrotron beam line. The advantages of using a plastic battery configuration to perform such a study is emphasized. The structural/thermal stability results are discussed in relation to the electrochemical performance of these materials. Numerous changes in the unit cell symmetry were observed during deintercalation. The NiO 2 end member is described with a single distorted CdI 2 -type structure, while two CdI 2 -type structures, both with reduced O–O interlayer distances, but differing by the presence of oxygen vacancies, are needed to describe the CoO 2 end member. The reduction in O–O spacing is explained by partial polymerization within oxide frameworks. Such a behavior, already observed with layered chalcogenides, can be explained on the basis of the elegant electron-hole chemistry pioneered by J. Rouxel who directly evidenced the role of the anion during an intercalation process.
- Published
- 1999
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34. Characteristics of the 4 V plateau in LiMn2(O4−xFx) studied by in situ synchrotron X-ray diffraction
- Author
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L. Seguin, Jean-Marie Tarascon, Y. Chabre, Glenn G. Amatucci, Michel Anne, Gavin Vaughan, Pierre Strobel, and Maria Rosa Palacín
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Diffraction ,Range (particle radiation) ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Inorganic chemistry ,Spinel ,Analytical chemistry ,Energy Engineering and Power Technology ,engineering.material ,Plateau (mathematics) ,Synchrotron ,law.invention ,law ,X-ray crystallography ,engineering ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Beam (structure) ,Stoichiometry - Abstract
Fluorine-substituted Li x Mn 2 O 4 was studied by synchrotron X-ray diffraction using Bellcore-type plastic batteries placed directly in the synchrotron beam. The results show that the `4 V plateau' actually contains three regions: (1) a single-phase range for 0.59≤ x ≤1, (2) a two-phase range for 0.23≤ x ≤0.59, (3) a narrow single-phase range for x ≤0.23. These three domains are fully reversible, but the plastic battery undergoes extraneous oxidation reactions for voltages ≥4.4 V. The structural features of this compound are qualitatively similar to those of stoichiometric Li x Mn 2 O 4 . In particular, no suppression of the two-phase range such as that observed on non-stoichiometric or Ni-substituted LiMn 2 O 4 was found.
- Published
- 1999
- Full Text
- View/download PDF
35. Electrochemical and structural study of the 3.3 V reduction step in defective LixMn2O4 and LiMn2O(4−y)Fy compounds
- Author
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Michel Anne, Glenn G. Amatucci, J. M. Tarascon, Y. Chabre, Pierre Strobel, Gavin Vaughan, Maria Rosa Palacín, and L. Seguin
- Subjects
In situ ,Electrode material ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Spinel ,Inorganic chemistry ,Energy Engineering and Power Technology ,engineering.material ,Electrochemistry ,Redox ,Reduction (complexity) ,chemistry.chemical_compound ,Lattice constant ,engineering ,Physical chemistry ,Lithium oxide ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry - Abstract
Non-stoichiometric or fluorine-substituted Li x Mn 2 O 4 are known to present a reversible redox step at 4.5 V as well as a reduction step at 3.3 V appearing to the expense of the usual 4.0–4.15 V. We present results of very slow stepwise potentiodynamic studies which allowed to localise the oxidation step associated to the 3.3 V reduction level close to 3.95 V. We propose the cubic spinel lattice parameter value as the key parameter for knowing a priori if these redox states will be present or not, with 8.215 A as threshold value. In situ XRD studies performed across the 3.3↔3.95 V redox step indicate that these additional states are probably associated to structural features.
- Published
- 1999
- Full Text
- View/download PDF
36. In SituStructural Study of 4V-Range Lithium Extraction/Insertion in Fluorine-Substituted LiMn2O4
- Author
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Gavin Vaughan, L. Seguin, Y. Chabre, Jean-Marie Tarascon, Glenn G. Amatucci, F. Le Cras, Maria Rosa Palacín, Pierre Strobel, and Michel Anne
- Subjects
Extraction (chemistry) ,Spinel ,Inorganic chemistry ,Analytical chemistry ,Oxide ,chemistry.chemical_element ,Crystal structure ,engineering.material ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Formula unit ,X-ray crystallography ,Materials Chemistry ,Ceramics and Composites ,engineering ,Lithium ,Orthorhombic crystal system ,Physical and Theoretical Chemistry - Abstract
The structural features accompanying the lithium extraction/insertion process in a fluorine-substituted spinel oxide with formula LiMn2(O3.74F0.26) were studiedin situusing Bellcore-type plastic batteries directly placed in a synchrotron X-ray beam. The initial material contains two phases, a cubic spinel and a slightly orthorhombically distorted one (major phase). It becomes entirely cubic on extraction of 0.17 Li atoms per formula unit. The lithium extraction reaction around 4 V vs Li/Li+can be divided into three regions as a function of lithium contentx: (1) a single-phase range for 0.59≤x≤0.83, (2) a two-phase range for 0.23≤x≤0.59 with equilibrium potential 4.122 V, (3) a narrow single-phase range III for 0.18≤x≤0.23. These three domains are fully reversible. With the exception of the presence of the initial orthorhombic distortion, the main features of the so-called electrochemical 4 V plateau are very similar to those of stoichiometric LixMn2O4.
- Published
- 1999
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37. On the synthesis of monovalent, divalent and trivalent element vanadates
- Author
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F Orsini, E. Baudrin, L. Seguin, Jean-Marie Tarascon, Sophie Denis, and Marcel Touboul
- Subjects
chemistry.chemical_classification ,Nickel ,chemistry ,Inorganic chemistry ,Materials Chemistry ,Chemical preparation ,chemistry.chemical_element ,Lithium ,Vanadate ,General Chemistry ,Soft chemistry ,Divalent - Abstract
A chimie douce method has been used to prepare vanadates (V 5+ ) of various elements, trivalent (Al, Cr, Fe, In, Y, Bi), divalent (Co, Ni), monovalent (Li, Tl), and a combination of nickel and lithium. By varying several parameters, especially the pH during the synthesis, several types of vanadates have been obtained ranging from orthovanadates (VO 4 3– ) to decavanadates (V 10 O 28 6– ). The pH conditions required to prepare the various vanadates fall nicely within the expectations of the previously reported cation charge-pH diagram.
- Published
- 1999
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38. P.2.e.003 Effect of acute administration of agomelatine on the memory processes triggered by threat responses to an auditory stimulus in rats
- Author
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E. Mocaër, C. Gabriel Gracia, Joseph E. LeDoux, L. Seguin, and Llorenç Díaz-Mataix
- Subjects
Pharmacology ,business.industry ,Stimulus (physiology) ,Psychiatry and Mental health ,Neurology ,Anesthesia ,Medicine ,Agomelatine ,Pharmacology (medical) ,Neurology (clinical) ,business ,Neuroscience ,Biological Psychiatry ,medicine.drug - Published
- 2015
- Full Text
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39. Ferroelectric and glassy states in La-modified lead zirconate titanate ceramics: A general picture
- Author
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R. Farhi, Dwight D. Viehland, L. Seguin, M. D. Glinchuk, J.-L. Dellis, and M. El Marssi
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Materials science ,Condensed matter physics ,Scattering ,General Physics and Astronomy ,Dielectric ,Lead zirconate titanate ,Ferroelectricity ,Pyroelectricity ,symbols.namesake ,Crystallography ,chemistry.chemical_compound ,chemistry ,symbols ,Texture (crystalline) ,Raman spectroscopy ,Raman scattering - Abstract
Raman scattering, pyroelectric current, and dielectric susceptibility measurements have been carried out on a series of tetragonal and rhombohedral-structured Pb1−xLax(ZryTi1−y)1−x/4O3 (PLZT) ceramics, under zero-field heating after zero-field cooling (ZFH/ZFC) and zero-field heating after field-cooling (ZFH/FC) conditions. The results have been shown to be in good agreement with previous transmission electron microscopy observations. A dependence of the Raman spectra on light polarization (i.e., Raman selection rules or RSR), which are known to be a characteristic property of single crystals, has been observed in the PLZT compositions 9/65/35, 12/65/35, 6/40/60, and 12/40/60 illuminated with a 2 μm wide laser spot (i.e., micro-Raman). The texture which has been observed by x-ray diffraction on 6/40/60 is discussed in conjunction with the Raman results. The combined data of Raman scattering experiments and electrical measurements, together with electromechanical and ferroelectric properties, are explained in terms of competing random fields. Furthermore, the disappearance of RSR in the ZFH/FC conditions for the ferroelectric relaxor PLZT 9/65/35 has given evidence for the existence of domains and grain boundaries in the field cooled conditions. Similar Raman spectra were found for the ferroelectric PLZT composition 5/65/35 in zero-field conditions. The occurrence of RSR in PLZT x/65/35 for x>8 (i.e., for only relaxor states with average cubic symmetry) are interpreted as resulting from second-order scattering effects. This supports a model of a cluster glass with short-range-ordered polar clusters rather than a multidomain state (i.e., a multitude of small ferroelectric domains) in these relaxor systems.
- Published
- 1998
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40. Metabolic and anti-atherogenic effects of long-term benfluorex in dyslipidemic insulin-resistant sand rats (Psammomys obesus)
- Author
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P. Hadjiisky, T. El Madani, N. Bennani, L. Seguin, M.T. Pieraggi, G. Marquié, D. Ravel, and M.L. Solera
- Subjects
Male ,medicine.medical_specialty ,Arteriosclerosis ,Hyperlipidemias ,General Biochemistry, Genetics and Molecular Biology ,Cholesterol, Dietary ,Impaired glucose tolerance ,chemistry.chemical_compound ,Insulin resistance ,Internal medicine ,Fenfluramine ,Hyperinsulinemia ,Animals ,Medicine ,General Pharmacology, Toxicology and Pharmaceutics ,Aorta ,Hypolipidemic Agents ,Benfluorex ,business.industry ,Cholesterol ,Body Weight ,Hypertriglyceridemia ,nutritional and metabolic diseases ,Lipid metabolism ,General Medicine ,Glucose Tolerance Test ,medicine.disease ,Lipids ,Rats ,Endocrinology ,Liver ,chemistry ,Animal Nutritional Physiological Phenomena ,Female ,lipids (amino acids, peptides, and proteins) ,Insulin Resistance ,Gerbillinae ,business ,Dyslipidemia - Abstract
Benfluorex is a clinical lipid-lowering agent with antihyperglycemic properties. The effect of long-term oral treatment (10 mg/kg/day for 7.5 months) on carbohydrate and lipid metabolism and aortic morphology was investigated in 24 insulin-resistant sand rats receiving a standard laboratory diet supplemented with cholesterol (2%). Untreated controls (n = 34) developed impaired glucose tolerance, hyperinsulinemia, hypertriglyceridemia, hypercholesterolemia and elevated plasma LDL- and VLDL-cholesterol, positively correlated with the proportion of the thoracic aorta displaying oil red O-positive atherosclerosis; ultrastructural examination showed intimal lipid deposits, foam cells, polymorph infiltrates and fibrosis. Benfluorex-treated animals showed significant decreases in glucose intolerance, hyperinsulinemia, hypertriglyceridemia, hypercholesterolemia, and plasma LDL- and VLDL-cholesterol, with no evidence of aortic atheroma. The metabolic benefits of benfluorex may protect against the long-term development of atherosclerosis in the insulin-resistant dyslipidemic syndrome.
- Published
- 1998
- Full Text
- View/download PDF
41. Oxygen Nonstoichiometry in Li–Mn–O Spinel Oxides: A Powder Neutron Diffraction Study
- Author
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F. Le Cras, Jean-Marie Tarascon, L. Seguin, Michel Anne, and Pierre Strobel
- Subjects
Chemistry ,Spinel ,Neutron diffraction ,Inorganic chemistry ,Analytical chemistry ,chemistry.chemical_element ,Crystal structure ,engineering.material ,Condensed Matter Physics ,Oxygen ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Ammonia ,chemistry.chemical_compound ,Lattice (order) ,Materials Chemistry ,Ceramics and Composites ,engineering ,Physical and Theoretical Chemistry ,Atomic displacement ,Stoichiometry - Abstract
Neutron powder diffraction has been carried out on two series of Li–Mn–O samples with spinel structure, which have been shown to lose oxygen with respect to initial stoichiometric spinels: (i) Li1.05Mn2O4quenched from 800 or 925°C, (ii) “Li1.33Mn1.67O4” (nominal) treated with ammonia gas at 200°C. The structural refinements unambiguously show that both 925°C quenching and low-temperature ammonia treatment induce oxygen vacancies in the spinel lattice. However, the mechanism of oxygen loss is markedly different between quenchings at 800 and 925°C. While the latter actually corresponds to the introduction of anionic vacancies at constant cation composition, the former is due to a rearrangement of the Li/Mn ratio in the spinel phase and the formation of an additional lithium-rich phase Li2MnO3. The presence of vacancies induce a significant increase in atomic displacement parameters of oxygen.
- Published
- 1998
- Full Text
- View/download PDF
42. Crystal Structure of LiB5O8∙5H2O
- Author
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Marcel Touboul, L. Seguin, and E. Bétourné
- Subjects
Crystallography ,chemistry.chemical_compound ,Materials science ,Lithium borate ,chemistry ,Mechanics of Materials ,Mechanical Engineering ,chemistry.chemical_element ,General Materials Science ,Crystal structure ,Condensed Matter Physics ,Hydrate ,Boron - Published
- 1996
- Full Text
- View/download PDF
43. Comparative Structure Refinement of MO3.1/3H2O (M = Mo, W) from X-Ray and Neutron Powder Diffraction Data and Dehydration Process
- Author
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Marcel Touboul, L. Seguin, G. Chevrier, and B. Gérand
- Subjects
Neutron powder diffraction ,Materials science ,Mechanical Engineering ,Neutron diffraction ,Thermal decomposition ,X-ray ,Condensed Matter Physics ,medicine.disease ,Crystallography ,Mechanics of Materials ,Scientific method ,medicine ,General Materials Science ,Dehydration ,Hydrate ,Powder diffraction - Published
- 1996
- Full Text
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44. The Marketing of Closed-end Fund IPOs: Evidence from Transactions Data
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Kathleen Weiss Hanley, Paul L. Seguin, and Charles M.C. Lee
- Subjects
Finance ,Economics and Econometrics ,business.industry ,Price stabilization ,Economics ,Closed-end fund ,Monetary economics ,business ,Initial public offering ,Syndicate ,Underwriting - Abstract
We examine aftermarket transactions for closed-end fund IPOs and document large sell-to-buy imbalances (“flipping”), extensive price stabilization, and sharp subsequent price drops. The timing of the price drop is related to both the amount of initial flipping, and use of the over-allotment options. The extent of the flipping activity is related to the composition of the syndicate. Moreover, aftermarket buys (sells) are mainly small (large) trades. These findings suggest that lead underwriters price stabilize and manage the supply of shares in the aftermarket, and that closed-end fund IPOs are marketed to a poorly informed public.
- Published
- 1996
- Full Text
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45. The soft chemistry of molybdenum and tungsten oxides: a review
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L. Seguin and B. Gerand
- Subjects
Hydrogen ,Chemistry ,Inorganic chemistry ,Intercalation (chemistry) ,Pyrochlore ,chemistry.chemical_element ,General Chemistry ,Tungsten ,engineering.material ,Condensed Matter Physics ,Soft chemistry ,Electrochromism ,Molybdenum ,engineering ,General Materials Science ,Lithium - Abstract
Through various examples the potential of soft chemistry is illustrated. Using the structural filiation between a mother and a daughter phase, supermetastable and metastable oxides have been obtained. Studies have shown that these oxides are good materials for comparative studies of intercalation chemistry. These studies have been performed in order to compare the intercalation effects of hydrogen and lithium in the metastable and supermetastable oxides in accordance with their structures (ID or 3D tunnels) and with the Mo/W ratio. It can be concluded that the more isotrope the structures are (3D tunnels of the pyrochlore structure for example), the less distorted they are. Lithium leads to an amorphization at high intercalation rates, which is not observed in the case of hydrogen. Molybdenum compounds allow high intercalation rates but deintercalation is difficult to perform; it is the reason why it is difficult to consider their use as electrochromic displays.
- Published
- 1996
- Full Text
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46. Infrared and Raman spectra of MoO3 molybdenum trioxides and MoO3 · xH2O molybdenum trioxide hydrates
- Author
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L Seguin, Jean-Claude Lassègues, M. Figlarz, and R Cavagnat
- Subjects
Hydrogen bond ,chemistry.chemical_element ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Molybdenum trioxide ,Bond length ,chemistry.chemical_compound ,symbols.namesake ,Crystallography ,chemistry ,Molybdenum ,symbols ,Molecule ,Orthorhombic crystal system ,Raman spectroscopy ,Instrumentation ,Spectroscopy ,Monoclinic crystal system - Abstract
The infrared and Raman spectra of powder samples of MoO3 (orthorhombic and monoclinic) and of MoO 3 · x H 2 O (x = 1 3 , 1 2 , 1 and 2) have been recorded and the most characteristic frequencies are discussed with reference to the available structural data and to previous vibrational assignments. A qualitative assignment is given in terms of group frequencies for the stretching vibrations of units involving oxygen atoms linked to one, two or three molybdenum atoms and a correlation is established between bond length and stretching force constant. In the case of the hydrates, partial deuteration allows the symmetry of the water molecules to be determined. Characteristic hydrogen bond distances are evaluated from the frequencies of the isolated HOD stretching vibrations.
- Published
- 1995
- Full Text
- View/download PDF
47. Chemically-diverse ligands at the glycine B site coupled to (NMDA) receptors selectively block the late phase of formalin-induced pain in mice
- Author
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L. Seguin and M.J. Millan
- Subjects
Chemistry ,General Neuroscience ,Memantine ,Stimulation ,Pharmacology ,Partial agonist ,Biochemistry ,Noxious stimulus ,medicine ,NMDA receptor ,HA-966 ,Receptor ,Glycine receptor ,medicine.drug - Abstract
The glycine B receptor partial agonists L 687,414, D-cycloserine and (+)-HA 966, and the glycine B receptor antagonists MDL 29,951 and 5,7-dichloro-2,4 dihydroxy-3-phenyl-quinoline dione (DCPQ) dose-dependently inhibited the late phase (LP) of formalin-induced licking (FIL) elicited by intraplantar formalin in mice at doses exerting little motor disruption in the rotarod test. In distinction, the early phase (EP) of FIL and the writhing response to intra-abdominal acetic acid were little influenced and, irrespective of stimulus intensity, they failed to modify the tail-flick response to phasic, thermal or mechanical stimulation of the tail. In contrast to glycine B ligands, competitive antagonists at the NMDA receptor recognition site (CPP, CGS 19755, CGP 34879 and 39551) and blockers of the associated ion channel ((+)-MK 801, (-)-MK 801, memantine and ketamine) all blocked both the LP and EP of FIL and induced ataxia at comparable doses. In conclusion, normalization of transmission at NMDA receptors by inhibition of the coupled glycine B site preferentially elicits antinociception against prolonged (chemical) noxious stimulation in the absence of a marked influence upon motor coordination.
- Published
- 1994
- Full Text
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48. Structure of MoO3 · 1/2H2O by Conventional X-Ray Powder Diffraction
- Author
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L. Seguin, D. Louër, M. Figlarz, and P. Bénard
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Diffraction ,Chemistry ,Ab initio ,Crystal structure ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Crystallography ,symbols.namesake ,Fourier transform ,Octahedron ,Materials Chemistry ,Ceramics and Composites ,symbols ,Physical and Theoretical Chemistry ,Hydrate ,Powder diffraction ,Monoclinic crystal system - Abstract
The crystal structure of the compound MoO3 · 1/2H2O was solved ab initio from conventional X-ray powder diffraction data and refined by the Rietveld method. This hydrate crystallizes in the monoclinic space group P21/m with unit cell dimensions a = 9.6715(2) A b = 3.701518(7) A, c = 7.01975(1) A, β = 102.403(1)°, and V = 248.40(1) A3, for Z = 4; 137 integrated intensities obtained by an iterative method were used to generate a Patterson map from which the initial positional parameters of two independent molybdenum atoms were derived. The remaining nonhydrogen atoms were located by Fourier methods. Refinement of the complete diffraction profile parameters (44 parameters, 575 reflections) converged to final agreement factors Rp = 0.088, Rwp = 0.113, and RF = 0.021. The structure consists of isolated layers parallel to (001), formed by double linear rows running along [010] and linked together through corner-sharing [MoO6] and [MoO5(H2O)] octahedra. A double chain is built up from strongly distorted [MoO6] octahedra sharing two common edges with each other, and the next one is in a similar layer, but with [MoO5(H2O)] octahedra. The successive layers are held together by hydrogen bonding to form a two-dimensional network.
- Published
- 1994
- Full Text
- View/download PDF
49. A novel supermetastable WO3 phase
- Author
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L. Seguin, J Pannetier, and M. Figlarz
- Subjects
Materials science ,Hexagonal crystal system ,Neutron diffraction ,Analytical chemistry ,Oxide ,Infrared spectroscopy ,General Chemistry ,Condensed Matter Physics ,medicine.disease ,chemistry.chemical_compound ,chemistry ,Phase (matter) ,Metastability ,medicine ,General Materials Science ,Dehydration ,Hydrate - Abstract
A new WO 3 phase has been identified by X-ray and neutron diffraction studies, heating infrared spectroscopy, DSC and TG analysis. This new phase, obtained from the dehydration of WO 3 ·1/3H 2 O, has a free energy greater than that of the metastable hexagonal WO 3 . The X-ray powder diffractogram of this supermetastable phase is the same as that of the hydrate oxide.
- Published
- 1993
- Full Text
- View/download PDF
50. Numerical Modelling of Thermomechanic Couplings in Frictional Contact: Application to Tire Rolling
- Author
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A. Kongo Kondé, I. Rosu, F. Lebon, N. Cocheteau, and L. Seguin
- Published
- 2010
- Full Text
- View/download PDF
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