25 results on '"John, Duda"'
Search Results
2. Understanding health care needs among Veterans with Parkinson's disease: A survey study
- Author
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Megan Feeney, John Duda, Amie Hiller, Jay Phillips, Christiana Evers, Nicole Yarab, Veronica Todaro, Lydia Rader, and Sheera Rosenfeld
- Subjects
Veterans ,Parkinson's disease ,comprehensive care ,mental health ,falls ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Among Veterans, it is estimated that 110,000 are living with Parkinson's disease (PD) in the United States. Whether or not Veterans living with PD are enrolled in the Veterans Health Administration (VHA), they may require special considerations when it comes to their care. We administered a survey to Parkinson's Foundation constituents with PD who had previously reported their Veteran status. Our goal was to identify areas where intervention can lead to improved health outcomes for Veterans living with Parkinson's disease. We specifically wanted to examine 1) the proportion of our Veteran constituents receiving services through the VHA, 2) the comprehensive care services that were utilized by Veterans living with PD, and 3) self-reported mental health and mobility status. We also wanted to compare those receiving care within and outside the VHA to see where there may be areas for improvement. With a response rate of 29.8% we received surveys from 409 United States Veterans with PD. As expected, mental health (MH) concerns in the previous 12 months were common with 36.0% of Veterans reporting concerns. Only 22.1% of respondents received care through VHA. Respondents with more falls and mental health concerns as well as those with higher levels of education and younger age were more likely to be seen at a VHA facility. In this sample, education level, household income, marital status, and VHA status were positively associated with increased health care utilization among Veterans. Those seen within the VHA were more likely to utilize MH and speech and language pathology consultation. This study highlights the importance of targeting educational outreach about care best practices for Veterans living with PD beyond VHA's current reach as well as the importance of access to good MH resources.
- Published
- 2022
- Full Text
- View/download PDF
3. Lewy Body Dementia Association’s Research Centers of Excellence Program: Inaugural Meeting Proceedings
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Bethany Peterson, Melissa Armstrong, Douglas Galasko, James E. Galvin, Jennifer Goldman, David Irwin, Henry Paulson, Daniel Kaufer, James Leverenz, Angela Lunde, Ian G. McKeith, Andrew Siderowf, Angela Taylor, Katherine Amodeo, Matt Barrett, Kimiko Domoto-Reilly, John Duda, Stephen Gomperts, Neill Graff-Radford, Samantha Holden, Lawrence Honig, Daniel Huddleston, Carol Lippa, Irene Litvan, Carol Manning, Karen Marder, Charbel Moussa, Chiadi Onyike, Fernando Pagan, Alexander Pantelyat, Victoria Pelak, Kathleen Poston, Joseph Quinn, Irene Richard, Liana S. Rosenthal, Marwan Sabbagh, Douglas Scharre, Sharon Sha, Holly Shill, Yasar Torres-Yaghi, Tina Christie, Todd Graham, Ian Richards, Mike Koehler, and Brad Boeve
- Subjects
Lewy body dementia ,Lewy Body Dementia Association ,Parkinson’s disease dementia ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract The first Lewy Body Dementia Association (LBDA) Research Centers of Excellence (RCOE) Investigator’s meeting was held on December 14, 2017, in New Orleans. The program was established to increase patient access to clinical experts on Lewy body dementia (LBD), which includes dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD), and to create a clinical trials-ready network. Four working groups (WG) were created to pursue the LBDA RCOE aims: (1) increase access to high-quality clinical care, (2) increase access to support for people living with LBD and their caregivers, (3) increase knowledge of LBD among medical and allied (or other) professionals, and (4) create infrastructure for a clinical trials-ready network as well as resources to advance the study of new therapeutics.
- Published
- 2019
- Full Text
- View/download PDF
4. Research Priorities of Individuals and Caregivers With Lewy Body Dementia
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Samantha K. Holden, Noheli Bedenfield, Angela S. Taylor, Ece Bayram, Chris Schwilk, Jori Fleisher, John Duda, Holly Shill, Henry L. Paulson, Kelly Stacy, Julia Wood, Pamela Corsentino, Sharon J. Sha, Irene Litvan, David J. Irwin, Joseph F. Quinn, Jennifer G. Goldman, Katherine Amodeo, John-Paul Taylor, Bradley F. Boeve, and Melissa J. Armstrong
- Subjects
Psychiatry and Mental health ,Clinical Psychology ,Geriatrics and Gerontology ,Gerontology - Published
- 2023
5. Predictors of multi-domain cognitive decline following DBS for treatment of Parkinson's disease
- Author
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Johannes C. Rothlind, Michele K. York, Ping Luo, Kim Carlson, William J. Marks, Frances M. Weaver, Matthew Stern, Kenneth A. Follett, John E. Duda, Domenic J. Reda, Kenneth Follett, Frances Weaver, Dolores Ippolito, Gatana Stoner, Tammy Barnett, Ken Bukowski, Rosemarie DeNicolo, Kwan Hur, Joyce Jimenez, Jan Motyka, Domenic Reda, Theresa Simon, Bharat Thakkar, Robert Woolson, Carol Fye, William Gagne, Crystal Harris, Jill Heemskerk, Claudia Moy, Paul Sheehy, Timothy O'Leary, Grant D. Huang, Louis Fiore, Robert Hall, Kevin Stroupe, Kim Burchiel, William Koller, Rajesh Pahwa, Johannes Rothlind, Oren Sagher, Roy Bakay, Rick Chappell, Robert Hart, Robert Holloway, George McCabe, Margaret Schenkman, Jamal Taha, Julia Buckelew, Marilyn Garin, Sharon Matzek, Donna Smith, Jeff Bronstein, John Duda, Penelope Hogarth, Kathryn Holloway, Stacy Horn, Eugene C. Lai, Ali Samii, null Farah Atassi, Cecilia Bello, Lisette Bunting-Perry, Tina Conn, Alice Cugley, Nanette Eubank, Linda Fincher, Romay Franks, Tammy Harris, Mariann Haselman, Susan Heath, Miriam Hirsch, Virginia Janovsky, Elaine Lanier, Mary Lloyd, Susan Loehner, Susan O'Connor, Ligaya Ordonez, Heather Maccarone, Kelli Massey-Makhoul, Mary Matthews, Elizabeth Meyn, Keiko Mimura, Wes Morrow, Tammy Searles, Jamye Valotta, Usha Vasthare, Monica Volz, Constance Ward, Rebecca Warker, Heidi Watson, Pamela Willson, Mark Baron, Matthew Brodsky, Vincent Calabrese, Gordon Campbell, Amy Colcher, Emad Farag, Eva Henry, Jyh-Gong Hou, Gail Kang, Galit Kleiner-Fisman, Jeff Kraakevik, John Nutt, Jill Ostrem, Aliya Sarwar, Indu Subramanian, Zeba Vanek, Gordon Baltuch, Antonio De Salles, Jorge Eller, Paul Larson, Richard Simpson, Philip Starr, William Carne, Tom Erikson, Jeffrey Kreutzer, Mario Mendez, Paul Moberg, John Ragland, Ronald Seel, Daniel Storzbach, Alexander Troster, Michele York, and Jurg Jaggi
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Neurology ,Subthalamic Nucleus ,Deep Brain Stimulation ,Humans ,Cognitive Dysfunction ,Parkinson Disease ,Neurology (clinical) ,Neuropsychological Tests ,Geriatrics and Gerontology ,Aged - Abstract
Statistically and clinically significant cognitive declines are observed in a small subset of individuals with Parkinson's Disease (PD) following treatment with Deep Brain Stimulation (DBS).We examine the association between multi-domain cognitive decline (MCD) and demographic and baseline clinical variables and the incidence of serious adverse events (SAE) arising within a six-month interval following DBS for PD.Study participants with PD who displayed MCD at 6-month follow-up evaluation after DBS (n = 18) were contrasted with individuals with PD from the same study who did not show cognitive decline after DBS (n = 146). Logistic regression analyses were employed to assess relationship between predictors, including age (70 years old), pre-DBS cognitive screening test performance, SAE, and MCD. MCD+ and MCD-groups were also compared on other baseline clinical and demographic variables.MCD showed modest association with older age and lower baseline neurocognitive screening performance, whereas the groups did not differ on most other baseline clinical and demographic variables. SAEs during the study interval were the most robust predictor of MCD in the DBS group. A variety of SAEs were documented in study participants experiencing MCD after DBS surgery, including, but not limited to, infections and small intracranial hemorrhages.Older age and lower baseline cognition measured prior to treatment are associated with MCD measured at six-months after DBS. SAE occurring following DBS surgery are also predictive of MCD. These predictors may reflect aspects of "frailty" in advanced PD. Risk factors for SAE warrant careful consideration in clinical trials.
- Published
- 2022
6. Excessive daytime sleepiness and topographic expansion of Lewy pathology
- Author
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Chol Shin, G. Webster Ross, Robert D. Abbott, Lon R. White, Jane Uyehara-Lock, Helen Petrovitch, K Masaki, Lenore J. Launer, John Duda, and Caroline M. Tanner
- Subjects
Lewy Body Disease ,Male ,Sleep Wake Disorders ,Aging ,Pathology ,medicine.medical_specialty ,Clinical Sciences ,Excessive daytime sleepiness ,Disorders of Excessive Somnolence ,Neurodegenerative ,Article ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,Lewy pathology ,80 and over ,Acquired Cognitive Impairment ,medicine ,Humans ,2.1 Biological and endogenous factors ,030212 general & internal medicine ,Aetiology ,Aged ,Aged, 80 and over ,Basal forebrain ,Parkinson's Disease ,Neurology & Neurosurgery ,Neocortex ,business.industry ,Neurosciences ,Brain ,Parkinson Disease ,Brain Disorders ,Olfactory bulb ,medicine.anatomical_structure ,Neurological ,alpha-Synuclein ,Lewy Bodies ,Dementia ,Female ,Cognitive Sciences ,Neurology (clinical) ,Brainstem ,medicine.symptom ,Sleep Research ,business ,Insula ,030217 neurology & neurosurgery - Abstract
ObjectiveWhile excessive daytime sleepiness (EDS) can predate the clinical diagnosis of Parkinson disease (PD), associations with underlying PD pathogenesis are unknown. Our objective is to determine if EDS is related to brain Lewy pathology (LP), a marker of PD pathogenesis, using clinical assessments of EDS with postmortem follow-up.MethodsIdentification of LP was based on staining for α-synuclein in multiple brain regions in a sample of 211 men. Data on EDS were collected at clinical examinations from 1991 to 1999 when participants were aged 72–97 years.ResultsAlthough EDS was more common in the presence vs absence of LP (p = 0.034), the association became stronger in neocortical regions. When LP was limited to the olfactory bulb, brainstem, and basal forebrain (Braak stages 1–4), frequency of EDS was 10% (4/40) vs 17.5% (20/114) in decedents without LP (p = 0.258). In contrast, compared to the absence of LP, EDS frequency doubled (36.7% [11/30], p = 0.023) when LP reached the anterior cingulate gyrus, insula mesocortex, and midfrontal, midtemporal, and inferior parietal neocortex (Braak stage 5). With further infiltration into the primary motor and sensory neocortices (Braak stage 6), EDS frequency increased threefold (51.9% [14/27], p < 0.001). Findings were similar across sleep-related features and persisted after adjustment for age and other covariates, including the removal of PD and dementia with Lewy bodies.ConclusionsThe association between EDS and PD includes relationships with extensive topographic LP expansion. The neocortex could be especially vulnerable to adverse relationships between sleep disorders and aggregation of misfolded α-synuclein and LP formation.
- Published
- 2019
7. BEYOND LUXURY COOPERATIVISM
- Author
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JOHN DUDA
- Published
- 2018
8. Archaeologies of the Future: The Desire Called Utopia and Other Science Fictions (review)
- Author
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John Duda
- Subjects
Linguistics and Language ,Literature and Literary Theory ,Language and Linguistics - Published
- 2005
9. Joe Hill: The IWW and the Making of a Revolutionary Workingclass Counterculture (review)
- Author
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John Duda
- Subjects
Linguistics and Language ,History ,Literature and Literary Theory ,Counterculture ,Art history ,Environmental ethics ,Making-of ,Language and Linguistics - Published
- 2004
10. Exercise Training Improves Outcomes of a Dyspnea Self-management Program
- Author
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Sibel Demir-Deviren, Amy H Tsang, Virginia Carrieri-Kohlman, Michael S. Stulbarg, Lewis Adams, Huong Q. Nguyen, Warren M. Gold, John Duda, and Steven M. Paul
- Subjects
Male ,medicine.medical_specialty ,Activities of daily living ,Pulmonary disease ,Walking ,law.invention ,Pulmonary Disease, Chronic Obstructive ,Quality of life ,Randomized controlled trial ,law ,Activities of Daily Living ,Exercise performance ,Humans ,Medicine ,Self management program ,Medical prescription ,Aged ,business.industry ,Rehabilitation ,Exercise Therapy ,Clinical trial ,Dyspnea ,Exercise Test ,Quality of Life ,Physical therapy ,Female ,business - Abstract
PURPOSE: The purpose of this study was twofold: (1) to determine whether exercise training adds to the benefit of a dyspnea self-management (DM) program; and (2) to determine if there is a “dose response” to supervised exercise training (0, 4, or 24 sessions) in dyspnea, exercise performance, and health-related quality of life. METHODS: Subjects with chronic obstructive pulmonary disease (n = 103, 46 men, 57 women; age 66 ± 8 years; forced expiratory volume in 1 second 44.8 ± 14% predicted) were randomized to DM, DM-exposure, or DM-training. Dyspnea self-management included individualized education about dyspnea management strategies, a home-walking prescription, and daily logs. Outcomes were measured at baseline and 2 months as part of a 1-year longitudinal randomized clinical trial. Outcomes included dyspnea during laboratory exercise and with activities of daily living (Chronic Respiratory Questionnaire [CRQ]), Shortness of Breath Questionnaire, Baseline/Transitional Dyspnea Index), exercise performance (incremental treadmill tests (ITTs) and endurance treadmill tests (ETTs), 6-minute walk (6MW), and health-related quality of life (SF-36). RESULTS: The DM-training group had significantly greater improvements than the DM-exposure and the DM groups in dyspnea at isotime during ITT (P = .006); exercise performance during ITT (P = .005), ETT (P = .003), and 6MW (P = .01); SF-36 Vitality (P = .031); and CRQ mastery (P = .007). There was a dose-dependent improvement in CRQ dyspnea scores (P < .05) with significant improvements only in the DM-training and DM-exposure groups. CONCLUSION: Exercise training substantially improved the impact of a dyspnea self-management program with a home walking prescription (DM). This impact tended to be dependent on the “dose” of exercise.
- Published
- 2002
11. A randomized controlled trial of home-based exercise for cancer-related fatigue in women during and after chemotherapy with or without radiation therapy
- Author
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Joanne B. Krasnoff, Marylin J. Dodd, Christine Miaskowski, John Duda, Steven M. Paul, Maria Cho, Kayee Alice Bank, Bruce A. Cooper, and Patricia Painter
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Sleep Wake Disorders ,medicine.medical_specialty ,Psychological intervention ,Pain ,Severity of Illness Index ,Article ,law.invention ,Randomized controlled trial ,law ,Neoplasms ,Severity of illness ,medicine ,Humans ,Single-Blind Method ,Medical prescription ,Karnofsky Performance Status ,Cancer-related fatigue ,Depression (differential diagnoses) ,Fatigue ,Sleep disorder ,Oncology (nursing) ,business.industry ,Depression ,Middle Aged ,medicine.disease ,Home Care Services ,Exercise Therapy ,Prescriptions ,Treatment Outcome ,Oncology ,Nursing Evaluation Research ,Physical therapy ,Patient Compliance ,Regression Analysis ,Female ,San Francisco ,medicine.symptom ,Exercise prescription ,business ,Follow-Up Studies - Abstract
Background—Few studies have evaluated an individualized home-based exercise prescription during and after cancer treatment. Objective—The purpose was to evaluate the effectiveness of a home-based exercise training intervention, the PRO-SELF FATIGUE CONTROL PROGRAM on the management of cancer related fatigue. Interventions/Methods—Participants (N=119) were randomized into one of three groups: Group 1 (EE) received the exercise prescription throughout the study; Group 2 (CE) received their exercise prescription after completing cancer treatment; Group 3 (CC) received usual care. Patients completed the Piper Fatigue Scale, General Sleep Disturbance Scale, Center for Epidemiological StudiesDepression scale, and Worst Pain Intensity Scale. Results—All groups reported mild fatigue levels, sleep disturbance and mild pain, but not depression. Using multilevel regression analysis significant linear and quadratic trends were found for change in fatigue and pain (i.e., scores increased, then decreased over time). No group differences were found in the changing scores over time. A significant quadratic effect for the trajectory of sleep disturbance was found, but no group differences were detected over time. No significant time or group effects were found for depression. Conclusions—Our home-based exercise intervention had no effect on fatigue or related symptoms associated with cancer treatment. The optimal timing of exercise remains to be determined. Implications for practice—Clinicians need to be aware that some physical activity is better than none, and there is no harm in exercise as tolerated during cancer treatment. Further analysis is needed to examine the adherence to exercise. More frequent assessments of fatigue, sleep disturbance, depression, and pain may capture the effect of exercise. Cancer-related fatigue (CRF) is a common problem in oncology patients and survivors that has received attention during the last two decades. Although the reported prevalence of CRF varies across studies, a consensus exists that it is high both during and after cancer treatment.
- Published
- 2010
12. Falling risk factors in Parkinson's disease
- Author
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Keith, Robinson, Andrew, Dennison, David, Roalf, Joseph, Noorigian, Heather, Cianci, Lisette, Bunting-Perry, Paul, Moberg, Galit, Kleiner-Fisman, Rebecca, Martine, John, Duda, Jurg, Jaggi, and Matthew, Stern
- Subjects
Male ,Disability Evaluation ,Risk Factors ,Activities of Daily Living ,Polypharmacy ,Humans ,Accidental Falls ,Parkinson Disease ,Aged - Abstract
To identify falling risk factors that are potentially modifiable among individuals who have idiopathic Parkinson's disease.A between group comparison of 19 fallers and 21 nonfallers who have Parkinson's disease, across an array of variables that have been identified as falling risk factors among the elderly and among those who have Parkinson's disease.Several variables were demonstrated significantly to distinguish fallers: disease duration and severity; dyskinesias associated with the use of dopaminergic agents; freezing; postural instability; depression; fear of falling; impaired fine motor control and motor planning in the feet; decreased proximal strength and muscular endurance in the legs; and a higher level of disability.Several of these variables can be viewed a potentially modifiable during a future intervention trial that aims to reduce falls in those who have Parkinson's disease using multidimensional risk factor modification.
- Published
- 2005
13. Qualification of the Sound Field in a Metadyne Anechoic Chamber
- Author
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John Duda, Mardi C. Hastings, and Richard D. Godfrey
- Abstract
The results of an experimental performance evaluation of a Metadyne chamber in both full anechoic and hemi-anechoic configurations over the frequency range from 60 to 10,000 Hz are presented. The Metadyne anechoic wedge, a fiberglas-filled wedge fully encapsulated in a perforated metal casing, was developed several years ago as an alternative to conventional fiberglas and foam wedges. The results of this evaluation show that the Metadyne chamber meets or exceeds all acoustic performance requirements for proper free field environmental conditions, noise reduction, and inside ambient levels. They also indicate that free field conditions exist much closer than a quarter wavelength from the wedge tips which allows use of nearly all the chamber volume for measurements. This chamber provides an environment for conducting highly accurate sound measurement tests.
- Published
- 1997
14. Prehospital use of nifedipine for severe hypertension
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Ronald B. Stewart, James J Menegazzi, Michael B. Heller, Robert J. Maha, Richard M Kaplan, Paul M. Paris, and John Duda
- Subjects
Adult ,Male ,Mean arterial pressure ,Emergency Medical Services ,Nifedipine ,medicine.medical_treatment ,Hemodynamics ,Administration, Oral ,Blood Pressure ,medicine ,Humans ,Prospective cohort study ,Adverse effect ,Chemotherapy ,business.industry ,General Medicine ,Blood Pressure Determinations ,Middle Aged ,Blood pressure ,Anesthesia ,Hypertension ,Emergency Medicine ,Emergencies ,business ,medicine.drug - Abstract
The prehospital management of severe hypertension is limited by a paucity of pharmacologic agents suitable for field use. This prospective study was designed to test the safety and efficacy of intraoral nifedipine therapy in 50 patients with severe hypertension being transported by an urban emergency medical service system. Ten milligrams of nifedipine were administered. Serial blood pressure determinations were obtained at 3, 5, 10, and 15 minutes and patients were observed for possible side effects. A marked effect on systolic blood pressure (SP), diastolic blood pressure (DP), and mean arterial pressure (MAP) was evident and was statistically significant in all three categories by 3 minutes. MAP decreased from 169 to 129 mm Hg (delta MAP of 40 mm Hg) at 15 minutes with parallel changes in the SP (55 mm Hg) and delta DP (32 mm Hg). These changes were highly significant (P less than .01) when compared with those of 50 historical controls. No evidence of severe adverse effects were noted. Nifedipine appears to be a promising agent for the prehospital treatment of severe hypertension, but its proper role is not yet defined.
- Published
- 1990
15. 'Paleolithic' Diets Improve Cardiovascular Responses at Rest and with Exercise
- Author
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Joanne B. Krasnoff, John Duda, Lynda A. Frassetto, Patricia Painter, and Michele Mietus-Snyder
- Subjects
medicine.medical_specialty ,business.industry ,Internal medicine ,medicine ,Cardiology ,Physical Therapy, Sports Therapy and Rehabilitation ,Orthopedics and Sports Medicine ,business ,Rest (music) - Published
- 2007
16. PHYSICAL FUNCTIONING FOLLOWING LAPAROSCOPIC KIDNEY DONATION
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P Recalde, John Duda, J P Roberts, Patricia Painter, and Joanne B. Krasnoff
- Subjects
medicine.medical_specialty ,Physical functioning ,business.industry ,medicine ,Kidney donation ,Physical Therapy, Sports Therapy and Rehabilitation ,Orthopedics and Sports Medicine ,Intensive care medicine ,business - Published
- 2003
17. MAXIMAL EXERCISE TESTING IN CANCER PATIENTS UNDERGOING CHEMOTHERAPY
- Author
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M L. Dodd, John Duda, Patricia Painter, and Joanne B. Krasnoff
- Subjects
Oncology ,medicine.medical_specialty ,Chemotherapy ,business.industry ,Internal medicine ,medicine.medical_treatment ,Medicine ,Cancer ,Physical Therapy, Sports Therapy and Rehabilitation ,Orthopedics and Sports Medicine ,Maximal exercise ,business ,medicine.disease - Published
- 2003
18. RANDOMIZED TRIAL OF DIET AND EXERCISE FOLLOWING LIVER TRANSPLANTATION
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Andrea Q. Vintro, J Chang, Patricia Painter, Nancy L. Ascher, John Duda, Joanne B. Krasnoff, T Bass, and M L. Dodd
- Subjects
medicine.medical_specialty ,Physical functioning ,Randomized controlled trial ,law ,business.industry ,medicine.medical_treatment ,Physical therapy ,medicine ,Physical Therapy, Sports Therapy and Rehabilitation ,Orthopedics and Sports Medicine ,Liver transplantation ,business ,law.invention - Published
- 2003
19. Differential Diagnosis of Staphylococcus aureus from Staphylococcus epidermidis and Staphylococcus saprophyticus by Alphazurine A Dye
- Author
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William W. Ayres and John Duda
- Subjects
Staphylococcus saprophyticus ,Micrococcaceae ,biology ,Chemistry ,Public Health, Environmental and Occupational Health ,General Medicine ,medicine.disease_cause ,biology.organism_classification ,Microbiology ,chemistry.chemical_compound ,Staphylococcus aureus ,Staphylococcus epidermidis ,medicine ,Trypticase soy agar ,Agar diffusion test ,Sheep blood ,Bacteria - Abstract
Staphylococcal bacterial suspensions were streaked on Trypticase soy agar with 5% sheep blood culture plates. Paper discs containing alphazurine A, a triphenylmethane dye, were placed on the inoculated plates which were incubated at 37 degrees C for 24 hours. A wide zone of inhibition of growth of Staphylococcus aureus was present around the paper discs. Growth of Staphylococcus epidermidis and Staphylococcus saprophyticus was not inhibited.
- Published
- 1993
20. Development of a high‐frequency precision anechoic test facility
- Author
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Guy Torio, John Duda, Martin Hirschorn, and Mark Gilbert
- Subjects
Test facility ,business.product_category ,Materials science ,Acoustics and Ultrasonics ,Anechoic chamber ,Microphone ,Acoustics ,Reverberation room ,Wedge (mechanical device) ,Sweep frequency response analysis ,Arts and Humanities (miscellaneous) ,Metadyne ,business ,Electrical impedance - Abstract
Although anechoic wedges with absorption coefficients of 0.99 as tested in typical impedance tubes meet ISO inverse square‐law standards, they may not be satisfactory for anechoic rooms used for measurements of microphone response characteristics. Due to size restrictions, impedance tube tests are limited to frequencies below about 250 Hz and there is no standard method to test wedges for absorption at higher frequencies. This paper describes how pulse signal and reverberation room tests were employed to rank the high‐frequency performance of three types of anechoic wedges considered for a microphone test facility: Standard patented MetadyneTM (perforated metal) wedges—conventional fiberglass wedges and an improved high performance Metadyne wedge system. The results of laboratory tests and tests conducted in anechoic rooms are presented. In all cases the preferred system, high‐performance Metadyne wedges, is shown to meet the stringent acoustic absorption requirements needed for this application. The paper indicates the need for new standards for laboratory testing of anechoic wedges at high frequencies and an alternate method to inverse square‐law tests for evaluating anechoic room performance such as stepped frequency sweep tests. Such a new standard will be proposed in the presentation.
- Published
- 1999
21. Anechoic structural elements and chamber
- Author
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John Duda
- Subjects
geography ,geography.geographical_feature_category ,Materials science ,Acoustics and Ultrasonics ,Arts and Humanities (miscellaneous) ,Anechoic chamber ,Acoustics ,Base (geometry) ,Free space ,Flat panel ,Layer (electronics) ,Sound (geography) - Abstract
A substantially enclosed sound absorbing unit (21) for an anechoic chamber is disclosed. The sound absorbing unit (12) includes a substantially flat panel member (25) comprising a layer of sound absorptive material. An anechoic member (21) is disposed adjacent to the flat panel member (25). The anechoic member (21) is disposed adjacent to a base (29) and a generally spaced apart sound transparent wall member (26). The wall member (26) includes a layer of sound absorptive material (27) and a cover sheet (20) made of perforated, substantially sound reflective material. The free space (30) of the perforated cover sheet (20) is at least 7 percent of the total area of the cover sheet (20).
- Published
- 1995
22. Basic Design Considerations for Anechoic Chambers
- Author
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John Duda
- Subjects
Engineering ,Design analysis ,Anechoic chamber ,Noise measurement ,business.industry ,law ,Acoustics ,Ventilation (architecture) ,General Engineering ,business ,law.invention - Published
- 1977
23. Economic Design and Construction of Anechoic Chambers
- Author
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John Duda and Arthur Oppenheim
- Subjects
Absorption (acoustics) ,business.product_category ,Optics ,Acoustics and Ultrasonics ,Arts and Humanities (miscellaneous) ,Anechoic chamber ,business.industry ,Acoustics ,Air space ,business ,Economic design ,Geology ,Wedge (mechanical device) - Abstract
For the past 16 years, the design of anechoic chambers has been the subject of a good deal of acoustic research. Prior research has yielded a design employing a large number of light‐density wedges (2.S lb/ft3) which had to be supported a fixed distance from the chamber wall. The design considerations which formed the nucleus of a research program by the Industrial Acoustics Company, Inc., were the following: (1) The wedge had to be made of a rigid material. (2) The over‐all length of any anechoic wedge must be maintained as short as physically possible. (3) The wall area covered by a single wedge should be made as large as possible. The first series of investigations made was to determine whether or not the conventional air space could be eliminated. Two figures showing test results of two particular experiments indicate that, if the wedge sizes were maintained constant, there is no advantage in having the air space behind them. It was also observed that the low‐frequency absorption could be matched to t...
- Published
- 1962
24. Jet‐Engine Exhaust Noise—A Measure of Thrust
- Author
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John Duda and Frederic M. Oran
- Subjects
Jet (fluid) ,Measure (data warehouse) ,Acoustics and Ultrasonics ,Acoustics ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Thrust ,Jet engine ,law.invention ,Noise ,Arts and Humanities (miscellaneous) ,law ,Range (aeronautics) ,Test program ,Environmental science ,Sound pressure - Abstract
The thrust of the jet engine is theoretically shown to be related to the over‐all sound pressure of the jet exhaust regardless of environmental conditions. Within the range of tolerances required to measure thrust accurately on a competitive basis with existing systems, it is found that over‐all sound‐pressure‐level measurements are not satisfactory. Numerous experiments have indicated that specific frequency regions of sound can be utilized to determine a correlation between sound and thrust. An instrument, the Jet Thrust Indicator (JTD), is described as having special filters such that the sound‐pressure level of the frequency ranges correlates with thrust. The JTD provides direct readout in pounds of thrust. Actual field‐test data are provided for aircraft and test stand‐mounted jet engines. Thrust‐measurement comparisons are made of the JTD with the conventional thrust‐measuring techniques presently employed. Data obtained from field tests conducted over a wide range of atmospheric conditions and with various engines are reviewed. Results of the test program indicate an average accuracy of 2%. Applications including measurement of jet‐engine thrust for ground check out on test stands and aircraft, go/no‐go indications, and other uses are discussed.
- Published
- 1962
25. Early and Accurate Identification of Parkinson Disease Among US Veterans.
- Author
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Mantri S, Duda JE, and Morley JF
- Abstract
Early and accurate identification and management of veterans at risk for Parkinson disease is an important priority area for the US Department of Veterans Affairs because of the substantial impact on quality of life and disability-adjusted life years., Competing Interests: Author disclosures The authors report no actual or potential conflicts of interest with regard to this article.
- Published
- 2019
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