116 research outputs found
Regional variation in angioplasty practice in the United States: A report from the Hirulog angioplasty study
Pla general de la font anomenada Homenatge
al poble, ubicada a la plaça Molina. A la part
superior de la font, a cada costat, hi ha un escut cisellat. Sota un d'aquests es troba la frase Gratitud al Ayuntamiento.Realitzada en pedra abans de 1874
Dinoflagellate blooms and physical systems in the Gulf of Maine
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 1990Numerous studies have shown dinoflagellate blooms to be
closely related to density discontinuities and fronts in the ocean. The
spatial and temporal patterns of the dinoflagellate population
depend on the predominant mode of physical forcing, and its scales
of variability. The present study combined field sampling of
hydrographic and biological variables to examine the relationship of
dinoflagellate population distributions to physical factors along the
southwestern cost of the Gulf of Maine.
A bloom of Ceratium longipes occurred along this coast during
the month of June, 1987. A simple model which coupled along-isopycnal
diffusion with the logistic growth equation suggested that
the cells had a growth rate of about 0.1 d-1 , and had reached a
steady horizontal across-shelf distribution within about 10 d.
Fur~her variations in population density appeared to be related to
fluctuations of light with periods of -10 d. To our knowledge, this
was the first use of this simple diffusion model as a diagnostic tool
for quantifying parameters describing the growth and movement of
a specific phytoplankton population.
Blooms of the toxic dinoflagellate, Alexandrium tamarense
have been nearly annual features along the coasts of southern
Maine, New Hampshire and Massachusetts since 1972; however the
mechanisms controlling the distribution of cells and concomitant
shellfish toxicity are relatively poorly understood. Analysis of field
data gathered from April to September, 1987-1989, showed that in
two years when toxicity was detected in the southern part of this
region, A. tamarense cells were apparently transported into the
study area between Portsmouth and Cape Ann, Massachusetts, in a
coastally trapped buoyant plume. This plume appears to have been
formed off Maine by the outflow from the Androscoggin and Kennebec Rivers. Flow rates of these rivers, hydrographic sections,
and satellite images suggest that the plume had a duration of about
a month, and extended alongshore for several hundred kilometers.
The distribution of cells followed the position of the plume as it was
influenced by wind and topography. Thus when winds were
downwelling-favourable, cells were moved alongshore to the south,
and were held to the coast; when winds were upwelling-favourable,
the plume sometimes separated from the coast, advecting the cells
offshore.
The alongshore advection of toxic cells within a coastally
trapped buoyant plume can explain the temporal and spatial
patterns of shellfish toxicity along the coast. The general observation
of a north-to-south temporal trend of toxicity is consistent with the
southward advection of the plume. In 1987 when no plume was
present, Alexandrium tamarense cells were scarce, and no toxicity
was recorded at the southern stations. A hypothesis was formulated
explaining the development and spread of toxic dinoflagellate
blooms in this region. This plume-advection hypothesis included:
source A. tamarense populations in the north, possibly associated
with the Androscoggin and Kennebec estuaries; a relationship
between toxicity patterns and river flow volume and timing of flow
peaks; and a relationship between wind stresses and the distribution
of low salinity water and cells. Predictions of the plume-advection hypothesis were tested
with historical records of shellfish toxicity, wind speed and direction,
and river flow. The predictions tested included the north-south
progression of toxic outbreaks, the occurrence of a peak in river flow
prior to the PSP events, the relationship of transit time of PSP
toxicity along the coast with river flow volume, and the influence of
surface wind stress on the timing and location of shellfish toxicity.
All the predictions tested were supported by the historical records.
In addition it was found that the plume-advection hypothesis
explains many details of the timing and spread of shellfish toxicity,
including the sporadic nature of toxic outbreaks south of
Massachusetts Bay, and the apparently rare occurrence of toxicity
well offshore on Nantucket Shoals and Georges Bank.This research was supported by
ONR contract N00014-87-K-0007 and ONR grant N00014-89-J-111
to Donald M. Anderson, and NOAA Office of Sea Grant contract
NA86AA-D-SG090
Regional variation in angioplasty practice in the United States: A report from the Hirulog angioplasty study
Systematic techniques for assisting recruitment to trials (START): study protocol for embedded, randomized controlled trials
BACKGROUND: Randomized controlled trials play a central role in evidence-based practice, but recruitment of participants, and retention of them once in the trial, is challenging. Moreover, there is a dearth of evidence that research teams can use to inform the development of their recruitment and retention strategies. As with other healthcare initiatives, the fairest test of the effectiveness of a recruitment strategy is a trial comparing alternatives, which for recruitment would mean embedding a recruitment trial within an ongoing host trial. Systematic reviews indicate that such studies are rare. Embedded trials are largely delivered in an ad hoc way, with interventions almost always developed in isolation and tested in the context of a single host trial, limiting their ability to contribute to a body of evidence with regard to a single recruitment intervention and to researchers working in different contexts. METHODS/DESIGN: The Systematic Techniques for Assisting Recruitment to Trials (START) program is funded by the United Kingdom Medical Research Council (MRC) Methodology Research Programme to support the routine adoption of embedded trials to test standardized recruitment interventions across ongoing host trials. To achieve this aim, the program involves three interrelated work packages: (1) methodology - to develop guidelines for the design, analysis and reporting of embedded recruitment studies; (2) interventions - to develop effective and useful recruitment interventions; and (3) implementation - to recruit host trials and test interventions through embedded studies. DISCUSSION: Successful completion of the START program will provide a model for a platform for the wider trials community to use to evaluate recruitment interventions or, potentially, other types of intervention linked to trial conduct. It will also increase the evidence base for two types of recruitment intervention. TRIAL REGISTRATION: The START protocol covers the methodology for embedded trials. Each embedded trial is registered separately or as a substudy of the host trial
Essential Components of Effective HIV Care: A Policy Paper of the HIV Medicine Association of the Infectious Diseases Society of America and the Ryan White Medical Providers Coalition
Human immunodeficiency virus (HIV) antiretroviral agents and effective HIV care management transformed HIV disease from a death sentence to a chronic condition for many in the United States. A comprehensive HIV care model was developed to meet the complex needs of HIV patients, with support from the Ryan White program, the Veterans Administration, and others. This paper identifies the essential components of an effective HIV care model. As access to health care expands under the National HIV/AIDS Strategy and the Patient Protection and Affordable Care Act, it will be critical to build upon the HIV care model to realize positive health outcomes for people with HIV infection
Immune reconstitution inflammatory syndrome in HIV infected late presenters starting integrase inhibitor containing antiretroviral therapy
Background: Integrase inhibitors (INI) induce a rapid decline of HIV-RNA in plasma and CD4+ T-cell recovery in blood. Both characteristics are also associated with immune reconstitution inflammatory syndrome (IRIS). Whether the use of INI-containing combination antiretroviral therapy (cART) increases the risk of IRIS is being questioned. Methods: Study within the Dutch ATHENA HIV observational cohort. HIV-1 infected late presenters initiating cART after March 2009 were included if they had <200 CD4+ T-cells per μL and were diagnosed with an opportunistic infection. IRIS was defined either according to the criteria by French et al. (IRISFRENCH) or by a clinical IRIS diagnosis of the physician (IRISCLINICAL). The primary outcomes were the association between INI and the occurrence of IRISFRENCH and IRISFRENCH+CLINICAL in multivariable logistic regression. Findings: 672 patients with a median CD4+ T-cell count of 35 cells per μL were included. Treatment with INI was independently associated with IRISFRENCH as well as IRISFRENCH+CLINICAL (OR 2·43, 95%CI:1·45-4·07, and OR 2·17, 95%CI:1·45-3·25). When investigating INI separately, raltegravir (RAL) remained significantly associated with IRISFRENCH (OR 4·04 (95%CI:1·99-8·19) as well as IRISFRENCH+CLINICAL (OR 3·07, 95%CI:1·66-5·69), while dolutegravir (DTG) became associated with IRISFRENCH+CLINICAL after it replaced RAL as preferred INI in the cohort after 2015 (OR 4·08, 95%CI:0·99-16·82, p=0·052). Too few patients used elvitegravir to draw meaningful conclusions. Steroid initiation for IRIS was more likely in those who initiated INI versus in those who did not, but no increased hospital (re)admission or mortality rates were observed. Interpretation: In HIV late presenters from a resource rich setting, INI based treatment initiation increased the risk of IRIS. This was observed for RAL and DTG when being initiated as preferential INI in the presence of specific AIDS-conditions, indicative of channeling bias. Although we controlled for all relevant measured confounders, we cannot exclude that the observed association is partially explained by residual confounding. INI use was not associated with mortality nor hospitalization. Therefore, our observation is no reason to avoid INI in late presenters. Funding: The ATHENA database is maintained by Stichting HIV Monitoring and supported by a grant from the Dutch Ministry of Health, Welfare and Sport through the Centre for Infectious Disease Control of the National Institute for Public Health and the Environment
Tuberculosis in HIV-Negative and HIV-Infected Patients in a Low-Incidence Country: Clinical Characteristics and Treatment Outcomes
BACKGROUND: In Switzerland and other developed countries, the number of tuberculosis (TB) cases has been decreasing for decades, but HIV-infected patients and migrants remain risk groups. The aim of this study was to compare characteristics of TB in HIV-negative and HIV-infected patients diagnosed in Switzerland, and between coinfected patients enrolled and not enrolled in the national Swiss HIV Cohort Study (SHCS).
METHODS AND FINDINGS: All patients diagnosed with culture-confirmed TB in the SHCS and a random sample of culture-confirmed cases reported to the national TB registry 2000-2008 were included. Outcomes were assessed in HIV-infected patients and considered successful in case of cure or treatment completion. Ninety-three SHCS patients and 288 patients selected randomly from 4221 registered patients were analyzed. The registry sample included 10 (3.5%) coinfected patients not enrolled in the SHCS: the estimated number of HIV-infected patients not enrolled in the SHCS but reported to the registry 2000-2008 was 146 (95% CI 122-173). Coinfected patients were more likely to be from sub-Saharan Africa (51.5% versus 15.8%, P<0.0001) and to present disseminated disease (23.9% vs. 3.4%, P<0.0001) than HIV-negative patients. Coinfected patients not enrolled in the SHCS were asylum seekers or migrant workers, with lower CD4 cell counts at TB diagnosis (median CD4 count 79 cells/µL compared to 149 cells/µL among SHCS patients, P = 0.07). There were 6 patients (60.0%) with successful outcomes compared to 82 (88.2%) patients in the SHCS (P = 0.023).
CONCLUSIONS: The clinical presentation of coinfected patients differed from HIV-negative TB patients. The number of HIV-infected patients diagnosed with TB outside the SHCS is similar to the number diagnosed within the cohort but outcomes are poorer in patients not followed up in the national cohort. Special efforts are required to address the needs of this vulnerable population
Tropical field stations yield high conservation return on investment
Conservation funding is currently limited; cost-effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations’ conservation return on investment and explored the impact of COVID-19. We surveyed leaders of field stations across tropical regions that host primate research; 157 field stations in 56 countries responded. Respondents reported improved habitat quality and reduced hunting rates at over 80% of field stations and lower operational costs per km2 than protected areas, yet half of those surveyed have less funding now than in 2019. Spatial analyses support field station presence as reducing deforestation. These “earth observatories” provide a high return on investment; we advocate for increased support of field station programs and for governments to support their vital conservation efforts by investing accordingly.Additional co-authors: Ekwoge Abwe, Tanvir Ahmed, Marc Ancrenaz, Raphali R. Andriantsimanarilafy, Andie Ang, Filippo Aureli, Louise Barrett, Jacinta C. Beehner, Marcela E. Benítez, Bruna M. Bezerra, Júlio César Bicca-Marques, Dominique Bikaba, Robert Bitariho, Christophe Boesch, Laura M. Bolt, Ramesh Boonratana, Thomas M. Butynski, Gustavo R. Canale, Susana Carvalho, Colin A. Chapman, Dilip Chetry, Susan M. Cheyne, Marina Cords, Fanny M. Cornejo, Liliana Cortés-Ortiz, Camille N. Z. Coudrat, Margaret C. Crofoot, Drew T. Cronin, Alvine Dadjo, S. Chrystelle Dakpogan, Emmanuel Danquah, Tim R. B. Davenport, Yvonne A. de Jong, Stella de la Torre, Andrea Dempsey, Judeline C. Dimalibot, Rainer Dolch, Giuseppe Donati, Alejandro Estrada, Rassina A. Farassi, Peter J. Fashing, Eduardo Fernandez-Duque, Maria J. Ferreira da Silva, Julia Fischer, César F. Flores-Negrón, Barbara Fruth, Terence Fuh Neba, Lief Erikson Gamalo, Jörg U. Ganzhorn, Paul A. Garber, Smitha D. Gnanaolivu, Mary Katherine Gonder, Sery Ernest Gonedelé Bi, Benoit Goossens, Marcelo Gordo, Juan M. Guayasamin, Diana C. Guzmán-Caro, Andrew R. Halloran, Jessica A. Hartel, Eckhard W. Heymann, Russell A. Hill, Kimberley J. Hockings, Gottfried Hohmann, Naven Hon, Mariano G. Houngbédji, Michael A. Huffman, Rachel A. Ikemeh, Inaoyom Imong, Mitchell T. Irwin, Patrícia Izar, Leandro Jerusalinsky, Gladys Kalema-Zikusoka, Beth A. Kaplin, Peter M. Kappeler, Stanislaus M. Kivai, Cheryl D. Knott, Intanon Kolasartsanee, Kathelijne Koops, Martin M. Kowalewski, Deo Kujirakwinja, Ajith Kumar, Quyet K. Le, Rebecca J. Lewis, Aung Ko Lin, Andrés Link, Luz I. Loría, Menladi M. Lormie, Edward E. Louis Jr., Ngwe Lwin, Suchinda Malaivijitnond, Lesley Marisa, Gráinne M. McCabe, W. Scott McGraw, Addisu Mekonnen, Pedro G. Méndez-Carvajal, Tânia Minhós, David M. Montgomery, Citlalli Morelos-Juárez, David Morgan, Amancio Motove Etingüe, Papa Ibnou Ndiaye, K. Anne-Isola Nekaris, Nga Nguyen, Vincent Nijman, Radar Nishuli, Marilyn A. Norconk, Luciana I. Oklander, Rahayu Oktaviani, Julia Ostner, Emily Otali, Susan E. Perry, Eduardo J. Pinel Ramos, Leila M. Porter, Jill D. Pruetz, Anne E. Pusey, Helder L. Queiroz, Mónica A. Ramírez, Guy Hermas Randriatahina, Hoby Rasoanaivo, Jonah Ratsimbazafy, Joelisoa Ratsirarson, Josia Razafindramanana, Onja H. Razafindratsima, Vernon Reynolds, Rizaldi Rizaldi, Martha M. Robbins, Melissa E. Rodríguez, Marleny Rosales-Meda, Crickette M. Sanz, Dipto Sarkar, Anne Savage, Amy L. Schreier, Oliver Schülke, Gabriel H. Segniagbeto, Juan Carlos Serio-Silva, Arif Setiawan, John Seyjagat, Felipe E. Silva, Elizabeth M. Sinclair, Rebecca L. Smith, Denise Spaan, Fiona A. Stewart, Shirley C. Strum, Martin Surbeck, Magdalena S. Svensson, Mauricio Talebi, Luc Roscelin Tédonzong, Bernardo Urbani, João Valsecchi, Natalie Vasey, Erin R. Vogel, Robert B. Wallace, Janette Wallis, Siân Waters, Roman M. Wittig, Richard W. Wrangham, Patricia C. Wright, Russell A. Mittermeie
Placing the library at the heart of plagiarism prevention: The University of Bradford experience.
yesPlagiarism is a vexed issue for Higher Education, affecting student transition, retention and attainment. This paper reports on two initiatives from the University of Bradford library aimed at reducing student plagiarism. The first initiative is an intensive course for students who have contravened plagiarism regulations. The second course introduces new students to the concepts surrounding plagiarism with the aim to prevent plagiarism breaches. Since the Plagiarism Avoidance for New Students course was introduced there has been a significant drop in students referred to the disciplinary programme. This paper discusses the background to both courses and the challenges of implementation
Productivity and Internationalization A Micro/Data Approach
An appropriate analysis of the effects of globalization requires a careful analysis of the various ways in which different firms operate in international markets. Micro data at the level of individual firms and employees can enhance our empirical understanding of the relationships between internationalization, firms, jobs and employees. These micro data become increasingly available. This paper provides an introduction to this special issue that illustrates the wide variation, richness and policy relevance of the emerging micro data driven research on the effects of internationalization and productivity. © 2011 The Author(s)
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