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1.
Psychosom Med ; 82(6): 548-560, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32412944

RESUMEN

OBJECTIVE: Decades of research suggest that there may be important ethnic differences in the hemodynamic mechanisms that co-determine arterial blood pressure, the primary diagnostic index of hypertension. In general, studies have observed that, compared with European Americans (EAs), African Americans (AAs) exhibit higher total peripheral resistance (TPR), an important summative index of peripheral vascular constriction. In contrast, EAs have been reliably shown to exhibit greater cardiac output (CO), which is directly linked to left ventricle and overall cardiac blood flow. We have previously proposed that elevated basal TPR, in particular, represents one component of the cardiovascular conundrum, characterized, paradoxically, by elevated resting heart rate variability among AAs relative to EAs. The present meta-analysis and systematic review of the literature sought to extend this previous work by establishing the magnitude of the empirically implied ethnic differences in resting TPR and CO. METHODS: A search of the literature yielded 140 abstracts on differences in TPR between AAs and EAs; 40 were included. Sample sizes, means, and standard deviations for baseline TPR with samples that included EAs and AAs were collected, and Hedges g was computed. RESULTS: Findings indicated that AAs had higher baseline TPR than did EAs (Hedges g = 0.307, SE = 0.043, confidence interval= 0.224 to 0.391, p < .001). In addition, EAs had higher resting CO than did AAs (Hedges g = -0.214, SE = 0.056, confidence interval = -0.324 to -0.104, p < .001). CONCLUSIONS: We discuss the present findings in the context of the role of elevated TPR in the deleterious effects of high blood pressure specifically for AAs.


Asunto(s)
Negro o Afroamericano/etnología , Frecuencia Cardíaca , Hipertensión/etnología , Resistencia Vascular , Población Blanca/etnología , Frecuencia Cardíaca/fisiología , Humanos , Resistencia Vascular/fisiología
2.
J Behav Med ; 42(1): 57-66, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30825089

RESUMEN

Meeting the behavioral medicine research and clinical needs of an increasingly diverse United States population is an issue of national concern. We examine the trends in the demographic representation of the behavioral medicine scientific workforce through an analysis of the training grants funded by National Institutes of Health for the field of behavioral medicine from 1980 to 2018. We report the topics of these training grants, and we depict the demographic representation of the training leaders. We provide the demographic representation of the trainees, and of the first authors of publications reported within those training grants. Finally, we report the topics addressed in these behavioral medicine publications, to determine if topic diversity increased as the behavioral medicine scientific workforce diversified. Visualizations are presented that tell a story of how we have, and have not, advanced representation within the field of behavioral medicine. Best practices for launching future successful behavioral medicine scientists are then presented, to ensure optimal representation and diversification occurs in our workforce, our science, and our delivery of our clinical care.


Asunto(s)
Medicina de la Conducta/tendencias , Investigación Conductal , Demografía/tendencias , Femenino , Humanos , Masculino , Estados Unidos , Recursos Humanos
3.
Psychosom Med ; 80(2): 208-215, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29206724

RESUMEN

OBJECTIVE: Racial discrimination is increasingly recognized as a contributor to increased cardiovascular disease (CVD) risk among African Americans. Previous research has shown significant overlap between racial discrimination and hostility, an established predictor of CVD risk including alterations in adrenergic receptor functioning. The present study examined the associations of racial discrimination and hostility with adrenergic receptor responsiveness. METHODS: In a sample (N = 57) of young to middle-aged African American adults (51% female) with normal and mildly elevated blood pressure, a standardized isoproterenol sensitivity test (CD25) was used to evaluate ß-AR responsiveness, whereas the dose of phenylephrine required to increase mean arterial pressure by 25 mm Hg (PD25) was used to assess α1-AR responsiveness. Racial discrimination was measured using the Perceived Racism Scale and hostility was assessed using the Cook-Medley Hostility Scale. RESULTS: In hierarchical regression models, greater racial discrimination, but not hostility, emerged as a significant predictor of decreased ß-adrenergic receptor responsiveness (ß = .38, p = .004). However, moderation analysis revealed that the association between racial discrimination and blunted ß-adrenergic receptor responsiveness was strongest among those with higher hostility (ß = .49, 95% confidence interval = .17-.82, p = .004). In addition, hostility, but not racial discrimination, significantly predicted α1-AR responsiveness. CONCLUSIONS: These findings suggest racial discrimination was associated with blunted ß-adrenergic receptor responsiveness, providing further evidence of the potential contribution of racial discrimination to increased CVD risk among African Americans. The adverse effects of discrimination on cardiovascular health may be enhanced in individuals with higher levels of hostility.


Asunto(s)
Agonistas de Receptores Adrenérgicos alfa 1/farmacología , Agonistas Adrenérgicos beta/farmacología , Negro o Afroamericano/etnología , Hostilidad , Racismo/etnología , Receptores Adrenérgicos alfa 1/efectos de los fármacos , Receptores Adrenérgicos beta/efectos de los fármacos , Adulto , Enfermedades Cardiovasculares/etnología , Femenino , Humanos , Isoproterenol/farmacología , Masculino , Persona de Mediana Edad , Fenilefrina/farmacología , Adulto Joven
4.
Ethn Dis ; 25(3): 245-54, 2015 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-26675362

RESUMEN

OBJECTIVE: Development of a new framework for the National Institute on Aging (NIA) to assess progress and opportunities toward stimulating and supporting rigorous research to address health disparities. DESIGN: Portfolio review of NIA's health disparities research portfolio to evaluate NIA's progress in addressing priority health disparities areas. RESULTS: The NIA Health Disparities Research Framework highlights important factors for health disparities research related to aging, provides an organizing structure for tracking progress, stimulates opportunities to better delineate causal pathways and broadens the scope for malleable targets for intervention, aiding in our efforts to address health disparities in the aging population. CONCLUSIONS: The promise of health disparities research depends largely on scientific rigor that builds on past findings and aggressively pursues new approaches. The NIA Health Disparities Framework provides a landscape for stimulating interdisciplinary approaches, evaluating research productivity and identifying opportunities for innovative health disparities research related to aging.


Asunto(s)
Envejecimiento , Investigación sobre Servicios de Salud/métodos , Servicios de Salud para Ancianos , Disparidades en Atención de Salud , National Institute on Aging (U.S.)/estadística & datos numéricos , Anciano , Humanos , Estados Unidos
5.
Trop Anim Health Prod ; 46(4): 691-6, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24510222

RESUMEN

At four times during November 2010, cattle with infections of Fasciola spp., in two communes of northern Vietnam, were allocated to two equivalent groups. Cattle in one group were treated with triclabendazole. Faecal samples collected monthly from both groups were tested for Fasciola copro-antigens and the presence of Fasciola eggs. Re-infection of treated cattle occurred from early March to late November, coinciding with high weekly totals of rainfall. Contamination of grazing areas by untreated cattle was high and relatively constant throughout the year. However, contamination was reduced to undetectable amounts for 8 to 12 weeks after treatment and even at 20 weeks was only 50% or less of the pre-treatment amounts. Therefore, treatments given in mid-September and again in early April, at the start of the wet season, may be sufficient to prevent contamination of grazing areas and reduce the prevalence and severity of Fasciola infections in cattle.


Asunto(s)
Enfermedades de los Bovinos/prevención & control , Fasciola/fisiología , Fascioliasis/veterinaria , Animales , Antihelmínticos/administración & dosificación , Bencimidazoles/administración & dosificación , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/parasitología , Enfermedades de los Bovinos/transmisión , Fascioliasis/epidemiología , Fascioliasis/prevención & control , Fascioliasis/transmisión , Heces/parasitología , Femenino , Óvulo , Recuento de Huevos de Parásitos/veterinaria , Prevalencia , Lluvia , Factores de Riesgo , Estaciones del Año , Temperatura , Triclabendazol , Vietnam/epidemiología
6.
PLoS One ; 19(6): e0306185, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38935743

RESUMEN

Among the consequences of systemic racism in health care are significant health disparities among Black/African American individuals with comorbid physical and mental health conditions. Despite decades of studies acknowledging health disparities based on race, significant change has not occurred. There are shockingly few evidence-based antiracism interventions. New paradigms are needed to intervene on, and not just document, racism in health care systems. We are developing a transformative paradigm for new antiracism interventions for primary care settings that integrate mental and physical health care. The paradigm is the first of its kind to integrate community-based participatory research and systems science, within an established model of early phase translation to rigorously define new antiracism interventions. This protocol will use a novel application of systems sciences by combining the qualitative systems sciences methods (group model building; GMB) with quantitative methods (simulation modeling) to develop a comprehensive and community-engaged view of both the drivers of racism and the potential impact of antiracism interventions. Community participants from two integrated primary health care systems will engage in group GMB workshops with researchers to 1) Describe and map the complex dynamic systems driving racism in health care practices, 2) Identify leverage points for disruptive antiracism interventions, policies and practices, and 3) Review and prioritize a list of possible intervention strategies. Advisory committees will provide feedback on the design of GMB procedures, screen potential intervention components for impact, feasibility, and acceptability, and identify gaps for further exploration. Simulation models will be generated based on contextual factors and provider/patient characteristics. Using Item Response Theory, we will initiate the process of developing core measures for assessing the effectiveness of interventions at the organizational-systems and provider levels to be tested under a variety of conditions. While we focus on Black/African Americans, we hope that the resulting transformative paradigm can be applied to improve health equity among other marginalized groups.


Asunto(s)
Equidad en Salud , Atención Primaria de Salud , Humanos , Racismo , Negro o Afroamericano , Investigación Participativa Basada en la Comunidad , Disparidades en Atención de Salud , Antiracismo
7.
Mol Cell Proteomics ; 8(5): 883-6, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19131327

RESUMEN

The lack of sensitive, specific, multiplexable assays for most human proteins is the major technical barrier impeding development of candidate biomarkers into clinically useful tests. Recent progress in mass spectrometry-based assays for proteotypic peptides, particularly those with specific affinity peptide enrichment, offers a systematic and economical path to comprehensive quantitative coverage of the human proteome. A complete suite of assays, e.g. two peptides from the protein product of each of the approximately 20,500 human genes (here termed the human Proteome Detection and Quantitation project), would enable rapid and systematic verification of candidate biomarkers and lay a quantitative foundation for subsequent efforts to define the larger universe of splice variants, post-translational modifications, protein-protein interactions, and tissue localization.


Asunto(s)
Proteoma/análisis , Biomarcadores/análisis , Humanos , Espectrometría de Masas , Proyectos Piloto , Proteoma/química , Proteómica
8.
Toxics ; 9(7)2021 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-34202026

RESUMEN

Clairton, Pennsylvania, is home to the largest coke works facility in the United States (US). On 24 December 2018, a large fire occurred at this facility and damaged pollution control equipment. Although repairs were not completed for several months, production continued at pre-fire capacity and daily emissions increased by 24 to 35 times, with multiple exceedances of monitored levels of outdoor air pollution (OAP). The aim of this study was to objectively evaluate the impact of this industrial incident and resultant OAP exceedances on asthma morbidity. We assessed pre-fire and post-fire rate ratios (RR) of outpatient and emergency department (ED) visits for asthma exacerbations among nearby adult residents. Pre-fire versus post-fire RRs increased for both visit types: RR = 1.82 (95% CI: 1.30, 2.53; p < 0.001) and 1.84 (95% CI: 1.05, 3.22; p = 0.032) for outpatient and ED visits, respectively. Additionally, total visit rates increased on days with OAP exceedances: RR = 2.47 (95% CI: 1.52, 4.01; p < 0.0001), 1.58 (95% CI: 1.00, 2.48; p = 0.048) and 1.79 (95% CI: 1.27, 2.54; p = 0.001) for PM2.5, SO2, and H2S exceedance days, respectively. These results show a near doubling of acute visits for asthma exacerbations in nearby adult residents during this industrial incident and underscore the need for prompt remediation and public notification of OAP exceedances to prevent adverse health impacts.

9.
J Med Entomol ; 58(1): 125-138, 2021 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-32901284

RESUMEN

Geographical range expansions of blacklegged tick [Ixodes scapularis Say (Acari: Ixodidae)] populations over time in the United States have been attributed to a mosaic of factors including 20th century reforestation followed by suburbanization, burgeoning populations of the white-tailed deer [Odocoileus virginianus Zimmerman (Artiodactyla: Cervidae)], and, at the northern edge of I. scapularis' range, climate change. Maine, a high Lyme disease incidence state, has been experiencing warmer and shorter winter seasons, and relatively more so in its northern tier. Maine served as a case study to investigate the interacting impacts of deer and seasonal climatology on the spatial and temporal distribution of I. scapularis. A passive tick surveillance dataset indexed abundance of I. scapularis nymphs for the state, 1990-2013. With Maine's wildlife management districts as the spatial unit, we used a generalized additive model to assess linear and nonlinear relationships between I. scapularis nymph abundance and predictors. Nymph submission rate increased with increasing deer densities up to ~5 deer/km2 (13 deer/mi2), but beyond this threshold did not vary with deer density. This corroborated the idea of a saturating relationship between I. scapularis and deer density. Nymphs also were associated with warmer minimum winter temperatures, earlier degree-day accumulation, and higher relative humidity. However, nymph abundance only increased with warmer winters and degree-day accumulation where deer density exceeded ~2 deer/km2 (~6/mi2). Anticipated increases in I. scapularis in the northern tier could be partially mitigated through deer herd management.


Asunto(s)
Ciervos/parasitología , Modelos Teóricos , Infestaciones por Garrapatas/veterinaria , Animales , Animales Salvajes/parasitología , Cambio Climático , Vectores de Enfermedades , Seguimiento de Parámetros Ecológicos , Humedad , Incidencia , Ixodes/fisiología , Enfermedad de Lyme/epidemiología , Maine/epidemiología , Ninfa/fisiología , Densidad de Población , Estaciones del Año , Temperatura , Infestaciones por Garrapatas/epidemiología
10.
Ethn Dis ; 20(3): 251-6, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20828098

RESUMEN

OBJECTIVE: To examine the interactive influence of urbanicity on cardiovascular reactivity to speech stressors among 103 urban and 93 rural Cameroonians. METHOD: Heart rate, systolic, and diastolic blood pressure (HR, SBP, and DBP) changes from baseline were assessed during a speech preparation period, speech stressor task, and post-speech recovery period. RESULTS: After adjusting for income, age, BMI, and sex, urban subjects showed greater diastolic reactivity to the pre-speech and speech conditions than to recovery. Urban subjects also showed greater reactivity to the speech stressor than to other conditions. Urban subjects showed greater HR reactivity to the speech stressor. Rural subjects showed greater diastolic reactivity to the pre-speech and speech stressor and less recovery. CONCLUSION: Urbanicity affects blood pressure and heart rate differently for urban and rural Cameroonians. It also affects recovery from stressors. More exploration into the influence of urbanization on hypertension risk factors in developing countries is warranted.


Asunto(s)
Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Estrés Psicológico/fisiopatología , Adolescente , Adulto , Análisis de Varianza , Camerún , Distribución de Chi-Cuadrado , Femenino , Humanos , Masculino , Persona de Mediana Edad , Población Rural , Habla , Encuestas y Cuestionarios , Población Urbana
11.
J Med Entomol ; 57(3): 755-765, 2020 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-31808817

RESUMEN

Lyme disease is caused by the bacterial spirochete Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt, and Brenner (Spirocheatales: Spirochaetaceae) which is transmitted through the bite of an infected blacklegged tick Ixodes scapularis Say (Ixodida: Ixodidae). Maine, USA, is a high Lyme disease incidence state, with rising incidence of Lyme disease and other tick-borne illnesses associated with increasing I. scapularis abundance and northward range expansion. Members of the public submitted ticks to a tick identification program (1990-2013). From these passive surveillance data, we characterized temporal trends in I. scapularis submission rate (an index of abundance), comparing Maine's northern tier (seven counties) versus southern tier (nine counties). In the northern tier, the I. scapularis submission rate increased throughout the duration of the time series, suggesting I. scapularis was emergent but not established. By contrast, in the southern tier, submission rate increased initially but leveled off after 10-14 yr, suggesting I. scapularis was established by the mid-2000s. Active (field) surveillance data from a site in the southern tier-bird tick burdens and questing adult tick collections-corroborated this leveling pattern. Lyme disease incidence and I. scapularis submission rate were temporally correlated in the northern but not southern tier. This suggested a decoupling of reported disease incidence and entomological risk.


Asunto(s)
Ixodes , Enfermedad de Lyme/epidemiología , Animales , Gatos , Perros , Femenino , Humanos , Incidencia , Maine/epidemiología , Masculino , Ninfa , Dinámica Poblacional
12.
Cureus ; 11(3): e4161, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31065467

RESUMEN

The aim of this study was to discern an abscopal effect by modifying the delivery of radiation for metastatic malignant melanoma. The effect would be directly evident with visible/radiographic regression of the disease and indirectly shown with an overall extension in survival and potential cure. Patients with locally advanced, metastatic palpable, or radiographic visible metastatic malignant melanoma were treated with twice-daily radiation therapy using a dose range of 100-135 centigray (cGy) per fraction. A 100% complete response/continued regression with no recurrence was achieved within the region of delivery for every patient so treated. Of those alive at three years, few demonstrate a progression of the disease. These results were achieved without the use of immunotherapy, created few side effects, and were accomplished at a fraction of the alternative's cost. Evidence of an immune-mediated response (abscopal effect) was commonly seen. Treatment was administered within acceptable dose ranges, historically used twice daily for other malignancies known to be sensitive to the effects of radiation.

13.
BMC Genomics ; 9: 5, 2008 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-18179705

RESUMEN

BACKGROUND: Most emerging health threats are of zoonotic origin. For the overwhelming majority, their causative agents are RNA viruses which include but are not limited to HIV, Influenza, SARS, Ebola, Dengue, and Hantavirus. Of increasing importance therefore is a better understanding of global viral diversity to enable better surveillance and prediction of pandemic threats; this will require rapid and flexible methods for complete viral genome sequencing. RESULTS: We have adapted the SISPA methodology 123 to genome sequencing of RNA and DNA viruses. We have demonstrated the utility of the method on various types and sources of viruses, obtaining near complete genome sequence of viruses ranging in size from 3,000-15,000 kb with a median depth of coverage of 14.33. We used this technique to generate full viral genome sequence in the presence of host contaminants, using viral preparations from cell culture supernatant, allantoic fluid and fecal matter. CONCLUSION: The method described is of great utility in generating whole genome assemblies for viruses with little or no available sequence information, viruses from greatly divergent families, previously uncharacterized viruses, or to more fully describe mixed viral infections.


Asunto(s)
Genoma Viral , Genómica/métodos , Secuencia de Bases , Cartilla de ADN/química , Virus ADN/química , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/métodos , Virus ARN/química , Análisis de Secuencia de ADN/métodos
14.
Ecol Appl ; 18(8 Suppl): A196-212, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19475925

RESUMEN

Mercury (Hg) trophic transfer and bioaccumulation in fish from a mine-impacted, eutrophic lake were examined in relation to foraging habitat, trophic position, and size. Diet analysis indicated that there were clear ontogenetic shifts in foraging habitats and trophic position. Pelagic diet decreased and benthic diet increased with increasing fish length in bluegill, black crappie, inland silverside, and largemouth bass, whereas there was no shift for prickly sculpin or threadfin shad. Stable carbon isotope values (delta13C) were inversely related to the proportion of pelagic prey items in the diet, but there was no clear relationship with benthic foraging. There were distinct differences between pelagic and benthic prey basal delta13C values, with a range of approximately -28 per thousand in pelagic zooplankton to approximately -20 per thousand in benthic caddisflies. Profundal prey such as chironomid larvae had intermediate delta13C values of approximately -24 per thousand, reflecting the influence of pelagic detrital subsidies and suppressing the propagation of the benthic carbon isotope signal up the food chain. Fish total mercury (TotHg) concentrations varied with habitat-specific foraging, trophic position, and size; however, the relationships differed among species and ages. When controlling for the effects of species, length, and trophic position, TotHg and delta13C were positively correlated, indicating that Hg trophic transfer is linked to benthic foraging. When examined on a species-specific basis, TotHg was positively correlated with delta13C only for bluegill, largemouth bass, and threadfin shad. However, diet-based multiple regression analyses suggested that TotHg also increased with benthic foraging for inland silverside and black crappie. In both species, benthic prey items were dominated by chironomid larvae, explaining the discrepancy with delta13C. These results illustrate the importance of foraging habitat to Hg bioaccumulation and indicate that pelagic carbon can strongly subsidize the basal energy sources of benthic organisms.


Asunto(s)
Conducta Alimentaria/fisiología , Peces/fisiología , Cadena Alimentaria , Agua Dulce/química , Mercurio/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , California , Eutrofización , Mercurio/química , Minería , Contaminantes Químicos del Agua/química
15.
Ecol Appl ; 18(8 Suppl): A213-26, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19475926

RESUMEN

The invasion, boom, collapse, and reestablishment of a population of the planktivorous threadfin shad in Clear Lake, California, USA, were documented over a 20-year period, as were the effects of changing shad populations on diet and mercury (Hg) bioaccumulation in nearshore fishes. Threadfin shad competitively displaced other planktivorous fish in the lake, such as inland silversides, young-of-year (YOY) largemouth bass, and YOY bluegill, by reducing zooplankton abundance. As a result, all three species shifted from a diet that was dominated by zooplankton to one that was almost entirely zoobenthos. Stable carbon isotopes corroborated this pattern with each species becoming enriched in delta13C, which is elevated in benthic vs. pelagic organisms. Concomitant with these changes, Hg concentrations increased by approximately 50% in all three species. In contrast, obligate benthivores such as prickly sculpin showed no relationship between diet or delta13C and the presence of threadfin shad, suggesting that effects of the shad were not strongly linked to the benthic fish community. There were also no changes in Hg concentrations of prickly sculpin. The temporary extirpation of threadfin shad from the lake resulted in zooplankton densities, foraging patterns, isotope ratios, and Hg concentrations in pelagic fishes returning to pre-shad values. These results indicate that even transient perturbations of the structure of freshwater food webs can result in significant alterations in the bioaccumulation of Hg and that food webs in lakes can be highly resilient.


Asunto(s)
Peces/fisiología , Cadena Alimentaria , Mercurio/metabolismo , Plancton/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , California , Dieta , Conducta Alimentaria/fisiología , Agua Dulce/química , Mercurio/química , Minería , Dinámica Poblacional , Factores de Tiempo , Contaminantes Químicos del Agua/química
16.
Ecol Appl ; 18(8 Suppl): A158-76, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19475923

RESUMEN

Considerable ecological research on mercury (Hg) has focused on higher trophic level species (e.g., fishes and birds), but less on lower trophic species. Clear Lake, site of the abandoned Sulphur Bank Mercury Mine, provides a unique opportunity to study a system influenced by mine-derived Hg. An exponentially decreasing gradient of total Hg (TotHg) away from the mine allowed us to evaluate Hg bioaccumulation in planktonic and benthic invertebrates and evaluate population- and community-level parameters that might be influenced by Hg. Studies from 1992-1998 demonstrated that TotHg in lower trophic species typically decreased exponentially away from the mine, similar to trends observed in water and sediments. However, a significant amount of invertebrate TotHg (approximately 60% for sediment-dwelling chironomid insect larvae) likely derives from Hg-laden particles in their guts. Spatially, whole-body methylmercury (MeHg) did not typically exhibit a significant decrease with increasing distance from the mine. Temporally, TotHg concentrations in plankton and chironomids did not exhibit any short-term (seasonal or annual) or long-term (multiyear) trends. Methylmercury, however, was elevated during late summer/fall in both plankton and chironomids, but it exhibited no long-term increase or decrease during this study. Although data from a 50-yr monitoring program for benthic chaoborid and chironomid larvae documented significant population fluctuations, they did not demonstrate population-level trends with respect to Hg concentrations. Littoral invertebrates also exhibited no detectable population- or community-level trends associated with the steep Hg gradient. Although sediment TotHg concentrations (1-1200 mg/kg dry mass) exceed sediment quality guidelines by up to 7000 times, it is notable that no population- or community-level effects were detected for benthic and planktonic taxa. In comparison with other sites worldwide, Clear Lake's lower trophic species typically have significantly higher TotHg concentrations, but comparable or lower MeHg concentrations, which may be responsible for the discrepancy between highly elevated TotHg concentrations and the general lack of observed population- or community-level effects. These data suggest that MeHg, as well as TotHg, should be used when establishing sediment quality guidelines. In addition, site-specific criteria should be established using the observed relationship between MeHg and observed ecological responses.


Asunto(s)
Cadena Alimentaria , Agua Dulce/química , Invertebrados/efectos de los fármacos , Mercurio/toxicidad , Plancton/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , California , Demografía , Mercurio/química , Minería , Tiempo , Movimientos del Agua , Contaminantes Químicos del Agua/química
17.
Ecol Appl ; 18(8 Suppl): A177-95, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19475924

RESUMEN

Clear Lake, California, USA, receives acid mine drainage and mercury (Hg) from the Sulphur Bank Mercury Mine, a U.S. Environmental Protection Agency (U.S. EPA) Superfund Site that was active intermittently from 1873 to 1957 and partially remediated in 1992. Mercury concentrations were analyzed primarily in four species of Clear Lake fishes: inland silversides (Menidia beryllina, planktivore), common carp (Cyprinus carpio, benthic scavenger/omnivore), channel catfish (Ictalurus punctatus, benthic omnivorous predator), and largemouth bass (Micropterus salmoides, piscivorous top predator). These data represent one of the largest fish Hg data sets for a single site, especially in California. Spatially, total Hg (TotHg) in silversides and bass declined with distance from the mine, indicating that the mine site represents a point source for Hg loading to Clear Lake. Temporally, fish Hg has not declined significantly over 12 years since mine site remediation. Mercury concentrations were variable throughout the study period, with no monotonic trends of increase or decrease, except those correlated with boom and bust cycles of an introduced fish, threadfin shad (Dorosoma petenense). However, stochastic events such as storms also influence juvenile largemouth bass Hg as evidenced during an acid mine drainage overflow event in 1995. Compared to other sites regionally and nationally, most fish in Clear Lake exhibit Hg concentrations similar to other Hg-contaminated sites, up to approximately 2.0 mg/kg wet mass (WM) TotHg in largemouth bass. However, even these elevated concentrations are less than would be anticipated from such high inorganic Hg loading to the lake. Mercury in some Clear Lake largemouth bass exceeded all human health fish consumption guidelines established over the past 25 years by the U.S. Food and Drug Administration (1.0 mg/kg WM), the National Academy of Sciences (0.5 mg/kg WM), and the U.S. EPA (0.3 mg/kg WM). Mercury in higher trophic level fishes exceeds ecotoxicological risk assessment estimates for concentrations that would be safe for wildlife, specifically the nonlisted Common Merganser and the recently delisted Bald Eagle. Fish populations of 11 out of 18 species surveyed exhibited a significant decrease in abundance with increasing proximity to the mine; this decrease is correlated with increasing water and sediment Hg. These trends may be related to Hg or other lake-wide gradients such as distribution of submerged aquatic vegetation.


Asunto(s)
Ecosistema , Peces/metabolismo , Agua Dulce/química , Mercurio/metabolismo , Minería , Contaminantes Químicos del Agua/metabolismo , Animales , California , Mercurio/química , Compuestos de Metilmercurio/química , Compuestos de Metilmercurio/metabolismo , Factores de Tiempo , Contaminantes Químicos del Agua/química
18.
J Psychosom Res ; 63(2): 207-16, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17662759

RESUMEN

OBJECTIVE: Previous research has demonstrated an association between educational attainment (EA) and negative physical and psychological outcomes. This study investigated whether EA is associated with regimen failure during initial therapy with highly active antiretroviral treatment (HAART) and whether adherence self-efficacy (ASE), a coping resource, moderates the relationship between EA and regimen failure. METHODS: A secondary analysis of AIDS Clinical Trial Group Protocol 384, an international, multicenter, randomized, partially double-blinded trial, included 799 male and 181 female antiretroviral-naïve subjects (age, 37.0+/-9.5 years). Participants were recruited from 1998 to 1999 and followed for a median of 2.3 years across 81 centers. The dependent variable was "time to first regimen failure." Covariates include baseline HIV-1 log(10)RNA and CD4(+) counts, self-reported adherence, study site, ASE, age, sex, race, treatment assignment, and baseline use of nonantiretroviral medications. RESULTS: ASE significantly moderated the relationship between EA and regimen failure. Results showed that for every 10-unit increase in ASE, individuals with "less than high school" education had a 17% reduction in regimen failure (hazard ratio=0.83; 95% confidence interval=0.70-0.98) when compared to the reference group "college/graduate," even after adjusting for baseline factors known to contribute to regimen failure. The time to first regimen failure was shorter with decreasing EA, trending toward significance (P=.08). CONCLUSIONS: There is a social gradient in HAART effectiveness, and ASE reduces the deleterious effects of lower EA on regimen failure. We recommend designing controlled interventions to evaluate the effectiveness of programs that increase ASE prior to initiation with HAART, particularly for those with lower EA.


Asunto(s)
Logro , Terapia Antirretroviral Altamente Activa/métodos , Infecciones por VIH/tratamiento farmacológico , VIH-1 , Método Doble Ciego , Femenino , Humanos , Masculino , Cooperación del Paciente/estadística & datos numéricos , Autoeficacia , Encuestas y Cuestionarios
19.
IEEE Trans Biomed Eng ; 54(7): 1186-90, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17605349

RESUMEN

The use of peripheral nerve blocks to control pain is an increasing practice. Many techniques include the use of stimulating needles to locate the nerve of interest. Though success rates are generally high, difficulties still exist. In certain deeper nerve blocks, two needles of different geometries are used in the procedure. A smaller needle first locates a nerve bundle, and then is withdrawn in favor of a second, larger needle used for injection. The distinct geometries of these needles are shown to generate different electric field distributions, and these differences may be responsible for failures of the second needle to elicit nerve stimulation when placed in the same location as the first. A 3-D finite-difference method has been employed to numerically calculate the electric field distributions for a commercial set of stimulating needles.


Asunto(s)
Cateterismo/métodos , Estimulación Eléctrica/instrumentación , Estimulación Eléctrica/métodos , Modelos Neurológicos , Agujas , Bloqueo Nervioso/métodos , Nervios Periféricos/fisiología , Anisotropía , Simulación por Computador , Electrodos Implantados , Campos Electromagnéticos , Análisis de Elementos Finitos , Humanos , Inyecciones/métodos
20.
Am Psychol ; 61(1): 1-9, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16435972

RESUMEN

This year marks the 60th anniversary of the American Psychologist (AP). Since the publication of its first issue in January 1946, AP has served as the flagship journal for the American Psychological Association (APA) and has played an important and unique role for the field of psychology. Because of the quality of the articles published in AP, the journal has evolved into one of the most influential and widely cited publications in psychology. The purpose of this editorial is to outline a revised set of policies for the journal that builds on and expands those developed by previous editors (see, e.g., Fowler, 1993; Goodstein, 1987; Kiesler, 1976; Pallack, 1981). Before outlining these policies, I would like to explore the relative status and influence of AP within the universe of psychological and social science journals.


Asunto(s)
Políticas Editoriales , Edición/normas , Humanos
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