42 research outputs found
Parkinson's disease biomarkers: perspective from the NINDS Parkinson's Disease Biomarkers Program
Biomarkers for Parkinson's disease (PD) diagnosis, prognostication and clinical trial cohort selection are an urgent need. While many promising markers have been discovered through the National Institute of Neurological Disorders and Stroke Parkinson's Disease Biomarker Program (PDBP) and other mechanisms, no single PD marker or set of markers are ready for clinical use. Here we discuss the current state of biomarker discovery for platforms relevant to PDBP. We discuss the role of the PDBP in PD biomarker identification and present guidelines to facilitate their development. These guidelines include: harmonizing procedures for biofluid acquisition and clinical assessments, replication of the most promising biomarkers, support and encouragement of publications that report negative findings, longitudinal follow-up of current cohorts including the PDBP, testing of wearable technologies to capture readouts between study visits and development of recently diagnosed (de novo) cohorts to foster identification of the earliest markers of disease onset
Influence of Site on Course of Intracerebral Hemorrhage
The Influence of Site of Hemorrhage on Presentation, Clinical Profile, Hospital Course, and Outcome Was Examined in 225 Patients with Intracerebral Hemorrhage in the NINDS Stroke Data Bank. Mode of Presentation Differed by Hemorrhage Site (Coma at Onset Was Most Typical of Pontine Hemorrhage and Headache with Vomiting Was Most Typical of Cerebellar Hemorrhage, Whereas Onset of Focal Deficit Sometimes with Headache Was Typical of Lobar and And Basal Ganglionic Hemorrhages). Distinct Clinical Profiles Were Found for Cerebellar (Ataxia, Drowsiness, and Horizontal Gaze Paresis), Pontine (Quadriparesis, Coma, Vertical and Horizontal Gaze Paresis), and Caudate Hemorrhages (Drowsiness and Hemiparesis). Putaminal, Thalamic, and Lobar Hemorrhages Presented Similarly with Hemiparesis, Sensory Loss, and Higher Cortical Function Deficits. However, Thalamic Hemorrhages Had More Sensory Loss, Putaminal Hemorrhages Had More Weakness, and Lobar Hemorrhages Had More Higher Cortical Function Deficits. Hemorrhage Volume Was Greatest for the Lobar and Putaminal Hemorrhages and Smallest for the Pontine and Cerebellar Hemorrhages. Clot Evacuations Were Performed for 28.9% of the Lobar Hemorrhages and 48.2% of the Cerebellar Hemorrhages. Few Basal Ganglionic Hemorrhages or Pontine Hemorrhages Had Clot Evacuations. Thirty-Day Survival Was Lowest for Caudate Hemorrhage (46.2%) and Highest for Cerebellar Hemorrhage (81.5%). Hydrocephalus, Intraventricular Blood, Larger Size, and Mass Effect Were Adverse Predictors of Survival at Most But Not All Hemorrhage Sites. History of Hypertension Was the Most Prevalent Risk Factor for Hemorrhage (64.0% of the Patients). Other Risk Factors for Hemorrhage Included Anticoagulants, Platelet Antiaggregating Drugs, Aneurysms, Arteriovenous Malformations, Pregnancy, Alcohol Use, Amyloid Angiopathy, Thrombocytopenia, Renal and Liver Failure, and Cocaine Use. the Most Common Medical Complications Were Pneumonia (15.5%), Urinary Tract Infection (15.0%), Arrhythmias (8.4%), and Seizures (8.0%). © 1993, National Stroke Association. All Rights Reserved
Reef sharks exhibit site-fidelity and higher relative abundance in marine reserves on the Mesoamerican Barrier Reef.
Carcharhinid sharks can make up a large fraction of the top predators inhabiting tropical marine ecosystems and have declined in many regions due to intense fishing pressure. There is some support for the hypothesis that carcharhinid species that complete their life-cycle within coral reef ecosystems, hereafter referred to as "reef sharks", are more abundant inside no-take marine reserves due to a reduction in fishing pressure (i.e., they benefit from marine reserves). Key predictions of this hypothesis are that (a) individual reef sharks exhibit high site-fidelity to these protected areas and (b) their relative abundance will generally be higher in these areas compared to fished reefs. To test this hypothesis for the first time in Caribbean coral reef ecosystems we combined acoustic monitoring and baited remote underwater video (BRUV) surveys to measure reef shark site-fidelity and relative abundance, respectively. We focused on the Caribbean reef shark (Carcharhinus perezi), the most common reef shark in the Western Atlantic, at Glover's Reef Marine Reserve (GRMR), Belize. Acoustically tagged sharks (N = 34) were detected throughout the year at this location and exhibited strong site-fidelity. Shark presence or absence on 200 BRUVs deployed at GRMR and three other sites (another reserve site and two fished reefs) showed that the factor "marine reserve" had a significant positive effect on reef shark presence. We rejected environmental factors or site-environment interactions as predominant drivers of this pattern. These results are consistent with the hypothesis that marine reserves can benefit reef shark populations and we suggest new hypotheses to determine the underlying mechanism(s) involved: reduced fishing mortality or enhanced prey availability
Abundance and size structure of a reef shark population within a marine reserve has remained stable for more than a decade
Marine reserves, areas protected from exploitative anthropogenic processes, are being widely implemented to conserve biodiversity and initiate species recovery. Evidence supports the effectiveness of marine reserves in improving biological attributes such as biodiversity, density, biomass, and body-size for sedentary species or those with r-selected life histories. However, there is limited long-term time series- based information determining the effectiveness of these protected areas for elasmobranchs. Marine reserve effectiveness is commonly evaluated spatially by examining differences in species’ biological parameters inside and outside of protective boundaries, which can often mask the occurrence of slow population declines. We used a temporal fishery-independent standardized longline survey at Glover’s Reef Marine Reserve, Belize, to monitor long-term population trends in the commercially important Caribbean reef sharkfor more than a decade. Linear models were performed to examine whether the factors habitat, year, or their interaction had a significant impact oncatch per unit effort (CPUE) and on catch demographic composition. Only the factor ‘habitat’ had a significant influence on CPUE, with the forereef catch significantly higher than in the lagoon. Our results support that the population of Caribbean reef shark at Glover’s Reef Marine Reserve appears stable with no significant decline in CPUE or decrease in mean total length detected. This is evidence that marine reserves can be an effective conservation tool for reef-associated shark species
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Species composition of the international shark fin trade assessed through a retail‐market survey in Hong Kong
The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species‐specific basis. Species‐specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the Hong Kong Special Administrative Region of China, one of the world's largest fin trading hubs, was partially assessed in 1999–2001. We randomly selected and genetically identified fin trimmings (n = 4800), produced during fin processing, from the retail market of Hong Kong in 2014–2015 to assess contemporary species composition of the fin trade. We used nonparametric species estimators to determine that at least 76 species of sharks, batoids, and chimaeras supplied the fin trade and a Bayesian model to determine their relative proportion in the market. The diversity of traded species suggests species substitution could mask depletion of vulnerable species; one‐third of identified species are threatened with extinction. The Bayesian model suggested that 8 species each comprised >1% of the fin trimmings (34.1–64.2% for blue [Prionace glauca], 0.2–1.2% for bull [Carcharhinus leucas] and shortfin mako [Isurus oxyrinchus]); thus, trade was skewed to a few globally distributed species. Several other coastal sharks, batoids, and chimaeras are in the trade but poorly managed. Fewer than 10 of the species we modeled have sustainably managed fisheries anywhere in their range, and the most common species in trade, the blue shark, was not among them. Our study and approach serve as a baseline to track changes in composition of species in the fin trade over time to better understand patterns of exploitation and assess the effects of emerging management actions for these animals.Composición de Especies del Mercado Internacional de Aleta de Tiburón Evaluada por medio de un Censo de Mercado al Menudeo en Hong KongResumenEl mercado de aleta de tiburón es un importante conductor de la explotación de tiburones a nivel mundial, la mayoría de los cuales no están manejados a un nivel específico de especie. La información específica de especies en el mercado resalta taxones de preocupación particular y puede usarse para avaluar la eficiencia de las medidas de manejo y anticipar las amenazas emergentes. La composición de especies en la Región Administrativa Especial de Hong Kong de la República Popular China, uno de los puntos más grandes de venta de aletas, fue evaluada parcialmente entre 1999 y 2001. Seleccionamos al azar e identificamos genéticamente pedazos de aletas (n = 4800) producidos durante el procesamiento de las aletas, en el mercado al menudeo de Hong Kong entre 2014 y 2015 para evaluar la composición contemporánea de especies dentro del mercado de aletas. Utilizamos estimadores no‐paramétricos de especies para determinar que al menos 76 especies de tiburones, batoideos y quimeras suministraban al mercado de aletas y un modelo bayesiano para determinar su proporción relativa dentro del mercado. La diversidad de las especies en el mercado sugiere que la sustitución de especies podría enmascarar la disminución de las especies vulnerables; un tercio de las especies identificadas enfrentan riesgos severos de extinción. El modelo bayesiano sugirió que cada una de ocho especies constituyó >1% de los pedazos de aletas (34.1‐64.2% para el tiburón azul [Prionace glauca]; 0.2‐1.2% para el tiburón toro [Carcharhinus leucas] y el tiburón mako [Isurus oxyrinchus]); así, el mercado estuvo sesgado a unas cuantas especies con distribución mundial. Muchos otros tiburones costeros, batoideos y quimeras están en el mercado pero con un manejo muy pobre. Menos de diez de las especies que modelamos tienen pesquerías manejadas sustentablemente en cualquier parte de su extensión, incluyendo a la especie más común en el mercado, el tiburón azul. Nuestro estudio y nuestra estrategia sirven como una línea de base para rastrear los cambios en la composición de las especies dentro del mercado de aletas a través del tiempo para entender mejor los patrones de explotación y evaluar los efectos de las acciones de manejo emergentes para estos animales.Article impact statement: One‐third of species traded in the Hong Kong shark fin market are threatened with extinction and <10 modeled have sustainably managed fisheries
Observed and predicted presence or absence of Caribbean reef sharks based on a model including only log-distance and days sampled.
<p>Observed and predicted presence or absence of Caribbean reef sharks based on a model including only log-distance and days sampled.</p
Number of BRUV deployments out of 50 per site in which one (solid portion of bars) or more (open portion of bars) Caribbean reef sharks were recorded at GRMR (reserve), CCAR (reserve), TU (fished) and SWC (fished).
<p>Number of BRUV deployments out of 50 per site in which one (solid portion of bars) or more (open portion of bars) Caribbean reef sharks were recorded at GRMR (reserve), CCAR (reserve), TU (fished) and SWC (fished).</p
Observed and predicted presence or absence of Caribbean reef sharks based on the AIC best model (days+ldist+habitat+ldist×shark).
<p>Observed and predicted presence or absence of Caribbean reef sharks based on the AIC best model (days+ldist+habitat+ldist×shark).</p