70 research outputs found
Impact of meteorological conditions on water resources in the Upper East Region of Ghana using remotely-sensed and modelled hydrological data
Study region:Â
The Upper East Region, Ghana, West Africa, lies within the Volta Basin, floods annually, and contributes substantially to Ghana's food production.Â
Study focus:Â
We assessed precipitation (P), evapotranspiration (ET), and total water storage anomalies from GRACE (TWSA) and GLDAS-Noah (TWCA) to study the influence of the UER's climate on water availability between 2002 and 2017. We analysed (1) the relative uncertainties of the data sets using the triple-cornered hat method, (2) the terrestrial water budget to validate TWSA/TWCA and (3) cross- and multi-correlation analyses to study the relationship between water storage (or availability) and meteorological variables.Â
New hydrological insights:Â
We found strong correlations between the different P products (r > 0.96), between the different GRACE products (r > 0.95), but not between the different ET products. The hybrid P, TWSA from the Jet Propulsion Laboratory, and ET from ERA-5 had the smallest relative uncertainties. TWSA increased by 9.8 ± 0.8 mm yr−1 while TWCA decreased. P and ET showed no evidence of a trend and were similarly influenced by the other meteorological variables. However, 93 of 183 months had water surplus and mean net P was positive – indicating the UER received more water than it lost. These agree with the increasing TWSA trend. The water budget validation also confirmed that GRACE can be used for water management; GLDAS-Noah underestimates storage in the UER.</p
Benefit of abciximab in patients with refractory unstable angina in relation to serum troponin T levels.
BACKGROUND: In patients with refractory unstable angina, the platelet
glycoprotein IIb/IIIa-receptor antibody abciximab reduces the incidence of
cardiac events before and during coronary angioplasty. We investigated
whether serum troponin T levels identify patients most likely to benefit
from therapy with this drug. METHODS: Among 1265 patients with unstable
angina who were enrolled in the c7E3 Fab Antiplatelet Therapy in Unstable
Refractory Angina (CAPTURE) trial, serum samples drawn at the time of
randomization to abciximab or placebo were available from 890 patients; we
used these samples for the determination of troponin T and creatine kinase
MB levels. Patients with postinfarction angina were not included. RESULTS:
Serum troponin T levels at the time of study entry were elevated (above
0.1 ng per milliliter) in 275 patients (30.9 percent). Among patients
receiving placebo, the risk of death or nonfatal myocardial infarction was
related to troponin T levels. The six-month cumulative event rate was 23.9
percent among patients with elevated troponin T levels, as compared with
7.5 percent among patients without elevated troponin T levels (P<0.001).
Among patients treated with abciximab, the respective six-month event
rates were 9.5 percent for patients with elevated troponin T levels and
9.4 percent for those without elevated levels. As compared with placebo,
the relative risk of death or nonfatal myocardial infarction associated
with treatment with abciximab in patients with elevated troponin T levels
was 0.32 (95 percent confidence interval, 0.14 to 0.62; P=0.002). The
lower event rates in patients receiving abciximab were attributable to a
reduction in the rate of myocardial infarction (odds ratio, 0.23; 95
percent confidence interval, 0.12 to 0.49; P<0.001). In patients without
elevated troponin T levels, there was no benefit of treatment with respect
to the relative risk of death or myocardial infarction at six months (odds
ratio, 1.26; 95 percent confidence interval, 0.74 to 2.31; P=0.47).
CONCLUSIONS: The serum troponin T level, which is considered to be a
surrogate marker for thrombus formation, identifies a high-risk subgroup
of patients with refractory unstable angina suitable for coronary
angioplasty who will particul
Genome-wide association study of panic disorder reveals genetic overlap with neuroticism and depression
Panic disorder (PD) has a lifetime prevalence of 2–4% and heritability estimates of 40%. The contributory genetic variants remain largely unknown, with few and inconsistent loci having been reported. The present report describes the largest genome-wide association study (GWAS) of PD to date comprising genome-wide genotype data of 2248 clinically well-characterized PD patients and 7992 ethnically matched controls. The samples originated from four European countries (Denmark, Estonia, Germany, and Sweden). Standard GWAS quality control procedures were conducted on each individual dataset, and imputation was performed using the 1000 Genomes Project reference panel. A meta-analysis was then performed using the Ricopili pipeline. No genome-wide significant locus was identified. Leave-one-out analyses generated highly significant polygenic risk scores (PRS) (explained variance of up to 2.6%). Linkage disequilibrium (LD) score regression analysis of the GWAS data showed that the estimated heritability for PD was 28.0–34.2%. After correction for multiple testing, a significant genetic correlation was found between PD and major depressive disorder, depressive symptoms, and neuroticism. A total of 255 single-nucleotide polymorphisms (SNPs) with p < 1 × 10−4 were followed up in an independent sample of 2408 PD patients and 228,470 controls from Denmark, Iceland and the Netherlands. In the combined analysis, SNP rs144783209 showed the strongest association with PD (pcomb = 3.10 × 10−7). Sign tests revealed a significant enrichment of SNPs with a discovery p-value of <0.0001 in the combined follow up cohort (p = 0.048). The present integrative analysis represents a major step towards the elucidation of the genetic susceptibility to PD
Brain-based classification of youth with anxiety disorders: transdiagnostic examinations within the ENIGMA-Anxiety database using machine learning
Neuroanatomical findings on youth anxiety disorders are notoriously difficult to replicate, small in effect size and have limited clinical relevance. These concerns have prompted a paradigm shift toward highly powered (that is, big data) individual-level inferences, which are data driven, transdiagnostic and neurobiologically informed. Here we built and validated supervised neuroanatomical machine learning models for individual-level inferences, using a case–control design and the largest known neuroimaging database on youth anxiety disorders: the ENIGMA-Anxiety Consortium (N = 3,343; age = 10–25 years; global sites = 32). Modest, yet robust, brain-based classifications were achieved for specific anxiety disorders (panic disorder), but also transdiagnostically for all anxiety disorders when patients were subgrouped according to their sex, medication status and symptom severity (area under the receiver operating characteristic curve, 0.59–0.63). Classifications were driven by neuroanatomical features (cortical thickness, cortical surface area and subcortical volumes) in fronto-striato-limbic and temporoparietal regions. This benchmark study within a large, heterogeneous and multisite sample of youth with anxiety disorders reveals that only modest classification performances can be realistically achieved with machine learning using neuroanatomical data.NWORubicon 019.201SG.022Advanced Behavioural Research MethodsHealth and Well-bein
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