51 research outputs found
Efficacy of menthol as an anesthetic for tambaqui (Colossoma macropomum, Characiformes: Characidae)
Anesthetics are important in fish culture to reduce handling stress and mortality. The objective of this work is to investigate menthol as an anesthetic for tambaqui. In the first series of tests, fish were exposed to various concentrations of menthol to evaluate induction time and stress responses. The second series examined the effect of exposure period to menthol at 150 mg/L on recovery time. The third assessed the best dosage for juveniles in larger tambaqui. The best concentration for surgical anesthesia is 150 mg/L. At this concentration the induction time is short, but their recovery time is significantly longer than that for lower concentrations. For biometry procedures, the best concentration is 100 mg/L. At this concentration the induction time is prolonged, but the recovery time is within the desired period. Recovery time for fish exposed to 150 mg/L is equal for 10, 20 or 30 minutes of exposure. The results confirmed that menthol is an adequate anesthetic for tambaqui.Os anestésicos são importantes na piscicultura para reduzir o estresse e a mortalidade no manejo. Este trabalho tem como objetivo determinar a eficácia do mentol para tambaqui durante o manejo. Na primeira série de testes, foi examinado o efeito da concentração de anestésico sobre indução à anestesia e o estresse de tambaqui. Na segunda série de testes, foi avaliada a recuperação dos peixes após a exposição a uma concentração de 150 mg/L de mentol por diferentes tempos. Na terceira série, foi avaliada se a melhor concentração encontrada para juvenil (150 mg/L) também era adequada para peixes maiores. A melhor concentração para uma anestesia cirúrgica foi 150 mg/L, pois o tempo de indução é rápido, porém a recuperação é significativamente mais demorada do que para as menores concentrações testadas. Para uma anestesia, com finalidade de biometria, a melhor concentração foi 100 mg/L. Nesta concentração o tempo de indução à anestesia é prolongado, porém o tempo de recuperação está dentro da faixa considerada adequada. O tempo de recuperação do tambaqui quando exposto a 150 mg/L é significativamente igual para 10, 20 e 30 minutos de anestesia. Os resultados obtidos mostram que o mentol é um anestésico eficiente para o tambaqui
Meta-analysis of type 2 Diabetes in African Americans Consortium
Type 2 diabetes (T2D) is more prevalent in African Americans than in Europeans. However, little is known about the genetic risk in African Americans despite the recent identification of more than 70 T2D loci primarily by genome-wide association studies (GWAS) in individuals of European ancestry. In order to investigate the genetic architecture of T2D in African Americans, the MEta-analysis of type 2 DIabetes in African Americans (MEDIA) Consortium examined 17 GWAS on T2D comprising 8,284 cases and 15,543 controls in African Americans in stage 1 analysis. Single nucleotide polymorphisms (SNPs) association analysis was conducted in each study under the additive model after adjustment for age, sex, study site, and principal components. Meta-analysis of approximately 2.6 million genotyped and imputed SNPs in all studies was conducted using an inverse variance-weighted fixed effect model. Replications were performed to follow up 21 loci in up to 6,061 cases and 5,483 controls in African Americans, and 8,130 cases and 38,987 controls of European ancestry. We identified three known loci (TCF7L2, HMGA2 and KCNQ1) and two novel loci (HLA-B and INS-IGF2) at genome-wide significance (4.15 × 10(-94)<P<5 × 10(-8), odds ratio (OR) = 1.09 to 1.36). Fine-mapping revealed that 88 of 158 previously identified T2D or glucose homeostasis loci demonstrated nominal to highly significant association (2.2 × 10(-23) < locus-wide P<0.05). These novel and previously identified loci yielded a sibling relative risk of 1.19, explaining 17.5% of the phenotypic variance of T2D on the liability scale in African Americans. Overall, this study identified two novel susceptibility loci for T2D in African Americans. A substantial number of previously reported loci are transferable to African Americans after accounting for linkage disequilibrium, enabling fine mapping of causal variants in trans-ethnic meta-analysis studies.Peer reviewe
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Track A Basic Science
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138319/1/jia218438.pd
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Long-term trends in aerosol and precipitation composition over the western North Atlantic Ocean at Bermuda
Since the 1980s, emissions of SO2 and NOx (NO +
NO2) from anthropogenic sources in the United States (US), Canada,
and Europe have decreased significantly suggesting that the export of
oxidized S and N compounds from surrounding continents to the atmosphere
overlying the North Atlantic Ocean (NAO) has also decreased. The chemical
compositions of aerosols and precipitation sampled daily on Bermuda
(32.27° N, 64.87° W) from 1989 to 1997 and from 2006 to
2009 were evaluated to quantify the magnitudes, significance, and
implications of associated tends in atmospheric composition. The chemical
data were stratified based on FLEXPART (FLEXible PARTicle dispersion model)
retroplumes into four discrete transport regimes: westerly flow from eastern
North America (NEUS/SEUS); easterly trade-wind flow from northern Africa and
the subtropical NAO (Africa); long, open-ocean, anticyclonic flow around the
Bermuda High (Oceanic); and transitional flow from the relatively clean open
ocean to the polluted eastern North America (North). Based on all data,
annual average concentrations of non-sea-salt (nss) SO42– associated
with aerosols and annual volume-weighted-average (VWA) concentrations in
precipitation decreased significantly (by 22% and 49%,
respectively) whereas annual VWA concentrations of NH4+ in
precipitation increased significantly (by 70%). Corresponding trends in
aerosol and precipitation NO3– and of aerosol NH4+ were
insignificant. Nss SO42– in precipitation under NEUS/SEUS and Oceanic
flow decreased significantly (61% each) whereas corresponding trends in
particulate nss SO42– under both flow regimes were insignificant.
Trends in precipitation composition were driven in part by decreasing
emissions of SO2 over upwind continents and associated decreases in
anthropogenic contributions to nss SO42– concentrations. Under
NEUS/SEUS and Oceanic flow, the ratio of anthropogenic to biogenic
contributions to nss SO42– in the column scavenged by precipitation
were relatively greater than those in near surface aerosol, which implies
that, for these flow regimes, precipitation is a better indicator of overall
anthropogenic impacts on the lower troposphere. Particulate nss SO42–
under African flow also decreased significantly (34%) whereas the
corresponding decrease in nss SO42– associated with precipitation was
insignificant. We infer that these trends were driven in part by reductions
in the emissions and transport of oxidized S compounds from Europe. The lack
of significant trends in NO3– associated with aerosols and
precipitation under NEUS/SEUS flow is notable in light of the large decrease
(37%) in NOx emissions in the US and Canada over the period of
record. Rapid chemical processing of oxidized N in marine air contributed to
this lack of correspondence. Decreasing ratios of nss SO42– to
NH4+ and the significant decreasing trend in precipitation acidity
(37%) indicate that the total amount of acidity in the multiphase
gas–aerosol system in the western NAO troposphere decreased over the period
of record. Decreasing aerosol acidities would have shifted the phase
partitioning of total NH3 (NH3 + particulate NH4+ towards
the gas phase thereby decreasing the atmospheric lifetime of total NH3
against wet plus dry deposition. The trend of increasing NH4+ in
precipitation at Bermuda over the period of record suggests that NH3
emissions from surrounding continents also increased. Decreasing particulate
nss SO42– in near-surface air under NEUS/SEUS flow over the period of
record implies that the corresponding shortwave scattering and absorption by
nss S and associated aerosols constituents also decreased. These changes in
radiative transfer suggest a corresponding lower limit for net warming over
the period in the range of 0.1–0.3 W m–2
The dichotomy in the DNA-binding behaviour of ruthenium(II) complexes bearing benzoxazole and benzothiazole groups
The substituted tris(bipyridine)ruthenium(II) complexes {[Ru(bpy)2(4,4′-bbob)]2+ and [Ru(bpy)2(5,5′-bbob)]2+ [where bpy = 2,2′-bipyridine and bbob = bis(benzoxazol-2-yl)-2,2′-bipyridine] have been prepared and compared to the previously studied complex [Ru(bpy)2(4,4′-bbtb)]2+ [where bbtb = bis(benzothiazol-2-yl)-2,2′-bipyridine]. From the UV/VIS titration studies, Δ-[Ru(bpy)2(4,4′-bbob)]2+ displays a stronger association than the Λ-isomer with calf-thymus DNA (ct-DNA). For [Ru(bpy)2(5,5′-bbob)]2+, there appears to be minimal interaction with ct-DNA. The results of fluorescence titration studies suggest that [Ru(bpy)2(4,4′-bbob)]2+ gives an increase in emission intensity with increasing ct-DNA concentrations, with an enantiopreference for the Δ isomer, confirmed by membrane dialysis studies. The fluorescent intercalation displacement studies revealed that [Ru(bpy)2(4,4′-bbob)]2+ and [Ru(bpy)2(5,5′-bbob)]2+ display a preference for more open DNA structures such as bulge and hairpin sequences. While Λ-[Ru(bpy)2(4,4′-bbtb)]2+ has shown the most significant affinity for all the oligonucleotides sequences screened in previous studies, it is the Δ isomer of the comparable benzoxazole ruthenium(II) complex (Δ-[Ru(bpy)2(4,4′-bbob)]2+) that preferentially binds to DNA
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