164 research outputs found

    The Epipelagic Fish Community of Beaufort Sea Coastal Waters, Alaska

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    A three-year study of epipelagic fishes inhabiting Beaufort Sea coastal waters in Alaska documented spatial and temporal patterns in fish distribution and abundance and examined their relationships to thermohaline features during summer. Significant interannual, seasonal, and geographical differences in surface water temperatures and salinities were observed. In 1990, sea ice was absent and marine conditions prevailed, whereas in 1988 and 1991, heavy pack ice was present and the dissolution of the brackish water mass along the coast proceeded more slowly. Arctic cod, capelin, and liparids were the most abundant marine fishes in the catches, while arctic cisco was the only abundant diadromous freshwater species. Age-0 arctic cod were exceptionally abundant and large in 1990, while age-0 capelin dominated in the other years. The alternating numerical dominances of arctic cod and age-0 capelin may represent differing species' responses to wind-driven oceanographic processes affecting growth and survival. The only captures of age-0 arctic cisco occurred during 1990. Catch patterns indicate they use a broad coastal migratory corridor and tolerate high salinities. As in the oceanographic data, geographical and temporal patterns were apparent in the fish catch data, but in most cases these patterns were not statistically testable because of excessive zero catches. The negative binomial distribution appeared to be a suitable statistical descriptor of the aggregated catch patterns for the more common species.Une étude de trois ans portant sur les poissons épipélagiques habitant les eaux côtières de la mer de Beaufort en Alaska décrit les schémas spatiaux et temporaux de la distribution et de l'abondance des poissons et examine leurs rapports avec les caractéristiques thermohalines durant l'été. On a observé d'importantes différences interannuelles, saisonnières et géographiques dans la température et la salinité de l'eau de surface. En 1990, la glace de mer était absente et des conditions marines régnaient, tandis qu'en 1988 et 1991, la glace de mer était épaisse et la dissolution de l'eau saumâtre le long du littoral s'est réalisée plus lentement. La morue polaire, le capelan et les liparis étaient les poissons marins qu'on retrouvait en plus grandes quantités dans les prises, tandis que le cisco arctique était la seule espèce d'eau douce diadrome qu'on retrouvait en abondance. En 1990, la morue polaire âgée de moins d'un an était particulièrement abondante et de taille importante, tandis que le capelan âgé de moins d'un an prédominait durant les autres années. L'alternance de la dominance numérique de la morue polaire et du capelan de moins d'un an pourrait signaler une réaction différente des espèces à des phénomènes océanographiques dus au vent, affectant la croissance et la survie. Les seules captures de cisco arctique de moins d'un an se sont produites en 1990. Les schémas de prises indiquent que les poissons utilisent un vaste corridor migratoire le long du littoral et tolèrent un taux élevé de salinité. Comme pour les données océanographiques, des schémas géographiques et temporaires étaient apparents pour les données des prises de poissons, mais, dans la plupart des cas, ces schémas ne pouvaient être testés sur le plan statistique en raison du trop grand nombre de prises nulles. La distribution binomiale négative semblait être un descripteur statistique approprié des schémas de prises cumulatifs pour les espèces plus courantes.

    The effect of music performance on the transcriptome of professional musicians

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    Music performance by professional musicians involves a wide-spectrum of cognitive and multi-sensory motor skills, whose biological basis is unknown. Several neuroscientific studies have demonstrated that the brains of professional musicians and non-musicians differ structurally and functionally and that musical training enhances cognition. However, the molecules and molecular mechanisms involved in music performance remain largely unexplored. Here, we investigated the effect of music performance on the genome-wide peripheral blood transcriptome of professional musicians by analyzing the transcriptional responses after a 2-hr concert performance and after a 'music-free' control session. The up-regulated genes were found to affect dopaminergic neurotransmission, motor behavior, neuronal plasticity, and neurocognitive functions including learning and memory. Particularly, candidate genes such as SNCA, FOS and DUSP1 that are involved in song perception and production in songbirds, were identified, suggesting an evolutionary conservation in biological processes related to sound perception/production. Additionally, modulation of genes related to calcium ion homeostasis, iron ion homeostasis, glutathione metabolism, and several neuropsychiatric and neurodegenerative diseases implied that music performance may affect the biological pathways that are otherwise essential for the proper maintenance of neuronal function and survival. For the first time, this study provides evidence for the candidate genes and molecular mechanisms underlying music performance.Peer reviewe

    Lactase persistence genotypes and malaria susceptibility in Fulani of Mali

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    Background: Fulani are a widely spread African ethnic group characterized by lower susceptibility to Plasmodium falciparum, clinical malaria morbidity and higher rate of lactase persistence compared to sympatric tribes. Lactase non-persistence, often called lactose intolerance, is the normal condition where lactase activity in the intestinal wall declines after weaning. Lactase persistence, common in Europe, and in certain African people with traditions of raising cattle, is caused by polymorphisms in the enhancer region approximately 14 kb upstream of the lactase gene. Methods: To evaluate the relationship between malaria and lactase persistence genotypes, a 400 bp region surrounding the main European C/T(-13910) polymorphism upstream of the lactase gene was sequenced. DNA samples used in the study originated from 162 Fulani and 79 Dogon individuals from Mali. Results: Among 79 Dogon only one heterozygote of the lactase enhancer polymorphism was detected, whereas all others were homozygous for the ancestral C allele. Among the Fulani, the main European polymorphism at locus C/T(-13910) was by far the most common polymorphism, with an allele frequency of 37%. Three other single-nucleotide polymorphisms were found with allele frequencies of 3.7%, 1.9% and 0.6% each. The novel DNA polymorphism T/C(-13906) was seen in six heterozygous Fulani. Among the Fulani with lactase non-persistence CC genotypes at the C/T(-13910) locus, 24% had malaria parasites detectable by microscopy compared to 18% for lactase persistent genotypes (P = 0.29). Pooling the lactase enhancer polymorphisms to a common presumptive genotype gave 28% microscopy positives for non-persistent and 17% for others (P = 0.11). Conclusions: Plasmodium falciparum parasitaemia in asymptomatic Fulani is more common in individuals with lactase non-persistence genotypes, but this difference is not statistically significant. The potential immunoprotective properties of dietary cow milk as a reason for the partial malaria resistance of Fulani warrant further investigation.Peer reviewe

    Clarifying the role of three-dimensional transvaginal sonography in reproductive medicine: an evidenced-based appraisal

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    This overview describes and illustrates the clinical applications of three-dimensional transvaginal sonography in reproductive medicine. Its main applications include assessment of uterine anomalies, intrauterine pathology, tubal patency, polycystic ovaries, ovarian follicular monitoring and endometrial receptivity. It is also useful for detailed evaluation of failed and/or ectopic pregnancy. Three-dimensional color Doppler sonography provides enhanced depiction of uterine, endometrial, and ovarian vascularity

    Investigating the Mini and Giant Radio Flare Episodes of Cygnus X-3

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    The microquasar Cygnus X-3 underwent a giant radio flare in 2017 April, reaching a maximum flux of similar to 16.5 Jy at 8.5 GHz. We present results from a long monitoring campaign carried out with Medicina at 8.5, 18.6, and 24.1 GHz, parallel to the Metsahovi radio telescope at 37 GHz, from 2017 April 4 to 11. We observe a spectral steepening from alpha = 0.2 to 0.5 (with S-nu proportional to nu(-alpha)) within 6 hr of the epoch of the flare's peak maximum, and rapid changes in the spectral slope in the following days during brief enhanced emission episodes while the general trend of the radio flux density indicated the decay of the giant flare. We further study the radio orbital modulation of Cyg X-3 emission associated with the 2017 giant flare and with six mini-flares observed in 1983, 1985, 1994, 1995, 2002, and 2016. The enhanced emission episodes observed during the decline of the giant flare at 8.5 GHz coincide with the orbital phase phi similar to 0.5 (orbital inferior conjunction). On the other hand, the light curves of the mini-flares observed at 15-22 GHz peak at phi similar to 0, except for the 2016 light curve, which is shifted 0.5 w.r.t. the other ones. We attribute the apparent phase shift to the variable location of the emitting region along the bent jet. This might be explained by the different accretion states of the flaring episodes (the 2016 mini-flare occurred in the hypersoft X-ray state)

    Characterization of TEM1/endosialin in human and murine brain tumors

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    <p>Abstract</p> <p>Background</p> <p><it>TEM1/endosialin </it>is an emerging microvascular marker of tumor angiogenesis. We characterized the expression pattern of <it>TEM1/endosialin </it>in astrocytic and metastatic brain tumors and investigated its role as a therapeutic target in human endothelial cells and mouse xenograft models.</p> <p>Methods</p> <p><it>In situ </it>hybridization (ISH), immunohistochemistry (IH) and immunofluorescence (IF) were used to localize <it>TEM1/endosialin </it>expression in grade II-IV astrocytomas and metastatic brain tumors on tissue microarrays. Changes in <it>TEM1/endosialin </it>expression in response to pro-angiogenic conditions were assessed in human endothelial cells grown <it>in vitro</it>. Intracranial U87MG glioblastoma (GBM) xenografts were analyzed in nude <it>TEM1/endosialin </it>knockout (KO) and wildtype (WT) mice.</p> <p>Results</p> <p><it>TEM1/endosialin </it>was upregulated in primary and metastatic human brain tumors, where it localized primarily to the tumor vasculature and a subset of tumor stromal cells. Analysis of 275 arrayed grade II-IV astrocytomas demonstrated <it>TEM1/endosialin </it>expression in 79% of tumors. Robust <it>TEM1/endosialin </it>expression occurred in 31% of glioblastomas (grade IV astroctyomas). <it>TEM1/endosialin </it>expression was inversely correlated with patient age. TEM1/endosialin showed limited co-localization with CD31, αSMA and fibronectin in clinical specimens. <it>In vitro</it>, <it>TEM1/endosialin </it>was upregulated in human endothelial cells cultured in matrigel. Vascular <it>Tem1/endosialin </it>was induced in intracranial U87MG GBM xenografts grown in mice. <it>Tem1/endosialin </it>KO vs WT mice demonstrated equivalent survival and tumor growth when implanted with intracranial GBM xenografts, although <it>Tem1/endosialin </it>KO tumors were significantly more vascular than the WT counterparts.</p> <p>Conclusion</p> <p><it>TEM1/endosialin </it>was induced in the vasculature of high-grade brain tumors where its expression was inversely correlated with patient age. Although lack of <it>TEM1/endosialin </it>did not suppress growth of intracranial GBM xenografts, it did increase tumor vascularity. The cellular localization of <it>TEM1/endosialin </it>and its expression profile in primary and metastatic brain tumors support efforts to therapeutically target this protein, potentially via antibody mediated drug delivery strategies.</p

    Delineating the molecular and phenotypic spectrum of the SETD1B-related syndrome

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    Purpose Pathogenic variants in SETD1B have been associated with a syndromic neurodevelopmental disorder including intellectual disability, language delay, and seizures. To date, clinical features have been described for 11 patients with (likely) pathogenic SETD1B sequence variants. This study aims to further delineate the spectrum of the SETD1B-related syndrome based on characterizing an expanded patient cohort. Methods We perform an in-depth clinical characterization of a cohort of 36 unpublished individuals with SETD1B sequence variants, describing their molecular and phenotypic spectrum. Selected variants were functionally tested using in vitro and genome-wide methylation assays. Results Our data present evidence for a loss-of-function mechanism of SETD1B variants, resulting in a core clinical phenotype of global developmental delay, language delay including regression, intellectual disability, autism and other behavioral issues, and variable epilepsy phenotypes. Developmental delay appeared to precede seizure onset, suggesting SETD1B dysfunction impacts physiological neurodevelopment even in the absence of epileptic activity. Males are significantly overrepresented and more severely affected, and we speculate that sex-linked traits could affect susceptibility to penetrance and the clinical spectrum of SETD1B variants. Conclusion Insights from this extensive cohort will facilitate the counseling regarding the molecular and phenotypic landscape of newly diagnosed patients with the SETD1B-related syndrome

    Overexpression of c-erbB2 is a negative prognostic factor in anaplastic astrocytomas

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    The epidermal growth factor receptor (EGFR) family, consisting of four tyrosine kinase receptors, c-erbB1-4, seems to be influential in gliomagenesis. The aim of this study was to investigate EGFR gene amplification and expression of c-erbB1-4 receptor proteins in human anaplastic astrocytomas. Formalin-fixed and paraffin-embedded sections from 31 cases were investigated by standard immunohistochemical procedures for expression of c-erbB1-4 receptor proteins using commercial antibodies. EGFR gene amplification was studied by fluorescence in situ hybridization using paraffin-embedded tissues. Two monoclonal antibodies, NCL-EGFR-384 and NCL-EGFR, were used for EGFR detection and they displayed positive immunoreactivity in 97% and 71%, respectively. For c-erbB2 detection three monoclonal antibodies, CB11, 3B5, and 5A2, were applied and they displayed positive immunoreactivity in 45%, 100%, and 52%, respectively. Positive immunostaining for c-erbB3 and c-erbB4 was encountered in 97% and 74%, respectively. The EGFR gene was amplified in 9 out of 31 tumors (29%). After adjusting for age, Karnofsky performance status, and extent of surgical resection, Cox multiple regression analysis with overall survival as the dependent variable revealed that c-erbB2 overexpression detected by the monoclonal antibody clone CB11 was a statistically significant poor prognostic factor (P = 0.004). This study shows the convenience and feasibility of immunohistochemistry when determining the expression of receptor proteins in tissue sections of human astrocytomas. The synchronous overexpression of c-erbB1-4 proteins in anaplastic astrocytomas supports their role in the pathogenesis of these tumors. Further, c-erbB2 overexpression seems to predict aggressive behaviour
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