665 research outputs found

    Analysis of DAX1 (NR0B1) and steroidogenic factor-1 (NR5A1) in children and adults with primary adrenal failure: Ten years' experience

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    Context: Primary adrenal failure is a life-threatening condition that can be caused by a range of etiologies, including autoimmune, metabolic, and developmental disorders. The nuclear receptors DAX1 (NR0B1) and steroidogenic factor-1 (SF1/Ad4BP, NR5A1) play an important role in adrenal development and function, and mutations in these transcription factors have been found in patients with adrenal hypoplasia.Objective: Our objective was to investigate the prevalence of DAX1 and SF1 mutations in children and adults with primary adrenal failure of unknown etiology (i.e. not caused by congenital adrenal hyperplasia, adrenoleukodystrophy, or autoimmune disease).Patients: One hundred seventeen patients were included. Eighty-eight individuals presented in infancy or childhood with adrenal hypoplasia or primary adrenal failure of unknown etiology (n = 64 46, XY phenotypic males; n = 17 46, XY gonadal dysgenesis/ impaired androgenization; n = 7 46, XX females). Twenty-nine individuals presented in adulthood with Addison's disease of unknown etiology.Methods: Mutational analysis of DAX1 ( NR0B1) ( including exon 2 alpha/1A) and SF1 ( NR5A1) was done by direct sequencing.Results: DAX1 mutations were found in 58% ( 37 of 64) of 46, XY phenotypic boys referred with adrenal hypoplasia and in all boys ( eight of eight) with hypogonadotropic hypogonadism and a family history suggestive of adrenal failure in males. SF1 mutations causing adrenal failure were found in only two patients with 46, XY gonadal dysgenesis. No DAX1 or SF1 mutations were identified in the adult-onset group.Conclusions: DAX1 mutations are a relatively frequent cause of adrenal failure in this group of boys. SF1 mutations causing adrenal failure in humans are rare and are more likely to be associated with significant underandrogenization and gonadal dysfunction in 46, XY individuals

    The Effects of Twitter Sentiment on Stock Price Returns

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    Social media are increasingly reflecting and influencing behavior of other complex systems. In this paper we investigate the relations between a well-know micro-blogging platform Twitter and financial markets. In particular, we consider, in a period of 15 months, the Twitter volume and sentiment about the 30 stock companies that form the Dow Jones Industrial Average (DJIA) index. We find a relatively low Pearson correlation and Granger causality between the corresponding time series over the entire time period. However, we find a significant dependence between the Twitter sentiment and abnormal returns during the peaks of Twitter volume. This is valid not only for the expected Twitter volume peaks (e.g., quarterly announcements), but also for peaks corresponding to less obvious events. We formalize the procedure by adapting the well-known "event study" from economics and finance to the analysis of Twitter data. The procedure allows to automatically identify events as Twitter volume peaks, to compute the prevailing sentiment (positive or negative) expressed in tweets at these peaks, and finally to apply the "event study" methodology to relate them to stock returns. We show that sentiment polarity of Twitter peaks implies the direction of cumulative abnormal returns. The amount of cumulative abnormal returns is relatively low (about 1-2%), but the dependence is statistically significant for several days after the events

    Icebergs in the North Atlantic: Modelling circulation changes and glacio-marine deposition

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    In order to investigate meltwater events in the North Atlantic, a simple iceberg generation, drift, and melting routine was implemented in a high-resolution OGCM. Starting from the modelled last glacial state, every 25th day cylindrical model icebergs 300 meters high were released at 32 specific points along the coasts. Icebergs launched at the Barents Shelf margin spread a light meltwater lid over the Norwegian and Greenland Seas, shutting down the deep convection and the anti-clockwise circulation in this area. Due to the constraining ocean circulation, the icebergs produce a tongue of relatively cold and fresh water extending eastward from Hudson Strait that must develop at this location, regardless of iceberg origin. From the total amount of freshwater inferred by the icebergs, the thickness of the deposited IRD could be calculated in dependance of iceberg sediment concentration. In this way, typical extent and thickness of Heinrich layers could be reproduced, running the model for 250 years of steady state with constant iceberg meltwater inflow

    COVID-19 Vaccine Acceptance and Hesitancy among Ethnic Minorities in Hong Kong

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    Ethnic minorities account for 8% of the Hong Kong population, most are Filipino and Indonesian domestic helpers taking care of children and the elderly. To understand the COVID-19 vaccination rates and factors associated with vaccine acceptance of ethnic minorities, we performed a cross-sectional questionnaire study recruiting Hong Kong ethnic minorities aged ≥18 years between 1 July and 18 July 2021 in public areas. Demographics, knowledge about COVID-19, vaccination status, intention and reasons to receive the vaccine, and planning to be re-vaccinated were analyzed. Continuous and categorical variables were compared using unpaired t-test and Chi-square test, respectively. Potential confounders were adjusted using multiple logistic regression. 2,012 ethnic minorities participated, with a mean age of 39 years, of which 97.6% were female, 79.5% were Filipino, and 17.5% were Indonesian. 80.6% of participants were categorized as vaccine acceptance, and 69.2% were willing to be re-vaccinated. There were significantly more Filipinos than Indonesians in the vaccine acceptance group (p < .001). Subjects in the vaccine acceptance group were more likely to have higher education (p < .001), a higher COVID-19 knowledge score (p < .001), received information from the Government website (p = .003) and not from their friends or family members (p = .02), and were more confident in judging the accuracy of the information (p < .001). Logistic regression showed the mean knowledge score (β = 3.07, p < .001) and receiving information from official Government websites (adjusted OR = 1.37, p = .03) were significant factors that positively influenced vaccine acceptance. The Hong Kong Government should improve COVID-19 vaccination acceptance among ethnic minorities through public education using official channels

    Antimony-doped graphene nanoplatelets

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    Heteroatom doping into the graphitic frameworks have been intensively studied for the development of metal-free electrocatalysts. However, the choice of heteroatoms is limited to non-metallic elements and heteroatom-doped graphitic materials do not satisfy commercial demands in terms of cost and stability. Here we realize doping semimetal antimony (Sb) at the edges of graphene nanoplatelets (GnPs) via a simple mechanochemical reaction between pristine graphite and solid Sb. The covalent bonding of the metalloid Sb with the graphitic carbon is visualized using atomic-resolution transmission electron microscopy. The Sb-doped GnPs display zero loss of electrocatalytic activity for oxygen reduction reaction even after 100,000 cycles. Density functional theory calculations indicate that the multiple oxidation states (Sb3+ and Sb5+) of Sb are responsible for the unusual electrochemical stability. Sb-doped GnPs may provide new insights and practical methods for designing stable carbon-based electrocatalystsclose0

    Reverse and Conventional Chemical Ecology Approaches for the Development of Oviposition Attractants for Culex Mosquitoes

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    Synthetic mosquito oviposition attractants are sorely needed for surveillance and control programs for Culex species, which are major vectors of pathogens causing various human diseases, including filariasis, encephalitis, and West Nile encephalomyelitis. We employed novel and conventional chemical ecology approaches to identify potential attractants, which were demonstrated in field tests to be effective for monitoring populations of Cx. p. quinquefasciatus in human dwellings. Immunohistochemistry studies showed that an odorant-binding protein from this species, CquiOBP1, is expressed in trichoid sensilla on the antennae, including short, sharp-tipped trichoid sensilla type, which house an olfactory receptor neuron sensitive to a previously identified mosquito oviposition pheromone (MOP), 6-acetoxy-5-hexadecanolide. CquiOBP1 exists in monomeric and dimeric forms. Monomeric CquiOBP1 bound MOP in a pH-dependent manner, with a change in secondary structure apparently related to the loss of binding at low pH. The pheromone antipode showed higher affinity than the natural stereoisomer. By using both CquiOBP1 as a molecular target in binding assays and gas chromatography-electroantennographic detection (GC-EAD), we identified nonanal, trimethylamine (TMA), and skatole as test compounds. Extensive field evaluations in Recife, Brazil, a region with high populations of Cx. p. quinquefasciatus, showed that a combination of TMA (0.9 µg/l) and nonanal (0.15 ng/µl) is equivalent in attraction to the currently used infusion-based lure, and superior in that the offensive smell of infusions was eliminated in the newly developed synthetic mixture

    Attitudes to smoking cessation and triggers to relapse among Chinese male smokers

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    BACKGROUND: Smoking is related to many diseases, and the relapse to smoking after cessation in China is noticeable. We examined the attitudes of Chinese male smokers regarding smoking cessation and reasons for relapse. METHODS: We interviewed 201 male smokers in Hangzhou City, Zhejiang province, China who had tried to quit smoking at least once in order to identify reasons for quitting and situations triggering relapse. RESULTS: The most significant reported reasons for quitting included personal health (77.1%), the cost of cigarettes (53.7%), and family pressures to quit (29.9%). The most common factors triggering relapse were social situations (34.3%), feeling negative or down (13.4%) and times of being alone (8.4%). CONCLUSION: Health and family concerns, personal factors, the influence of others and a lack of cessation resources were cited as salient factors concerning smoking cessation among male smokers in this study. Effective smoking control efforts in China will require attention to these influences if China is to curb its current smoking epidemic
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