313 research outputs found

    Microbial abundance in surface ice on the Greenland Ice Sheet

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    Measuring microbial abundance in glacier ice and identifying its controls is essential for a better understanding and quantification of biogeochemical processes in glacial ecosystems. However, cell enumeration of glacier ice samples is challenging due to typically low cell numbers and the presence of interfering mineral particles. We quantified for the first time the abundance of microbial cells in surface ice from geographically distinct sites on the Greenland Ice Sheet (GrIS), using three enumeration methods: epifluorescence microscopy (EFM), flow cytometry (FCM), and quantitative polymerase chain reaction (qPCR). In addition, we reviewed published data on microbial abundance in glacier ice and tested the three methods on artificial ice samples of realistic cell (10(2)–10(7) cells ml(−1)) and mineral particle (0.1–100 mg ml(−1)) concentrations, simulating a range of glacial ice types, from clean subsurface ice to surface ice to sediment-laden basal ice. We then used multivariate statistical analysis to identify factors responsible for the variation in microbial abundance on the ice sheet. EFM gave the most accurate and reproducible results of the tested methodologies, and was therefore selected as the most suitable technique for cell enumeration of ice containing dust. Cell numbers in surface ice samples, determined by EFM, ranged from ~ 2 × 10(3) to ~ 2 × 10(6) cells ml(−1) while dust concentrations ranged from 0.01 to 2 mg ml(−1). The lowest abundances were found in ice sampled from the accumulation area of the ice sheet and in samples affected by fresh snow; these samples may be considered as a reference point of the cell abundance of precipitants that are deposited on the ice sheet surface. Dust content was the most significant variable to explain the variation in the abundance data, which suggests a direct association between deposited dust particles and cells and/or by their provision of limited nutrients to microbial communities on the GrIS

    An association between TRP64ARG polymorphism of the B3 adrenoreceptor gene and some metabolic disturbances

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    <p>Abstract</p> <p>Backgrounds</p> <p>B3 adrenoreceptors (ADRB3) are abundant in adipose tissue and play the role in its metabolism and lipolysis. Some variants of the ADRB3 gene may predispose subjects for the development obesity and metabolic abnormalities in the setting of modern sedentary lifestyle. ADRB3 gene polymorphism association with metabolic disturbances has never been studied before in the ethnic Kyrgyz population.</p> <p>Aim</p> <p>To study an association between Trp64Arg polymorphism of the ADRB3 and metabolic syndrome (MS) components in an ethnic Kyrgyz group.</p> <p>Materials and methods</p> <p>213 Ethnic Kyrgyz volunteers over the age of 30 were enrolled in the study. The assessment plan for each individual comprised of general physical and anthropometric exams as well as laboratory tests (glucose, lipid panel, insulin) and genotyping by Trp64Arg polymorphism of the ADRB3. MS diagnosis was consistent with modified ATP III criteria (2005). Logistic regression analysis was performed to test the potential independent association between Arg64 allele with obesity, abdominal obesity (AO) and arterial hypertension (AH).</p> <p>Results</p> <p>Trp64Arg polymorphism of the ADRB3 was assessed in 213 individuals (145 men, 68 women) aged 30-73 (mean age 50.7 ¹ 7.6). Arg64 allele frequency was 0.239; ADRB3 genotype distribution among participants was: Trp64 homozygotes 54.5%, Trp64Arg 43.2% and Arg64 homozygotes 2.3%. There was an association between Trp64Arg и Arg64Arg genotypes and higher BMI, WC and obesity frequency (p < 0.00009), AO (p < 0.01), type 2 diabetes mellitus (DM) (p < 0.005) and lower high density cholesterol (HDL-C) level (p < 0.03). The logistic regression analysis showed the correlation of the Arg64 allele with obesity (OR 3.159; 95% CI 1.789-5.577) and AO (OR 1.973; 95% CI 1.118-3.481). The association between Arg64 allele and AH lost its significance after adjustment for obesity.</p> <p>Conclusion</p> <p>Arg64 allele of the ADRB3 gene in the studied group has an association with MS components such as obesity, AO and decreased HDL-C level.</p

    Inserting “OFF-to-ON” BODIPY Tags into Cytokines: A Fluorogenic Interleukin IL-33 for Real-Time Imaging of Immune Cells

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    The essential functions that cytokine/immune cell interactions play in tissue homeostasis and during disease have prompted the molecular design of targeted fluorophores to monitor their activity in real time. Whereas activatable probes for imaging immune-related enzymes are common, many immunological functions are mediated by binding events between cytokines and their cognate receptors that are hard to monitor by live-cell imaging. A prime example is interleukin-33 (IL-33), a key cytokine in innate and adaptive immunity, whose interaction with the ST2 cell-surface receptor results in downstream signaling and activation of NF-ÎşB and AP-1 pathways. In the present work, we have designed a chemical platform to site-specifically introduce OFF-to-ON BODIPY fluorophores into full cytokine proteins and generate the first native-like fluorescent analogues of IL-33. Among different incorporation strategies, chemical aminoacylation followed by bioorthogonal derivatization led to the best labeling results.Importantly, the BODIPY-labeled IL-33 derivatives -unlike IL-33-GFP constructs- exhibited ST2-specific binding and downstream bioactivity profiles comparable to those of the wild-type interleukin. Real-time fluorescence microscopy assays under no wash conditions confirmed the internalization of IL-33 through ST2 receptors and its intracellular trafficking through the endosomal pathway. We envision that the modularity and versatility of our BODIPY labeling platform will facilitate the synthesis of minimally tagged fluorogenic cytokines as the next generation of imaging reagents for real-time visualization of signaling events in live immune cells

    Alcohol consumption patterns across Europe and adherence to the European guidelines in coronary patients : findings from the ESC-EORP EUROASPIRE V survey

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    Background and aims: Alcohol consumption is an important risk factor for cardiovascular morbidity and mortality worldwide. The highest levels of alcohol consumption are observed in Europe, where alcohol as contributing cause of coronary heart disease (CHD) is also most significant. We aimed to describe alcohol consumption patterns across European regions and adherence to the current guidelines in patients with a recent CHD event. Methods: The ESC-EORP survey (EUROASPIRE V) has been conducted in 2016-2017 at 131 centers in 27 Eu-ropean countries in 7350 patients with a recent CHD. Median alcohol consumption, as well as the proportion of abstainers and excessive drinkers (i.e. >70 g/week for women and >140 for men, as recommended by the European guidelines on cardiovascular prevention), was calculated for each region. To assess adherence to guidelines, proportions of participants who were advised to reduce excessive alcohol consumption and participants who were incorrectly not advised were calculated per region. Results: Mean age was 64 years (SD: 9.5), 75% were male. Abstention rates were 53% in males and 77% in females, whereas excessive drinking was reported by 9% and 5% of them, respectively. Overall, 57% of the participants were advised to reduce alcohol consumption. In the total population, 3% were incorrectly not advised, however, this percentage differed per region (range: 1%-9%). In regions where alcohol consumption was highest, participants were less often advised to reduce their consumption. Conclusion: In this EUROASPIRE V survey, the majority of CHD patients adhere to the current drinking guidelines, but substantial heterogeneity exists between European regions

    Turkish D-light : accentuating heritage values with daylight

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    Historic buildings have their own cultural identity, which is often related to their aesthetic qualities such as period characteristics (geometry, size, colour, form and shape), materials and construction. Daylight is one of the primary elements contributing to the distinctiveness of the visual environment of many historic buildings, but is rarely considered as one of the components that shape the character of a building when adaptive preservation schemes of historical buildings are planned. Many historic buildings were originally designed to accommodate activities different to their new use and preserving the quality of daylight that originally contributed to their visual identity is a challenging task. Maintaining the ‘day-lit appearance’ of a building can be particularly problematic if the building is to be used as a museum or a gallery owing to the artefacts’ conservation requirements. This work investigated the opportunities of maintaining the original ambient conditions of renovated historical buildings while meeting the required daylight levels of the proposed new use. The study utilised an annual daylight simulation method and hourly weather data to preserve daylight conditions in renovated historic buildings. The model was piloted in a Turkish bathhouse situated in Bursa, Turkey, that is currently under renovation. The simulation model produces 4483 hourly values of daylight illuminance for a period of a whole year using the computer program Radiance. It is concluded that daylight characteristics should be taken into account when developing a renovation scheme. With increasing pressure on valuing historic buildings in many parts of the world, the work reported here should be beneficial to those concerned with the conservation and adaptive reuse of historic buildings. The study findings could also be useful to those interested in predicting potential energy savings by combining daylighting and electric lighting in historic buildings

    Efficient Verifiable Computation of XOR for Biometric Authentication

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    This work addresses the security and privacy issues in remotebiometric authentication by proposing an efficient mechanism to verifythe correctness of the outsourced computation in such protocols.In particular, we propose an efficient verifiable computation of XORingencrypted messages using an XOR linear message authenticationcode (MAC) and we employ the proposed scheme to build a biometricauthentication protocol. The proposed authentication protocol is bothsecure and privacy-preserving against malicious (as opposed to honest-but-curious) adversaries. Specifically, the use of the verifiable computation scheme together with an homomorphic encryption protects the privacy of biometric templates against malicious adversaries. Furthermore, in order to achieve unlinkability of authentication attempts, while keeping a low communication overhead, we show how to apply Oblivious RAM and biohashing to our protocol. We also provide a proof of security for the proposed solution. Our simulation results show that the proposed authentication protocol is efficient

    Perception of Loudness Is Influenced by Emotion

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    Loudness perception is thought to be a modular system that is unaffected by other brain systems. We tested the hypothesis that loudness perception can be influenced by negative affect using a conditioning paradigm, where some auditory stimuli were paired with aversive experiences while others were not. We found that the same auditory stimulus was reported as being louder, more negative and fear-inducing when it was conditioned with an aversive experience, compared to when it was used as a control stimulus. This result provides support for an important role of emotion in auditory perception
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