521 research outputs found

    Correlation among Cirrus Ice Content, Water Vapor and Temperature in the TTL as Observed by CALIPSO and Aura-MLS

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    Water vapor in the tropical tropopause layer (TTL) has a local radiative cooling effect. As a source for ice in cirrus clouds, however, it can also indirectly produce infrared heating. Using NASA A-Train satellite measurements of CALIPSO and Aura/MLS we calculated the correlation of water vapor, ice water content and temperature in the TTL. We find that temperature strongly controls water vapor (correlation r =0.94) and cirrus clouds at 100 hPa (r = 0.91). Moreover we observe that the cirrus seasonal cycle is highly (r =0.9) anticorrelated with the water vapor variation in the TTL, showing higher cloud occurrence during December-January-February. We further investigate the anticorrelation on a regional scale and find that the strong anticorrelation occurs generally in the ITCZ (Intertropical Convergence Zone). The seasonal cycle of the cirrus ice water content is also highly anticorrelated to water vapor (r = 0.91) and our results support the hypothesis that the total water at 100 hPa is roughly constant. Temperature acts as a main regulator for balancing the partition between water vapor and cirrus clouds. Thus, to a large extent, the depleting water vapor in the TTL during DJF is a manifestation of cirrus formation

    Zoonotic potential of guinea pigs: Outbreak of cryptosporidiosis combined with chlamydiosis in a breeding guinea pig herd.

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    In a guinea pig herd with 26 breeding animals, several individuals of all age categories died (16/26) after three animals had been newly introduced from another herd. Furthermore, the population suffered of apathy, anorexia, severe weight loss and conjunctivitis, as well as abortions and stillbirths. At the same time, the owner experienced a SARS-CoV-2 infection with pneumonia, which was confirmed by taking a PCR test. Chlamydia caviae was detected from the conjunctiva and vagina/uterus in one juvenile animal together with an intestinal Cryptosporidium wrairi infection. Oocysts were found histologically in the small intestine, which was confirmed by PCR. C. wairi is a parasite adapted to guinea pigs with zoonotic potential, which causes diarrhoea with frequent deaths in larger guinea pig herds. C. caviae is also a zoonotic pathogen and often the cause of conjunctivitis, pneumonia and abortions in guinea pigs and can lead to upper respiratory tract disease, conjunctivitis but also severe pneumonia in humans. The increased death cases and the clinical signs could be traced back to an infection with Cryptosporidium wrairi, complicated by a co-infection of C. caviae. We suspect that the abortions were caused by C. caviae, but since the population was treated with various antibiotics effective against chlamydial infections, it was no longer possible to verify this by PCR testing. Unfortunately, more animals succumbed and finally only two animals of the originally 26 were left. With this case report, we would like to point out to veterinarians that guinea pigs can be an important source of zoonotic infections for various pathogens, especially since they are popular pets and often come into close contact with children where hygiene might not always be strictly followed

    Is there a genetic relationship between alcoholism and depression?

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    The Collaborative Study on the Genetics of Alcoholism (COGA) seeks to identify genes contributing to alcoholism and related traits (i.e., phenotypes), including depression. Among alcoholic subjects the COGA study found an increased prevalence of depressive syndrome (i.e., depression that may or may not occur in conjunction with increased drinking). This combination of alcoholism and depression tends to run in families. Comorbid alcoholism and depression occurred substantially more often in first-degree relatives of COGA participants with alcoholism than in relatives of control participants. Based on these data, COGA investigators defined three phenotypes—“alcoholism,” “alcoholism and depression,” and “alcoholism or depression”—and analyzed whether these phenotypes were linked to specific chromosomal regions. These analyses found that the “alcoholism or depression” phenotype showed significant evidence for genetic linkage to an area on chromosome 1. This suggests that a gene or genes on chromosome 1 may predispose some people to alcoholism and others to depression (which may be alcohol induced)

    LUH-GRACE2018

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    In this contribution, we present the LUH-GRACE2018 time series of monthly gravity field solutions covering the period January 2003–March 2016. The solutions are obtained from GRACE K-Band Range Rate (KBRR) measurements as main observations. The monthly solutions are computed using the in-house developed GRACE-SIGMA software. The processing is based on dynamic orbit and gravity field determination using variational equations and consists of two main steps. In the first step, 3-hourly orbital arcs of the two satellites and the state transition and sensitivity matrices are dynamically integrated using a modified Gauss-Jackson integrator. In this step, initial state vectors and 3D accelerometer bias parameters are adjusted using GRACE Level-1B reduced-dynamic positions as observations. In the second step, normal equations are accumulated and the normalized spherical harmonic coefficients up to degree and order 80 are estimated along with arc-wise initial states, accelerometer biases and empirical KBRR parameters. Here KBRR measurements are used as main observations and reduced-dynamic positions are introduced to solve for the low frequency coefficients. In terms of error degree standard deviations as well as Equivalent Water Heights (EWH), our gravity field solutions agree well with RL05 solutions of CSR, GFZ and JPL

    Widely used, short 16S rRNA mitochondrial gene fragments yield poor and erratic results in phylogenetic estimation and species delimitation of amphibians.

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    BACKGROUND The 16S mitochondrial rRNA gene is the most widely sequenced molecular marker in amphibian systematic studies, making it comparable to the universal CO1 barcode that is more commonly used in other animal groups. However, studies employ different primer combinations that target different lengths/regions of the 16S gene ranging from complete gene sequences (~ 1500 bp) to short fragments (~ 500 bp), the latter of which is the most ubiquitously used. Sequences of different lengths are often concatenated, compared, and/or jointly analyzed to infer phylogenetic relationships, estimate genetic divergence (p-distances), and justify the recognition of new species (species delimitation), making the 16S gene region, by far, the most influential molecular marker in amphibian systematics. Despite their ubiquitous and multifarious use, no studies have ever been conducted to evaluate the congruence and performance among the different fragment lengths. RESULTS Using empirical data derived from both Sanger-based and genomic approaches, we show that full-length 16S sequences recover the most accurate phylogenetic relationships, highest branch support, lowest variation in genetic distances (pairwise p-distances), and best-scoring species delimitation partitions. In contrast, widely used short fragments produce inaccurate phylogenetic reconstructions, lower and more variable branch support, erratic genetic distances, and low-scoring species delimitation partitions, the numbers of which are vastly overestimated. The relatively poor performance of short 16S fragments is likely due to insufficient phylogenetic information content. CONCLUSIONS Taken together, our results demonstrate that short 16S fragments are unable to match the efficacy achieved by full-length sequences in terms of topological accuracy, heuristic branch support, genetic divergences, and species delimitation partitions, and thus, phylogenetic and taxonomic inferences that are predicated on short 16S fragments should be interpreted with caution. However, short 16S fragments can still be useful for species identification, rapid assessments, or definitively coupling complex life stages in natural history studies and faunal inventories. While the full 16S sequence performs best, it requires the use of several primer pairs that increases cost, time, and effort. As a compromise, our results demonstrate that practitioners should utilize medium-length primers in favor of the short-fragment primers because they have the potential to markedly improve phylogenetic inference and species delimitation without additional cost

    Using digital and hand printing techniques to compensate for loss: re-establishing colour and texture in historic textiles

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    Conservators use a range of 'gap filling' techniques to improve the structural stability and presentation of objects. Textile conservators often use fabric supports to provide reinforcement for weak areas of a textile and to provide a visual infill in missing areas. The most common technique is to use dyed fabrics of a single colour but while a plain dyed support provides good reinforcement, it can be visually obtrusive when used with patterned or textured textiles. Two recent postgraduate dissertation projects at the Textile Conservation Centre (TCC) have experimented with hand printing and digital imaging techniques to alter the appearance of support fabrics so that they are less visually obtrusive and blend well with the colour and texture of the textile being supported. Case studies demonstrate the successful use of these techniques on a painted hessian rocking horse and a knitted glove from an archaeological context

    NKG2D regulation of lung pathology and dendritic cell function following respiratory syncytial virus infection

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    © The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. Background. Respiratory syncytial virus (RSV) is a common cause of respiratory tract infection in vulnerable populations. Natural killer (NK) cells and dendritic cells (DC) are important for the effector functions of both cell types following infection. Methods. Wild-type and NKG2D-deficient mice were infected with RSV. Lung pathology was assessed by histology. Dendritic cell function and phenotype were evaluated by enzyme-linked immunosorbent assay and flow cytometry. The expression of NKG2D ligands on lung and lymph node DCs was measured by immunostaining and flow cytometry. Adoptive transfer experiments were performed to assess the importance of NKG2D-dependent DC function in RSV infection. Results. NKG2D-deficient mice exhibited greater lung pathology, marked by the accumulation of DCs following RSV infection. Dendritic cells isolated from NKG2D-deficient mice had impaired responses toward Toll-like receptor ligands. Dendritic cells expressed NKG2D ligands on their surface, which was further increased in NKG2D-deficient mice and during RSV infection. Adoptive transfer of DCs isolated from wild-type mice into the airways of NKG2D-deficient mice ameliorated the enhanced inflammation in NKG2D-deficient mice after RSV infection. Conclusion. NKG2D-dependent interactions with DCs control the phenotype and function of DCs and play a critical role in pulmonary host defenses against RSV infection
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