162 research outputs found
Synchronous development in open-source projects: A higher-level perspective
Mailing lists are a major communication channel for supporting developer coordina tion in open-source software projects. In a recent study, researchers explored tempo ral relationships (e.g., synchronization) between developer activities on source code
and on the mailing list, relying on simple heuristics of developer collaboration (e.g.,
co-editing fles) and developer communication (e.g., sending e-mails to the mailing
list). We propose two methods for studying synchronization between collaboration
and communication activities from a higher-level perspective, which captures the
complex activities and views of developers more precisely than the rather technical
perspective of previous work. On the one hand, we explore developer collaboration
at the level of features (not fles), which are higher-level concepts of the domain and
not mere technical artifacts. On the other hand, we lift the view of developer com munication from a message-based model, which treats each e-mail individually, to
a conversation-based model, which is semantically richer due to grouping e-mails
that represent conceptually related discussions. By means of an empirical study, we
investigate whether the diferent abstraction levels afect the observed relationship
between commit activity and e-mail communication using state-of-the-art time series analysis. For this purpose, we analyze a combined history of 40 years of data
for three highly active and widely deployed open-source projects: QEMU, BusyBox,
and OpenSSL. Overall, we found evidence that a higher-level view on the coordina tion of developers leads to identifying a stronger statistical dependence between the
technical activities of developers than a less abstract and rather technical view
Rituximab-Containing Treatment Regimens May Imply a Long-Term Risk for Difficult-To-Treat Chronic Hepatitis E
Hepatitis E virus (HEV) infection is an emerging disease in industrialized countries which is usually characterized by a self-limited course. However, there is an increased risk of HEV persistence in immunocompromised risk populations, comprising patients following solid organ transplantation or hematological malignancies. Recently, chronic HEV infection following rituximab-containing treatment regimens has been described. Here we report five patients with chronic hepatitis E after prior rituximab therapy for various indications. We determined the immunological characteristics of these patients and analyzed the development of ribavirin (RBV) treatment failure-associated mutations in the HEV genome. One patient became chronically HEV-infected 110 months after administration of rituximab (RTX). Immunological characterization revealed that all patients exhibited significant hypogammaglobulinemia and CD4+ T cell lymphopenia. One patient permanently cleared HEV following weight-based ribavirin treatment while three patients failed to reach a sustained virological response. In depth mutational analysis confirmed the presence of specific mutations associated with RBV treatment failure in these patients. Our cases indicate that rituximab-containing treatment regimens might imply a relevant risk for persistent HEV infection even years after the last rituximab application. Moreover, we provide further evidence to prior observations suggesting that chronically HEV infected patients following RTX-containing treatment regimens might be difficult to treat
Viral Myocarditis—From Pathophysiology to Treatment
The diagnosis of acute and chronic myocarditis remains a challenge for clinicians. Characterization of this disease has been hampered by its diverse etiologies and heterogeneous clinical presentations. Most cases of myocarditis are caused by infectious agents. Despite successful research in the last few years, the pathophysiology of viral myocarditis and its sequelae leading to severe heart failure with a poor prognosis is not fully understood and represents a significant public health issue globally. Most likely, at a certain point, besides viral persistence, several etiological types merge into a common pathogenic autoimmune process leading to chronic inflammation and tissue remodeling, ultimately resulting in the clinical phenotype of dilated cardiomyopathy. Understanding the underlying molecular mechanisms is necessary to assess the prognosis of patients and is fundamental to appropriate specific and personalized therapeutic strategies. To reach this clinical prerequisite, there is the need for advanced diagnostic tools, including an endomyocardial biopsy and guidelines to optimize the management of this disease. The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has currently led to the worst pandemic in a century and has awakened a special sensitivity throughout the world to viral infections. This work aims to summarize the pathophysiology of viral myocarditis, advanced diagnostic methods and the current state of treatment options.Peer Reviewe
Interferon-β Suppresses Transcriptionally Active Parvovirus B19 Infection in Viral Cardiomyopathy: A Subgroup Analysis of the BICC-Trial
Human parvovirus B19 (B19V) is the predominant virus currently detected in endomyocardial biopsies (EMBs). Recent findings indicate that, specifically, transcriptionally active B19V with detectable viral RNA is of prognostic relevance in inflammatory viral cardiomyopathy. We aimed to evaluate B19V replicative status (viral RNA) and beneficial effects in a sub-collective of the prospective randomized placebo-controlled phase II multi-center BICC-Trial (Betaferon In Chronic Viral Cardiomyopathy) after interferon beta-1b (IFN-β) treatment. EMBs of n = 64 patients with B19V mono-infected tissue were retrospectively analyzed. Viral RNA could be detected in n = 18/64 (28.1%) of B19V DNA positive samples (mean age 51.7 years, 12 male), of whom n = 13 had been treated with IFN-ß. Five patients had received placebo. PCR analysis confirmed in follow-up that EMBs significantly reduced viral RNA loads in n = 11/13 (84.6%) of IFN-ß treated patients (p = 0.001), independently from the IFN-ß dose, in contrast to the placebo group, where viral RNA load was not affected or even increased. Consequently, a significant improvement of left ventricular ejection fraction (LVEF) after treatment with IFN-ß was observed (LVEF mean baseline 51.6 ± 14.1% vs. follow-up 61.0 ± 17.5%, p = 0.03). In contrast, in the placebo group, worsening of LVEF was evaluated in n = 4/5 (80.0%) of patients. We could show for the first-time the beneficial effects from treatment with IFN-ß, suppressing B19V viral RNA and improving the hemodynamic course. Our results need further verification in a larger prospective randomized controlled trial.Peer Reviewe
Identification of a Putative Novel Genotype of Avian Hepatitis E Virus from Apparently Healthy Chickens in Southwestern Nigeria
Avian hepatitis E virus (aHEV) is the major etiological agent of hepatitis-splenomegaly syndrome (HSS), big liver and spleen disease (BLSD), and hepatic rupture hemorrhage syndrome (HRHS) in chickens. Infections with aHEV cause a significant decrease in egg production and increased mortality in chickens worldwide. However, studies on the prevalence of aHEV in Nigeria are scarce. In this study, serum (n = 88) and fecal samples (n = 110) obtained from apparently healthy layer chickens from three states in southwestern Nigeria were analyzed by nested reverse transcription-polymerase chain reaction (nRT-PCR) targeting the helicase and capsid gene for the presence of aHEV. Avian HEV was detected in 12.5% (n = 11/88) of serum samples and 9.1% (n = 10/110) of fecal samples tested. Phylogenetic analysis showed that five of the twelve identified aHEV sequences belonged to genotype 2. The remaining seven sequences were only distantly related to other known aHEV isolates. After amplification of the near-complete ORF2 fragment (1618 bp) and part of the ORF1 (582 bp) of isolate YF40_aHEV_NG phylogenetic analysis revealed a nucleotide sequence identity between 79.0 and 82.6% and 80.1 and 83.5%, respectively, to other known aHEV strains, indicating that the Nigerian isolate YF40_aHEV_NG belongs to a novel aHEV genotype. This is the first report of co-circulation of aHEV genotypes in chickens in Nigeria.Peer Reviewe
Presence and Diversity of Different Enteric Viruses in Wild Norway Rats (Rattus norvegicus)
Abstract:
Rodents are common reservoirs for numerous zoonotic pathogens, but knowledge about
diversity of pathogens in rodents is still limited. Here, we investigated the occurrence and genetic
diversity of enteric viruses in 51 Norway rats collected in three different countries in Europe. RNA of
at least one virus was detected in the intestine of 49 of 51 animals. Astrovirus RNA was detected
in 46 animals, mostly of rat astroviruses. Human astrovirus (HAstV-8) RNA was detected in one,
rotavirus group A (RVA) RNA was identified in eleven animals. One RVA RNA could be typed as
rat G3 type. Rat hepatitis E virus (HEV) RNA was detected in five animals. Two entire genome
sequences of ratHEV were determined. Human norovirus RNA was detected in four animals
with the genotypes GI.P4-GI.4, GII.P33-GII.1, and GII.P21. In one animal, a replication competent
coxsackievirus A20 strain was detected. Additionally, RNA of an enterovirus species A strain was
detected in the same animal, albeit in a different tissue. The results show a high detection rate and
diversity of enteric viruses in Norway rats in Europe and indicate their significance as vectors for
zoonotic transmission of enteric viruses. The detailed role of Norway rats and transmission pathways
of enteric viruses needs to be investigated in further studies.Peer Reviewe
Concordance between self-reported and measured HIV and hepatitis C virus infection status among people who inject drugs in Germany
Background: People who inject drugs (PWID) are disproportionately affected by both HIV and hepatitis C infection (HCV). Awareness of infection status is essential to ensure linkage to appropriate healthcare for those infected, who need treatment and regular follow-up, as well as for uninfected individuals, who need access to targeted testing and counselling services. In this paper we compare self-reported HIV and HCV status with serological markers of infection among PWID recruited through respondent driven sampling. Methods: From 2011 through 2014, biological and behavioural data was collected from 2,077 PWID in Germany. Dried blood spots from capillary blood samples were collected and screened for HCV antibodies, HCV RNA and HIV-1/-2 antibodies. HIV reactive samples were confirmed by Western blot. Results: Laboratory testing revealed that 5 % were infected with HIV and 81 % were aware of being infected. Chronic HCV infection was detected in 41 % of the participants, 2 % had an acute HCV infection, 22 % had a cleared infection, and 34 % were unexposed to HCV. The concordance between self-reported and measured HCV status was lower than for HIV, with 73 % of those with chronic HCV infection being aware of their infection. Conclusions: We found a relatively high awareness of HIV and HCV infection status among PWID. Nevertheless, access to appropriate testing, counselling and care services targeted to the needs of PWID should be further improved, particularly concerning HCV. Trial registration: Ethical approval was received from the ethics committee at the medical university of Charité, Berlin, Germany in May 2011 and with an amendment approved retrospectively on 19/11/2012 (No EA4/036/11). The German Federal Commissioner for Data Protection and Freedom of Information approved the study protocol retrospectively on 29/11/2012 (III-401/008#0035)
results from a cross-sectional study using respondent-driven sampling in eight German cities (2011–14)
Background People who inject drugs (PWID) are at increased risk of acquiring
and transmitting HIV and Hepatitis C (HCV) due to sharing injection
paraphernalia and unprotected sex. To generate seroprevalence data on HIV and
HCV among PWID and related data on risk behaviour, a multicentre sero- and
behavioural survey using respondent driven sampling (RDS) was conducted in
eight German cities between 2011 and 2014. We also evaluated the feasibility
and effectiveness of RDS for recruiting PWID in the study cities. Methods
Eligible for participation were people who had injected drugs within the last
12 months, were 16 years or older, and who consumed in one of the study
cities. Participants were recruited, using low-threshold drop-in facilities as
study sites. Initial seeds were selected to represent various sub-groups of
people who inject drugs (PWID). Participants completed a face-to-face
interview with a structured questionnaire about socio-demographics, sexual and
injecting risk behaviours, as well as the utilisation of health services.
Capillary blood samples were collected as dried blood spots and were
anonymously tested for serological and molecular markers of HIV and HCV. The
results are shown as range of proportions (min. and max. values (%)) in the
respective study cities. For evaluation of the sampling method we applied
criteria from the STROBE guidelines. Results Overall, 2,077 PWID were
recruited. The range of age medians was 29–41 years, 18.5–35.3 % of
participants were female, and 9.2–30.6 % were foreign born. Median time span
since first injection were 10–18 years. Injecting during the last 30 days was
reported by 76.0–88.4 % of participants. Sharing needle/syringes (last 30
days) ranged between 4.7 and 22.3 %, while sharing unsterile paraphernalia
(spoon, filter, water, last 30 days) was reported by 33.0–43.8 %. A majority
of participants (72.8–85.8 %) reported incarceration at least once, and
17.8–39.8 % had injected while incarcerated. Between 30.8 and 66.2 % were
currently in opioid substitution therapy. Unweighted HIV seroprevalence ranged
from 0–9.1 %, HCV from 42.3–75.0 %, and HCV-RNA from 23.1–54.0 %. The
implementation of RDS as a recruiting method in cooperation with low-threshold
drop in facilities was well accepted by both staff and PWID. We reached our
targeted sample size in seven of eight cities. Conclusions In the recruited
sample of mostly current injectors with a long duration of injecting drug use,
seroprevalence for HIV and HCV varied greatly between the city samples. HCV
was endemic among participants in all city samples. Our results demonstrate
the necessity of intensified prevention strategies for blood-borne infections
among PWID in Germany
Outcome of the First wwPDB Hybrid / Integrative Methods Task Force Workshop
Structures of biomolecular systems are increasingly computed by integrative modeling that relies on varied types of experimental data and theoretical information. We describe here the proceedings and conclusions from the first wwPDB Hybrid/Integrative Methods Task Force Workshop held at the European Bioinformatics Institute in Hinxton, UK, on October 6 and 7, 2014. At the workshop, experts in various experimental fields of structural biology, experts in integrative modeling and visualization, and experts in data archiving addressed a series of questions central to the future of structural biology. How should integrative models be represented? How should the data and integrative models be validated? What data should be archived? How should the data and models be archived? What information should accompany the publication of integrative models
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