106 research outputs found
Scientific value of systematic reviews: survey of editors of core clinical journals.
BACKGROUND: Synthesizing research evidence using systematic and rigorous methods has become a key feature of evidence-based medicine and knowledge translation. Systematic reviews (SRs) may or may not include a meta-analysis depending on the suitability of available data. They are often being criticised as 'secondary research' and denied the status of original research. Scientific journals play an important role in the publication process. How they appraise a given type of research influences the status of that research in the scientific community. We investigated the attitudes of editors of core clinical journals towards SRs and their value for publication.¦METHODS: We identified the 118 journals labelled as "core clinical journals" by the National Library of Medicine, USA in April 2009. The journals' editors were surveyed by email in 2009 and asked whether they considered SRs as original research projects; whether they published SRs; and for which section of the journal they would consider a SR manuscript.¦RESULTS: The editors of 65 journals (55%) responded. Most respondents considered SRs to be original research (71%) and almost all journals (93%) published SRs. Several editors regarded the use of Cochrane methodology or a meta-analysis as quality criteria; for some respondents these criteria were premises for the consideration of SRs as original research. Journals placed SRs in various sections such as "Review" or "Feature article". Characterization of non-responding journals showed that about two thirds do publish systematic reviews.¦DISCUSSION: Currently, the editors of most core clinical journals consider SRs original research. Our findings are limited by a non-responder rate of 45%. Individual comments suggest that this is a grey area and attitudes differ widely. A debate about the definition of 'original research' in the context of SRs is warranted
Factorization and Non-Factorization of In-Medium Four-Quark Condensates
It is well-established for the vacuum case that in the limit of a large
number of colors N_c the four-quark condensates factorize into products of the
two-quark condensate. It is shown that in the combined large-N_c and
linear-density approximation four-quark condensates do not factorize in a
medium of pions (finite temperature system) but do factorize in a medium of
nucleons (nuclear system).Comment: 4 page
Indigenous communities’ responses to the COVID-19 pandemic and consequences for maternal and neonatal health in remote Peruvian Amazon: a qualitative study based on routine programme supervision
Aim: To explore indigenous communities’ responses to the COVID-19 pandemic and its consequences for maternal and neonatal health (MNH) care in the Peruvian Amazon. Methods: Mamás del Río is a community-based, MNH programme with comprehensive supervision covering monthly meetings with community health workers (CHW), community leaders and health facilities. With the onset of the lockdown, supervisors made telephone calls to discuss measures against COVID-19, governmental support, CHW activities in communities and provision of MNH care and COVID-19 preparedness at facilities. As part of the programme’s ongoing mixed methods evaluation, we analysed written summaries of supervisor calls collected during the first 2 months of Peru’s lockdown. Results: Between March and May 2020, supervisors held two rounds of calls with CHWs and leaders of 68 communities and staff from 17 facilities. Most communities banned entry of foreigners, but about half tolerated residents travelling to regional towns for trade and social support. While social events were forbidden, strict home isolation was only practised in a third of communities as conflicting with daily routine. By the end of April, first clusters of suspected cases were reported in communities. COVID-19 test kits, training and medical face masks were not available in most rural facilities. Six out of seven facilities suspended routine antenatal and postnatal consultations while two-thirds of CHWs resumed home visits to pregnant women and newborns. Conclusions: Home isolation was hardly feasible in the rural Amazon context and community isolation was undermined by lack of external supplies and social support. With sustained community transmission, promotion of basic hygiene and mask use becomes essential. To avoid devastating effects on MNH, routine services at facilities need to be urgently re-established alongside COVID-19 preparedness plans. Community-based MNH programmes could offset detrimental indirect effects of the pandemic and provide an opportunity for local COVID-19 prevention and containment
Study protocol: Evaluation of the Mamás del Río programme - a community-based, maternal and neonatal health intervention in Rural Amazonian Peru
Study protocol for the outcome and process evaluation of the Mamás del Río programme – a community-based, maternal and neonatal health intervention aiming to improve ENC practices and healthcare seeking in rural Amazonian Peru through educational home visits by community-health workers, sensitization of traditional birth attendants and supportive facility strengthening
An exploration of the three-layer model including stakeholders, markets and technologies for assessments of residential smart grids
In this paper, a framework is presented for the evaluation of smart grid environment which is called the three-layer model. This three-layer model comprises three specific categories, or 'layers', namely, the stakeholder, market and technologies layers. Each layer is defined and explored herein, using an extensive literature study regarding their key elements, their descriptions and an overview of the findings from the literature. The assumption behind this study is that a solid understanding of each of the three layers and their interrelations will help in more effective assessment of residential smart grid pilots in order to better design products and services and deploy smart grid technologies in networks. Based on our review, we conclude that, in many studies, social factors associated with smart grid pilots, such as markets, social acceptance, and end-user and stakeholder demands, are most commonly defined as uncertainties and are therefore considered separately from the technical aspects of smart grids. As such, it is recommended that, in future assessments, the stakeholder and market layers should be combined with the technologies layer so as to enhance interaction between these three layers, and to be able to better evaluate residential smart energy systems in a multidisciplinary context.</p
QCD sum rule analysis for light vector and axial-vector mesons in vacuum and nuclear matter
Extending previous work we study the constraints of QCD sum rules on mass and
width of light vector and axial-vector mesons in vacuum and in a medium with
finite nuclear density. For the latter case especially the effect of nuclear
pions leading to vector-axial-vector mixing is included in the analysis.Comment: RevTeX, 32 pages, 10 eps figure
On QCD sum rules for vector mesons in nuclear medium
Vector mesons show up in the electromagnetic current-current correlator. QCD
sum rules provide a constraint on hadronic models for this correlator. This
constraint is discussed for the case of finite nuclear density concerning the
longitudinal as well as the transverse part of the current-current correlator
at finite three-momentum.Comment: RevTeX, 38 pages, 5 figure
A community-based survey on influenza and vaccination knowledge, perceptions and practices in Peru.
BACKGROUND: Although Peru provides safe and effective influenza vaccines free-of-charge, coverage among vaccine target groups like pregnant women and older adults remains low. To improve risk communication messages and vaccine uptake, we explored knowledge, perceptions and practices about influenza illness and vaccination. METHODS: A cross-sectional, community-based survey with a three-stage cluster sampling design was conducted in three cities in Peru. We included mothers of young children, pregnant women and persons ≥65 years. Participants completed a questionnaire about knowledge, perceptions and practices about influenza illness and vaccination against influenza during the past year. Generalized linear models were used to explore factors associated with vaccination in the past year. RESULTS: 624/645 (97%) mothers, 54/55 (98%) pregnant women and 622/673 (92%) older adults approached provided informed consent and were surveyed. While most mothers, pregnant women and older adults (94%, 96% and 91%, respectively) perceived influenza as a potentially serious illness, few pregnant women (13%) and older adults (34%) self-identified themselves as a target group for influenza vaccination. Only 28% of mothers, 19% pregnant women, and 27% older adults were vaccinated against influenza during the previous year. Among the participants that did not get vaccinated against influenza in the previous year, "being afraid of vaccination and its effects" was the most commonly cited barrier. Knowledge of the recommendation for annual vaccination was significantly associated with vaccination status among pregnant women (p = 0.048) and older adults (p = 0.004). CONCLUSION: Despite a government subsidized vaccine program, vaccine utilization remained low among pregnant women and older adults, who seemed typically unaware of their status as high-risk groups targeted for vaccination. Those aware of the recommendations for annual vaccination were more likely to be vaccinated. Information campaigns addressing fears and highlighting populations at risk for severe influenza illness that are targeted for vaccination might increase vaccine coverage in Peru
A nationwide evaluation of deceased donor kidney transplantation indicates detrimental consequences of early graft loss
Early graft loss (EGL) is a feared outcome of kidney transplantation. Consequently, kidneys with an anticipated risk of EGL are declined for transplantation. In the most favorable scenario, with optimal use of available donor kidneys, the donor pool size is balanced by the risk of EGL, with a tradeoff dictated by the consequences of EGL. To gauge the consequence of EGL we systematically evaluated its impact in an observational study that included all 10,307 deceased-donor kidney transplantations performed in The Netherlands between 1990 and 2018. Incidence of EGL, defined as graft loss within 90 days, in primary transplantation was 8.2% (699/8,511). The main causes were graft rejection (30%), primary nonfunction (25%), and thrombosis or infarction (20%). EGL profoundly impacted short- and long-term patient survival (adjusted hazard ratio; 95% confidence interval: 8.2; 5.1-13.2 and 1.7; 1.3-2.1, respectively). Of the EGL recipients who survived 90 days after transplantation (617/699) only 440 of the 617 were relisted for re-transplantation. Of those relisted, only 298 were ultimately re-transplanted leading to an actual re-transplantation rate of 43%. Noticeably, re-transplantation was associated with a doubled incidence of EGL, but similar long-term graft survival (adjusted hazard ratio 1.1; 0.6-1.8). Thus, EGL after kidney transplantation is a medical catastrophe with high mortality rates, low relisting rates, and increased risk of recurrent EGL following re-transplantation. This implies that detrimental outcomes also involve convergence of risk factors in recipients with EGL. The 8.2% incidence of EGL minimally impacted population mortality, indicating this incidence is acceptable
De novo sequencing, assembly and analysis of the genome of the laboratory strain Saccharomyces cerevisiae CEN.PK113-7D, a model for modern industrial biotechnology
Saccharomyces cerevisiae CEN.PK 113-7D is widely used for metabolic engineering and systems biology research in industry and academia. We sequenced, assembled, annotated and analyzed its genome. Single-nucleotide variations (SNV), insertions/deletions (indels) and differences in genome organization compared to the reference strain S. cerevisiae S288C were analyzed. In addition to a few large deletions and duplications, nearly 3000 indels were identified in the CEN.PK113-7D genome relative to S288C. These differences were overrepresented in genes whose functions are related to transcriptional regulation and chromatin remodelling. Some of these variations were caused by unstable tandem repeats, suggesting an innate evolvability of the corresponding genes. Besides a previously characterized mutation in adenylate cyclase, the CEN.PK113-7D genome sequence revealed a significant enrichment of non-synonymous mutations in genes encoding for components of the cAMP signalling pathway. Some phenotypic characteristics of the CEN.PK113-7D strains were explained by the presence of additional specific metabolic genes relative to S288C. In particular, the presence of the BIO1 and BIO6 genes correlated with a biotin prototrophy of CEN.PK113-7D. Furthermore, the copy number, chromosomal location and sequences of the MAL loci were resolved. The assembled sequence reveals that CEN.PK113-7D has a mosaic genome that combines characteristics of laboratory strains and wild-industrial strains
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