Summary
Background
The human virome consists of animal‐cell viruses causing transient infections, bacteriophage (phage) predators of bacteria and archaea, endogenous retroviruses and viruses causing ...persistent and latent infections. High‐throughput, inexpensive, sensitive sequencing methods and metagenomics now make it possible to study the contribution dsDNA, ssDNA and RNA virus‐like particles make to the human virome, and in particular the intestinal virome.
Aim
To review and evaluate the pioneering studies that have attempted to characterise the human virome and generated an increased interest in understanding how the intestinal virome might contribute to maintaining health, and the pathogenesis of chronic diseases.
Methods
Relevant virome‐related articles were selected for review following extensive language‐ and date‐unrestricted, electronic searches of the literature.
Results
The human intestinal virome is personalised and stable, and dominated by phages. It develops soon after birth in parallel with prokaryotic communities of the microbiota, becoming established during the first few years of life. By infecting specific populations of bacteria, phages can alter microbiota structure by killing host cells or altering their phenotype, enabling phages to contribute to maintaining intestinal homeostasis or microbial imbalance (dysbiosis), and the development of chronic infectious and autoimmune diseases including HIV infection and Crohn's disease, respectively.
Conclusions
Our understanding of the intestinal virome is fragmented and requires standardised methods for virus isolation and sequencing to provide a more complete picture of the virome, which is key to explaining the basis of virome‐disease associations, and how enteric viruses can contribute to disease aetiologies and be rationalised as targets for interventions.
As online and blended learning has become common place educational strategy in higher education, educators need to reconceptualise fundamental issues of teaching, learning and assessment in non ...traditional spaces. These issues include concepts such as validity and reliability of assessment in online environments in relation to serving the intended purposes, as well as understanding how formative assessment functions within online and blended learning. This article provides a systematic qualitative review of the research literature on online formative assessment in higher education. As an integrative narrative review, the method applied in this review entailed systematic searching, reviewing, and writing this review of the literature to bring together key themes and findings of research in this field. The authors applied qualitative thematic criteria in selecting and reviewing the available literature from which they focused on identifying and analyzing the core themes that are central to the concept of formative assessment with a key focus on application of formative assessment within blended and online contexts. Various techniques were identified for formative assessment by the individual, peers and the teacher, many of which were linked with online tools such as self-test quiz tools, discussion forums and e-portfolios. The benefits identified include improvement of learner engagement and centrality in the process as key actors, including the development of a learning community. The key findings are that effective online formative assessment can foster a learner and assessment centered focus through formative feedback and enhanced learner engagement with valuable learning experiences. Ongoing authentic assessment activities and interactive formative feedback were identified as important characteristics that can address threats to validity and reliability within the context of online formative assessment.
► Formative assessment functions within online learning. ► Formative assessment by the individual, peers and the teacher. ► Threats to validity and reliability in the context of online formative assessment. ► Ongoing authentic assessment deters threats to validity and reliability. ► Interactive formative feedback addresses threats to validity and reliability.
The purpose of this article is to review research on the construction of gender ideology and its consequences. The article begins with a summary of research focused on measuring gender ...ideology—individuals' levels of support for a division of paid work and family responsibilities that is based on the belief in gendered separate spheres. We describe the ways this concept has been operationalized in widely available data sources and provide a categorization schema for the items used to measure gender ideology. We also review the research predicting gender ideology, focusing on social and demographic characteristics while concurrently examining studies using cross-sectional, trend, and panel data. Finally, this article summarizes research focused on the consequences of gender ideology, both in families and family-related behaviors and in other areas of social life where beliefs about gender are relevant, such as the workplace. We conclude with implications for future research for measurement tools, predictors of gender ideology, and consequences of ideology in individuals' lives.
: Alpha-glucosidase inhibitors (AGIs) - oral antihyperglycemic drugs, inhibit upper gastrointestinal enzymes that break down complex carbohydrates into glucose. As a result, the absorption of glucose ...is delayed, postprandial glucose reduced, and glycemic control improved.
: In this review, the authors describe the current recommendations on the use of the three major approved AGIs (acarbose, miglitol, voglibose). Efficacy and safety parameters together with ethnic considerations have been highlighted throughout the manuscript. The article also discusses potential diabetes prevention and cardiovascular effects of these medications.
: The overall safety and efficacy of this class of drug appears to be high: AGIs do not increase the risk of hypoglycemia, do not cause weight gain; they also significantly improve postprandial hyperglycemia, have been associated with the reduction in risk factors for cardiovascular disease and may also delay the progression of prediabetes to T2DM. In general, we continue to believe that acarbose, miglitol, and voglibose should be used as third-line add on treatment options to other anti-hyperglycemic agents. However, this class can have earlier consideration in elderly and/or when metformin is contraindicated.
Mechanisms of control of microRNA biogenesis Davis-Dusenbery, Brandi N; Hata, Akiko
Journal of Biochemistry/The journal of biochemistry,
10/2010, Letnik:
148, Številka:
4
Journal Article
Recenzirano
Odprti dostop
MicroRNAs (miRNAs) are a class of ~22 nt non-coding RNAs that control diverse biological functions in animals, plants and unicellular eukaryotes by promoting degradation or inhibition of translation ...of target mRNAs. miRNA expression is often tissue specific and developmentally regulated. Aberrant expression of miRNAs has been linked to developmental abnormalities and human diseases, including cancer and cardiovascular disorders. The recent identification of mechanisms of miRNA biogenesis regulation uncovers that various factors or growth factor signalling pathways control every step of the miRNA biogenesis pathway. Here, we review the mechanisms that control the regulation of miRNA biogenesis discovered in human cells. Further understanding of the mechanisms that control of miRNA biogenesis may allow the development of tools to modulate the expression of specific miRNAs, which is crucial for the development of novel therapies for human disorders derived from aberrant expression of miRNAs.
Subseasonal weather prediction can reduce economic disruption and loss of life, especially during "windows of opportunity" when noteworthy events in the Earth system are followed by characteristic ...weather patterns. Sudden stratospheric warmings (SSWs), breakdowns of the winter stratospheric polar vortex, are one such event. They often precede warm temperatures in Northern Canada and cold, stormy weather throughout Europe and the United States - including the most recent SSW on January 5th, 2021. Here we assess the drivers of surface weather in the weeks following the SSW through initial condition "scrambling" experiments using the real-time CESM2(WACCM6) Earth system prediction framework. We find that the SSW itself had a limited impact, and that stratospheric polar vortex stretching and wave reflection had no discernible contribution to the record cold in North America in February. Instead, the tropospheric circulation and bidirectional coupling between the troposphere and stratosphere were dominant contributors to variability.
microRNAs are small, non-coding RNAs that influence diverse biological functions through the repression of target genes during normal development and pathological responses. Widespread use of ...microRNA arrays to profile microRNA expression has indicated that the levels of many microRNAs are altered during development and disease. These findings have prompted a great deal of investigation into the mechanism and function of microRNA-mediated repression. However, the mechanisms which govern the regulation of microRNA biogenesis and activity are just beginning to be uncovered. Following transcription, mature microRNA are generated through a series of coordinated processing events mediated by large protein complexes. It is increasingly clear that microRNA biogenesis does not proceed in a 'one-size-fits-all' manner. Rather, individual classes of microRNAs are differentially regulated through the association of regulatory factors with the core microRNA biogenesis machinery. Here, we review the regulation of microRNA biogenesis and activity, with particular focus on mechanisms of post-transcriptional control. Further understanding of the regulation of microRNA biogenesis and activity will undoubtedly provide important insights into normal development as well as pathological conditions such as cardiovascular disease and cancer.
The phenotype of vascular smooth muscle cells (VSMCs) is dynamically regulated in response to various stimuli. In a cellular process known as phenotype switching, VSMCs alternate between a ...contractile and synthetic phenotype state. Deregulation of phenotype switching is associated with vascular disorders such as atherosclerosis, restenosis after angioplasty, and pulmonary hypertension. An important role for microRNAs (miRNAs) in VSMC development and phenotype switching has recently been uncovered. Individual miRNAs are involved in promoting both contractile and synthetic VSMC phenotype. In this review, we summarize recent advances in the understanding of miRNA function in the regulation of VSMC phenotype regulation.
Numerous studies have concluded that historical Hadley cell expansion simulated in reanalyses is much larger than the future expansion predicted by climate model simulations. Is Hadley cell expansion ...too weak in climate models, or are the trends in reanalyses spuriously large? This study shows that the mean meridional circulation in reanalyses generally does not conserve mass. The mass imbalance projects onto trends in the Hadley cell edge latitudes by modifying both the mean and anomalous circulation. In correcting for the imbalance, the majority of Hadley cell expansion trends in early‐generation reanalyses in both hemispheres are revised to be smaller in magnitude, bringing them into closer agreement with the trends in modern reanalyses and climate models. While the methodology presented here is statistical in nature, it produces quantitatively similar results to a more sophisticated mass budget correction method.
Plain Language Summary
Reanalyses are weather forecast models that use observations to constrain hindcasts of the past evolution of Earth's atmosphere. They are one tool used to study the Hadley cells, two large circulation cells in the tropics with far‐reaching impacts on Earth's climate. The amount the Hadley cells expanded in older reanalysis products was much larger than what was simulated in climate models. However, some of this expansion is due to the violation of a basic physical law. When this is corrected, the expansion in older reanalyses is closer to the expansion in more modern reanalyses. It is possible that some of the supposed discrepancy between models and reanalyses was due to these sorts of problems in the older reanalyses.
Key Points
Hadley cell expansion trends in early‐generation reanalyses are larger than those in modern reanalyses
The majority of these larger trends are impacted by mass nonconservation in the mean meridional circulation
When this is corrected, Hadley cell expansion trends in early‐generation reanalyses converge toward those in modern reanalyses
This is the first of two papers that document the creation of the New European Wind Atlas (NEWA). It describes the sensitivity analysis and evaluation procedures that formed the basis for choosing ...the final setup of the mesoscale model simulations of the wind atlas. The suitable combination of model setup and parameterizations, bound by practical constraints, was found for simulating the climatology of the wind field at turbine-relevant heights with the Weather Research and Forecasting (WRF) model. Initial WRF model sensitivity experiments compared the wind climate generated by using two commonly used planetary boundary layer schemes and were carried out over several regions in Europe. They confirmed that the most significant differences in annual mean wind speed at 100 m a.g.l. (above ground level) mostly coincide with areas of high surface roughness length and not with the location of the domains or maximum wind speed. Then an ensemble of more than 50 simulations with different setups for a single year was carried out for one domain covering northern Europe for which tall mast observations were available. We varied many different parameters across the simulations, e.g. model version, forcing data, various physical parameterizations, and the size of the model domain. These simulations showed that although virtually every parameter change affects the results in some way, significant changes in the wind climate in the boundary layer are mostly due to using different physical parameterizations, especially the planetary boundary layer scheme, the representation of the land surface, and the prescribed surface roughness length. Also, the setup of the simulations, such as the integration length and the domain size, can considerably influence the results. We assessed the degree of similarity between winds simulated by the WRF ensemble members and the observations using a suite of metrics, including the Earth Mover's Distance (EMD), a statistic that measures the distance between two probability distributions. The EMD was used to diagnose the performance of each ensemble member using the full wind speed and direction distribution, which is essential for wind resource assessment. We identified the most realistic ensemble members to determine the most suitable configuration to be used in the final production run, which is fully described and evaluated in the second part of this study (Dörenkämper et al., 2020).
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