204 research outputs found
Polarized inclusive leptoproduction, , and the hadron helicity density matrix, : possible measurements and predictions
We discuss the production of hadrons in polarized lepton nucleon interactions
and in the current jet fragmentation region; using the QCD hard scattering
formalism we compute the helicity density matrix of the hadron and show how its
elements, when measurable, can give information on the spin structure of the
nucleon and the spin dependence of the quark fragmentation process. The cases
of vector mesons and baryons are considered in more details
and, within simplifying assumptions, some estimates are given.Comment: 17 pages + 4 figures, plain LATeX, figures appended as uuencoded,
compressed postscript fil
Biomarkers of Extracellular Matrix Metabolism (MMP-9 and TIMP-1) and Risk of Stroke, Myocardial Infarction, and Cause-Specific Mortality: Cohort Study
Objective: Turnover of the extracellular matrix in all solid organs is governed mainly by a balance between the degrading matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). An altered extracellular matrix metabolism has been implicated in a variety of diseases. We investigated relations of serum levels of MMP-9 and TIMP-1 to mortality risk from an etiological perspective. Design: The prospective Uppsala Longitudinal Study of Adult Men (ULSAM) cohort, followed from 1991–1995 for up to 18.1 years. A random population-based sample of 1,082 71-year-old men, no loss to follow-up. Endpoints were all-cause (n = 628), cardiovascular (n = 230), non-cardiovascular (n = 398) and cancer mortality (n = 178), and fatal or non-fatal myocardial infarction (n = 138) or stroke (n = 163). Results: Serum MMP-9 and TIMP-1 levels were associated with risk of all-cause mortality (Cox proportional hazard ratio [HR] per standard deviation 1.10, 95% confidence interval [CI] 1.03–1.19; and 1.11, 1.02–1.20; respectively). TIMP-1 levels were mainly related to risks of cardiovascular mortality and stroke (HR per standard deviation 1.22, 95% CI 1.09–1.37; and 1.18, 1.04–1.35; respectively). All relations except those of TIMP-1 to stroke risk were attenuated by adjustment for cardiovascular disease risk factors. Relations in a subsample without cardiovascular disease or cancer were similar to those in the total sample. Conclusion: In this community-based cohort of elderly men, serum MMP-9 and TIMP-1 levels were related to mortality risk. An altered extracellular matrix metabolism may be involved in several detrimental pathways, and circulating MMP-9 or TIMP-1 levels may be relevant markers thereof
Расширенная оценка технологической сложности отливок на основе применения методов нейросетей
Материалы XIII Междунар. науч.-техн. конф. (науч. чтения, посвящ. 125-летию со дня рождения П. О. Сухого), Гомель, 22 окт. 2020 г
Early growth response 1 regulates hematopoietic support and proliferation in human primary bone marrow stromal cells
Human bone marrow stromal cells (BMSC) are key elements of the
hematopoietic environment and they play a central role in bone
and bone marrow physiology. However, how key stromal cell
functions are regulated is largely unknown. We analyzed the role of the
immediate early response transcription factor EGR1 as key stromal cell
regulator and found that EGR1 was highly expressed in prospectivelyisolated primary BMSC, down-regulated upon culture, and low in noncolony-forming CD45neg stromal cells. Furthermore, EGR1 expression
was lower in proliferative regenerating adult and fetal primary cells compared to adult steady-state BMSC. Overexpression of EGR1 in stromal
cells induced potent hematopoietic stroma support as indicated by an
increased production of transplantable CD34+
CD90+ hematopoietic stem
cells in expansion co-cultures. The improvement in bone marrow stroma
support function was mediated by increased expression of hematopoietic supporting genes, such as VCAM1 and CCL28. Furthermore, EGR1
overexpression markedly decreased stromal cell proliferation whereas
EGR1 knoc
Bilateral Sensory Abnormalities in Patients with Unilateral Neuropathic Pain; A Quantitative Sensory Testing (QST) Study
In patients who experience unilateral chronic pain, abnormal sensory perception at the non-painful side has been reported. Contralateral sensory changes in these patients have been given little attention, possibly because they are regarded as clinically irrelevant. Still, bilateral sensory changes in these patients could become clinically relevant if they challenge the correct identification of their sensory dysfunction in terms of hyperalgesia and allodynia. Therefore, we have used the standardized quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain (DFNS) to investigate somatosensory function at the painful side and the corresponding non-painful side in unilateral neuropathic pain patients using gender- and age-matched healthy volunteers as a reference cohort. Sensory abnormalities were observed across all QST parameters at the painful side, but also, to a lesser extent, at the contralateral, non-painful side. Similar relative distributions regarding sensory loss/gain for non-nociceptive and nociceptive stimuli were found for both sides. Once a sensory abnormality for a QST parameter at the affected side was observed, the prevalence of an abnormality for the same parameter at the non-affected side was as high as 57% (for Pressure Pain Threshold). Our results show that bilateral sensory dysfunction in patients with unilateral neuropathic pain is more rule than exception. Therefore, this phenomenon should be taken into account for appropriate diagnostic evaluation in clinical practice. This is particularly true for mechanical stimuli where the 95% Confidence Interval for the prevalence of sensory abnormalities at the non-painful side ranges between 33% and 50%
The mosaic oat genome gives insights into a uniquely healthy cereal crop
Cultivated oat (Avena sativa L.) is an allohexaploid (AACCDD, 2n = 6x = 42) thought to have been domesticated more than 3,000 years ago while growing as a weed in wheat, emmer and barley fields in Anatolia1,2. Oat has a low carbon footprint, substantial health benefits and the potential to replace animal-based food products. However, the lack of a fully annotated reference genome has hampered efforts to deconvolute its complex evolutionary history and functional gene dynamics. Here we present a high-quality reference genome of A. sativa and close relatives of its diploid (Avena longiglumis, AA, 2n = 14) and tetraploid (Avena insularis, CCDD, 2n = 4x = 28) progenitors. We reveal the mosaic structure of the oat genome, trace large-scale genomic reorganizations in the polyploidization history of oat and illustrate a breeding barrier associated with the genome architecture of oat. We showcase detailed analyses of gene families implicated in human health and nutrition, which adds to the evidence supporting oat safety in gluten-free diets, and we perform mapping-by-sequencing of an agronomic trait related to water-use efficiency. This resource for the Avena genus will help to leverage knowledge from other cereal genomes, improve understanding of basic oat biology and accelerate genomics-assisted breeding and reanalysis of quantitative trait studies
A framework to assess the resilience of farming systems
Agricultural systems in Europe face accumulating economic, ecological and societal challenges, raising concerns
about their resilience to shocks and stresses. These resilience issues need to be addressed with a focus on the
regional context in which farming systems operate because farms, farmers’ organizations, service suppliers and
supply chain actors are embedded in local environments and functions of agriculture. We define resilience of a farming
system as its ability to ensure the provision of the system functions in the face of increasingly complex and
accumulating economic, social, environmental and institutional shocks and stresses, through capacities of robustness,
adaptability and transformability. We (i) develop a framework to assess the resilience of farming systems, and (ii)
present a methodology to operationalize the framework with a view to Europe’s diverse farming systems. The
framework is designed to assess resilience to specific challenges (specified resilience) as well as a farming system’s
capacity to deal with the unknown, uncertainty and surprise (general resilience). The framework provides a heuristic to
analyze system properties, challenges (shocks, long-term stresses), indicators to measure the performance of system
functions, resilience capacities and resilience-enhancing attributes. Capacities and attributes refer to adaptive cycle
processes of agricultural practices, farm demographics, governance and risk management. The novelty of the
framework pertains to the focal scale of analysis, i.e. the farming system level, the consideration of accumulating
challenges and various agricultural processes, and the consideration that farming systems provide multiple functions
that can change over time. Furthermore, the distinction between three resilience capacities (robustness, adaptability,
transformability) ensures that the framework goes beyond narrow definitions that limit resilience to robustness. The
methodology deploys a mixed-methods approach: quantitative methods, such as statistics, econometrics and
modelling, are used to identify underlying patterns, causal explanations and likely contributing factors; while qualitative
methods, such as interviews, participatory approaches and stakeholder workshops, access experiential and contextual
knowledge and provide more nuanced insights. More specifically, analysis along the framework explores multiple
nested levels of farming systems (e.g. farm, farm household, supply chain, farming system) over a time horizon of 1-2
generations, thereby enabling reflection on potential temporal and scalar trade-offs across resilience attributes. The
richness of the framework is illustrated for the arable farming system in Veenkoloniën, the Netherlands. The analysis
reveals a relatively low capacity of this farming system to transform and farmers feeling distressed about
transformation, while other members of their households have experienced many examples of transformation
Melanocortin-1 receptor, skin cancer and phenotypic characteristics (M-SKIP) project
Background: For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods. Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer dev
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