435 research outputs found

    MicroRNA expression profile in bovine cumulus–oocyte complexes: Possible role of let-7 and miR-106a in the development of bovine oocytes

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    The objectives of this study included: (1) identify the expression of miRNAs specific to bovine cumulus–oocyte complexes (COCs) during late oogenesis, (2) characterize the expression of candidate miRNAs as well as some miRNA processing genes, and (3) computationally identify and characterize the expression of target mRNAs for candidate miRNAs. Small RNAs in the 16–27 bp range were isolated from pooled COCs aspirated from 1- to 10-mm follicles of beef cattle ovaries and used to construct a cDNA library. A total 1798 putative miRNA sequences from the cDNA library of small RNA were compared to known miRNAs. Sixty-four miRNA clusters matched previously reported sequences in the miRBase database and 5 miRNA clusters had not been reported. TaqMan miRNA assays were used to confirm the expression of let-7b, let-7i, and miR-106a from independent collections of COCs. Real-time PCR assays were used to characterize expression of miRNA processing genes and target mRNAs (MYC and WEE1A) for the candidate miRNAs from independent collections of COCs. Expression data were analyzed using general linear model procedures for analysis of variance. The expression of let-7b and let-7i were not different between the cellular populations from various sized follicles. However, miR-106a expression was greater (P \u3c 0.01) in oocytes compared with COCs and granulosa cells. Furthermore, all the miRNA processing genes have greater expression (P \u3c 0.001) in oocytes compared with COCs and granulosa cells. The expression of potential target mRNAs for let-7 and let-7i (i.e., MYC), and miR-106a (i.e., WEE1A) were decreased (P \u3c 0.05) in oocytes compared with COCs and granulosa cells. These results demonstrate specific miRNAs within bovine COCs during late oogenesis and provide some evidence that miRNAs may play a role regulating maternal mRNAs in bovine oocytes

    BMI and cardiovascular function in children and adolescents of Mauritius Island

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    Among countries which have undergone a rapid socio-economic and nutrition transition over the past few decades, the Indian Ocean island of Mauritius is among those with the greatest surge in the prevalence of type 2 diabetes and CVD. The aim of the present study was to characterise the BMI and cardiovascular functions of children and adolescents of this at-risk population. Data were collected through measurements of anthropometry, resting heart rate and blood pressure in a nationally representative sample (n 2489) of children (5-10 years) and adolescents (11-18 years), and analysed according to sex and ethnic identity: South Asian Hindus and Muslims (both of Indian ancestry), Creole (of varying degrees of African ancestry) and Chinese (of mainland China ancestry). Based on standards of the WHO or International Obesity Task Force, one in six of these young individuals exhibit a high BMI-for-age. Analysis by ethnicity revealed that Creole males and females show higher BMI-for-age but also lower heart rate (P < 0·001) even after adjustment for BMI. Additionally, Chinese males and females show higher systolic blood pressure (P < 0·01), independently of BMI. None of these ethnic differences could be related to household income, diet type (vegetarian v. non-vegetarian) or to fruit consumption. This study in children and adolescents of this multi-ethnic at-risk population for CVD reveal ethnic differences in BMI-for-age as well as consistent BMI-independent ethnic differences in heart rate and systolic blood pressure. These findings underscore the need to establish the BMI-fat % relationship across the various ethnic groups and for more detailed investigations about their differences in lifestyle and dietary habits that might explain their differential cardiovascular functions prior to adulthood

    Three-dimensional random Voronoi tessellations: From cubic crystal lattices to Poisson point processes

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    We perturb the SC, BCC, and FCC crystal structures with a spatial Gaussian noise whose adimensional strength is controlled by the parameter a, and analyze the topological and metrical properties of the resulting Voronoi Tessellations (VT). The topological properties of the VT of the SC and FCC crystals are unstable with respect to the introduction of noise, because the corresponding polyhedra are geometrically degenerate, whereas the tessellation of the BCC crystal is topologically stable even against noise of small but finite intensity. For weak noise, the mean area of the perturbed BCC and FCC crystals VT increases quadratically with a. In the case of perturbed SCC crystals, there is an optimal amount of noise that minimizes the mean area of the cells. Already for a moderate noise (a>0.5), the properties of the three perturbed VT are indistinguishable, and for intense noise (a>2), results converge to the Poisson-VT limit. Notably, 2-parameter gamma distributions are an excellent model for the empirical of of all considered properties. The VT of the perturbed BCC and FCC structures are local maxima for the isoperimetric quotient, which measures the degre of sphericity of the cells, among space filling VT. In the BCC case, this suggests a weaker form of the recentluy disproved Kelvin conjecture. Due to the fluctuations of the shape of the cells, anomalous scalings with exponents >3/2 is observed between the area and the volumes of the cells, and, except for the FCC case, also for a->0. In the Poisson-VT limit, the exponent is about 1.67. As the number of faces is positively correlated with the sphericity of the cells, the anomalous scaling is heavily reduced when we perform powerlaw fits separately on cells with a specific number of faces

    The role of negative emotions in the social processes of entrepreneurship: Power rituals and shame-related appeasement behaviors

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    This paper examines the role of negative emotions in the social processes of entrepreneurship. Drawing on a study of Russian entrepreneurs, we develop a model of the emotional effects of social interactions between entrepreneurs and state officials. We found that negative emotions were elicited by these interactions and, in turn, fueled three forms of shame-related corrective appeasement behavior (reactive, anticipatory, and sporadic), which served to corrode entrepreneurial motivation and direct attention and energy away from business growth and development

    Anthropogenic Space Weather

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    Anthropogenic effects on the space environment started in the late 19th century and reached their peak in the 1960s when high-altitude nuclear explosions were carried out by the USA and the Soviet Union. These explosions created artificial radiation belts near Earth that resulted in major damages to several satellites. Another, unexpected impact of the high-altitude nuclear tests was the electromagnetic pulse (EMP) that can have devastating effects over a large geographic area (as large as the continental United States). Other anthropogenic impacts on the space environment include chemical release ex- periments, high-frequency wave heating of the ionosphere and the interaction of VLF waves with the radiation belts. This paper reviews the fundamental physical process behind these phenomena and discusses the observations of their impacts.Comment: 71 pages, 35 figure

    Observation of Orbitally Excited B_s Mesons

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    We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let

    Daratumumab, lenalidomide, and dexamethasone in relapsed/refractory myeloma: a cytogenetic subgroup analysis of POLLUX

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    High cytogenetic risk abnormalities confer poor outcomes in multiple myeloma patients. In POLLUX, daratumumab/lenalidomide/dexamethasone (D-Rd) demonstrated significant clinical benefit versus lenalidomide/dexamethasone (Rd) in relapsed/refractory multiple myeloma (RRMM) patients. We report an updated subgroup analysis of POLLUX based on cytogenetic risk. The cytogenetic risk was determined using fluorescence in situ hybridization/karyotyping; patients with high cytogenetic risk had t(4;14), t(14;16), or del17p abnormalities. Minimal residual disease (MRD; 10–5) was assessed via the clonoSEQ® assay V2.0. 569 patients were randomized (D-Rd, n = 286; Rd, n = 283); 35 (12%) patients per group had high cytogenetic risk. After a median follow-up of 44.3 months, D-Rd prolonged progression-free survival (PFS) versus Rd in standard cytogenetic risk (median: not estimable vs 18.6 months; hazard ratio [HR], 0.43; P < 0.0001) and high cytogenetic risk (median: 26.8 vs 8.3 months; HR, 0.34; P = 0.0035) patients. Responses with D-Rd were deep, including higher MRD negativity and sustained MRD-negativity rates versus Rd, regardless of cytogenetic risk. PFS on subsequent line of therapy was improved with D-Rd versus Rd in both cytogenetic risk subgroups. The safety profile of D-Rd by cytogenetic risk was consistent with the overall population. These findings demonstrate the improved efficacy of daratumumab plus standard of care versus standard of care in RRMM, regardless of cytogenetic risk

    Influence of psychological factors in food risk assessment - A review

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    Background: Typically, food-related risk assessments are carried out within a four step, technical framework, as detailed by the Codex Alimentarius Commission (World Health Organization/ Food and Agricultural Organization of the United Nations, 2015). However, the technical framework presumes a level of ‘objective risk’ and does not take into account that risk is complex and psychologically constructed, something which is rarely acknowledged within risk analysis as a whole. It is well documented that people's perceptions of risk are based on more than merely probability of occurrence, but reflect other non-technical psychological factors (e.g., risk origin, severity, controllability, familiarity). Moreover, the basis of these risk perceptions is largely similar for experts and non-experts. Scope and approach: In this review, we consider each stage of the risk assessment process from a psychological perspective, reviewing research on non-technical factors which could affect assessments of risk and subsequent risk management decisions, with a particular focus on food safety. Key Findings and Conclusions: We identify 12 factors from the psychological literature which could potentially influence how risks are assessed and characterised. Drawing on insights from this research, we propose a number of recommendations to standardise approaches in risk assessment. Acknowledging and working with the subjectivity of risk is key to ensuring the efficacy of the wider risk analysis process

    A pessimistic view of optimistic belief updating

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    Received academic wisdom holds that human judgment is characterized by unrealistic optimism, the tendency to underestimate the likelihood of negative events and overestimate the likelihood of positive events. With recent questions being raised over the degree to which the majority of this research genuinely demonstrates optimism, attention to possible mechanisms generating such a bias becomes ever more important. New studies have now claimed that unrealistic optimism emerges as a result of biased belief updating with distinctive neural correlates in the brain. On a behavioral level, these studies suggest that, for negative events, desirable information is incorporated into personal risk estimates to a greater degree than undesirable information (resulting in a more optimistic outlook). However, using task analyses, simulations and experiments we demonstrate that this pattern of results is a statistical artifact. In contrast with previous work, we examined participants’ use of new information with reference to the normative, Bayesian standard. Simulations reveal the fundamental difficulties that would need to be overcome by any robust test of optimistic updating. No such test presently exists, so that the best one can presently do is perform analyses with a number of techniques, all of which have important weaknesses. Applying these analyses to five experiments shows no evidence of optimistic updating. These results clarify the difficulties involved in studying human ‘bias’ and cast additional doubt over the status of optimism as a fundamental characteristic of healthy cognition
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