3,248 research outputs found
Crystallization and preliminary crystallographic data for the augmenter of liver regeneration
A new cellular growth factor termed augmenter of liver regeneration (ALR) has been crystallized. ALR has been shown to have a proliferative effect on liver cells while at the same time producing an immunosuppressive effect on liver-resident natural killer cells and liver-resident mononuclear leukocytes. In addition, ALR appears to play an important role in the synthesis and stabilization of mitochondrial gene transcripts inactively regenerating cells. ALR crystals diffract to beyond 2 Å resolution and belong to space group P21212, with a = 125.1, b = 108.1 and c = 38.5 Å. Based on four molecules per asymmetric unit, the Matthews coefficient is calculated to be 2.16 Å3 Da-1 which corresponds to a solvent content of 43%
The molecular control of tomato fruit quality traits: the trade off between visual attributes, shelf life and nutritional value
Tomato (Solanum lycopersicum) is an established model to study fleshy fruit development and ripening and is an important crop in terms of its economic and nutritional value. Tomato fruit quality is a function of metabolite content which is prone to physiological changes related to fruit development and ripening. It has been described some ripening tomato mutants, delayed fruit deterioration (DFD), non-ripening (NOR) and ripening-inhibitor (RIN) which substantially extend “shelf life” in tomato for up to several months when defined in terms of softening, water loss and resistance to postharvest biotic infection. However, it is not known whether this extension in “shelf life” is in fact a desirable objective from the perspective of nutritional quality of the fruits. The aim of this work was to use a metabolomics approach join to genomic tools to characterize compositional changes (sugars, amino acids, organic acids and carotenoids) of non-softening tomato mutants reported (DFD, NOR and RIN) in comparison with the normally softening fruits (Ailsa Craig and M82) during ripening and postharvest shelf-life. Important results related with ripening gene expression and metabolic evolutions are shown
Evolution: Complexity, uncertainty and innovation
Complexity science provides a general mathematical basis for evolutionary thinking. It makes us face the inherent, irreducible nature of uncertainty and the limits to knowledge and prediction. Complex, evolutionary systems work on the basis of on-going, continuous internal processes of exploration, experimentation and innovation at their underlying levels. This is acted upon by the level above, leading to a selection process on the lower levels and a probing of the stability of the level above. This could either be an organizational level above, or the potential market place. Models aimed at predicting system behaviour therefore consist of assumptions of constraints on the micro-level – and because of inertia or conformity may be approximately true for some unspecified time. However, systems without strong mechanisms of repression and conformity will evolve, innovate and change, creating new emergent structures, capabilities and characteristics. Systems with no individual freedom at their lower levels will have predictable behaviour in the short term – but will not survive in the long term. Creative, innovative, evolving systems, on the other hand, will more probably survive over longer times, but will not have predictable characteristics or behaviour. These minimal mechanisms are all that are required to explain (though not predict) the co-evolutionary processes occurring in markets, organizations, and indeed in emergent, evolutionary communities of practice. Some examples will be presented briefly
The effects of menstrual cycle stage and hormonal contraception on alcohol consumption and craving: A pilot investigation
Background and aims: Although alcohol research often comments on observed sex differences (i.e. patterns of consumption), there is a lack of investigation into the reasons for these differences. For females, the regular hormonal fluctuations across the menstrual cycle are a potential influencing factor for alcohol consumption. In this pilot we aimed to investigate the relationship between menstrual cycle phase (follicular-phase [FP] and luteal-phase [LP]) and status (naturally-cycling [NC] and hormonal-contraception [HC]) on alcohol consumption and craving of casual drinkers, and identify potential influencing factors in this relationship. Methods: Study One: participants (n = 28; 15 HC, 13 NC) were either NC or HC (between subject factor: hormonal status) and attended two lab-based sessions corresponding with their FP and LP (within factor: cycle phase [NC] or time [HC]). Participants completed a mock alcohol taste-test, in addition to pre- and post-consumption measures of craving, anxiety, stress, and mood. Study Two: participants (n = 262; 144 HC, 118 NC) were either NC or HC (between subject factor) and completed an online study assessing menstrual cycle phase, alcohol use, craving, impulsivity, and stress. Results: Study One: A significant effect of cycle phase was found on alcohol craving (p = .019): craving was higher during the FP compared to the LP for NC participants, with HC participants showing no difference across sessions. There was no effect of phase or status on alcohol consumption, stress, or mood (ps > .05). Study Two: Regression analyses showed that age, craving, impulsivity and stress were significantly associated with alcohol consumption for NC participants (ps < .05), however only age and craving were associated with consumption for the HC participants (ps < .001). Conclusions: Alcohol craving was higher during the follicular, compared to the luteal, phase for the naturally cycling group, and different factors may be associated with drinking behaviour across women who are NC and those using HC. Future alcohol research should consider the menstrual cycle and contraceptive status for females
Social cohesion as a real-life phenomenon: assessing the explanatory power of the universalist and particularist perspectives
Chordal Editing is Fixed-Parameter Tractable
Graph modification problems typically ask for a small set of operations that transforms a given graph to have a certain property. The most commonly considered operations include vertex deletion, edge deletion, and edge addition; for the same property, one can define significantly different versions by allowing different operations. We study a very general graph modification problem that allows all three types of operations: given a graph and integers k(1), k(2), and k(3), the CHORDAL EDITING problem asks whether G can be transformed into a chordal graph by at most k(1) vertex deletions, k(2) edge deletions, and k(3) edge additions. Clearly, this problem generalizes both CHORDAL DELETION and CHORDAL COMPLETION (also known as MINIMUM FILL-IN). Our main result is an algorithm for CHORDAL EDITING in time 2(O(klog k)). n(O(1)), where k:=k(1) + k(2) + k(3) and n is the number of vertices of G. Therefore, the problem is fixed-parameter tractable parameterized by the total number of allowed operations. Our algorithm is both more efficient and conceptually simpler than the previously known algorithm for the special case CHORDAL DELETION
Rotation and Spin in Physics
We delineate the role of rotation and spin in physics, discussing in order
Newtonian classical physics, special relativity, quantum mechanics, quantum
electrodynamics and general relativity. In the latter case, we discuss the
generalization of the Kepler formula to post-Newtonian order )
including spin effects and two-body effects. Experiments which verify the
theoretical results for general relativistic spin-orbit effects are discussed
as well as efforts being made to verify the spin-spin effects
Menstrual Cycle Phase, Hormonal Contraception, and Alcohol Consumption in Premenopausal Females: A Systematic Review
Women may be particularly vulnerable to alcohol harm, but many current theories fail to acknowledge the unique factors that influence female alcohol use. The biological mechanisms underlying female alcohol consumption have largely been unexplored, although recently the menstrual cycle has been highlighted as a potentially important factor. This systematic review, using a narrative synthesis, examined the association between the menstrual cycle phases on alcohol consumption and aimed to determine whether hormonal contraception influences this association. The review follows PRISMA and SWiM guidelines, registration number: CRD42018112744. Electronic searches were conducted in the relevant databases with keyword (e.g., “menstrua*”; “alcohol”). Thousand six hundred and sixty-two titles were identified, 16 of which were included in the review. Results were inconsistent regarding whether an association between menstrual cycle phase and alcohol consumption was found. Furthermore, there was inconsistency regarding which phase was associated with higher consumption, and different factors were reported to have moderated the direction, e.g., family history of alcohol use disorder (AUD), premenstrual syndrome (PMS). These conflicting results may be partly explained by variability in both study quality and design, and differences in measurement of cycle phase and alcohol consumption. More robust research is needed before conclusions can be drawn with regard to the role of the menstrual cycle and hormonal contraception on female drinking behavior. This review provides recommendations to strengthen research in this area
Forty years studying British politics : the decline of Anglo-America
The still present belief some 40 years ago that British politics was both exceptional and superior has been replaced by more theoretically sophisticated analyses based on a wider and more rigorously deployed range of research techniques, although historical analysis appropriately remains important. The American influence on the study of British politics has declined, but the European Union dimension has not been fully integrated. The study of interest groups has been in some respects a fading paradigm, but important questions related to democratic health have still to be addressed. Public administration has been supplanted by public policy, but economic policy remains under-studied. A key challenge for the future is the study of the management of expectations
Total humerus replacement for osteosarcoma with proximal part of humerus: a case report
Incisional biopsy and intramedullary pinning were performed for pathological fracture associated with a malignant bone tumor of the proximal humerus. Osteosarcoma, for which preoperative chemotherapy had been performed, was confirmed by postoperative pathological examination. To achieve wide resection and acquire a safe resected margin, total humerus replacement was performed, and the whole humerus was reconstructed using the Howmedica Modular Reconstruction system. The patient resumed normal activities, although mild contracture of the elbow joint remains 8 years after surgery
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