Quiver Structure of Heterotic Moduli

We analyse the vector bundle moduli arising from generic heterotic compactifications from the point of view of quiver representations. Phenomena such as stability walls, crossing between chambers of supersymmetry, splitting of non-Abelian bundles and dynamic generation of D-terms are succinctly encoded into finite quivers. By studying the Poincar\'e polynomial of the quiver moduli space using the Reineke formula, we can learn about such useful concepts as Donaldson-Thomas invariants, instanton transitions and supersymmetry breaking.Comment: 38 pages, 5 figures, 1 tabl

Historic landmarks in clinical transplantation: Conclusions from the consensus conference at the University of California, Los Angeles

The transplantation of organs, cells, and tissues has burgeoned during the last quarter century, with the development of multiple new specialty fields. However, the basic principles that made this possible were established over a three-decade period, beginning during World War II and ending in 1974. At the historical consensus conference held at UCLA in March 1999, 11 early workers in the basic science or clinical practice of transplantation (or both) reached agreement on the most significant contribution of this era that ultimately made transplantation the robust clinical discipline it is today. These discoveries and achievements are summarized here is six tables and annotated with references

Application of feedback principles to marking proformas increases student efficacy, perceived utility of feedback, and likelihood of use

Pedagogical and psychological literature identifies numerous factors contributing to feedback effectiveness, including type, frequency, and specificity (e.g., Gibbs & Simpson, 2004). Despite this wealth of research, feedback practice at universities is often reported as problematic or poor by students (NSS; Williams & Kane, 2008; 2009) despite lecturers perceiving their feedback as useful (Carless, 2006; Maclellan, 2001). The present research employed a quantitative counterbalanced experimental design to compare the perceived utility of a pedagogically informed feedback proforma, designed to provide detailed, timely, and constructive feedback, to standard practice. Results suggest that the presentation of feedback is important to students; more functional and comprehensible feedback increases the likelihood of students using the feedback provided, and can reduce likely marking time per script without compromising perceived feedback quality. Further to this, post-submission feedback proformas increase students’ confidence in their ability to complete the assignment when provided alongside the assignment title. In summary, the research supports the application of principles of feedback in the provision of summative feedback to enhance students’ likelihood of use, perceived value of the feedback received, and confidence

The free retraction of natural rubber: A momentum-based model

LBT thanks the Soft Matter Group for postdoctoral funding. The authors are very grateful for the use of the Vision Research Phantom V7.3 high speed camera which was borrowed from the EPSRC (Engineering and Physical Sciences Research Council) Engineering Instrument Pool, UK

Review on the Economic Impacts of Solar Thermal Power Plants

Data availability: No data was used for the research described in the article.Copyright © 2023 The Author(s). A systematic literature review on the economic performance of solar thermal power plants including integrated solar combined cycle (ISCC) plants was conducted. A number of solar thermal technologies like parabolic trough (PT), solar tower (ST), linear Fresnel reflector (LFR) and solar dish (SD) were evaluated. The evaluation revealed that solar tower plants typically had the highest capital costs, followed by parabolic-trough and linear Fresnel plants. The results of the studies showed that at smaller capacities of 10–50 MW, PT plants achieved lower LCOE than ST plants, while at larger capacities of 100 MW and above, ST tend to have lower LCOE than PT. There was limited comparative studies on the economic performance of LFR and SD plants. Hence, future studies should focus on the economic impact of different solar thermal technologies including LFR and SD of various capacities using homogeneous modelling conditions. The economic performance of direct steam generation (DSG)-ISCC plants was compared to ISCC, combined cycle gas turbine (CCGT) and conventional solar thermal plants and the results showed that DSG-ISCC plants achieved the lowest LCOE values. Studies also showed that in general, hybrid plants achieved lower LCOE than standalone solar thermal plants. LCOE and capital costs were the dominant financial metrics used in the literature, with very few studies using total life cycle cost, revenues, payback time and internal rate of return. Future studies should include these metrics in order to provide a comprehensive financial assessment of solar thermal power plants, enabling their economic performance to be compared with other renewable and non-renewable energy systems.EU Horizon 2020 research and innovation programme, Application of Solar Thermal processes in Industrial Processes (ASTEP), under grant agreement No 884411

Modelling Motivational Dynamics: Demonstrating When, Why, and How We Self-Regulate Motivation

Motivation quality affects the initiation and maintenance of behavior and physical and psychological health. Despite this, we understand little about how situational fluctuations occur and are regulated. In this paper we analyze the utility of applying basic psychological needs theory (a sub-theory of self-determination theory) and reversal theory as frameworks for understanding- ing motivational dynamics. Specifically, we posit a causal model linking acute consequences of need satisfaction and the purpose and direction of meta-motivational state shifts. This model is tested in two sequential experiments, demonstrating: (i) that thwarting or satisfying psychological​ needs increases meta-motivational reversal frequency and (ii) that individuals use meta-motivational shifts to compensate for imbalances in need satisfaction. Broad-ranging implications include informing therapeutic support for preventing maladaptive emotions and behaviors and promoting psychological health and well-being. In respect to modelling the dynamics of human motivation, this study adds clarity to understanding when (following need deprivation), why (to regain and balance need satisfaction), and how (through changing meta- motivational states) we self-regulate

Abdominal aortic calcification quantified by the Morphological Atherosclerotic Calcification Distribution (MACD) index is associated with features of the metabolic syndrome

<p>Abstract</p> <p>Background</p> <p>Abdominal aortic calcifications (AAC) predict cardiovascular mortality. A new scoring model for AAC, the Morphological Atherosclerotic Calcification Distribution (MACD) index may contribute with additional information to the commonly used Aortic Calcification Severity (AC24) score, when predicting death from cardiovascular disease (CVD). In this study we investigated associations of MACD and AC24 with traditional metabolic-syndrome associated risk factors at baseline and after 8.3 years follow-up, to identify biological parameters that may account for the differential performance of these indices.</p> <p>Methods</p> <p>Three hundred and eight healthy women aged 48 to 76 years, were followed for 8.3 ± 0.3 years. AAC was quantified using lumbar radiographs. Baseline data included age, weight, blood pressure, blood lipids, and glucose levels. Pearson correlation coefficients were used to test for relationships.</p> <p>Results</p> <p>At baseline and across all patients, MACD correlated with blood glucose (r²= 0.1, P< 0.001) and to a lesser, but significant extent with traditional risk factors (p < 0.01) of CVD. In the longitudinal analysis of correlations between baseline biological parameters and the follow-up calcification assessment using radiographs we found LDL-cholesterol, HDL/LDL, and the ApoB/ApoA ratio significantly associated with the MACD (P< 0.01). In a subset of patients presenting with calcification at both baseline and at follow-up, all cholesterol levels were significantly associated with the MACD (P< 0.01) index. AC24 index was not correlated with blood parameters.</p> <p>Conclusion</p> <p>Patterns of calcification identified by the MACD, but not the AC24 index, appear to contain useful biological information perhaps explaining part of the improved identification of risk of cardiovascular death of the MACD index. Correlations of MACD but not the AC24 with glucose levels at baseline suggest that hyperglycemia may contribute to unique patterns of calcification indicated by the MACD.</p

High (but Not Low) Urinary Iodine Excretion Is Predicted by Iodine Excretion Levels from Five Years Ago

Background: It has not been investigated whether there are associations between urinary iodine (UI) excretion measurements some years apart, nor whether such an association remains after adjustment for nutritional habits. The aim of the present study was to investigate the relation between iodine-creatinine ratio (ICR) at two measuring points 5 years apart. Methods: Data from 2,659 individuals from the Study of Health in Pomerania were analyzed. Analysis of covariance and Poisson regressions were used to associate baseline with follow-up ICR. Results: Baseline ICR was associated with follow-up ICR. Particularly, baseline ICR >300 mu g/g was related to an ICR >300 mu g/g at follow-up (relative risk, RR: 2.20; p < 0.001). The association was stronger in males (RR: 2.64; p < 0.001) than in females (RR: 1.64; p = 0.007). In contrast, baseline ICR <100 mu g/g was only associated with an ICR <100 mu g/g at follow-up in males when considering unadjusted ICR. Conclusions: We detected only a weak correlation with respect to low ICR. Studies assessing iodine status in a population should take into account that an individual with a low UI excretion in one measurement is not necessarily permanently iodine deficient. On the other hand, current high ICR could have been predicted by high ICR 5 years ago. Copyright (C) 2011 S. Karger AG, Base

Wikipedia as an encyclopaedia of life

In his 2003 essay E O Wilson outlined his vision for an &#x201c;encyclopaedia of life&#x201d; comprising &#x201c;an electronic page for each species of organism on Earth&#x201d;, each page containing &#x201c;the scientific name of the species, a pictorial or genomic presentation of the primary type specimen on which its name is based, and a summary of its diagnostic traits.&#x201d; Although the &#x201c;quiet revolution&#x201d; in biodiversity informatics has generated numerous online resources, including some directly inspired by Wilson&#x27;s essay (e.g., &#x22;http://ispecies.org&#x22;:http://ispecies.org, &#x22;http://www.eol.org&#x22;:http://www.eol.org), we are still some way from the goal of having available online all relevant information about a species, such as its taxonomy, evolutionary history, genomics, morphology, ecology, and behaviour. While the biodiversity community has been developing a plethora of databases, some with overlapping goals and duplicated content, Wikipedia has been slowly growing to the point where it now has over 100,000 pages on biological taxa. My goal in this essay is to explore the idea that, largely independent of the efforts of biodiversity informatics and well-funded international efforts, Wikipedia (&#x22;http://en.wikipedia.org/wiki/Main_Page&#x22;:http://en.wikipedia.org/wiki/Main_Page) has emerged as potentially the best platform for fulfilling E O Wilson&#x2019;s vision