Miracle-dz/UniFAR-FTUs huggingface dataset:
Stochastic electron acceleration during spontaneous turbulent reconnection in a strong shock wave

Shocking! Particle accelerators in space The acceleration of charged particles to high energies has been a major mystery, with a number of competing theories based on plasma physics. Many include the concept of turbulence, but with different roles. For example, shock-based theories emphasize the importance of turbulence developed from an unstable shock layer, whereas turbulent reconnection theories emphasize interactions of multiple reconnection sites. Matsumoto et al. present results of a large particle-in-cell simulation and examine how electrons are accelerated in the transition layer of a fast nonrelativistic shock (see the Perspective by Ji and Zweibel). Surprisingly, they find that when the shock is strong enough, charged particles (electrons in this case) are efficiently accelerated by turbulent reconnection within a turbulent shock layer containing multiscale structures. Science, this issue p. 974; see also p. 944 Sufficiently powerful astrophysical shocks can yield relativistic particles via magnetic reconnection. [Also see Perspective by Ji and Zweibel] Explosive phenomena such as supernova remnant shocks and solar flares have demonstrated evidence for the production of relativistic particles. Interest has therefore been renewed in collisionless shock waves and magnetic reconnection as a means to achieve such energies. Although ions can be energized during such phenomena, the relativistic energy of the electrons remains a puzzle for theory. We present supercomputer simulations showing that efficient electron energization can occur during turbulent magnetic reconnection arising from a strong collisionless shock. Upstream electrons undergo first-order Fermi acceleration by colliding with reconnection jets and magnetic islands, giving rise to a nonthermal relativistic population downstream. These results shed new light on magnetic reconnection as an agent of energy dissipation and particle acceleration in strong shock waves.
Quercetin ameliorates hyperglycemia and dyslipidemia and improves antioxidant status in type 2 diabetic db/db mice

This study investigated the hypoglycemic, hypolipidemic, and antioxidant effects of dietary quercetin in an animal model of type 2 diabetes mellitus. Four-week-old C57BL/KsJ-db/db mice (n = 18) were offered an AIN-93G diet or a diet containing quercetin at 0.04% (low quercetin, LQE) or 0.08% of the diet (high quercetin, HQE) for 6 weeks after 1 week of adaptation. Plasma glucose, insulin, adiponectin, and lipid profiles, and lipid peroxidation of the liver were determined. Plasma glucose levels were significantly lower in the LQE group than in the control group, and those in the HQE group were even further reduced compared with the LQE group. The homeostasis model assessment for insulin resistance (HOMA-IR) showed lower values for LQE and HQE than for the control group without significant influence on insulin levels. High quercetin increased plasma adiponectin compared with the control group. Plasma triglycerides in the LQE and HQE groups were lower than those in the control group. Supplementation with high quercetin decreased plasma total cholesterol and increased HDL-cholesterol compared with the control group. Consumption of low and high quercetin reduced thiobarbituric acid reactive substances (TBARS) levels and elevated activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the liver. Thus, quercetin could be effective in improving hyperglycemia, dyslipidemia, and antioxidant status in type 2 diabetes.
Exercise, character strengths, well-being, and learning climate in the prediction of performance over a 6-month period at a call center

Background: Performance monitoring might have an adverse influence on call center agents' well-being. We investigate how performance, over a 6-month period, is related to agents' perceptions of their learning climate, character strengths, well-being (subjective and psychological), and physical activity. Method: Agents (N = 135) self-reported perception of the learning climate (Learning Climate Questionnaire), character strengths (Values In Action Inventory Short Version), well-being (Positive Affect, Negative Affect Schedule, Satisfaction With Life Scale, Psychological Well-Being Scales Short Version), and how often/intensively they engaged in physical activity. Performance, “time on the phone,” was monitored for 6 consecutive months by the same system handling the calls. Results: Performance was positively related to having opportunities to develop, the character strengths clusters of Wisdom and Knowledge (e.g., curiosity for learning, perspective) and Temperance (e.g., having self-control, being prudent, humble, and modest), and exercise frequency. Performance was negatively related to the sense of autonomy and responsibility, contentedness, the character strengths clusters of Humanity and Love (e.g., helping others, cooperation) and Justice (e.g., affiliation, fairness, leadership), positive affect, life satisfaction and exercise Intensity. Conclusion: Call centers may need to create opportunities to develop to increase agents' performance and focus on individual differences in the recruitment and selection of agents to prevent future shortcomings or worker dissatisfaction. Nevertheless, performance measurement in call centers may need to include other aspects that are more attuned with different character strengths. After all, allowing individuals to put their strengths at work should empower the individual and at the end the organization itself. Finally, physical activity enhancement programs might offer considerable positive work outcomes.
UvA-DARE ( Digital Academic Repository ) Physical parametres of GRB 970508 and GRB 971214 from their afterglow synchroton emission

We have calculated synchrotron spectra of relativistic blast waves and Ðnd predicted characteristic frequencies that are more than an order of magnitude di†erent from previous calculations. For the case of an adiabatically expanding blast wave, which is applicable to observed gamma-ray burst (GRB) afterglows at late times, we give expressions to infer the physical properties of the afterglow from the measured spectral features. We show that enough data exist for GRB 970508 to compute unambiguously the ambient density, n \ 0.03 cm~3, and the blast wave energy per unit solid angle, E\ 3 ] 1052 ergs/4n sr. We also compute the energy density in electrons and magnetic Ðeld. We Ðnd that they are 12% and 9%, respectively, of the nucleon energy density and thus conÐrm for the Ðrst time that both are close to but below equipartition. For GRB 971214, we discuss the break found in its spectrum by Ramaprakash et al. It can be interpreted either as the peak frequency or as the cooling frequency ; both interpretations have some problems, but on balance the break is more likely to be the cooling frequency. Even when we assume this, our ignorance of the self-absorption frequency and presence or absence of beaming make it impossible to constrain the physical parameters of GRB 971214 very well. Subject headings : gamma rays : bursts È gamma rays : theory È radiation mechanisms : nonthermal È shock waves
Differential distributions of red–green and blue–yellow cone opponency across the visual field

The color vision of Old World primates and humans uses two cone-opponent systems; one differences the outputs of L and M cones forming a red–green (RG) system, and the other differences S cones with a combination of L and M cones forming a blue–yellow (BY) system. In this paper, we show that in human vision these two systems have a differential distribution across the visual field. Cone contrast sensitivities for sine-wave grating stimuli (smoothly enveloped in space and time) were measured for the two color systems (RG & BY) and the achromatic (Ach) system at a range of eccentricities in the nasal field (0–25 deg). We spatially scaled our stimuli independently for each system (RG, BY, & Ach) in order to activate that system optimally at each eccentricity. This controlled for any differential variations in spatial scale with eccentricity and provided a comparison between the three systems under equivalent conditions. We find that while red–green cone opponency has a steep decline away from the fovea, the loss in blue–yellow cone opponency is more gradual, showing a similar loss to that found for achromatic vision. Thus only red–green opponency, and not blue–yellow opponency, can be considered a foveal specialization of primate vision with an overrepresentation at the fovea. In addition, statistical calculations of the level of chance cone opponency in the two systems indicate that selective S cone connections to postreceptoral neurons are essential to maintain peripheral blue–yellow sensitivity in human vision. In the red–green system, an assumption of cone selectivity is not required to account for losses in peripheral sensitivity. Overall, these results provide behavioral evidence for functionally distinct neuro-architectural origins of the two color systems in human vision, supporting recent physiological results in primates.
Effects of Prolactin Level on Burn-Induced Aberrations in Myelopoiesis

In this study, we sought to determine if prolactin (PRL) had any influence on burn-induced alterations in myelopoiesis and serum IL-6, IL-10, IL-12, IFN-&ggr;, TNF-&agr;, and MCP-1 levels. To do this, we used mice that were PRL normal, PRL deficient, or hyperprolactinemic and had received a 15% total body surface area burn, sham treatment, or no treatment. We performed clonogenic assays of bone marrow cells, and we found that sham treatment significantly decreased monocyte/macrophage (M) colony formation relative to the control group in the PRL-deficient and PRL-normal mice (P < 0.01). Hyperprolactinemia attenuated the sham-induced decrease in M colony formation. Burn injury significantly increased M colony formation relative to the sham group with an equal significance in the PRL-deficient and PRL-normal mice (P < 0.05). We also showed that burn led to a significant increase in GM colony formation relative to the sham group. This burn-induced increase was significant in the PRL-normal (P < 0.05) and the PRL-deficient (P < 0.01) mice. In the PRL-normal mice, burn injury caused a 2.1-fold increase in the GM colony number, whereas in the PRL-deficient mice burn led to a 2.6-fold increase in GM colony number. When comparing the effects of burn injury on colony formation to the control groups, there were no significant differences seen, irrespective of the PRL level. We observed that all of the cytokines studied, with the exception of IL-10, were influenced by either sham treatment, burn injury, or both forms of stress. This stress-induced response occurred most often in animals that were either hypo- or hyperprolactinemic. We conclude that the PRL level was able to influence the sham-induced and burn-induced alterations in GM and M colony formation. Under euprolactinemic conditions, mice exhibited less often with stress-induced serum cytokine level alterations. We did not find any significant correlations with any of the serum cytokine levels and the ability to form colonies. Importantly, the sham treatment led to immune alterations independent of, and sometimes opposite of burn-induced effects.
Persistence in Staphylococcus aureus bacteremia: Incidence, characteristics of patients and outcome

Staphylococcus aureus bacteremia often persists. The reasons for persistence and its outcome are poorly defined. We conducted a prospective-observational study among 245 consecutive S. aureus (MRSA: n=125; MSSA: n=120) bacteremias (≥1 positive blood cultures (BC)) among 234 adults (18–103-y-old; median = 59 y) hospitalized during 1 January 2002–31 December 2002 at a 600-bed teaching hospital. Measurements included bacteremia duration, complication-rate (metastatic infection, relapse or attributable mortality) and outcome. Bacteremia duration was measured based on follow-up BC among 193 patients and estimated based on symptoms resolution in the rest. Measured (1–59 d; median = 2) and estimated (median = 1 d) duration correlated (r=0.885) though positive follow-up BC was often detected without fever (57/105 patients, 54.3%). Persistence (defined as bacteremia for ≥3 d) was noted in 84 cases (38.4%). Complication-rate increased steadily with bacteremia duration (6.6%, 24.0% and 37.7% in bacteremia for 1–2, 3 and ≥4 d, respectively; p=0.05). Cox regression analysis revealed that bacteremia duration correlated positively with endovascular sources (p=0.006), vancomycin treatment (p=0.016), cardiovascular prosthesis (p=0.025), metastatic infections (p=0.025) and diabetes (p=0.038). It is concluded that persistent bacteremia is a feature of S. aureus infection, irrespective of oxacillin susceptibility, associated with worse outcome. Risk factors include endovascular sources, cardiovascular prosthesis, metastatic infections, vancomycin treatment and diabetes. Patients at risk may benefit from novel treatment strategies.
Zinc levels in seminal plasma of fertile and infertile men

Summary Zinc levels were measured in seminal plasma from 78 men classified on the basis of spermogram analyses into five groups: normo‐, oligo‐, astheno‐, oligoastheno‐ and azoospermia. Higher zinc levels were found in seminal plasma from the group of asthenozoospermia men in comparison to normo‐, oligoastheno‐ (p < 0.001), oligo‐ and azoospermia men (p < 0.01), while no significant differences appeared when other group pairs were compared. Seminal plasma zinc levels were positively correlated with sperm density (r = 0.6358, p < 0.01) in asthenozoospermia men, whereas a significant negative correlation was seen in all groups between percentage forms showing normal progressive motility and zinc concentration in seminal plasma. Although zinc is required in seminal plasma for normal spermatozoon functionality, excessively high levels of this ion may be related with defective motility in asthenozoospermia samples.
GATE Monte Carlo simulations for variations of an integrated PET/MR hybrid imaging system based on the Biograph mMR model

A simulation toolkit, GATE (Geant4 Application for Tomographic Emission), was used to develop an accurate Monte Carlo (MC) simulation of a fully integrated 3T PET/MR hybrid imaging system (Siemens Biograph mMR). The PET/MR components of the Biograph mMR were simulated in order to allow a detailed study of variations of the system design on the PET performance, which are not easy to access and measure on a real PET/MR system. The 3T static magnetic field of the MR system was taken into account in all Monte Carlo simulations. The validation of the MC model was carried out against actual measurements performed on the PET/MR system by following the NEMA (National Electrical Manufacturers Association) NU 2-2007 standard. The comparison of simulated and experimental performance measurements included spatial resolution, sensitivity, scatter fraction, and count rate capability. The validated system model was then used for two different applications. The first application focused on investigating the effect of an extension of the PET field-of-view on the PET performance of the PET/MR system. The second application deals with simulating a modified system timing resolution and coincidence time window of the PET detector electronics in order to simulate time-of-flight (TOF) PET detection. A dedicated phantom was modeled to investigate the impact of TOF on overall PET image quality. Simulation results showed that the overall divergence between simulated and measured data was found to be less than 10%. Varying the detector geometry showed that the system sensitivity and noise equivalent count rate of the PET/MR system increased progressively with an increasing number of axial detector block rings, as to be expected. TOF-based PET reconstructions of the modeled phantom showed an improvement in signal-to-noise ratio and image contrast to the conventional non-TOF PET reconstructions. In conclusion, the validated MC simulation model of an integrated PET/MR system with an overall accuracy error of less than 10% can now be used for further MC simulation applications such as development of hardware components as well as for testing of new PET/MR software algorithms, such as assessment of point-spread function-based reconstruction algorithms.
Rewrite-Based Equational Theorem Proving with Selection and Simplification

We present various refutationally complete calculi for first-order clauses with equality that allow for arbitrary selection of negative atoms in clauses. Refutation completeness is established via the use of well-founded orderings on clauses for defining a Herbrand model for a consistent set of clauses. We also formulate an abstract notion of redundancy and show that the deletion of redundant clauses during the theorem proving process preserves refutation completeness. It is often possible to compute the closure of nontrivial sets of clauses under application of non-redundant inferences. The refutation of goals for such complete sets of clauses is simpler than for arbitrary sets of clauses, in particular one can restrict attention to proofs that have support from the goals without compromising refutation completeness. Additional syntactic properties allow to restrict the search space even further, as we demonstrate for so-called quasiHorn clauses. The results in this paper contain as special cases or generalize many known results about Knuth-Bendix-like completion procedures (for equations, Horn clauses, and Horn clauses over built-in Booleans), completion of first-order clauses by clausal rewriting, and inductive theorem proving for Horn clauses.
Microbial contamination of clinical islet transplant preparations is associated with very low risk of infection.

BACKGROUND Several published studies have analyzed microbial contamination rates of islet products, ranging from 0% to 16%. However, few studies make reference to potential clinical consequences for transplant recipients and possible impact on islet survival. MATERIALS AND METHODS The current study defines rates of microbiological contamination of islet products under current good manufacturing practice conditions in 164 patients receiving 343 transplants at a single institution. RESULTS Nineteen (5.5%) islet preparations showed positive microbial growth with a majority (79.4%) due to Gram-positive organisms. The most frequently identified microorganism was coagulase-negative Staphylococcus (nine of 19 [47.3%]), followed by polymicrobial organisms (eight of 19 [42.1%]). No patient developed signs of clinical infection, and there were no hepatic abscesses evident on imaging by ultrasound or magnetic resonance imaging (none of 19 [0%]), despite the use of potent T-depletional induction. Finally, we could not demonstrate any negative impact of microbiological contamination on long-term islet graft survival. CONCLUSIONS Microbiological contamination of the final islet preparation appears to have little or no effect on patients or on islet survival when appropriate antibiotics are given. However, preparation sterility should be guaranteed at all cost in order maximize patient safety and avoid potential complications in immunosuppressed patients.
Extensions and Applications of the Cox‐Aalen Survival Model

Summary. Cox's regression model is the standard regression tool for survival analysis in most applications. Often, however, the model only provides a rough summary of the effect of some covariates. Therefore, if the aim is to give a detailed description of covariate effects and to consequently calculate predicted probabilities, more flexible models are needed. In another article, Scheike and Zhang (2002, Scandinavian Journal of Statistics29, 75–88), we suggested a flexible extension of Cox's regression model, which aimed at extending the Cox model only for those covariates where additional flexibility are needed. One important advantage of the suggested approach is that even though covariates are allowed a nonparametric effect, the hassle and difficulty of finding smoothing parameters are not needed. We show how the extended model also leads to simple formulae for predicted probabilities and their standard errors, for example, in the competing risk framework.
Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) comprises a disease spectrum ranging from benign hepatic steatosis to non-alcoholic steatohepatitis with inflammation (NASH) and liver cirrhosis. NAFLD is now recognised as the hepatic manifestation of the metabolic syndrome. Simple steatosis is benign, whereas NASH can progress to cirrhosis with its resultant complications. Liver biopsy remains the gold standard in the diagnosis of NAFLD/NASH. Lifestyle and dietary modifications to achieve sustained weight loss is the cornerstone of NAFLD/NASH treatment.
The Coach-Athlete Relationship in Married Couples: An Exploratory Content Analysis

This study examined the interpersonal athletic relationship of four married coach-athlete dyads. In order to facilitate the examination of this unique relationship, the interpersonal constructs of closeness, co-orientation, and complementarity were integrated into a conceptual-based model. The main purpose of this study was to establish the utility of the constructs in understanding the coach-athlete relationship in married couples. Following in-depth interviews, the responses of the participants were content analyzed. Analysis revealed that the coaches and athletes’ close relationship facilitated the formulation of a cooriented view of relevant and important issues which subsequently affected the way in which cooperative interactions were expressed in training. The relationship-oriented aspects of this unique dyad are discussed in relation to a proposed conceptualization of the coach-athlete relationship, and future directions are presented.
An Unsupervised Learning Method Exploiting Sequential Output Statistics

We address a class of unsupervised learning problems where the same goal of supervised learning is aimed except with no output labels provided for training classifiers. This type of unsupervised learning is highly valuable in machine learning practice since obtaining labels in training data is often costly. Instead of pairing input-output samples, we exploit sequential statistics of output labels, in the form of N-gram language models, which can be obtained independently of input data and thus with low or no cost. We introduce a novel cost function in this unsupervised learning setting, whose profiles are analyzed and shown to be highly non-convex with large barriers near the global optimum. A new stochastic primal-dual gradient method is developed to optimize this very difficult type of cost function via the use of dual variables to reduce the barriers. We demonstrate in experimental evaluation, with both synthetic and real-world data sets, that the new method for unsupervised learning gives drastically lower errors and higher learning efficiency than the standard stochastic gradient descent, reaching classification errors about twice of those obtained by fully supervised learning. We also show the crucial role of labels' sequential statistics exploited for label-free training with the new method, reflected by the significantly lower classification errors when higher-order language models are used in unsupervised learning than low-order ones.
Speaking of work and family: Spousal collaboration on defining role‐identities and developing shared meanings

Twelve married couples’ individual and joint accounts of their arrangements for managing work and parenting were examined to identify forms of symbolic collaboration. These couples could be observed collaborating directly on selecting applicable cultural discourses, co‐producing interpretative repertoires, and mediating between conflicting repertoires. Further, these pairs of spouses could be observed collaborating indirectly through positioning; spouses used each other as a symbolic resource in the construction of self‐identity, by mirroring and interlocking.