Miracle-dz/UniFAR-FTUs huggingface dataset:
Magnetic Field Diffusion in Self-consistently Turbulent Accretion Disks

We show how the level of turbulence in accretion disks can be derived from a self-consistency requirement that the associated effective viscosity should match the instantaneous accretion rate. This method is applicable when turbulence has a direct energy cascade. Only limited information on the origin and properties of the turbulence, such as its injection scale and anisotropy, is needed. The method is illustrated by considering the case of turbulence originating from the magnetic shearing instability. The corresponding effective kinematic viscosity coefficient is shown to scale as the 1/3 power of surface mass density at a given radius in optically thick disks, and to be describable by a Shakura-Sunyaev law with α≈ 0.04. Mass flow in disks fed at a localized hot spot is calculated for accretion regimes driven by such turbulence, as well as passive magnetic field diffusion and dragging. An important result of this analysis is that thin disks supported by turbulence driven by the magnetic shearing instability, and more generally any turbulence with injection scale of order of the disk thickness, are very low magnetic Reynolds number systems. Turbulent viscosity-driven solutions with negligible field dragging and no emission of cold winds or jets are natural consequences of such regimes. Disks of accreting objects that are magnetized enough to be shielded by a magnetopause, however, may not operate in their innermost regions in the magnetic shearing instability regime. The possibility therefore remains to be explored of centrifugally driven winds emanating from such regions.
Randomized, prospective trial of bilevel versus continuous positive airway pressure in acute pulmonary edema.

OBJECTIVE To evaluate whether bilevel positive airway pressure, by actively assisting inhalation, more rapidly improves ventilation, acidemia, and dyspnea than continuous positive airway pressure (CPAP) in patients with acute pulmonary edema. DESIGN Randomized, controlled, double-blind trial. SETTING Emergency department in a university hospital. PATIENTS Twenty-seven patients, presenting with acute pulmonary edema, characterized by dyspnea, tachypnea, tachycardia, accessory muscle use, bilateral rales, and typical findings of congestion on a chest radiograph. INTERVENTIONS In addition to standard therapy, 13 patients were randomized to receive nasal CPAP (10 cm H2O), and 14 patients were randomized to receive nasal bilevel positive airway pressure (inspiratory and expiratory positive airway pressures of 15 and 5 cm H2O, respectively) in the spontaneous/timed mode that combines patient flow-triggering and backup time-triggering. MEASUREMENTS AND MAIN RESULTS After 30 mins, significant reductions in breathing frequency (32 +/- 4 to 26 +/- 5 breaths/min), heart rate (110 +/- 21 to 97 +/- 20 beats/min), blood pressure (mean 117 +/- 28 to 92 +/- 18 mm Hg), and Paco2 (56 +/- 15 to 43 +/- 9 torr [7.5 +/- 2 to 5.7 +/- 1.2 kPa]) were observed in the bilevel positive airway pressure group, as were significant improvements in arterial pH and dyspnea scores (p < .05 for all of these parameters). Only breathing frequency improved significantly in the CPAP group (32 +/- 4 to 28 +/- 5 breaths/min, p < .05). At 30 mins; the bilevel positive airway pressure group had greater reductions in Paco2 (p = .057), systolic blood pressure (p = .005), and mean arterial pressure (p = .03) than the CPAP group. The myocardial infarction rate was higher in the bilevel positive airway pressure group (71%) compared with both the CPAP group (31%) and historically matched controls (38%) (p = .05). Duration of ventilator use, intensive care unit and hospital stays, and intubation and mortality rates were similar between the two groups. CONCLUSIONS Bilevel positive airway pressure improves ventilation and vital signs more rapidly than CPAP in patients with acute pulmonary edema. The higher rate of myocardial infarctions associated with the use of bilevel positive airway pressure highlights the need for further studies to clarify its effects on hemodynamics and infarction rates, and to determine optimal pressure settings.
HIV-1 Subtype C Unproductively Infects Human Cardiomyocytes In Vitro and Induces Apoptosis Mitigated by an Anti-Gp120 Aptamer

HIV-associated cardiomyopathy (HIVCM) is of clinical concern in developing countries because of a high HIV-1 prevalence, especially subtype C, and limited access to highly active antiretroviral therapy (HAART). For these reasons, we investigated the direct and indirect effects of HIV-1 subtype C infection of cultured human cardiomyocytes and the mechanisms leading to cardiomyocytes damage; as well as a way to mitigate the damage. We evaluated a novel approach to mitigate HIVCM using a previously reported gp120 binding and HIV-1 neutralizing aptamer called UCLA1. We established a cell-based model of HIVCM by infecting human cardiomyocytes with cell-free HIV-1 or co-culturing human cardiomyocytes with HIV-infected monocyte derived macrophages (MDM). We discovered that HIV-1 subtype C unproductively (i.e. its life cycle is arrested after reverse transcription) infects cardiomyocytes. Furthermore, we found that HIV-1 initiates apoptosis of cardiomyocytes through caspase-9 activation, preferentially via the intrinsic or mitochondrial initiated pathway. CXCR4 receptor-using viruses were stronger inducers of apoptosis than CCR5 utilizing variants. Importantly, we discovered that HIV-1 induced apoptosis of cardiomyocytes was mitigated by UCLA1. However, UCLA1 had no protective effective on cardiomyocytes when apoptosis was triggered by HIV-infected MDM. When HIV-1 was treated with UCLA1 prior to infection of MDM, it failed to induce apoptosis of cardiomyocytes. These data suggest that HIV-1 causes a mitochondrial initiated apoptotic cascade, which signal through caspase-9, whereas HIV-1 infected MDM causes apoptosis predominantly via the death-receptor pathway, mediated by caspase-8. Furthermore the data suggest that UCLA1 protects cardiomyocytes from caspase-mediated apoptosis, directly by binding to HIV-1 and indirectly by preventing infection of MDM.
Particulate Matter and Hospital Admissions for Stroke in Beijing, China: Modification Effects by Ambient Temperature

Background The impact of particulate matter (PM) on stroke may vary by particle size, stroke subtype, and patient characteristics and temperature. We examined the association of stroke admissions with PM in different subgroups in Beijing, China, during 2013–2014. Methods and Results A time‐stratified case‐crossover design was used to assess the relation between PM of different particle sizes and hospital admissions for ischemic and hemorrhagic stroke. Stratified analyses were performed by age, sex, and temperature. In total, there were 147 624 stroke admissions during the study period. In the whole‐period analysis, both PM2.5 and PM10 were positively associated with ischemic stroke admissions on the day of hospital admission and negatively associated with ischemic stroke at lag2 and lag3 day. In warm days (>13.5°C), the odds ratios of ischemic stroke admissions were 2.071 (95% CI 1.959–2.190), 1.470 (95% CI 1.391–1.554), and 1.590 (95% CI 1.493–1.694) per IQR increase in the same‐day PM2.5 (82.0 μg/m3), PM2.5–10 (36.6 μg/m3), and PM10 (93.5 μg/m3), respectively. For hemorrhagic stroke, the corresponding values were 1.941 (95% CI 1.658–2.273), 1.590 (95% CI 1.366–1.851), and 1.527 (95% CI 1.278–1.826). The positive associations were also observed in the other lag structures and were higher than in cold days (≤13.5°C). Conclusions This study suggests that the associations of PM2.5, PM2.5–10, and PM10 with stroke admissions differed across levels of temperature. Short‐term exposure to PM2.5, PM2.5–10, and PM10 was positively associated with hospital admissions for ischemic and hemorrhagic stroke on warm days (>13.5°C).
Control theory for principled heap sizing

We propose a new, principled approach to adaptive heap sizing based on control theory. We review current state-of-the-art heap sizing mechanisms, as deployed in Jikes RVM and HotSpot. We then formulate heap sizing as a control problem, apply and tune a standard controller algorithm, and evaluate its performance on a set of well-known benchmarks. We find our controller adapts the heap size more responsively than existing mechanisms. This responsiveness allows tighter virtual machine memory footprints while preserving target application throughput, which is ideal for both embedded and utility computing domains. In short, we argue that formal, systematic approaches to memory management should be replacing ad-hoc heuristics as the discipline matures. Control-theoretic heap sizing is one such systematic approach.
Diversity, identity and belonging in e-learning communities: some theories and paradoxes

It is often assumed that online collaborative learning is inclusive of diversity. In this exploratory paper, I challenge this notion by developing a theory which proposes that inclusion occurs through congruence between learners’ social identities and the identities implicitly supported through the interactions in a particular community. To build identity congruence, e-learning communities need spaces for both commonality and diversity, and I present three paradoxes which underlie the aims of online learners and teachers to embrace diversity online. I illustrate these with some examples from online learning and teaching. The ability to ‘listen’ to each other online offers a way forward, and the paper ends with some future possibilities about how we can ensure that e-learning communities benefit from diversity.
An Exploratory Study of the Nature of Family Resilience in Families Affected by Parental Alcohol Abuse

Resilient families are able to adapt to adversities, but the nature of family resilience is not well understood. This study examines patterns of family functioning that may protect families from the negative impact of alcohol abuse. Naturally occurring patterns of family functioning are identified and associations between these patterns and parenting, current parental alcohol use, recent family stressful events, supportive relationships outside the family, and demographic characteristics are assessed. Cross-sectional data are analyzed from racially diverse American and Canadian families (N = 674) who have at least one parent with an alcohol abuse problem and a child between ages 9 and 12 years. Cluster analyses derived from family functioning indicators are used to identify naturally occurring family patterns. Multivariate assessments evaluated relationships between family functioning clusters and potentially influencing factors. The study results reveal a continuum of family functioning associated with parenting, child’s perception of teacher caring, and race.
Histology and ultrastructure of the thymus during development in tilapia, Oreochromis niloticus

The thymus in teleost fishes plays an important role in producing functionally competent T‐lymphocytes. However, the thymus in tilapia is not well known, which greatly hampers investigations into the immune responses of tilapia infected by aquatic pathogens. The histological structure and ultrastructure of the thymus in Oreochromis niloticus, including embryos and larvae at different developmental stages, juveniles, and adult fish, were systematically investigated using whole mount in situ hybridization (WISH), and light and transmission electron microscopy (TEM). The position of the thymus primordium was first labeled in the embryo at 2 days post‐fertilization (dpf) with the thymus marker gene recombination activating gene 1 (Rag1), when the water temperature was 27 °C. Obvious structures of the thymus were easily observed in 4‐dpf embryos. At this stage, the thymus was filled with stem cells. At 6 dpf, the thymus differentiated into the cortex and medulla. The shape of the thymus was ‘broad bean’‐like during the early stages from 4 to 10 dpf, and became wedge‐shaped in fish larvae at 20 dpf. At 6 months post‐fertilization (mpf), the thymus differentiated into the peripheral zone, central zone, and inner zone. During this stage, myoid cells and adipocytes appeared in the inner zone following thymus degeneration. Then, the thymus displayed more advanced degeneration by 1 year post‐fertilization (ypf), and the separation of cortex and medulla was not observed at this stage. The thymic trabecula and lobule were absent during the entire course of development. However, the typical Hassall's corpuscle was present and underwent degeneration. Additionally, TEM showed that the thymic tissues contained a wide variety of cell types, namely lymphocytes, macrophages, epithelial cells, fibroblasts, and mastocytes.
Influence of quaternary sea-level variations on a land bird endemic to Pacific atolls

Little is known about the effect of quaternary climate variations on organisms that inhabited carbonate islands of the Pacific Ocean, although it has been suggested that one or several uplifted islands provided shelter for terrestrial birds when sea-level reached its highest. To test this hypothesis, we investigated the history of colonization of the Tuamotu reed-warbler (Acrocephalus atyphus) in southeastern Polynesia, and found high genetic structure between the populations of three elevated carbonate islands. Estimates of time since divergence support the hypothesis that these islands acted as refugia during the last interglacial maximum. These findings are particularly important for defining conservation priorities on atolls that endure the current trend of sea-level rise owing to global warming.
Cognitive Factors in Learning about Structured Sequences

Cognitive science has developed a number of experimental techniques for studying how people learn about sequentially structured stimulus material. We describe these techniques, review findings they have produced, and discuss the findings' relevance for understanding the mastery of syntax during second language learning. Three issues are addressed: (a) the nature or content of what is learned and how it might be represented in the language learner's knowledge base, paying special heed to acquiring abstract rules versus generalizing across stored examples, (b) the role of conscious awareness in syntactic learning, and (c) the role of limited-capacity processing or focal attention in syntactic learning. Care is taken to distinguish between the latter two factors—Focal attention to the task of learning about syntax and conscious awareness of particular syntactic structures are not the same thing and may well play different roles in successful acquisition.
Real‐time enzymatic degradation of human dentin collagen fibrils exposed to exogenous collagenase: an AFM study in situ

Objective: This study was carried out to observe the enzymatic degradation of human dentin collagen fibrils exposed to exogenous collagenase in situ using atomic force microscopy, to understand the characteristics of the enzymatic degradation of collagen fibrils on dentin specimens. Methods: Polished dentin specimens from caries‐free third molars were etched with citric acid, and then treated with an aqueous solution of 6.5% NaOCl for 120 s. The specimen was then put into a fluid cell and treated with a mixed solution of collagenase I (MMP‐1) and collagenase II (MMP‐8) for 9 h. AFM with contact mode was performed in situ to monitor the enzymatic degradation process of the dentin collagen fibrils. The distinctly topographic changes of the dentin surface were recorded continuously during different stages of the enzymatic degradation process. Results: The mixed solution of exogenous collagenase I and collagenase II could degrade dentin organic matrix (mainly collagen) efficiently, and the structures of dentin substrate were clearly exposed. Conclusion: It is possible to carry out real‐time observations on the enzymatic biodegradation process of human dentin collagen fibrils on dentin specimens with atomic force microscopy in situ. By this means, the fine structures of the etched dentin substrate were clearly revealed, possibly contributing to the related study of human dentin in vitro.
Learned predictiveness influences automatic evaluations in human contingency learning

Experiments used an affective priming procedure to investigate whether evaluative conditioning in humans is subject to bias as a consequence of differences in the learned predictiveness of the cues involved. Experiment 1, using brief prime presentation, demonstrated stronger affective priming for cues that had been predictive of a neutral attribute prior to evaluative conditioning than for those that had been nonpredictive. Experiment 2, using longer prime presentation, found a reversed priming effect for previously predictive cues but not for previously nonpredictive cues. The implication is that the effect observed with brief prime presentation reflects the operation of fast-acting, automatic evaluation mechanisms and hence that evaluative conditioning can be biased by our previous learning about the predictiveness of cues.
Structure/Function Analysis of the Amino-terminal Region of the α1 and α2 Subunits of Na,K-ATPase*

The α2 isoform of the Na,K-ATPase exhibits kinetic behavior distinct from that of the α1 isoform. The distinctive behavior is apparent when the reaction is carried out under conditions (micromolar ATP concentration) in which the K+ deocclusion pathway of the reaction cycle is rate-limiting; the α1 activity is inhibited by K+, whereas α2 is stimulated. When 32 NH2-terminal amino acid residues are removed from α1, the kinetic behavior of the mutant enzyme (α1M32) is similar to that of α2 (Daly, S. E., Lane, L. K., and Blostein, R. (1994) J. Biol. Chem. 269, 23944-23948). In the current study, the region of the α1 NH2 terminus involved in modulating this kinetic behavior has been localized to the highly charged sequence comprising residues 24-32. Within this nonapeptide, differences between α1 and α2 are conservative and are confined to residues 25-27. The behavior of two chimeric enzymes: (i) α1 with the first 32 residues identical to the α2 sequence, α1 (1-32α2), and (ii) α2 with the first 32 residues identical to the α1 sequence, α2(1-32α1), indicates that the distinctive kinetic behavior of α1 and α2 is not due to the 24-32 NH2-terminal domain, per se, but rather to its interaction with other, isoform-specific region(s) of the α1 protein. We also demonstrate that the distinct K+ activation profiles of either α2 or α1M32, compared to α1 is due to a faster release of K+ from the K+-occluded enzyme, and to a higher affinity for ATP. This was determined in studies using two approaches: (i) kinetic analysis of the reaction modeled according to a branched pathway of K+ deocclusion through low and high affinity ATP pathways and, (ii) measurements of the (rapid) phosphorylation of the enzyme (E1 conformation) by [γ-32P]ATP following the rate-limiting formation of the K+-free enzyme from the K+-occluded state (E2(K) → E1 + K+). The observed kinetic differences between α2 and α1 suggest that these Na,K-ATPase isoforms differ in the steady-state distribution of E1 and E2 conformational states.
Personal Recommendation Based on Weighted Bipartite Networks

Recently, network based recommendation algorithms have demonstrated much better performance than the standard collaborative filtering method, and most of which have been focused on the unweighted cases even in a multigraded rating system. However, these modifications from multigraded rating data to binary data may lose information, thus hinder the expressing of user’s preference and finally misleading the recommendation systems. In this paper, we propose to use weighted bipartite user-object networks to model the recommender systems. The weight of the edge is directly the rate that a user giving on an object. We use a benchmark dataset, i.e., Moivelens dataset, to test the performance. The results show that weighted theme has higher recommendation accuracy than its unweighted counterpart.
Noncommutative Bundles and Instantons in Tehran

We present an introduction to the use of noncommutative geometry for gauge theories with emphasis on a construction of instantons for a class of four dimensional toric noncommutative manifolds. These instantons are solutions of self-duality equations and are critical points of an action functional. We explain the crucial role of twisted symmetries as well as methods from noncommutative index theorems.
Frailty, HIV Infection, and Mortality in an Aging Cohort of Injection Drug Users

Background Frailty is associated with morbidity and premature mortality among elderly HIV-uninfected adults, but the determinants and consequences of frailty in HIV-infected populations remain unclear. We evaluated the correlates of frailty, and the impact of frailty on mortality in a cohort of aging injection drug users (IDUs). Methods Frailty was assessed using standard criteria among HIV-infected and uninfected IDUs in 6-month intervals from 2005 to 2008. Generalized linear mixed-model analyses assessed correlates of frailty. Cox proportional hazards models estimated risk for all-cause mortality. Results Of 1230 participants at baseline, the median age was 48 years and 29% were HIV-infected; the frailty prevalence was 12.3%. In multivariable analysis of 3,365 frailty measures, HIV-infected IDUs had an increased likelihood of frailty (OR, 1.66; 95% CI, 1.24–2.21) compared to HIV-uninfected IDUs; the association was strongest (OR, 2.37; 95% CI, 1.62–3.48) among HIV-infected IDUs with advanced HIV disease (CD4<350 cells/mm3 and detectable HIV RNA). No significant association was seen with less advanced disease. Sociodemographic factors, comorbidity, depressive symptoms, and prescription drug abuse were also independently associated with frailty. Mortality risk was increased with frailty alone (HR 2.63, 95% CI, 1.23–5.66), HIV infection alone (HR 3.29, 95% CI, 1.85–5.88), and being both HIV-infected and frail (HR, 7.06; 95%CI 3.49–14.3). Conclusion Frailty was strongly associated with advanced HIV disease, but IDUs with well-controlled HIV had a similar prevalence to HIV-uninfected IDUs. Frailty was independently associated with mortality, with a marked increase in mortality risk for IDUs with both frailty and HIV infection.
Topological Requirements and Signaling Properties of T Cell–activating, Anti-CD28 Antibody Superagonists

Full activation of naive T cells requires both engagement of the T cell antigen receptor (TCR; signal 1) and costimulatory signaling by CD28 (signal 2). We previously identified two types of rat CD28-specific monoclonal antibodies (mAbs): “conventional,” TCR signaling–dependent costimulatory mAbs and “superagonistic” mAbs capable of inducing the full activation of primary resting T cells in the absence of TCR ligation both in vitro and in vivo. Using chimeric rat/mouse CD28 molecules, we show that the superagonists bind exclusively to the laterally exposed C′′D loop of the immunoglobulin-like domain of CD28 whereas conventional, costimulatory mAbs recognize an epitope close to the binding site for the natural CD80/CD86 ligands. Unexpectedly, the C′′D loop reactivity of a panel of new antibodies raised against human CD28 could be predicted solely on the basis of their superagonistic properties. Moreover, mouse CD28 molecules engineered to express the rat or human C′′D loop sequences activated T cell hybridomas without TCR ligation when cross-linked by superagonistic mAbs. Finally, biochemical analysis revealed that superagonistic CD28 signaling activates the nuclear factor κB pathway without inducing phosphorylation of either TCRζ or ZAP70. Our findings indicate that the topologically constrained interactions of anti-CD28 superagonists bypass the requirement for signal 1 in T cell activation. Antibodies with this property may prove useful for the development of T cell stimulatory drugs.