Miracle-dz/UniFAR-FTUs huggingface dataset:
Iron-Based Catalysts with Improved Oxygen Reduction Activity in Polymer Electrolyte Fuel Cells

Iron-based catalysts for the oxygen-reduction reaction in polymer electrolyte membrane fuel cells have been poorly competitive with platinum catalysts, in part because they have a comparatively low number of active sites per unit volume. We produced microporous carbon–supported iron-based catalysts with active sites believed to contain iron cations coordinated by pyridinic nitrogen functionalities in the interstices of graphitic sheets within the micropores. We found that the greatest increase in site density was obtained when a mixture of carbon support, phenanthroline, and ferrous acetate was ball-milled and then pyrolyzed twice, first in argon, then in ammonia. The current density of a cathode made with the best iron-based electrocatalyst reported here can equal that of a platinum-based cathode with a loading of 0.4 milligram of platinum per square centimeter at a cell voltage of ≥0.9 volt.
Coding-Sequence Determinants of Gene Expression in Escherichia coli

the magnitude of FCT. Because active torque is proportional to n 2 and passive torque to n, the ratio of active to passive torque increases as n increases (Eq. 5), even while both quantities increase individually ˙ w a ˙ w FCT ¼ − ðg − 1Þ Fn ðd % ϕ=d % t Þ 8w ð5Þ The increase in the ratio indicates an enhanced capability for active maneuvers and active stabilization , whereas the increase in FCT adds to passive stability. Thus, increasing wingbeat frequency enhances both maneuverability and stability. Hum-mingbirds provide an interesting example; males typically have greater wingbeat frequencies (21) and smaller body sizes as compared to females of the same species, potentially conferring a benefit in maneuverability and therefore an advantage in display flights (22) as well as greater stability when experiencing an external perturbation. These benefits are not without cost, because increasing wingbeat frequency increases the inertial and profile power requirements of flapping flight. Finally, the success of our FCT model in predicting yaw deceleration dynamics implies that passive damping may be important to flight control in flying animals across a wide range of body sizes. For example, if a steadily flapping animal experiences a brief perturbation in midstroke, by the time it is prepared to execute a corrective wingbeat, FCT will have eroded much of the effect of the perturbation, regardless of the wingbeat frequency employed by the animal. Thus, FCT provides open loop stability for some aspects of animal flight, reducing its neuromuscular and neurosensory requirements. These are not eliminated , because FCT results in asymmetric forces from symmetric flapping, implying that the ani-mal's muscles must generate asymmetric forces and suggesting neural regulation to enforce symmetry. Furthermore, FCT does not address all the stability problems faced by flying animals. This study is limited to yaw dynamics in hovering or slow-speed flight; FCT is likely to be influential in fast forward flight, but no data are available to test such predictions. More important, a full description of body dynamics involves many factors beyond FCT and includes modes such as pitching and longitudinal dynamics known to be inherently unstable in open loop conditions (23, 24) and subject to active control (25, 26). Finally, yaw damping due to FCT is a feature of flapping flight that is not found in human-made fixed-wing or rotary-wing flyers and may lead to improvements in the stability and maneuverability of biomimetic …
Late Pleistocene Demography and the Appearance of Modern Human Behavior

War and Peace? Modern behavior, including the development of advanced tools, musical instruments, and art, seems to have arisen in humans in stages. The earliest hints are seen in Africa about 70 to 90,000 years ago, but later in Europe about 45,000 years ago. An ongoing discussion centers on the origins and significance of human prosociality. During early human development, could the benefits of altruistic behavior have outweighed its costs (see the Perspective by Mace)? Bowles (p. 1293) constructed a model of conflict between groups of humans and extracted estimates of the critical parameters from archaeological and ethnographic data sets. Provocatively, it appears that warfare might have enhanced the emergence and persistence of altruistic behavior. Powell et al. (p. 1298) present a population model that shows that the development of modern behaviors may rely on the attainment of critical population densities and migratory patterns required for stable cultural transmission. The model is consistent with genetic inferences of population dynamics in Africa and Europe and suggests that these cultural changes may not solely reflect increased cognitive evolution. Population size and migration account for modern human behavior appearing in Africa about 90,000 years ago but much later across Europe. The origins of modern human behavior are marked by increased symbolic and technological complexity in the archaeological record. In western Eurasia this transition, the Upper Paleolithic, occurred about 45,000 years ago, but many of its features appear transiently in southern Africa about 45,000 years earlier. We show that demography is a major determinant in the maintenance of cultural complexity and that variation in regional subpopulation density and/or migratory activity results in spatial structuring of cultural skill accumulation. Genetic estimates of regional population size over time show that densities in early Upper Paleolithic Europe were similar to those in sub-Saharan Africa when modern behavior first appeared. Demographic factors can thus explain geographic variation in the timing of the first appearance of modern behavior without invoking increased cognitive capacity.
The Role of Human Leukocyte Antigen Matching in the Development of Multiethnic “Haplobank” of Induced Pluripotent Stem Cell Lines

Among the tools of regenerative medicine, induced pluripotent stem cells (iPSCs) are interesting because the donor genotype can be selected. The construction of banks of iPSC cell lines selected from human leukocyte antigen (HLA) homozygous donors has been proposed to be an effective way to match a maximal number of patients receiving cell therapy from iPSC lines. However, what effort would be required to constitute such a bank for a worldwide application has remained unexplored. We developed a probabilistic model to compute the number of donors to screen for constituting banks of best‐chosen iPSC lines with homozygous HLA haplotypes (haplobanks) in four ancestry backgrounds. We estimated what percentage of the patients would be provided with single HLA haplotype matched cell lines. Genetic diversity leads to different outcomes for the four sets in all terms. A bank comprising iPSC lines representing the 20 most frequent haplotypes in each population would request quite different number of donors to screen, between 26,000 for European Americans and 110,000 for African Americans. It would also match different fractions of the recipient population, namely, more than 50% of the European Americans and 22% of African Americans. Conversely, a bank comprising the 100 iPSC lines with the most frequent HLA in each population would leave out only 22% of the European Americans, but 37% of the Asians, 48% of the Hispanics, and 55% of the African Americans. The constitution of a haplobank of iPSC lines is achievable through a large‐scale concerted worldwide collaboration. STEM CELLS 2012; 30:180–186.
Headache diagnosis, disability and co-morbidities in a multi-ethnic, heterogeneous paediatric Asian population

This was a questionnaire survey on headache and migraine prevalence in 2873 Singaporean schoolchildren aged 6 to 16 years. ICHD-II headache classification, disability assessment with PedMIDAS and screening of psychosocial co-morbidities with the Paediatric Symptom Checklist were conducted. Lifetime headache prevalence was high at 80.6%, migraine prevalence was 8.6% and tension headache prevalence was 10.0%. Headache and migraine prevalence was high compared with that found in other Asian studies. Factors significantly associated with headache included adolescent age (OR = 1.5 [95% CI 1.3–1.9], p < .001), female gender at primary (OR = 1.4 [95% CI 1.1–1.8], p = .003) and secondary (OR = 1.8 [95% CI 1.3–2.5], p < .001) levels and Malay ethnicity at the primary level (OR = 2.8 [95% CI 1.6–4.9], p < .001). The average PedMIDAS score for headache disability was 3.2 ± 8.4, and migraine disability (PedMIDAS 8.1 ± 11.2–15.2 ± 29.6) was lower than in some studies. Self-medication (20.5%) and use of alternative therapy (59.0%) were high among chronic daily headache sufferers. Routine sleep and stress screening is recommended for children with headaches. Recognition of the influence of genetics, lifestyle and cultural factors on headache management should be emphasized.
Orbitofrontal disinhibition of pain in migraine with aura: An interictal EEG-mapping study

This study aimed to identify the cortical mechanisms underlying the processes of interictal dishabituation to experimental pain in subjects suffering from migraine with aura (MWA). In 21 subjects with MWA and 22 healthy controls, cortical responses to two successive trials of noxious contact-heat stimuli were analyzed using EEG-tomography software. When compared with controls, MWA patients showed significantly increased pain-evoked potential amplitudes accompanied by reduced activity in the orbitofrontal cortex (OFC) and increased activity in the pain matrix regions, including the primary somatosensory cortex (SI) (p < .05). Similarly to controls, MWA subjects displayed an inverse correlation between the OFC and SI activities, and positive interrelations between other pain-specific regions. The activity changes in the OFC negatively correlated with lifetime headache duration and longevity (p < .05). Reduced inhibitory functioning of the prefrontal cortex is a possible cause for disinhibition of the pain-related sensory cortices in migraine. The finding of OFC hypofunction over the disease course is in keeping with current concepts of migraine as a progressive brain disorder.
Analysis and testing of black‐box component‐based systems by inferring partial models

From experience in component‐based software engineering, it is known that the integration of high‐quality components may not yield high‐quality software systems. It is difficult to evaluate all possible interactions between the components in the system to uncover inter‐component misfunctions. The problem is even harder when the components are used without source code, specifications or formal models. Such components are called black boxes in literature. This paper presents an iterative approach of combining model learning and testing techniques for the formal analysis of a system of black‐box components. In the approach, individual components in the system are learned as finite state machines that (partially) model the behavioural structure of the components. The learned models are then used to derive tests for refining the partial models and/or finding integration faults in the system. The approach has been applied on case studies that have produced encouraging results. Copyright © 2013 John Wiley & Sons, Ltd.
No arguments for increased endothelial nitric oxide synthase activity in migraine based on peripheral biomarkers

Objectives: To assess whether migraine patients display a chronic nitric oxide synthase (NOS) hyperactivity by comparing the nitric oxide (NO) production before and following a loading dose of L-arginine between migraine patients (interictally) and matched healthy control subjects. In addition, we evaluated whether a loading dose of L-arginine triggers an acute migraine headache in migraineurs. Subjects and methods: Twenty healthy subjects and 20 migraine patients participated in a 2-period, randomised, double-blind, placebo-controlled study. Each subject received a 30-min infusion, by peripheral vein, of 30 g L-arginine hydrochloride or placebo (i.e. an equal volume of 0.9% saline solution). Meanwhile, biomarkers associated with the L-arginine–NO pathway (i.e. exhaled NO/nasal NO), plasma citrulline and urinary excretion of nitrite/nitrate and cGMP were assessed before and for 6 h following the start of the infusion. Results: At baseline, exhaled NO and nasal NO were higher in migraineurs compared to healthy subjects (mean ± 95% confidence interval): 15.9 (8.8, 23.0) parts per billion (ppb) versus 10.8 (7.0, 14.5) ppb for exhaled NO (P = 0.04) and 76.3 (61.2, 91.4) versus 61.6 (51.2, 72.0) ppb for nasal NO (P = 0.03), respectively. The AUC0–6 in ppb for exhaled NO and nasal NO following L-arginine or saline infusion did not differ between both groups. The increase in L-citrulline, following L-arginine infusion, was smaller in migraine patients (15 (13, 18) µmol/l) compared to healthy volunteers (19 (16, 23) µmol/l; P = 0.046). In healthy subjects, both nitrate and cGMP excretion were higher following L-arginine compared to placebo infusion: 132.63 (100.24, 165.02) versus 92.07 (66.33, 117.82) µmol/mmol creatinine for nitrate (P = 0.014) and 50.53 (42.19, 58.87) versus 39.64 (33.94, 45.34) nmol/mmol creatinine for cGMP (P = 0.0003), respectively. In migraineurs, excretion of these biomarkers was comparable following L-arginine or saline infusion. Conclusions: The results of the present study do not support the idea of a generalised increase in NO synthase activity in migraine patients outside of a migraine attack. The smaller increase in plasma L-citrulline, urinary nitrate and cGMP excretion following L-arginine infusion in migraine patients might indicate dysfunction of endothelial NO synthase.
Polarization Control of Electron Tunneling into Ferroelectric Surfaces

Ferroelectric Patterning with High Fields Ferroelectric oxides have a net polarization that can switch direction upon application of a sufficiently high electric field. In principle, a ferroelectric thin film should be able to act as a polar switch—tunneling an electron through the film would effectively switch on or off depending on the direction of the polarization. In practice, the length scale needed for a sufficiently small tunneling barrier is nearly the same as the scale at which films no longer support ferroelectricity. Maksymovych et al. (p. 1421) now show that the tip of an atomic force microscope can be used to pattern polarization domains in a thin film of lead zirconate titanate in high electric fields similar to those for field emission tips. High electric fields delivered with an atomic force microscope tip pattern polarization domains in ferroelectric thin films. We demonstrate a highly reproducible control of local electron transport through a ferroelectric oxide via its spontaneous polarization. Electrons are injected from the tip of an atomic force microscope into a thin film of lead-zirconate titanate, Pb(Zr0.2Ti0.8)O3, in the regime of electron tunneling assisted by a high electric field (Fowler-Nordheim tunneling). The tunneling current exhibits a pronounced hysteresis with abrupt switching events that coincide, within experimental resolution, with the local switching of ferroelectric polarization. The large spontaneous polarization of the PZT film results in up to 500-fold amplification of the tunneling current upon ferroelectric switching. The magnitude of the effect is subject to electrostatic control via ferroelectric switching, suggesting possible applications in ultrahigh-density data storage and spintronics.
Enhanced Bayesian MMSE channel estimation for visible light communication

Visible light communication (VLC) is considered as a potential candidate of five generation (5G) technologies and thus attracts increasing research interest recently. Optical orthogonal frequency division multiplexing (O-OFDM) has been proposed for VLC systems to eliminate the multi-path interference, while also facilitating frequency domain equalisation (FDE). In comparison to conventional radio frequency (RF) based wireless communication, there has been limited considerations on channel estimation (CE) for VLC, where the indoor optical wireless channel model differs from the traditional RF case. In this paper, we present a new channel estimation algorithm for indoor downlink (DL) VLC systems that exploits historical information in an adaptive and efficient way. The proposed scheme is capable of offering superior performance at the cost of modest complexity under practical scenarios. Detailed theoretical analysis is provided along with extensive numerical results, demonstrating the effectiveness of the proposed CE approach.
Coverage‐based regression test case selection, minimization and prioritization: a case study on an industrial system

This paper presents a case study of coverage‐based regression testing techniques on a real world industrial system with real regression faults. The study evaluates four common prioritization techniques, a test selection technique, a test suite minimization technique and a hybrid approach that combines selection and minimization. The study also examines the effects of using various coverage criteria on the effectiveness of the studied approaches. The results show that prioritization techniques that are based on additional coverage with finer grained coverage criteria perform significantly better in fault detection rates. The study also reveals that using modification information in prioritization techniques does not significantly enhance fault detection rates. The results show that test selection does not provide significant savings in execution cost (<2%), which might be attributed to the nature of the changes made to the system. Test suite minimization using finer grained coverage criteria could provide significant savings in execution cost (79.5%) while maintaining a fault detection capability level above 70%, thus representing a possible trade‐off. The hybrid technique did not provide a significant improvement over traditional minimization techniques. Copyright © 2015 John Wiley & Sons, Ltd.
Growth Factors, Matrices, and Forces Combine and Control Stem Cells

Stem cell fate is influenced by a number of factors and interactions that require robust control for safe and effective regeneration of functional tissue. Coordinated interactions with soluble factors, other cells, and extracellular matrices define a local biochemical and mechanical niche with complex and dynamic regulation that stem cells sense. Decellularized tissue matrices and synthetic polymer niches are being used in the clinic, and they are also beginning to clarify fundamental aspects of how stem cells contribute to homeostasis and repair, for example, at sites of fibrosis. Multifaceted technologies are increasingly required to produce and interrogate cells ex vivo, to build predictive models, and, ultimately, to enhance stem cell integration in vivo for therapeutic benefit.
Elective home education and special educational needs

This paper reviews the literature on home education with reference to special educational needs (SEN). A rapid expansion in home educating families is noted. Parents present a variety of reasons for this, including those with concerns about the provision for their child's SEN. In one Local Education Authority (LEA), data were obtained through questionnaires from 65 families when they first registered their children for home education. In addition, 12 families, who had been home educating their children for more than 2 years, were interviewed about their experiences. Many of the children involved had SEN, but most of the parents and children expressed satisfaction with their present arrangements. However, there was often a feeling expressed that they would have preferred their children to have attended school, if their special needs could have been met. Implications for education services policy and schools’ practice are discussed.
Melasma in North Indians: A clinical, epidemiological, and etiological study

Background: Melasma is a common, acquired and symmetrical hypermelanosis characterized by more/less dark brownish macules, with an irregular contour, but clear limits, on photoexposed sites. The pathogenesis is unknown, but several clinical patterns and etiological factors have been implicated. Aims: Our present study aims to elucidate the epidemiology, clinical patterns and etiological factors in the causation of melasma in North Indians. Methods: A total of 200 consecutive patients attending the out-patient clinic from September 2013 to February 2104 with the clinical diagnosis of melasma were enrolled for the study. Photographic record was kept to study the clinical patterns. Results: The mean age of patients with melasma was 32.9 years, ranging from 18 to 60 years. Female patients out-numbered male patients, and ratio of female to male patients was 6.14:1. Patients sought medical treatment on an average of 1.79 years after appearance of melasma. 48.84% of female patients and 78.57% of males reported exacerbation with sun exposure. 36.4% of the females reported onset of melasma during pregnancy. Family history was observed in 29.07% of our female patients and 14.28% of males. History of use of mustard oil either for massage or for cooking was given by 54.07% of females and 32.14% of males, while 45.35% of females and 32.14% of males used topical corticosteroids or over-the-counter products for the treatment of melasma. Centro-facial was the most common pattern observed in 76.74% of the female patients while the malar pattern was seen in 85.71% of males. Other patterns we observed were mandibular (3.5%), lateral cheek (1.5%) and brachial (1%). Conclusion: The exact pathogenesis of melasma is unknown. Here in we have tried to elucidate the epidemiology, clinical patterns, and etiological factors in the causation of this pigmentary imperfection.
LOW‐DOSE LIDOCAINE REDUCES SECONDARY HYPERALGESIA BY A CENTRAL MODE OF ACTION

Sodium channel blockers are approved for intravenous administration in the treatment of neuropathic pain states. Preclinical studies have suggested antihyperalgesic effects on the peripheral as well as the central nervous system. The objective of this study was to determine mechanisms of action of low-dose Lidocaine in experimental induced, secondary hyperalgesia. In a first experimental trial, participants (n = 12) received lidocaine systemically (a bolus injection of 2 mg/kg in 10 min followed by an intravenous infusion of 2 mg kg(−1) h(−1) for another 50 min). In a second trial, a modified intravenous regional anesthesia (IVRA) was administered to exclude possible central analgesic effects. In one arm, patients received an infusion of 40 mi lidocaine, 0.05%; in the other arm 40 mi NaCl, 0.9%, served as a control. In both trials capsaicin, 20 mu g, was injected intradermally and time course of capsaicin-induced pain, allodynia and hyperalgesia as well as axon reflex flare was determined. The capsaicin-induced pain was slightly reduced after systemic and regional application of the anesthetic. The area of pin-prick hyperalgesia was significantly reduced by systemic lidocaine, whereas the inhibition of hyperalgesia was absent during regional administration of lidocaine. In contrast, capsaicin-induced flare was significantly decreased after both treatments. We conclude that systemic lidocaine reduces pin-prick hyperalgesia by a central mode of action, which could involve blockade of terminal branches of nociceptors. A possible role for tetrodotoxin resistant sodium channels in the antihyperalgesic effect of low-dose lidocaine is discussed.