Miracle-dz/UniFAR-FTUs huggingface dataset:
Advanced age protects microvascular endothelium from aberrant Ca2+ influx and cell death induced by hydrogen peroxide

Calcium signalling in endothelial cells of resistance arteries is integral to blood flow regulation. Oxidative stress and endothelial dysfunction can prevail during advanced age and we questioned how calcium signalling may be affected. Intact endothelium was freshly isolated from superior epigastric arteries of Young (∼4 months) and Old (∼24 months) male C57BL/6 mice. Under resting conditions, with no difference in intracellular calcium levels, hydrogen peroxide (H2O2) availability was ∼1/3 greater in endothelium of Old mice while vascular catalase activity was reduced by nearly half. Compared to Old, imposing oxidative stress (200 μm H2O2) for 20 min increased intracellular calcium to 4‐fold greater levels in endothelium of Young in conjunction with twice the calcium influx. Prolonged (60 min) exposure to H2O2 induced 7‐fold greater cell death in endothelium of Young. Microvascular adaptation to advanced age may protect endothelial cells during elevated oxidative stress to preserve functional viability of the intima.
A measurement platform for energy harvesting and software characterization in WSNs

Wireless Sensor Network (WSN) nodes are resource- constrained computing devices. Adaptive behavior of autonomously working WSNs tries to maximize the cost efficiency of deployments. This includes maximizing the lifetime through power consumption optimization and recharging energy reservoirs with the use of energy harvesting. The adaptive behavior that leads to efficient resource usage needs information about the WSNs energy balance for decision making. We present a novel platform to measure the harvested, stored and dissipated energy. For being applicable to different environments it allows to attach different energy harvesting devices (EHDs). EHDs do not provide power continuously. Power availability patterns are used to determine how these sources can be used efficiently. Models from harvesting theory try to adapt to it. We implement a model that targets energy neutrality on our platform. It is used to evaluate the model and improve it. Our novel platform can be used to evaluate theories that model different sources. It can utilize and characterize thermoelectric, piezoelectric and magnetic induction generators and solar cells. The measurement platform tracks energy dissipation too. Mote software is implemented to establish communication to the platform. A sample application on top of it shows that the system can be used for software characterization. This paper contributes a novel modular and low-power design for measurement platforms for WSNs. It shows utilization of different energy sources and the ability to supply different mote types. Our work shows how theories for energy harvesting can be evaluated and improved. Our work also contributes to the field of simulation and emulation through online software characterization. The approach improves in accuracy and completeness over the capabilities of offline simulation.
Limited Sequence Evolution within Persistently Targeted CD8 Epitopes in Chronic Human Immunodeficiency Virus Type 1 Infection

ABSTRACT Studies in acute human immunodeficiency virus type 1 (HIV-1) infection indicate viral evolution under CD8 T-cell immune selection pressure, but the effects of ongoing immune pressure on epitope evolution during chronic infection are not well described. In this study, we performed a detailed longitudinal analysis of viral sequence variation within persistently targeted cytotoxic T-lymphocyte (CTL) epitopes in two HIV-1-infected persons during 6 years of persistent viremia. Responses were quantitated using freshly isolated peripheral blood lymphocytes in direct lytic assays as well as by gamma interferon (IFN-γ) Elispot assays on cryopreserved cells. Seven targeted epitopes were identified in each person. In the majority of cases, the dominant epitope sequence did not change over time, even in the presence of responses of sufficient magnitude that they were detectable using fresh peripheral blood mononuclear cells in direct lytic assays. Only 4 of the 14 autologous epitopes tested represented potential CTL escape variants; however, in most cases strong responses to these epitopes persisted for the 6 years of study. Although persistent IFN-γ responses were detected to all epitopes, direct lytic assays demonstrated declining responses to some epitopes despite the persistence of the targeted sequence in vivo. These data indicate limited viral evolution within persistently targeted CD8 T-cell epitopes during the chronic phase of infection and suggest that these regions of the virus are either refractory to sequence change or that persistently activated CD8 T-cell responses in chronic infection exert little functional selection pressure.
Light-Dependent Changes of the Cytoplasmic H and Cl Activity in the Green Alga Eremosphaera viridis.

Ion-sensitive microelectrodes were used to measure Cl(-) and H(+) activities in the cytoplasm of the unicellular green alga Eremosphaera viridis de Bary. In the light, cytoplasmic Cl(-) activity was 2.2 millimolar at most and cytoplasmic H(+) activity was about 5.4. 10(-8) molar (pH 7.3). Darkening resulted in a permanent increase of the Cl(-) activity to 3.2 millimolar and in a transient acidification, which was compensated within 3 to 5 minutes. Switching light on again decreased the Cl(-) activity to the light level (2.2 millimolar). Simultaneously, a transient alkalization of the cytoplasm was observed. The transient character of the light-dependent pH changes was probably caused by pH-stat mechanisms, whereas the light-dependent Cl(-) activity changes were compensated to a much smaller degree. Studies with different inhibitors (3-(3,4-dichlorophenyl)-1, 1-dimethylurea, piretanide, venturicidin) indicated a direct relation between the light-driven H(+) flow across the thylakoid membrane and the observed light-dependent Cl(-) and H(+) activity changes in the cytoplasm. It is suggested that light-driven H(+) flux across the thylakoid membrane was in part electrically compensated by a parallel Cl(-) flux. The resulting Cl(-) and H(+) activity changes in the stroma were compensated by Cl(-) and H(+) fluxes across the chloroplast envelope giving rise to the observed Cl(-) and H(+) activity changes in the cytoplasm.
Significance of the dimensions and attributes of hotel mobile website from the perceptions of users

ABSTRACT Research on the application of mobile technology in the hotel industry is still in its nascent stage. Most studies on mobile technology in the hotel industry have investigated mobile applications. However, studies on mobile websites remain limited. Mobile websites are significant sources of information of smartphone users for their purchasing decisions. A well-designed and well-managed mobile website can satisfy the needs of customers, whereas a poorly managed one can make them frustrated and dissatisfied. However, a particular mobile website evaluation model for the hotel industry has yet to be developed. Moreover, studies have yet to investigate user requirements for hotel mobile websites. Hotels cannot develop an effective and efficient mobile website to satisfy the users’ needs, create a favorable experience for them, and influence their intention to purchase via mobile websites without understanding users’ needs with regard to mobile websites. To fill in this research gap, this study applied qualitative and quantitative research methods to collect primary data and develop a comprehensive mobile website performance evaluation model for the hotel industry. This model includes usability and functionality dimensions that have been identified from the existing literature on mobile website and hotel website evaluation. All identified dimensions and attributes were validated by a group of hotel suppliers, information technology experts, users of hotel mobile website, and smartphone users. A total of 47 attributes and 7 dimensions were rated by 456 hotel mobile website users and ranked based on their importance thereafter. The weighting scores for each dimension and attribute were analyzed using a numerical computation method. Findings indicated that users preferred an easy-to-use mobile website design and structure, as well as simple information on hotel mobile websites. Users perceived all functionality dimensions as significant. Thus, an excellent hotel mobile website should present simple information while providing users with access to detailed information if necessary.
Fluid-resistive bending sensor having perfect compatibility with flexible pneumatic balloon actuator

This paper proposes a novel bending sensor for flexible micro structures, especially Pneumatic Balloon Actuator (PBA) made of PDMS (polydi- methylsiloxan). Proposed sensor detects fluid resistance change depending on bending of fluidic structure. Structure of PBA with pneumatic channel is diverted to the fluid-resistive bending sensor without adding extra structure for sensor. Consequently, the proposed sensor has a perfect compatibility with PBA. A stiffness sensor is also designed by combining PBA and proposed bending sensor. 5 mm times 10 mm times 300 mum PDMS cantilever type stiffness sensor integrated with PBA and bending sensor could perform successfully. This paper describes the fluid-resistive bending sensor for flexible PBA and its application for stiffness sensor toward medical application.
Altered Spatial Profile of Distraction in People With Schizophrenia

Attention is critical for effective processing of incoming information and has long been identified as a potential area of dysfunction in people with schizophrenia (PSZ). In the realm of visual processing, both spatial attention and feature-based attention are involved in biasing selection toward task-relevant stimuli and avoiding distraction. Evidence from multiple paradigms has suggested that PSZ may hyperfocus and have a narrower “spotlight” of spatial attention. In contrast, feature-based attention seems largely preserved, with some suggestion of increased processing of stimuli sharing the target-defining feature. In the current study, we examined the spatial profile of feature-based distraction using a task in which participants searched for a particular color target and attempted to ignore distractors that varied in distance from the target location and either matched or mismatched the target color. PSZ differed from healthy controls in terms of interference from peripheral distractors that shared the target-color presented 200 ms before a central target. Specifically, PSZ showed an amplified gradient of spatial attention, with increased distraction to near distractors and less interference to far distractors. Moreover, consistent with hyperfocusing, individual differences in this spatial profile were correlated with positive symptoms, such that those with greater positive symptoms showed less distraction by target-colored distractors near the task-relevant location.
Dosimetric validation of Acuros XB with Monte Carlo methods for photon dose calculations.

PURPOSE The dosimetric accuracy of the recently released Acuros XB advanced dose calculation algorithm (Varian Medical Systems, Palo Alto, CA) is investigated for single radiation fields incident on homogeneous and heterogeneous geometries, and a comparison is made to the analytical anisotropic algorithm (AAA). METHODS Ion chamber measurements for the 6 and 18 MV beams within a range of field sizes (from 4.0 x 4.0 to 30.0 x 30.0 cm2) are used to validate Acuros XB dose calculations within a unit density phantom. The dosimetric accuracy of Acuros XB in the presence of lung, low-density lung, air, and bone is determined using BEAMnrc/DOSXYZnrc calculations as a benchmark. Calculations using the AAA are included for reference to a current superposition/convolution standard. RESULTS Basic open field tests in a homogeneous phantom reveal an Acuros XB agreement with measurement to within +/- 1.9% in the inner field region for all field sizes and energies. Calculations on a heterogeneous interface phantom were found to agree with Monte Carlo calculations to within +/- 2.0% (sigmaMC = 0.8%) in lung (p = 0.24 g cm(-3)) and within +/- 2.9% (sigmaMC = 0.8%) in low-density lung (p = 0.1 g cm(-3)). In comparison, differences of up to 10.2% and 17.5% in lung and low-density lung were observed in the equivalent AAA calculations. Acuros XB dose calculations performed on a phantom containing an air cavity (p = 0.001 g cm(-3)) were found to be within the range of +/- 1.5% to +/- 4.5% of the BEAMnrc/DOSXYZnrc calculated benchmark (sigmaMC = 0.8%) in the tissue above and below the air cavity. A comparison of Acuros XB dose calculations performed on a lung CT dataset with a BEAMnrc/DOSXYZnrc benchmark shows agreement within +/- 2%/2mm and indicates that the remaining differences are primarily a result of differences in physical material assignments within a CT dataset. CONCLUSIONS By considering the fundamental particle interactions in matter based on theoretical interaction cross sections, the Acuros XB algorithm is capable of modeling radiotherapy dose deposition with accuracy only previously achievable with Monte Carlo techniques.
Controlled electroplating and electromigration in nickel electrodes for nanogap formation

We report the fabrication of nickel nanospaced electrodes by electroplating and electromigration for nanoelectronic devices. Using a conventional electrochemical cell, nanogaps can be obtained by controlling the plating time alone and after a careful optimization of electrodeposition parameters such as electrolyte bath, applied potential, cleaning, etc. During the process, the gap width decreases exponentially with time until the electrode gaps are completely bridged. Once the bridge is formed, the ex situ electromigration technique can reopen the nanogap. When the gap is ∼ 1 nm, tunneling current–voltage characterization shows asymmetry which can be corrected by an external magnetic field. This suggests that charge transfer in the nickel electrodes depends on the orientation of magnetic moments.
Preservation of the Semantic Verbal Fluency Advantage in a Large Population-Based Sample: Normative Data from the TILDA Study

Abstract Objectives: It is widely believed that phonemic fluency is more difficult than naming exemplars from a semantic category. Normative data in this regard are scarce, and there is considerable disagreement in the literature regarding the pattern in normal ageing and neurodegenerative conditions. Our objective was to provide normative data for semantic phonemic discrepancy scores from a large sample of older adults. Methods: A total of 5780 community-dwelling older adults were included in this prospective, longitudinal study. Discrepancy scores were calculated by subtracting phonemic fluency score from semantic fluency score for each participant. Quantile regression was used to estimate normative values stratified for age. Results: Subjects did better on testing of semantic fluency. The average discrepancy score was 9.18±6.89 words, (range, −20 to 37; n=5780). At the fiftieth percentile, those in their fifth decade produced 10 more “animals” than “letter F” words. Subjects scored one word less per decade, with an average of seven more “animal” words produced by those in their eighth decade. Conclusions: Our study is the first to provide normative data and confirms that, for animal versus letter F fluency, the semantic advantage persists into later life in a population-based sample of community-dwelling older adults. Given that a majority of clinical samples have confirmed a reverse of this pattern in Alzheimer’s dementia (i.e., loss of semantic advantage in Alzheimer’s disease, yielding a phonemic advantage), our findings support the clinical utility of brief fluency tests and encourage further research into their use in diagnosis and prediction of progression to dementia. (JINS, 2016, 22, 1–7)
Disulfide-linked propeptides stabilize the structure of zymogen and mature pancreatic serine proteases.

Chymotrypsinogen and proelastase 2 are the only pancreatic proteases with propeptides that remain attached to the active enzyme via a disulfide bridge. It is likely, although not proven, that these propeptides are functionally important in the active enzymes, as well as in the zymogens. A mutant chymotrypsin was constructed to test this hypothesis, but it was demonstrated that the lack of the propeptide had no effect on the catalytic efficiency, substrate specificity, or folding of the protein [Venekei, I. , et al. (1996) FEBS Lett. 379, 139-142]. In this paper, we investigate the role of the disulfide-linked propeptide in the conformational stability of chymotrypsin(ogen). We compare the stabilities of the wild-type and mutant proteins (lacking propeptide-enzyme interactions) in their zymogen (chymotrypsinogen) and active (chymotrypsin) forms. The mutants exhibited a substantially increased sensitivity to heat denaturation and guanidine hydrochloride unfolding, and a faster loss of activity at extremes of pH relative to those of their wild-type counterparts. From guanidine hydrochloride denaturation experiments, we determined that covalently linked propeptide provides about 24 kJ/mol of free energy of extra stabilization (DeltaDeltaG). In addition, the mutant chymotrypsinogen lacked the normal resistance to digestion by pepsin. This may also explain (besides keeping the zymogen inactive) the evolutionary conservation of the propeptide-enzyme interactions. Tryptophan fluorescence, circular dichroism, microcalorimetric, and activity measurements suggest that the propeptide of chymotrypsin restricts the relative mobility between the two domains of the molecule. In pancreatic serine proteases, such as trypsin, that lose the propeptide upon activation, this function appears to be accomplished via alternative interdomain contacts.
PEEC modelling of toroidal magnetic inductor in frequency domain

In this paper, a detailed 3D Partial Element Equivalent Circuit (PEEC) model of a toroidal coil with a magnetic core is developed. The PEEC problem in the presence of magnetic materials is solved in the frequency domain via a magnetic current/charge approach, i.e. replacing the magnetized objects by a distribution of equivalent fictitious magnetic currents/charges in free space. The simulation parameters are the winding and magnetic core properties. The permeability is either taken from datasheets or determined by measuring the series equivalent impedance. To verify the proposed 3D PEEC model, calculated and measured impedance values are compared for several winding arrangements and core materials. A good agreement between simulation and measurements is presented up to the first resonant frequency. For higher frequencies, a more accurate specification of the permeability is required, as well as the core dielectric property has to be considered.
Characterization of a novel Neisseria meningitidis Fur and iron‐regulated operon required for protection from oxidative stress: utility of DNA microarray in the assignment of the biological role of hypothetical genes

We have previously shown that in the human pathogen Neisseria meningitidis group B (MenB) more than 200 genes are regulated in response to growth with iron. Among the Fur‐dependent, upregulated genes identified by microarray analysis was a putative operon constituted by three genes, annotated as NMB1436, NMB1437 and NMB1438 and encoding proteins with so far unknown function. The operon was remarkably upregulated in the presence of iron and, on the basis of gel retardation analysis, its regulation was Fur dependent. In this study, we have further characterized the role of iron and Fur in the regulation of the NMB1436–38 operon and we have mapped the promoter and the Fur binding site. We also demonstrate by mutant analysis that the NMB1436–38 operon is required for protection of MenB to hydrogen peroxide‐mediated killing. By using both microarray analysis and S1 mapping, we demonstrate that the operon is not regulated by oxidative stress signals. We also show that the deletion of the NMB1436–38 operon results in an impaired capacity of MenB to survive in the blood of mice using an adult mouse model of MenB infection. Finally, we show that the NMB1436–38 deletion mutant exhibits increased susceptibility to the killing activity of polymorphonuclears (PMNs), suggesting that the ‘attenuated’ phenotype is mediated in part by the increased sensitivity to reactive oxygen species‐producing cells. This study represents one of the first examples of the use of DNA microarray to assign a biological role to hypothetical genes in bacteria.
Mass spectrometric identification of mitochondrial oxidative phosphorylation subunits separated by two‐dimensional blue‐native polyacrylamide gel electrophoresis

Blue‐native polyacrylamide gel electrophoresis is a powerful tool for the separation of intact membrane protein complexes mainly applied to the analysis of the enzymes of the mitochondrial oxidative phosphorylation system (OXPHOS). Combined with sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), it reveals a two‐dimensional pattern showing the individual subunits of the five OXPHOS multi‐enzyme complexes. This pattern is useful in the diagnostic analysis of several diseases related to disorders in the oxidative phosphorylation system. However, in order to use this method for systematic diagnostic purposes and to be able to link disease with absence or reduced expression of specific subunits, an unambiguous identification of the individual subunits is necessary. In this study, we completed this task, implementing peptide mass fingerprinting and mass spectrometric sequence analysis. In the course of these analyses, we discovered a novel variant of a cytochrome c oxidase subunit VIc.
Clinical skills required of ophthalmic nurse practitioners in tertiary level public hospitals in the Western Cape Province.

BACKGROUND South Africa has a 32-year history of training ophthalmic nurse practitioners (ONPs). The role and required skills and competencies of ONPs are not well documented in the international literature and are also absent from South African publications, including South African Nursing Council publications. AIM This study aims to inform curriculum development and human resource planning by reporting on the clinical skills expected of ONPs by members of multidisciplinary ophthalmology teams. METHOD A limited survey was undertaken in the ophthalmology wards and outpatient departments of three tertiary level hospitals in the Western Cape Province. A researcher-designed structured self-completion questionnaire was distributed to 30 ophthalmology practitioners: doctors, nurses and technicians. Respondents were asked to indicate the expected clinical skills of ONPs. FINDINGS All questionnaires were completed. All respondents favoured ONPs taking histories and performing emergency eye irrigations. There was less support for more complex procedures, such as B-scans. One-third of respondents did not expect ONPs to have skills in eight key areas, including examination of the anterior chamber angle for glaucoma. No statistically significant differences were found between responses of doctors and nurses, with one exception: more nurses (15/18) than doctors (4/10) had confidence in the ONP undertaking basic eye examinations for ocular motility (Fisher's exact test, P = 0.035). CONCLUSION In the study settings, ONPs are not using their specialist skills to the full. Not all practitioners were receptive to ONPs using the skills that they had acquired during their postgraduate diploma, threatening the educational effectiveness of this initiative.