Miracle-dz/UniFAR-FTUs huggingface dataset:
Ionic basis of the hyperpolarizing action of adenyl compounds on sinus venosus of the tortoise heart.

The ionic mechanism underlying the hyperpolarizing action of adenosine and adenine nucleotides was studied by measuring the efflux of 43K or 86Rb from sinus venosus and interauricular septum of tortoise heart. Preparations rendered quiescent by high‐K (27 mM) Ringer solution were used. Adenosine and ATP increased the efflux of 43K and 86Rb from sinus venosus. The magnitude of the responses varied from preparation to preparation, but in the same tissue adenosine and ATP were of equal efficacy. When dose‐response relationships could be determined, the adenyl compounds were found to be of similar potency. Km for adenosine was 6.2 X 10(‐6) M, for ATP 8.3 X 10(‐6) M. Regional variations in the magnitude of the responses were observed. The largest responses were obtained from the muscular strip of sinus venosus near its junction with atrium, and from the right horn of the sinus venosus. In interauricular septum the adenyl compounds caused only a slight increase in isotope efflux. Acetylcholine, by contrast, produced large increases in 86Rb efflux from all these preparations. Thus the distribution of the purinoceptors in the tortoise heart is more confined than that of the muscarinic receptors. Antagonism of the response to adenyl compounds by theophylline and 8‐phenyltheophylline was studied. The apparent Ki for theophylline was 10(‐5) M; that for 8‐phenyltheophylline about 10(‐6) M. Atropine did not inhibit the responses to the adenyl compounds. These results indicate that the changes in K permeability produced by adenosine and ATP are mediated by P1‐purinoceptors. The adenosine transport inhibitors, dipyridamole and nitrobenzylthioinosine (NBMPR), had no effect on the adenyl‐induced responses, indicating that adenosine uptake is of little importance in tortoise sinus venosus. The effects of phosphate‐modified ATP analogues were studied. Adenylimidodiphosphate (APPNP) produced increases in 86Rb efflux similar to those found with ATP, confirming that breakdown of ATP to adenosine is not obligatory for its action at P1‐purinoceptors. Alpha‐beta methylene ATP (APCPP) and beta‐gamma methylene ATP (APPCP) produced much smaller effects, which may be explained by their structural and chemical differences from ATP. The use of 86Rb as a tracer (Rb: K less than 0.01 in load solution) gives qualitatively similar results to those obtained when 43K is used to study the permeability increases produced by the adenyl compounds or acetylcholine. Quantitative differences in the measures obtained with the two isotopes, however, become apparent when the efflux of both is studied simultaneously. (ABSTRACT TRUNCATED AT 400 WORDS)
The Choice of Screening Instrument Matters: The Case of Problematic Cannabis Use Screening in Spanish Population of Adolescents

The aim of this study was to examine the feasibility of problem cannabis use screening instruments administration within wide school surveys, their psychometric properties, overlaps, and relationships with other variables. Students from 7 Spanish regions, aged 14–18, who attended secondary schools were sampled by two-stage cluster sampling (net sample 14,589). Standardized, anonymous questionnaire including DSM-IV cannabis abuse criteria, Cannabis Abuse Screening Test (CAST), and Severity of Dependence Scale (SDS) was self-completed with paper and pencil in the selected classrooms. Data was analysed using classical psychometric theory, bivariate tests, and multinomial logistic regression analysis. Not responding to instruments' items (10.5–12.3%) was associated with reporting less frequent cannabis use. The instruments overlapped partially, with 16.1% of positives being positive on all three. SDS was more likely to identify younger users with lower frequency of use who thought habitual cannabis use posed a considerable problem. CAST positivity was associated with frequent cannabis use and related problems. It is feasible to use short psychometric scales in wide school surveys, but one must carefully choose the screening instrument, as different instruments identify different groups of users. These may correspond to different types of problematic cannabis use; however, measurement bias seems to play a role too.
Effect of Noise-Optimized Monoenergetic Postprocessing on Diagnostic Accuracy for Detecting Incidental Pulmonary Embolism in Portal-Venous Phase Dual-Energy Computed Tomography

Objectives The aim of this study was to evaluate the diagnostic accuracy of virtual monoenergetic images (MEI+) at low kiloelectronvolt levels for the detection of incidental pulmonary embolism (PE) in oncological follow-up portal-venous phase dual-energy (DE-CTpv) staging. Materials and Methods Twenty-six patients with incidental PE in DE-CTpv staging, which was confirmed by computed tomography pulmonary angiography (CTPA), were included in this study. In addition, 26 matched control patients who were negative for PE in both DE-CTpv and CTPA were included. All examinations were performed on a third-generation DE-CT system in single-energy (CTPA) and dual-energy mode (DE-CTpv). Subsequently, 2 series of MEI+ data sets were reconstructed at 40 and 55 keV from the DE-CTpv data and compared with CTPA and the linearly blended CTpv images. Diagnostic accuracy and diagnostic confidence were calculated and compared for MEI+ reconstructions and for CTpv images regarding the detection of PE with CTPA as standard of reference. Results In 3 patients, PE was only detectable in CTPA and in the 40-kV and 55-kV MEI+ reconstructions but not in CTpv images. Diagnostic accuracy increased significantly for both MEI+ series (40 keV; area under the curve [AUC], 0.928; 95% confidence interval [CI], 0.879–0.978; 55 keV; AUC, 0.960; 95% CI, 0.922–0.998) as compared with CTpv (AUC, 0.814; 95% CI, 0.741–0.887; P ⩽ 0.004). Diagnostic confidence was rated highest in CTPA (median, 5; range, 3–5) followed by 55-keV MEI+ and 40-keV MEI+ (median, 5; range, 2–5 and median, 5; range, 2–5, respectively) and was lowest for CTpv (median, 4; range, 1–5), with significant differences to CTPA and MEI+ reconstructions (P ⩽ 0.001). Conclusions Monoenergetic image reconstructions from DE-CT data sets at low kiloelectronvolt levels improve diagnostic accuracy for the detection of incidental PE in oncological follow-up DE-CTpv staging, with the highest subjective diagnostic confidence in MEI+ at 55 keV.
Ecology and Physiology of the Competition for Light Between Chlorobium limicola and Chlorobium phaeobacteroides in Natural Habitats

Accurate studies of the pigment composition and isolation in pure cultures of Chlorobiaceae from samples of eight Spanish lakes show that there are two main coexisting groups of green and brown Chlorobium spp. represented respectively by Chlorobium limicola and Chlorobium phaeobacteroides. Laboratory experiments with pure and mixed cultures of the isolated strains show that light quality plays a selective role on the species composition among Chlorobiaceae. This selection depends on the pigment composition which determines the in vivo absorption spectrum of the cells as well as on their ability to adjust the intracellular concentration of light-harvesting pigments to the spectral distribution and energy of light. Correlation analysis performed with field data resulted in significant, but low, correlation coefficients. Nevertheless, they were consistent with laboratory data showing that brown Chlorobiaceae were dominant in deep layers in meromictic lakes, whereas green Chlorobiaceae dominated in layers nearer the surface or underneath plates of Chromatiaceae. The combination of laboratory and field observations stress the role of biological light filtering in determining the species composition among Chlorobiaceae in lakes.
Development and validation of a self-efficacy measure for people with multiple sclerosis: the Multiple Sclerosis Self-efficacy Scale

The aim of this study is to develop and validate a brief measure of self-efficacy specifically for use with people with multiple sclerosis (MS). Self-efficacy is the subjective belief that one can overcome challenges that one is faced with. In order to incorporate the subjective experiences of individuals with MS, a ‘patient-fo cused’ methodology has been adopted. O pen-ended interviews were used to generate potential scale items. Items were piloted on an initial sample of individuals with MS and reduced to 14 items on the basis of their perceived relevance to this patient group. The final 14-item scale was then used with a further 142 individuals in order to assess its psychometric properties. The scale demonstrated high internal consistency (C ronbach’s alpha-0.81) and test-retest reliability (r-0.81, P-0.001) and acceptable validity. Issues concerning the assessment of validity are discussed in terms of the scale’s relevancy to individuals with MS and the theoretical issues around the construct of self-efficacy. The scale has shown sensitivity to detect change following a brief therapeutic intervention, with an effect size of 0.502. This MS Self-efficacy Scale could, therefore, be a useful tool in the assessment of psychological adjustment and quality-of-life of individuals with MS.
Overlapping Groundwater Service Markets in a Palm Grove in the Algerian Sahara

Groundwater service markets are important and dynamic institutions that provide water to a wide range of farmers in many regions. However, these institutions represent arenas of complex and often antagonistic relations, which determine which farmers gain access to water and how. This study analyses the emergence and functioning of groundwater service markets from a historical perspective to advance the understanding of the role of social power games in shaping these institutions. The study was conducted in the Sidi Okba oasis in the Algerian Sahara, where over recent decades, four (in)formal, often overlapping, groundwater service markets have emerged. These markets were shaped progressively by socio‐ethnic antagonism, state intervention and economic competition between water sellers. By continuously adjusting these institutions, the highly diverse irrigation community prevented the emergence of a monopoly in groundwater sales and maintained the balance of power between water sellers and buyers by countering possible control of groundwater access by a single socio‐ethnic or economic group. The demonstrated ability of the irrigation community to craft rules to ensure these groundwater service markets function should encourage public actors to mobilize this capacity to deal with the drop in water tables, which is one adverse outcome of the ‘success' of these markets. Copyright © 2020 John Wiley & Sons, Ltd.
Ethical challenges related to next of kin - nursing staffs’ perspective

Background: Patients in clinical settings are not lonely islands; they have relatives who play a more or less active role in their lives. Objectives: The purpose of this article is to elucidate the ethical challenges nursing staff encounter with patients’ next of kin and to discuss how these challenges affect clinical practice. Research design: The study is based on data collected from ethical group discussions among nursing staff in a nursing home. The discussions took place in 2011 and 2012. The data were analysed and interpreted by using hermeneutic methodology. Ethical considerations: All the data have been anonymised and handled with confidentiality. Written informed consent was obtained from all participants. Findings: Ethical challenges relating to patients’ next of kin were found to be an issue frequently discussed in the groups. Our findings indicate that next of kin have different characteristics, categorised as ‘the professionals’ and ‘the shadows’. In this article, we will describe the next of kin’s characteristics and the ethical challenges and practical implications that nursing staff experience in this connection. Discussion: We will discuss the findings in the light of the four basic principles of medical ethics and propose interventions to help nurses manage ethical challenges related to next of kin. Conclusion: The study reveals the need to enhance nursing staffs’ communicative and ethical skills on an individual level, but most importantly, to establish routines in clinical settings for informing and following up next of kin in a systematic and structured way.
Spectroscopic study of conformational changes accompanying self‐assembly of HCV core protein

Electron microscopy and infrared and Raman spectroscopy have been used here to study the morphology, size distribution, secondary and tertiary structures of protein particles assembled from a truncated hepatitis C virus (HCV) core protein covering the first 120 aa. Particles of pure protein, having similar morphology and size distribution of those of nucleocapsids found in sera from HCV‐infected patients, have been visualized for the first time. The secondary structure of these protein particles involve β‐sheet enrichment in relation to its protein monomer. Tertiary/quaternary structure has also been studied using the dynamics of H/D exchange. With this aim infrared spectra were measured as a function of H/D exchange time and subsequently analyzed by principal component analysis and two‐dimensional correlation spectroscopy. Temporal dynamics of exchange for these protein particles were as follows: arginine residues exchanged first, followed by turn and unordered structures, followed by β‐sheets which may act as linkers of protein monomers. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Expression patterns of MITF during human cutaneous embryogenesis: evidence for bulge epithelial expression and persistence of dermal melanoblasts

Background: The mechanisms whereby melanocytes populate the epidermis and developing hair follicles during embryogenesis are incompletely understood. Recent evidence implicates an intermediate mesenchymal stage in this evolutionary process in which HMB‐45‐positive melanocyte precursors (‘melanoblasts’) exist both in intradermal as well as intraepithelial and intrafollicular compartments. The melanocyte master transcriptional regulator, microphthalmia transcription factor (MITF), identifies mature melanocytes as well as melanocyte precursor stem cells that reside in the bulge region of the hair follicle.
Drug resistance mutations can affect dimer stability of HIV‐1 protease at neutral pH

The monomer‐dimer equilibrium for the human immunodeficiency virus type 1 (HIV‐1) protease has been investigated under physiological conditions. Dimer dissociation at pH 7.0 was correlated with a loss in β‐sheet structure and a lower degree of ANS binding. An autolysis‐resistant mutant, Q7K/L33I/L63I, was used to facilitate sedimentation equilibrium studies at neutral pH where the wild‐type enzyme is typically unstable in the absence of bound inhibitor. The dimer dissociation constant (KD) of the triple mutant was 5.8 μM at pH 7.0 and was below the limit of measurement (˜100 nM) at pH 4.5. Similar studies using the catalytically inactive D25N mutant yielded a KD value of 1.0 μMat pH 7.0. These values differ significantly from a previously reported value of 23 nM obtained indirectly from inhibitor binding measurements (Darke et al., 1994). We show that the discrepancy may result from the thermodynamic linkage between the monomer‐dimer and inhibitor binding equilibria. Under conditions where a significant degree of monomer is present, both substrates and competitive inhibitors will shift the equilibrium toward the dimer, resulting in apparent increases in dimer stability and decreases in ligand binding affinity. Sedimentation equilibrium studies were also carried out on several drug‐resistant HIV‐1 protease mutants: V82F, V82F/I84V, V82T/I84V, and L90M. All four mutants exhibited reduced dimer stability relative to the autolysis‐resistant mutant at pH 7.0. Our results indicate that reductions in drug affinity may be due to the combined effects of mutations on both dimer stability and inhibitor binding.
THERMALLY DRIVEN ATMOSPHERIC ESCAPE: TRANSITION FROM HYDRODYNAMIC TO JEANS ESCAPE

Thermally driven escape from planetary atmospheres changes in nature from an organized outflow (hydrodynamic escape) to escape on a molecule-by-molecule basis (Jeans escape) with increasing Jeans parameter, λ, the ratio of the gravitational to thermal energy of the atmospheric molecules. This change is described here for the first time using the direct simulation Monte Carlo method. When heating is predominantly below the lower boundary of the simulation region, R0, and well below the exobase of a single-component atmosphere, the nature of the escape process changes over a surprisingly narrow range of Jeans parameters, λ0, evaluated at R0. For an atomic gas, the transition occurs over λ0 ∼ 2–3, where the lower bound, λ0 ∼ 2.1, corresponds to the upper limit for isentropic, supersonic outflow. For λ0 > 3 escape occurs on a molecule-by-molecule basis and we show that, contrary to earlier suggestions, for λ0 > ∼6 the escape rate does not deviate significantly from the familiar Jeans rate. In a gas composed of diatomic molecules, the transition shifts to λ0 ∼ 2.4–3.6 and at λ0 > ∼4 the escape rate increases a few tens of percent over that for the monatomic gas. Scaling by the Jeans parameter and the Knudsen number, these results can be applied to thermally induced escape of the major species from solar and extrasolar planets.
Interaction between ryanodine receptor function and sarcolemmal Ca2+ currents.

We used the whole cell voltage-clamp technique to investigate the effects of disruption of Ca2+ release from the sarcoplasmic reticulum (SR) on sarcolemmal Ca2+ currents of chick myotubes kept in culture for 7 or 8 days. Ca2+ currents were recorded in 145 mM tetraethylammonium chloride and 10 mM Ca2+ with pipettes containing cesium and 10 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. We found two components of Ca2+ current: 1) relatively large T-type currents that were activated near -50 mV and inactivated during 100-ms depolarizations to potentials positive to -60 mV (they were of similar magnitude in Ba2+ or Ca2+ and were insensitive to nifedipine) and 2) L-type currents that were activated near 0 mV and showed little or no inactivation during 100-ms depolarizations (they were larger when Ba2+ was the charge carrier and were blocked by 10 microM nifedipine). Addition of 1 or 100 microM ryanodine to the culture medium for 6-7 days caused a modest but significant increase in the L-type Ca2+ current density (pA/pF). Ryanodine (1 or 100 microM) exposure for 1-7 days reduced the T-type Ca2+ current density to < 10% of control. In contrast, exposure to 1 microM ryanodine for 0.5-3 h had no significant effect on either component of Ca2+ current. These data indicate that ryanodine has no direct action on Ca2+ currents in chick myotubes. However, disruption of SR Ca2+ release for > 24 h changes sarcolemmal Ca2+ channel expression or function.
Stochastic tragedy of the commons – A Markov model of resource conservation and depletion

Abstract Tragedy of the Commons predicts an open-access resource will be depleted by those who share it. Classical game theory shows how trigger strategies can allow players to sustain a cooperative equilibrium, but the unrealistic determinism of these strategies doesn't match observable human behavior. In this paper we build a stochastic model of Tragedy of the Commons in its highest generality. We consider a two-player repeated game where a shared resource is capable of renewing its natural capital over time provided it is not fully depleted. If the players fully deplete the resource, it can only be regenerated at a cultivation cost whose payment requires cooperation. This paper analyzes the likely evolution of the game and conditions under which cooperation is rational.
Young Children’s Understanding of the Limits and Benefits of Group Ownership

Group ownership is ubiquitous—property is owned by countries, corporations, families, and clubs. However, people cannot understand group ownership by simply relying on their conceptions of ownership by individuals, as group ownership is subject to complexities that do not arise when property is individually owned. We report 6 experiments investigating whether children ages 3 to 6 (N = 540) understand group ownership. In Experiments 1 and 2 children were asked who different objects belong to, and they appropriately judged that certain objects are more likely to belong to a group than to individual people. Experiments 3 and 4 investigated whether children understand the limits of group ownership. Children saw vignettes where agents modified or depleted property. Children ages 3 and older understood that individual members of a group should not deplete group-owned property, and children ages 5 and 6 understood that individual members should not modify group-owned property. Finally, Experiments 5 and 6 investigated whether children understand the benefits of group ownership. Children ages 5 and 6 judged that it is more acceptable for a group member to take group property than for a nonmember to do this, and children ages 4 to 6 judged that group members can take more group resources than can nonmembers. Together, these results are informative about how children conceive of group ownership rights, and about children’s conceptions of groups.
Optimal Portfolios of an Insurer and a Reinsurer with Proportional Reinsurance through Exponential Utility Maximization under Constant Elasticity of Variance Model

This work studied optimal portfolios of an insurer and a reinsurer under proportional reinsurance and exponential utility preference, aiming at obtaining the optimal strategies for both the insurer and the reinsurer and determined the condition that would warrant reinsurance according to the proportional reinsurance chosen by the insurer and accepted by the reinsurer. The insurer and the reinsurer invested in a market where the price processes of the risky asset adopted constant elasticity of variance (CEV) model and their surplus processes approximated by stochastic differential equations (SDEs). Hamilton-Jacobi-Bellman equations (HJB) were derived and closed form solutions obtained, giving the optimal values of the insurer’s and the reinsurer’s portfolio. Obtained also was the condition for proportional reinsurance.
Free p-Cresol Sulfate Is Associated with Survival and Function of Vascular Access in Chronic Hemodialysis Patients

Background: Protein-bound uremic toxins indoxyl sulfate (IS) and p-cresol sulfate (p-CS) have been implicated as an important factor in uremic syndrome. Recent evidence indicates that both IS and p-CS are predictors of cardiovascular as well as all-cause mortality among chronic dialysis patients. We conducted a study to analyze the relationship between IS and p-CS and vascular access (VA) outcome in chronic hemodialysis (HD) patients. Methods: A total of 91 chronic stable HD patients were divided into groups according to survival of VA and frequency of VA dysfunction. Demographic and biochemical data were reviewed and recorded. Serum levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1, and the total and free forms of IS and p-CS were determined. Results: Patients with a history of frequent VA failure and dysfunction had lower albumin and higher levels of ICAM-1, free IS, free and total p-CS. Diabetes was associated with higher IS and p-CS. Logistic regression revealed that diabetes and free p-CS were independent factors associated with poor outcome of VA. Conclusion: Endothelial dysfunction and uremic toxins were associated with survival and function of VA. Diabetes and free p-CS were significantly related to the outcome of VA among chronic HD patients.