Reaction-Diffusion System in a Vesicle with Semi-Permeable Membrane

We study the Schloegl model in a vesicle with semi-permeable membrane. The diffusion constant takes a smaller value in the membrane region, which prevents the outflow of self-catalytic product. A nonequilibrium state is stably maintained inside of the vesicle. Nutrients are absorbed and waste materials are exhausted through the membrane by diffusion. It is interpreted as a model of primitive metabolism in a cell.Comment: 8 pages, 6 figure

Creation and Reproduction of Model Cells with Semipermeable Membrane

A high activity of reactions can be confined in a model cell with a semipermeable membrane in the Schl\"ogl model. It is interpreted as a model of primitive metabolism in a cell. We study two generalized models to understand the creation of primitive cell systems conceptually from the view point of the nonlinear-nonequilibrium physics. In the first model, a single-cell system with a highly active state confined by a semipermeable membrane is spontaneously created from an inactive homogeneous state by a stochastic jump process. In the second model, many cell structures are reproduced from a single cell, and a multicellular system is created.Comment: 11 pages, 7 figure

Decoupling of functional and structural language networks in temporal lobe epilepsy

OBJECTIVE: To identify functional and structural alterations in language networks of people with temporal lobe epilepsy (TLE), who frequently present with naming and word-finding difficulties. METHODS: Fifty-five patients with unilateral TLE (29 left) and 16 controls were studied with auditory and picture naming functional magnetic resonance imaging (fMRI) tasks. Activation maxima in the left posterobasal temporal lobe were used as seed regions for whole-brain functional connectivity analyses (psychophysiological interaction). White matter language pathways were investigated using diffusion tensor imaging and neurite orientation dispersion and density imaging metrics extracted along fiber bundles starting from fMRI-guided seeds. Regression analyses were performed to investigate the correlation of functional connectivity with diffusion MRI metrics. RESULTS: In the whole group of patients and controls, weaker functional connectivity from the left posterobasal temporal lobe (1) to the bilateral anterior temporal lobe, precentral gyrus, and lingual gyrus during auditory naming and (2) to the bilateral occipital cortex and right fusiform gyrus during picture naming was associated with decreased neurite orientation dispersion and higher free water fraction of white matter tracts. Compared to controls, TLE patients exhibited fewer structural connections and an impaired coupling of functional and structural metrics. SIGNIFICANCE: TLE is associated with an impairment and decoupling of functional and structural language networks. White matter damage, as evidenced by diffusion abnormalities, may contribute to impaired functional connectivity and language dysfunction in TLE

The hyperfine transition in light muonic atoms of odd Z

The hyperfine (hf) transition rates for muonic atoms have been re-measured for select light nuclei, using neutron detectors to evaluate the time dependence of muon capture. For $^{19}$F $\Lambda$$_{h}$ = 5.6 (2) $\mu$s$^{-1}$ for the hf transition rate, a value which is considerably more accurate than previous measurements. Results are also reported for Na, Al, P, Cl, and K; that result for P is the first positive identification.Comment: 12 pages including 5 tables and 4 figures, RevTex, submitted to Phys. Rev.

Anxiety and depression symptoms in young people with perinatally acquired HIV and HIV affected young people in England

Adolescents with perinatal HIV (PHIV) may be at higher risk of anxiety and depression than HIV negative young people. We investigated the prevalence of symptoms of anxiety and depression in PHIV and HIV-affected (siblings of PHIV and/or had an HIV positive mother) young people in England. Symptoms were measured using the Hospital Anxiety and Depression Scale (HADS) scores. A cross-sectional analysis was conducted of data from 283 young people with PHIV aged 13-21 years and 96 HIV-affected young people aged 13-23 years in the Adolescents and Adults Living with Perinatal HIV (AALPHI) cohort. Linear regression investigated factors associated with higher (worse) anxiety and depression scores.115 (41%) and 29 (30%) PHIV and HIV-affected young people were male, median age was 16 [interquartile range 15,18] and 16 [14,18] years and 241 (85%) and 71 (74%) young people were black African, respectively. There were no differences in raw or z-scores of anxiety and depression, or self-esteem, between PHIV and HIV-affected participants (all p values >0.1). Across both PHIV and HIV-affected groups, factors associated with higher anxiety scores were having more carers in childhood, speaking a language other than English at home, lower self-esteem, and ever thinking life was not worth living and lower social functioning. Factors associated with higher depression scores were male sex, death of one or both parents, ever excluded from school, lower self-esteem and lower social functioning. This study found anxiety and depression scores were similar among PHIV and HIV-affected young people and similar to that of population norms. Other studies have found an association between poorer mental health and worse health outcomes in young people with PHIV, highlighting the need to identify young people at increased risk and provide timely support

GUP1 and its close homologue GUP2, encoding multi-membrane-spanning proteins involved in active glycerol uptake in Saccharomyces cerevisiae

Many yeast species can utilise glycerol, both as sole carbon source and as an osmolyte. In Saccharomyces cerevisiae, physiological studies have previously shown the presence of an active uptake system driven by electrogenic proton symport. We have used transposon mutagenesis to isolate mutants affected in the transport of glycerol into the cell. Here we present the identification of YGL084c, encoding a multi-membrane-spanning protein, as being essential for proton symport of glycerol into Saccharomyces cerevisiae. The gene is named GUP1 (Glycerol UPtake) and is important for growth on glycerol as carbon and energy source, as well as for osmotic protection by added glycerol, of a strain deficient in glycerol production. Another ORF, YPL189w, presenting a high degree of homology to YGL084c, similarly appears to be involved in active glycerol uptake in salt-containing glucose-based media in strains deficient in glycerol production. Analogously, this gene is named GUP2. To our knowledge, this is the first report on a gene product involved in active transport of glycerol in yeasts. Mutations with the same phenotypes occurred in two other open reading frames of previously unknown function, YDL074c and YPL180w.Comunidade Europeia (CE) - contract BIO4-CT95-0161

Cognitive Function in Young Persons With and Without Perinatal HIV in the AALPHI Cohort in England: Role of Non-HIV-Related Factors

BACKGROUND:  There is limited evidence about the cognitive performance of older adolescents with perinatally acquired human immunodeficiency virus (HIV) compared with HIV-negative (HIV-) adolescents. METHODS:  A total of 296 perinatally HIV-infected (PHIV+) and 97 HIV- adolescents (aged 12-21 and 13-23 years, respectively) completed 12 tests covering 6 cognitive domains. The HIV- participants had PHIV+ siblings and/or an HIV-infected mother. Domain-specific and overall (NPZ-6) z scores were calculated for PHIV+ participants, with or without Centers for Disease Control and Prevention (CDC) stage C disease, and HIV- participants. Linear regression was performed to explore predictors of NPZ-6. RESULTS:  One hundred twenty-five (42%) of the PHIV+ and 31 (32%) of the HIV- participants were male; 251 (85%) and 69 (71%), respectively, were black African; and their median ages (interquartile range) were 16 (15-18) and 16 (14-18) years, respectively. In PHIV+ participants, 247 (86%) were receiving antiretroviral therapy, and 76 (26%) had a previous CDC C diagnosis. The mean (standard deviation) NPZ-6 score was -0.81 (0.99) in PHIV+ participants with a CDC C diagnosis (PHIV+/C), -0.45 (0.80) in those without a CDC C diagnosis (PHIV+/no C), and -0.32 (0.76) in HIV- participants (P < .001). After adjustment, there was no difference in NPZ-6 scores between PHIV+/no C and HIV- participants (adjusted coefficient, -0.01; 95% confidence interval, -.22 to .20). PHIV+/C participants scored below the HIV- group (adjusted coefficient, -0.44; -.70 to -.19). Older age predicted higher NPZ-6 scores, and black African ethnicity and worse depression predicted lower NPZ-6 scores. In a sensitivity analysis including PHIV+ participants only, no HIV-related factors apart from a CDC C diagnosis were associated with NPZ-6 scores. CONCLUSIONS:  Cognitive performance was similar between PHIV+/no C and HIV- participants and indicated relatively mild impairment compared with normative data. The true impact on day-to-day functioning needs further investigation

Very-high energy gamma-ray astronomy: A 23-year success story in high-energy astroparticle physics

Very-high energy (VHE) gamma quanta contribute only a minuscule fraction - below one per million - to the flux of cosmic rays. Nevertheless, being neutral particles they are currently the best "messengers" of processes from the relativistic/ultra-relativistic Universe because they can be extrapolated back to their origin. The window of VHE gamma rays was opened only in 1989 by the Whipple collaboration, reporting the observation of TeV gamma rays from the Crab nebula. After a slow start, this new field of research is now rapidly expanding with the discovery of more than 150 VHE gamma-ray emitting sources. Progress is intimately related with the steady improvement of detectors and rapidly increasing computing power. We give an overview of the early attempts before and around 1989 and the progress after the pioneering work of the Whipple collaboration. The main focus of this article is on the development of experimental techniques for Earth-bound gamma-ray detectors; consequently, more emphasis is given to those experiments that made an initial breakthrough rather than to the successors which often had and have a similar (sometimes even higher) scientific output as the pioneering experiments. The considered energy threshold is about 30 GeV. At lower energies, observations can presently only be performed with balloon or satellite-borne detectors. Irrespective of the stormy experimental progress, the success story could not have been called a success story without a broad scientific output. Therefore we conclude this article with a summary of the scientific rationales and main results achieved over the last two decades.Comment: 45 pages, 38 figures, review prepared for EPJ-H special issue "Cosmic rays, gamma rays and neutrinos: A survey of 100 years of research

Right ventricular dysfunction is a predictor of non-response and clinical outcome following cardiac resynchronization therapy

<p>Abstract</p> <p>Background</p> <p>Cardiac resynchronization therapy (CRT) is an established treatment in advanced heart failure (HF). However, an important subset does not derive a significant benefit. Despite an established predictive role in HF, the significance of right ventricular (RV) dysfunction in predicting clinical benefit from CRT remains unclear. We investigated the role of RV function, assessed by cardiovascular magnetic resonance (CMR), in predicting response to and major adverse clinical events in HF patients undergoing CRT.</p> <p>Methods</p> <p>Sixty consecutive patients were evaluated with CMR prior to CRT implantation in a tertiary cardiac centre. The primary end-point was a composite of death from any cause or unplanned hospitalization for a major cardiovascular event. The secondary end-point was response to therapy, defined as improvement in left ventricular ejection fraction ≥ 5% on echocardiography at one year.</p> <p>Results</p> <p>Eighteen patients (30%) met the primary end-point over a median follow-up period of 26 months, and 27 out of 56 patients (48%) were considered responders to CRT. On time-to-event analysis, only atrial fibrillation (HR 2.6, 95% CI 1.02-6.84, p = 0.047) and RV dysfunction, either by a reduced right ventricular ejection fraction-RVEF (HR 0.96, 95% CI 0.94-0.99, p = 0.006) or tricuspid annular plane systolic excursion-TAPSE (HR 0.88, 95% CI, 0.80-0.96, p = 0.006), were significant predictors of adverse events. On logistic regression analysis, preserved RVEF (OR 1.05, 95% CI 1.01-1.09, p = 0.01) and myocardial scar burden (OR 0.90, 95% CI 0.83-0.96, p = 0.004) were the sole independent predictors of response to CRT. Patients with marked RV dysfunction (RVEF < 30%) had a particularly low response rate (18.2%) to CRT.</p> <p>Conclusions</p> <p>Right ventricular function is an important predictor of both response to CRT and long-term clinical outcome. Routine assessment of the right ventricle should be considered in the evaluation of patients for CRT.</p