julilili42/papers huggingface dataset:
Molecular Identification of Falciparum Malaria and Human Tuberculosis Co-Infections in Mummies from the Fayum Depression (Lower Egypt)
2013-04-02

Due to the presence of the lake Quarun and to the particular nature of its irrigation system, it has been speculated that the Fayum, a large depression 80 kilometers south-west of modern Cairo, was exposed to the hazards of malaria in historic times. Similarly, it has been speculated that, in the same area, also human tuberculosis might have been far more widespread in the antiquity than in its recent past. If these hypotheses were confirmed, it would imply that frequent cases of co-infection between the two pathogens might have occurred in ancient populations. To substantiate those speculations, molecular analyses were carried out on sixteen mummified heads recovered from the necropolis of Abusir el Meleq (Fayum) dating from the 3(rd) Intermediate Period (1064-656 BC) to the Roman Period (30 BC-300 AD). Soft tissue biopsies were used for DNA extractions and PCR amplifications using well-suited protocols. A partial 196-bp fragment of Plasmodium falciparum apical membrane antigen 1 gene and a 123-bp fragment of the Mycobacterium tuberculosis complex insertion sequence IS6110 were amplified and sequenced in six and five of the sixteen specimens, respectively. A 100% concordance rates between our sequences and those of P. falciparum and M. tuberculosis complex ones were obtained. Lastly, concomitant PCR amplification of P. falciparum and M. tuberculosis complex DNA specific fragments was obtained in four mummies, three of which are (14)C dated to the Late and Graeco-Roman Periods. Our data confirm that the hydrography of Fayum was extremely conducive to the spread of malaria. They also support the notion that the agricultural boom and dense crowding occurred in this region, especially under the Ptolemies, highly increased the probability for the manifestation and spread of tuberculosis. Here we extend back-wards to ca. 800 BC new evidence for malaria tropica and human tuberculosis co-occurrence in ancient Lower Egypt.
The Time-Course of Lexical Activation in Japanese Morphographic Word Recognition: Evidence for a Character-Driven Processing Model
2013-04-02

This lexical decision study with eye tracking of Japanese two-kanji-character words investigated the order in which a whole two-character word and its morphographic constituents are activated in the course of lexical access, the relative contributions of the left and the right characters in lexical decision, the depth to which semantic radicals are processed, and how nonlinguistic factors affect lexical processes. Mixed-effects regression analyses of response times and subgaze durations (i.e., first-pass fixation time spent on each of the two characters) revealed joint contributions of morphographic units at all levels of the linguistic structure with the magnitude and the direction of the lexical effects modulated by readers' locus of attention in a left-to-right preferred processing path. During the early time frame, character effects were larger in magnitude and more robust than radical and whole-word effects, regardless of the font size and the type of nonwords. Extending previous radical-based and character-based models, we propose a task/decision-sensitive character-driven processing model with a level-skipping assumption: Connections from the feature level bypass the lower radical level and link up directly to the higher character level.
Opposing Actions of Sevoflurane on GABAergic and Glycinergic Synaptic Inhibition in the Spinal Ventral Horn
2013-04-02

At high concentrations, sevoflurane mediates neuronal inhibition in the spinal ventral horn primarily via glycine receptors, and less via GABA(A) receptors. Our results support the hypothesis that the impact of GABA(A) receptors in mediating the immobilizing properties of volatile anesthetics is less essential in comparison to glycine receptors.
Experience-Dependent Modulation of Feedback Integration during Singing: Role of the Right Anterior Insula
2013-04-03

Somatosensation plays an important role in the motor control of vocal functions, yet its neural correlate and relation to vocal learning is not well understood. We used fMRI in 17 trained singers and 12 nonsingers to study the effects of vocal-fold anesthesia on the vocal-motor singing network as a function of singing expertise. Tasks required participants to sing musical target intervals under normal conditions and after anesthesia. At the behavioral level, anesthesia altered pitch accuracy in both groups, but singers were less affected than nonsingers, indicating an experience-dependent effect of the intervention. At the neural level, this difference was accompanied by distinct patterns of decreased activation in singers (cortical and subcortical sensory and motor areas) and nonsingers (subcortical motor areas only) respectively, suggesting that anesthesia affected the higher-level voluntary (explicit) motor and sensorimotor integration network more in experienced singers, and the lower-level (implicit) subcortical motor loops in nonsingers. The right anterior insular cortex (AIC) was identified as the principal area dissociating the effect of expertise as a function of anesthesia by three separate sources of evidence. First, it responded differently to anesthesia in singers (decreased activation) and nonsingers (increased activation). Second, functional connectivity between AIC and bilateral A1, M1, and S1 was reduced in singers but augmented in nonsingers. Third, increased BOLD activity in right AIC in singers was correlated with larger pitch deviation under anesthesia. We conclude that the right AIC and sensory-motor areas play a role in experience-dependent modulation of feedback integration for vocal motor control during singing.
LABOR MARKET VOLATILITY, SKILLS, AND FINANCIAL GLOBALIZATION
2013-04-03

We analyze the impact of financial globalization on volatilities of hours worked and wages of high-skilled and low-skilled workers. Using cross-country, industry-level data for the years 1970–2004, we establish stylized facts that document how volatilities of hours worked and wages of workers with different skill levels have changed over time. We then document that the volatility of hours worked by low-skilled workers has increased the most in response to the increase in financial globalization. We develop a dynamic stochastic general equilibrium model of a small open economy that is consistent with the empirical results. The model predicts that greater financial globalization increases the volatility of hours worked, and this effect is strongest for low-skilled workers.
Skin diseases among schoolchildren in Ghana, Gabon, and Rwanda
2013-04-04

Abstract Objectives Skin diseases, especially skin infections, among schoolchildren in A frica can be a major health problem. The objective of this study was to determine the prevalences of skin diseases among children in rural and urban schools in three different A frican countries and to study the influence of socioeconomic level. Methods Cross‐sectional, population‐based studies were performed in G hana, G abon, and R wanda. Point prevalences of skin diseases were estimated on the basis of physical examination by at least one dermatologist. Results A total of 4839 schoolchildren were seen. The overall prevalence of schoolchildren with any skin disease was high and amounted to 34.6% and 42.0% in two G hanaian studies, 45.8% in G abon, and 26.7% in R wanda. In children with skin diseases, skin infections represented the greatest proportion of disease, accounting for 14.7% and 17.6% of skin disease in the G hanaian studies, and 27.7% and 22.7% in G abon and R wanda, respectively. Diseases with the highest prevalence were tinea capitis and bacterial skin infections, especially in rural areas and in schools serving children living at lower socioeconomic levels. Conclusions The prevalences of skin diseases among A frican schoolchildren were high. Skin infections such as tinea capitis and pyoderma predominated.
Protoplanetary disk evolution and stellar parameters of T Tauri binaries in Chamaeleon I
2013-04-04

&lt;BR /&gt; Aims: This study aims to determine the impact of stellar binary companions on the lifetime and evolution of circumstellar disks in the Chamaeleon I (Cha I) star-forming region by measuring the frequency and strength of accretion and circumstellar dust signatures around the individual components of T Tauri binary stars. &lt;BR /&gt; Methods: We used high-angular resolution adaptive optics JHKsL' -band photometry and 1.5-2.5 μm spectroscopy of 19 visual binary and 7 triple stars in Cha I - including one newly discovered tertiary component - with separations between ~25 and ~1000 AU. The data allowed us to infer stellar component masses and ages and, from the detection of near-infrared excess emission and the strength of Brackett-γ emission, the presence of ongoing accretion and hot circumstellar dust of the individual stellar components of each binary. &lt;BR /&gt; Results: Of all the stellar components in close binaries with separations of 25-100 AU, 10+15-5% show signs of accretion. This is less than half of the accretor fraction found in wider binaries, which itself appears significantly reduced (~44%) compared with previous measurements of single stars in Cha I. Hot dust was found around 50+30-15% of the target components, a value that is indistinguishable from that of Cha I single stars. Only the closest binaries (&lt;25 AU) were inferred to have a significantly reduced fraction (≲25%) of components that harbor hot dust. Accretors were exclusively found in binary systems with unequal component masses Msecondary/Mprimary &lt; 0.8, implying that the detected accelerated disk dispersal is a function of mass-ratio. This agrees with the finding that only one accreting secondary star was found, which is also the weakest accretor in the sample. &lt;BR /&gt; Conclusions: The results imply that disk dispersal is more accelerated the stronger the dynamical disk truncation, i.e., the smaller the inferred radius of the disk. Nonetheless, the overall measured mass accretion rates appear to be independent of the cluster environment or the existence of stellar companions at any separation ≳25 AU, because they agree well with observations from our previous binary study in the Orion Nebula cluster and with studies of single stars in these and other star-forming regions. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile. ESO Data ID: 086.C-0762.Tables 2, 4, and Appendix A are available in electronic form at &lt;A href="http://www.aanda.org"&gt;http://www.aanda.org&lt;/A&gt;
Association of L-Ficolin Levels and FCN2 Genotypes with Chronic Chagas Disease
2013-04-04

The very first study on Brazilian cohort associates both L-ficolin plasma levels and FCN2 variants to Chagas disease and subsequent disease progression. The prognostic value of L-ficolin levels and the FCN2*A258S polymorphism should be further evaluated in other settings.
Evolution of thef-mode instability in neutron stars and gravitational wave detectability
2013-04-04

We study the dynamical evolution of the gravitational-wave driven instability\\nof the f-mode in rapidly rotating relativistic stars. With an approach based on\\nlinear perturbation theory we describe the evolution of the mode amplitude and\\nfollow the trajectory of a newborn neutron star through its instability window.\\nThe influence on the f-mode instability of the magnetic field and the presence\\nof an unstable r-mode is also considered. Two different configurations are\\nstudied in more detail; an N = 1 polytrope with a typical mass and radius and a\\nmore massive polytropic N = 0.62 model with gravitational mass M = 1.98 Msun.\\nWe study several evolutions with different initial rotation rates and\\ntemperature and determine the gravitational waves radiated during the\\ninstability. In more massive models, an unstable f-mode with a saturation\\nenergy of about 1e-6 Msun c^2 may generate a gravitational-wave signal which\\ncan be detected by the Advanced LIGO/Virgo detector from the Virgo cluster. The\\nmagnetic field affects the evolution and then the detectability of the\\ngravitational radiation when its strength is higher than 1e12 G, while the\\neffects of an unstable r-mode become dominant when this mode reaches the\\nmaximum saturation value allowed by non-linear mode couplings. However, the\\nrelative saturation amplitude of the f- and r-modes must be known more\\naccurately in order to provide a definitive answer to this issue. From the\\nthermal evolution we find also that the heat generated by shear viscosity\\nduring the saturation phase completely balances the neutrinos' cooling and\\nprevents the star from entering the regime of mutual friction. The evolution\\ntime of the instability is therefore longer and the star loses significantly\\nlarger amounts of angular momentum via gravitational waves.\\n
Cryptic diversity in the Antherospora vaillantii complex on Muscari species
2013-04-04

The anther smut fungi in the ustilaginomycetous genus Antherospora (Floromycetaceae, Urocystidales) that infect monocots, are currently placed in nine species. Against the background of the generally observed high host specificity in smut fungi, the broad host range reported for some of the species suggests much higher diversity. Antherospora vaillantii s. lato includes anther smuts on different Muscari species. In this study, specimens of anther smuts on Muscari armeniacum, M. botryoides, M. comosum, and M. tenuiflorum were analysed by rDNA sequences and morphology to determine whether they represented one polyphagous or several host specific species. The molecular phylogeny revealed three distinct lineages that were correlated with host plants, yet had only slight morphological differences. These lineages are assigned to three cryptic species: Antherospora hortensis sp. nov. on Muscari armeniacum, A. muscari-botryoidis comb. nov. (syn. Ustilago muscari-botryoidis) on M. botryoides, and A. vaillantii s. str. on M. comosum and M. tenuiflorum. All species on Muscari form a monophyletic group within Antherospora, and the phylogenetic relations within this group coincide well with the subgeneric classification of the respective host species. This indicates a common ancestry of Muscari anther smuts and co-evolution as a driver of their diversification.
Microbotryum silenes-saxifragae sp. nov. sporulating in the anthers of Silene saxifraga in southern European mountains
2013-04-04

Currently, the monophyletic lineage of anther smuts on Caryophyllaceae includes 22 species classified in the genus Microbotryum. They are model organisms studied in many disciplines of fungal biology. A molecular phylogenetic approach was used to resolve species boundaries within the caryophyllaceous anther smuts, as species delimitation based solely on phenotypic characters was problematic. Several cryptic species were found amongst the anther smuts on Caryophyllaceae, although some morphologically distinct species were discernible, and most species were characterized by high host-specificity. In this study, anther smut specimens infecting Silene saxifraga were analysed using rDNA sequences (ITS and LSU) and morphology to resolve their specific status and to discuss their phylogenetic position within the lineage of caryophyllaceous anther smuts. The molecular phylogeny revealed that all specimens form a monophyletic lineage that is supported by the morphological trait of reticulate spores with tuberculate interspaces (observed in certain spores). This lineage cannot be attributed to any of the previously described species, and the anther smut on Silene saxifraga is described and illustrated here as a new species, Microbotryum silenes-saxifragae. This species clusters in a clade that includes Microbotryum species, which infect both closely and distantly related host plants growing in diverse ecological habitats. It appears possible that host shifts combined with changes to ecological host niches drove the evolution of Microbotryum species within this clade.
Topological Wiener–Wintner theorems for amenable operator semigroups
2013-04-04

Abstract Inspired by topological Wiener–Wintner theorems we study the mean ergodicity of amenable semigroups of Markov operators on and show the connection to the convergence of strong and weak ergodic nets. The results are then used to characterize mean ergodicity of Koopman semigroups corresponding to skew product actions on compact group extensions.
Inhibition of Trypanothione Synthetase as a Therapeutic Concept
2013-04-04

Trypanothione synthetase (TryS) has been shown to synthesize both steps of trypanothione biosynthesis in all trypanosomatids so far investigated, to be essential for sustaining the entire trypanothione system and for survival of Trypanosoma brucei and likely of other trypanosomatids, proved to be druggable, and is therefore considered a most attractive target for the design of trypanocidal drugs. More recent insights into structure, catalytic mechanism, and substrate binding of TryS are briefly reviewed in respect of drug design options, and related achievements are compiled. Lead compounds corroborating the therapeutic concept of trypanothione synthesis inhibition have been identified. The growing knowledge on the enzyme's mechanism of action and structure offers ample further chances to design trypanocidal drugs that, due to the target's peculiarities, can be expected to be as efficacious as safe.
Screening Approaches Towards Trypanothione Reductase
2013-04-04

Trypanosomes and Leishmania, the causative agents of African sleeping sickness, Chagas disease, and Leishmaniasis, are responsible for over half a million human deaths per year in subtropical and tropical regions around the world. Only a handful of chemotherapeutics are available, and their efficacy suffers from drug resistance and serious side-effects. Therefore, new inhibiting compounds of essential targets are urgently needed. Trypanosomes lack both glutathione reductase and thioredoxin reductase, but possess the phylogenetically related trypanothione reductase (TR), a validated drug target and key enzyme of the unique trypanothione-based thiol metabolism. By inhibiting this essential flavoenzyme the parasite becomes vulnerable against oxidative stress induced by the host defense system and drug treatment. Here, we provide an overview of published TR screenings, and present an alternative approach combining in silico and in vitro experiments. Starting from an in vitro screen of 2816 highly diverse compounds, 21 novel TR actives could be identified. These inhibitors were used as the starting point to identify similar substances within a compound library of 200 000 available chemicals by a ligand-based in silico screening. In vitro screening of the resulted in silico-enriched dataset led to the identification of 61 additional TR actives. All 82 TR inhibitors showed IC50 values down to the nanomolar range. Subsequently, the dataset of known actives was used to implement a novel structure-based in silico screening approach that might identify further potential novel TR inhibitors.
Life and Death of Trypanosoma Brucei : New Perspectives for Drug Development
2013-04-04

Cell death is a life-long companion for any cell and molecular processes evolved in order to deal with life-threatening situations like starvation or poisoning. It is also known that in metazoa different pathways exist by which a cell undergoes suicide for the benefit of the whole organism, collectively known as apoptosis. Although protozoa generally lack caspases, a formerly thought indispensable prerequisite for apoptosis, an inducible caspase-independent form of apoptosis as a mechanism of cell density regulation has been described in African trypanosomes. Here, we review the current status of cell death mechanisms in Trypanosoma brucei including necrosis, autophagy, and apoptosis. We will discuss which of these events are necessary to cope with stressful situations, and which are probably needed to ensure continuance of infection and transmittance to the insect vector. Since autophagy and apoptosis are essential for the parasite's survival, we will also discuss possible pathway junctions suitable for drug development.
Correlating Structure and Morphology to Device Performance of Molecular Organic Donor–Acceptor Photovoltaic Cells Based on Diindenoperylene (DIP) and C60
2013-04-05

Abstract The performance of organic photovoltaic cells (OPVCs) shows a critical dependence on morphology and structure of the active layers. In small molecule donor/acceptor (D/A) cells fabrication parameters, like substrate temperature and evaporation rate, play a significant role for crystallization and roughening of the film. In particular, the fraction of mixed material at the interface between donor and acceptor is highly relevant for device performance. While an ideal planar heterojunction (PHJ) exhibits the smallest possible interface area resulting in suppressed recombination losses, mixed layers suffer strongly from recombination but show higher exciton dissociation efficiencies. In this study we investigate PHJ and planar‐mixed heterojunction (PM‐HJ) solar cells based on diindenoperylene (DIP) as donor and C 60 as acceptor, fabricated under different growth conditions. Grazing incidence small angle X‐ray scattering (GISAXS), X‐ray reflectometry (XRR) and atomic force microscopy (AFM) are used to obtain detailed information about in‐ and out‐of‐plane structures and topography. In that way we find that surface and bulk domain distances are correlated in size for PHJs, while PM‐HJs show no correlation at all. The resulting solar cell characteristics are strongly affected by the morphology, as reorganizations in structure correlate with changes in the solar cell performance.
Magnetite Formation by the Novel Fe(III)-reducingGeothrix fermentansStrain HradG1 Isolated from a Hydrocarbon-Contaminated Sediment with Increased Magnetic Susceptibility
2013-04-05

Abstract Surface sediments at the former military base Hradcany, Czech Republic, heavily contaminated with hydrocarbons, were remediated over years by air-sparging. The sediments show a strong magnetic enhancement at the groundwater fluctuation zone. Here we describe the isolation of a new Fe(III)-reducing and magnetite-producing bacterial strain Geothrix fermentans HradG1from this magnetic and redox-dynamic layer. This isolation underlines that the genus Geothrix is a relevant group of bacteria in hydrocarbon-contaminated environments that undergo dynamic oxic-anoxic redox fluctuations. The Fe(III)-reducing metabolic activity of these organisms potentially leads to changing magnetic soil properties that can potentially be used to identify biogeochemical hotspots. Keywords: biodegradationbiomineralizationgroundwateriron reductionmolecular ecology
Gravitationally driven electromagnetic perturbations of neutron stars and black holes
2013-04-05

Gravitational perturbations of neutron stars and black holes are well known sources of gravitational radiation. If the compact object is immersed in or endowed with a magnetic field, the gravitational perturbations would couple to electromagnetic perturbations and potentially trigger synergistic electromagnetic signatures. We present a detailed analytic calculation of the dynamics of coupled gravitational and electromagnetic perturbations for both neutron stars and black holes. We discuss the prospects for detecting the electromagnetic waves in these scenarios and the potential that these waves have for providing information about their source.