julilili42/papers huggingface dataset:
Animal or Plant: Which Is the Better Fog Water Collector?
2012-04-03

Occasional fog is a critical water source utilised by plants and animals in the Namib Desert. Fog basking beetles (Onymacris unguicularis, Tenebrionidae) and Namib dune bushman grass (Stipagrostris sabulicola, Poaceae) collect water directly from the fog. While the beetles position themselves optimally for fog water collection on dune ridges, the grass occurs predominantly at the dune base where less fog water is available. Differences in the fog-water collecting abilities in animals and plants have never been addressed. Here we place beetles and grass side-by-side in a fog chamber and measure the amount of water they collect over time. Based on the accumulated amount of water over a two hour period, grass is the better fog collector. However, in contrast to the episodic cascading water run-off from the grass, the beetles obtain water in a steady flow from their elytra. This steady trickle from the beetles' elytra to their mouth could ensure that even short periods of fog basking--while exposed to predators--will yield water. Up to now there is no indication of specialised surface properties on the grass leafs, but the steady run-off from the beetles could point to specific property adaptations of their elytra surface.
Purchase and redemption decisions of mutual fund investors and the role of fund families
2012-04-03

This paper investigates the purchases and redemptions of a large cross-sectional sample of German equity funds. We find that investors not only punish bad performance by selling their shares, but also have a tendency to sell winners. Investors in large fund families show higher sales and redemption rates. Furthermore, family size also affects the flow-performance relationship: investors in large families punish bad performance more. Last, we find that inner family rankings play an important part for redemptions, with investors strongly redeeming their shares from intra-family losers. This result provides a potential reconciliation to the apparent contradiction between the low average holding period of mutual fund investors and the lack of investor discipline.
Dilaton in a soft-wall holographic approach to mesons and baryons
2012-04-04

We discuss a holographic soft-wall model developed for the description of mesons and baryons with adjustable quantum numbers n, J, L, S. This approach is based on an action which describes hadrons with broken conformal invariance and which incorporates confinement through the presence of a background dilaton field. We show that in the case of the bound-state problem (hadronic mass spectrum) two versions of the model with a positive and negative dilaton profile are equivalent to each other by a special transformation of the bulk field. We also comment on recent works which discuss the dilaton sign in the context of soft-wall approaches.
Haploidentical allogeneic hematopoietic cell transplantation in adults using CD3/CD19 depletion and reduced intensity conditioning: a phase II study
2012-04-04

This regimen allows successful haploidentical hematopoietic stem cell transplantation with reduced intensity conditioning in high-risk patients lacking a suitable donor. (clinicaltrials.gov identifier:NCT00202917).
Topical Timolol for Small Hemangiomas of Infancy
2012-04-04

Abstract: Propranolol has become the treatment of choice of large and complicated infantile hemangiomas. There is a controversy concerning the safety of systemic propranolol. Here we show that topical use of the beta‐blocker timolol can also inhibit the growth and promote regression of infantile hemangiomas. In this case series we treated 11 infantile hemangiomas in nine children including six preterm babies with the nonselective betablocker timolol. A timolol containing gel was manufactured from an ophthalmic formulation of timolol 0.5% eyedrops. This gel was applied using a standardized occlusive dressing (Finn‐Chambers) containing approximately 0.25 mg of timolol. In all infants topical timolol was associated with growth arrest, a reduction in redness and thickness within the first 2 weeks. Seven hemangiomas showed almost complete resolution, and four became much paler and thinner. No data are available on the transdermal absorption of timolol. Even supposing complete absorption of timolol from the occlusive dressing, a maximum dose of 0.25 mg of timolol would result per day and hemangioma. Regression of infantile hemangiomas treated using 0.5% timolol gel in this case series occurred earlier than spontaneous regression which is generally not observed before the age of 9–12 months. The promising results need to be verified in prospective randomized trials on topical beta blocker administration for infantile hemangiomas which should address dose, duration, and mode of application.
Magnetars: super(ficially) hot and super(fluid) cool
2012-04-04

We examine to what extent the inferred surface temperature of magnetars in quiescence can constrain the presence of a superfluid in the neutron star core and the role of magnetic field decay in the core. By performing detailed simulations of neutron star cooling, we show that extremely strong heating from field decay in the core cannot produce the high observed surface temperatures nor delay the onset of neutron superfluidity in the core. We verify the results of Kaminker et al., namely that the high magnetar surface temperatures require heating in the neutron star crust, and crust heating is decoupled from cooling/heating in the core. Therefore, because crust heating masks core heating, it is not possible to conclude that magnetar cores are in a non-superfluid state purely from high surface temperatures. From our interior temperature evolutions and after accounting for proton superconductivity in the core, we find that neutron superfluidity in the core occurs less than a few hundred years after neutron star formation. This onset time is unaffected by heating due to core field decay at fields < 10^16 G. Thus all known neutron stars, including magnetars, without a core containing exotic particles, should have a core of superfluid neutrons and superconducting protons.
Mutational analysis of a phenazine biosynthetic gene cluster in Streptomyces anulatus 9663
2012-04-04

The biosynthetic gene cluster for endophenazines, i.e., prenylated phenazines from Streptomyces anulatus 9663, was heterologously expressed in several engineered host strains derived from Streptomyces coelicolor M145. The highest production levels were obtained in strain M512. Mutations in the rpoB and rpsL genes of the host, which result in increased production of other secondary metabolites, had no beneficial effect on the production of phenazines. The heterologous expression strains produced, besides the known phenazine compounds, a new prenylated phenazine, termed endophenazine E. The structure of endophenazine E was determined by high-resolution mass spectrometry and by one- and two-dimensional NMR spectroscopy. It represented a conjugate of endophenazine A (9-dimethylallylphenazine-1-carboxylic acid) and L-glutamine (L-Gln), with the carboxyl group of endophenazine A forming an amide bond to the α-amino group of L-Gln. Gene inactivation experiments in the gene cluster proved that ppzM codes for a phenazine N -methyltransferase. The gene ppzV apparently represents a new type of TetR-family regulator, specifically controlling the prenylation in endophenazine biosynthesis. The gene ppzY codes for a LysR-type regulator and most likely controls the biosynthesis of the phenazine core. A further putative transcriptional regulator is located in the vicinity of the cluster, but was found not to be required for phenazine or endophenazine formation. This is the first investigation of the regulatory genes of phenazine biosynthesis in Streptomyces .
BK Channels Mediate Pathway-Specific Modulation of Visual Signals in theIn VivoMouse Retina
2012-04-04

The modulatory role of large-conductance Ca 2+ -activated K + (BK) channels in the nervous system has been extensively studied. In the retina, it has been shown that BK channels play a pivotal role in modulating feedback from A17 amacrine cells to rod bipolar cells (RBCs). Here, we used electroretinography to examine the functional role of BK channels for rod and cone vision in the retina in vivo using a genetically engineered mouse lacking functional BK channels ( Bk −/− ). Under dark-adapted and light-adapted conditions, the lack of BK channels had no effect on photoreceptor activity, suggesting that these ion channels do not modulate photoreceptor responses. At the bipolar cell level, the ERG signals attributed to RBCs in Bk −/− mice were not different from those in wild-type mice at low scotopic stimulus intensities. However, at high scotopic and low mesopic stimulus intensities, close to RBC saturation, a significant reduction of ERG signals reflecting RBC activity was present in the Bk −/− retina. At higher mesopic stimulus intensities activating both RBCs and cone bipolar cells (CBCs), no difference in ERG signals between Bk −/− and wild-type mice was found. In photopic stimulus paradigms, activity of ON- and OFF-CBCs in Bk −/− and wild-type retinae was indistinguishable. These findings demonstrate that BK channels modulate visual responses in vivo at the bipolar cell level at intermediate stimulus conditions.
Loss of the Ceramide Transfer Protein Augments EGF Receptor Signaling in Breast Cancer
2012-04-04

Abstract Triple-negative breast cancers (TNBC) are especially refractory to treatment due to their negative hormone receptor and ErbB2/HER2 status. Therefore, the identification of cancer-associated deregulated signaling pathways is necessary to develop improved targeted therapies. Here, we show that expression of the ceramide transfer protein CERT is reduced in TNBCs. CERT transfers ceramide from the endoplasmic reticulum to the Golgi complex for conversion into sphingomyelin (SM). We provide evidence that by regulating cellular SM levels, CERT determines the signaling output of the EGF receptor (EGFR/ErbB1), which is upregulated in approximately 70% of TNBCs. CERT downregulation in breast cancer cells enhanced ErbB1 lateral mobility, ligand-induced autophosphorylation, internalization, and chemotaxis. Together, our findings provide a link between lipid metabolism at the Golgi with signaling at the plasma membrane, thereby implicating CERT loss in the progression of TNBCs. Cancer Res; 72(11); 2855–66. ©2012 AACR.
Faculty Opinions recommendation of The 2'-O-methylation status of a single guanosine controls transfer RNA-mediated Toll-like receptor 7 activation or inhibition.
2012-04-04

Foreign RNA serves as pathogen-associated molecular pattern (PAMP) and is a potent immune stimulator for innate immune receptors. However, the role of single bacterial RNA species in immune activation has not been characterized in detail. We analyzed the immunostimulatory potential of transfer RNA (tRNA) from different bacteria. Interestingly, bacterial tRNA induced type I interferon (IFN) and inflammatory cytokines in mouse dendritic cells (DCs) and human peripheral blood mononuclear cells (PBMCs). Cytokine production was TLR7 dependent because TLR7-deficient mouse DCs did not respond and TLR7 inhibitory oligonucleotides inhibited tRNA-mediated activation. However, not all bacterial tRNA induced IFN-α because tRNA from Escherichia coli Nissle 1917 and Thermus thermophilus were non-immunostimulatory. Of note, tRNA from an E. coli knockout strain for tRNA (Gm18)-2'-O-methyltransferase (trmH) regained immunostimulatory potential. Additionally, in vitro methylation of this immunostimulatory Gm18-negative tRNA with recombinant trmH from T. thermophilus abolished its IFN-α inducing potential. More importantly, Gm18-modified tRNA acted as TLR7 antagonist and blocked IFN-α induction of influenza A virus-infected PBMCs. PMID: 22312111
Sleep‐dependent consolidation of procedural motor memories in children and adults: the pre‐sleep level of performance matters
2012-04-05

Abstract In striking contrast to adults, in children sleep following training a motor task did not induce the expected (offline) gain in motor skill performance in previous studies. Children normally perform at distinctly lower levels than adults. Moreover, evidence in adults suggests that sleep dependent offline gains in skill essentially depend on the pre‐sleep level of performance. Against this background, we asked whether improving children’s performance on a motor sequence learning task by extended training to levels approaching those of adults would enable sleep‐associated gains in motor skill in this age group also. Children (4–6 years) and adults (18–35 years) performed on the motor sequence learning task (button‐box task) before and after ∼2‐hour retention intervals including either sleep (midday nap) or wakefulness. Whereas one group of children and adults, respectively, received the standard amount of 10 blocks of training before retention intervals of sleep or wakefulness, a further group of children received an extended training on 30 blocks (distributed across 3 days). A further group of adults received a restricted training on only two blocks before the retention intervals. Children after standard training reached lowest performance levels, whereas in adults performance after standard training was highest. Children with extended training and adults after reduced training reached intermediate performance levels. Only at these intermediate performance levels did sleep induce significant gains in motor sequence skill, whereas performance did not benefit from sleep in the low‐performing children or in the high‐performing adults. Spindle counts in the post‐training nap were correlated with performance gains at retrieval only in the adults benefitting from sleep. We conclude that, across age groups, sleep induces the most robust gain in motor skill at an intermediate pre‐sleep performance level. In low‐performing children sleep‐dependent improvements in skill may be revealed only after enhancing the pre‐sleep performance level by extended training.
Geochronological evidence and tectonic significance of Carboniferous magmatism in the southwest Trabzon area, eastern Pontides, Turkey
2012-04-05

The northern and southern zones of the eastern Pontides (northeast Turkey) contain numerous plutons of varying ages and compositions. Geochemical and isotopic results on two Hercynian granitoid bodies located in the northern zone of the eastern Pontides allow a proper reconstruction of their origin for the first time. The intrusive rocks comprise four distinct bodies, two of which we investigated in detail. Based on LA–ICP–MS U–Pb zircon dating, the Derinoba and Kayadibi granites have similar 206Pb/238U versus 207Pb/235U Concordia ages of 311.1 ± 2.0 and 317.2 ± 3.5 million years for the former and 303.8 ± 1.5 million years for the latter. Aluminium saturation index values of both granites are between 0.95 and 1.35, indicating dominant peraluminous melt compositions. Both intrusions have high SiO2 (74–77 wt.%) contents and show high-K calc-alkaline and I- to S-type characteristics. Primitive mantle-normalized element diagrams display enrichment in K, Rb, Th, and U, and depletion in Ba, Nb, Ta, Sr, P, and Ti. Chondrite-normalized rare earth element patterns are characterized by concave-upward shapes and pronounced negative Eu anomalies with Lacn/Ybcn = 4.6–9.7 and Eucn/Eu* = 0.11–0.59 (Derinoba), and Lacn/Ybcn = 2.7–5.5 and Eucn/Eu* = 0.31–0.37 (Kayadibi). These features imply crystal-melt fractionation of plagioclase and K-feldspar without significant involvement of garnet. The Derinoba samples have initial εNd values between –6.1 and –7.1 with Nd model ages and T DM between 1.56 and 2.15 thousand million years. The Kayadibi samples show higher initial εNd(I) values, –4.5 to –6.2, with Nd model ages between 1.50 and 1.72 thousand million years. This study demonstrates that the Sr isotope ratios generally display negative correlation with Nd isotopes; Sr isotope ratios were lowered in some samples by hydrothermal interaction or alteration. Isotopic and petrological data suggest that both granites were produced by the partial melting of early Palaeozoic lower crustal rocks, with minor contribution from the mantle. Collectively, these rocks represent a late stage of Hercynian magmatism in the eastern Pontides.
Scale‐up of TB and HIV programme collaborative activities in Zambia – a 10‐year review
2012-04-05

Abstract Objective To review the activities, progress, achievements and challenges of the Zambia Ministry of Health tuberculosis (TB)/HIV collaborative activities over the past decade. Methods Analysis of Zambia Ministry of Health National TB and HIV programme documents and external independent programme review reports pertaining to 2000–2010. Results The number of people testing for HIV increased from 37 557 persons in 2003 to 1 327 995 persons in 2010 nationally. Those receiving anti‐retroviral therapy (ART) increased from 143 in 2003 to 344 304 in 2010. The national HIV prevalence estimates declined from 14.3% in 2001 to 13.5% in 2009. The proportion of TB patients being tested for HIV increased from 22.6% in 2006 to 84% in 2010 and approximately 70% were HIV positive. The proportion of the HIV‐infected TB patients who: (i) started on ART increased from 38% in 2006 to 50% in 2010; (ii) commenced co‐trimoxazole preventive therapy (CPT) increased from 31% in 2006 to 70% in 2010; and (iii) were successfully treated increased to an average of 80% resulting in decline of deaths from 13% in 2006 to 9% in 2010. Conclusions The scale‐up of TB/HIV collaborative programme activities in Zambia has steadily increased over the past decade resulting in increased testing for TB and HIV, and anti‐retroviral (ARV) rollout with improved treatment outcomes among TB patients co‐infected with HIV. Getting service delivery points to adhere to WHO guidelines for collaborative TB/HIV activities remains problematic, especially those meant to reduce the burden of TB in people living with HIV/AIDS (PLWHA).
Discovery of VHEγ-ray emission and multi-wavelength observations of the BL Lacertae object 1RXS J101015.9 − 311909
2012-04-06

1RXS J101015.9-311909 is a galaxy located at a redshift of z=0.14 hosting an\\nactive nucleus belonging to the class of bright BL Lac objects. Observations at\\nhigh (HE, E &gt; 100 MeV) and very high (VHE, E &gt; 100 GeV) energies provide\\ninsights into the origin of very energetic particles present in such sources\\nand the radiation processes at work. We report on results from VHE observations\\nperformed between 2006-10 with H.E.S.S. H.E.S.S. data have been analysed with\\nenhanced analysis methods, making the detection of faint sources more\\nsignificant. VHE emission at a position coincident with 1RXS J101015.9-311909\\nis detected with H.E.S.S. for the first time. In a total good-quality livetime\\nof about 49 h, we measure 263 excess counts, corresponding to a significance of\\n7.1\\\\sigma. The photon spectrum above 0.2 TeV can be described by a power-law\\nwith a photon index of \\\\Gamma\\\\ = 3.08\\\\pm0.42_{stat}\\\\pm0.20_{sys}. The integral\\nflux above 0.2 TeV is about 0.8% of the flux of the Crab nebula and shows no\\nsignificant variability over the time reported. In addition, public Fermi/LAT\\ndata are analysed to search for high energy emission from the source. The\\nFermi/LAT HE emission is significant at 8.3\\\\sigma\\\\ in the chosen 25-month\\ndataset. UV and X-ray contemporaneous observations with the Swift satellite in\\nMay 2007 are also reported, together with optical observations performed with\\nthe ATOM telescope located at the H.E.S.S. site. Swift observations reveal an\\nabsorbed X-ray flux of F_{0.3-7 keV} = 1.04^{+0.04}_{-0.05} \\\\times 10^{-11}\\nerg.cm^{-2}.s^{-1} in the 0.3-7 keV range. Finally, all the available data are\\nused to study the source's multi-wavelength properties. The SED can be\\nreproduced using a simple one-zone SSC model with emission from a region with a\\nDoppler factor of 30 and a magnetic field between 0.025 and 0.16 G. These\\nparameters are similar to those obtained for other sources of this type.\\n
Response to enemies in the invasive plant Lythrum salicaria is genetically determined
2012-04-06

The findings support two predictions of the EICA hypothesis - a genetically determined difference between native and invasive plants in plant vigour and response to enemies - and point to the importance of experiments that control for maternal effects and include the entire spectrum of native range enemies.
Outer-membrane cytochrome-independent reduction of extracellular electron acceptors in Shewanella oneidensis
2012-04-08

Dissimilatory metal reduction under pH-neutral conditions is dependent on an extended respiratory chain to the cell surface. The final reduction is catalysed by outer-membrane cytochromes that transfer respiratory electrons either directly to mineral surfaces and metal ions bound in larger organic complexes such as Fe(III) citrate, or indirectly using endogenous or exogenous electron shuttles such as humic acids and flavins. Consequently, a Shewanella oneidensis deletion mutant devoid of outer-membrane cytochromes is unable to reduce Fe(III) citrate or manganese oxide minerals and reduces humic acids at lower rates. Surprisingly, the phenotype of this quintuple deletion mutant can be rescued by a suppressor mutation, which enables metal or humic acid reduction without any outer-membrane cytochrome. Furthermore, the type II secretion system, essential for metal reduction in wild-type S. oneidensis, is not necessary for the suppressor strain. Using genome sequencing we identified two point mutations in key genes for metal reduction: mtrA and mtrB. These mutations are necessary and sufficient to account for the observed phenotype. This study is the first evidence for a catabolic, outer-membrane cytochrome-independent electron transport chain to ferric iron, manganese oxides and humic acid analogues operating in a mesophilic organism. Available bioinformatic data allow the hypothesis that outer-membrane cytochrome-independent electron transfer might resemble an evolutionary intermediate between ferrous iron-oxidizing and ferric iron-reducing micro-organisms.
A Miniaturized Ligand Binding Assay for EGFR
2012-04-08

In order to study receptor abundance and its function in solutions or in homogenates from clinical specimen, methods such as sandwich or radioimmunoassays are most commonly employed. For the determination of epidermal growth factor receptor (EGFR), we describe the development of a miniaturized bead-based ligand binding assay using its ligand EGF as immobilized capture reagent. This assay was used to analyze lysates from cell lines, and the ligand-bound EGFR was detected using an EGFR-specific antibody combined with a fluorescence-based reporter system. In a proof-of concept study with lysates from breast biopsies, the assay allowed to classify breast cancer samples in accordance to clinically the relevant EGFR cut-off level. The study suggests that such a ligand binding receptor assay could become an integral part of protein profiling procedures to provide additional information about receptor functionality in addition to its abundance.