pinecone/core-2020-05-10-deduplication huggingface dataset:
Structure and dynamics of ER: minimal networks and biophysical constraints.

Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.PMCID: PMC4129489The endoplasmic reticulum (ER) in live cells is a highly mobile network whose structure dynamically changes on a number of timescales. The role of such drastic changes in any system is unclear, although there are correlations with ER function. A better understanding of the fundamental biophysical constraints on the system will allow biologists to determine the effects of molecular factors on ER dynamics. Previous studies have identified potential static elements that the ER may remodel around. Here, we use these structural elements to assess biophysical principles behind the network dynamics. By analyzing imaging data of tobacco leaf epidermal cells under two different conditions, i.e., native state (control) and latrunculin B (treated), we show that the geometric structure and dynamics of ER networks can be understood in terms of minimal networks. Our results show that the ER network is well modeled as a locally minimal-length network between the static elements that potentially anchor the ER to the cell cortex over longer timescales; this network is perturbed by a mixture of random and deterministic forces. The network need not have globally minimum length; we observe cases where the local topology may change dynamically between different Euclidean Steiner network topologies. The networks in the treated cells are easier to quantify, because they are less dynamic (the treatment suppresses actin dynamics), but the same general features are found in control cells. Using a Langevin approach, we model the dynamics of the nonpersistent nodes and use this to show that the images can be used to estimate both local viscoelastic behavior of the cytoplasm and filament tension in the ER network. This means we can explain several aspects of the ER geometry in terms of biophysical principles.Engineering and Physical Sciences Research Council (EPSRC)Biotechnology and Biological Sciences Research Council (BBSRC)Endoplasmic ReticulumGeometryDynamic
Differential top-antitop cross-section measurements as a function of observables constructed from final-state particles using pp collisions at â\u88\u9as = 7 TeV in the ATLAS detector

Â© 2015, The Author(s).Abstract: Various differential cross-sections are measured in top-quark pair (tt) events produced in proton-proton collisions at a centre-of-mass energy of â\u88\u9as = 7 TeV at the LHC with the ATLAS detector. These differential cross-sections are presented in a data set corresponding to an integrated luminosity of 4.6 fbâ\u88\u921. The differential cross-sections are presented in terms of kinematic variables, such as momentum, rapidity and invariant mass, of a top-quark proxy referred to as the pseudo-top-quark as well as the pseudo-top-quark pair system. The dependence of the measurement on theoretical models is minimal. The measurements are performed on tt events in the lepton+jets channel, requiring exactly one charged lepton and at least four jets with at least two of them tagged as originating from a b-quark. The hadronic and leptonic pseudo-top-quarks are defined via the leptonic or hadronic decay mode of the W boson produced by the top-quark decay in events with a single charged lepton. Differential cross-section measurements of the pseudo-top-quark variables are compared with several Monte Carlo models that implement next-to-leading order or leading-order multi-leg matrix-element calculations
The influence of melt flux and crustal processing on Re–Os isotope systematics of ocean island basalts: Constraints from Galápagos

New rhenium–osmium data for high-MgO (>9 wt.%) basalts from the Galápagos Archipelago reveal a large variation in 187Os/188Os (0.1304 to 0.173), comparable with the range shown by primitive global ocean island basalts (OIBs). Basalts with the least radiogenic 187Os/188Os occur closest to the Galápagos plume stem: those in western Galápagos have low 187Os/188Os, moderate 87Sr/86Sr, 143Nd/144Nd, 206Pb/204Pb and high 3He/4He whereas basalts in the south also have low 187Os/188Os but more radiogenic 87Sr/86Sr, 143Nd/144Nd, 206Pb/204Pb and 3He/4He. Our new Os isotope data are consistent with the previously established spatial zonation of the common global isotopic mantle reservoir “C” and ancient recycled oceanic crust in the mantle plume beneath western and southern parts of Galápagos, respectively.\ud
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Galápagos basalts with the most radiogenic 187Os/188Os (up to 0.1875) typically have moderate MgO (7–9 wt.%) and low Os (<50 pg g−1) but have contrastingly unenriched Sr, Nd and Pb isotope signatures. We interpret this decoupling of chalcophile and lithophile isotopic systems as due to assimilation of young Pacific lower crust during crystal fractionation. Mixing models show the assimilated crust must have higher contents of Re and Os, and more radiogenic 187Os/188Os (0.32), than previously proposed for oceanic gabbros. We suggest the inferred, exceptionally-high radiogenic 187Os of the Pacific crust may be localised and due to sulfides precipitated from hydrothermal systems established at the Galápagos Spreading Centre.\ud
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High 187Os/188Os Galápagos basalts are found where plume material is being dispersed laterally away from the plume stem to the adjacent spreading centre (i.e. in central and NE parts of the archipelago). The extent to which crustal processing influences 187Os/188Os appears to be primarily controlled by melt flux: as distance from the stem of the Galápagos plume increases, the melt flux decreases and crustal assimilation becomes proportionally greater, accounting for co-variations in Os and 187Os/188Os. The Os concentration threshold below which the 187Os/188Os of Galápagos basalts are contaminated (100 pg g−1) is higher than the canonical value (<50 pg g−1) assumed for many other global OIBs (e.g. for Iceland, Grande Comore and Hawaii). This most likely reflects the low overall melt flux to the crust from the Galápagos plume, which has only a moderate excess temperature and buoyancy flux. Our findings have implications for the interpretation of 187Os/188Os ratios in other ocean island settings, especially those where large variations in 187Os/188Os have been linked to heterogeneity in mantle lithology or sulfide populations: the effect of crustal contamination on 187Os/188Os may be greater than previously recognised, particularly for basalts associated with weak, low melt flux mantle plumes, such as Tristan, Bouvet, Crozet and St Helena
Penalized nonparametric drift estimation for a multidimensional diffusion process

We consider a multi-dimensional diffusion process $\left(\mathbf{X}_{t}\right)_{t\geq0}$ with drift vector $\mathbf{b}$ and diffusion matrix $\Sigma$. This process is observed at $n+1$ discrete times with regular sampling interval $\Delta$. We provide sufficient conditions for the existence and unicity of an invariant density. In a second step, we assume that the process is stationary, and estimate the drift function $\mathbf{b}$ on a compact set $K$ in a nonparametric way. For this purpose, we consider a family of finite dimensional linear subspaces of $L^{2}\left(K\right)$, and compute a collection of drift estimators on every subspace by a penalized least squares approach. We introduce a penalty function and select the best drift estimator. We obtain a bound for the risk of the resulting adaptive estimator. Our method fits for any dimension $d$, but, for safe of clarity, we focus on the case $d=2$. We also provide several examples of two-dimensional diffusions satisfying our assumptions, and realize various simulations. Our results illustrate the theoretical properties of our estimators
FeCoCp3 Molecular Magnets as Spin Filters

Metallorganic molecules have been proposed as excellent spin filters in molecular spintronics because of the large spin polarization of their electronic structure. However, most of the studies involving spin transport have disregarded fundamental aspects such as the magnetic anisotropy of the molecule and the excitation of spin-flip processes during electron transport. Here, we study a molecule containing a Co and an Fe atom stacked between three cyclopentadienyl rings, which presents a large magnetic anisotropy and a S = 1. These figures are superior to other molecules with the same transition metal and improves the spin-filtering capacities of the molecule. Nonequilibrium Green’s functions calculations based on density functional theory predict excellent spin-filtering properties both in tunnel and contact transport regimes. However, exciting the first magnetic state drastically reduces the current’s spin polarization. Furthermore, a difference of temperature between electrodes leads to strong thermoelectric effects that also suppress spin polarization. Our study shows that in principle good molecular candidates for spintronics need to be confronted with inelastic and thermoelectric effects.Fil: Abufager, Paula Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); Argentina. Institut Catala de Nanociencia i Nanotecnologia; EspañaFil: Robles, R.. Institut Catala de Nanociencia i Nanotecnologia; EspañaFil: Lorente, N.. Institut Catala de Nanociencia i Nanotecnologia; España. Consejo Superior de Investigaciones Científicas. Centro de Física de Materiales; España. Donostia International Physics Center; Españ
Novel methodology based on biomimetic superhydrophobic substrates to immobilize cells in hydrogel spheres for tissue engineering applications

The low retention/integration of injected cells by host structures represents
an important challenge in cell based therapies for regenerative
medicine purposes. Cell immobilization in hydrogels for target cell
delivery has been developed to circumvent this issue. However, the
existing immobilization methodologies sometimes have several steps
under wet conditions and present some drawbacks, including poor
encapsulation efficiency and the use of harmful conditions for cells or
other fragile molecules, such as proteins or growth factors. In order to
surpass these problems mesenchymal stem cells isolated from rats
(rMSCs) bone marrow and fibronectin (FN) were immobilized in alginate
beads to mimic extracellular matrix environment using an innovative
approach involving the jellification of the liquid precursor droplets
onto superhydrophobic surfaces. The alginate drops with cells and FN
hardened very fast, at room temperature, into hydrogels spheres in an
isolated environment which avoided the loss of FN and any contamination
or exchange of molecules with other liquid phase. The process for
particle fabrication employed allowed a very high efficiency on FN
encapsulation and also the mild conditions prevented the loss of cell
viability. Encapsulated rMSCs remained viable and were slowly
released from the beads during more than 20 days
The 2dF galaxy redshift survey : near-infrared galaxy luminosity functions.

We combine the Two Micron All Sky Survey (2MASS) Extended Source Catalogue and the 2dF Galaxy Redshift Survey to produce an infrared selected galaxy catalogue with 17 173 measured redshifts. We use this extensive data set to estimate the galaxy luminosity functions in the J- and KS-bands. The luminosity functions are fairly well fitted by Schechter functions with parameters MJ*−5 log  h=−22.36±0.02, αJ=−0.93±0.04, ΦJ*=0.0104±0.0016 h3 Mpc3 in the J-band and MKS*−5 log  h=−23.44±0.03, αKS=−0.96±0.05, ΦKS*=0.0108±0.0016 h3 Mpc3 in the KS-band (2MASS Kron magnitudes). These parameters are derived assuming a cosmological model with Ω0=0.3 and Λ0=0.7. With data sets of this size, systematic rather than random errors are the dominant source of uncertainty in the determination of the luminosity function. We carry out a careful investigation of possible systematic effects in our data. The surface brightness distribution of the sample shows no evidence that significant numbers of low surface brightness or compact galaxies are missed by the survey. We estimate the present-day distributions of bJ−KS and J−KS colours as a function of the absolute magnitude and use models of the galaxy stellar populations, constrained by the observed optical and infrared colours, to infer the galaxy stellar mass function. Integrated over all galaxy masses, this yields a total mass fraction in stars (in units of the critical mass density) of Ωstarsh =(1.6±0.24)×103 for a Kennicutt initial mass function (IMF) and Ωstarsh =(2.9±0.43)×103 for a Salpeter IMF. These values are consistent with those inferred from observational estimates of the total star formation history of the Universe provided that dust extinction corrections are modest
Tau anomalous magnetic moment form-factor at super B/flavor factories.

The proposed high-luminosity B/flavor factories offer new opportunities for the improved determination of the fundamental physical parameters of standard heavy leptons. Compared to the electron or the muon case, the magnetic properties of the tau lepton are largely unexplored. We show that the electromagnetic properties of the tau, and in particular its magnetic form factor, may be measured competitively in these facilities, using unpolarized or polarized electron beams. Various observables of the tau's produced on top of the gamma resonances, such as cross-section and normal polarization for unpolarized electrons or longitudinal and transverse asymmetries for polarized beams, can be combined in order to increase the sensitivity on the magnetic moment form factor. In the case of polarized electrons, we identify a special combination of transverse and longitudinal tau polarizations able to disentangle this anomalous magnetic form factor from both the charge form factor and the interference with the Z-mediating amplitude. For an integrated luminosity of 15 x 10(18)b(-1) one could achieve a sensitivity of about 10(-6), which is several orders of magnitude below any other existing high- or low-energy bound on the magnetic moment. Thus one may obtain a QED test of this fundamental quantity to a few % precision
Measurement of the WW cross section in √(s)=7 TeV pp collisions with the ATLAS detector and limits on anomalous gauge couplings

This Letter reports a measurement of the W W production cross section in root s = 7 TeV pp collisions using data corresponding to an integrated luminosity of 1.02 fb(-1) collected with the ATLAS detector. Using leptonic decays of oppositely charged W bosons, the total measured cross section is sigma (pp -> W W) = 54.4 +/- 4.0 (stat.) +/- 3.9 (syst.) +/- 2.0 (lumi.) pb, consistent with the Standard Model prediction of sigma (pp -> W W)= 44.4 +/- 2.8 pb. Limits on anomalous electroweak triple-gauge couplings are extracted from a fit to the transverse-momentum distribution of the leading charged lepton in the event
Nursing Team Leader handover in the intensive care unit contains diverse information and lacks structure: An observational study

Background: Despite a proliferation of evidence and the development  of standardised tools to improve communication at handover, evidence to guide the handover of critical patient information between nursing team leaders in the intensive care unit is limited. \ud
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Objective: The study aim was to determine the content of  information  handed  over  during  intensive care nursing team leader shift-to-shift handover. \ud
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Design: A prospective observational study.\ud
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Setting: A 21-bed medical/surgical adult intensive care unit  specialising in cardiothoracic surgery at a tertiary referral hospital in Queensland, Australia. \ud
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Participants: Senior nurses (Grade  5  and  6  Registered nurses)  working in team leader roles, employed in the intensive care unit were sampled. \ud
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Method: After obtaining consent from nursing staff, team leader  handovers were audiotaped over 20 days. Audio recordings were transcribed and analysed using deductive and inductive content analysis. The frequency of content discussed at handover that fell within the a priori categories of the ISBAR schema (Identify-Situation-Background-Assessment-Recommendation) was calculated. \ud
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Results: Forty nursing team leader handovers were recorded resulting in 277 patient handovers and a median of 7 (IQR 2) patients discussed at each handover. The majority of nurses discussed the Identity (99%), Situation (96%) and Background(88%)of the patient, however Assessment (69%) content was varied and patient  Recommendations (60%) were  discussed less frequently.  A diverse  range of additional information was discussed that did not fit into the ISBAR schema.\ud
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Conclusions: Despite universal acknowledgement of the importance  of nursing team leader handover, there are no previous studies assessing its content. Study findings indicate that nursing team leader handovers contain diverse and inconsistent content, which could lead to inadequate handovers that compromise patient safety. Further work is required to develop structured handover processes for nursing team leader handovers
Neonatal infections: case definition and guidelines for data collection, analysis, and presentation of immunisation safety data.

Maternal vaccination is an important area of research and requires appropriate and internationally comparable definitions and safety standards. The GAIA group, part of the Brighton Collaboration was created with the mandate of proposing standardised definitions applicable to maternal vaccine research. This study proposes international definitions for neonatal infections. The neonatal infections GAIA working group performed a literature review using Medline, EMBASE and the Cochrane collaboration and collected definitions in use in neonatal and public health networks. The common criteria derived from the extensive search formed the basis for a consensus process that resulted in three separate definitions for neonatal blood stream infections (BSI), meningitis and lower respiratory tract infections (LRTI). For each definition three levels of evidence are proposed to ensure the applicability of the definitions to different settings. Recommendations about data collection, analysis and presentation are presented and harmonized with the Brighton Collaboration and GAIA format and other existing international standards for study reporting
Frequency and duration of physical activity bouts in school-aged children:A comparison within and between days

Understanding how physical activity (PA) patterns vary within and between days may guide PA promotion in young people. We aimed to 1) describe and compare the frequency (bouts/day) and duration (min/bout) of bouts of moderate-to-vigorous intensity PA (MVPA) on weekdays vs. weekends and in-school vs. out-of-school, and 2) assess associations of bout frequency and duration in these time-segments with overall PA. We used cross-sectional accelerometer data from 2737 children (aged 6-19 years) in the United States National Health and Nutrition Examination Survey (NHANES) 2003-2006. A bout was defined as MVPA (≥ 2000 counts per minute [cpm]) lasting ≥ 3 min. Adjusted Wald tests were used to assess differences in bout characteristics between time-segments. Linear regression was used to examine the association of time-segment specific bout characteristics with daily minutes of MVPA and PA volume (average cpm). Bout frequency was higher on weekdays than weekends (median [IQR] 4.3 [2.2-7.2] vs. 3.0 [1.0-6.5] bouts/day, p < 0.001); however, bout duration did not differ (4.7 [4.0-5.7] vs. 4.5 [3.7-5.8] min/bout, p = 0.33). More bouts were accumulated out-of-school compared with in-school (2.2 [1.0-4.0] vs. 1.8 [0.8-3.2] bouts/day, p < 0.001), but bout duration was similar (4.7 [3.8-5.8] vs. 4.5 [3.8-5.7] min/bout, p = 0.158). For all time-segments, the frequency and duration of bouts of MVPA were independently and positively associated with overall MVPA and PA volume. In conclusion, the characteristics of children's PA vary within and between days; accounting for this in intervention design may improve future interventions. However, increasing bout frequency or duration in any time-segment may be beneficial for overall PA
Age-related patterns of vigorous-intensity physical activity in youth:The International Children's Accelerometry Database

Physical activity declines during youth but most evidence reports on combined moderate and vigorous-intensity physical activity. We investigated how vigorous-intensity activity varies with age. Cross-sectional data from 24,025 participants (5.0-18.0 y; from 20 studies in 10 countries obtained 2008-2010) providing ≥ 1 day accelerometer data (International Children's Accelerometry Database (ICAD)). Linear regression was used to investigate age-related patterns in vigorous-intensity activity; models included age (exposure), adjustments for monitor wear-time and study. Moderate-intensity activity was examined for comparison. Interactions were used to investigate whether the age/vigorous-activity association differed by sex, weight status, ethnicity, maternal education and region. A 6.9% (95% CI 6.2, 7.5) relative reduction in mean vigorous-intensity activity with every year of age was observed; for moderate activity the relative reduction was 6.0% (5.6%, 6.4%). The age-related decrease in vigorous-intensity activity remained after adjustment for moderate activity. A larger age-related decrease in vigorous activity was observed for girls (- 10.7%) versus boys (- 2.9%), non-white (- 12.9% to - 9.4%) versus white individuals (- 6.1%), lowest maternal education (high school (- 2.0%)) versus college/university (ns) and for overweight/obese (- 6.1%) versus healthy-weight participants (- 8.1%). In addition to larger annual decreases in vigorous-intensity activity, overweight/obese individuals, girls and North Americans had comparatively lower average vigorous-intensity activity at 5.0-5.9 y. Age-related declines in vigorous-intensity activity during youth appear relatively greater than those of moderate activity. However, due to a higher baseline, absolute moderate-intensity activity decreases more than vigorous. Overweight/obese individuals, girls, and North Americans appear especially in need of vigorous-intensity activity promotion due to low levels at 5.0-5.9 y and larger negative annual differences