Nitrogen doping of TiO2 photocatalyst forms a second eg state in the Oxygen (1s) NEXAFS pre-edge

Close inspection of the pre-edge in oxygen near-edge x-ray absorption fine structure spectra of single step, gas phase synthesized titanium oxynitride photocatalysts with 20 nm particle size reveals an additional eg resonance in the VB that went unnoticed in previous TiO2 anion doping studies. The relative spectral weight of this Ti(3d)-O(2p) hybridized state with respect to and located between the readily established t2g and eg resonances scales qualitatively with the photocatalytic decomposition power, suggesting that this extra resonance bears co-responsibility for the photocatalytic performance of titanium oxynitrides at visible light wavelengths

Laser-induced fusion of human embryonic stem cells with optical tweezers

published_or_final_versio

The importance for immunoregulation for long-term cancer control.

Immune checkpoint blockades have recently emerged as a breakthrough treatment for solid tumors showing high response rates and long durability. In melanoma, the combination of ipilimumab with nivolumab showed high efficacy. However, still half the patients do not respond to this treatment. In order to increase the therapeutic ratio in melanoma and other cancers, different approaches are under evaluation. Three relevant questions are at the moment driving the research community: how to maximize benefit while minimizing toxicity; how to better identify patients who are more likely to benefit from immunotherapy; how to convert nonresponders into responders. In this review we summarize the most recent findings and we outline the most likely future challenges

Prioritized Sweeping Neural DynaQ with Multiple Predecessors, and Hippocampal Replays

During sleep and awake rest, the hippocampus replays sequences of place cells that have been activated during prior experiences. These have been interpreted as a memory consolidation process, but recent results suggest a possible interpretation in terms of reinforcement learning. The Dyna reinforcement learning algorithms use off-line replays to improve learning. Under limited replay budget, a prioritized sweeping approach, which requires a model of the transitions to the predecessors, can be used to improve performance. We investigate whether such algorithms can explain the experimentally observed replays. We propose a neural network version of prioritized sweeping Q-learning, for which we developed a growing multiple expert algorithm, able to cope with multiple predecessors. The resulting architecture is able to improve the learning of simulated agents confronted to a navigation task. We predict that, in animals, learning the world model should occur during rest periods, and that the corresponding replays should be shuffled.Comment: Living Machines 2018 (Paris, France

Recombination rate and selection strength in HIV intra-patient evolution

The evolutionary dynamics of HIV during the chronic phase of infection is driven by the host immune response and by selective pressures exerted through drug treatment. To understand and model the evolution of HIV quantitatively, the parameters governing genetic diversification and the strength of selection need to be known. While mutation rates can be measured in single replication cycles, the relevant effective recombination rate depends on the probability of coinfection of a cell with more than one virus and can only be inferred from population data. However, most population genetic estimators for recombination rates assume absence of selection and are hence of limited applicability to HIV, since positive and purifying selection are important in HIV evolution. Here, we estimate the rate of recombination and the distribution of selection coefficients from time-resolved sequence data tracking the evolution of HIV within single patients. By examining temporal changes in the genetic composition of the population, we estimate the effective recombination to be r=1.4e-5 recombinations per site and generation. Furthermore, we provide evidence that selection coefficients of at least 15% of the observed non-synonymous polymorphisms exceed 0.8% per generation. These results provide a basis for a more detailed understanding of the evolution of HIV. A particularly interesting case is evolution in response to drug treatment, where recombination can facilitate the rapid acquisition of multiple resistance mutations. With the methods developed here, more precise and more detailed studies will be possible, as soon as data with higher time resolution and greater sample sizes is available.Comment: to appear in PLoS Computational Biolog

H-alpha +[NII] Observations of the HII Regions in M81

In a first of a series of studies of the H-alpha + [NII] emission from nearby spiral galaxies, we present measurements of H-alpha + [NII] emission from HII regions in M81. Our method uses large-field-CCD images and long-slit spectra, and is part of the ongoing Beijing-Arizona-Taipei-Connecticut Sky Survey. The CCD images are taken with the NAOC 0.6/0.9m f/3 Schmidt telescope at the Xinglong Observing Station, using a multicolor filter set. Spectra of 10 of the brightest HII regions are obtained using the NAOC 2.16m telescope with a Tek 1024 X 1024 CCD. The continua of the spectra are calibrated by flux-calibrated images taken from the Schmidt observations. We determine the continuum component of our H-alpha + [NII] image via interpolation from the more accurately-measured backgrounds (M81 starlight) obtained from the two neighboring (in wavelength) BATC filter images. We use the calibrated fluxes of H-alpha + [NII] emission from the spectra to normalize this interpolated, continuum-subtracted H-alpha + [NII] image. We estimate the zero point uncertainty of the measured H-alpha + [NII] emission flux to be $\sim$ 8%. A catalogue of H-alpha + [NII] fluxes for 456 HII regions is provided, with those fluxes are on a more consistent linear scale than previously available. The logarithmically-binned H-alpha + [NII] luminosity function of HII regions is found to have slope $\alpha$ = -0.70, consistent with previous results (which allowed $\alpha=-0.5 \sim -0.8$). From the overall H-alpha + [NII] luminosity of the HII regions, the star formation rate of M81 is found to be $\sim 0.68 M_{\odot} {\rm yr}^{-1}$, modulo uncertainty with extinction corrections.Comment: 18 pages, 7 figures, accepted for publication in the Astronomical Journa

Holographic Correlation Functions for Open Strings and Branes

In this paper, we compute holographically the two-point and three-point functions of giant gravitons with open strings. We consider the maximal giant graviton in $S^5$ and the string configurations corresponding to the ground states of Z=0 and Y=0 open spin chain, and the spinning string in AdS$_5$ corresponding to the derivative type impurities in Y=0 or Z=0 open spin chain as well. We treat the D-brane and open string contribution separately and find the corresponding D3-brane and string configurations in bulk which connect the composite operators at the AdS$_5$ boundary. We apply a new prescription to treat the string state contribution and find agreements for the two-point functions. For the three-point functions of two giant gravitons with open strings and one certain half-BPS chiral primary operator, we find that the D-brane contributions to structure constant are always vanishing and the open string contribution for the Y=0 ground state is in perfect match with the prediction in the free field limit.Comment: 25 page

Spotting Trees with Few Leaves

We show two results related to the Hamiltonicity and $k$-Path algorithms in undirected graphs by Bj\"orklund [FOCS'10], and Bj\"orklund et al., [arXiv'10]. First, we demonstrate that the technique used can be generalized to finding some $k$-vertex tree with $l$ leaves in an $n$-vertex undirected graph in $O^*(1.657^k2^{l/2})$ time. It can be applied as a subroutine to solve the $k$-Internal Spanning Tree ($k$-IST) problem in $O^*(\min(3.455^k, 1.946^n))$ time using polynomial space, improving upon previous algorithms for this problem. In particular, for the first time we break the natural barrier of $O^*(2^n)$. Second, we show that the iterated random bipartition employed by the algorithm can be improved whenever the host graph admits a vertex coloring with few colors; it can be an ordinary proper vertex coloring, a fractional vertex coloring, or a vector coloring. In effect, we show improved bounds for $k$-Path and Hamiltonicity in any graph of maximum degree $\Delta=4,\ldots,12$ or with vector chromatic number at most 8

Trends in prescribing of non-steroidal anti-inflammatory drugs in patients with cardiovascular disease: influence of national guidelines in UK primary care

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat pain, but have potential side effects in patients with cardiovascular disease (CVD). Objectives: To determine trends in NSAIDs prescribing between 2002 and 2010 in patients with CVD, and ascertain whether prescribing patterns changed following publication of major national (the Medicines and Healthcare products Regulatory Agency (MHRA) and the National Institute for Health and Clinical Excellence (NICE)) guidance to GPs. Methods: This was an observational database study of adult patients in 11 practices (Staffordshire, England). NSAIDs were categorised into basic, COX-2 and topical. Study duration was divided on a quarterly basis from 2002-quarter-1 to 2010q4. CVD patients were identified using pre-defined Read Codes recorded in the two years prior to each quarter. Quarterly prevalence was determined. Times of significant changes in prescribing trends were determined using Joinpoint Regression, and compared to dates of the five major guidelines (in 2004q4, 2005q1, 2005q3, 2006q4, 2008q1). Results: In CVD patients, the prescription of basic NSAIDs showed a decreasing trend throughout the study period, from 774 (95% CI, 691-863) per 10000 patients in 2002q1 to 245 (204-291) in 2010q4. COX-2 prescribing increased from 232/10000 (187-286) in 2002q1 to 403/10000 (348-464) in 2004q3. Prescribing then fell sharply to 102/10000 (76-134) in 2005q2 before stabilising around 55/10000. Topical NSAIDs prescribing showed a steady increase, starting at 115/10000 (108-123) in 2002q1 and ending at 270/10000 (258-281) in 2010q4. Similar trends were observed in patients without CVD, particularly a sharp drop in COX-2 prescribing also occurred from 2004q4 when initial MHRA guidance was issued. Conclusion: Despite guidelines and a trend toward decreased prescribing, the use of potentially harmful NSAIDs continued in CVD patients. The MHRA directives potentially might have affected patients without CVD who may have inappropriately restricted their use of COX-2

Steps towards online monitoring systems and interoperability

In the health area, there is, on a daily basis, an enormous amount of data being produced and disseminated. The fast-growing amount of collected data and the rich knowledge, possibly life-saving, that could be extracted from these data has demanded the search of new ways to ensure the reliability and availability of the information with an emphasis on the efficient use of information technology tools. Although the main focus of the information systems is the health professionals who contact directly with the patient, it is also imperative to have tools for the background of the health units (information services, managers of systems, etc.). The main purpose of this work is the development of an innovative and interactive web platform for the daily monitoring of the web services activities of a Portuguese hospital, Centro Hospitalar do Porto (CHP). This platform is a web application developed in React that aims to ensure the correct functioning of the web services, that are responsible for numerous tasks within the hospital environment, and which failure could result in disastrous consequences, both for the health institution and for the patients. The development of the web application followed the six stages of the Design Science Research (DSR) methodology and was submitted to the Strengths Weaknesses Opportunities and Threats (SWOT) analysis, which results were considered optimistic.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/201