Untangling the White Dwarf Luminosity Functions

The inversion of the white dwarf luminosity function provides an independent way to prove the past star formation history of the Milky Way independent of any cosmological models. In Rowell & Hambly (2011), the effective volume method uses the average properties of all the objects in a given bin, so a significant amount of information is lost in the early stage of the analysis, in this work, I explore the possibility of assigning objects individually in a probabilistic way using the generalised Schmidt density estimator (1/Vmax)

Cool White Dwarfs Selection with Pan-STARRS Proper Motions

The use of Reduced Proper Motion in identifying isolated white dwarfs has long been used as a proxy for the absolute magnitude in a population with known kinematics. This, however, introduces a proper motion detection limit on top of the existing photometric limit. How the survey volume is hampered by this extra parameter is discussed in Hambly et al. (2012). In this work, we discuss some robust outlier rejection methods in order to minimise the proper motion limit and hence maximise the survey volume. The generalised volume, corrected for the distance of the Sun from the Galactic Plane, is integrated explicitly

A PC-based system for long-term monitoring of animal activity

This paper describes a PC-based animal locomotor and sound activities synchronous analysis and recording system. In the former, using video recording and image analysis techniques, the geometric locations of an animal in a cage and its bodily displacement areas between consecutive time in two-dimensions were detected. Tremendous data reduction rate has also been obtained (512×512:4), which facilitates our PC computer (Pentium 100) to perform a long-term (up to several weeks according to the space of hard disk) and on-line (1 sec) analysis and storage of the animal locomotor signals. In the latter, the sounds generated by the animal were recorded at the cage over a consecutive 1-sec time and its root mean square (RMS) value was used to index the sound level. Our preliminary study showed that such a combination of monitoring and recording system gives a faithful and comprehensive representation of animal activity.published_or_final_versio

Confirmation of Monoperiodicity Above 20 Seconds for Two Blue Large-Amplitude Pulsators

Blue Large-Amplitude Pulsators (BLAPs) are a new class of pulsating variable star. They are located close to the hot subdwarf branch in the Hertzsprung-Russell diagram and have spectral classes of late O or early B. Stellar evolution models indicate that these stars are likely radially pulsating, driven by iron group opacity in their interiors. A number of variable stars with a similar driving mechanism exist near the hot subdwarf branch with multi-periodic oscillations caused by either pressure (p) or gravity (g) modes. No multi-periodic signals were detected in the OGLE discovery light curves since it would be difficult to detect short period signals associated with higher-order p modes with the OGLE cadence. Using the RISE instrument on the Liverpool Telescope, we produced high cadence light curves of two BLAPs, OGLE-BLAP-009 ($m_{\mathrm{v}}=15.65$ mag) and OGLE-BLAP-014 ($m_{\mathrm{v}}=16.79$ mag) using a $720$ nm longpass filter. Frequency analysis of these light curves identify a primary oscillation with a period of $31.935\pm0.0098$ mins and an amplitude from a Fourier series fit of $0.236$ mag for BLAP-009. The analysis of BLAP-014 identifies a period of $33.625\pm0.0214$ mins and an amplitude of $0.225$ mag. Analysis of the residual light curves reveals no additional short period variability down to an amplitude of $15.20\pm0.26$ mmag for BLAP-009 and $58.60\pm3.44$ mmag for BLAP-014 for minimum periods of $20$ s and $60$ s respectively. These results further confirm that the BLAPs are monoperiodic

Effects of fear-avoidance beliefs on Chinese patients with neck pain.

Key Messages 1. The Chinese version of the Fear-Avoidance Beliefs Questionnaire (FABQ) has good content validity, testretest reliability, internal consistency, construct validity, responsiveness, and factor structure. Thus, fear-avoidance beliefs can be used in Chinese patients with neck pain. 2. The validated FABQ facilitates future research on the effects of fear-avoidance behaviour on patients with neck pain and hence a better service for and evaluation of patients with neck pain can be provided. It may also facilitate cross-cultural studies on this common problem between western and Chinese populations. 3. The construct of fear-avoidance beliefs can be applied to patients with neck pain. 4. The fear-avoidance beliefs are an important psychosocial measure in predicting future disability level and return to complete work capacity (immediately and 3 months after physiotherapy).published_or_final_versio

Smoking makes Marlboro cowboy 'unfit'

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Activation of autophagy by FOXO3 regulates redox homeostasis during osteogenic differentiation

Bone remodeling is a continuous physiological process that requires constant generation of new osteoblasts from mesenchymal stem cells (MSCs). Differentiation of MSCs to osteoblast requires a metabolic switch from glycolysis to increased mitochondrial respiration to ensure the sufficient energy supply to complete this process. As a consequence of this increased mitochondrial metabolism, the levels of endogenous reactive oxygen species (ROS) rise. In the current study we analyzed the role of forkhead box O3 (FOXO3) in the control of ROS levels in human MSCs (hMSCs) during osteogenic differentiation. Treatment of hMSCs with H2O2 induced FOXO3 phosphorylation at Ser294 and nuclear translocation. This ROS-mediated activation of FOXO3 was dependent on mitogen-activated protein kinase 8 (MAPK8/JNK) activity. Upon FOXO3 downregulation, osteoblastic differentiation was impaired and hMSCs lost their ability to control elevated ROS levels. Our results also demonstrate that in response to elevated ROS levels, FOXO3 induces autophagy in hMSCs. In line with this, impairment of autophagy by autophagy-related 7 (ATG7) knockdown resulted in a reduced capacity of hMSCs to regulate elevated ROS levels, together with a reduced osteoblast differentiation. Taken together our findings are consistent with a model where in hMSCs, FOXO3 is required to induce autophagy and thereby reduce elevated ROS levels resulting from the increased mitochondrial respiration during osteoblast differentiation. These new molecular insights provide an important contribution to our better understanding of bone physiology

Overexpression of protein kinase C-beta 1 isoenzyme suppresses SC-236-induced apoptosis in gastric epithelial cells

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Tracking key virulence loci encoding aerobactin and salmochelin siderophore synthesis in Klebsiella pneumoniae.

BACKGROUND: Klebsiella pneumoniae is a recognised agent of multidrug-resistant (MDR) healthcare-associated infections; however, individual strains vary in their virulence potential due to the presence of mobile accessory genes. In particular, gene clusters encoding the biosynthesis of siderophores aerobactin (iuc) and salmochelin (iro) are associated with invasive disease and are common amongst hypervirulent K. pneumoniae clones that cause severe community-associated infections such as liver abscess and pneumonia. Concerningly, iuc has also been reported in MDR strains in the hospital setting, where it was associated with increased mortality, highlighting the need to understand, detect and track the mobility of these virulence loci in the K. pneumoniae population. METHODS: Here, we examined the genetic diversity, distribution and mobilisation of iuc and iro loci amongst 2503 K. pneumoniae genomes using comparative genomics approaches and developed tools for tracking them via genomic surveillance. RESULTS: Iro and iuc were detected at low prevalence (< 10%). Considerable genetic diversity was observed, resolving into five iro and six iuc lineages that show distinct patterns of mobilisation and dissemination in the K. pneumoniae population. The major burden of iuc and iro amongst the genomes analysed was due to two linked lineages (iuc1/iro1 74% and iuc2/iro2 14%), each carried by a distinct non-self-transmissible IncFIBK virulence plasmid type that we designate KpVP-1 and KpVP-2. These dominant types also carry hypermucoidy (rmpA) determinants and include all previously described virulence plasmids of K. pneumoniae. The other iuc and iro lineages were associated with diverse plasmids, including some carrying IncFII conjugative transfer regions and some imported from Escherichia coli; the exceptions were iro3 (mobilised by ICEKp1) and iuc4 (fixed in the chromosome of K. pneumoniae subspecies rhinoscleromatis). Iro/iuc mobile genetic elements (MGEs) appear to be stably maintained at high frequency within known hypervirulent strains (ST23, ST86, etc.) but were also detected at low prevalence in others such as MDR strain ST258. CONCLUSIONS: Iuc and iro are mobilised in K. pneumoniae via a limited number of MGEs. This study provides a framework for identifying and tracking these important virulence loci, which will be important for genomic surveillance efforts including monitoring for the emergence of hypervirulent MDR K. pneumoniae strains

Laying the Groundwork for the Development of the Data Archive of the New Robotic Telescope

The Liverpool Telescope has been in fully autonomous operation since 2004. The supporting data archive facility has largely been untouched. The data provision service has not been an issue although some modernisation of the system is desirable. This project is timely. Not only does it suit the upgrade of the current LT data archive, it is in line with the design phase of the New Robotic Telescope which will be online in the early-2020s; and with the development of a new data archive facility for a range of telescopes at the National Astronomical Research Institute of Thailand. The Newton Fund enabled us to collaborate in designing a new versatile generic system that serves all purposes. In the end, we conclude that a single system would not meet the needs of all parties and only adopt similar front-ends while the back-ends are bespoke to our respective systems and data-flows