The HI Content of Local Late-Type Galaxies

We present a solid relationship between the neutral hydrogen (HI) disk mass and the stellar disk mass of late-type galaxies in the local universe. This relationship is derived by comparing the stellar disk mass function from the Sloan Digital Sky Survey and the HI mass function from the HI Parkes All Sky Survey (HIPASS). We find that the HI mass in late-type galaxies tightly correlates with the stellar mass over three orders of magnitude in stellar disk mass. We cross-check our result with that obtained from a sample of HIPASS objects for which the stellar mass has been obtained by inner kinematics. In addition, we derive the HI versus halo mass relationship and the dependence of all the baryonic components in spirals on the host halo mass. These relationships bear the imprint of the processes ruling galaxy formation, and highlight the inefficiency of galaxies both in forming stars and in retaining their pristine HI gas.Comment: 6 pages, 5 figures. Match to the published version. References update

Inclusive Masculinity and Facebook Photographs Among Early Emerging Adults at a British University

Central to debates about the construction of masculinity in sociology is the influence of culture and what constitutes acceptable displays of masculinity. This article adopts a novel approach in examining this question. It adopts a summative content analysis, combined with a semiotic analysis, of 1,100 Facebook photographs, in order to explore the underlying meanings within the photos and the performances of masculinity. Facebook photographs from 44, straight, White, male, early emerging adults attending the same university are used as a representation of an individual’s ideal self. These are then analyzed in order to determine the behaviors endorsed by peer culture. It was found that the sample overwhelmingly adopted inclusive behaviors (including homosocial tactility, dancing, and kissing each other), and inclusive masculinity theory was utilized to contextualize participants’ constructions of masculinity. Thus, this research shows that emerging adult males at this university construct their masculine identities away from previous orthodox archetypes. It is argued that the reducing importance of gendered behavior patterns may represent an adoption of what are perceived as wider cultural norms and act as a symbol of adulthood to these early emerging adults

Constraining The Assembly Of Normal And Compact Passively Evolving Galaxies From Redshift z=3 To The Present With CANDELS

We study the evolution of the number density, as a function of the size, of passive early-type galaxies with a wide range of stellar masses 10^10<M*/Msun<10^11.5) from z~3 to z~1, exploiting the unique dataset available in the GOODS-South field, including the recently obtained WFC3 images as a part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). In particular, we select a sample of 107 massive (M*>10^10 M_sun), passive (SSFR<10^-2 Gyr^-1) and morphologically spheroidal galaxies at 1.2<z<3, taking advantage of the panchromatic dataset available for GOODS, including VLT, CFHT, Spitzer, Chandra and HST ACS+WFC3 data. We find that at 1<z<3 the passively evolving early-type galaxies are the reddest and most massive objects in the Universe, and we prove that a correlation between mass, morphology, color and star-formation activity is already in place at that epoch. We measure a significant evolution in the mass-size relation of passive early-type galaxies (ETGs) from z~3 to z~1, with galaxies growing on average by a factor of 2 in size in a 3 Gyr timescale only. We witness also an increase in the number density of passive ETGs of 50 times over the same time interval. We find that the first ETGs to form at z>2 are all compact or ultra-compact, while normal sized ETGs (meaning ETGs with sizes comparable to those of local counterparts of the same mass) are the most common ETGs only at z<1. The increase of the average size of ETGs at 0<z<1 is primarily driven by the appearance of new large ETGs rather than by the size increase of individual galaxies.Comment: 9 pages, 5 figures, submitted to Ap

Surface Brightness Profiles of Composite Images of Compact Galaxies at z~4-6 in the HUDF

The Hubble Ultra Deep Field (HUDF) contains a significant number of B, V and i'-band dropout objects, many of which were recently confirmed to be young star-forming galaxies at z~4-6. These galaxies are too faint individually to accurately measure their radial surface brightness profiles. Their average light profiles are potentially of great interest, since they may contain clues to the time since the onset of significant galaxy assembly. We separately co-add V, i' and z'-band HUDF images of sets of z~4,5 and 6 objects, pre-selected to have nearly identical compact sizes and the roundest shapes. From these stacked images, we are able to study the averaged radial structure of these objects at much higher signal-to-noise ratio than possible for an individual faint object. Here we explore the reliability and usefulness of a stacking technique of compact objects at z~4-6 in the HUDF. Our results are: (1) image stacking provides reliable and reproducible average surface brightness profiles; (2) the shape of the average surface brightness profiles show that even the faintest z~4-6 objects are resolved; and (3) if late-type galaxies dominate the population of galaxies at z~4-6, as previous HST studies have shown, then limits to dynamical age estimates for these galaxies from their profile shapes are comparable with the SED ages obtained from the broadband colors. We also present accurate measurements of the sky-background in the HUDF and its associated 1-sigma uncertainties.Comment: 10 pages, 9 figures, 2 tables, emulateapj; Accepted for publication in The Astronomical Journa

Cocaine Use Prediction with Tensor-based Machine Learning on Multimodal MRI Connectome Data

This paper considers the use of machine learning algorithms for predicting cocaine use based on magnetic resonance imaging (MRI) connectomic data. The study utilized functional MRI (fMRI) and diffusion MRI (dMRI) data collected from 275 individuals, which was then parcellated into 246 regions of interest (ROIs) using the Brainnetome atlas. After data preprocessing, the datasets were transformed into tensor form. We developed a tensor-based unsupervised machine learning algorithm to reduce the size of the data tensor from $275$ (individuals) $\times 2$ (fMRI and dMRI) $\times 246$ (ROIs) $\times 246$ (ROIs) to $275$ (individuals) $\times 2$ (fMRI and dMRI) $\times 6$ (clusters) $\times 6$ (clusters). This was achieved by applying the high-order Lloyd algorithm to group the ROI data into 6 clusters. Features were extracted from the reduced tensor and combined with demographic features (age, gender, race, and HIV status). The resulting dataset was used to train a Catboost model using subsampling and nested cross-validation techniques, which achieved a prediction accuracy of 0.857 for identifying cocaine users. The model was also compared with other models, and the feature importance of the model was presented. Overall, this study highlights the potential for using tensor-based machine learning algorithms to predict cocaine use based on MRI connectomic data and presents a promising approach for identifying individuals at risk of substance abuse

Enzymatic- and temperature-sensitive controlled release of ultrasmall superparamagnetic iron oxides (USPIOs)

<p>Abstract</p> <p>Background</p> <p>Drug and contrast agent delivery systems that achieve controlled release in the presence of enzymatic activity are becoming increasingly important, as enzymatic activity is a hallmark of a wide array of diseases, including cancer and atherosclerosis. Here, we have synthesized clusters of ultrasmall superparamagnetic iron oxides (USPIOs) that sense enzymatic activity for applications in magnetic resonance imaging (MRI). To achieve this goal, we utilize amphiphilic poly(propylene sulfide)-<it>bl</it>-poly(ethylene glycol) (PPS-b-PEG) copolymers, which are known to have excellent properties for smart delivery of drug and siRNA.</p> <p>Results</p> <p>Monodisperse PPS polymers were synthesized by anionic ring opening polymerization of propylene sulfide, and were sequentially reacted with commercially available heterobifunctional PEG reagents and then ssDNA sequences to fashion biofunctional PPS-bl-PEG copolymers. They were then combined with hydrophobic 12 nm USPIO cores in the thin-film hydration method to produce ssDNA-displaying USPIO micelles. Micelle populations displaying complementary ssDNA sequences were mixed to induce crosslinking of the USPIO micelles. By design, these crosslinking sequences contained an EcoRV cleavage site. Treatment of the clusters with EcoRV results in a loss of R₂negative contrast in the system. Further, the USPIO clusters demonstrate temperature sensitivity as evidenced by their reversible dispersion at ~75°C and re-clustering following return to room temperature.</p> <p>Conclusions</p> <p>This work demonstrates proof of concept of an enzymatically-actuatable and thermoresponsive system for dynamic biosensing applications. The platform exhibits controlled release of nanoparticles leading to changes in magnetic relaxation, enabling detection of enzymatic activity. Further, the presented functionalization scheme extends the scope of potential applications for PPS-b-PEG. Combined with previous findings using this polymer platform that demonstrate controlled drug release in oxidative environments, smart theranostic applications combining drug delivery with imaging of platform localization are within reach. The modular design of these USPIO nanoclusters enables future development of platforms for imaging and drug delivery targeted towards proteolytic activity in tumors and in advanced atherosclerotic plaques.</p

Hypervelocity Stars from the Andromeda Galaxy

Hypervelocity stars (HVSs) discovered in the Milky Way (MW) halo are thought to be ejected from near the massive black hole (MBH) at the galactic centre. In this paper we investigate the spatial and velocity distributions of the HVSs which are expected to be similarly produced in the Andromeda galaxy (M31). We consider three different HVS production mechanisms: (i) the disruption of stellar binaries by the galactocentric MBH; (ii) the ejection of stars by an in-spiraling intermediate mass black hole; and (iii) the scattering of stars off a cluster of stellar-mass black holes orbiting around the MBH. While the first two mechanisms would produce large numbers of HVSs in M31, we show that the third mechanism would not be effective in M31. We numerically calculate 1.2*10^6 trajectories of HVSs from M31 within a simple model of the Local Group and hence infer the current distribution of these stars. Gravitational focusing of the HVSs by the MW and the diffuse Local Group medium leads to high densities of low mass (~ solar mass) M31 HVSs near the MW. Within the virialized MW halo, we expect there to be of order 1000 HVSs for the first mechanism and a few hundred HVSs for the second mechanism; many of these stars should have distinctively large approach velocities (< -500 km/s). In addition, we predict ~5 hypervelocity RGB stars within the M31 halo which could be identified observationally. Future MW astrometric surveys or searches for distant giants could thus find HVSs from M31.Comment: 14 pages, 6 figures, changed to match version accepted by MNRA

Research on the experience of staff with disabilities within the NHS workforce

NHS England has commissioned a primarily quantitative research project, focusing on the experiences of staff with disabilities working within the NHS, drawing upon two national data sets: • The 2014 NHS staff survey, completed by 255,000 staff, reporting their experiences of working in the NHS • The Electronic Staff Record (ESR), comprising data on the entire NHS workforce, gathered for workforce planning, personnel and wage payment purposes. The research tender required a focus on the following issues: a. What is staff with disabilities’ representation at all levels of the NHS and covering different types of disability? b. Why is there a disparity between the proportion of staff who declare a disability on the Electronic Staff Record System and of those who declare a disability on the anonymous NHS staff survey? c. How well are staff supported who become disabled during the course of their employment? Is there a process for recording this on the staff survey? d. What are appraisal rates for staff with disabilities compared to non-disabled staff? e. Do staff with disabilities have similar levels of access to training and development as non-disabled staff? f. How well do NHS organisations make reasonable adjustments for staff with disabilities, from the recruitment process to the end of employment? g. What difference does the ‘two ticks’ symbol make to recruitment and employment? h. What are the numbers of staff with disabilities who are the subject of employment processes and procedures, for example disciplinary and capability processes? i. What are the turn-over, retention and stability rates for staff with disabilities within the NHS? Key findings are: Staff with disabilities’ representation at all levels of the NHS and covering different types of disability Levels of reported disability are around 17% in the NHS Staff survey, and around 3% in the ESR. Neither data set allows for more specific analysis between different types or degrees of disability. The most likely reasons for the disparity between reported levels of disability are: 1. Differences in definition of disability used in the two data sets 2. Differing conditions for self-disclosure (NHS staff survey is anonymous) 3. Time of disclosure (ESR reports disability at the time of staff appointment, and is not reliably updated) Differences in quality of support between staff with and without disabilities There was not a specific survey question that addressed this issue, but it was possible to identify a number of questions that the report argues can be taken as acting as ‘indicators’: What are the levels of bullying and harassment?; How far do staff feel ‘Pressure to work when feeling unwell’?; Do staff feel their organisation acts fairly with regard to career progression? Relative to non-disabled staff, staff with disabilities felt more bullied, in particular from their managers (12 percentage points more); more pressure to work when feeling unwell (11 percentage points more); and less confident that their organisation acts fairly with regard to career progression (8 points difference). The report concludes that, relative to non-disabled staff, staff with disabilities rate themselves as substantially less well supported. Appraisal rates Rates of appraisal between staff with and without disabilities were broadly comparable. However there were substantial differences in how the value of appraisal was rated. Staff with disabilities are less satisfied with the effects of their appraisal. 7 percentage points fewer felt that appraisals improved their performance. Moreover, 9 percentage points more disabled staff report that their appraisal left them feeling that their work is not valued by their organisation. Experience of training The NHS staff survey indicates that most staff had training within the last 12 months and only 5 - 25% staff received no training in each specified topic. There is very little disparity between disabled and non-disabled staff in the proportion not receiving training in any of the topics, or in their satisfaction with the training. Reasonable adjustments The NHS Staff survey asks if ‘employer has made adequate adjustment(s) to enable you to carry on your work’. 40% respond ‘Yes’, 14% ‘No’ and 46% ‘No adjustment required’. The proportion responding ‘No’ varies substantially depending on the Trust involved, from a low of 5% to a high of 41%. The proportion also varies by ethnicity, with white British staff with disabilities expressing the lowest rate of dissatisfaction with the adjustments their employer made, while all other ethnic categories have consistently higher rates. The relatively small groups of Bangladeshi and ‘Other black background’ staff have the highest rates of dissatisfaction. Job satisfaction Staff with disabilities rate themselves as more dissatisfied with the recognition, support, responsibility and opportunities they have in their jobs, even though there is no difference in the satisfaction they report in the quality of care they give to patients. Staff with disabilities felt less recognised for their good work undertaken (8 percentage points fewer); they felt less supported by their immediate managers (5 percentage points fewer); they felt less supported by their work colleagues (3 percentage points fewer); they were more dissatisfied with the levels of responsibility they had been given (4 percentage points fewer); they felt they had less opportunity to use their skills (5 percentage points fewer); and finally, they were substantially less satisfied with their level of remuneration, and they thought they were valued less highly by their organisation for the contribution they were making (both 9 percentage points fewer). What difference does the ‘two ticks’ symbol make to recruitment and employment? The evidence from previous studies suggests that the Two Ticks award does not make a great deal of difference in terms of an organisation’s awareness of disability issues or in its capacity to address any inequalities or inadequacies in practice. We found in our study that the great majority of Trusts now have ‘Two Tick’ status. Using the NHS Jobs website, Trust websites and other evidence available online, as well as a DWP list, an estimate was made of the current ‘Two Ticks’ status of every Trust. 18 of 244 (7%) Trusts were found to not have the award. A comparison was made between Trusts with and without the ‘Two Ticks’ award of the extent to which staff who declare a disability report that their employer failed to make ‘adequate adjustments’ to enable them to carry out their work. Although in our study, there was a consistent finding that Trusts that have the ‘Two Ticks’ award have marginally higher average rates of ‘adequate adjustments’ reported by staff with disabilities, the difference is small, the number of ‘No award’ Trusts is small (just 1 in the case of Ambulance and Community Trusts) and the range among all Trusts is very large (from 5% to 41 %). Given also that the overall performance of Trusts was poor with respect to a variety of issues summarized above, such as levels of bullying and harassment, impact of appraisal etc., it would seem that ‘Two Ticks’ status achieves relatively little in terms of improved performance against these metrics