Pulsation of M-type Mira variables with moderately different mass: search for observable mass effects

Models of M-type Miras with masses of 1 $M_\odot$ and 1.2 $M_\odot$, i.e. with envelope masses of about 0.4 $M_\odot$ and 0.6 $M_\odot$, have been constructed, and a comparison has been made of their observable properties. Geometric pulsation of continuum-forming layers is found to be little affected by the mass difference. The influence of molecular contamination of near-infrared continuum bandpasses upon interferometrically measured fit diameters ranges from undetectable to quite significant. Some pulsation cycles of the lower-mass model Mira show substantially stronger contamination than that found in any cycle of the higher-mass star. Observations which sample pulsation phase well and continuously are crucial for avoiding misinterpretations, because the assignment of absolute pulsation phases is inherently uncertain by at least 0.1 cycles, diameter changes may be strongly phase-dependent, and cycle-to-cycle variations may be substantial. In accord with expectations, we find that cycle-to-cycle variations that show up in light curves and in near-continuum diameters tend to be larger and more common in the low-mass models, leading to one possible way to discriminate mass. Two other methods, based on high-precision measurements of the pulsation amplitude and on derivation of pre-maximum effective temperatures from diameter measurements, are also discussed. High-layer features that may be strongly affected by mass are not well described by present dust-free models.Comment: Accepted for MNRAS, 8 Pages, 8 Figure

Patient-level predictors of detection of depressive symptoms, referral, and uptake of depression counseling among chronic care patients in KwaZulu-Natal, South Africa

Background: Integration of depression treatment into primary care could improve patient outcomes in low-resource settings. Losses along the depression care cascade limit integrated service effectiveness. This study identified patient-level factors that predicted detection of depressive symptoms by nurses, referral for depression treatment, and uptake of counseling, as part of integrated care in KwaZulu-Natal, South Africa. Methods: This was an analysis of baseline data from a prospective cohort. Participants were adult patients with at least moderate depressive symptoms at primary care facilities in Amajuba, KwaZulu-Natal, South Africa. Participants were screened for depressive symptoms prior to routine assessment by a nurse. Generalized linear mixed-effects models were used to estimate associations between patient characteristics and service delivery outcomes. Results: Data from 412 participants were analyzed. Nurses successfully detected depressive symptoms in 208 [50.5%, 95% confidence interval (CI) 38.9-62.0] participants; of these, they referred 76 (36.5%, 95% CI 20.3-56.5) for depression treatment; of these, 18 (23.7%, 95% CI 10.7-44.6) attended at least one session of depression counseling. Depressive symptom severity, alcohol use severity, and perceived stress were associated with detection. Similar factors did not drive referral or counseling uptake. Conclusions: Nurses detected patients with depressive symptoms at rates comparable to primary care providers in high-resource settings, though gaps in referral and uptake persist. Nurses were more likely to detect symptoms among patients in more severe mental distress. Implementation strategies for integrated mental health care in low-resource settings should target improved rates of detection, referral, and uptake

When people co-occur with good or bad events: graded effects of relational qualifiers on evaluative conditioning

Studies on evaluative conditioning show that a change in liking can occur whenever stimuli are paired. Such instances of attitude change are known to depend on the type of relation established between stimuli (e.g., “Bob is a friend of Mike” vs. “Bob is an enemy of Mike”). Research has so far only compared assimilative and contrastive relational qualifiers (e.g., friend vs. enemy). For the first time, we compared the effect of non-oppositional qualifiers on attitude change in a EC procedure (e.g., “Bob causes Positive Outcomes” vs. “Bob predicts Positive Outcomes”). Differential effects of non-oppositional relational qualifiers were observed on explicit and implicit evaluations. We discuss the implications of our findings for attitude research, theories of attitude change, and for optimizing evaluative conditioning for changing attitudes in applied settings

On the buildup of massive early-type galaxies at z<~1. I- Reconciling their hierarchical assembly with mass-downsizing

Several studies have tried to ascertain whether or not the increase in abundance of the early-type galaxies (E-S0a's) with time is mainly due to major mergers, reaching opposite conclusions. We have tested it directly through semi-analytical modelling, by studying how the massive early-type galaxies with log(M_*/Msun)>11 at z~0 (mETGs) would have evolved backwards-in-time, under the hypothesis that each major merger gives place to an early-type galaxy. The study was carried out just considering the major mergers strictly reported by observations at each redshift, and assuming that gas-rich major mergers experience transitory phases of dust-reddened, star-forming galaxies (DSFs). The model is able to reproduce the observed evolution of the galaxy LFs at z<~1, simultaneously for different rest-frame bands (B, I, and K) and for different selection criteria on color and morphology. It also provides a framework in which apparently-contradictory results on the recent evolution of the luminosity function (LF) of massive, red galaxies can be reconciled, just considering that observational samples of red galaxies can be significantly contaminated by DSFs. The model proves that it is feasible to build up ~50-60% of the present-day mETG population at z<~1 and to reproduce the observational excess by a factor of ~4-5 of late-type galaxies at 0.8<z<1 through the coordinated action of wet, mixed, and dry major mergers, fulfilling global trends that are in general agreement with mass-downsizing. The bulk of this assembly takes place during ~1 Gyr elapsed at 0.8<z<1. The model suggests that major mergers have been the main driver for the observational migration of mass from the massive-end of the blue galaxy cloud to that of the red sequence in the last ~8 Gyr.(Abridged)Comment: Accepted for publication in Astronomy & Astrophysics; 21 pages, 8 figures. Minor corrections included, shortened title. Results and conclusions unchange

And now for something completely different? The impact of group membership on perceptions of creativity

Authors' draft; final version published in Social influence; available online at http://www.informaworld.com/ Embargo until 1 July 2010A wealth of historical, cultural, and biographical evidence points to the fact that there is considerable variation in different people's judgments of creative products. What is creative to one person is deviant to another, and creative efforts often fail to be given the enthusiastic reception that their creators anticipate and think they deserve. Unpacking the roots of these discrepancies, this paper develops an analysis of creativity that is informed by the social identity approach. This analysis is supported by a review of previous research that points to the way in which perceptions of creativity are structured by both self-categorization and social norms (and their interaction). Further support for the analysis is provided by two experiments (Ns = 100, 125) which support the hypothesis that ingroup products are perceived to be more creative than those of outgroups independently of other factors with which group membership is typically correlated in the world at large (e.g., quality). The studies also indicate that this pattern is not simply a manifestation of generic ingroup bias since judgments of creativity diverge from those of both likeability (Experiment 1) and beauty (Experiment 2). The theoretical and practical significance of these findings is discussed with particular reference to innovation resistance and the “not invented here” syndrome.This research was supported by a grant from the Economic and Social Research Council (RES-062-23-0135)

Bottom-up Infrastructures: Aligning Politics and Technology in building a Wireless Community Network

Contemporary innovation in infrastructures is increasingly characterized by a close relationship between experts and lay people. This phenomenon has attracted the attention from a wide range of disciplines, including computer-supported cooperative work (CSCW), science and technology studies (S&TS), organization studies and participatory design (PD). Connecting to this broad area of research, the article presents a qualitative case study concerning the building and maintenance of a grassroots, bottom-up information infrastructure in Italy, defined as wireless community network (WCN). Methodologically, the research is based on qualitative interviews with participants to the WCN, ethnographic observations and document analysis. The aim of the article is to understand the alignment between the technical work implied in building this bottom-up infrastructure and the political and cultural frameworks that move people to participate to this project. Relying on the field of science & technology studies, and in particular on the notions of ‘inverse infrastructure’ and ‘research in the wild’, we disclose the WCN’s peculiar innovation trajectory, localized outside conventional spaces of research and development. Overall, the presentation of the qualitative and ethnographic data allows to point out a more general reflection on bottom-up infrastructures and to enrich the academic debate concerning bottom-up infrastructuring work and other similar typologies of collaborative design projects in the domain of infrastructures

Four-Gene Pan-African Blood Signature Predicts Progression to Tuberculosis.

Rationale: Contacts of patients with tuberculosis (TB) constitute an important target population for preventive measures because they are at high risk of infection with Mycobacterium tuberculosis and progression to disease.Objectives: We investigated biosignatures with predictive ability for incident TB.Methods: In a case-control study nested within the Grand Challenges 6-74 longitudinal HIV-negative African cohort of exposed household contacts, we employed RNA sequencing, PCR, and the pair ratio algorithm in a training/test set approach. Overall, 79 progressors who developed TB between 3 and 24 months after diagnosis of index case and 328 matched nonprogressors who remained healthy during 24 months of follow-up were investigated.Measurements and Main Results: A four-transcript signature derived from samples in a South African and Gambian training set predicted progression up to two years before onset of disease in blinded test set samples from South Africa, the Gambia, and Ethiopia with little population-associated variability, and it was also validated in an external cohort of South African adolescents with latent M. tuberculosis infection. By contrast, published diagnostic or prognostic TB signatures were predicted in samples from some but not all three countries, indicating site-specific variability. Post hoc meta-analysis identified a single gene pair, C1QC/TRAV27 (complement C1q C-chain / T-cell receptor-α variable gene 27) that would consistently predict TB progression in household contacts from multiple African sites but not in infected adolescents without known recent exposure events.Conclusions: Collectively, we developed a simple whole blood-based PCR test to predict TB in recently exposed household contacts from diverse African populations. This test has potential for implementation in national TB contact investigation programs

A strong limit on the very-high-energy emission from GRB 150323A

On 2015 March 23, VERITAS responded to a $Swift$-BAT detection of a gamma-ray burst, with observations beginning 270 seconds after the onset of BAT emission, and only 135 seconds after the main BAT emission peak. No statistically significant signal is detected above 140 GeV. The VERITAS upper limit on the fluence in a 40 minute integration corresponds to about 1% of the prompt fluence. Our limit is particularly significant since the very-high-energy (VHE) observation started only $\sim$2 minutes after the prompt emission peaked, and $Fermi$-LAT observations of numerous other bursts have revealed that the high-energy emission is typically delayed relative to the prompt radiation and lasts significantly longer. Also, the proximity of GRB~150323A ($z=0.593$) limits the attenuation by the extragalactic background light to $\sim 50$ % at 100-200 GeV. We conclude that GRB 150323A had an intrinsically very weak high-energy afterglow, or that the GeV spectrum had a turnover below $\sim100$ GeV. If the GRB exploded into the stellar wind of a massive progenitor, the VHE non-detection constrains the wind density parameter to be $A\gtrsim 3\times 10^{11}$ g cm$^{-1}$, consistent with a standard Wolf-Rayet progenitor. Alternatively, the VHE emission from the blast wave would be weak in a very tenuous medium such as the ISM, which therefore cannot be ruled out as the environment of GRB 150323A.Comment: 6 pages, 1 figure. Accepted for publication in The Astrophysical Journa

A Transcriptional “Scream” Early Response of E. coli Prey to Predatory Invasion by Bdellovibrio

We have transcriptionally profiled the genes differentially expressed in E. coli prey cells when predatorily attacked by Bdellovibrio bacteriovorus just prior to prey cell killing. This is a brief, approximately 20–25 min period when the prey cell is still alive but contains a Bdellovibrio cell in its periplasm or attached to and penetrating its outer membrane. Total RNA was harvested and labelled 15 min after initiating a semi-synchronous infection with an excess of Bdellovibrio preying upon E. coli and hybridised to a macroarray spotted with all predicted ORFs of E. coli. SAM analysis and t-tests were performed on the resulting data and 126 E. coli genes were found to be significantly differentially regulated by the prey upon attack by Bdellovibrio. The results were confirmed by QRT-PCR. Amongst the prey genes upregulated were a variety of general stress response genes, potentially “selfish” genes within or near prophages and transposable elements, and genes responding to damage in the periplasm and osmotic stress. Essentially, the presence of the invading Bdellovibrio and the resulting damage to the prey cell elicited a small “transcriptional scream”, but seemingly no specific defensive mechanism with which to counter the Bdellovibrio attack. This supports other studies which do not find Bdellovibrio resistance responses in prey, and bodes well for its use as a “living antibiotic”