The dense gas in the largest molecular complexes of the antennae: HCN and HCO+ observations of NGC 4038/39 using ALMA

We present observations of the dense molecular gas tracers $\mathrm{HCN}$, $\mathrm{HNC}$, and ${\mathrm{HCO}}^{+}$ in the $J=1-0$ transition using the Atacama Large Millimeter/submillimeter Array. We supplement our data sets with previous observations of $\mathrm{CO}$ $J=1-0$, which trace the total molecular gas content. We separate the Antennae into seven bright regions in which we detect emission from all three molecules, including the nuclei of NGC 4038 and NGC 4039, five super giant molecular complexes in the overlap region, and two additional bright clouds. We find that the ratio of ${L}_{\mathrm{HCN}}/{L}_{\mathrm{CO}}$, which traces the dense molecular gas fraction, is greater in the two nuclei (${L}_{\mathrm{HCN}}/{L}_{\mathrm{CO}}$ $\sim \quad 0.07-0.08$) than in the overlap region (${L}_{\mathrm{HCN}}/{L}_{\mathrm{CO}}$ $\lt 0.05$). We attribute this to an increase in pressure due to the stellar potential within the nuclei; a similar effect to what has been seen previously in the Milky Way and nearby spiral galaxies. Furthermore, the ratio of ${L}_{\mathrm{HNC}}/{L}_{\mathrm{HCN}}$ $\sim \quad 0.3-0.4$ does not vary by more than a factor of 1.5 between regions. By comparing our measured ratios to photon dominated region (PDR) models including mechanical heating, we find that the ratio of ${L}_{\mathrm{HNC}}/{L}_{\mathrm{HCN}}$ is consistent with mechanical heating contributing gsim5%–10% of the PDR surface heating to the total heating budget. Finally, the ratio of ${L}_{\mathrm{HCN}}/{L}_{\mathrm{HCO}+}$ varies from ~1 in the nucleus of NGC 4038 down to ~0.5 in the overlap region. The lower ratio in the overlap region may be due to an increase in the cosmic ray rate from the increased supernova rate within this region

In vitro evidence of cellular adaptation to ozone toxicity in the rat trachea.

Adaptation to prolonged ozone (O3) exposure occurs in the tracheal epithelium of rats and is marked by the presence of ciliated cells with uniform short cilia but is not accompanied by shifts in cell populations, altered characteristics of epithelial secretory cell products, increased cell turnover, or elevated tracheal superoxide dismutase activity. The purpose of this study was to test the hypothesis that adaptation is a result of alterations intrinsic to epithelial cells or to the cells and their matrix, and not due to systemic or neural influences. Rats were preexposed to either filtered air (FA) or 0.96 ppm O3 for 8 hr/night for 60 days, and then their tracheae were removed and exposed to 3 ppm O3 in an explant culture system where behavioral, nasal, exudative, and secretory product influences can be eliminated. After exposure to 3 ppm O3 in vitro, quantitative electron microscopic evaluation demonstrated that the epithelia from the FA preexposure group had significantly more necrotic cells and sloughed cells and fewer ciliated cells than the epithelia from the O3 preexposure group. Thus previous exposure to ozone in vivo induces a change in tracheal epithelium which confers resistance to ozone-induced injury in the explant exposure system

Absorbate-Induced Piezochromism in a Porous Molecular Crystal

Atmospherically stable porous frameworks and materials are interesting for heterogeneous solid–gas applications. One motivation is the direct and selective uptake of pollutant/hazardous gases, where the material produces a measurable response in the presence of the analyte. In this report, we present a combined experimental and theoretical rationalization for the piezochromic response of a robust and porous molecular crystal built from an extensively fluorinated trispyrazole. The electronic response of the material is directly determined by analyte uptake, which provokes a subtle lattice contraction and an observable bathochromic shift in the optical absorption onset. Selectivity for fluorinated absorbates is demonstrated, and toluene is also found to crystallize within the pore. Furthermore, we demonstrate the application of electronic structure calculations to predict a physicochemical response, providing the foundations for the design of electronically tunable porous solids with the chemical properties required for development of novel gas-uptake media

Correlation functions quantify super-resolution images and estimate apparent clustering due to over-counting

We present an analytical method to quantify clustering in super-resolution localization images of static surfaces in two dimensions. The method also describes how over-counting of labeled molecules contributes to apparent self-clustering and how the effective lateral resolution of an image can be determined. This treatment applies to clustering of proteins and lipids in membranes, where there is significant interest in using super-resolution localization techniques to probe membrane heterogeneity. When images are quantified using pair correlation functions, the magnitude of apparent clustering due to over-counting will vary inversely with the surface density of labeled molecules and does not depend on the number of times an average molecule is counted. Over-counting does not yield apparent co-clustering in double label experiments when pair cross-correlation functions are measured. We apply our analytical method to quantify the distribution of the IgE receptor (Fc{\epsilon}RI) on the plasma membranes of chemically fixed RBL-2H3 mast cells from images acquired using stochastic optical reconstruction microscopy (STORM) and scanning electron microscopy (SEM). We find that apparent clustering of labeled IgE bound to Fc{\epsilon}RI detected with both methods arises from over-counting of individual complexes. Thus our results indicate that these receptors are randomly distributed within the resolution and sensitivity limits of these experiments.Comment: 22 pages, 5 figure

A Web-based Intervention for Abused Women: The New Zealand Isafe Randomised Controlled Trial Protocol

Background: Intimate partner violence (IPV) and its associated negative mental health consequences are significant for women in New Zealand and internationally. One of the most widely recommended interventions is safety planning. However, few women experiencing violence access specialist services for safety planning. A safety decision aid, weighing the dangers of leaving or staying in an abusive relationship, gives women the opportunity to prioritise, plan and take action to increase safety for themselves and their children. This randomised controlled trial is testing the effectiveness of an innovative, interactive web-based safety decision aid. The trial is an international collaborative concurrent replication of a USA trial (IRIS study NCT01312103), regionalised for the Aotearoa New Zealand culture and offers fully automated online trial recruitment, eligibility screening and consent. Methods/Design: In a fully automated web-based trial (isafe) 340 abused women will be randomly assigned in equal numbers to a safety decision aid intervention or usual safety planning control website. Intervention components include: (a) safety priority setting, (b) danger assessment and (c) an individually tailored safety action plan. Self-reported outcome measures are collected at baseline and 3, 6, and 12-months post-baseline. Primary outcomes are depression (measured by Center for Epidemiologic Studies Depression Scale, Revised) and IPV exposure (measured by Severity Violence Against Women Scale) at 12 months post-baseline. Secondary outcomes include PTSD, psychological abuse, decisional conflict, safety behaviors and danger in the relationship. Discussion: This trial will provide much-needed information on the potential relationships mong safety planning, improved mental health, reduced violence as well as decreased decisional conflict related to safety in the abusive relationship. The novel web-based safety decision aid intervention may provide a cost-effective, easily accessed safety-planning resource that can be translated into clinical and community practice by multiple health disciplines and advocates. The trial will also provide information about how women in abusive relationships safely access safety information and resources through the Internet. Finally, the trial will inform other research teams on the feasibility and acceptability of fully automated recruitment, eligibility screening, consent and retention procedures. Trial registration: Trial registered on 03 July 2012 on the Australian New Zealand Clinical Trials Registry ACTRN12612000708853

Tearing Out the Income Tax by the (Grass)Roots

Landscapes are increasingly fragmented, and conservation programs have started to look at network approaches for maintaining populations at a larger scale. We present an agent-based model of predator–prey dynamics where the agents (i.e. the individuals of either the predator or prey population) are able to move between different patches in a landscaped network. We then analyze population level and coexistence probability given node-centrality measures that characterize specific patches. We show that both predator and prey species benefit from living in globally well-connected patches (i.e. with high closeness centrality). However, the maximum number of prey species is reached, on average, at lower closeness centrality levels than for predator species. Hence, prey species benefit from constraints imposed on species movement in fragmented landscapes since they can reproduce with a lesser risk of predation, and their need for using anti-predatory strategies decreases.authorCount :

Are there valid proxy measures of clinical behaviour?

Background: Accurate measures of health professionals' clinical practice are critically important to guide health policy decisions, as well as for professional self-evaluation and for research-based investigation of clinical practice and process of care. It is often not feasible or ethical to measure behaviour through direct observation, and rigorous behavioural measures are difficult and costly to use. The aim of this review was to identify the current evidence relating to the relationships between proxy measures and direct measures of clinical behaviour. In particular, the accuracy of medical record review, clinician self-reported and patient-reported behaviour was assessed relative to directly observed behaviour. Methods: We searched: PsycINFO; MEDLINE; EMBASE; CINAHL; Cochrane Central Register of Controlled Trials; science/social science citation index; Current contents (social & behavioural med/clinical med); ISI conference proceedings; and Index to Theses. Inclusion criteria: empirical, quantitative studies; and examining clinical behaviours. An independent, direct measure of behaviour (by standardised patient, other trained observer or by video/audio recording) was considered the 'gold standard' for comparison. Proxy measures of behaviour included: retrospective self-report; patient-report; or chart-review. All titles, abstracts, and full text articles retrieved by electronic searching were screened for inclusion and abstracted independently by two reviewers. Disagreements were resolved by discussion with a third reviewer where necessary. Results: Fifteen reports originating from 11 studies met the inclusion criteria. The method of direct measurement was by standardised patient in six reports, trained observer in three reports, and audio/video recording in six reports. Multiple proxy measures of behaviour were compared in five of 15 reports. Only four of 15 reports used appropriate statistical methods to compare measures. Some direct measures failed to meet our validity criteria. The accuracy of patient report and chart review as proxy measures varied considerably across a wide range of clinical actions. The evidence for clinician self-report was inconclusive. Conclusion: Valid measures of clinical behaviour are of fundamental importance to accurately identify gaps in care delivery, improve quality of care, and ultimately to improve patient care. However, the evidence base for three commonly used proxy measures of clinicians' behaviour is very limited. Further research is needed to better establish the methods of development, application, and analysis for a range of both direct and proxy measures of behaviour

The Herschel Exploitation of Local Galaxy Andromeda (HELGA) II: Dust and Gas in Andromeda

We present an analysis of the dust and gas in Andromeda, using Herschel images sampling the entire far-infrared peak. We fit a modified-blackbody model to ~4000 quasi-independent pixels with spatial resolution of ~140pc and find that a variable dust-emissivity index (beta) is required to fit the data. We find no significant long-wavelength excess above this model suggesting there is no cold dust component. We show that the gas-to-dust ratio varies radially, increasing from ~20 in the center to ~70 in the star-forming ring at 10kpc, consistent with the metallicity gradient. In the 10kpc ring the average beta is ~1.9, in good agreement with values determined for the Milky Way (MW). However, in contrast to the MW, we find significant radial variations in beta, which increases from 1.9 at 10kpc to ~2.5 at a radius of 3.1kpc and then decreases to 1.7 in the center. The dust temperature is fairly constant in the 10kpc ring (ranging from 17-20K), but increases strongly in the bulge to ~30K. Within 3.1kpc we find the dust temperature is highly correlated with the 3.6 micron flux, suggesting the general stellar population in the bulge is the dominant source of dust heating there. At larger radii, there is a weak correlation between the star formation rate and dust temperature. We find no evidence for 'dark gas' in M31 in contrast to recent results for the MW. Finally, we obtained an estimate of the CO X-factor by minimising the dispersion in the gas-to-dust ratio, obtaining a value of (1.9+/-0.4)x10^20 cm^-2 [K kms^-1]^-1.Comment: 19 pages, 18 figures. Submitted to ApJ April 2012; Accepted July 201