4,854 research outputs found
The correlation of dust and gas emission in star-forming environments
We present ammonia maps of portions of the W3 and Perseus molecular clouds in order to compare gas emission with submillimetre continuum thermal emission which are commonly used to trace the same mass component in star-forming regions, often under the assumption of local thermodynamic equilibrium (LTE).
The Perseus and W3 star-forming regions are found to have significantly different physical characteristics consistent with the difference in size scales traced by our observations. Accounting for the distance of the W3 region does not fully reconcile these differences, suggesting that there may be an underlying difference in the structure of the two regions.
Peak positions of submillimetre and ammonia emission do not correlate strongly. Also, the extent of diffuse emission is only moderately matched between ammonia and thermal emission. Source sizes measured from our observations are consistent between regions, although there is a noticeable difference between the submillimetre source sizes with sources in Perseus being significantly smaller than those in W3.
Fractional abundances of ammonia are determined for our sources which indicate a dip in the measured ammonia abundance at the positions of peak submillimetre column density.
Virial ratios are determined which show that our sources are generally bound in both regions, although there is considerable scatter in both samples. We conclude that sources in Perseus are bound on smaller scales than in W3 in a way that may reflect their previous identification as low- and high-mass, respectively.
Our results indicate that assumptions of local thermal equilibrium and/or the coupling of the dust and gas phases in star-forming regions may not be as robust as commonly assumed
The correlation of dust and gas emission in star-forming environments
This is the final version of the article. Available from the publisher via the DOI in this record.We present ammonia maps of portions of the W3 and Perseus molecular clouds in order to compare gas emission with submillimetre continuum thermal emission which are commonly used to trace the same mass component in star-forming regions, often under the assumption of local thermodynamic equilibrium (LTE). The Perseus and W3 star-forming regions are found to have significantly different physical characteristics consistent with the difference in size scales traced by our observations. Accounting for the distance of theW3 region does not fully reconcile these differences, suggesting that there may be an underlying difference in the structure of the two regions. Peak positions of submillimetre and ammonia emission do not correlate strongly. Also, the extent of diffuse emission is only moderately matched between ammonia and thermal emission. Source sizes measured from our observations are consistent between regions, although there is a noticeable difference between the submillimetre source sizes with sources in Perseus being significantly smaller than those in W3. Fractional abundances of ammonia are determined for our sources which indicate a dip in the measured ammonia abundance at the positions of peak submillimetre column density. Virial ratios are determined which show that our sources are generally bound in both regions, although there is considerable scatter in both samples. We conclude that sources in Perseus are bound on smaller scales than in W3 in a way that may reflect their previous identification as low-and high-mass, respectively. Our results indicate that assumptions of local thermal equilibrium and/or the coupling of the dust and gas phases in star-forming regions may not be as robust as commonly assumed. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.The authors would like to thank Neal Evans and Erik Rosolowsky
for insightful and thorough comments on this work which have considerably
improved its quality. The authors acknowledge the data
analysis facilities provided by the Starlink Project under continual
development by the JAC. In addition, the following Starlink packages
have been used: Kappa, Cupid, GAIA, Convert and Coco. We
would like to thank the helpful staff of the GBT in the collection of
data used in this paper related to the project GBT10C_024. LKM is
supported by a STFC postdoctoral grant (ST/G001847/1) and DJE
is supported by a STFC PhD studentship. This research would not
have been possible without the SIMBAD astronomical data base service operated at CDS, Strasbourg, France and the NASA Astrophysics
Data System Bibliographic Services
Are lay people good at recognising the symptoms of schizophrenia?
©2013 Erritty, Wydell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Aim: The aim of this study was to explore the general public’s perception of schizophrenia symptoms and the need to seekhelp for symptoms. The recognition (or ‘labelling’) of schizophrenia symptoms, help-seeking behaviours and public
awareness of schizophrenia have been suggested as potentially important factors relating to untreated psychosis.
Method: Participants were asked to rate to what extent they believe vignettes describing classic symptoms (positive and
negative) of schizophrenia indicate mental illness. They were also asked if the individuals depicted in the vignettes required help or treatment and asked to suggest what kind of help or treatment.
Results: Only three positive symptoms (i.e., Hallucinatory behaviour, Unusual thought content and Suspiciousness) of schizophrenia were reasonably well perceived (above 70%) as indicating mental illness more than the other positive or negative symptoms. Even when the participants recognised that the symptoms indicated mental illness, not everyone recommended professional help.
Conclusion: There may be a need to improve public awareness of schizophrenia and psychosis symptoms, particularly regarding an awareness of the importance of early intervention for psychosis
Proof of concept study of a novel pacemapping algorithm as a basis to guide ablation of ventricular arrhythmias.
Aims: To determine if a software algorithm can use an individualized distance-morphology difference model, built from three initial pacemaps, to prospectively locate the exit site (ES) of ventricular arrhythmias (VA). Methods and results: Consecutive patients undergoing ablation of VA from a single centre were recruited. During mapping, three initial pacing points were collected in the chamber of interest and the navigation algorithm applied to predict the ES, which was corroborated by conventional mapping techniques. Thirty-two patients underwent ES prediction over 35 procedures. Structural heart disease was present in 16 (7 ischaemic cardiomyopathy, 9 non-ischaemic cardiomyopathy), median ejection fraction 45% [Interquartile range (IQR) 26]. The remainder had normal hearts. The navigation algorithm was applied to 46 VA (24 left ventricle, 11 right ventricular outflow tract, 5 left ventricular outflow tract, 4 right ventricle, 2 epicardial) and successfully located the site of best pacemap match in 45 within a median area of 196.5 mm2 (IQR 161.3, range 46.6-1288.2 mm2). Conclusions: In a diverse population of patients with and without structural heart disease, the ES of VA can be accurately and reliably identified to within a clinically useful target area using a simple software navigation algorithm based on pacemapping
Dynamics of trimming the content of face representations for categorization in the brain
To understand visual cognition, it is imperative to determine when, how and with what information the human brain categorizes the visual input. Visual categorization consistently involves at least an early and a late stage: the occipito-temporal N170 event related potential related to stimulus encoding and the parietal P300 involved in perceptual decisions. Here we sought to understand how the brain globally transforms its representations of face categories from their early encoding to the later decision stage over the 400 ms time window encompassing the N170 and P300 brain events. We applied classification image techniques to the behavioral and electroencephalographic data of three observers who categorized seven facial expressions of emotion and report two main findings: (1) Over the 400 ms time course, processing of facial features initially spreads bilaterally across the left and right occipito-temporal regions to dynamically converge onto the centro-parietal region; (2) Concurrently, information processing gradually shifts from encoding common face features across all spatial scales (e.g. the eyes) to representing only the finer scales of the diagnostic features that are richer in useful information for behavior (e.g. the wide opened eyes in 'fear'; the detailed mouth in 'happy'). Our findings suggest that the brain refines its diagnostic representations of visual categories over the first 400 ms of processing by trimming a thorough encoding of features over the N170, to leave only the detailed information important for perceptual decisions over the P300
Prevalence of Anaplasma phagocytophilum infection and effect on lamb growth
Background: A major challenge in sheep farming during the grazing season along the coast of south-western
Norway is tick-borne fever (TBF) caused by the bacteria Anaplasma phagocytophilum that is transmitted by the tick
Ixodes ricinus.
Methods: A study was carried out in 2007 and 2008 to examine the prevalence of A. phagocytophilum infection
and effect on weaning weight in lambs. The study included 1208 lambs from farms in Sunndal Ram Circle in Møre
and Romsdal County in Mid-Norway, where ticks are frequently observed. All lambs were blood sampled and
serum was analyzed by an indirect fluorescent antibody assay (IFA) to determine an antibody status (positive or
negative) to A. phagocytophilum infection. Weight and weight gain and possible effect of infection were analyzed
using ANOVA and the MIXED procedure in SAS.
Results: The overall prevalence of infection with A. phagocytophilum was 55%. A lower weaning weight of 3%
(1.34 kg, p < 0.01) was estimated in lambs seropositive to an A. phagocytophilum infection compared to
seronegative lambs at an average age of 137 days.
Conclusions: The results show that A. phagocytophilum infection has an effect on lamb weight gain. The study
also support previous findings that A. phagocytophilum infection is widespread in areas where ticks are prevalent,
even in flocks treated prophylactic with acaricides
Targeting HOX transcription factors in prostate cancer
YesBackground: The HOX genes are a family of transcription factors that help to determine cell and tissue identity
during early development, and which are also over-expressed in a number of malignancies where they have been
shown to promote cell proliferation and survival. The purpose of this study was to evaluate the expression of HOX
genes in prostate cancer and to establish whether prostate cancer cells are sensitive to killing by HXR9, an inhibitor
of HOX function.
Methods: HOX function was inhibited using the HXR9 peptide. HOX gene expression was assessed by RNA
extraction from cells or tissues followed by quantitative PCR, and siRNA was used to block the expression of the
HOX target gene, cFos. In vivo modelling involved a mouse flank tumour induced by inoculation with LNCaP cells.
Results: In this study we show that the expression of HOX genes in prostate tumours is greatly increased with
respect to normal prostate tissue. Targeting the interaction between HOX proteins and their PBX cofactor induces
apoptosis in the prostate cancer derived cell lines PC3, DU145 and LNCaP, through a mechanism that involves a
rapid increase in the expression of cFos, an oncogenic transcription factor. Furthermore, disrupting HOX/PBX
binding using the HXR9 antagonist blocks the growth of LNCaP tumours in a xenograft model over an extended
period.
Conclusion: Many HOX genes are highly over-expressed in prostate cancer, and prostate cancer cells are sensitive
to killing by HXR9 both in vitro and in vivo. The HOX genes are therefore a potential therapeutic target in prostate
cancer.The authors gratefully acknowledge the support of the Prostate Project charity (UK)
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Tilted frames of reference have similar effects on perception of the gravitational vertical and the planning of vertical saccadic eye movements
We investigated the effects of a tilted reference frame (i.e., allocentric visual context) on perception of the gravitational vertical and saccadic eye movements along a planned egocentric vertical path. Participants (n=5) in a darkened room fixated a point in the center of a circle on an LCD display, and decided which of two sequentially presented dots was closer to the unmarked ‘6 o’clock’ position on that circle (i.e., straight down towards their feet). The slope of their perceptual psychometric functions showed that participants were able to locate which dot was nearer the vertical with a precision of 1-2°. For three of the participants, a square frame centered at fixation and tilted (in the roll direction) 5.6° from the vertical caused a strong perceptual bias, manifest as a shift in the psychometric function, in the direction of the traditional ‘rod and frame’ effect, without affecting precision. The other two participants showed negligible or no equivalent biases. The same subjects participated in the saccade version of the task, in which they were instructed to shift their gaze to the 6 o’clock position as soon as the central fixation point disappeared. The participants who showed perceptual biases showed biases of similar magnitude in their saccadic end points, with a strong correlation between perceptual and saccadic biases across all subjects. Tilting of the head 5.6° reduced both perceptual and saccadic biases in all but one observer, who developed a strong saccadic bias. Otherwise, the overall pattern and significant correlations between results remained the same. We conclude that our observers' saccades-to-the-vertical were dominated by perceptual input, which outweighed any gravitational or head-centered input
Seeing the baby, doing family: commercial ultrasound as family practice?
Medical sociologists and anthropologists have studied the social significance of obstetric ultrasound for families but little is known about how women and families make use of commercially available ultrasound scans. This article draws on interviews with women who booked a scan with a commercial company in the UK. For some women, commercial ultrasound can be understood as a family practice. We investigate this theme by examining who accompanies women to commercial scan appointments, how scan images are shared and how sonograms are used as prompts to resemblance talk. We argue that commercial scans are more than an additional opportunity to acquire ‘baby’s first picture’ and offer a flexible resource to do family, creating and affirming family relationships and rehearsing roles as parents, siblings and grandparents. Our findings confirm the importance of imagination in doing family and raise questions about the role of technology and commercial interests in shaping family practices
New directions in cellular therapy of cancer: a summary of the summit on cellular therapy for cancer
A summit on cellular therapy for cancer discussed and presented advances related to the use of adoptive cellular therapy for melanoma and other cancers. The summit revealed that this field is advancing rapidly. Conventional cellular therapies, such as tumor infiltrating lymphocytes (TIL), are becoming more effective and more available. Gene therapy is becoming an important tool in adoptive cell therapy. Lymphocytes are being engineered to express high affinity T cell receptors (TCRs), chimeric antibody-T cell receptors (CARs) and cytokines. T cell subsets with more naïve and stem cell-like characteristics have been shown in pre-clinical models to be more effective than unselected populations and it is now possible to reprogram T cells and to produce T cells with stem cell characteristics. In the future, combinations of adoptive transfer of T cells and specific vaccination against the cognate antigen can be envisaged to further enhance the effectiveness of these therapies
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