930 research outputs found
The magnetic environment of the Orion-Eridanus superbubble as revealed by Planck
Using the 353-GHz polarization observations by the Planck satellite we
characterize the magnetic field in the Orion-Eridanus superbubble, a nearby
expanding structure that spans more than 1600 square degrees in the sky. We
identify a region of both low dispersion of polarization orientations and high
polarization fraction associated with the outer wall of the superbubble
identified in the most recent models of the large-scale shape of the region. We
use the Davis-Chandrasekhar-Fermi method to derive plane-of-the-sky magnetic
field strengths of tens of microGauss toward the southern edge of the bubble.
The comparison of these values with existing Zeeman splitting observations of
HI in emission suggests that the large-scale magnetic field in the region was
primarily shaped by the expanding superbubble.Comment: 7 pages, 8 figures. Accepted for publication as a Letter in A&A,
section 1. Letters to the Editor (08/12/2017
Kinematics of dense gas in the L1495 filament
We study the kinematics of the dense gas of starless and protostellar cores
traced by the N2D+(2-1), N2H+(1-0), DCO+(2-1), and H13CO+(1-0) transitions
along the L1495 filament and the kinematic links between the cores and the
surrounding molecular cloud.
We measure velocity dispersions, local and total velocity gradients and
estimate the specific angular momenta of 13 dense cores in the four transitions
using the on-the-fly observations with the IRAM 30 m antenna. To study a
possible connection to the filament gas, we use the fit results of the
C18O(1-0) survey performed by Hacar et al. (2013).
All cores show similar properties along the 10 pc-long filament. N2D+(2-1)
shows the most centrally concentrated structure, followed by N2H+(1-0) and
DCO+(2-1), which show similar spatial extent, and H13CO+(1-0). The non-thermal
contribution to the velocity dispersion increases from higher to lower density
tracers. The change of magnitude and direction of the total velocity gradients
depending on the tracer used indicates that internal motions change at
different depths within the cloud. N2D+ and N2H+ show smaller gradients than
the lower density tracers DCO+ and H13CO+, implying a loss of specific angular
momentum at small scales. At the level of cloud-core transition, the core's
external envelope traced by DCO+ and H13CO+ is spinning up, consistent with
conservation of angular momentum during core contraction. C18O traces the more
extended cloud material whose kinematics is not affected by the presence of
dense cores. The decrease in specific angular momentum towards the centres of
the cores shows the importance of local magnetic fields to the small scale
dynamics of the cores. The random distributions of angles between the total
velocity gradient and large scale magnetic field suggests that the magnetic
fields may become important only in the high density gas within dense cores.Comment: Accepted for publication in A&A. The abstract is shortene
Mid-J CO Shock Tracing Observations of Infrared Dark Clouds I
Infrared dark clouds (IRDCs) are dense, molecular structures in the
interstellar medium that can harbour sites of high-mass star formation. IRDCs
contain supersonic turbulence, which is expected to generate shocks that
locally heat pockets of gas within the clouds. We present observations of the
CO J = 8-7, 9-8, and 10-9 transitions, taken with the Herschel Space
Observatory, towards four dense, starless clumps within IRDCs (C1 in
G028.37+00.07, F1 and F2 in G034.43+0007, and G2 in G034.77-0.55). We detect
the CO J = 8-7 and 9-8 transitions towards three of the clumps (C1, F1, and F2)
at intensity levels greater than expected from photodissociation region (PDR)
models. The average ratio of the 8-7 to 9-8 lines is also found to be between
1.6 and 2.6 in the three clumps with detections, significantly smaller than
expected from PDR models. These low line ratios and large line intensities
strongly suggest that the C1, F1, and F2 clumps contain a hot gas component not
accounted for by standard PDR models. Such a hot gas component could be
generated by turbulence dissipating in low velocity shocks.Comment: 14 pages, 8 figures, 5 tables, accepted by A&A, minor updates to
match the final published versio
Disordered speech disrupts conversational entrainment: a study of acoustic-prosodic entrainment and communicative success in populations with communication challenges
Conversational entrainment, a pervasive communication phenomenon in which dialogue partners adapt their behaviors to align more closely with one another, is considered essential for successful spoken interaction. While well-established in other disciplines, this phenomenon has received limited attention in the field of speech pathology and the study of communication breakdowns in clinical populations. The current study examined acoustic-prosodic entrainment, as well as a measure of communicative success, in three distinctly different dialogue groups: (i) healthy native vs. healthy native speakers (Control), (ii) healthy native vs. foreign-accented speakers (Accented), and (iii) healthy native vs. dysarthric speakers (Disordered). Dialogue group comparisons revealed significant differences in how the groups entrain on particular acoustic–prosodic features, including pitch, intensity, and jitter. Most notably, the Disordered dialogues were characterized by significantly less acoustic-prosodic entrainment than the Control dialogues. Further, a positive relationship between entrainment indices and communicative success was identified. These results suggest that the study of conversational entrainment in speech pathology will have essential implications for both scientific theory and clinical application in this domain
Zooplankton abundance and distribution at Minicoy lagoon, Lakshadweep
The environmental parameters such as water temperature, salinity, cloud cover wind foree, rainfall
and tide that influence the distribution and abundance of zooplankton at two sites in Minicoy lagoon
were siudied from August 1994 to July 1995. The northern part of the lagoon with more live corals had
better abundance of ooplankton when compared to the southern area, Zooplankton from different
lagoon bottoms namely coralline, sandy and seagrass bed did not how significant variation between
sites. Copepods, 8mphipods and decapod larvae were the dominant groups
Prevalence of Non - Communicable Diseases and their Risk Factors in Tribal South India: A Community Based Cross Sectional study
BACKGROUND : Non communicable diseases are the leading cause of morbidity and mortality in India. Cardio vascular disease accounts for majority of non communicable diseases related deaths. This cross-sectional study was conducted among the residents of Jawadhu hills which is situated in Vellore and Tiruvannamalai districts of Tamil Nadu. The main objective of this study was to estimate the prevalence of diabetes mellitus, hypertension, dyslipidaemia and metabolic syndrome and their risk factors among the residents of Jawadhu hills aged between 30-60 years.
METHODS : This study was conducted in 14 villages of Jawadhu hills in Tiruvannamalai district. Two stage cluster sampling method was used. Villages were selected by probability proportionate to size sampling. Consecutive Households were selected from village starting point in clockwise direction as per the algorithm until the required sample size was obtained. Totally 480 people (males-225 & females-255) were surveyed from February 2016 to July 2016 using modified WHO-STEPS questionnaire. Socio demographic factors, behavioural and metabolic risk factors and anthrometric measures were collected. Fasting and post prandial (2 hour) blood glucose were collected for 480 people by using glucometer. Among the subset of 138 people (one participant from alternate household) fasting lipid samples were collected.
RESULTS: Of the subjects (480) studied, 3.3% had diabetes mellitus,7.6% had prediabetes, 17.7% had hypertension. Among the sub group of 138 people, 51.5% had abnormalities in any one of the lipid parameters. 16.7% of the study population had hypercholestremia, 24.6% had hyper triglyceridemia, 26.8% had low HDL, 18.1% had high LDL, 10.8% had high total cholesterol/HDL ratio (>4.5) and 12.3% had metabolic syndrome. Out of 480 people, 11.7% had low physical activity (less than the WHO recommended). Using Asian cutoff, prevalence of obesity, overweight and central obesity were 20%, 4.8% and 9.8% respectively. Most of the participants were from low socio economic status. Alcohol use and smoking is common among men (72.9%and 64% respectively). In the multivariate analysis, overweight was significantly associated with hypertension and dyslipidaemia. Low levels of physical activity and obesity were associated with and metabolic syndrome.
CONCLUSION : Prevalence of diabetes in this tribal population is low (3.3%). However, 51.5% had dyslipidaemia and 17.7% had hypertension. High prevalence of behavioural and metabolic risk factors calls for urgent intervention
Molecular dissection of translation initiation factor IF2. Evidence for two structural and functional domains.
By means of limited proteolysis of Bacillus stearothermophilus initiation factor IF2 and genetic manipulation of its structural gene, infB, we have been able to produce (or hyperproduce) and purify two polypeptide fragments corresponding to two structurally and functionally separate domains of the protein. The first is the G-domain (approximately 41 kDa), which makes up the central part of the molecule and contains the conserved structural elements found in all GTP/GDP-binding sites of G-proteins. This domain is resistant to proteolysis in the presence of GTP or GDP, retains the capacity to interact with the 50 S subunit, binds weakly to the 30 S subunit, and displays ribosome-dependent GTPase activity with an approximately 2-fold higher Km for GTP and the same Vmax as compared with intact IF2. The second is the C-domain (approximately 24 kDa), which corresponds to the COOH-terminal part of IF2 and constitutes an extraordinarily compact domain containing the fMet-tRNA binding site of IF2. In spite of its negligible affinity for the ribosomes, the C-domain weakly stimulates the ribosomal binding of fMet-tRNA, presumably by affecting the conformation of the initiator tRNA molecule
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