1,313 research outputs found
فراوانی مصرف داروهای بدون نسخه و عوامل مرتبط در دانشجویان علوم پزشکی گلستان
The Prevalence of Non-Prescription Drugs and Related Factors in
Students of Medical Sciences
In this descriptive cross- sectional study using convince sampling 262 of the students
were participated. The data collected by valid and reliable questionnaire consisted two parts; demographic and
specific questions related to medication consumption. The data analyzed using SPSS.16 and interpreted by
Chi-Square and T-Test
Quality improvement of liver ultrasound images using fuzzy techniques
Background: Liver ultrasound images are so common and are applied so often to diagnose diffuse liver diseases like fatty liver. However, the low quality of such images makes it difficult to analyze them and diagnose diseases. The purpose of this study, therefore, is to improve the contrast and quality of liver ultrasound images. Methods: In this study, a number of image contrast enhancement algorithms which are based on fuzzy logic were applied to liver ultrasound images - in which the view of kidney is observable - using Matlab2013b to improve the image contrast and quality which has a fuzzy definition; just like image contrast improvement algorithms using a fuzzy intensification operator, contrast improvement algorithms applying fuzzy image histogram hyperbolization, and contrast improvement algorithms by fuzzy IF-THEN rules. Results: With the measurement of Mean Squared Error and Peak Signal to Noise Ratio obtained from different images, fuzzy methods provided better results, and their implementation - compared with histogram equalization method - led both to the improvement of contrast and visual quality of images and to the improvement of liver segmentation algorithms results in images. Conclusion: Comparison of the four algorithms revealed the power of fuzzy logic in improving image contrast compared with traditional image processing algorithms. Moreover, contrast improvement algorithm based on a fuzzy intensification operator was selected as the strongest algorithm considering the measured indicators. This method can also be used in future studies on other ultrasound images for quality improvement and other image processing and analysis applications. © 2016 Azadeh Bayani, Leila Shahmoradi, Mostafa Langarizadeh, Amir Reza Radmard, and Ahmadreza Farzaneh Nejad
Fine-tuned Sentiment Analysis of COVID-19 Vaccine-Related Social Media Data: Comparative Study
This study investigated and compared public sentiment related to COVID-19
vaccines expressed on two popular social media platforms, Reddit and Twitter,
harvested from January 1, 2020, to March 1, 2022. To accomplish this task, we
created a fine-tuned DistilRoBERTa model to predict sentiments of approximately
9.5 million Tweets and 70 thousand Reddit comments. To fine-tune our model, our
team manually labeled the sentiment of 3600 Tweets and then augmented our
dataset by the method of back-translation. Text sentiment for each social media
platform was then classified with our fine-tuned model using Python and the
Huggingface sentiment analysis pipeline. Our results determined that the
average sentiment expressed on Twitter was more negative (52% positive) than
positive and the sentiment expressed on Reddit was more positive than negative
(53% positive). Though average sentiment was found to vary between these social
media platforms, both displayed similar behavior related to sentiment shared at
key vaccine-related developments during the pandemic. Considering this similar
trend in shared sentiment demonstrated across social media platforms, Twitter
and Reddit continue to be valuable data sources that public health officials
can utilize to strengthen vaccine confidence and combat misinformation. As the
spread of misinformation poses a range of psychological and psychosocial risks
(anxiety, fear, etc.), there is an urgency in understanding the public
perspective and attitude toward shared falsities. Comprehensive educational
delivery systems tailored to the population's expressed sentiments that
facilitate digital literacy, health information-seeking behavior, and precision
health promotion could aid in clarifying such misinformation.Comment: 11 Pages, 5 Figures, and 1 Tabl
Mode Coupling Analysis of Hollow Ring-Core Fibers for OAM Transmission
We present an analytical and numerical description of coupling between OAM modes in hollow ring-core fibers affected by stress birefringence and ellipticity The analysis paves the way to a better modeling of propagation in these fibers
Exploring celebrity influence on public attitude towards the COVID-19 pandemic: social media shared sentiment analysis
The COVID-19 pandemic has introduced new opportunities for health
communication, including an increase in the public use of online outlets for
health-related emotions. People have turned to social media networks to share
sentiments related to the impacts of the COVID-19 pandemic. In this paper we
examine the role of social messaging shared by Persons in the Public Eye (i.e.
athletes, politicians, news personnel) in determining overall public discourse
direction. We harvested approximately 13 million tweets ranging from 1 January
2020 to 1 March 2022. The sentiment was calculated for each tweet using a
fine-tuned DistilRoBERTa model, which was used to compare COVID-19
vaccine-related Twitter posts (tweets) that co-occurred with mentions of People
in the Public Eye. Our findings suggest the presence of consistent patterns of
emotional content co-occurring with messaging shared by Persons in the Public
Eye for the first two years of the COVID-19 pandemic influenced public opinion
and largely stimulated online public discourse. We demonstrate that as the
pandemic progressed, public sentiment shared on social networks was shaped by
risk perceptions, political ideologies and health-protective behaviours shared
by Persons in the Public Eye, often in a negative light.Comment: 7 Pages, 4 Figure
Features of childhood acute myeloid leukemia in Iran: A report from double center study
Acute Myeloblastic Leukemia is one of the important malignancies in children. For better managing the prognosis of this disease, there should be enough information about common features of this malignancy. The aim of this study was to evaluate these common features in children with Acute Myeloblastic Leukemia. A total of 104 eligible children less than 15-year-old have been referred from 2007-2011 to two referral centers for childhood malignancies. Basic epidemiological information recorded in checklists for each individual. Analyzes have been done by SPSS version 22. Out of patients, 57 cases were males (54.8). The male/female ratio was 1.2. The mean age of patients was 6.5 ± 4.3 years. The majority subtypes of patients were M3, M4, non-M3, and M2, respectively. The common molecular abnormalities were t (15;17) and inv (16). Of patients, 19.2 had an early relapse. The mean age of relapse in patients was 6.7 ± 3.9 years. Sixty patients (57.7) were alive, and 44 cases (42.3) died during or after therapy. The three years overall survival rate of patients was 42 in this study. According to our data, AML has the same frequency as compared with data from developing countries. But different epidemiological characteristic was a lower rate of three years overall survival in patients. These data may serve the health authorities for more effective environmental and preventive measurements, purposeful allocation of resources for facilitating upto-date diagnostic and treatment modalities, psychological support programs for respective family members and educational purposes. © 2015 Tehran University of Medical Sciences. All rights reserved
The ortho-to-para ratio of ammonia in the L1157 outflow
We have measured the ortho-to-para ratio of ammonia in the blueshifted gas of
the L1157 outflow by observing the six metastable inversion lines from (J, K) =
(1, 1) to (6, 6). The highly excited (5, 5) and (6, 6) lines were first
detected in the low-mass star forming regions. The rotational temperature
derived from the ratio of four transition lines from (3, 3) to (6, 6) is
130-140 K, suggesting that the blueshifted gas is heated by a factor of ~10 as
compared to the quiescent gas. The ortho-to-para ratio of the NH3 molecules in
the blueshifted gas is estimated to be 1.3--1.7, which is higher than the
statistical equilibrium value. This ratio provides us with evidence that the
NH3 molecules have been evaporated from dust grains with the formation
temperature between 18 and 25 K. It is most likely that the NH3 molecules on
dust grains have been released into the gas phase through the passage of strong
shock waves produced by the outflow. Such a scenario is supported by the fact
that the ammonia abundance in the blueshifted gas is enhanced by a factor of ~5
with respect to the dense quiescent gas.Comment: 16 pages, including 3 PS figures. To appear in the ApJ (Letters).
aastex macro
Molecular Tracers of the Central 12 pc of the Galactic Center
We have used the BIMA array to image the Galactic Center with a 19-pointing
mosaic in HCN(1-0), HCO+(1-0), and H 42-alpha emission with 5 km/s velocity
resolution and 13'' x 4'' angular resolution. The 5' field includes the
circumnuclear ring (CND) and parts of the 20 and 50 km/s clouds. HCN(1-0) and
HCO+ trace the CND and nearby giant molecular clouds while the H 42-alpha
emission traces the ionized gas in Sgr A West. We find that the CND has a
definite outer edge in HCN and HCO+ emission at ~45'' radius and appears to be
composed of two or three distinct streams of molecular gas rotating around the
nucleus. Outside the CND, HCN and HCO+ trace dense clumps of high-velocity gas
in addition to optically thick emission from the 20 and 50 km/s clouds. A
molecular ridge of compressed gas and dust, traced in NH3 emission and
self-absorbed HCN and HCO+, wraps around the eastern edge of Sgr A East. Just
inside this ridge are several arcs of gas which have been accelerated by the
impact of Sgr A East with the 50 km/s cloud. HCN and HCO+ emission trace the
extension of the northern arm of Sgr A West which appears to be an independent
stream of neutral and ionized gas and dust originating outside the CND. Broad
line widths and OH maser emission mark the intersection of the northern arm and
the CND. Comparison to previous NH3 and 1.2mm dust observations shows that HCN
and HCO+ preferentially trace the CND and are weaker tracers of the GMCs than
NH3 and dust. We discuss possible scenarios for the emission mechanisms and
environment at the Galactic center which could explain the differences in these
images.Comment: 24 pages, including 17 figures; to appear in The Astrophysical
Journa
Non-negative data-driven mapping of structural connections with application to the neonatal brain
Mapping connections in the neonatal brain can provide insight into the crucial early stages of neurodevelopment that shape brain organisation and lay the foundations for cognition and behaviour. Diffusion MRI and tractography provide unique opportunities for such explorations, through estimation of white matter bundles and brain connectivity. Atlas-based tractography protocols, i.e. a priori defined sets of masks and logical operations in a template space, have been commonly used in the adult brain to drive such explorations. However, rapid growth and maturation of the brain during early development make it challenging to ensure correspondence and validity of such atlas-based tractography approaches in the developing brain. An alternative can be provided by data-driven methods, which do not depend on predefined regions of interest. Here, we develop a novel data-driven framework to extract white matter bundles and their associated grey matter networks from neonatal tractography data, based on non-negative matrix factorisation that is inherently suited to the non-negative nature of structural connectivity data. We also develop a non-negative dual regression framework to map group-level components to individual subjects. Using in-silico simulations, we evaluate the accuracy of our approach in extracting connectivity components and compare with an alternative data-driven method, independent component analysis. We apply non-negative matrix factorisation to whole-brain connectivity obtained from publicly available datasets from the Developing Human Connectome Project, yielding grey matter components and their corresponding white matter bundles. We assess the validity and interpretability of these components against traditional tractography results and grey matter networks obtained from resting-state fMRI in the same subjects. We subsequently use them to generate a parcellation of the neonatal cortex using data from 323 new-born babies and we assess the robustness and reproducibility of this connectivity-driven parcellation
Systematic Molecular Differentiation in Starless Cores
(Abridged) We present evidence that low-mass starless cores, the simplest
units of star formation, are systematically differentiated in their chemical
composition. Molecules including CO and CS almost vanish near the core centers,
where the abundance decreases by one or two orders of magnitude. At the same
time, N2H+ has a constant abundance, and the fraction of NH3 increases toward
the core center. Our conclusions are based on a study of 5 mostly-round
starless cores (L1498, L1495, L1400K, L1517B, and L1544), which we have
mappedin C18O(1-0), C17O(1-0), CS(2-1), C34S(2-1), N2H+(1-0), NH3(1,1) and
(2,2), and the 1.2 mm continuum. For each core we have built a model that fits
simultaneously the radial profile of all observed emission and the central
spectrum for the molecular lines. The observed abundance drops of CO and CS are
naturally explained by the depletion of these molecules onto dust grains at
densities of 2-6 10^4 cm-3. N2H+ seems unaffected by this process up to
densities of several 10^5, while the NH3 abundance may be enhanced by reactions
triggered by the disappearance of CO from the gas phase. With the help of our
models, we show that chemical differentiation automatically explains the
discrepancy between the sizes of CS and NH3 maps, a problem which has remained
unexplained for more than a decade. Our models, in addition, show that a
combination of radiative transfer effects can give rise to the previously
observed discrepancy in the linewidth of these two tracers. Although this
discrepancy has been traditionally interpreted as resulting from a systematic
increase of the turbulent linewidth with radius, our models show that it can
arise in conditions of constant gas turbulence.Comment: 25 pages, 9 figures, accepted by Ap
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