10,453 research outputs found
Scrambling for higher metrics in the Journal Impact Factor bubble period: a real-world problem in science management and its implications
Universities and funders in many countries have been using Journal Impact Factor (JIF) as an indicator for research and grant assessment despite its controversial nature as a statistical representation of scientific quality. This study investigates how the changes of JIF over the years can affect its role in research evaluation and science management by using JIF data from annual Journal Citation Reports (JCR) to illustrate the changes. The descriptive statistics find out an increase in the median JIF for the top 50 journals in the JCR, from 29.300 in 2017 to 33.162 in 2019. Moreover, on average, elite journal families have up to 27 journals in the top 50. In the group of journals with a JIF of lower than 1, the proportion has shrunk by 14.53% in the 2015–2019 period. The findings suggest a potential ‘JIF bubble period’ that science policymaker, university, public fund managers, and other stakeholders should pay more attention to JIF as a criterion for quality assessment to ensure more efficient science management
Evaluation of Learning Guidelines During the Covid-19 Pandemic
The Covid-19 epidemic has led in significant changes across the board, particularly in the realm of education. Every level of education seems to be being 'forced' to adapt in order to accommodate students studying from home via online media. Educators are expected to be innovative in their delivery of curriculum using online learning medium. The Covid-19 epidemic is a worldwide pandemic, and the National Public Health Board has declared a national emergency. A number of preventative measures have been implemented by the government in order to avoid and reduce the spread of the virus. It is hoped that we would acquire acclimated to the existing system as a learning culture in educational institutions
Temporal fluctuation of multidrug resistant salmonella typhi haplotypes in the mekong river delta region of Vietnam.
BACKGROUND: typhoid fever remains a public health problem in Vietnam, with a significant burden in the Mekong River delta region. Typhoid fever is caused by the bacterial pathogen Salmonella enterica serovar Typhi (S. Typhi), which is frequently multidrug resistant with reduced susceptibility to fluoroquinolone-based drugs, the first choice for the treatment of typhoid fever. We used a GoldenGate (Illumina) assay to type 1,500 single nucleotide polymorphisms (SNPs) and analyse the genetic variation of S. Typhi isolated from 267 typhoid fever patients in the Mekong delta region participating in a randomized trial conducted between 2004 and 2005. PRINCIPAL FINDINGS: the population of S. Typhi circulating during the study was highly clonal, with 91% of isolates belonging to a single clonal complex of the S. Typhi H58 haplogroup. The patterns of disease were consistent with the presence of an endemic haplotype H58-C and a localised outbreak of S. Typhi haplotype H58-E2 in 2004. H58-E2-associated typhoid fever cases exhibited evidence of significant geo-spatial clustering along the Sông H u branch of the Mekong River. Multidrug resistance was common in the established clone H58-C but not in the outbreak clone H58-E2, however all H58 S. Typhi were nalidixic acid resistant and carried a Ser83Phe amino acid substitution in the gyrA gene. SIGNIFICANCE: the H58 haplogroup dominates S. Typhi populations in other endemic areas, but the population described here was more homogeneous than previously examined populations, and the dominant clonal complex (H58-C, -E1, -E2) observed in this study has not been detected outside Vietnam. IncHI1 plasmid-bearing S. Typhi H58-C was endemic during the study period whilst H58-E2, which rarely carried the plasmid, was only transient, suggesting a selective advantage for the plasmid. These data add insight into the outbreak dynamics and local molecular epidemiology of S. Typhi in southern Vietnam
The Demand for Cost Management Accounting Information: The Case of Vietnamese Construction Firms
This study is conducted for assessing the demand for information in cost management accounting of managers in Vietnamese construction firms. Data were collected from 161 construction firms in Vietnam. Basing on quantitative research method, the differences in demand for cost information between domestic and foreign construction contract management were investigated. The result indicates that the management of construction contracts that have foreign factors requires cost information with higher level and quality. In particular, managers have a high demand for estimated and analyzed cost information in the investment decision-making process. On the other hand, the demand for cost information depends on the firm size and management level. Through this finding, some recommendations are given for improving the expense management accounting with a view to meeting the information demand of managers in the context of integration. Keywords: Management accounting, Information, Construction, Vietna
Direct evidence of oxygen evolution from Li1+ x (Ni1/3Mn1/3Co1/3)1− x O2 at high potentials
Li1+x (Ni1/3Mn1/3Co1/3)1−x O2 (NMC) oxides are among the most promising positive electrode materials for future lithium-ion batteries. A voltage "plateau” was observed on the first galvanostatic charging curve of NMC in the extended voltage region positive to 4.5V vs. Li/Li+ for compounds with x>0 (overlithiated compounds). Differences were observed in the cycling stability of the overlithiated and stoichiometric (x=0) NMC oxides in this potential region. A differential plot of the charge vs. potential profile in the first cycle revealed that, for the overlithiated compounds, a large irreversible oxidative peak arises positive to 4.5V vs. Li/Li+, while in the same potential region only a small peak due to the electrolyte oxidation is detected for the stoichiometric material. Differential Electrochemical Mass Spectrometry (DEMS) was used to investigate the high voltage region for both compounds and experimental evidence for oxygen evolution was provided for the overlithiated compounds at potentials positive to 4.5V vs. Li/Li+. No oxygen evolution was detected for the stoichiometric compoun
Analysis of profit of generation company in power market
In recent decades, the operation of power systems in the power market model has been researched and applied by many countries. The profit of generation companies is always interested in research to ensure operation and balance of power market. This paper studies and analysis profit of generation companies to participate in the power market. In addition, this paper has analyzed the participation of new generation in the power market with 39-bus IEEE power system
Finite Element Method Analysis of Resonant Cavity for Whispering Gallery Acoustic Sensing Microscopy
Whispering Gallery Acoustic Sensing (WGAS) has been studied by Department of Physics at Portland State University as a mean of controlling sample to probe distance in tuning-folk-based scanning probe microscopy (TF-SPM). WGAS uses the microscope frame as a resonance acoustic cavity. The setup shows high potential because of high-quality factor nature of acoustic cavity as well as using mechanical motions of the TF itself instead of electrical signals. However, the analytic solution of the eigenfrequencies of the current microscope frame is very complex due to the asymmetric geometry. The purpose of this study is to use finite element method to simulate the frequency response of the acoustic cavity. We specifically get the response around 32kHz which is also the operate frequency of current WGAS system. Our simulation result is verified by comparing with experiment result of a much simpler symmetric cavity. The study is not only on investigating WGAS working principle but also to find ways to improve the signal to noise ratio by finding sensor position and modifying the frame geometry
Impacts of flood on health: epidemiologic evidence from Hanoi, Vietnam
Vietnam is one of the most disaster-prone countries in the world. The country suffers from many kinds of natural disasters, of which the most common and serious one is flooding. Long and heavy rainfall during the last days of October and the first week of November 2008 resulted in a devastating flood unseen for over three decades in the capital city of Hanoi. It caused a substantial health impact on residents in and around the city and compromised the capacity of local health services. The aim of this study is to ascertain the vulnerability and health impacts of the devastating flood in Hanoi by identifying the differences in mortality, injuries, and morbidity patterns (dengue, pink eye, dermatitis, psychological problems, and hypertension) between flood affected and non-affected households. A cross-sectional study was carried out involving 871 households in four selected communes (two heavily flood affected and two comparatively less affected) from two severely flooded districts of Hanoi. Participants were interviewed and information collected on the social, economic, and health impacts of the devastation within 1 month after the flood. The self-reported number of deaths and injuries reported in this study within 1 month after the heavy rainfall were a bit higher in severely affected communes as compared to that of the less affected communes of our study. The findings showed higher incidences of dengue fever, pink eye, dermatitis, and psychological problems in communes severely affected by flood as compared to that of the controlled communes. For people in flood prone areas (at risk for flooding), flood prevention and mitigation strategies need to be seriously thought through and acted upon, as these people are exposed to greater health problems such as psychological issues and communicable diseases such as pink eye or dermatitis
Colour Gradients and the Colour-Magnitude Relation: Different Properties of Brightest Cluster Galaxies and E/S0 Galaxies in the Sloan Digital Sky Survey
We examine the colour-magnitude relation of approximately 5000 Brightest
Cluster Galaxies (BCGs) in the Sloan Digital Sky Survey, and compare with
non-BCG E/S0 galaxies. The colour-magnitude and colour-sigma (velocity
dispersion) relations are flatter in slope (by a factor of about 2) for BCGs
than for non-BCG E/S0s, and the BCGs also tend to be redder by 0.01 magnitudes
in g-r. We investigate radial colour gradients in both samples, using the ratio
of the de Vaucouleurs radii in the g and r bands. We find BCGs have
significantly flatter (by 23%) mean colour gradients than other high luminosity
E/S0s. In early-type galaxies, the colour gradients are strongest at
intermediate luminosities of Mr=-22. Colour gradients in E/S0s increase with
radius (up to 10kpc) and are negatively correlated with 10sigma + Mr (velocity
dispersion relative to luminosity) and with mass density. The gradients also
tend to decrease with increasing stellar age. These trends are weak or not seen
in BCGs, in which the mean colour gradient is low whatever the other
properties. We discuss possible explanations, which involve a greater amount of
dry merging in the formation history of the BCGs.Comment: 16 pages, 24 figures, revised, accepted for publication in MNRAS
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