1,695 research outputs found
Creating Capacity for Research Data Services at Regional Universities: A Case Study
Understanding the processes of research design and of data collection, organization, storage, preservation, and sharing is critical to the success of any project, regardless of the scope of the research. From research design and conceptualization to the potential sharing of data with other researchers for replicability, as well as preserving data for the benefit of the wider research community, unique challenges, as well as opportunities for research data management (RDM) and research data services (RDS) teams, are presented; these include problems, issues, and concerns regarding how to prepare a data management plan (DMP) and how to manage data collection, analysis, storage, and preservation. In response to these concerns, academic institutions typically have structured RDS for students and faculty through the support of many stakeholders: academic librarians who are familiar with the disciplinary resources and have skills in archives, data curation, and institutional repositories; information technology services staff who provide solutions to infrastructure issues regarding storage and archiving; and other campus research administration entities that deal with the funding, integrity, and administration aspects of the research
The UV Continuum of Quasars: Models and SDSS Spectral Slopes
We measure long (2200-4000 ang) and short (1450-2200 ang) wavelength spectral
slopes \alpha (F_\nu proportional to \nu^\alpha) for quasar spectra from the
Sloan Digital Sky Survey. The long and short wavelength slopes are computed
from 3646 and 2706 quasars with redshifts in the z=0.76-1.26 and z=1.67-2.07
ranges, respectively. We calculate mean slopes after binning the data by
monochromatic luminosity at 2200 ang and virial mass estimates based on
measurements of the MgII line width and 3000 ang continuum luminosity. We find
little evidence for mass dependent variations in the mean slopes, but a
significant luminosity dependent trend in the near UV spectral slopes is
observed with larger (bluer) slopes at higher luminosities. The far UV slopes
show no clear variation with luminosity and are generally lower (redder) than
the near UV slopes at comparable luminosities, suggesting a slightly concave
quasar continuum shape. We compare these results with Monte Carlo distributions
of slopes computed from models of thin accretion disks, accounting for
uncertainties in the mass estimates. The model slopes produce mass dependent
trends which are larger than observed, though this conclusion is sensitive to
the assumed uncertainties in the mass estimates. The model slopes are also
generally bluer than observed, and we argue that reddening by dust intrinsic to
the source or host galaxy may account for much of the discrepancy.Comment: To be published in ApJ, 18 pages, 10 figure
Gravitational Collapse of Dust with a Cosmological Constant
The recent analysis of Markovic and Shapiro on the effect of a cosmological
constant on the evolution of a spherically symmetric homogeneous dust ball is
extended to include the inhomogeneous and degenerate cases. The histories are
shown by way of effective potential and Penrose-Carter diagrams.Comment: 2 pages, 2 figures (png), revtex. To appear in Phys. Rev.
Preparation and Characterization of Organic Nanoparticles of Oxadiazole Derivative in Aqueous Media
A novel oxadiazole derivative, 2,5-disubstituted-1,3,4-oxadiazole (Z)-4-((1-(5-(4-hydroxyphenyl)-1,3,4-oxadiazol-2-yl)prop-1-en-2-yl)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (HOPA) was synthesized from reaction of (Z)-3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]but-2-enehydrazide, with 4-hydroxybenzaldehyde in the presence of iodine as catalyst .The structure of HOPA was characterized by using IR,1H-NMR and mass spectroscopy. Nanoparticles of the prepared compound HOPA have been fabricated in aqueous media using re-precipitation method. Characterizations of the organic nanoparticles (ONPs) have been performed by using UV-Vis spectrophotometry, and scanning electron microscope (SEM). The HOPA NPs were approximately monodisperse even without using capping agent or surfactant. The size of the nanoparticles were around 150-200 nm as indicated by SEM. The maximum of absorption spectrum of the dispersed nanoparticles is red shifted by 5 nm from the molecular absorption spectra of the HOPA in the solution, which indicate head to head alignment (J aggregate) of the molecules of HOPA during the aggregation. The well dispersed organic nanoparticles in aqueous media holds potential application in future to be used as a tag for biomedical imagining. Keywords: Nanoscience, Organic Nanoparticle, Reprecipitation, Oxdiazoles
Characteristics of patients with HBeAg negative chronic hepatitis B virus infection in Duhok, Kurdistan region
Background: The objective of this study was to characterize patients with HBeAg-negative chronic hepatitis B in Duhok province.Methods: We recruited all patients with HBeAg negative chronic hepatitis B virus infections who visited viral hepatitis clinic in Azadi Teaching Hospital between September 2015-December 2017. The main evaluation parameters were: serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, serum albumin, total serum bilirubin (TSB), viral load. Few patients were subjected to Fibro-test, Fibroscan, or liver biopsy.Results: There were 251 patients. The mean age of the patients was 35.75±14.40 years. One hundred fifty-seven cases were male and 94 cases were female. The baseline mean of ALT, AST and viral load was 42.09±2.71U/L, 30.26±19.65U/L, and 1421197.08±14436692.04IU/ml, respectively. Compared with women, men have significantly higher values of ALT and AST, serum albumin, and TSB. There were 217 chronic inactive carrier (IC) patients and 34 chronic active hepatitis (AH) patients. ALT, AST, and viral load levels were significantly higher among AH patients.Conclusions: The majority of patients showed nil to mild liver injury. The higher level of ALT in males is a supporting guide to follow the American Association for the Study of Liver Diseases (AASLD) considering 30U/L and 19U/L levels for males and females, respectively. There was preponderance of males in AH, which indicates greater frequency of advanced fibrosis in such patients. There was a greater probability of AH in old aged people. Serum albumin and TSB were not good markers for differentiation between AH and IC state. Twenty-four patients had ALT above twice upper limit of normal level, but 34 patients showed AH based on liver biopsy, firboscan or fibrotest
Growth performance, feed utilization, survival and body composition of rabbitfish Siganus canaliculatus raised at two different stocking densities in sea net cages
Over a period of 213-day, the effect of two stocking densities (8 and 12 fish/m3)
on the performance of the rabbitfish, Siganus canaliculatus (3.38g ±0.14) in floating cage
nets was tested. The results of the study revealed no differences (p < 0.05) in the growth
performance and survival of the two groups. Comparatively, the fish group under the higher
stocking density (12 fish/m3) exhibited a lower survival rate. The values of feed intake, feed
utilization efficiency and final body composition for both treatments did not differ
significantly (p < 0.05). In conclusion, the study suggested the possibility of applying higher
stocking density in commercial rabbitfish farming. However, more studies are needed on
the effects of high stocking densities on fish survival
Spray-Dried Proliposome Microparticles for High-Performance Aerosol Delivery Using a Monodose Powder Inhaler
Proliposome formulations containing salbutamol sulphate (SS) were developed using spray drying, and the effects of carrier type (lactose monohydrate (LMH) or mannitol) and lipid to carrier ratio were evaluated. The lipid phase comprised soy phosphatidylcholine (SPC) and cholesterol (1:1), and the ratios of lipid to carrier were 1:2, 1:4, 1:6, 1:8 or 1:10 w/w. X-ray powder diffraction (XRPD) revealed an interaction between the components of the proliposome particles, and scanning electron microscopy (SEM) showed that mannitol-based proliposomes were uniformly sized and spherical, whilst LMH-based proliposomes were irregular and relatively large. Using a two-stage impinger (TSI), fine particle fraction (FPF) values of the proliposomes were higher for mannitol-based formulations, reaching 52.6%, which was attributed to the better flow properties when mannitol was used as carrier. Following hydration of proliposomes, transmission electron microscopy (TEM) demonstrated that vesicles generated from mannitol-based formulations were oligolamellar, whilst LMH-based proliposomes generated ‘worm-like’ structures and vesicle clusters. Vesicle size decreased upon increasing carrier to lipid ratio, and the zeta potential values were negative. Drug entrapment efficiency (EE) was higher for liposomes generated from LMH-based proliposomes, reaching 37.76% when 1:2 lipid to carrier ratio was used. The in vitro drug release profile was similar for both carriers when 1:6 lipid to carrier ratio was used. This study showed that spray drying can produce inhalable proliposome microparticles that can generate liposomes upon contact with an aqueous phase, and the FPF of proliposomes and the EE offered by liposomes were formulation-dependent
Performance of white shrimp, Penaeus indicus, in highly saline pond waters
The first shrimp culture trial in the United Arab Emirates
(UAE) was initiated in the mid-1980s by the Marine Resources
Research Center (MRRC) at Umm Al Qaiwain, Ministry of
Agriculture & Fisheries (MAF). This trial involved the rearing
of wild Penaeus semisulcatus larvae averaging 0.01 g in 500 l
plastic tanks where they attained an average body weight of 15.8
g within a period of seven months (Ministry of Agriculture and
Fisheries 1984). In the early 1990s, the potential of two additional
species, P. monodon and P. indicus, was also evaluated. Trials
with P. monodon indicated its unsuitability for culture in UAE
because of its poor tolerance to low temperature (17˚C) during the
winter. The first trial with P. indicus involved the culture of 2.36
g juveniles, imported from Saudi Arabia, in a 1600 m2 concrete
pond stocked at the rate of 14.7 individuals/m2 and reared for
11 months. The average body weight and feed conversion ratio
attained were 22.74 g and 4.96. A second attempt was made with
larvae produced at MRRC hatchery but all the shrimp died in the
pond within two months. A third trial was carried out with larvae
averaging 0.16 g that were stocked in the previously mentioned
pond at the rate of 36/m2 that were fed commercial shrimp feed
twice a day. The mean body weight achieved after a culture period
of five months was 19.29 g (Ishikawa 1995)
First breeding of the spangled emperor, Lethrinus nebulosus (Forsskäl, 1775), in the United Arab Emirates
The spangled emperor Lethrinus
nebulosus, locally known as Sheeri,
is a top grade food fish in the United
Arab Emirates (UAE) with a high
market demand the year round. The
fish, the largest representative of the
family Lethrinidae, has a wide geographical
distribution ranging from
Indo-West Pacific, Red Sea, Arabian
Gulf and East Africa to southern
Japan and Samoa. The fish is a marine
species occurring in a variety of
habitats from coral reefs to seagrass
beds and mangroves, from nearshore
to at least 75 m
Matrix Factorizations and Homological Mirror Symmetry on the Torus
We consider matrix factorizations and homological mirror symmetry on the
torus T^2 using a Landau-Ginzburg description. We identify the basic matrix
factorizations of the Landau-Ginzburg superpotential and compute the full
spectrum, taking into account the explicit dependence on bulk and boundary
moduli. We verify homological mirror symmetry by comparing three-point
functions in the A-model and the B-model.Comment: 41 pages, 9 figures, v2: reference added, minor corrections and
clarifications, version published in JHE
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