5,597 research outputs found
Comparative ploidy response to experimental hydrogen peroxide exposure in Atlantic salmon (Salmo salar)
While research into the growth, survival, nutrition and, more recently, disease susceptibility of triploid Atlantic salmon has expanded, there remains an overall lack of studies assessing the response of triploids to chemical treatments. It is essential that the response of triploids to disease treatments be characterised to validate their suitability for commercial production. This study aimed to investigate and compare the stress and immune responses of triploid and diploid Atlantic salmon following an experimental treatment with hydrogen peroxide (H2O2). A dose response test was first undertaken to determine a suitable test dose for both diploid and triploid Atlantic salmon. Following this, diploids and triploids were exposed to H2O2 (1800âŻppm) for 20âŻmin, as per commercial practices, after which blood glucose and lactate, and plasma cortisol and lysozyme were measured, along with the expression of oxidative stress and immune-related genes. In the first 6âŻh post-exposure to H2O2, comparable mortalities occurred in both diploid and triploid Atlantic salmon. Cortisol, glucose and lactate were not significantly influenced by ploidy suggesting that, physiologically, triploid Atlantic salmon are able to cope with the stress associated with H2O2 exposure as well as their diploid counterparts. Exposure to H2O2 significantly elevated the expression of cat and sod2 in diploid livers and gr, il1ÎČ and crp/sap1b in diploid gills, while it significantly decreased the expression of saa5 and crp/sap1a in diploid gills. In triploids, the expression levels of cat, hsp70, sod1, saa5, crp/sap1a and crp/sap1b in liver was significantly higher in fish exposed to H2O2 compared to control fish. The expression of gr, sod1 and il1ÎČ in triploid gills was also elevated in response to H2O2 exposure. This study represents the first experimental evidence of the effects of H2O2 exposure on triploid Atlantic salmon and continues to support their application into commercial production
A Temporally Dynamic Gut Microbiome in Atlantic Salmon During Freshwater Recirculating Aquaculture System (RAS) Production and Post-seawater Transfer
This study was funded by the UKRI project ROBUSTSMOLT (BBSRC BB/S004270/1 and BB/S004432/1). There was also cofunding from the Scottish Aquaculture Innovation Centre. ACKNOWLEDGMENTS The authors would like to thank John Richmond and staff at MOWI and the Centre for Genome Enabled Biology and Medicine (CGEBM) at the University of Aberdeen, particularly Dr. Ewan Campbell, for help with amplification protocols, conducting 16S library preparation and sequencing. The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: https://www.ncbi.nlm.nih.gov/bioproject/PRJNA729215.Peer reviewedPublisher PD
Response of triploid Atlantic salmon (Salmo salar) to commercial vaccines
While triploid Atlantic salmon represent a practical and affordable solution to the issues associated with sexual maturation in the salmonid aquaculture industry, empirical evidence suggests triploids are more susceptible to disease and vaccine side-effects than diploids. With vaccination now part of routine husbandry, it is essential their response be studied to confirm their suitability for commercial production. This study tested the response of triploid and diploid Atlantic salmon to vaccination with commercially available vaccines. Triploid and diploid Atlantic salmon siblings were injected with one of three commercial vaccines (or sham-vaccinated) and monitored for performance throughout a commercial production cycle. Sampling at smolt and harvest was undertaken along with individual weight and length assessments through the cycle. Antibody response to Aeromonas salmonicida vaccination was similar in both ploidy, with a positive response in vaccine-injected fish. For both adhesions and melanin, analysis found that higher scores were more likely to occur as the anticipated severity of the vaccine increased. In addition, for adhesion scores at smolt and melanin scores at smolt and harvest, triploids were statistically more likely to exhibit high scores than diploids. Triploids maintained a significantly higher body weight during freshwater and until 11 months post-seawater transfer, with diploids weighing significantly more at harvest. Growth, represented by thermal growth coefficient (TGC), decreased in both ploidy as the severity of adhesions increased, and regression patterns did not differ significantly between ploidy. Vertebral deformity prevalence was consistently higher in triploids (smolt 12.3 ± 4.5%; harvest 34.9 ± 5.9%) than diploids (smolt 0.8 ± 0.5%; harvest 15.9 ± 1.9%), with no significant difference between vaccine groups in each ploidy. This study demonstrates that triploids respond as well to vaccination as diploids and provides further supporting evidence of triploid robustness for commercial aquaculture
Optimizing Hepatitis C Virus (HCV) Treatment in a US Colocated HCV/Opioid Agonist Therapy Program
Background
A minority of patients with opioid use disorder are treated for hepatitis C virus infection (HCV). While colocated HCV and opioid agonist therapy (OAT) along with harm reduction can facilitate prevention and cascade to cure, there are few real-world examples of such embedded care models in the United States in the direct-acting antiviral (DAA) era. Methods
We conducted a retrospective chart review to determine sustained virologic response (SVR) and reinfection rates during the first 5-year period of DAA availability among individuals tested and treated on-site at Rhode Islandâs only nonprofit methadone maintenance program. Results
Of 275 who initiated DAAs, the mean age (range) was 43 (22â71) years, 34.5% were female, 57.5% had genotype 1a, 23.3% had cirrhosis, and 92% were Medicaid recipients. SVR was 85.0% (232/273), while modified intent-to-treat SVR was 93.2% (232/249); 17 patients did not achieve SVR, 2 awaited SVR 12 weeks post-end-of-treatment, and 24 were lost to follow-up. Thirty reinfections were identified over 375.5 person-years of follow-up (rate, 7.99/100 person-years). The median time to first reinfection (interquartile range) was 128 (85.25â202.5) days. Before July 1, 2018, 72 patients accessed DAAs over 3.7 years; after Medicaid DAA restrictions were lifted, 109 patients accessed DAAs over 1.3 years. The Prior Authorization (PA) process requires many steps, differing across 11 RI insurers, taking 45â120 minutes per patient. Conclusions
DAA treatment was effective among a marginalized population in an urban colocated OAT/HCV program. Removing DAA restrictions facilitates treatment initiation. The PA process remains a modifiable barrier to expanding capacity in the United States
Sustained maternal inflammation during the early third trimester yields fetal adaptations that impair subsequent skeletal muscle growth and glucose metabolism in sheep
Intrauterine growth restriction (IUGR) is linked to metabolic dysfunction in offspring, but the mediating mechanisms are still under investigation (Barker et al., 1993). IUGR fetuses adapt to their poor intrauterine environment by repartitioning nutrients to organs critical for survival (i.e., brain, heart) at the expense of tissues such as muscle (Yates et al., 2012c). These developmental adaptations help the fetus to survive in utero but have lifelong consequences in offspring; persistent reduction of highly metabolic muscle mass is detrimental to glucose homeostasis (DeFronzo et al., 1981). Glucose metabolism is regulated primarily by insulin, and nutrient depravation is associated with impaired ÎČ-cell mass, insulin secretion, and insulin action in the IUGR fetus (Limesand et al., 2006). Moreover, inflammation disrupts insulin action and aids in the development of insulin resistance (Bach et al., 2013). We recently showed that inflammatory cytokines acutely stimulate glucose metabolism despite their antagonistic effects on insulin signaling (Cadaret et al., 2017b). However, we hypothesize that chronic exposure alters responsiveness to cytokines and results in basal cytokine concentrations having a greater inhibitory tone. Furthermore, chronic maternal inflammation may induce fetal inflammatory adaptations that impair muscle growth and metabolism. Therefore, our objective was to determine the effects of sustained maternal inflammation on fetal growth, islet function, and muscle glucose metabolism
Sustained maternal inflammation during the early third trimester yields fetal adaptations that impair subsequent skeletal muscle growth and glucose metabolism in sheep
Intrauterine growth restriction (IUGR) is linked to metabolic dysfunction in offspring, but the mediating mechanisms are still under investigation (Barker et al., 1993). IUGR fetuses adapt to their poor intrauterine environment by repartitioning nutrients to organs critical for survival (i.e., brain, heart) at the expense of tissues such as muscle (Yates et al., 2012c). These developmental adaptations help the fetus to survive in utero but have lifelong consequences in offspring; persistent reduction of highly metabolic muscle mass is detrimental to glucose homeostasis (DeFronzo et al., 1981). Glucose metabolism is regulated primarily by insulin, and nutrient depravation is associated with impaired ÎČ-cell mass, insulin secretion, and insulin action in the IUGR fetus (Limesand et al., 2006). Moreover, inflammation disrupts insulin action and aids in the development of insulin resistance (Bach et al., 2013). We recently showed that inflammatory cytokines acutely stimulate glucose metabolism despite their antagonistic effects on insulin signaling (Cadaret et al., 2017b). However, we hypothesize that chronic exposure alters responsiveness to cytokines and results in basal cytokine concentrations having a greater inhibitory tone. Furthermore, chronic maternal inflammation may induce fetal inflammatory adaptations that impair muscle growth and metabolism. Therefore, our objective was to determine the effects of sustained maternal inflammation on fetal growth, islet function, and muscle glucose metabolism
Assessment of genetic diversity and population structure of U.S. Polypay sheep from breed origins to future genomic selection
Knowledge of past and present genetic diversity within a breed is critical for the design and optimization of breeding programs as well as the development of strategies for the conservation of genetic resources. The Polypay sheep breed was developed at the U.S. Sheep Experiment Station (USSES) in 1968 with the goal of improving productivity in Western U.S. range flocks. It has since flourished in the more intensively managed production systems throughout the U.S. The genetic diversity of the breed has yet to be documented. Therefore, the primary objective of this study was to perform a comprehensive evaluation of the genetic diversity and population structure of U.S. Polypay sheep using both pedigree- and genomic-based methods. Pedigree data from 193 Polypay flocks participating in the National Sheep Improvement Program (NSIP) were combined with pedigree records from USSES (n = 162,997), tracing back to the breedâs origin. A subset of these pedigreed sheep from 32 flocks born from 2011 to 2023 were genotyped with the GGP Ovine 50K BeadChip containing 51,867 single nucleotide polymorphisms (SNPs). Four subgroups were used for the pedigree-based analyses: 1) the current generation of animals born in 2020â2022 (n = 20,701), 2) the current generation with a minimum of four generations of known ancestors (n = 12,685), 3) only genotyped animals (n = 1,856), and 4) the sires of the current generation (n = 509). Pedigree-based inbreeding for the full population was 2.2%, with a rate of inbreeding of 0.22% per generation. Pedigree-based inbreeding, Wrightâs inbreeding, and genomic inbreeding based on runs of homozygosity were 2.9%, 1.3%, and 5.1%, respectively, for the genotyped population. The effective population size ranged from 41 to 249 for the pedigree-based methods and 118 for the genomic-based estimate. Expected and observed heterozygosity levels were 0.409 and 0.403, respectively. Population substructure was evident based on the fixation index (FST), principal component analysis, and model-based population structure. These analyses provided evidence of differentiation from the foundation flock (USSES). Overall, the Polypay breed exhibited substantial genetic diversity and the presence of a population substructure that provides a basis for the implementation of genomic selection in the breed
UV-Optical Pixel Maps of Face-On Spiral Galaxies -- Clues for Dynamics and Star Formation Histories
UV and optical images of the face-on spiral galaxies NGC 6753 and NGC 6782
reveal regions of strong on-going star formation that are associated with
structures traced by the old stellar populations. We make NUV--(NUV-I) pixel
color-magnitude diagrams (pCMDs) that reveal plumes of pixels with strongly
varying NUV surface brightness and nearly constant I surface brightness. The
plumes correspond to sharply bounded radial ranges, with (NUV-I) at a given NUV
surface brightness being bluer at larger radii. The plumes are parallel to the
reddening vector and simple model mixtures of young and old populations, thus
neither reddening nor the fraction of the young population can produce the
observed separation between the plumes. The images, radial surface-brightness,
and color plots indicate that the separate plumes are caused by sharp declines
in the surface densities of the old populations at radii corresponding to disk
resonances. The maximum surface brightness of the NUV light remains nearly
constant with radius, while the maximum I surface brightness declines sharply
with radius. An MUV image of NGC 6782 shows emission from the nuclear ring. The
distribution of points in an (MUV-NUV) vs. (NUV-I) pixel color-color diagram is
broadly consistent with the simple mixture model, but shows a residual trend
that the bluest pixels in (MUV-NUV) are the reddest pixels in (NUV-I). This may
be due to a combination of red continuum from late-type supergiants and [SIII]
emission lines associated with HII regions in active star-forming regions. We
have shown that pixel mapping is a powerful tool for studying the distribution
and strength of on-going star formation in galaxies. Deep, multi-color imaging
can extend this to studies of extinction, and the ages and metallicities of
composite stellar populations in nearby galaxies.Comment: LaTeX with AASTeX style file, 29 pages with 12 figures (some color,
some multi-part). Accepted for publication in The Astrophysical Journa
PhosphoregDB: The tissue and sub-cellular distribution of mammalian protein kinases and phosphatases
BACKGROUND: Protein kinases and protein phosphatases are the fundamental components of phosphorylation dependent protein regulatory systems. We have created a database for the protein kinase-like and phosphatase-like loci of mouse that integrates protein sequence, interaction, classification and pathway information with the results of a systematic screen of their sub-cellular localization and tissue specific expression data mined from the GNF tissue atlas of mouse. RESULTS: The database lets users query where a specific kinase or phosphatase is expressed at both the tissue and sub-cellular levels. Similarly the interface allows the user to query by tissue, pathway or sub-cellular localization, to reveal which components are co-expressed or co-localized. A review of their expression reveals 30% of these components are detected in all tissues tested while 70% show some level of tissue restriction. Hierarchical clustering of the expression data reveals that expression of these genes can be used to separate the samples into tissues of related lineage, including 3 larger clusters of nervous tissue, developing embryo and cells of the immune system. By overlaying the expression, sub-cellular localization and classification data we examine correlations between class, specificity and tissue restriction and show that tyrosine kinases are more generally expressed in fewer tissues than serine/threonine kinases. CONCLUSION: Together these data demonstrate that cell type specific systems exist to regulate protein phosphorylation and that for accurate modelling and for determination of enzyme substrate relationships the co-location of components needs to be considered
Studies of Vibrational Properties in Ga Stabilized d-Pu by Extended X-ray Absorption Fine Structure
Temperature dependent extended x-ray absorption fine structure (EXAFS)
spectra were measured for a 3.3 at% Ga stabilized Pu alloy over the range T= 20
- 300 K at both the Ga K-edge and the Pu L_III-edge. The temperature dependence
of the pair-distance distribution widths, \sigma(T) was accurately modeled
using a correlated-Debye model for the lattice vibrational properties,
suggesting Debye-like behavior in this material. We obtain pair- specific
correlated-Debye temperatures, \Theta_cD, of 110.7 +/- 1.7 K and 202.6 +/- 3.7
K, for the Pu-Pu and Ga-Pu pairs, respectively. These results represent the
first unambiguous determination of Ga-specific vibrational properties in PuGa
alloys, and indicate the Ga-Pu bonds are significantly stronger than the Pu-Pu
bonds. This effect has important implications for lattice stabilization
mechanisms in these alloys.Comment: 7 pages, 4 figures, Phys. Rev. B in pres
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