58 research outputs found
Variation in the food intake of grass carp, Ctenopharyngodon idella (Val.), fed singly or in groups
Each animal may be assumed to possess a unique
combination of physiological traits (Bennett, 1987).
However, there is little information on thc effects of
interindividual variation in fish (Cui and Liu, 1990).
Individual differences in competitive ability, aggressiveness
and or size can lead to the establishment of
dominance hierarchies within groups of fish (Metcalfe,
1989; Metcalfe et al., 1989). The variation in
growth rates in groups of fish are rclated to dominance
hierarchies and preferential access to food
resources by dominant individuals (Jenkins, 1969;
Fausch, 1984; Koebele, 1985). Recently, radiography
has been used to measure individual consumption
rates for groups of salmonids and has demonstrated
considerable inter-individual variation in food intake
(Jobling et al., 1989; Carter et al., 1992a; McCarthy
et al., 1992). Two aims of this study were to use
radiography to examine the variation in the food
consumption rate of grass carp, Ctenopharyngodon
idellu (Val.), held together and to assess whcther variation
in growth rates could bc explained by variation
in consumption rates. A final aim of this study was
to compare the day to day variation in consumption
rates of grass carp held in a group to thosc held
individually, in terms of the individual meal share, in
order to examine the cffect of endogenous influences
on appetite
Age is no barrier: predictors of academic success in older learners
Although predictors of academic success have been identified in young adults, such predictors are unlikely to translate directly to an older student population, where such information is scarce. The current study aimed to examine cognitive, psychosocial, lifetime, and genetic predictors of university-level academic performance in older adults (50–79 years old). Participants were mostly female (71%) and had a greater than high school education level (M = 14.06 years, SD = 2.76), on average. Two multiple linear regression analyses were conducted. The first examined all potential predictors of grade point average (GPA) in the subset of participants who had volunteered samples for genetic analysis (N = 181). Significant predictors of GPA were then re-examined in a second multiple linear regression using the full sample (N = 329). Our data show that the cognitive domains of episodic memory and language processing, in conjunction with midlife engagement in cognitively stimulating activities, have a role in predicting academic performance as measured by GPA in the first year of study. In contrast, it was determined that age, IQ, gender, working memory, psychosocial factors, and common brain gene polymorphisms linked to brain function, plasticity and degeneration (APOE, BDNF, COMT, KIBRA, SERT) did not influence academic performance. These findings demonstrate that ageing does not impede academic achievement, and that discrete cognitive skills as well as lifetime engagement in cognitively stimulating activities can promote academic success in older adults
Is it pleasure or health from leisure that we benefit from most?:An analysis of well-being alternatives and implications for policy
International policy now constantly advocates a need for populations to engage in more physical activity to promote health and to reduce society’s health care costs. Such policy has developed guidelines on recommended levels and intensity of physical activity and implicitly equates health with well-being. It is assumed that individual, and hence social welfare will be enhanced if the activity guidelines are met. This paper challenges that claim and raises questions for public policy priorities. Using an instrumental variable analysis to value the well-being from active leisure, it is shown that the well-being experienced from active leisure that is not of a recommended intensity to generate health benefits, perhaps due to its social, recreational or fun purpose, has a higher value of well-being than active leisure that does meet the guidelines. This suggests rethinking the motivation and foundation of existing policy and perhaps a realignment of priorities towards activity that has a greater contribution to social welfare through its intrinsic fun and possibly social interaction
Exogenous Ether Lipids Predominantly Target Mitochondria
Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking
Immunosuppressive potential of human amnion epithelial cells in the treatment of experimental autoimmune encephalomyelitis
BACKGROUND: Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system (CNS). In recent years, it has been found that cells such as human amnion epithelial cells (hAECs) have the ability to modulate immune responses in vitro and in vivo and can differentiate into multiple cell lineages. Accordingly, we investigated the immunoregulatory effects of hAECs as a potential therapy in an MS-like disease, EAE (experimental autoimmune encephalomyelitis), in mice. METHODS: Using flow cytometry, the phenotypic profile of hAECs from different donors was assessed. The immunomodulatory properties of hAECs were examined in vitro using antigen-specific and one-way mixed lymphocyte proliferation assays. The therapeutic efficacy of hAECs was examined using a relapsing-remitting model of EAE in NOD/Lt mice. T cell responsiveness, cytokine secretion, T regulatory, and T helper cell phenotype were determined in the peripheral lymphoid organs and CNS of these animals. RESULTS: In vitro, hAECs suppressed both specific and non-specific T cell proliferation, decreased pro-inflammatory cytokine production, and inhibited the activation of stimulated T cells. Furthermore, T cells retained their naïve phenotype when co-cultured with hAECs. In vivo studies revealed that hAECs not only suppressed the development of EAE but also prevented disease relapse in these mice. T cell responses and production of the pro-inflammatory cytokine interleukin (IL)-17A were reduced in hAEC-treated mice, and this was coupled with a significant increase in the number of peripheral T regulatory cells and naïve CD4+ T cells. Furthermore, increased proportions of Th2 cells in the peripheral lymphoid organs and within the CNS were observed. CONCLUSION: The therapeutic effect of hAECs is in part mediated by inducing an anti-inflammatory response within the CNS, demonstrating that hAECs hold promise for the treatment of autoimmune diseases like MS
The Relationship Between Early Sexual Debut and Psychosocial Outcomes: A Longitudinal Study of Dutch Adolescents
In a longitudinal dataset of 470 Dutch adolescents, the current study examined the ways in which early sexual initiation was related to subsequent attachment, self-perception, internalizing problems, and externalizing problems. For male adolescents, analyses revealed general attachment to mother and externalizing problems at Wave 1 to predict to early transition at Wave 2. However, there was no differential change in these psychosocial factors over time for early initiators of sexual intercourse and their non-initiating peers. For female adolescents, the model including psychosocial factors at Wave 1 did not predict to sexual initiation at Wave 2. However, univariate repeated measures analyses revealed early initiators to have significantly larger increases in self-concept and externalizing problems than their non-initiating female peers. While the difference between female early initiators and non-initiators were statistically significant, the mean levels of problem behaviors were very low. The findings suggest that, contrary to previous research, early sexual initiation does not seem to be clustered with problem behaviors for this sample of Dutch adolescents
Immunosuppressive potential of human amnion epithelial cells in the treatment of experimental autoimmune encephalomyelitis
Evidence-based Kernels: Fundamental Units of Behavioral Influence
This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior
The impact of viral mutations on recognition by SARS-CoV-2 specific T cells.
We identify amino acid variants within dominant SARS-CoV-2 T cell epitopes by interrogating global sequence data. Several variants within nucleocapsid and ORF3a epitopes have arisen independently in multiple lineages and result in loss of recognition by epitope-specific T cells assessed by IFN-γ and cytotoxic killing assays. Complete loss of T cell responsiveness was seen due to Q213K in the A∗01:01-restricted CD8+ ORF3a epitope FTSDYYQLY207-215; due to P13L, P13S, and P13T in the B∗27:05-restricted CD8+ nucleocapsid epitope QRNAPRITF9-17; and due to T362I and P365S in the A∗03:01/A∗11:01-restricted CD8+ nucleocapsid epitope KTFPPTEPK361-369. CD8+ T cell lines unable to recognize variant epitopes have diverse T cell receptor repertoires. These data demonstrate the potential for T cell evasion and highlight the need for ongoing surveillance for variants capable of escaping T cell as well as humoral immunity.This work is supported by the UK Medical Research Council (MRC); Chinese Academy of Medical Sciences(CAMS) Innovation Fund for Medical Sciences (CIFMS), China; National Institute for Health Research (NIHR)Oxford Biomedical Research Centre, and UK Researchand Innovation (UKRI)/NIHR through the UK Coro-navirus Immunology Consortium (UK-CIC). Sequencing of SARS-CoV-2 samples and collation of data wasundertaken by the COG-UK CONSORTIUM. COG-UK is supported by funding from the Medical ResearchCouncil (MRC) part of UK Research & Innovation (UKRI),the National Institute of Health Research (NIHR),and Genome Research Limited, operating as the Wellcome Sanger Institute. T.I.d.S. is supported by a Well-come Trust Intermediate Clinical Fellowship (110058/Z/15/Z). L.T. is supported by the Wellcome Trust(grant number 205228/Z/16/Z) and by theUniversity of Liverpool Centre for Excellence in Infectious DiseaseResearch (CEIDR). S.D. is funded by an NIHR GlobalResearch Professorship (NIHR300791). L.T. and S.C.M.are also supported by the U.S. Food and Drug Administration Medical Countermeasures Initiative contract75F40120C00085 and the National Institute for Health Research Health Protection Research Unit (HPRU) inEmerging and Zoonotic Infections (NIHR200907) at University of Liverpool inpartnership with Public HealthEngland (PHE), in collaboration with Liverpool School of Tropical Medicine and the University of Oxford.L.T. is based at the University of Liverpool. M.D.P. is funded by the NIHR Sheffield Biomedical ResearchCentre (BRC – IS-BRC-1215-20017). ISARIC4C is supported by the MRC (grant no MC_PC_19059). J.C.K.is a Wellcome Investigator (WT204969/Z/16/Z) and supported by NIHR Oxford Biomedical Research Centreand CIFMS. The views expressed are those of the authors and not necessarily those of the NIHR or MRC
Identification of 55,000 Replicated DNA Methylation QTL
DNA methylation plays an important role in the regulation of transcription. Genetic control of DNA methylation is a potential candidate for explaining the many identified SNP associations with disease that are not found in coding regions. We replicated 52,916 cis and 2,025 trans DNA methylation quantitative trait loci (mQTL) using methylation from whole blood measured on Illumina HumanMethylation450 arrays in the Brisbane Systems Genetics Study (n = 614 from 177 families) and the Lothian Birth Cohorts of 1921 and 1936 (combined n = 1366). The trans mQTL SNPs were found to be over-represented in 1 Mbp subtelomeric regions, and on chromosomes 16 and 19. There was a significant increase in trans mQTL DNA methylation sites in upstream and 5' UTR regions. The genetic heritability of a number of complex traits and diseases was partitioned into components due to mQTL and the remainder of the genome. Significant enrichment was observed for height (p = 2.1 × 10), ulcerative colitis (p = 2 × 10), Crohn's disease (p = 6 × 10) and coronary artery disease (p = 5.5 × 10) when compared to a random sample of SNPs with matched minor allele frequency, although this enrichment is explained by the genomic location of the mQTL SNPs
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