Effect of feed restriction and hypothermia on fetal mice

Abstract only availableLow birth weights result in high mortality in highly prolific pigs. Anecdotal evidence in sheep and cattle suggests restricting feed early in gestation and/or cooling late in gestation increase birth weights. Therefore, the objective of this study was to determine the effect of early gestation feed restriction in combination with late gestational chilling on term decidual and fetal weights, and prenatal survival in mice. The study used 37 ICR male mice each mated with 4 females except for one male with 5 females. Once a female had a vaginal plug, she was removed from the male and placed into her own cage. Pregnant females were allocated to four groups: full feed-normal temperature, full feed-chilled temperature, restricted feed-normal temperature, and restricted feed-chilled temperature (n = 18, 19, 23 and 16, respectively). The restricted feed females were fed 80% of their previous five day's average intake from day 5 to 10 of gestation while full feed females were fed ad libitum. All females were fed ad libitum from day 10 to 18. On day 14 the chilled temperature females were moved to an 18 °C environmental chamber while the normal temperature females were housed at 22 °C. On day 18 the females were sacrificed and the fetal weight, respective fetus's decidual weight, and number of corpora lutea and implantations were recorded. During restriction, intake of restricted mice was 68% of full feed mice. Immediately after restriction, there was a compensatory increase in intake by restricted mice, but overall, restricted mice consumed 93.8% that of full feed mice. There were no significant differences in survival rates among the four groups. There was also no significant difference between chilled temperature and normal temperature for decidual or fetal weights. However, full feed mice had greater (P<0.05) birth weights than restricted feed mice (1.36 vs. 1.31 g). In conclusion, restricting feed and chilling during gestation did not increase birth weights in mice.F.B. Miller Undergraduate Research Program in Animal Science

The role of ecotypic variation and the environment on biomass and nitrogen in a dominant prairie grass

Citation: Mendola, M. L., Baer, S. G., Johnson, L. C., & Maricle, B. R. (2015). The role of ecotypic variation and the environment on biomass and nitrogen in a dominant prairie grass. Ecology, 96(9), 2433-2445. doi:10.1890/14-1492.1Knowledge of the relative strength of evolution and the environment on a phenotype is required to predict species responses to environmental change and decide where to source plant material for ecological restoration. This information is critically needed for dominant species that largely determine the productivity of the central U.S. grassland. We established a reciprocal common garden experiment across a longitudinal gradient to test whether ecotypic variation interacts with the environment to affect growth and nitrogen (N) storage in a dominant grass. We predicted plant growth would increase from west to east, corresponding with increasing precipitation, but differentially among ecotypes due to local adaptation in all ecotypes and a greater range of growth response in ecotypes originating from west to east. We quantified aboveground biomass, root biomass, belowground net primary production (BNPP), root C:N ratio, and N storage in roots of three ecotypes of Andropogon gerardii collected from and reciprocally planted in central Kansas, eastern Kansas, and southern Illinois. Only the ecotype from the most mesic region (southern Illinois) exhibited more growth from west to east. There was evidence for local adaptation in the southern Illinois ecotype by means of the local vs. foreign contrast within a site and the home vs. away contrast when growth in southern Illinois was compared to the most distant site in central Kansas. Root biomass of the eastern Kansas ecotype was higher at home than at either away site. The ecotype from the driest region, central Kansas, exhibited the least response across the environmental gradient, resulting in a positive relationship between the range of biomass response and precipitation in ecotype region of origin. Across all sites, ecotypes varied in root C: N ratio (highest in the driest-origin ecotype) and N storage in roots (highest in the most mesic-origin ecotype). The low and limited range of biomass, higher C: N ratio of roots, and lower N storage in the central Kansas ecotype relative to the southern Illinois ecotype suggests that introducing ecotypes of A. gerardii from much drier regions into highly mesic prairie would reduce productivity and alter belowground ecosystem processes under a wide range of conditions

A Comprehensive Model for Re-engaging Out-of-School Youth: Turning the Hearts Center

Student research project on the Turning the Hearts Center which includes a needs assessment, program design & methodology, social marketing plan, evaluation plan and budget.https://digital.sandiego.edu/npi-bpl-programdesign/1008/thumbnail.jp

Effect of Levodopa on Reward and Impulsivity in a Rat Model of Parkinson's Disease

The use of dopamine replacement therapies (DRT) in the treatment of Parkinson's disease (PD) can lead to the development of dopamine dysregulation syndrome (DDS) and impulse control disorders (ICD), behavioral disturbances characterized by compulsive DRT self-medication and development of impulsive behaviors. However, the mechanisms behind these disturbances are poorly understood. In animal models of PD, the assessment of the rewarding properties of levodopa (LD), one of the most common drugs used in PD, has produced conflicting results, and its ability to promote increased impulsivity is still understudied. Moreover, it is unclear whether acute and chronic LD therapy differently affects reward and impulsivity. In this study we aimed at assessing, in an animal model of PD with bilateral mesostriatal and mesocorticolimbic degeneration, the behavioral effects of LD therapy regarding reward and impulsivity. Animals with either sham or 6-hydroxydopamine (6-OHDA)-induced bilateral lesions in the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) were exposed to acute and chronic LD treatment. We used the conditioned place preference (CPP) paradigm to evaluate the rewarding effects of LD, whereas impulsive behavior was measured with the variable delay-to-signal (VDS) task. Correlation analyses between behavioral measurements of reward or impulsivity and lesion extent in SNc/VTA were performed to pinpoint possible anatomical links of LD-induced behavioral changes. We show that LD, particularly when administered chronically, caused the development of impulsive-like behaviors in 6-OHDA-lesioned animals in the VDS. However, neither acute or chronic LD administration had rewarding effects in 6-OHDA-lesioned animals in the CPP. Our results show that in a bilateral rat model of PD, LD leads to the development of impulsive behaviors, strengthening the association between DRT and DDS/ICD in PD.Portuguese Foundation for Science and Technology: Ciência 2007 Program and IF Development Grant (IF/00111/2013) to AJS, Portuguese Foundation for Science and Technology PhD scholarships attributed to MMC (SFRH/BD/51061/2010), FLC (SFRH/BD/47311/2008) and CS-C (SFRH/BD/51992/2012), and Post-Doctoral Fellowship to HL-A (SFRH/BPD/80118/2011). Neurochemical analysis was funded from ELKE/UOA: 11650. This article has been developed under the scope of the project NORTE-01-0145-FEDER-000013 and NORTE-01-0145-FEDER-000023, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038info:eu-repo/semantics/publishedVersio

Genotype by environment interaction estimated by using reaction norms in cattle

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on August 13, 2009)Thesis (M.S.) University of Missouri-Columbia 2008.The objective of this study was to evaluate GxE by comparing reaction norms among U.S. Angus bulls. Dependent variables were adjusted weights at birth, 205 d weaning, and 365 d yearling. Environments were defined as progeny groups based upon data record location. Data were included in the analysis if each sire had at least 100 progeny, at least 6 progeny per environment, and at least 5 environments represented, while each environment required at least 6 qualifying bulls. The average performance of progeny within each herd environment was defined as the environmental mean. Four statistical models were analyzed using herd environment (categorical (CM) and genotype by environment (GEM)) or environmental mean (continuous environment (CEM) and random regression (RRM)) for estimating breeding values and heritabilities. Fixed effects included year-season, contemporary group, and sex. The RRM produced reaction norms for each bull which were calculated by regressing progeny means within an environment on environment means (SAS PROC GLM and ASREML). Regression coefficients differed among bulls for all traits (P [less than] 0.0001). Heritability estimates with pedigree information ranged from 0.293 to 0.401 for birth weight; 0.141 to 0.289 for weaning weight; and 0.147 to 0.259 for yearling weight. The RRM had the best fit when evaluated using environmental mean. These results suggest that bulls differ in the consistency of their progeny's performance across environments. Estimates of genetic merit of regressions from reaction norms may be a useful selection tool for ranking bulls to be used across diverse environments.Includes bibliographical reference