Search results for "litter"
showing 10 items of 315 documents
Maternal Motivation: Exploring the Roles of Prolactin and Pup Stimuli
2020
Motherhood entails increased motivation for pups, which become strong reinforcers and guide maternal behaviours. This depends on steroids and lactogens acting on the brain of females during pregnancy and postpartum. Since virgin female mice exposed to pups are nearly spontaneously maternal, the specific roles of endocrine and pup-derived signals in the induction of maternal motivation remain unclear. This work investigates maternal motivation in dams and virgin female mice, using a novel variant of the pup retrieval paradigm, the motivated pup retrieval test. We also analyse the role of prolactin (PRL) and of stimuli derived from a litter of pups and its mother, in the acquisition of matern…
Mellom fragment og totalitet : en lesning av Øystein Lønns roman Hirtshals Hirtshals med spesielt fokus på form, erkjennelse og identitet
2006
Masteroppgave i Nordisk språk og litteratur 2006 - Høgskolen i Agder, Kristiansand Romanens fortelleteknikk er hovedfokus i kapittel 2. Her forsøker jeg å applisere erkjennelses- og identitesaspektet på tekstens formale dimensjon. I denne delen av oppgaven ser vi hvordan den impliserte forfatteren kompliserer forståelsesprosessen ved sin tilbaketrukkethet. Fortelleren medierer situasjoner nøytralt, uten ytterligere forklaringer og vurderinger. Resultatet er en diskurs som ligner på fotografienes virkelighetsgjengivelse og filmens montasjeteknikk, og den mosaikken teksten skaper tvinger leseren inn i en aktiv deltakelse fordi sammenhengen ikke ligger ferdig fortolket. Kapitlet viser hvordan …
Multiple paternity in clutches of Common lizard Lacerta vivipara: data from microsatellite markers
2004
The common lizard (Lacerta vivipara) is a small live-bearing lacertid that reproduces once a year. In order to document the poorly known mating system of this species, we present here an assessment of multiple paternity using microsatellite markers. Paternities were established within 122 clutches belonging to two wild populations from contrasted areas and to four seminatural enclosed populations. The proportion of multiply sired clutches was found to be very high (between 50.0% and 68.2%) and similar among populations, which suggests that the mating system of this species may be insensitive to environmental and population conditions.
A moderate diet restriction during pregnancy alters the levels of endocannabinoids and endocannabinoid-related lipids in the hypothalamus, hippocampu…
2017
Existe para su consulta material suplementario aportado por el editor. Undernutrition during pregnancy has been associated to increased vulnerability to develop metabolic and behavior alterations later in life. The endocannabinoid system might play an important role in these processes. Therefore, we investigated the effects of a moderate maternal calorie-restricted diet on the levels of the endocannabinoid 2-arachidonoyl glycerol (2-AG), arachidonic acid (AA) and the N-acylethanolamines (NAEs) anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in the brain of newborn rat offspring. We focused on brain structures involved in metabolism, feeding behavior, as well as em…
Short-term moderate diet restriction in adulthood can reverse oxidative, cardiovascular and metabolic alterations induced by postnatal overfeeding in…
2016
AbstractWe aimed to determine whether moderate diet restriction could restore cardiac, oxidative and metabolic alterations induced by postnatal overfeeding (PNOF). Litters of C57BL/6 male mice were either maintained at 9 (normal litter, NL), or reduced to 3 (small litter, SL) in order to induce PNOF. At 6 months, half of the NL and SL mice were subjected to 20% calorie-restriction (CR: NLCR, SLCR) for one month, while the other half continued to eat ad libitum (AL: NLAL, SLAL). Six-month old SL mice presented overweight, fat accumulation, hyperleptinemia, glucose intolerance, insulin resistance, increased cardiac ROS production and decreased left ventricular ejection fraction (LVEF). After …
New In-Depth Analytical Approach of the Porcine Seminal Plasma Proteome Reveals Potential Fertility Biomarkers
2018
A complete characterization of the proteome of seminal plasma (SP) is an essential step to understand how SP influences sperm function and fertility after artificial insemination (AI). The purpose of this study was to identify which among characterized proteins in boar SP were differently expressed among AI boars with significantly different fertility outcomes. A total of 872 SP proteins, 390 of them belonging specifically to Sus Scrofa taxonomy, were identified (Experiment 1) by using a novel proteomic approach that combined size exclusion chromatography and solid-phase extraction as prefractionation steps prior to Nano LC-ESI-MS/MS analysis. The SP proteomes of 26 boars showing significan…
Development of mouse testis and epididymis following intrauterine exposure to a static magnetic field
1999
In order to test if the in utero exposure to static magnetic fields affects testis and epididymis development in mice, females were exposed to 0.5–0.7 T, generated by a permanent magnet, from day 7 of gestation to the day of birth. No significant differences were found between exposed and sham-exposed animals with respect to body weight gain of dam during the gestational period, litter size, body weight of male pups at the day of birth, and body or testis-epididymis weight gain of pups from birth to day 35. Histopathologic evaluation of testis and epididymis of pups of 1, 5, 15, and 35 days of age showed no detectable alterations due to in utero exposure to static magnetic fields. Bioelectr…
A Bayesian analysis of boar spermatozoa kinematics and head morphometrics and their relationship with litter size fertility variables
2021
The semen movement and sperm head size patterns of boar ejaculates were analyzed using computer-assisted semen analysis (CASA)-Mot and -Morph systems. The aim of the present study was to compare morphometric and kinematics variables from boars and to determine the relationship with sow fertility variables related to litter size. The females were from maternal crossing schemes such as the continuous 3-generation cross between York (Y), Landrace (L), and Pietrain (P) hybrid sows and Pietrain boars. Semen samples were collected from 11 sexually mature boars from two sire lines. Samples were analyzed using the ISAS® v1 system to evaluate eight kinematic variables of sperm velocity, progressiven…
THE COST OF REPRODUCTION INDUCED BY BODY SIZE AT BIRTH AND BREEDING DENSITY
2007
Body size at birth has implications for the quality of individuals throughout their life. Although large body size is generally considered an advantage, the relationship between body size at birth and long-term fitness is often complicated. Under spatial or temporal variation in environmental conditions, such as the seasonally changing densities of Fennoscandian vole populations, selection should favor variation in offspring phenotypes, as different qualities may be beneficial in different conditions. We performed an experiment in which a novel hormonal manipulation method was used to increase phenotypic variance in body size at birth in the bank vole (Myodes glareolus). The effects of body…
Breed, sex, and litter effects in 2-month old puppies’ behaviour in a standardised open-field test
2017
AbstractA considerable number of studies have reported differences among dog breeds with respect to their genetic profile, cognitive abilities or personality traits. Each dog breed is normally treated as a homogeneous group, however, researchers have recently questioned whether the behavioural profile of modern breeds still reflects their historical function or if the intense divergent selective pressures and geographical barriers have created a more fragmented picture. The majority of studies attempting to assess and compare modern breeds’ personality focused on the evaluation of adult dogs where the potential effects of environmental/human factors on the dogs’ behaviour are hard to discer…