• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 155
  • 18
  • 10
  • 4
  • 4
  • 3
  • 1
  • 1
  • Tagged with
  • 242
  • 155
  • 67
  • 67
  • 44
  • 24
  • 24
  • 22
  • 21
  • 18
  • 15
  • 15
  • 13
  • 13
  • 12
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

LPS induced chorioamnionitis promotes IL-1 and TNF dependent recruitment of MAIT cells in fetal lung

Isaacs, Travis 16 June 2020 (has links)
No description available.
152

Sexually Differentiated Object Preference in Rhesus Monkeys (Macaca mulatta)

Berkowitz, Jamie 01 January 2009 (has links) (PDF)
Children have strong preferences for sex-typed toys; boys prefer trucks, whereas girls prefer dolls. These preferences appear to be driven by complex interactions of hormones and the socio-cultural environment. The relative contribution of each of these factors in children is impossible to isolate given ethical limitations. Non-human primate species afford the opportunity to examine preferences in the absence of societal values and influences that children experience. In two previous studies with non-human primates, one with vervet monkeys and one with rhesus monkeys, monkeys showed sex-typed object preferences that paralleled those of children. However, several uncontrolled variables could have influenced these preferences. Our study considered object characteristics and we controlled for possible color preferences. We also tested monkeys individually to eliminate the effects of social facilitation and dominance rank. In experiment 1, monkeys were given a choice between similar objects of different colors (Phase A) and moving vs. non-moving objects (Phase B). In experiment 2, monkeys were given a choice between dolls and trucks (Phase A) and subsequent phases looked at the influence of moving wheels (Phase B) and hardness (Phase C). Contrary to previous findings, monkeys did not show sex-typed object preferences. Instead, the monkeys preferred blue objects, hard PVC objects such as trucks and hard dolls, and dolls with wheels. The influence of previous reward based cognitive testing, familiarity of substrate materials, and rearing condition are considered as possible explanations for these findings.
153

The Effects of Testosterone on Emotional Processing in Male Rhesus Monkeys (Macaca Mulatta)

King, Hanna M 01 January 2010 (has links) (PDF)
The effects of testosterone (T) extend beyond reproductive behavior to the areas of cognitive and emotional functioning. While T effects on cognition have been extensively investigated, less is known about the role of T in the processing of emotional stimuli. Considering the role that T plays in aggressive behavior and dominance status, it is of particular interest to determine whether T modulates the processing of social threat. Due to their similarities to humans in brain organization, reproductive endocrinology and affective regulation, rhesus monkeys (macaca mulatta) provide an excellent model to investigate this relationship. In a within-subjects design, six male rhesus monkeys underwent treatment to suppress endogenous T and received either T or oil replacement. Tests of anxiety, attention and memory for social and non-social emotional stimuli, and risk-taking were administered to animals during both treatments. Data analyses indicate that T treatment resulted in faster response times, but had no effect on anxiety, attention or memory for emotional stimuli, or on risk-taking behavior. There are several limitations to this study that may account for the lack of effect of T and therefore, further investigation of the relationship between T and emotional processing is warranted.
154

The relationship between aggression and self injurious behavior in Rhesus macaques (Macaca mulatta).

Rulf Fountain, Alyssa 01 January 1997 (has links) (PDF)
No description available.
155

Factors Contributing to Premature Maternal Rejection and Its Effects on Offspring

Bassett, Ashley Mariah Sproul 13 July 2010 (has links) (PDF)
Typically, rhesus mothers begin rejecting their infants' attempts to nurse when the infants are approximately three months of age in order to begin the process of weaning. A small subgroup of mothers begin rejecting their infants earlier, at one or two months of age, typically before infants seek and maintain independence from their mother. The effects of this early maternal rejection on the development of infants and some potential factors that contribute to premature maternal rejection were explored in this study. Infants who were rejected early were hypothesized to subsequently spend less time in positive contact with their mother, have lower activity levels, were groomed less by their mother and, as a consequence of the maternal rejections, display a higher frequency of aggression toward other group members when compared to infants experiencing maternal rejection after the age-typical, three months of age. Mothers who were primiparous and/or had a poor early-rearing experience were hypothesized to be more likely to reject their infants prematurely. Consistent with these hypotheses, infants who were rejected early spent less time on their mother's ventrum and were groomed less by their mother, suggesting that early maternal rejection may lead to less positive mother-infant interactions and a more distant mother-infant relationship. Infants rejected early were also more likely engage in aggression. Given the punitive nature of the maternal rejection, the results suggest that aggression is transmitted from mother to infant through their interactions. Prematurely rejected infants were found to spend significantly more time in a passive, withdrawn behavioral state. When assessing the causes of premature rejections, primiparous mothers were not more likely to prematurely reject their infants, indicating that premature rejection was not simply a lack of experience with an infant. There was evidence that the mothers engaging in early rejection had poor early-rearing experiences, with surrogate-peer-reared mothers showing more early rejections than those who were reared by an adult female, and with mothers who were peer-reared having higher rates of rejection overall. The present results suggest that early rejection is associated with more difficult mother-infant relationships and may lead to increased likelihood of aggression in infants.
156

Predicting Alcohol Consumption in Adolescent Rhesus Macaques (Macaca mulatta)

Sorenson, Andrea Nichole 27 June 2014 (has links) (PDF)
Numerous studies show that a low level of response to the intoxicating effects of alcohol is considered a risk factor for future alcoholism. However, assessing this sensitivity usually requires administering a controlled dose of alcohol, which has a number of inherent problems. Early observations in our lab suggest that the response to anesthetics that show cross tolerance with alcohol, like ketamine, are blunted in nonhuman primates at risk for high alcohol intake, and may be a viable measure of future alcohol consumption. This study was designed to test potential predictors of future alcohol consumption using the change in ketamine across repeated exposures (i.e., tolerance). In addition, potential mediating factors of alcohol consumption, including early temperament and behavior, were assessed. Subjects were 16 three-year-old, alcohol naïve rhesus macaque males raised by their biological mothers. Ketamine Exposure-Each subject was exposed to three 10.0 mg/kg intramuscular doses of ketamine. The time from injection to recovery from anesthetic was recorded for each dose, to be used as a measure of subject's sensitivity and developed tolerance. Alcohol Intake Assessment-Two weeks after the final ketamine dose, subjects were allowed ad libitum access to a palatable 8.4% alcohol solution for two-hours a day, five days a week, for six weeks. During the Two-Choice phase of testing, subjects were simultaneously given ad libitum access to the 8.4% alcohol solution and to a sweetened solution for two-hours a day, five days a week, for four weeks. Solution consumption was recorded daily and averaged across the weeks for each phase of alcohol testing. Temperament and Behavior-As infants, all subjects participated in a bio-behavioral assessment (BBA), when they were between 90 and 120 days of age. Data collected during the BBA on subjects' temperament (Vigilance, Gentleness, Confidence, and Nervousness) and Behavior (Activity and Emotionality) were used in analyses. Results showed a relationship between the tolerance developed between ketamine doses and average alcohol consumption during the Alcohol-Only phase (r = 0.61, R2 = 0.372, F (1,14) = 8.300, p = 0.012). Average alcohol consumption during the Alcohol-Only phase was also related to ratings of Confidence (r = 0.499, R2=0.249, F(1,14)=4.647, p = 0.049), Activity (Day 1: r = 0.503, R2 = 0.253, F(1,14) = 4.732, p = 0.047; Day 2: r = 0.455, R2 = 0.207, F(1,14) = 3.652, p = 0.077), and Emotionality (r = 0.466, R2 = 0.217, F(1,14) = 3.885, p=0.069). The results of this study suggest that change in ketamine recovery time and early life temperament and behaviors may be measures of future risk for alcohol abuse disorders. This data is limited by the small sample size and future study is necessary to further tease out the relationships between these variables and alcohol consumption.
157

Distribution of astrocytes in the prefrontal and visual cortices of the middle-aged rhesus monkey

Castro Mendoza, Paola B. 30 January 2023 (has links)
Neuroscience research has been largely focused on neurons, while an equally important cell type, glia, was sidelined until recently. Astrocytes are star-shaped glial cells responsible for a variety of homeostatic processes of the central nervous system in addition to participating in synaptogenesis and neuronal signal transmission. A variety of immunohistochemical markers have been utilized to visualize these cells in the brain including glial fibrillary acidic protein (GFAP), vimentin, and aldehyde dehydrogenase 1 family member L1 (ALDH1L1). The current study makes use of a multiplex immunohistochemistry protocol developed in collaboration with General Electric to stain rhesus monkey brain tissue samples from the lateral prefrontal cortex (LPFC; n=5) and the primary visual cortex (V1; n=4) with a large number of markers, including GFAP, vimentin, and ALDH1L1 as well as neuronal, microglial, and oxidative stress markers. Using algorithms and manual cell classification, we were able to obtain neuronal and astrocytic counts and use these to estimate astrocyte-to-neuron ratios (ANRs) of the individual brain areas and laminae as well as assess the relative intensity of the markers of interest between areas. Among our findings there was higher ANRs in LPFC compared to V1 gray matter as well as in layer 1 compared to layer 2 in both areas studied. There is also a higher density of astrocytes in layer 1 potentially due to the recognized lack of neurons in this layer. We found significantly higher intensities of GFAP across all gray matter layers in V1 compared to LPFC as well as higher intensities for TSPO and Cleaved Caspase-3 in some V1 layers compared to their LPFC counterparts. This higher intensity of V1 reactive astrocyte markers are potentially due to the increased number of neurons these astrocytes need to support as demonstrated by the low ANR seen in V1 when compared to LPFC. In order to further our knowledge of normal astrocyte properties in these brain areas, it is imperative that we confirm our counts with stereologic studies and include oligodendrocyte markers in our multiplex staining protocol in order to better assess glial numbers within our sections. Additionally, morphological studies assessing rhesus monkey astrocytes identified with a variety of markers is important as we have shown that no one marker stains all astrocytes even though most astrocytes express more than one marker at a time.
158

Origem e distribui??o antim?rica dos nervos do plexo braquial em Macaca mulatta (Zimmermann, 1780) (Cercopithecidae, Primates) / Origin and antimeric distribution of the brachial plexus nerve in Macaca mulatta (Zimmermann, 1780) (Cercopithecidae, Primates).

Sousa, Carlos Augusto dos Santos 03 February 2016 (has links)
Submitted by Leticia Schettini (leticia@ufrrj.br) on 2017-04-24T14:23:01Z No. of bitstreams: 1 2016 - Carlos Augusto dos Santos Sousa.pdf: 2340153 bytes, checksum: 5ef373f242c2c4700a9a9e55280bc62c (MD5) / Made available in DSpace on 2017-04-24T14:23:01Z (GMT). No. of bitstreams: 1 2016 - Carlos Augusto dos Santos Sousa.pdf: 2340153 bytes, checksum: 5ef373f242c2c4700a9a9e55280bc62c (MD5) Previous issue date: 2016-02-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Morphology studies provide knowledge that allow us to understand how animals interact with the natural environment or in captivity. In this context, the comparative anatomy of the formation of the brachial plexus awakens interest since the nineteenth century and remains one of the most intriguing topics of contemporary anatomy. The aim of this study was to describe the origin and the antimeric distribution of the brachial plexus nerves in Macaca mulatta, as well as the innervated muscles. Ten male rhesus monkeys (Macaca mulatta) were used, from the Non-human Primates? Breeding Department at the Laboratory Animals Breeding Centre (Cecal/Fiocruz), donated to the Animal Anatomy Department of the Rural Federal University of Rio de Janeiro (UFRRJ). The specimens were fixed in formaldehyde solution by infusion of 10% solution. They were subsequently wrapped in a low-density polythene container with 500 liters of formaldehyde 30% solution over a period of 12 months. After this period, they were washed in running water and subjected to X-ray examinations of the neck at the Small Animals Veterinary Hospital of the UFRRJ to characterize the number of cervical vertebrae. Then, they had both antimeres dissected aiming at the exposure of the origins and the nerves arising from the brachial plexus. Data were presented both in absolute frequency and in simple percentage. In 11 (55%) animals the resulting nerves were constituted by the connections between the ventral spinal branches C5, C6, C7, C8 and T1. In 5 (25%) animals, the participants roots were C4, C5, C6, C7, C8, T1 and T2. In 2 (10%) animals C5, C6, C7, C8, T1 and T2. In the other 2 (10%) animals the formation of the plexus was observed from C6, C7, C8, T1 and T2. The ventral branches formed three nerve trunks: cranial, middle and caudal. The suprascapular nerves, subscapular, axillary, musculocutaneous, radial, median, ulnar innervated the intrinsic muscles and the subclavian nerve innervated the thoracodorsal, medial cutaneous arm and forearm, long thoracic, cranial pectoral and caudal pectoral innervate extrinsic muscles. The results obtained in this study contribute to the comparative anatomy of primates and to the information for applied research, serving as basis for clinical and surgical procedures that uses this species as an animal model. / Estudos morfol?gicos fornecem conhecimentos que permitem entender o modo como os animais interagem com o ambiente natural ou em cativeiro. O objetivo desse estudo foi descrever a origem e a distribui??o antim?rica dos nervos do plexo braquial em Macaca mulatta, assim como dos m?sculos inervados. Foram utilizados 10 cad?veres de Macaca mulatta do sexo masculino, oriundos do Servi?o de Cria??o de Primatas N?o Humanos do Centro de Cria??o de Animais de Laborat?rio (Cecal/Fiocruz) doados a ?rea de Anatomia Animal da Universidade Federal Rural do Rio de Janeiro (UFRRJ). Os esp?cimes foram fixados com perfus?o de solu??o de formalde?do a 10%. Posteriormente, foram acondicionados em caixas de polietileno de baixa densidade com capacidade de 500 litros contendo solu??o de formalde?do a 30% por um per?odo de 12 meses. Ap?s este per?odo, foram lavados em ?gua corrente e submetidos a exames radiogr?ficos da regi?o cervical no Hospital Veterin?rio de Pequenos Animais da UFRRJ para a caracteriza??o do n?mero de v?rtebras cervicais. Em seguida, foram dissecados at? a exposi??o das origens e dos nervos oriundos do plexo braquial. Os dados foram representados em frequ?ncia absoluta e percentual simples. Em 11 (55%) os nervos resultantes foram constitu?dos das conex?es entre os ramos espinhais ventrais de C5, C6, C7, C8 e T1. Em 5 (25%) as ra?zes participantes foram C4, C5, C6, C7, C8, T1 e T2. Em 2 (10%) de C5, C6, C7, C8, T1 e T2. Em outros 2 (10%) verificamos a constitui??o do plexo a partir de C6, C7, C8, T1 e T2. Os ramos ventrais formaram tr?s troncos nervosos: cranial, m?dio e caudal. Os nervos supraescapular, subescapulares, axilar, musculocut?neo, radial, mediano, ulnar inervaram a musculatura intr?nseca e os nervos subcl?vios, toracodorsal, tor?cico longo, peitoral cranial e peitoral caudal inervaram a musculatura extr?nseca. Tamb?m foram registrados os nervos cut?neos oriundos do plexo braquial, sendo eles o nervo cut?neo medial do bra?o, nervo cut?neo medial do antebra?o e ramos para a musculatura cut?nea do tronco. Os dados descritos neste estudo contribuem para a anatomia comparada de primatas e fornecem informa??es para a pesquisa aplicada, servindo como base para procedimentos cl?nico-cir?rgicos em que venha a se utilizar esta esp?cie como modelo experimental.
159

Test stálosti objektu u primátů / Test of object permanence in primates

Gálik, Michal January 2014 (has links)
5 ABSTRACT Object permanence is a cognitive ability to perceive the continuous existence of objects, even if they cannot be directly observed, respectively perceived by other senses (Piaget 1954). In humans object permanence develops in 6 qualitatively different stages. By using a comparative approach, it was found that the last stage 6 of this ability also occurs in great apes, gibbons and some New World monkeys (capuchin, marmoset and tamarin). In this study, we conducted a study with a series of invisible displacements of an object, in which we investigated whether two rhesus macaques (Macaca mulatta) have fully developed the ability of object permanence and don't rely on simple alternative cognitive strategies, while solving the different tasks. With one test subject, we confirmed that he solved the tasks with stage 6 object permanence abilities. Although the second individual reached significant performance in some sessions, the overall results are ambiguous, because during the testing he had a tendency to use simple alternative strategies. Our study concludes that under certain circumstances macaques have the cognitive capacity for a fully developed ability of object permanence. Key words: Object permanence, rhesus macaque, invisible displacement, cognitive functions
160

A Search for the Masked Mechanism Behind IgG-Mediated Suppression of Antibody Responses

Bergström, Joakim January 2017 (has links)
Antibodies passively administered together with their specific antigen can enhance or suppress the specific antibody response. This phenomenon is known as antibody feedback regulation. Whether this modulation causes up- or downregulation of the antibody response depends both on the antibody isotype and the antigen used. IgG antibodies passively administered together with particulate antigens, e.g. erythrocytes, can completely prevent the induction of an antibody response to the antigen. The suppressive capacity of IgG has been routinely used in the clinic since the 1960’s in RhD-prophylaxis to prevent hemolytic disease of the fetus and newborn. Although studied for decades, the underlying mechanism of IgG-suppression has remained elusive. The main focus of this thesis has been to elucidate the mechanism behind IgG-suppression of antibody responses in vivo in mouse models using intravenous immunization with specific IgG together with native or haptenated sheep red blood cells, SRBC. We show that IgG-suppression of IgM and long-term serum IgG-responses operates independently of activating FcγRI, III, IV, or the inhibitory FcγRIIB, thus confirming and extending previous findings. Moreover, we demonstrate for the first time that C1q, C3 and CR1/2 are dispensable for IgG-suppression of antibody responses. These findings strongly argue against the involvement of Fc-dependent mechanisms as the explanation for IgG-suppression. Interestingly, GC formation occurs in IgG-suppressed mice although the antibody response to surface SRBC epitopes are completely suppressed. The data suggests that these GCs develop in response to intracellular SRBC epitopes as well as to the passively administered suppressive IgG. Moreover, we demonstrate that passively administered IgG suppresses several parameters of an antibody/B cell response including antigen specific GC and non-GC B cells, extra-follicular antibody secreting cells, long-lived plasma cells and induction of immunological memory. Before the onset of the present study, two mechanisms appeared compatible with the majority of experimental findings: IgG-mediated antigen clearance and epitope masking. Herein we show that the contribution of IgG-mediated antigen clearance is negligible and that suppression of IgG-responses is strictly epitope specific. This provides compelling evidence that a very important mechanism underlying IgG-suppression is epitope masking.

Page generated in 0.0935 seconds