Research suggests biological sex differences may affect pain perception, however the difference in analgesic tolerance between male and females not been extensively studied. Therefore, here we studied the response of male and female Sprague-Dawley rats to prolonged duration local anesthetics; including conventional amino-amide anesthetics (bupivacaine), site 1 sodium channel blockers (tetrodotoxin) and a prolonged duration liposomal formulation (Exparel). This study examined the incidence and duration of sensory and motor blockade; systemic side effects, as well as local neurotoxicity and myotoxicity in both male and female rodents in an in vivo model of sciatic nerve blockade. The data collected does not indicate a sexual dimorphism among the agents studied. / 2019-07-03T00:00:00Z

Opuntioideae constitui uma das três subfamílias tradicionalmente reconhecidas em Cactaceae, apresentando cerca de 220-350 espécies com hábitos arborescente, arbustivos ou cespitosos, e distribuição no Canadá, América do Norte, Caribe, América Central e do Sul. A subfamília é reconhecida com mais derivadas que não suculentas e folhosas Pereskioideae e menos derivadas que as Cactoideae. No presente estudo são abordados aspectos anatômicos da região areolar, sistema fundamental e de revestimento, bem como dos padrões vasculares, através do desenvolvimento dessas estruturas no segmento caulinar de quatro espécies de Opuntioideae. Os resultados deste estudo, incorporados à literatura disponível serão essenciais para esclarecer importantes paradigmas dos estudos em Cactaceae, como a evolução do lenho e a função das traqueídes vasculares nos diferentes tipos de polimorfismo do lenho e a origem foliar dos espinhos nas aréolas. / Opuntioideae constitui uma das três subfamílias tradicionalmente reconhecidas em Cactaceae, apresentando cerca de 220-350 espécies com hábitos arborescente, arbustivos ou cespitosos, e distribuição no Canadá, América do Norte, Caribe, América Central e do Sul. A subfamília é reconhecida com mais derivadas que não suculentas e folhosas Pereskioideae e menos derivadas que as Cactoideae. No presente estudo são abordados aspectos anatômicos da região areolar, sistema fundamental e de revestimento, bem como dos padrões vasculares, através do desenvolvimento dessas estruturas no segmento caulinar de quatro espécies de Opuntioideae. Os resultados deste estudo, incorporados à literatura disponível serão essenciais para esclarecer importantes paradigmas dos estudos em Cactaceae, como a evolução do lenho e a função das traqueídes vasculares nos diferentes tipos de polimorfismo do lenho e a origem foliar dos espinhos nas aréolas. Palavras chave: Cactaceae, Opuntioideae, anatomia, aréolas, dimorfismo. ABSTRACT Opuntioideae constitutes one of the three recognized subfamilies traditionally in Cactaceae, with 220-350 species with habits arborescent, shrub or caespitose and distribution in Canada, North America, Caribbean, Central and South America. The subfamily is viewed as more derived than the leafy, nonsucculent Pereskioideae and less derived than Cactoideae. In the present research are showed anatomical characters on the areoles, skin and growth system and vascular patterns, through the development of these structures on the stem segments of four Opuntioideae species. The results this study, incorporated to available literature will be essential for important paradigms of the studies in Cactaceae, as the wood evolution and function of the vascular tracheids in the different types of polymorphism of the wood and foliar origin of the spines in the areoles.

Myelin is an extensive cell membrane produced by oligodendrocytes to ensheath neuronal axons in the central nervous system with the primary goal of maximizing the efficiency of electrochemical impulse transmission. During brain development, oligodendrocytes differentiate into myelin forming cells in a tightly regulated process which makes them vulnerable to multiple insults. Previous results from the laboratory showed that the timing of oligodendrocyte differentiation and rat brain myelination were altered by perinatal exposure to buprenorphine and methadone, opioid analogues used for treating pregnant addicts. The mechanism by which these opioids exerted their effects involved two opioid receptors, the μ-opioid receptor (MOR) and the nociceptin/orphanin FQ receptor (NOR). However, the role of these receptors and their endogenous ligands in controlling the timing of myelination under normal physiological conditions of brain development is not known. In this dissertation, we found that the endogenous MOR ligand endomorphin-1 (EM-1) acts as a strong promoter of rat pre-oligodendrocyte differentiation, but surprisingly, this effect is observed only in cells isolated from female pups. Interestingly, the stimulatory action of EM-1 was abolished upon co-incubation with the endogenous NOR ligand, nociceptin. Moreover, injections of NOR antagonist to 9-day-old female and male rat pups accelerated rat brain myelination in female rat pups with no significant changes in their male counterparts. Interestingly, the lack of major sex-dependent differences in developmental brain levels of EM-1 and nociceptin and the presence of the two receptors MOR and NOR in male and female oligodendrocytes suggested that the observed sex-specific responses may be highly dependent on critical intrinsic sex-dependent differences within these cells. Although nociceptin alone did not exert observable effects on pre-oligodendrocyte maturation, it increased the number of cells expressing Ki-67, a cell proliferation indicator, in oligodendrocyte progenitor cultures. These results suggest that nociceptin may be playing a stage specific role in oligodendrocyte development during brain maturation. The finding of critical functions of EM-1 and nociceptin in the developing female oligodendrocytes and brain myelination highlights the need for considering sexual dimorphism in the design of safer and more effective therapeutic approaches for treating opioid abuse, pain, and demyelinating disease as multiple sclerosis.

No description available.

Sexual differences are dramatic and widespread across taxa. However, a common genome between males and females should hinder phenotypic divergence. In this thesis I have used experimental, genomic, and theoretical approaches to study processes that can facilitate and maintain differences between males and females. I studied two mechanisms for the evolution of sexual dimorphism - condition-dependence and gene duplication. If sex-specific traits are costly, then individuals should only express such traits when they possess enough resources to do so. I experimentally manipulated adult condition and found that the sex-biased gene expression depends on condition. Second, duplication events can permit different gene copies to adopt sex-specific expression. I showed that half of all duplicate families have paralogs with different sex-biased expression patterns between members. I investigated how current sexual dimorphism may support novel dimorphism. With regards gene duplication, I found that related duplicates did not always have different expression patterns. However, duplicating a pre-existing sex-biased gene effectively increases organismal sexual dimorphism overall. From a theoretical perspective, I investigated how sexually dimorphic recombination rates allow novel sexually antagonistic variation to invade. Male and female recombination rates separately affect invasion probabilities of new alleles. Finally, I examined the assumption that a common genetic architecture impedes the evolution of sexual dimorphism. First, I conducted a literature review to test whether additive genetic variances in shared traits were different between the sexes. There were few significant statistical differences. However, extreme male-biased variances were more common than extreme female-biased variances. Sexual dimorphism is expected to evolve easily in such traits. Second, I compared these results to findings from the multivariate literature. In contrast to single trait studies, almost all multivariate studies of sexual dimorphism have found variance differences, both in magnitude and orientation, between males and females. Overall, this thesis concludes that sexual dimorphism can evolve by processes that generate novel sexual dimorphism or that take advantage of pre-existing dimorphism. Furthermore, a common genome is not necessarily a strong barrier if genetic variances differ between the sexes. It will be an exciting challenge to understand how mutation and selection work together to allow organisms differ in their ability evolve sexual dimorphism.

Life-history theory proposes that different activities, such as growth, maintenance and reproduction compete for limited resources and therefore, life-history traits are bound together by physiological trade-offs. In dioecious species, females are assumed to invest a higher amount of resources in reproduction in comparison with males and this higher investment in reproduction is then assumed to have numerous consequences for the expression of other life-history traits. Some recent papers have, however, suggested that although common, this investment pattern may not be the case in all dioecious plant species. One notable exception is Silene latifolia. Therefore, I examined whether the male sex could be investing more in reproduction than females in a closely related Silene species, Silene dioica. This study was carried out on three islands in the Skeppsvik Archipelago, Umeå, where I examined possible differences between the sexes in different life history traits. On each island, 20 patches were laid out in two different successional zones. In each patch, flowering date was recorded and stem diameter, length and width of cauline leaves, flower diameter, and number of open flowers on male and female plants was measured. At the end of the study, flowering stems were collected and thereafter dried so they could be weighed to estimate biomass allocated to male and female vegetative and reproductive structures. The hypothesis that males of S. dioica should have a higher reproductive cost seemed to be confirmed since males started flowering earlier, produced more and larger flowers, produced smaller and fewer leaves and thinner stems. The males also allocated a greater proportion of their total biomass to reproductive parts and as a consequence, had a higher sink to source ratio. This study has shown that there are exceptions to the "rule" of females having a higher cost of reproduction and when doing research on dioecious species, it is important not to assume that only one and the same sex has the higher investment in reproduction in all species. This higher cost may have consequences for survival and reproductive fitness and can select for differences in other ecological traits, such as phenology, growth, chemical composition and morphology, which could in turn affect the competitive ability and the susceptibility to herbivores and pathogens.

Sexual differentiation is divided into gonadal sexual differentiation and brain sexual differentiation in the teleosts. Gonadal sexual differentiation is regulated by brain sexual differentiation. Brain sexual differentiation is resulted from the neural development, which lead to the sexual dimorphism of both structure and functions of brain. The neural development is influenced by the genetic factors and the external environmental factors. The lower temperature induces a higher proportion of female while the elevated temperature induces a higher proportion of male in tilapia. In addition, there is sexual difference in effects of temperature on the activity of brain neurochemicals. Water temperature plays an important role on the development of central neurotransmitter systems and sexual differentiation during the developing period. In the present study, the primary neural culture cloned from the female and male tilapia¡AOreochromis mossambicus was used. The difference of the physiological characteristics between the neural cells derived from the females and males, were investigated. These results show that the elevated temperature has an effect to enhance the proliferation in both primary neural culture of females and males.

Many species use color during courtship displays, with the more colorful individuals often selected as potential mates. Female blue crabs, Callinectes sapidus, display prominent red markings on their chelipeds, which is absent in males. I tested the hypothesis that females use this sexual dimorphism as an effective signal to potential mates. Body size was positively correlated with size of the colorful pattern on the crusher dactyl. Digital imaging techniques were used to examine and quantify a pattern of coloration in the female blue crab. Morphometric measurements were made using digital images of the carapace and chelae of crabs collected along the Gulf of Mexico coast in Galveston, Texas. Color complexity was examined on digital images of the chelae using Adobe? Photoshop? and Image J. Specific wavelengths were selected and their presence within the attribute quantified and evaluated. To determine whether male blue crabs prefer more colorful females, males were given a choice between females of different female coloration. Males displayed more often and directed more courtship displays towards the more colorful females. I hypothesize that male blue crabs use cheliped coloration as a visual cue for mate selection.

Thesis (M.S.)--University of North Carolina at Wilmington, 2004. / Includes bibliographical references (leaves : [79]-88).

The evolutionary importance of genetic constraints has always been recognized by biologists, but very little data is available to quantitatively assess the role of constraints in shaping the biology of organisms. The field of quantitative genetics provides the tools necessary to study evolutionary constraints, mainly through the estimation of the matrix of additive genetic variance and covariance (the G matrix). The main goals of this Ph.D. dissertation were to study the persistence of constraints across environments and across species, to explore the consequences of constraints on species divergence, and to try to understand some morphological and life history characteristics of field crickets in light of genetic variation. Populations of seven wing-dimorphic cricket species from the genera Gryllus and Teleogryllus were sampled from the wild and reared in the laboratory. Using multiple statistical approaches to the comparison of G matrices, results revealed little variation in G matrices across species. Moreover, the relatively small effect of rearing environment and of the two wing morphologies on G were shown to be of the same magnitude as variation between species, therefore confirming the general constancy of genetic constraints through evolutionary time scales. Mean trait values, selection regimes and phylogenetic distances were all shown not to be predictors of G matrix variation. In agreement with the constraint hypothesis of quantitative genetic theory, morphological divergence between species was shown to be predictable from a reconstructed ancestral G matrix. In addition, information on genetic variation was used to explain various patterns relating to size, ovipositor length, wing morphology and diapause occurrence in field crickets. Overall, we suggest that genetic constraints, as described by quantitative genetics, have played a major role in shaping the observed biological diversity of field cricket species, a conclusion tha