958 resultados para Item-Response-Theory
Resumo:
Objective. To investigate whether poor response to controlled ovarian stimulation (COS) is due to a qualitative decline in ovarian function. Methods. This retrospective cohort study included 436 patients younger than 35-years old, undergoing COS for intracytoplasmic sperm injection (ICSI). Patients with four or fewer MII oocytes after COS (poor-responder group, PR, n = 52) were age-matched with normoresponder patients (NR, n = 364). Results. Although similar duration of stimulation (10.5 +/- 0.4 and 9.3 +/- 0.8 days; p = 0.1358), increased doses of gonadotrophins (2510 +/- 865 and 2253 +/- 572 IU; p = 0.0061) were used in the PR. The results show a increased chance of cycle ending of PR (PR: 26.9% and NR: 3.1%; p < 0.0001). Although the lower total number of oocytes retrieved (2.4 +/- 1.4 and 16.2 +/- 9.3; p < 0.0001), equal rate of fertilization (70.2% and 72.0%, p = 0.1190) and high quality embryos were obtained (50.0% and 45.2%; p = 0.4895), resulting in similar implantation (14.5% and 19.7%; p = 0.2246) and abortion (10.0% and 15.4%; p = 1.00) rates, respectively. A trend towards increased pregnancy rate per embryo transfer in NR group was noted (PR: 26.3% and NR: 42.2%; p = 0.0818). Conclusions. Low ovarian response could be associated mainly with a quantitative rather than a qualitative decline in ovarian function. Therefore, even if the ovarian response to stimulation is low, patients aged <= 35 years should process to oocyte retrieval.
Resumo:
Animals inheriting the slick hair gene have a short, sleek, and sometimes glossy coat. The objective of the present study was to determine whether slick-haired Holstein cows regulate body temperature more effectively than wild-type Holstein cows when exposed to an acute increase in heat stress. Lactating slick cows (n = 10) and wild-type cows (n = 10) were placed for 10 h in an indoor environment with a solid roof, fans, and evaporative cooling or in an outdoor environment with shade cloth and no fans or evaporative cooling. Cows were exposed to both environments in a single reversal design. Vaginal temperature, respiration rate, surface temperature, and sweating rate were measured at 1200, 1500, 1800, and 2100 h (replicate 1) or 1200 and 1500 h (replicate 2), and blood samples were collected for plasma cortisol concentration. Cows in the outdoor environment had higher vaginal and surface temperatures, respiration rates, and sweating rates than cows in the indoor environment. In both environments, slick-haired cows had lower vaginal temperatures (indoor: 39.0 vs. 39.4 degrees C; outdoor 39.6 vs. 40.2 degrees C; SEM = 0.07) and respiration rate (indoor: 67 vs. 79 breaths/min; outdoor 97 vs. 107 breaths/min; SEM = 5.5) than wild-type cows and greater sweating rates in unclipped areas of skin (indoor: 57 vs. 43 g.h(-1)/m(2); outdoor 82 vs. 61 g.h(-1)/m(2); SEM = 8). Clipping the hair at the site of sweating measurement eliminated the difference between slick-haired and wild-type cows. Results indicate that slick-haired Holstein cows can regulate body temperature more effectively than wild-type cows during heat stress. One reason slick-haired animals are better able to regulate body temperature is increased sweating rate.
Resumo:
Cutaneous leishmaniasis (CL) includes different clinical manifestations displaying diverse intensities of dermal Inflammatory infiltrate Diffuse CL (DCL) cases are hyporesponsive and lesions show very few lymphocytes and a predominance of macrophages In contrast localized CL (LCL) cases are responsive to leishmanial antigen and lesions exhibit granulocytes and mononuclear cell infiltration in the early phases changing to a pattern with numerous lymphocytes and macrophages later in the lesion Therefore different chemokines may affect the predominance of cell infiltration in distinct clinical manifestations In lesions from LCL patients we examined by flow cytometry the presence of different chemokines and their receptors in T cells and we verified a higher expression of CXCR3 in the early stages of LCL (less than 30 days of infection) and a higher expression of CCR4 in the late stages of disease (more than 60 days of infection) We also observed a higher frequency of T cells producing IL-10 in the late stage of LCL Using immunohistochemistry we observed a higher expression of CCL7 CCL17 in lesions from late LCL as well as CCR4 suggesting a preferential recruitment of regulatory T cells in the late LCL Comparing lesions from LCL and DCL patients we observed a higher frequency of CCL7 in DCL lesions These results point out the Importance of the chemokines defining the different types of cells recruited to the site of the infection which could be related to the outcome of infection as well as the clinical form observed (C) 2010 American Society for Histocompatibility and Immunogenetics Published by Elsevier Inc All rights reserved
Resumo:
Candida albicans is recognized by phagocytic cells through a set of recognition receptors patterns. Recently, we showed the importance of TLR2 in the regulation of neutrophil survival after C. albicans infection. In the present work, we analyzed the involvement of TLR4 in the recognition of C. albicans by neutrophils and macrophages. Our results show that the absence of functional TLR4 resulted in lower chemotaxis of neutrophils to the site of infection, lower levels of TNF-alpha, CXCL1 and nitric oxide, and dissemination and persistence of the pathogen in lymph nodes and spleen. In vitro, the phagocytic activity, nitric oxide production and myeloperoxidase activity, CXCL1, IL-1 beta production by neutrophils from TLR4-defective mice were not changed. In contrast, macrophages from TLR4-defective mice demonstrated lower phagocytosis and lower levels of CXCL1, IL-1 beta and TNF-alpha. Together, these data demonstrate that TLR4 signals are important for the recognition of C. albicans by macrophages and their absence allows persistence of the infection.
Resumo:
Considers the relevance of A.K. Sen’s theory of entitlements to the situation facing indigenous tribal people, its relationship to institutionalism, and to theories of property rights. Changing world views about the resource entitlements that should be given to local communities are outlined concentrating on the views expressed by the World Conservation Union (IUCN). These changing views have relevance for the resource entitlements of indigenous tribal communities and are reflected in differences in the policy approaches inherent in the Convention on International Trade in Endangered Species (CITES) and the more recent Convention on Biological Diversity. The latter embodies the view that provision of greater resource entitlements to local communities can provide economic incentives for nature conservation. There is a case for Indigenous Australians to be given greater rights to market the natural produce from their lands. Despite progress with land rights, they are not entitled to market much of the natural produce from their land. The socioeconomic status of Australian Aborigines is outlined. Their standard of living and their life expectancy are low by world standards and in comparison to other Australians. This is partly a result of historical events that have restricted their rights. These events are outlined briefly. Views differ about the appropriate development paths for Indigenous Australians and these are assessed. Concern on environmental and economic grounds is expressed about the view that the economic development of Australian Aboriginal communities would be accelerated by replacing their communal land titles by private land titles and encouraging Western-style agriculture and commercial development of their lands. Some comparisons are also made with the situation of India’s Tribals.
Resumo:
This study evaluated the biomechanical and microscopic response of previously grafted bone to titanium implants. The lower incisors of 16 rabbits were surgically extracted, and bilateral perforations communicating with the remaining sockets were created distally. A socket/perforation defect on each mandible was chosen at random to be immediately filled with a xenogenic graft, whereas the contralateral perforation was left to heal naturally and served as a paired control. After 60 days, titanium implants were installed in the previously operated areas. After periods of 2 and 6 months, the animals were killed, and the force necessary to retrieve implants as well as the bone-implant contact (BIC) and bone mass (BM) were quantified and statistically compared by 2-way analysis of variance and Tukey`s test (alpha = .05). No significant differences in removal torque were observed, either by time or by treatment condition. Differences in BIC and BM between experimental and control groups were not statistically significant through the intervals studied (P < .05). The presence of a xenogenic graft did not influence the microscopic tissue response to titanium implants or fixation into newly formed or mature bone.
Resumo:
The main issue regarding pediatric audiology diagnosis is determining procedures to configure reliable results which can be used to predict frequency-specific hearing thresholds. Aim: To investigate the correlation between auditory steady-state response (ASSR) with other tests in children with sensorineural hearing loss. Methods: Prospective cross-sectional contemporary cohort study. Twenty-three children (ages 1 to 7; mean, 3 years old) were submitted to ASSR, behavioral audiometry, click audiometry brain stem response (ABR), tone burst ABR, and predicting hearing level from the acoustic reflex. Results: the correlation between behavioral thresholds and ASSR was (0.70- 0.93), for the ABR tone burst it was (0.73 -0.93), for the ABR click it was (0.83-0.89) only at 2k and 4 kHz. The match between the ASSR and the hearing threshold prediction rule was considered moderate. Conclusion: there was a significant correlation between the ASSR and audiometry, as well as between ABR click (2k and 4 kHz) and for the ABR tone burst. The acoustic reflex can be used to add information to diagnosis in children.
Resumo:
Proportionally balanced designs were introduced by Gray and Matters in response to a need for the allocation of markers of the Queensland Core Skills Test to have a certain property. Put simply, markers were allocated to pairs of units in proportions that reflected the relative numbers of markers allocated in total to each unit. In this paper, the first author extends the theoretical results relating to such designs and provides further instances, and two general constructions, in the case that the design comprises blocks of precisely two sizes.
Resumo:
Uncontrolled systems (x) over dot is an element of Ax, where A is a non-empty compact set of matrices, and controlled systems (x) over dot is an element of Ax + Bu are considered. Higher-order systems 0 is an element of Px - Du, where and are sets of differential polynomials, are also studied. It is shown that, under natural conditions commonly occurring in robust control theory, with some mild additional restrictions, asymptotic stability of differential inclusions is guaranteed. The main results are variants of small-gain theorems and the principal technique used is the Krasnosel'skii-Pokrovskii principle of absence of bounded solutions.
Resumo:
An important feature of some conceptual modelling grammars is the features they provide to allow database designers to show real-world things may or may not possess a particular attribute or relationship. In the entity-relationship model, for example, the fact that a thing may not possess an attribute can be represented by using a special symbol to indicate that the attribute is optional. Similarly, the fact that a thing may or may not be involved in a relationship can be represented by showing the minimum cardinality of the relationship as zero. Whether these practices should be followed, however, is a contentious issue. An alternative approach is to eliminate optional attributes and relationships from conceptual schema diagrams by using subtypes that have only mandatory attributes and relationships. In this paper, we first present a theory that led us to predict that optional attributes and relationships should be used in conceptual schema diagrams only when users of the diagrams require a surface-level understanding of the domain being represented by the diagrams. When users require a deep-level understanding, however, optional attributes and relationships should not be used because they undermine users' abilities to grasp important domain semantics. We describe three experiments which we then undertook to test our predictions. The results of the experiments support our predictions.
Resumo:
Large bone defects represent major clinical problems in the practice of reconstructive orthopedic and craniofacial surgery. The aim of this study was to examine, through immunohistochemistry approach, the involvement of MMP-9 and CD68(+) cells during tissue remodeling in response to natural hydroxyapatite (HA) implanted in rat subcutaneous tissue. Before experimentation, forty animals were randomly distributed into two experimental groups: Group-I (Gen-Ox (TM) micro-granules) and Group-II (Gen-Ox (TM) macro-granules). Afterwards, the biopsies were collected after 10, 20, 30, and 60 days post-implantation. Our results showed that at 10 days, a low-renewal foreign body type granuloma formation was observed in most of the cases. Macrophage- and fibroblast-like cells were the predominant type of cells positively stained for MMP-9 in both groups. Once macrophage-like cells seemed to be the major source of MMP9, antibody against pan-CD68 epitope was used to correlate these findings. In agreement, MMP-9 and CD68(+) cells were distributed at the periphery and the central region of the granuloma in all experimental periods, however no staining was observed in cell contacting to material. Besides macrophages, the lysosomal glycoprotein epitope recognized by CD68 antibodies can be expressed by mast cell granules and sometimes by fibroblasts. Taken together, our results suggest that xenogenic HA promotes extracellular matrix remodeling through induction of MMP-9 activity and presence of CD68(+) cells.