884 resultados para negative assortative mating


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In schizophrenia, nonverbal behavior, including body movement, is of theoretical and clinical importance. Although reduced nonverbal expressiveness is a major component of the negative symptoms encountered in schizophrenia, few studies have objectively assessed body movement during social interaction. In the present study, 378 brief, videotaped role-play scenes involving 27 stabilized outpatients diagnosed with paranoid-type schizophrenia were analyzed using Motion Energy Analysis (MEA). This method enables the objective measuring of body movement in conjunction with ordinary video recordings. Correlations between movement parameters (percentage of time in movement, movement speed) and symptom ratings from independent PANSS interviews were calculated. Movement parameters proved to be highly reliable. In keeping with predictions, reduced movement and movement speed correlated with negative symptoms. Accordingly, in patients who exhibited noticeable movement for less than 20% of the observation time, prominent negative symptoms were highly probable. As a control measure, the percentage of movement exhibited by the patients during role-play scenes was compared to that of their normal interactants. Patients with negative symptoms differed from normal interactants by showing significantly reduced head and body movement. Two specific positive symptoms were possibly related to movement parameters: suspiciousness tended to correlate with reduced head movement, and the expression of unusual thought content tended to relate to increased movement. Overall, a close and theoretically meaningful association between the objective movement parameters and the symptom profiles was found. MEA appears to be an objective, reliable and valid method for quantifying nonverbal behavior, an aspect which may furnish new insights into the processes related to reduced expressiveness in schizophrenia.

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Triple-negative breast cancer does not express estrogen and progesterone receptors, and no overexpression/amplification of the HER2-neu gene occurs. Therefore, this subtype of breast cancer lacks the benefits of specific therapies that target these receptors. Today chemotherapy is the only systematic therapy for patients with triple-negative breast cancer. About 50% to 64% of human breast cancers express receptors for gonadotropin-releasing hormone (GnRH), which might be used as a target. New targeted therapies are warranted. Recently, we showed that antagonists of gonadotropin-releasing hormone type II (GnRH-II) induce apoptosis in human endometrial and ovarian cancer cells in vitro and in vivo. This was mediated through activation of stress-induced mitogen-activated protein kinases (MAPKs) p38 and c-Jun N-terminal kinase (JNK), followed by activation of proapoptotic protein Bax, loss of mitochondrial membrane potential, and activation of caspase-3. In the present study, we analyzed whether GnRH-II antagonists induce apoptosis in MCF-7 and triple-negative MDA-MB-231 human breast cancer cells that express GnRH receptors. In addition, we ascertained whether knockdown of GnRH-I receptor expression affects GnRH-II antagonist-induced apoptosis and apoptotic signaling.

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It is unclear whether patients with different clinical subtypes of Parkinson disease (PD) differ in their risk of developing levodopa-induced dyskinesia (LID) and whether resting tremor is negatively correlated with this risk.

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To evaluate maxillary dental arch dimensions in pre-school children with a complete unilateral cleft lip and palate (CUCLP) after early alveolar bone grafting.

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CpG island methylator phenotype (CIMP) is being investigated for its role in the molecular and prognostic classification of colorectal cancer patients but is also emerging as a factor with the potential to influence clinical decision-making. We report a comprehensive analysis of clinico-pathological and molecular features (KRAS, BRAF and microsatellite instability, MSI) as well as of selected tumour- and host-related protein markers characterizing CIMP-high (CIMP-H), -low, and -negative colorectal cancers. Immunohistochemical analysis for 48 protein markers and molecular analysis of CIMP (CIMP-H: ? 4/5 methylated genes), MSI (MSI-H: ? 2 instable genes), KRAS, and BRAF were performed on 337 colorectal cancers. Simple and multiple regression analysis and receiver operating characteristic (ROC) curve analysis were performed. CIMP-H was found in 24 cases (7.1%) and linked (p < 0.0001) to more proximal tumour location, BRAF mutation, MSI-H, MGMT methylation (p = 0.022), advanced pT classification (p = 0.03), mucinous histology (p = 0.069), and less frequent KRAS mutation (p = 0.067) compared to CIMP-low or -negative cases. Of the 48 protein markers, decreased levels of RKIP (p = 0.0056), EphB2 (p = 0.0045), CK20 (p = 0.002), and Cdx2 (p < 0.0001) and increased numbers of CD8+ intra-epithelial lymphocytes (p < 0.0001) were related to CIMP-H, independently of MSI status. In addition to the expected clinico-pathological and molecular associations, CIMP-H colorectal cancers are characterized by a loss of protein markers associated with differentiation, and metastasis suppression, and have increased CD8+ T-lymphocytes regardless of MSI status. In particular, Cdx2 loss seems to strongly predict CIMP-H in both microsatellite-stable (MSS) and MSI-H colorectal cancers. Cdx2 is proposed as a surrogate marker for CIMP-H.

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Rapid speciation in Lake Victoria cichlid fish of the genus Pundamilia may be facilitated by sexual selection: female mate choice exerts sexual selection on male nuptial coloration within species and maintains reproductive isolation between species. However, declining water transparency coincides with increasingly dull coloration and increasing hybridization. In the present study, we investigated the mechanism underlying this pattern in Pundamilia nyererei, a species that interbreeds with a sister species in turbid but not in clear water. We compared measures of intraspecific sexual selection between two populations from locations that differ in water transparency. First, in laboratory mate-choice experiments, conducted in clear water and under broad-spectrum illumination, we found that females originating from turbid water have significantly weaker preferences for male coloration than females originating from clear water. Second, both the hue and body coverage of male coloration differ between populations, which is consistent with adaptation to different photic habitats. These findings suggest that the observed relationship between male coloration and water transparency is not mediated by environmental variation alone. Rather, female mating preferences are indicated to have changed in response to this variation, constituting the first evidence for intraspecific preference-trait co-evolution in cichlid fish. (C) 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 398-406.

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Colour polymorphisms have fascinated evolutionary ecologists for a long time. Yet, knowledge on the mechanisms that allow their persistence is restricted to a handful of well-studied cases. We studied two species of Lake Victoria cichlid fish, Neochromis omnicaeruleus and Neochromis greenwoodi, exhibiting very similar sex-linked colour polymorphisms. The ecology and behaviour of one of these species is well studied, with colour-based mating and aggression preferences. Here, we ask whether the selection potentially resulting from female and male mating preferences and aggression biases reduces gene flow between the colour morphs and permits differentiation in traits other than colour. Over the past 14 years, the frequencies of colour morphs have somewhat oscillated, but there is no evidence for directional change, suggesting the colour polymorphism is persistent on an ecological timescale. We find limited evidence of ecomorphological differentiation between sympatric ancestral (plain) and derived (blotched) colour morphs. We also find significantly nonrandom genotypic assignment and an excess of linkage disequilibrium in the plain morph, which together with previous information on mating preferences suggests nonrandom mating between colour morphs. This, together with negative frequency-dependent sexual selection, found in previous studies, may facilitate maintenance of these polymorphisms in sympatry

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Sexual selection by female mating preference for male nuptial coloration has been suggested as a driving force in the rapid speciation of Lake Victoria cichlid fish. This process could have been facilitated or accelerated by genetic associations between female preference loci and male coloration loci. Preferences, as well as coloration, are heritable traits and are probably determined by more than one gene. However, little is known about potential genetic associations between these traits. In turbid water, we found a population that is variable in male nuptial coloration from blue to yellow to red. Males at the extreme ends of the phenotype distribution resemble a reproductively isolated species pair in clear water that has diverged into one species with blue-grey mates and one species with bright red males. Females of the turbid water population vary in mating preference coinciding with the male phenotype distribution. For the current study, these females were mated to blue males. We measured the coloration of the sires and male offspring. Parents-offspring regression showed that the sires did not affect male offspring coloration, which confirms earlier findings that the blue species breeds true. In contrast, male offspring coloration was determined by the identity of the dams, which suggests that there is heritable variation in male color genes between females. However, we found that mating preferences of the dams were not correlated with male offspring coloration. Thus, there is no evidence for strong genetic linkage between mating preference and the preferred trait in this population [Current Zoology 56 (1): 57-64 2010].

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The International Breast Cancer Study Group Trial VIII compared long-term efficacy of endocrine therapy (goserelin), chemotherapy [cyclophosphamide, methotrexate and fluorouracil (CMF)], and chemoendocrine therapy (CMF followed by goserelin) for pre/perimenopausal women with lymph-node-negative breast cancer.