991 resultados para MORPHOLOGY TRANSITION


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Teen Triple P is a multilevel system of intervention that is designed to provide parents with specific strategies to promote the positive development of their teenage children as they make the transition into high school and through puberty. The program is based on a combination of education about the developmental needs of adolescents, skills training to improve communication and problem-solving, plus specific modules to deal with common problems encountered by parents and adolescents that can escalate into major conflict and violence. It is designed to increase the engagement of parents of adolescent and pre-adolescent children by providing them with easy access to evidencebased parenting advice and support. This paper presents data collected as part of a survey of over 1400 students in first year high school at 9 Brisbane schools. The survey instrument was constructed to obtain students' reports about behaviour which is known to be associated with their health and wellbeing, and also on the extent to which their parents promoted or discouraged such behaviour at home, at school, and in their social and recreational activities in the wider community. Selected data from the survey were extracted and presented to parents at a series of parenting seminars held at the schools to promote appropriate parenting of teenagers. The objectives were to provide parents with accurate data about teenagers' behaviour, and about teenagers' reports of how they perceived their parents' behaviour. Normative data on parent and teenager behaviour will be presented from the survey as well as psychometric data relating to the reliability and validity of this new measure. Implications of this strategy for increasing parent engagement in parenting programs that aim to reduce behavioural and emotional problems in adolescents will be discussed.

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A Cellular-Automaton Finite-Volume-Method (CAFVM) algorithm has been developed, coupling with macroscopic model for heat transfer calculation and microscopic models for nucleation and growth. The solution equations have been solved to determine the time-dependent constitutional undercooling and interface retardation during solidification. The constitutional undercooling is then coupled into the CAFVM algorithm to investigate both the effects of thermal and constitutional undercooling on columnar growth and crystal selection in the columnar zone, and formation of equiaxed crystals in the bulk liquid. The model cannot only simulate microstructures of alloys but also investigates nucleation mechanisms and growth kinetics of alloys solidified with various solute concentrations and solidification morphologies.

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Using the exact Bethe ansatz solution of the Hubbard model and Luttinger liquid theory, we investigate the density profiles and collective modes of one-dimensional ultracold fermions confined in an optical lattice with a harmonic trapping potential. We determine a generic phase diagram in terms of a characteristic filling factor and a dimensionless coupling constant. The collective oscillations of the atomic mass density, a technique that is commonly used in experiments, provide a signature of the quantum phase transition from the metallic phase to the Mott-insulator phase. A detailed experimental implementation is proposed.

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We consider a kinetic Ising model which represents a generic agent-based model for various types of socio-economic systems. We study the case of a finite (and not necessarily large) number of agents N as well as the asymptotic case when the number of agents tends to infinity. The main ingredient are individual decision thresholds which are either fixed over time (corresponding to quenched disorder in the Ising model, leading to nonlinear deterministic dynamics which are generically non-ergodic) or which may change randomly over time (corresponding to annealed disorder, leading to ergodic dynamics). We address the question how increasing the strength of annealed disorder relative to quenched disorder drives the system from non-ergodic behavior to ergodicity. Mathematically rigorous analysis provides an explicit and detailed picture for arbitrary realizations of the quenched initial thresholds, revealing an intriguing ""jumpy"" transition from non-ergodicity with many absorbing sets to ergodicity. For large N we find a critical strength of annealed randomness, above which the system becomes asymptotically ergodic. Our theoretical results suggests how to drive a system from an undesired socio-economic equilibrium (e. g. high level of corruption) to a desirable one (low level of corruption).

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In the Anomura, studies on growth patterns are infrequent, possibly because the heterogeneity of the group, especially in terms of morphology, makes it difficult to construct generalized growth models. Particularly hermit crabs are an interesting group to evaluate aspects of growth, because of their unique body. Isocheles sawayai, a hermit crab found only in the western Atlantic Ocean, poorly known with respect to its sexual dimorphism and maturity, was investigated here based on morphometry. Monthly collections (July 2001 through June 2003) were made from a shrimp fishing boat in the Caraguatatuba region on the northern coast of the state of SA o pound Paulo, Brazil. The specimens were measured and weighed, and had their sex checked. Throughout the sampling period, 374 specimens of I. sawayai were collected (11.23% nonovigerous females, 6.69% ovigerous females, 79.41% males and 2.67% intersexes). The size at which morphological sexual maturity was reached by both sexes ranged from 4.0 to 4.3 mm shield length, according to the relative growth and the size of the smallest ovigerous female. Sexual dimorphism was shown by males, which were significantly larger than females, and by differences in growth pattern between the sexes, especially for relationships that involved the pleopods, which is related to their different functions in males and females. The present study is one of the first to use pleopod morphometry to determine sexual maturity and dimorphism in hermit crabs, especially for species with intersexuality such as I. sawayai.

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The pocilloporin Rtms5 and an engineered variant Rtms5(H146S) undergo distinct color transitions (from blue to red to yellow to colorless) in a pH-dependent manner. pK(a) values of 4.1 and 3.2 were determined for the blue (absorption lambda(max), 590 nm) to yellow (absorption lambda(max), similar to 453 nm) transitions of Rtms5 and Rtms5H(146). The pK(a) for the blue-yellow transition of Rtms5H(146S) increased by 1.4 U in the presence of 0.1 M KI, whereas the pK(a) for the same transition of Rtms5 was relatively insensitive to added halides. To understand the structural basis for these observations, we have determined to 2.0 A resolution the crystal structure of a yellow form of Rtms5(H146S) at pH 3.5 in the presence of iodide. Iodide was found occupying a pocket in the structure with a pH of 3.5, forming van der Waals contacts with the tyrosyl moiety of the chromophore. Elsewhere, it was determined that this pocket is occupied by a water molecule in the Rtms5(H141S) structure (pH 8.0) and by the side chain of histidine 146 in the wild-type Rtms5 structure. Collectively, our data provide an explanation for the observed linkage between color transitions for Rtms5(H146S) and binding to halides.

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Under the conditions of the rotating wave approximation (RWA), a transition strongly driven by a resonant oscillating field displays the well known symmetric Autler-Townes doublet. However, if the counter-rotating component, neglected in the RWA, is taken into account, the Bloch-Siegert shift gives rise to an Autler-Townes doublet of unequal intensity even in the case of a resonant driving field. This effect is investigated theoretically in a V-shaped three-level double-resonance configuration and the results are presented in this paper. An interesting observation is that the level of asymmetry not only depends on the driving-field intensity but also on the characteristics of the driven system including relaxation rates and equilibrium population distributions.

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Epithelial to mesenchymal transition (EMT) is a process implicated in cancer progression in which the underlying cellular changes have been identified mainly using in vitro models. We determined the expression of some putative EMT biomarkers including E-cadherin, beta-catenin, zinc finger factor Snail (Snail), transforming growth factor beta 1 (TGF beta 1), TGF beta type II receptor (TBRII) and the HGF receptor (c-met) and their possible correlation to progression and overall survival in a series of breast ductal carcinoma in situ (DCIS) and invasive ductal carcinomas (IDC). Biomarkers were immunohistochemically determined in 55 IDC specimens from which 21 had lymph node metastases and in 95 DCIS specimens, 46 of these cases associated to invasive carcinoma, in a tissue microarray (TMA). Positive cytoplasmic staining of TGF beta 1 (78.2%), c-met (43.6%), Snail (34.5%), TBRII (100%), membranous E-cadherin (74.5%) and membranous/cytoplasmic beta-catenin (71%) were detected in the IDC samples. Metastatic lymph node samples displayed similar frequencies. A significant increase of c-met and TGF beta 1 positivity along DCIS to IDC progression was noted but only TGF beta 1 positivity was associated with presence of lymph node metastases and advanced stages in IDC. The evaluation of the other EMT markers in DCIS did not show differences in positivity rate as compared to invasive carcinomas. DCIS either pure or associated to IDC showed similar expression of the analyzed biomarkers. All the carcinomas exhibited positive expression of TBRII. Associations between the markers, determined by Spearman`s correlation coefficient, showed a significant association between TGF beta 1 and respectively E-cadherin, beta-catenin and cmet in DCIS cases, but in invasive carcinomas only cadherin and catenin were positively correlated. Kaplan-Meier survival curves revealed that none of the EMT biomarkers analyzed were correlated with survival, which was significantly determined only by clinical and hormone receptor parameters.

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Otitis media with effusion (OME) affects 28-38% of pre-school children, and it occurs due to the dysfunction of the auditory tube. Anatomical development of the auditory tube depends on the craniofacial growth and development. Deviations of normal. craniofacial. morphology and growth using cephatometric studies, may predict the evolution of otitis. Our goal in this paper is to determine if there are differences in craniofacial morphology between children with adenoid enlargement, with and without otitis media with effusion. This is a prospective study in which the sample consisted of 67 children (mate and female) from 5 to 10 years old. All patients presented chronic upper airway obstruction due to tonsil. and adenoid enlargement (>80% degree of obstruction). Thirty-three patients presented otitis media with effusion, for more than 3 months and 34 did not. The tatter composed the control group. Standardized lateral head radiographs were obtained for all. subjects. Radiographs were taken with patient positioned by a cephalostat and stayed with mandibles in centric occlusion and Lips at rest. Radiographs were digitalized and specific Landmarks were identified using a computer program Radiocef 2003, 5th edition. Measurements, angles and tines were taken of the basicranium, maxilla and mandible according to the modified Ricketts analysis. In addition, facial height and facial axis were determined. Children with otitis media with effusion present differences in the morphology of the face, regarding these measures: N-S (anterior cranial base length), N-ANS (upper facial height), ANS-PNS (size of the hard palate), Po-Or.N-Pog (facial depth), Ba-N.Ptm-Gn (facial axis), Go-Me (mandibular Length) and Vaia--Vaip (inferior pharyngeal airway). (C) 2008 Elsevier Ireland Ltd. All rights reserved.

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Objective: To determine the effects of melatonin on rat endometrium morphology and embryo implantation. Design: Experimental study. Setting: Federal University of Sao Paulo, Brazil. Animal(s): Forty female rats. Intervention(s): GI: control, GII: sham-operated, GIII: pinealectomized, and GIV: pinealectomized rats that received melatonin during 3 months. The GI, GII, and Gin groups received the vehicle of melatonin (NaCl + ethanol). At the end of the treatment, the animals were killed during the estrous phase; the uterus was removed for morphometric analysis. Urine was collected for 6-sulfatoxymelatonin. Blood was collected for estrogen (E) and progesterone (P) level determinations. In a second experiment, female rats were used to evaluate the endometrial embryo implantation. Main Outcome Measure(s): Endometrial morphology and embryo implantation. Result(s): Gin presented the highest values for endometrial area and thickness index, number of endometrial glands, and eosinophils. The number of vessels of groups I, II, and IV was fewer than that of Gin. The highest number of eosinophils was detected in Gin in comparison to other groups. The implantation rate in Gin was the lowest of all groups. This implantation rate was significantly increased and restored toward normal in GIV. Conclusion(s): Our data suggested that, in nonphotoperiodic animals such as rats, melatonin may positively affect the endometrial morphology and improve embryo implantation.

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Carcinoma ex-pleomorphic adenoma (CXPA) is an aggressive salivary gland malignancy, usually derived from a long-standing or a recurrent benign tumor, the pleomorphic adenoma (PA). In the context of dynamic reciprocity, changes in the composition and structure of extracellular matrix proteins and cell surface receptors have been frequently associated with dysfunctional adhesion and invasive behavior of tumor cells. It is not fully understood if these changes are involved in the conversion of PA to CXPA. In this study, different progression stages of CXPA were investigated regarding the expression of the major extracellular matrix proteins, collagen type I, and of E-cadherin and beta-catenin, the components of adherens junctions. By immunohistochemical analysis, we have demonstrated that direct contact of tumor cells with fibrillar type I collagen, particularly near the invasive front and in invasive areas prevailing small nests of CXPA cells, could be associated with reduced expression of the E-cadherin and beta-catenin adhesion molecules and with invasive behavior of epithelial; but not of CXPA with myoepithelial component. Our results also suggested that this association could depend on the organization of collagen molecules, being prevented by high-order polymeric structures. These findings could implicate the local microenvironment in the transition from the premalignant PA to invasive CXPA.

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in humans, adverse pregnancy outcomes (low birth weight, prematurity, and intrauterine growth retardation) are associated with exposure to urban air pollution. Experimental data have also shown that such exposure elicits adverse reproductive outcomes. We hypothesized that the effects of urban air pollution on pregnancy outcomes could be related to changes in functional morphology of the placenta. To test this, future dams were exposed during pregestational and gestational periods to filtered or nonfiltered air in exposure chambers. Placentas were collected from near-term pregnancies and prepared for microscopical examination. Fields of view on vertical uniform random tissue slices were analyzed using stereological methods. Volumes of placental compartments were estimated, and the labyrinth was analyzed further in terms of its maternal vascular spaces, fetal capillaries, trophoblast, and exchange surface areas. From these primary data, secondary quantities were derived: vessel calibers (expressed as diameters), trophoblast thickness (arithmetic mean), and total and mass-specific morphometric diffusive conductances for oxygen of the intervascular barrier. Two-way analysis of variance showed that both periods of exposure led to significantly smaller fetal weights. Pregestational exposure to nonfiltered air led to significant increases in fetal capillary surface area and in total and mass-specific conductances. However, the calibers of maternal blood spaces were reduced. Gestational exposure to nonfiltered air was associated with reduced volumes, calibers, and surface areas of maternal blood spaces and with greater fetal capillary surfaces and diffusive conductances. The findings indicate that urban air pollution affects placental functional morphology. Fetal weights are compromised despite attempts to improve diffusive transport across the placenta.