Sexually and physically abused foster care children and posttraumatic stress disorder.

Considerable debate exists regarding the possible relationship between child abuse and posttraumatic stress disorder (PTSD). In this study, 3 groups of foster care children were compared. The groups included 50 sexually abused, 50 physically abused, and 50 nonabused foster care children. Participants completed the Child Post-Traumatic Stress Reaction Index, the Childhood PTSD Interview, and the Modified Stroop Procedure (MSP), which included sexual abuse and nonsexual abuse stimuli. The MSP has not been previously used in child abuse research. Results indicated that sexually and physically abused children demonstrated PTSD at a high level. The MSP discriminated between the sexually abused children with PTSD and those without PTSD. Responses to the MSP sexual abuse stimuli resulted in significantly longer color-naming times than responses to nonsexual abuse stimuli. Preadolescents demonstrated more severe PTSD than early adolescent children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vibration analysis of initially curved single walled carbon nanotube with vacancy defect for ultrahigh frequency nanoresonators

Single walled carbon nanotubes (SWCNTs) are ideal choices for resonators due to its ultrahigh natural frequency. Fundamental frequency of resonators significantly affects their functionality and performance; therefore, an accurate prediction of SWCNTs’ natural frequency is vital for designing and developing such devices. In reality, CNTs are not straight and perfect; indeed, they have some degree of vacancy defect and waviness, which occurs during growth and manipulation processes. This research investigates for the first time the combination effects of both initial curvature and vacancy defects on vibrational behaviour of SWCNTs in order to make the simulation closer to the “real world”. In this study, an efficient method based on the molecular dynamics model and the finite element method is used to simulate wavy SWCNTs with vacancy defects. Zigzag carbon nanotube with chirality indices (5, 0) is considered. Accuracy of our modelling method is verified by comparing our results with the results obtained from previous studies in simulating ideal SWCNT natural frequency. The effects of vacancy, vacancy location, curvature and aspect ratio on natural vibration of the defected wavy SWCNTs have been investigated, and a parameter of critical waviness ratio has been defined for the first time to emphasize the combination effect of vacancies and waviness on the natural frequency of SWCNTs. Our results show that critical waviness is sensitive to the aspect ratio and indicate that by increasing the length of SWCNTs, the critical waviness ratio increases.     

The diffusion of technological knowledge through interlaced networks

In the last decade, many papers discussed the basic features of the networks formed by knowledge diffusion. In this paper, we show that a network formed by the spreading of technological information, represented by the patents citation network, does not obey the expected power law behavior and, therefore, is not a scale-free network. We mapped a network formed by almost 600 000 patents, covering a 40 years period. Although the complete network is not scale-free, small portions within the whole network can be described by power laws. The network combines several fields of knowledge, but those power law portions belong to specific fields of technological knowledge. A mathematical model is introduced, which can explain the basic dynamics of the formation of this network.     

Accelerating Time and Depth Seismic Migration by CPU and GPU Cooperation

In this paper, we discuss the porting strategy and the achieved performance of Petrobras production code that implements Kirchhoff prestack time and depth seismic migration algorithms on a cluster of 64 GPUs and 256 CPU cores. The time migration of a real-world survey was 20 times faster in the full cluster with GPUs than in the full cluster without GPUs. The introduction of GPUs accelerated the depth migration of another real-world survey by a factor of 5. In both cases, a large fraction of the achieved gains were due to the porting strategy that privileges CPU-GPU cooperation instead of pure GPU speed. Another strategy that contributed to the high gains was GPU overloading by multiple MPI processes. To cope with the heterogeneous load of real-world data, we developed a dynamic load balancing scheme that significantly speeds up computation.     

Role of surgical therapy in the treatment of refractory ascites

In 5-10% of cases ascites is not controlled by medical therapy and is defined refractory. These patients may be submitted to one of the four following surgical options: portal-systemic shunt, peritoneo-venous shunt, transjugular intrahepatic portal-systemic shunt, orthotopic liver transplantation. Although the portal-systemic shunt is efficient in clearing ascites, it does not improve the survival, which depends on liver function, and it is complicated by an important incidence of encephalopathy. Since the patients with refractory ascites and good hepatic risk are not usually many, it is possible to understand why derivative surgery has been disappointing with this indication. Although the peritoneo-venous shunt is associated with a significant rate of valve obstruction, it is an easy, effective and not expensive treatment. So, till now, it has been considered the first choice procedure of refractory ascites, if any situations, determinating the onset of postoperative complications, are not present. Recently a new method has been introduced in the therapy of portal hypertension, the transjugular intrahepatic portal-systemic shunt. This is a bloodless portal-systemic derivation and so it has caused great enthusiasm even if the available data are insufficient to give a definitive opinion on its role in management of ascites. Certainly the liver transplantation, which presents the great advantage to treat both the cirrhosis and its complications, seems to be the most rational therapy for these patients. However, at least for this moment, the well-known absence of organ donors makes still actual the palliative surgical measures.     

Nitric oxide participates in the corpus luteum regression in ovaries isolated from pseudopregnant rats

In previous reports we found that nitric oxide is involved in corpus luteum regression in the rat by increasing prostaglandin F2 alpha synthesis during the luteolytic phase. In the present study we were interested in determining whether nitric oxide synthase activity is modulated with the corpus luteum development. For this purpose ovarian tissues obtained from pseudopregnant rats at different stages of pseudopregnancy, early, middle, and late, were used. Working with different doses of two competitive nitric oxide synthase inhibitors, NG-monomethyl-L-arginine (L-NMMA) and aminoguanidine (AG), we investigated the possible role of endogenous nitric oxide in the regulation of prostaglandin F2 alpha production by rat ovaries in the three different phases mentioned. We found that nitric oxide synthase activity diminishes with the corpus luteum development and that the calcium-independent activity was the predominant form of this enzyme in all stages studied. Endogenous nitric oxide increased prostaglandin F2 alpha synthesis only during the late phase of the corpus luteum. In the study of the possible role of nitric oxide regulating ovarian steroidogenesis, we found that L-NMMA increased progesterone production and diminished prostaglandin F2 alpha synthesis in ovarian tissue from pseudopregnant rats in the late phase. These results suggest that nitric oxide could participate in the corpus luteum demise in the rat by modulating part of prostaglandin F2 alpha and progesterone production.     

Robot calibration using a 3D vision-based measurement system with a single camera

One of the problems that slows the development of off-line programming is the low static and dynamic positioning accuracy of robots. Robot calibration improves the positioning accuracy and can also be used as a diagnostic tool in robot production and maintenance. This work presents techniques for modeling and performing robot calibration processes with off-line programming using a 3D vision-based measurement system. The measurement system is portable, accurate and low cost, consisting of a single CCD camera mounted on the robot tool flange to measure the robot end-effector pose relative to a world coordinate system. Radial lens distortion is included in the photogrammetric model. Scale factors and image centers are obtained with innovative techniques, making use of a multiview approach. Results show that the achieved average accuracy using a common off-the-shelf CCD camera varies from 0.2 to 0.4 mm, at distances from 600 to 1000 mm from the target, respectively, with different camera orientations. Experimentation is performed on two industrial robots to test their position accuracy improvement using the calibration system proposed: an ABB IRB-2400 and a PUMA-500. The robots were calibrated at different regions and volumes within their workspace achieving accuracy from three to six times better when comparing errors before and after calibration, if measured locally. The proposed off-line robot calibration system is fast, accurate and easy to set up.     

In2O3 microcrystals obtained from rapid calcination in domestic microwave oven

The simple way to prepare In₂O₃ microcrystals is reported in this paper. The precursor, In(OH)₃ microstructures, were obtained using the Microwave-Assisted Hydrothermal (MAH) Method. By annealing as-prepared In(OH)₃ precursor at 500 °C for 5 min in a domestic microwave oven (MO), In₂O₃ microcrystals were prepared, inheriting the morphology of their precursor while still slightly distorted and collapsed due to the In(OH)₃ dehydration process which was studied by thermal analysis. The In(OH)₃ and In₂O₃ were characterized using powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Raman spectroscopy. These techniques confirm the chemical dehydration of In(OH)₃ and the formation of In₂O₃ powders. The domestic MO promotes a rapid structural organization as compared with a CF (conventional furnace). The MAH method and the subsequent annealing in a domestic MO were shown to be a low cost route for the production of In₂O₃, with the advantages of lower temperature and smaller time.     

Morphology of Flux Avalanches in Patterned Superconducting Films

It is well known that under certain circumstances, magnetic fields applied perpendicularly to the plane of superconducting films can trigger flux avalanches. In such cases, the penetration has a tree-like profile. However, in samples where a regular array of antidots, ADs, is present, the avalanches follow the rows of ADs as if they were guiding lines for the abrupt penetration. In this work, we used the magnetooptical imaging technique to study the morphology of flux avalanches in two Nb films with a square lattice of square ADs, each one with a different lateral size, and a plain film for reference. We show that the morphology of the flux avalanches is greatly influenced by the size of the interstitial region.