Experimental evidence of early-time saturation of the ion-Weibel instability in counterstreaming plasmas of CH, Al, and Cu.

The collisionless ion-Weibel instability is a leading candidate mechanism for the formation of collisionless shocks in many astrophysical systems, where the typical distance between particle collisions is much larger than the system size. Multiple laboratory experiments aimed at studying this process utilize laser-driven (I≳10^{15} W/cm^{2}), counterstreaming plasma flows (V≲2000 km/s) to create conditions unstable to Weibel-filamentation and growth. This technique intrinsically produces temporally varying plasma conditions at the midplane of the interaction where Weibel-driven B fields are generated and studied. Experiments discussed herein demonstrate robust formation of Weibel-driven B fields under multiple plasma conditions using CH, Al, and Cu plasmas. Linear theory based on benchmarked radiation-hydrodynamic FLASH calculations is compared with Fourier analyses of proton images taken ∼5-6 linear growth times into the evolution. The new analyses presented here indicate that the low-density, high-velocity plasma-conditions present during the first linear-growth time (∼300-500 ps) sets the spectral characteristics of Weibel filaments during the entire evolution. It is shown that the dominant wavelength (∼300µm) at saturation persists well into the nonlinear phase, consistent with theory under these experimental conditions. However, estimates of B-field strength, while difficult to determine accurately due to the path-integrated nature of proton imaging, are shown to be in the ∼10-30 T range, an order of magnitude above the expected saturation limit in homogenous plamas but consistent with enhanced B fields in the midplane due to temporally varying plasma conditions in experiments.

Absolute dosimetric characterization of Gafchromic EBT3 and HDv2 films using commercial flat-bed scanners and evaluation of the scanner response function variability.

Radiochromic films (RCF) are commonly used in dosimetry for a wide range of radiation sources (electrons, protons, and photons) for medical, industrial, and scientific applications. They are multi-layered, which includes plastic substrate layers and sensitive layers that incorporate a radiation-sensitive dye. Quantitative dose can be retrieved by digitizing the film, provided that a prior calibration exists. Here, to calibrate the newly developed EBT3 and HDv2 RCFs from Gafchromic™, we used the Stanford Medical LINAC to deposit in the films various doses of 10 MeV photons, and by scanning the films using three independent EPSON Precision 2450 scanners, three independent EPSON V750 scanners, and two independent EPSON 11000XL scanners. The films were scanned in separate RGB channels, as well as in black and white, and film orientation was varied. We found that the green channel of the RGB scan and the grayscale channel are in fact quite consistent over the different models of the scanner, although this comes at the cost of a reduction in sensitivity (by a factor ∼2.5 compared to the red channel). To allow any user to extend the absolute calibration reported here to any other scanner, we furthermore provide a calibration curve of the EPSON 2450 scanner based on absolutely calibrated, commercially available, optical density filters.

El consumo de alcohol y/o drogas favorece la reincidencia en el traumatismo y reduce el período sin traumatismos / Alcohol and/or drug abuse favors trauma recurrence and reduces the trauma-free period

Objetivo Nuestro objetivo ha sido determinar la influencia del consumo de alcohol y/o drogas en la reincidencia de pacientes traumatizados y, en pacientes no reincidentes, analizar el papel de estas sustancias en el tiempo de aparición del primer episodio de traumatismo. Diseño Estudio observacional prospectivo. Ámbito Unidad de cuidados intensivos (UCI) de un hospital terciario. Pacientes traumatizados ingresados en UCI. Intervención Ninguna. Variables principales La reincidencia en el traumatismo se definió por antecedentes de traumatismo previo que requiriera atención médica. Se ha determinado la presencia de alcohol y otras drogas de abuso al ingreso tras un traumatismo grave. Resultados De los 166 pacientes con traumatismo ingresados en la UCI durante el período de estudio, se incluyeron 102 (87 hombres). Se detectó alguna sustancia en 51 pacientes (50%), alcohol (39%), cannabis (12%) y cocaína (7%). De los 102 pacientes, 42 eran reincidentes, de los cuales 32 (76%) dieron positivo a alguna sustancia y solo en 10 se obtuvieron resultados negativos (p<0,001). De los 60 pacientes no reincidentes, 19 (32%) dieron resultados positivos a alguna sustancia, estos últimos eran significativamente más jóvenes (34,3±9 años) que los 41 con resultados negativos (48±23 años) (p<0,001).Conclusión El consumo de alcohol y/o drogas aumenta la probabilidad de reincidencia en el traumatismo y adelanta en casi 15 años la presentación del primer traumatismo (AU)

Aim A study is made of the influence of alcohol and/or drug abuse upon traumatism o recurrence, with an analysis of the influence of such abuse upon the time to appearance of first injury in patients without antecedents of trauma. Design A prospective observational study was made. Setting Trauma patients admitted to the Intensive care Unit (ICU) of a University Hospital. Patients Trauma patients admitted to the ICU. Intervention None. Main measurements Trauma recurrence was defined by a history of previous trauma requiring medical care. The presence of alcohol and other drugs of abuse were determined upon admission after severe trauma. Results Out of the 166 trauma patients admitted to the ICU during the study period, 102 (87 males) were included in the study. Some substance was detected in 51 patients (50%), most frequently in the males (48/87, p<0.02). The most frequently detected substance was alcohol (39%), followed by cannabis (12%) and cocaine (7%), while more than one substance was found in 10 patients (9.8%). Of the 102 patients, 42 were recurrent trauma cases, and 32 (76%) of them were substance-positive, while only 10 were substance-negative (p<0.001). Of the 60 patients without antecedents of trauma, 19 (32%) were substance-positive, and these were significantly younger (34.3±9 years) than the 41 subjects who were substance-negative (48±23 years) (p<0.001).Conclusion Alcohol and/or drug abuse increases the likelihood of recurrent trauma and may shorten the mean trauma-free period among patients without a history of trauma by almost 15 years (AU)

Alcohol and/or drug abuse favors trauma recurrence and reduces the trauma-free period.

AIM: A study is made of the influence of alcohol and/or drug abuse upon traumatismo recurrence, with an analysis of the influence of such abuse upon the time to appearance of first injury in patients without antecedents of trauma. DESIGN: A prospective observational study was made. SETTING: Trauma patients admitted to the Intensive care Unit (ICU) of a University Hospital. PATIENTS: Trauma patients admitted to the ICU. INTERVENTION: None. MAIN MEASUREMENTS: Trauma recurrence was defined by a history of previous trauma requiring medical care. The presence of alcohol and other drugs of abuse were determined upon admission after severe trauma. RESULTS: Out of the 166 trauma patients admitted to the ICU during the study period, 102 (87 males) were included in the study. Some substance was detected in 51 patients (50%), most frequently in the males (48/87, p<0.02). The most frequently detected substance was alcohol (39%), followed by cannabis (12%) and cocaine (7%), while more than one substance was found in 10 patients (9.8%). Of the 102 patients, 42 were recurrent trauma cases, and 32 (76%) of them were substance-positive, while only 10 were substance-negative (p<0.001). Of the 60 patients without antecedents of trauma, 19 (32%) were substance-positive, and these were significantly younger (34.3±9 years) than the 41 subjects who were substance-negative (48±23 years) (p<0.001). CONCLUSION: Alcohol and/or drug abuse increases the likelihood of recurrent trauma and may shorten the mean trauma-free period among patients without a history of trauma by almost 15 years.

Attention training for school-aged children with ADHD: results of an open trial.

OBJECTIVE: The article discusses a feasibility study conducted to examine whether Pay Attention!, an intervention training sustained, selective, alternating, and divided attention, could be utilized in a clinical setting with children diagnosed with ADHD, and whether children who received the intervention made attention and executive functioning gains. METHOD: After a diagnostic and baseline evaluation, 23 school-aged children with ADHD participate in up to 16 sessions of Pay Attention! and the outcomes are evaluated. RESULTS: Results show the intervention is feasible to administer and acceptable to participants. Parents and clinicians rate fewer ADHD symptoms following the intervention and report improvements in executive function. Child performance on neuropsychological tests showed improvements in fluid reasoning and cognitive flexibility and working memory. CONCLUSION: The findings suggest that a randomized clinical trial of Pay Attention! is warranted to investigate its viability as a treatment for attention and executive functioning deficits in ADHD.

Effect of fluoxetine on contractile activity of pregnant rat uterine rings.

OBJECTIVE: We sought to compare the effects of fluoxetine, imipramine, and nortriptyline on spontaneous and serotonin-activated contractile activity of the uterine rings from midterm and term pregnant rats. STUDY DESIGN: Uterine rings from timed-pregnant Sprague-Dawley rats on day 14 (midgestation) and day 22 (term gestation) were used for isometric tension recording. Responses to cumulative concentrations of fluoxetine, imipramine, nortriptyline, and serotonin in the absence and presence of the monoamine reuptake inhibitors were studied. RESULTS: Neither of the monoamine reuptake inhibitors significantly influenced spontaneous contractile activity, whereas the concentration-dependent increase in activity induced by serotonin was inhibited in rings from both midterm and term pregnant rats. CONCLUSIONS: The reported increase in preterm delivery in women receiving fluoxetine during the third trimester cannot be explained by a direct effect on uterine contractility.

An alpha-actinin isoform which may cross-link intermediate filaments and microfilaments.

The G.3.5 antigen (named for the monoclonal antibody which recognizes it) has been characterized as an intermediate filament-associated protein found in a variety of tissue types, including human and rat astrocytes, rat skeletal and cardiac myocytes, fibroblasts, rat hepatocytes, and chicken and fish retinal tissues. Sequencing of proteolytic fragments indicated a high degree of similarity to alpha-actinin. Comparison of the G.3.5 antigen to alpha-actinin revealed that alpha-actinin and the G.3.5 antigen migrated similarly in reducing and non-reducing environments and had similar molecular masses (approximately 100,000). Overlay-immunoblotting assays indicated that the G.3.5 antigen and alpha-actinin could bind filamentous actin and desmin simultaneously. In contrast, immunocytochemistry indicated the G.3.5 antigen and alpha-actinin were immunologically distinct in tissue sections. The results of this study suggest that the G.3.5 antigen is an isoform of alpha-actinin which may serve to cross-link intermediate filaments to microfilaments, and that other isoforms of alpha-actinin may also share this property.

A novel intermediate filament-associated protein: further characterization of the G.3.5 antigen.

Several novel intermediate filament-associated proteins (IFAPs) have been discovered using hybridoma technology on multiple sclerosis plaque tissue. One of these, designated the G.3.5 antigen, is a desmin-binding IFAP in skeletal and cardiac muscle. It has been suggested that because of sequence similarities to alpha-actinin the G.3.5 antigen is an alpha-actinin-like protein which may cross-link actin and intermediate filaments in the cytoskeleton. In this study, it is reported that (1) the G.3.5 antigen is present in hepatocytes in addition to the previously described astrocytes, skeletal and cardiac myocytes, fibroblasts, and several other non-nervous tissues; (2) in myocytes and hepatocytes, the G.3.5 and alpha-actinins do not co-localize; (3) by transmission electron microscopy the G.3.5 antigen appears to be a rod-shaped dimer similar to alpha-actinin; (4) isolation of the G.3.5 antigen does not simultaneously isolate alpha-actinin; and (5) limited proteolysis of the G.3.5 antigen and alpha-actinin generates dissimilar maps. In binding studies, alpha-actinin cross-links actin but has no effect on desmin; the G.3.5 antigen does not appear to cross-link actin, desmin or mixtures of both under the assay conditions. These results support the hypothesis that the G.3.5 antigen is a novel IFAP related to alpha-actinin, but do not support a role for the antigen as a cross-linker between intermediate filaments and actin.