Radiation therapy strategies for skull-base malignancies.

INTRODUCTION: The management of skull base malignancies continues to evolve with improvements in surgical technique, advances in radiation delivery and novel systemic agents. METHODS: In this review, we aim to discuss in detail the management of common skull base pathologies which typically require multimodality therapy, focusing on the radiotherapeutic aspects of care. RESULTS: Technological advances in the administration of radiation therapy have led to a wide variety of different treatment strategies for the treatment of skull base malignances, with outcomes summarized herein. CONCLUSION: Radiation treatment plays a key and critical role in the management of patients with skull base tumors. Recent advancements continue to improve the risk/benefit ratio for radiotherapy in this setting.

Thermal Temperature Measurements of Inertial Fusion Implosions.

Accurate measurement of the thermal temperature in inertially confined fusion plasmas is essential for characterizing ignition performance and validating the basic physics understanding of the stagnation conditions. We present experimental results from cryogenic deuterium-tritium implosions on the National Ignition Facility using a differential filter spectrometer designed to measure the thermal electron temperature from x-ray continuum emission from the stagnated plasma. Furthermore, electron temperature measurements, used in conjunction with the Doppler-broadened DT neutron spectra, allow one to infer the partition of energy in the hot spot between internal energy and unconverted kinetic energy.

Improved Performance of High Areal Density Indirect Drive Implosions at the National Ignition Facility using a Four-Shock Adiabat Shaped Drive.

Hydrodynamic instabilities can cause capsule defects and other perturbations to grow and degrade implosion performance in ignition experiments at the National Ignition Facility (NIF). Here, we show the first experimental demonstration that a strong unsupported first shock in indirect drive implosions at the NIF reduces ablation front instability growth leading to a 3 to 10 times higher yield with fuel ρR>1 g/cm(2). This work shows the importance of ablation front instability growth during the National Ignition Campaign and may provide a path to improved performance at the high compression necessary for ignition.

Differential ablator-fuel adiabat tuning in indirect-drive implosions.

We propose a design adjustment to the high foot laser pulse [T. R. Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014)] that is predicted to lower the fuel adiabat, increase compression and neutron production, but maintain similar ablation front growth. This is accomplished by lowering the laser power between the first and the second pulses (the "trough") so that the first shock remains strong initially but decays as it transits the ablator and enters the capsule fuel in a process similar to direct-drive "adiabat shaping" [S. E. Bodner et al., Phys. Plasmas 7, 2298 (2000)]. Integrated hohlraum simulations show that hohlraum cooling is sufficient to launch decaying shocks with adequate symmetry control, suggesting that adiabat shaping may be possible with indirect-drive implosions. Initial experiments show the efficacy of this technique.

Reduced instability growth with high-adiabat high-foot implosions at the National Ignition Facility.

Hydrodynamic instabilities are a major obstacle in the quest to achieve ignition as they cause preexisting capsule defects to grow and ultimately quench the fusion burn in experiments at the National Ignition Facility. Unstable growth at the ablation front has been dramatically reduced in implosions with "high-foot" drives as measured using x-ray radiography of modulations at the most dangerous wavelengths (Legendre mode numbers of 30-90). These growth reductions have helped to improve the performance of layered DT implosions reported by O. A. Hurricane et al. [Nature (London) 506, 343 (2014)], when compared to previous "low-foot" experiments, demonstrating the value of stabilizing ablation-front growth and providing directions for future ignition designs.

2D X-ray radiography of imploding capsules at the national ignition facility.

First measurements of the in-flight shape of imploding inertial confinement fusion (ICF) capsules at the National Ignition Facility (NIF) were obtained by using two-dimensional x-ray radiography. The sequence of area-backlit, time-gated pinhole images is analyzed for implosion velocity, low-mode shape and density asymmetries, and the absolute offset and center-of-mass velocity of the capsule shell. The in-flight shell is often observed to be asymmetric even when the concomitant core self-emission is round. A ∼ 15 µm shell asymmetry amplitude of the Y(40) spherical harmonic mode was observed for standard NIF ICF hohlraums at a shell radius of ∼ 200 µm (capsule at ∼ 5× radial compression). This asymmetry is mitigated by a ∼ 10% increase in the hohlraum length.

Fighting obesity or obese persons? Public perceptions of obesity-related health messages.

OBJECTIVE: This study examined public perceptions of obesity-related public health media campaigns with specific emphasis on the extent to which campaign messages are perceived to be motivating or stigmatizing. METHOD: In summer 2011, data were collected online from a nationally representative sample of 1014 adults. Participants viewed a random selection of 10 (from a total of 30) messages from major obesity public health campaigns from the United States, the United Kingdom and Australia, and rated each campaign message according to positive and negative descriptors, including whether it was stigmatizing or motivating. Participants also reported their familiarity with each message and their intentions to comply with the message content. RESULTS: Participants responded most favorably to messages involving themes of increased fruit and vegetable consumption, and general messages involving multiple health behaviors. Messages that have been publicly criticized for their stigmatizing content received the most negative ratings and the lowest intentions to comply with message content. Furthermore, messages that were perceived to be most positive and motivating made no mention of the word 'obesity' at all, and instead focused on making healthy behavioral changes without reference to body weight. CONCLUSION: These findings have important implications for framing messages in public health campaigns to address obesity, and suggest that certain types of messages may lead to increased motivation for behavior change among the public, whereas others may be perceived as stigmatizing and instill less motivation to improve health.

Motivating or stigmatizing? Public perceptions of weight-related language used by health providers.

BACKGROUND: Research demonstrates that health providers express negative attitudes toward overweight and obese patients that can be conveyed through weight-related language, yet little is known about people's perceptions of weight-related language used by providers. The current study examined public preferences and perceptions of weight-based terminology used by health-care providers to describe excess weight. METHOD: A national sample of American adults (N=1064) completed an online survey to assess perceptions and preferences associated with 10 common terms to describe body weight. Participants rated how much they perceived each term to be desirable, stigmatizing, blaming or motivating to lose weight (using five-point Likert scales), and how they would react if stigmatized by their doctor's reference to their weight. RESULTS: The terms 'weight' (3.43, 95% confidence interval (CI) 3.35-3.50) and 'unhealthy weight' (3.24, 95% CI 3.15-3.33) were rated most desirable, and the terms 'unhealthy weight' (3.77, 95% CI 3.69-3.84) and 'overweight' (3.51, 95% CI 3.43-3.58) were rated most motivating to lose weight. The terms 'morbidly obese', 'fat' and 'obese' were rated as the most undesirable (95% CI 1.61-2.06), stigmatizing (95% CI 3.66-4.05) and blaming (95% CI 3.62-3.94) language used by health providers. Notably, participant ratings were consistent across socio-demographic variables and body weight categories. A total of 19% of participants reported they would avoid future medical appointments and 21% would seek a new doctor if they felt stigmatized about their weight from their doctor. CONCLUSION: This study advances our understanding of why individuals prefer particular weight-related terms, and how patients may react if their provider uses stigmatizing language to refer to their weight. It also offers suggestions for practical strategies that providers can use to improve discussions about weight-related health with patients.

Suppression of electron temperature gradient turbulence via negative magnetic shear in NSTX.

Negative magnetic shear is found to suppress electron turbulence and improve electron thermal transport for plasmas in the National Spherical Torus Experiment (NSTX). Sufficiently negative magnetic shear results in a transition out of a stiff profile regime. Density fluctuation measurements from high-k microwave scattering are verified to be the electron temperature gradient (ETG) mode by matching measured rest frequency and linear growth rate to gyrokinetic calculations. Fluctuation suppression under negligible E×B shear conditions confirm that negative magnetic shear alone is sufficient for ETG suppression. Measured electron temperature gradients can significantly exceed ETG critical gradients with ETG mode activity reduced to intermittent bursts, while electron thermal diffusivity improves to below 0.1 electron gyro-Bohms.

Perceived condom norms and HIV risks among social and sexual networks of young African American men who have sex with men.

The association between condom norms and unprotected sexual intercourse was examined within social and sexual networks of young African American men who have sex with men (MSM) in an HIV epicenter of the southern United States. We used a chain-link design to recruit 158 young African American men: 95 initial participants, 56 contacts of participants (alters) and 7 contacts of alters. Men in the high-risk group, compared with those in the no-risk group, perceived significantly lower approval concerning condom use in their social and sexual networks. Also, 100 participants could be connected to each other in 86 dyads of social and sexual networks. Within these dyads, men perceived that their friends and acquaintances approved for them to use condoms but that their friends and acquaintances did not use condoms themselves. Low HIV risk behavior appears associated with perceived social norms that support one's use of condoms, even when perceived norms do not support condom use by network members themselves.

A liquid metal flume for free surface magnetohydrodynamic experiments.

We present an experiment designed to study magnetohydrodynamic effects in free surface channel flow. The wide aspect ratio channel (the width to height ratio is about 15) is completely enclosed in an inert atmosphere to prevent oxidization of the liquid metal. A custom-designed pump reduces entrainment of oxygen, which was found to be a problem with standard centrifugal and gear pumps. Laser Doppler velocimetry experiments characterize velocity profiles of the flow. Various flow constraints mitigate secondary circulation and end effects on the flow. Measurements of the wave propagation characteristics in the liquid metal demonstrate the surfactant effect of surface oxides and the damping of fluctuations by a cross-channel magnetic field.

Predictors of HIV disclosure to secondary partners and sexual risk behavior among a high-risk sample of HIV-positive MSM: results from six epicenters in the US.

This study sought to identify predictors of HIV disclosure and serodiscordant unprotected anal intercourse (SDUAI) among HIV-positive men who have sex with men (MSM). Between January 2005 and April 2006, 675 HIV-positive MSM were recruited into the Positive Connections intervention trial held in six US cities with intentional over-sampling of HIV-positive MSM of Color (74%) and men engaging in unprotected anal intercourse (UAI) in the previous year. Baseline survey data showed 30 and 31%, respectively, of participants disclosed to none or some of their secondary sex partners in the last 90 days. Greater disclosure to secondary partners was associated with having fewer sexual partners, being extremely out as MSM, longer HIV diagnosis, knowledge of CD4 count, detectable viral load and being white. Disclosure to all secondary partners was associated with lower SDUAI. Recommendations for prevention for HIV-positive MSM include the promotion of serodisclosure to all secondary partners and increasing comfort with, and outness about, one's sexuality.

Modulation of aggrecan and ADAMTS expression in ovine tendinopathy induced by altered strain.

OBJECTIVE: To evaluate histologic, immunohistochemical, and molecular changes in tendon induced by altered strain in a large-animal model. METHODS: A full-thickness partial-width laceration of the infraspinatus tendon was created in 5 sheep, while 5 sham-operated sheep were used as controls. Sheep were killed after 4 weeks, and 4 differentially stressed tendon regions (tensile or near bone attachment from overstressed or stress-deprived halves) were evaluated for histopathology, proteoglycan (PG) accumulation, and characterization of glycosaminoglycans and aggrecan catabolites. Gene expression of matrix components, enzymes, and inhibitors was analyzed by reverse transcriptase-polymerase chain reaction. RESULTS: Histopathologic changes were detected in both overstressed and stress-deprived tensile tendon, but only in stress-deprived tendon near bone. In overstressed and stress-deprived tensile tendon, levels of keratan sulfate, chondroitin 4-sulfate, and chondroitin 6-sulfate were increased. In overstressed tensile tendon, levels of ADAMTS-generated aggrecan catabolites were increased. There was increased matrix metalloproteinase 13 (MMP-13) and decreased fibromodulin and decorin expression in all regions. Increased MMP-1, MMP-9, MMP-14, and ADAMTS-1 expression, and decreased type II collagen expression were restricted to stress-deprived tendon. In stress-deprived bone-attachment regions, messenger RNA (mRNA) for aggrecan was decreased, and ADAMTS was increased. In overstressed tensile tendon, aggrecan mRNA was increased, and ADAMTS was decreased. CONCLUSION: The distinct molecular changes in adjacent tissue implicate altered strain rather than humoral factors in controlling abnormal tenocyte metabolism, and highlight the importance of regional sampling. Tendon abnormalities induced by increased strain are accompanied by increased aggrecan, decreased ADAMTS, and low PG expression, which may negatively impact the structural integrity of the tissue and predispose to rupture.

Prevalence and correlates of HIV testing in a multi-site sample of young men who have sex with men.

This study assessed HIV testing among 2,621 urban young men who have sex with men (YMSM). Of these, 77% were men of colour, 30% reported recent unprotected anal intercourse (UAI), 22% had never tested for HIV and 71% had not tested recently. Ever testing was associated with older age (OR=1.28), being employed (OR=1.34), exposure to more types of HIV preventions (linear trend p=0.02), sex with a main partner (OR=1.92), sex with a non-main partner (OR=1.36), UAI with a non-main partner (OR=0.53), UAI in the last three months (OR=1.32), knowing a comfortable place for testing (OR=5.44) and social support (OR=1.47). Rates of ever testing increased with behavioural risk with main partners; rates were lowest for men reporting high-risk with non-main partners. Recent testing was associated with greater numbers of HIV-prevention exposures (linear trend p = <0.001), sex with a main partner (OR=1.30), knowing a comfortable place for testing (OR=2.31) and social support (OR=1.23). Findings underscore the urgency of promoting testing among YMSM, point to components for the recruitment and retention of young MSM of colour in testing programmes and highlight the need for a theory-based approach to intervention development.

Nicotine serves as a feature-positive modulator of Pavlovian appetitive conditioning in rats.

The present experiments examined whether a nicotine state could set the occasion for a pairing between visual cues and a rewarding outcome in rats. Following nicotine administration, presentation of a conditional stimulus (CS; light-on) was followed by brief access to a sucrose solution. When saline was administered, the same CS was presented but was not followed by any consequence. In Experiment 1, two groups assessed whether rats could acquire this Pavlovian feature-positive discrimination via different training procedures. An anticipatory food-seeking conditioned response (CR) developed during the CS on nicotine sessions but not on saline sessions in both groups. In Experiment 2, centrally acting antagonists of nicotinic acetylcholine and opiate receptors (mecamylamine and naloxone, respectively) dose-dependently blocked nicotine's control of the CR, whereas the peripherally acting nicotinic antagonist hexamethonium had no effect. Increasing or decreasing the interval between nicotine administration and testing also attenuated the CR. These results are consistent with the hypothesis that nicotine can occasion appetitive Pavlovian relations via its action at central nervous system cholinergic receptors.

A test system to evaluate the susceptibility of Oregon, USA, native stream invertebrataes to triclopyr and carbaryl.

The susceptibility of six indigenous macroinvertebrate species representative of U.S. Pacific Northwest streams (Ameletus sp., Brachycentrus americanus, Calineuria californica, Cinygma sp., Lepidostoma unicolor, Psychoglypha sp. early and late instar) to formulated triclopyr ester (herbicide) and carbaryl (insecticide) was determined using laboratory bioassays. Acute toxicity was expressed as the lethal concentration to 50% (LC50) and 1% (LC1) of the test population based on a 96-h exposure duration. Carbaryl was found to be 1,000 times more toxic than triclopyr for all the organisms tested. The LCI values (7.5, 28.8, 9.0, 3.0, 9.5, 14.8, 33.8 microg/L, respectively, for carbaryl and 1.8, 3.9, 4.0, 4.2, 29.0, 16.1 mg/L, respectively, for triclopyr) were used in the calculation of hazardous concentration to 5% of the stream macroinvertebrate community (HC5) based on the lower 95% confidence limit (HC5/95). The hazardous concentration (HC5/95) for triclopyr was 0.11 mg/L and for carbaryl ranged from 0.43 to 0.66 microg/L, respectively. Triclopyr and carbaryl symptomology were analyzed for two organisms, C. californica and Cinygma sp. Carbaryl symptomology included knockdown and moribund states with severity and time of appearance being a function of dose. In triclopyr poisoning, death occurred suddenly with little or no symptomology. Time to 50% mortality (LT50) values were consistently higher for C. californica than for Cinygma sp. exposed to both chemicals at similar concentrations.

Effect of varying pesticide exposure duration and concentration on the toxicity of carbaryl to two field-collected stream invertebrates, Calineuria californica (Plecoptera: Perlidae) and Cinygma sp (Ephemeroptera: Heptageniidae).

The effect of exposure duration on the toxicity of a forest insecticide (carbaryl) was assessed under environmentally realistic exposure regimes against two stream invertebrates indigenous to the United States Pacific Northwest, Calineuria californica (Plecoptera: Perlidae) and Cinygma sp. (Ephemeroptera: Heptageniidae). Laboratory bioassays were conducted to evaluate the relationship between pulsed exposures of 15, 30, and 60 min and toxicity for a range of chemical concentrations (10.2-1,730 microg/L). For Cinygma sp., the 50% lethal concentration (LC50) values were calculated as 848 microg/L (15 min), 220 microg/L (30 min), and 165 microg/L (60 min). The C. californica consistently had lower mortality at a given concentration compared with Cinygma sp. Fifteen- and 30-min exposures did not elicit 50% mortality with C. californica, and it had a 60-min LC50 of 1,139 microg/L. Time to 50% mortality over 96 h after a 15-, 30-, or 60-min exposure, with the rest of the test period in freshwater (PLT50), was a function of exposure duration and concentration. Analysis of symptomology throughout the test period for C. californica gave evidence of recovery from the knockdown and moribund states, but this was not the case for Cinygma sp. The pulse duration resulting in 50% mortality was calculated as 43 min for Cinygma sp. exposed at 204 microg/L and 16 min at 408 microg/L. A three-dimensional probit plane model [Y = -10.86 + 4.83(ln C) + 3.0(ln T)], where Y is probit mortality, C is concentration in microg/L and T is time in hours, was used to explain the interaction between concentration (microg/L) and duration of exposure (hours) for Cinygma sp.

A comparative evaluation of three self-rating scales for acute mania.

This study compared the performance of three self-rating mania scales, The Internal State Scale (ISS), the Self-Report Manic Inventory (SRMI), and the Altman Self-Rating Mania Scale (ASRM), in a group of patients with acute mania. Forty-four adult inpatients with bipolar disorder, manic or mixed, completed all scales shortly after admission, and 31 patients completed them again after 4-6 weeks of pharmacotherapy. Patients also were rated by clinicians on the Clinician-Administered Rating Scale for Mania (CARS-M). At baseline, scores on the ASRM and the ISS well-being subscale were significantly correlated with CARS-M scores. Posttreatment scores were significantly decreased for the ASRM, SRMI, and the ISS activation subscale. The sensitivities for each scale to correctly identify patients with acute symptoms was 45% for the ISS, 86% for the SRMI, and 93% for the ASRM. Specificities were 73%, 46.6%, and 33%, respectively. The ASRM and SRMI were more sensitive than the ISS in screening patients with acute mania. All three measures were sensitive to treatment effects; however, the item content of the SRMI and the poor sensitivity of the ISS may limit their utility in inpatient settings.

The application of signal detection theory to decision-making in forensic science.

Signal Detection Theory (SDT) has come to be used in a wide variety of fields where noise and imperfect signals present challenges to the task of separating hits and correct rejections from misses and false alarms. The application of SDT helps illuminate and improve the quality of decision-making in those fields in a number of ways. The present article is designed to make SDT more accessible to forensic scientists by: (a) explaining what SDT is and how it works, (b) explicating the potential usefulness of SDT to forensic science, (c) illustrating SDT analysis using forensic science data, and (d) suggesting ways to gain the benefits of SDT analyses in the course of carrying out existing programs of quality assessment and other research on forensic science examinations.

Finding the "community" in community-level HIV/AIDS interventions: formative research with young African American men who have sex with men.

Data from 76 qualitative interviews with 18- to 29-year-old African American men who have sex with men (MSM) in Chicago and Atlanta were examined to identify perceptions of "community" and components of a community-level HIV/AIDS intervention. Many men reported feeling marginal to African American and gay White communities because of perceived homophobia and racism. Those who reported feeling part of gay African American communities characterized communities in terms of settings, social structures, and functions, including social support, socialization, and mobility. Despite these positive functions, divisions among groups of MSM, lack of settings for nonsexual interaction with other MSM, lack of leadership, and negative attitudes toward homosexuality may make it difficult for men to participate in activities to alter community contexts that influence behavior. Rather, changing norms, increasing social support, and community building should be part of initial community-level interventions. Community building might identify leaders, create new settings, and create opportunities for dialogue between MSM and African American community groups to address negative perceptions of homosexuality.