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The purpose of this study was to determine how initial HIV prevention efforts for homeless youth were received and to determine areas where homeless youth's beliefs and behaviors continue to put them at risk for HIV infection. Interviews were conducted with 289 Seattle homeless youth. Youth reported using condoms with casual partners during vaginal and anal sex and with clients during oral, anal and vaginal sex. Condoms are often not used during vaginal sex with main partners or during oral sex with casual or main partners. Knowledge of HIV protective strategies differed according to youth's behavioral characteristics with heterosexual youth having the weakest knowledge of HIV protective strategies especially compared with young men who have sex with men. There is room for improvement in youth's knowledge and beliefs about HIV. [ABSTRACT FROM AUTHOR]

Six states require health plans to provide or authorize second medical opinions (SMOs). The intent of such legislation is to preserve consumer choice, to improve the flow of information, and to improve health outcomes in this era of managed care. However, it is unclear who benefits from these laws. This paper reviews the changing role of second opinions and, using a nationally representative data set from the Commonwealth Fund, examines who gets them. Of persons who had visited a doctor in the previous year, 19 percent received a second opinion, for an estimated cost of $3.2 billion in 1994. Findings suggest that cultural norms and sociocultural factors may partially determine who may benefit from SMO legislation. [ABSTRACT FROM AUTHOR]

Ultrasmall gold nanoparticles were functionalized with peptides of two to seven amino acids that contained one cysteine molecule as anchor via a thiol-gold bond and a number of alanine residues as nonbinding amino acid. The cysteine was located either in the center of the molecule or at the end (C-terminus). For comparison, gold nanoparticles were also functionalized with cysteine alone. The particles were characterized by UV spectroscopy, differential centrifugal sedimentation (DCS), high-resolution transmission electron microscopy (HRTEM), and small-angle X-ray scattering (SAXS). This confirmed the uniform metal core (2 nm diameter). The hydrodynamic diameter was probed by 1 H-DOSY NMR spectroscopy and showed an increase in thickness of the hydrated peptide layer with increasing peptide size (up to 1.4 nm for heptapeptides; 0.20 nm per amino acid in the peptide). 1 H NMR spectroscopy of water-dispersed nanoparticles showed the integrity of the peptides and the effect of the metal core on the peptide. Notably, the NMR signals were very broad near the metal surface and became increasingly narrow in a distance. In particular, the methyl groups of alanine can be used as probe for the resolution of the NMR spectra. The number of peptide ligands on each nanoparticle was determined using quantitative 1 H NMR spectroscopy. It decreased with increasing peptide length from about 100 for a dipeptide to about 12 for a heptapeptide, resulting in an increase of the molecular footprint from about 0.1 to 1.1 nm 2 .

Objective: To analyze the impact of Resolution 2.173/2017 of the Federal Council of Medicine on results from the Central Estadual de Transplantes de Santa Catarina., Methods: This was a cross-sectional observational study of medical records of all patients (1,605) with suspected brain death notified to the Central Estadual de Transplantes de Santa Catarina; for this study, procedures to confirm this diagnosis were initiated between July 2016 and December 2017 and between January 2018 and June 2019. The median duration of the protocol in each period was considered for the comparison between the intervals. The collected data were transformed into rates (per million population). The mean rates for the periods before and after the implementation of the protocol were analyzed by Student's t-test, and qualitative variables were analyzed by Pearson's chi-squared test., Results: The mean duration of brain death confirmation procedures decreased more than 1 hour in the second period compared to the first period, with statistical significance (p = 0.001). The rates of harvested livers and transplanted pancreas, the number of notifications by hospital size and the rate of cardiac arrest in the macro-region of the Itajaí Valley were significantly different between the two periods., Conclusion: In the period after the new resolution on brain death, there was a reduction in the duration for diagnosis. However, other indicators did not change significantly, providing evidence for the multidimensional nature of the organ transplantation process in Santa Catarina and the need for further studies to better understand and optimize the process.

Processes related to eruptions at arc volcanoes are linked by structures that transect the entire crust. Imaging the mid- to lower-crustal portions (here, ~5-15 km and >15 km respectively) of these magmatic systems where intermediate storage may occur has been a longstanding challenge. Tomography, local seismic source studies, geodetic, and geochemical constraints, are typically most sensitive to shallow (<5 km) storage and/or have insufficient resolution at these depths. Geophysical methods are even further limited at frequently-erupting volcanoes where well-developed trans-crustal magmatic systems are likely to exist, due to a lack of deep seismicity. Here we show direct evidence for mid-crustal magma storage beneath the frequently erupting Cleveland volcano, Alaska, using a novel application of seismic receiver functions. We use P-s scattered waves from the Moho as virtual sources to investigate S-wave velocities between the Moho and the surface. Our forward modeling approach allows us to provide direct constraints on the geometry of low velocity regions beneath volcanoes despite having a comparatively sparse seismic network. Our results show clear evidence of mid-crustal magma storage beneath the depths of located volcanic seismicity. Future work using similar approaches will enable an unprecedented comparative examination of magmatic systems beneath sparsely instrumented volcanoes globally.

Objective: To determine whether topical hypotensive medications prevent postoperative ocular hypertension (POH) after phacoemulsification., Animals Studied: 52 client-owned dogs (88 eyes)., Procedures: Diabetic and nondiabetic dogs having undergone phacoemulsification were included in this retrospective study. The control group received no ocular hypotensive medications. The treatment groups received latanoprost, dorzolamide, or dorzolamide/timolol, beginning immediately after surgery, for 2-week duration. IOPs were obtained at initial examination followed by 4 h, 24 h, 7 days, and 14 days postoperatively. POH was defined as an IOP above 20 mmHg (POH20) or 25 mmHg (POH25)., Results: POH20 occurred in 33 of 87 eyes (37.93%), including 11 of 21 eyes (52.38%) in the control group, three of 23 eyes (13.04%) in the latanoprost group, eight of 15 eyes (53.33%) in the dorzolamide group, and 11 of 28 eyes (39.29%) in the dorzolamide/timolol group. Active treatment groups were compared to the control group, and the overall group effect was not significant (P = 0.11). POH25 occurred in 22 of 86 eyes (25.58%), including seven of 21 eyes (33.33%) in the control group, two of 23 eyes (8.70%) in the latanoprost group, five of 15 eyes (33.33%) in the dorzolamide group, and eight of 27 eyes (29.63%) in the dorzolamide/timolol group. Active treatment groups were compared to the control group, and the overall group effect was not significant (P = 0.31). Intraoperative use of intracameral tissue plasminogen activator significantly decreased the chances of POH25 (P = 0.0063)., Conclusions and Clinical Relevance: The latanoprost group had a substantially lower percentage of POH 20 and POH25 compared to the control and other active treatment groups, although statistical significance was not achieved. Intraoperative intracameral tissue plasminogen activator decreased the incidence of POH25., (© 2017 American College of Veterinary Ophthalmologists.)

The industrial plasticizer bisphenol A (BPA) is a ubiquitous endocrine disruptor to which the general human population is routinely exposed. Although BPA is well known as an estrogenic mimic, there have been some suggestions that this compound may also alter activity at the androgen receptor. To determine whether BPA does have antiandrogenic properties, we evaluated BPA effects in the spinal nucleus of the bulbocavernosus and dorsolateral nucleus, sexually dimorphic groups of motor neurons in the lumbar spinal cord that are critically dependent on androgens for survival and maintenance, as well as the monomorphic retrodorsolateral nucleus. In experiment 1, we administered varying concentrations of BPA to juvenile rats pre- and postnatally and examined both the number and size of motor neurons in adulthood. In experiment 2, different doses of BPA were given to adult rats for 28 days, after which the soma size of motor neurons were measured. Although no effect of BPA on neural survival or soma size was noted after perinatal BPA exposure, BPA exposure did result in a decrease in soma size in all motor neuron pools after chronic exposure in adulthood. These findings are discussed with regard to putative antiandrogenic effects of BPA; we argue that BPA is not antiandrogenic but is acting through nonandrogen receptor-dependent mechanisms.

Flat-slab subduction occurs when the descending plate becomes horizontal at some depth before resuming its descent into the mantle. It is often proposed as a mechanism for the uplifting of deep crustal rocks ('thick-skinned' deformation) far from plate boundaries, and for causing unusual patterns of volcanism, as far back as the Proterozoic eon. For example, the formation of the expansive Rocky Mountains and the subsequent voluminous volcanism across much of the western USA has been attributed to a broad region of flat-slab subduction beneath North America that occurred during the Laramide orogeny (80-55 million years ago). Here we study the largest modern flat slab, located in Peru, to better understand the processes controlling the formation and extent of flat slabs. We present new data that indicate that the subducting Nazca Ridge is necessary for the development and continued support of the horizontal plate at a depth of about 90 kilometres. By combining constraints from Rayleigh wave phase velocities with improved earthquake locations, we find that the flat slab is shallowest along the ridge, while to the northwest of the ridge, the slab is sagging, tearing, and re-initiating normal subduction. On the basis of our observations, we propose a conceptual model for the temporal evolution of the Peruvian flat slab in which the flat slab forms because of the combined effects of trench retreat along the Peruvian plate boundary, suction, and ridge subduction. We find that while the ridge is necessary but not sufficient for the formation of the flat slab, its removal is sufficient for the flat slab to fail. This provides new constraints on our understanding of the processes controlling the beginning and end of the Laramide orogeny and other putative episodes of flat-slab subduction.

Introduction: Despite improvement in the computational capabilities of visual displays in flight simulators, intersensory visual-vestibular conflict remains the leading cause of simulator sickness (SS). By using galvanic vestibular stimulation (GVS), the vestibular system can be synchronized with a moving visual field in order to lessen the mismatch of sensory inputs thought to result in SS., Methods: A multisite electrode array was used to deliver combinations of GVS in 21 normal subjects. Optimal electrode combinations were identified and used to establish GVS dose-response predictions for the perception of roll, pitch, and yaw. Based on these data, an algorithm was then implemented in flight simulator hardware in order to synchronize visual and GVS-induced vestibular sensations (oculo-vestibular-recoupled or OVR simulation). Subjects were then randomly exposed to flight simulation either with or without OVR simulation. A self-report SS checklist was administered to all subjects after each session. An overall SS score was calculated for each category of symptoms for both groups., Results: The analysis of GVS stimulation data yielded six unique combinations of electrode positions inducing motion perceptions in the three rotational axes. This provided the algorithm used for OVR simulation. The overall SS scores for gastrointestinal, central, and peripheral categories were 17%, 22.4%, and 20% for the Control group and 6.3%, 20%, and 8% for the OVR group, respectively., Conclusions: When virtual head signals produced by GVS are synchronized to the speed and direction of a moving visual field, manifestations of induced SS in a cockpit flight simulator are significantly reduced.

Galvanic stimulation has long been used as a nonmechanical means of activating the vestibular apparatus through direct action on the vestibular nerve endings. This stimulation has been reported to be safe, but no studies have examined the potential changes in the corresponding cochlear receptors. The aim of the present study was to evaluate the effect of galvanic vestibular stimulation (GVS) on distortion product otoacoustic emissions (DPOAEs). Fourteen subjects underwent DPOAEs during several conditions of GVS. The DPOAEs ranged from ∼ 1 kHz to ∼ 8 kHz at 65/55 dB for f1/f2 and with an f2/f1 ratio of 1.2. The subjects were evaluated at 10 stimulation conditions that ranged from -2.0 mA to +2.0 mA for each frequency. Statistical analysis showed no significant differences in DPOAE amplitudes for all conditions with and without GVS. Results also showed no significant differences between DPOAE amplitudes before and after GVS. Multivariate analysis found subject variability in DPOAE amplitude, which was not thought to be GVS related. Results indicated that GVS produced neither temporary nor permanent changes in DPOAEs.

Background: A few studies in the literature have reported postural changes with hypoxia, but none have quantified the magnitude of change. Further understanding of this condition could have implications for patients at risk for falls, individuals undergoing acute altitude exposure, and pilots and commercial passengers. The objective of this study was to evaluate the effect of different levels of hypoxia (oxygen nitrogen mixtures) on postural standing balance using the computerized dynamic posturography (CDP) system. This improves upon previous protocols by manipulating vision and standing balance with a sway-referenced visual field and/or platform. Additionally, normative data were available for comparison with the cumulative test scores and scores for each condition., Methods: Altitude hypoxia was simulated by use of admixing nitrogen to the breathing gas to achieve equivalent altitudes of 1524 m, 2438 m, and 3048 m. Subjects were evaluated using the CDP system., Results: Subjects showed an overall trend toward decreased performance at higher simulated altitudes consistent with the initial hypothesis. Composite standing balance sway scores for the sensory organization subtest of CDP were decreased compared to baseline for simulated altitudes as low as 2438 m (mean sway scores: 81.92 at baseline; 81.85 at 1524 m; 79.15 at 2438 m; 79.15 at 3048 m). Reaction times to unexpected movements in the support surface for the motor control subtest (MCT) increased compared to baseline (mean composite scores: 133.3 at baseline; 135.9 ms at 1524 m; 138.0 ms at 2438 m; 140.9 ms at 3048 m)., Conclusions: The CDP testing provided a reliable objective measurement of degradation of balance under hypoxic conditions.

Purpose: Given stereotypes of older adults, there is the perception that older adults will not use health information technologies. One concern is that practitioners might shy away from providing older patients with health information, and in particular, computerized information. The study's primary objective was to evaluate whether a health information intervention had a differential effect for people of different ages., Design and Methods: Quasi-experimental survey data from an assessment of a communitywide informational intervention were used. People were asked about their use of medical reference books, telephone advice nurses, or computers for health information in the past few months. In total, 5,909 surveys were completed., Results: The data show that older adults were no less likely (and were sometimes more likely) to use health information as a result of the intervention than younger adults. For telephone advice nurses and computers, the effect of the intervention was not significantly different for the different age groups. Yet, compared with persons 18-29 years of age, those over the age of 65 had a 17-percentage point increase in using a self-care book., Implications: We find convincing evidence to counter the stereotype that older adults are resistant to trying new health information technologies.