Accommodative movements of the choroid in the optic nerve head region of human eyes, and their relationship to the lens.

The ciliary muscle (CM) powers the accommodative response, and during accommodation the CM pulls the choroid forward in the region of the ora serrata. Our goal was to elucidate the accommodative movements of the choroid in the optic nerve region in humans and to determine whether these movements are related to changes in the lens dimensions that occur with aging, in the unaccommodated and accommodated state. Both eyes of 12 human subjects (aged 18-51 yrs) were studied. Homatropine (1 drop/5%) was used to relax the ciliary muscle (unaccommodated or "resting" eye) and pilocarpine was used to induce the maximum accommodative response (2 drops/4%) (accommodated eye). Images of the fundus and choroid were collected in the region of the optic nerve (ON) via Spectralis OCT (infrared and EDI mode), and choroidal thickness was determined. Ultrasound biomicroscopy (UBM; 50 MHz, 35 MHz) images were collected in the region of the lens/capsule and ciliary body. OCT and UBM images were collected in the resting and accommodated state. The unaccommodated choroidal thickness declined significantly with age (p = 0.0073, r = 0.73) over the entire age range of the subjects studied (18-51 years old). The choroidal thickness was significantly negatively correlated with lens thickness in the accommodated (p = 0.01) and the unaccommodated states (p = 0.005); the thicker the lens the thinner the choroid. Choroid movements around the optic nerve during accommodation were statistically significant; during accommodation the choroid both thinned and moved centrifugally (outward/away from the optic nerve head). The accommodative choroid movements did not decline significantly with age and were not correlated with accommodative amplitude. Measurement of the choroidal thickness is possible with the Spectralis OCT instrument using EDI mode and can be used to determine the accommodative changes in choroidal thickness. The choroidal thickness decreased with age and during accommodation. It may be that age-related choroidal thinning is due to changes in the geometry of the accommodative apparatus to which it is attached (i.e., ciliary muscle/lens complex) such that when the lens is thicker, the choroid is thinner. Accommodative decrease in choroidal thickness and stretch of the retina/choroid may indicate stress/strain forces in the region of the optic nerve during accommodation and may have implications for glaucoma.

Novel life cycle stages of Colpodella sp. (Apicomplexa) identified using Sam-Yellowe's trichrome stains and confocal and electron microscopy.

Colpodella spp. are free-living flagellates closely related to the apicomplexans. Human infections by Colpodella sp. have been reported. A biflagellated trophozoite and cyst stage comprise the known life cycle stages of Colpodella sp. However, the process of encystation and excystation within the life cycle is unclear. Life cycle stages initiating human infections are unknown. We performed a detailed investigation of the life cycle of Colpodella sp. (ATCC 50594) in culture using Sam-Yellowe's trichrome stains and differential interference contrast (DIC) for light microscopy and fluorescence microscopy of Congo red-stained cells and investigated ultrastructure using transmission electron microscopy (TEM). We report previously undocumented stages of Colpodella sp. Asymmetric and asynchronous division was detected inside cysts by trichrome staining and by TEM. Odd-numbered juveniles and cysts containing more than four juvenile trophozoites were identified. Live imaging of active cultures captured the excystation and egress of juvenile trophozoites and confirmed the presence of multinucleate cysts. The ultrastructure of the multinucleate cyst is reminiscent of apicomplexan schizonts. Insights gained from the life cycle stages observed in culture allowed the construction of the life cycle of Colpodella sp. Knowledge of the life cycle will aid biochemical and molecular characterization of Colpodella sp. and help identify stages in human infections.

A 0.43 g Wireless Battery-Less Neural Recorder With On-Chip Microelectrode Array and Integrated Flexible Antenna.

This work presents a single-chip battery-less neural recorder with 12 on-die microelectrodes. It can be powered wirelessly up to 16 cm away from a horn antenna at 915 MHz and only consumes 104 µW dc power for accessing 10 enabled recording sites simultaneously, transmitting at 5 Mbps. The implantable device integrated with a flexible antenna weighs only 0.43 gram. In vivo measurements on an unrestricted mouse have been successfully conducted, showing response to visual stimuli.

Easy Access to Energy Fluctuations in Nonequilibrium Quantum Many-Body Systems.

We combine theoretical and experimental efforts to propose a method for studying energy fluctuations, in particular, to obtain the related bistochastic matrix of transition probabilities by means of simple measurements at the end of a protocol that drives a many-body quantum system out of equilibrium. This scheme is integrated with numerical optimizations in order to ensure a proper analysis of the experimental data, leading to physical probabilities. The method is experimentally evaluated employing a two interacting spin-1/2 system in a nuclear magnetic resonance setup. We show how to recover the transition probabilities using only local measures, which enables an experimental verification of the detailed fluctuation theorem in a many-body system driven out of equilibrium.

Experimental Validation of Fully Quantum Fluctuation Theorems Using Dynamic Bayesian Networks.

Fluctuation theorems are fundamental extensions of the second law of thermodynamics for small systems. Their general validity arbitrarily far from equilibrium makes them invaluable in nonequilibrium physics. So far, experimental studies of quantum fluctuation relations do not account for quantum correlations and quantum coherence, two essential quantum properties. We here apply a novel dynamic Bayesian network approach to experimentally test detailed and integral fully quantum fluctuation theorems for heat exchange between two quantum-correlated thermal spins-1/2 in a nuclear magnetic resonance setup. We concretely verify individual integral fluctuation relations for quantum correlations and quantum coherence, as well as for the sum of all quantum contributions. We further investigate the thermodynamic cost of creating correlations and coherence.

Prevalence and Correlates of Sexual Violence Experienced by Young Adult Black Men Who Have Sex with Men.

Men who have sex with men (MSM) experience high prevalence of sexual violence (SV), and SV has well-documented effects on health. Research gaps are especially evident for young Black MSM (YBMSM), who experience significant HIV disparities and syndemics, including multiple forms of violence victimization. We examined lifetime prevalence of SV (having been forced or frightened into sexual activity) in a cross-sectional sample of YBMSM (N = 1732), and tested associations of demographic, psychosocial, and structural factors using multivariable regression. YBMSM were recruited between 2013 and 2015 using modified venue-based time-location sampling (e.g., at bars and clubs) in Dallas and Houston, Texas. Approximately 17% of YBMSM experienced any SV in their lifetimes. SV was associated with high school non-completion (OR 1.78; 95% CI 1.15-2.77), lower psychological resilience (OR 0.84; 95% CI 0.71-0.98), lifetime history of homelessness (OR 5.52; 95% CI 3.80-8.02), recent financial hardship (OR 2.16; 95% CI 1.48-3.14), and recent transactional sex (OR 3.87; 95% CI 2.43-6.15). We also examined differences by age of SV onset (childhood versus adulthood). YBMSM with adolescent/emerging adult-onset SV may have been more ambivalent in reporting lifetime SV experience, compared to men with childhood-onset SV, and correlates differed by age of onset. Childhood-onset SV was associated with high school non-completion, lower levels of psychological resilience, history of homelessness, recent financial hardship, and recent transactional sex. Adolescent/emerging adult-onset SV was associated with greater depressive symptoms, history of homelessness, and recent financial hardship. There is a need for multi-level approaches to SV prevention and treatment, including services and supports that are culturally-relevant and responsive to the needs of YBMSM.

New trichrome stains identify cysts of Colpodella sp. (Apicomplexa) and Bodo caudatus.

Colpodella species are free-living close relatives of apicomplexans that were recently reported to cause red blood cell infection in an immunocompromised human host and in a tick-borne human infection resulting in neurological symptoms. Unambiguous identification of the life cycle stages of Colpodella sp. using routine stains for light microscopy will aid rapid diagnosis in infections. Similarly, cells in culture and environmental samples can be rapidly identified by staining. Staining protocols are currently unavailable for cell detection by light microscopy. In this study, we investigated the feasibility of performing routine staining techniques for light microscopy for differentiating Colpodella sp. (ATCC 50594) and Bodo caudatus cysts in Hay medium cultures. We tested different basic and acidic dyes alone and in combination and also utilized a commercial trichrome staining protocol. The nonspecific fluorescent dye Calcofluor white was also evaluated. Staining times, dye concentrations, use of tap or distilled water rinses, use of a mordant and inclusion, or omission of decolorizers after staining were evaluated. We compared the intensity of color, clarity of morphological features, and cytoplasmic structures detected after staining. We report a new trichrome staining technique that allowed clear identification and differentiation of cyst stages of Colpodella sp. and B. caudatus. Immature Colpodella sp. cysts were identified as having an irregular, dual-colored (demilune), dark blue-purple and white appearance. Mature Colpodella sp. cysts stained dark red-blue and were identified in four-way mitotic division, while cysts of B. caudatus in diprotist or monoprotist (ATCC 30905) cultures were detected as spherical and red-pink in appearance.

Experimental Characterization of a Spin Quantum Heat Engine.

Developments in the thermodynamics of small quantum systems envisage nonclassical thermal machines. In this scenario, energy fluctuations play a relevant role in the description of irreversibility. We experimentally implement a quantum heat engine based on a spin-1/2 system and nuclear magnetic resonance techniques. Irreversibility at a microscope scale is fully characterized by the assessment of energy fluctuations associated with the work and heat flows. We also investigate the efficiency lag related to the entropy production at finite time. The implemented heat engine operates in a regime where both thermal and quantum fluctuations (associated with transitions among the instantaneous energy eigenstates) are relevant to its description. Performing a quantum Otto cycle at maximum power, the proof-of-concept quantum heat engine is able to reach an efficiency for work extraction (η≈42%) very close to its thermodynamic limit (η=44%).

Effect of a Community-Level HIV Prevention Intervention on Psychosocial Determinants of HIV Risk Behaviors among Young Black Men Who Have Sex with Men (YBMSM).

In contrast to intervention studies that assess psychosocial factors only as mediators or moderators of HIV risk, the present study assessed the effects of an Mpowerment-based community-level intervention on psychosocial determinants (e.g., depressive symptoms, sexual stigma) of HIV risk behavior among young black MSM. Approximately 330 respondents were surveyed annually for 4 years in each of two sites. General linear models examined change across time between the intervention and comparison communities, and participation effects in the intervention site. Social diffusion (spreading information within networks) of safer sex messages (p < 0.01) and comfort with being gay (p < 0.05) increased with time in intervention versus control. Cross-sectionally, intervention participants responded more favorably (p < 0.05) on social diffusion and depressive symptoms, but less favorably (p < 0.01) on sex in difficult situations and attitudes toward condom use. Findings suggest a need to address broader health issues of MSM as well as sexual risk.

A Person-Centered Approach to HIV-Related Protective and Risk Factors for Young Black Men Who Have Sex with Men: Implications for Pre-exposure Prophylaxis and HIV Treatment as Prevention.

Although young Black men who have sex with men (YBMSM) are disproportionately affected by HIV, they may be more heterogeneous as a group than is typically appreciated. Thus, the present study used a person-centered data-analytic approach to determine profiles of HIV-related risk among YBMSM and whether these profiles could be distinguished by age, HIV status, and socioeconomic risk (i.e., socioeconomic distress). YBMSM (N = 1808) aged 18 to 29 years completed a survey of sociodemographic characteristics, HIV status, and HIV-related behavioral and attitudinal factors (i.e., safer-sex self-efficacy, negative condom attitudes, being in difficult sexual situations, being in difficult sexual relationships, HIV treatment optimism, perceived HIV stigma). Latent profile analysis was used to identify HIV risk profiles and whether age, HIV status, and socioeconomic distress were associated with these profiles. Four profiles emerged: low-, medium-, and high-risk profiles, respectively, and a mixed profile characterized by a tendency to be in difficult sexual situations and relationships while also reporting high safer-sex self-efficacy and low negative attitudes toward condom use. Difficult sexual situations emerged as the key defining indicator of whether a profile reflected higher or lower risk. Younger age, being HIV-positive, and socioeconomic distress were associated with having a higher-risk profile. Given that unique risk profiles emerged that were differentially predicted by sociodemographic characteristics and HIV status, these findings have implications for tailoring interventions to the needs of different subgroups of YBMSM. Also, disempowering or risky sexual situations and relationships among YBMSM must be addressed.

Survey of medical malpractice cases and settlements with pathology or laboratory standard of care issues.

Medicolegal liability is an issue of concern for all physicians, including pathologists. Identification of the key clinical issues that tend to lead to medical malpractice litigation, as well as the settlement values for such claims, can be useful for prospective risk management. This review analyzes medical malpractice claims filed in state and federal courts as published in legal databases. Additionally, this review also analyzes the reported settlement values for such claims.

The Role of the Primary Romantic Relationship in HIV Care Engagement Outcomes Among Young HIV-Positive Black Men Who Have Sex with Men.

The primary romantic relationship plays a fundamental role in health maintenance, but little is known about its role in HIV care engagement among young Black men who have sex with men (MSM) living with HIV. We examined how HIV care engagement outcomes (i.e., having a primary healthcare provider, receiving HIV treatment, taking antiretroviral medication, and medication adherence) vary by partnership status (single vs. concordant-positive vs. discordant) in a sample of young Black MSM living with HIV. Results showed mixed findings. Partnership status was significantly associated with HIV care engagement, even after adjusting for individual, social, and structural factors. While partnered men were consistently more likely than their single counterparts to have a regular healthcare provider, to receive recent treatment, and to have ever taken antiretroviral medication, they were less likely to report currently receiving antiretroviral therapy. Moreover, men with a discordant partner reported better adherence compared to men with a concordant or no partner. The association between partnership status and HIV care engagement outcomes was not consistent across the stages of the HIV Care Continuum, highlighting the complexity in how and why young Black men living with HIV engage in HIV healthcare. Given the social context of HIV disease management, more research is needed to explicate underlying mechanisms involved in HIV care and treatment that differ by relational factors for young Black MSM living with HIV.

Online Aerial Terrain Mapping for Ground Robot Navigation.

This work presents a collaborative unmanned aerial and ground vehicle system which utilizes the aerial vehicle's overhead view to inform the ground vehicle's path planning in real time. The aerial vehicle acquires imagery which is assembled into a orthomosaic and then classified. These terrain classes are used to estimate relative navigation costs for the ground vehicle so energy-efficient paths may be generated and then executed. The two vehicles are registered in a common coordinate frame using a real-time kinematic global positioning system (RTK GPS) and all image processing is performed onboard the unmanned aerial vehicle, which minimizes the data exchanged between the vehicles. This paper describes the architecture of the system and quantifies the registration errors between the vehicles.

Kinetic Model Development for Accelerated Stability Studies.

Accelerated stability coupled with modeling to predict the stability of compounds, blends, and products at long-term storage conditions provides significant benefits in science-based decision-making throughout drug substance and drug product development. The study can often be completed, including data analysis in the space of three working weeks, and the information gathered and learning made in this time period can rival years of traditional analysis. The speed of the studies allows an earlier assessment of risk to quality enabling appropriate risk mitigation strategies to be implemented in a timely manner. The scientific foundation is based upon Arrhenius kinetic equations that can be linear or nonlinear in time, and can be based upon water vapor pressure or liquid water activity (relative humidity). A variety of kinetic models are evaluated, and the best model is chosen based upon both Bayesian information criteria and an automated assessment of kinetic model parameters fitting within acceptable ranges. Confidence intervals are estimated based upon a bootstrapping approach. Moisture vapor transmission rate models are applied on top of the resulting kinetic models in order to simulate different packaging types and the use of desiccant. The kinetic models are integrated with the prediction of packaging humidity over time to create a long-term prediction of impurities and other phenomena. The resulting models have been shown to be useful for not only the prediction of drug product impurities in long-term storage but other physical phenomena as well such as hydrate development and solvate loss.

Experimental Rectification of Entropy Production by Maxwell's Demon in a Quantum System.

Maxwell's demon explores the role of information in physical processes. Employing information about microscopic degrees of freedom, this "intelligent observer" is capable of compensating entropy production (or extracting work), apparently challenging the second law of thermodynamics. In a modern standpoint, it is regarded as a feedback control mechanism and the limits of thermodynamics are recast incorporating information-to-energy conversion. We derive a trade-off relation between information-theoretic quantities empowering the design of an efficient Maxwell's demon in a quantum system. The demon is experimentally implemented as a spin-1/2 quantum memory that acquires information, and employs it to control the dynamics of another spin-1/2 system, through a natural interaction. Noise and imperfections in this protocol are investigated by the assessment of its effectiveness. This realization provides experimental evidence that the irreversibility in a nonequilibrium dynamics can be mitigated by assessing microscopic information and applying a feed-forward strategy at the quantum scale.

The association between AIDS-related stigma and aggression toward gay men and lesbians.

This study examined whether self-identified race and prior contact with a gay man or lesbian moderate the association between AIDS-related stigma and aggression toward gay men and lesbians when controlling for sexual prejudice. A regional, community-recruited sample of 194 heterosexual men (50% Black, 50% White) completed measures of AIDS-related stigma, sexual prejudice, and prior contact with gay men and lesbians. Regression analyses showed that AIDS-related stigma was positively associated with aggression toward gay men and lesbians among White men who reported no prior contact, but not among White men who endorsed prior contact and Black men regardless of prior contact. Findings suggest that intergroup contact may be a key component to reducing the effects of AIDS-related stigma towards stigmatized groups. Implications for aggression theory and intervention are discussed. Aggr. Behav. 42:542-554, 2016. © 2016 Wiley Periodicals, Inc.

Dissolution curve comparisons through the F(2) parameter, a Bayesian extension of the f(2) statistic.

Dissolution (or in vitro release) studies constitute an important aspect of pharmaceutical drug development. One important use of such studies is for justifying a biowaiver for post-approval changes which requires establishing equivalence between the new and old product. We propose a statistically rigorous modeling approach for this purpose based on the estimation of what we refer to as the F2 parameter, an extension of the commonly used f2 statistic. A Bayesian test procedure is proposed in relation to a set of composite hypotheses that capture the similarity requirement on the absolute mean differences between test and reference dissolution profiles. Several examples are provided to illustrate the application. Results of our simulation study comparing the performance of f2 and the proposed method show that our Bayesian approach is comparable to or in many cases superior to the f2 statistic as a decision rule. Further useful extensions of the method, such as the use of continuous-time dissolution modeling, are considered.

Racial differences in sexual prejudice and its correlates among heterosexual men.

Previous research has consistently found sexual prejudice to be a predictor of antigay aggression and has also revealed specific correlates and antecedents of sexual prejudice. However, extant literature reveals mixed findings about potential racial group differences in sexual prejudice, and few studies have examined racial differences in the correlates of sexual prejudice. The aims of this descriptive study were to determine whether there are (a) racial group differences in reports of sexual prejudice and (b) racial group differences in previously identified correlates of sexual prejudice. Participants were 195 heterosexual males, ages 18 to 30 (98 Blacks and 97 Whites), recruited from a large metropolitan city in the southeastern United States. Based on cultural differences in the influence of religion and in attitudes about male sexuality, it was hypothesized that Black participants would report higher sexual prejudice than White participants. Additionally, based on cultural differences in racial views on masculinity and in sociocultural experiences of male gender roles, it was hypothesized that Blacks would report greater endorsement of religious fundamentalism and the traditional male role norm of status than Whites. Results confirmed all of the hypothesized racial differences and revealed additional differences, including a differential effect of the traditional male role norm of status on sexual prejudice, which explains, at least in part, the racial differences found in sexual prejudice. These findings may reflect underlying cultural differences between Black and White males and may aid in the development of future efforts to reduce sexual prejudice and consequently antigay aggression toward sexual minorities.