Assistive technology including virtual reality and augmented reality has gained interest as a novel intervention in a range of clinical settings. This technology has the potential to provide mental stimulation, a connection to autobiographical memory through reminiscence, and enhanced quality of life (QoL) to people living with dementia (PLWD) and mild cognitive impairment (MCI). In this mini-review, we examine the available evidence from studies reporting on the potential benefits of virtual and augmented reality to provide enjoyable, leisurely activities that may promote QoL and psychological well-being and facilitate social interaction. In total, 10 studies of varying study designs and durations (5 min to 6 months) using virtual (n = 9) and augmented reality (n = 1) were examined in PLWD (n = 6) and MCI (n= 3), in addition to 1 study that included participants with both conditions. Overall, the virtual experiences were enjoyed by the participants, improved their mood and apathy, and were preferred when compared with nonvirtual experiences. However, small sample sizes and variations in study design limit the generalizability of the results. Nevertheless, the use of virtual and augmented reality technology for PLWD and MCI is a novel and emerging method which may provide cognitive stimulation and improve well-being. Future research should explore the potential application of this technology to promote social interaction in both the community and aged care settings. We suggest future studies in PLWD and MCI assess the effects of more sustained use of virtual and augmented reality technology on psychological outcomes including QoL, apathy, and depressive symptoms, with the incorporation of physiological biomarker outcomes.

Polarimetric remote sensing of structures in geophysical media is studied in this paper based on their symmetry properties. Orientations of spheroidal scatterers described by spherical, uniform, planophile, plagiothile, erectophile, and extremophile distributions are considered to derive their polarimetric backscattering characteristics. These distributions can be identified from the observed scattering coefficients by comparison with theoretical symmetry calculations. A new parameter is defined to study scattering structures in geophysical media. Experimental observations from polarimetric data acquired by the Jet Propulsion Laboratory airborne synthetic aperture radar over forests, sea ice, and sea surface are presented to illustrate the use of symmetry properties. For forests, the coniferous forest in Mount Shasta area and mixed forests near Presque Isle show evidence of the centrical symmetry at C band. In sea ice from the Beaufort Sea, multiyear sea ice has a cross‐polarized ratio e close to e0, calculated from symmetry, due to the randomness in the scattering structure. For first‐year sea ice, e is much smaller than e0 as a result of preferential alignment of the columnar structure of the ice. From polarimetric data of a sea surface in the Bering sea, it is observed that e and e0 are increasing with incident angle and e is greater than e0 at L band because of the directional feature of sea surface waves. Use of symmetry properties of geophysical media for polarimetric radar calibration is also suggested.

Background Personal care products may contain many chemicals, some of which are suspected endocrine disrupters. This is an important source of chemical exposure for women, but little is known about how chemical exposure differs among different races/ethnicities. Objective This study examines differences in personal care product use among Black, Latina, Vietnamese, Mixed Race, and White women in California. Methods We used a community-based participatory process to create and administer a personal care product usage survey to 321 Black, Latina, Vietnamese, Mixed Race, and White women. We used multivariate regression models with pairwise comparisons to examine the frequency of product use by race/ethnicity. Results We found distinct trends of personal care product use by race/ethnicity: Latina women typically used makeup most frequently; Black women used certain hair products or styles most frequently; and Vietnamese women were most likely to use facial cleansing products compared to other races/ethnicities. Latina and Vietnamese women were less likely to try to avoid certain ingredients in their products. Significance These findings can help estimate disparities in chemical exposure from personal care product use and complement future research on health inequities due to chemical exposures in the larger environmental and social context.

Consider a multiperiod airline overbooking problem that relates to a single-leg flight and a single service class. Passengers may cancel their reservations at any time, including being no-shows at flight-time. At that time, the airline bumps passengers in excess of flight capacity and pays a penalty for so doing. We give conditions on the fares, refunds, and distributions of passenger demand for reservations and cancellations in each period, and on the bumping penalty function, that ensure that a booking-limit policy is optimal, i.e., in each period the airline accepts reservation requests up to a booking limit if the number of initial reservations is less than that booking limit, and declines reservation requests otherwise. The optimal booking limits are easily computed. We give conditions under which the optimal booking limits are monotone in the time to flight departure. The model is applied to the discount allocation problem in which lower fare classes book prior to higher fare classes. E ffective yield management can save airlines hundreds of millions of dollars each year (Smith et al. 1992). Two of the more important among the airline yield management problems are the overbooking and the seat-or discount-allocation problems. In this paper we introduce two closely related models that address the airline overbooking problem for a single-leg flight with a single fare class. The second model can also be applied to the seatallocation problem in which the airline determines when to refuse reservation requests from lower fare class customers in order to protect seats for subsequent requests from higher fare classes.The two overbooking models presented in this paper are dynamic in nature and include customer reservation requests, cancellations, and no-shows explicitly. They are dynamic because in determining the booking rules the models consider not only the reservations currently on hand and the likelihood of such reservations canceling prior to flight time or being a no-show at flight time, but also the possibility of future customer reservation requests and subsequent cancellations.While dynamic models of airline (and the related hotel) overbooking have been presented previously, in this paper we extend the earlier work by developing the theory of the structure of the optimal solution. The major advance is an investigation of the circumstances under which a bookinglimit policy is optimal, i.e., in each period the airline accepts reservation requests up to a booking limit if the number of initial reservations is less than that booking limit, and declines reservation requests otherwise. By applying the theory of total positivity we are able to give sufficient conditions for the optimality of booking limit policies. These conditions are less restrictive than those imposed by previous researchers, and the results obtained are more powerful. For example, we allow the distribution of requests for reservations to depend on the number of current bookings, and we allow for more general cancellation distributions than sim...

Youths and adolescents are vulnerable to HIV/STIs from unprotected sex. Promotion of young population’s awareness about risky sexual behaviors is essential to develop contextualized interventions. A cross-sectional study was conducted in five Vietnamese provinces to document current attitudes and practices regarding sexual behaviors among youths. The information on sociodemographic characteristics, substance use, and sexual behaviors was collected via self-reported questionnaires. The factors associated with risky sexual behaviors were identified by the multivariate logistic regression. Among the 1200 participants, 73.5% reported having sex in their lifetime, and 48.1% used condoms at their latest sexual intercourse. Participants in urban areas were more likely not to intend to use condoms and had a higher unintended pregnancy rate than in rural areas. Older age was positively associated with not wanting to use and not using condoms. Substance-using participants were more likely to not use condoms. The participants taking alcohol or other stimulants before sex had a higher likelihood of unintended pregnancy. Respondents’ attitudes and practices regarding sexual behaviors were associated with gender and employment. This study indicated that young population’s awareness in Vietnam is high, however, risky sexual behaviors also remain common. Sex-related educational programs about the consequences of substance use, multiple sex partners, and unprotected sex should be developed.