Hazardous Drinkers and Drug Users in HMO Primary Care: Prevalence, Medical Conditions and Costs

Summarizes a study of the links between frequent heavy drinking and drug use and medical conditions, the frequency of hazardous drinkers' and drug users' primary care and psychiatry visits, and the resulting costs of their health care

Windows into Non-Euclidean Spaces

Two microlens arrays that are separated by the sum of their focal lengths form arrays of micro-telescopes. Parallel light rays that pass through corresponding lenses remain parallel, but the direction of the transmitted light rays is different. This remains true if corresponding lenses do not share an optical axis (i.e. if the two microlens arrays are shifted with respect to each other). The arrays described above are examples of generalized confocal lenslet arrays, and the light-ray-direction change in these devices is well understood [Oxburgh et al., Opt. Commun. 313, 119 (2014)]. Here we show that such micro-telescope arrays change light-ray direction like the interface between spaces with different metrics. To physicists, the concept of metrics is perhaps most familiar from General Relativity (where it is applied to spacetime, not only space, like it is here) and Transformation Optics [Pendry et al., Science 312, 1780 (2006)], where different materials are treated like spaces with different optical metrics. We illustrate the similarities between micro-telescope arrays and metric interfaces with raytracing simulations. Our results suggest the possibility of realising transformation-optics devices with micro-telescope arrays, which we investigate elsewhere

Predictability of biotic stress structures plant defence evolution

To achieve ecological and reproductive success, plants need to mitigate a multitude of stressors. The stressors encountered by plants are highly dynamic but typically vary predictably due to seasonality or correlations among stressors. As plants face physiological and ecological constraints in responses to stress, it can be beneficial for plants to evolve the ability to incorporate predictable patterns of stress in their life histories. Here, we discuss how plants predict adverse conditions, which plant strategies integrate predictability of biotic stress, and how such strategies can evolve. We propose that plants commonly optimise responses to correlated sequences or combinations of herbivores and pathogens, and that the predictability of these patterns is a key factor governing plant strategies in dynamic environments.</p

Substance abuse and HIV risk behaviours amongst primary health care service users in Cape Town

Objective: To document prevalence of, and association between, substance use and HIV risk behaviours among primary care patients.Method: Cross-sectional survey. Four primary care clinics in Cape Town. We selected clinics using stratified sampling, and systematically selected 131 patients from attendance logs. We assessed substance use with the Alcohol, Smoking and Substance Involvement Screening Test, and HIV risk with items addressing injection drug use, blood-sharing rituals, and sexual risk behaviours. Results: Substances most used at hazardous levels were tobacco (28.2%) and alcohol (14.8%). Among possible HIV risk factors, highest prevalence was participation in blood-sharing rituals (25%), and having had an STI (19.8%). An association between substance use and sexual risk behaviours was only found among those aged 18-24. Conclusion: In younger patients, presence of substance use or HIV risk behaviours increases the probability that the other is present. Keywords: substance abuse, HIV risk behaviours, primary care South African Psychiatry Review Vol. 8(4) 2005: 160-16

An early block in the replication of the atypical bluetongue virus serotype 26 in culicoides cells is determined by its capsid proteins

Arboviruses such as bluetongue virus (BTV) replicate in arthropod vectors involved in their transmission between susceptible vertebrate-hosts. The “classical” BTV strains infect and replicate effectively in cells of their insect-vectors (Culicoides biting-midges), as well as in those of their mammalian-hosts (ruminants). However, in the last decade, some “atypical” BTV strains, belonging to additional serotypes (e.g., BTV-26), have been found to replicate efficiently only in mammalian cells, while their replication is severely restricted in Culicoides cells. Importantly, there is evidence that these atypical BTV are transmitted by direct-contact between their mammalian hosts. Here, the viral determinants and mechanisms restricting viral replication in Culicoides were investigated using a classical BTV-1, an “atypical” BTV-26 and a BTV-1/BTV-26 reassortant virus, derived by reverse genetics. Viruses containing the capsid of BTV-26 showed a reduced ability to attach to Culicoides cells, blocking early steps of the replication cycle, while attachment and replication in mammalian cells was not restricted. The replication of BTV-26 was also severely reduced in other arthropod cells, derived from mosquitoes or ticks. The data presented identifies mechanisms and potential barriers to infection and transmission by the newly emerged “atypical” BTV strains in Culicoides.</p

Costs of care for persons with opioid dependence in commercial integrated health systems

BACKGROUND: When used in general medical practices, buprenorphine is an effective treatment for opioid dependence, yet little is known about how use of buprenorphine affects the utilization and cost of health care in commercial health systems. METHODS: The objective of this retrospective cohort study was to examine how buprenorphine affects patterns of medical care, addiction medicine services, and costs from the health system perspective. Individuals with two or more opioid-dependence diagnoses per year, in two large health systems (System A: n = 1836; System B: n = 4204) over the time span 2007–2008 were included. Propensity scores were used to help adjust for group differences. RESULTS: Patients receiving buprenorphine plus addiction counseling had significantly lower total health care costs than patients with little or no addiction treatment (mean health care costs with buprenorphine treatment = $13,578; vs. mean health care costs with no addiction treatment =$31,055; p < .0001), while those receiving buprenorphine plus addiction counseling and those with addiction counseling only did not differ significantly in total health care costs (mean costs with counseling only: $17,017; p = .5897). In comparison to patients receiving buprenorphine plus counseling, those with little or no addiction treatment had significantly greater use of primary care (p < .001), other medical visits (p = .001), and emergency services (p = .020). Patients with counseling only (compared to patients with buprenorphine plus counseling) used less inpatient detoxification (p < .001), and had significantly more PC visits (p = .001), other medical visits (p = .005), and mental health visits (p = .002). CONCLUSIONS: Buprenorphine is a viable alternative to other treatment approaches for opioid dependence in commercial integrated health systems, with total costs of health care similar to abstinence-based counseling. Patients with buprenorphine plus counseling had reduced use of general medical services compared to the alternatives