Examining Psychologist Prescriptive Authority as a Cost-Effective Strategy for Reducing Suicide Rates.

Six states (NM, LA, IL, IA, ID, CO) grant prescriptive authority to qualified psychologists, and research has shown that these policies are associated with a reduction in suicides. In this study, we assess the cost-effectiveness of these policies in reducing suicide rates. This study used a Markov Model with a time horizon of 20 years to estimate the incremental net monetary benefit (INMB) of the policy from the societal perspective with a simulated cohort of 100,000 people. Transition probabilities and utilities were collected from the literature, and costs were assessed using a mixed macro-micro costing approach. Using this approach, we found that the 20-year INMB for the policy was estimated to be $12.81 million ($USD) per quality-adjusted life year (QALY). The probability of cost-effectiveness was greater than 50% at a willingness-to-pay threshold as low as $10,000 per QALY. The probability of cost-effectiveness was only modestly associated with the implementation costs of the policy, but was sensitive to the estimated effect of the policy intervention. The models estimated in this study support prescriptive authority for psychologists as a cost-effective strategy for reducing state-level suicide rates. A considerable amount of research is needed to understand the impact of this policy with finer granularity.

A mind in motion: Exercise improves cognitive flexibility, impulsivity and alters dopamine receptor gene expression in a Parkinsonian rat model.

Cognitive impairment, particularly deficits in executive function (EF) is common in Parkinson's disease (PD) and may lead to dementia. There are currently no effective treatments for cognitive impairment. Work from our lab and others has shown that physical exercise may improve motor performance in PD but its role in cognitive function remains poorly eludicated. In this study in a rodent model of PD, we sought to examine whether exercise improves cognitive processing and flexibility, important features of EF. Rats received 6-hydroxydopamine lesions of the bilateral striatum (caudate-putamen, CPu), specifically the dorsomedial CPu, a brain region central to EF. Rats were exercised on motorized running wheels or horizontal treadmills for 6-12 weeks. EF-related behaviors including attention and processing, as well as flexibility (inhibition) were evaluated using either an operant 3-choice serial reaction time task (3-CSRT) with rule reversal (3-CSRT-R), or a T-maze task with reversal. Changes in striatal transcript expression of dopamine receptors (Drd1-4) and synaptic proteins (Synaptophysin, PSD-95) were separately examined following 4 weeks of exercise in a subset of rats. Exercise/Lesion rats showed a modest, yet significant improvement in processing-related response accuracy in the 3-CSRT-R and T-maze, as well as a significant improvement in cognitive flexibility as assessed by inhibitory aptitude in the 3-CSRT-R. By four weeks, exercise also elicited increased expression of Drd1, Drd3, Drd4, synaptophysin, and PSD-95 in the dorsomedial and dorsolateral CPu. Our results underscore the observation that exercise, in addition to improving motor function may benefit cognitive performance, specifically EF, and that early changes (by 4 weeks) in CPu dopamine modulation and synaptic connectivity may underlie these benefits.

Language-based embedded performance validity measures in traumatic brain injury.

No studies to date have investigated the Boston Naming Test (BNT) as an embedded performance validity test (PVT). This study investigated the classification accuracy of the Boston Naming Test (BNT) and the Verbal Fluency Test (FAS and Animal Fluency), as embedded PVTs in a compensation-seeking mild traumatic brain injury (MTBI) sample (N = 57) compared to a non-compensation-seeking moderate-to-severe TBI (STBI) sample (N = 61). Participants in the MTBI sample who failed two or more PVTs were included, as were STBI participants who passed all PVTs. The classification accuracy of the individual tests and a logistically derived combined (LANGPVT) measure were studied. Results showed significant group differences (p < .05) on BNT, Animal Fluency, and LANGPVT between the MTBI and STBI groups. However, receiver operating characteristic (ROC) analyses indicated that only LANGPVT had acceptable classification accuracy (area under the curve > .70). Setting specificity at approximately .90, the recommended LANGPVT cutoff scores had sensitivity of .26. Results indicated that, similar to other embedded PVTs, these measures had low sensitivity when adequate specificity levels were maintained. However, extremely low scores on these measures are unlikely to occur in non-compensation-seeking, non-language-impaired, STBI cases.

Radiological safety at a broad scope radioactive materials license: Texas A&M University.

Operating a radiological safety program under a broad-scope license at a major research university introduces many elements not encountered by general or industrial licenses. This article outlines elements of the radiological safety program in place at Texas A&M University.

Recrafting the neighbor-joining method.

BACKGROUND: The neighbor-joining method by Saitou and Nei is a widely used method for constructing phylogenetic trees. The formulation of the method gives rise to a canonical Theta(n3) algorithm upon which all existing implementations are based. RESULTS: In this paper we present techniques for speeding up the canonical neighbor-joining method. Our algorithms construct the same phylogenetic trees as the canonical neighbor-joining method. The best-case running time of our algorithms are O(n2) but the worst-case remains O(n3). We empirically evaluate the performance of our algoritms on distance matrices obtained from the Pfam collection of alignments. The experiments indicate that the running time of our algorithms evolve as Theta(n2) on the examined instance collection. We also compare the running time with that of the QuickTree tool, a widely used efficient implementation of the canonical neighbor-joining method. CONCLUSION: The experiments show that our algorithms also yield a significant speed-up, already for medium sized instances.