Shoulder instability: evaluation with MR imaging.

Instability of the glenohumeral joint is a common cause of chronic shoulder pain and disability. One or more episodes of subluxation or dislocation may result in a tear, detachment, or attenuation of the glenoid labrum, stripping of the joint capsule from the scapula, or trauma to the tendons or muscles of the rotator cuff. A series of 27 shoulders examined with magnetic resonance (MR) imaging showed changes of glenohumeral instability, which were confirmed with open or arthroscopic surgery. MR imaging was capable of displaying common types of pathologic conditions resulting from instability, including labral trauma, capsular detachment, and retraction of the subscapularis muscle. MR imaging is a valuable diagnostic tool for the evaluation of glenohumeral instability

How active perception and attractor dynamics shape perceptual categorization: A computational model

We propose a computational model of perceptual categorization that fuses elements of grounded and sensorimotor theories of cognition with dynamic models of decision-making. We assume that category information consists in anticipated patterns of agent–environment interactions that can be elicited through overt or covert (simulated) eye movements, object manipulation, etc. This information is firstly encoded when category information is acquired, and then re-enacted during perceptual categorization. The perceptual categorization consists in a dynamic competition between attractors that encode the sensorimotor patterns typical of each category; action prediction success counts as ‘‘evidence’’ for a given category and contributes to falling into the corresponding attractor. The evidence accumulation process is guided by an active perception loop, and the active exploration of objects (e.g., visual exploration) aims at eliciting expected sensorimotor patterns that count as evidence for the object category. We present a computational model incorporating these elements and describing action prediction, active perception, and attractor dynamics as key elements of perceptual categorizations. We test the model in three simulated perceptual categorization tasks, and we discuss its relevance for grounded and sensorimotor theories of cognition.Peer reviewe

Dark energy and particle mixing

We show that the vacuum condensate due to particle mixing is responsible of a dynamically evolving dark energy. In particular, we show that values of the adiabatic index close to -1 for vacuum condensates of neutrinos and quarks imply, at the present epoch, contributions to the vacuum energy compatible with the estimated upper bound on the dark energy.Comment: 11 page

Prophylactic treatment uptake and compliance with recommended follow up among HIV exposed infants: a retrospective study in Addis Ababa, Ethiopia

<p>Abstract</p> <p>Background</p> <p>Children are being infected by HIV/AIDS mainly through mother-to-child transmission. In Ethiopia currently more than 135,000 children are living with HIV/AIDS. The aim of this study was to describe the pattern of ARV uptake after birth, co-trimoxazole prophylaxis and follow up compliance, and to examine which factors are associated with the intervention outcome.</p> <p>Methods</p> <p>A retrospective quantitative study design was used for data collection through two hospitals. All infants who were delivered by HIV infected mothers between October 2008 and August 2009 were included and information regarding treatment adherence during their first 6 months of age was collected.</p> <p>Findings</p> <p>118 HIV exposed infant-mother pairs were included in the study. 107 (90.7%) infants received ARV prophylaxis at birth. Sixty six (56%) of the infants were found to be adherent to co-trimoxazole prophylactic treatment. The majority (<it>n </it>= 110(93.2%)) of infants were tested HIV negative with DNA/PCR HIV test at the age of sixth weeks. Infants who took ARV prophylaxis at birth were found to be more likely to adhere with co-trimoxazole treatment: [OR = 9.43(95% CI: 1.22, 72.9)]. Similarly, infants whose mothers had been enrolled for HIV/ART care in the same facility [OR = 14(95% CI: 2.6, 75.4)], and children whose fathers were tested and known to be HIV positive [OR = 3.0(95% CI: 1.0, 9.0)] were more likely to adhere than their counterparts. Infants feeding practice was also significantly associated with adherence <it>χ</it>²-test, <it>p </it>< 0.01.</p> <p>Conclusion</p> <p>The proportion of ARV uptake at birth among HIV exposed infants were found to be high compared to other similar settings. Mother-infant pair enrolment in the same facility and the infant's father being tested and knew their HIV result were major predictors of infants adhering to treatment and follow up. However, large numbers of infants were lost to follow up.</p

Cost-Effectiveness of HIV Testing Referral Strategies among Tuberculosis Patients in India

Background: Indian guidelines recommend routine referral for HIV testing of all tuberculosis (TB) patients in the nine states with the highest HIV prevalence, and selective referral for testing elsewhere. We assessed the clinical impact and cost-effectiveness of alternative HIV testing referral strategies among TB patients in India. Methods and Findings: We utilized a computer model of HIV and TB disease to project outcomes for patients with active TB in India. We compared life expectancy, cost, and cost-effectiveness for three HIV testing referral strategies: 1) selective referral for HIV testing of those with increased HIV risk, 2) routine referral of patients in the nine highest HIV prevalence states with selective referral elsewhere (current standard), and 3) routine referral of all patients for HIV testing. TB-related data were from the World Health Organization. HIV prevalence among TB patients was 9.0% in the highest prevalence states, 2.9% in the other states, and 4.9% overall. The selective referral strategy, beginning from age 33.50 years, had a projected discounted life expectancy of 16.88 years and a mean lifetime HIV/TB treatment cost of US$100. The current standard increased mean life expectancy to 16.90 years with additional per-person cost of US$10; the incremental cost-effectiveness ratio was US$650/year of life saved (YLS) compared to selective referral. Routine referral of all patients for HIV testing increased life expectancy to 16.91 years, with an incremental cost-effectiveness ratio of US$730/YLS compared to the current standard. For HIV-infected patients cured of TB, receiving antiretroviral therapy increased survival from 4.71 to 13.87 years. Results were most sensitive to the HIV prevalence and the cost of second-line antiretroviral therapy. Conclusions: Referral of all patients with active TB in India for HIV testing will be both effective and cost-effective. While effective implementation of this strategy would require investment, routine, voluntary HIV testing of TB patients in India should be recommended

Altered Connectivity Pattern of Hubs in Default-Mode Network with Alzheimer's Disease: An Granger Causality Modeling Approach

Background: Evidences from normal subjects suggest that the default-mode network (DMN) has posterior cingulate cortex (PCC), medial prefrontal cortex (MPFC) and inferior parietal cortex (IPC) as its hubs; meanwhile, these DMN nodes are often found to be abnormally recruited in Alzheimer’s disease (AD) patients. The issues on how these hubs interact to each other, with the rest nodes of the DMN and the altered pattern of hubs with respect to AD, are still on going discussion for eventual final clarification. Principal Findings: To address these issues, we investigated the causal influences between any pair of nodes within the DMN using Granger causality analysis and graph-theoretic methods on resting-state fMRI data of 12 young subjects, 16 old normal controls and 15 AD patients respectively. We found that: (1) PCC/MPFC/IPC, especially the PCC, showed the widest and distinctive causal effects on the DMN dynamics in young group; (2) the pattern of DMN hubs was abnormal in AD patients compared to old control: MPFC and IPC had obvious causal interaction disruption with other nodes; the PCC showed outstanding performance for it was the only region having causal relation with all other nodes significantly; (3) the altered relation between hubs and other DMN nodes held potential as a noninvasive biomarker of AD. Conclusions: Our study, to the best of our knowledge, is the first to support the hub configuration of the DMN from the perspective of causal relationship, and reveal abnormal pattern of the DMN hubs in AD. Findings from young subject

Hippocampal–anterior thalamic pathways for memory: uncovering a network of direct and indirect actions

This review charts recent advances from a variety of disciplines that create a new perspective on why the multiple hippocampal–anterior thalamic interconnections are together vital for human episodic memory and rodent event memory. Evidence has emerged for the existence of a series of parallel temporal–diencephalic pathways that function in a reciprocal manner, both directly and indirectly, between the hippocampal formation and the anterior thalamic nuclei. These extended pathways also involve the mammillary bodies, the retrosplenial cortex and parts of the prefrontal cortex. Recent neuropsychological findings reveal the disproportionate importance of these hippocampal–anterior thalamic systems for recollective rather than familiarity-based recognition, while anatomical studies highlight the precise manner in which information streams are kept separate but can also converge at key points within these pathways. These latter findings are developed further by electrophysiological stimulation studies showing how the properties of the direct hippocampal–anterior thalamic projections are often opposed by the indirect hippocampal projections via the mammillary bodies to the thalamus. Just as these hippocampal–anterior thalamic interactions reflect an interdependent system, so it is also the case that pathology in one of the component sites within this system can induce dysfunctional changes to distal sites both directly and indirectly across the system. Such distal effects challenge more traditional views of neuropathology as they reveal how extensive covert pathology might accompany localised overt pathology, and so impair memory