Controllability and controller-observer design for a class of linear time-varying systems

“The final publication is available at Springer via http://dx.doi.org/10.1007/s10852-012-9212-6"In this paper a class of linear time-varying control systems is considered. The time variation consists of a scalar time-varying coefficient multiplying the state matrix of an otherwise time-invariant system. Under very weak assumptions of this coefficient, we show that the controllability can be assessed by an algebraic rank condition, Kalman canonical decomposition is possible, and we give a method for designing a linear state-feedback controller and Luenberger observer

Malignant pheochromocytoma in a pig

Abstract. Endocrine tumors are rarely observed in pigs, and pheochromocytomas have been only punctually described. The current report describes a white and firm, 15-cm in diameter, neoplastic mass located in the adrenal gland with metastasis to regional lymph nodes in a 2.5-year-old sow. The masses had marked desmoplasia that supported a population of polygonal-tospindle– shaped neoplastic cells arranged into cords and packets within a delicate fibrovascular stroma. Immunohistochemical staining of the tumor was positive for chromogranin and negative for neurofilament protein in adrenal and lymph node masses, which was characteristic of a malignant pheochromocytoma

The 12-item WHO Disability Assessment Schedule II as an outcome measure for treatment of common mental disorders.

BACKGROUND: Common mental disorders (CMD) are among the most significant contributors to disability worldwide. Patient-reported disability outcomes should be included as a key metric in the comparative assessment of value across global mental health interventions. This study aims to evaluate the validity of a widely used, cross-cultural tool - the 12-item World Health Organization Disability Assessment Schedule II (WHODAS) - as a functional outcome measure for CMD treatment. METHODS: The study population includes 1024 participants with CMD enrolled in the MANAS trial in India. CMD was assessed using the Revised Clinical Interview Schedule (CIS-R). Disability was assessed using the 12-item WHODAS II plus a measure of disability days. This analysis presents the correlations between these disability items and CMD symptom severity at 2 months after enrollment (convergent validity) and the items' associations with CMD recovery 4 months later (external responsiveness). RESULTS: All items showed a positive correlation of disability with CMD symptom severity (p < 0.001). The WHODAS items of 'standing,' 'household responsibilities,' and 'emotional disturbance' explained the most variance in CMD symptom severity. Improvements in 'disability days,' 'emotional disturbance,' 'standing,' 'household responsibilities,' 'day-to-day work,' and 'concentrating' were significantly associated with CMD recovery over follow-up. CONCLUSIONS: Further research is recommended on a CMD-specific WHODAS subscale comprised of the six WHODAS items found to be most strongly associated with CMD severity and recovery. This shorter, CMD-specific disability subscale would critically serve as a common metric to compare intervention impact on patient-centered outcomes and, in turn, to allocate global mental health resources efficiently

Written education materials for stroke patients and their carers: perspectives and practices of health professionals

Inadequacies in the provision of written education materials to stroke patients and their carers have been reported. In this study, 20 stroke team health professionals were surveyed regarding their use of and perspectives on written education materials. Seventy percent of participants provided materials to 25% or fewer stroke patients and 90% believed that patients and carers are only occasionally or rarely provided with sufficient written information. Health professionals were uncertain which team members provided written information and identified the need to improve the quality of materials used. Stroke teams should implement a system that facilitates the routine provision of quality written materials to patients and carers, communication among team members, and documentation and verbal reinforcement of the information provided

TRASER - Total Reflection Amplification of Spontaneous Emission of Radiation

Background and Objective: Light and lasers in medical therapy have made dramatic strides since their invention five decades ago. However, the manufacture of lasers can be complex and expensive which often makes treatments limited and costly. Further, no single laser will provide the correct parameters to treat all things. Hence, laser specialists often need multiple devices to practice their specialty. A new concept is described herein that has the potential to replace many lasers and light sources with a single ‘tunable ’ device. Study Design/Material and Methods: This device amplifies spontaneous emission of radiation by capturing and retaining photons through total internal reflection, hence the acronym Total Reflection Amplification of Spontaneous Emission of Radiation, or TRASER. Results: Specific peaks of light can be produced in a reproducible manner with high peak powers of variable pulse durations, a large spot size, and high repetition rate. Conclusion: Considering the characteristics and parameters of Traser technology, it is possible that this one device woul

Valley-spin blockade and spin resonance in carbon nanotubes

Manipulation and readout of spin qubits in quantum dots made in III-V materials successfully rely on Pauli blockade that forbids transitions between spin-triplet and spin-singlet states. Quantum dots in group IV materials have the advantage of avoiding decoherence from the hyperfine interaction by purifying them with only zero-spin nuclei. Complications of group IV materials arise from the valley degeneracies in the electronic bandstructure. These lead to complicated multiplet states even for two-electron quantum dots thereby significantly weakening the selection rules for Pauli blockade. Only recently have spin qubits been realized in silicon devices where the valley degeneracy is lifted by strain and spatial confinement. In carbon nanotubes Pauli blockade can be observed by lifting valley degeneracy through disorder. In clean nanotubes, quantum dots have to be made ultra-small to obtain a large energy difference between the relevant multiplet states. Here we report on low-disorder nanotubes and demonstrate Pauli blockade based on both valley and spin selection rules. We exploit the bandgap of the nanotube to obtain a large level spacing and thereby a robust blockade. Single-electron spin resonance is detected using the blockade.Comment: 31 pages including supplementary informatio

Recent translational research: stem cells as the roots of breast cancer

Common phenotypes of cancer and stem cells suggest that breast cancers arise from stem cells. Breast epithelial cells with stem cell phenotypes have been shown to be more susceptible to immortalization and neoplastic transformation. Breast tumor stem cells with CD44(+)/CD24(-/low)Lineage(- )markers have been isolated. The role of these cells in tumor progression and clinical outcome is not clear. The relationship between breast stem cell and tumor stem cell may be elucidated by further studies of carcinogenesis of nonadherent mammosphere cells with stem cell features and by derivation of CD44(+)/CD24(-/low )cells from an adherent breast epithelial stem cell type

Toward a Surrogate Marker of Malaria Exposure: Modeling Longitudinal Antibody Measurements under Outbreak Conditions

Background: Biomarkers of exposure to Plasmodium falciparum would be a useful tool for the assessment of malaria burden and analysis of intervention and epidemiological studies. Antibodies to pre-erythrocytic antigens represent potential surrogates of exposure. Methods and Findings: In an outbreak cohort of U.S. Marines deployed to Liberia, we modeled pre- and post-deployment IgG against P. falciparum sporozoites by immunofluorescence antibody test, and both IgG and IgM against the P. falciparum circumsporozoite protein by enzyme-linked immunosorbant assay. Modeling seroconversion thresholds by a fixed ratio, linear regression or nonlinear regression produced sensitivity for identification of exposed U.S. Marines between 58-70% and specificities between 87-97%, compared with malaria-naïve U.S. volunteers. Exposure was predicted in 30-45% of the cohort. Conclusion: Each of the three models tested has merits in different studies, but further development and validation in endemic populations is required. Overall, these models provide support for an antibody-based surrogate marker of exposure to malaria

Systematic review and meta-analysis of hepatitis C virus infection and HIV viral load: New insights into epidemiologic synergy

INTRODUCTION: Hepatitis C virus (HCV) and HIV infection frequently co-occur due to shared transmission routes. Co-infection is associated with higher HCV viral load (VL), but less is known about the effect of HCV infection on HIV VL and risk of onward transmission. METHODS: We undertook a systematic review comparing 1) HIV VL among ART-naïve, HCV co-infected individuals versus HIV mono-infected individuals and 2) HIV VL among treated versus untreated HCV co-infected individuals. We performed a random-effects meta-analysis and quantified heterogeneity using the I2 statistic. We followed Cochrane Collaboration guidelines in conducting our review and PRISMA guidelines in reporting results. RESULTS AND DISCUSSION: We screened 3925 articles and identified 17 relevant publications. A meta-analysis found no evidence of increased HIV VL associated with HCV co-infection or between HIV VL and HCV treatment with pegylated interferon-alpha-2a/b and ribavirin. CONCLUSIONS: This finding is in contrast to the substantial increases in HIV VL observed with several other systemic infections. It presents opportunities to elucidate the biological pathways that underpin epidemiological synergy in HIV co-infections and may enable prediction of which co-infections are most important to epidemic control

A Systematic Review of Online Sex Addiction and Clinical Treatments Using CONSORT Evaluation

Researchers have suggested that the advances of the Internet over the past two decades have gradually eliminated traditional offline methods of obtaining sexual material. Additionally, research on cybersex and/or online sex addictions has increased alongside the development of online technology. The present study extended the findings from Griffiths’ (2012) systematic empirical review of online sex addiction by additionally investigating empirical studies that implemented and/or documented clinical treatments for online sex addiction in adults. A total of nine studies were identified and then each underwent a CONSORT evaluation. The main findings of the present review provide some evidence to suggest that some treatments (both psychological and/or pharmacological) provide positive outcomes among those experiencing difficulties with online sex addiction. Similar to Griffiths’ original review, this study recommends that further research is warranted to establish the efficacy of empirically driven treatments for online sex addiction