Experimental demonstration of fiber-accessible metal nanoparticle plasmon waveguides for planar energy guiding and sensing

Experimental evidence of mode-selective evanescent power coupling at telecommunication frequencies with efficiencies up to 75 % from a tapered optical fiber to a carefully designed metal nanoparticle plasmon waveguide is presented. The waveguide consists of a two-dimensional square lattice of lithographically defined Au nanoparticles on an optically thin silicon membrane. The dispersion and attenuation properties of the waveguide are analyzed using the fiber taper. The high efficiency of power transfer into these waveguides solves the coupling problem between conventional optics and plasmonic devices and could lead to the development of highly efficient plasmonic sensors and optical switches.Comment: 1 file, 3 figure

Low-loss fiber accessible plasmon waveguide for planar energy guiding and sensing

A metal nanoparticle plasmon waveguide for electromagnetic energy transport utilizing dispersion engineering to increase lateral energy confinement via a two-dimensional pattern of Au dots on an optically thin Si membrane is described. Using finite-difference time-domain simulations and coupled-mode theory, we show that phase-matched evanescent excitation from conventional fiber tapers is possible with efficiencies >90% for realistic geometries. Energy loss in this waveguide is mainly due to material absorption, allowing for 1/e energy decay distances of about 320 µm for excitation at telecommunication frequencies. This concept can be extended to the visible regime and promises applications in optical energy guiding, optical sensing, and switching

Family-Focused Treatment for Adolescents and Young Adults at High Risk for Psychosis: Results of a Randomized Trial

Objective: Longitudinal studies have begun to clarify the phenotypic characteristics of adolescents and young adults at clinical high risk for psychosis. This 8-site randomized trial examined whether a 6-month program of family psychoeducation was effective in reducing the severity of attenuated positive and negative psychotic symptoms and enhancing functioning among individuals at high risk. Method: Adolescents and young adults (mean age 17.4 +/- 4.1 years) with attenuated positive psychotic symptoms, brief and intermittent psychosis, or genetic risk with functional deterioration were randomly assigned to 18 sessions of family-focused therapy for individuals at clinical high risk (FFT-CHR) in 6 months or 3 sessions of family psychoeducation (enhanced care [EC]. FFT-CHR included psychoeducation about early signs of psychosis, stress management, communication training, and problem-solving skills training, whereas EC focused on symptom prevention. Independent evaluators assessed participants at baseline and 6 months on positive and negative symptoms and social-role functioning. Results: Of 129 participants, 102 (79.1%) were followed up at 6 months. Participants in FFT-CHR showed greater improvements in attenuated positive symptoms over 6 months than participants in EC (F-1,F-97 = 5.49, p = .02). Negative symptoms improved independently of psychosocial treatments. Changes in psychosocial functioning depended on age: participants more than 19 years of age showed more role improvement in FFT-CHR, whereas participants between 16 and 19 years of age showed more role improvement in EC. The results were independent of concurrent pharmacotherapy. Conclusion: Interventions that focus on improving family relationships may have prophylactic efficacy in individuals at high risk for psychosis. Future studies should examine the specificity of effects of family intervention compared to individual therapy of the same duration and frequency. Clinical trial registration information-Prevention Trial of Family Focused Treatment in Youth at Risk for Psychosis

Reducing the duration of untreated psychosis and its impact in the U.S.: the STEP-ED study

Background: Early intervention services for psychotic disorders optimally interlock strategies to deliver: (i) Early Detection (ED) to shorten the time between onset of psychotic symptoms and effective treatment (i.e. Duration of Untreated Psychosis, DUP); and (ii) comprehensive intervention during the subsequent 2 to 5 years. In the latter category, are teams (‘First-episode Services’ or FES) that integrate several empirically supported treatments and adapt their delivery to younger patients and caregivers. There is an urgent need to hasten access to established FES in the U.S. Despite improved outcomes for those in treatment, these FES routinely engage patients a year or more after psychosis onset. The Scandinavian TIPS study was able to effectively reduce DUP in a defined geographic catchment. The guiding questions for this study are: can a U.S. adaptation of the TIPS approach to ED substantially reduce DUP and improve outcomes beyond existing FES? Methods/Design The primary aim is to determine whether ED can reduce DUP in the US, as compared to usual detection. ED will be implemented by one FES (STEP) based in southern Connecticut, and usual detection efforts will continue at a comparable FES (PREPR) serving the greater Boston metropolitan area. The secondary aim is to determine whether DUP reduction can improve presentation, engagement and early outcomes in FES care. A quasi-experimental design will compare the impact of ED on DUP at STEP compared to PREPR over 3 successive campaign years. The campaign will deploy 3 components that seek to transform pathways to care in 8 towns surrounding STEP. Social marketing approaches will inform a public education campaign to enable rapid and effective help-seeking behavior. Professional outreach and detailing to a wide variety of care providers, including those in the healthcare, educational and judicial sectors, will facilitate rapid redirection of appropriate patients to STEP. Finally, performance improvement measures within STEP will hasten engagement upon referral. Discussion STEP-ED will test an ED campaign adapted to heterogeneous U.S. pathways to care while also improving our understanding of these pathways and their impact on early outcomes. Trial registration ClinicalTrials.gov: NCT02069925. Registered 20 February 2014

Tandem repeat regions within the Burkholderia pseudomallei genome and their application for high resolution genotyping

BACKGROUND: The facultative, intracellular bacterium Burkholderia pseudomallei is the causative agent of melioidosis, a serious infectious disease of humans and animals. We identified and categorized tandem repeat arrays and their distribution throughout the genome of B. pseudomallei strain K96243 in order to develop a genetic typing method for B. pseudomallei. We then screened 104 of the potentially polymorphic loci across a diverse panel of 31 isolates including B. pseudomallei, B. mallei and B. thailandensis in order to identify loci with varying degrees of polymorphism. A subset of these tandem repeat arrays were subsequently developed into a multiple-locus VNTR analysis to examine 66 B. pseudomallei and 21 B. mallei isolates from around the world, as well as 95 lineages from a serial transfer experiment encompassing ~18,000 generations. RESULTS: B. pseudomallei contains a preponderance of tandem repeat loci throughout its genome, many of which are duplicated elsewhere in the genome. The majority of these loci are composed of repeat motif lengths of 6 to 9 bp with 4 to 10 repeat units and are predominately located in intergenic regions of the genome. Across geographically diverse B. pseudomallei and B.mallei isolates, the 32 VNTR loci displayed between 7 and 28 alleles, with Nei's diversity values ranging from 0.47 and 0.94. Mutation rates for these loci are comparable (>10(-5 )per locus per generation) to that of the most diverse tandemly repeated regions found in other less diverse bacteria. CONCLUSION: The frequency, location and duplicate nature of tandemly repeated regions within the B. pseudomallei genome indicate that these tandem repeat regions may play a role in generating and maintaining adaptive genomic variation. Multiple-locus VNTR analysis revealed extensive diversity within the global isolate set containing B. pseudomallei and B. mallei, and it detected genotypic differences within clonal lineages of both species that were identical using previous typing methods. Given the health threat to humans and livestock and the potential for B. pseudomallei to be released intentionally, MLVA could prove to be an important tool for fine-scale epidemiological or forensic tracking of this increasingly important environmental pathogen

Cell Type–Specific Transcriptome Analysis Reveals a Major Role for Zeb1 and miR-200b in Mouse Inner Ear Morphogenesis

Cellular heterogeneity hinders the extraction of functionally significant results and inference of regulatory networks from wide-scale expression profiles of complex mammalian organs. The mammalian inner ear consists of the auditory and vestibular systems that are each composed of hair cells, supporting cells, neurons, mesenchymal cells, other epithelial cells, and blood vessels. We developed a novel protocol to sort auditory and vestibular tissues of newborn mouse inner ears into their major cellular components. Transcriptome profiling of the sorted cells identified cell type–specific expression clusters. Computational analysis detected transcription factors and microRNAs that play key roles in determining cell identity in the inner ear. Specifically, our analysis revealed the role of the Zeb1/miR-200b pathway in establishing epithelial and mesenchymal identity in the inner ear. Furthermore, we detected a misregulation of the ZEB1 pathway in the inner ear of Twirler mice, which manifest, among other phenotypes, malformations of the auditory and vestibular labyrinth. The association of misregulation of the ZEB1/miR-200b pathway with auditory and vestibular defects in the Twirler mutant mice uncovers a novel mechanism underlying deafness and balance disorders. Our approach can be employed to decipher additional complex regulatory networks underlying other hearing and balance mouse mutants

Risk factors for positive and negative COVID-19 tests: a cautious and in-depth analysis of UK Biobank data

Background The recent COVID-19 outbreak has generated an unprecedented public health crisis, with millions of infections and hundreds of thousands of deaths worldwide. Using hospital-based or mortality data, several COVID-19 risk factors have been identified, but these may be confounded or biased. Methods Using SARS-CoV-2 infection test data (N=4,509 tests; 1,325 positive) from Public Health England, linked to the UK Biobank study, we explored the contribution of demographic, social, health risk, medical, and environmental factors to COVID-19 risk. We used multivariable and penalised logistic regression models for the risk of (i) being tested, (ii) testing positive/negative in the study population and, adopting a test negative design, (iv) the risk of testing positive within the tested population. Results In the fully adjusted model, variables independently associated with the risk of being tested for COVID-19 with OR >1.05 were: male sex; Black ethnicity; social disadvantage (as measured by education, housing and income); occupation (healthcare worker, retired, unemployed); ever smoker; severely obese; comorbidities; and greater exposure to PM2.5-absorbance. Of these, only male sex, non-White ethnicity, lower educational attainment, and none of the comorbidities or health risk factors, were associated with testing positive among tested individuals. Conclusions We adopted a careful and exhaustive approach within a large population-based cohort, which enabled us to triangulate evidence linking, male sex, lower educational attainment, non-White ethnicity with the risk of COVID-19. The elucidation of the joint and independent effects of these factors is a high-priority area for further research to inform on COVID-19 natural history

Individual nutrition therapy and exercise regime: A controlled trial of injured, vulnerable elderly (INTERACTIVE trial)

© 2008 Thomas et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background Proximal femoral fractures are amongst the most devastating consequences of osteoporosis and injurious accidental falls with 25–35% of patients dying in the first year post-fracture. Effective rehabilitation strategies are evolving however, despite established associations between nutrition, mobility, strength and strength-related functional outcomes; there has been only one small study with older adults immediately following fragility fracture where a combination of both exercise and nutrition have been provided. The aim of the INTERACTIVE trial is to establish whether a six month, individualised exercise and nutrition program commencing within fourteen days of surgery for proximal femur fracture, results in clinically and statistically significant improvements in physical function, body composition and quality of life at an acceptable level of cost and resource use and without increasing the burden of caregivers. Methods and Design This randomised controlled trial will be performed across two sites, a 500 bed acute hospital in Adelaide, South Australia and a 250 bed acute hospital in Sydney, New South Wales. Four hundred and sixty community-dwelling older adults aged > 70 will be recruited after suffering a proximal femoral fracture and followed into the community over a 12-month period. Participants allocated to the intervention group will receive a six month individualised care plan combining resistance training and nutrition therapy commencing within 14 days post-surgery. Outcomes will be assessed by an individual masked to treatment allocation at six and 12 months. To determine differences between the groups at the primary end-point (six months), ANCOVA or logistic regression will be used with models adjusted according to potential confounders. Discussion The INTERACTIVE trial is among the first to combine nutrition and exercise therapy as an early intervention to address the serious consequence of rapid deconditioning and weight loss and subsequent ability to regain pre-morbid function in older patients post proximal femoral fracture. The results of this trial will guide the development of more effective rehabilitation programs, which may ultimately lead to reduced health care costs, and improvements in mobility, independence and quality of life for proximal femoral fracture sufferers. Trial registration Australian Clinical Trials Registry: ACTRN12607000017426