Ultra-miniature dual-wavelength spatial frequency domain imaging for micro-endoscopy

There is a need for a cost-effective, quantitative imaging tool that can be deployed endoscopically to better detect early stage gastrointestinal cancers. Spatial frequency domain imaging (SFDI) is a low-cost imaging technique that produces near-real time, quantitative maps of absorption and reduced scattering coefficients, but most implementations are bulky and suitable only for use outside the body. We present an ultra-miniature SFDI system comprised of an optical fiber array (diameter 0.125 mm) and a micro camera (1 x 1 mm package) displacing conventionally bulky components, in particular the projector. The prototype has outer diameter 3 mm, but the individual components dimensions could permit future packaging to < 1.5 mm diameter. We develop a phase-tracking algorithm to rapidly extract images with fringe projections at 3 equispaced phase shifts in order to perform SFDI demodulation. To validate performance, we first demonstrate comparable recovery of quantitative optical properties between our ultra-miniature system and a conventional bench-top SFDI system with agreement of 15% and 6% for absorption and reduced scattering respectively. Next, we demonstrate imaging of absorption and reduced scattering of tissue-mimicking phantoms providing enhanced contrast between simulated tissue types (healthy and tumour), done simultaneously at wavelengths of 515 nm and 660 nm. This device shows promise as a cost-effective, quantitative imaging tool to detect variations in optical absorption and scattering as indicators of cancer.Comment: 26 Pages, 7 Figure

Less-structured time in children's daily lives predicts self-directed executive functioning.

Executive functions (EFs) in childhood predict important life outcomes. Thus, there is great interest in attempts to improve EFs early in life. Many interventions are led by trained adults, including structured training activities in the lab, and less-structured activities implemented in schools. Such programs have yielded gains in children's externally-driven executive functioning, where they are instructed on what goal-directed actions to carry out and when. However, it is less clear how children's experiences relate to their development of self-directed executive functioning, where they must determine on their own what goal-directed actions to carry out and when. We hypothesized that time spent in less-structured activities would give children opportunities to practice self-directed executive functioning, and lead to benefits. To investigate this possibility, we collected information from parents about their 6-7 year-old children's daily, annual, and typical schedules. We categorized children's activities as "structured" or "less-structured" based on categorization schemes from prior studies on child leisure time use. We assessed children's self-directed executive functioning using a well-established verbal fluency task, in which children generate members of a category and can decide on their own when to switch from one subcategory to another. The more time that children spent in less-structured activities, the better their self-directed executive functioning. The opposite was true of structured activities, which predicted poorer self-directed executive functioning. These relationships were robust (holding across increasingly strict classifications of structured and less-structured time) and specific (time use did not predict externally-driven executive functioning). We discuss implications, caveats, and ways in which potential interpretations can be distinguished in future work, to advance an understanding of this fundamental aspect of growing up

Carnivorous Spadefoot (Spea bombifrons Cope) Tadpoles and Fairy Shrimp in Western Iowa

Amphibian larval polymorphisms, rarely found in the Midwest, are more common in arid western regions. We have discovered that Plains spadefoot toad, Spea bombifrons Cope, tadpoles occur as carnivorous and omnivorous morphological forms in flooded soybean and corn fields on the Missouri River flood plain of western Iowa. Carnivores have longer snouts, larger beaks with an upper cusp and lower notch, shorter intestines with fewer loops than the omnivores, and they feed on fairy shrimp. A similar polymorphism in Spea multiplicata Cope enhances survival in the desert because the carnivore develops faster after consuming fairy shrimp and is able to metamorphose in rapidly drying ponds. However, the omnivore develops slower in deeper ponds, stores more fat and has better postmetamorphic success. Fairy shrimp ingestion triggers development of the S. multiplicata carnivores, but whether this is also true for S. bomifrons remains to be seen. Distributions and abundance of both carnivorous S. bombifrons tadpoles and fairy shrimp need to be determined across the Great Plains and in Iowa

Social Support Seeking And Early Adolescent Depression And Anxiety Symptoms: The Moderating Role Of Rumination

This study examined how social support seeking and rumination interacted to predict depression and anxiety symptoms 6 months later in early adolescents (N = 118; 11-14 years at baseline). We expected social support seeking would be more helpful for adolescents engaging in low rather than high levels of rumination. Adolescents self-reported on all measures at baseline, and on depression and anxiety symptoms 6 months later. Social support seeking predicted fewer symptoms of depression and anxiety at low rumination levels but was not associated with benefits as rumination increased. For depression symptoms, social support seeking predicted more symptoms at high rumination levels. Results were stronger for emotion-focused than problem-focused support seeking and for depression compared with anxiety symptoms. These findings suggest that cognitive risk factors like rumination may explain some inconsistencies in previous social support literature, and highlight the importance of a nuanced approach to studying social support seeking

Chronicity and Mental Health Service Utilization for Anxiety, Mood, and Substance Use Disorders among Black Men in the United States; Ethnicity and Nativity Differences.

This study investigated ethnic and nativity differences in the chronicity and treatment of psychiatric disorders of African American and Caribbean Black men in the U.S. Data were analyzed from the National Survey of American Life, a population-based study which included 1859 self-identified Black men (1222 African American, 176 Caribbean Black men born within the U.S., and 461 Caribbean Black men born outside the U.S.). Lifetime and twelve-month prevalence of DSM-IV mood, anxiety, and substance use disorders (including Bipolar I and Dysthmia), disorder chronicity, and rate of mental health services use among those meeting criteria for a lifetime psychiatric disorder were examined. Logistic regression models were employed to determine ethnic differences in chronicity, and treatment utilization for disorders. While rates of DSM-IV disorders were generally low in this community sample of Black men, their disorders were chronic and remained untreated. Caribbean Black men born in the U.S. had higher prevalence of Post-Traumatic Stress Disorder, Major Depressive Disorder, and Alcohol Abuse Disorder compared with African American men. Foreign born Caribbean Black men experienced greater chronicity in Social Phobia and Generalized Anxiety Disorder compared to other Black Men. Utilization of mental health service was low for all groups of Black Men, but lowest for the foreign born Caribbean Black men. Results underscore the large unmet needs of both African American and Caribbean Black men in the United States. Results also highlight the role of ethnicity and nativity in mental disorder chronicity and mental health service utilization patterns of Black men

Making intelligent systems team players: Case studies and design issues. Volume 1: Human-computer interaction design

Initial results are reported from a multi-year, interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. The objective is to achieve more effective human-computer interaction (HCI) for systems with real time fault management capabilities. Intelligent fault management systems within the NASA were evaluated for insight into the design of systems with complex HCI. Preliminary results include: (1) a description of real time fault management in aerospace domains; (2) recommendations and examples for improving intelligent systems design and user interface design; (3) identification of issues requiring further research; and (4) recommendations for a development methodology integrating HCI design into intelligent system design

Development and validation of a chemostat gut model to study both planktonic and biofilm modes of growth of Clostridium difficile and human microbiota

Copyright: 2014 Crowther et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The human gastrointestinal tract harbours a complex microbial community which exist in planktonic and sessile form. The degree to which composition and function of faecal and mucosal microbiota differ remains unclear. We describe the development and characterisation of an in vitro human gut model, which can be used to facilitate the formation and longitudinal analysis of mature mixed species biofilms. This enables the investigation of the role of biofilms in Clostridium difficile infection (CDI). A well established and validated human gut model of simulated CDI was adapted to incorporate glass rods that create a solid-gaseous-liquid interface for biofilm formation. The continuous chemostat model was inoculated with a pooled human faecal emulsion and controlled to mimic colonic conditions in vivo. Planktonic and sessile bacterial populations were enumerated for up to 46 days. Biofilm consistently formed macroscopic structures on all glass rods over extended periods of time, providing a framework to sample and analyse biofilm structures independently. Whilst variation in biofilm biomass is evident between rods, populations of sessile bacterial groups (log10 cfu/g of biofilm) remain relatively consistent between rods at each sampling point. All bacterial groups enumerated within the planktonic communities were also present within biofilm structures. The planktonic mode of growth of C. difficile and gut microbiota closely reflected observations within the original gut model. However, distinct differences were observed in the behaviour of sessile and planktonic C. difficile populations, with C. difficile spores preferentially persisting within biofilm structures. The redesigned biofilm chemostat model has been validated for reproducible and consistent formation of mixed species intestinal biofilms. This model can be utilised for the analysis of sessile mixed species communities longitudinally, potentially providing information of the role of biofilms in CDI.Peer reviewe

Towards a middle-range theory of mental health and well-being effects of employment transitions: Findings from a qualitative study on unemployment during the 2009-2010 economic recession.

This article builds upon previous theoretical work on job loss as a status passage to help explain how people's experiences of involuntary unemployment affected their mental well-being during the 2009-2010 economic recession. It proposes a middle-range theory that interprets employment transitions as status passages and suggests that their health and well-being effects depend on the personal and social meanings that people give to them, which are called properties of the transitions. The analyses, which used a thematic approach, are based on the findings of a qualitative study undertaken in Bradford (North England) consisting of 73 people interviewed in 16 focus groups. The study found that the participants experienced their job losses as divestment passages characterised by three main properties: experiences of reduced agency, disruption of role-based identities, for example, personal identity crises, and experiences of 'spoiled identities', for example, experiences of stigma. The proposed middle-range theory allows us to federate these findings together in a coherent framework which makes a contribution to illuminating not just the intra-personal consequences of unemployment, that is, its impact on subjective well-being and common mental health problems, but also its inter-personal consequences, that is, the hidden and often overlooked social processes that affect unemployed people's social well-being. This article discusses how the study findings and the proposed middle-range theory can help to address the theoretical weaknesses and often contradictory empirical findings from studies that use alternative frameworks, for example, deprivation models and 'incentive theory' of unemployment