Nano-droplets deposited in microarrays by femtosecond Ti:sapphire laser-induced forward transfer

The authors present the deposition of nanoscale droplets of Cr using femtosecond Ti:Sapphire Laser-Induced Forward Transfer. Deposits around 300 nm in diameter, significantly smaller than any previously reported, are obtained from a 30 nm thick source film. Deposit size, morphology, and adhesion to a receiver substrate as functions of applied laser fluence are investigated. We show that deposits can be obtained from previously irradiated areas of the source material film with negligible loss of deposition quality, allowing sub-spot size period microarrays to be produced without the need to move the source film

Effectiveness of residential treatment for substance-abusing youth: Benefits of the Pine River Institute program

We investigated the effectiveness treatment for substance abusing youth at an innovative residential program in Canada, the Pine River Institute (PRI). We explored (a) whether pretreatment problems were predicted by individual differences; (b) what predicted treatment progression; (c) the amount of improvement preto posttreatment; and (d) what predicted those improvements. From data from 148 youths, we found that (a) parental divorce and mental health issues were associated with pretreatment problems; (b) youths who attended PRI in more recent years progressed further through treatment; (c) improvements were significant and large; and (d) youths who progress further in treatment experience greater improvements.Social Sciences and Humanities Research Council (SSHRC

Links between soil microbial communities and plant traits in a species-rich grassland under long-term climate change

Climate change can influence soil microorganisms directly by altering their growth and activity but also indirectly via effects on the vegetation, which modifies the availability of resources. Direct impacts of climate change on soil microorganisms can occur rapidly, whereas indirect effects mediated by shifts in plant community composition are not immediately apparent and likely to increase over time. We used molecular fingerprinting of bacterial and fungal communities in the soil to investigate the effects of 17 years of temperature and rainfall manipulations in a species‐rich grassland near Buxton, UK. We compared shifts in microbial community structure to changes in plant species composition and key plant traits across 78 microsites within plots subjected to winter heating, rainfall supplementation, or summer drought. We observed marked shifts in soil fungal and bacterial community structure in response to chronic summer drought. Importantly, although dominant microbial taxa were largely unaffected by drought, there were substantial changes in the abundances of subordinate fungal and bacterial taxa. In contrast to short‐term studies that report high resistance of soil fungi to drought, we observed substantial losses of fungal taxa in the summer drought treatments. There was moderate concordance between soil microbial communities and plant species composition within microsites. Vector fitting of community‐weighted mean plant traits to ordinations of soil bacterial and fungal communities showed that shifts in soil microbial community structure were related to plant traits representing the quality of resources available to soil microorganisms: the construction cost of leaf material, foliar carbon‐to‐nitrogen ratios, and leaf dry matter content. Thus, our study provides evidence that climate change could affect soil microbial communities indirectly via changes in plant inputs and highlights the importance of considering long‐term climate change effects, especially in nutrient‐poor systems with slow‐growing vegetation

Is there an association of vitamin B12 status with neurological function in older people? A systematic review.

Low vitamin B12 status is common in older people; however, its public health significance in terms of neurological manifestations remains unclear. The present systematic review evaluated the association of vitamin B12 status with neurological function and clinically relevant neurological outcomes in adults aged 50+ years. A systematic search of nine bibliographic databases (up to March 2013) identified twelve published articles describing two longitudinal and ten cross-sectional analyses. The included study populations ranged in size (n 28-2287) and mean/median age (range 65-81 years). Studies reported various neurological outcomes: nerve function; clinically measured signs and symptoms of nerve function; self-reported neurological symptoms. Studies were assessed for risk of bias, and results were synthesised qualitatively. Among the general population groups of older people, one longitudinal study reported no association, and four of seven cross-sectional studies reported limited evidence of an association of vitamin B12 status with some, but not all, neurological outcomes. Among groups with clinical and/or biochemical evidence of low vitamin B12 status, one longitudinal study reported an association of vitamin B12 status with some, but not all, neurological outcomes and three cross-sectional analyses reported no association. Overall, there is limited evidence from observational studies to suggest an association of vitamin B12 status with neurological function in older people. The heterogeneity and quality of the evidence base preclude more definitive conclusions, and further high-quality research is needed to better inform understanding of public health significance in terms of neurological function of vitamin B12 status in older people

Traffic Collision Avoidance System: False Injection Viability

Safety is a simple concept but an abstract task, specifically with aircraft. One critical safety system, the Traffic Collision Avoidance System II (TCAS), protects against mid-air collisions by predicting the course of other aircraft, determining the possibility of collision, and issuing a resolution advisory for avoidance. Previous research to identify vulnerabilities associated with TCAS’s communication processes discovered that a false injection attack presents the most comprehensive risk to veritable trust in TCAS, allowing for a mid-air collision. This research explores the viability of successfully executing a false injection attack against a target aircraft, triggering a resolution advisory. Monetary constraints precluded access to a physical TCAS unit; instead, this research creates a novel program, TCAS-False Injection Environment (TCAS-FIE), that incorporates real-world distributed computing systems to simulate a ground-based attacker scenario which explores how a false injection attack could target an operational aircraft. TCAS-FIEs’ simulation models are defined by parameters to execute tests that mimic real-world TCAS units during Mode S message processing. TCAS-FIE simulations execute tests over applicable ranges (5–30 miles), altitudes (25–45K ft), and bearings standard for real-world TCAS tracking. The comprehensive tests compare altitude, measure range closure rate, and measure signal strength from another aircraft to determine the delta in bearings over time. In the attack scenario, the ground-based adversary falsely injects a spoofed aircraft with characteristics matching a Boeing 737-800 aircraft, targeting an operational Boeing 737-800 aircraft. TCAS-FIE completes 555,000 simulations using the various ranges, altitudes, and bearings. The simulated success rate to trigger a resolution advisory is 32.63%, representing 181,099 successful resolution advisory triggers out of 555,000 total simulations. The results from additional analysis determine the required ranges, altitudes, and bearing parameters to trigger future resolution advisories, yielding a predictive threat map for aircraft false injection attacks. The resulting map provides situational awareness to pilots in the event of a real-world TCAS anomaly

Examining Learning Styles and Perceived Benefits of Analogical Problem Construction on SQL Knowledge Acquisition

The demand for Information Systems (IS) graduates with expertise in Structured Query Language (SQL) and database management is vast and projected to increase as ‘big data’ becomes ubiquitous. To prepare students to solve complex problems in a data-driven world, educators must explore instructional strategies to help link prior knowledge to new knowledge. This study examined learning styles and the perceived benefits of analogical problem construction on SQL knowledge acquisition. The data collected from 80 participants suggests there is a perceived positive benefit to using analogical problem construction for learning introductory database concepts. The learning style of the majority of students in the sample is ‘Active-Sensing-Visual-Sequential.’ However, learning styles were not related to student perceived impact of analogical problem construction to understand database concepts. Student analogies were collected for a variety of SQL concepts; noteworthy examples are highlighted. While results related to learning styles are intriguing, the most promising path for further exploration (for both research and practice) is the use of analogy problem construction in Information Systems educational environments

Risk Factors for Suboptimal Antiretroviral Therapy Adherence in HIV-Infected Adolescents in Gaborone, Botswana: A Pilot Cross-Sectional Study

Objective: Little is known about factors associated with suboptimal antiretroviral treatment (ART) adherence among adolescents in Sub-Saharan Africa. Our objective was to determine the level of ART adherence and predictors of non-adherence among human immunodeficiency virus (HIV)-infected adolescents at the Botswana-Baylor Children\u27s Clinical Centre of Excellence in Gaborone, Botswana. Methods: In a cross-sectional study, 82 HIV-infected adolescents receiving ART and their caregivers were administered a structured questionnaire. The patient\u27s clinical information was retrieved from medical records. Outcome measures included excellent pill count ART adherence (\u3e95%) and virologic suppression (HIV viral load \u3c400 copies/mL). Multivariate logistic regression analysis was performed to identify independent predictors of ART non-adherence. Results: The overall median (interquartile range) ART adherence was 99% (96.5–100) (N = 82). Seventy-six percent of adolescents had excellent pill count ART adherence levels and 94% achieved virologic suppression. Male adolescents made up 65% of the non-adherent group (P = 0.02). Those who displayed suboptimal ART adherence were more likely to report having ever missed ART doses due to failure to pick up medication at the pharmacy (30.0% versus 9.7%, P = 0.03). In the multivariate logistic regression model, male sex (odds ratio [OR] 3.29, 95% confidence interval [CI] 1.13–9.54; P = 0.03) was the only factor which was independently associated with suboptimal ART adherence. Conclusions: A high proportion of HIV-infected adolescents studied had excellent ART adherence and virologic suppression, with male adolescents at higher risk of suboptimal adherence than females. Further research to investigate how gender relates to suboptimal adherence may aid in the design of targeted intervention strategies

Regulation of Class-Switch Recombination and Plasma Cell Differentiation by Phosphatidylinositol 3-Kinase Signaling

SummaryClass-switch recombination (CSR) is essential for humoral immunity. However, the regulation of CSR is not completely understood. Here we demonstrate that phosphatidylinositol 3-kinase (PI3K) actively suppressed the onset and frequency of CSR in primary B cells. Consistently, mice lacking the lipid phosphatase, PTEN, in B cells exhibited a hyper-IgM condition due to impaired CSR, which could be restored in vitro by specific inhibition of PI3Kδ. Inhibition of CSR by PI3K was partially dependent on the transcription factor, BLIMP1, linking plasma cell commitment and cessation of CSR. PI3K-dependent activation of the serine-threonine kinase, Akt, suppressed CSR, in part, through the inactivation of the Forkhead Box family (Foxo) of transcription factors. Reduced PI3K signaling enhanced the expression of AID (activation-induced cytidine deaminase) and accelerated CSR. However, ectopic expression of AID could not fully overcome inhibition of CSR by PI3K, suggesting that PI3K regulates both the expression and function of AID