Interfacing Laboratory Instruments to Multiuser, Virtual Memory Computers

Computers based on virtual memory, multiuser architecture have recently become economically available to medium sized research groups (about 25 members). These new computers offer advantages to the experimentalist, though acceptance has been sometimes limited. One of the most important advantages of a virtual memory machine is the capability of fast access to arrays having dimensions greater than 64 kbytes. Arrays larger than 64 kbytes were available on some older computers based on physical memory. The access time to the memory beyond 64 kbytes is extremely slow for these systems. Fast access to large arrays is particularly important now where large data sets are required for research system

An investigation of gender, perceived gender-barriers to a future occupation, and academic achievement among delinquent adolescents

The current study assesses perceptions of gender-related barriers to a future occupation and its association with academic achievement among delinquent adolescents aged 12-19 years old. It was hypothesized that the perception of gender related barriers to a future occupation would have similar effects on male and female adolescents\u27 academic achievement. Data included self-reported perceived barriers to a future occupation and academic achievement. Results indicated that females and males reported similar amounts of perceived barriers to a future occupation. Regression analysis indicated the relationship between perceived barriers and academic achievement varied across gender. For males, more perceived gender-barriers were associated with lower academic achievement, whereas, for females gender-barriers did not predict academic achievement. Although our hypothesis was not supported, the findings reveal an interesting phenomenon provoking the need for further study of gender, perceived barriers, and academic outcomes in delinquent populations

Systems for ultrasonic scanning, analysis and imagery

A variety of ultrasonic scanning and imagery techniques are used to investigate various aspects of materials and microstructures. Two ultrasonic scanning systems are in use by the Lewis Research Center's Structural Integrity Branch: an immersion scanner and a contact scanning system. The basic principles of scanning are reviewed, examples of images are presented, and structural features suggested by these images are discussed. Both of these systems are custom designed; their capabilities, advantages, and disadvantages are highlighted

Promoting self-determination for transition-age youth: Views of high school general and special educators

This is the published version, also found here: http://cec.metapress.com/content/m5781621105k3332/?p=a26d6505487b4343b14b0042308735be&pi=2Recent developments in policy and practice have emphasized the importance of promoting self-determination and supporting access to the general curriculum for youth with disabilities. To understand how these trends align, we examined the efforts of 340 general and special educators to promote student self-determination in high school classrooms. Educators attached considerable importance to providing instruction in skills related to self-determination and reported addressing these skills with moderate to high frequency in their classrooms. Although opportunities for students with disabilities to learn skills that promote self-determination were reported to be available across the curriculum, there were some differences across teachers and curricular area. We discuss avenues for promoting student self-determination within the general curriculum, as well as offer recommendations for future research

Aluminium metallisation for interdigitated back contact silicon heterojunction solar cells

Back contact silicon heterojunction solar cells with an efficiency of 22 were manufactured, featuring a simple aluminium metallisation directly on the doped amorphous silicon films. Both the open circuit voltage and the fill factor heavily depend on the parameters of the annealing step after aluminium layer deposition. Using numerical device simulations and in accordance with the literature, we demonstrate that the changes in solar cell parameters with annealing can be explained by the formation of an aluminium silicide layer at temperatures as low as 150 C, improving the contact resistance and thus enhancing the fill factor. Further annealing at higher temperatures initialises the crystallisation of the amorphous silicon layers, yielding even lower contact resistances, but also introduces more defects, diminishing the open circuit voltag

Is It Always Unethical to Use a Placebo in a Clinical Trial?

Background to the debate: Placebos are used in trials to conceal whether a treatment is being given or not and hence to control for the psychosomatic effects of offering treatment. Placebo-controlled trials are controversial. Critics of such trials argue that if a proven effective therapy exists, a placebo should not be used. But proponents argue that placebo trials are still crucial to prove the efficacy and safety of many treatments

Biomarkers of the L-arginine / dimethylarginine / nitric oxide pathway in people with chronic airflow obstruction and obstructive sleep apnoea

Background: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea (OSA) are common chronic diseases that are associated with chronic and intermittent hypoxemia, respectively. Patients affected by the overlap of COPD and OSA have a particularly unfavourable prognosis. The L-arginine/nitric oxide (NO) pathway plays an important role in regulating pulmonary vascular function. Asymmetric (ADMA) and symmetric dimethylarginine (SDMA) interfere with NO production. Methods: We analysed the serum concentrations of ADMA, SDMA, L-arginine, L-citrulline, and L-ornithine in a large sample of the Icelandic general population together with chronic airflow obstruction (CAO), a key physiological marker of COPD that was assessed by post-bronchodilator spirometry (FEV1/FVC 0.5. SDMA was significantly higher in individuals with CAO (0.518 [0.461–0.616] vs. 0.494 [0.441–0.565] µmol/L; p = 0.005), but ADMA was not. However, ADMA was significantly associated with decreasing FEV1 percent predicted among those with CAO (p = 0.002). ADMA was 0.50 (0.44–0.56) µmol/L in MAP ≤ 0.5 versus 0.52 (0.46–0.58) µmol/L in MAP > 0.5 (p = 0.008). SDMA was 0.49 (0.44–0.56) µmol/L versus 0.51 (0.46–0.60) µmol/L, respectively (p = 0.004). The highest values for ADMA and SDMA were observed in individuals with overlap of CAO and MAP > 0.5, which was accompanied by lower L-citrulline levels. Conclusions: The plasma concentrations of ADMA and SDMA are elevated in COPD patients with concomitant intermittent hypoxaemia. This may account for impaired pulmonary NO production, enhanced pulmonary vasoconstriction, and disease progression

Fruit crops, 1980: a summary of research

Performance of selected apple cultivars on semi-standard rootstocks in southern Ohio / David C. Ferree, Donald A. Chandler, and John C. Schmid -- Influence of summer pruning and alar on growth, flowering, and fruit set of Jerseymac apple trees / D. C. Ferree and E. J. Stang -- Influence of promalin on Delicious in Ohio / D. C. Ferree, E. J. Stang and R. C. Funt -- The effects of overtree misting for bloom delay on soil water status, net photosynthesis, transpiration, and carbohydrate levels of apple trees / R. M. Crassweller and D. C. Ferree -- Effect of orchard heaters on vertical temperature profiles / R. D. Fox, R. D. Brazee, and D. C. Ferree -- The effect of orchard heaters on air movement and temperature / R. D. Fox, R. D. Brazee, and D. C. Ferree -- Organotins and mite control on apples in Ohio / Franklin R. Hall -- Model of the air sprayer / R. D. Fox, R. D. Brazee, D. L. Reichard and F. R. Hall -- Effects of application equipment variables on spray deposition by orchard air sprayers / D. L. Reichard, F. R. Hall and H. R. Krueger -- Fungi associated with moldy-core of apple and their location within fruit / Michael A. Ellis -- Nutrient content of twelve french and american hybrid grape cultivars grown under a wide range of soil conditions / Garth A. Cahoo