Assessment of the fertilizer requirement of improved pasture from remote sensing information

The feasibility of using remote sensing measurements to determine the fertilizer needs of improved pastures was studied. Measures of spectral reflectance of pasture similar to those obtained by satellites, such as LANDSAT, were shown to be related to fertilizer treatment in a factorial fertilizer times stocking rate experiment. A classification based on measures of spectral reflectance of the pasture produced similar treatment groups to a classification based on the phosphorus content of the plant material and available soil phosphate. The results suggest that remote sensing data of pasture reflectance might be used to classify and map areas of improved pasture that require additional fertilizer. Problems of developing such a method are discussed and the areas where additional research is needed are noted. In addition, the value of such a method on a farming scale is considered.     

Spatial context learning survives interference from working memory load.

The human visual system is constantly confronted with an overwhelming amount of information, only a subset of which can be processed in complete detail. Attention and implicit learning are two important mechanisms that optimize vision. This study addressed the relationship between these two mechanisms. Specifically we asked, Is implicit learning of spatial context affected by the amount of working memory load devoted to an irrelevant task? We tested observers in visual search tasks where search displays occasionally repeated. Observers became faster when searching repeated displays than unrepeated ones, showing contextual cuing. We found that the size of contextual cuing was unaffected by whether observers learned repeated displays under unitary attention or when their attention was divided using working memory manipulations. These results held when working memory was loaded by colors, dot patterns, individual dot locations, or multiple potential targets. We conclude that spatial context learning is robust to interference from manipulations that limit the availability of attention and working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of image quality using 1 : 1 pitch and 1.5 : 1 pitch helical CT in children: a comparative study

OBJECTIVE: The objective of this study was to compare the quality of 1 : 1 and 1.5 : 1 pitch helical contrast-enhanced thoracic and abdominal CT images in children who cannot cooperate for breath holding. MATERIALS AND METHODS: This is a retrospective study of 33 contrast-enhanced CT examinations in 11 children of 0-4 years of age. All children had an initial CT study using 1 : 1 pitch helical scanning followed over the next 6-36 months by one to four CT examinations with 1.5 : 1 pitch. Radiation dose with the two techniques was measured with a pencil ionization chamber. RESULTS: The two techniques provided comparable overall image quality. There was 33 % less radiation dose with 1.5 : 1 pitch helical scanning. CONCLUSION: The 1.5 : 1 pitch helical CT provides comparable quality images and a smaller radiation dose than 1 : 1 pitch in examining children aged 0-4 years.     

Development and initial validation of a new procedure for evaluating adequacy of effort given during neuropsychological testing: The letter memory test.

The authors report on results from a new procedure for evaluating adequacy of effort given during neuropsychological testing. The letter memory test (LMT) is a computer-administered, 45-item, forced-choice recognition task that uses consonant letters as stimuli and manipulates face difficulty level along 2 dimensions: number of letters to be remembered and number of choices amongst which the target stimulus must be identified. In 3 studies that included either analogue or known groups designs, the LMT discriminated poorly motivated from well-motivated groups at a moderately high level of accuracy, which was comparable to that of the Digit Memory Test and superior to that of the 21-item Test. The internal consistency reliability of the LMT was also high. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antigen-specific blastogenesis assays for duck hepatitis B virus using duck peripheral blood and splenic mononuclear cells

An antigen-specific lymphoblastogenesis assay for duck hepatitis B surface antigen (DHBsAg) and duck hepatitis B core antigen (DHBcAg) was developed using mononuclear cells from the peripheral blood (PBMC) or spleens (SMC) of immune ducks. Optimal culture conditions for the assay were determined by testing a number of variables, including antigen concentration, cell numbers/well, and the day of harvest. The specificity of the assay was assessed. The assay used 10% pooled duck serum supplement, and 8 x 10(5) cells/well for PBMC or 5 x 10(5) cells/well for SMC. The optimum antigen concentration ranged from 0.01 to 0.1 microgram/ml for both DHBsAg and DHBcAg. Maximum antigen-specific blastogenesis occurred between 4 to 7 days after establishment of the culture. The use of PHA (10 micrograms/ml) mitogenesis could predict the optimal cell numbers/well for antigen-specific blastogenesis. The assay demonstrated specific responses by immune ducks compared with those of unexposed ducklings and adult ducks (for DHBsAg P < 0.001; DHBcAg P < 0.05). For immune ducks, PBMC from all 8 ducks responded to DHBsAg, however, cells from only 4 of 7 immune ducks, responded to DHBcAg. Splenic mononuclear cells from all immune ducks responded to either DHBsAg or DHBcAg or both antigens.     

Determinants of consumer interest in fuel economy: Lessons for strengthening the conservation argument

With an outlook for higher global energy prices and concomitant increase of agricultural resources for the pursuit of fuel, consumers are expected to seek more fuel-economic transportation alternatives. This paper examines factors that influence the importance consumers place on fuel economy, with attention given to differences between American and European consumers. In a survey conducted simultaneously in the United States (U.S.) and Belgium in the fall of 2006, respondents in both countries ranked fuel economy high among characteristics considered when purchasing a new vehicle. Overall, respondents in the U.S. placed greater emphasis on fuel economy as a new-vehicle characteristic. Respondents' budgetary concerns carried a large weight when purchasing a new vehicle as reflected in their consideration of a fuel's relative price (e.g. gasoline vs. diesel vs. biofuel) and associated car repair and maintenance costs. On the other hand, high-income Americans displayed a lack of concern over fuel economy. Concern over the environment also played a role since consumers who felt empowered to affect the environment with their purchasing decisions (buying low and clean emission technology and fuels) placed greater importance on fuel economy. No statistically significant effects on fuel economy rankings were found related to vehicle performance, socio-demographic parameters of age, gender or education. Importantly, the tradeoff between using agricultural inputs for energy rather than for food, feed and fiber had no impact on concerns over fuel economy. Finally, contrary to expectations, U.S. respondents who valued domestically produced renewable fuels did not tend to value fuel economy.     

Long-lasting decreases of AMPA responses following postsynaptic activity in single hippocampal neurons

The Windows program Visuelle Welt allows the demonstration of various visual phenomena such as geometrical-optical illusions, subjective contours, apparent movement, and Gestalt principles. One of the program's most interesting features is that the illusion-inducing context can be switched off, and in addition for many phenomena parameters can be varied interactively.