Ocular torsion quantification with video images

Describes a technique to quantify eye rotations about the visual axis (ocular torsion). Two digitized polar transformed images of the iris are displayed on a video monitor in order to facilitate a visual comparison and manual interaction. Emphasis is placed on error analysis and the method's simplicity when applied to static ocular torsion measurement. The implementation, applying averaging over ocular torsion determined in partitioned iris images, yields a theoretical resolution of 5' of arc. In a control experiment with an artificial eye, the accuracy showed to be better than 14' of arc. In practice, the measuring device was validated with the data from the literature by means of an experiment about ocular torsion in humans during tilt and hypergravity conditions (up to 3 g)     

Increased frequency and severity of angio-oedema related to long-term therapy with angiotensin-converting enzyme inhibitor in two patients

Adverse reactions to drugs are well recognized as a cause of acute or chronic urticaria, and angio-oedema. Angiotensin-converting enzyme (ACE) inhibitors, used to treat hypertension and congestive heart failure, were introduced in Europe in the middle of the eighties, and the use of these drugs has increased progressively. Soon after the introduction of ACE inhibitors, acute bouts of angio-oedema were reported in association with the use of these drugs. We wish to draw attention to the possibility of adverse reactions to ACE inhibitors after long-term use and in patients with pre-existing angio-oedema.     

Procedural and distributive justice: What is fair depends more on what comes first than on what comes next.

In this article, 2 experiments are presented, with 324 undergraduates. In both experiments, the independent variables were whether the procedure was accurate or inaccurate, whether the outcome was favorable or unfavorable, and whether participants were informed about the procedure before or after they were informed about the outcome. The independent variables were manipulated by means of scenarios in Exp 1 and by means of the R. Vermunt et al (1996) paradigm in Exp 2. As predicted on the basis of the authors' analysis of fairness heuristic theory, the findings revealed that what people judge to be fair is more strongly affected by information that is received first than by subsequently received information. The findings are discussed in terms of recent developments toward an integration of the procedural and distributive justice domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Activation of the Rap1 GTPase by the B cell antigen receptor

The B cell antigen receptor (BCR) activates Ras, a GTPase that promotes cell proliferation by activating the Raf-1/MEK/ERK signaling module and other signaling enzymes. In its active GTP-bound form, the Rap1 GTPase may act as a negative regulator of Ras-mediated signaling by sequestering Ras effectors (e.g., Raf-1) and preventing their activation. In this report, we show that BCR engagement activates Rap1 and that this is dependent on production of diacylglycerol (DAG) by phospholipase C-gamma. Activation of Rap1 by the BCR was greatly reduced in phospholipase C-gamma-deficient B cells, whereas both a synthetic DAG and phorbol dibutyrate could activate Rap1 in B cells. We had previously shown that C3G, an activator of Rap1, associates with the Crk adaptor proteins in B cells and that BCR engagement causes Crk to bind to the Cas and Cbl docking proteins. However, the DAG-dependent pathway by which the BCR activates Rap1 apparently does not involve Crk signaling complexes since phorbol dibutyrate could activate Rap1 without inducing the formation of these complexes. Thus, the BCR activates Rap1 via a novel DAG-dependent pathway.     

The contribution of six chronic conditions to the total burden of mobility disability in the Dutch population

OBJECTIVES: This study assessed the proportions of the burden of mobility disability in the Dutch population that are attributable to musculoskeletal diseases, lung diseases, neurological disorders, heart diseases, diabetes, and cancer. METHODS: National survey data were analyzed with an elimination technique that combines the results of logistic regression analysis and the disease prevalence. RESULTS: Of the total prevalence of disability (20.5%), 33.7% can be attributed to these six chronic conditions. Musculoskeletal disorders account for the major part, whereas the contribution of cancer is very small. CONCLUSIONS: The potential benefits of effective curative or preventive treatments for chronic conditions, in terms of reduction of the disability burden in the population, are limited.     

Exercise improves memory acquisition and retrieval in the Y-maze task: Relationship with hippocampal neurogenesis.

Enhanced physical activity is associated with improvements in cognitive function in rodents as well as in humans. The authors examined in detail which aspects of learning and memory are influenced by exercise, using a spatial Y-maze test combined with a 14-day exercise paradigm at different stages of learning. The authors show that 14 days of wheel running promotes memory acquisition, memory retention, and reversal learning. The exercise paradigm that was employed also significantly increased the number of maturing neurons, suggesting that an increase in neurogenesis underlies the positive effects of exercise on Y-maze performance. Finally, the authors show that memory acquisition in itself does not have a major impact on the number of immature neurons. However, memory retention testing and reversal learning both cause a significant reduction in the number of doublecortin and Ser133- phosphorylated pCREB-positive cells, indicating that a decrease in neurogenesis might be a prerequisite for optimal memory retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comprehending user behaviour using psycholinguistics

This article explores the use of psycholinguistics in attempting to comprehend user behaviour. It aims at getting an idea of what cognitive processes underlie the generation and interpretation of interactions with computers. The key claim of the article is that the cognitive processes underlying artificial language processing in human-computer interaction are analogous lo the ones underlying natural language processing in inter-human communication. The article presents a tentative model of the user's cognitive processes. The model generates interesting hypotheses and provides possible explanations of interaction phenomena.     

Towards Quantitative Structure Determination Through Electron Holographic Methods

The problem of quantitative interpretation of high-resolution electron microscopy is studied in the framework of parameter estimation. Ideally, quantitative interpretation means that unknown structural parameters of an object such as atom types and coordinates are determined from fitting with the experimental dataset. However, in the imaging process, the influence of these parameters is completely scrambled over a large area of the image. As a consequence, the fitting becomes a search process in the higher dimensional space of all coupled parameters. The real importance of holographic methods such as off-axis holography and focus variation is that they restore (deblur) to some extent the imaging process so as to unscramble the influence of the different model parameters. In this way the dimension of the search space becomes manageable. In this framework the concept of resolution in the sense of Rayleigh is not valid anymore, but it has to be replaced by the notice of parameter precision. In case two atoms are very close, the parameter space may become degenerate so that the atoms cannot be discriminated. The probability of this degeneracy is a function of the distance between the atoms and the dose of the imaging particles.     

Saving a creek one bid at a time: A uniform price auction for urban stormwater retention

Urban stormwater runoff degrades waterway health. We describe a market-based approach to identify the most efficient investments to reduce urban stormwater impacts at minimum cost. The framework involves the joint consideration of public and private supply of environmental services across scales; a metric to compare the benefits of interventions across and within scales; an environmental procurement auction to reveal and minimise the cost of private interventions; and an endogenous reserve price to select the optimal portfolio of investments. The paper discusses the economic and environmental rationale for the proposed approach, along with the results of Stormwater Tender, a field trial in Melbourne, Australia. To conceptualize the optimal portfolio of investments we draw the aggregate supply curve and the production possibility frontier (PPF) using data from the field trial. We find considerable heterogeneity in both the private and public cost of providing environmental benefits, highlighting the need to consider interventions across a range of scales. We also find that existing theory is limited in its ability to predict bidders' behaviour. Despite this, it is evident that using the PPF to select projects considerably improves the cost effectiveness of the investment. We therefore conclude that the approach is an effective way of maximising the benefits of policy interventions to reduce the impacts of stormwater on urban waterways.