General purpose algorithms for characterization of slow and fast phase nystagmus

In the overall aim for a better understanding of the vestibular and optokinetic systems and their roles in space motion sickness, the eye movement responses to various dynamic stimuli are measured. The vestibulo-ocular reflex (VOR) and the optokinetic response, as the eye movement responses are known, consist of slow phase and fast phase nystagmus. The specific objective is to develop software programs necessary to characterize the vestibulo-ocular and optokinetic responses by distinguishing between the two phases of nystagmus. The overall program is to handle large volumes of highly variable data with minimum operator interaction. The programs include digital filters, differentiation, identification of fast phases, and reconstruction of the slow phase with a least squares fit such that sinusoidal or psuedorandom data may be processed with accurate results. The resultant waveform, slow phase velocity eye movements, serves as input data to the spectral analysis programs previously developed for NASA to analyze nystagmus responses to pseudorandom angular velocity inputs

Cross-contamination of oilseeds by insecticide residues during storage

Pesticide residues are found in oilseeds (rapeseed and sunflower) and crude oils: they are mainly organophosphate insecticides (pirimiophos-methyl, malathion when authorized) used in empty storage facilities and for direct application to stored cereal grain. Even if some secondary pests are found in stored oilseeds, French regulations do not allow use of these insecticides on stored oilseeds. These residues arise from cross-contamination from storage bins and grain handling equipment of grain stores, and not from illegal use. This uptake of insecticide residues from their storage environment by oilseeds may lead to residue contents that exceed regulatory limits. A three-year investigation in grain storage companies allowed us to follow the course of sunflower batches and rapeseed batches during storage seasons 2006-2007, 2007-2008 and 2008-2009, from reception at the storage facility to outloading. Each of these batches was sampled at outloading, and was analyzed for insecticide residues. Traceability of oilseeds established by grain-store managers allowed us to identify cross-contamination sources. The insecticides that were most commonly detected were pirimiophos-methyl, malathion, and dichlorvos (in sunflower 2006-2007), plus chlorpyriphos-methyl and deltamethrin. Pirimiophos-methyl was the most commonly detected active substance, and caused the most cases of non-accordance with regulatory levels in rapeseed. Cross-contamination could have occurred when cereal grains were treated upon receipt, when rapeseed was also delivered, especially when treatments were done systematically to the cereal grains. For sunflower, the main cross-contamination hazard resulted from treatment of cereals at the period of receipt or at their outloading, just before sunflower seeds batches were outloaded. Another situation led to cross-contamination, but generally at a lower extent: oilseeds stored in bins that contained previously treated cereals, or loaded in empty bins with handling equipment treated before the receipt of oilseeds.Keywords: Oilseed storage, Cross-contamination, Insecticide residues, Rapeseed, Sunflowe

Characterization of slow and fast phase nystagmus

A current literature review of the analog and digital process of vestibular and optical kinetic nystagmus reveals little agreement in the methods used by various labs. The strategies for detection of saccade (fast phase velocity component of nystagmus) vary between labs, and most of the process have not been evaluated and validated with a standard database. A survey was made of major vestibular labs in the U.S. that perform computer analyses of vestibular and optokinetic reflexes to stimuli, and a baseline was established from which to standardize data acquisition and analysis programs. The concept of an Error Index was employed as the criterium for evaluating the performance of the vestibular analysis software programs. The performance criterium is based on the detection of saccades and is the average of the percentages of missed detections and false detections. Evaluation of the programs produced results for lateral gaze with saccadic amplitude of one, two, three, five, and ten degrees with various signal-to-noise ratios. In addition, results were obtained for sinusoidal pursuit of 0.05, 0.10, and 0.50 Hz with saccades from one to ten degrees at various signal-to-noise ratios. Selection of the best program was made from the performance in the lateral gaze with three degrees of saccadic amplitude and in the 0.10 Hz sinusoid with three degrees of saccadic amplitude

Optimal Force Generation of 3-RRR Decoupled Planar Robots for Ensuring Unlimited Platform Rotation

International audienceThis paper deals with the optimal dynamics of the 3-RRR decoupled robot in which the linear displacements of the platform are decoupled from its orientation. The particularity of the 3-RRR decoupled robot is that an optimal choice of the leg's geometric parameters allows an unlimited platform rotation, which can be attractive for many industrial applications. However, a singular configuration is necessarily encountered during full platform rotation. In order to generate a stable motion in the presence of singularities, optimal dynamic conditions are disclosed. The suggested optimal conditions ensuring unlimited platform rotation are illustrated and validated by numerical simulations with ADAMS

Therapeutic interventions for lipid-induced insulin resistance in skeletal muscle: mechanisms of action

It has long been known that in addition to disruptions in glucose homeostasis, individuals with insulin resistance have a breakdown in lipid dynamics, often manifested by elevated levels of circulating fatty acids (FA) together with accumulation of lipids in insulin-sensitive tissues, including skeletal muscle. However, little is known about how common therapies used to treat insulin resistant individuals (such as Rosiglitazone and exercise training) improve skeletal muscle lipid and glucose metabolism. Thus, the primary aim of the studies undertaken for this thesis was to enhance our understanding of the mechanisms by which Rosiglitazone and exercise training improve skeletal muscle lipid metabolism and insulin sensitivity in two distinct models of insulin resistance. The first investigation determined the effect of chronic Rosiglitazone treatment on the accumulation of lipid metabolites and enzymatic regulators of lipid metabolism in the skeletal muscle of obese Zucker rats. The observation that Rosiglitazone treatment exacerbated the accumulation of muscle ceramide and diacylglycerol in skeletal muscle, while improving glucose tolerance led to the conclusion that this insulin sensitising drug improves insulin sensitivity by mechanisms other than reduction of fatty acid metabolites in this tissue. Accordingly, the second investigation sought to identify an alternative mechanism by which Rosiglitazone treatment may improve skeletal muscle insulin sensitivity. It was found that Rosiglitazone restored AMP-activated protein kinase (AMPK) á2 activity in the skeletal muscle of obese Zucker rats, providing a potential peroxisome proliferator activated receptor (PPAR) ã-independent mechanism by which this drug may mediate its insulinsensitising actions. The final experiment undertaken for this thesis determined the independent and interactive effects on Rosiglitazone and exercise training on various aspects of skeletal muscle glucose and lipid metabolism in a model of diet-induced insulin resistance, the high-fat fed rat. Exercise training, but not Rosiglitazone treatment restored skeletal muscle insulin sensitivity in high-fat fed rats. Improvements in insulin sensitivity with exercise training were associated with increased FA oxidation, increased AMPK activity and a normalisation of the expression of the Akt substrate, AS160. In contrast, Rosiglitazone treatment was associated with increased FA uptake and decreased insulin-stimulated glucose uptake in skeletal muscle. Exercise prevented the accumulation of skeletal muscle lipids in Rosiglitazone-treated animals when the two treatments were combined. In summary, the results from the studies undertaken for this thesis provide novel information regarding the mechanisms by which two insulinsensitising therapies, exercise training and Rosiglitazone treatment, act to improve glucose and lipid metabolism in skeletal muscle.It has long been known that in addition to disruptions in glucose homeostasis, individuals with insulin resistance have a breakdown in lipid dynamics, often manifested by elevated levels of circulating fatty acids (FA) together with accumulation of lipids in insulin-sensitive tissues, including skeletal muscle. However, little is known about how common therapies used to treat insulin resistant individuals (such as Rosiglitazone and exercise training) improve skeletal muscle lipid and glucose metabolism. Thus, the primary aim of the studies undertaken for this thesis was to enhance our understanding of the mechanisms by which Rosiglitazone and exercise training improve skeletal muscle lipid metabolism and insulin sensitivity in two distinct models of insulin resistance. The first investigation determined the effect of chronic Rosiglitazone treatment on the accumulation of lipid metabolites and enzymatic regulators of lipid metabolism in the skeletal muscle of obese Zucker rats. The observation that Rosiglitazone treatment exacerbated the accumulation of muscle ceramide and diacylglycerol in skeletal muscle, while improving glucose tolerance led to the conclusion that this insulin sensitising drug improves insulin sensitivity by mechanisms other than reduction of fatty acid metabolites in this tissue. Accordingly, the second investigation sought to identify an alternative mechanism by which Rosiglitazone treatment may improve skeletal muscle insulin sensitivity. It was found that Rosiglitazone restored AMP-activated protein kinase (AMPK) á2 activity in the skeletal muscle of obese Zucker rats, providing a potential peroxisome proliferator activated receptor (PPAR) ã-independent mechanism by which this drug may mediate its insulinsensitising actions. The final experiment undertaken for this thesis determined the independent and interactive effects on Rosiglitazone and exercise training on various aspects of skeletal muscle glucose and lipid metabolism in a model of diet-induced insulin resistance, the high-fat fed rat. Exercise training, but not Rosiglitazone treatment restored skeletal muscle insulin sensitivity in high-fat fed rats. Improvements in insulin sensitivity with exercise training were associated with increased FA oxidation, increased AMPK activity and a normalisation of the expression of the Akt substrate, AS160. In contrast, Rosiglitazone treatment was associated with increased FA uptake and decreased insulin-stimulated glucose uptake in skeletal muscle. Exercise prevented the accumulation of skeletal muscle lipids in Rosiglitazone-treated animals when the two treatments were combined. In summary, the results from the studies undertaken for this thesis provide novel information regarding the mechanisms by which two insulinsensitising therapies, exercise training and Rosiglitazone treatment, act to improve glucose and lipid metabolism in skeletal muscle

African-American patients with cancer Talking About Clinical Trials (TACT) with oncologists during consultations: evaluating the efficacy of tailored health messages in a randomised controlled trial—the TACT study protocol

Introduction Low rates of accrual of African-American (AA) patients with cancer to therapeutic clinical trials (CTs) represent a serious and modifiable racial disparity in healthcare that impedes the development of promising cancer therapies. Suboptimal physician–patient consultation communication is a barrier to the accrual of patients with cancer of any race, but communication difficulties are compounded with AA patients. Providing tailored health messages (THM) to AA patients and their physician about CTs has the potential to improve communication, lower barriers to accrual and ameliorate health disparities. Objective (1) Demonstrate the efficacy of THM to increase patient activation as measured by direct observation. (2) Demonstrate the efficacy of THM to improve patient outcomes associated with barriers to AA participation. (3) Explore associations among preconsultation levels of: (A) trust in medical researchers, (B) knowledge and attitudes towards CTs, (C) patient-family member congruence in decision-making, and (D) involvement/information preferences, and group assignment. Methods and analysis First, using established methods, we will develop THM materials. Second, the efficacy of the intervention is determined in a 2 by 2 factorial randomised controlled trial to test the effectiveness of (1) providing 357 AA patients with cancer with THM with 2 different ‘depths’ of tailoring and (2) either providing feedback to oncologists about the patients\u27 trial THM or not. The primary analysis compares patient engaged communication in 4 groups preconsultation and postconsultation. Ethics and dissemination This study was approved by the Virginia Commonwealth University Institutional Review Board. To facilitate use of the THM intervention in diverse settings, we will convene ‘user groups’ at 3 major US cancer centres. To facilitate dissemination, we will post all materials and the implementation guide in publicly available locations

Aspects of topology of condensates and knotted solitons in condensed matter systems

The knotted solitons introduced by Faddeev and Niemi is presently a subject of great interest in particle and mathematical physics. In this paper we give a condensed matter interpretation of the recent results of Faddeev and Niemi.Comment: v2: Added a reference to the paper E. Babaev, L.D. Faddeev and A.J. Niemi cond-mat/0106152 where an exact equivalence was shown between the two-condensate Ginzburg-Landau model and a version of Faddeev model. Miscelaneous links related to knotted solitons are available at the author homepage at http://www.teorfys.uu.se/PEOPLE/egor/ . Animations of knotted solitons by Hietarinta and Salo are available at http://users.utu.fi/h/hietarin/knots/c45_p2.mp

A New Analysis Method for Reconstructing the Arrival Direction of TeV Gamma-rays Using a Single Imaging Atmospheric Cherenkov Telescope

We present a method of atmospheric Cherenkov imaging which reconstructs the unique arrival direction of TeV gamma rays using a single telescope. The method is derived empirically and utilizes several features of gamma-ray induced air showers which determine, to a precision of 0.12 degrees, the arrival direction of photons, on an event-by-event basis. Data from the Whipple Observatory's 10 m gamma-ray telescope is utilized to test selection methods based on source location. The results compare these selection methods with traditional techniques and three different camera fields of view. The method will be discussed in the context of a search for a gamma-ray signal from a point source located anywhere within the field of view and from regions of extended emission.Comment: 24 pages, 16 figures, accepted for publication in Astroparticle Physics May 11, 200

Convergence de la variabilité dans les modèles polygéniques gaussiens

International audienc