Adaptive optics using a liquid crystal phase modulator in conjunction with a Shack-Hartmann wave front sensor and zonal control algorithm

Multi-segment liquid crystal spatial light modulators have received much attention recently for use as high-precision wavefront control devices for use in astronomical and non-astronomical applications. They act much like piston only segmented deformable mirrors. In this paper we investigate the use of these devices in conjunction with a Shack-Hartmann wave-front sensor. Previous investigators have considered Zernike modal control algorithms. In this paper we consider a zonal algorithm in order to take advantage of high speed matrix multiply hardware which we have in hand.

Computational approach for probing the flow through artificial heart devices

Computational fluid dynamics (CFD) has become an indispensable part of aerospace research and design. The solution procedure for incompressible Navier-Stokes equations can be used for biofluid mechanics research. The computational approach provides detailed knowledge of the flowfield complementary to that obtained by experimental measurements. This paper illustrates the extension of CFD techniques to artificial heart flow simulation. Unsteady incompressible Navier-Stokes equations written in three-dimensional generalized curvilinear coordinates are solved iteratively at each physical time step until the incompressibility condition is satisfied. The solution method is based on the pseudocompressibility approach. It uses an implicit upwind-differencing scheme together with the Gauss-Seidel line-relaxation method. The efficiency and robustness of the time-accurate formulation of the numerical algorithm are tested by computing the flow through model geometries. A channel flow with a moving indentation is computed and validated by experimental measurements and other numerical solutions. In order to handle the geometric complexity and the moving boundary problems, a zonal method and an overlapped grid embedding scheme are employed, respectively. Steady-state solutions for the flow through a tilting-disk heart valve are compared with experimental measurements. Good agreement is obtained. Aided by experimental data, the flow through an entire Penn State artificial heart model is computed.

Report cards: tools for managing pathways and outcomes

An overriding concern of many health care providers is how to maintain quality in such a turbulent, cost-driven environment. It is essential for health care providers to determine the effectiveness of their care and to institute changes in practice to affect patient outcomes in a positive fashion. Determining the appropriate outcomes to measure and formatting the report in an easy-to-read manner with meaningful information is important for presentation to a variety of audiences. We describe a report card methodology for disseminating outcome information that can easily be adapted in other settings.

Clinical global measures of dementia. Position paper from the International Working Group on Harmonization of Dementia Drug Guidelines

Following is the report of the committee working on clinical global measures for antidementia drug guidelines. The concepts involved in global scales, the distinctions between change and severity scales, advantages and disadvantages of structured interviews, and anchoring of change scores are discussed, and selected existing clinical global scales are described. In addition, the committee assessed the utility of global scales in clinical trials for antidementia drugs. There was a consensus among the members of the working group on the following: (1) Clinical global scales are interview based; in most cases, they include information obtained from caregivers as well as directly from patients, but they can rely on information from the subject only. (2) Clinicians' global ratings are intended to assess clinically meaningful change based on multidimensional clinical assessment and take into account the clinical heterogeneity of dementia by assessing at least cognition, behavior, and functioning. (3) There are two distinct types of clinical global measures: (a) clinicians' interview-based global severity scales, which generally incorporate classification by stage or severity of illness and (b) clinicians' interview-based global change scales, which incorporate global assessment ratings of clinical change. The committee could not reach a consensus on whether global scales should be required in phase II and phase III clinical trials, or whether other specific assessments such as well-designed activities of daily living, cognition, and behavior measures could, when used in appropriate combinations, replace the global as assessments of clinical meaningfulness.

Experience-dependent changes in the number of chemosensory sensilla on the mouthparts and antennae of

The effect of diet on the number of gustatory and olfactory sensilla was investigated in locusts. Insects fed for the final two stadia on nutritionally adequate synthetic foods have fewer sensilla on the maxillary palps and antennae than insects fed on the usual rearing diet of seedling wheat. This effect was seen irrespective of the nutritional balance of the foods and was independent of the concentration of nutrients present or the size of the insect. Supplying wheat odour to locusts fed synthetic foods had no effect on the number of sensilla present on the palps, but completely reversed the decrease in the number of olfactory sensilla of the antennae and partially reversed the decrease in the number of antennal uniporous trichoid sensilla. Locusts that were allowed to select between two nutritionally unbalanced but complementary synthetic foods had a higher number of sensilla on the maxillary palps than those fed individual synthetic foods, providing the two foods differed substantially in their protein:carbohydrate ratios. Insects also developed more sensilla if they were fed on two foods of identical nutritional composition but with different added flavours (1% tannic acid or amygdalin). Exposing locusts to synthetic foods for a single stadium did not cause any significant decrease in sensilla number. The results suggest that the number of sensilla that develop in a given sensory field is influenced by the variety of chemical stimuli experienced and the chemical complexity of the environment as provided by the presence of distinct individual sources of stimulation.

Fever

Fever is a host defense response that provides a sign of an ongoing process related to infection, inflammation, drug reactions, neoplasms, autoimmune diseases, and vascular disorders. The most frequent causes of fever in acutely ill patients are infection and inflammation, but fever may be caused by one or more of a long list of pathophysiologic processes.

The five Cs of choice. Outcome measures for individuals with severe and persistent mental illness

In a time when mental health service providers are cutting costs and services, stakeholders need adequate information in the form of outcome measures to evaluate services based on quality. Outcome measures are particularly important for high-risk populations, where severe and persistent mental illness results in serious functional impairment of daily life. A client-oriented method of gauging rehabilitation of real-world behavior over the long-term, as well as the short-term, and which allows for comparison with other programs, must be developed. Lack of agreement on the domains to be measured, however, has hindered the development of common standards, making it difficult to track accountability and service effectiveness. Four authors provide a framework to help organizations choose and develop appropriate outcome measures, as well as core data suggested to measure longitudinal changes in rehabilitation.

Experimental measurements of estimator bias and the signal-to-noise ratio for deconvolution from wave-front sensing

Deconvolution from wave-front sensing (DWFS) has been proposed as a method for achieving high-resolution images of astronomical objects from ground-based telescopes. The technique consists of the simultaneous measurement of a short-exposure focal-plane speckled image, as well as the wave front, by use of a Shack-Hartmann sensor placed at the pupil plane. In early studies it was suspected that some problems would occur in poor seeing conditions; however, it was usually assumed that the technique would work well as long as the wave-front sensor subaperture spacing was less than r(0) (L/r(0) < 1). Atmosphere-induced phase errors in the pupil of a telescope imaging system produce both phase errors and magnitude errors in the effective short-exposure optical transfer function (OTF) of the system. Recently it has been shown that the commonly used estimator for this technique produces biased estimates of the magnitude errors. The significance of this bias problem is that one cannot properly estimate or correct for the frame-to-frame fluctuations in the magnitude of the OTF but can do so only for fluctuations in the phase. An auxiliary estimate must also be used to correct for the mean value of the magnitude error. The inability to compensate for the magnitude fluctuations results in a signal-to-noise ratio (SNR) that is less favorable for the technique than was previously thought. In some situations simpler techniques, such as the Knox-Thompson and bispectrum methods, which require only speckle gram data from the focal plane of the imaging system, can produce better results. We present experimental measurements based on observations of bright stars and the Jovian moon Ganymede that confirm previous theoretical predictions.

Treatment of psoriasis with intermittent short course cyclosporin (Neoral). A multicentre study

A 1 year, prospective multicentre study was performed to investigate the efficacy and safety of intermittent treatment with cyclosporin in psoriasis vulgaris. Subjects received cyclosporin (Neoral) 5 mg/kg per day until achieving 90% reduction in area affected, or for a maximum of 12 weeks. Those failing to demonstrate a satisfactory response were withdrawn. When further treatment was required, cyclosporin was recommenced. This cycle was repeated up to three times. Psoriasis activity was recorded using the area affected and sign scores for erythema, scaling and infiltration. Overall assessments of response and tolerability were recorded. Forty-one subjects, mean age 36, mean PASI 12.8, entered the first treatment period. Thirty-three received a second period of treatment and 16 a third. Eighteen failed to complete the study as planned: five were withdrawn due to adverse events, four due to treatment failure and nine due to protocol violations. At the end of each treatment period, significant improvements were seen in all efficacy parameters. Overall response was graded as 'considerable improvement' or 'minimal or no symptoms', by over 80% of subjects and investigators. Median intervals to relapse for subjects remaining in the study were 72 days (range 28-329) and 53 days (range 14-141) after periods 1 and 2, respectively. There were significant increases in mean serum creatinine and blood pressure during each treatment period. However, there were no significant differences in either parameter between baseline and the final follow-up visit. At the end of each treatment period, overall tolerability of the treatment was considered 'good' or 'very good' by over 80% of subjects and investigators.

Health promotion: an essential component of rehabilitation for persons with chronic disabling conditions

This qualitative study was undertaken to clarify an emerging explanatory model of health-promoting behaviors, and quality of life in individuals with chronic disabling conditions. Twenty individuals with multiple sclerosis shared their stories regarding health promotion, domains of quality of life, and factors that affected these domains. Health-promoting behaviors were viewed as essential to the process of rehabilitation and maintaining an acceptable quality of life. Important quality-of-life issues were related to domains other than function. Implications are that health promotion efforts need to be encouraged and supported in individuals with chronic disabling conditions.

A highly specific inhibitor of human p38 MAP kinase binds in the ATP pocket

The crystal structure of human p38 mitogen-activated protein (MAP) kinase in complex with a potent and highly specific pyridinyl-imidazole inhibitor has been determined at 2.0 A resolution. The structure of the kinase, which is in its unphosphorylated state, is similar to that of the closely-related ERK2. The inhibitor molecule is bound in the ATP pocket. A hydrogen bond is made between the pyridyl nitrogen of the inhibitor and the main chain amido nitrogen of residue 109, analogous to the interaction from the N1 atom of ATP. The crystal structure provides possible explanations for the specificity of this class of inhibitors. Other protein kinase inhibitors may achieve their specificity through a similar mechanism. The structure also reveals a possible second binding site for this inhibitor, with currently unknown function.

Alendronate in the treatment of Paget's disease of bone

We studied four treatment regimens of oral alendronate in 60 patients with active Paget's disease. Two groups received an oral daily dose of either 40 or 80 mg of alendronate for 3 months, followed by placebo for a further 3 months: the other two groups received treatment with 40 or 80 mg per day for 6 months. Activity of alkaline phosphatase and urinary hydroxyproline excretion were measured before, during, and after treatment, at intervals for a total follow-up of 1 year. A transiliac bone biopsy was performed in 24 patients before and after the treatment. An additional 16 patients had a third biopsy more than a year after stopping treatment. Alendronate induced a marked suppression in the urinary excretion of hydroxyproline within 2 weeks (p < 0.01) followed by a fall in serum activity of alkaline phosphatase at 1 month (p < 0.01) in all treatment groups. Nine months after the start of treatment patients treated with 80 mg for 6 months had a significantly lower mean alkaline phosphatase activity compared to the other treatment groups (p < 0.02), which persisted at 1 year (p < 0.05). Alkaline phosphatase decreased to within the laboratory reference range in all patients given 80 mg for 6 months. In contrast, alkaline phosphatase decreased to within the laboratory reference range in 73-83% of patients given 80 mg for 3 months and the 40 mg dose. Histomorphometric assessment showed a decrease in indices of bone turnover in the pagetic biopsies. None of the biopsies taken after treatment showed evidence of impaired mineralization of bone. Gastrointestinal side effects occurred in 25% of patients of whom two withdrew from treatment. We conclude that oral alendronate is an effective agent for the treatment of Paget's disease of bone.

The experience of fatigue and strategies of self-care among persons with multiple sclerosis

Fatigue is one of the most common and least understood symptoms of many chronic and disabling conditions. This qualitative study used a convenience sample (N = 13) of individuals with multiple sclerosis (MS). A semistructured interview guide was used to elicit a description of the experience of fatigue. Its perceived antecedents, and the self-care strategies used to manage it. Data were gathered during two 90 minute interviews. Five themes were identified that describe the experience of fatigue for persons with MS. Categories of self-care strategies included energy conservation, recharge efforts, enhancing resistance to fatigue, and temperature control. Further research is needed to explore the effects of specific interventions in the management of fatigue.

The effect of placing an aortic Wallstent across the renal artery origins in an animal model

OBJECTIVES

To assess the effect on renal blood flow and renal function of placing a Wallstent (Schneider (Europe) AG) across the renal artery origins in an animal model.

DESIGN

Laboratory animal study.

MATERIALS AND METHODS

Six Large White pigs had Wallstents placed across the origins of one or both renal arteries. Preoperative jugular venous blood samples were submitted for blood count and urea and electrolyte estimation. The pigs were recovered for 6 weeks. At sacrifice the renal arteries and their origins were examined by aortography and direct pressure measurements were recorded from the renal arteries and both the stented and unstented portions of the aorta. Renal venous blood samples were submitted for blood count, urea and electrolyte and renin estimation while renal arterial blood samples were submitted to examination for red blood cell fragmentation. The aorta with contained stent, renal arteries and kidneys were submitted for histological examination.

RESULTS

At sacrifice no renal arteries had occluded and the stent-covered origins appeared normal with no evidence of stenosis. This was confirmed histologically. There was no statistically significant difference between the arterial pressures measured in the stented and unstented portions of aorta and the renal arteries whether or not their origins had been covered by the stent. There was no statistically significant difference between the urea and electrolyte and renin levels of renal venous blood samples irrespective of whether or not the relevant kidney had a stent across its renal artery origin. Renal arterial blood samples showed no evidence of red blood cell fragmentation and histological examination of the kidneys showed no evidence of infarction or micro-emboli. Examination of the specimens by light and scanning electron microscopy demonstrated partial endothelialisation of the stents but the renal artery origins remained widely patent despite being crossed by at least one wire in all cases.

CONCLUSIONS

It may be necessary to place stents across renal artery origins during endovascular repair of abdominal aortic aneurysms. It would appear that covering renal artery origins with a Wallstent has no effect on renal perfusion pressure or function in this short-term animal model.