Handgrip strength and physical activity in frail elderly

Abstract OBJECTIVE To investigate the association between handgrip strength (HS) and physical activity in physical frailty elderly. METHOD Cross-sectional quantitative study with a sample of 203 elderly calculated based on the population estimated proportion. Tests were applied to detect cognitive impairment and assessment of physical frailty. Descriptive statistics and multivariate analysis by binary logistic regression were used, and also Student's t-test and Fisher's exact test. RESULTS A total of 99 (64.3%) elderly showed decreased handgrip strength and 90 (58.4%) elderly presented decrease in physical activity levels. There was a statistically significant difference between these two components (p=0.019), in which elderly who have decreased HS have lower levels of physical activity. For low levels of physical activity and decreased HS, there was no evidence of significant difference in the probability of the classification as frail elderly (p<0.001). CONCLUSION The components handgrip strength and physical activity are associated with the frail elderly. The joint presence of low levels of physical activity and decreased handgrip strength leads to a significantly higher probability of the elderly to be categorized as frailty.

Audit report on the Iowa Water Pollution Control Works Financing Program (Clean Water Program) and the Iowa Drinking Water Facilities Financing Program (Drinking Water Program), joint programs of the Iowa Finance Authority and the Iowa Department of Natural Resources, for the year ended June 30, 2006

Audit report on the Iowa Water Pollution Control Works Financing Program (Clean Water Program) and the Iowa Drinking Water Facilities Financing Program (Drinking Water Program), joint programs of the Iowa Finance Authority and the Iowa Department of Natural Resources, for the year ended June 30, 2006

Microcrystals As Damps And Their Role In Joint Inflammation

The concept of danger signals as important triggers of inflammation and immune activation has passed from fanciful hypothesis to a widely accepted biological process with receptors, signalling cascades and mediators. Products of cell death or cell stress are prime examples of DAMPs. They interact with receptors on the cell surface such as TLRs as well as cytoplasmic proteins such as the NLRs to modulate cellular metabolism and activation. Recently, the identification of the inflammasomes and their role in processing IL-1b and IL18 provided further insights into how DAMPs provoke inflammation. A class of substances that are potent activators of the inflammasome is microcrystals. All three microcrystals associated with joint disease in man : urate, CPP and hydroxyapatite require the NLRP3 inflammasome to process and release IL-1b from leucocytes. This mechanism most probably explain the inflammatory phase of acute crystal arthritis. However, microcrystals can also induce apoptosis, cell death as well as cell activation, depending on the cell type they are in contact with. These different cellular effects could well explain the role crystals can play in degenerative joint diseases, where inflammation is not as prominent. Our understanding of the intracellular pathways linking microcrystals to inflammation and cell activation is currently still very sketchy, and we hope that the detailed analysis of these pathways may lead to better comprehension and treatment of microcrystal induced joint diseases.Disclosures : The author has declared no conflicts of interest.

Stepwise multiple testing as formalized data snooping

It is common in econometric applications that several hypothesis tests arecarried out at the same time. The problem then becomes how to decide whichhypotheses to reject, accounting for the multitude of tests. In this paper,we suggest a stepwise multiple testing procedure which asymptoticallycontrols the familywise error rate at a desired level. Compared to relatedsingle-step methods, our procedure is more powerful in the sense that itoften will reject more false hypotheses. In addition, we advocate the useof studentization when it is feasible. Unlike some stepwise methods, ourmethod implicitly captures the joint dependence structure of the teststatistics, which results in increased ability to detect alternativehypotheses. We prove our method asymptotically controls the familywise errorrate under minimal assumptions. We present our methodology in the context ofcomparing several strategies to a common benchmark and deciding whichstrategies actually beat the benchmark. However, our ideas can easily beextended and/or modied to other contexts, such as making inference for theindividual regression coecients in a multiple regression framework. Somesimulation studies show the improvements of our methods over previous proposals. We also provide an application to a set of real data.

Fusion of data sets in multivariate linear regression with errors-in-variables

We consider the application of normal theory methods to the estimation and testing of a general type of multivariate regressionmodels with errors--in--variables, in the case where various data setsare merged into a single analysis and the observable variables deviatepossibly from normality. The various samples to be merged can differ on the set of observable variables available. We show that there is a convenient way to parameterize the model so that, despite the possiblenon--normality of the data, normal--theory methods yield correct inferencesfor the parameters of interest and for the goodness--of--fit test. Thetheory described encompasses both the functional and structural modelcases, and can be implemented using standard software for structuralequations models, such as LISREL, EQS, LISCOMP, among others. An illustration with Monte Carlo data is presented.

Research joint ventures in an international economy

D'Aspremont and Jacquemin's (1988) model is extended to studyalternative configurations of research agreements in a two--country integratedworld economy. Under unambiguous conditions on spillovers we show that:1) Allowing national firms to cooperate in R\&D confers them an advantageover foreign rivals, an effect similar to R\&D subsidies. 2) In a policygame, each government would allow national cooperative agreements. 3) Contraryto other trade policies which lead to a ``prisoners' dilemma'' result,welfare in both countries increases when they both allow R\&D cooperation.4) Welfare is even higher if a generalized (international) coalition isformed.

A new approach to accurate measurement of uniaxial joint angles based on a combination of accelerometers and gyroscopes.

A new method of measuring joint angle using a combination of accelerometers and gyroscopes is presented. The method proposes a minimal sensor configuration with one sensor module mounted on each segment. The model is based on estimating the acceleration of the joint center of rotation by placing a pair of virtual sensors on the adjacent segments at the center of rotation. In the proposed technique, joint angles are found without the need for integration, so absolute angles can be obtained which are free from any source of drift. The model considers anatomical aspects and is personalized for each subject prior to each measurement. The method was validated by measuring knee flexion-extension angles of eight subjects, walking at three different speeds, and comparing the results with a reference motion measurement system. The results are very close to those of the reference system presenting very small errors (rms = 1.3, mean = 0.2, SD = 1.1 deg) and excellent correlation coefficients (0.997). The algorithm is able to provide joint angles in real-time, and ready for use in gait analysis. Technically, the system is portable, easily mountable, and can be used for long term monitoring without hindrance to natural activities.

Direct MR arthrography of the shoulder under axial traction: Feasibility study to evaluate the superior labrum-biceps tendon complex and articular cartilage.

PURPOSE: To assess the value of adding axial traction to direct MR arthrography of the shoulder, in terms of subacromial and glenohumeral joint space widths, and coverage of the superior labrum-biceps tendon complex and articular cartilage by contrast material. MATERIALS AND METHODS: Twenty-one patients investigated by direct MR arthrography of the shoulder were prospectively included. Studies were performed with a 3 Tesla (T) unit and included a three-dimensional isotropic fat-suppressed T1-weighted gradient-recalled echo sequence, without and with axial traction (4 kg). Two radiologists independently measured the width of the subacromial, superior, and inferior glenohumeral joint spaces. They subsequently rated the amount of contrast material around the superior labrum-biceps tendon complex and between glenohumeral cartilage surfaces, using a three-point scale: 0 = no, 1 = partial, 2 = full. RESULTS: Under traction, the subacromial (Δ = 2.0 mm, P = 0.0003), superior (Δ = 0.7 mm, P = 0.0001) and inferior (Δ = 1.4 mm, P = 0.0006) glenohumeral joint space widths were all significantly increased, and both readers noted significantly more contrast material around the superior labrum-biceps tendon complex (P = 0.014), and between the superior (P = 0.001) and inferior (P = 0.025) glenohumeral cartilage surfaces. CONCLUSION: Direct MR arthrography of the shoulder under axial traction increases subacromial and glenohumeral joint space widths, and prompts better coverage of the superior labrum-biceps tendon complex and articular cartilage by contrast material. J. Magn. Reson. Imaging 2013;37:1228-1233. © 2012 Wiley Periodicals, Inc.

Constant coefficient tests for random coefficient regression

Random coefficient regression models have been applied in differentfields and they constitute a unifying setup for many statisticalproblems. The nonparametric study of this model started with Beranand Hall (1992) and it has become a fruitful framework. In thispaper we propose and study statistics for testing a basic hypothesisconcerning this model: the constancy of coefficients. The asymptoticbehavior of the statistics is investigated and bootstrapapproximations are used in order to determine the critical values ofthe test statistics. A simulation study illustrates the performanceof the proposals.