The Relationship of Activity Restriction and Replacement With Depressive Symptoms Among Older Adults.

Activity restriction is known to mediate the disease-depression relationship. Data from 423 older Israeli adults showed that having to give up activities because of failing health was related to more depressive symptoms (DS), whereas satisfactorily replacing these activities was related to DS levels comparable to those of healthier older adults. Giving up and replacing activities mediated, in part, the effect of functional limitations on DS, after controlling for health status, demographics, and resources. Such questions about activities given up and replaced could contribute to the means of assessing the extent and impact of functional limitations on older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antecedents of self-esteem in deaf people: A meta-analytic review.

Presents a meta-analysis of 42 empirical studies that assessed the effect of 6 constructs on self-esteem (SE): hearing status, parents' hearing status, type of school attended, communication mode used at home and in school, and group identification. Differences in SE between deaf and hearing people varied based on the SE measure and its format, and the communication mode in which tests were administered. People whose parents were deaf compared favorably to those whose parents were hearing, as did people whose parents used sign language at home compared to those who used oral communication. School setting and classroom communication were unrelated to SE. Finally, group identification was positively related to SE. Recommendations for guiding hearing parents in fostering SE in their deaf children are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Magnetic resonance imaging (MRI) and relaxation spectrum analysis as methods to investigate swelling in whey protein gels

Effective means for controlled delivery of nutrients and nutraceuticals are needed. Whey protein-based gels, as a model system and as a potential delivery system, exhibit pH-dependent swelling when placed in aqueous solutions. Understanding the physics that govern gel swelling is thus important when designing gel-based delivery platforms. The extent of swelling over time was monitored gravimetrically. In addition to gravimetric measurements, magnetic resonance imaging (MRI) a real-time noninvasive imaging technique that quantified changes in geometry and water content of these gels was utilized. Heat-set whey protein gels were prepared at pH 7 and swelling was monitored in aqueous solutions with pH values of 2.5, 7, and 10. Changes in dimension over time, as characterized by the number of voxels in an image, were correlated to gravimetric measurements. Excellent correlations between mass uptake and volume change (R(2)= 0.99) were obtained for the gels in aqueous solutions at pH 7 and 10, but not for gels in the aqueous solution at pH 2.5. To provide insight into the mechanisms for water uptake, nuclear magnetic resonance (NMR) relaxation times were measured in independent experiments. The relaxation spectrum for the spin-spin relaxation time (T(2)) showed the presence of 3 proton pools for pH 7 and 10 trials and 4 proton pools for pH 2.5 trials. Results demonstrate that MRI and NMR relaxation measurements provided information about swelling in whey protein gels that can constitute a new means for investigating and developing effective delivery systems for foods.     

Individual time-dependent spectral boundaries for improved accuracy in time-frequency analysis of heart rate variability

Heart rate variability (HRV) is a major noninvasive technique for evaluating the autonomic nervous system (ANS). Use of time-frequency approach to analyze HRV allows investigating the ANS behavior from the power integrals, as a function of time, in both steady-state and non steady-state. Power integrals are examined mainly in the low-frequency and the high-frequency bands. Traditionally, constant boundaries are chosen to determine the frequency bands of interest. However, these ranges are individual, and can be strongly affected by physiologic conditions (body position, breathing frequency). In order to determine the dynamic boundaries of the frequency bands more accurately, especially during autonomic challenges, we developed an algorithm for the detection of individual time-dependent spectral boundaries (ITSB). The ITSB was tested on recordings from a series of standard autonomic maneuvers with rest periods between them, and the response to stand was compared to the known physiological response. A major advantage of the ITSB is the ability to reliably define the mid-frequency range, which provides the potential to investigate the physiologic importance of this range.     

Intermolecular interactions in phytochemical model systems studied by NMR diffusion measurements

Novel functional foods, such as tomato juice with soy, represent a new strategy to increase consumption of health promoting ingredients and phytochemicals. Interactions between soy protein, isoflavones, and tomato carotenoids could impact the bioaccessibility and bioavailability of individual phytochemicals. The primary objective of this study was to assess possible interactions between daidzein and daidzin, soy protein and carotenoids using proton one-dimensional and two-dimensional pulsed field gradient nuclear magnetic resonance spectroscopy experiments.     

Characterizing and designing polycation-clay nanocomposites as a basis for imazapyr controlled release formulations

A novel controlled release formulation (CRF) of the herbicide imazapyr (IMP) was designed to reduce its leaching,which causes soil and water contamination. The anionic herbicide IMP was bound to polydiallyldimethylammonium-chloride (PDADMAC)-montmorillonite composites. PDADMAC adsorption reached a high loading of polymer, which resulted in charge reversal of the clay and promoted IMP binding. The composites were characterized by Fourier transform infrared, zeta potential, and X-ray diffraction measurements, indicating electrostatic interactions of the polycation with the surface, polycation intercalation in the clay and suggesting a configuration as loops and tails on the surface at high loadings. IMP binding to the composites is affected by polycation loading and flocculation. Upon adding high concentrations of IMP to a composite of 0.16 g/g, we obtained high herbicide loadings (66% active ingredient). IMP release from the CRFs applied on a thin layer of soil was substantially slower than its release from the commercial formulation (Arsenal). Accordingly, soil column bioassays indicated reduced herbicide leaching (nearly 2-fold) upon applying the CRFs while maintaining good herbicidal activity. The new PDADMAC-clay formulations are promising from the environmental and weed control management points of view.     

The Multi-strand Graph for a PTZ Tracker

High-resolution images can be used to resolve matching ambiguities between trajectory fragments (tracklets), which is a key challenge in multiple-target tracking. A pan–tilt–zoom (PTZ) camera, which can pan, tilt and zoom, is a powerful and efficient tool that offers both close-up views and wide area coverage on demand. The wide area enables tracking of many targets, while the close-up view allows individuals to be identified from high-resolution images of their faces. A central component of a PTZ tracking system is a scheduling algorithm that determines which target to zoom in on, particularly when the high-resolution images are also used for tracklet matching. In this paper, we study this scheduling problem from a theoretical perspective. We propose a novel data structure, the Multi-strand Tracking Graph (MSG), which represents the set of tracklets computed by a tracker and the possible associations between them. The MSG allows efficient scheduling as well as resolving of matching ambiguities between tracklets. The main feature of the MSG is the auxiliary data saved in each vertex, which allows efficient computation while avoiding time-consuming graph traversal. Synthetic data simulations are used to evaluate our scheduling algorithm and to demonstrate its superiority over a naïve one.     

An approximate method for the study of large deformations of membranes

A method is described to give approximate solutions to problems concerned with the deformation of highly extensible, rubberlike membranes. This is based on a principle first described by Rayleigh, involving the minimization of the elastic strain energy of the membrane. The method, which enables rapid solution under a variety of boundary conditions, is applied to three typical problems with no known closed-form solutions, namely: the stretching of a clamped rubber sheet; the stretching of a rubber tube; and the axial movement of the inner ring of an annulus with respect to its outer periphery.     

Allocation of routinely monitored mixing ratios of nitrogen oxides to their sources

In many urban areas throughout the world, the rising mean and peak levels of nitrogen oxides (NOx) are a concern. Road traffic and local industry are usually the major NOx sources in urban environments, buttheir relative contributions to the spatial distribution of the NOx volumetric mixing ratio is normally unknown. This missing piece of information is required for designing effective abatement measures to reduce ambient NOx levels. A new method for estimating the shares of which traffic and industry contribute to the mean ambient NOx mixing ratios observed in urban environments is proposed in this paper. The estimation is based on data obtained by routine air pollution monitoring, using a few assumptions aboutthe temporal emission patterns of NOx and SO2 in the area of study. A set of equations is formulated for the unknown industry and traffic contributions to the NOx mixing ratios at each monitoring site. These equations are solved using the gradient projection optimization method. The bootstrap technique is used to estimate the errors in the process. Spatial maps of the separate shares of industry and traffic in the total ambient NOx levels can be obtained where a sufficient aerial coverage of stations is available. An application of the method to the allocation of NOx mixing ratios to traffic and industrial sources in the Haifa Bay area, Israel, is demonstrated. The results are expected to be useful for future planning of traffic thoroughfares and industrial development in the area.     

When is it Possible to Identify 3D Objects From Single Images Using Class Constraints?

One approach to recognizing objects seen from arbitrary viewpoint is by extracting invariant properties of the objects from single images. Such properties are found in images of 3D objects only when the objects are constrained to belong to certain classes (e.g., bilaterally symmetric objects). Existing studies that follow this approach propose how to compute invariant representations for a handful of classes of objects. A fundamental question regarding the invariance approach is whether it can be applied to a wide range of classes. To answer this question it is essential to study the set of classes for which invariance exists. This paper introduces a new method for determining the existence of invariant functions for classes of objects together with the set of images from which these invariants can be computed. We develop algebraic tests that determine whether the objects in a given class can be identified from single images. These tests apply to classes of objects undergoing affine projection. In addition, these tests allow us to determine the set of views of the objects which are degenerate. We apply these tests to several classes of objects and determine which of them is identifiable and which of their views are degenerate.