Adaptive Hierarchical Data Aggregation using Compressive Sensing (A-HDACS) for Non-smooth Data Field

Compressive Sensing (CS) has been applied successfully in a wide variety of applications in recent years, including photography, shortwave infrared cameras, optical system research, facial recognition, MRI, etc. In wireless sensor networks (WSNs), significant research work has been pursued to investigate the use of CS to reduce the amount of data communicated, particularly in data aggregation applications and thereby improving energy efficiency. However, most of the previous work in WSN has used CS under the assumption that data field is smooth with negligible white Gaussian noise. In these schemes signal sparsity is estimated globally based on the entire data field, which is then used to determine the CS parameters. In more realistic scenarios, where data field may have regional fluctuations or it is piecewise smooth, existing CS based data aggregation schemes yield poor compression efficiency. In order to take full advantage of CS in WSNs, we propose an Adaptive Hierarchical Data Aggregation using Compressive Sensing (A-HDACS) scheme. The proposed schemes dynamically chooses sparsity values based on signal variations in local regions. We prove that A-HDACS enables more sensor nodes to employ CS compared to the schemes that do not adapt to the changing field. The simulation results also demonstrate the improvement in energy efficiency as well as accurate signal recovery

Effect of Physical Activity and Obesity on Type 2 Diabetes in a Middle-Aged Population

Background. The physical activity has been associated with a reduced risk of type 2 diabetes. The aim of this study was to examine the effect of physical activities such as occupational, household and daily lifestyle activities and obesity on the prevalence of type 2 diabetes in middle-aged population. Methods. All people (n = 2053), aged 45–64 years were selected for this study from the large sample of population-based cross-sectional data collected in the 1990–1994 by National Health Survey of Pakistan. The participants completed in-person interviews at baseline; the overall response rate was 92.6%. The Cox proportional hazards model was used to estimate the risk of developing the type 2 diabetes. Results. Stair climbing was found to be inversely associated with the risk of diabetes and cycling was also associated with a reduced risk of type 2 diabetes (RR = 0.82; 95% CI 0.68–1.00, P = .048). The relationship between physical activity and reduced risk of diabetes adjusted for age and body mass index was statistically significant only in women (P < .01). Conclusions. This study provides an incentive that physical activity in leisure-time exercise or daily activity reduces the risk of type 2 diabetes in a high-risk population

A new class of two-channel biorthogonal filter banks and wavelet bases

We propose a novel framework for a new class of two-channel biorthogonal filter banks. The framework covers two useful subclasses: i) causal stable IIR filter banks. ii) linear phase FIR filter banks. There exists a very efficient structurally perfect reconstruction implementation for such a class. Filter banks of high frequency selectivity can be achieved by using the proposed framework with low complexity. The properties of such a class are discussed in detail. The design of the analysis/synthesis systems reduces to the design of a single transfer function. Very simple design methods are given both for FIR and IIR cases. Zeros of arbitrary multiplicity at aliasing frequency can be easily imposed, for the purpose of generating wavelets with regularity property. In the IIR case, two new classes of IIR maximally flat filters different from Butterworth filters are introduced. The filter coefficients are given in closed form. The wavelet bases corresponding to the biorthogonal systems are generated. the authors also provide a novel mapping of the proposed 1-D framework into 2-D. The mapping preserves the following: i) perfect reconstruction; ii) stability in the IIR case; iii) linear phase in the FIR case; iv) zeros at aliasing frequency; v) frequency characteristic of the filters

A Value-Chain Perspective on Wheat Flour Fortification in Pakistan

Food fortification is a popular strategy for addressing ‘hidden hunger’, and staple foods are seen as promising if unproven vehicles for the delivery of essential micronutrients to the poor in developing countries. This paper examines wheat flour fortification with iron in Pakistan as a case of technocratic optimism in the face of institutional constraints. An evaluative framework based on the analysis of the entire value chain can provide a reality check on technocratic optimism. Poor people base their preferences for different types of flour on price as well as perceptions of nutritional value. Many of these flour types are not covered by fortification programmes. Fortification interventions meanwhile have attempted to leverage public-private partnerships in a segment of the wheat flour value chain which is beset with regulatory weaknesses. This paper illustrates why technical interventions should support, rather than ignore, a broader agenda of reforms in food policy.UKAIDDFI