Context modeling based lossless compression of radio-frequency data for software-based ultrasound beamforming

A new lossless compression method using context modeling for ultrasound radio-frequency (RF) data is presented. In the proposed compression method, the combination of context modeling and entropy coding is used for effectively lowering the data transfer rates for modern software-based medical ultrasound imaging systems. From the phantom and in vivo data experiments, the proposed lossless compression method provides the average compression ratio of 0.45 compared to the Burg and JPEG-LS methods (0.52 and 0.55, respectively). This result indicates that the proposed compression method is capable of transferring 64-channel 40-MHz ultrasound RF data with a 16-lane PCI-Express 2.0 bus for software beamforming in real time.     

An investigation of body mass distributional changes in Australia, 1995–2017/18

This study investigates changes in the distribution of body mass for adult Australians between 1995 and 2017/18. Using three nationally representative health surveys, we first apply the parametric generalised entropy (GE) class of inequality indices to measure the level of disparity in the body mass distribution. Results from the GE measure reveal that, while growth of body mass inequality is a population-wide experience, demographic and socio-economic factors explain only a modest portion of total inequality. We then apply the relative distributions (RD) method to garner richer insights on changes to the body mass distribution. The non-parametric RD method reveals growth in the proportion of adult Australians falling into the upper deciles of the body mass distribution since 1995. Then, hypothetically keeping the shape of the distribution unchanged, we discern that body mass increases across all deciles of the distribution (location effect) is an important contributor to the observed distributional change. After removing the location effect, however, we find a non-trivial role for distributional shape changes (growth of the proportion of adults at the upper and lower parts of the distribution as the proportion in the middle diminish). While our findings support current policy directions that target the population as a whole, factors driving shape changes to the body mass distribution also need consideration when designing anti-obesity campaigns, especially when aimed at women.     

Evaluation of human brain hyperthermia using exergy balance equation

Hyperthermia is caused by disturbance in the thermoregulatory system of the human body and requires emergency treatment to prevent disability or possible mortality. To design any therapeutic device for hyperthermia, an exhaustive effort is required to establish the extremities of such thermal traumas. In this context, the authors have incorporated the human-body exergy-balance equation to compute the hyperthermia thresholds. This is a pioneer attempt to model hyperthermia states. An induced-hyperthermia technique is used to evaluate the extremities of metabolic heat generation and other dependent parameters. Moreover, a case study is also presented to calculate the parameters of prime importance i.e. exergy consumption (EC) and entropy generation rate (δS_g) to provide the body's accumulative and exhaustive thermal energy maxima, respectively. Furthermore, the thresholds have been evaluated and simulated by the varying body and/or environmental conditions. The resulting states have been analysed to setup critical ranges to provide the guidelines for rehabilitation therapy. A thermal manikin has also been developed, mimicking the blood circulation in humans, to further substantiate the use of an exergy-based approach. The results indicate that the exergy-based approach is well suited to model hyperthermia at pathophysiological boundaries, contrary to existing approaches which predominantly are limited to the physiological domain.     

Ecological succession as an energy dispersal process

Ecological succession is described by the 2nd law of thermodynamics. According to the universal law of the maximal energy dispersal, an ecosystem evolves toward a stationary state in its surroundings by consuming free energy via diverse mechanisms. Species are the mechanisms that conduct energy down along gradients between repositories of energy which consist of populations at various thermodynamic levels. The salient characteristics of succession, growing biomass production, increasing species richness and shifting distributions of species are found as consequences of the universal quest to diminish energy density differences in least time. The analysis reveals that during succession the ecosystem's energy transduction network, i.e., the food web organizes increasingly more effective in the free energy reduction by acquiring new, more effective and abandoning old, less effective species of energy transduction. The number of species does not necessarily peak at the climax state that corresponds to the maximum-entropy partition of species maximizing consumption of free energy. According to the theory of evolution by natural selection founded on statistical physics of open systems, ecological succession is one among many other evolutionary processes.     

Assessing high conservation value areas for rare,endemic and threatened (RET) species: A study in high altitude Changthang landscape of India

The Forest Stewardship Council developed the concept of High Conservation Values (HCVs) as a criteria in the forest certification process in order to promote sustainable forest management. It has six major components or values and component one and two of HCVs deal with the habitat for viable populations of “rare, endemic and threatened (RET) species” using the IUCN Red List category and other national / regional / local lists. But a consistent robust methodology for identification of these areas, does not exist. The present study tried to develop for the first time, a straight forward inclusive methodology for identification of HCVAs for the RET species on a spatio-temporal scale. A total of 50 RET and other significant species (32 flora, 10 fauna and 8 avifauna) were identified after a thorough literature review, field surveys and consultations with experts. Occurrence data of the selected species was collected from different secondary sources, field surveys, institutes and scientists who have worked on them. A 10 km grid-based approach and stratified random sampling was used for the primary GPS field surveys conducted during 2018–2019. MaxEnt species distribution model (SDM) software was used based on the occurrence data and environmental variables for identification of potential suitable habitats for the selected species. Linear support vector machine (LSVM) model was used for assessing the performance of the SDMs. The performance of each SDM has been validated through Cohen's Kappa (KAPPA), true skill statistic (TSS) and receiver operating characteristics (ROC) models. The proposed methodology addresses the urgent need for a holistic and robust set of techniques to apply the HCV toolkit. This is key to identify and map HCVAs for RET species at the landscape level and can be easily adapted to and adopted at the national, regional, state or local level in India. The methods offer an efficient, reliable approach for the application of the HCV concept, elsewhere in the world.     

The Burrows-Wheeler similarity distribution between biological sequences based on Burrows-Wheeler transform

This work aims at the similarity of biological sequences. Based on the Burrows-Wheeler transform, a definition of Burrows-Wheeler similarity distribution of two sequences is proposed to compare two sequences. Some distance measures are naturally followed by the distribution. The expectation and entropy of the similarity distribution are used to construct phylogenetic trees on two independent data sets. The result demonstrates that the method is efficient and powerful.     

Commentary on: “Photosynthesis and negative entropy production” by Jennings and coworkers

This commentary argues against the view that photochemical energy conversion violates the second law of thermodynamics, as expressed in a recent paper [R.C. Jennings, E. Engelmann, F. Garlaschi, A.P. Casazza, G. Zucchelli. Photosynthesis and negative entropy production. Biochim. Biophys. Acta 1709 (2005) 251-255]. The basic principles of free energy conversion by a photo-electrochemical cell are outlined, emphasizing the fact that the potential depends on the relative population of the excited state and thus on the illumination intensity.