Extended Non-Binary Low-Density Parity-Check Codes over Erasure Channels

Based on the extended binary image of non-binary LDPC codes, we propose a method for generating extra redundant bits, such as to decreases the coding rate of a mother code. The proposed method allows for using the same decoder, regardless of how many extra redundant bits have been produced, which considerably increases the flexibility of the system without significantly increasing its complexity. Extended codes are also optimized for the binary erasure channel, by using density evolution methods. Nevertheless, the results presented in this paper can easily be extrapolated to more general channel models.Comment: ISIT 2011, submitte

Infection dynamics of four gill Monogenean species from Tilapia zillii (Gervais, 1848) in man-made Lake Ayame I, Côte d’Ivoire

The study of the gills of 359 Tilapia zillii, which were caught between August 2004 and July 2005, have been investigated in the Ayame man-made lake (Côte d’Ivoire), so as to collect first data on the population dynamics of the Monogeneans parasites in a wild population. Standard methods of  parasitological examination were used for identification of Monogenean species. Four Cichlidogyrus species were identified on the gills of host fish: C. digitatus, C. aegypticus, C. vexus and C. yanni. Rates of parasites species were calculated. Prevalence and mean intensity of the Monogenean showed clear fluctuations throughout the year. The parasites were found to settle more on the larger host fish. However, no sex effect was observed on the infestation of T. zillii by the Monogeneans. Throughout the period of study,  all parasite species were present, because the recruitment of these organisms, although relatively low, is continuous; this logically results in their  accumulation in this fish species.Keywords: Monogeneans parasitic, Tilapia zillii, population dynamics

Scheduled-PEG construction of LDPC codes for Upper-Layer FEC

International audienceThe Progressive Edge Growth (PEG) algorithm is one of the most widely-used methods for constructing fi nite length LDPC codes. In this paper we consider the PEG algorithm together with a scheduling distribution, which specifi es the order in which edges are established in the graph. The goal is to find a scheduling distribution that yields "the best" performance in terms of decoding overhead, performance metric speci c to erasure codes and widely used for upper-layer forward error correction (UL-FEC). We rigorously formulate this optimization problem, and we show that it can be addressed by using genetic optimization algorithms. We also exhibit PEG codes with optimized scheduling distribution, whose decoding overhead is less than half of the decoding overhead of their classical-PEG counterparts

Generational Differences and Determinants of Purchase Behavior towards Sustainable Clothing in a Developing Economy

The fashion industry contributes significant plastic pollution and greenhouse gas emissions globally. One approach to minimize the industry’s environmental impact is through a shift to sustainable clothing. This study determined the predictors of purchase behavior towards sustainable clothing in a developing economy, which is the Philippines. Furthermore, this paper compared Filipinos from Generations X and Z. Results of a multiple regression analysis from a sample of 212 participants in an online survey showed that generation and environmental knowledge predicted the purchase of sustainable clothing. Moreover, Gen Z scored higher in environmental knowledge and purchase of sustainable clothing. The findings provide insights on increasing the usage of sustainable clothing, which can significantly reduce the environmental impact of the fashion industry

The use of phylogeny to interpret cross-cultural patterns in plant use and guide medicinal plant discovery: an example from Pterocarpus (Leguminosae)

The study of traditional knowledge of medicinal plants has led to discoveries that have helped combat diseases and improve healthcare. However, the development of quantitative measures that can assist our quest for new medicinal plants has not greatly advanced in recent years. Phylogenetic tools have entered many scientific fields in the last two decades to provide explanatory power, but have been overlooked in ethnomedicinal studies. Several studies show that medicinal properties are not randomly distributed in plant phylogenies, suggesting that phylogeny shapes ethnobotanical use. Nevertheless, empirical studies that explicitly combine ethnobotanical and phylogenetic information are scarce.In this study, we borrowed tools from community ecology phylogenetics to quantify significance of phylogenetic signal in medicinal properties in plants and identify nodes on phylogenies with high bioscreening potential. To do this, we produced an ethnomedicinal review from extensive literature research and a multi-locus phylogenetic hypothesis for the pantropical genus Pterocarpus (Leguminosae: Papilionoideae). We demonstrate that species used to treat a certain conditions, such as malaria, are significantly phylogenetically clumped and we highlight nodes in the phylogeny that are significantly overabundant in species used to treat certain conditions. These cross-cultural patterns in ethnomedicinal usage in Pterocarpus are interpreted in the light of phylogenetic relationships.This study provides techniques that enable the application of phylogenies in bioscreening, but also sheds light on the processes that shape cross-cultural ethnomedicinal patterns. This community phylogenetic approach demonstrates that similar ethnobotanical uses can arise in parallel in different areas where related plants are available. With a vast amount of ethnomedicinal and phylogenetic information available, we predict that this field, after further refinement of the techniques, will expand into similar research areas, such as pest management or the search for bioactive plant-based compounds

Molecular mechanism of edema formation in nephrotic syndrome: therapeutic implications

Sodium retention and edema are common features of nephrotic syndrome that are classically attributed to hypovolemia and activation of the renin–angiotensin–aldosterone system. However, numbers of clinical and experimental findings argue against this underfill theory. In this review we analyze data from the literature in both nephrotic patients and experimental models of nephrotic syndrome that converge to demonstrate that sodium retention is not related to the renin–angiotensin–aldosterone status and that fluid leakage from capillary to the interstitium does not result from an imbalance of Starling forces, but from changes of the intrinsic properties of the capillary endothelial filtration barrier. We also discuss how most recent findings on the cellular and molecular mechanisms of sodium retention has allowed the development of an efficient treatment of edema in nephrotic patients

Pch2 Links Chromosome Axis Remodeling at Future Crossover Sites and Crossover Distribution during Yeast Meiosis

Segregation of homologous chromosomes during meiosis I depends on appropriately positioned crossovers/chiasmata. Crossover assurance ensures at least one crossover per homolog pair, while interference reduces double crossovers. Here, we have investigated the interplay between chromosome axis morphogenesis and non-random crossover placement. We demonstrate that chromosome axes are structurally modified at future crossover sites as indicated by correspondence between crossover designation marker Zip3 and domains enriched for axis ensemble Hop1/Red1. This association is first detected at the zygotene stage, persists until double Holliday junction resolution, and is controlled by the conserved AAA+ ATPase Pch2. Pch2 further mediates crossover interference, although it is dispensable for crossover formation at normal levels. Thus, interference appears to be superimposed on underlying mechanisms of crossover formation. When recombination-initiating DSBs are reduced, Pch2 is also required for viable spore formation, consistent with further functions in chiasma formation. pch2Δ mutant defects in crossover interference and spore viability at reduced DSB levels are oppositely modulated by temperature, suggesting contributions of two separable pathways to crossover control. Roles of Pch2 in controlling both chromosome axis morphogenesis and crossover placement suggest linkage between these processes. Pch2 is proposed to reorganize chromosome axes into a tiling array of long-range crossover control modules, resulting in chiasma formation at minimum levels and with maximum spacing