Arbitrary Pattern Formation on a Continuous Circle by Oblivious Robot Swarm

In the field of distributed system, Arbitrary Pattern Formation (APF) problem is an extensively studied problem. The purpose of APF is to design an algorithm to move a swarm of robots to a particular position on an environment (discrete or continuous) such that the swarm can form a specific but arbitrary pattern given previously to every robot as an input. In this paper the solvability of the APF problem on a continuous circle has been discussed for a swarm of oblivious and silent robots without chirality under a semi synchronous scheduler. Firstly a class of configurations called \textit{Formable Configuration}($FC$) has been provided which is necessary to solve the APF problem on a continuous circle. Then considering the initial configuration to be an $FC$, an deterministic and distributed algorithm has been provided that solves the APF problem for $n$ robots on a continuous circle of fixed radius within $O(n)$ epochs without collision

Multiple paralogues of α-SNAP in Giardia lamblia exhibit independent subcellular localization and redistribution during encystation and stress

Abstract Background The differently-diverged parasitic protist Giardia lamblia is known to have minimal machinery for vesicular transport. Yet, it has three paralogues of SNAP, a crucial component that together with NSF brings about disassembly of the cis-SNARE complex formed following vesicle fusion to target membranes. Given that most opisthokont hosts of this gut parasite express only one α-SNAP, this study was undertaken to determine whether these giardial SNAP proteins have undergone functional divergence. Results All three SNAP paralogues are expressed in trophozoites, encysting trophozoites and cysts. Even though one of them clusters with γ-SNAP sequences in a phylogenetic tree, functional complementation analysis in yeast indicates that all the three proteins are functionally orthologous to α-SNAP. Localization studies showed a mostly non-overlapping distribution of these α-SNAPs in trophozoites, encysting cells and cysts. In addition, two of the paralogues exhibit substantial subcellular redistribution during encystation, which was also seen following exposure to oxidative stress. However, the expression of the three genes remained unchanged during this redistribution process. There is also a difference in the affinity of each of these α-SNAP paralogues for GlNSF. Conclusions None of the genes encoding the three α-SNAPs are pseudogenes and the encoded proteins are likely to discharge non-redundant functions in the different morphological states of G. lamblia. Based on the difference in the interaction of individual α-SNAPs with GlNSF and their non-overlapping pattern of subcellular redistribution during encystation and under stress conditions, it may be concluded that the three giardial α-SNAP paralogues have undergone functional divergence. Presence of one of the giardial α-SNAPs at the PDRs of flagella, where neither GlNSF nor any of the SNAREs localize, indicates that this α-SNAP discharges a SNARE-independent role in this gut pathogen

Risk correlates of diarrhea in children under 5 years of age in slums of Bankura, West Bengal

Background: Diarrheal diseases are an important cause of mortality and morbidity globally in children under 5 years of age. Objective: To find the prevalence and risk factors of diarrhea among children under 5 years. Materials and Methods: A population-based analytical cross-sectional study was conducted in the urban slums of Bankura, West Bengal on the prevalence of diarrhea and feeding practices, nutrition, and immunization among 152 children under 5 years (69 males and 83 females). Results: Overall prevalence of diarrhea was 22.36%; 21.73% males and 22.89% females were affected with diarrhea. There were 57.69% diarrhea cases in children of 7-12 months age group, followed by 25.71% in those of 13-24 months age group; with increasing age, the prevalence of diarrhea gradually decreased. Diarrhea was noted to be 20.33% in exclusively breastfed children and 31.57% in children who were breastfed for less than 6 months. In bottle-fed children, the frequency of diarrhea was 26.08%.The prevalence of diarrhea was 21.83% in completely immunized children and 30% in partially immunized children. Risk of diarrhea was 19.80% in normal participants and 27.45% in undernourished children. Conclusion: The present study identified a high prevalence of diarrhea in children under the age of 5 years. Findings of the study also revealed the demographic features, feeding practices, immunization practices, and nutritional status as risk factors of diarrhea, which can be tackled by effective education of the community

A staphylococcal anti-sigma factor possesses a single-domain, carries different denaturant-sensitive regions and unfolds via two intermediates.

RsbW, an anti-sigma factor possessing kinase activity, is expressed by many Gram-positive bacteria including Staphylococcus aureus. To obtain clues about the domain structure and the folding-unfolding mechanism of RsbW, we have elaborately studied rRsbW, a recombinant S. aureus RsbW. Sequence analysis of the protein fragments, generated by the limited proteolysis of rRsbW, has proposed it to be a single-domain protein. The unfolding of rRsbW in the presence of GdnCl or urea was completely reversible in nature and occurred through the formation of at least two intermediates. The structure, shape, and the surface hydrophobicity of no intermediate completely matches with those of other intermediates or the native rRsbW. Interestingly, one of the intermediates, formed in the presence of less GdnCl concentrations, has a molten globule-like structure. Conversely, all of the intermediates, like native rRsbW, exist as dimers in aqueous solution. The putative molten globule and the urea-generated intermediates also have retained some kinase activity. Additionally, the putative ATP binding site/catalytic site of rRsbW shows higher denaturant sensitivity than the tentative dimerization region of this enzyme

Emerging new roles of the lysosome and neuronal ceroid lipofuscinoses

Abstract Neuronal Ceroid Lipofuscinoses (NCLs), commonly known as Batten disease, constitute a group of the most prevalent neurodegenerative lysosomal storage disorders (LSDs). Mutations in at least 13 different genes (called CLNs) cause various forms of NCLs. Clinically, the NCLs manifest early impairment of vision, progressive decline in cognitive and motor functions, seizures and a shortened lifespan. At the cellular level, all NCLs show intracellular accumulation of autofluorescent material (called ceroid) and progressive neuron loss. Despite intense studies the normal physiological functions of each of the CLN genes remain poorly understood. Consequently, the development of mechanism-based therapeutic strategies remains challenging. Endolysosomal dysfunction contributes to pathogenesis of virtually all LSDs. Studies within the past decade have drastically changed the notion that the lysosomes are merely the terminal degradative organelles. The emerging new roles of the lysosome include its central role in nutrient-dependent signal transduction regulating metabolism and cellular proliferation or quiescence. In this review, we first provide a brief overview of the endolysosomal and autophagic pathways, lysosomal acidification and endosome-lysosome and autophagosome-lysosome fusions. We emphasize the importance of these processes as their dysregulation leads to pathogenesis of many LSDs including the NCLs. We also describe what is currently known about each of the 13 CLN genes and their products and how understanding the emerging new roles of the lysosome may clarify the underlying pathogenic mechanisms of the NCLs. Finally, we discuss the current and emerging therapeutic strategies for various NCLs

Characterization of intermediates made by urea.

<p>(A) Analyses of proteolytic fragments of rRsbW by SDS-13.5% PAGE. Protein aliquots, pre-equilibrated with 0–7 M urea, were digested with (+)/without (-) trypsin for 8 min prior to gel analysis. Arrowheads indicate either new protein fragments or the fragments with a comparatively increased intensity at 1–4 M urea. (B) Near-UV CD spectra of equimolar concentrations of rRsbW at the indicated concentrations of urea. (C) Crosslinking of 0–7 M urea-treated rRsbW with (+)/without (-) glutaraldehyde (GCHO). The crosslinked molecules were separated by SDS-13.5% PAGE. ‘D’ indicates dimeric rRsbW. (D) The dimer-specific band intensity values were estimated from panel C and plotted versus the corresponding urea concentrations. (E) Gel filtration chromatography of rRsbW at 0–5 M urea. (F) Kinase assay. The assay was performed using the 0–7 M urea-exposed rRsbW, rRsbV, and 1 mM ATP for 10 min at room temperature. The reaction mixtures were analyzed by a 12% native PAGE. The protein bands corresponding to rRsbW, rRsbW-rRsbV complex, phosphorylated rRsbV, and non-phosphorylated rRsbV are indicated. The phosphorylated rRsbV bands were scanned to determine their intensity values at 0–7 M urea. Considering that the extent of rRsbV phosphorylation at 0 M urea corresponds to 100% kinase activity, kinase activities of rRsbW at 1–7 M urea were determined. After normalization, the kinase activity values were plotted against the corresponding urea concentrations (G).</p

Urea-induced unfolding of rRsbW.

<p>(A) The ellipticity values of rRsbW at 222 nm (θ₂₂₂), were derived from their far-UV CD spectra (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195416#pone.0195416.s001" target="_blank">S1 Fig</a>), normalized (Nor), and plotted versus the corresponding urea concentrations. The ANS fluorescence intensity values at 480 nm (B) and the intrinsic Tyr fluorescence intensity values at 308 nm (C) were obtained from the corresponding spectra of rRsbW (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195416#pone.0195416.s001" target="_blank">S1 Fig</a>) were plotted similarly.</p

Characterization of intermediates produced by GdnCl.

<p>(A) Near-UV CD spectra of rRsbW at 0–4 M GdnCl. (B) SDS-13.5% PAGE analysis of 0–3.5 M GdnCl-exposed rRsbW molecules crosslinked with (+)/without (-) glutaraldehyde (GCHO). (C) The plot of dimer-specific band intensity versus the matching GdnCl concentrations. The dimer-specific band intensity values were estimated from panel B as demonstrated above. (D) Gel filtration chromatography of rRsbW at 0–3 M GdnCl. (E) Kinase assay. The assay was carried out using a similar method as stated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195416#pone.0195416.g004" target="_blank">Fig 4F</a>. Only urea-treated rRsbW was replaced with the indicated GdnCl-treated rRsbW. (F) The plot of kinase activity versus equivalent GdnCl concentrations. The plot was made using the intensity of phosphorylated rRsbV bands as stated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195416#pone.0195416.g004" target="_blank">Fig 4F</a>.</p

A schematic representation of the urea- and GdnCl-induced unfolding of rRsbW.

<p>Intermediates are indicated by I1 to I4.</p