Volunteer Selection in Collaborative Crowdsourcing with Adaptive Common Working Time Slots

Skill-based volunteering is an expanding branch of crowdsourcing where one may acquire sustainable services, solutions, and ideas from the crowd by connecting with them online. The optimal mapping between volunteers and tasks with collaboration becomes challenging for complex tasks demanding greater skills and cognitive ability. Unlike traditional crowdsourcing, volunteers like to work on their own schedule and locations. To address this problem, we propose a novel two-phase framework consisting of Initial Volunteer-Task Mapping (i-VTM) and Adaptive Common Slot Finding (a-CSF) algorithms. The i-VTM algorithm assigns volunteers to the tasks based on their skills and spatial proximity, whereas the a-CSF algorithm recommends appropriate common working time slots for successful volunteer collaboration. Both the algorithms aim to maximize the overall utility of the crowdsourcing platform. Experimenting with the UpWork dataset demonstrates the efficacy of our framework over existing state-of-the-art methods

Glycosylation of Erythrocyte Spectrin and Its Modification in Visceral Leishmaniasis

Using a lectin, Achatinin-H, having preferential specificity for glycoproteins with terminal 9-O-acetyl sialic acid derivatives linked in α2-6 linkages to subterminal N-acetylgalactosamine, eight distinct disease-associated 9-O-acetylated sialoglycoproteins was purified from erythrocytes of visceral leishmaniaisis (VL) patients (RBCVL). Analyses of tryptic fragments by mass spectrometry led to the identification of two high-molecular weight 9-O-acetylated sialoglycoproteins as human erythrocytic α- and β-spectrin. Total spectrin purified from erythrocytes of VL patients (spectrinVL) was reactive with Achatinin-H. Interestingly, along with two high molecular weight bands corresponding to α- and β-spectrin another low molecular weight 60 kDa band was observed. Total spectrin was also purified from normal human erythrocytes (spectrinN) and insignificant binding with Achatinin-H was demonstrated. Additionally, this 60 kDa fragment was totally absent in spectrinN. Although the presence of both N- and O-glycosylations was found both in spectrinN and spectrinVL, enhanced sialylation was predominantly induced in spectrinVL. Sialic acids accounted for approximately 1.25 kDa mass of the 60 kDa polypeptide. The demonstration of a few identified sialylated tryptic fragments of α- and β-spectrinVL confirmed the presence of terminal sialic acids. Molecular modelling studies of spectrin suggest that a sugar moiety can fit into the potential glycosylation sites. Interestingly, highly sialylated spectrinVL showed decreased binding with spectrin-depleted inside-out membrane vesicles of normal erythrocytes compared to spectrinN suggesting functional abnormality. Taken together this is the first report of glycosylated eythrocytic spectrin in normal erythrocytes and its enhanced sialylation in RBCVL. The enhanced sialylation of this cytoskeleton protein is possibly related to the fragmentation of spectrinVL as evidenced by the presence of an additional 60 kDa fragment, absent in spectrinN which possibly affects the biology of RBCVL linked to both severe distortion of erythrocyte development and impairment of erythrocyte membrane integrity and may provide an explanation for their sensitivity to hemolysis and anemia in VL patients

Role of sialoglycoproteins exclusively induced on host�s erythrocytes in Indian Visceral Leishmaniasis

Leishmaniasis occurs in as many as 88 countries, (Figure. 1.2) with an approximate total population of 350 million people, most often in tropical and subtropical areas [WHO, 2010]. The geographical settings, where leishmaniasis occurs, range from Central and Couth American rain forests to West Asian deserts, with 90 percent of visceral leishmaniasis cases occurring in India, Nepal, Bangladesh, Sudan, and Brazil. Other areas where Leishmaniasis is found range from Mexico, to Texas, from Northern Argentina, to Southern Europe, from Asia, to The Middle East, and Africa [Chappuis et al., 2007].Although it is true that the distribution of Leishmania is limited by the habitats of the sandfly vectors, human leishmaniasis continues to increase worldwid

Аналіз профілю піків рентгенівської дифракційної картини наноструктури оксиду цинку

Рентгенівська дифракція є важливим інструментом для аналізу кристалічної структури будьякого кристалічного матеріалу. За допомогою відповідного аналізу піків рентгенівської дифракції можна визначити розмір кристалітів та мікронапруження. Також можуть бути визначені інші параметри, такі як анізотропія росту, кристалічність, густина дислокацій та питома площа поверхні. У роботі вивчалася рентгенівська дифракційна картина нанострижнів ZnO. Розмір кристалітів і деформацію розраховували для всіх піків дифракційної картини. Середнє значення розміру кристалітів становило 47,7 нм. Для різних кристалографічних площин деформація була різною. Використовуючи стандартну формулу, були розраховані параметри решітки структури вюрциту, які виявились рівними a = b = 3,2467 Å та c = 5,2004 Å. Підготовлений зразок має дуже велику середню питому площу поверхні 2,26×105 см2г – 1. Інтенсивність різних дифракційних піків різна, що свідчить про анізотропний ріст кристала.X-ray diffraction is an important tool to analyze the crystal structure of any crystalline material. By appropriate analysis of X-ray diffraction peaks, the crystallite size and microstrain can be determined. Other parameters such as growth anisotropy, crystallinity, dislocation density and specific surface area can also be determined. We studied here the X-ray diffraction pattern of ZnO nanorods. The crystallite size and strain were calculated for all diffraction peaks of the pattern. The average value of the crystallite size was 47.7 nm. The strain was found to be different for different crystallographic planes. Using the standard formula, the lattice parameters of the wurtzite structure were calculated and found to be equal to a = b = 3.2467 Å and c = 5.2004 Å. The prepared sample has a very large average specific surface area of 2.26×105 cm2g – 1. The intensities of various diffraction peaks are different indicating that the growth of the crystal is anisotropic

Scalable Skill-Oriented Task Allocation in Crowdsourcing within a Serverless Ecosystem

Allocating the most competent crowdworkers to each upcoming task is a fundamental challenge in crowdsourcing. The mechanism becomes complicated when the arriving tasks require a high level of expertise within a constrained budget. The validation of skill matching between tasks and crowdworkers adds a new dimension to the traditional problem of task allocation. In addition, in real-world scenarios, the influx of both tasks and workers is dynamic, making it nearly impossible to predict the precise amount of computational resources required for the crowdsourcing platform to operate efficiently. Serverless computing is a new pay-per-use, auto-scalable, Function-as-a-Service based model, that ensures parallel execution of lightweight event-driven functions. The developer with serverless can solely concentrate on writing application logic with zero effort on resource provision, server management, environmental configuration, and availability. Today, collaboration has become the new competition. In light of these considerations, we propose a novel framework to facilitate task allocation strategies for crowdsourcing applications, deployed within a serverless platform in order to improve performance. The results obtained are compared to the baseline, Online-Greedy, and simulations are run in both serverless and local environments

Erythrophagocytosis Assay.

a<p>RBC_VL and RBC_N (2×10⁶), without or with sensitization by anti-<i>O</i>-AcSGP IgG_VL and anti-<i>O</i>-AcSGP IgG_NHS antibodies and processed for erythrophagocytosis assay as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042361#s2" target="_blank">Materials and Methods</a>. Results represent the mean ± S.D. of five separate determinations.</p>b<p>Positive macrophages (%) are the percentage of macrophages that ingested one or more erythrocytes and was used as the index of phagocytosis. Results represent the mean ± S.D. of five separate determinations.</p

Activation of calpain I in RBC_VL or RBC_N.

<p><b>A.</b> Cells (2×10⁷) were incubated with or without anti-9-<i>O</i>-AcSGP IgG_VL, anti-9-<i>O</i>-AcSGP IgG_NHS (10 µg/ml) or the Ca²⁺ ionophore A23187 in the absence or presence of EGTA (25 mM) for 60 min at 37°C in Ringer solution, washed with same buffer and lysed by sonication on ice. After removal of cell debris by centrifugation the lysates were separated by SDS-PAGE, and calpain I was detected by Western blot analysis with an anti-calpain-I antibody. <b>B... </b><i>Enhanced degradation of α-spectrin in sensitized RBC_VL</i>. RBC_VL and RBC_N were suspended separately in Ringer solution and sensitized with anti-9-<i>O</i>-AcSGP IgG_VL, anti-9-<i>O</i>-AcSGP IgG_NHS or A23187 in the absence or presence of EGTA for 30 min at 37°C. The cells were then lysed as before and the lysates subjected to SDS-PAGE and Western blot analysis with a spectrin-specific antibody. <b>C... </b><i>Involvement of calpain I in the degradation of spectrin in RBC_VL</i>. RBC_VL and RBC_N were pre-incubated with the calpain I inhibitor ALLN in Ringer solution for 30 min at 37°C before sensitization or co-incubated together with anti-9-<i>O</i>-AcSGP IgG_VL or A23187 as positive controls. The cells were processed as before and spectrin detected by Western blot after SDS-PAGE of the cellulaproteins. <b>D... </b><i>Dependence of the hemolysis of RBC_N on the activation of calpain I</i>. RBC_N were incubated without or with A23187 and with A23187 plus EGTA or ALLN for 1 h at 37°C, and the degree of hemolysis determined spetrophotometrically as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042361#pone-0042361-g001" target="_blank">Figure 1</a>. The results are shown as representative bar graphs of three independent experiments.</p

Degradation of purified α-spectrin by activated calpain I.

<p><b>A... </b><i>Characterization of purified spectrins</i>. Spectrin_VL and spectrin_N were purified from RBC_VL and RBC_N as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042361#s2" target="_blank">Materials and Methods</a>, and analyzed on SDS-PAGE (7.5%). The purified spectrins were Western blotted and detected with polyclonal rabbit anti-spectrin antibodies. <b>B... </b><i>Proteolysis of purified spectrin_VL and spectrin_N by active calpain I</i>. Spectrin_N and Spectrin_VL (3.0 µg) were digested with different doses of active calpain I as indicated in reaction buffer, the reaction was stopped with EGTA and the products analyzed by SDS-PAGE. <b>C... </b><i>Inhibition of proteolysis by the calpain I inhibitor ALLN</i>. Calpain I was preincubated with ALLN for 15 min on ice prior to addition of reaction buffer containing purified spectrin_VL or spectrin_N and processed as before.</p

Sialoglycosylation of RBC in Visceral Leishmaniasis Leads to Enhanced Oxidative Stress, Calpain-Induced Fragmentation of Spectrin and Hemolysis

Visceral leishmaniasis (VL) caused by the intracellular parasite Leishmania donovani accounts for an estimated 12 million cases of human infection. It is almost always associated with anemia, which severely complicates the disease course. However, the pathological processes leading to anemia in VL have thus far not been adequately characterized to date. In studying the glycosylation patterns of peripheral blood cells we found that the red blood cells (RBC) of VL patients (RBCVL) express eight 9-O-acetylated sialoglycoproteins (9-O-AcSGPs) that are not detected in the RBC of healthy individuals (RBCN). At the same time, the patients had high titers of anti-9-O-AcSGP IgG antibodies in their sera. These two conditions appear to be linked and related to the anemic state of the patients, as exposure of RBCVL but not RBCN to anti-9-O-AcSGPs antibodies purified from patient sera triggered a series of responses. These included calcium influx via the P/Q-type but not L-type channels, activation of calpain I, proteolysis of spectrin, enhanced oxidative stress, lipid peroxidation, externalization of phosphatidyl serine with enhanced erythrophagocytosis, enhanced membrane fragility and, finally, hemolysis. Taken together, this study suggests that the enhanced hemolysis is linked to an impairment of membrane integrity in RBCVL which is mediated by ligand-specific interaction of surface 9-O-AcSGPs. This affords a potential explanation for the structural and functional features of RBCVL which are involved in the hemolysis related to the anemia which develops in VL patients