701 research outputs found

    Securely Outsourcing Large Scale Eigen Value Problem to Public Cloud

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    Cloud computing enables clients with limited computational power to economically outsource their large scale computations to a public cloud with huge computational power. Cloud has the massive storage, computational power and software which can be used by clients for reducing their computational overhead and storage limitation. But in case of outsourcing, privacy of client's confidential data must be maintained. We have designed a protocol for outsourcing large scale Eigen value problem to a malicious cloud which provides input/output data security, result verifiability and client's efficiency. As the direct computation method to find all eigenvectors is computationally expensive for large dimensionality, we have used power iterative method for finding the largest Eigen value and the corresponding Eigen vector of a matrix. For protecting the privacy, some transformations are applied to the input matrix to get encrypted matrix which is sent to the cloud and then decrypting the result that is returned from the cloud for getting the correct solution of Eigen value problem. We have also proposed result verification mechanism for detecting robust cheating and provided theoretical analysis and experimental result that describes high-efficiency, correctness, security and robust cheating resistance of the proposed protocol

    Bidirectional Associations Between Coparenting Relations and Family Member Anxiety: A Review and Conceptual Model

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    Research into anxiety has largely ignored the dynamics of family systems in anxiety development. Coparenting refers to the quality of coordination between individuals responsible for the upbringing of children and links different subsystems within the family, such as the child, the marital relationship, and the parents. This review discusses the potential mechanisms and empirical findings regarding the bidirectional relations of parent and child anxiety with coparenting. The majority of studies point to bidirectional associations between greater coparenting difficulties and higher levels of anxiety. For example, the few available studies suggest that paternal and perhaps maternal anxiety is linked to lower coparental support. Also, research supports the existence of inverse links between coparenting quality and child anxiety. A child’s reactive temperament appears to have adverse effects on particularly coparenting of fathers. A conceptual model is proposed that integrates the role of parental and child anxiety, parenting, and coparenting, to guide future research and the development of clinical interventions. Future research should distinguish between fathers’ and mothers’ coparenting behaviors, include parental anxiety, and investigate the coparental relationship longitudinally. Clinicians should be aware of the reciprocal relations between child anxiety and coparenting quality, and families presenting for treatment who report child (or parent) anxiety should be assessed for difficulties in coparenting. Clinical approaches to bolster coparenting quality are called for.FSW – Publicaties zonder aanstelling Universiteit Leide

    Experimental Study on the Explosive Spalling in High-Performance Concrete: Role of Aggregate and Fiber Types

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    A complete description of the mechanical behavior of High-Performance Concrete in fire still requires further efforts to fully understand the tricky phenomenon of spalling, whose complexity comes from the interaction among different phenomena, namely: the microstructural changes occurring in concrete at high temperature, the pressure rising in the pores, and the stress induced by both thermal gradients and external loads. To what extent these different aspects influence each other is still not completely clear, and within this context a comprehensive experimental campaign has been launched at the Politecnico di Milano, focusing on the role played by concrete grade, aggregate type, and fiber type and content. Eleven concrete mixes are investigated considering three grades (fc ≥ 40, 60 and 90 MPa), three aggregate types (silico-calcareous, basalt and calcareous aggregates) and different fiber types and contents (steel and monofilament or fibrillated polypropylene fibers)

    Effects of deforestation on physicochemical properties and microbial population of soils in a South-East Asian tropical forest

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    The study was conducted in deforested land and adjacent natural forest in Chittagong Forest South Division, Bangladesh, to explore the effects of deforestation on physico-chemical properties of soil and the soil microbial population. Soil samples from surface (0-10 cm depth) or subsurface (10-20 cm depth) of two hill positions (top and bottom) of deforested land and an adjacent natural forest were collected and analysed for their physico-chemical properties and microbial population. The study reveals that there was no significant (p≤0.05) difference in soil texture for soil surfaces or hill positions between the deforested land and natural forest. However, significantly (p≤0.05) low moisture content and high pH was observed in both the surfaces and hill position in deforested land compared to the natural forest. The microbial community i.e., the fungal and bacterial population was also significantly (p≤0.05) lower in both surfaces (0-10 cm and 10-20 cm) of hill positions in the deforested land compared to natural forest. Fungal population ranged from 59 to 76 million g-1 and 78 to 153 million g-1 of dry soil in deforested land and in natural forest, respectively, whereas bacterial population ranged from 70 to 146 million g-1 in deforested land and from 127 to 218 million g-1 in natural forest. A total of seven genera of fungi were primarily identified from the soils of natural forest and six from the deforested land. The six common genera of identified fungi in both the land used were Mucor, Aspergillus, Rhizopus, Fusarium, Penicillium and Trichoderma and the different one was Colletotrichum from the natural forest. Three genera of bacteria coccus, Streptococcus and Basillus were noticed in natural forest and two genera (coccus and Streptococcus) were recorded from deforested land

    Effects of Albizia saman (Jacq. Mull) leaf mulch on vegetative growth of maize (Zea mays L.) and soil chemical properties through biomass transfer

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    The study presents the effects of Albizia saman (Jacq. Mull) leaves in a biomass transfer as a source of organic fertilizer on the soil chemical properties and vegetative growth of maize (Zea mays) compared with NPK (15-15-15) in greenhouse condition. Albizia saman leaves and NPK (15-15-15) were applied at the rate of 2.5, 5.0 and 7.5 t/ha or 60, 90 and 120 kg/ha respectively, separately or in combination. The findings revealed that application of 2.5 t/ha A. saman leaves produced the maximum values for mean leaf number, leaf area and stem height (7.77, 212.24 cm2 and 49.67 cm, respectively) among the leaf much treatments but were not significantly different from those obtained by applying 90 kg/ha NPK fertilizer (7.86, 225.55 cm2 and 48.78 cm, respectively). However, the maximum number of leaf (8.4), leaf area (240.5 cm2), plant height (54.64 cm) and biomass (16.17 g) were obtained from the combination of 2.5 t/ha leaves with 90 kg/ha NPK. There was significant improvement in the soil chemical status with the application of 2.5 or 5.0 t/ha A. saman leaves whereas the application of 5.0 t/ha A. saman leaves experienced the highest value for organic carbon (3.56%), total nitrogen (0.23%) and potassium (0.16 mg/kg) and 2.5 t/ha leaves gave the highest value for available phosphorus (22.30 mg/kg). It can, therefore, be inferred that the application of 2.5 t/ha A. saman leaves as source of organic fertilizer will give a better growth of maize and the combination of this quantity with 90 kg/ha of NPK would give better results in crop yield and maintenance of soil fertility

    Antigen-Specific Memory B-cell Responses to Enterotoxigenic Escherichia coli Infection in Bangladeshi Adults

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    Background: Multiple infections with diverse enterotoxigenic E. coli (ETEC) strains lead to broad spectrum protection against ETEC diarrhea. However, the precise mechanism of protection against ETEC infection is still unknown. Therefore, memory B cell responses and affinity maturation of antibodies to the specific ETEC antigens might be important to understand the mechanism of protection. Methodology In this study, we investigated the heat labile toxin B subunit (LTB) and colonization factor antigens (CFA/I and CS6) specific IgA and IgG memory B cell responses in Bangladeshi adults (n = 52) who were infected with ETEC. We also investigated the avidity of IgA and IgG antibodies that developed after infection to these antigens. Principal Findings Patients infected with ETEC expressing LT or LT+heat stable toxin (ST) and CFA/I group or CS6 colonization factors developed LTB, CFA/I or CS6 specific memory B cell responses at day 30 after infection. Similarly, these patients developed high avidity IgA and IgG antibodies to LTB, CFA/I or CS6 at day 7 that remained significantly elevated at day 30 when compared to the avidity of these specific antibodies at the acute stage of infection (day 2). The memory B cell responses, antibody avidity and other immune responses to CFA/I not only developed in patients infected with ETEC expressing CFA/I but also in those infected with ETEC expressing CFA/I cross-reacting epitopes. We also detected a significant positive correlation of LTB, CFA/I and CS6 specific memory B cell responses with the corresponding increase in antibody avidity. Conclusion: This study demonstrates that natural infection with ETEC induces memory B cells and high avidity antibodies to LTB and colonization factor CFA/I and CS6 antigens that could mediate anamnestic responses on re-exposure to ETEC and may help in understanding the requirements to design an effective vaccination strategies

    Circulating Mucosal Associated Invariant T Cells Are Activated in Vibrio cholerae O1 Infection and Associated with Lipopolysaccharide Antibody Responses

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    Background: Mucosal Associated Invariant T (MAIT) cells are innate-like T cells found in abundance in the intestinal mucosa, and are thought to play a role in bridging the innate-adaptive interface. Methods: We measured MAIT cell frequencies and antibody responses in blood from patients presenting with culture-confirmed severe cholera to a hospital in Dhaka, Bangladesh at days 2, 7, 30, and 90 of illness. Results: We found that MAIT (CD3+CD4−CD161hiVα7.2+) cells were maximally activated at day 7 after onset of cholera. In adult patients, MAIT frequencies did not change over time, whereas in child patients, MAITs were significantly decreased at day 7, and this decrease persisted to day 90. Fold changes in MAIT frequency correlated with increases in LPS IgA and IgG, but not LPS IgM nor antibody responses to cholera toxin B subunit. Conclusions: In the acute phase of cholera, MAIT cells are activated, depleted from the periphery, and as part of the innate response against V. cholerae infection, are possibly involved in mechanisms underlying class switching of antibody responses to T cell-independent antigens

    Persistence of benthiocarb in soil: influence of ultraviolet and sunlight

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    Persistence of benthiocarb in soil as affected by UV and sunlight exposure was studied. Treated soil was placed in petri-plate, brought to field capacity moisture and then exposed to UV and sunlight. Residues of benthiocarb in soil dissipated with half-lives of 2.10, 11.85 and 43.63 days under UV, sunlight and dark condition, respectively. Soil samples kept under dark showed the slowest dissipation. Further, benthiocarb residues dissipated quickly under UV light as compared to sunlight. Exposure of thin film of benthiocarb confirmed that it is photo labile and dissipated very fast with half-life of 1.16 and 1.77days following exposure to UV and sunlight, respectively. The study revealed that UV component of sunlight is an important factor for benthiocarb dissipation

    Teachers’ narratives from initial virtual classrooms and professional development during the Covid-19 pandemic in developing Bangladesh

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    In the face of sudden migration to online teaching due to Covid-19 pandemic, education is going under trying times globally, especially in the low resource contexts of the Global South. Little is, however, known about how this forced migration to and coping with emergency remote teaching (ERT) are happening in the low resource context of developing Bangladesh, particularly in the Higher Education (HE). This paper, therefore, aims to understand how virtual classrooms look like in the Higher Education context in Bangladesh through TESOL teachers’ narratives from initial virtual classrooms imparting ERT. Employing narrative inquiry, four teachers from four different public and private universities in Bangladesh share their experiences of doing, undergoing and reflecting as they try to adopt, adapt and strive in imparting ERT and carrying out education in HE. Insights from these initial teacher narratives may inform higher education pedagogies, teacher development in distance education environments in Bangladesh and similar contexts in the Global South. As the paper addresses HE teachers’ initial orientation to ERT without exclusively dealing with TESOL education, it has multidisciplinary approach to migration to and coping with ERT in HE in general
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