197 research outputs found

    Temporoparietal encoding of space and time during vestibular-guided orientation

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    When we walk in our environment, we readily determine our travelled distance and location using visual cues. In the dark, estimating travelled distance uses a combination of somatosensory and vestibular (i.e., inertial) cues. The observed inability of patients with complete peripheral vestibular failure to update their angular travelled distance during active or passive turns in the dark implies a privileged role for vestibular cues during human angular orientation. As vestibular signals only provide inertial cues of self-motion (e.g., velocity, °/s), the brain must convert motion information to distance information (a process called 'path integration') to maintain our spatial orientation during self-motion in the dark. It is unknown, however, what brain areas are involved in converting vestibular-motion signals to those that enable such vestibular-spatial orientation. Hence, using voxel-based lesion-symptom mapping techniques, we explored the effect of acute right hemisphere lesions in 18 patients on perceived angular position, velocity and motion duration during whole-body angular rotations in the dark. First, compared to healthy controls' spatial orientation performance, we found that of the 18 acute stroke patients tested, only the four patients with damage to the temporoparietal junction showed impaired spatial orientation performance for leftward (contralesional) compared to rightward (ipsilesional) rotations. Second, only patients with temporoparietal junction damage showed a congruent underestimation in both their travelled distance (perceived as shorter) and motion duration (perceived as briefer) for leftward compared to rightward rotations. All 18 lesion patients tested showed normal self-motion perception. These data suggest that the cerebral cortical regions mediating vestibular-motion ('am I moving?') and vestibular-spatial perception ('where am I?') are distinct. Furthermore, the congruent contralesional deficit in time (motion duration) and position perception, seen only in temporoparietal junction patients, may reflect a common neural substrate in the temporoparietal junction that mediates the encoding of motion duration and travelled distance during vestibular-guided navigation. Alternatively, the deficits in timing and spatial orientation with temporoparietal junction lesions could be functionally linked, implying that the temporoparietal junction may act as a cortical temporal integrator, combining estimates of self-motion velocity over time to derive an estimate of travelled distance. This intriguing possibility predicts that timing abnormalities could lead to spatial disorientation

    Determinants of Success and Failure of Entrepreneurs of SMEs in Bangladesh- An Explorative Study

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    Entrepreneurs and entrepreneurship are significantly correlated with the economic development of a country. Entrepreneurs cannot easily succeed in doing successful business venture without facing risk that arises from internal and external conditions. So, the present study has been undertaken in order to identify the factors contributing to the success; and influencing the failure of entrepreneurs of SMEs in Bangladesh by employing  sophisticated multivariate technique-Varimax Rotated Factor Analytical Technique. The study has collected and used only primary data; and consulted available literature for designing the questionnaire and study. The study has considered 18 variables responsible for failure, and 10 variables contributing to the success of entrepreneurs. The study has identified factors responsible for success of Entrepreneurs of SMEs: Relationship Factor; and Organization Factor in order of magnitude. It has identified factors influencing the failure of Entrepreneurs of SMEs: sustainable Factor, Supply Factor, and Product Related Factor in order of magnitude. The study has suggested entrepreneurs of SMEs to consider these factors while developing policies and strategies for SMEs

    Determinants of Success and Failure of Entrepreneurs of SMEs in Bangladesh- An Explorative Study

    Get PDF
    Entrepreneurs and entrepreneurship are significantly correlated with the economic development of a country. Entrepreneurs cannot easily succeed in doing successful business venture without facing risk that arises from internal and external conditions. So, the present study has been undertaken in order to identify the factors contributing to the success; and influencing the failure of entrepreneurs of SMEs in Bangladesh by employing sophisticated multivariate technique-Varimax Rotated Factor Analytical Technique. The study has collected and used only primary data; and consulted available literature for designing the questionnaire and study. The study has considered 18 variables responsible for failure, and 10 variables contributing to the success of entrepreneurs. The study has identified factors responsible for success of Entrepreneurs of SMEs: Relationship Factor; and Organization Factor in order of magnitude. It has identified factors influencing the failure of Entrepreneurs of SMEs: sustainable Factor, Supply Factor, and Product Related Factor in order of magnitude. The study has suggested entrepreneurs of SMEs to consider these factors while developing policies and strategies for SMEs

    A Novel Approach for Integrated Shortest Path Finding Algorithm (ISPSA) Using Mesh Topologies and Networks-on-Chip (NOC)

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    A novel data dispatching or communication technique based on circulating networks of any network IP is suggested for multi data transmission in multiprocessor systems using Networks-On-Chip (NoC). In wireless communication network management have some negatives have heavy data losses and traffic of data sending data while packet scheduling and low performance in the varied network due to workloads. To overcome the drawbacks, in this method proposed system is Integrated Shortest Path Search Algorithm (ISPSA) using mesh topologies. The message is sent to IP (Internet Protocol) in the network until the specified bus accepts it. Integrated Shortest Path Search Algorithm for communication between two nodes is possible at any one moment. On-chip wireless communications operating at specific frequencies are the most capable option for overcoming metal interconnects multi-hop delay and excessive power consumption in Network-on-Chip (NoC) devices. Each node can be indicated by a pair of coordinates (level, position), where the level is the tree's vertical level and the view point is its horizontal arrangement in the sequence of left to right. The output gateway node's n nodes are linked to two nodes in the following level, with all resource nodes located at the bottommost vertical level and the constraint of this topology is its narrow bisection area. The software Xilinx 14.5 tool by using that overall performance analysis of mesh topology, each method are reduced data losses with better accuracy although the productivity of the delay is decreased by 21 % was evaluated and calculated.

    Human resource development practices in Bangladesh : a study of selected business enterprises

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    Human Resource Development (HRD) has been an important issue in the socio-economic arena in Bangladesh.  Human resource development is directly related to the corporate goal.  An effective human resouce management practice is required for the accomplishment of corporate goal.  Besides, business enterprises cannot keep pace in the changing world without human resource development.  In view of the situation, reserachers are interested to undertake the present study to evaluate the human resource management practices in some select enterprises in Bangladesh.  The study attempts to analyse (i) the factors considered in selecting trainers.  Eventuallu after analyzing these factors, the paper would suggest some policy implications for the effective exercise of human resource management practices in Bangladesh

    Nutrients and energy digestibility of microalgal biomass for fish feed applications

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    Aquafeed accounts for at least 75-90% of aquaculture's operating costs. Traditional aquafeed ingredients such as fishmeal, fish oil, and soybean meal are unsustainable; further, their increasing cost necessities developing alternative feed ingredients. Microalgae-based aquafeed is not only environmentally friendly, but it can also be cost-effective with proper optimization. In addition, the nutrition profile of microalgae is similar to that of many fishes. The digestibility of a feed is one of the most important factors to consider in feed formulation. A highly digestible feed can lower production costs, reduce feed waste, and reduce the risk of eutrophication. This review discusses the digestibility of various nutrients such as protein, lipid, carbohydrate, amino acids, and fatty acids (including omega-3 fatty acids), dry matter, and energy of various microalgae in fish. Other commonly used aquafeed ingredients were also compared to microalgae in terms of nutrient and energy digestibility in fish. The intrinsic characteristics of microalgae, biomass pretreatment, and feed preparation methods are all discussed as factors that contribute to the nutrient and energy digestibility of microalgae in fish. Furthermore, methods for increasing the digestibility of microalgal biomass in fish are suggested. Finally, the review concludes with the challenges and prospects of using microalgae as a fish feed in terms of digestibility. 2021 by the authors. Licensee MDPI, Basel, Switzerland.This research was funded by Qatar National Research Fund (QNRF, a member of Qatar Foundation), grant number MME01-0910-190028.Scopu

    Microstructure, texture and tensile properties of ultrafine/nano grained magnesium alloy processed by accumulative back extrusion

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    An AZ31 wrought magnesium alloy was processed by employing multipass accumulative back extrusion process. The obtained microstructure, texture and room temperature tensile properties were characterized and discussed. Ultrafine grained microstructure including nano grains were developed, where the obtained mean grain size was decreased from 8 to 0.5 µm by applying consecutive passes. The frequency of both low angle and high angle boundaries increased after processing. Strength of the experimental alloy was decreased after processing, which was attributed to the obtained texture involving the major component lying inclined to the deformation axis. Both the uniform and post uniform elongations of the processed materials were increased after processing, where a total elongation of 68 pct was obtained after six-pass deformation. The contribution of different twinning and slip mechanism was described by calculating corresponding Schmid factors. The operation of prismatic slip was considered as the major deformation contributor. The significant increase in post uniform deformation of the processed material was discussed relying on the occurrence of grain boundary sliding associated with the operation of prismatic slip.Postprint (author's final draft

    PEG–Polypeptide Block Copolymers as pH-Responsive Endosome-Solubilizing Drug Nanocarriers

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    Herein we report the potential of click chemistry-modified polypeptide-based block copolymers for the facile fabrication of pH-sensitive nanoscale drug delivery systems. PEG–polypeptide copolymers with pendant amine chains were synthesized by combining N-carboxyanhydride-based ring-opening polymerization with post-functionalization using azide–alkyne cycloaddition. The synthesized block copolymers contain a polypeptide block with amine-functional side groups and were found to self-assemble into stable polymersomes and disassemble in a pH-responsive manner under a range of biologically relevant conditions. The self-assembly of these block copolymers yields nanometer-scale vesicular structures that are able to encapsulate hydrophilic cytotoxic agents like doxorubicin at physiological pH but that fall apart spontaneously at endosomal pH levels after cellular uptake. When drug-encapsulated copolymer assemblies were delivered systemically, significant levels of tumor accumulation were achieved, with efficacy against the triple-negative breast cancer cell line, MDA-MB-468, and suppression of tumor growth in an in vivo mouse model.Novartis Institutes of Biomedical ResearchNational Institutes of Health (U.S.) (Centers for Cancer Nanotechnology Excellence Grant P30 CA14051)National Institutes of Health (U.S.) (Centers for Cancer Nanotechnology Excellence Grant 5 U54 CA151884-02)National Science Foundation (U.S.). Graduate Research FellowshipNatural Sciences and Engineering Research Council of Canada (Postdoctoral Fellowship

    Demography, Diagnosis and Complications of Spinal Cord Injury Patients in a Rehabilitation Center of Bangladesh

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    Background: Spinal cord injury and its health related complications pose a major impact on the overall morbidity and mortality as well as cause economic constrains. It was aimed at looking into the demographic distribution, diagnosis, as well as complications in patients with spinal cord injury. Methods: The study was conducted at Centre for the Rehabilitation of the Paralysed (CRP) between 2012 and 2013 from 201 respondents with the help of a structured preformed pretested questionnaire by face to face interview. Results: Out of 201 respondents 176 (87.6%) were male and 25 (12.4%) were female; majority of the patients were in their 3rd decade which consisted 28.6%, followed by 27.4% in between 21-30 years and 26.8% in between 41-50. Most of the respondents of this study had traumatic paraplegia (56.5%) and Buttock was found to be the predominant site for developing site pressure sore as evident form 67.5%. Conclusion: Productive males are more prone to spinal cord injury and the most common diagnosis is paraplegia with the most risky area is buttock for developing pressure sore. The findings may add in the way of developing awareness among stakeholders regarding demography, diagnosis and the pattern of the complications in a country like Bangladesh
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