1,102 research outputs found

    GC/MS Analysis of Phytoconstituents and Antimicrobial Evaluation Leaf Extract of Garcinia imberti Bourd

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    Garcinia imberti Bourd. is a strict endemic and endangered tree species belonging to the family Clusiaceae (Guttiferae), locally known as Manjakanji. The trees were over exploited for its unknown multi-usage valuable chemical compounds. The present study has been attempted to investigate the GC/MS analysis of chemical composition and antimicrobial activity of leaf extracts of Garcinia imberti. Powdered plant leaves were subjected to successive extract with petroleum ether, chloroform and methanol by soxhlet extraction method. Totally 24 different compounds from methanolic leaf extract were identified, Squalene, Supraene, Phenol, Dinoctyl phthalate, Gitoxigenin, Digitoxin and Bis (2ethylhexyl) Phthalate are found as dominate. In addition, antimicrobial activity was also studied using agar well diffusion method at various concentrations (100 µg/ml, 150 µg/ml and 200 µg/ml) of petroleum ether, chloroform and methanolic extracts. These extract inhibited severely on the growth of microorganisms, and implied antimicrobial activity on gram-positive bacteria, gram-negative bacteria and fungi. These extract was effectively tested against microorganisms which was well comparable with standard antibiotics (Ampicillin for bacteria and Amphotericin B for fungi). Among these three extracts evaluated methanol extract showed higher inhibitory activity against all the tested pathogenic bacteria and fungi and these three concentrations of the extracts tested at higher concentration (200 µg/ml). The high degree of antimicrobial activity seems to confirm the folk therapy of infections and traditional therapeutic claims of this rare tree

    Homology modeling of major intrinsic proteins in rice, maize and Arabidopsis: comparative analysis of transmembrane helix association and aromatic/arginine selectivity filters

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    BACKGROUND: The major intrinsic proteins (MIPs) facilitate the transport of water and neutral solutes across the lipid bilayers. Plant MIPs are believed to be important in cell division and expansion and in water transport properties in response to environmental conditions. More than 30 MIP sequences have been identified in Arabidopsis thaliana, maize and rice. Plasma membrane intrinsic proteins (PIPs), tonoplast intrinsic proteins (TIPs), Nod26-like intrinsic protein (NIPs) and small and basic intrinsic proteins (SIPs) are subfamilies of plant MIPs. Despite sequence diversity, all the experimentally determined structures belonging to the MIP superfamily have the same "hour-glass" fold. RESULTS: We have structurally characterized 39 rice and 31 maize MIPs and compared them with that of Arabidopsis. Homology models of 105 MIPs from all three plant species were built. Structure-based sequence alignments were generated and the residues in the helix-helix interfaces were analyzed. Small residues (Gly/Ala/Ser/Thr) are found to be highly conserved as a group in the helix-helix interface of MIP structures. Individual families sometimes prefer one or another of the residues from this group. The narrow aromatic/arginine (ar/R) selectivity filter in MIPs has been shown to provide an important constriction for solute permeability. Ar/R regions were analyzed and compared between the three plant species. Seventeen TIP, NIP and SIP members from rice and maize have ar/R signatures that are not found in Arabidopsis. A subgroup of rice and maize NIPs has small residues in three of the four positions in the ar/R tetrad, resulting in a wider constriction. These MIP members could transport larger solute molecules. CONCLUSION: Small residues are group-conserved in the helix-helix interface of MIP structures and they seem to be important for close helix-helix interactions. Such conservation might help to preserve the hour-glass fold in MIP structures. Analysis and comparison of ar/R selectivity filters suggest that rice and maize MIPs could transport more diverse solutes than Arabidopsis MIPs. Thus the MIP members show conservation in helix-helix interfaces and diversity in aromatic/arginine selectivity filters. The former is related to structural stability and the later can be linked to functional diversity

    The Digital Wallet: Opportunities and Prototypes

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    Methylphenidate modulates activity within cognitive neural networks of patients with post-stroke major depression: A placebo-controlled fMRI study

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    Rajamannar Ramasubbu1, Bradley G Goodyear21Departments of Psychiatry and Clinical Neurosciences; 2Department of Radiology and Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Calgary, AB, CanadaBackground: Methylphenidate (MP) is a dopamine- and noradrenaline-enhancing agent beneficial for post-stroke depression (PSD) and stroke recovery due to its therapeutic effects on cognition, motivation, and mood; however, the neural mechanisms underlying its clinical effects remain unknown. This study used functional magnetic resonance imaging (fMRI) to investigate the effect of MP on brain activity in response to cognitive tasks in patients with PSD.Methods: Nine stroke outpatients with DSM IV defined major depression underwent fMRI during two cognitive tasks (2-back and serial subtraction) on four occasions, on the first and third day of a three-day treatment of MP and placebo. Nine healthy control (HC) subjects matched for age and sex scanned during a single session served as normative data for comparison. The main outcome measure was cognitive task-dependent brain activity.Results: For the 2-back task, left prefrontal, right parietal, posterior cingulate, and temporal and bilateral cerebellar regions exhibited significantly greater activity during the MP condition relative to placebo. Less activity was detected in rostral prefrontal and left parietal regions. For serial subtraction, greater activity was detected in medial prefrontal, biparietal, bitemporal, posterior cingulate, and bilateral cerebellar regions, as well as thalamus, putamen, and insula. Further, underactivation observed during the placebo condition relative to HC improved or reversed during MP treatment. No significant differences in behavioral measures were found between MP and placebo conditions or between patients and HC.Conclusions: Short-term MP treatment may improve and normalize activity in cognitive neuronal networks in patients with PSD.Keywords: methylphenidate, post-stroke depression, functional MRI, cognitio

    Leveraging Global Resources: A Process Maturity Framework for Managing Distributed Software Product Development

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    Distributed software development is pervasive in the software industry as companies vie to leverage global resources. However popular quality and process frameworks do not specifically address the key processes needed for managing distributed software development. We develop an evolutionary process maturity framework for globally distributed software development that incorporates 24 new key process areas essential for managing distributed software product development We test the validity of our process framework using data collected from more than sixty large, distributed enterprise product development projects. We believe we have laid new ground for software process research by extending generic quality process frameworks to address the distributed development scenario

    Modeling Coordination in Offshore Software Development

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    Controlling and minimizing coordination costs has been shown to be an important factor to reduce overall project performance in distributed software development. In this research-in-progress paper we investigate the effects of software complexity, software integration, distributed labor division policies, learning effects on software coordination costs. Drawing from data collected on 130 software construction cycles in 34 large projects of a leading offshore development firm, we first present our analysis on how coordination costs relate to team organization factors and complexity of evolving software. We base our analytic model of coordination costs in offshore software development on these empirical relationships, and give an overview of our modeling approach. We apply our model of software coordination costs to develop resource allocation policies in the projects we studied. We consider both waterfall and iterative software development methodologies and also tandem and parallel integration schemes. Our modeling approach helps managers to develop a dynamic coordination policy to aid iterative software development in distributed development environments

    A Bit Stream Feature-Based Energy Estimator for HEVC Software Encoding

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    The total energy consumption of today's video coding systems is globally significant and emphasizes the need for sustainable video coder applications. To develop such sustainable video coders, the knowledge of the energy consumption of state-of-the-art video coders is necessary. For that purpose, we need a dedicated setup that measures the energy of the encoding and decoding system. However, such measurements are costly and laborious. To this end, this paper presents an energy estimator that uses a subset of bit stream features to accurately estimate the energy consumption of the HEVC software encoding process. The proposed model reaches a mean estimation error of 4.88% when averaged over presets of the x265 encoder implementation. The results from this work help to identify properties of encoding energy-saving bit streams and, in turn, are useful for developing new energy-efficient video coding algorithms.Comment: arXiv admin note: text overlap with arXiv:2207.0267

    Orchestrating Service Innovation Using Design Moves: The Dynamics of Fit between Service and Enterprise IT Architectures

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    Service science perspectives highlight the central role of information technology (IT) in transforming the design and delivery of services. To discern the mechanisms through which IT impacts service innovation, we explore the dynamics of the relationship between enterprise IT and service architectures, and how these dynamics influence the performance of service innovation projects. We conducted six case studies to investigate how firms orchestrated service innovation, focusing on the design of the service architecture and its relationship to enterprise systems. We synthesize the case findings to develop a set of propositions on the antecedents and consequences of fit (or misfit) between service architecture and enterprise IT architecture. We then study how the case firms attempted to achieve congruence between the service and system architectures—both in design and in operation—by viewing the design moves they made as efforts to build and strike digital options
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