189 research outputs found

    Bending rigidity of charged lipid bilayer membranes

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    Hypotensive Activity of Moringa oleifera Lam (Moringaceae) Root Extracts and its Volatile Constituents

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    Purpose: To explore the hypotensive activity and chemical composition of Moringa oleifera Lam (Moringaceae) roots.Methods: The fresh roots of M. oleifera was cut into small pieces and successively extracted with petroleum ether (PE) and dichloromethane (DC). PE extract was  further divided into MRP and MRP -1. DC extract showed a thick mass during evaporation which was separated as MRDC - IN. The mother liquor left was divided into MRDC and MRDC -1. All residues were analyzed by gas chromatographymass spectroscopy (GC-MS) using ZB-5 column. Identification of each extract and fraction was based on comparison of their retention indices (RI), by co-injecting authentic compounds, as well as by comparing literature data available in NIST Standard Reference Database. Hypotensive activity was determined on urethane-anesthetized normotensive Sprague Dawly rats.Results: Petroleum ether (MRP) and dichloromethane (MRDC) extracts of M. oleifera roots showed 50.06 ± 3.48 and 48.16 ± 1.79 % fall in mean arterial blood  pressure (MABP), respectively, at a dose of 30 mg/kg (p < 0.01 and p < 0.05, respectively) compared with control. GC-MS analysis of MRP and MRDC extracts and fractions resulted in the identification of seventy four (74) compounds. Methyl hexadecanoate (7, 20.3 %) , stigmastan - 3, 5, diene (24, 19.32 %), methyl  14-hydroxy-5-tetradecenoate (9, 19.22 %), 1 , 11 diphenyl undecane (47, 18.78 %) and cyclopentanyl hexadecane (39, 14.44 %) were the major constituents  among the various hydrocarbons, fatty acids, esters, alcohols, aldehydes, isothiocyanate, aromatics, steroids, terphenyl and sulphur-containing compounds. Conclusion: The findings reveal the hypotensive potential of M. oleifera roots and the presence of specific hydrocarbons, fatty acid esters, thioureides, steroids and isothiocyanates in active fractions. Further study is required to determine the suitability of the plant as an antihypertensive remedy.Keywords: Moringa oleifera, Methyl hexadecanoate, Methyl 14-hydroxy-5-tetradecenoate, Petroleum ether, Stigmastan - 3, 5, diene, Cyclopentanyl hexadecan

    The typology of connectivity in landscape architecture: a review of studies on landscape connectivity (LC)

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    Connectivity is an important landscape characteristic that is essential for health, welfare and aesthetic values in human societies as well as for the protection of native ecosystems. Diversity in objectives, approaches, definitions and methods in studies on connectivity and its widespread use in the field of landscape ecology are reasons why Landscape Connectivity (LC) in landscape architecture has been deemed as the counterpart of Ecological Connectivity leading to neglect of other aspects of this comprehensive concept. This study, reviews and classifies studies carried out in the field of landscape with a focus on connectivity in order to achieve a comprehensive definition of LC and its various components in landscape architecture literature. The research method used in this study was quantitative-qualitative. In the first phase, the literature was collected using library research and internet search via a descriptive-analytical approach. Then, an inductive constructionist strategy using Delphi technique was used to classify and categorize relevant studies, and logical argumentation was used to develop the concept of LC in landscape architecture literature. Finally, the objectivist Descriptive/Synthetic Modelling strategy was used to provide a conceptual model of urban landscape connectivity (ULC). The key finding of this study is the researcher-made conceptual model of ULC, its corresponding components and parameters with the viewpoint of landscape architecture

    Branch-pipe: Improving graph skeletonization around branch points in 3D point clouds

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    Modern plant phenotyping requires tools that are robust to noise and missing data, while being able to efficiently process large numbers of plants. Here, we studied the skeletonization of plant architectures from 3D point clouds, which is critical for many downstream tasks, including analyses of plant shape, morphology, and branching angles. Specifically, we developed an algorithm to improve skeletonization at branch points (forks) by leveraging the geometric properties of cylinders around branch points. We tested this algorithm on a diverse set of high-resolution 3D point clouds of tomato and tobacco plants, grown in five environments and across multiple developmental timepoints. Compared to existing methods for 3D skeletonization, our method efficiently and more accurately estimated branching angles even in areas with noisy, missing, or non-uniformly sampled data. Our method is also applicable to inorganic datasets, such as scans of industrial pipes or urban scenes containing networks of complex cylindrical shapes

    An empirical qualitative study of students’ perceived intrinsic motivation

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    Foreign language and culture learning suffers from a bad image in Danish Upper Secondary schools and German is not an exception. It means that the majority of Danish Upper Secondary school students are not particularly interested in learning the language. Therefore, intrinsic motivation plays a pivotal role in German language and culture learning in Denmark. One didactic initiative proposed to remedy the lack of intrinsic motivation is the introduction of various ICT (Information and Communication Technology) tools. This is the background for the research described in this article. Our study which was conducted on the basis of semi-structured focus group interviews with n=50 high school students and n=2 high school teachers shows that the ICT tools Photostory, MovieMaker and Voki indeed have an influence on students’ perceived intrinsic motivation in connection with German language and culture learning. Depending on the nature of the tool, our thematic analysis indicates that such tools facilitate different aspects of perceived intrinsic motivation. Still, our study shows that the tools have a limited effect on perceived intrinsic motivation, unless they are addressed and used strategically in the proper pedagogical context

    A persistent neutrophil-associated immune signature characterizes post-COVID-19 pulmonary sequelae.

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    Interstitial lung disease and associated fibrosis occur in a proportion of individuals who have recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection through unknown mechanisms. We studied individuals with severe coronavirus disease 2019 (COVID-19) after recovery from acute illness. Individuals with evidence of interstitial lung changes at 3 to 6 months after recovery had an up-regulated neutrophil-associated immune signature including increased chemokines, proteases, and markers of neutrophil extracellular traps that were detectable in the blood. Similar pathways were enriched in the upper airway with a concomitant increase in antiviral type I interferon signaling. Interaction analysis of the peripheral phosphoproteome identified enriched kinases critical for neutrophil inflammatory pathways. Evaluation of these individuals at 12 months after recovery indicated that a subset of the individuals had not yet achieved full normalization of radiological and functional changes. These data provide insight into mechanisms driving development of pulmonary sequelae during and after COVID-19 and provide a rational basis for development of targeted approaches to prevent long-term complications
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