4,383 research outputs found
Climate is changing: are we changing too?
Many problems in the urban landscape can be reduced or eliminated by proper plant selection and by maintaining trees healthy so that they can fully provide their benefits. In a climate change scenario possible adaptation measures include changes to establishment practices and tree management, better matching of species to site, both under current and future climates, and the planting of non-native species and provenances in anticipation of climate change. Current opinion is to encourage the planting of local provenances of native species, citing adaptation of provenances to local conditions, and the requirement to maintain biodiversity and a native genetic base. However, local provenances may not be able to adapt to a changing climate, particularly given the rate of change predicted. Sourcing planting stock from regions with a current climate similar to that predicted for the future may provide one option, although care must be taken to ensure that suitable provenances are selected which are not at risk from, for example, spring frost damage as a result of early flushing. In this paper we'll focused on the technical and practical solutions for the selection of trees that might be the best choice in urban environments for the next future, given differences in urban sites (infrastructures, climate, soils etc), species attributes, management requirements and climate
Corrosion resistance of AZ91 magnesium alloy with pulse electrodeposited Ni-SiC nanocomposite coating
Magnesium and its alloys are the lightest of the structural metals, which makes
them one of the most promising materials to minimize vehicle weight, but poor surface
properties restrict the application of these alloys. In this paper, Ni-SiC nanocomposite
coatings were applied on AZ91 magnesium alloy from Watts bath with SiC content 0
g.L-1 (pure Ni), 10 g.L-1 (Ni-10SiC) and 15 g.L-1 (Ni-15SiC) by application of pulse
electrodeposition technique. The morphology and phase analysis were carried out by
Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) analysis, respectively.
Micro-hardness of specimens was measured and the results revealed a significant
enhancement: from 74 Vickers for bare AZ91 magnesium alloy to 523 Vickers for
coated specimen in the bath containing 15 g.L-1 SiC. The Corrosion behavior of the
samples was studied by potentiodaynamic polarization, and the obtained data showed
the superior corrosion resistance for the coated AZ91 magnesium alloy, i.e. the corrosion
current density decreased from 2.69 mA.cm-2, for the uncoated sample, to 0.00046
mA.cm-2, for coated specimen in the bath containing 15 g.L-1 SiC and the corrosion
potential increased from -2.069 V to -0.33 V for the same conditions
Mouth Care in Patients Receiving Mechanical Ventilation: A Systematic Review
Context: Studies show that despite the role of mouth care in preventing ventilator-associated pneumonia, there is no high quality evidences for it. This study reviewed the literature related to mouth care in patients receiving mechanical ventilation.
Evidence Acquisition: PubMed, Ovide, Elsevier, ProQuest, IranMedex, SID, and Magiran databases were searched using key terms such as oral care, mouth care, critical care, and intensive care. Fifty-seven full-text articles in total were retrieved and included in the study.
Results: Totally, 15 review articles and 42 research articles were reviewed. Only 13 articles introduced or evaluated the validity of instruments or caring guidelines in the area of mouth care. Only one study discussed about designing and validating the psychometric properties of a mouth assessment scale. Most of the articles emphasized on brushing the teeth as the best method for mouth care, but there was no consensus on the frequency of washing and the best washing solution.
Conclusions: Despite the importance of mouth care, few original studies are conducted in this area and there is no approved clinical guideline for this procedure
The Extension Workers' Competency in Developing Small Agribusiness Capital in the District of Bogor, West Java
Extension agents had to develop their competencies in promoting small agribusiness capital. They needed this new skill so they could assist small farmers to develop their agribusinesses. Every enterprise – what ever its scale -- needed capital. In conjunction with this, the objectives of this research were: (1) to describe the distribution of extension agents on selected characteristics, (2) to identify the agents' competencies in promoting small agribusiness capital, as well as (3) to analyze the relationship of the agents' characteristics and their competencies in promoting small agribusiness capital. Data were collected through interviews with the agents. The obtained data were analyzed by using qualitative as well as quantitative procedures. The research results demonstrated that: firstly, the Extension agents mostly indicated their generic competencies in Agricultural Extension, and lack in specific competencies in farm management, especially in small agribusiness capital formation. Secondly, agents considered promoting the small farmers self-help capability, facilitating the promotion of village financial institution, and evaluating extension program as the three most important competencies, and thirdly, regardless of their characteristics, most of the agents interviewed agreed to the rank order of nine competency areas
The n-acetyl phenylalanine glucosamine derivative attenuates the inflammatory/catabolic environment in a chondrocyte-synoviocyte co-culture system
Osteoarthritis (OA), the most prevalent degenerative joint disease, still lacks a true disease-modifying therapy. The involvement of the NF-κB pathway and its upstream activating kinases in OA pathogenesis has been recognized for many years. The ability of the N-acetyl phenylalanine glucosamine derivative (NAPA) to increase anabolism and reduce catabolism via inhibition of IKKα kinase has been previously observed in vitro and in vivo. The present study aims to confirm the chondroprotective effects of NAPA in an in vitro model of joint OA established with primary cells, respecting both the crosstalk between chondrocytes and synoviocytes and their phenotypes. This model satisfactorily reproduces some features of the previously investigated DMM model, such as the prominent induction of ADAMTS-5 upon inflammatory stimulation. Both gene and protein expression analysis indicated the ability of NAPA to counteract key cartilage catabolic enzymes (ADAMTS-5) and effectors (MCP-1). Molecular analysis showed the ability of NAPA to reduce IKKα nuclear translocation and H3Ser10 phosphorylation, thus inhibiting IKKα transactivation of NF-κB signalling, a pivotal step in the NF-κB-dependent gene expression of some of its targets. In conclusion, our data confirm that NAPA could truly act as a disease-modifying drug in OA
Role of Vegetation as a Mitigating Factor in the Urban Context
It is known that the urban environment amplifies the effects of climate change, sometimes with disastrous consequences that put people at risk. These aspects can be affected by urban vegetation and planting design but, while there are thousands of papers related to the effects of climate change, a relatively limited number of them are directly aimed at investigating the role of vegetation as a mitigating factor in the urban context. This paper focuses on reviewing the research on the role of urban vegetation in alleviating the adverse conditions of the urban environment in order to provide some practical guidelines to be applied by city planners. Through an analysis of the documents found in Scopus, Web of Science, and Google Scholar using urban vegetation and climate change-related keywords we selected five major issues related to the urban environment: (1) particulate matter, (2) gaseous pollution, (3) noise pollution, (4) water runoff, (5) urban heat island effect. The analysis of existing knowledge reported here indicates that the roles of urban vegetation on the adverse effect of climate change could not be simply deemed positive or negative, because the role of urban green is also strongly linked to the structure, composition, and distribution of vegetation, as well as to the criteria used for management. Therefore, it could help to better understand the roles of urban green as a complex system and provide the foundation for future studie
A novel real-time detailed feedback collection and interaction tool for large classes
CONTEXT The existing approaches towards interactive student feedback and question collection have two major drawbacks. First, instructors are only provided with generic feedback, typically at the end of a teaching period. Second, students are not provided with opportunity to give content-specific feedback or raise questions on specific sections of content during the lecture. The latter is especially important in large classes with students from non-English speaking background who are generally less likely to actively participate in discussions. PURPOSE This paper aims to develop and test a user-friendly and automated platform, with efficient data management structure, which facilitates real-time collection and addressing of students’ feedback on a specific part of topics discussed during the class. APPROACH A web-based software has been developed using annotation technologies which assists students in providing anonymous and content-specific comments on lecture materials. The software equips lecturers with a real-time platform for retrieval of comments classified based on their area, type and frequency. The platform contains features that enable users, teachers, for analytical assessment of both teaching and learning performance. RESULTS The trial use of the designed platform has primarily increased engagement of students in the class discussions. This trend is specifically observed amongst international students who have gained confidence to raise more questions, compared to the traditional teaching methods. Concurrently, the lecturer has dramatically decreased his response period to students’ queries to nearly real-time through receiving classified comments adhered to a particular part of the lecture. CONCLUSIONS The software allows for structured analysis of course materials and students’ feedback which can be further used to update teaching standards. Moreover, it improves teacher-student relationships through timely and purposeful addressing of instructional issues
Bile acid structure-activity relationship: evaluation of bile acid lipophilicity using 1-octanol/water partition coefficient and reverse phase HPLC.
Two independent methods have been developed and compared to determine the lipophilicity of a representative series of naturally occurring bile acids (BA) in relation to their struc- ture. The BA included cholic acid (CA), chenodeoxycholic acid (CDCA), ursodeoxycholic acid (UDCA), deoxycholic acid (DCA), hyodeoxycholic acid (HDCA), ursocholic acid (UCA), hyocholic acid (HCA), as well as their glycine and taurine ami- dates. Lipophilicity was determined using a 1-octanol/water shake-flask procedure and the experiments were performed at different pH and ionic strengths and at initial BA concentrations below their critical micellar concentrations (CMC) and the water solubility of the protonated form. The experimental data show that both the protonated (HA) and ionized (A-) forms of BA can distribute in 1-octanol, and consequently a partition co- efficient for HA (logP' HA) and for A- (logP' A-) must be defined. An equation to predict a weighted apparent distribution coefficient (D) value as a function of pH and pKa has been de- veloped and fits well with the experimental data. Differences be- tween logP for protonated and ionized species for unconjugated BA were in the order of 1 log unit, which increased to 2 for glycine-amidated BA. The partition coefficient of the A- form in- creased with Na+ concentration and total ionic strength, suggest- ing an ion-pair mechanism for its partition into 1-octanol. Lipophilicity was also assessed using reverse phase chromatogra- phy (C-18-HPLC), and a capacity factor (K') for ionized species was determined. Despite a broad correlation with the logP data, some BA behaved differently. The logP values showed that the order of lipophilicity was DCA >CDCA >UDCA > HDCA > HCA>CA >UCA for both the protonated and ionized uncon- jugated and glycine-amidated BA, while the K' data showed an inversion for some BA, i.e., DCA>CDCA >CA> HCA> UDCA > HDCA >UCA. The logP data fitted well with other in- direct measurements of BA monomeric lipophilicity such as al- bumin binding or accessible total hydrophobic surface area data calculated by energy minimization and molecular computer graphics. Differences between unconjugated and amidated BA are consistent with the presence of an amide bond and a lower pKa when pH dependence was studied. Capacity factors, on the other hand, were related to properties of BA micelles such as cholesterol-solubilizing capacity and membrane disruption, reflecting the BA detergency. The extrapolation of these data to biological phenomena must carefully consider the experimental conditions in which the interaction occurs, Le., total BA concen- tration, ionic strength, Na+ concentration, and pH, which in turn determine the BA species existing in solution that coul
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