337 research outputs found
Sustainable development of production in Russia: an informative aspect
This paper is devoted to the study of the problems of introduction of the concept of sustainable development of production at modern enterprises. The paper substantiates the necessity of application of this concept at enterprises, gives reasons hindering this process. In addition, the analysis of the notion of sustainable development of production, wherein this process is represented as development of production by means of rational and economical use of resources oriented to provision of a long-term competitive advantage, was conducted in the paper. Moreover, the paper presents the basic principles of successful introduction of the concept of sustainable development of production. By the example of Toyota Company the benefits, which can be derived by an enterprise from application of this concept, were shown
Crystal structures of a halophilic archaeal malate synthase from Haloferax volcanii and comparisons with isoforms A and G
<p>Abstract</p> <p>Background</p> <p>Malate synthase, one of the two enzymes unique to the glyoxylate cycle, is found in all three domains of life, and is crucial to the utilization of two-carbon compounds for net biosynthetic pathways such as gluconeogenesis. In addition to the main isoforms A and G, so named because of their differential expression in <it>E. coli </it>grown on either acetate or glycolate respectively, a third distinct isoform has been identified. These three isoforms differ considerably in size and sequence conservation. The A isoform (MSA) comprises ~530 residues, the G isoform (MSG) is ~730 residues, and this third isoform (MSH-halophilic) is ~430 residues in length. Both isoforms A and G have been structurally characterized in detail, but no structures have been reported for the H isoform which has been found thus far only in members of the halophilic Archaea.</p> <p>Results</p> <p>We have solved the structure of a malate synthase H (MSH) isoform member from <it>Haloferax volcanii </it>in complex with glyoxylate at 2.51 Å resolution, and also as a ternary complex with acetyl-coenzyme A and pyruvate at 1.95 Å. Like the A and G isoforms, MSH is based on a β8/α8 (TIM) barrel. Unlike previously solved malate synthase structures which are all monomeric, this enzyme is found in the native state as a trimer/hexamer equilibrium. Compared to isoforms A and G, MSH displays deletion of an N-terminal domain and a smaller deletion at the C-terminus. The MSH active site is closely superimposable with those of MSA and MSG, with the ternary complex indicating a nucleophilic attack on pyruvate by the enolate intermediate of acetyl-coenzyme A.</p> <p>Conclusions</p> <p>The reported structures of MSH from <it>Haloferax volcanii </it>allow a detailed analysis and comparison with previously solved structures of isoforms A and G. These structural comparisons provide insight into evolutionary relationships among these isoforms, and also indicate that despite the size and sequence variation, and the truncated C-terminal domain of the H isoform, the catalytic mechanism is conserved. Sequence analysis in light of the structure indicates that additional members of isoform H likely exist in the databases but have been misannotated.</p
Climate Change and Utah Ski Resorts: Impacts, Perceptions, and Adaptation Strategies
Climate change is a threat to ski resorts, the ski industry, and mountain communities that rely on ski tourism. Ski resorts may be able to mitigate some of the social and economic impacts caused by climate change with proactive adaptation strategies. Using historical weather data, future climate projections, and interviews with ski resort managers in Utah (United States), this research investigates the effects of climate change on ski resorts across the state. We examine temperature change at all resorts within the state from 1980–2018 and climate projections from 2021–2100 under different climate change scenarios (RCPs 2.6, 4.5, and 8.5). We also report on semistructured interviews with resort managers to provide insights into how resort leadership perceives the impacts of climate change, is implementing adaptation strategies, and is addressing barriers to adaptation. Many resorts in Utah are warming faster than global averages, and minimum temperatures are rising faster than maximum temperatures. By the end of the century, winter (December–March) minimum daily temperatures in Utah could warm an additional 6.0°C under the RCP 8.5 scenario near northern Utah resorts and 6.6°C near southern Utah resorts. Resort managers are concerned about shorter season lengths, shifting ski seasons, less snow cover, and poorer snow quality. Many resorts are already adapting, with the most common adaptations being snowmaking and diversifying outdoor recreation offerings (particularly during the summer and shoulder seasons). Barriers to adaptation reported by managers include financial costs, adequate water availability for snowmaking, and uncertainty about climate change projections. Climate change is already impacting Utah ski resorts, but adaptation practices can reduce the negative impacts to some degree at most resorts
Effects of Photoperiod Treatments on Stock Plants and Cutting Rooting of Winecups
Production of attractive and water-efficient plants native to the plains and prairies of central North America can sometimes be limited because of problems associated with successful rooting of vegetative cuttings. Winecups (Callirhoe involucrata) is an attractive native plant, valued for its long period of bloom, drought tolerance, and winterhardiness, but can be difficult to propagate from seeds and vegetative cuttings. Seed dormancy issues can result in unreliable germination and seedling variations, which reduces crop uniformity. Although propagation from rooted cuttings maintains crop uniformity, cuttings often fail to root or root poorly. Manipulating the growing conditions of stock plants to suppress reproductive growth may improve rooting success of vegetative cuttings. Based on research conducted earlier with other ornamental perennials and programmed photoperiods, winecups plants were grown under three programmed photoperiods to determine if a particular photoperiod could be used to suppress reproductive growth and promote vegetative growth. The study consisted of three experiments, all conducted in similar fashion but at different times during the year. Results indicate that plants grown under 10-hour and 8-hour photoperiods remained vegetative longer when compared with plants grown under 12-hour photoperiod. Vegetative cuttings harvested from plants grown under 8-hour photoperiod had higher percent rooting when compared with vegetative cuttings harvested from plants grown under 10-hour and 12-hour photoperiods. Based on the findings from this research, plant propagators may be able to increase production of winecups by growing stock plants under 8-hour photoperiod
Characterization of metabolic and inflammatory responses following administration of three commercially available Mannheimia haemolytica vaccines to beef heifers
To evaluate the acute physiological and immunological responses to Mannheimia haemolytica vaccines, weaned heifers (n = 32; body weight [BW] = 296 ± 6.4 kg) were used in a completely randomized design. Heifers were balanced by BW and randomly assigned to one of three vaccine treatments: Nuplura PH (Elanco, Greenfield, IN; NP), OneShot (Zoetis, Parsippany, NJ; OS), or Presponse SQ (Boehringer Ingelheim, St. Joseph, MO; PS). Serial blood samples were collected for 7 d following vaccine administration to quantify multiple serum biomarkers and complete blood cell counts. Heifers were fitted with indwelling vaginal temperature recording devices for the duration of the study. No differences were noted in most CBC variables (P ≥ 0.27) except for PS heifers having greater lymphocytes (P = 0.02) and eosinophils (P < 0.01) than NP and OS heifers. Cortisol remained at or below basal concentrations for the duration of the study (P = 0.23). Glucose concentrations were greater for NP than OS, with PS being intermediate (P = 0.05). There was a tendency (P = 0.08) for a treatment × time interaction for circulating haptoglobin concentrations as NP heifers had a spike of greater magnitude but decreased duration. Likewise, a tendency (P = 0.07) was detected for decreased ceruloplasmin concentrations in PS heifers. The concentration of interleukin-6 (IL-6) was lesser in OS heifers than PS and NP heifers (P = 0.02), but PS heifers had decreased IL-4 concentrations (P < 0.01). No differences were observed in circulating interferon-gamma concentrations among treatments (P = 0.20). Overall, each vaccine treatment elicited similar physiological and inflammatory immune responses despite differences in vaccine composition. Although select immunological markers differed relative to vaccine treatment, it is unlikely these differences resulted in biologically relevant differences
15th Annual Environmental Law Institute
Materials from the 15th Annual Environmental Law Institute held by UK/CLE in March 1999
Challenges of Elephant Conservation: Insights from Oral Histories of Colonialism and Landscape in Tsavo, Kenya
Proteomic Analysis of Resistance of Gram-Negative Bacteria to Chlorhexidine and Impacts on Susceptibility to Colistin, Antimicrobial Peptides, and Ceragenins
Use of chlorhexidine in clinical settings has led to concerns that repeated exposure of bacteria to sub-lethal doses of chlorhexidine might result in chlorhexidine resistance and cross resistance with other cationic antimicrobials including colistin, endogenous antimicrobial peptides (AMPs) and their mimics, ceragenins. We have previously shown that colistin-resistant Gram-negative bacteria remain susceptible to AMPs and ceragenins. Here, we investigated the potential for cross resistance between chlorhexidine, colistin, AMPs and ceragenins by serial exposure of standard strains of Gram-negative bacteria to chlorhexidine to generate resistant populations of organisms. Furthermore, we performed a proteomics study on the chlorhexidine-resistant strains and compared them to the wild-type strains to find the pathways by which bacteria develop resistance to chlorhexidine. Serial exposure of Gram-negative bacteria to chlorhexidine resulted in four- to eight-fold increases in minimum inhibitory concentrations (MICs). Chlorhexidine-resistant organisms showed decreased susceptibility to colistin (8- to 32-fold increases in MICs) despite not being exposed to colistin. In contrast, chlorhexidine-resistant organisms had the same MICs as the original strains when tested with representative AMPs (LL-37 and magainin I) and ceragenins (CSA-44 and CSA-131). These results imply that there may be a connection between the emergence of highly colistin-resistant Gram-negative pathogens and the prevalence of chlorhexidine usage. Yet, use of chlorhexidine may not impact innate immune defenses (e.g., AMPs) and their mimics (e.g., ceragenins). Here, we also show that chlorhexidine resistance is associated with upregulation of proteins involved in the assembly of LPS for outer membrane biogenesis and virulence factors in Pseudomonas aeruginosa. Additionally, resistance to chlorhexidine resulted in elevated expression levels of proteins associated with chaperones, efflux pumps, flagella and cell metabolism. This study provides a comprehensive overview of the evolutionary proteomic changes in P. aeruginosa following exposure to chlorhexidine and colistin. These results have important clinical implications considering the continuous application of chlorhexidine in hospitals that could influence the emergence of colistin-resistant strains
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