981 research outputs found
Properties of Bipolar Fuzzy Hypergraphs
In this article, we apply the concept of bipolar fuzzy sets to hypergraphs
and investigate some properties of bipolar fuzzy hypergraphs. We introduce the
notion of tempered bipolar fuzzy hypergraphs and present some of their
properties. We also present application examples of bipolar fuzzy hypergraphs
Optical control of internal electric fields in band-gap graded InGaN nanowires
InGaN nanowires are suitable building blocks for many future optoelectronic
devices. We show that a linear grading of the indium content along the nanowire
axis from GaN to InN introduces an internal electric field evoking a
photocurrent. Consistent with quantitative band structure simulations we
observe a sign change in the measured photocurrent as a function of photon
flux. This negative differential photocurrent opens the path to a new type of
nanowire-based photodetector. We demonstrate that the photocurrent response of
the nanowires is as fast as 1.5 ps
A comparison of atmospheric composition using the Carbon Bond and Regional Atmospheric Chemistry Mechanisms
We incorporate the recently developed Regional Atmospheric Chemistry Mechanism (version 2, RACM2) into the Community Multiscale Air Quality modeling system for comparison with the existing 2005 Carbon Bond mechanism with updated toluene chemistry (CB05TU). Compared to CB05TU, RACM2 enhances the domain-wide monthly mean hydroxyl radical concentrations by 46% and nitric acid by 26%. However, it reduces hydrogen peroxide by 2%, peroxyacetic acid by 94%, methyl hydrogen peroxide by 19%, peroxyacetyl nitrate by 40%, and organic nitrate by 41%. RACM2 enhances ozone compared to CB05TU at all ambient levels. Although it exhibited greater overestimates at lower observed concentrations, it displayed an improved performance at higher observed concentrations. The RACM2 ozone predictions are also supported by increased ozone production efficiency that agrees better with observations. Compared to CB05TU, RACM2 enhances the domain-wide monthly mean sulfate by 10%, nitrate by 6%, ammonium by 10%, anthropogenic secondary organic aerosols by 42%, biogenic secondary organic aerosols by 5%, and in-cloud secondary organic aerosols by 7%. Increased inorganic and organic aerosols with RACM2 agree better with observed data. Any air pollution control strategies developed using the two mechanisms do not differ appreciably
Altered Macrophage Phenotype Transition Impairs Skeletal Muscle Regeneration
Monocyte/macrophage polarization in skeletal muscle regeneration is ill defined. We used CD11b-diphtheria toxin receptor transgenic mice to transiently deplete monocytes/macrophages at multiple stages before and after muscle injury induced by cardiotoxin. Fat accumulation within regenerated muscle was maximal when ablation occurred at the same time as cardiotoxin-induced injury. Early ablation (day 1 after cardiotoxin) resulted in the smallest regenerated myofiber size together with increased residual necrotic myofibers and fat accumulation. However, muscle regeneration after late (day 4) ablation was similar to controls. Levels of inflammatory cells in injured muscle following early ablation and associated with impaired muscle regeneration were determined by flow cytometry. Delayed, but exaggerated, monocyte [CD11b+(CD90/B220/CD49b/NK1.1/Ly6G)−(F4/80/I-Ab/CD11c)−Ly6C+/−] accumulation occurred; interestingly, Ly6C+ and Ly6C− monocytes were present concurrently in ablated animals and control mice. In addition to monocytes, proinflammatory, Ly6C+ macrophage accumulation following early ablation was delayed compared to controls. In both groups, CD11b+F4/80+ cells exhibited minimal expression of the M2 markers CD206 and CD301. Nevertheless, early ablation delayed and decreased the transient accumulation of CD11b+F4/80+Ly6C−CD301− macrophages; in control animals, the later tissue accumulation of these cells appeared to correspond to that of anti-inflammatory macrophages, determined by cytokine production and arginase activity. In summary, impairments in muscle regeneration were associated with exaggerated monocyte recruitment and reduced Ly6C− macrophages; the switch of macrophage/monocyte subsets is critical to muscle regeneration
Effect of tillage and organic mulches on growth, yield and quality of autumn planted maize (Zea mays L.) and soil physical properties
see the effect of organic
mulches and tillage practices on growth,
yield and quality of autumn planted maize
and soil physical properties. Four types of
tillage practices i.e. conventional tillage,
zero tillage, bar harrow tillage, subsoiler
tillage and two types of mulching material
i.e. wheat straw mulch and saw dust mulch
was used. The mulching material was
partially incorporated in the field after
germination of crop. The experiment was
carried out in randomized complete block
design (RCBD) with three replications.
Control treatment was kept for comparison.
All other practices were kept uniform
throughout the crop period. Data about
growth and yield components were
collected and analyzed statistically by fisher
analysis of variance and treatment
significance was measured by significant
difference test at 5v% level. The results
showed that zero tillage + wheat straw
mulch gave maximum 1000-grain weight
(341.67 g) and grain yield (6.33 t ha-1) and it
was followed by conventional tillage + saw
dust mulch (4.92 t ha-1). Higher protein
content was recorded in Subsoiler tillage
(10.26 %). Conducive soil physical
conditions were observed in the zero tillage
practices over the other tillage practices. On
the basis of these results it could be
proposed that the tillage and mulching is a
very important practice to increase the yield
of crop. Among different practices, zero
tillage with wheat straw mulching gave
maximum yield and net benefits
Safe and just operating spaces for regional social-ecological systems
Humanity faces a major global challenge in achieving wellbeing for all, while simultaneously ensuring that the biophysical processes and ecosystem services that underpin wellbeing are exploited within scientifically informed boundaries of sustainability. We propose a framework for defining the safe and just operating space for humanity that integrates social wellbeing into the original planetary boundaries concept (Rockström et al., 2009a,b) for application at regional scales. We argue that such a framework can: (1) increase the policy impact of the boundaries concept as most governance takes place at the regional rather than planetary scale; (2) contribute to the understanding and dissemination of complexity thinking throughout governance and policy-making; (3) act as a powerful metaphor and communication tool for regional equity and sustainability. We demonstrate the approach in two rural Chinese localities where we define the safe and just operating space that lies between an environmental ceiling and a social foundation from analysis of time series drawn from monitored and palaeoecological data, and from social survey statistics respectively. Agricultural intensification has led to poverty reduction, though not eradicated it, but at the expense of environmental degradation. Currently, the environmental ceiling is exceeded for degraded water quality at both localities even though the least well-met social standards are for available piped water and sanitation. The conjunction of these social needs and environmental constraints around the issue of water access and quality illustrates the broader value of the safe and just operating space approach for sustainable development
Purification and medium optimization of α-amylase from Bacillus subtilis 168
α-Amylase was first time isolated and purified from Bacillus subtilis 168 (1A1). Purified α-amylase fraction showed a single protein band with a molecular weight of 55 kD. Chemical characterization of the purified α-amylase revealed optimum amylolytic activity at 37°C and pH 7.0 using starch as substrate. It was stable at pH 5.0 to 9.0 and at temperatures 25–70°C. Culture conditions were optimized by using statistics-based experimental designs to enhanced α-amylase (EC.3.2.1.1) production. A two level fractional factorial Plackett-Burman design was used for the preliminary screening significant media components and conditions. Response surface methodology (RSM) involving a 24 full-factorial central composite design (CCD) and a second-order polynomial equation was then employed to identify the relationship between the α-amylase yield and the four significant variables. Optimal levels of the significant variables for the maximum α-amylase yield were starch 2.55 g/l, yeast extract 8.4 g/l, sodium chloride 8.1% and 48 h of incubation. Mean value of α-amylase yield was 639.7 IU/ml, which was in excellent agreement with the predicted value (633.5 IU/ml).Key words: Bacillus, α-amylase, optimization, Plackett-Burman design, response surface methodology
- …