Pilot-scale biopesticide production by Bacillus thuringiensis subsp. kurstaki using starch industry wastewater as raw material

Pilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (K_La) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material.     

Effect of processing on the disappearance of pesticide residues in fresh-cut lettuce: Bioavailability and dietary risk

The aim of this research is to establish the processing factors of six pesticides durong the preparation of fresh-cut lettuce and to assess the risk of ingestion of pesticide residues associated with the consumption of the same. A field study was carried out on the dissipation of three insecticides (imidacloprid, tebufenozide, cypermethrin) and three fungicides (metalaxyl, tebuconazole, azoxystrobin) during treatment conditions simulating those used for commercial fresh-cut lettuce. A simultaneous residue analysis method is validated using QuEChERS extraction with acetonitrile and CG-MS and LC-MS/MS analysis. The residues detected after field application never exceed the established Maximum Residue Limits. The processing factors were generally less than 1 (between 0.34 for tebufenozide and 0.53 for imidacloprid), indicating that the process, as a whole, considerably reduces residue levels in processed lettuce compared to fresh lettuce. It is confirmed that cutting, followed by washing and drying, considerably reduces the residues. A matrix effect in the dialyzation of the pesticides is observed and the in vitro study of bioavailability establishes a low percentage of stomach absorption capacity (<15%). The EDI/ADI ratios found in all cases were well below their ADI values, and the dietary exposure assessed (EDI) in fresh-cut lettuce showed no concerns for consumer health.     

Fish recruitment prediction, using robust supervised classification methods

Improving our ability to predict recruitment is a key element in fisheries management. However, the interactions between population dynamics and different environmental factors are complex and often non-linear, making it difficult to produce robust predictions. ‘Machine-learning’ techniques (in particular, supervised classification methods) have been proposed as useful tools, to overcome such difficulties. In this study, a methodology is proposed to build a robust classifier for fish recruitment prediction with sparse and noisy data. The methodology consists of 4 steps: (1) a semi-automated recruitment discretization method; (2) supervised discretization of predictors; (3) multivariate and non-redundant predictors selection; (4) learning a probabilistic classifier. In terms of fisheries management, the classifier estimated performance has important consequences and, to be useful, the manager needs to know the risk that is being taken when using this number. Probabilistic classifiers such as ‘naive Bayes’, have the advantage that, in addition to the predictions, estimate also the probability of each possible outcome. Anchovy (Engraulis encrasicolus) and hake (Merluccius merluccius) recruitments are used as application examples. ‘Two-intervals’ recruitment discretization accomplishes 70% accuracies and Brier scores of around 0.10, for both anchovy and hake recruitment. In comparison, ‘three-intervals’ recruitment discretization accomplishes 50% accuracies; and Brier scores of around 0.25 for anchovy and 0.30 for hake recruitment. These statistics are the result of validating not only the classifier, but also the previous steps, as a whole methodology.     

Deviations from predictions of the metabolic theory of ecology can be explained by violations of assumptions

The metabolic theory of ecology (MTE) is based on models derived from the first principles of thermodynamics and biochemical kinetics. The MTE predicts that the relationship between temperature and species richness of ectotherms should show a specific slope. Testing the validity of this model, however, depends on whether empirical data do not violate assumptions and are obtained within contour conditions. When dealing with richness gradients, the MTE must be empirically tested only for ectothermic organisms at high organization levels and when their body size as well as abundance does not vary with temperature gradients. Here we evaluate whether the magnitude of the deviations in slope expected from the MTE to empirical data for New World amphibians is due to the violations of model assumptions and to lack of generality due to restricting contour conditions. We found that the MTE correctly predicted biodiversity patterns only at higher levels of organization and when assumptions of the basic model were not violated. Approximately 60% of the deviations from the MTE-predicted slope across amphibian families were due to violations of the model assumptions. The hypothesis that richness patterns are a function of environmental temperature is too restrictive and does not take complex environmental and ecological processes into account. However, our results suggest that it may be possible to obtain multiple derivations of the MTE equation if idiosyncrasies in spatial and biological/ecological issues that are essential to understanding biodiversity patterns are considered.     

Spatial variation of phosphorus fractionation in the coral reef sediments of Lakshadweep Archipelago,Indian Ocean

Surface sediments were collected from the shore and lagoons of Kavaratti, Kadamat and Agatti islands of Lakshadweep Archipelago during May 2015 and analysed for the spatial distribution of the micronutrient element, phosphorus. Phosphorus was separated by sequential extraction procedure into five fractions – exchangeable (Ex-P), iron bound, (Fe-P), calcium bound (Ca-P), organic and residual fractions (OP) and total phosphorus (TP). The average relative contribution of each P species to TP was: OP?>?Ca –P?>?Ex – P?>?Fe – P. The high concentration of organic and residual phosphorus (87–96%) compared to inorganic phosphorus is particularly evident at stations characterised by higher total phosphorus concentrations. Among the three forms of IP in the sediments, Ca-P was dominant at all stations. The OC/OP ratio ranged from 3 to 163 in the sediments, suggesting that the organic matter in sediments had been subjected to degradation. Hence, the major contribution towards organic and residual phosphorus form is from the residual fraction comprising biologically resistant or non-available phosphorus form composed of refractory materials. The concentration of phosphorus reported in the present study is higher than that of the earlier studies in Lakshadweep, indicating a terrestrial and anthropogenic in?uence on the sediment.     

Comparative study of degradation of toluene and methyl isobutyl ketone (MIBK) in aqueous solution by pulsed corona discharge plasma

Effectiveness of pulsed power plasma for the degradation of two toxic volatile organic compounds (VOCs), toluene and methyl isobutyl ketone (MIBK), in aqueous solution was evaluated. The plasma degradation of MIBK has been studied for the first time. The influence of initial concentration of target compound, solution pH and scavengers on percentage degradation was evaluated. 100% removal of 200 mg/L of toluene and MIBK was achieved both in liquid and gaseous phases after 12 and 16 min of plasma treatment, respectively. The first order rate constant of toluene and MIBK degradation (for 200 mg/L each) was 0.421 and 0.319 min^?1 respectively when they were treated individually, and these values decreased slightly during degradation of their mixture. MIBK degradation was slower than toluene and it might be due to semi volatile and hydrophilic nature of MIBK. The effect of initial concentration of toluene and MIBK showed different degradation patterns. Highest degradation of both the compounds was obtained in neutral pH and in absence of scavengers. ?OH radical was the major reactive species involved in their degradation. Their degradation in real environmental matrices showed that removal reduced significantly in secondary effluent due to scavenging of reactive species by various ions and organic matter. The total number of degradation intermediates identified in case of toluene and MIBK was 11 and 14 respectively and formate was the one recalcitrant byproduct generated. The degradation pathway of toluene and MIBK involving reactions of reactive oxygen and nitrogen species and reductive species is proposed.     

Political transition and emergent forest‐conservation issues in Myanmar

Political and economic transitions have had substantial impacts on forest conservation. Where transitions are underway or anticipated, historical precedent and methods for systematically assessing future trends should be used to anticipate likely threats to forest conservation and design appropriate and prescient policy measures to counteract them. Myanmar is transitioning from an authoritarian, centralized state with a highly regulated economy to a more decentralized and economically liberal democracy and is working to end a long‐running civil war. With these transitions in mind, we used a horizon‐scanning approach to assess the 40 emerging issues most affecting Myanmar's forests, including internal conflict, land‐tenure insecurity, large‐scale agricultural development, demise of state timber enterprises, shortfalls in government revenue and capacity, and opening of new deforestation frontiers with new roads, mines, and hydroelectric dams. Averting these threats will require, for example, overhauling governance models, building capacity, improving infrastructure‐ and energy‐project planning, and reforming land‐tenure and environmental‐protection laws. Although challenges to conservation in Myanmar are daunting, the political transition offers an opportunity for conservationists and researchers to help shape a future that enhances Myanmar's social, economic, and environmental potential while learning and applying lessons from other countries. Our approach and results are relevant to other countries undergoing similar transitions.     

Defining and operationalizing theory

Over the last 50 years, the organizational sciences have gone from being largely atheoretical to relying heavily on theory. For various reasons, our approach to theory building has strayed from the principles of scientific acceptability. In this paper, I explore the problems with our approach to theory, the systemic causes of these problems, and the changes that are needed to get us back on track. Copyright © 2016 John Wiley & Sons, Ltd.     

新千年的能源

本文讨论了有关能源的思想观念的演变.20年前当几位作者开始携手合作研究能源时,人们一般是以发展的眼光、从供应方的角度来考虑能源问题,将注意力集中到消费趋势以及如何扩大供给以满足不断增长的需求上.这种方法在能源利用的环境影响、安全性和公平合理性方面的研究局限深深地困扰着他们.例如,大约有20亿人口经济条件有限,买不起现代能源,这严重限制了他们生活水平的提高.此外,能源还是造成环境问题的重要因素,其中包括室内空气污染、城市空气污染、酸化和全球气候变暧等.笔者认为,应当树立新的能源供给观念,使能源的供给方式有助于解决这些严重问题.笔者主张,能源必须成为推进可持续发展——经济上可行、以需要为导向、自力更生的能及无损于环境的发展——的工具,而且,应当将研究重点放在能源的终端用途上和能源供应的服务上.有助于实现可持续发展目标的能源技术方案也在本文进行了讨论.文中强调了制订和运用新型能源技术解决方案的必要性.笔者以巴西乙醇的利用为例,阐述了使发展中国家避免重复工业化国家所犯错误而在技术上实现跨越式发展的可能性.文中还重点介绍了在发展中国家引进先进技术过程中外国直接投资可能起到的作用,阐述了农村能源的近期和远期战略.最后,介绍了促进能源系统的发展,使之与可持续发展的步调一致并且支持可持续发展的相关政策.     

Geochemical Distribution and Bioavailability of Heavy Metals and Oxalate in Street Sediments from Rio de Janeiro, Brazil: A Preliminary Investigation

As urbanisation accelerates within less-economically developed countries, populations in cities such as Rio de Janeiro are subject to numerous health risks relating to “heavy metal”, sewage and vehicle pollution. These risks apply especially to children, through inhalation and dermal contact with pollutant-rich street sediments that reflect contamination from atmospheric deposition and act as effective sinks for heavy metals and oxalates. To assess the nature and extent of these risks street sediments were collected from industrial, commercial, residential and recreational areas with varying traffic densities within Rio de Janeiro. A modified selective extraction procedure was used to study the geochemical partitioning and bioavailability of Fe, Mn, Zn, Cu, Cr, Ni, Pb and C₂O ₄ ⁻ . Oxalate partitioning has not been studied by traditional sequential methods and results from this procedure highlight the potential bioavailability of both oxalates and “heavy metals”, especially Pb and C₂O ₄ ⁻ in industrial and recreational areas.