Metal stress consequences on frost hardiness of plants at northern high latitudes: a review and hypothesis

Since sewage discharges can significantly contribute to the contaminant loadings in coastal areas, it is important to identify sources, pathways and environmental sinks. Sterol and fatty alcohol biomarkers were quantified in source materials, suspended sediments and settling matter from the Ria Formosa Lagoon. Simple ratios between key biomarkers including 5beta-coprostanol, cholesterol and epi-coprostanol were able to identify the sewage sources and effected deposition sites. Multivariate methods (PCA) were used to identify co-varying sites. PLS analysis using the sewage discharge as the signature indicated approximately 25% of the variance in the sites could be predicted by the sewage signature. A new source of sewage derived organic matter was found with a high sewage predictable signature. The suspended sediments had relatively low sewage signatures as the material was diluted with other organic matter from in situ production. From a management viewpoint, PLS provides a useful tool in identifying the pathways and accumulation sites for such contaminants.     

Teams as boundaries: How intra‐team and inter‐team brokerage influence network changes in knowledge‐seeking networks

What role does an ego's brokerage location—within a team (intra‐team) or outside the team (inter‐team)—play in the evolution of an instrumental knowledge‐seeking network in terms of both proximal (i.e., within the team) and distal (i.e., outside the team) tie formation and tie decay? We address this question by drawing on literature about social networks, brokerage, and teams. We use temporally separated data from 302 students embedded in 97 teams to test our hypotheses about the impacts of intra‐team and inter‐team brokerage on proximal and distal network evolution, specifically on four network changes in knowledge‐seeking networks: proximal tie formation, proximal tie decay, distal tie formation, and distal tie decay. We find that these four changes depend on individual network brokerage location even after controlling for personality and task characteristics. Specifically, inter‐team brokers change their networks both within and outside their teams, whereas intra‐team brokers curtail their network changes. We argue that these opposite effects occur because inter‐team brokers have greater autonomy than intra‐team brokers. This study adds to the ongoing dialog about network evolution in social network literature and to the conversations about brokerage and its location in the context of team‐based work.     

Yield and Water Productivity of Winter Wheat under Various Irrigation Capacities

The Agricultural Production Systems sIMulator model validated in a prior study for winter wheat was used to simulate yield, aboveground crop biomass (BM), transpiration (T), and evapotranspiration under four irrigation capacities (ICs) (0, 1.7, 2.5, and 5 mm/day) with two nitrogen (N) application rates (N1, 94 kg N/ha; N2, 160 kg N/ha) to (1) understand the performance of winter wheat under different ICs and (2) develop crop water production function under various ICs and N rates. Evaluation was based on yield, aboveground crop BM, transpiration productivity (TP), crop water productivity (WP), and irrigation WP (IWP). Simulation results showed winter wheat yield increased with increase in N application rate and IC. However, the rate of yield increase gradually reduced with additional irrigation beyond 2.5 mm/day. A 5 mm/day IC required a total of 190 mm irrigation and produced a 5%–16% yield advantage over 2.5 mm/day. This indicates it is possible to reduce groundwater use for wheat by 50% incurring only 5%–16% yield loss relative to 5 mm/day. The TP and IWP for grain were slightly higher under IC of 1.7 mm/day (15.2–16.1 kg/ha/mm and 0.98–1.6 kg/m³) when compared to 5 mm/day (14.7–15.5 kg/ha/mm and 0.6–1.06 kg/m³), respectively. Since TP and IWPs are relatively higher under lower ICs, winter wheat could be a suitable crop under lower ICs in the region. Relationship between yield–T and yield–ET was linear with a slope of 15–16 and 9.5–10 kg/ha/mm, respectively. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.     

Public participation in NGO-oriented communities for disaster prevention and mitigation (N-CDPM) in the Longmen Shan fault area during the Wenchuan and Lushan earthquake periods

ABSTRACT

The Longmen Shan fault area in southwest China is one of the world’s most active earthquake zones. The epicenters of the two most recent earthquakes, the 2008 Wenchuan earthquake (8.0?Ms) and the 2013 Lushan earthquake (7.0?Ms), both of which caused serious losses, were only 85?km apart. Community-based disaster risk reduction is the foundation of the disaster management system pyramid and is critical to the success of ‘sustainable hazard mitigation’. Based on multiple collaborative stakeholder perspectives, this paper examines public participation in an NGO-oriented Community for Disaster Prevention and Mitigation (N-CDPM) in the period between the two earthquakes as a multi-stage problem; N-CDPM establishment, normal operations, disaster testing, and continuous improvement. Multi-stage field research was conducted in the affected areas in the Longmen Shan fault area to examine the collaboration in each stage, after which the differences were compared across the four stages based on eight key indices; scales, core stakeholders, core network stability, mean number of lines, mean collaborative level, governments, and individual and public organization participation. The government participation, individual participation, and public organization participation are then discussed. This paper provides a novel research approach to CDPM in multiple earthquake regions and gives rich insights into the collaboration between the government and the public for N-CDPM.     

Toxicity of endosulfan on growth,photosynthesis, and nitrogenase activity in two species of Nostoc (Nostoc muscorum and Nostoc calcicola)

Treatments of the cyanobacteria Nostoc muscorum and Nostoc calcicola with the insecticide endosulfan (5, 10, and 20?µg?mL^?1) inhibited growth, photosynthetic pigments, photosynthetic, and nitrogenase activities. The sensitivity of N. muscorum to endosulfan was higher than that of N. calcicola. The toxic effect of endosulfan was more pronounced on phycocyanin; however, a considerable reduction in chlorophyll a and carotenoids was also noticed. ¹⁴C-fixation appeared to be more sensitive to the insecticide than photosynthetic oxygen evolution. Endosulfan caused strong inhibition of photosystem (PS) II activity whereas PS I was least affected. The inhibition of PS II activity was partially restored by electron donors (DPC, NH₂OH, and MnCl₂) at low dose of endosulfan. Nitrogenase activity was significantly suppressed in both species by the endosulfan at high dose (20?µg?mL^?1). On the basis of our comparative analysis, N. calcicola was found to be endosulfan resistant and can be used in paddy fields for better productivity under pesticide stress.     

Large-scale green synthesis of Cu nanoparticles

This article reports a novel, eco-friendly herbal method to synthesize Cu nanoparticles in large scales. Cu nanoparticles are an alternative to Ag and Au nanoparticles and have potential applications in many industrial areas. Many synthetic routes have been documented for the preparation of copper nanoparticles, but very few routes are eco-friendly and large-scale. We report here the preparation of Cu nanoparticles from aqueous CuSO₄ using non-toxic and inexpensive materials like curd, milk, and herbal extracts such as tamarind and lemon juice as capping agents. X-ray diffraction and transmission electron microscopy show that produced particles are nanocrystalline copper 20–50 nm in size with a face-centered cubic structure. Fourier-transformed infrared spectroscopy evidences the role of organic acids in the capping process. The novelty of this work is the synthesis of Cu nanoparticles from CuSO₄ without electricity and using non-toxic, cheap capping agents.     

Effect of pH and salinity on pathogenicity of Flavobacterium columnare and Myxobacterium sp. in Indian cat fish, Clarias batrachus (Linn.) and Heteropneustes fossilis (Bloch.)

Flavobacterium columnare (FC) and Myxobacterium sp. recorded persistently associated in fish hatchery and culture system of Himalayan and Sub - Himalayan regions were found to be pathogenic. The pH and salinity played a significant role on the pathogenicity of these potent pathogens in case of Clarias batrachus and Heteropneustes fossilis. LD50 value of FC was 10(4.5) CFU in both the fishes and those of Myxobacterium sp it was 10(6) CFU ml(-1) fish(-1). Fish challenged with F. columnare and Myxobacterium sp. (@ 0.2 ml fish(-1)) individually consisting 10(5-6) cfu ml(-1) exhibited explicit symptoms of columnaris disease and marked with ulceration and saddle back lesion on the dorsal side of body. Maximum reisolation of inoculated bacteria was recorded at pH 7.0 and 7.5 and at 0.0-0.5 (F. columnare) and 0.0-1.0% (Myxobacterium sp.) salinity. Foregoing results elucidated that F. columnare was more sensitive to salinity in comparison to Myxobacterium sp. and their pathogenicity significantly (p<0.05) depends on the salinity and pH that might be one of the physical factors to control their proliferation.     

Fire risk evaluation using multicriteria analysis—a case study

Forest fires are one of the major causes of ecological disturbance and environmental concerns in tropical deciduous forests of south India. In this study, we use fuzzy set theory integrated with decision-making algorithm in a Geographic Information Systems (GIS) framework to map forest fire risk. Fuzzy set theory implements classes or groupings of data with boundaries that are not sharply defined (i.e., fuzzy) and consists of a rule base, membership functions, and an inference procedure. We used satellite remote sensing datasets in conjunction with topographic, vegetation, climate, and socioeconomic datasets to infer the causative factors of fires. Spatial-level data on these biophysical and socioeconomic parameters have been aggregated at the district level and have been organized in a GIS framework. A participatory multicriteria decision-making approach involving Analytical Hierarchy Process has been designed to arrive at a decision matrix that identified the important causative factors of fires. These expert judgments were then integrated using spatial fuzzy decision-making algorithm to map the forest fire risk. Results from this study were quite useful in identifying potential “hotspots” of fire risk, where forest fire protection measures can be taken in advance. Further, this study also demonstrates the potential of multicriteria analysis integrated with GIS as an effective tool in assessing “where and when” forest fires will most likely occur.     

Effect of industrial effluent on properties of groundwater

Field survey was conducted to assess the quality of underground water in four major industrial areas of Hyderabad, Andhra Pradesh, and viz., Patancheru, Katedhan, Nacharam and Jeedimetla. Ground water samples were collected from wells at different lateral distances from the effluent streams i.e., starting from a minimum distance of 20 meters to a maximum distance of 620 meters from the effluent streams and analysed for different characteristics. The survey revealed that indiscriminate disposal of the effluent of industrial complexes around Hyderabad has aggrevated the acidity, EC, TDS, COD, Cl-, SO4(2-), PO4(3-), NO3-, F and heavy metals in the ground waters. As the sampling distance from the polluting stream increased a gradual improvement in the quality of ground water was noticed.