Relationships among five forms of commitment: an empirical assessment

This paper examined whether Morrow's (1993) model of five universal forms of work commitment (affective organizational commitment, continuance organizational commitment, career commitment, job involvement and work ethic endorsement) has empirical support. The paper explored the discriminant validity among the five scales of these commitment forms. It also tested Morrow's model regarding the interrelationships among them in comparison with an alternative conceptualization proposed by Randall and Cote (1991). Two hundred and thirty‐eight nursing staff from two hospitals in western Canada were surveyed. Results of confirmatory factor analysis (LISREL VIII) and correlation analysis showed an acceptable discriminant validity among the five commitment foci. The results of path analysis (LISREL VIII) showed a poor fit with the data of Morrow's model and a better fit with the alternative model of Randall and Cote. Revised models based on the modification indices from both models were tested, and supported the Randall and Cote approach. The paper concludes with implications regarding the continuing assessment of Morrow's conceptualization to establish an acceptable definition and measurement of universal forms of work commitment. Copyright © 1999 John Wiley & Sons, Ltd.     

Transition Pathways to Sustainable Agricultural Water Management: A Review of Integrated Modeling Approaches

Agricultural water management (AWM) is an interdisciplinary concern, cutting across traditional domains such as agronomy, climatology, geology, economics, and sociology. Each of these disciplines has developed numerous process‐based and empirical models for AWM. However, models that simulate all major hydrologic, water quality, and crop growth processes in agricultural systems are still lacking. As computers become more powerful, more researchers are choosing to integrate existing models to account for these major processes rather than building new cross‐disciplinary models. Model integration carries the hope that, as in a real system, the sum of the model will be greater than the parts. However, models based upon simplified and unrealistic assumptions of physical or empirical processes can generate misleading results which are not useful for informing policy. In this article, we use literature and case studies from the High Plains Aquifer and Southeastern United States regions to elucidate the challenges and opportunities associated with integrated modeling for AWM and recommend conditions in which to use integrated models. Additionally, we examine the potential contributions of integrated modeling to AWM — the actual practice of conserving water while maximizing productivity. 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.     

Feasibility of landfill gas as a liquefied natural gas fuel source for refuse trucks

The purpose of this paper is to develop a methodology to evaluate the feasibility of using landfill gas (LFG) as a liquefied natural gas (LNG) fuel source for heavy-duty refuse trucks operating on landfills. Using LFG as a vehicle fuel can make the landfills more self-sustaining, reduce their dependence on fossil fuels, and reduce emissions and greenhouse gases. Acrion Technologies Inc. in association with Mack Trucks Inc. developed a technology to generate LNG from LFG using the CO2 WASH process. A successful application of this process was performed at the Eco Complex in Burlington County, PA. During this application two LNG refuse trucks were operated for 600 hr each using LNG produced from gases from the landfill. The methodology developed in this paper can evaluate the feasibility of three LFG options: doing nothing, electricity generation, and producing LNG to fuel refuse trucks. The methodology involved the modeling of several components: LFG generation, energy recovery processes, fleet operations, economic feasibility, and decision-making. The economic feasibility considers factors such as capital, maintenance, operational, and fuel costs, emissions and tax benefits, and the sale of products such as surplus LNG and food-grade carbon dioxide (CO2). Texas was used as a case study. The 96 landfills in Texas were prioritized and 17 landfills were identified that showed potential for converting LFG to LNG for use as a refuse truck fuel. The methodology was applied to a pilot landfill in El Paso, TX. The analysis showed that converting LFG to LNG to fuel refuse trucks proved to be the most feasible option and that the methodology can be applied for any landfill that considers this option.     

Identification of two mutations for ataxia telangiectasia among the Druze community

Ataxia telangiectasia (AT) is a rare autosomal recessive disease characterized by progressive cerebellar ataxia, immunodeficiency, susceptibility to lymphoreticular malignancies and cancer predisposition, hypersensitivity to ionic radiation and chromosomal instability. In this study, we report a founder effect of AT with two different mutations: 1339 C > T and 6672 del GG together with 6677 del TACG, found in four Israeli Druze clans originating from three different Druze centers in the Middle East (Lebanon, Syria and Jordan). The 1339 C > T mutation, which results in a stop codon at position 447 of the ATM protein, was observed in two unrelated clans originating from Lebanon and Jordan. The 6672 del GG/6677 del TACG mutation was observed in two unrelated clans originating from Syria and Lebanon. In the present study, simple and fast detection assays were developed for both mutations. The ability to identify AT carriers routinely provides a unique opportunity for prenatal diagnosis, genetic counseling as well as marriage guidance in the Druze community. Copyright © 2004 John Wiley & Sons, Ltd.     

Refining Nitrogen and Phosphorus Fertilization Strategies for Controlling the Toxigenic Alga Prymnesium parvum1

Kurten, Gerald L., Aaron Barkoh, Drew C. Begley, and Loraine T. Fries, 2010. Refining Nitrogen and Phosphorus Fertilization Strategies for Controlling the Toxigenic Alga Prymnesium parvum. Journal of the American Water Resources Association (JAWRA) 46(1):170-186. DOI: 10.1111/j.1752-1688.2009.00401.x Abstract: Previous studies have shown that three times weekly applications of phosphorus (30 μg P/l) and nitrogen (300 μg N/l) were effective at reducing the density and toxicity of the alga Prymnesium parvum in limnocorrals simulating a 40-day moronid (e.g., striped bass, Morone saxatilis, and palmetto bass, M. saxatilis ×Morone chrysops) fingerling culture period. However, this fertilization regime produced high pH and unionized ammonia-N concentrations that are detrimental to the survival of moronid fry and fingerlings. In two follow-up experiments we changed the source of N from ammonia to nitrate, reduced fertilization rates, and examined the effect of N-only or P-only fertilization. In the first experiment P fertilization rates were reduced by one-half to 15 μg P/l and NO₃-N was substituted for NH₃-N at the previously used rate of 300 μg N/l. In the second experiment, N fertilization rates were reduced to 150 μg N/l and the frequency of fertilization was determined by pH and P. parvum responses. Nitrate appeared to be as effective as ammonia as a source of N and when used in combination with P reduced P. parvum cell density and ichthyotoxicity. However, reduced N and P application rates and lower pond water temperatures during the study appeared to have decreased the speed at which fertilization produced these effects. While lower fertilization rates reduced algal productivity, high pH remained a concern for fish culture although pH was reduced to levels that might be acceptable with careful management of fish culture activities. Neither N-only nor P-only fertilization had a measurable effect on algal productivity or eliminated P. parvum and its toxicity. Furthermore, P-only fertilization may have increased P. parvum density and toxicity. For controlling P. parvum density and ichthyotoxicity we recommend a fertilization rate of 212 μg NO₃-N/l plus 30 μg PO₄-P/l applied three times weekly for aquaculture ponds where high pH is not a concern. Where high pH is a concern we recommend a fertilization rate of 117 μg NO₃-N/l plus 16 μg PO₄-P/l applied three times weekly with careful attention to afternoon pond pH.     

Climate policy in India: what shapes international, national and state policy?

At the international level, India is emerging as a key actor in climate negotiations, while at the national and sub-national levels, the climate policy landscape is becoming more active and more ambitious. It is essential to unravel this complex landscape if we are to understand why policy looks the way it does, and the extent to which India might contribute to a future international framework for tackling climate change as well as how international parties might cooperate with and support India's domestic efforts. Drawing on both primary and secondary data, this paper analyzes the material and ideational drivers that are most strongly influencing policy choices at different levels, from international negotiations down to individual states. We argue that at each level of decision making in India, climate policy is embedded in wider policy concerns. In the international realm, it is being woven into broader foreign policy strategy, while domestically, it is being shaped to serve national and sub-national development interests. While our analysis highlights some common drivers at all levels, it also finds that their influences over policy are not uniform across the different arenas, and in some cases, they work in different ways at different levels of policy. We also indicate what this may mean for the likely acceptability within India of various climate policies being pushed at the international level.