University of Nebraska–Lincoln

Total carbon (C) in soils is the sum of both organic and inorganic C. Organic C is present in the soil organic matter fraction, whereas inorganic C is largely found in carbonate minerals. The wet combustion analysis of soils by chromic acid digestion has long been a standard method for determining total C, giving results in good agreement with dry combustion. Methods for total C are basic for many of the procedures used to determine organic C in soils. In contrast to noncalcareous soils, inorganic C must be removed from calcareous or limed soils before the analysis if wet or dry combustion techniques are used to directly measure the organic C present. The organic matter content of soil may be indirectly estimated through multiplication of the organic C concentration by the ratio of organic matter to organic C commonly found in soils.

The recent proliferation of scholarship on collective action frames and framing processes in relation to social movements indicates that framing processes have come to be regarded, alongside resource mobilization and political opportunity processes, as a central dynamic in understanding the character and course of social movements. This review examines the analytic utility of the framing literature for understanding social movement dynamics. We first review how collective action frames have been conceptualized, including their characteristic and variable features. We then examine the literature related to framing dynamics and processes. Next we review the literature regarding various contextual factors that constrain and facilitate framing processes. We conclude with an elaboration of the consequences of framing processes for other movement processes and outcomes. We seek throughout to provide clarification of the linkages between framing concepts/processes and other conceptual and theoretical formulations relevant to social movements, such as schemas and ideology.

Abstract The Normalized Difference Water Index (NDWI) is a new method that has been developed to delineate open water features and enhance their presence in remotely-sensed digital imagery. The NDWI makes use of reflected near-infrared radiation and visible green light to enhance the presence of such features while eliminating the presence of soil and terrestrial vegetation features. It is suggested that the NDWI may also provide researchers with turbidity estimations of water bodies using remotely-sensed digital data.

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is thatthere is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the completeprocess including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defined as increasedautophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in manycases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as forreviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multipleassays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation, it is imperative to target by gene knockout or RNA interference more than one autophagyrelated protein. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways implying that not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular assays, we hope to encourage technical innovation in the field.

Long, balanced electron and hole diffusion lengths greater than 100 nanometers in the polycrystalline organolead trihalide compound CH3NH3PbI3 are critical for highly efficient perovskite solar cells. We found that the diffusion lengths in CH3NH3PbI3 single crystals grown by a solution-growth method can exceed 175 micrometers under 1 sun (100 mW cm(-2)) illumination and exceed 3 millimeters under weak light for both electrons and holes. The internal quantum efficiencies approach 100% in 3-millimeter-thick single-crystal perovskite solar cells under weak light. These long diffusion lengths result from greater carrier mobility, longer lifetime, and much smaller trap densities in the single crystals than in polycrystalline thin films. The long carrier diffusion lengths enabled the use of CH3NH3PbI3 in radiation sensing and energy harvesting through the gammavoltaic effect, with an efficiency of 3.9% measured with an intense cesium-137 source.

With the continued interest in the role of the gut microbiota in health, attention has now turned to how to harness the microbiota for the benefit of the host. This Consensus Statement outlines the definition and scope of the term 'prebiotic' as determined by an expert panel convened by the International Scientific Association for Probiotics and Prebiotics in December 2016. In December 2016, a panel of experts in microbiology, nutrition and clinical research was convened by the International Scientific Association for Probiotics and Prebiotics to review the definition and scope of prebiotics. Consistent with the original embodiment of prebiotics, but aware of the latest scientific and clinical developments, the panel updated the definition of a prebiotic: a substrate that is selectively utilized by host microorganisms conferring a health benefit. This definition expands the concept of prebiotics to possibly include non-carbohydrate substances, applications to body sites other than the gastrointestinal tract, and diverse categories other than food. The requirement for selective microbiota-mediated mechanisms was retained. Beneficial health effects must be documented for a substance to be considered a prebiotic. The consensus definition applies also to prebiotics for use by animals, in which microbiota-focused strategies to maintain health and prevent disease is as relevant as for humans. Ultimately, the goal of this Consensus Statement is to engender appropriate use of the term 'prebiotic' by relevant stakeholders so that consistency and clarity can be achieved in research reports, product marketing and regulatory oversight of the category. To this end, we have reviewed several aspects of prebiotic science including its development, health benefits and legislation.

Contents: Turbulent times for survey methodology -- The tailored design method -- Coverage and sampling -- The basics of crafting good questions -- Constructing open- and closed-ended questions -- From questions to a questionnaire -- Implementation procedures -- When more than one survey mode is needed -- Longitudinal and internet panel surveys -- Customer feedback surveys and alternative delivery technologies -- Effects of sponsorship and the data collection organization -- Surveying businesses and other establishments -- Coping with

Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs-exploratory sequential, explanatory sequential, and convergent-and through four advanced frameworks-multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods.

The fundamental properties and ultimate performance limits of organolead trihalide MAPbX3 (MA = CH3NH3(+); X = Br(-) or I(-)) perovskites remain obscured by extensive disorder in polycrystalline MAPbX3 films. We report an antisolvent vapor-assisted crystallization approach that enables us to create sizable crack-free MAPbX3 single crystals with volumes exceeding 100 cubic millimeters. These large single crystals enabled a detailed characterization of their optical and charge transport characteristics. We observed exceptionally low trap-state densities on the order of 10(9) to 10(10) per cubic centimeter in MAPbX3 single crystals (comparable to the best photovoltaic-quality silicon) and charge carrier diffusion lengths exceeding 10 micrometers. These results were validated with density functional theory calculations.

A Monte Carlo simulation examined the performance of 4 missing data methods in structural equation models: full information maximum likelihood (FIML), listwise deletion, pairwise deletion, and similar response pattern imputation. The effects of 3 independent variables were examined (factor loading magnitude, sample size, and missing data rate) on 4 outcome measures: convergence failures, parameter estimate bias, parameter estimate efficiency, and model goodness of fit. Results indicated that FIML estimation was superior across all conditions of the design. Under ignorable missing data conditions (missing completely at random and missing at random), FIML estimates were unbiased and more efficient than the other methods. In addition, FIML yielded the lowest proportion of convergence failures and provided near-optimal Type 1 error rates across both simulations.

Two studies were conducted to analyze how hope, resilience, optimism, and efficacy individually and as a composite higher‐order factor predicted work performance and satisfaction. Results from Study 1 provided psychometric support for a new survey measure designed to assess each of these 4 facets, as well as a composite factor. Study 2 results indicated a significant positive relationship regarding the composite of these 4 facets with performance and satisfaction. Results from Study 2 also indicated that the composite factor may be a better predictor of performance and satisfaction than the 4 individual facets. Limitations and practical implications conclude the article.

Soybean (Glycine max) is one of the most important crop plants for seed protein and oil content, and for its capacity to fix atmospheric nitrogen through symbioses with soil-borne microorganisms. We sequenced the 1.1-gigabase genome by a whole-genome shotgun approach and integrated it with physical and high-density genetic maps to create a chromosome-scale draft sequence assembly. We predict 46,430 protein-coding genes, 70% more than Arabidopsis and similar to the poplar genome which, like soybean, is an ancient polyploid (palaeopolyploid). About 78% of the predicted genes occur in chromosome ends, which comprise less than one-half of the genome but account for nearly all of the genetic recombination. Genome duplications occurred at approximately 59 and 13 million years ago, resulting in a highly duplicated genome with nearly 75% of the genes present in multiple copies. The two duplication events were followed by gene diversification and loss, and numerous chromosome rearrangements. An accurate soybean genome sequence will facilitate the identification of the genetic basis of many soybean traits, and accelerate the creation of improved soybean varieties. Soybean (Glycine max) is an important commercial crop providing both protein and oil, and its symbiotic relationship to nitrogen-fixing bacteria makes it a profitable crop in rotation systems. Its genome has now been sequenced: it is the first legume and at 1.1 gigabases, the largest plant genome to be sequenced by whole-genome shotgun techniques. Soybean has a colourful genetic past; genome duplications occurred at 59 and 13 million years ago, resulting in a highly duplicated genome with nearly 75% of the genes present in multiple copies. An accurate soybean genome sequence should accelerate the creation of improved soybean varieties. Soybean is an important crop plant, providing seed protein and oil and fixing atmospheric nitrogen through symbioses with soil-borne microorganisms. Using a whole-genome shotgun approach, its 1.1-gigabase genome is now sequenced and integrated with physical and high-density genetic maps to create a chromosome-scale draft sequence assembly.

Building on Kahn's (1990) ethnographic work, a field study in a U.S. Midwestern insurance company explored the determinants and mediating effects of three psychological conditions — meaningfulness, safety and availability — on employees' engagement in their work. Results from the revised theoretical framework revealed that all three psychological conditions exhibited significant positive relations with engagement. Meaningfulness displayed the strongest relation. Job enrichment and work role fit were positively linked to psychological meaningfulness. Rewarding co‐worker and supportive supervisor relations were positively associated with psychological safety, whereas adherence to co‐worker norms and self‐consciousness were negatively associated. Psychological availability was positively related to resources available and negatively related to participation in outside activities. Finally, the relations of job enrichment and work role fit with engagement were both fully mediated by the psychological condition of meaningfulness. The association between adherence to co‐worker norms and engagement was partially mediated by psychological safety. Theoretical and practical implications related to psychological engagement at work are discussed.

This study developed and tested a theory-based measure of authentic leadership using five separate samples obtained from China, Kenya, and the United States. Confirmatory factor analyses supported a higher order, multidimensional model of the authentic leadership construct (the Authentic Leadership Questionnaire [ALQ]) comprising leader self-awareness, relational transparency, internalized moral perspective, and balanced processing. Structural equation modeling (SEM) demonstrated the predictive validity for the ALQ measure for important work-related attitudes and behaviors, beyond what ethical and transformational leadership offered. Finally, results revealed a positive relationship between authentic leadership and supervisor-rated performance. Implications for research and practice are discussed.

(1992). How College Affects Students. The Journal of Higher Education: Vol. 63, No. 3, pp. 355-358.

The integrative literature review is a distinctive form of research that generates new knowledge about the topic reviewed. Little guidance is available on how to write an integrative literature review. This article discusses how to organize and write an integrative literature review and cites examples of published integrative literature reviews that illustrate how this type of research has made substantive contributions to the knowledge base of human resource development.

The occurrence of widespread, severe drought in Africa, India, North America, China, the USSR, Australia, and western Europe has once again underscored the vulnerability of developed and developing societies to drought. The occurrence of severe drought during 1982–83 is shown in figure 1. These recent droughts have emphasized the need for more research on the causes as well as the impacts of drought and the need for additional planning to help mitigate the possible worst effects of future droughts. Drought has been the subject of a great deal of systematic study, particularly reconstructions of drought history, computations of drought frequency, and to a lesser extent, investigations of first-, second-, and even third-order impacts of drought on society.

This article discusses some procedural issues related to the mixed-methods sequential explanatory design, which implies collecting and analyzing quantitative and then qualitative data in two consecutive phases within one study. Such issues include deciding on the priority or weight given to the quantitative and qualitative data collection and analysis in the study, the sequence of the data collection and analysis, and the stage/stages in the research process at which the quantitative and qualitative data are connected and the results are integrated. The article provides a methodological overview of priority, implementation, and mixing in the sequential explanatory design and offers some practical guidance in addressing those issues. It also outlines the steps for graphically representing the procedures in a mixed-methods study. A mixed-methods sequential explanatory study of doctoral students’ persistence in a distance-learning program in educational leadership is used to illustrate the methodological discussion.

Counseling psychologists face many approaches from which to choose when they conduct a qualitative research study. This article focuses on the processes of selecting, contrasting, and implementing five different qualitative approaches. Based on an extended example related to test interpretation by counselors, clients, and communities, this article provides a detailed discussion about five qualitative approaches— narrative research; case study research; grounded theory; phenomenology; and participatory action research—as alternative qualitative procedures useful in understanding test interpretation. For each approach, the authors offer perspectives about historical origins, definition, variants, and the procedures of research.

Abstract This essay draws from the emerging positive psychology movement and the author's recent articles on the need for and meaning of a positive approach to organizational behavior. Specifically, the argument is made that at this time, the OB field needs a proactive, positive approach emphasizing strengths, rather than continuing in the downward spiral of negativity trying to fix weaknesses. However, to avoid the surface positivity represented by the non‐sustainable best‐sellers, the case is made for positive organizational behavior (POB) to take advantage of the OB field's strength of being theory and research driven. Additional criteria for this version of POB are to identify unique, state‐like psychological capacities that can not only be validly measured, but also be open to development and performance management. Confidence, hope, and resiliency are offered as meeting such POB inclusion criteria. The overall intent of the essay is to generate some positive thinking and excitement for the OB field and ‘hopefully’ stimulate some new theory building, research, and effective application. Copyright © 2002 John Wiley & Sons, Ltd.