University of Nebraska at Kearney

Abstract Workplace stress is a growing concern for human resource managers. Although considerable scholarly and practical attention has been devoted to stress management over the years, the time has come for new perspectives and research. Drawing from the emerging field of positive organizational behavior, this study offers research findings with implications for combating occupational stress. Specifically, data from a large sample of working adults across a variety of industries suggest that psychological capital (the positive resources of efficacy, hope, optimism, and resilience) may be key to better understanding the variation in perceived symptoms of stress, as well as intentions to quit and job search behaviors. The article concludes with practical strategies aimed at leveraging and developing employees' psychological capital to help them better cope with workplace stress. © 2009 Wiley Periodicals, Inc.

Reconstructing the phylogenetic relationships that unite all lineages (the tree of life) is a grand challenge. The paucity of homologous character data across disparately related lineages currently renders direct phylogenetic inference untenable. To reconstruct a comprehensive tree of life, we therefore synthesized published phylogenies, together with taxonomic classifications for taxa never incorporated into a phylogeny. We present a draft tree containing 2.3 million tips-the Open Tree of Life. Realization of this tree required the assembly of two additional community resources: (i) a comprehensive global reference taxonomy and (ii) a database of published phylogenetic trees mapped to this taxonomy. Our open source framework facilitates community comment and contribution, enabling the tree to be continuously updated when new phylogenetic and taxonomic data become digitally available. Although data coverage and phylogenetic conflict across the Open Tree of Life illuminate gaps in both the underlying data available for phylogenetic reconstruction and the publication of trees as digital objects, the tree provides a compelling starting point for community contribution. This comprehensive tree will fuel fundamental research on the nature of biological diversity, ultimately providing up-to-date phylogenies for downstream applications in comparative biology, ecology, conservation biology, climate change, agriculture, and genomics.

Maximum entropy (Maxent) modeling has great potential for identifying distributions and habitat selection of wildlife given its reliance on only presence locations. Recent studies indicate Maxent is relatively insensitive to spatial errors associated with location data, requires few locations to construct useful models, and performs better than other presence-only modeling approaches. Further advances are needed to better define model thresholds, to test model significance, and to address model selection. Additionally, development of modeling approaches is needed when using repeated sampling of known individuals to assess habitat selection. These advancements would strengthen the utility of Maxent for wildlife research and management.

A SEGS LS-2 parabolic trough solar collector was tested to determine the collector efficiency and thermal losses with two types of receiver selective coatings, combined with three different receiver configurations: glass envelope with either vacuum or air in the receiver annulus, and glass envelope removed from the receiver. As expected, collector performance was significantly affected by each variation in receiver configuration. Performance decreased when the cermet selective coating was changed to a black chrome coating, and progressively degraded as air was introduced into the vacuum annulus, and again when the glass envelope was removed from the receiver. For each receiver configuration, performance equations were derived relating collector efficiency and thermal losses to the operating temperature. For the bare receiver (no glass envelope) efficiency and thermal losses are shown as a function of wind speed. An incident angle modifier equation was also developed for each receiver case. Finally, equations were derived showing collector performance as a function of input insolation value, incident angle, and operating temperature. Results from the experiments were compared with predictions from a one-dimensional analytical model of the solar receiver. Differences between the model and experiment were generally within the band of experimental uncertainty.

Drought stress is a major obstacle to crop productivity, and the severity and frequency of drought are expected to increase in the coming century. Certain root-associated bacteria have been shown to mitigate the negative effects of drought stress on plant growth, and manipulation of the crop microbiome is an emerging strategy for overcoming drought stress in agricultural systems, yet the effect of drought on the development of the root microbiome is poorly understood. Through 16S rRNA amplicon and metatranscriptome sequencing, as well as root metabolomics, we demonstrate that drought delays the development of the early sorghum root microbiome and causes increased abundance and activity of monoderm bacteria, which lack an outer cell membrane and contain thick cell walls. Our data suggest that altered plant metabolism and increased activity of bacterial ATP-binding cassette (ABC) transporter genes are correlated with these shifts in community composition. Finally, inoculation experiments with monoderm isolates indicate that increased colonization of the root during drought can positively impact plant growth. Collectively, these results demonstrate the role that drought plays in restructuring the root microbiome and highlight the importance of temporal sampling when studying plant-associated microbiomes.

We present a 6-gene, 420-species maximum-likelihood phylogeny of Ascomycota, the largest phylum of Fungi. This analysis is the most taxonomically complete to date with species sampled from all 15 currently circumscribed classes. A number of superclass-level nodes that have previously evaded resolution and were unnamed in classifications of the Fungi are resolved for the first time. Based on the 6-gene phylogeny we conducted a phylogenetic informativeness analysis of all 6 genes and a series of ancestral character state reconstructions that focused on morphology of sporocarps, ascus dehiscence, and evolution of nutritional modes and ecologies. A gene-by-gene assessment of phylogenetic informativeness yielded higher levels of informativeness for protein genes (RPB1, RPB2, and TEF1) as compared with the ribosomal genes, which have been the standard bearer in fungal systematics. Our reconstruction of sporocarp characters is consistent with 2 origins for multicellular sexual reproductive structures in Ascomycota, once in the common ancestor of Pezizomycotina and once in the common ancestor of Neolectomycetes. This first report of dual origins of ascomycete sporocarps highlights the complicated nature of assessing homology of morphological traits across Fungi. Furthermore, ancestral reconstruction supports an open sporocarp with an exposed hymenium (apothecium) as the primitive morphology for Pezizomycotina with multiple derivations of the partially (perithecia) or completely enclosed (cleistothecia) sporocarps. Ascus dehiscence is most informative at the class level within Pezizomycotina with most superclass nodes reconstructed equivocally. Character-state reconstructions support a terrestrial, saprobic ecology as ancestral. In contrast to previous studies, these analyses support multiple origins of lichenization events with the loss of lichenization as less frequent and limited to terminal, closely related species.

The idea that noncrop habitat enhances pest control and represents a win-win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win-win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.

The throwing shoulder in pitchers frequently exhibits a paradox of glenohumeral joint motion, in which excessive external rotation is present at the expense of decreased internal rotation. The object of this study was to determine the role of humeral head retroversion in relation to increased glenohumeral external rotation. Glenohumeral joint range of motion and laxity along with humeral head and glenoid version of the dominant versus nondominant shoulders were studied in 25 professional pitchers and 25 nonthrowing subjects. Each subject underwent a computed tomography scan to determine bilateral humeral head and glenoid version. The throwing group demonstrated a significant increase in the dominant shoulder versus the nondominant shoulder in humeral head retroversion, glenoid retroversion, external rotation at 90 degrees, and external rotation in the scapular plane. Internal rotation was decreased in the dominant shoulder. Total range of motion, anterior glenohumeral laxity, and posterior glenohumeral laxity were found to be equal bilaterally. The nonthrowing group demonstrated no significant difference in humeral head retroversion, glenoid retroversion, external rotation at 90 degrees or external rotation in the scapular plane between shoulders, and no difference in internal rotation at 90 degrees, total motion, or laxity. A comparison of the dominant shoulders of the two groups indicated that both external rotation at 90 degrees and humeral head retroversion were significantly greater in the throwing group.

BACKGROUND: Hypoxia inducible factor-1 (HIF-1) plays a critical role in angiogenesis during vascular development. The authors tested the hypothesis that HIF-1 expression correlates with progression and angiogenesis in brain tumors. METHODS: The authors investigated the expression of the HIF-1alpha and HIF-1beta subunits in human glioma cell lines and brain tumor tissues using Western blot analysis and immunohistochemistry. RESULTS: In glioblastomas multiforme (GBMs), HIF-1alpha primarily was localized in pseudopalisading cells around areas of necrosis and in tumor cells infiltrating the brain at the tumor margin. In contrast, HIF-1alpha was expressed in stromal cells throughout hemangioblastomas (HBs). Like HIF-1alpha, HIF-1beta was most highly expressed in high grade tumors but was expressed more widely than HIF-1alpha, including cells away from necrotic zones. In the brains of mice injected with Glioma 261 cells, a pattern of HIF-1alpha expression identical to that observed in human GBMs was noted. CONCLUSIONS: In GBMs, the heterogeneous pattern of HIF-1alpha expression appears to be determined at least in part by tissue oxygenation, whereas in HBs the homogeneous expression of HIF-1alpha may be driven by an oncogenic rather than a physiologic stimulus.

Business process redesign (BPR) is a pervasive but challenging tool for transforming organizations. Information technology plays an important role by either enabling or constraining successful BPR. This paper explores the links between firm-wide IT infrastructure and business process change. IT infrastructure is the base foundation of the IT portfolio, which is shared throughout the firm in the form of reliable services, and is usually coordinated by the IS group. IT infrastructure capability includes both the technical and managerial expertise required to provide reliable physical services and extensive electronic connectivity within and outside the firm. Exploratory case analysis of four firms (two in retail and two in petroleum) was used to understand the ways IT infrastructure contributes to success in implementing BPR. The finding was that all firms needed a basic level of IT infrastructure capability to implement BPR. The firms that had developed a higher level of IT infrastructure capabilities, before or concurrent with undertaking business process redesign, were able to implement extensive changes to their business processes over relatively short time frames. The higher level of infrastructure capability was provided in the form of (1) a set of infrastructure services that spanned organizational boundaries such as those between functions, business units, or firms, and (2) the ability of the infrastructure to reach particular constituencies inside and outside the firm to transfer information and process complex transactions. The more extensive business process changes were more innovative and radical, crossing business and functional unit boundaries, and resulted in more significant business impact. The practical implication of the study is that before embarking on any form of BPR, managers should complete a business audit of their IT infrastructure capabilities, as these capabilities have an important impact on the speed and nature of business process change.

The authors conducted a grounded theory study of academic procrastination to explore adaptive and maladaptive aspects of procrastination and to help guide future empirical research. They discuss previous research on the definition and dimensionality of procrastination and describe the study in which interview data were collected in 4 stages, identifying 33 initial categories and 29 macrothemes. Findings were validated by member checks. The authors describe in detail informants' perceptions of procrastination, which were used to construct a 5-component paradigm model that includes adaptive (i.e., cognitive efficiency, peak experience) and maladaptive (i.e., fear of failure, postponement) dimensions of procrastination. These dimensions, in turn, are related to conditions that affect the amount and type of procrastination, as well as cognitive (i.e., prioritizing, optimization) and affective (i.e., reframing, self-handicapping) coping mechanisms. The authors propose 6 general principles and relate them and the paradigm model to previous research. Limitations of the research are discussed, as well as implications for future theory development and validation.

With a growing body of literature linking systems of high-performance work practices to organizational performance outcomes, recent research has pushed for examinations of the underlying mechanisms that enable this connection. In this study, based on a large sample of Welsh public-sector employees, we explored the role of several individual-level attitudinal factors--job satisfaction, organizational commitment, and psychological empowerment--as well as organizational citizenship behaviors that have the potential to provide insights into how human resource systems influence the performance of organizational units. The results support a unit-level path model, such that department-level, high-performance work system utilization is associated with enhanced levels of job satisfaction, organizational commitment, and psychological empowerment. In turn, these attitudinal variables were found to be positively linked to enhanced organizational citizenship behaviors, which are further related to a second-order construct measuring departmental performance.

This study examines relationships among high-performance work systems (HPWS), job control, employee anxiety, role overload, and turnover intentions. Building on theory that challenges the rhetoric versus reality of HPWS, the authors explore a potential “dark side” of HPWS that suggests that HPWS, which are aimed at creating a competitive advantage for organizations, do so at the expense of workers, thus resulting in negative consequences for individual employees. However, the authors argue that these consequences may be tempered when HPWS are also implemented with a sufficient amount of job control, or discretion given to employees in determining how to implement job responsibilities. The authors draw on job demands–control theory and the stress literatures to hypothesize moderated-mediation relationships relating the interaction of HPWS utilization and job control to anxiety and role overload, with subsequent effects on turnover intentions. The authors examine these relationships in a multilevel sample of 1,592 government workers nested in 87 departments from the country of Wales. Results support their hypotheses, which highlight several negative consequences when HPWS are implemented with low levels of job control. They discuss their findings in light of the critique in the literature toward the utilization of HPWS in organizations and offer suggestions for future research directions.

This study explores central questions related to the connections between a firm's human resources (HR) system and its ability to exhibit “organizational ambidexterity.” We build from existing work on the behavioral view of ambidexterity to assess the extent to which the utilization of certain HR practices may be linked to a context marked by discipline, stretch, trust, and support. We further argue that these disparate practices may be combined into a single high-performance work system (HPWS), which allows the firm to achieve both the alignment and the adaptability necessary to produce ambidexterity. Thus, we examine HPWS as a systematic tool for enhancing organizational ambidexterity. We explore this link using data from 215 high-tech small to medium-sized enterprises (SMEs) and find that HPWS utilization is positively related to a measure of organizational ambidexterity. In turn, ambidexterity mediates the relationship between HPWS utilization and firm growth.

Plant response to drought stress involves fungi and bacteria that live on and in plants and in the rhizosphere, yet the stability of these myco- and micro-biomes remains poorly understood. We investigate the resistance and resilience of fungi and bacteria to drought in an agricultural system using both community composition and microbial associations. Here we show that tests of the fundamental hypotheses that fungi, as compared to bacteria, are (i) more resistant to drought stress but (ii) less resilient when rewetting relieves the stress, found robust support at the level of community composition. Results were more complex using all-correlations and co-occurrence networks. In general, drought disrupts microbial networks based on significant positive correlations among bacteria, among fungi, and between bacteria and fungi. Surprisingly, co-occurrence networks among functional guilds of rhizosphere fungi and leaf bacteria were strengthened by drought, and the same was seen for networks involving arbuscular mycorrhizal fungi in the rhizosphere. We also found support for the stress gradient hypothesis because drought increased the relative frequency of positive correlations.

This research uses theories of flow, telepresence, positive emotions, and brand equity to examine the effect of using two-dimensional versus three-dimensional virtual world environments on telepresence, enjoyment, brand equity, and behavioral intention. The findings suggest that the 3D virtual world environment produces both positive and negative effects on brand equity when compared to the 2D environment. The positive effect of the 3D virtual world environment on brand equity occurs through telepresence, a specific aspect of flow, as well as enjoyment. The negative effect on brand equity can be explained using distraction–conflict theory in which attentional conflicts faced by users of a highly interactive and rich medium resulted in distractions from attending to the brand. Brand equity, in turn, has a positive effect on behavioral intention. The results suggest that although the 3D virtual world environment has the potential to increase brand equity by offering an immersive and enjoyable virtual product experience, the rich environment can also be a distraction. Therefore, developers of virtual world branding sites need to take into account limitations in the information processing capacity and attention span of users when designing their sites in order to avoid cognitive overload, which can lead to users being distracted from branding information. This paper not only provides a theoretical foundation for explaining users’ experience with 2D versus 3D virtual world branding sites, but also provides insights to practitioners for designing 3D virtual world sites to enhance brand equity and intentions through user engagement.

The purpose of this study was to develop a theory about the process through which community formed in adult computer-mediated asynchronous distance learning classes. A grounded theory design incorporated archived class input as well as interviews with twenty-one students and three faculty members from three graduate-level distance education classes.A three-stage phenomenon was ascertained. The first stage was making friends on-line with whom students felt comfortable communicating. The second stage was community conferment (acceptance) which occurred when students were part of a long, thoughtful, threaded discussion on a subject of importance after which participants felt both personal satisfaction and kinship. The third stage was camaraderie which was achieved after long-term or intense association with others involving personal communication. Each of these stages involved a greater degree of engagement in both the class and the dialogue.Causal conditions, intervening conditions, strategies and consequences were enumerated. A visual model of the entire process of community-building was advanced. Benefits of community were noted, and suggestions were made to facilitate the formation of an on-line community.

Community assembly of crop-associated fungi is thought to be strongly influenced by deterministic selection exerted by the plant host, rather than stochastic processes. Here we use a simple, sorghum system with abundant sampling to show that stochastic forces (drift or stochastic dispersal) act on fungal community assembly in leaves and roots early in host development and when sorghum is drought stressed, conditions when mycobiomes are small. Unexpectedly, we find no signal for stochasticity when drought stress is relieved, likely due to renewed selection by the host. In our experimental system, the host compartment exerts the strongest effects on mycobiome assembly, followed by the timing of plant development and lastly by plant genotype. Using a dissimilarity-overlap approach, we find a universality in the forces of community assembly of the mycobiomes of the different sorghum compartments and in functional guilds of fungi.

Purpose The leadership of entrepreneurs/business founders, as perceived by their employees, has received limited research attention. Using the Authentic Leadership Model as a guiding framework, this study seeks to provide an exploratory examination of the linkage between employees' perception of the business founder as an authentic leader and the employees' attitudes and happiness. Design/methodology/approach Participants are employees ( n =179) of 62 newer, smaller businesses. Each business represented in the study had been founded by a single owner still active in the daily operations of the company. Hierarchical linear modeling was used to analyze the two levels of data (individual and business level) gathered in the study. Findings As hypothesized, the employees' perception of authentic leadership serves as the strongest single predictor of employee job satisfaction ( t =6.453, p =0.000), organizational commitment ( t =6.665, p =0.000), and work happiness ( t =5.488, p =0.000). Research limitations/implications A convenience sampling method limits the generalizability of results. Experimental and longitudinal future research is needed to assess issues of causality as well as the strength and duration of relationships noted. Future research should focus on how the authentic leadership of the founder/entrepreneur impacts not only employee attitudes, but also the performance and long‐term viability of the emerging organization. Originality/value This exploratory study offers the first application of the Authentic Leadership Model within the context of entrepreneurial ventures, and provides new insights into the relationship between entrepreneur/leader behavior and employee attitudes. Findings indicate that if employees in newer, small organizations view their founder/entrepreneur as an authentic leader, it can have a positive impact on their work‐related attitudes and happiness.

Potted `Cabernet Sauvignon' and `Pinot noir' grapevines ( Vitis vinifera L.) grown in a sunlit phytotron were used to study the influence of cluster light exposure during various stages of fruit development on berry growth and composition. Clusters grown without light during berry development stages I and II, stage III, or stages I, II, and III, were compared to clusters exposed to light throughout fruit development (control). The temperature of light-exposed and nonexposed fruit was similar. The weights and diameters of berries grown without light during stages I and II, or stages I, II, and III, were similar and significantly lower than those of the control. Fruit softening in both cultivars, as well as the initiation of berry coloration, was delayed when berries were grown without light during stages I and II. Following fruit softening, berries grown without light during stages I, II, and III were lower in sugar than the control. On the final sample date, `Cabernet Sauvignon' berries grown without light during stages I, II, and III were higher in malate compared to the control. `Pinot noir' berries grown without light during stages I and II, or stages I, II, and III, were lower in malate before fruit softening, and higher in malate following fruit softening, than the control. Control berries had greater skin anthocyanins and phenolics compared to the remaining treatments. Berries grown without light during stages I and II, or stage III, were greater in anthocyanins and phenolics than fruit grown without light during stages I, II, and III. Light had no effect on fruit tartrate concentration or juice pH. Light had its greatest impact on fruit development during the initial stages of berry growth. Berry growth was reduced and ripening delayed when fruit were grown without light during stages I and II. Normal fruit development was not fully restored when these fruit were exposed to light during stage III.