5,190 research outputs found

    Different landscape factors explain establishment and persistence of river red gum (Eucalyptus camaldulensis) in agricultural landscapes of southeast Queensland

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    Riparian and floodplain ecosystems in production landscapes are considerably degraded and under continued pressure from surrounding land use. However, little is known about how remnant ecosystems respond to land use and hydrological factors in small non-riverine wetlands. River red gum (Eucalyptus camaldulensis) is a dominant tree species within these scattered remnants, which provides critical ecological functions for the remaining biodiversity. In this study, we investigated how different life stages of E. camaldulensis responded to land use and hydrological variables in the Condamine catchment of south east Queensland. We used logistic regression to develop models for different life stages of E. camaldulensis in two regions with differing land use intensity histories. Broad regional differences and land use practices at smaller scales best explained differences in E. camaldulensis occurrence for younger life stages, while hydrology (groundwater and connectivity to rivers) and land use practices (dryland agriculture and grazing) best explained differences in older life stages. The results indicate that different factors are important in determining the establishment and persistence of E. camaldulensis and that land use practices at the regional scale are key factors in determining the establishment and potential future persistence of E. camaldulensis in floodplain wetlands

    If and to What Extent Does Organizational Learning Culture Predict Turnover Intentions of Telecommuting Call Center Agents?

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    This study focuses on measuring the relationship between organizational learning culture (OLC) and turnover intentions of telecommuting call center agents. Although many studies involve the call center industry from different perspectives, the literature is scant in studies that have assessed the relationship between OLC and turnover intent in telecommuting call center agents. Call centers exist in almost every organization worldwide. Organizations have centralized their customer service process through computerbased technologies allowing call center agents to work from home. In addition, in the post-COVID-19 era, telecommuting has become a permanent option for many call center employees. Indeed, in the call center industry, telecommuting has become an essential part of the business strategy that seeks to attract new and maintain current employees. In the call center industry, learning is a factor that influences job satisfaction and turnover intentions. Specifically, OLC increases job satisfaction and performance in telecommuting call center agents, influencing employees’ turnover intentions. The study’s findings indicate that OLC is a needed factor that helps lower turnover intentions of telecommuting call center agents in the United States

    Understanding Leadership for Adaptive Change in Catholic Schools: A Complexity Perspective

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    In an era of decline and crisis, Catholic school leaders have been encouraged to find innovative ways to enhance a school’s operational vitality. Yet to this point, most research on educational change in Catholic schools has focused on the technical tasks school principals can take to “save” individual schools. In this article, we apply a complexity perspective to educational change leadership in Catholic education: leadership for adaptive change. Based on a new empirical analysis of the professional experiences of two Catholic school principals working at four different parish schools, we demonstrate in this article how leadership for adaptive change can operate in Catholic elementary parish schools and assess whether and how the attributes of complex adaptive schools were present in these four elementary schools. We also highlight the organizational and social conditions these two principals confronted that both undermined and promoted their ability to lead for adaptive change at these four schools. Ultimately, we suggest in this article the utility of using a “complex adaptive” approach to understanding change leadership in Catholic elementary schools as opposed to “technically rational” approaches commonly found in contemporary Catholic school leadership research

    An X-Ray View of the Jet-Cycle in the Radio Loud AGN 3C120

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    We present a study of the central engine in the broad-line radio galaxy 3C120 using a multi-epoch analysis of a deep XMM-Newton observation and two deep Suzaku pointings (in 2012). In order to place our spectral data into the context of the disk-disruption/jet-ejection cycles displayed by this object, we monitor the source in the UV/X-ray bands, and in the radio band. We find three statistically acceptable spectral models, a disk-reflection model, a jet-model and a jet+disk model. Despite being good descriptions of the data, the disk-reflection model violates the radio constraints on the inclination, and the jet-model has a fine-tuning problem, requiring a jet contribution exceeding that expected. Thus, we argue for a composite jet+disk model. Within the context of this model, we verify the basic predictions of the jet-cycle paradigm, finding a truncated/refilling disk during the Suzaku observations and a complete disk extending down to the innermost stable circular orbit (ISCO) during the XMM-Newton observation. The idea of a refilling disk is further supported by the detection of the ejection of a new jet knot approximately one month after the Suzaku pointings. We also discover a step-like event in one of the Suzaku pointings in which the soft band lags the hard band. We suggest that we are witnessing the propagation of a disturbance from the disk into the jet on a timescale set by the magnetic field.Comment: 14 pages, 10 figures, accepted for publication in Ap

    Information/knowledge design in contextual hypermedia systems

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 1998.Includes bibliographical references (leaves 51-55).As we begin to comprehend the ways we interact with the data/information/knowledge structures which construct our individual perception of reality, we see a shift from the dyadic Cartesian method of reading our environment, to a triadic, or Systems View, which accounts for individual perceptual readings and individual realities. This shift in thinking relates that we are dynamic, self-organizing, complex systems which form an individual perception of our environment based on the relationships we identify between ourselves and the interrelated systems of data/information around us. Recognizing this shift, the research project associated with this thesis, utilizes interactive digital multimedia, or hypermedia, in the design of a set of tools with which to identify and illustrate these interrelated systems. It is the author's belief that once identified, these dynamic relationships will provide an ideal source of user-defined navigation of the group of interrelated objects. The dynamic qualities of hypermedia, which provide the author different modes of linking information of many different data types to one another, making it an ideal venue for the illustration and navigation of systemic relationships. Employing two and three dimensional methods of visual and spatial representation, integrated with in various combinations of graphic organizational models, the product of th is thesis will provide the user an information-rich environment in which to identify and navigate the associative relationships found amongst a group of physical objects, in th is case furniture of modern design. The thesis also looks ahead to speculate on the impact of emerging technologies such as Augmented Reality, Virtual Reality, and Tangible User Interfaces, on the design of information knowledge "spaces". The author will propose a future implementation of these technologies in relation to the current subject of illustration.by Andrew F. Miller.S.M

    Seed size and its rate of evolution correlate with species diversification across angiosperms

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    Species diversity varies greatly across the different taxonomic groups that comprise the Tree of Life (ToL). This imbalance is particularly conspicuous within angiosperms, but is largely unexplained. Seed mass is one trait that may help clarify why some lineages diversify more than others because it confers adaptation to different environments, which can subsequently influence speciation and extinction. The rate at which seed mass changes across the angiosperm phylogeny may also be linked to diversification by increasing reproductive isolation and allowing access to novel ecological niches. However, the magnitude and direction of the association between seed mass and diversification has not been assessed across the angiosperm phylogeny. Here, we show that absolute seed size and the rate of change in seed size are both associated with variation in diversification rates. Based on the largest available angiosperm phylogenetic tree, we found that smaller-seeded plants had higher rates of diversification, possibly due to improved colonisation potential. The rate of phenotypic change in seed size was also strongly positively correlated with speciation rates, providing rare, large-scale evidence that rapid morphological change is associated with species divergence. Our study now reveals that variation in morphological traits and, importantly, the rate at which they evolve can contribute to explaining the extremely uneven distribution of diversity across the ToL

    Critical Rhetoric and Collaboration: Missing Principle #9 and ProfsDoPop.com

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    As part of this Special Section on critical rhetoric, this article examines the role of collaboration in the future of critical rhetoric. Building on McKerrow’s original eight principles of praxis, the authors advocate for a missing ninth principle that reflects the need for critical rhetoric to be a shared venture across both individual projects and larger discourses. As an example of this type of work, they provide ProfsDoPop.com, an academic, online blog designed to bring academic sensibilities and concepts to popular audiences through the critique of popular culture

    Modification of β-Sheet Forming Peptide Hydrophobic Face: Effect on Self-Assembly and Gelation

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    β-Sheet forming peptides have attracted significant interest for the design of hydrogels for biomedical applications. One of the main challenges is the control and understanding of the correlations between peptide molecular structure, the morphology, and topology of the fiber and network formed as well as the macroscopic properties of the hydrogel obtained. In this work, we have investigated the effect that functionalizing these peptides through their hydrophobic face has on their self-assembly and gelation. Our results show that the modification of the hydrophobic face results in a partial loss of the extended β-sheet conformation of the peptide and a significant change in fiber morphology from straight to kinked. As a consequence, the ability of these fibers to associate along their length and form large bundles is reduced. These structural changes (fiber structure and network topology) significantly affect the mechanical properties of the hydrogels (shear modulus and elasticity)

    A method to search for long duration gravitational wave transients from isolated neutron stars using the generalized FrequencyHough

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    We describe a method to detect gravitational waves lasting O(hoursdays)O(hours-days) emitted by young, isolated neutron stars, such as those that could form after a supernova or a binary neutron star merger, using advanced LIGO/Virgo data. The method is based on a generalization of the FrequencyHough (FH), a pipeline that performs hierarchical searches for continuous gravitational waves by mapping points in the time/frequency plane of the detector to lines in the frequency/spindown plane of the source. We show that signals whose spindowns are related to their frequencies by a power law can be transformed to coordinates where the behavior of these signals is always linear, and can therefore be searched for by the FH. We estimate the sensitivity of our search across different braking indices, and describe the portion of the parameter space we could explore in a search using varying fast Fourier Transform (FFT) lengths.Comment: 15 figure
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