113 research outputs found

    Linking Succession Planning to Employee Training: A Study of Federal Employees

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    The purpose of this study was to examine whether differences emerged in federal male and female middle managers and supervisors\u27 perceptions concerning organizational career development culture, succession planning components used for linking employee-training activities, reasons for succession planning and barriers impacting succession planning within their organization. Quantitative methodology supported this research study. A test-retest of the eighty-two-statement survey instrument was conducted for reliability among 40 participants (20 male and 20 female). The survey was then administered to 300 federal middle managers and supervisors (150 male and 150 female). Participants\u27 grade level ranged from general schedule (GS) GS-12 to GS-15. Of the 300 surveys, 152 (51 percent) were returned. Grade level and gender were used as independent variables. The survey statements were identified as dependent variables. One and two-way ANOVA\u27s were used to test the twelve hypotheses. The study revealed four categories that referenced gender differences in perceptions concerning the need to promote organizational career development culture: (a) communication; (b) morale; (c) career development; and (d) coaching and mentoring. Seventy-one percent of female participants at the GS-13 and GS-14 grade level responded with negative perceptions concerning these four categories. The theme that generated the most significant difference in support by both management level and gender was job rotational assignments. The themes of increased job opportunities, changing workload demands, database automation, identifying organizational short and long-term goals, and monitoring individual development plans were identified as participants\u27 primary reasons for succession planning. Additionally, findings suggest that: (a) overburden of work; (b) managers placed in key positions without the necessary qualifications; (c) insufficient support from senior executives; and (d) senior executives\u27 quick fix attitude were recognized as barriers impacting succession planning. Overall, 55 percent of the survey statements produced significant differences (α = .05). The findings resulted in four primary recommendations: (a) a need for additional research; (b) establishment of organizational career development culture; (c) implementation of a coaching and mentoring program; and (d) implementation of a succession-planning program. Both a coaching and mentoring model and a succession-planning model are included in this study

    Epistemologies Of Assessment Instruments

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    Chemical carcinogenicity revisited 2: Current knowledge of carcinogenesis shows that categorization as a carcinogen or non-carcinogen is not scientifically credible

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    Abstract Developments in the understanding of the etiology of cancer have undermined the 1970s concept that chemicals are either "carcinogens" or "non-carcinogens". The capacity to induce cancer should not be classified in an inflexible binary manner as present (carcinogen) or absent (non-carcinogen). Chemicals may induce cancer by three categories of mode of action: direct interaction with DNA or DNA replication including DNA repair and epigenetics; receptor-mediated induction of cell division; and non-specific induction of cell division. The long-term rodent bioassay is neither appropriate nor efficient to evaluate carcinogenic potential for humans and to inform risk management decisions. It is of questionable predicitiveness, expensive, time consuming, and uses hundreds of animals. Although it has been embedded in practice for over 50 years, it has only been used to evaluate less than 5% of chemicals that are in use. Furthermore, it is not reproducible because of the probabilisitic nature of the process it is evaluating combined with dose limiting toxicity, dose selection, and study design. The modes of action that lead to the induction of tumors are already considered under other hazardous property categories in classification (Mutagenicity/Genotoxicity and Target Organ Toxicity); a separate category for Carcinogenicity is not required and provides no additional public health protection

    Chemical carcinogenicity revisited 3: Risk assessment of carcinogenic potential based on the current state of knowledge of carcinogenesis in humans

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    Abstract Over 50 years, we have learned a great deal about the biology that underpins cancer but our approach to testing chemicals for carcinogenic potential has not kept up. Only a small number of chemicals has been tested in animal-intensive, time consuming, and expensive long-term bioassays in rodents. We now recommend a transition from the bioassay to a decision-tree matrix that can be applied to a broader range of chemicals, with better predictivity, based on the premise that cancer is the consequence of DNA coding errors that arise either directly from mutagenic events or indirectly from sustained cell proliferation. The first step is in silico and in vitro assessment for mutagenic (DNA reactive) activity. If mutagenic, it is assumed to be carcinogenic unless evidence indicates otherwise. If the chemical does not show mutagenic potential, the next step is assessment of potential human exposure compared to the threshold for toxicological concern (TTC). If potential human exposure exceeds the TTC, then testing is done to look for effects associated with the key characteristics that are precursors to the carcinogenic process, such as increased cell proliferation, immunosuppression, or significant estrogenic activity. Protection of human health is achieved by limiting exposures to below NOEALs for these precursor effects. The decision tree matrix is animal-sparing, cost effective, and in step with our growing knowledge of the process of cancer formation

    Chemical carcinogenicity revisited 1: A unified theory of carcinogenicity based on contemporary knowledge

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    Abstract Developments in the understanding of the etiology of cancer have profound implications for the way the carcinogenicity of chemicals is addressed. This paper proposes a unified theory of carcinogenesis that will illuminate better ways to evaluate and regulate chemicals. In the last four decades, we have come to understand that for a cell and a group of cells to begin the process of unrestrained growth that is defined as cancer, there must be changes in DNA that reprogram the cell from normal to abnormal. Cancer is the consequence of DNA coding errors that arise either directly from mutagenic events or indirectly from cell proliferation especially if sustained. Chemicals that act via direct interaction with DNA can induce cancer because they cause mutations which can be carried forward in dividing cells. Chemicals that act via non-genotoxic mechanisms must be dosed to maintain a proliferative environment so that the steps toward neoplasia have time to occur. Chemicals that induce increased cellular proliferation can be divided into two categories: those which act by a cellular receptor to induce cellular proliferation, and those which act via non-specific mechanisms such as cytotoxicity. This knowledge has implications for testing chemicals for carcinogenic potential and risk management

    SOCS1 Is a Critical Inhibitor of Interferon γ Signaling and Prevents the Potentially Fatal Neonatal Actions of this Cytokine

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    AbstractMice lacking suppressor of cytokine signaling-1 (SOCS1) develop a complex fatal neonatal disease. In this study, SOCS1−/− mice were shown to exhibit excessive responses typical of those induced by interferon γ (IFNγ), were hyperresponsive to viral infection, and yielded macrophages with an enhanced IFNγ-dependent capacity to kill L. major parasites. The complex disease in SOCS1−/− mice was prevented by administration of anti-IFNγ antibodies and did not occur in SOCS1−/− mice also lacking the IFNγ gene. Although IFNγ is essential for resistance to a variety of infections, the potential toxic action of IFNγ, particularly in neonatal mice, appears to require regulation. Our data indicate that SOCS1 is a key modulator of IFNγ action, allowing the protective effects of this cytokine to occur without the risk of associated pathological responses

    A review of the diversity and impact of invasive non-native species in tropical marine ecosystems

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    Tropical marine ecosystems are biologically diverse and economically invaluable. However, they are severely threatened from impacts associated with climate change coupled with localized and regional stressors, such as pollution and overfishing. Non-native species (sometimes referred to as ‘alien’ species) are another major threat facing these ecosystems, although rarely discussed and overshadowed by the other stressors mentioned above. NNS can be introduced accidentally (for example via shipping activities) and/or sometimes intentionally (for aquaculture or by hobbyists). Understanding the extent of the impacts NNS have on native flora and fauna often remains challenging, along with ascertaining when the species in question actually became ‘invasive’. Here we review the status of this threat across key tropical marine ecosystems such as coral reefs, algae meadows, mangroves, and seagrass beds. We aim to provide a baseline of where invasive NNS can be found, when they are thought to have been introduced and what impact they are thought to be having on the native ecosystems they now inhabit. In the appended material we provide a comprehensive list of NNS covering key groups such as macroalgae, sponges, seagrasses and mangroves, anthozoans, bryozoans, ascidians, fishes, and crustaceans.N

    A communal catalogue reveals Earth's multiscale microbial diversity

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    Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe
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