86 research outputs found

    Analysis of environmental influences in nuclear half-life measurements exhibiting time-dependent decay rates

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    In a recent series of papers evidence has been presented for correlations between solar activity and nuclear decay rates. This includes an apparent correlation between Earth-Sun distance and data taken at Brookhaven National Laboratory (BNL), and at the Physikalisch-Technische Bundesanstalt (PTB). Although these correlations could arise from a direct interaction between the decaying nuclei and some particles or fields emanating from the Sun, they could also represent an "environmental" effect arising from a seasonal variation of the sensitivities of the BNL and PTB detectors due to changes in temperature, relative humidity, background radiation, etc. In this paper, we present a detailed analysis of the responses of the detectors actually used in the BNL and PTB experiments, and show that sensitivities to seasonal variations in the respective detectors are likely too small to produce the observed fluctuations

    Bi-fluorescent Staphylococcus aureus infection enables single-cell analysis of intracellular killing in vivo

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    Techniques for studying the clearance of bacterial infections are critical for advances in understanding disease states, immune cell effector functions, and novel antimicrobial therapeutics. Intracellular killing of Staphylococcus aureus by neutrophils can be monitored using a S. aureus strain stably expressing GFP, a fluorophore that is quenched when exposed to the reactive oxygen species (ROS) present in the phagolysosome. Here, we expand upon this method by developing a bi-fluorescent S. aureus killing assay for use in vivo. Conjugating S. aureus with a stable secondary fluorescent marker enables the separation of infected cell samples into three populations: cells that have not engaged in phagocytosis, cells that have engulfed and killed S. aureus, and cells that have viable internalized S. aureus. We identified ATTO647N-NHS Ester as a favorable dye conjugate for generating bi-fluorescent S. aureus due to its stability over time and invariant signal within the neutrophil phagolysosome. To resolve the in vivo utility of ATTO647N/GFP bi-fluorescent S. aureus, we evaluated neutrophil function in a murine model of chronic granulomatous disease (CGD) known to have impaired clearance of S. aureus infection. Analysis of bronchoalveolar lavage (BAL) from animals subjected to pulmonary infection with bi-fluorescent S. aureus demonstrated differences in neutrophil antimicrobial function consistent with the established phenotype of CGD

    How combinations of control elements create tensions and how these can be managed:An embedded case study

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    This paper explores how combinations of management control (MC) elements can create tensions, and what supervisors can do to manage these tensions. We extend the literature on the interplay of MC elements by examining the underlying micro-processes that give rise to tensions between MC elements. Specifically, drawing on both the MC and the organization literature, we investigate how interactions between MC elements can simultaneously enhance and diminish control effectiveness, for which we coin the term tension complexity, and how these tensions can change over time, which we label tension dynamics. We empirically inform our study with an embedded case study in a public sector organization in the Netherlands. Using interviews, desk research, and observations, this study specifically investigates how an organization-level MC element (the value 'self-management') relates to departmental MC elements, creating tensions. The findings highlight that tensions, because of their dynamic and complex nature, require continuous attention from managers. Furthermore, the case findings demonstrate how department managers can influence the tensions by affecting the balance, balance tendency, and intensity of the MC elements within them. We conclude by providing suggestions for further research into the interactions of MC elements

    Influence of Lifestyle Redesign® on health, social participation, leisure and mobility of older French-Canadians

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    Importance: Developed in California to enable community-dwelling older adults to maintain healthy and meaningful activities, Lifestyle Redesign® is a well-known cost-effective preventive occupational therapy intervention. The impact of a newly adapted French version on older French-Canadians was, however, unknown. Objective: To explore the influence of Lifestyle Redesign on older French-Canadians’ health, social participation, leisure, and mobility. Design: A mixed-methods design included a preexperimental component (questionnaires administered before and after the intervention and 3 and 6 mo postintervention) and an exploratory descriptive qualitative clinical study. Individual semidirected interviews were digitally audiotaped and transcribed, then underwent thematic content analysis using mix extraction grids. Setting: Community. Participants: Sixteen volunteers (10 women) aged 65–90 yr (mean = 76.4, standard deviation = 7.6), 10 without and 6 with disabilities. Inclusion criteria were age ≥65 yr, normal cognitive functions, residence in a conventional or senior home, and French speaking. Intervention: French-Canadian 6-mo version of Lifestyle Redesign. Outcomes and Measures: Health, social participation, leisure, and mobility were measured using the 36-item Short Form Health Survey, Social Participation Scale, Leisure Profile, and Life-Space Assessment, as well as a semistructured interview guide. Results: The French-Canadian Lifestyle Redesign had a beneficial effect on participants’ mental health (p = .02) and interest in leisure (p = .02) and, in those with disabilities, social participation (p = .03) and attitudes toward leisure (p = .04). Participants reported positive effects on their mental health, leisure, mobility, and social participation, including frequency and quality of social interactions, and indicated that having an occupational routine fostered better health. None of the participants reported no effect. Conclusion and Relevance: The translated and culturally adapted Lifestyle Redesign is a promising occupational therapy intervention for community-dwelling older French-Canadians

    Examining the joint effects of strategic priorities, use of management control systems, and personal background on hospital performance

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    This study aims to respond to recent calls for a better understanding of the factors that support the effectiveness of formal control practices in hospitals. Based on survey data from 117 top-level managers in Belgian hospitals, the study investigates the performance effects of the alignment between the use of performance measurement systems (PMS), strategic priorities, and the particular role top-level managers’ personal background plays in this context. The quantitative results suggest that it is the top-level managers’ personal background that brings to life the benefits of the alignment between the use of PMS and strategic priorities in hospitals. Specifically, this paper shows that when the emphasis on partnership or governance strategic priority is high, the effect of the interactive use of PMS on hospital performance is more positive for top-level managers with a clinical background than for those with an administrative background. This study offers value for practitioners in that it supports the argument that hospitals can benefit from involving physicians in the top-level management team

    Antioxidant Machinery Differs between Melanic and Light Nestlings of Two Polymorphic Raptors

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    Colour polymorphism results from the expression of multiallelic genes generating phenotypes with very distinctive colourations. Most colour polymorphisms are due to differences in the type or amount of melanins present in each morph, which also differ in several behavioural, morphometric and physiological attributes. Melanin-based colour morphs could also differ in the levels of glutathione (GSH), a key intracellular antioxidant, because of the role of this molecule in melanogenesis. As GSH inhibits the synthesis of eumelanin (i.e. the darkest melanin form), individuals of darker morphs are expected to have lower GSH levels than those of lighter morphs. We tested this prediction in nestlings of two polymorphic raptors, the booted eagle Hieraaetus pennatus and the Eleonora's falcon Falco eleonorae, both of which occur in two morphs differing in the extent of eumelanic plumage. As expected, melanic booted eagle nestlings had lower blood GSH levels than light morph eagle nestlings. In the Eleonora's falcon, however, melanic nestlings only had lower GSH levels after controlling for the levels of other antioxidants. We also found that melanic female eagle nestlings had higher levels of antioxidants other than GSH and were in better body condition than light female eagle nestlings. These findings suggest an adaptive response of melanic nestlings to compensate for reduced GSH levels. Nevertheless, these associations were not found in falcons, indicating species-specific particularities in antioxidant machinery. Our results are consistent with previous work revealing the importance of GSH on the expression of melanic characters that show continuous variation, and suggest that this pathway also applies to discrete colour morphs. We suggest that the need to maintain low GSH levels for eumelanogenesis in dark morph individuals may represent a physiological constraint that helps regulate the evolution and maintenance of polymorphisms

    Microenvironmental regulation of metastasis

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    Metastasis is a multistage process that requires cancer cells to escape from the primary tumour, survive in the circulation, seed at distant sites and grow. Each of these processes involves rate-limiting steps that are influenced by non-malignant cells of the tumour microenvironment. Many of these cells are derived from the bone marrow, particularly the myeloid lineage, and are recruited by cancer cells to enhance their survival, growth, invasion and dissemination. This Review describes experimental data demonstrating the role of the microenvironment in metastasis, identifies areas for future research and suggests possible new therapeutic avenues
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