393 research outputs found

    Characterization of mild whole-body hyperthermia protocols using human breast, ovarian, and colon tumors grown in severe combined immunodeficient mice.

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    OBJECTIVE: We have shown that one treatment of fever-like whole body hyperthermia (WBH) on mice bearing human breast tumors results in a tumor growth delay. Our goal was to repeat this study in mice bearing human ovarian or colon tumors. We further evaluated this WBH protocol by performing multiple and interrupted WBH treatments. METHODS: Human tumors were grown in severe combined immunodeficient (SCID) mice. For WBH, core body temperatures were maintained at 39.8+/-0.2 degrees C for 6-8 hours. Multiple treatments were given 6-7 days apart. Interrupted WBH consisted of three 2-hour heatings, 15 minutes apart. Tumor growth time (TGT) was the number of days to grow 1.5 or 2 times in volume. RESULTS: For WBH-treated ovarian tumors, TGT was 12+/-1.2d, compared with 5.0+/-0.1d for untreated mice (P < 0.05). For colon tumors with one WBH treatment TGT was 4.4+/-1.1d. Two and three treatments had TGTs of 9+/-2.3d and 8+/-1.6d. For the untreated tumors, TGT was 2+/-0.7d (P < 0.01 for one, two, and three treatments). Histological examination indicated that one and two treatments were associated with cellular damage within the tumors. With a slower growing colon tumor, the TGT was 24+/-3.3d with three WBH treatments, compared with 14+/-1.8d for controls (P < 0.01). The TGT of breast tumors treated with interrupted WBH was not significantly different than the noninterrupted, with TGT of 7.3+/-0.8d and 6.2+/-1.0d, respectively. CONCLUSIONS: These data illustrate that WBH causes a tumor growth delay in mice bearing human ovarian and colon tumors. This response is enhanced with a second treatment of WBH. Interrupted and noninterrupted WBH give comparable anti-tumor results. We will continue to evaluate WBH in various animal models to optimize its potential for clinical administration and maximize the anti-tumor response

    Creating A Creative State of Mind: Promoting Creativity Through Proactive Vitality Management and Mindfulness

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    Most research on employee creativity has been focused on relatively distal antecedents, such as personality or job characteristics, which has resulted in top-down organizational approaches to promote employee creativity. However, such approaches overlook the self-regulating potential of employees and may not explain intraindividual fluctuations in creativity. In the present research, we build on proactive motivation theory to examine how employees may promote their own creativity on a daily basis through the use of proactive vitality management (PVM). To better understand the PVM-creativity link, we zoom in on this process by examining the role of mindfulness as an underlying mechanism. In two daily diary studies, employees from the United States (N = 133 persons, n = 521 data points) and the creative industry in Germany (N = 62 persons, n = 232 data points) reported on their use of PVM and states of mindfulness for five consecutive workdays. Additionally, participants completed a daily creativity test (brainstorming task) in Study 1, whereas supervisors rated participants' daily creative work performance in Study 2. In both studies, multilevel analyses showed that daily PVM was positively related to creative performance through daily mindfulness, supporting our hypotheses. These replicated findings suggest that individuals may bring themselves in a cognitive, creative state of mind on a daily basis, emphasizing the importance of proactive behavior in the creative process

    Modelling job crafting behaviours: Implications for work engagement

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    In this study among 206 employees (103 dyads), we followed the job demands–resources approach of job crafting to investigate whether proactively changing one’s work environment influences employee’s (actor’s) own and colleague s (partner’s) work engagement. Using social cognitive theory, we hypothesized that employees would imitate each other’s job crafting behaviours, and therefore influence each other’s work engagement. Results showed that the crafting of social and structural job resources, and the crafting of challenge job demands was positively related to own work engagement, whereas decreasing hindrance job demands was unrelated to own engagement. As predicted, results showed a reciprocal relationship between dyad members’ job crafting behaviours – each of the actor’s job crafting behaviours was positively related to the partner’s job crafting behaviours. Finally, employee’s job crafting was related to colleague’s work engagement through colleague’s job crafting, suggesting a modelling process

    Transfer of self-leadership skills within the Dutch police:A three-wave study

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    This three-wave study examined the training-to-work transfer process of a self-leadership skills training programme for crime scene investigators working for the Dutch police force. The transfer process is complex and depends on numerous factors. Two important steps forward are taken in the present study. First, we take into account all transfer steps in one study to gain insights into the transfer process, and second, by being specific about the work situation in which transfer outcomes should occur, we address the "criterion problem" that is often mentioned in transfer research. Based on the Ability Motivation Opportunity model, we hypothesised that the posttraining transfer process starts with being motivated to transfer and that this motivation increases the use of self-leadership during work. Another aspect that may facilitate the use of trained skills is supervisor support, as it offers opportunities to use self-leadership skills during work. In turn, self-leadership skills at work were hypothesised to lead to increased work performance. We tested our transfer model in two different work situations experienced by crime fighters. Our findings show that the use of self-leadership skills is positively related to the detached concern of crime fighters in specific situations. Additionally, our findings show that the use of self-leadership skills mediates the relation between the motivation to transfer and work performance in specific situations. Finally, our findings show that including different transfer steps (i.e. the motivation to transfer, use of skills, and performance), different performance measures, and different work situations in the transfer process provides more insight into when and how transfer-to-work after training occurs. These findings suggest that if organisations aspire to improve such transfer, then they should be specific about the intended posttraining behaviours and performance and the situations in which these outcomes should emerge

    Determination of total I and 129I concentrations in freshwater of Argentina

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    Total iodine and129-iodine in rivers and lakes of Argentina were measured by means of inductively coupled plasma mass spectrometry and accelerator mass spectrometry respectively. The obtained isotopic ratios, higher than the natural level, are explained

    Conditioning carry trades: Less risk, more return

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    Prior studies show that extreme interest rate dfferentials (IRDs) and high foreign exchange rate (FX) volatility have substantial explanatory power for the validity of UIP. We show that these contemporaneous drivers also have predictive power by implementing a conditional currency carry trade (CT) strategy that excludes regimes for which UIP is likely to hold. Conditioning high FX volatility only, or on both FX volatility and extreme IRDs outperforms the base-case unconditional CT strategy in virtually any of the settings analyzed. Conditioning on very large IRDs only shows mixed findings. Our strategy works best for smaller CT portfolios

    The Role of the Gut Microbiota in the Effects of Early-Life Stress and Dietary Fatty Acids on Later-Life Central and Metabolic Outcomes in Mice

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    Early-life stress (ELS) leads to increased vulnerability for mental and metabolic disorders. We have previously shown that a low dietary ω-6/ω-3 polyunsaturated fatty acid (PUFA) ratio protects against ELS-induced cognitive impairments. Due to the importance of the gut microbiota as a determinant of long-term health, we here study the impact of ELS and dietary PUFAs on the gut microbiota and how this relates to the previously described cognitive, metabolic, and fatty acid profiles. Male mice were exposed to ELS via the limited bedding and nesting paradigm (postnatal day (P)2 to P9 and to an early diet (P2 to P42) with an either high (15) or low (1) ω-6 linoleic acid to ω-3 alpha-linolenic acid ratio. 16S rRNA was sequenced and analyzed from fecal samples at P21, P42, and P180. Age impacted α- and β-diversity. ELS and diet together predicted variance in microbiota composition and affected the relative abundance of bacterial groups at several taxonomic levels in the short and long term. For example, age increased the abundance of the phyla Bacteroidetes, while it decreased Actinobacteria and Verrucomicrobia; ELS reduced the genera RC9 gut group and Rikenella, and the low ω-6/ω-3 diet reduced the abundance of the Firmicutes Erysipelotrichia. At P42, species abundance correlated with body fat mass and circulating leptin (e.g., Bacteroidetes and Proteobacteria taxa) and fatty acid profiles (e.g., Firmicutes taxa). This study gives novel insights into the impact of age, ELS, and dietary PUFAs on microbiota composition, providing potential targets for noninvasive (nutritional) modulation of ELS-induced deficits. IMPORTANCE Early-life stress (ELS) leads to increased vulnerability to develop mental and metabolic disorders; however, the biological mechanisms leading to such programming are not fully clear. Increased attention has been given to the importance of the gut microbiota as a determinant of long-term health and as a potential target for noninvasive nutritional strategies to protect against the negative impact of ELS. Here, we give novel insights into the complex interaction between ELS, early dietary ω-3 availability, and the gut microbiota across ages and provide new potential targets for (nutritional) modulation of the long-term effects of the early-life environment via the microbiota

    Settling the half-life of ⁶⁰Fe: fundamental for a versatile astrophysical chronometer

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    In order to resolve a recent discrepancy in the half-life of ⁶⁰Fe, we performed an independent measurement with a new method that determines the ⁶⁰Fe content of a material relative to Fe55 (t1/2=2.744yr) with accelerator mass spectrometry. Our result of (2.50±0.12)×10⁶yr clearly favors the recently reported value (2.62±0.04)×10⁶yr, and rules out the older result of (1.49±0.27)×10⁶yr. The present weighted mean half-life value of (2.60±0.05)×10⁶yr substantially improves the reliability as an important chronometer for astrophysical applications in the million-year time range. This includes its use as a sensitive probe for studying recent chemical evolution of our Galaxy, the formation of the early Solar System, nucleosynthesis processes in massive stars, and as an indicator of a recent nearby supernova.Part of this work was funded by the Austrian Science Fund (FWF) Projects No. AP20434 and AI00428 (FWF and CoDustMas, Eurogenesis via ESF)

    Plutonium in Soils from Northeast China and Its Potential Application for Evaluation of Soil Erosion

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    Surface and soil core samples from northeast China were analyzed for Pu isotopes. The measured Pu-240/Pu-239 atomic ratios and Pu239 + 240/Cs-137 activity ratios revealed that the global fallout is the dominant source of Pu and Cs-137 at these sites. Migration behavior of Pu varying with land type and human activities resulted in different distribution of Pu in surface soils. A sub-surface maximum followed by exponential decline of Pu239 + 240 concentrations was observed in an undisturbed soil core, with a total Pu239 + 240 inventory of 86.9 Bq/m(2) and more than 85% accumulated in 0 similar to 20 cm layers. While only half inventory of Pu was obtained in another soil core and no sub-surface maximum value occurred. Erosion of topsoil in the site should be the most possible reason for the significantly lower Pu inventory, which is also supported by the reported Cs-137 profiles. These results demonstrated that Pu could be applied as an ideal substitute of Cs-137 for soil erosion study in the future.</p

    Conservative management versus open reduction and internal fixation for mid-shaft clavicle fractures in adults - The Clavicle Trial: Study protocol for a multicentre randomized controlled trial

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    Background: Clavicle fractures account for around 4% of all fractures and up to 44% of fractures of the shoulder girdle. Fractures of the middle third (or mid-shaft) account for approximately 80% of all clavicle fractures. Management of this group of fractures is often challenging and the outcome can be unsatisfactory. In particular it is not clear whether surgery produces better outcomes than non-surgical management. Currently there is much variation in the use of surgery and a lack of good quality evidence to inform our decision.Methods/Design: We aim to undertake a multicentre randomised controlled trial evaluating the effectiveness and safety of conservative management versus open reduction and internal fixation for displaced mid-shaft clavicle fractures in adults. Surgical treatment will be performed using the Acumed clavicle fixation system. Conservative management will consist of immobilisation in a sling at the side in internal rotation for 6 weeks or until clinical or radiological union. We aim to recruit 300 patients. These patients will be followed-up for at least 9 months. The primary endpoint will be the rate of non-union at 3 months following treatment. Secondary endpoints will be limb function measured using the Constant-Murley Score and the Disabilities of the Arm, Shoulder and Hand (DASH) Score at 3 and 9 months post-operatively.Discussion: This article presents the protocol for a multicentre randomised controlled trial. It gives extensive details of, and the basis for, the chosen methods, and describes the key measures taken to avoid bias and to ensure validity.Trial Registration: United Kingdom Clinical Research Network ID: 8665. The date of registration of the trial is 07/09/2006. The date the first patient was recruited is 18/12/2007. © 2011 Longo et al; licensee BioMed Central Ltd
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