32 research outputs found

    Constraints on Non-Newtonian Gravity from Recent Casimir Force Measurements

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    Corrections to Newton's gravitational law inspired by extra dimensional physics and by the exchange of light and massless elementary particles between the atoms of two macrobodies are considered. These corrections can be described by the potentials of Yukawa-type and by the power-type potentials with different powers. The strongest up to date constraints on the corrections to Newton's gravitational law are reviewed following from the E\"{o}tvos- and Cavendish-type experiments and from the measurements of the Casimir and van der Waals force. We show that the recent measurements of the Casimir force gave the possibility to strengthen the previously known constraints on the constants of hypothetical interactions up to several thousand times in a wide interaction range. Further strengthening is expected in near future that makes Casimir force measurements a prospective test for the predictions of fundamental physical theories.Comment: 20 pages, crckbked.cls is used, to be published in: Proceedings of the 18th Course of the School on Cosmology and Gravitation: The Gravitational Constant. Generalized Gravitational Theories and Experiments (30 April- 10 May 2003, Erice). Ed. by G. T. Gillies, V. N. Melnikov and V. de Sabbata, 20pp. (Kluwer, in print, 2003

    Communicating uncertainty - how Australian television reported H1N1 risk in 2009: a content analysis

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    <p>Abstract</p> <p>Background</p> <p>Health officials face particular challenges in communicating with the public about emerging infectious diseases of unknown severity such as the 2009 H1N1(swine 'flu) pandemic (pH1N1). Statements intended to create awareness and convey the seriousness of infectious disease threats can draw accusations of scare-mongering, while officials can be accused of complacency if such statements are not made. In these communication contexts, news journalists, often reliant on official sources to understand issues are pivotal in selecting and emphasising aspects of official discourse deemed sufficiently newsworthy to present to the public. This paper presents a case-study of news communication regarding the emergence of pH1N1.</p> <p>Methods</p> <p>We conducted a content analysis of all television news items about pH1N1. We examined news and current affairs items broadcast on 5 free-to-air Sydney television channels between April 25 2009 (the first report) and October 9 (prior to the vaccine release) for statements about <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> the seriousness of the disease <abbrgrp><abbr bid="B2">2</abbr></abbrgrp> how the public could minimise contagion <abbrgrp><abbr bid="B3">3</abbr></abbrgrp> government responses to emerging information.</p> <p>Results</p> <p>pH1N1 was the leading health story for eight of 24 weeks and was in the top 5 for 20 weeks. 353 news items were identified, yielding 3086 statements for analysis, with 63.4% related to the seriousness of the situation, 12.9% providing advice for viewers and 23.6% involving assurances from government. Coverage focused on infection/mortality rates, the spread of the virus, the need for public calm, the vulnerability of particular groups, direct and indirect advice for viewers, and government reassurances about effective management.</p> <p>Conclusions</p> <p>Overall, the reporting of 2009 pH1N1 in Sydney, Australia was generally non-alarmist, while conveying that pH1N1 was potentially serious. Daily infection rate tallies and commentary on changes in the pandemic alert level were seldom contextualised to assist viewers in understanding personal relevance. Suggestions are made about how future reporting of emerging infectious diseases could be enhanced.</p

    KHS101 disrupts energy metabolism in human glioblastoma cells and reduces tumor growth in mice

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    Pharmacological inhibition of uncontrolled cell growth with small-molecule inhibitors is a potential strategy for treating glioblastoma multiforme (GBM), the most malignant primary brain cancer. We showed that the synthetic small-molecule KHS101 promoted tumor cell death in diverse GBM cell models, independent of their tumor subtype, and without affecting the viability of noncancerous brain cell lines. KHS101 exerted cytotoxic effects by disrupting the mitochondrial chaperone heat shock protein family D member 1 (HSPD1). In GBM cells, KHS101 promoted aggregation of proteins regulating mitochondrial integrity and energy metabolism. Mitochondrial bioenergetic capacity and glycolytic activity were selectively impaired in KHS101-treated GBM cells. In two intracranial patient-derived xenograft tumor models in mice, systemic administration of KHS101 reduced tumor growth and increased survival without discernible side effects. These findings suggest that targeting of HSPD1-dependent metabolic pathways might be an effective strategy for treating GBM

    Cognitive Dysfunction Is Sustained after Rescue Therapy in Experimental Cerebral Malaria, and Is Reduced by Additive Antioxidant Therapy

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    Neurological impairments are frequently detected in children surviving cerebral malaria (CM), the most severe neurological complication of infection with Plasmodium falciparum. The pathophysiology and therapy of long lasting cognitive deficits in malaria patients after treatment of the parasitic disease is a critical area of investigation. In the present study we used several models of experimental malaria with differential features to investigate persistent cognitive damage after rescue treatment. Infection of C57BL/6 and Swiss (SW) mice with Plasmodium berghei ANKA (PbA) or a lethal strain of Plasmodium yoelii XL (PyXL), respectively, resulted in documented CM and sustained persistent cognitive damage detected by a battery of behavioral tests after cure of the acute parasitic disease with chloroquine therapy. Strikingly, cognitive impairment was still present 30 days after the initial infection. In contrast, BALB/c mice infected with PbA, C57BL6 infected with Plasmodium chabaudi chabaudi and SW infected with non lethal Plasmodium yoelii NXL (PyNXL) did not develop signs of CM, were cured of the acute parasitic infection by chloroquine, and showed no persistent cognitive impairment. Reactive oxygen species have been reported to mediate neurological injury in CM. Increased production of malondialdehyde (MDA) and conjugated dienes was detected in the brains of PbA-infected C57BL/6 mice with CM, indicating high oxidative stress. Treatment of PbA-infected C57BL/6 mice with additive antioxidants together with chloroquine at the first signs of CM prevented the development of persistent cognitive damage. These studies provide new insights into the natural history of cognitive dysfunction after rescue therapy for CM that may have clinical relevance, and may also be relevant to cerebral sequelae of sepsis and other disorders

    A many-analysts approach to the relation between religiosity and well-being

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    The relation between religiosity and well-being is one of the most researched topics in the psychology of religion, yet the directionality and robustness of the effect remains debated. Here, we adopted a many-analysts approach to assess the robustness of this relation based on a new cross-cultural dataset (N=10,535 participants from 24 countries). We recruited 120 analysis teams to investigate (1) whether religious people self-report higher well-being, and (2) whether the relation between religiosity and self-reported well-being depends on perceived cultural norms of religion (i.e., whether it is considered normal and desirable to be religious in a given country). In a two-stage procedure, the teams first created an analysis plan and then executed their planned analysis on the data. For the first research question, all but 3 teams reported positive effect sizes with credible/confidence intervals excluding zero (median reported β=0.120). For the second research question, this was the case for 65% of the teams (median reported β=0.039). While most teams applied (multilevel) linear regression models, there was considerable variability in the choice of items used to construct the independent variables, the dependent variable, and the included covariates

    Are the fundamental forces four, or more?

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    Fundamental forces: Are there more than four?

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    Spectroscopic investigations on the interactions of potent platinum(II) anticancer agents with bovine serum albumin

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    The interactions of three platinum(II)-based anticancer complexes [(5,6-dimethyl-1,10-phenanthroline)(1S,2S-diaminocyclohexane)platinum(II)](2+), [(5,6-dimethyl-1,10-phenanthroline)(1R,2R-diaminocyclohexane)platinum(II)](2+), and [(5,6-dimethyl-1,10-phenanthroline)(1,2-diaminoethane)platinum(II)](2+) (56MEEN) with BSA have been examined by circular dichroism (CD), fluorescence and (1)H pulsed gradient spin–echo (PGSE) diffusion NMR spectroscopy. The number of association constants and sites differed depending upon the spectroscopic method. This may be because each technique monitors different types of interaction/s and/or as a consequence of the different concentration ranges required for each technique. The titration of BSA with the achiral 56MEEN as monitored by CD indicates a reduction in the α-helical nature of the albumin, with the association constant calculated to be ~5 × 10(6) M(−1) for one site. Due to the chiral nature of the other two complexes, their association with albumin was not monitored using CD but was examined using fluorescence and PGSE diffusion NMR. Titration of BSA with any of the three metal complexes resulted in quenching of fluorescence, with the number of association sites calculated to be ~1.1, with an association constant of ~2 × 10(5) M(−1). PGSE diffusion NMR provided insights into interactions occurring with the BSA in its entirety, rather than with individual regions. Metal complex binding sites were estimated (~10 equivalent) from the diffusion data, with the average association constant for all sites ~10(2)–10(3)M(−1). These experiments highlight the information that can be elucidated from complementary spectroscopic techniques and demonstrate the usefulness of PGSE diffusion NMR in monitoring multiple weak binding sites, which is of great importance in studying drug-biomolecule interactions. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12154-012-0074-1) contains supplementary material, which is available to authorized users
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