60 research outputs found

    Measuring black-hole parameters and testing general relativity using gravitational-wave data from space-based interferometers

    Get PDF
    Among the expected sources of gravitational waves for the Laser Interferometer Space Antenna (LISA) is the capture of solar-mass compact stars by massive black holes residing in galactic centers. We construct a simple model for such a capture, in which the compact star moves freely on a circular orbit in the equatorial plane of the massive black hole. We consider the gravitational waves emitted during the late stages of orbital evolution, shortly before the orbiting mass reaches the innermost stable circular orbit. We construct a simple model for the gravitational-wave signal, in which the phasing of the waves plays the dominant role. The signal's behavior depends on a number of parameters, including μ\mu, the mass of the orbiting star, MM, the mass of the central black hole, and JJ, the black hole's angular momentum. We calculate, using our simplified model, and in the limit of large signal-to-noise ratio, the accuracy with which these quantities can be estimated during a gravitational-wave measurement. Our simplified model also suggests a method for experimentally testing the strong-field predictions of general relativity.Comment: ReVTeX, 16 pages, 5 postscript figure

    Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology

    Get PDF
    notes: As the primary author, O’Malley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. ‘Macrobe’ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes – the dominant life form on the planet, both now and throughout evolutionary history – will transform some of the philosophy of biology’s standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology – including biofilm formation, chemotaxis, quorum sensing and gene transfer – that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations

    Addressing climate change with behavioral science:A global intervention tournament in 63 countries

    Get PDF

    Addressing climate change with behavioral science:A global intervention tournament in 63 countries

    Get PDF
    Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions' effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior-several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people's initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors.</p

    Addressing climate change with behavioral science:A global intervention tournament in 63 countries

    Get PDF
    Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions' effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior-several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people's initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors.</p

    Avaliação do efeito do alho (Allium sativum L.) sobre o colesterol plasmático em coelhos com hipercolesterolemia induzida

    Get PDF
    The use of plants to treat diseases or even to cure them is a high diffused popular tradition, and several studies discuss the therapeutic and pharmacological properties of garlic in the reduction of hyperlipidaemias. The objective of the present study was to investigate the influence of the aqueous extract of garlic (Allium sativum) to treat the serum cholesterol of rabbits with experimental hypercholesterolemia. The animals were divided into G1 (control group) and G2 (group treated with garlic). The experiment was developed according to 3 phases: during the 1st phase, all animals were provided with a regular diet to evaluate the basal cholesterol; during the 2nd phase, all animals received a supplemented diet until the end of the experiment, in order to develop hypercholesterolemia and, in the 3rd phase, the animals on G2 received the garlic treatment. The cholesterol registered on the 1st phase was 39.94 ± 9.57 mg dL-1. On the 2nd phase, there was an increase on the serum cholesterol level in both groups - higher than 100 mg dL-1. Concerning the treatment, the garlic did not reduce the serum cholesterol in rabbits.A utilização de plantas no tratamento de doenças ou como meio curativo é uma tradição popular e altamente difundida, sendo que muitos trabalhos abordam as propriedades terapêuticas e farmacológicas do alho na redução das hiperlipidemias. O objetivo deste estudo foi investigar a influência do extrato aquoso (E.A.) do alho (Allium sativum L.) no tratamento do colesterol plasmático em coelhos com hipercolesterolemia experimental. Os animais foram divididos em G1 (grupo controle) e G2 (grupo tratado com alho). O experimento foi desenvolvido em três fases: na 1ª fase os animais receberam dieta comercial de coelhos para avaliar o nível basal de colesterol nos animais; na 2ªfase, todos os animais passaram a receber dieta suplementada com gema de ovo, até o final do experimento, para desenvolver hipercolesterolemia, e; na 3ª fase os animais do grupo G2 receberam o tratamento com E. A. de alho. O colesterol na 1ª fase foi de 39,94 ± 9,57 mg dL-1. Na 2ª fase houve elevação significativa (p<0,05) no nível de colesterol plasmático nos dois grupos -acima de 100 mg dL-1. Com relação ao tratamento, o alho não promoveu redução no colesterol plasmático dos coelhos, contrapondo os dados da literatura.Unesp Instituto de Biociências Departamento de FisiologiaUnesp Instituto de Biociências Departamento de Fisiologi

    Whole-genome sequencing reveals host factors underlying critical COVID-19

    Get PDF
    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    SECONDARY METABOLITES | Culinary Uses and Nutritional Value

    No full text

    SECONDARY METABOLITES | Medicinal and Pharmaceutical Uses

    No full text
    corecore