1,513 research outputs found
Comparison of the induction of pulmonary neoplasms in Sprague-Dawley rats by fission neutrons and radon daughters
Lung carcinomas in Sprague-Dawley rats after exposure to low doses of radon daughters, fission neutrons, or γ-rays
PSS5 RESTOR® VERSUS ACRILISA® : ND-YAG LASER INCIDENCE RATE COMPARISON 18 MONTHS AFTER SURGERY
Digitalitzat per Artypla
Phenotypic and genetic differentiation between native and introduced plant populations
Plant invasions often involve rapid evolutionary change. Founder effects, hybridization, and adaptation to novel environments cause genetic differentiation between native and introduced populations and may contribute to the success of invaders. An influential idea in this context has been the Evolution of Increased Competitive Ability (EICA) hypothesis. It proposes that after enemy release plants rapidly evolve to be less defended but more competitive, thereby increasing plant vigour in introduced populations. To detect evolutionary change in invaders, comparative studies of native versus introduced populations are needed. Here, we review the current empirical evidence from: (1) comparisons of phenotypic variation in natural populations; (2) comparisons of molecular variation with neutral genetic markers; (3) comparisons of quantitative genetic variation in a common environment; and (4) comparisons of phenotypic plasticity across different environments. Field data suggest that increased vigour and reduced herbivory are common in introduced plant populations. In molecular studies, the genetic diversity of introduced populations was not consistently different from that of native populations. Multiple introductions of invasive plants appear to be the rule rather than the exception. In tests of the EICA hypothesis in a common environment, several found increased growth or decreased resistance in introduced populations. However, few provided a full test of the EICA hypothesis by addressing growth and defence in the same species. Overall, there is reasonable empirical evidence to suggest that genetic differentiation through rapid evolutionary change is important in plant invasions. We discuss conceptual and methodological issues associated with cross-continental comparisons and make recommendations for future research. When testing for EICA, greater emphasis should be put on competitive ability and plant tolerance. Moreover, it is important to address evolutionary change in characteristics other than defence and growth that could play a role in plant invasion
Mathematical methods and models for radiation carcinogenesis studies
Research on radiation carcinogenesis requires a twofold approach. Studies of primary molecular lesions and subsequent cytogenetic changes are essential, but they cannot at present provide numerical estimates of the risk of small doses of ionizing radiations. Such estimates require extrapolations from dose, time, and age dependences of tumor rates observed in animal studies and epidemiological investigations, and they necessitate the use of statistical methods that correct for competing risks. A brief survey is given of the historical roots of such methods, of the basic concepts and quantities which are required, and of the maximum likelihood estimates which can be derived for right censored and double censored data. Non-parametric and parametric models for the analysis of tumor rates and their time and dose dependences are explained
Dynamics of simple liquids at heterogeneous surfaces : Molecular Dynamics simulations and hydrodynamic description
In this paper we consider the effect of surface heterogeneity on the slippage
of fluid, using two complementary approaches. First, MD simulations of a
corrugated hydrophobic surface have been performed. A dewetting transition,
leading to a super-hydrophobic state, is observed for pressure below a
``capillary'' pressure. Conversely a very large slippage of the fluid on this
composite interface is found in this superhydrophobic state. Second, we propose
a macroscopic estimate of the effective slip length on the basis of continuum
hydrodynamics, in order to rationalize the previous MD results. This
calculation allows to estimate the effect of a heterogeneous slip length
pattern on the composite interface. Comparison between the two approaches are
in good agreement at low pressure, but highlights the role of the exact shape
of the liquid-vapor interface at higher pressure. These results confirm that
small variations in the roughness of a surface can lead to huge differences in
the slip effect. On the basis of these results, we propose some guidelines to
design highly slippery surfaces, motivated by potential applications in
microfluidics.Comment: submitted to EPJ
Archivo Eduardo Torroja. La sede del itcc (1949-1953). Inéditos anteproyectos previos a su construcción
El contenido de este artículo representa el eslabón que falta en la historia publicada por la revista Informes de la Construcción sobre el proyecto y construcción de la nueva sede del Instituto, que fue el hábitat de investigación más innovador jamás construido por la Modernidad. Su difusión completa y cierra esta historia, a la vez que potencia el mensaje que Eduardo Torroja quiso transmitir agrupando los artículos que relatan esta historia, bajo un mismo título común; “El Instituto es Así”, seguramente porque durante mucho tiempo (1949-1953), defendió que no podía ser de otra manera
Diagnosis and management of anaemia and iron deficiency in patients with haematological malignancies or solid tumours in France in 2009-2010: the AnemOnHe study
OBJECTIVE: To describe the management of anaemia in 2009-2010 in France in patients with haematological malignancies (HM) or solid tumours (ST). METHODS: Retrospective observational study in 57 centres, enrolling adult patients with HM or ST treated for an episode of anaemia (duration of the episode >/= 3 months occurring in the last 12 months). RESULTS: 220 patients with ST (breast, 18%; lung, 18%) and 56 with HM (lymphoma, 60%) were included (median age, 68 years; female, 53%). Mean haemoglobin level at anaemia diagnosis was 9.3 +/- 1.4 g/dL (<8 g/dL for 16%) and 9.8 +/- 1.1g/dL (<8 g/dL for 6%) in HM and ST patients, respectively. At least one parameter of iron deficiency (ferritin, transferrin saturation) was assessed in 26% of HM and 19% of ST patients. Treatment of anaemia included erythropoiesis-stimulating agents (ESA) for 98% of HM and 89% of ST patients. Iron was prescribed to 14% (oral, 12%; intravenous, 2%) of HM patients and to 42% (oral, 17%; intravenous, 25%) of ST patients. The rates of blood transfusions were high: 70% in HM and 46% in ST patients; transfusions alone or administrated with ESA were more frequent in patients with Hb <8 g/dL. CONCLUSION: Although recent guidelines recommend evaluating iron deficiency and correcting anaemia by using intravenous iron, our study in cancer patients evidenced that ESA and blood transfusions are still frequently used as the treatment of anaemia in cancer patients. Iron deficiency is insufficiently assessed (only one patient among five) and as a consequence iron deficiency is most likely insufficiently treated
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