Search results for "modes"
showing 10 items of 235 documents
Hypoxia and hypothermia as rival agents of selection driving the evolution of viviparity in lizards
2017
[Aim]: The evolution of key innovations promotes adaptive radiations by opening access to new ecological opportunity. The acquisition of viviparity (live-bearing reproduction) has emerged as one such innovation explaining reptile proliferations into extreme climates. By evolving viviparity, females provide embryos with internally stable environments to complete development. The classical hypothesis suggests that natural selection for viviparity arises from low temperatures in cold climates, which promote prolonged egg retention in the mother's body. An alternative hypothesis proposes that declines in atmospheric oxygen at high elevations create natural selection for embryo retention to prov…
Diagnóstico de Metástasis Ováricas de un linfoma B diseminado mediante ecografía 3D
2018
RESUMEN La participación del aparato genitourinario en el contexto de la enfermedad hematológica maligna es bien conocida. No obstante, la afectación ovárica por linfomas es inusual, ya sea de novo o como manifestación tardía de linfoma diseminado. El objetivo de esta comunicación es exponer la aportación diagnóstica de la ecografía tridimensional (3D) en la detección de metástasis ováricas, cuando todavía algunas de las pruebas de imagen estándar como la tomografía computarizada (TAC) son normales. En este caso presentamos una paciente con linfoma B difuso de células grandes mediastínico de crecimiento rápido y diseminación precoz a aparato gastrointestinal y genitourinario. ABSTRACT Genit…
Letters to the editor: Still vigorous after all these years?
2006
Abstract This paper investigates Letters to the Editor, a section in biomedical journals used by scientists since the early 19th century to question already validated research. The aim of this study is to highlight some of the discursive strategies and to bring to the fore the linguistic characteristics of this particular genre, to analyze its goal, role and use within a community of French researchers. It is based on a corpus of 200 letters selected from two scientific journals in the fields of biology and medicine: The American Journal of Clinical Nutrition and The Lancet published between 1999 and 2002. The strategy of questioning is analyzed as an explicit and implicit mode of criticism…
Baseline prediction of combination therapy outcome in hepatitis C virus 1b infected patients by discriminant analysis using viral and host factors.
2010
Background Current treatment of chronic hepatitis C virus (HCV) infection has limited efficacy −especially among genotype 1 infected patients−, is costly, and involves severe side effects. Thus, predicting non-response is of major interest for both patient wellbeing and health care expense. At present, treatment cannot be individualized on the basis of any baseline predictor of response. We aimed to identify pre-treatment clinical and virological parameters associated with treatment failure, as well as to assess whether therapy outcome could be predicted at baseline. Methodology Forty-three HCV subtype 1b (HCV-1b) chronically infected patients treated with pegylated-interferon alpha plus ri…
Exceptional cryptic diversity and multiple origins of parthenogenesis in a freshwater ostracod.
2009
The persistence of asexual reproduction in many taxa depends on a balance between the origin of new asexual lineages and the extinction of old ones. This turnover determines the diversity of extant asexual populations and so influences the interaction between sexual and asexual modes of reproduction. Species with mixed reproduction, like the freshwater ostracod (Crustacea) morphospecies Eucypris virens, are a good model to examine these dynamics. This species is also a geographic parthenogen, in which sexual females and males co-exist with asexual females in the circum-Mediterranean area only, whereas asexual females occur all over Europe. A molecular phylogeny of E. virens based on the mit…
Bone mineral density of the proximal femur after hip resurfacing arthroplasty: 1-year follow-up study
2011
Abstract Background Hip resurfacing arthroplasty (HRA) is considered a bone-preserving procedure and may eliminate proximal femoral stress shielding and osteolysis. However, in addition to implant-related stress-shielding factors, various patient-related factors may also have an effect on bone mineral density (BMD) of the proximal femur in patients with HRA. Thus, we studied the effects of stem-neck angle, demographic variables, and physical functioning on the BMD of the proximal femur in a one-year follow-up. Methods Thirty three patients (9 females and 24 males) with a mean (SD) age of 55 (9) years were included in the study. BMD was measured two days and 3, 6, and 12 months postoperative…
The choice of master international franchising – A modified transaction cost model
2022
Abstract This study develops and tests a novel transaction cost model of master international franchising. Based on data from international franchise firms headquartered in six countries, we show that master international franchising is the franchisor’s preferred governance mode under the following conditions: large bilateral franchisor’s and franchisees’ transaction-specific investments, high institutional uncertainty and high behavioral uncertainty. Our model extends the literature by presenting a modified transaction cost model of master international franchising that investigates the bonding effect of bilateral transaction-specific investments and environmental uncertainty as determinan…
MRF Model-Based Approach for Image Segmentation Using a Chaotic MultiAgent System
2006
In this paper, we propose a new Chaotic MultiAgent System (CMAS) for image segmentation. This CMAS is a distributed system composed of a set of segmentation agents connected to a coordinator agent. Each segmentation agent performs Iterated Conditional Modes (ICM) starting from its own initial image created initially from the observed one by using a chaotic mapping. However, the coordinator agent receives and diversifies these images using a crossover and a chaotic mutation. A chaotic system is successfully used in order to benefit from the special chaotic characteristic features such as ergodic property, stochastic aspect and dependence on initialization. The efficiency of our approach is s…
Experimental design of the bearing performances of flax fiber reinforced epoxy composites by a failure map
2018
Abstract This paper represents the first effort aimed to the investigation of the pin/hole contact stress and failure mechanisms of epoxy composites reinforced with woven flax fabrics, underwent to tensile bearing tests. In particular, the maximum loads and failure modes are evaluated at varying the laminate geometrical configuration. In order to optimize the use of polymer composites reinforced with flax fibers in structural applications, an experimental failure map, identifying main failure modes of mechanically fastened joints, is obtained as function of hole diameter, distance of the hole from the free edge of the laminate and laminate width. Moreover, a theoretical approach based on th…
Bearing strength and failure behavior of pinned hybrid glass-flax composite laminates
2018
Abstract The aim of the present work is to evaluate the influence of external layers of glass woven fabric on the pin-hole strength of flax/epoxy laminates. Single lap bearing tests were carried out to evaluate the fastened joint performances depending on laminate stacking sequence. In order to better identify the mechanical behavior of the hybrid laminate, full glass and flax laminates were also compared. In particular, bearing stress and failure mechanisms were investigated at varying joint geometry. Furthermore, an experimental failure map, clustering main failure modes of pinned hybrid composite laminate, was used to better clarify the relationship between mechanical failure and geometr…