Search results for "570 Life sciences"
showing 10 items of 313 documents
Biology of the sauropod dinosaurs: the evolution of gigantism
2010
The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to ha…
Personality predicts social dominance in female zebra finches, Taeniopygia guttata, in a feeding context.
2011
6 pages; International audience; Although personality has been defined as a suite of correlated behaviours, most studies of animal personality actually consider correlations between a few traits. We examined the repeatability and correlational structure of five potential personality traits (activity, neophobia, exploratory tendencies, risk-taking behaviour and obstinacy), in female zebra finches. In addition, we assessed to what extent personality influenced social dominance in a feeding context in this gregarious species. All personality traits were found to be highly repeatable within individuals. In addition, except for obstinacy, all of them were related to each other, thus defining a b…
Spectrum of mutations in the renin-angiotensin system genes in autosomal recessive renal tubular dysgenesis
2012
Autosomal recessive renal tubular dysgenesis (RTD) is a severe disorder of renal tubular development characterized by early onset and persistent fetal anuria leading to oligohydramnios and the Potter sequence, associated with skull ossification defects. Early death occurs in most cases from anuria, pulmonary hypoplasia, and refractory arterial hypotension. The disease is linked to mutations in the genes encoding several components of the renin-angiotensin system (RAS): AGT (angiotensinogen), REN (renin), ACE (angiotensin-converting enzyme), and AGTR1 (angiotensin II receptor type 1). Here, we review the series of 54 distinct mutations identified in 48 unrelated families. Most of them are no…
The effects of experimentally manipulated yolk androgens on growth and immune function of male and female nestling collared flycatchers Ficedula albi…
2009
Hormone-mediated maternal effects may be an important mechanism for adjusting offspring phenotype to particular requirements of the environment. We manipulated the levels of testosterone and androstenedione in the yolk of collared flycatcher Ficedula albicollis eggs to investigate the effects of pre-natal exposure to androgens on growth and immune function. Androgen treatment tended to reduce the growth of males, and enhance the growth of females, as indicated by significant interaction between sex and androgen treatment. Cellular immune function was not affected by androgen treatment or sex. Survival of nestlings until fledging was not related to androgen treatment. Our results indicate th…
Prospective Validation of Facial Nerve Monitoring to Prevent Nerve Damage During Robotic Drilling
2019
Facial nerve damage has a detrimental effect on a patient's life, therefore safety mechanisms to ensure its preservation are essential during lateral skull base surgery. During robotic cochlear implantation a trajectory passing the facial nerve at <0.5 mm is needed. Recently a stimulation probe and nerve monitoring approach were developed and introduced clinically, however for patient safety no trajectory was drilled closer than 0.4 mm. Here we assess the performance of the nerve monitoring system at closer distances. In a sheep model eight trajectories were drilled to test the setup followed by 12 trajectories during which the ENT surgeon relied solely on the nerve monitoring system and…
Cohort profile: Thrombolysis in Ischemic Stroke Patients (TRISP): a multicentre research collaboration
2018
PurposeThe ThRombolysis in Ischemic Stroke Patients (TRISP) collaboration aims to address clinically relevant questions about safety and outcomes of intravenous thrombolysis (IVT) and endovascular thrombectomy. The findings can provide observational information on treatment of patients derived from everyday clinical practice.ParticipantsTRISP is an open, investigator-driven collaborative research initiative of European stroke centres with expertise in treatment with revascularisation therapies and maintenance of hospital-based registries. All participating centres made a commitment to prospectively collect data on consecutive patients with stroke treated with IVT using standardised definiti…
Assessment of genetically modified oilseed rape MS8, RF3 and MS8×RF3 for renewal of authorisation under regulation (EC) No 1829/2003 (application EFS…
2017
Efsa Panel On Genetically Modified Organisms (gmo)Opinion scientificRequestor: European CommissionQuestion number: EFSA-Q-2016-00569; Following the submission of application EFSA-GMO-RX-004 under Regulation (EC) No 1829/2003 from Bayer CropScience, the Panel on Genetically Modified Organisms of the European Food Safety Authority (GMO Panel) was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application of the genetically modified (GM) herbicide-tolerant oilseed rape MS8, RF3 and MS89RF3. The data received in the context of this renewal application contain post-market environmental monitoring reports, systematic searches and…
De novo Transcriptome Assembly and Comparison of C3, C3-C4, and C4 Species of Tribe Salsoleae (Chenopodiaceae)
2017
C4 photosynthesis is a carbon-concentrating mechanism that evolved independently more than 60 times in a wide range of angiosperm lineages. Among other alterations, the evolution of C4 from ancestral C3 photosynthesis requires changes in the expression of a vast number of genes. Differential gene expression analyses between closely related C3 and C4 species have significantly increased our understanding of C4 functioning and evolution. In Chenopodiaceae, a family that is rich in C4 origins and photosynthetic types, the anatomy, physiology and phylogeny of C4, C2, and C3 species of Salsoleae has been studied in great detail, which facilitated the choice of six samples of five representative …
Sex Allocation Theory for Facultatively Sexual Organisms Inhabiting Seasonal Environments: The Importance of Bet Hedging
2018
Adaptive explanations for dormancy often invoke bet hedging, where reduced mean fitness can be adaptive if it associates with reduced fitness variance. Sex allocation theory typically ignores variance effects and focuses on mean fitness. For many cyclical parthenogens, these themes become linked, as only sexually produced eggs undergo the dormancy needed to survive harsh conditions. We ask how sex allocation and the timing of sex evolve when this constraint exists in the form of a trade-off between asexual reproduction and sexual production of dormant eggs—the former being crucial for within-season success and the latter for survival across seasons. We show that male production can be tempo…
Global urban environmental change drives adaptation in white clover
2022
Made available in DSpace on 2022-04-28T19:52:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-03-18 Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied am…