Search results for "Adapta"
showing 10 items of 1961 documents
The logic of forms in the light of developmental biology and palaeontology.
2010
11 pages; If you ask palaeontologists, and indeed anyone interested in the theory of evolution, for the key words that encapsulate it, you will obtain the following results: adaptation, natural selection, speciation, but also ontogeny and phylogeny. The first three key words apply to the future of the individual and by extension to the future of the species: we are therefore dealing with adults of a reproductive age. The two other key words concern (i) the evolution of the morphology from the egg to the adult (individual ontogeny: short timescale) and especially what goes on in the black box called embryogenesis, and (ii) the modification of ontogenetic sequences over time, resulting in cha…
Parasite Infection and Host’s Behavior
2010
Animal behavior and parasitism are more tightly linked, from an ecological and evolutionary point of view, than commonly thought. In the past 30 years, the growing field of evolutionary parasitology has tackled both proximate and ultimate answers to the following question: Why and how should the behavior of hosts exposed to the risk of a disease or that of parasitized hosts be altered? Altered behavior may simply be a symptom of disease without obvious connection with host resistance or parasite-transmission strategies. However, natural selection may have shaped behavior to avoid infection, get rid of parasites, or limit their pathogenicity. Alternatively, manipulative parasites may alter t…
Morphological variation of the Oncocyclus irises (Iris: Iridaceae) in the southern Levant
2002
Morphological traits of Iris section Oncocyclus (Siems.) Baker in the southern Levant (Israel, Jordan, The Palestinian Authority and Sinai/Egypt) were analysed in order to clarify taxonomic relationships among taxa and the validity of diagnostic characters. Floral and vegetative characters were measured in 42 populations belonging to nine species during the peak of the flowering season in 1998‐2000. Pearson’s Coefficient of Racial Likelihood (CRL) was used to calculate morphological distances between populations. Twelve of the measured populations, distributed along the north-south aridity gradient in Israel, were further explored for morphological changes along the gradient. Cluster analys…
An improved version of the Atlantic cod genome and advancements in functional genomics: implications for the future of cod farming
2016
Abstract Recent advancements within state-of-the-art genomic tools and the generation of the first version of the Atlantic cod genome (Star et al., 2011) have proven to be valuable resources, improving our understanding of this species’ biology. In this chapter we describe some aspects and implications of using these resources to identify genes and molecular pathways involved in Atlantic cod growth and development, as well as responses to nutritional changes, pathogens and other immune stimuli, and environmental stressors (e.g., temperature, stress, or pollutants). Additionally, we highlight the immunological puzzle of the Atlantic cod that lacks components of the adaptive immune system pre…
T-2 toxin and its metabolites: Characterization, cytotoxic mechanisms and adaptive cellular response in human hepatocarcinoma (HepG2) cells
2020
Abstract The T-2 toxin (T-2) is a type A trichothecene produced by Fusarium species, and the most cytotoxic mycotoxin of the group. A study was made to determine T-2 cytotoxicity in human hepatocarcinoma (HepG2) cells; evaluate whether there is an adaptive response of HepG2 cells exposed to low concentrations of T-2; identify the T-2 metabolites by LC-Q-TOF MS; and determine whether T-2 disrupts cell proliferation in HepG2 cells. The IC50 values obtained ranged from 61.9 ± 2.4 nM to 70.7 ± 7.4 nM. No adaptive response was observed. There was no evidence of extra- or intracellular accumulation of T-2 after 24 h of exposure as determined by LC-Q-TOF MS. However, some T-2 metabolites such as H…
Emergence of hierarchical networks and polysynchronous behaviour in simple adaptive systems
2011
We describe the dynamics of a simple adaptive network. The network architecture evolves to a number of disconnected components on which the dynamics is characterized by the possibility of differently synchronized nodes within the same network (polysynchronous states). These systems may have implications for the evolutionary emergence of polysynchrony and hierarchical networks in physical or biological systems modeled by adaptive networks.
Hypertrophic adaptations of lower limb muscles in response to three different resistance training regimens
2020
Introduction: The research tested the effects of training in three different load zones. The hypothesis is that this type of training can provide more complete hypertrophic gains compared to workouts performed in a specific, single load area. Materials and methods: 37 participants were divided into 4 groups (SE; S; E; C). The first group trained simultaneously with high loads and low repetitions and with low loads and high repetitions; the second group trained in the high load condition, the third with low loads and high repetitions brought to the point of fatigue and the last control group had not practiced any type of training. The participants performed the training program 3 times a wee…
Experiences faced by next of kin during their older family members’ transition into long-term care in a Norwegian nursing home
2013
Aims and objectives To describe and explore experiences of next of kin during the older persons’ transition into long-term care. Background Moving into long-term care is a challenge for both resident and next of kin. Next of kin experience transitions at the same time as they play significant parts in their family members’ transition into long-term care placement. Design Constructivist hermeneutical design. Methods Ten next of kin to newly admitted eight residents were recruited by purposeful sampling and interviewed. Periodic participant observation periods following new residents on arrival day and the first week after admission and some written documentation were the backdrops to the int…
Ergosterol biosynthesis: a fungal pathway for life on land?
2012
International audience; Sterols, essential lipids of most eukaryotic cells, ensure important structural and signaling functions. The selection pressure that has led to different dominant sterols in the three eukaryotic kingdoms remains unknown. Here, we investigated the influence of the progression in the different steps of the ergosterol biosynthetic pathway (EBP) on the yeast resistance to transitions from aqueous to aerial media, typical perturbations of the higher fungi habitats. Five mutants of the EBP (ergΔ), accumulating different sterol intermediates in the EBP, and the wild-type (WT) strain were exposed to drying under atmospheric air or nitrogen and wetting. Results show that the …
Mutual-information based rate-adaptation for Multi-User TH-IR-UWB coded system
2011
In this paper we present a coding rate adaptation technique for a Time-Hopping Impulse-Radio Ultra-Wide Band (TH-IR-UWB) system assuming that the Multi-User Interference (MUI) is modeled as an additive interference noise following a Generalized Gaussian Distribution (GGD). The shape parameter induced by the GGD model is in general time-variant since it strongly depends on the essential UWB system parameters and the received signal power of the active users. In this paper, we show that the performance of a TH-IR-UWB LDPC coded system is quite independent of the GGD shape parameter when we consider the mutual information between the soft input to the decoder and the transmitted sequence, espe…