656 research outputs found
Morphology of the <i>Buccal apparatus</i> and related structures in four species of Carapidae
The aims of this study were (1) to compare the morphology of the Buccal apparatus, the suspensorium and the opercle in four species of Carapidae (Carapus acus, Encheliophis boraborensis, Encheliophis homei and Encheliophis gracilis) and (2) to investigate the relationships between their cranial anatomy, their carnivorous diet, and their well known ability to enter holothurians.The complex and strong dentition and the wide hyomandibular with thickenings that seem to suit the constraints of the adductor mandibulae muscles partly inserted on the neurocranium are signs of a carnivorous diet.C. acus, E. boraborensis and E. homei have extremely strong buccal pieces and can protrude their upper jaws. However, in E. gracilis, the jaws are more slender, and the insertions of the Al along the entire length of the maxillary associated with the lack of mobility between the maxillary and the premaxillary prevent buccal protrusion. These differences could be related to the diet: C. acus, E. boraborensis and E. homei can feed on fishes and crustaceans, whereas E. gracilis feeds only on holothurian tissue.The cephalic morphology of the four species is not incompatible with entering the host. However, the neutralisation of the suboperculum spine by 'cartilaginous' tissue could be considered to be a particular adaptation to this behaviour
Morphological particularities of the head in four Carapidae (Ophidiiformes)
A study of the skull and the musculature of the oral and pharyngeal region of four adult Carapidae species (Encheliophis boraboreruis, E. homei. E. gracilis and Carapus acus) has been undertaken to compare it with the diet related characters. The cephalic organization of E. boraborensis and E. gracilis seems related to diet (mainly fishes and shrimps for the first one and holothurian tissues for the other): these species are respectively commensal and parasitic. Although the feeding characters of E. homei and C. acus are closely similar to those of E. boraborensis, there are sparse observations of holothurian tissues in their stomach contents. It is suggested that these fishes are commensal when they are adults and have parasitic tendency when they are juveniles
Diminution de la résistance aux antibiotiques des souches de Streptococcus pneumoniae isolées d’infections invasives en France entre 2005 et 2011 : résultats des Observatoires Régionaux du Pneumocoque (ORP)
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Comparative analysis of a BAC contig of porcine chromosome 13q31-q32 and human chromosome 3q21-q22
BACKGROUND: The gene(s) encoding the ETEC F4ab/ac receptors, involved in neonatal diarrhoea in pigs (a disease not yet described in humans), is located close to the TF locus on Sscr13. In order to reveal and characterize possible candidate genes encoding these receptors, a porcine physical map of the TF region is indispensable. RESULTS: A contig of 33 BAC clones, covering approximately 1.35 Mb surrounding the TF locus on Sscr13q31-q32, was built by chromosome walking. A total of 22,552 bp from the BAC contig were sequenced and compared with database sequences to identify genes, ESTs and repeat sequences, and to anchor the contig to the syntenic region of the human genome sequence (Hsap3q21-q22). The contig was further annotated based on this human/porcine comparative map, and was also anchored to the Sanger porcine framework map and the integrated map of Sscr13 by RH mapping. CONCLUSION: The annotated contig, containing 10 genes and 2 ESTs, showed a complete conservation of linkage (gene order and orientation) with the human genome sequence, based on 46 anchor points. This underlines the importance of the human/porcine comparative map for the identification of porcine genes associated with genetic defects and economically important traits, and for assembly of the porcine genome sequence
Transitions dipolaires induites par collisions sur un faisceau de formaldéhyde. Effet d'un champ électrique
Using a H2CO molecular beam, a method is first described which permits the observation of rotational transitions ΔJ = ± n (n ≽ 1), induced by collisions with the molecules of a target gas. In the case H2CO → H 2CO, selection rules are defined and rotational resonance effects are observed on the differential cross sections for some ΔJ = — 1 transitions. It appears that a direct electric field E considerably modifies the H2CO cross sections σJ. Using the pair H 2CO → NH3, the study of σJ variations with E shows that the ΔJ = 0 transitions become forbidden, when E is intense. The experimental results are compared with the theoretical transition probabilities variations, due to E and calculated in the Born approximation. An experimental method is deduced which permits, by application of an electric field, to select AJ = 0 transitions on a molecular beam.Nous présentons d'abord une méthode expérimentale qui permet d'observer les transitions rotationnelles ΔJ = ± n (n ≽ 1) induites par collisions entre les molécules d'un faisceau de formaldéhyde et un gaz tampon. En prenant H2CO comme gaz tampon, nous précisons les règles de sélection et, sur les sections de collisions correspondant à plusieurs transitions ΔJ = — 1, nous mettons en évidence des effets de résonance rotationnelle. Nous constatons qu'un champ électrique continu modifie considérablement les sections de collisions du formaldéhyde. Sur le système dipolaire H2 CO-NH3, l'étude des variations caractéristiques de celles-ci en fonction du champ appliqué montre que les transitions ΔJ. = 0 de H2CO deviennent interdites en champ fort. Nous comparons les résultats expérimentaux aux variations de probabilité de transition dues au champ électrique et calculées dans l'approximation de Born. On déduit une méthode expérimentale permettant de trier par effet de champ les transitions ΔJ = 0 sur le faisceau moléculaire
The cytosolic glutamine synthetase GLN1;2 plays a role in the control of plant growth and ammonium homeostasis in Arabidopsis rosettes when nitrate supply is not limiting
Glutamine synthetase (EC 6.3.1.2) is a key enzyme of ammonium assimilation and recycling in plants where it catalyses the synthesis of glutamine from ammonium and glutamate. In Arabidopsis, five GLN1 genes encode GS1 isoforms. GLN1;2 is the most highly expressed in leaves and is over-expressed in roots by ammonium supply and in rosettes by ample nitrate supply compared with limiting nitrate supply. It is shown here that the GLN1;2 promoter is mainly active in the minor veins of leaves and flowers and, to a lower extent, in the parenchyma of mature leaves. Cytoimmunochemistry reveals that the GLN1;2 protein is present in the companion cells. The role of GLN1;2 was determined by examining the physiology of gln1;2 knockout mutants. Mutants displayed lower glutamine synthetase activity, higher ammonium concentration, and reduced rosette biomass compared with the wild type (WT) under ample nitrate supply only. No difference between mutant and WT can be detected under limiting nitrate conditions. Despite total amino acid concentration was increased in the old leaves of mutants at high nitrate, no significant difference in nitrogen remobilization can be detected using 15N tracing. Growing plants in vitro with ammonium or nitrate as the sole nitrogen source allowed us to confirm that GLN1;2 is induced by ammonium in roots and to observe that gln1;2 mutants displayed, under such conditions, longer root hair and smaller rosette phenotypes in ammonium. Altogether the results suggest that GLN1;2 is essential for nitrogen assimilation under ample nitrate supply and for ammonium detoxification
Ecological Assessment of Everyday Executive Functioning at Home and at School using the BRIEF Questionnaire following Childhood Traumatic Brain Injury (TBI)
IntroductionCognitive and behavioural aspects of executive functioning (EF) are frequently impaired following childhood TBI. The Behavior Rating Inventory of Executive Function (BRIEF) questionnaire provides an ecological assessment of EFs in everyday life in home and school environments. The aims of this study were to describe the dysexecutive disorders in children with TBI using the BRIEF; to compare parent- and teacher-ratings and to analyse the demographic and medical variables influencing outcome.MethodsParticipants: Children/adolescents aged 5–17 years 11 months, referred to a paediatric rehabilitation department following TBI. Outcome measures: the parent–and the teacher-report of the BRIEF were collected during neuropsychological assessment (2009–2014), as well as the teacher-report (from 2014). Age at injury and assessment, parental education and TBI severity were collected.Results194 patients (142 boys) participated in the study [mild (n=13), moderate (n=12) or severe (n=169: mean duration of coma 7.2 days; SD=6.5)]. 193 parent-reports and 28 complete teacher reports of the BRIEF were available. Mean age at injury/assessment were 6.9 (SD=4.4), and 11.8 (SD=3.5) years respectively. According to parent-ratings, children had significantly elevated scores in all BRIEF indices [Global Executive Composite (GEC), Behaviour Regulation Index (BRI), Metacognition Index (MI)], and subscales (mean T-scores 61–64; all P<.0001), with 24% to 48.0% scoring in the clinical range. Teachers’ ratings indicated similar deficits in all sub-scales (mean T-scores 63–70; all P<.001), with 39.3–57.2% scoring in the clinical range. For patients with teacher and parent-reports (n=27), no significant difference was found between parent and teacher ratings, which were significantly correlated (r: .44–.72). Regression analyses indicated that GEC was significantly predicted by older age at assessment. The regression model for BRI was not significant. For MI, younger age at injury and older age at assessment were significant predictors.Discussion and conclusionThis study highlights elevated levels of executive dysfunction in everyday life following childhood TBI, evident in home and school environments. Younger age at injury seems to influence the cognitive rather than the behavioural aspects of EFs, whereas older age at assessment is related to higher levels of complaints, probably due to the increasing levels of expectations
Ammonia volatilization from arable land after application of cattle slurry. 2. Derivation of a transfer model
Brachyplatystom a promagdalena, new species, a fossil goliath catfish (Siluriformes: Pimelodidae) from the Miocene of Colombia, South America
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