The Poultry Red Mite, Dermanyssus gallinae, travels far but not frequently, and takes up permanent residence on farms.

Management of Dermanyssus gallinae, a cosmopolitan hematophagous mite responsible for damage in layer poultry farming, is hampered by a lack of knowledge of its spatio-temporal population dynamics. Previous studies have shown that the circulation of this pest between farms is of strictly anthropogenic origin, that a mitochondrial haplogroup has been expanding on European farms since the beginning of the 21st century and that its local population growth may be particularly rapid. To refine our understanding of how D. gallinae spreads within and among farms, we characterized the genetic structure of mite populations at different spatial scales and sought to identify the main factors interrupting gene flow between poultry houses and between mitochondrial haplogroups. To this end, we selected and validated the first set of nuclear microsatellite markers for D. gallinae and sequenced a region of the CO1-encoding mitochondrial gene in a subsample of microsatellite-genotyped mites. We also tested certain conditions required for effective contamination of a poultry house through field experimentation, and conducted a survey of practices during poultry transfers. Our results confirm the role of poultry transport in the dissemination of mite populations, but the frequency of effective contamination after the introduction of contaminated material into poultry houses seems lower than expected. The high persistence of mites on farms, even during periods when poultry houses are empty and cleaned, and the very large number of nodes in the logistic network (large number of companies supplying pullets or transporting animals) undoubtedly explain the very high prevalence on farms. Substantial genetic diversity was measured in farm populations, probably as a result of the mite's known haplodiploid mode of sexual reproduction, coupled with the dense logistic network. The possibility of the occasional occurrence of asexual reproduction in this sexually reproducing mite was also revealed in our analyses, which could explain the extreme aggressiveness of its demographic dynamics under certain conditions.

Communicating chronic hydrocephalus: A review.

Formerly called normal pressure hydrocephalus, communicating chronic hydrocephalus (CCH) is a condition affecting 0.1 to 0.5% of patients over 60years of age. The pathophysiology of this disease is poorly understood, but a defect in cerebrospinal fluid (CSF) resorption appears to be commonly defined as the cause of the neurological disorders. The last important discovery is the description of the glymphatic system and its implication in CCH and CSF resorption. Comorbidities (Alzheimer's disease, microangiopathy, parkinsonism) are very frequent, and involve a diagnostic challenge. The clinical presentation is based on the Hakim and Adams triad, comprising gait disorders, mainly impairing walking, cognitive disorders, affecting executive functions, episodic memory, visuospatial cognition, and sphincter disorders as urinary incontinence (detrusor hyperactivity). The diagnosis is suspected through a set of arguments, combining the clinical presentation, the radiological data of the magnetic resonance imaging (MRI) showing a ventriculomegaly associated with signs of transependymomous resorption of the CSF and disappearance of the cortical sulci, and the clinical response to the depletion of CSF. In the presence of all these elements, or a strong clinical suspicion, the standard treatment will be of a permanent CSF shunt, using a ventriculoatrial or ventriculoperitoneal shunt. The effectiveness of this treatment defines the diagnosis. The clinical improvement is better when treatment occurs early after the onset of the disorders, reaching 75 to 90% of motor improvement.

Sacroiliac joint pain after lumbar fusion. A study with anesthetic blocks.

Low back pain persisting or appearing after a technically successful lumbar fusion challenges clinicians. In this context, the sacroiliac joint could be a possible source of pain, but the frequency of its responsibility is not really known. We used sacroiliac anesthetic blocks, the gold standard for diagnosis, to determine this frequency. Our second goal was to search predictive factors for a positive block. Our prospective series consisted of 40 patients with persistent low back pain after a technically successful fusion who received a sacroiliac anesthetic block under fluoroscopic control. The diagnostic criterion was a relief of more than 75% of the pain on a visual analog scale. We found a 35% rate of positive blocks. The only criterion that characterized these patients was a postoperative pain different from the preoperative pain in its distribution ( p =0.017). A free interval of more than 3 months between surgery and appearance of the pain had an indicative value ( p =0.17). An increased uptake in the sacroiliac on bone scintigraphy or a past history of posterior iliac bone-graft harvesting had no significant value ( p =0.74 and p =1.0, respectively). The sacroiliac joint is a possible source of pain after lumbar fusion. The anesthetic block under fluoroscopic control remains the gold standard.

QTL analysis of photosynthesis and water status traits in sunflower (Helianthus annuus L.) under greenhouse conditions.

The identification of QTL for several physiological traits in sunflower is described. Traits related to photosynthesis (leaf chlorophyll concentration, net photosynthesis and internal CO(2) concentration) and water status (stomatal conductance, transpiration, predawn leaf water potential, and relative water content) were evaluated in a population of recombinant inbred lines under greenhouse conditions. Narrow-sense heritabilities were low to average. Using an AFLP linkage map, 19 QTL were detected explaining 8.8-62.9% of the phenotypic variance for each trait. Among these, two major QTL for net photosynthesis were identified on linkage group IX. One QTL co-location was found on linkage group VIII for stomatal movements and water status. Coincident locations for QTL regulating photosynthesis, transpiration and leaf water potential were described on linkage group XIV. These results lead to the first description of the organization of genomic regions related to yield in sunflower.

Infectious risk associated with wastewater reuse: an epidemiological approach applied to the case of Clermont-Ferrand, France.

Wastewater reuse raises the question of health risk and the epidemiological surveys needed. An epidemiological and environmental approach was used to check the security for the exposed populations (surrounding and agricultural population in Clermont-Ferrand. Four information systems were set up: two sentinel systems joining general physicians (15) and pharmacists (7) for the surrounding population and two follow-up surveys among field workers and farmers. Water quality monitoring and a study of aerosols from spray irrigation were performed. No epidemic event was identified with only some case clusters (not related to water exposure) being observed. All the declared cases were benign. The workers' survey underlined a substantial incidence of nettle rashes, itchy skins, sunburns, and cuts. The follow-up study among farmers and their families did not reveal any particular phenomena. The bacteriological quality of treated wastewater throughout conformed with the recommendations of the Superior Council of Public Health of France (1,000 faecal coliforms/100 mL). No faecal bacteria were observed in aerosols with water concentrations equal to 10(3) cfu/100 mL and an exposure time of 20 min. The survey of such an irrigation system, towards potential and actual risks, required the conjunction of different epidemiological information sources and microbiological data.

[Assessment of three filters for respiratory function tests]. / Evaluation de trois filtres destinés aux explorations fonctionnelles respiratoires.

Several filters specific for respiratory function tests have been on the market for several years. Recommended by the manufacturers to avoid contaminating the equipment and thus improve patient safety, these filters require a considerable financial investment. We studied the passage of diluted blood into artificial saliva in a patient model simulating inspiration tests and rapid forced expiration to assess the retention capacity of three filters used for respiratory function tests: Multi SPIRO MI-90016 (MultiSPIRO), PF 30S (Pall Biomedical) and Spirobac (Dar. S.p.A). The mean percentage of passage was 1.48% through the MI-90016 filter, 57.15% through the PF 30 S filter and 70.45% through the Spirobac filter. These findings provide further elements for choosing filters for respiratory function tests. Indeed, despite the manufacturers' commercial arguments, the technical documents provided do not give necessary information on the filtering capacity of the filters on the market. We have observed that two out of the three filters tested do no meet the standards expected by clinicians.

Response of Photochemical Processes of Photosynthesis to Dinitrogen Fixation in Soybean.

Symbiotic N2 fixation activity brings about changes in the photochemical processes of photosynthesis in soybean (Glycine max L. Merr.). For a potential photochemical efficiency ([phi]Po) similar to that obtained with an exclusively mineral nutrition, soybean, at full bloom stage (R2) with a moderate N2 fixation activity, had a better electron transfer quantum yield ([phi]PSII) and a higher photochemical quenching. At the beginning seed stage (R5), corresponding to more intense N2 fixation, the same phenomena were enhanced; in addition, an effect on the photochemical (k2b) and nonphotochemical (Kn-k22) transfer rates and an earlier activation of the electron transfer chain were characterized using a new parameter, the relative induction time of PSII fluorescence (Ap/Fm). The response of the photochemical parameters was related to the N2 fixation level (performance of the host plant-microsymbiont association): the energetic cost of symbiotic N2 fixation appeared to be met by a better photochemical efficiency of photosynthesis coupled with a decrease in thermal dissipation (kn - k22), by faster thylakoid energization, and by faster reopening of photosystem II centers at the time of fluorescence induction, as shown by decreased Ap/Fm.

Comparison of two extraction procedures for urinary organic acids prior to gas chromatography-mass spectrometry.

We have compared a new isolation procedure for urinary organic acids using strong anion-exchange columns with a solvent partition (ethyl acetate) method. Urinary samples from two healthy children and from nine children with organic acidurias were analysed by both procedures. Although the solid-phase extraction is more efficient for polyhydroxy acids, some polar acids, and some glycine derivatives, clinically important compounds such as oxalic, methylcitric, pyruvic, glyoxylic and 2-ketoglutaric acids, are not recovered or are only poorly recovered. However, both procedures may be used as a routine method for the diagnosis of the organic acidurias included in this study.

Divergent selection for dinitrogen fixation and yield in soybean.

Nitrogen fixation is generally considered to be a major parameter of productivity in soybean (Glycine max). The aim of the investigations reported here was to analyse the genetic behaviour of this trait in view of its possible use as an indirect criterion of selection for productivity. Divergent selection for nitrogen fixation rate was carried out on F2 populations obtained from crosses between high-yielding cultivars that are well adapted to French climatic conditions. The genetic component of nitrogen fixation and yield was isolated through the analysis of (1) the nitrogen fixation potentials of the genotypes under controlled conditions and (2) the field yields under favourable conditions. Divergent selection resulted in two groups of genotypes whose nitrogen fixation abilities are significantly different. The F6 filial progeny obtained by single seed descent from the two groups displayed significantly different abilities for nitrogen fixation and for field productivity. The gain achieved for the nitrogen fixation activity with respect to the mean value of the parents ranged from 20% to 33% for the positive selection, depending on the crosses. The occurrence of positive and significant correlations between the level of nitrogen fixation activity in F2 plants and N2 fixation or yield in the F6 generation corroborates the relatively high heritability of this trait and suggests its possible use as an indirect selection criterion for yield.

Role of D-genome chromosomes in photosynthesis expression in wheats.

The role of D-genome chromosomes in the expression of net photosynthesis in wheats was analysed with the nullitetrasomic and ditelosomic lines of the bread wheat cultivar 'Chinese Spring'. The two arms of chromosome 3 D and the short arm of chromosome 6 D control major mechanisms of photosynthesis. The effect of chromosome 6 D can be thoroughly compensated by that of its homoeologues of genomes A or B, contrary to what can be observed for chromosome 3 D. Chromosome 7 D is responsible for the low photosynthesis of flag leaves developed under high irradiances in genotypes possessing the D-genome, as the likely result of ontogeny or of a loss in adaptability to irradiance.

[Gamma-ray angioencephalography and computerized tomography of the brain in tumoral pathology. Comparative results]. / Gamma-angio-encéphalographie et tomodensitométrie encéphalique en pathologie tumorale. Résultats comparatifs.

Gamma-ray angioencephalography and computerized tomography (CT) were used to explore 151 patients with suspected intracranial tumour. The reliability of each method for the aetiological, topographical and pathological diagnosis was evaluated. The results obtained showed that the two methods correlated well and supplemented each other, bringing the proportion of positive diagnosis of intracranial tumour to more than 90%. While CT remains the first-choice examination to detect expansive lesions, gamma-ray angioencephalography represents the finest physiopathological approach and provides the most precise information on the nature of the tumour.

Effect of the D genome and of selection on photosynthesis in wheat.

Photosynthesis and transpiration in wheats and in their progenitors were analyzed in relation to their genome, ploidy and selection. The values of these parameters markedly depend on a specific effect of the D genome and on leaf enlargement in the course of evolution in wheats. Leaf enlargement has had a marked effect on photosynthesis in the genotypes that are devoid of the D genome; in addition, their photosynthetic capacity is greater in forms with lower leaf area. The increase in the mesophyll resistance rm to CO2 transfer is in relation to the increase in leaf area and is mainly responsible for the decrease in photosynthesis rate.Owing to its stomatal regulation, Triticum aestivum L. is characterized by good water use efficiency in spite of its large leaves and of its low net photosynthesis. On the basis of the photosynthesis rate, the "large leaf factor does not appear to be a good selection criterion for the Triticum durum genotypes that are devoid of the D genome.

Responses of photosynthesis to irradiance and temperature in soybean, Glycine max (L.) Merr.

The response of photosynthesis to irradiance and temperature during growth was investigated in two soybean genotypes. Soybean is a species that can modify its structure and metabolism so as to adapt to differing light conditions; its responses to rapid changes in irradiance are characterized by their flexibility. However, the temperature during growth can change the response to irradiance: moreover, there may be a marked interaction with genotype.The response of photosynthesis to irradiance consists of changes in leaf thickness, which bring about variations in the mesophyll resistance to CO2 transfer. The increase in net photosynthesis per unit of leaf area is due to the increase in the amount of assimilating material beneath unit of area, as corroborated by the stability of the net photosynthesis per unit volume. Moreover, the response of photosynthesis to temperature is due to the mesophyll diffusion 'constant' which decreases with the growth temperature.

Cerebrovascular accident and abnormal focus of hyperactivity revealed by dynamic study in scintiangioencephalography.

A 75-year-old female was admitted to the hospital for suspicion of a cerebrovascular accident. An important focus of hyperactivity was noted during a dynamic study by scintiangioencephalography, consistent with a highly vascular tumor, but corresponding in fact to a focal transitory hyperfusion with accompanying intense neuronal activity.