In vitro susceptibility to antimonials and amphotericin B of Leishmania infantum strains isolated from dogs in a region lacking drug selection pressure

The aim of this study was to evaluate the susceptibility to anti-leishmanial agents of 24 strains isolated from dogs living in the urban area of Alger lacking drug selection pressure. Two different Leishmania infantum zymodemes, MON-1 and MON-281, were identified in these dogs. The in vitro susceptibility to the main forms of antimonial and amphotericin were assessed on promastigote and amastigote life stages in culture. The results obtained for both parasite life stages were concordant whatever the molecule tested. Moreover, our data showed that isolates belonging to the relatively rare zymodeme of L. infantum, MON-281, were less susceptible to antimony than MON-1, when at the same time there was no significant difference for amphotericin B.     

Role of Luteinizing Hormone in Primiparous Sow Responses to Split Weaning

In 45 primiparous sows, we examined endocrine, ovarian and reproductive responses to split-weaning or five injections per day of 800 ng GnRH from 18 to 21 days of lactation. There was no effect of treatment on absolute or changes in sow weight or backfat depth during lactation. Average piglet growth rates were similar among treatments except that piglets suckling split-weaned sows grew faster (p < 0.05) during days 18–21. On day 18, mean plasma LH concentrations and LH pulse frequency remained relatively stable in conventionally weaned sows but increased (p < 0.01) in response to split-weaning and GnRH. Prior to weaning on day 21, mean plasma LH concentrations remained elevated in GnRH-treated sows but had returned to control levels in split weaned sows. There was no treatment effect on preweaning LH pulse frequency noted on day 21. Weaning was associated with an increase in plasma LH concentrations in all the treatment groups. Mean plasma IGF-I remained relatively constant in conventionally weaned and GnRH sows, decreased in response to split weaning on day 18 (p < 0.02), but were elevated (p < 0.03) in split wean sows on day 21. On the day after weaning, split wean sows had more (p < 0.04) ovarian follicles ≥3 mm than conventionally weaned sows, with GnRH sows being intermediate. The wean-to-oestrus interval was reduced in split-wean sows compared with those conventionally weaned (p < 0.01), with GnRH sows being intermediate. There was no effect of treatment on ovulation rates, numbers of embryos, or embryonic survival rates. These data indicate that split-weaning of litters results in a more rapid return to oestrus after weaning and that this effect is associated with a transient acute increase in circulating gonadotrophins and earlier resumption of ovarian follicular development.     

Why are wheat yields stagnating in Europe? A comprehensive data analysis for France

The last two decades are witnessing a decline in the growth trend of cereal yields in many European countries. The present study analyses yield trends in France using various sources of data: national and regional statistics, scattered trials, results of agroclimatic models using climatic data. Effects in genetic changes through breeding, agronomy and climate are investigated as possible causes. Our results show that genetic progress has not declined but it was partly counteracted, from 1990 on, by climate change which in general is unfavorable to cereal yields in temperate climates because of heat stress during grain filling and drought during stem elongation. We cannot however, from the decade beginning in 2000, rule out agronomic causes, related to policy and economy, in particular the decline of legumes in the cereal rotations, replaced by oilseed rape and to a lesser extent the decrease in nitrogen fertilization.     

Effects of food deprivation and particle size of ground wheat on digestibility of food components in broilers fed on a pelleted diet

The first aim of the experiment was to study the effect of wheat (Triticum aestivum) particle size on the digestibility of starch in a pelleted diet given to broilers. The second aim was to study the consequences of food deprivation before the excreta collection period (from 21 to 24 d). Wheat from a strong hardness cultivar was incorporated at 546.1 g/kg in diets. The other main ingredients were soybean meal (353.5 g/kg) and rapeseed oil (55.0 g/kg). Diets were given as pellets. The experimental design was a 2 x 2 factorial design testing two particle sizes of wheat flour and two procedures of a balance experiment (with or without food deprivation). Birds given diet C (wheat coarse grinding before pelleting) had significantly greater gizzard weight than birds fed on diet F (wheat fine grinding before pelleting). Starch digestibility value was significantly increased when birds were fed on diet F. This effect was halved by food deprivation. No significant effect of grain particle size was observed for protein and lipid digestibility values. However, food deprivation decreased apparent protein digestibility, with an effect which was more pronounced for fine than for coarse grinding. AMEN of the diet was significantly improved by fine grinding of wheat and decreased by food deprivation. However, no significant differences in growth performance were induced by differences in wheat grinding. No significant effect of grinding was observed on the water excretion:feed intake ratio. No significant difference was observed for vent score between treatments. There was over-excretion of starch in the first hours of refeeding following food deprivation.     

Follicle Development in Mares

The mare provides a unique experimental model for studying follicle development in monovular species. Development of antral follicles in horses is characterized by the periodic growth of follicular waves which often involve the selection of a single dominant follicle. If properly stimulated, the dominant follicle will complete development and eventually ovulate a fertile oocyte. Regulation of follicular wave emergence and follicle selection involves an interplay between circulating gonadotropins and follicular factors that ensures that individual follicles are properly stimulated to grow (or to regress) at any given stage of follicular wave development. Periodic development of follicular waves continuously occurs during most of post-natal life in the mare and is influenced by factors such as stage of oestrous cycle, season, pregnancy, age, breed and individual so that different types of follicular waves (minor or major, ovulatory or anovulatory) and different levels of activity within waves may develop under different physiological conditions. Changes in gonadotropin levels and/or in the sensitivity of follicles to circulating gonadotropins seem to account largely for these physiological variations in follicle development.     

Agronomic characteristics, grain quality and flour rheology of 372 bread wheats in a worldwide core collection

A core collection of 372 accessions representative of worldwide hexaploid bread wheat diversity [Balfourier, F., Roussel, V., Strelchenko, P., Exbrayat-Vinson, F., Sourdille, P., Boutet, G., Koenig, J., Ravel, C., Mitrofanova, O., Beckert, M., Charmet, G., 2007. A worldwide bread wheat core collection arrayed in a 384-well plate. Theoretical and Applied Genetics 114, 1265–1275] was used to evaluate the available genetic diversity of agronomic and quality characteristics. The traits assessed during the vegetative period were date of ear-emergence, date of flowering, lodging, disease susceptibility and pre-harvest sprouting. Thousand kernel weight, test weight, grain hardness, grain protein content, pentosan viscosity and grain colour were also measured. The rheological properties of the derived white flours were estimated using mixograph and alveograph tests. For most of the traits, a wide phenotypic variation was observed across all the accessions. Several parameters (mixograph width parameters before and after peak time, alveograph dough tenacity and extensibility, near infrared measurements, like those for protein content, and absorbance measurements of palmitic acid and linoleic acid content) made it easier to discriminate between the cultivars. The largest ranges of variation were found in landraces and old cultivars rather than in more recent varieties. This is evidence that there is sufficient variability available for rare alleles, which have been eliminated in breeding modern varieties to be detected. Such a core collection will therefore be a useful resource for future genetic studies on wheat quality.     

A Study of Puroindoline b Gene Involvement in the Milling Behavior of Hard‐Type Common Wheats

Differences in milling behavior among hard‐type common wheat (Triticum aestivum) cultivars are well known to millers. Among them, the French cultivar Soissons, which contains the Pinb‐D1d allelic form of the puroindoline b gene, is particularly distinguished for its high milling value. Near‐isogenic lines (NILs) differing by the allelic forms of the puroindoline b gene, Pinb‐D1d or Pinb‐D1b (one of the most frequent alleles found in the European wheat population), were constructed. Grain characteristics obtained after wheat cultivation in distinct environmental conditions were compared between NILs and the cultivar Soissons, as was their fractionation behavior. Results showed that NILs containing the Pinb‐D1d allele displayed lower values of grain hardness and vitreousness than did the corresponding lines containing the Pinb‐D1b allelic form under the same cultivation conditions. Both genetic background and environmental conditions appeared to affect grain texture. Measured single‐kernel characterization system hardness index values of the samples under study were found to be correlated with the vitreousness values. Studies of the milling behavior helped to point out that grain vitreousness is an important factor acting on endosperm breakage ability, whatever the genetic background of the wheat. Our results also demonstrated that, at similar levels of vitreousness, the endosperm of Soissons could more easily be reduced than that of other wheat lines.     

Hoxa2- and rhombomere-dependent development of the mouse facial somatosensory map

In the mouse trigeminal pathway, sensory inputs from distinct facial structures, such as whiskers or lower jaw and lip, are topographically mapped onto the somatosensory cortex through relay stations in the thalamus and hindbrain. In the developing hindbrain, the mechanisms generating such maps remain elusive. We found that in the principal sensory nucleus, the whisker-related map is contributed by rhombomere 3-derived neurons, whereas the rhombomere 2-derived progeny supply the lower jaw and lip representation. Moreover, early Hoxa2 expression in neuroepithelium prevents the trigeminal nerve from ectopically projecting to the cerebellum, whereas late expression in the principal sensory nucleus promotes selective arborization of whisker-related afferents and topographic connectivity to the thalamus. Hoxa2 inactivation further results in the absence of whisker-related maps in the postnatal brain. Thus, Hoxa2- and rhombomere 3-dependent cues determine the whisker area map and are required for the assembly of the whisker-to-barrel somatosensory circuit.