Bt maize: a tool for improving food safety of grains at harvest

A new EU (European Union) regulation came into force in 2007 with Regulation (EC) No. 1126/2007 which established maximum levels for fumonisins B1 and B2 (4000 ppb), deoxynivalenol (1750 ppb) and zearalenone (350 ppb) in maize and maize products. In order to evaluate French maize food safety, studies were carried out by the national Biological Risk Monitoring (BRM) Network. In this study, field trials involving 84 plots were conducted with Bt maize (MON 810) and its isogenic non-Bt counterpart in 2005 and 2006 in South-western France. Mycotoxin levels were determined in grain at harvest. Fumonisins B1 and B2, deoxynivalenol, and zearalenone were analyzed by LC-MS-MS and the results treated statistically using non parametric tests for mycotoxins and analysis of variance test for weather variables. As the climate was homogenous inside the experimental area, the transgenic event introduced into the maize was the only key parameter which differed between Bt and non-Bt maize plots. Our results showed that all mycotoxin families were not impacted in the same way. The efficacy of Bt maize reduced mycotoxins more than 90% for fumonisins and more than 50% for zearalenone although deoxynivalenol was lightly increased. Therefore a competition between the different Fusarium spp. which produced fumonisins or trichothecenes is hypothesized. According to Regulation (EC) No. 1126/2007, 93% of the maize of Bt maize plots were able to be commercialized compared to only 45% for non-Bt maize plots. The results of this work showed that Bt maize improved food safety and constituted an useful tool to reduce significantly mycotoxin levels in harvested and stored grains. Keywords: Bt (MON810) maize, Fumonisins B1 and B2, Deoxynivalenol (DON), Zearalenone, EC regulation 1126/2007 threshold

Evaluation of a Tetracycline-Inducible Promoter in Staphylococcus aureus In Vitro and In Vivo and Its Application in Demonstrating the Role of sigB in Microcolony Formation

An inducible promoter system provides a powerful tool for studying the genetic basis for virulence. A variety of inducible systems have been used in other organisms, including pXyl-xylR-inducible promoter, the pSpac-lacI system, and the arabinose-inducible PBAD promoter, but each of these systems has limitations in its application to Staphylococcus aureus. In this study, we demonstrated the efficacy of a tetracycline-inducible promoter system in inducing gene expression in S. aureus in vitro and inside epithelial cells as well as in an animal model of infection. Using the xyl/tetO promoter::gfpuvr fusion carried on a shuttle plasmid, we demonstrated that dose-dependant tetracycline induction, as measured by bacterial fluorescence, occurred in each of the above environments while basal activation under noninduced conditions remained low. To ascertain how the system can be used to elucidate the genetic basis of a pathogenic phenotype, we cloned the sigB gene downstream of the inducible promoter. Induction of SigB expression led to dose-dependent attachment of the tested strain to polystyrene microtiter wells. Additionally, bacterial microcolony formation, an event preceding mature biofilm formation, also increased with tetracycline induction of SigB

Can Vitex Agnus Castus be Used for the Treatment of Mastalgia? What is the Current Evidence?

There have been many treatments suggested for the management of mastalgia; one of these is the fruit extract of Vitex Agnus castus L. commonly known as Agnus castus, an extract of a deciduous shrub native to Mediterranean Europe and Central Asia. It is postulated that A. castus suppresses the stress-induced latent hyperprolactinemia which is a release of supra-physiological levels of prolactin in some patients in response to stressful stimuli. It is postulated that A. castus could be effective in the treatment of cyclical mastalgia by inhibiting the release of excess prolactin by blocking Dopamine-2 receptor type on pituitary. The adverse events following A. castus treatment are mild and reversible. The aim of this review is assess the efficacy of A. castus in the treatment of mastalgia. Data from randomized and non-randomized studies regarding the efficacy and safety of A. castus is reviewed in a systematic fashion. It is concluded that A. castus can be considered as an efficient alternative phytotherapeutic agent in the treatment of mastalgia

Spin dependence of the masses of heavy baryons

It is argued from the systematics of spin-depen\-dent forces between quarks that two proposed baryon states, named $\Sigma_c(2380)$ and $\Sigma_b(5760)$, do not exist.Comment: 6 pages, plainte

Structure, chemistry, and charge transfer resistance of the interface between Li7La3Zr2O12 electrolyte and LiCoO2 cathode

All-solid-state batteries promise significant safety and energy density advantages over liquid-electrolyte batteries. The interface between the cathode and the solid electrolyte is an important contributor to charge transfer resistance. Strong bonding of solid oxide electrolytes and cathodes requires sintering at elevated temperatures. Knowledge of the temperature dependence of the composition and charge transfer properties of this interface is important for determining the ideal sintering conditions. To understand the interfacial decomposition processes and their onset temperatures, model systems of LiCoO2 (LCO) thin films deposited on cubic Al-doped Li7La3Zr2O12 (LLZO) pellets were studied as a function of temperature using interface-sensitive techniques. X-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS), and energy-dispersive X-ray spectroscopy (EDS) data indicated significant cation interdiffusion and structural changes starting at temperatures as low as 300°C. La2Zr2O7 and Li2CO3 were identified as decomposition products after annealing at 500°C by synchrotron X-ray diffraction (XRD). X-ray absorption spectroscopy (XAS) results indicate the presence of also LaCoO3, in addition to La2Zr2O7 and Li2CO3. Based on electrochemical impedance spectroscopy, and depth profiling of the Li distribution upon potentiostatic hold experiments on symmetric LCO|LLZO|LCO cells, the interfaces exhibited significantly increased impedance, up to 8 times that of the as-deposited samples after annealing at 500°C. Our results indicate that lower-temperature processing conditions, shorter annealing time scales, and CO2-free environments are desirable for obtaining ceramic cathode-electrolyte interfaces that enable fast Li transfer and high capacity

IL-22 mediates goblet cell hyperplasia and worm expulsion in intestinal helminth infection.

Type 2 immune responses are essential in protection against intestinal helminth infections. In this study we show that IL-22, a cytokine important in defence against bacterial infections in the intestinal tract, is also a critical mediator of anti-helminth immunity. After infection with Nippostrongylus brasiliensis, a rodent hookworm, IL-22-deficient mice showed impaired worm expulsion despite normal levels of type 2 cytokine production. The impaired worm expulsion correlated with reduced goblet cell hyperplasia and reduced expression of goblet cell markers. We further confirmed our findings in a second nematode model, the murine whipworm Trichuris muris. T.muris infected IL-22-deficient mice had a similar phenotype to that seen in N.brasiliensis infection, with impaired worm expulsion and reduced goblet cell hyperplasia. Ex vivo and in vitro analysis demonstrated that IL-22 is able to directly induce the expression of several goblet cell markers, including mucins. Taken together, our findings reveal that IL-22 plays an important role in goblet cell activation, and thus, a key role in anti-helminth immunity

Effets du dérangement par la chasse sur les oiseaux d'eau : revue de littérature

La chasse aux oiseaux d'eau, activité humaine largement pratiquée sur les zones humides du continent eurasiatique, présente deux composantes pouvant affecter la dynamique des populations de ces espèces migratrices : le prélèvement (qui concerne la mortalité) et le dérangement. Ce dernier aspect fait l'objet d'études de plus en plus nombreuses et détaillées, ici synthétisées, incluant des protocoles expérimentaux et des approches conceptuelles. Le dérangement par la chasse est considéré comme important pour une espèce lorsque les modifications qu'il induit ont un effet sur la « fitness » des individus de cette espèce (diminution de la survie et/ou du succès reproducteur). Les études montrent que le dérangement modifie presque toujours la distribution géographique des oiseaux en favorisant leur regroupement (5 à 50 fois plus) sur des espaces non chassés, induisant une sous-exploitation des ressources trophiques présentes sur les espaces chassés. Le dérangement peut aussi provoquer un accroissement du taux de renouvellement (« turnover ») des individus sur leur étape migratoire. Ces transferts d'oiseaux, bien quantifiés localement, ont un impact encore inconnu sur la taille des populations concernées, la large distribution de ces populations sur plusieurs continents rendant cette évaluation difficile. Le dérangement provoque une modification comportementale soit en favorisant des activités plus coûteuses que celles pratiquées sans dérangement, soit en diminuant le temps passé à des activités qui permettent d'acquérir de l'énergie. Les estimations ou simulations de ces pertes peuvent atteindre 25 % de la dépense énergétique journalière. Les oiseaux dérangés développent des capacités d'adaptation physiologique face aux contraintes associées au dérangement, par exemple une augmentation de la prise alimentaire, une augmentation du rendement de l'assimilation énergétique ou une augmentation de la sécrétion de corticostérone qui stimule l'activité de recherche de nourriture. L'évaluation directe du bilan énergétique de ces adaptations n'a pas encore été réalisée et l'on peut admettre qu'elles permettent à l'oiseau de maintenir un apport énergétique analogue à celui obtenu sans dérangement; mais le coût à terme de cette acquisition est élevé. Ainsi, une étude récente sur la Grande Oie des neiges Anser caerules-cens atlantica au Canada révèle que lorsque les individus sont dérangés par la chasse sur leur étape migratoire de printemps, ils sont contraints d'exploiter des sites moins riches que s'il n'y avait pas de chasse; ils sont alors dans de moins bonnes conditions corporelles (lipidiques et protéiniques) lors du départ vers leurs lieux de reproduction et ils ont finalement un moindre succès de reproduction que les individus n'ayant pas subi le dérangement par la chasse. Certes, des lacunes et des incertitudes persistent, par exemple au niveau spécifique (peu d'études sur les limicoles), mais tous les auteurs qui les ont mises en évidence s'accordent aussi pour reconnaître que, pour contrebalancer les effets du dérangement par la chasse, des mesures de protection doivent être prises.Waterbird hunting is a widespread human activity over wetlands of the Eurasian continent. It has two components that can influence the population dynamics of migratory species : mortality and disturbance. Disturbance is the focus of an increasing number of detailed studies, using both experimental and theoretical approaches. They are synthesized herein. Disturbance is considered important when induced changes influence the fitness of the individuals of a species (decrease in survival or breeding success). Studies show that disturbance almost always change the geographical distribution of birds, conducting to an under-exploitation of food resources available in hunting areas. Disturbance can also favour an increase in the turnover rate of individuals on their migratory stopover. These changes in bird distribution, although precisely quantified at a local scale, have an unknown impact on the population size of the concerned species. The wide distribution of several of these species ranging over several continents makes the precise evaluation of this impact difficult. Disturbance changes behaviour either by increasing time spent in activities more costly than those done without disturbance or by decreasing time spent gaining energy. Estimation or simulation of these lost can reach 25% of the daily energy expenses. Facing disturbance, birds can develop several physiological adaptations, for instance an increased food intake, an increased efficiency of energy assimilation or an augmentation of corticosterone secretion stimulating food searching. The direct evaluation of the energy balance of these adaptations has not been made yet and it can be acknowledged that they allow birds to maintain energy gains similar to those obtained without disturbance. However, the long-term cost of this compensation is high. A recent study of the Greater Snow Goose Anser caerulescens atlantica on their spring stopover in Canada indicates that hunting disturbance makes geese use lower quality habitats, decreases their body condition (fat and protein) when they depart to the breeding sites and decreases their breeding success relative to individuals that have not experienced hunting. Uncertainties remain, for instance at the species level (few studies on waders), but all authors that emphasized them also agree to acknowledge that protection measures must be taken to counter-balance the effects of hunting disturbance. They recommend the increase of protected areas (hunt-free areas), the elaboration of a network of reserves and the establishment of non hunted zones around existing reserves to reduce to the minimum the negative effects of disturbance on birds that use these reserves. The implementation of these management actions must favour the widening of the distribution of these populations and facilitate the local and regional increase of their numbers. These protection measures are positive responses to the recommendations of the European Union birds and habitats directives