Human ascariasis: diagnostics update

Soil-transmitted helminths (STHs) infect over one billion people worldwide. Ascariasis may mimic a number of conditions, and individual clinical diagnosis often requires a thorough work-up. Kato-Katz thick smears are the standard detection method for Ascaris and, despite low sensitivity, are often used for mapping and monitoring and evaluation of national control programmes. Although increased sampling (number of stools) and diagnostic (number of examinations per stool) efforts can improve sensitivity, Kato-Katz is less sensitive than other microscopy methods such as FLOTAC®. Antibody-based diagnostics may be a sensitive diagnostic tool; however, their usefulness is limited to assessing transmission in areas aiming for elimination. Molecular diagnostics are highly sensitive and specific, but high costs limit their use to individual diagnosis, drug - efficacy studies and identification of Ascaris suum. Increased investments in research on Ascaris and other STHs are urgently required for the development of diagnostic assays to support efforts to reduce human suffering caused by these infections

Superconductivity of SrTiO_{3-\delta}

Superconducting SrTiO_{3-\delta} was obtained by annealing single crystalline SrTiO_3 samples in ultra high vacuum. An analysis of the V(I) characteristics revealed very small critical currents I_c which can be traced back to a unavoidable doping inhomogeneity. R(T) curves were measured for a range of magnetic fields B at I<<I_c, thereby probing only the sample regions with the highest doping level. The resulting curves B_{c2}(T) show upward curvature, both at small and strong doping. These results are discussed in the context of bipolaronic and conventional superconductivity with Fermi surface anisotropy. We conclude that the special superconducting properties of SrTiO_{3-\delta} can be related to its Fermi surface and compare this finding with properties of the recently discovered superconductor MgB_2.Comment: EPJ style, 6 pages, 8 figures; minor changes, Fig. 5 replaced; use PDF version for printout

Impact de la variation nucléotidique de gènes de la voie de biosynthèse des caroténoïdes sur leur accumulation dans la racine de carotte cultivée

Impact of nucleotide variation in carotenoids biosynthesis genes on their accumulation in the cultivated carrot root Due to the carotenoid content, carrot, Daucus carota L., exhibits a great nutritional value and root color variability, obtained by anthropic selection. Still partially known, the genetic determinism of carotenoid content is an important issue for breeding to market segmentation. This work focuses on the identification of genetic factors involved in the root carotenoids accumulation, related with color. An association mapping approach was used to link candidate gene polymorphisms, mostly located in the carotenoid biosynthetic pathway, and carotenoid content and root color variations. The study resolution has been previously evaluated by measuring the extent of linkage disequilibrium. The genetic resources structuration of the species was studied to evaluate the risk of false positives detection when testing for associations. This study was conducted on two populations, a structured panel of lines and an unstructured population. The results highlight the key role of anabolism and catabolism genes in the overall accumulation of carotenoids. In particular, the zeaxanthin epoxidase gene was associated with the β­carotene and total carotenoids content, and may be involved in the yellow or orange color and is probably the underlying gene of the locus Y2. More specifically, lycopene β­cyclases and carotene hydroxylase could be responsible for the accumulation of lycopene and α­carotene, respectively. These results show the complementarity of the populations used to improve the detection of potential associations. Biosynthetic pathway functioning schemes leading to different types of colored carrot are proposed

Checking sequence construction using adaptive and preset distinguishing sequences

Methods for testing from finite state machine-based specifications often require the existence of a preset distinguishing sequence for constructing checking sequences. It has been shown that an adaptive distinguishing sequence is sufficient for these methods. This result is significant because adaptive distinguishing sequences are strictly more common and up to exponentially shorter than preset ones. However, there has been no study on the actual effect of using adaptive distinguishing sequences on the length of checking sequences. This paper describes experiments that show that checking sequences constructed using adaptive distinguishing sequences are almost consistently shorter than those based on preset distinguishing sequences. This is investigated for three different checking sequence generation methods and the results obtained from an extensive experimental study are given

Magnetic anisotropies and magnetization reversal of the Co2_2Cr0.6_{0.6}Fe0.4_{0.4}Al Heusler compound

Magnetic anisotropies and magnetization reversal properties of the epitaxial Heusler compound Co$_2$Cr$_{0.6}$Fe$_{0.4}$Al (CCFA) deposited on Fe and Cr buffer layers are studied. Both samples exhibit a growth-induced fourfold anisotropy, and magnetization reversal occurs through the formation of stripy domains or 90 degree domains. During rotational magnetometric scans the sample deposited on Cr exhibits about 2 degree sharp peaks in the angular dependence of the coercive field, which are oriented along the hard axis directions. These peaks are a consequence of the specific domain structure appearing in this particular measurement geometry. A corresponding feature in the sample deposited on Fe is not observed.Comment: 11 pages, 7 figure

Caractéristiques moléculaires de l'immunité des plantes induite par les rhizobactéries non pathogènes

Molecular characteristics of the rhizobacteria-triggered plant immunity. Recognition of certain non-pathogenic rhizobacteria by plants can trigger a systemic resistance reaction that renders the host less susceptible to subsequent infection by a virulent agent. Used in combination with other approaches, this induced systemic resistance (ISR) phenomenon is considered as a promising strategy for plant disease control both in greenhouse cultures and under field conditions. This review emphasizes the molecular aspects of this three-step process involving sequentially the perception by plant cells of elicitors produced by the inducing agents that initiates the phenomenon, signal transduction that is needed to propagate the induced state systemically through the plant and expression of defense mechanisms sensu stricto that limit or inhibit pathogen penetration into the host tissues. The current state of knowledge about rhizobacteria-stimulated ISR is discussed in parallel with the better characterized systemic acquired resistance induced by incompatible pathogens

A Brief History of Web Crawlers

Web crawlers visit internet applications, collect data, and learn about new web pages from visited pages. Web crawlers have a long and interesting history. Early web crawlers collected statistics about the web. In addition to collecting statistics about the web and indexing the applications for search engines, modern crawlers can be used to perform accessibility and vulnerability checks on the application. Quick expansion of the web, and the complexity added to web applications have made the process of crawling a very challenging one. Throughout the history of web crawling many researchers and industrial groups addressed different issues and challenges that web crawlers face. Different solutions have been proposed to reduce the time and cost of crawling. Performing an exhaustive crawl is a challenging question. Additionally capturing the model of a modern web application and extracting data from it automatically is another open question. What follows is a brief history of different technique and algorithms used from the early days of crawling up to the recent days. We introduce criteria to evaluate the relative performance of web crawlers. Based on these criteria we plot the evolution of web crawlers and compare their performanc