measurement of the lattice parameter of a silicon crystal

The silicon crystal WASO04 is a reference in the adjustment of fundamental physical constants, but its lattice parameter has never been measured in absolute terms. In the framework of an international project meant to base the kilogram definition on the molar volume and the lattice parameter of 28Si, the WASO04 crystal has been used to manufacture an interferometer prototype for the performance testing and the fine-tuning of a new experimental apparatus for lattice parameter measurements by combined x-ray and optical interferometry. The present paper discusses the test results and gives an accurate lattice parameter determination. With respect to previous determinations, the value obtained, d220(WASO04)=192.015 570 2(10) pm, displays a four-fold improvement in accurracy

Development of two multiplex PCRs for microsatellite analysis in Alpine chamois (Rupicapra r. rupicapra)

The study of the genetic diversity gives important information about structure, subdivision in subunits and evolution of populations. Chamois (Rupicapra rupicapra, Linneus 1758) are mountain ungulates belonging to the subfamily Caprinae. They are presently distributed over most of the medium to high altitude mountains in the Southern Europe. Ten distinct geographical populations have been recognised as subspecies (Masini and Lovari, 1988); one of this subspecies, R. r. rupicapra, includes also the chamois living on the Italian Alps

Canine leishmaniasis: the key points for qPCR result interpretation

Background: Diagnosis and follow up of CanL is difficult since the range of clinical signs is varied and seroprevalence is high in endemic areas. The aims of this study were: i) demonstrate the advantages of Leishmania qPCR to diagnose and control CanL and highlight its prognostic value and ii) propose guidelines for tissue selection and infection monitoring. Findings: This study included 710 dogs living in an endemic area of leishmaniasis. Forty percent (285/710) exhibited clinical signs consistent with CanL. Infection was detected in 36.3% (258/710) of the dogs of which 4.5% (32/710) were detected by qPCR, 16.2% (115/710) detected by ELISA and 15.6% (111/710) tested positive for both tests. Only 17.9% (127/710) of the dogs were classified sick (affected) with CanL. All symptomatic dogs with medium or high ELISA titers were qPCR-positive in blood samples. All dogs with inconclusive or low ELISA results with high or medium qPCR parasitemia values developed the disease. Seventy one percent of asymptomatic ELISA-positive dogs confirmed by qPCR (medium to high parasitemia) developed the disease. Bone marrow or lymph node aspirate should be selected to ensure the absence of the parasite in asymptomatic dogs: 100-1,000 parasites/ml in bone marrow are detectable in blood, whereas lower parasite loads are usually negative. Almost 10% of negative samples in blood were positive in conjunctival swabs. Conclusions: Because qPCR allows parasite quantification, it is an effective tool to confirm a diagnosis of CanL in (i) cases of inconclusive ELISA results, (ii) when the dog has not yet seroconverted, or (iii) for treatment monitoring