First evidence of the tooth eruption sequence of the upper jaw in Hyaenodon (Hyaenodontidae,Mammalia) and new information on the ontogenetic development of its dentition

Juvenile material with the main focus on the upper jaw of the fossil predator Hyaenodon was evaluated to study the tooth eruption sequence and to examine the ontogeny of its dentition in detail. The comparison in size of milk to permanent teeth indicates a growth rate of 12–16 % in Hyaenodon. The thin section of a deciduous canine of a North American taxon shows four dental rings. Based on the knowledge of recent carnivores, this implies an age of 3–4 years in the last stage of tooth eruption and thus a long juvenile phase. The mandibles ascertained the most recent established tooth eruption sequence for North American and European species. For the first time ever, juvenile material from Asia is documented and interpreted. This study likewise shows a difference in the sequence of the upper jaw: the first upper premolar erupts before the first upper molar in North American species, whereas the European taxa show an earlier eruption of the first upper molar. This fact further confirms the divergence between the Hyaenodon lineages from North America and Europe.     

Second-harmonic generation from organic molecules incorporated in sol-gel matrices

Orientation of optically nonlinear organic molecules inside sol-gel matrices upon application of an external D.C. electrical field is demonstrated for the first time. The quadratic nonlinear response of silicon oxide or transition metal oxide based gels containing organic molecules has been determined from Electric Field Induced Second Harmonic (EFISH) measurements. Large concentrations of Optically Nonlinear Organic Molecules (ONOM) have been either incorporated inside the macromolecular network or chemically bonded to the oxide backbone of the gels. These results demonstrate the feasibility of permanently poled doped sol-gel matrices. Moreover, EFISH measurements performed on organic molecules appear to be a useful tool for monitoring the changes occurring during sol-gel transformations.     

Statistical comparison of proximity matrices: applications in animal behaviour

Animal behaviour studies often require the diagnosis and statistical evaluation of patterns among individuals of a group. However, association values derived for all pairs of individuals are mathematically interrelated and, hence, difficult to evaluate. A general method of matrix comparison, called the Mantel test, is described which accounts for such interdependencies. In this test, two square difference matrices are compared to determine whether a statistical association exists between corresponding elements. For example, distances in one of the matrices might represent differences in songs for each pair of a group of birds, while distances in the other matrix could be the geographic distances between each of the same bird pairs; the test would assess whether or not birds close to one another have songs that are more similar than those pairs that are located further apart geographically. Distances in the matrices can be of a variety of sorts (depending on the application), including for instance geographic distances, morphological differences, or behavioural differences. The test has wide applicability in studies of animal behaviour, and we present three examples. First, dialects of splendid sunbirds (Nectarinia coccinigaster) were investigated to determine whether local or regional patterns of geographic variation in song were present, and whether birds with similar dialects were concentrated within the same habitat. Second, dominance hierarchies of white-throated sparrows (Zonotrichia albicollis) and dark-eyed juncos (Junco hyemalis oreganus) were analysed by constructing appropriate hypothesis matrices that were contrasted against a matrix summarizing behavioural interrelationships of flock members. In the third application, involving progressions of yellow baboons (Papio cynocephalus), an approach was developed to assess whether members of a given sex occur adjacent (or at least closer) to one another in progression order more often than expected by chance, and also whether individuals of a given sex tend to be found at or near the end of a progression more frequently than predicted. Other possible applications of the Mantel test are discussed, and a detailed computational example is included.     

First Evaluation after Implementation of a Quality Control System for the Second Line Drug Susceptibility Testing of Mycobacterium tuberculosis Joint Efforts in Low and High Incidence Countries

Three networks/projects involving 27 European countries were established to investigate the quality of second-line drug (SLD) susceptibility testing with conventional and molecular methods. 1. The “Baltic-Nordic TB-Laboratory Network” comprised 11 reference laboratories in the Baltic-Nordic States. They performed SLD testing in the first phase with a panel of 20 Mycobacterium tuberculosis strains. After several laboratories made technical changes a second panel of 10 strains with a higher proportion of resistant strains were tested. Although the concordance for Ofloxacin, Kanamycin, and Capreomycin was consistently high, the largest improvements in performance were achieved for the analysis of Ofloxacin resistant (from 88.9 to 95.0%), and Capreomycin resistant (from 71.0 to 88.9%) strains. 2. Within the FP7 TB PAN-NET project (EU Grant agreement 223681) a quality control panel to standardize the EQA (External Quality Assurance) for first-line drugs (FLD) and SLD testing for phenotypic and molecular methods was established. The strains were characterized by their robustness, unambiguous results when tested, and low proportion of secondary drug resistances. 3. The (European Reference Laboratory Network-TB) ERLN-TB network analyzed four different panels for drug resistance testing using phenotypic and molecular methods; in two rounds in 2010 the 31 participating laboratories began with 5 strains, followed by 10 strains and 6 additional crude DNA extracts in 2011 and 2012 were examined by conventional DST and molecular methods. Overall, we demonstrated the importance of developing inter-laboratory networks to establish quality assurance and improvement of SLD testing of M. tuberculosis.