Culex torrentium mosquitoes from Germany are negative for Wolbachia

Wolbachia (Rickettsiales: Anaplasmataceae) infects a wide range of arthropods, including several mosquito species. The bacterium is known to induce a plethora of phenotypes in its host, examples being the reproductive phenotype cytoplasmic incompatibility or resistance against infection with arboviruses. The latter is especially relevant when assessing the vector competence of mosquito species for emerging arboviruses. Thus, knowledge of Wolbachia infection status is important for the assessment of vector competence. To facilitate Wolbachia screening in mosquito populations, a quantitative polymerase chain reaction (qPCR) assay was developed to enable high‐throughput analysis of mosquito samples. Using this assay, the Wolbachia infection status of the two most common Culex mosquito species in Germany, Culex pipiens biotype pipiens Linnaeus (Diptera: Culicidae) and Culex torrentium Martini (Diptera: Culicidae), was assessed. About 93% of all tested C. pipiens biotype pipiens individuals were positive for Wolbachia, whereas none of the C. torrentium samples was found to be infected. Furthermore, other applications of the qPCR assay were explored by assessing a potential link between the levels of Wolbachia and West Nile virus (WNV) infections in German C. pipiens biotype pipiens mosquitoes. No relationship was found between the two variables, indicating that a Wolbachia‐induced antiviral phenotype in this mosquito population is not exclusively attributable to the general level of bacterial infection.     

Population Dynamics of Marine Copepods: The Importance of Photoperiodism

SYNOPSIS. Biological oceanographers have traditionally emphasizedfood and temperature as the most important factors governingthe population dynamics of marine copepods. This paper addressesthe importance of light and light-dark periods as stimuli forthe induction of specific biological processes and activities.Attention is focused on photoperiodic control of dormancy andvertical migration, and the rhythmic expression of daily functionssuch as the timing of feeding and egg-laying. Emphasis is placedon relating the genetic basis of photoperiodically determinedresponses and activity rhythms to the population dynamics, ecologyand evolution of marine copepods, and the maintenance of diversezooplankton communities.     

Arboreal walking performance in seven didelphid marsupials as an aspect of their fundamental niche

Abstract Species of didelphid marsupials (Didelphimorphia, Didelphidae) differ in their use of the forest strata, but it is not clear whether these differences are in fundamental or realized niches. The fundamental niche of seven species of didelphids (Caluromys philander, Didelphis aurita, Gracilinanus microtarsus, Marmosops incanus, Metachirus nudicaudatus, Micoureus demerarae, and Philander frenatus) was compared using their performance in arboreal walking. The association between performance and vertical use of the forest also was tested accounting for phylogenetic and allometric effects. Tests consisted of making the animal cross five 3 m long horizontal supports of different diameters, 1 m from the ground. The cycle of maximum speed was chosen to measure stride length, frequency and velocity. Arboreal species performed better than the terrestrial ones, but a major part of the variation in stride length (70.95%) and stride frequency (88.10%) was associated with body size. Part of the variation in stride length independent of body size (14.05%) was associated with the degree of vertical use of the forest, after phylogenetic effects were accounted for. Fundamental niches of six of the seven species were discriminated with the performance tests used. Discrepancies between the realized and fundamental niches can be inferred for two of these species, D. aurita and P. frenatus.     

Reliability of Fine Needle Aspiration Cytology For Distinguishing Between Carcinoma,Lymphoma and Sarcoma; the Influence of Clinical Information

To investigate interobserver variation of fine needle aspiration (FNA) cytological diagnosis with respect to distinguishing between carcinoma, sarcoma and lymphoma, a set of 80 randomly sampled slides was randomized twice and read ‘blindly’by five cytopathologists. In the first round the slides were read without any information, and in the second round clinical information was provided. Histology was used as a reference standard. In the first round, the positive predictive values for the cytological diagnosis of carcinoma, sarcoma and lymphoma were 93%, 94% and 86% respectively. In the second round the positive predictive values for the cytological diagnoses of carcinoma, sarcoma and lymphoma were 95%, 99% and 99%, respectively. Interobserver variability, tested with weighted kappa scores (range 0.73–0.92) between histological and cytological diagnosis, was low. the most accurate FNA cytologic classification was obtained when the clinical context was known. L'étude de la variabilité interobservateur du diagnostic différentiel entre carcinome, sarcome et lymphome par cytoponction à l'aiguille fine a été conduite sur 80 cas pris au hasard. Deux lectures successives ont été faites ‘en aveugle’par 5 cytopathologistes. Les renseignements cliniques n'one été fournis que lors de la deuxième lecture. L'histopathologie est le standard de référence. Après la première lecture, la valeur prédictive positive moyenne du diagnostic de carcinome, de sarcome et de lymphome est respectivement de 93%, 94% et 86%. Après la seconde lecture, ces valeurs sont respectivement de 95%, 99% et 99%. La variabilité interobservateur, testée par le score kappa pondéré (intervalle de 0.73 à 0.92) entre les diagnostics histologiquest et cytologiques est faible. Le meilleur résultat est obtenu lorsque le contexte clinique est connu. Zur Überprüfung der Übereinstimmung zwischen verschiedenen Zytopathologen wurden 80 Präparate von Karzinomen, Sarkomen und Lymphomen zweimal randomisiert und von 5 Zytopathologen blind ausgewertet. In der 1. Runde erfolgte dies ohne Zusatzinformation, in der 2. mit klinischen Informationen. Bezugsstandard war die Histologie. In der 1. Runde waren die positiven praediktiven Werte für Karzinom, Sarkom und Lymphom 93%, 94% bzw. 86%. In der 2. Runde betrugen die Werte 95%, 99% und 99%. Testet man die Variabilität zwischen den Auswertern mit Kappawerten (0.73–0.92), so ergeben sich nur geringe Unterschiede in der Zuverlässigkeit zwischen histologischer und zytologischer Diagnose. Die besten zytologischen Ergebnisse werden erreicht, wenn die klinischen Daten bekannt sind.