Comparing aspirations: intercalibration of ecological status concepts across European lakes for littoral diatoms

Eleven European countries participated in an exercise to harmonise diatom-based methods used for status assessment in lakes. Lakes were divided into low, medium and high alkalinity types for this exercise. However, it was not possible to perform a full intercalibration on low alkalinity lakes due to the short gradient and confounding factors. Values of the Trophie Index were computed for all samples in order that national datasets could all be expressed on a common scale. Not all participants had reference sites against which national methods could be standardised and, therefore, a Generalised Linear Modelling approach was used to control the effect of national differences in datasets. This enabled the high/good and good/moderate status boundaries to be expressed on a common scale and for deviations beyond ±0.25 class widths to be identified. Those countries which had relaxed boundaries were required to adjust these to within ±0.25 class widths whilst the intercalibration rules allowed those countries with more stringent boundaries to retain these. Despite biogeographical and typological differences between countries, there was broad agreement on the characteristics of high, good and moderate status diatom assemblages, and the exercise has ensured consistent application of Water Framework Directive assessments around Europe.     

Do chemical signals mediate reproductive behavior of Trupanea vicina,an emerging pest of ornamental marigold production in California?

A variety of signals mediate reproductive behaviors of Tephritidae, and studies of such behaviors have focused predominantly on economically important tephritid pest species. Trupanea vicina (Wulp) (Diptera: Tephritidae: Tephritinae), an Asteraceae‐feeding fruit fly, was not considered a pest until recently, when large populations developed on marigolds in California (USA) nurseries. Understanding courtship behavior and the signals that mediate mating behavior in T. vicina could produce leads for new methods of controlling this emerging pest species. Most of the sexual behaviors observed in T. vicina were expressed by males and reflected the general characteristics of known reproductive behaviors in the genus Trupanea. Analyses of headspace volatiles indicated the presence of almost exclusively one male‐specific compound, 1‐nonanol. Age‐related changes were observed in the amount but not in the composition of the male‐produced volatiles. Aerations of males showed no diel periodicity in 1‐nonanol production, but an increase after mating. Solid‐phase microextraction wipe samples from various body parts of male T. vicina showed that 1‐nonanol was concentrated on the abdomens of males exhibiting pleural distension. Laboratory bioassays failed to detect any strong attraction of either sex to synthetic 1‐nonanol. Although the functional role of 1‐nonanol in T. vicina's biology is not yet clear, we suggest that it must have some role in the life history of this species, given the relatively large amounts in which it is produced, and the specialized structures used in its production and release. Analysis of cuticular hydrocarbons extracted from males and females showed pronounced sexual dimorphism in the cuticular lipid profiles, suggesting that these compounds may have a role as short‐range and contact pheromones.     

Sweet or salty? The origin of freshwater gastrotrichs (Gastrotricha,Chaetonotida) revealed by molecular phylogenetic analysis

Chaetonotidae is the most diverse and widely distributed family of the order Chaetonotida (Gastrotricha) and includes both marine and freshwater species. Although the family is regarded as a sister taxon to the exclusively marine Xenotrichulidae, the type of environment, marine or freshwater, where Chaetonotidae originated is still not known. Here, we reconstructed the phylogeny of the family based on molecular sequence data and mapped both morphological and ecological characters to determine the ancestral environment of the first members of the family. Our results revealed that the freshwater genus Bifidochaetus is the earliest branching lineage in the paraphyletic Chaetonotidae (encompassing Dasydytidae and Neogosseidae). Moreover, we reconstructed Lepidochaetus-Cephalionotus clade as a monophyletic sister group to the remaining chaetonotids, which supports Kisielewski's morphological based hypothesis concerning undifferentiated type of body scales as a most primary character in Chaetonotidae. We also found that reversals to marine habitats occurred independently in different Chaetonotidae lineages, thus marine species in the genera Heterolepidoderma, Halichaetonotus, Aspidiophorus and subgenera Chaetonotus (Schizochaetonotus) or Chaetonotus (Marinochaetus) should be assumed as having secondarily invaded the marine environment. Character mapping revealed a series of synapomorphies that define the clade that includes Chaetonotidae (with Dasydytidae and Neogosseidae), the most important of which may be those linked to reproduction.     

Intra-Abdominal Pressure Correlates with Extracellular Water Content

Background

Secondary increase in intra-abdominal pressure (IAP) may result from extra-abdominal pathology, such as massive fluid resuscitation, capillary leak or sepsis. All these conditions increase the extravascular water content. The aim of this study was to analyze the relationship between IAP and body water volume.

Material and Methods

Adult patients treated for sepsis or septic shock with acute kidney injury (AKI) and patients undergoing elective pharyngolaryngeal or orthopedic surgery were enrolled. IAP was measured in the urinary bladder. Total body water (TBW), extracellular water content (ECW) and volume excess (VE) were measured by whole body bioimpedance. Among critically ill patients, all parameters were analyzed over three consecutive days, and parameters were evaluated perioperatively in surgical patients.

Results

One hundred twenty patients were studied. Taken together, the correlations between IAP and VE, TBW, and ECW were measured at 408 time points. In all participants, IAP strongly correlated with ECW and VE. In critically ill patients, IAP correlated with ECW and VE. In surgical patients, IAP correlated with ECW and TBW. IAP strongly correlated with ECW and VE in the mixed population. IAP also correlated with VE in critically ill patients. ROC curve analysis showed that ECW and VE might be discriminative parameters of risk for increased IAP.

Conclusion

IAP strongly correlates with ECW.     

Circulating Betatrophin Is Strongly Increased in Pregnancy and Gestational Diabetes Mellitus

Aims/hypothesis

Betatrophin has recently been introduced as a novel hormone and promotor of beta cell proliferation and improved glucose tolerance in mouse models of insulin resistance. In obese and diabetic humans altered levels were reported and a role in pathophysiology of metabolic diseases was therefore hypothesized. However its release and regulation in women with gestational diabetes mellitus (GDM), as well as its associations with markers of obesity, glucose and lipid metabolism during pregnancy still remain unclear.

Methods

Circulating betatrophin was quantified in 21 women with GDM and 19 pregnant body mass index-matched women with normal glucose tolerance (NGT) as well as 10 healthy age-matched non-pregnant women by enzyme-linked immunosorbent assay. Additionally we performed radioimmunassay (RIA) to confirm the results.

Results

Betatrophin concentrations measured by ELISA were significantly higher in GDM than in NGT (29.3±4.4 ng/ml vs. 18.1±8.7 ng/ml, p<0.001) which was confirmed by RIA. Betatrophin did not correlate with BMI or insulin resistance but showed a weak association with leptin levels in pregnancy and negative relationship with fasting C-peptide levels in all women. Moreover it correlated significantly with lipid parameters including triglycerides and total cholesterol in pregnancy, as well as estrogen, progesteron and birth weight.

Conclusions/interpretation

Circulating betatrophin concentrations are dramatically increased in pregnancy and are significantly higher in GDM versus pregnant NGT. In the light of the previously reported role in lipid metabolism, betatrophin may represent a novel endocrine regulator of lipid alterations in pregnancy. However additional studies are needed to elucidate whether hormonal factors, such as estrogen, control the production of betatrophin and if targeting betatrophin could hold promise in the fight against metabolic disease.     

Factors affecting the density of the middle spotted woodpecker Dendrocopos medius: a macrohabitat approach

The main goals of this study were to investigate the relationships between densities of the breeding population of the middle spotted woodpecker Dendrocopos medius obtained on 19 large-scale plots, and the share of different habitats and age of forest stands. An average crude density based on an area defined arbitrarily by observers was 0.66±0.43 territories/10 ha, while the ecological density based on an area including habitats potentially used by organisms reached 1.09±0.64 territories/10 ha. Stepwise multiple regression indicated that the crude density was negatively affected by the share of coniferous forest thereby explaining 50% of variation. The ecological density was negatively correlated with the percentage of young deciduous stands (0–40 years old). This variable explained 36% of the total variation. These results suggest that on the level of macrohabitat analysis, the share of unsuitable forest stands seem to play a major role in determining the density of the middle spotted woodpecker.     

Female competition for availability of males in insects: the Nezara viridula (Linnaeus, 1758) model

Multimodal communication in solitary stinkbugs enables them to meet, mate and copulate. Many plant‐dwelling species exchange information during the calling phase of mating behavior using substrate‐borne vibratory signals. A female‐biased gender ratio induces rivalry and competition for a sexual partner. Female competition for males, first described among Heteroptera in three stinkbug species, revealed species specific differences and opened the question of plasticity in individually emitted temporal and frequency signal characteristics during calling and rival alternation. To address this question and gain an insight into the mechanisms underlying stinkbug female rivalry, we compared the characteristics of alternated signals in the southern green stinkbug Nezara viridula (Linnaeus, 1758) (Hemiptera: Pentatomidae). Compared to male rivalry, female rivalry is more complex, lasts longer and runs through successive phases by a combination of different song types. The male pheromone triggers alternation between females, producing song pulses that occasionally overlap each other. One female initiates the rivalry by changing individual pulses into pulse trains of three different types. The competing female alternates with pulses of changed temporal characteristics at lower levels of rivalry and by varying the frequency characteristics of pulse trains at higher levels. During female rivalry, the male either stops responding or occasionally emits calling and courtship signals in response to the female that has produced signals of steady temporal characteristics. Female rivalry shows complex and species specific patterns of information exchange at different levels with a broad‐range variation of temporal and frequency characteristics of, until now, unidentified vibratory emissions.