Predicting the response of communities to climate change is a major challenge for ecology. Communities may well not respond as entities but be disrupted, particularly if trophic levels respond differently, but as yet there is no evidence for differential responses from natural systems. We therefore analyzed unusually detailed plant and animal data collected over 20 years from two grassland communities to determine whether functional group climate sensitivity differed between trophic levels. We found that sensitivity increases significantly with increasing trophic level. This differential sensitivity would lead to community destabilization under climate change, not simple geographical shifts, and consequently must be incorporated in predictive ecological climate models.
In our group of metastatic breast cancer patients, elevated HER-2/neu ECD levels are associated with decreased overall survival. With regard to progression-free survival, particularly patients with high HER-2/neu ECD levels seem to benefit from taxane-containing chemotherapy.
Theory predicts negative effects of increasing plant diversity on the abundance of specialist insect herbivores, but little is known about how plant diversity affects the performance and abundance of generalist insect herbivores. We studied oviposition rates and offspring numbers in females of the generalist grasshopper Chorthippus parallelus that were collected in 15 montane grasslands in 2005 and 2007 along a gradient of plant species richness in central Germany. In addition to plant species richness, we determined evenness and plant community composition in the grasslands and measured aboveground plant biomass and other habitat variables such as leaf area index, vegetation height, and solar radiation. There was substantial variation among sites in grasshopper fecundity and the number of nymphs that hatched from the egg pods. Both fitness measures were positively influenced by plant species richness at the sites, while female fitness did not correlate with any of the other habitat parameters. Abundance of C. parallelus in the grasslands was positively correlated with plant species richness, plant community composition, and incident solar radiation of the sites. There were no phenological differences between grasshoppers from the different study sites. Our results suggest that decreasing biodiversity threatens the persistence not only of specialist, but also of generalist insect herbivores via a variety of mechanisms including a decrease in diversity of the generalists' food plants.
1. Generalist insect herbivores occupy a variety of habitats that differ in food plant composition. Dietary mixing has been proposed as a possibility for generalists to overcome nutritional deficiencies of single plant species, but only a few studies have investigated herbivore feeding and fitness for diets that resemble natural scenarios. We studied feeding behaviour, survival, and reproduction of the generalist grasshopper Chorthippus parallelus raised on food plants of four typical habitats.
2. Grasshopper diet consisted of grasses (92.5%), legumes (6.7%) and, in small quantities, other forbs (0.8%). Diet selection differed between the four food plant mixtures, and depended on grasshopper sex and developmental stage. There was no correlation between the relative abundance of plant species in the field and the fraction of these species in the grasshopper diet.
3. Grasshoppers survived on average for 40.4 ± 1.0 days before maturity, grew 106.8 mg until maturity moult, and females laid 4.1 ± 0.4 egg pods, each of which contained 8.5 ± 0.4 eggs. However, despite the differences in feeding behaviour, grasshopper fitness was the same in all of the four food plant mixtures. While the digestibility of ingested food was similar in the four different treatments, indices indicated differences in the conversion efficiency to body mass.
4. Our results show that C. parallelus is a plastic feeder with no fixed preferences in diet composition. The results emphasise that generalist herbivores can counteract putative quality deficiencies of single food plants by selective dietary mixing.
Aims This is an official guideline published and coordinated by the German Society of Gynecology and Obstetrics (DGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). Because of their rarity and heterogeneous histopathology, uterine sarcomas are challenging in terms of how they should be managed clinically, and treatment requires a multidisciplinary approach. To our knowledge, there are currently no binding evidence-based recommendations for the appropriate management of this heterogeneous group of tumors.
Methods This S2k guideline was first published in 2015. The update published here is the result of the consensus of a representative interdisciplinary group of experts who carried out a systematic search of the literature on uterine sarcomas in the context of the guidelines program of the DGGG, OEGGG and SGGG. Members of the participating professional societies achieved a formal consensus after a moderated structured consensus process.
Recommendations The consensus-based recommendations and statements include the epidemiology, classification, staging, symptoms, general diagnostic work-up and general pathology of uterine sarcomas as well as the genetic predisposition to develop uterine sarcomas. Also included are statements on the management of leiomyosarcomas, (low and high-grade) endometrial stromal sarcomas and undifferentiated uterine sarcomas and adenosarcomas. Finally, the guideline considers the follow-up and morcellation of uterine sarcomas and the information provided to patients.
Many animals show altitudinal clines in size, shape and body colour. Increases in body size and reduction in the length of body appendices in colder habitats are usually attributed to improved heat conservation at lower surface-to-volume ratios (known as Bergmann’s and Allen’s rule, respectively). However, the patterns are more variable and sometimes reversed in small ectotherms that are affected by shortened growing seasons. Altitude can also affect colouration. The thermal melanism hypothesis predicts darker colours under cooler conditions because of a thermoregulatory advantage. Darker colours may also be favoured at high altitudes for reasons of UV protection or habitat-dependent crypsis. We studied altitudinal variation in morphology and colour in the colour-polymorphic meadow grasshopper Pseudochorthippus parallelus based on 563 individuals from 17 populations sampled between 450 and 2,500 m asl. Pronotum length did not change with altitude, while postfemur length decreased significantly in both sexes. Tegmen (forewing) length decreased in males, but not in females. The results indicate that while body size, as best quantified by pronotum length, was remarkably constant, extended appendices were reduced at high altitudes. The pattern thus follows Allen’s rule, but neither Bergmann’s nor converse Bergmann’s rule. These results indicate that inference of converse Bergmann’s rule based on measurements from appendices should be treated with some caution. Colour morph ratios showed significant changes in both sexes from lowland populations dominated by green individuals to high-altitude populations dominated by brown ones. The increase of brown morphs was particularly steep between 1,500 and 2,000 m asl. The results suggest shared control of colour in males and females and local adaptation along the altitudinal gradient following the predictions of the thermal melanism hypothesis. Interestingly, both patterns, the reduction of body appendices and the higher frequency of brown individuals, may be explained by a need for efficient thermoregulation under high-altitude conditions.
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