Decreased efficiency of pollen collection due to Sulfoxaflor exposure leads to a reduction in the size of bumble bee workers in late European summer

Bumble bees (Bombus terrestris) are important pollinators of wild and crop plants. Despite their importance in the process of fruit and seed production on crop sites, their activity may be impaired due to exposure to pesticides. This species has a yearly life cycle and colony success may rely on effective foraging of workers on ruderal plants late in summer when most crops are no longer flowering. In the current study, we investigated the effect of chronic exposure to Sulfoxaflor on aspects of the foraging behavior of bumble bees and whether Sulfoxaflor influences the body size of workers of B. terrestris in a crop landscape. We found that 2 weeks of continuous exposure to Sulfoxaflor influenced workers’ foraging dynamics and collection of resources. However, there was no evidence that the 5 ppb dose of the pesticide impacted the ability of bees to handle flowers with different traits. Workers from colonies exposed to Sulfoxaflor were smaller. The effect on worker size may be explained as a consequence of the reduced pollen income per unit of worker foraging. Thus, if the effects of Sulfoxaflor applied directly to crops had the same effect as that observed on commercial bumble bees after our chronic exposure, it might negatively impact colony success due to the impact on pollen collection and the reduction in the size of workers.

Phylogenetic relatedness of food plants reveals highest insect herbivore specialization at intermediate temperatures along a broad climatic gradient

The composition and richness of herbivore and plant assemblages change along climatic gradients, but knowledge about associated shifts in specialization is scarce and lacks controlling for the abundance and phylogeny of interaction partners. Thus, we aimed to test whether the specialization of phytophagous insects in insect-plant interaction networks decreases toward cold habitats as predicted by the 'altitude niche-breadth hypothesis' to forecast possible consequences of interaction rewiring under climate change. We used a non-invasive, standardized metabarcoding approach to reconstruct dietary relationships of Orthoptera species as a major insect herbivore taxon along a broad temperature gradient (~12°C) in Southern Germany. Based on Orthoptera surveys, feeding observations, collection of fecal pellets from >3,000 individuals of 54 species, and parallel vegetation surveys on 41 grassland sites, we quantified plant resource availability and its use by herbivores. Herbivore assemblages were richer in species and individuals at sites with high summer temperatures, while plant richness peaked at intermediate temperatures. Corresponding interaction networks were most specialized in warm habitats. Considering phylogenetic relationships of plant resources, however, the specialization pattern was not linear but peaked at intermediate temperatures, mediated by herbivores feeding on a narrow range of phylogenetically related resources. Our study provides empirical evidence of resource specialization of insect herbivores along a climatic gradient, demonstrating that resource phylogeny, availability, and temperature interactively shape the specialization of herbivore assemblages. Instead of low specialization levels only in cold, harsh habitats, our results suggest increased generalist feeding due to intraspecific changes and compositional differences at both ends of the microclimatic gradient. We conclude that this nonlinear change of phylogeny-based resource specialization questions predictions derived from the 'altitude-niche breadth hypothesis' and highlights the currently limited understanding of how plant-herbivore interactions will change under future climatic conditions.

Do amino and fatty acid profiles of pollen provisions correlate with bacterial microbiomes in the mason bee Osmia bicornis?

Bee performance and well-being strongly depend on access to sufficient and appropriate resources, in particular pollen and nectar of flowers, which constitute the major basis of bee nutrition. Pollen-derived microbes appear to play an important but still little explored role in the plant pollen-bee interaction dynamics, e.g. through affecting quantities and ratios of important nutrients. To better understand how microbes in pollen collected by bees may affect larval health through nutrition, we investigated correlations between the floral, bacterial and nutritional composition of larval provisions and the gut bacterial communities of the solitary megachilid bee Osmia bicornis. Our study reveals correlations between the nutritional quality of pollen provisions and the complete bacterial community as well as individual members of both pollen provisions and bee guts. In particular pollen fatty acid profiles appear to interact with specific members of the pollen bacterial community, indicating that pollen-derived bacteria may play an important role in fatty acid provisioning. As increasing evidence suggests a strong effect of dietary fatty acids on bee performance, future work should address how the observed interactions between specific fatty acids and the bacterial community in larval provisions relate to health in O. bicornis. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.

Radionecrosis after repeated courses of radiotherapy under stereotactic conditions for brain metastases: Analysis of clinical and dosimetric data from a retrospective cohort of 184 patients

PURPOSE

Between 10 and 40% of patients with cancer will develop one or more brain metastases (BMs). Stereotactic radiotherapy (SRT) is part of the therapeutic arsenal for the treatment of de novo or recurrent BM. Its main interest is to delay whole brain radiation therapy (WBRT), which may cause cognitive toxicity. However, SRT is not exempt from long-term toxicity, and the most widely known SRT is radionecrosis (RN). The objective of this study was to analyze the occurrence of RN per BM and per patient.

MATERIAL AND METHODS

Between 2010 and 2020, data from 184 patients treated for 915 BMs by two to six SRT sessions for local or distant brain recurrence without previous or intercurrent WBRT were retrospectively reviewed. RN was examined on trimestral follow-up MRI and potentially confirmed by surgery or nuclear medicine. For each BM and SRT session plan, summation V_12Gy, V_14Gy, V_21Gy and V_23Gy isodoses were collected. Volumes of intersections were created between the 12Gy isodose at the first SRT and the 18Gy isodose of the following SRT (V_18-12Gy).

RESULTS

At the end of follow-up, 23.0% of patients presented RN, and 6.3% of BM presented RN. Median follow-up of BM was 13.3 months (95%CI 18.3-20.8). The median interval between BM irradiation and RN was 8.7 months (95% CI 9.2-14.7). Six-, 12- and 24-month RN-free survival rates per BM were 75%, 54% and 29%, respectively. The median RN-free survival per patient was 15.3 months (95% CI 13.6-18.1). In multivariate analysis, the occurrence of RN per BM was statistically associated with local reirradiation (P<0.001) and the number of SRTs (P<0.001). In univariate analysis, the occurrence of RN per patient was statistically associated with the sum of all V_18-12Gy (P=0.02). No statistical association was found in multivariate analysis. A sum of all V_18-12Gy of less than 1.5ml was associated with a 14.6% risk of RN, compared with 35.6% when the sum of all V_18-12Gy was superior to 1.5ml. The sum of all V_18-12Gy larger than 1.5ml was associated with a 74% specificity and 53% sensitivity of RN (P<0.001).

CONCLUSION

Based on these results, a small number of BMs show RN during repeated SRT for local or distant recurrent BMs. Local reirradiation was the most predictive factor of brain RN. A V_18-12Gy larger than 7.6ml in the case of local reirradiation or larger than 1.5ml in proximity reirradiation were prognostic factors of RN. The more BM patients need radiation therapy, and the longer they survive after irradiation, the higher their individual risk of developing RN.

Wild bee larval food composition in five European cities

Urbanization poses threats and opportunities for the biodiversity of wild bees. At the same time, cities can harbour diverse wild bee assemblages, partily due to the unique plant assemblages providing resources. While bee dietary preferences have been investigated in different studies, bee dietary studies have been done mostly in non urban ecosystems and data based on plant visitation observations or palynological techniques. This data set describes the larval food preferences four wild bee species (i.e. Chelostoma florisomne, Hylaeus communis, Osmica bicornis and Osmia cornuta) common in urban areas in five different European cities (i.e. Antwerp, Paris, Poznan, Tartu and Zurich). In addition, this data set also describes the larval food preferences from individuals of three wild bee genera (i.e. Chelostoma sp., Hylaeus sp, and Osmia sp.) that cloud not be identified to the species level. This data results from a European-level study aimed at understanding the effects of urbanization on biodiversity across different cities and cityscapes, and a Swiss project aimed at understanding the effects of urban ecosystems in wild bee feeding behaviour. Wild bees were sampled using standardized trap-nests in 80 sites (32 in Zurich and 12 in each of the remaining cities), selected following a double gradient of available habitat at local and landscape scales. Larval pollen was obtained from the bee nests and identified using DNA metabarcoding. The data provide the plant composition at species or genus level preferred by each bee. This unique data can be used for a wide array of research questions, including urban ecology (e.g. diversity of food sources along urban gradients), bee ecology (characterisation of bee feeding preferences) or comparative studies on urban evolution of behavioural traits between urban and non-urban sites. In addition, the data can be applied for informing urban planning and conservation strategies, particularly concerning the flower resources (e.g. importance of exotic species and thus management activities). This data set can be freely used for non-commercial purposes and this data paper should be cited if you use the data; we request collaboration with the data set contact person be considered if this data set represents an important part of the data analyzed in a study.

Is Substantial Lymphovascular Space Invasion Prognostic for Clinical Outcomes in Type II Endometrial Cancer?

AIMS

Substantial lymphovascular space invasion (LVSI) compared with none or focal LVSI is predictive of lymph node involvement and worse clinical outcomes in endometrioid-type endometrial carcinoma. We aimed to quantify the incidence of substantial LVSI in type II (clear cell and serous) endometrial cancer and correlate the extent of LVSI with clinical outcomes.

MATERIALS AND METHODS

A retrospective review was conducted on type II endometrial cancer patients who underwent surgical management from July 2017 to December 2019 using the three-tier LVSI scoring system. Binary logistic regression and Cox regression were used to analyse predictors of lymph node involvement or survival outcomes, respectively. The Kaplan-Meier method and Log-rank test were used to analyse differences in locoregional disease-free survival (LR-DFS), distant metastasis disease-free survival (DM-DFS) and overall survival between patients with substantial versus none/focal LVSI.

RESULTS

In 79 patients with type II endometrial carcinoma, no LVSI, focal LVSI and substantial LVSI was present in 48.1%, 15.2% and 36.7% of patients, respectively. Lymph nodes were involved in 0.0% with no LVSI, 20.0% with focal LVSI and 60.0% with substantial LVSI (P < 0.001). The median follow-up was 22.2 months. In patients with none/focal versus substantial LVSI, the 2-year LR-DFS and DM-DFS rates were 91.5% versus 71.4% (P = 0.01) and 90.2% versus 63.8% (P = 0.005), respectively. On univariate analysis, myometrial invasion ≥50%, tumour size ≥3.6 cm, substantial versus none/focal LVSI, lymph node involvement and omission of adjuvant radiotherapy were significant predictors for worse LR-DFS and DM-DFS (P < 0.05).

DISCUSSION

Substantial LVSI has a high incidence in type II pathology at our institution and predicts for lymph node involvement and worse clinical outcomes.

Measuring Early Germ-Layer Specification Bias in Human Pluripotent Stem Cells

Human pluripotent stem cells have a wide variety of potential applications, ranging from clinical translation to in vitro disease modeling. However, there is significant variation in the potential of individual cell lines to differentiate towards each of the three germ layers as a result of (epi)genetic background, culture conditions, and other factors. We describe here in detail a methodology to evaluate this bias using short directed differentiation towards neuroectoderm, mesendoderm, and definitive endoderm in combination with quantification by RT-qPCR and immunofluorescent stains.

Critical links between biodiversity and health in wild bee conservation

Wild bee populations are declining due to human activities, such as land use change, which strongly affect the composition and diversity of available plants and food sources. The chemical composition of food (i.e., nutrition) in turn determines the health, resilience, and fitness of bees. For pollinators, however, the term 'health' is recent and is subject to debate, as is the interaction between nutrition and wild bee health. We define bee health as a multidimensional concept in a novel integrative framework linking bee biological traits (physiology, stoichiometry, and disease) and environmental factors (floral diversity and nutritional landscapes). Linking information on tolerated nutritional niches and health in different bee species will allow us to better predict their distribution and responses to environmental change, and thus support wild pollinator conservation.

The Impact of Acquired Genetic Abnormalities on the Clinical Translation of Human Pluripotent Stem Cells

Human pluripotent stem cells (hPSC) are known to acquire chromosomal abnormalities, which range from point mutations to large copy number changes, including full chromosome aneuploidy. These aberrations have a wide-ranging influence on the state of cells, in both the undifferentiated and differentiated state. Currently, very little is known on how these abnormalities will impact the clinical translation of hPSC, and particularly their potential to prime cells for oncogenic transformation. A further complication is that many of these abnormalities exist in a mosaic state in culture, which complicates their detection with conventional karyotyping methods. In this review we discuss current knowledge on how these aberrations influence the cell state and how this may impact the future of research and the cells’ clinical potential.

Preservation methods of honey bee-collected pollen are not a source of bias in ITS2 metabarcoding

Pollen metabarcoding is emerging as a powerful tool for ecological research and offers unprecedented scale in citizen science projects for environmental monitoring via honey bees. Biases in metabarcoding can be introduced at any stage of sample processing and preservation is at the forefront of the pipeline. While in metabarcoding studies pollen has been preserved at - 20 °C (FRZ), this is not the best method for citizen scientists. Herein, we compared this method with ethanol (EtOH), silica gel (SG) and room temperature (RT) for preservation of pollen collected from hives in Austria and Denmark. After ~ 4 months of storage, DNAs were extracted with a food kit, and their quality and concentration measured. Most DNA extracts exhibited 260/280 absorbance ratios close to the optimal 1.8, with RT samples from Austria performing slightly worse than FRZ and SG samples (P < 0.027). Statistical differences were also detected for DNA concentration, with EtOH samples producing lower yields than RT and FRZ samples in both countries and SG in Austria (P < 0.042). Yet, qualitative and quantitative assessments of floral composition obtained using high-throughput sequencing with the ITS2 barcode gave non-significant effects of preservation methods on richness, relative abundance and Shannon diversity, in both countries. While freezing and ethanol are commonly employed for archiving tissue for molecular applications, desiccation is cheaper and easier to use regarding both storage and transportation. Since SG is less dependent on ambient humidity and less prone to contamination than RT, we recommend SG for preserving pollen for metabarcoding. SG is straightforward for laymen to use and hence robust for widespread application in citizen science studies.

Sex differences in cardiovascular research

Background

Women are underrepresented in cardiovascular publications. We sought to investigate sex-specific differences in cardiovascular research over the last decade.

Methods and results

All 387,463 cardiovascular publications between 2010–2019 were retrieved from Web-of-Science and analyzed regarding the authors' sex, the average impact factor (IF), the number of citations, co-authors per article, and international collaborations. The number of cardiovascular research articles increased between 2010–2019 from 19,960 to 29,604 articles per year. The number of articles written by female first authors increased by 48.3% (6434 articles in 2010 and 11,343 articles in 2019) and by 35.0% for male first authors (13,526 articles in 2010 and 18,261 articles in 2019). The last/senior author was more likely to be female in articles with female first authors compared with male first authors (28.2% vs. 14.1%; odds ratio 2.48, 95% confidence interval 2.43–2.53, p&lt;0.001). The average IF for articles by female first authors was lower compared to male (3.1±3.8 vs. 3.5±4.9, p&lt;0.001). Likewise, the H-Index was lower for female than male first authors (1.07±0.74 vs. 1.25±0.98, p&lt;0.001), as was the number of citations per articles (14.0±31.1 vs. 18.0±68.8 citations, p&lt;0.001). Female first authors had fewer co-authors per article than their male peers (7.4±19.6 vs. 8.2±35.2; p&lt;0.001) and were less represented in articles with &gt;15 co-authors (3,623 articles by female and 8,941 by male first authors; ratio female to male 0.41). Scientific advancement as the ratio between female to male first authorships was highest in publications from Latin America (ratio 0.92) and lowest in Asia (ratio 0.40). Female authorship articles reached the highest IF in North America (average IF 3.7), the lowest Africa (average IF 1.8).

Conclusions

Publications in cardiovascular research have increased over the last decade, particularly by female authors. Female researchers are cited less often compared with their male peers and publish with fewer co-authors. The IF remains lower for articles by female researchers. Efforts to further increase women-led research activities are needed

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Cardiac SocietyGerman Research Foundation (DFG)