A Differential Role of Volatiles from Conspecific and Heterospecific Competitors in the Selection of Oviposition Sites by the Aphidophagous Hoverfly Sphaerophoria rueppellii

The selection of oviposition sites by syrphids and other aphidophagous insects is influenced by the presence of con- and heterospecific competitors. Chemical cues play a role in this selection process, some of them being volatile semiochemicals. Yet, little is known about the identity and specificity of chemical signals that are involved in the searching behavior of these predators. In this study, we used olfactometer bioassays to explore the olfactory responses of gravid females and larvae of the syrphid Sphaerophoria rueppellii, focussing on volatiles from conspecific immature stages, as well as odors from immature stages of the competing coccinellid Adalia bipunctata. In addition, a multiple-choice oviposition experiment was conducted to study if females respond differently when they can also sense their competitors through visual or tactile cues. Results showed that volatiles from plants and aphids did not affect the behavior of second-instars, whereas adult females strongly preferred odors from aphid colonies without competitors. Odors from conspecific immature stages had a repellent effect on S. rueppellii adult females, whereas their choices were not affected by volatiles coming from immature heterospecific A. bipunctata. The results imply that the syrphid uses odors to avoid sites that are already occupied by conspecifics. They did not avoid the odor of the heterospecific competitor, although in close vicinity they were found to avoid laying eggs on leaves that had traces of the coccinellid. Apparently adult syrphids do not rely greatly on volatile semiochemicals to detect the coccinellid, but rather use other stimuli at close range (e. g., visual or non-volatile compounds) to avoid this competitor.

The human IgG anti-carbohydrate repertoire exhibits a universal architecture and contains specificity for microbial attachment sites.

Despite the paradigm that carbohydrates are T cell-independent antigens, isotype-switched glycan-specific immunoglobulin G (IgG) antibodies and polysaccharide-specific T cells are found in humans. We used a systems-level approach combined with glycan array technology to decipher the repertoire of carbohydrate-specific IgG antibodies in intravenous and subcutaneous immunoglobulin preparations. A strikingly universal architecture of this repertoire with modular organization among different donor populations revealed an association between immunogenicity or tolerance and particular structural features of glycans. Antibodies were identified with specificity not only for microbial antigens but also for a broad spectrum of host glycans that serve as attachment sites for viral and bacterial pathogens and/or exotoxins. Tumor-associated carbohydrate antigens were differentially detected by IgG antibodies, whereas non-IgG2 reactivity was predominantly absent. Our study highlights the power of systems biology approaches to analyze immune responses and reveals potential glycan antigen determinants that are relevant to vaccine design, diagnostic assays, and antibody-based therapies.

Ignoring heterozygous sites biases phylogenomic estimates of divergence times: implications for the evolutionary history of Microtus voles

Phylogenetic reconstruction of the evolutionary history of closely related organisms may be difficult because of the presence of unsorted lineages and of a relatively high proportion of heterozygous sites that are usually not handled well by phylogenetic programs. Genomic data may provide enough fixed polymorphisms to resolve phylogenetic trees, but the diploid nature of sequence data remains analytically challenging. Here, we performed a phylogenomic reconstruction of the evolutionary history of the common vole (Microtus arvalis) with a focus on the influence of heterozygosity on the estimation of intraspecific divergence times. We used genome-wide sequence information from 15 voles distributed across the European range. We provide a novel approach to integrate heterozygous information in existing phylogenetic programs by repeated random haplotype sampling from sequences with multiple unphased heterozygous sites. We evaluated the impact of the use of full, partial, or no heterozygous information for tree reconstructions on divergence time estimates. All results consistently showed four deep and strongly supported evolutionary lineages in the vole data. These lineages undergoing divergence processes split only at the end or after the last glacial maximum based on calibration with radiocarbon-dated paleontological material. However, the incorporation of information from heterozygous sites had a significant impact on absolute and relative branch length estimations. Ignoring heterozygous information led to an overestimation of divergence times between the evolutionary lineages of M. arvalis. We conclude that the exclusion of heterozygous sites from evolutionary analyses may cause biased and misleading divergence time estimates in closely related taxa.

Sensitivity of splice sites to antisense oligonucleotides in vivo.

A series of HeLa cell lines which stably express beta-globin pre-mRNAs carrying point mutations at nt 654, 705, or 745 of intron 2 has been developed. The mutations generate aberrant 5' splice sites and activate a common 3' cryptic splice site upstream leading to aberrantly spliced beta-globin mRNA. Antisense oligonucleotides, which in vivo blocked aberrant splice sites and restored correct splicing of the pre-mRNA, revealed major differences in the sensitivity of these sites to antisense probes. Although the targeted pre-mRNAs differed only by single point mutations, the effective concentrations of the oligonucleotides required for correction of splicing varied up to 750-fold. The differences among the aberrant 5' splice sites affected sensitivity of both the 5' and 3' splice sites; in particular, sensitivity of both splice sites was severely reduced by modification of the aberrant 5' splice sites to the consensus sequence. These results suggest large differences in splicing of very similar pre-mRNAs in vivo. They also indicate that antisense oligonucleotides may provide useful tools for studying the interactions of splicing machinery with pre-mRNA.

Research Note—Why Following Friends Can Hurt You: An Exploratory Investigation of the Effects of Envy on Social Networking Sites among College-Age Users

Research findings on how participation in social networking sites (SNSs) affects users’ subjective well-being are equivocal. Some studies suggest a positive impact of SNSs on users’ life satisfaction and mood, whereas others report undesirable consequences such as depressive symptoms and anxiety. However, whereas the factors behind the positive effects have received significant scholarly attention, little is known about the mechanisms that underlie the unfavorable consequences. To fill this gap, this study uses social comparison theory and the responses of 1,193 college-age Facebook users to investigate the role of envy in the SNS context as a potential contributor to those undesirable outcomes. Arising in response to social information consumption, envy is shown to be associated with reduced cognitive and affective well-being as well as increased reactive self-enhancement. These preliminary findings contribute to the growing body of information systems research investigating the dysfunctional consequences of information technology adoption in general and social media participation in particular.

Material culture entanglements of early wetland sites in central Switzerland (4300-3850 BC)

In central Switzerland, the earliest wetland settlements with definitely attested finds and features date into the second half of the 5th millennium BC. Combining the information they have yielded with that from dryland sites, we can construct a detailed picture of material culture at the turn of the 5th to the 4th millennium. On this basis, the definition of clearly delimited archaeological cultures seems questionable, not only from a theoretical point of view. Similiarities and differences in the pottery show small-scale regional units defined via vessel forms as well as stylistic and technological aspects. Yet there are also inter-regional connections: roundbased vessels with opposing handles are typical for Lake Zurich, central and western Switzerland, the Valais and the central Rhône valley. In turn, ‘foreign‘ types such as shoulder-band beakers indicate regular connections between groups living in central Switzerland and those in Alsace and southern Germany. Are these beakers ‘imports‘ or locally produced items (‘imitations‘) indicating the adoption of ‘foreign‘ vessel types and concepts? This and similar material culture phenomena result in a picture of many material entanglements and problematise the kinds of relationships and mobility which might have existed. Our paper addresses these questions and discusses how and whether these interwoven connections changed in the early 4th millennium.

Soft Tissue Alterations in Esthetic Postextraction Sites: A 3-Dimensional Analysis.

Dimensional alterations of the facial soft and bone tissues following tooth extraction in the esthetic zone play an essential role to achieve successful outcomes in implant therapy. This prospective study is the first to investigate the interplay between the soft tissue dimensions and the underlying bone anatomy during an 8-wk healing period. The analysis is based on sequential 3-dimensional digital surface model superimpositions of the soft and bone tissues using digital impressions and cone beam computed tomography during an 8-wk healing period. Soft tissue thickness in thin and thick bone phenotypes at extraction was similar, averaging 0.7 mm and 0.8 mm, respectively. Interestingly, thin bone phenotypes revealed a 7-fold increase in soft tissue thickness after an 8-wk healing period, whereas in thick bone phenotypes, the soft tissue dimensions remained unchanged. The observed spontaneous soft tissue thickening in thin bone phenotypes resulted in a vertical soft tissue loss of only 1.6 mm, which concealed the underlying vertical bone resorption of 7.5 mm. Because of spontaneous soft tissue thickening, no significant differences were detected in the total tissue loss between thin and thick bone phenotypes at 2, 4, 6, and 8 wk. More than 51% of these dimensional alterations occurred within 2 wk of healing. Even though the observed spontaneous soft tissue thickening in thin bone phenotypes following tooth extraction conceals the pronounced underlying bone resorption pattern by masking the true bone deficiency, spontaneous soft tissue thickening offers advantages for subsequent bone regeneration and implant therapies in sites with high esthetic demand (Clinicaltrials.gov NCT02403700).

Phosphatidylethanolamine and phosphatidylcholine biosynthesis by the Kennedy pathway occurs at different sites in Trypanosoma brucei

Phosphatidylethanolamine (PE) and phosphatidylcholine (PC) are among the most abundant phospholipids in biological membranes. In many eukaryotes, the CDP-ethanolamine and CDP-choline branches of the Kennedy pathway represent major and often essential routes for the production of PE and PC, with ethanolamine and choline/ethanolamine phosphotransferases (EPT and CEPT, respectively) catalysing the last reactions in the respective pathways. Although the site of PE and PC synthesis is commonly known to be the endoplasmic reticulum (ER), detailed information on the localization of the different phosphotransferases is lacking. In the unicellular parasite, Trypanosoma brucei, both branches of the Kennedy pathway are essential for cell growth in culture. We have previously reported that T. brucei EPT (TbEPT) catalyses the production of ether-type PE molecular species while T. brucei CEPT (TbCEPT) synthesizes diacyl-type PE and PC molecular species. We now show that the two enzymes localize to different sub-compartments of the ER. By expressing a series of tagged forms of the two enzymes in T. brucei parasites, in combination with sub-cellular fractionation and enzyme activity measurements, TbEPT was found exclusively in the perinuclear ER, a distinct area located close to but distinct from the nuclear membrane. In contrast, TbCEPT was detected in the bulk ER.

Conserved sequences and cell-specific DNase I hypersensitive sites upstream from the co-ordinately expressed alpha I- and alpha II-globin genes of Xenopus laevis

The globin gene family of Xenopus laevis comprises pairs of closely related genes that are arranged in two clusters, each pair of genes being co-ordinately and stage-specifically expressed. To get information on putative regulatory elements, we compared the DNA sequences and the chromatin conformation 5' to the co-ordinately expressed adult alpha-globin genes. Sequence analysis revealed a relatively conserved region from the cap site up to position -289, and further upstream seven distinct boxes of homology, separated by more diverged sequences or deletions/insertions. The homology boxes comprise 22 to 194 base-pairs showing 78 to 95% homology. Analysis of chromatin conformation showed that DNase I preferentially cuts the upstream region of both genes at similar positions, 5' to the T-A-T-A and the C-C-A-A-T boxes, only in chromatin of adult erythroblasts and erythrocytes, where adult globin genes are expressed, but not in chromatin of adult liver cells or larval erythrocytes, where these genes are silent. This suggests that cell- and stage-specific activation of these genes coincides with specific changes in chromatin conformation within the proximal upstream region. No difference was found in the nucleotide sequence within the DNase I hypersensitive region proximal to the adult alpha 1-globin gene in DNA from embryonic cells, in which this gene is inactive, and adult erythrocytes, expressing this gene.

Trends of mean and extreme temperature indices since 1874 at low-elevation sites in the Southern Alps

We describe the recovery of three daily meteorological records for the southern Alps (Domodossola, Riva del Garda, and Rovereto), all starting in the second half of the nineteenth century. We use these new data, along with additional records, to study regional changes in the mean temperature and extreme indices of heat waves and cold spells frequency and duration over the period 1874–2015. The records are homogenized using subdaily cloud cover observations as a constraint for the statistical model, an approach that has never been applied before in the literature. A case study based on a record of parallel observations between a traditional meteorological window and a modern screen shows that the use of cloud cover can reduce the root-mean-square error of the homogenization by up to 30% in comparison to an unaided statistical correction. We find that mean temperature in the southern Alps has increased by 1.4°C per century over the analyzed period, with larger increases in daily minimum temperatures than maximum temperatures. The number of hot days in summer has more than tripled, and a similar increase is observed in duration of heat waves. Cold days in winter have dropped at a similar rate. These trends are mainly caused by climate change over the last few decades.

Functional sites involved in modulation of the GABAA receptor channel by the intravenous anesthetics propofol, etomidate and pentobarbital.

GABAA receptors are the major inhibitory neurotransmitter receptors in the brain and are the target for many clinically important drugs. Among the many modulatory compounds are also the intravenous anesthetics propofol and etomidate, and barbiturates. The mechanism of receptor modulation by these compounds is of mayor relevance. The site of action of these compounds has been located to subunit interfaces in the intra-membrane region of the receptor. In α1β2γ2 GABAA receptors there are five such interfaces, two β+/α- and one each of α+/β-, α+/γ- and γ+/β- subunit interfaces. We have used reporter mutations located in the second trans-membrane region in different subunits to probe the effects of changes at these subunit interfaces on modulation by propofol, etomidate and pentobarbital. We provide evidence for the fact that each of these compounds either modulates through a different set of subunit interfaces or through the same set of subunit interfaces to a different degree. As a GABAA receptor pentamer harbors two β+/α- subunit interfaces, we used concatenated receptors to dissect the contribution of individual interfaces and show that only one of these interfaces is important for receptor modulation by etomidate.

New Sites, New Challenges? Ethical and Methodological Questions in the Context of Research on Migration Exclusion

The challenges of research ethics and methodologies have been reflected on extensively, but – aside from the context of feminist methodologies – less so in relation to research on particular migration sites such as in transit, detention centres, at the borders or within migration administration. First attempts in this direction have been made (Düvell et al. 2010, Fresia et al. 2005, Riedner 2014, van Liempt/Bilger2009), however, more reflection and theorization is needed, considering the contested nature of these temporal and volatile sites. In this workshop, we thus aim at examining methodological as well as ethical questions that arise during field work: We attempt to reflect the power relations involved in the research process, the ethics of research design, the dissemination of research results, the question of gaining access to and – whenever necessary – staying in contact with our research subjects. How can we negotiate informed consent with subjects whose life is currently marked by transit and insecurity concerning their own future, and who are in an uncertain situation in which substantial information (legal, social, cultural etc.) is likely to be missing? How do we deal with the dilemma of possibly contributing to knowledge production that might facilitate removals and deportations in the future, considering that the reception of the results is not in the hands of the researchers? How do we deal with the anticipated as well as unexpected impacts of our research on social and political practice? Regarding fieldwork in state institutions, how do we negotiate the multiple loyalties we often find ourselves faced with as social researchers, both with the excluded migrants and with the authorities implementing the exclusions – two groupings considered to be opposite to each other (Lavanchy 2013)? Which different roles do researchers need to take on? The aim of our workshop is first and foremost to exchange experiences on fieldwork with others doing qualitative research on related topics and to consider its possible implications – including affective dimensions – for all participants involved in the research process: the migrants, the security staff of detention centres, its social workers, border police and bureaucrats and, last but not least, the researchers themselves. Furthermore, we generally wish to reflect upon the question of how best to conduct research in this contested field, applying an interdisciplinary perspective.