Expression of Recombinant Potato leafroll virus Structural and Non‐structural Proteins for Antibody Production

Vector pMPM‐A4Ω and vectors pQE‐30 and pET‐45b(+) containing the 6x His‐tag sequence were used for expression of Potato leafroll virus (PLRV) structural and non‐structural proteins in Escherichia coli. Coat protein (CP) and RNA‐dependent RNA polymerase (RdRp)–fragments RdRp_43‐616 and RdRp_304‐537 were chosen for expression. A high level of CP and RdRp_304‐537 was obtained only in an expression system using pET‐45b(+) vector and E. coli Rosetta‐gami 2(DE3) cells. After purification, the His‐tagged PLRV proteins were used for immunization of rabbits.     

Comparison of carbonate C and O stable isotope records across the Jurassic/Cretaceous boundary in the Tethyan and Boreal Realms

Carbon and oxygen stable isotope records were compared for Jurassic/Cretaceous (J/K) boundary sections located in the Tethyan Realm (Brodno, Western Slovakia, and Puerto Escaño, Southern Spain; bulk limestones), and the Boreal Realm (Nordvik Peninsula, Northern Siberia, belemnites). Since a detailed biostratigraphic correlation of these Tethyan and Boreal sections is impossible due to different faunal assemblages, correlation of the isotope records was based on paleomagnetic data. This novel approach can improve our understanding of the synchroneity of individual isotope excursions in sections where detailed biostratigraphic correlation is impossible. No significant excursions in either the carbon or oxygen isotope records to be used for future Boreal/Tethyan correlations were found around the J/K boundary (the upper Tithonian and lower Berriasian; magnetozones M20n to M18n) in the studied sections. At the Nordvik section, where a much longer section (middle Oxfordian–basal Boreal Berriasian) was documented, the transition from the middle Oxfordian to the Kimmeridgian and further to the Volgian is characterized by a decrease in belemnite δ¹⁸O values (from δ¹⁸O values up to + 1.6‰ vs. V-PDB in the Oxfordian to values between + 0.3 and ? 0.8‰ in the late Volgian and earliest Boreal Berriasian). This trend, which has previously been reported from the Russian Platform and Tethyan Realm sections, corresponds either to gradual warming or a decrease in seawater δ¹⁸O. Supposing that the oxygen isotope compositions of seawater in the Arctic/Boreal and Tethyan Realms were similar, then the differences between oxygen isotope datasets for these records indicate differences in temperature. The Boreal/Tethyan temperature difference of 7–9 °C in the middle and late Oxfordian decreases towards the J/K boundary, indicating a significant decrease in latitudinal climatic gradients during the Late Jurassic. Two positive carbon isotope excursions recorded for the middle Oxfordian and upper Kimmeridgian in the Nordvik section can be correlated with a similar excursion described earlier for the Russian Platform. Minor influence of biofractionation at the carbon isotopes, and the influence of migration of belemnites to deeper, slightly cooler water at the oxygen isotopes, cannot be excluded for the obtained belemnite data.     

The fine-scale utilization of forest edges by mammalian mesopredators related to patch size and conservation issues in Central European farmland

The marked negative impact of habitat fragmentation and the edge effect on many populations of bird species is a recent major concern in conservation biology. Here, we focus on the edge effect in different sized forest patches in Central European farmland. In particular, we tested whether the distribution of mammalian mesopredators is related to fragment size and distance to habitat edge, and whether the contribution of these factors is additive or interactive. To assess fine-scale utilization of forest edges, we established transects of four scent stations at different distances from forest edges into the interior (0, 25, 50, 100 m) in 146 forest fragments of variable patch size (3.2–5099.6 ha) from May to June, 2008–2009. This large sample size allowed us to perform detailed analyses separately for all detected species. Our findings confirm that mammalian mesopredators strongly prefer habitat edges and small forest fragments. The probability of occurrence tended to decrease with increasing distance from the edge for all seven carnivore species detected. The carnivores’ occurrence was also negatively correlated with forest fragment area. All detected species tended to prefer small fragments, with the exception of the Eurasian badger (showing the reverse but non-significant pattern) and the red fox (no effect of fragment size). In addition, the non-significant interaction between fragment size and distance to edge suggests that both of these factors contribute independently and additively to mesopredator-mediated effects on biota in a fragmented landscape.     

Does Threat to the Nest Affect Incubation Rhythm in a Small Passerine?

Nest predation is a crucial factor influencing breeding success in birds. One possible way to protect nests is to modify parental activity in the vicinity of the nest. Here, we provide experimental evidence for an adjustment of incubation pattern during periods when there is an increased risk of nest predation in a small passerine. We compared the behaviour of incubating meadow pipit (Anthus pratensis) females during presentations of stuffed dummies of a nest predator (the magpie Pica pica) and a harmless intruder (the crossbill Loxia curvirostra) and during an undisturbed control incubation period. Females significantly decreased their activity in the presence of the nest predator. Specifically, after being flushed out, they returned to the nest later and moved to and from the nest less than when the harmless intruder was present. These results document the ability of birds to assess the nest predation risk and adjust their appropriate incubation strategy.     

Factors Affecting Sleep/vigilance Behaviour in Incubating Mallards

Vigilance is a behavioural tactic that allows individuals to control their surroundings and to assess predation risk. In contrast, sleep is unique behavioural state with widely hypothesized restorative and energy‐saving functions, but reducing attentiveness and increasing susceptibility to predation. Sleeping birds resolve this conflict by interrupting sleep with short periods of eye opening (termed ‘scans’) during vigilant sleep. Miscellaneous environmental factors and sleeping postures may affect the perception of risk and corresponding vigilance level. Here, we investigated the influence of nest vegetation concealment, time of day and sleeping postures on the sleep/vigilance trade‐off in incubating Mallards (Anas platyrhynchos). We found that incubating females increased their vigilance with increasing nest vegetation cover facing the vigilant eye during both the day and the night periods; however, mean nest vegetation concealment did not affect female vigilance. Females also reduced their total vigilance along with scan frequency during the night period, while displaying the opposite pattern during the daylight. The rest‐sleeping position was preferred more during the night compared with the daylight period, and females were more vigilant in this position at night. Our data show that the nest vegetation concealment regardless of visual abilities during different light conditions, time of day and sleeping posture play an underlying role in antipredator vigilance during sleep in this cryptic ground‐nesting bird.     

Evaluating the stability of the classification of community data

We propose a method for a posteriori evaluation of classification stability which compares the classification of sites in the original data set (a matrix of species by sites) with classifications of subsets of its sites created by without‐replacement bootstrap resampling. Site assignments to clusters of the original classification and to clusters of the classification of each subset are compared using Goodman‐Kruskal's lambda index. Many resampled subsets are classified and the mean of lambda values calculated for the classifications of these subsets is used as an estimation of classification stability. Furthermore, the mean of the lambda values based on different resampled subsets, calculated for each site of the data set separately, can be used as a measure of the influence of particular sites on classification stability. This method was tested on several artificial data sets classified by commonly used clustering methods and on a real data set of forest vegetation plots. Its strength lies in the ability to distinguish classifications which reflect robust patterns of community differentiation from unstable classifications of more continuous patterns. In addition, it can identify sites within each cluster which have a transitional species composition with respect to other clusters.     

Lasting the distance: The survival of alien birds shipped to New Zealand in the 19th century

Invasive alien species are a major threat to biodiversity and human activities, providing a strong incentive to understand the processes by which alien invasion occurs. While it is important to understand the determinants of success at each of several invasion stages—transport, introduction, establishment, and spread—few studies have explored the first of these stages. Here, we quantify and analyze variation in the success of individual animals in surviving the transport stage, based on shipping records of European passerines destined for New Zealand. We mined the original documents of Acclimatisation Societies, established in New Zealand for the purpose of introducing supposedly beneficial alien species, in combination with recently digitized newspaper archives, to produce a unique dataset of 122 ships that carried passerines from Europe to New Zealand between 1850 and 1885. For 37 of these shipments, data on the survival of individual species were available. Using generalized linear mixed models, we explored how survival was related to characteristics of the shipments and the species. We show that species differed greatly in their survival, but none of the tested traits accounted for these differences. Yet, survival increased over time, which mirrors the switch from early haphazard shipments to larger organized shipments. Our results imply that it was the quality of care received by the birds that most affected success at this stage of the invasion process.     

Leaving uncut refuges during meadow harvesting increases the functional diversity of Orthoptera

In the past, insect species richness was high in Central European seminatural grasslands, which were characterized by low‐intensity land use. Currently, however, the hay in most of these grasslands is mechanically harvested, which negatively impacts insect biodiversity. One way to reduce this negative effect is to leave unmown patches as refuges. In the current research we evaluated the short‐term effects of leaving an unmown patch on the taxonomic and functional diversity of the Orthoptera assemblage in a meadow. We found that orthopteran species richness and abundance were significantly reduced by mowing, whether or not a patch was left uncut. In contrast, functional evenness, indicating distribution of species abundances in a niche space, was reduced by mowing only if the plot lacked an uncut refuge. Functional richness, indicating the amount of niche space occupied by species, was elevated if the plot had an uncut refuge. Larger species were negatively affected by mowing, while habitat specialists, mobile species and soil‐ovipositing species benefitted from it. We infer that the presence of an uncut patch increased the diversity of habitats available to orthopterans and maintained even distribution of species among niche space. In summary, leaving an unmown refuge in grasslands could increase the functional diversity of orthopterans, even if it does not preserve taxonomic diversity.     

Transgelin Silencing Induces Different Processes in Different Breast Cancer Cell Lines

Transgelin is a protein reported to be a marker of several cancers. However, previous studies have shown both up‐ and down‐regulation of transgelin in tumors when compared with non‐tumor tissues and the mechanisms whereby transgelin may affect the development of cancer remain largely unknown. Transgelin is especially abundant in smooth muscle cells and is associated with actin stress fibers. These contractile structures participate in cell motility, adhesion, and the maintenance of cell morphology. Here, the role of transgelin in breast cancer is focused on. Initially, the effects of transgelin on cell migration of the breast cancer cell lines, BT 549 and PMC 42, is studied. Interestingly, transgelin silencing increased the migration of PMC 42 cells, but decreased the migration of BT 549 cells. To clarify these contradictory results, the changes in protein abundances after transgelin silencing in these two cell lines are analyzed using quantitative proteomics. The results confirmed the role of transgelin in the migration of BT 549 cells and suggest the involvement of transgelin in apoptosis and small molecule biochemistry in PMC 42 cells. The context‐dependent function of transgelin reflects the different molecular backgrounds of these cell lines, which differ in karyotypes, mutation statuses, and proteome profiles.