Neisseria gonorrhoeae Suppresses Dendritic Cell-Induced, Antigen-Dependent CD4 T Cell Proliferation

Neisseria gonorrhoeae is the second most common sexually transmitted bacterial pathogen worldwide. Diseases associated with N. gonorrhoeae cause localized inflammation of the urethra and cervix. Despite this inflammatory response, infected individuals do not develop protective adaptive immune responses to N. gonorrhoeae. N. gonorrhoeae is a highly adapted pathogen that has acquired multiple mechanisms to evade its host's immune system, including the ability to manipulate multiple immune signaling pathways. N. gonorrhoeae has previously been shown to engage immunosuppressive signaling pathways in B and T lymphocytes. We have now found that N. gonorrhoeae also suppresses adaptive immune responses through effects on antigen presenting cells. Using primary, murine bone marrow-derived dendritic cells and lymphocytes, we show that N. gonorrhoeae-exposed dendritic cells fail to elicit antigen-induced CD4+ T lymphocyte proliferation. N. gonorrhoeae exposure leads to upregulation of a number of secreted and dendritic cell surface proteins with immunosuppressive properties, particularly Interleukin 10 (IL-10) and Programmed Death Ligand 1 (PD-L1). We also show that N. gonorrhoeae is able to inhibit dendritic cell- induced proliferation of human T-cells and that human dendritic cells upregulate similar immunosuppressive molecules. Our data suggest that, in addition to being able to directly influence host lymphocytes, N. gonorrhoeae also suppresses development of adaptive immune responses through interactions with host antigen presenting cells. These findings suggest that gonococcal factors involved in host immune suppression may be useful targets in developing vaccines that induce protective adaptive immune responses to this pathogen.     

Climate change, breeding date and nestling diet: how temperature differentially affects seasonal changes in pied flycatcher diet depending on habitat variation

1.?Climate warming has led to shifts in the seasonal timing of species. These shifts can differ across trophic levels, and as a result, predator phenology can get out of synchrony with prey phenology. This can have major consequences for predators such as population declines owing to low reproductive success. However, such trophic interactions are likely to differ between habitats, resulting in differential susceptibility of populations to increases in spring temperatures. A mismatch between breeding phenology and food abundance might be mitigated by dietary changes, but few studies have investigated this phenomenon. Here, we present data on nestling diets of nine different populations of pied flycatchers Ficedula hypoleuca, across their breeding range. This species has been shown to adjust its breeding phenology to local climate change, but sometimes insufficiently relative to the phenology of their presumed major prey: Lepidoptera larvae. In spring, such larvae have a pronounced peak in oak habitats, but to a much lesser extent in coniferous and other deciduous habitats. 2.?We found strong seasonal declines in the proportions of caterpillars in the diet only for oak habitats, and not for the other forest types. The seasonal decline in oak habitats was most strongly observed in warmer years, indicating that potential mismatches were stronger in warmer years. However, in coniferous and other habitats, no such effect of spring temperature was found. 3.?Chicks reached somewhat higher weights in broods provided with higher proportions of caterpillars, supporting the notion that caterpillars are an important food source and that the temporal match with the caterpillar peak may represent an important component of reproductive success. 4.?We suggest that pied flycatchers breeding in oak habitats have greater need to adjust timing of breeding to rising spring temperatures, because of the strong seasonality in their food. Such between-habitat differences can have important consequences for population dynamics and should be taken into account in studies on phenotypic plasticity and adaptation to climate change.     

Influence of artificial accelerated ageing on the colour stability of paints used for ocular prosthesis iris painting

doi: 10.1111/j.1741‐2358.2010.00473.x
Influence of artificial accelerated ageing on the colour stability of paints used for ocular prosthesis iris painting Objectives: To evaluate the colour stability of paints used for ocular prosthesis iris painting submitted for accelerated artificial ageing (AAA). Materials and methods: Forty specimens of acrylic resin for sclera (16 × 2 mm) were made and separated into eight groups (n = 10) according to the type of paint (gouache, GP; oil, OP; acrylic AP; and composite resin for characterisation, CR) and the colours used (blue/brown). After drying (72 h), a new layer of colourless acrylic resin was applied and the initial colour readout was performed (Spectrophotometer PCB 6807). New colour readouts were performed after AAA, and ΔE was calculated. Results: Statistical analysis (two‐way anova –Bonferroni, p < 0.05) demonstrated that the brown colour showed lower ΔE means in comparison with the blue colour, with statistically significant difference for AP only. Blue colour showed no statistically significant difference with regard to the type of paint used. Brown AP showed lower ΔE than the other groups, with significant difference for OP and GP. GP showed greater alteration in ΔE for the brown colour, being statistically similar only to OP. Conclusions: Only the AP group for brown pigment shows clinically acceptable values for colour stability after AAA.     

Structural and Functional Studies of gpX of Escherichia coli Phage P2 Reveal a Widespread Role for LysM Domains in the Baseplates of Contractile-Tailed Phages

A variety of bacterial pathogenicity determinants, including the type VI secretion system and the virulence cassettes from Photorhabdus and Serratia, share an evolutionary origin with contractile-tailed myophages. The well-characterized Escherichia coli phage P2 provides an excellent system for studies related to these systems, as its protein composition appears to represent the “minimal” myophage tail. In this study, we used nuclear magnetic resonance (NMR) spectroscopy to determine the solution structure of gpX, a 68-residue tail baseplate protein. Although the sequence and structure of gpX are similar to those of LysM domains, which are a large family associated with peptidoglycan binding, we did not detect a peptidoglycan-binding activity for gpX. However, bioinformatic analysis revealed that half of all myophages, including all that possess phage T4-like baseplates, encode a tail protein with a LysM-like domain, emphasizing a widespread role for this domain in baseplate function. While phage P2 gpX comprises only a single LysM domain, many myophages display LysM domain fusions with other tail proteins, such as the DNA circulation protein found in Mu-like phages and gp53 of T4-like phages. Electron microscopy of P2 phage particles with an incorporated gpX-maltose binding protein fusion revealed that gpX is located at the top of the baseplate, near the junction of the baseplate and tail tube. gpW, the orthologue of phage T4 gp25, was also found to localize to this region. A general colocalization of LysM-like domains and gpW homologues in diverse phages is supported by our bioinformatic analysis.     

Sea ice resource selection models for polar bears in the Barents Sea subpopulation

The extent, thickness and age of Arctic sea ice has dramatically declined since the late 1990s, and these trends are predicted to continue. Exploring the habitat use of sea‐ice‐dependent species can help us understand which resources they use and how their distribution responds to a changing environment. The goal of this study was to develop predictive models of the habitat use of an Arctic apex predator. Polar bear Ursus maritimus habitat use in the Barents Sea subpopulation was modelled with seasonal resource selection functions (RSFs) using satellite‐linked telemetry data from 294 collars deployed on female polar bears between 1991 and 2015. Polar bears selected habitat in the Marginal Ice Zone, with a preference for intermediate sea ice concentrations (40–80%). They spent most time in areas with relatively short travel distances to 15 or 75% ice concentration, and during spring and autumn they exhibited a preference for sea ice areas over the continental shelf or over shallower bathymetry). Predictions of the distribution of polar bears in the Barents Sea area can be made for specific sea ice scenarios using these models. Two such predictive distribution maps based on the autumn seasonal model were made and validated against two independent polar bear survey datasets collected in August 2004 and August 2015. The distribution of optimal polar bear habitat has shifted strongly northwards in all seasons of the year during the 25 yr study period.     

Total phenolics,resveratrol content and antioxidant activity of seeds and calluses of pinto peanut (<Emphasis Type="Italic">Arachis pintoi</Emphasis> Krapov. &amp; W.C. Greg.)

Arachis pintoi is a peanut species native to Brazil, which is cultivated in many countries for animal forage, soil cover, landscaping, and recovery of degraded areas. Tissue culture studies for this species have been focused in plant production, whereas works on in vitro secondary metabolites production are scarce. The goal of the present work was to establish callus cultures from different seed explants of A. pintoi, aiming at evaluating the potential for metabolites production and antioxidant activity. Embryonic axes, leaflets, and cotyledons were cultured on solidified MS medium supplemented with picloram (PIC), 2,4-dichlorophenoxyacetic acid (2,4-D), thidiazuron (TDZ) or different combinations of 6-benzyladenine (BA) and α-naphthaleneacetic acid (NAA), under light or dark conditions. Friable calluses with a high biomass (4.3?±?0.3 g FW per callus) were obtained from embryonic leaflets cultured on medium supplemented with 17.6 µM BA plus 5.4 µM NAA, in the dark. Cotyledons and embryonic axes cultured in the presence of 4.4 µM BA combined with 10.8 µM NAA formed heterogeneous calluses with a compact base and a large friable surface. Trans-resveratrol and other stilbenes that were not found in seeds were detected in callus extracts, especially those originated from cotyledons, although these materials showed lower total phenolic contents (TPC) when compared with seeds with and without testa, as well as cotyledons. Extracts from seeds with testa and from calluses derived from cotyledons and embryonic axes showed the highest EC₅₀ in DPPH assays. No correlation between TPC, trans-resveratrol and antioxidant activity was observed.     

The intertidal mudflats of Barr Al Hikman,Sultanate of Oman,as feeding,reproduction and nursery grounds for brachyuran crabs

Brachyuran crabs are an important ecological and economical, yet often unstudied aspect of intertidal mudflats of the Arabian Peninsula. Here we provide baseline density estimates of crabs at the relatively pristine intertidal mudflats of Barr Al Hikman (Sultanate of Oman) and provide information on their life cycle and habitat preference. Across the winters of 2012–2015 crabs were sampled on a grid covering the entire intertidal depth gradient. 29 species were found and average densities varied between 12 and 54 crabs/m². Deposit-feeding and herbivorous crabs were the most abundant species across all winters. Size frequency data and the presence of ovigerous females show that most crabs species reproduce in the intertidal area. P. segnis, the most important crab for local fisheries, was found to use the intertidal area as a nursery ground. We analysed the relationships between the two most abundant crab species, Macrophthalmus sulcatus and Thalamita poissonii and the environmental variables: seagrass density, tidal elevation, median grain size and sediment depth using Random Forest models. The predictive capacity of the models and the relative importance of the environmental predictors varied between years, but crab densities in general were positively associated with seagrass density, presumably because seagrass offers feeding habitat.

     

Divergent movement patterns of adult and juvenile ‘Akohekohe,an endangered Hawaiian Honeycreeper

The movement patterns of birds across a landscape are often highly variable and influenced by complex interactions between individuals and environments. Because periods of movement can be marked by high mortality, especially among juvenile birds, understanding these patterns may be vital for the conservation of many bird species. However, these patterns can be challenging to quantify. We used radio-telemetry to document the movement patterns of ‘Akohekohe (Palmeria dolei), an endangered Hawaiian Honeycreeper endemic to Maui Island, Hawai'i. This species is believed to be highly susceptible to mosquito-transmitted avian malaria (Plasmodium relictum) and only breeds in high-elevation wet forests on the windward side of east Maui (> 1715 m) that serve as mosquito-free refugia. Over a 2-yr period (2013–2014), we used radio-telemetry and resightings of color-banded birds to track the movements of juveniles (N = 11) and adults (N = 24) and quantified home ranges with minimum convex polygons (MCP) and 95% fixed kernels (KHR). Movement patterns and home range sizes of adult and juvenile ‘Akohekohe were significantly different, with adults having relatively small home ranges (0.57 ha, MCP; 1.09 ha, KHR) and juveniles moving greater distances and having larger home ranges (25.02 ha, MCP; 90.56 ha, KHR). Only juveniles moved into lower-elevation forests that can support mosquito populations, at least seasonally. The absence of adults in this transitional malaria zone suggests that adult ‘Akohekohe cannot maintain long-term home ranges in areas with an increased risk of malaria infection. In addition, the long-distance movements of juveniles during the post-fledging, pre-breeding period likely increases their risk of contracting avian malaria and could be a key factor limiting the population of this species.     

Climatic Factors Influencing the Anthrax Outbreak of 2016 in Siberia,Russia

In 2016, an outbreak of anthrax killing thousands of reindeer and affecting dozens of humans occurred on the Yamal peninsula, Northwest Siberia, after 70 years of epidemiological situation without outbreaks. The trigger of the outbreak has been ascribed to the activation of spores due to permafrost thaw that was accelerated during the summer heat wave. The focus of our study is on the dynamics of local environmental factors in connection with the observed anthrax revival. We show that permafrost was thawing rapidly for already 6 years before the outbreak. During 2011–2016, relatively warm years were followed by cold years with a thick snow cover, preventing freezing of the soil. Furthermore, the spread of anthrax was likely intensified by an extremely dry summer of 2016. Concurrent with the long-term decreasing trend in the regional annual precipitation, the rainfall in July 2016 was less than 10% of its 30-year mean value. We conclude that epidemiological situation of anthrax in the previously contaminated Arctic regions requires monitoring of climatic factors such as warming and precipitation extremes.