A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus superbubble

The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shockwaves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-gigaelectronvolt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population.     

Tuberculin-active carbohydrate that induces inhibition of macrophage migration but not lymphocyte transformation

A tuberculin carbohydrate fraction, GAE, in sensitized animals induced a delayed type of skin reactivity and inhibited the migration of macrophages but failed to stimulate lymphocyte transformation in vitro. Tuberculin protein-containing fractions were active in each test. These results show that in vitro lymphocyte transformation is not necessarily a corollary of delayed type hypersensitivity.     

Phenology of marine turtle nesting revealed by statistical model of the nesting season

Background  

Marine turtles deposit their eggs on tropical or subtropical beaches during discrete nesting seasons that span several months. The number and distribution of nests laid during a nesting season provide vital information on various aspects of marine turtle ecology and conservation.     

Resistance breeding strategy for Stenocarpella maydis and Fusarium graminearum cob rots in tropical maize

Maize cob rot caused by Fusarium graminearum and Stenocarpella maydis affects grain yield and quality. The objective of this study was to investigate the appropriateness of multiple infection as a selection and breeding strategy for multiple resistance to F. graminearum and S. maydis. Twelve tropical inbred lines with varying resistance to either or both pathogens were mated in a full diallel and the progeny and their parents evaluated for reaction to single or multiple infection. Under multiple inoculation, S. maydis suppressed colonization of cobs by F. graminearum. General combining ability (GCA) effects indicated that inbred WL 118–10 effectively transmitted resistance to both diseases. Hybrids' resistant to S. maydis was also resistant to F. graminearum, but the reverse was not true. Therefore, efficient screening should initially involve screening for S. maydis followed by F. graminearum. Overall, the suppression of F. graminearum by S. maydis shows that multiple infection cannot be used as an appropriate breeding strategy to obtain multiple resistance. The use of F. graminearum and S. maydis separately is, therefore, the best breeding strategy.     

Stability of <Emphasis Type="Italic">Solanum aethiopicum</Emphasis> Shum accessions under varied water deficit stress levels and identification of pertinent breeding traits for resistance to water shortage

Drought is a major constraint to productivity of Solanum aethiopicum ‘Shum’ group due to loss in market and nutrient value of stressed plants. This study evaluated S. aethiopicum Shum group accessions to identify genotypes (G) that excel across moisture deficit stress levels (WLs). A split-plot arrangement composed of four WLs and twenty accessions of S. aethiopicum as main plot and sub-plot factors, respectively, was implemented in a screenhouse, and repeated for two experiments. In each experiment, there was a highly significant effect of at least two WLs on mean performance among at least two accessions for most of the traits at p < 0.05. Further, very highly significant WL × G interactions were obtained for leaf relative water content (LRWC), leaves per plant (LPP) and plant height (PH), and non-significant for leaf blade length and leaf blade width. The order of priority as breeding traits for stability superiority across WLs was suggested as LRWC > PH > LPP. Consequently, based on LRWC, the most superiorly stable accessions were identified as accession 160 followed by accessions 145, 137, 108P and 184G while the least stable ones were identified as accessions 163G, 141, 163 and 108. The broad sense heritability (H ²) for each of the three recommended traits for drought resistance breeding was above 0.9 thus supportive for a good response to selection. Drought stress negatively affected the performance of S. aethiopicum Shum group but the exhibited variation allowed for selection of superiorly stable genotypes.     

Resistance to Ivermectin and the Effect of Topical Eprinomectin on Faecal Egg Counts in St Croix White Hair Sheep

Veterinary Research Communications -     

Activation of stress-responsive mitogen-activated protein kinase pathways in hybrid poplar (Populus trichocarpa x Populus deltoides)

Plant mitogen-activated protein kinase (MAPK) cascades are important amplifying modules that can rapidly transduce stress signals into various appropriate intracellular responses. Several extracellular regulated kinase (ERK)-type MAPKs involved in plant defense signaling have been identified in herbaceous species, but no MAPK cascade has yet been characterized in a tree species. We examined the signal transduction events that lead to activation of defense mechanisms in poplar, a major forest species of economic and ecological importance which is becoming the model tree system for studying stress and adaptation responses. We show that, in poplar cell suspensions and leaf tissue, chitosan, a non-host-specific elicitor, and ozone, a strong oxidant and atmospheric pollutant, induce rapid and transient activation of at least two myelin basic protein (MBP) kinases with apparent molecular masses of 44 and 47 kD. The chitosan- and ozone-activated kinases have characteristics of MAPKs-they preferentially phosphorylate MBP, require tyrosine and threonine phosphorylation to be activated and are specifically recognized by anti-ERK and anti-pERK antibodies. Moreover, activation of these poplar MAPKs by chitosan or ozone is dependent on the production of reactive oxygen species; the influx of calcium ions via membrane channels; the activation of an upstream, membrane-localized component; and a cognate MAPK kinase (MAPKK). These data suggest that biotic and abiotic challenges activate MAPKs in poplar, as in herbaceous species, which then function as a convergence point for pathogen defense and oxidant stress signaling cascades.     

Characteristics of Beet Yellows Closterovirus Transmission to Sugar Beets by Aphis fabae

ABSTRACT Laboratory studies were conducted on the characteristics of beet yellows closterovirus (BYV) transmission to sugar beets by the bean aphid, Aphis fabae. The relative transmission efficiency and the retention, acquisition, and inoculation thresholds were evaluated using clonal aphid colonies. Transmission efficiency was studied between different apterous aphid species (A. fabae and Myzus persicae ), between alate and apterous morphs of A. fabae and M. persicae, and among five clonal aphid colonies of A. fabae. Results indicated, on average, that apterous M. persicae transmitted twice as efficiently as apterous A. fabae (60 and 34%, respectively), apterous forms of A. fabae were equally efficient in transmitting BYV as compared with alate A. fabae (28 and 29%, respectively), and the five clonal colonies of A. fabae ranged from 28 to 40% transmission efficiency with an average of 34%. The maximum retention time recorded for BYV by A. fabae was between 24 and 48 h. After a 1-h acquisition access, a transmission efficiency of 10% was obtained, with maximum transmission efficiency (the highest average percent transmission that is statistically different from all other previous averages) of 39% reached after 6 h of acquisition access. Inoculation thresholds occurred within 1 h, with maximum transmission efficiency (42%) reached after a 6-h inoculation access. Using an electronic monitoring system, a range of 9 to 38 min (20.5 mean) was recorded for the stylets of A. fabae to reach the phloem sieve elements. This was consistent with our threshold of a 20-min acquisition access recorded through direct observation.