Identification and validation of genomic regions that affect shoot fly resistance in sorghum [<Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.) Moench]

Shoot fly is one of the most important pests affecting the sorghum production. The identification of quantitative trait loci (QTL) affecting shoot fly resistance enables to understand the underlying genetic mechanisms and genetic basis of complex interactions among the component traits. The aim of the present study was to detect QTL for shoot fly resistance and the associated traits using a population of 210 RILs of the cross 27B (susceptible) × IS2122 (resistant). RIL population was phenotyped in eight environments for shoot fly resistance (deadheart percentage), and in three environments for the component traits, such as glossiness, seedling vigor and trichome density. Linkage map was constructed with 149 marker loci comprising 127 genomic-microsatellite, 21 genic-microsatellite and one morphological marker. QTL analysis was performed by using MQM approach. 25 QTL (five each for leaf glossiness and seedling vigor, 10 for deadhearts, two for adaxial trichome density and three for abaxial trichome density) were detected in individual and across environments. The LOD and R ² (%) values of QTL ranged from 2.44 to 24.1 and 4.3 to 44.1%, respectively. For most of the QTLs, the resistant parent, IS2122 contributed alleles for resistance; while at two QTL regions, the susceptible parent 27B also contributed for resistance traits. Three genomic regions affected multiple traits, suggesting the phenomenon of pleiotrophy or tight linkage. Stable QTL were identified for the traits across different environments, and genetic backgrounds by comparing the QTL in the study with previously reported QTL in sorghum. For majority of the QTLs, possible candidate genes were identified. The QTLs identified will enable marker assisted breeding for shoot fly resistance in sorghum.     

Aprotinin reverses ECG abnormalities induced by Mesobuthus tamulus concanesis, Pocock venom in adult rats

The kinins are implicated in the pathogenesis of scorpion envenomation. Therefore, this study was carried out to examine the involvement of kinins for the ECG abnormalities induced by M. tamulus concanesis, (BT) venom in anaesthetized rats. ECG was recorded using needle electrodes with limb lead II configuration. The PR interval, QRS wave pattern, QRS duration, ST segment and heart rate were examined in saline only, venom alone, and venom after aprotinin groups. BT venom (5 mg/kg) produced heart block of varying degree and ischemia-like changes in ECG wave pattern and the animals died within 30 min after exposure to venom. In aprotinin pretreated animals, the initial ECG changes produced by venom persisted, but after 15 min the ECG pattern improved and the animals survived for the entire period of observation (120 min). The results indicate that aprotinin protected the rats against the cardiotoxicity induced by BT venom.     

Sensitivity of Escherichia albertii, a potential food-borne pathogen, to food preservation treatments

Escherichia albertii is a potential food-borne pathogen because of its documented ability to cause diarrheal disease by producing attachment and effacement lesions. Its tolerances to heat (56 degrees C), acid (pH 3.0), and pressure (500 MPa [5 min]) were evaluated and found to be significantly less than those of wild-type E. coli O157:H7.     

Shoot regeneration from organogenic callus of sweet cherry (<Emphasis Type="Italic">Prunus avium</Emphasis> L.)

A complete method to regenerate adventitious shoots and to produce field-ready trees from three commercial cultivars of sweet cherry (Prunus avium L.) is described. The effects of explant types, pre-treatments, basal media, and phloroglucinol on cultivars Bing, Sweetheart, and Lapins were investigated. Callus developed on four explant types: apical shoot tips isolated from orchard trees; and punctured shoot tips, stem sections, and shoot bases of in vitro shoot cultures. Callus formed on Bing (5%), Sweetheart (8%), and Lapins (20%) shoot tips from orchard trees after 4 months on Murashige and Skoog medium (MS) at half-strength with 3 μM benzylaminopurine (BA). In vitro-derived explants formed callus after 3 months on Woody Plant Medium with 3 μM BA (W3B): punctured shoot tips (Sweetheart and Lapins 67%), stem sections (Sweetheart 31%, Lapins 27%), and shoot bases (Sweetheart 10%, Lapins 17%). Pre-treatment of shoot cultures on MS with 3 μM BA and 1 mM phloroglucinol increased callus formation three-fold on shoot base explants. Callus was separated from parental explants and maintained on MS with 3 μM BA. Shooting was induced by transferring callus to W3B. At 2 weeks, shoot development approached 100%. By 4 weeks, 7–17 shoots had formed on each explant. Callus was maintained for 1.5 years with no decrease in shoot production. Shoots were grafted onto Mazzard (P. avium) rootstocks with 54% (Sweetheart), 57% (Lapins), and 21% (Bing) success after 5 weeks.     

Characterization of antibody-binding sites on proteins: development of a knowledgebase and its applications in improving epitope prediction

Immunoinformatics provides tools for reverse vaccinology and encompasses development of knowledge bases and algorithms for prediction of epitopes. AgAbDb, a database archiving molecular interactions of antigen-antibody co-crystal structures, has been developed (http://202.41.70.51:8080/agabdb2/). Analyses of antibody-binding sites on proteins helped to fine-tune the parameters for prediction of sequential and conformational B-cell epitopes.     

Sensitivity of Escherichia albertii, a Potential Food-Borne Pathogen, to Food Preservation Treatments

Escherichia albertii is a potential food-borne pathogen because of its documented ability to cause diarrheal disease by producing attachment and effacement lesions. Its tolerances to heat (56°C), acid (pH 3.0), and pressure (500 MPa [5 min]) were evaluated and found to be significantly less than those of wild-type E. coli O157:H7.     

N‐Heterocyclic‐based adsorbents for antibody purification—effect of ligand structure

A new set of ligands based on substituted pyridine and other N‐heterocyclic structures, possessing an aliphatic primary amino group tether and an exocyclic sulphur atom, has been prepared and immobilized onto epoxy‐activated matrices such as Sepharose 6 Fast Flow®. The derived adsorbents have been evaluated for their utility to capture and purify humanized monoclonal antibodies. Favourable binding properties were assessed from screening assays to determine optimal conditions for the capture and elution of the monoclonal antibodies. Static and dynamic binding experiments were employed to derive the equilibrium dissociation constants K_D's and binding capacities Q_max's. Typically, the K_D values were in the range of 2–5 μM and the Q_max values between 20 and 75 mg mAb/ml resin, depending on the stereo‐electronic properties of the substituent in the N‐heterocyclic ring structure. The effect of ligand structure on the selectivity of these adsorbents was also investigated, and criteria for their use in the purification of monoclonal antibodies from cell culture supernatants established. Copyright © 2014 John Wiley & Sons, Ltd.     

Kilovoltage beam model for flat panel imaging system with bow-tie filter for scatter prediction and correction

PurposeKilovoltage flat-panel imaging systems are used for cone-beam Computed Tomography (CBCT) and digital Tomosynthesis (DTS). Hereby, the presence of scatter and relatively large dose from imaging are challenging factors. In this study a phenomenological beam model was developed to characterize imager response to imaging beams with a bow-tie filter (Varian OBI system).Materials and methodThe kilovoltage beam model was based on dose ratio formalism and thus was using standard concepts of megavoltage dose calculation such as scatter factors, tissue maximum ratio and off-axis ratio. Primary and scatter (head and phantom scatter) were modeled with three Gaussian kernels. Parameters were based on measured transmission images for slabs of solid water of different total thickness and various jaw settings.ResultsThe beam model was used to evaluate contributions from primary, secondary and tertiary contributions for different geometrical objects such as cylinders and step-like phantoms. Theoretical predictions of radiographs using the model for known objects are consistent with the measurements.ConclusionSecondary and tertiary contributions were interpreted as scatter and can be subtracted from CBCT projections based on the analytical model. Therefore our model can provide a basis for improvement of image quality (less artifacts due to scatter, better contrast and resolution) in CBCT reconstruction.     

Role of anionic charges of osmoregulated periplasmic glucans of Salmonella enterica serovar Typhimurium SL1344 in mice virulence

opgB gene of Salmonella enterica serovar Typhimurium was identified earlier in a genome-wide screen for mice virulence (Valentine et al. in Infect Immun 66:3378-3383, 1998). Although mutation in opgB resulted in avirulent Salmonella strain, how this gene contributes to pathogenesis remains unclear. Based on DNA homology, opgB is predicted to be responsible for adding phosphoglycerate residues to osmoregulated periplasmic glucans (OPGs) giving them anionic characteristics. In Escherichia coli, yet another gene, opgC, is also reported to contribute to anionic characteristics of OPGs by adding succinic acid residues. We constructed opgB, opgC, and opgBC double mutants of S. enterica serovar Typhimurium strain SL1344. As predicted opgBC mutant synthesized neutral OPGs that were devoid of any anionic substituents. However, opgB, opgC, and opgBC mutations had no significant impact on mice virulence as well as on competitive organ colonization. In low osmotic conditions, opgB, opgC, and opgBC mutants exhibited delay in growth initiation in the presence of sodium deoxycholate. Anionic substituents of OPGs from Salmonella although appear to be needed to overcome resistance of deoxycholate in hypoosmotic growth media, no evidence was found for their role in mice virulence.     

Agroforestry: a refuge for tropical biodiversity?

As rates of deforestation continue to rise in many parts of the tropics, the international conservation community is faced with the challenge of finding approaches which can reduce deforestation and provide rural livelihoods in addition to conserving biodiversity. Much of modern-day conservation is motivated by a desire to conserve 'pristine nature' in protected areas, while there is growing recognition of the long-term human involvement in forest dynamics and of the importance of conservation outside protected areas. Agroforestry -- intentional management of shade trees with agricultural crops -- has the potential for providing habitats outside formally protected land, connecting nature reserves and alleviating resource-use pressure on conservation areas. Here we examine the role of agroforestry systems in maintaining species diversity and conclude that these systems can play an important role in biodiversity conservation in human-dominated landscapes.