New sources of resistance to Fusarium wilt and sterility mosaic disease in a mini-core collection of pigeonpea germplasm

Fusarium wilt (FW) and Sterility mosaic disease (SMD) are important biotic constraints to pigeonpea production worldwide. Host plant resistance is the most durable and economical way to manage these diseases. A pigeonpea mini-core collection consisting of 146 germplasm accessions developed from a core collection of 1290 accessions from 53 countries was evaluated to identify sources of resistance to FW and SMD under artificial field epiphytotic conditions during 2007–08 and 2008–09 crop seasons. Resistant sources identified in the field were confirmed in the greenhouse using a root dip screening technique for FW and a leaf stapling technique for SMD. Six accessions (originated from India and Italy were found resistant to FW (<10% mean disease incidence). High level of resistance to SMD was found in 24 accessions (mean incidence <10%). These SMD resistant accessions originated from India, Italy, Kenya, Nepal, Nigeria, Philippines and United Kingdom. Combined resistance to FW and SMD was found in five accessions (ICPs 6739, 8860, 11015, 13304 and 14819). These diverse accessions that are resistant to FW or SMD will be useful to the pigeonpea resistance breeding program.     

Development and validation of an ELISA for the detection of leptospire-specific antibodies in rodents

An enzyme-linked immunosorbent assay (ELISA) for the detection of IgG antibodies in rodents was developed and validated with the microscopic agglutination test (MAT) and leptospiral cultures. Sonicated antigen from cultures of serovars tarassovi and pyrogenes was used. As conjugate, a combination of anti-rat and anti-hamster IgG labeled with peroxidase was used. The optimal cut-off point was determined by plotting the sensitivity and specificity for various cut-off point values by means of receiver operating characteristic (ROC) curve. Concordance between ELISA and each of the MAT titers was measured by kappa (kappa). Proportions of positive results were compared by means of McNemar's test. Total 214 rodents were trapped, but only 117 could be processed by the three techniques (culture, ELISA, MAT; 1:20, 1:40, 1:50) and used for statistical analysis. Although, MAT titers in rodents infected with the serogroup Ballum tended to be lower than those infected with the serogroup Icterohaemorrhagiae, all (20/20) were ELISA-positive and almost all (19/20) were MAT-positive.The percentage of positive results obtained by ELISA, 47.0% exceeded significantly the 40.2% obtained by MAT (1:50). Difference between ELISA and MAT (1:40) was not significant and no differences were observed between ELISA and MAT (1:20). Agreement, specificity, sensitivity and the consequent area under the ROC curve between ELISA and MAT were higher as MAT cut-off points were lowered, being optimal at 1:20. The fact that differences between ELISA and MAT were significant at 1:50, but not at 1:40 or 1:20, supports the suggestion that lower MAT titers should be considered positive in rodents. The ELISA developed to detect leptospire-specific antibodies had optimal sensitivity and specificity in relation to MAT and it is concluded that it may constitute a very useful indicator for epidemiological purposes of past or present leptospiral infection in rodents.     

Rumen-protected conjugated linoleic acid supplementation to dairy cows in late pregnancy and early lactation: effects on milk composition,milk yield,blood metabolites and gene expression in liver

Background

Conjugated linoleic acid (CLA) is a collective term for isomers of octadecadienoic acid with conjugated double-bond system. Thus, it was the objective to investigate whether milk composition and metabolic key parameters are affected by adding CLA to the diet of dairy cows in the first four weeks of lactation.

Methods

A study was carried out with five primiparous cows fed a CLA supplemented diet compared to five primiparous cows without CLA supplementation. CLA supplemented cows received 7.5 g CLA/day (i.e. 50% cis(c)9,trans(t)11- and 50% t10,c12-CLA) starting two weeks before expected calving and 20 g CLA/day (i.e. 50% c9,t11- and 50% t10,c12-CLA) throughout day 1 to 28 of lactation.

Results

The CLA supplement was insufficiently accepted by the animals: only 61.5% of the intended amount was ingested. Fed CLA were detectable in milk fat, whereas contents of c9,t11-CLA and t10,c12-CLA in milk fat were higher for CLA supplemented cows compared to the control group. On average over the entire treatment period, there was a decrease of saturated fatty acids (FA) in milk fat of CLA supplemented cows, combined with a higher content of monounsaturated and trans FA.Our study revealed no significant effects of c9,t11- and t10,c12-CLA supplementation either on milk yield and composition or on metabolic key parameters in blood. Furthermore the experiment did not indicate significant effects of c9,t11- and t10,c12-CLA-supplementation on gene expression of peroxisome proliferator-activated receptor-alpha (PPARα), PPARγ, sterol regulatory element-binding protein-1 and tumor necrosis factor-alpha in liver tissue.

Conclusions

Feeding c9,t11- and t10,c12-CLA during the first weeks after calving did not affect metabolic key parameters of blood serum or milk composition of fresh cows. Milk fatty acid composition was changed by feeding c9,t11- and t10,c12-CLA resulting in higher contents of these isomers in milk fat. High contents of long chain FA in milk fat indicate that CLA supplementation during the first four weeks of lactation did not affect massive peripheral lipomobilization.     

Design of Nonionic Surfactants for Supercritical Carbon Dioxide

Interfacially active block copolymer amphiphiles have been synthesized and their self-assembly into micelles in supercritical carbon dioxide (CO2) has been demonstrated with small-angle neutron scattering (SANS). These materials establish the design criteria for molecularly engineered surfactants that can stabilize and disperse otherwise insoluble matter into a CO2 continuous phase. Polystyrene-b-poly(1,1-dihydroperfluorooctyl acrylate) copolymers self-assembled into polydisperse core-shell-type micelles as a result of the disparate solubility characteristics of the different block segments in CO2. These nonionic surfactants for CO2 were shown by SANS to be capable of emulsifying up to 20 percent by weight of a CO2-insoluble hydrocarbon into CO2. This result demonstrates the efficacy of surfactant-modified CO2 in reducing the large volumes of organic and halogenated solvent waste streams released into our environment by solvent-intensive manufacturing and process industries.     

Immunisation against ovine caseous lymphadenitis: correlation between Corynebacterium pseudotuberculosis toxoid content and protective efficacy in combined clostridial-corynebacterial vaccines

Groups of sheep were dosed with vaccines containing Corynebacterium pseudotuberculosis toxoid combined in varying amounts with 5 clostridial antigens. Resistance of the sheep to infection with C pseudotuberculosis was tested at 1, 6 and 12 months after vaccination by infection with pus from ovine lymph glands actively infected with C pseudotuberculosis. The outcome was assessed 3 months after challenge by slaughter and inspection of the sheep for caseous lymphadenitis lesions. Protection was demonstrated by a significant reduction in the proportion of immunised sheep exhibiting lesions compared with control sheep, and by fewer abscesses in affected immunised sheep than in affected control sheep. A positive correlation was found between amount of C pseudotuberculosis toxoid administered and degree of protection obtained. Chromatographically-purified toxoid induced essentially the same protection, suggesting that anti-toxic immunity is the major factor in protection.     

Vaccination withanaplasma centrale: Response after an experimental challenge withanaplasma marginale

Summary The haematological and clinical responses to vaccination withAnaplasma centrale and to subsequent challenge withAnaplasma marginale were evaluated. Twenty Holstein steers 14 to 16 months of age were divided into two groups of 12 and eight animals respectively (groups I and II). Group I was inoculated on day zero with 10⁷ A. centrale-infected erythrocytes and group II was kept as a control. On day 125 both groups were challenged with 5 × 10⁷ A. marginale-infected erythrocytes.A. centrale inoculation produced low parasitaemias (maximum -x 2.7%), moderate packed cell volume (PCV) falls (minimum -x 20.5%) and no clinical symptoms. After the challenge group I had significantly lower parasitaemia (maximum -x 2.3%) and higher PCV (minimum -x 20.1%) than group II (7.5% and 14.5% respectively). Four steers from group II developed acute anaplasmosis and required treatment.

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Vacunacion ConAnaplasma Centrale: Respuesta Despues del Desafio Experimental ConAnaplasma Marginale

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Vaccination AvecAnaplasma Centrale: Resultats Apres une Confrontation Experimentale AvecA. Marginale

Résumé Les auteurs ont évalué les résultats hématologiques et clinique de la vaccination avecAnaplasma centrale et secondairement ceux d'un essai comparatif expérimental avecAnaplasma marginale. Vingt bouvillons Holstein agés de 14 à 16 mois ont été divisés en deux groupes (I et II) respectivement de 12 et 8 sujets. Le groupe I a re?u au jour J⁰ une injection de 10⁷ érytrhocytes infectés parAnaplasma centrale. Le groupe II a servi de lot témoin. Au 125 ème jour les deux groupes ont été soumis à une injection de 5 × 10⁷ érythrocytes infectés parAnaplasma marginale. L'injection d'A. centrale a produit une parasitémie légère (maximum -x 2,7 p.100), une chute modérèe du volume de l'Hématocrite (PVC) (minimum -x 20,5 p.100) et aucun sympt?me clinique. Par rapport au groupe II et après l'épreuve expérimentale, le groupe I présentait significativement une parasitémie plus basse (maximum -x 2,3 p.100) et de taux plus élevés (minimum -x 20,1 p.100), contre 7,5 et 14,5 p.100 respectivement. Quatre bouvillons du groupe II ont été atteints d'une anaplasmose aigüe exigeant un traitement. Resumen Se evaluó la respuesta clínica y hematológica despues de la vacunación conA. centrale, seguida del desafío conA. marginale. Un grupo de novillos Holstein de 14 a 16 meses de edad, se dividieron en dos grupos de 12 y ocho animales respectivamente (grupos I y II). El grupo I se inoculó el día cero con 10⁷ eritrocitos infectados conA. centrale, sirviendo el grupo II de testigo. El día 125, ambos grupos recibieron una descarga de 5 × 10⁷ eritrocitos infectados conA. marginale. La inoculación conA. centrale produjo parasitémias bajas (máximo -x 2.7%), caídas moderadas del volumen corpuscular (PCV), (mínimo -x 20.5%) y no se presentaron síntomas clínicos, Despues de la descarga, el grupo I tuvo parasitémias significativamente más bajas (máximo -x 2.3%) y volumenes corpusculares (PCV) más altos (mínimo 20.1%) que el grupo II (7.5% y 14.5% respectivamente). Cuatro novillos del grupo II desarrollaron anaplasmosis aguda y fueron tratados.