Iron deficiency and zinc toxicity in soybean grown in nutrient solution with different levels of sulfur

A typical symptom of iron (Fe) deficiency in plants is yellowing or chlorosis of leaves. Heavy metal toxicity, including that of zinc (Zn), is often also expressed by chlorosis and may be called Fe chlorosis. Iron deficiency and Zn toxicity were evaluated in soybean (Glycine max [L.] Merr.) at two levels each of Zn (0.8 and 40 μM), Fe (0 and 20 μM), and sulfur (S) (0.02 and 20 mM). Reduction in dry matter yield and leaf chlorosis were observed in plants grown under the high level of Zn (toxic level), as well as in the absence of Fe. Zinc toxicity, lack of Fe, and the combination of these conditions reduced dry matter yield to the same extent when compared to the yield of the control plants. The symptoms of Zn toxicity were chlorosis in the trifoliate leaves and a lack of change in the orientation of unifoliate leaves when exposed to light. The main symptoms of Fe deficiency were chlorosis in the whole shoot and brown spots and flaccid areas in the leaves. The latter symptom did not appear in plants grown with Fe but under Zn toxicity. It seems that Fe deficiency is a major factor impairing the growth of plants exposed to high levels of Zn. Under Zn toxicity, Fe and Zn translocation from roots to shoots increased as the S supply to the plants was increased.     

Antimicrobial Susceptibility of Coagulase-Positive and Coagulase-Negative Staphylococci in Ready-to-Eat Sashimi

The aim of this study was to investigate the antimicrobial susceptibility pattern of Staphylococcus spp. isolated from sashimi meals collected in Japanese restaurants from northern Portugal. One hundred and thirty-six isolates of Staphylococcus spp. were recovered from sashimi samples. The antimicrobial susceptibility test showed high levels of resistance to β-lactams, macrolides, and lincosamides. All Staphylococcus isolates were sensitive to trimethoprim-sulfamethoxazole, ciprofloxacin, and chloramphenicol. Multidrug-resistant staphylococci (25%) were found in sashimi samples. It is of the utmost need to improve the hygienic practices in handling in order to reduce the occurrence of Staphylococcus species, potentially resistant to antimicrobial agents.     

Field Experiences on Post-cervical Artificial Insemination in the Sow

The present study was performed in order to evaluate the effects of post-cervical artificial insemination (post-CAI) in eastern European continental climate with multiparous sows. The sows were randomly allocated into two groups, and were AI by using CAI with 3 x 10(9) spermatozoa per dose (group 1, n = 859) or by post-CAI, using pooled semen with 1 x 10(9) spermatozoa per dose (group 2, n = 924). Wean-to-oestrus intervals, duration of oestrus, day 24 pregnancy rates, farrowing rates, and total pigs born were evaluated. Wean-to-oestrus intervals (CAI 114.3 +/- 4.1 h; post-CAI 115.2 +/- 5.2 h), duration of oestrus (CAI 64.1 +/- 4.1 h; post-CAI 65.0 +/- 5.2 h), day 24 pregnancy rates (CAI 90.2 +/- 1.7%; post-CAI 89.3 +/- 1.8%) and farrowing rates (CAI 88.1 +/- 2.3%; post-CAI 87.8 +/- 2.9%) did not differ significantly between CAI and post-CAI inseminated sows. The total number of pigs born differed significantly (p < 0.01) between the groups (CAI 12.3 +/- 1.1; post-CAI 10.2 +/- 0.9).     

Transmission studies of Hendra virus (equine morbilli-virus) in fruit bats, horses and cats

Objective To determine the infectivity and transmissibility of Hendra virus (HeV). Design A disease transmission study using fruit bats, horses and cats. Procedure Eight grey-headed fruit bats (Pteropus poliocephalus) were inoculated and housed in contact with three uninfected bats and two uninfected horses. In a second exper iment, four horses were inoculated by subcutaneous injection and intranasal inoculation and housed in contact with three uninfected horses and six uninfected cats. In a third experi ment, 12 cats were inoculated and housed in contact with three uninfected horses. Two surviving horses were inoculated at the conclusion of the third experiment: the first orally and the second by nasal swabbing. All animals were necropsied and examined by gross and microscopic pathological methods, immunoperoxidase to detect viral antigen in formalin-fixed tissues, virus isolation was attempted on tissues and SNT and ELISA methods were used to detect HeV-specific antibody. Results Clinical disease was not observed in the fruit bats, although six of eight inoculated bats developed antibody against HeV, and two of six developed vascular lesions which contained viral antigen. The in-contact bats and horses did not seroconvert. Three of four horses that were inoculated devel oped acute disease, but in-contact horses and cats were not infected. In the third experiment, one of three in-contact horses contracted disease. At the time of necropsy, high titres of HeV were detected in the kidneys of six acutely infected horses, in the urine of four horses and the mouth of two, but not in the nasal cavities or tracheas. Conclusions Grey-headed fruit bats seroconvert and develop subclinical disease when inoculated with HeV. Horses can be infected by oronasal routes and can excrete HeV in urine and saliva. It is possible to transmit HeV from cats to horses. Transmission from P poliocephalus t o horses could not be proven and neither could transmission from horses to horses or horses to cats. Under the experimental conditions of the study the virus is not highly contagious.     

Estimation of the diagnostic accuracy of the glyco-C and US9 gene-based polymerase chain reaction technique for the detection of bovine Herpesvirus type 5 DNA in decomposed brain suspension from a slaughter house using Bayesian analysis, Brazil

Brazil represents the greatest beef producer among tropical countries, and the major obstacle for meat international trade is sanitary problems especially closely related to viral encephalitis. The goal of this study was to estimate the accuracy of the glycol and US9 gene-based polymerase chain reactions (PCRs) for the detection of bovine Herpesvirus type 5 (BoHV-5) from decomposed brain samples (n = 95). For this purpose, a latent-class (Bayesian) approach was used. Sensitivity (Se) was estimated to be 70% (95% probability interval, 40–80) and specificity (Sp) 100% in the statistical analysis for both PCRs used. Accordingly, a minimum of ≥40% of the calves was estimated to harbor BoHV-5 DNA even after 72 h of decomposition at room temperature. It was concluded that US9 gene-based PCR could also be considered a cost-effective alternative in sanitary programmers. However, given the importance of veterinary diagnoses, PCR-positive samples should be further confirmed through in vitro isolation and/or sequencing.     

Expression and Characterization of Constitutive Heat Shock Protein 70.1 (HSPA‐1A) Gene in In Vitro Produced and In Vivo‐Derived Buffalo (Bubalus bubalis) Embryos

Cells are blessed with a group of stress protector molecules known as heat shock proteins (HSPs), amongst them HSP70, encoded by HSPA‐1A gene, is most abundant and highly conserved protein. Variety of stresses hampers the developmental competence of embryos under in vivo and in vitro conditions. Present work was designed to study the quantitative expression of HSPA‐1A mRNA in immature oocytes (IMO), matured oocytes (MO), in vitro produced (IVP) and in vivo‐derived (IVD) buffalo embryos to assess the level of stress to which embryos are exposed under in vivo and in vitro culture conditions. Further, HSPA‐1A gene sequence was analysed to determine its homology with other mammalian sequences. The mRNA expression analysis was carried out on 72 oocytes (40 IMO; 32 MO), 76 IVP and 55 IVD buffalo embryos. Expression of HSPA‐1A was found in oocytes and throughout the developmental stages of embryos examined irrespective of the embryo source; however, higher (p < 0.05) expression was observed in 8–16 cell, morula and blastocyst stages of IVP embryos as compared to IVD embryos. Phylogenetic analysis of bubaline HSPA‐1A revealed that it shares 91–98% identity with other mammalian sequences. It can be concluded that higher level of HSPA‐1A mRNA in IVP embryos in comparison with in vivo‐derived embryos is an indicator of cellular stress in IVP system. This study suggests need for further optimization of in vitro culture system in which HSPA‐1A gene could be used as a stress biomarker during pre‐implantation development.     

X-ray imaging of shock waves generated by high-pressure fuel sprays

Synchrotron x-radiography and a fast x-ray detector were used to record the time evolution of the transient fuel sprays from a high-pressure injector. A succession of 5.1-microsecond radiographs captured the propagation of the spray-induced shock waves in a gaseous medium and revealed the complex nature of the spray hydrodynamics. The monochromatic x-radiographs also allow quantitative analysis of the shock waves that has been difficult if not impossible with optical imaging. Under injection conditions similar to those found in operating engines, the fuel jets can exceed supersonic speeds and result in gaseous shock waves.     

Critical phosphorus concentrations in potato plant parts at two growth stages

Adequately evaluating the phosphorus (P) nutritional status of a potato crop is dependent upon sampling the appropriate plant part at a defined growth stage. To establish P critical concentration levels in various potato plant parts (leaves, stems, tubers, leaflets, and petioles) at two growth stages [20 and 50 days after plant emergence (DAE)], an experiment under Brazilian climatic and soil conditions was conducted using seven P treatment levels (0, 40, 80, 160, 320, 640, and 1,280 kg P₂O₅ ha^‐1) applied in a randomized complete block design with four replications. ‘Baraka’ potato tubers were seeded at a spacing of 0.80 x 0.30 m following agronomic cultural practices recommended for this crop. Phosphorus concentrations in all the potato plant parts were significantly affected by the P fertilizer rates applied. The highest correlation between the P concentration in the various plant parts and marketable yield and optimum profit yield was obtained for the petiole taken 20 days DAE. Critical P levels associated with optimum profit yield were lower than those for maximum marketable tuber yield, and they were, 0.41, 0.39,0.39,0.57, and 0.57 g P 100 mg^‐1 DM in the leaf, stem, tuber, petiole, and leaflet, respectively.     

Varying Nitrogen Concentrations to Optimize Basic Seed Potato Minitubers Production in a Three-Phase Hydroponic System

In hydroponics, nutrient management is the limiting factor to obtaining optimal production, and nitrogen (N) is the key component to consider when optimizing nutrient management in these types of systems. The objective of this study is to evaluate different combinations of N fertilizer concentrations in order to optimize the yield of basic seed potato minitubers in a three-phase hydroponic system. Treatments consisted of five combinations of N concentrations, applied before and after 21 days after plant transplant as follows, respectively: 1) 13 and 13, 2) 13 and 0, 3) 13 and 7.8, 4) 13 and 16, and 5) 13 and 26 mmol L^?1. Propagation was performed by transplanting 3–4 cm potato plantlets cv. Agata from sprouts. There were significant effects of N treatments on all measured variables (root, leaf, stem, and plant dry weight and minituber number and weight). To obtain the maximum minituber number yield, 9.51 minitubers/plant, corresponding to 67 minitubers/m², post 21-day adjusted N concentration was 18.4 mmol/L. Treatment 4 promoted higher basic seed potato minituber yield in a three-phase hydroponic system.