Evaluation of a covalent mix-enzyme linked immunosorbent assay for screening of Salmonella antibodies in pig serum

In this study, a commercial Salmonella covalent mix-enzyme linked immunosorbent assay (ELISA) for serological detection of Salmonella infection in swine was evaluated by comparing it with the conventional fecal culture method and inter-laboratory proficiency testing, using a panel of sera tested in 5 laboratories from Europe and North America. Comparison with culture results showed that 88.5% of 26 culture-positive animals were ELISA positive, as were 55% of 60 animals from 2 culture-positive pig herds. Of 90 animals from 2 high health farms with no clinical symptoms of salmonellosis, 98.9% tested negative. The interlaboratory comparison study found a kappa value of 0.9 between our laboratory (using an automated system) and the manufacturer laboratory (using the manual method). Comparison of ELISA results from all 5 participating laboratories showed very good to excellent agreement, between 85% and 97.5%. We found this assay to be useful for the screening of antibodies against Salmonella present in swine serum. It agrees well with bacterial cultures, is reproducible, sensitive, specific, repeatable, and suitable for automation.     

ULTRASONOGRAPHIC APPEARANCE OF OVARIAN TUMORS IN 10 DOGS

Signalment, clinical history, physical examination, clinicopathologic, readiographic and ultrasonographic findings of 10 female dogs with histologically confirmed ovarian neoplasms were reviewed. Ultrasonographic images and reports were reviewed for (1) location, size, outer margins, and echogenicity of the mass(es), (2) presence of free abdominal fluid, (3) evidence of uterine abnormalities, and (4) signs of metastatic disease. The masses were classified according to their ultrasonographic pattern in solid, solid with cystic component, and cystic. The masses were ultrasonographically reported as being of ovarian origin in eight dogs, and this origin was included in the list of differentials in the remaining two dogs. When present, abdominal effusions and uterine abnormalities were diagnosed by means of ultrasound.     

Simple and rapid field tests for brucellosis in livestock

Four simple and rapid field tests for the serodiagnosis of brucellosis in cattle, goat, sheep and swine were developed. The performance of the assays was investigated using serum samples collected in Portugal from animals originating from herds with a defined sanitary status with respect to the presence of brucellosis. The sensitivity calculated for the bovine, caprine, ovine and swine Brucella lateral flow assays based on results obtained for samples collected from animals with culture confirmed brucellosis was 90%, 100%, 90% and 73%, respectively. None of the samples from animals from herds free of brucellosis reacted in the flow assays indicating a high specificity. However, as expected, some degree of reactivity was observed when testing selected serum samples that reacted non-specific in reference tests for brucellosis.     

Improving seed yield in red clover through marker assisted parentage analysis

Red clover (Trifolium pratense L.) is an important perennial forage crop in Europe. Unfortunately, seed production of modern cultivars is often unsatisfactory and breeding progress for higher seed yield is slow. We evaluated whether marker assisted parentage analysis could identify progeny plants with two high seed-yielding parents in a diploid selection trial. Furthermore, we studied if breeding for high seed yield could be speeded up by selecting progeny plants with two high seed-yielding parents, compared to traditional selection on the mother plant only. In this study, 111 genotypes with excellent vegetative traits from a first cycle selection trial were allowed to pollinate each other in isolation. After seed harvest, ten high seed-yielding plants were identified and their seeds were used to grow ten half-sib progeny populations, with 1,121 plants in total. Two multiplex primer sets targeting 18 SSR loci were designed and used to fingerprint parental and progeny plants. Parentage was reliably determined for 1,083 progeny plants: 135 plants were the result of a cross between two high seed-yielding parents. In a 2-year seed yield trial, the seed yield of these 135 progeny plants was compared to that of a control group of 216 progeny plants from the same ten high seed-yielding mother plants but with no selection on the male contribution, as is current practice. Compared to the control group, progeny plants with two high seed-yielding parents had significantly higher seed yields, 23.0 and 75.9 % higher in 2012 and 2013 respectively, and a significantly higher thousand seed weight, 6.6 and 5.7 % higher in 2012 and 2013 respectively. Seed yield was strongly correlated with flower abundance (r = 0.643) and plant volume (r = 0.593 in 2012 and r = 0.509 in 2013) and negatively correlated with susceptibility to mildew (r = ?0.145). We conclude that breeding programs aiming at increasing seed yield in diploid red clover cultivars would strongly benefit from the integration of marker assisted parentage analysis to identify those progeny plants that are the result of a cross between two high seed-yielding plants. This goal cannot be achieved with traditional family selection where only the seed yield of the mother plant is known.     

Multibiomarker response shows how native and non‐native freshwater bivalves differentially cope with heat‐wave events

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Infection process of <Emphasis Type="Italic">Gilbertella persicaria</Emphasis> in papaya (<Emphasis Type="Italic">Carica papaya</Emphasis> L.) fruits

Gilbertella persicaria is a pathogenic fungus recently reported as a causative agent of soft rot in papaya fruits. Here the interactions between G. persicaria and papaya fruits was analyzed under laboratory conditions using histological techniques and optical microscopy to elucidate the process of pathogenesis. Healthy and disinfested fruits of papaya cv. Maradol were also inoculated with a suspension of sporangiospores of G. persicaria. Tissue sections were cut, which were subjected to differential staining with safranin-fast green for different times. Sporangiospores presumably adhered to the cuticle of the fruit by 3 h post inoculation (hpi) and germinated by 6 hpi; invasive intracellular hyphae were growing in host cells by 9 hpi. By 15 hpi, fruit epidermis was macerated, presumably by enzymatic activity reported for mucoral fungal species and appeared as a wet-looking lesion on the cuticle. Fruit mesocarp was colonized by 30 hpi, and asexual reproduction structures had formed by 48 hpi. This process of infection and disease development of G. persicaria in papaya fruits corresponds to that used by pathogens with a necrotrophic lifestyle.     

Effects of site productivity on forest harvest scheduling subject to green-up and maximum area restrictions

Green-up requirements are of great interest for forests near cities since these forests are commonly used for recreational activities by the local population as well as for commercial forestry activities. We present three formulations to establish green-up requirements, based on a dynamic green-up approach and constructed by means of: (i) a predefined fixed length for the green-up time, (ii) a predefined variable length for the green-up time and (iii) height information produced by the growth simulator. Additionally, restrictions on harvested volume and maximum open areas were applied. All the green-up formulations were applied to five datasets comprising different initial forest conditions regarding age and site index distribution. Results show that higher net present values are obtained by the formulation that allow a predefined variable length for the green-up time and by using the height information from the growth simulator compared to the formulations using a predefined fixed length for the green-up time. The increase in NPV was most pronounced for the old forest datasets and varied between 4.23% and 8.15%. The optimal solution was always found when modeling the green-up requirement using the height information. This formulation also tended to find optimal solutions faster than other formulations.     

The annual pattern of sap flow in two Eucalyptus species established in the vicinity of gold-mine tailings dams in central South Africa

Several hundred mine tailings dams occur in the Witwatersrand Basin Goldfields in central South Africa. Seepage of acid mine drainage (AMD) from these unlined structures is widespread, and a variety of contaminants is released into soil and groundwater. The ‘Mine Woodlands Project’ is aimed at evaluating the use of high-density tree stands over surrounding contaminant plumes to limit the spread of contaminants through hydraulic control of groundwater and enhanced uptake or immobilisation of contaminants. The annual pattern of hourly sap flow in four contiguous Eucalyptus dunnii trees (aged three years) was followed over a full year in a species trial situated near Carltonville. The annual pattern of hourly sap flow was also recorded in four contiguous sample trees (aged four years) of the clonal hybrid E. grandis × E. camaldulensis (E. G×C) at another trial near Orkney. Both species showed high sap flow rates close to reference evaporation rates in response to summer rains. Both showed greatly reduced sap flow rates during the latter half of the dry winter season. Sap flow rates only recovered after the arrival of the first spring rains. Annual sap flow (E. dunnii, 673 mm; E. G×C, 767 mm) was similar to the recorded annual rainfall at each site (E. dunnii, 629 mm; E. G×C, 795 mm), and was substantially lower than total annual reference evaporation (E. dunnii, 1 273 mm; E. G×C, 1 330 mm). We conclude that the roots of both species are not yet deep enough to access the AMD-influenced groundwater, which lies at depths of 14 and 10 m below the ground at the Carltonville and Orkney sites, respectively. Despite prolonged water deficits, both species survived well and maintained sufficient vigour to permit the quick recovery of high transpiration rates in the following summer. This resilience is essential to hasten root growth and improve the chance of contact with groundwater plumes.