Transvenous electrical cardioversion of equine atrial fibrillation: technical considerations

Conventional treatment of equine atrial fibrillation (AF) involves administration of quinidine salts. Most uncomplicated cases respond to treatment, but pharmacologic cardioversion involves a range of adverse effects, and some horses are unable to tolerate medication. A study was undertaken to develop transvenous electrical cardioversion (TVEC) as an alternative treatment. Safety issues and catheter placement techniques with catheter-integrated cardioversion electrodes were investigated, and responses to shock application were evaluated. After the premortem catheterization of elective-euthanasia horses, no tissue abnormalities were detected at postmortem examination. To evaluate the response to the application of shocks and appropriate electrode positions, an electrical cardioversion of research horses in chronic AF was then attempted. After catheterization of the right atrium (RA) and pulmonary artery through the right jugular vein, horses were placed under general anesthesia. Biphasic, truncated exponential shock waves were delivered at incremental energies until cardioversion was achieved or until a maximum energy of 300 J was reached. Five treatment events were applied to 3 horses, with cardioversion achieved in one of the treatment events. No adverse effects of cardioversion attempts or general anesthesia were observed. The procedure was then applied to 8 client-owned horses, with cardioversion achieved in 7. No adverse responses to appropriately delivered shocks were observed. No antiarrhythmic medications were administered to any horse at any stage. Catheter design and placement technique evolved throughout the study, with combined ultrasonography and pressure guidance proving most effective in achieving appropriate electrode placement. Results suggest TVEC, as applied in the present study, is a safe, effective, and realistic therapeutic option for equine AF.     

Bermudagrass (Cynodon spp) dose-response relationships with clethodim, glufosinate and glyphosate

Greenhouse studies were conducted to evaluate the sensitivity of three commercial cultivars, eight experimental cultivars and common bermudagrass to clethodim, glufosinate and glyphosate. Each herbicide was applied at eight doses. Data were regressed on herbicide dose using a log-logistic curve (R2 = 0.56-0.95 for clethodim, R2 = 0.60-0.94 for glufosinate, and R2 = 0.70-0.96 for glyphosate). The herbicide rate that elicited a 50% plant response (I50) in the bermudagrass cultivars ranged from 0.04 to 0.19 kg ha(-1) clethodim, 0.19 to 1.33 kg ha(-1) glufosinate and 0.34 to 1.14 kg ha(-1) glyphosate. Relative to other cultivars, common bermudagrass was intermediate in its response to clethodim and among the most tolerant cultivars to glufosinate and glyphosate. TifSport was relatively tolerant to clethodim and glufosinate compared with other cultivars, but relatively sensitive to glyphosate. One cultivar, 94-437, was consistently among the most sensitive cultivars to each of the herbicides. While there were differential herbicide tolerances among the tested bermudagrass cultivars, there did not appear to be any naturally occurring herbicide resistance that could be commercially utilized. However, research indicated that breeding efforts should target herbicide resistance that is at least four times the registered use rate. Also, TifSport and Tifway have been identified as suitable representatives of triploid hybrid bermudagrass cultivars to be used to evaluate the success of turfgrass renovation programs.     

Effect of Temperature and Screw Speed on Stability of Fumonisin B1 in Extrusion-Cooked Corn Grits

Corn grits spiked with fumonisin B₁ (FB₁) at a level of 5 μg/g were extrusion cooked in a corotating twin-screw extruder at different temperatures (140, 160, 180, and 200°C) and screw speeds (40, 80, 120, and 160 rpm). Good recoveries of FB₁ were obtained from the nonextruded as well as the extruded grits by using high-performance liquid chromatography. Both the barrel temperature and the screw speed significantly (P ≤ 0.05) affected the extent of fumonisin reduction in extruded grits. As expected, the FB₁ recovered decreased with an increase in temperature and a decrease in screw speed. The amount of FB₁ lost from cooking grits at the different extrusion parameters used in this study ranged from 34 to 95%. About 46–76% of the spiked FB₁ was lost when the grits were cooked at temperatures and screw speeds that resulted in acceptable product expansion and color.     

Genomic prediction of grain yield in commercial Finnish oat (Avena sativa) and barley (Hordeum vulgare) breeding programmes

Genomic selection has been adopted in many plant breeding programmes. In this paper, we cover some aspects of information necessary before starting genomic selection. Spring oat and barley breeding data sets from commercial breeding programmes were studied using single, multitrait and trait-assisted models for predicting grain yield. Heritabilities were higher when estimated using multitrait models compared to single-trait models. However, no corresponding increase in prediction accuracy was observed in a cross-validation scenario. On the other hand, forward prediction showed a slight, but not significant, increase in accuracy of genomic estimated breeding values for breeding cohorts when a multitrait model was applied. When a correlated trait was used in a trait-assisted model, on average the accuracies increased by 9%–14% for oat and by 11%–28% for barley compared with a single-trait model. Overall, accuracies in forward validation varied between breeding cohorts and years for grain yield. Forward prediction accuracies for multiple cohorts and multiple years’ data are reported for oat for the first time.     

First report of Calonectria montana causing damping‐off disease on pine and spruce seedlings in Europe

In 2015–2016, damping‐off symptoms were observed on Pinus sylvestris and Picea abies seedlings in four forest nurseries in Poland. Some Calonectria isolates were obtained from symptomatic seedlings by culturing pieces of necrotic tissue on malt extract agar.Morphological and molecular analyses revealed that isolates represent Calonectria montana, a recently described species from natural forests in China. The isolates represent the first detection of this species outside of Asia. Pathogenicity tests demonstrated that C. montana is a severe pathogen of P. sylvestris seedlings.     

Cast Films from Soy Protein Isolates and Fractions

Glycerol-plasticized soy protein films were cast from alkaline aqueous film-forming solutions of laboratory-prepared 7S, 11S, and soy isolate (LSI) fractions and from commercial soy isolate (CSI). Tensile strength (TS), elongation at break (E), water vapor permeability (WVP), total soluble matter (TSM), protein solubility (PS), and Hunter L, a, and b color values of these films were determined. The 11S films had greater TS than 7S films (P < 0.05), while LSI films had greater TS than CSI films (P < 0.05). No significant differences were detected among mean E values and among mean WVP values of all films (P > 0.05). The 7S films had higher TSM and PS values than 11S films (P < 0.05). CSI films were significantly darker (lower L value) and more yellow (greater positive b value) than LSI films (P < 0.05).     

Flavor Retention in Pregelatinized and Internally Flavored Starch Extrudates

Corn starch (25% amylose content) was pregelatinized in a twin-screw extruder. The extrudate was ground and reextruded after adjusting moisture content to 9, 13, or 17% (db) and blending with 5% (w/w) of flavor compounds cinnamaldehyde, eugenol, nonanoic acid, or 3-octanone. Initial moisture content significantly influenced radial expansion, specific mechanical energy, and flavor retention. Significantly higher flavor retention was obtained when flavor was injected into the extruder barrel as compared to preblending of flavors in pregelatinized starch. Flavor retention upon extrusion was lower with pregelatinized starch than with raw starch.     

Immunoglobulin M (IgM) indirect enzyme-linked immunosorbent assay and the involvement of IgM-rheumatoid factor in the serodiagnosis of BHV-1 infection.

An IgM enzyme-linked immunosorbent assay (IgM-ELISA) for the detection of antibodies to bovine herpesvirus-1 (BHV-1) was developed. Its applicability was examined by serological studies in two calves experimentally infected with virulent BHV-1 over a period of 60 days. IgM antibodies were detected by ELISA on day 6 after infection, and there was an increase in IgG antibodies on day 9. Serum neutralizing (SN) antibodies were detected only on day 13, confirming the higher sensitivity of the ELISAs. A similar study of four calves treated with a commercial inactivated virus vaccine indicated no detectable IgM-ELISA response, and late SN and IgG-ELISA reactivity. Thus IgM-ELISA appears to be of value in assessing recent infection, whereas IgG-ELISA and SN cannot distinguish between infection and vaccination. The possible limitations imposed on the specific IgM-ELISA by the presence of IgM rheumatoid factor (IgM-RF) in bovine serum were examined. IgM-RF levels were determined in bovines of various ages. Elevated values of IgM-RF were found in the sera of older animals; their occurrence may lead to false IgM-positive diagnosis (16%) of BHV-1 infection. This was examined in 113 serum specimens from suspected cases of BHV-1 infection and in 32 bulls at an insemination center. Pretreatment of serum samples with an antibovine IgG serum eliminated false positivity of the IgM-ELISA. It is concluded that IgM-ELISA should be of particular value in the diagnosis of recent infection with BHV-1, mainly in calves.