Goat horns: Platforms for viroid transmission to fruit trees?

Mechanical inoculations with contaminating tools and propagation of infected budwood were considered the main causes for the omnipresence of multiple viroid species among citrus and other Middle Eastern and Mediterranean fruit trees and grapevines. However, neither means could explain viroid infections of wild trees — scattered on terrains inaccessible to humans — nor the finding of similar viroids among graft-incompatible plants. Northern hybridization of RNA extracts made of scrapings from the surfaces of goat (Capra hircus) horns that were rubbed against etrog (Citrus medica) stems infected with a citrus viroids complex, revealed accumulation of considerable amounts ofCitrus exocortis viroids (CEVd) andHop stunt viroids (HSVd). Experimental transmission of both CEVd and HSVd was obtained by rubbing healthy citrus plants with goat horns that had been rubbed 24 h earlier on infected etrog stems. These results implicate goats as possible vectors of viroids. Transmissionvia goats could have facilitated the long-range spread of viroids among cultivated and wild plants andvice versa and also among graft-incompatible plants.     

Comparison of different bronchial closure techniques following pneumonectomy in dogs

The comparison of the histologic healing and bronchopleural fistula (BPF) complications encountered with three different BS closure techniques (manual suture, stapler and manual suture plus tissue flab) after pneumonectomy in dogs was investigated for a one-month period. The dogs were separated into two groups: group I (GI) (n = 9) and group II (GII) (n = 9). Right and left pneumonectomies were performed on the animals in GI and GII, respectively. Each group was further divided into three subgroups according to BS closure technique: subgroup I (SGI) (n = 3), manual suture; subgroup II (SGII) (n = 3), stapler; and subgroup III (SGIII) (n = 3), manual suture plus tissue flab. The dogs were sacrificed after one month of observation, and the bronchial stumps were removed for histological examination. The complications observed during a one-month period following pneumonectomy in nine dogs (n = 9) were: BPF (n = 5), peri-operative cardiac arrest (n = 1), post-operative respiratory arrest (n = 1), post-operative cardiac failure (n = 1) and cardio-pulmonary failure (n = 1). Histological healing was classified as complete or incomplete healing. Histological healing and BPF complications in the subgroups were analyzed statistically. There was no significant difference in histological healing between SGI and SGIII (p = 1.00; p > 0.05), nor between SGII and SGIII (p = 1.00; p > 0.05). Similarly, no significant difference was observed between the subgroups in terms of BPF (p = 0.945; p > 0.05). The results of the statistical analysis indicated that manual suture, stapler or manual suture plus tissue flab could be alternative methods for BS closure following pneumonectomy in dogs.     

Neural networks with artificial bee colony algorithm for modeling daily reference evapotranspiration

The study investigates the ability of artificial neural networks (ANN) with artificial bee colony (ABC) algorithm in daily reference evapotranspiration (ET₀) modeling. The daily climatic data, solar radiation, air temperature, relative humidity, and wind speed from two stations, Pomona and Santa Monica, in Los Angeles, USA, are used as inputs to the ANN–ABC model so as to estimate ET₀ obtained using the FAO-56 Penman–Monteith (PM) equation. In the first part of the study, the accuracy of ANN–ABC models is compared with those of the ANN models trained with Levenberg–Marquardt (LM) and standard back-propagation (SBP) algorithms and those of the following empirical models: The California Irrigation Management System (CIMIS) Penman, Hargreaves, and Ritchie methods. The mean square error (MSE), mean absolute error (MAE) and determination coefficient (R²) statistics are used for evaluating the accuracy of the models. Based on the comparison results, the ANN–ABC and ANN–LM models are found to be superior alternative to the ANN–SBP models. In the second part of the study, the potential of the ANN–ABC, ANN–LM, and ANN–SBP models in estimation ET₀ using nearby station data is investigated.     

Least squares support vector machine for modeling daily reference evapotranspiration

The accuracy of a least square support vector machine (LSSVM) in modeling of reference evapotranspiration (ET₀) was examined in this study. The daily weather data, solar radiation, air temperature, relative humidity and wind speed of two stations, Glendale and Oxnard, in southern district of California, were used as inputs to the LSSVM models to estimate ET₀ obtained using the FAO-56 Penman–Monteith equation. In the first part of the study, LSSVM estimates were compared with those of the following empirical models: Priestley–Taylor, Hargreaves and Ritchie methods. The comparison results indicated that the LSSVM performed better than the empirical models. In the second part of the study, the LSSVM results were compared with those of the conventional feed-forward artificial neural networks (ANN). It was found that the LSSVM models were superior to the ANN in modeling ET₀ process.     

A Case of Schistosoma Reflexum in a Cat with Chromosomal Aberrations

A 2‐year‐old, female Persian cat was presented with a history of distocia. In her first pregnancy, she had whelped four kittens and had eaten all of them right after parturition. She had mated again with the same tomcat. Well‐developed foetuses with weak foetal heart beats were observed in the ultrasonographic examination. En block ovariohysterectomy was performed. Three live and mature foetuses were obtained from the uterus; two of them were female foetuses and had no anatomical problem but the third one exhibiting multiple malformations was a male and diagnosed as ‘schistosoma reflexum’ (SR). The vertebral column deviated markedly to the right (scoliosis) at thoracolumbar region, and the middle lumbar and the sacral vertebrae were directed dorsocranially (lordosis). The entire small intestine, a part of large intestine, stomach, spleen and the right kidney were displayed out of the body, and it seemed that the listed internal organs were protruded from an abdominal cleft associated with the allantoic membrane. Liver, lungs and heart were hypoplastic. The large intestine was seen to have blind end (atresia recti), but anus was normal. Cerebrum and cerebellum were noticed as normal in sizes. Chromosome preparations from lymphocyte cultures of the foetus showed chromosomal aberrations including chromatid and chromosome breaks, exchange figures, non‐homologous pairing, whereas no abnormalities were detected in the chromosome preparations from mother’s cultures. This is probably the first case of SR in a cat, which was examined in detail from clinical, pathological, radiological and chromosomal angles.