Accuracy of the modified vertebral heart score and the cardio-vertebral ratio for radiographic evaluation of cardiomegaly in ferrets

Thoracic radiography is commonly used to assess the size of the heart and diagnose cardiac disease in ferrets. Several standardized radiographic heart size indicators have been introduced in this species and values in healthy ferrets have been reported. To date, none of these indicators has been tested in ferrets with cardiac disease. The aim of this prospective and retrospective, analytical observational design study was to assess the accuracy of the modified vertebral heart score (mVHS) and the cardio-vertebral ratio (CVR) in the radiographic detection of cardiomegaly in ferrets. Thoracic radiographs of 24 ferrets with confirmed heart diseases, 22 ferrets with non-cardiac diseases and normal-sized hearts on echocardiogram, and 24 healthy ferrets were mixed and examined by three independent and blinded radiologists who measured mVHS and CVR in right lateral (RL) and ventrodorsal (VD) radiographs. For all readers, ferrets with cardiac disease had significantly higher mVHS and CVR than ferrets without cardiac disease on echocardiography. Optimal cut-points for predicting cardiac enlargement were 6.25 vertebrae and 7.25 vertebrae for RL-mVHS and VD-mVHS, and 1.58 and 1.80 for RL-CVR and VD-CVR, respectively. Using these cut-points, the accuracy was good for indicators measured in RL radiographs (92.9% for RL-mVHS; 91.4% for RL-CVR) and moderate for indicators measured in VD radiographs (88.6% for VD-mVHS; 85.7% for VD-CVR). Findings supported the use of mVHS and CVR for evaluating the size of the heart in diseased ferrets, with caution in values interpretation when pericardial fat prevents precise delineation of the cardiac silhouette contour especially on VD radiographs.     

Intra‐cohort cannibalism in early life stages of pikeperch

Cannibalism has been described in 390 teleost fish species belonging to 104 families. In rearing conditions, intra‐cohort cannibalism is one of the major bottlenecks during the early life stages of pikeperch (Sander lucioperca). This study aims to describe precisely the occurrence and the onset of cannibalism of this species during the first two post‐hatching months. In a first step, the cannibalistic behaviour was analysed through observations in three experiments. In each experiment, the number of cannibalistic cases was similar. From 14 to 48 days post‐hatching (dph), more than 60 % of prey ingestions were realized by tail‐first, but after 48 dph, the number of prey ingestions by head‐first increased. In a second step, the behavioural sequence exhibited to attack and to capture a conspecific was analysed, taking into account the size ratio between the cannibal and its prey. The behavioural sequence to capture was always the same, similar to a predatory sequence and it seems that the cannibal chose its prey about 10 s before attacking. Moreover, prey choice by a cannibal was based more on the size ratio between the cannibal and its prey than the previous activity of the potential prey. These new results could lead to solutions to decrease cannibalism in pikeperch rearing.     

Are Phenological Observations Sufficient to Estimate the Quality of Seed Crops from a <Emphasis Type="Italic">Eucalyptus grandis</Emphasis> Open-pollinated Seed Orchard? Consequences for Seed Collections

Reproductive phenology was observed over three years in a Eucalyptus grandis seed orchard in Madagascar to determine the impact of geographic differences of parental selections on the expected genetic composition of seed crops. Pollen flow (observed pollen cloud) was deduced from a paternity assignment based on sampling from one year’s seed production. The two approaches were used to verify whether knowledge of phenology is sufficient to predict the genetic quality of the seeds collected. Despite the high flowering level, with a constant cycle over three years, the results demonstrated wide reproductive phenological differences associated with the parents’ origin, suggesting putative pollination disequilibrium. From both observed and expected pollen clouds, the results showed preferential mating among different provenances, which has consequences for seed crop composition. Phenological observations, which can be made inexpensively, can be used to promote methods of effective seed orchard management in order to improve the genetic quality of seeds.     

In search of a maize ideotype for cell wall enzymatic degradability using histological and biochemical lignin characterization

Grass cell wall degradability is conventionally related to the lignin content and to the ferulic-mediated cross-linking of lignins to polysaccharides. To better understand the variations in degradability, 22 maize inbred lines were subjected to image analyses of Fasga- and M?ule-stained stem sections and to chemical analyses of lignins and p-hydroxycinnamic acids. For the first time, the nearness of biochemical and histological estimates of lignin levels was established. Combination of histological and biochemical traits could explain 89% of the variations for cell wall degradability and define a maize ideotype for cell wall degradability. In addition to a reduced lignin level, such an ideotype would contain lignins richer in syringyl than in guaiacyl units and preferentially localized in the cortical region rather than in the pith. Such enrichment in syringyl units would favor wall degradability in grasses, contrary to dicots, and could be related to the fact that grass syringyl units are noticeably p-coumaroylated. This might affect the interaction capabilities of lignins and polysaccharides.     

Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production

Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with two marine bacterial exopolymers as alternative treatment agents. In field studies, the combination treatment resulted in a significant reduction in graft failures vs. untreated controls. The combination of tachyplesin (73 mg/L) with two bacterial exopolysaccharides (0.5% w/w) acting as filming agents, reduces graft-associated bacterial contamination. The survival data were similar to that reported for antibiotic treatments. These data suggest that non-antibiotic treatments of pearl oysters may provide an effective means of improving oyster survival following grafting procedures.     

The reproductive biology of okra. 1. Study of the breeding system in four Abelmoschus species

Summary The breeding system of Abelmoschus species is not well known. Although being self-compatibles allogamy reaches 63%. The aim of the study was to place four Abelmoschus species on the log P/O scale devised by Cruden (1977). On this scale P = pollen grains per anther × anthers per flower and O = ovules production. Pollens and ovules productions were therefore assessed for 68 accessions of two cultivated species, A. esculentus and A. caillei, and two wild, A. manihot and A. moschatus. Extreme log P/O values ranged from 1.69 for the variety Clemson Spineliss (A. esculentus) to 2.94 for ORS 278 (A. manihot). Averages of wild species A. moschatus (2.17) and A. manihot (2.19) indicate facultative autogamy. Averages for cultivated species A. esculentus (2.00) and A. caillei (2.05) suggest more autogamy.     

Sexual and somatic hybridization in the genus Lactuca

Summary Various genes for disease resistance identified in wild Lactuca are difficult, even impossible to exploit in lettuce breeding, due to sexual incompatibility between L. sativa and wild Lactuca sp. We adapted two cellular biology techniques to overcome these interspecific barriers: in vitro embryo rescue and protoplast fusion. In vitro rescue of immature embryos was used successfully for sexual hybridization between L. sativa and L. virosa. Vigorous hybrid plants were produced between L. sativa and seven accessions of L. virosa. Protoplast fusion permitted the regeneration of somatic hybrids between L. sativa and either L. tatarica or L. perennis. Hybrids between L. sativa and L. tatarica were backcrossed to L. sativa.     

The reproductive biology of okra. 2. Self-fertilization kinetics in the cultivated okra (Abelmoschus esculentus), and consequences for breeding

Summary The use of Cruden's index (1977), for studying okra sexual reproductive allocations, indicates a facultative autogamy mode. The purpose of the research described is to obtain more accurate information on the self-fertilization process. For this, self-pollen grain germination was stopped at different times of the day. Twelve varieties of Abelmoschus esculentus were used. Self-fertilization kinetics—expressed by the setting rate—displayed an increase between 7.00 to 16.00 hr. Study of obtained progenies, by stimulated allogamy, confirmed the process and showed that allo-pollen grains deposited on a stigma after midday had only a very little chance of contributing to fertilization. As a result, the polymorphism of the flower structure and particularly the distance between anther and stigmas, insect types and movement habits play major roles in governing okra allogamy. We also show that self-fertilization kinetics can be used to improve controlled hybrid production.