Identification of selected internal wood characteristics in computed tomography images of black spruce: a comparison study

The feasibility of identifying internal wood characteristics in computed tomography (CT) images of black spruce was investigated using two promising classifiers: the maximum likelihood classifier (MLC) and the back propagation (BP) artificial neural network (ANN) classifier. Nine image features including one spectral feature (gray level values), a distance feature, and seven textural features were employed to develop the classifiers. The selected internal wood characteristics to be identified included heartwood, sapwood, bark, and knots. Twenty cross-sectional CT images of a black spruce log were randomly selected to develop the two classifiers. The results suggest that both classifiers produced high classification accuracy. Compared with the MLC classifier (80.9% overall accuracy), the BP ANN classifier had better classification performance (97.6% overall accuracy). Moreover, statistical analysis reveals that the heartwood of the black spruce log used in this study is the easiest to identify by either classifier compared with the other three log features. The results also suggest that the separability of one wood characteristic from the other wood characteristics in black spruce CT images is mainly related to moisture content.     

Genetic Analysis of Water Use Efficiency in Rice (Oryza sativa L.) at the Leaf Level

Carbon isotope discrimination (?¹³C) is considered as an index of leaf-level water use efficiency, an important objective for plant breeders seeking to conserve water resources. We report in rice a genetic analysis for ?¹³C, leaf structural parameters, gas exchange, stomatal conductance, and leaf abscisic acid (ABA) concentrations. Doubled haploid and recombinant inbred populations, both derived from the cross IR64 × Azucena, were used for quantitative trait locus (QTL) analysis following greenhouse experiments. ?¹³C QTLs on the long arms of chromosomes 4 and 5 were colocalized with QTLs associated with leaf blade width, length, and flatness, while a QTL cluster for ?¹³C, photosynthesis parameters, and ABA was observed in the near-centromeric region of chromosome 4. These results are consistent with phenotypic correlations and suggest that genetic variation in carbon assimilation and stomatal conductance contribute to the genetic variation for ?¹³C in this population.     

Beitrag zur Bestimmung der relativen Resistenz gegen Potato Virus X (PVX) an In-vitro-Pflanzen der Kartoffel

Zusammenfassung In-vitro-Pflanzen von PVX-resistenten (‘Schwalbe’, ‘Karella N’) und--anf?lligen Genotypen (‘Turbella N’, ‘Ogonjok’) in unsteriler Kultur auf Kiessubstrat wurden mechanisch inokuliert (Isolat PVX-‘Erstling’, Glasst?bchen). Eine quantitative Absch?tzung der relativen Viruskonzentration mittels ELISA 7...42 Tage nach der Inokulation (dpi) ergab bei den resistenten Genotypen im Mittel von 5 Versuchen mit 82 und 83% (70...90%) einen gegenüber den anf?lligen Formen (19 und 20%, 0...40%) signifikant h?heren Anteil Pflanzen mit gehemmter Virusvermehrung (E_{405 nm}≤1,0). Eine damit übereinstimmende Einstufung erfuhren die 4 geprüften Genotypen bei Absch?tzung der relativen Viruskonzentration an prim?rinfizierten Topf- und sekund?rinfizierten Freilandpflanzen.

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Summary The suitability of in vitro plants for determining relative (quantitative) PVX resistance was examined using resistant (‘Schwalbe’, ‘Karella N’) and susceptible (‘Turbella N’, ‘Ogonjok’) genotypes. They were grown in non-sterile gravel augmented with 2 ml of 0.45% Wopil solution (a mixture of nutrient salts with trace elements; VEB Chemiekombinat, Bitterfeld, DDR) and mechanically inoculated (glass rod) with the ‘Erstling’ isolate of PVX. The relative virus concentration in 10–15 in vitro plantlets of each genotype was estimated quantitatively using ELISA after 7, 14, 21, 28, 35 and 42 days (Fig. 1). The resistant genotypes had significantly higher proportions of plants with restricted virus multiplication (E_{405 nm}≤1.0) than the susceptible ones: means over five experiments were 82 and 83% for the resistant genotypes (70...90%) and 19 and 20% for the susceptible (0...40%)-Fig. 2. Estimation of the virus concentration in primary infected pot and secondary infected field plants of the four tested genotypes showed good agreement with established resistance rankings.

     

Relationships between muscle growth potential,intramuscular fat content and different indicators of muscle fibre types in young Charolais bulls

Genetic selection in favor of muscle growth at the expense of fat should affect characteristics of muscles, and therefore beef quality. This study was conducted with two extreme groups of six animals selected among 64 Charolais young bulls ranked according to their genetic potential for muscle growth. Muscle characteristics were assessed in Rectus abdominis (RA, slow oxidative) and Semitendinosus (ST, fast glycolytic) muscles. Intramuscular fat content and proportions of myosin heavy chains I (slow) and IIA (fast oxido‐glycolytic) and certain indicators of oxidative metabolism (activities of citrate synthase (CS), isocitrate dehydrogenase and cytochrome‐c oxidase (COX); expression of H‐fatty acid binding protein (FABP)) were higher in RA than in ST muscle. Genetic selection for muscle growth reduced intramuscular fat content and the activities of some oxidative metabolism indicators (namely CS, COX only). The positive correlation between muscle triacylglycerol content and A‐FABP messenger RNA level (a marker of adipocyte differentiation) (r = 0.53, P < 0.05) suggests that A‐FABP may be a good marker of the ability of bovines to deposit intramuscular fat. In conclusion, the metabolic muscle characteristics which respond to the selection process in favor of muscle growth clearly differ from the muscle characteristics which allow muscle types to be differentiated.     

Evaluating the effect of intraoperative peritoneal lavage on bacterial culture in dogs with suspected septic peritonitis

This pilot study describes the effect of intraoperative peritoneal lavage (IOPL) on bacterial counts and outcome in clinical cases of septic peritonitis. Intraoperative samples were cultured before and after IOPL. Thirty-three dogs with presumed septic peritonitis on the basis of cytology were managed surgically during the study period. Positive pre-lavage bacterial cultures were found in 14 cases, 13 of which were a result of intestinal leakage. The post-lavage cultures showed fewer isolates in 9 cases and in 1 case became negative. The number of dogs with a decrease in the concentration of bacteria cultured from pre-lavage to post-lavage samples was not statistically significant. There was no significant effect of the change in pre- to post-lavage culture, single versus multiple types of bacteria, selection of an appropriate empiric antimicrobial on survival or the need for subsequent surgery.     

Congenital duplex gallbladder and biliary mucocele associated with partial hepatic cholestasis and cholelithiasis in a cat

A 6-year-old neutered male domestic shorthair cat was presented for acute onset of vomiting. Exploratory laparotomy identified a duplex gallbladder and left cholecystectomy was performed. Histopathology confirmed biliary mucocele and hepatic cholestasis. While rare, biliary mucoceles should be considered as a differential diagnosis for feline extrahepatic bile duct obstruction.     

Influence of repeated prescribed burning on incorporation of C from cellulose by forest soil fungi as determined by RNA stable isotope probing

Repeated prescribed burning is frequently used as a forest management tool and can influence soil microbial diversity and activity. Soil fungi play key roles in carbon and nutrient cycling processes and soil fungal community structure has been shown to alter with increasing burning frequency. Such changes are accompanied by changes to soil carbon and nitrogen pools, however, we know little regarding how repeated prescribed burning alters functional diversity in soil fungal communities. We amended soil with ¹³C-cellulose and used RNA stable isotope probing to investigate the effect of biennial repeated prescribed burning over a 34-year period on cellulolytic soil fungi. Results indicated that repeated burning altered fungal community structure. Moreover, fungal community structure and diversity in ¹²C and ¹³C fractions from the unburned soil were not significantly different from each other, while those from the biennial burned soils differed from each other. The data indicate that fewer active fungi in the biennially burned soil incorporated ¹³C from the labelled cellulose and that repeated prescribed burning had a significant impact on the diversity of an important functional group of soil fungi (cellulolytic fungi) that are key drivers of forest soil decomposition and carbon cycling processes.     

A prospective comparison of postoperative morbidity associated with the use of scalpel blades and lasers for onychectomy in cats

This study compared patient discomfort for 10 d following feline onychectomies performed using a CO2 surgical laser versus a scalpel blade. Both techniques appeared to result in discomfort of a similar duration, although the laser caused significantly less lameness than blade excision during the first 7 d.