Establishing climate–growth relationships for yelloweye rockfish (Sebastes ruberrimus) in the northeast Pacific using a dendrochronological approach

We applied dendrochronology (tree‐ring) methods to develop multidecadal growth chronologies from the increment widths of yelloweye rockfish (Sebastes ruberrimus) otoliths. Chronologies were developed for the central California coast, a site just north of Vancouver Island, British Columbia, and at Bowie Seamount west of the Queen Charlotte Islands, British Columbia. At each site, synchronous growth patterns were matched among otoliths via the process of cross‐dating, ensuring that the correct calendar year was assigned to all increments. Each time series of growth‐increment measurements was divided by the values predicted by a best‐fit negative exponential function, thereby removing age‐related trends. These detrended time series were averaged into a master chronology for each site, and chronologies were correlated with monthly averages of sea surface temperatures, upwelling, the Northern Oscillation Index, and the Pacific Decadal Oscillation. The two northern growth chronologies positively correlated with indices of warm ocean conditions, especially from the prior summer through the spring of the current year. During the same period, the California chronology positively correlated with indices of cool ocean conditions, indicating an opposing productivity regime for yelloweye rockfish between the California Current and the Gulf of Alaska. Overall, this study demonstrates how tree‐ring techniques can be applied to quickly develop annually resolved chronologies and establish climate–growth relationships across various temporal and spatial scales.     

Appropriate bacterial identification systems for small plant-pathology laboratories overseas incorporating the Biolog method

Diagnostic services in developing countries are severely limited by the availability of funding and trained personnel. While common fungal pathogens can be identified with minimal equipment and media, the conventional methods for identification of bacterial pathogens are time-consuming and require a wide range of costly media and reagents. In addition, excessive time and resources are often devoted to the identification of contaminating saprophytic bacteria. The Biolog system for identifying bacteria by metabolic profiles has been evaluated and adapted for use in routine diagnosis in small plant pathology laboratories overseas. Although Biolog is costly, it can be combined with a system for the preliminary identification and elimination of non-pathogens using a limited number of conventional tests. The database of Gram-negative profiles supplied by Biolog needs to be supplemented by user-defined database(s). Bacterial Identifier software (Blackwell Scientific Publications) is advocated as a cost-effective alternative.     

牦牛大肠埃希氏菌病灭活疫苗的制备

用本实验室分离鉴定的致病性牦牛大肠埃希氏菌，按常规方法制备了4批氢氧化铝胶灭活疫苗。对牦牛大肠埃希氏菌的菌液培养、纯粹检验、活菌计数、灭活等进行了探索，并对用该菌研制成的疫苗进行了常规检验。结果4批灭活疫苗经无菌检验为阴性；经物理性状检验为：静置后上层是淡黄色的澄明液体，下层为灰白色沉淀，振荡后呈均匀混浊液；经牦牛安全检验结果为安全；经牦牛效力试验有效。牦牛大肠埃希氏菌病灭活疫苗为免疫预防该病打下了良好的基础。     

Influence of Temperament Score and Handling Facility on Stress,Reproductive Hormone Concentrations,and Fixed Time AI Pregnancy Rates in Beef Heifers

The objectives were (i) to evaluate the effect of temperament, determined by modified 2‐point chute exit and gait score, on artificial insemination (AI) pregnancy rates in beef heifers following fixed time AI and (ii) to determine the effect of temperament on cortisol, substance‐P, prolactin and progesterone at initiation of synchronization and at the time of AI. Angus beef heifers (n = 967) at eight locations were included in this study. At the initiation of synchronization (Day 0 = initiation of synchronization), all heifers received a body condition score (BCS), and temperament score (0 = calm; slow exit and walk or 1 = excitable; fast exit or jump or trot or run). Blood samples were collected from a sub‐population of heifers (n = 86) at both synchronization initiation and the time of AI to determine the differences in serum progesterone, cortisol, prolactin and substance‐P concentrations between temperament groups. Heifers were synchronized with 5‐day CO‐Synch+ controlled internal drug release (CIDR) protocol and were inseminated at 56 h after CIDR removal. Heifers were examined for pregnancy by ultrasound 70 days after AI to determine AI pregnancy. Controlling for synchronization treatment (p = 0.03), facility design (p = 0.05), and cattle handling facility design by temperament score interaction (p = 0.02), the AI pregnancy differed between heifers with excitable and calm temperament (51.9% vs 60.3%; p = 0.01). The alley‐way with acute bends and turns, and long straight alley‐way had lower AI pregnancy rate than did the semicircular alley‐way (53.5%, 56.3% and 67.0% respectively; p = 0.05). The serum hormone concentrations differed significantly between different types of cattle handling facility (p < 0.05). The cattle handling facility design by temperament group interactions significantly influenced progesterone (p = 0.01), cortisol (p = 0.01), prolactin (p = 0.02) and substance‐P (p = 0.04) both at the initiation of synchronization and at the time of AI. Inter‐ and intra‐rater agreement for temperament scoring were moderate and good (Kappa = 0.596 ± 0.07 and 0.797 ± 0.11) respectively. The predictive value for calm and pregnant to AI was 0.87, and excited and non‐pregnant to AI was 0.76. In conclusion, the modified 2‐point temperament scoring method can be used to identify heifers with excitable temperament. Heifers with excitable temperament had lower AI pregnancy. Further, cattle handling facility design influenced the temperament and AI pregnancy.     

Electrophoretic variation in triazine-resistant and-susceptible populations of the allogamous weed Brassica rapa

Levels of genetic variation, as estimated from electrophoretic data, were investigated in three triazine-resistant (R) and seven susceptible (S) populations of the allogamous weed Brassica rapa ssp. sylvestris (L.) Jan, from Ouebec, Canada. No significant differences were detected between R and S populations in the percentage of polymorphic loci (37–39.2%), but allelic diversity (mean number of alleles per locus) and observed and expected levels of heterozygosity were significantly (P<0.10) lower in the R populations than in the S populations. Overall low levels of population differentiation were evident among populations. Nei's genetic distances between population pairs ranged from 0.003 to 0.054, with an overall species mean of 0.019, with slightly greater divergence among the three R populations. Most of the total gene diversity was found within populations for both S and R populations. A mean of 3.7% of the variation occurred among S populations, with a higher value of 12.1% distributed among the R populations. A comparison of observed levels of heterozygosity with expected levels under random mating, provided evidence for significant departures from random mating, as lower mean values than expected were observed for both the R populations (0.133 vs. 0.153) and S populations (0.159 and 0.184), suggesting that a low level of selfing may be occurring in these populations. The distribution of genetic variation among and within populations of B. rapa was consistent with predicted pattems for predominantly allogamous species. The reduced levels of genetic variation observed for the three R populations were not as striking as that previously reported for triazine-resistant auto-gamous species. Variation électrophorètique chez les populations risistantes et sensibles aux triazines de l'adventice allogame Brassica rapa Les niveaux de variation génétique, estimés a partir de données venant de l'électrophorèse ont étéétudiés chez 3 populations résistantes aux triazines (R) et 7 sensibles (S) de l'adventice allogame Brassica rapa ssp sylvestris (L.) Jan, du Quebec, Canada, Aucune différence significative n'a été trouvée entre les populations R et S dans le pourcentage des loci polymorphes, mais la diversité allélique (nombre moyen d'allèles par locus) et les taux d'heterozygosité attendus et observés étaient significativement (P<0,10) moins élevés chez les populations R que chez les S. En général de faibles niveaux de différenciation de populations apparaissaient dans les populations. Les distances génétiques entre 2 populations allaient de 0,003 à 0,054, avec une moyenne générale de l'espfèce de 0,019 avec une légèrement plus élevée divergence dans les 3 populations R. La majorité de la diversité génetique était trouvée a l'intérieur des populations tant S que R. Une moyenne de 3,7% de variation est apparue dans les populations S, avec une valeur plus élevée de 12,1% dans les populations R. Une comparaison des niveaux d'heterozygosité observés avec ceux attendus avec croisement au hasard, a montré une différence significative, avec des valeurs moyennes observées, plus basses que celles attendues à la fois pour les populations R (0,133 contre 0,153) et pour les S (0,159 et 0,184), donnant à penser qu'un faible taux d'autofécondation peut survenir dans ces populations. La distribution de la variation génétique dans les populations de B. rapaétait conforme au schéma prévisible pour une espèce majoritairement allogame. Les niveaux réduits de variation génétique observés pour les 3 populatioiis résistantes n'étaient pas aussi marquant que ce qui avait été précédemment décrit pour des espèces résistantes aux triazines autogames. Elektrophoretische Untersuchung der genetischen Unterschiede Triazin-resistenter und-empfindlicher Populationen von Brassica rapa Bei der Untersuchung der genetischen Unterschiede 3 Triazin-resistenter (R) und 7 -empfindlicher (S) Populationen des allogamen Unkrauts Brassica rapa ssp. sylvestris (L.) Jan. aus Quebec, Kanada, war aufgrund elektropho-retischer Daten der Prozentsatz polymorpher Loci bei R- und S-Populationen nicht signifikant verschieden (37…39,2%), aber die Allel-diversität (mittlere Anzahl Allele pro Locus) und der beobachtete und erwartete Grad der Heterozygotie waren bei den R-Populationen signifikant geringer (P<0,10) als bei den S-Populationen. Die Populationen waren offen-sichtlich allgemein wenig differenziert. Die genetische Distanz zwischen Populationen-paaren reichte von 0,003 bis 0,054 mit einem Artmittel von 0,019 und bei etwas größerer Divergenz der 3 R-Populationen. Bei den S-Populationen lag das Variationsmittel bei 3,7%, höher bei den R-Populationen mit 12,1%. Beim Vergleich der beobachteten Heterozygotie mit der erwarteten ergeben sich signifikante Abweichungen von der zufäligen Paarung, indem sowohl fur die R- als auch für die S-Populationen geringere Werte gefunden wurden (0,133 gegen 0,153 bzw. 0,159 und 0,184), ein Hinweis auf eine geringe Selbstbe-fruchtung. Die genetischen Unterschiede zwischen und in den Brassica-rapa-Populationen entsprach dem Muster vorwiegend allogamer Arten. Die geringeren genetischen Unterschiede der 3 R-Populationen waren nicht so überraschend wie die früher berichtenen von Triazin-resistenten autogamen Arten.     

Changes in the Proximal Femur and Coxofemoral Joint Following Intramedullary Pinning of Diaphyseal Fractures in Young Dogs

We report radiographic changes and clinical results seen in the proximal femur and coxofemoral joint of 7 young dogs following intramedullary pinning. Changes seen radiographically included coxa valga, a small malformed femoral head, a short thin femoral neck, and coxofemoral subluxation. Epiphyseal trauma, ischemia, and mechanical impairment of normal femoral neck growth due to presence of the intramedullary pin are discussed as possible etiologic factors.