Root and shoot allometry of bareroot and container Douglas-fir seedlings

Detailed root and shoot development of bareroot and container Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedling stocktypes were compared during the first growing season after outplanting. The study was installed in raised beds with ideal environmental conditions and at a field reforestation site. Survival at both sites was 98% and did not differ between stocktypes. Seedlings were excavated in spring (5, 8, 12, and 16 weeks after planting) and in fall (35, 40, and 45 weeks after planting). In spring, container seedlings had more numbers of new roots and greater new root and shoot biomass than bareroot seedlings at both sites. In fall, bareroot seedlings consistently averaged more new root growth (though nonsignificant) than container seedlings suggesting that stocktype differences may not continue long-term. Container seedlings had significantly greater water percent than bareroot seedlings at the field site (all sample dates) and the raised bed site (weeks 5, 8, and 40 only). Regardless of environmental conditions or season, seedlings at both sites maintained water percent between 60 and 70% of fresh weight. Seedlings grown in the raised beds had much greater growth than those grown in the field. However, relative growth patterns for the two stocktypes were very similar on each site. The data generated establish baseline differences between stocktypes for root initiation, growth, and allometry during the first year after planting. Challenges associated with root development research are discussed.     

On the bonding of manganese,copper and cadmium to peptides of the xylem sap of plant roots

Water, Air, & Soil Pollution - In the xylem sap of pumpkin roots peptides or peptide similar compounds of M (molecular weight) up to 10,000 were established. The bonding of Mn, Cu and Cd to...     

Comparison of experimental models for Streptococcus suis infection of conventional pigs

Four different experimental models for Streptococcus suis-induced disease were compared to find a model that closely mimics naturally occurring disease in conventional pigs. Fourteen, 2-week old pigs free of S. suis type 2 were used in 2 experiments. In experiment 1, 3 pigs were inoculated intravenously (IV) and 3 pigs intranasally (IN) with S. suis. Two out of 3 of the IV-inoculated pigs exhibited signs of severe central nervous system disease (CNS) and were euthanized. Streptococcus suis type 2 was isolated from whole blood, joints, and serosal surfaces of both pigs. No clinical signs and no growth of S. suis were detected in the IN-inoculated pigs. In experiment 2, 4 pigs were inoculated IV and another 4 were inoculated IN with the same isolate as in experiment 1. One hour before inoculation the IN-inoculated pigs were given 5 mL of 1% acetic acid intranasally (IN-AA). All the IV-inoculated pigs showed CNS disease and lameness, and 2 of the pigs became severely affected and were euthanized. All the IN-AA inoculated pigs exhibited roughened hair coats and 2 pigs developed severe CNS disease and were euthanized. Streptococcus suis was isolated from the joints and blood of 3 pigs in the IV-inoculated group. Streptococcus suis was isolated from blood of 2 pigs, meninges of 3 pigs, and joints of 1 pig in the IN-AA inoculated group. Natural exposure to S. suis most likely occurs by the intranasal route. The IN-AA model should serve as a good model for S. suis-induced disease, because the natural route of exposure is intranasal and the IN-AA model was effective in inducing disease that mimics what is observed in the field.     

Dynamics of seed imbibition and germination of Austrian pine (<Emphasis Type="Italic">Pinus</Emphasis><Emphasis Type="Italic">nigra</Emphasis> Arnold) from extreme habitat conditions within five Balkan provenances

Seed was collected from two habitat types (harsh/rocky and favorable/control) within five Balkan provenances. An experiment was conducted to examine water uptake (grams water per gram of fresh seed) during 48 h after exposure to water. A second experiment investigated the effect of simulated-drought conditions (4% sucrose solution) compared to non-drought conditions (distilled water) on subsequent germination percentage. Seed from rocky habitats had less water uptake than those from control habitats for three of the provenances. However, water uptake was not correlated with subsequent germination. Drought simulation decreased germination but patterns for seed within each provenance were similar to germination under non-drought conditions. With the exception of one provenance, seed from the rocky habitats had lower germination than seed from control habitats. The data suggests some degree of adaptation to environmental conditions although variability was very high within each provenance’s habitat types. This is of particular importance when considering potential impacts of climate change and the anticipated migration of species due to changes in habitat.     

Cardiopulmonary effects of sufentanil long acting on sevoflurane anaesthesia in dogs

OBJECTIVE: To evaluate the cardiopulmonary effects of sufentanil long acting (SLA) in sevoflurane-anaesthetized dogs. STUDY DESIGN: Randomized prospective study. Animals Forty female dogs (beagles) aged 1-2 years, weighing 11.97 +/- 1.40 kg. MATERIALS AND METHODS: The dogs were divided into five groups of eight. Two control groups were used: group A received intramuscular (IM), SLA (50 microg kg(-1)) alone, while group B received the SLA vehicle followed by sevoflurane anaesthesia for 90 minutes. In the other groups, SLA (50 microg kg(-1) IM) was given immediately before (group C(0)), 15 minutes before (group D(15)) or 30 minutes (group E(30)) before induction [with intravenous (IV) thiopental] of sevoflurane anaesthesia lasting for 90 minutes. Heart rate, arterial blood pressure, respiratory rate (f(r)), arterial oxygen haemoglobin saturation and end-tidal sevoflurane concentration (Fe'SEVO) were measured every 10 minutes during anaesthesia and at 2, 4 and 24 hours after induction (not Fe'SEVO). Acid-base and blood gas analyses were performed. RESULTS: Sufentanil LA reduced heart rate and increased arterial CO(2) tensions during anaesthesia. Respiratory depression was least in group E(30) compared with groups C(0) and D(15). Bradycardia was present for at least 24 hours. Respiratory rate was least in group B although arterial O(2) and CO(2) tension values were acceptable up to 24 hours after anaesthesia. CONCLUSIONS: Pre-anaesthetic medication with SLA moderately aggravated the cardiopulmonary effects of sevoflurane. CLINICAL RELEVANCE: In spite of a moderate depressant effect on cardiorespiratory parameters, SLA may be of use as pre-anaesthetic medication before sevoflurane anaesthesia in dogs. Intermittent positive pressure ventilation may occasionally be necessary.     

Effect of recombinant canine distemper vaccine on antibody titers in previously vaccinated dogs

Two canine distemper virus (CDV) vaccine types are currently commercially available: modified-live virus (MLV) vaccines and a canarypox recombinant CDV (rCDV) vaccine (Recombitek, Merial). This study compared the ability of the rCDV vaccine and MLV vaccines to significantly enhance (boost) the antibody response of previously immunized adult and juvenile dogs. A significant (fourfold or greater) increase in titer occurred in significantly more dogs revaccinated with Recombitek C-4 or Recombitek C-6 than with the MLV-CDV vaccines. This study demonstrates that Recombitek, the only vaccine for dogs containing rCDV, is more likely to significantly boost the CDV antibody response in previously vaccinated dogs than are the MLV-CDV vaccines. Because rCDV vaccine can boost the antibody titer of dogs previously vaccinated with an MLV vaccine, it can and should be used when core vaccines are readministered.     

Overweight and impaired insulin sensitivity present in growing cats

Obesity is a growing problem in pets as well as in humans. Overweight and obesity are linked to insulin sensitivity and subsequently in older cats, to an increased risk of developing diabetes mellitus. In the experimental cat population of the Institute of Animal Nutrition of the Vetsuisse Faculty, University of Zurich, an overweight phenotype in intact cats younger than 1 year became evident. The aims of the present study were to determine whether an association between insulin sensitivity and body condition score (BCS) or feline body mass index (FBMI) is already present during young adulthood in these cats and to test the hypothesis that the phenotype lean/overweight is significantly associated with monthly body weight during the growing period. Therefore, 41 kittens from the mentioned cat breeding colony were studied. They were weighed weekly and checked monthly (third to eighth month after birth) for BCS and FBMI. At the age of 8 months, they were classified into an overweight and lean phenotype based on BCS on a scale of 9 (median; maximum and minimum: overweight male (6.4; 6.8; 6.0); overweight female (6.1; 6.2; 6.0); lean male (5.4; 5.7; 5.0); lean female (5.2; 5.6; 5.0). A significant association between the phenotype and body weight was obvious during the growing period from the third to the 8 months (p = 0.0001). At month 8, body fat content was measured by dual energy X‐ray absorptiometry and a glucose tolerance test to determine the insulin sensitivity index was performed. Insulin sensitivity was significantly associated with BCS (p = 0.0007) and body fat content (p < 0.0001) but not with sex (p = 0.61). Our data provide evidence that already in young intact cats; insulin insensitivity is significantly associated with BCS or a presumed phenotype lean/overweight.     

Impact of microarthropod biomass on the composition of the soil fauna community and ecosystem processes

The effect of soil organisms on ecosystem processes strongly depends on the composition of the overall community. Community composition however undergoes constant shifts due to pronounced spatio-temporal patterns in biomass and abundance of individual fauna groups. On this background the present experiment aimed to assess the potential impacts of shifts in the biomass of a dominant soil fauna group (microarthropods) on total community composition and on ecosystem processes mediated by fauna or microbes (e.g. decomposition, nitrogen mineralization).Microcosms, filled with spruce litter, hosted soil fauna communities that either contained ambient microarthropod biomass (control) or two elevated levels of microarthropod biomass (1.5 and 2 fold increase), while initial microbial biomass and that of other faunal groups remained unaltered. After an incubation period of 2 months, the biomass of microorganisms and fauna groups as well as ecosystem process variables were determined.The increase in microarthropod biomass at the investigated levels induced changes in the faunal community; mainly via negative or positive feeding interactions between microarthropods and the affected animal groups (Enchytraeidae, Nematoda). The abundance and activity of microorganisms at lower trophic levels however remained unaffected by these alterations; buffering the effect of shifts in the community structure on ecosystem processes.