Replanting conifer seedlings after pine weevil emigration in spring decreases feeding damage and seedling mortality

Replanting at appropriate times after harvesting a coniferous forest stand can help efforts to suppress seedling mortality caused by the pine weevil Hylobius abietis, but optimal times are uncertain. We hypothesized that planting in June rather than May in the third season after harvest would reduce feeding damage by the pine weevil and increase seedling survival rates in central Sweden, where new-generation weevils mainly fly away from their development sites in May/early June. An experimental test of the hypothesis in eight clear-cuts confirmed that planting in June instead of May reduced proportions of seedlings attacked by pine weevil, bark removal from seedlings’ stems, and proportions of seedlings killed by feeding damage. These differences between seedlings planted in May and June declined to some extent with time but still remained significant after two growing seasons. The total seedling mortality after two seasons did, however, not differ significantly between seedlings planted in May and June. Overall, 29% of all seedlings were killed by pine weevil, 4.0% by Hylastes bark beetles, and 2.3% by drought. The results indicate that replanting in spring during the third season after harvest can advantageously continue until mid-June with respect to damage and mortality.     

Energetic eco‐physiology of the soil microbiota in two landscapes of southern and northern Germany

Interactions between microbial communities and organic matter were analyzed for soils from the project regions ’︁Ecosystem Research in the Agricultural Landscape/FAM, Munich’ in southern Germany and ’︁Ecosystem Research in the Bornhöved Lake district’ from northern Germany using ratios between microbial biomass content (C_mic), microbial metabolic quotient (qCO₂) and organic carbon content (C_org). In the agricultural soils in southern Germany, the qCO₂/C_org ratio differed significantly with respect to agricultural management in contrast to ecophysiological C_mic/C_org ratio. In addition, C_mic/C_org ratio decreased from 39 to 21 mg C_mic g^—1 C_org and qCO₂/C_org ratio increased from 72 to 180 mg CO₂‐C g^—1 C_mic h^—1 (g C_org g^—1 soil)^—1 with increasing soil depth. For the upper soil horizons from the landscape in northern Germany the two quotients differed significantly with reference to land use showing highest microbial colonization under grassland and lowest under beech forest. In contrast, C use efficiency was lowest in arable field under maize monoculture and highest in a wet grassland having a high organic C content.     

Urinary and faecal N-methylhistamine concentrations do not serve as markers for mast cell activation or clinical disease activity in dogs with chronic enteropathies

Background

This study sought to correlate faecal and urinary N-methylhistamine (NMH) concentrations with resting versus degranulated duodenal mast cell numbers in dogs with chronic enteropathies (CE), and investigate correlations between intestinal mast cell activation and clinical severity of disease as assessed by canine chronic enteropathy clinical activity index (CCECAI), and between urinary and faecal NMH concentrations, mast cell numbers, and histopathological scores. Twenty-eight dogs with CE were included. Duodenal biopsies were stained with haematoxylin and eosin (H&E), toluidine blue, and by immunohistochemical labelling for tryptase. Duodenal biopsies were assigned a histopathological severity score, and duodenal mast cell numbers were counted in five high-power fields after metachromatic and immunohistochemical staining. Faecal and urinary NMH concentrations were measured by gas chromatography–mass spectrometry.

Results

There was no correlation between the CCECAI and faecal or urinary NMH concentrations, mast cell numbers, or histopathological score – or between faecal or urinary NMH concentration and mast cell numbers. Post hoc analysis revealed a statistically significant difference in toluidine blue positive mast cells between two treatment groups (exclusion diet with/without metronidazole versus immunosuppression (IS)), with higher numbers among dogs not requiring IS.

Conclusion

Faecal and urinary NMH concentrations and duodenal mast cell numbers were not useful indicators of severity of disease as assessed by the CCECAI or histological evaluation. The number of duodenal mast cells was higher in dogs that did not need IS, i.e. in dogs responding to an exclusion diet (with/without metronidazole), than in dogs requiring IS. Further studies comparing the role of mast cells in dogs with different forms of CE are needed.     

Effect of show jumping training on the development of locomotory muscle in young horses

OBJECTIVE: To investigate whether training for show jumping that is commenced early after birth affects the characteristics of equine locomotory muscle. ANIMALS: 19 Dutch Warmblood horses. PROCEDURES: Horses were assigned to a trained or not trained (control) group. After weaning, training (free jumping [2 d/wk] that was alternated with a 20-minute period of exercise in a mechanical rotating walker [3 d/wk]) was started and continued until horses were 3 years old. Fiber type composition (determined from myosin heavy chain [MyHC] content), fiber area, diffusion index (area supplied by 1 capillary), citrate synthase activity, and Na(+),K(+)-ATPase content were assessed in gluteus medius muscle specimens collected at 0.5, 1, 2, and 3 years. RESULTS: Developmental changes included an increase in MyHC fiber type IIa and a decrease in type IIad; increases in fiber area, diffusion index, and citrate synthase activity; and a decrease in Na(+),K(+)-ATPase content. The MyHC fiber type I and type IId were detected in high and low proportions, respectively. Training increased Na(+),K(+)-ATPase content, but did not affect other variables. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, show jumping training at an early age resulted in increased Na(+),K(+)-ATPase content of the deep portions of the gluteus medius muscle. The lack of training effects on the other muscle characteristics can partly be explained by the fact that an appropriate (aerobic) fiber type composition was already established at training commencement. These data also suggested that the developmental changes in equine muscle represent sufficient adaptation to meet the demands of this specific training.     

Gene expression of selected signature cytokines of T cell subsets in duodenal tissues of dogs with and without inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common cause of chronic diarrhoea in dogs. In people, specific cytokine patterns attributed to T cell subsets, especially T helper cell [Th]1, Th17 and regulatory T(reg) cells have emerged in IBD. In contrast, no specific involvement of a distinct T cell subset has been described so far in canine IBD. Thus, the aim of the present study was to assess gene expression of signature cytokines in duodenal tissues from 18 German shepherd dogs with IBD (group 1), 33 dogs of other breeds with IBD (group 2) and 15 control dogs (group 3). Relative quantification of IL-17A, IL-22, IL-10, IFNy and TGFβ was performed. Expression of IL-17A was significantly lower in groups 1 and 2 compared to group 3 (p=0.014), but no difference in the expression of IL-22 (p=0.839), IFNγ (p=0.359), IL-10 (p=0.085) or TGFβ (p=0.551) across groups was detected. Thus, no clear evidence for the involvement of Th-17 signature cytokines in canine IBD at the mRNA level could be shown. The contribution of specific T cell subsets to the pathogenesis of canine IBD warrants further investigation.     

Pharmacokinetics of harpagoside in horses after intragastric administration of a Devil's claw (Harpagophytum procumbens) extract

Devil's claw is used for the treatment of inflammatory symptoms and degenerative disorders in horses since many years, but without the substantive pharmacokinetic data. The pharmacokinetic parameters of harpagoside, the main active constituent of Harpagophytum procumbens DC ex Meisn., were evaluated in equine plasma after administration of Harpagophytum extract FB 8858 in an open, single‐dose, two‐treatment, two‐period, randomized cross‐over design. Six horses received a single dose of Harpagophytum extract, corresponding to 5 mg/kg BM harpagoside, and after 7 days washout period, 10 mg/kg BM harpagoside via nasogastric tube. Plasma samples at certain time points (before and 0–24 hr after administration) were collected, cleaned up by solid‐phase extraction, and harpagoside concentrations were determined by LC‐MS/MS using apigenin‐7‐glucoside as internal standard. Plasma concentration‐time data and relevant parameters were described by noncompartmental model through PKSolver software. Harpagoside could be detected up to 9 hr after administration. C_max was found at 25.59 and 55.46 ng/ml, t_1/2 at 2.53 and 2.32 hr, respectively, and t_max at 1 hr in both trials. AUC_0–inf was 70.46 and 117.85 ng hr ml^?1, respectively. A proportional relationship between dose, C_max and AUC was observed. Distribution (V_z/F) was 259.04 and 283.83 L/kg and clearance (CL/F) 70.96 and 84.86 L hr^?1 kg^?1, respectively. Treatment of horses with Harpagophytum extract did not cause any clinically detectable side effects.     

Occupational swine exposure and Hepatitis E virus,Leptospira, Ascaris suum seropositivity and MRSA colonization in Austrian veterinarians, 2017–2018—A cross‐sectional study

We investigated the prevalence of Hepatitis E Virus (HEV), Leptospira and Ascaris suum (A. suum) seropositivity, and of nasal methicillin‐resistant Staphylococcus aureus (MRSA) colonization among Austrian practising veterinarians, and assessed the association with occupational swine livestock exposure. The 261 participants completed a questionnaire on demographics, intensity of occupational swine livestock contact and glove use during handling animals and their secretions. Participants' blood samples were tested for HEV, Leptospira and A. suum seropositivity and nasal swabs cultured for MRSA. We compared swine veterinarians (defined as >3 swine livestock visits/week) to non‐swine veterinarians (≤3 swine livestock visits/week) with regard to the outcomes through calculating prevalence ratio (PR) and 95% confidence interval (CI). Furthermore, the relationship between occupational swine livestock contact and the study outcomes was examined by age (</≥55 years) and glove usage. The prevalence of nasal MRSA colonization was 13.4% (95% CI: 9.3–17.6), of HEV seropositivity 20.8% (95% CI: 15.8–25.7) and A. suum seropositivity 44% (95% CI: 37.7–50.2). The highest anti‐leptospiral antibodies titres were 1:200 (L. hebdomadis) and 1:100 (L. autumnalis, L. caicola) found in three non‐swine veterinarians. Compared to non‐swine veterinarians, swine veterinarians were 1.9 (95% CI: 1.0–3.4) and 1.5 (95%CI: 1.0–2.3) times more likely HEV seropositive and A. suum seropositive, respectively, and 4.8 (95%CI: 2.5; 9.3) times more likely nasally colonized with MRSA. Among glove‐using veterinarians, occupational swine contact was no longer a determinant for HEV seropositivity (PR 1.6; 95% CI: 0.8–2.9). Similar was found for A. suum seropositivity, which was no longer associated with occupational swine livestock contact in the subgroup of glove using, ≥55‐year‐old veterinarians (PR: 1.07; 95% CI: 0.4–3.3). Our findings indicate that >3 occupational swine livestock visits per week is associated with HEV and A. suum seropositivity and nasal MRSA colonization and that glove use may play a putative preventive role in acquiring HEV and A. suum. Further analytical epidemiological studies have to prove the causality of these associations.     

Pipeline right‐of‐way construction activities impact on deep soil compaction

A 762‐mm‐diameter pipe 1,886 km long was installed to transfer crude oil in the USA from North Dakota to Illinois. To investigate the impact of construction and restoration practices on long‐term soil productivity and crop yield, vertical soil stresses induced by a Caterpillar (CAT) pipe liner PL 87 (475 kN vehicle load) and semi‐trailer truck (8.9 kN axle load) were studied in a farm field. Soil properties (bulk density and cone penetration resistance) were measured on field zones within the right‐of‐way (ROW) classified according to construction machine trafficking and subsoil tillage (300‐mm‐depth tillage and 450‐mm‐depth tillage in two repeated passes) treatments. At 200 mm depth from the subsoiled surface, the magnitude of peak vertical soil stress from trafficking by the semi‐truck trailer and CAT pipe liner PL 87 was 133 kPa. The peak vertical soil stress at 400 mm soil depth appeared to be influenced by vehicle weight, where the Caterpillar pipe liner PL 87 created soil compaction a magnitude of 1.5 greater than from the semi‐trailer truck. Results from the soil bulk density and soil cone penetration resistance measurements also showed the ROW zones had significantly higher soil compaction than adjacent unaffected corn planted fields. Tillage to 450 mm depth alleviated the deep soil compaction better than the 300‐mm‐depth tillage as measured by soil cone penetration resistance within the ROW zones and the unaffected zone. These results could be incorporated into agricultural mitigation plans in ROW construction utilities to minimize soil and crop damage.     

Infectivity and acetylene reduction of diazotrophic rhizosphere bacteria in wheat (Triticum aestivum) seedlings under gnotobiotic conditions

Summary Wheat seedlings were inoculated with rhizosphere nitrogen-fixing bacteria and grown gnotobiotically for 15 days. The growth medium consisted of semisolid agar with or without plant nutrients. The bacteria, isolated from roots of field-grown wheat, were three unidentified Gram-negative rods (A1, A2, E1), one Enterobacter agglomerans (C1) and two Bacillus polymyxa (B1, B2). A strain of Azospirillum brasilense (USA 10) was included for comparison.Nitrogenase activity (acetylene reduction activity, ARA) was tested on intact plants after 8 and 15 days of growth. In semisolid agar without plant nutrients, five isolates showed ARA of 0.01–0.9 nmol C₂H₄ plant^–1 h^–1, while the two strains of B. polymyxa had higher ARA of 3.3–10.6 nmol C₂H₄ plant^–1 h^–1.Plant development was not affected by inoculation with bacteria, except that inoculation with B. polymyxa resulted in shorter shoots and lower root weight.Transmission electronmicroscopy of roots revealed different degrees of infection. A. brasilense, A1 and A2, occurred mainly in the mucilage on the root surface and between outer epidermal cells (low infectivity). B. polymyxa strains and E1 were found in and between epidermal cells (intermediate infectivity) while E. agglomerans invaded the cortex and was occasionally found within the stele (high infectivity).     

Whole-genome shotgun sequencing of mitochondria from ancient hair shafts

Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections.