Characterization of Lasiodiplodia theobromae (Pat.) Griffon & Maubl causing stem canker on Teak (Tectona grandis L.) in Ecuador

Teak is a very important tropical timber in Ecuador. In 2017, teak samples displaying stem canker symptoms were collected in two provinces of Ecuador. From 11 symptomatic trees, 11 isolates resembling a species of Lasiodiplodia were obtained. All isolates obtained induced stem canker on teak plants after artificial inoculation, confirming them as the cause of the observed canker symptoms. Bayesian inference with concatenated sequences of complete ITS and partial TEF-α and β-TUB gene sequences from two representative isolates clustered teak isolates with other sequences of Lasiodiplodia theobromae available in Genbank. This is the first report of L. theobromae causing stem canker on teak plants in Ecuador.     

Comparison of 15N natural abundance and difference methods for estimating N2 fixation of soybeans grown in a tropical soil

Abstract

A study was carried out to compare the difference or N-yield method with the ¹⁵N natural abundance method for the estimation of the fractional contribution of biological N₂ fixation in the different plant parts of nodulating and non-nodulating isolines of soybeans. The results indicated that the δ¹⁵N values of most plant parts of soybeans were significantly lower (p<0.05) in the nodulating than in the non-nodulating isoline. However, in the case of the root+nodule component, the δ¹⁵N value was higher in the nodulating than in the non-nodulating isoline possibly due to isotopic discrimination of ¹⁵N over ¹⁴N which may have occurred in the nodules. Inoculation of soybeans with the Bradyrhizobium japonicum strain CB 1809 increased significantly (p<0.05) the δ¹⁵N value of the root+nodule component implying that the effectiveness of the soybean-rhizobium symbiosis had increased by inoculation.

Percentage of plant N derived from atmospheric N₂ fixation (%Ndfa) estimated by the ¹⁵N natural abundance method was highly correlated (r=0.762, p<0.01) with that by the difference or N-yield method and the differences between the two methods were not statistically significant. The agreement between the two methods was closer at maturity than at the early reproductive stage.

The %Ndfa obtained by the difference method ranged from 48.4 to 92.6% whereas the %Ndfa obtained by the ¹⁵N natural abundance method ranged from 43.2 to 92.4% in the different plant parts. Based on the ¹⁵N natural abundance method, approximately 15% of the N in pod, shoot, grain, and shell was derived from the soil but in the case of stover, this fraction was about 55%.     

Elephant grass, sugarcane, and rice bran in diets for confined sheep

We aimed to evaluate the effects of diets, based on elephant grass or sugarcane as roughage and corn meal or rice bran as energy concentrate, on performance and body composition in terms of diet intake and digestibility. A total of 30 Santa Ines crossbreds (SIC), castrated male sheep with 19.8?±?2.0?kg initial body weight (BW) were used. Six animals were slaughtered at the onset of the experiment to estimate the initial body composition for the other animals. The remaining 24 animals were distributed in a completely randomized 2?×?2 factorial design, with four treatments (two roughages and two concentrates) and six replicates. The sheep were slaughtered when they reached 30.0?kg BW. Elephant grass diets provided higher intake and digestibility than sugarcane diets for the following contents: dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre, minerals, total carbohydrates (TC), and total digestible nutrients (TDN). Among the concentrates, corn meal diets were associated with higher intakes than rice bran diets for the following contents: DM, OM, CP, TC, and TDN. Animals from all of the treatments exhibited low average daily weight gain and low protein and high fat and energy body levels. Sugarcane and rice bran can be used as ingredients in diets for sheep with low weight gain potential. Regardless of roughage or concentrate types used in diets for confined SIC sheep, performance and body composition remained unaltered.     

Expression of matrix metalloproteinases, type IV collagen, and interleukin-10 in rabbits treated with morphine after lamellar keratectomy

Purpose To study the effects of topical administration of 1% morphine on corneal analgesia in rabbits submitted to lamellar keratectomy and to assess the expression of matrix metalloproteinase‐1, metalloproteinase‐2, metalloproteinase‐9 (MMPs), type IV collagen, and interleukin‐10 (IL‐10) during the treatment. Methods Morphine group (MG) received 50 μL of topical 1% morphine four times daily, while the control group received saline instead. Corneal touch threshold (CTT) and the wound area were assessed until corneal healing. Corneal samples were processed for routine histology, immunohistochemistry, zymography, and ELISA. Results Following keratectomy, CTT increased significantly from 6 to 96 h time points. Mean corneal re‐epithelization rate and scores of leukocyte infiltration did not differ significantly between treatment groups. Immunolabeling pattern for MMP‐1, MMP‐9, and type IV collagen was similar in both treatment groups. In the MG, zymography indicated significantly higher levels of active MMP‐2 on days 6 and 12; and in the latent MMP‐9, on days 3 and 6, and in the active MMP‐9, on day 6. Latent MMP‐2 and MMP‐9, and active MMP‐9 decreased to values close to those of healthy corneas on day 12, but levels of active MMP‐2 remained significantly elevated in the MG. IL‐10 levels measured on days 1–6 were reduced as compared to those of healthy corneal tissue and returned to levels close to those of healthy corneas on day 12. Conclusion Topical morphine promoted corneal analgesia for up to 4 days and did not delay corneal re‐epithelization. The re‐establishment of MMPs and IL‐10 to levels close to baseline values at the end of the study and the expression of type IV collagen in both groups reinforce that, with caution, 1% morphine can be used after lamellar keratectomy in rabbits.     

Health evaluation of a radiocollared population of free-ranging Baird's tapirs (Tapirus bairdii) in Costa Rica.

The health of a population of free-ranging tapirs (Tapirus bairdii) inhabiting Corcovado National Park, Costa Rica, was assessed as part of an ongoing ecologic study. Nineteen tapirs were immobilized between March 1997 and February 2000, and samples of blood, skin biopsies, and ectoparasites were collected. Ticks were identified as Amblyomma oblongoguttatum or A. coelebs. Hematology and serum biochemistry results suggest statistically significant differences between free-ranging and captive populations that should be interpreted with caution in view of inherent environmental differences between the two populations. Five of 17 animals tested positive for Leptospira bratislava, and 12 individuals tested positive for Venezuelan equine encephalitis. One of nine skin biopsies examined was abnormal and diagnosed as leukoderma. This report represents the first health assessment of a free-ranging population of tapirs.     

Calvaria and orbital metastases of pulmonary adenosquamous carcinoma in a cat: a diagnostic challenge

An 11-year-old cat with a 4-month history of lethargy, inappetence, dysphagia, partial mandibular paralysis and weight loss, was euthanized due to the rapid deterioration of his condition. Post-mortem radiographic examination revealed severe bone lysis of the left zygomatic arch, temporal and parietal bones. Magnetic resonance imaging of the head showed a large isointense mass of the left side of the skull associated with extensive lysis of the parietal and temporal bones and destruction of the adjacent tympanic bulla. Gross and histological examinations revealed a pulmonary adenosquamous carcinoma of the left lung, with metastases to the spleen, liver, mesenteric lymph nodes, mesentery, diaphragm, abdominal aorta, left orbit and calvaria. No limb or digit metastases were detected.     

Estimating the number of undetected multi-resistant Salmonella Typhimurium DT104 infected pig herds in Denmark

In Denmark, the detection of multi-resistant Salmonella Typhimurium DT104 (MRDT104)-infected pig herds relies on the national Salmonella surveillance programme at the farm and slaughterhouse levels of production. With the surveillance sampling protocol and the diagnostic methods currently used, some herds might remain undetected. The number of undetected Danish pig herds infected with MRDT104 in the period 1 August 2001–31 July 2002 was estimated and compared with the number of culture-confirmed detected herds. A flow chart was constructed to illustrate where infected herds will go undetected in the surveillance system and Monte Carlo simulation was used to model the actual number of pig herds infected with MRDT1104. We estimated that 52 (90% CI [28, 178]) finisher herds were infected with MRDT104 compared to 23 (44%) detected. Among sow herds with production of weaners or growers, we estimated that 38 (90% CI [23, 74]) were infected with MRDT104 compared to 7 (18%) actually detected. Among breeder and multiplier herds, we estimated that five (90% CI [3, 8]) herds were infected with MRDT104 compared to three (60%) detected. In total, we estimated that 102 pig herds were infected with MRDT104 from 1 August 2001 till 31 July 2002 (90% CI [63, 228]). In comparison, 33 (32%) infected herds were detected in this period. The predicted proportion of undetected herds varied considerably with herd type. We infer that the proportion of detected MRDT104 infected herds depended on the intensity of the combined serological and bacteriological testing.