The decomposition of turfgrass clippings is fast at high air humidity and moderate temperature

Abstract

In grassland areas where herbage production has no economic value, the cut grass is often left on the sward surface where its decomposition is influenced by weather conditions. Although the influence of temperature and humidity on decomposition has been investigated under controlled lab conditions, experimentation has generally been under ideal moisture conditions that have not tested the combinations of climatic limitations that might occur in the field. The decomposition of mown turfgrass clippings deposited at different times of vegetation period was studied in situ using nylon bags during the first 8 weeks after deposition to investigate the effect of weather conditions (the air temperature, relative humidity, precipitation) on decomposition. Decomposition is the highest in the case of high air humidity and temperature of 10°C. Limiting factors for decomposition at temperatures above 10°C is the air humidity and below 10°C the air temperature. The general tendency was that the rate of decomposition increased with increasing air temperature up to 10°C, but with further increases of air temperature the decomposition rate slowed down. Relative air humidity had a variable impact (at the beginning of the decomposition process (weeks 1–2) the influence was negative, during weeks 3–8 of the decomposition process the effect was positive), and hence had no generalized relationship with decomposition over the studied decomposition period (weeks 1–8). The most significant influence of weather conditions on the decomposition rate was recorded directly after cutting. If the cutting was done during hot weather conditions, the material was drying fast and therefore decomposed slowly. Our results indicate that for fast decomposition of clippings it is important to maintain the freshness of material. Lower decomposition rates occurred during conditions of hot and dry weather, and also cooler (temperature near to 0°C) weather, and can be compensated as soon as favourable weather arrives.     

Effects of drought and canopy ozone exposure on antioxidants in fine roots of mature European beech (Fagus sylvatica)

We quantified ascorbate, glutathione and alpha-tocopherol in fine roots of mature Fagus sylvatica L. under free-air canopy ozone (O(3)) exposure (twice ambient O(3) concentration, 2x[O(3)]) during two growing seasons that differed in the extent of summer drought (exceptional drought year 2003, average year 2004). This design allowed us to test whether O(3) exposure or drought, or both, affected root antioxidants during the growing season. In both years, root ascorbate and alpha-tocopherol showed a similar relationship with volumetric soil water content (SWC): ascorbate concentrations on a root dry mass basis increased from about 6 to 12 micromol g(-1) when SWC dropped from 25 to 20%, and a-tocopherol increased from 100 to 150 nmol g(-1) at SWC values below 20%. Root glutathione showed no relationship with SWC or differences between the dry and the average year, but it was significantly and consistently diminished by 2x[O(3)]. Our results were inconclusive as to whether shoot-root translocation of glutathione or glutathione production in the roots was diminished. Phloem glutathione concentrations in the canopy remained constant, but reduced transport velocity in the phloem and, as a consequence, reduced mass flow of glutathione cannot be ruled out.     

Reconstruction of the lower eyelid by third eyelid lateral advancement and local transposition cutaneous flap after "en bloc" resection of squamous cell carcinoma in 5 cats

OBJECTIVE: To describe a novel technique for blepharoplasty to cover a tissue defect involving >/=50% of the lower eyelid. STUDY DESIGN: Prospective clinical study. ANIMALS: Five cats with lower eyelid squamous cell carcinoma (SCC). METHODS: En bloc resection of SCC by removing >/=50% of the lower lid with either the medial or lateral canthus was performed without other adjunctive treatment for SCC. The lid defect was reconstructed with a transposition skin flap derived from the frontal (medial defect) or temporal (lateral defect) region. The third eyelid was advanced laterally without dissection from its insertion; its outer conjunctival layer was removed, and the skin flap was sutured with single interrupted sutures dorsally over the nictitating membrane, ventrally to the cutaneous edge of the surgical wound and medially or laterally (depending on the canthus removed) to the skin of the remaining lower lid. RESULTS: Satisfactory cosmetic and functional results were achieved and the Schirmer tear tests were normal. In 2 cats, the skin flap needed monthly hair trimming to avoid corneal lesions. CONCLUSIONS: After en bloc resection of SCC involving >/=50% of the lower eyelid, reconstruction can be achieved by relocation of the third eyelid and use of a cutaneous transposition flap sutured to the scarified external surface of the third eyelid. Eyelid apposition and lacrimal function were preserved. CLINICAL RELEVANCE: Blepharoplasty using a cutaneous transposition flap sutured to the scarified surface of a relocated third eyelid should be considered for reconstruction of lower eyelid defects with >/=50% tissue loss of the lid margin.     

Evaluation of assays for perinuclear antineutrophilic cytoplasmic antibodies and antibodies to Saccharomyces cerevisiae in dogs with inflammatory bowel disease

OBJECTIVE: To evaluate the use of immunofluorescence asssays for perinuclear antineutrophilic cytoplasmic antibodies (pANCAs) and antibodies to Saccharomyces cerevisiae (ASCAs) in dogs with inflammatory bowel disease (IBD) and assess the clinical value of these serologic markers of the disease. ANIMALS: 39 dogs with IBD, 18 dogs with acute diarrhea, 19 dogs with chronic non-IBD-associated diarrhea, 26 healthy dogs of various breeds and age, and 22 healthy young working dogs. PROCEDURE: Sera obtained from the dogs in each group were added to canine granulocyte- and Saccharomyces cerevisiae-mounted slides for detection of pANCAs and ASCAs via immunofluorescence techniques. Sensitivity and specificity (with 95% confidence intervals [CIs]) were calculated for the group of dogs with IBD versus each of the 2 groups of healthy dogs, the group of dogs with acute diarrhea, and the group of dogs with chronic non-IBD-associated diarrhea. RESULTS: Among the 39 dogs with IBD, 20 yielded positive results via the pANCA assay (sensitivity, 0.51 [95% CI, 0.35 to 0.67]) and 17 yielded positive results via the ASCA assay (sensitivity, 0.44 [95% CI, 0.22 to 0.69]). The specificity of the pANCA assay in the 4 groups of non-IBD-affected dogs ranged from 0.83 (95% CI, 0.85 to 0.96) to 0.95 (95% CI, 0.72 to 1.00). CONCLUSIONS AND CLINICAL RELEVANCE: Immunofluorescence assays for pANCA and ASCA appear to be useful for the detection of IBD in dogs. The pANCA immunofluorescence assay had high specificity for canine IBD, and pANCAs appear to be accurate markers of intestinal inflammation.     

Markers of Borna disease virus infection in cats with staggering disease

Borna disease virus (BDV) is a RNA-virus causing neurological disorders in a wide range of mammals. In cats, BDV infection may cause staggering disease. Presently, staggering disease is a tentative clinical diagnosis, only confirmed at necropsy. In this study, cats with staggering disease were investigated to study markers of BDV infection aiming for improvement of current diagnostics. Nineteen cats fulfilled the inclusion criteria based on neurological signs and pathological findings. In 17/19 cats, BDV infection markers (BDV-specific antibodies and/or BDV-RNA) were found, and antibodies in serum (13/16, 81%) were the most common marker. BDV-RNA was found in 11/19 cats (58%). In a reference population without neurological signs, 4/25 cats were seropositive (16%). The clinical history and neurological signs in combination with presence of BDV infection markers, where serology and rRT-PCR on blood can be helpful tools, improve the diagnostic accuracy in the living cat.     

Antigen presenting cells in mucosal sites of veterinary species

The ability of antigen presenting cells, in particular dendritic cells, to integrate a variety of environmental signals, together with their ability to respond appropriately by initiating either tolerance or defensive immune responses make them cells of particular relevance and importance in the mucosal environment. They have been demonstrated in a variety of mucosal tissues in veterinary species and have been characterized to varying degrees, showing that fundamental immunological principles apply throughout all species, but also highlighting some species differences. A major advantage of carrying out immunological research in veterinary species is their size: it is possible to cannulate lymphatic ducts and obtain information about cell migration between different tissues. It is also possible to obtain pure populations of relatively rare cell types such as the plasmacytoid dendritic cells or mucosal dendritic cells ex vivo for the study of immune responses to diseases in their natural host and for other thorough functional studies. Two major myeloid antigen presenting cell (APC) (dendritic cells, DC) cell populations have been described in gut draining lymph and other mucosal sites in ruminants and pigs, characterised by the presence or absence of surface molecules, their enzyme profiles, their ability to phagocytose and their different potential as APC. There is evidence that one of these subsets has migrated from the diffuse mucosal tissue, where it is found as a phagocytic as well as stimulatory APC population, which in turn may be derived from blood macrophages. In addition, the presence and role in viral infection of the IFN-alpha producing plasmacytoid DC in mucosal tissue is discussed, based on studies in pigs.     

Cold tolerance during juvenile development in sorghum: a comparative analysis by genomewide association and linkage mapping

Improved cold tolerance during the juvenile phase is a major breeding goal to develop new sorghum cultivars suitable as an alternative energy crop in temperate regions. The objectives of this study were to identify marker‐trait associations for cold tolerance in a sorghum diversity panel fingerprinted with 2620 single nucleotide polymorphism (SNP) markers and to detect quantitative trait loci (QTL) in two F_2:3 populations. Traits of interest were dry matter growth rate (DMGR), leaf appearance rate (LAR), chlorophyll content (SPAD) and chlorophyll fluorescence (F_v′/F_m′ and Ф_PSII) in relation to temperature. The association panel comprised 194 genotypes, while the F_2:3 populations consisted of 80 and 92 genotypes. All populations were tested under controlled conditions in a minimum of four temperature regimes ranging from 9.4°C to 20.8°C. QTL were identified for means across environments and regression parameters describing temperature effects. Several marker‐trait associations for mean (m) DMGR, base temperature (T_b) of SPAD and Ф_PSII and temperature effect on LAR were validated by QTL detected in population 1 or 2. Promising QTL regions were found on chromosomes SBI‐01, SBI‐02, SBI‐03, SBI‐04, SBI‐06 and SBI‐09, among them genomic regions where candidate genes involved in the C‐repeat binding pathway or encoding cold‐shock proteins are located.     

Nod2 mutation in Crohn's disease potentiates NF-kappaB activity and IL-1beta processing

Variants of NOD2, an intracellular sensor of bacteria-derived muramyl dipeptide (MDP), increase susceptibility to Crohn's disease (CD). These variants are thought to be defective in activation of nuclear factor kappaB (NF-kappaB) and antibacterial defenses, but CD clinical specimens display elevated NF-kappaB activity. To illuminate the pathophysiological function of NOD2, we introduced such a variant to the mouse Nod2 locus. Mutant mice exhibited elevated NF-kappaB activation in response to MDP and more efficient processing and secretion of the cytokine interleukin-1beta (IL-1beta). These effects are linked to increased susceptibility to bacterial-induced intestinal inflammation and identify NOD2 as a positive regulator of NF-kappaB activation and IL-1beta secretion.