Phosphorus release from forest harvesting on an upland blanket peat catchment     

Michael Rodgers  Mark O’Connor  Mark Gerard Healy  Connie O’Driscoll  Zaki-ul-Zaman Asam  Mika Nieminen  Russell Poole  Markus Müller  Liwen Xiao 《Forest Ecology and Management》2010

The aim of this study was to investigate the release of phosphorus (P) to receiving waters resulting from harvesting 34-year-old lodgepole pine trees in an upland peat catchment. The study site was within a 25.3-hectare (ha) area, and was drained by a stream that received flows from ploughed furrows, mainly, via collector drains, and discharged directly to the salmonid Shrahrevagh River, Burrishoole, Co. Mayo, Ireland. The study site was divided into two parts: the upstream part was left intact and the downstream part was harvested in early Autumn 2005 following implementation of forest guidelines. Good management practices such as proper use of brash mats and harvesting only in dry weather were implemented. Two instrumented stations were established – one just upstream (US) and the other just downstream (DS) of the clearfelled area. The measurement of P concentrations at the two stations commenced in May 2005, two months before the harvesting started. The daily mean P concentration at the DS station increased from about 6 μg L⁻¹ of total reactive phosphorus (TRP) during pre-clearfelling to 429 μg L⁻¹ in August 2006. By October 2009, four years after clearfelling, the P concentrations at the DS station had returned to pre-clearfelling levels. In the first three years after harvesting, up to 5.15 kg ha⁻¹ of TRP was released from the harvested catchment to the receiving water; in the second year alone, 2.3 kg ha⁻¹ of TRP was released. Linear regression can be used to describe the relationship between TRP load and water discharge. About 80% of the total phosphorus (TP) in the study stream was soluble and more than 70% of the P release occurred in storm events, indicating that traditional buffer strips with widths of 15–20 m might not be efficient for P immobilization. The P concentrations were affected by antecedent weather conditions and highest concentrations occurred during storm events following prolonged drought periods. The water extractable phosphorus (WEP) contents in the soil were significantly higher below windrow/brash material than in brash-free areas, and whole-tree harvesting should be studied as one of the means to decrease P export from blanket peats.  相似文献   

Grape Seed-Derived Procyanidins Decrease Dipeptidyl-peptidase 4 Activity and Expression     

N González-Abuín  N Martínez-Micaelo  M Blay  G Pujadas  S Garcia-Vallvé  M Pinent  A Ardévol 《Journal of agricultural and food chemistry》2012,60(36):9055-9061

Dipeptidyl-peptidase 4 (DPP4) inhibitors are among the newest treatments against type 2 diabetes. Since some flavonoids modulate DPP4 activity, we evaluated whether grape seed-derived procyanidins (GSPEs), which are antihyperglycemic, modulate DPP4 activity and/or expression. In vitro inhibition assays showed that GSPEs inhibit pure DPP4. Chronic GSPE treatments in intestinal human cells (Caco-2) showed a decrease of DPP4 activity and gene expression. GSPE was also assayed in vivo. Intestinal but not plasmatic DPP4 activity and gene expression were decreased by GSPE in healthy and diet-induced obese animals. Healthy rats also showed glycemia improvement after oral glucose consumption but not after an intraperitoneal glucose challenge. In genetically obese rats, only DPP4 gene expression was down-regulated. Thus, procyanidin inhibition of intestinal DPP4 activity, either directly and/or via gene expression down-regulation, could be responsible for some of their effects in glucose homeostasis.  相似文献   

Predicting soil N mineralization using organic matter fractions and soil properties: A re-analysis of literature data     

Gerard H. Ros 《Soil biology & biochemistry》2012

Extractable organic matter (EOM) fractions have been used to assess the capacity of soils to supply nitrogen (N), but their role in N mineralization and their potential to improve agricultural fertilizer management are still under debate. This paper shows evidence that the relationship between EOM and soil N supply is an indirect relationship reflecting the soils' organic matter content. Data from 59 published experiments were re-analyzed using multivariate PLS modelling. Nitrogen mineralization was primarily related to the size of total and extractable organic matter fractions whereas variables reflecting soil texture and organic matter quality were less important. All EOM fractions reflected the soil organic matter content of the soil rather than a specific bioavailable fraction. There is strong need for research that explores the biochemical basis for relationships among total organic matter, extractable organic matter and soil N mineralization using mechanistic approaches.  相似文献   

The Effectiveness and Feasibility of Using Ochre as a Soil Amendment to Sequester Dissolved Reactive Phosphorus in Runoff   总被引：1，自引：0，他引：1  

Owen Fenton  Laura Kirwan  Daire Ó hUallacháin  Mark Gerard Healy 《Water, air, and soil pollution》2012,223(3):1249-1261

Incidental losses of dissolved reactive phosphorus (DRP) to a surface waterbody originate from direct losses during land application of fertilizer, or where a rainfall event occurs immediately thereafter. Another source is the soil. One way of immobilising DRP in runoff before discharge to a surface waterbody, is to amend soil within the edge of field area with a high phosphorus (P) sequestration material. One such amendment is iron ochre, a by-product of acid mine drainage. Batch experiments utilising two grassland soils at two depths (topsoil and sub-soil), six ochre amendment rates (0, 0.15, 1.5, 7.5, 15 and 30 g kg⁻¹ mass per dry weight of soil) and five P concentrations (0, 5, 10, 20 and 40 mg L⁻¹) were carried out. A proportional equation, which incorporated P sources and losses, was developed and used to form a statistical model. Back calculation identified optimal rates of ochre amendment to soil to ameliorate a specific DRP concentration in runoff. Ochre amendment of soils (with no further P inputs) was effective at decreasing DRP concentrations to acceptable levels. A rate of 30 g ochre kg⁻¹ soil was needed to decrease DRP concentrations to acceptable levels for P inputs of ≤10 mg L⁻¹, which represents the vast majority of cases in grassland runoff experiments. However, although very quick and sustained metal release above environmental limits occurred, which makes it unfeasible for use as a soil amendment to control P release to a waterbody, the methodology developed within this paper may be used to test the effectiveness and feasibility of other amendments.  相似文献   

Successful treatment of infectious (Salmonella type III: 44) polyarthritis and osteomyelitis in a 4‐week‐old foal     

K. Close  M. Gerard  G. Davidson  M. Schramme 《Equine Veterinary Education》2011,23(3):121-126

This article describes the acute onset of infectious polyarthritis and osteomyelitis in a 4‐week‐old foal. Analysis of synovial fluid obtained from the left femoropatellar and right tarsocrural joints combined with clinical signs consisting of joint effusion and lameness yielded a diagnosis of septic arthritis. Bacterial culture of synovial fluid from the left stifle revealed Salmonella type III: 44. Rapid, sustained clinical improvement was noted following discontinuation of empirical antimicrobial therapy (potassium penicillin and amikacin sulphate) and initiation of treatment with ceftiofur and ampicillin. The importance of combining knowledge of veterinary pharmacology and microbiology so that appropriate antimicrobials may be selected with regard to the local environment in which they are to eradicate infection is emphasised. Despite frequent reference to amikacin sulphate as an effective antimicrobial for treating infections in foals caused by Salmonella, factors are discussed that explain why amikacin may not be clinically effective for treating infectious arthritis caused by Salmonella.  相似文献   

Evaluation of Amendments to Control Phosphorus Losses in Runoff from Dairy-Soiled Water     

Owen Fenton  Ana Serrenho  Mark Gerard Healy 《Water, air, and soil pollution》2011,222(1-4):185-194

Amendments with the potential to reduce phosphorus (P) losses from agricultural grassland arising from the land application of dairy-soiled water (DSW) were investigated. Optimal application rates were studied, and associated costs and feasibility were estimated. First, batch tests were carried out to identify appropriate chemicals or phosphorus sorbing materials to control P in runoff from DSW. Then, the best four treatments were examined in an agitator test. In this test, soil??placed in a beaker??was loaded with DSW or amended DSW at a rate equivalent to 5 mm ha^?1 (the maximum permissible application rate of DSW allowable in a 42-day period in Ireland). The soil was overlain with continuously stirred water to simulate runoff on land-applied DSW. Optimum application rates were selected based on percentage removal of dissolved reactive phosphorus in overlying water and the estimated cost of amendment. The costs of the amendments, per cubic metre of DSW, increased in the order: bottom ash (1.55 ?), alum (1.67 to 1.92 ?), FeCl₂·4H₂O (3.55 to 8.15 ?), and lime (20.31 to 88.65 ?). The feasibility of the amendments, taking into account their cost, potential adverse effects, public perception, and their performance, decreased in the order: alum?>?FeCl₂·4H₂O?>?bottom ash?>?lime. Amendments to DSW could be introduced in critical source areas??areas where high soil test P and direct migration pathways to a receptor overlap.  相似文献   

Vestibular disease in dogs under UK primary veterinary care: Epidemiology and clinical management     

Sinziana Maria Radulescu  Karen Humm  Louis Mark Eramanis  Holger A. Volk  David B. Church  David Brodbelt  Dan Gerard O'Neill 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(5):1993-2004

  相似文献   

The Path of Carbon in Photosynthesis. XXV. Plant and Algal Growth Responses to Glycopyranosides     

Andrew A. Benson  Arthur M. Nonomura  Valrie A. Gerard 《Journal of plant nutrition》2013,36(7):1185-1200

Substituted glycopyranosides were applied to various plant species as foliar and root treatments, with and without nutrient supplements, and growth was compared to untreated or nutrient controls. When formulated with specific fertilizers, particularly available nitrogen, methyl and ethyl glycopyranosides significantly enhanced the overall growth of vascular plants compared to controls provided with the same nutrients. In contrast, vascular plants treated with alkylglycopyranosides without nutrients showed growth equivalent to that of untreated controls. Nitrogen-supplemented alkylglycopyranosides provided as foliar applications of 100 mM, or as root treatments between 35 and 50 mM, consistently enhanced root and shoot productivity. In addition to the vascular plant species tested, the brown alga Laminaria saccharina exhibited significant growth enhancement over nutrient controls when treated with alkylglycopyranosides supplemented with nutrients, especially under low irradiance. Overall, these results indicate that growth of photosynthetic organisms is enhanced by exogenous alkylglycopyranosides supplemented with nitrogen and micronutrients, but not by alkylglycopyranosides alone.  相似文献   

PRIMARY IRRADIATION OF CANINE INTRACRANIAL MASSES     

Enrico P.  Spugnini DVM  Donald E.  Thrall DVM  PhD  G. Sylvester  Price DVM  PhD  Nicholas J.  Sharp BVM  PhD  Karen  Munana DVM  Rodney L.  Page DVM 《Veterinary radiology & ultrasound》2000,41(4):377-380

Twenty-nine dogs received primary radiation therapy for intracranial lesions and clinical signs suggestive of neoplasia. Presumptive diagnosis and tumor categorization was based on computed tomographic or magnetic resonance images. Meningioma was the most likely tumor type in 22 dogs and glioma or choroid plexus tumors were tentatively identified in 4 and 3 dogs, respectively. Cobalt-60 radiation was delivered in 3 Gy fractions on a daily, Monday-through-Friday basis for a total dose of 48 Gy (16 fractions) in 28 dogs; one dog received 54 Gy. Two of 29 dogs died during treatment of signs suggestive of progressive tumor growth but were included in the overall evaluation of response to treatment. Median overall survival was 250 days (range 21-804). Mild acute radiation effects on normal tissue developed and did not influence outcome in any dog. Late radiation effects could not be evaluated in this study. No significant predictive indicators were identified from the clinical or imaging data. Radiation therapy is superior to medical treatment of brain tumors in dogs with steroids, is useful for tumors that are not currently operable and may be preferable to surgical resection in dogs if the mass appears infiltrative. However, 22/29 (76%) dogs died of recurrent progressive neuropathy suggestive of tumor regrowth or progression. Thus, alternative methods for delivery of radiation to dogs with brain tumors or novel combinations of therapy should continue to undergo evaluation.  相似文献   

Diagnostic de la rage sur culture cellulaire Comparaison des resultats de l'inoculation au neuroblastome murin et de l'inoculation a la souris     

J. Barrat  Marie Jos  Barrat  Monique Picard  M. F. A. Aubert  collaboration technique  Y. Gerard  Chantal Patron  Josiane Ambert  B  atrice Quillou 《Comparative immunology, microbiology and infectious diseases》1988,11(3-4):207-214

Mouse inoculation test (MIT) is a highly sensitive test for rabies diagnosis but slow and expensive. To detect rabies virus an in vitro technique using Neuro 2a cell culture (CC) was compared with MIT in two laboratories.

In one laboratory, CC appeared to be on the whole more sensitive than MIT, nevertheless MIT was the only one to detect some positive samples. In the other laboratory, MIT was more sensitive. These results justify the use of CC for epidemiological diagnosis but emphasize the interest of MIT (the reference technique) for special cases.  相似文献