Evaluation of enzymes inhibition activities of medicinal plant from Burkina Faso     

Bangou MJ  Kiendrebeogo M  Meda NT  Coulibaly AY  Compaoré M  Zeba B  Millogo-Rasolodimby J  Nacoulma OG 《Pakistan journal of biological sciences: PJBS》2011,14(2):99-105

The aim of the present study was to evaluate some enzymes inhibitory effects of 11 plant species belonging to 9 families from Burkina Faso. Methanolic extracts were used for their Glutathione-s-transferase (GST), Acetylcholinesterase (AChE), Carboxylesterase (CES) and Xanthine Oxidase (XO) inhibitory activities at final concentration of 100 microg mL(-1). The total phenolics, flavonoids and tannins were also determined spectrophotometrically using Folin-Ciocalteu, AlCl3 and ammonium citrate iron reagents, respectively. Among the 11 species tested, the best inhibitory percentages were found with Euphorbia hirta, Sclerocarya birrea and Scoparia dulcis (inhibition > 40%) followed by Annona senegalensis, Annona squamosa, Polygala arenaria and Ceratotheca sesamoides (inhibition > 25%). The best total phenolic and tannin contents were found with S. birrea with 56.10 mg GAE/100 mg extract and 47.75 mg TAE/100 mg extract, respectively. E hirta presented the higher total flavonoids (9.96 mg QE/100 mg extract). It's was found that Sclerocarya birrea has inhibited all enzymes at more than 30% and this activity is correlated to total tannins contents. Contrary to S. birrea, the enzymatic activities of E. hirta and S. dulcis are correlated to total flavonoids contents. Present findings suggest that the methanolic extracts of those plant species are potential inhibitors of GST, AChE, CES and XO and confirm their traditional uses in the treatment of mental disorders, gout, painful inflammations and cardiovascular diseases.  相似文献   

Immunity to virus X in potato: Selection of immune plants in the breeding program     

Roland G. Timian  C. E. Peterson  W. J. Hooker 《American Journal of Potato Research》1955,32(11):411-417

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Nitrogen mineralization from mature bio‐waste compost in vineyard soils. III Simulation of soil mineral‐nitrogen dynamics     

Claas Nendel  Kurt‐Christian Kersebaum  Rolf Nieder  Roland Kubiak 《植物养料与土壤学杂志》2007,170(5):598-607

A model for nitrogen (N) dynamics in compost‐amended vineyard soils was tested for its predictive power. A soil–mineral N data set from a 3‐year field study on four different vineyard sites was used for model evaluation. The soils were treated with mature bio‐waste compost (30 and 50 Mg ha^–1 fresh matter, respectively). The model calculated soil mineral‐N contents at all sites with an overall mean bias error of –2.2 kg N ha^–1 for layers of 0.1 m thickness and an overall mean absolute error of 7.4 kg N ha^–1 layer^–1. Modeling efficiencies for the simulations of the respective treatments ranged from –0.05 to 0.41, and Willmott's Index of Agreement showed values of between 0.41 and 0.81. Acceptable model predictions as defined by the observed variability of mineral‐N contents in the respective soils ranged from 40% to 72%. A strong increase in soil mineral‐N concentration following the compost application at all sites could not be reproduced with the model, thereby reducing the prediction accuracy significantly. The model performance confirms that previously derived N‐mineralization parameters are suitable to describe the N release from soil‐applied mature bio‐waste compost under the environmental conditions of vineyards in Germany.  相似文献   

An investigation of humus disintegration by spatial-temporal regression analysis     

Roland?FriedEmail author 《Journal of Agricultural, Biological & Environmental Statistics》2004,9(2):138-157

We examine the hypothesis of an increase of humus disintegration by analyzing chemical substances measured in the seepage water of a German forest. Problems arise because of a large percentage of missing observations. We use a regression model with spatial and temporal effects constructed in an exploratory data analysis. Spatial dependencies are modeled by random effects and an autoregressive structure for observations in distinct soil depths resulting in a recursive linear mixed model structure. Temporal dependencies are included by an autoregressive structure of the random effects. For parameter estimation an EM algorithm is deduced assuming the errors to be Gaussian. As a result of the data analysis we specify chemical substances which possibly affect the process of humus disintegration. In particular, we find evidence that the presence of aluminum ions is important, but because of the high correlations among the regressors this might be due to confounding with iron.  相似文献   

Do invertebrate decomposers affect the disappearance rate of litter mixtures?     

Martin Schädler  Roland Brandl 《Soil biology & biochemistry》2005,37(2):329-337

We designed an experiment using litter bags with fine and coarse mesh size to analyse interacting effects between invertebrate decomposers and the number of litter species on litter disappearance rates. We used litter of nine broad-leaved tree species to compare disappearance rates of litter from single species with mixtures of two to six species. Species composition of litter and invertebrates interacted strongly in their effects on litter disappearance rate. Contribution of invertebrates to litter disappearance increased with time mainly for litter which disappeared slower in the absence of invertebrates. Disappearance rates were positively correlated with initial N content and negatively correlated to initial C content of litter. These relationships were stronger in the presence of invertebrates, suggesting that their activity is positively related to initial litter chemistry. Number of component litter species, however, had no effect on disappearance rate irrespective of the activity of invertebrates. Using individual rates of disappearance for single species, we calculated the expected rates of disappearance for each of the experimental mixtures of leaf litters. We found that mixtures of several species of leaf litter resulted in significant deviations from the expected values. These deviations showed a significant effect of the number of component litter species. However, this result was caused by a strong negative deviation of one single mixture of six species. The presence of invertebrates resulted in even greater deviations from the expected values, suggesting an important contribution of invertebrates to the effects of litter mixing on litter disappearance rates. Hence, our results underline the importance of idiosyncratic effects of species traits in mixtures. Our results suggest that the influence of invertebrate decomposers interacts with litter chemistry during decomposition, but is not affected by litter species richness per se.  相似文献   

ALUMINIUM TOXICITY AND TOLERANCE IN THREE HEATHLAND SPECIES     

de Graaf  Maaike C. C.  Bobbink  Roland  Verbeek  Peter J. M.  Roelofs  Jan G. M. 《Water, air, and soil pollution》1997,98(3-4):229-239

Arnica montana and Cirsium dissectum are characteristic species of species-rich heathlands and adjacent grasslands, which declined during the last decades in the Netherlands. It has been shown in a recent field survey that the decline of A. montana and C. dissectum might be caused by soil acidification. Calluna vulgaris is not susceptible to soil acidification. It was hypothesized that increased aluminium concentrations in the soil as a result of acidifying atmospheric inputs caused the decline of A. montana and C. dissectum whereas C. vulgaris would not be sensitive to enhanced aluminium concentrations. We studied the effects of different Al:Ca-ratios and of Al concentrations on the development of A. montana, C. dissectum and C. vulgaris in nutrient solution experiments. All three species showed aluminium accumulation in the shoots related with increased aluminium concentrations in the nutrient solutions. This accumulation was correlated with a reduction in growth when plants were cultured at high Al concentrations (200–500 µmol l^-1), in both A. montana and C. dissectum. In addition, indications of Al toxicity were observed in these plant species, e.g. poor root development, yellowish leaves and reduced contents of Mg and P in the plants. C. vulgaris did not show reduced growth or poor plant development due to high Al concentrations. The negative effects of aluminium in A. montana and C. dissectum were partly counterbalanced when plants were grown on the same Al concentrations but with increased Ca concentrations, resulting in lower Al:Ca-ratios. No effects of enhanced calcium concentrations on C. vulgaris have been observed.  相似文献   

Microbial regulation of net N mineralisation is driven by C,N, P content and stoichiometry     

Qiqi Wang  Wei Gao  Roland Bol  Qiong Xiao  Lei Wu  Wenju Zhang 《European Journal of Soil Science》2022,73(3):e13257

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Rice varietal difference in sheath blight development and its association with yield loss at different levels of N fertilization     

Qiyuan Tang  Shaobing Peng  Roland J. Buresh  Yingbin Zou  Nancy P. Castilla  Twng W. Mew  Xuhua Zhong 《Field Crops Research》2007

Variety and nitrogen (N) fertilizer input are the two main factors that influence the development of sheath blight (ShB) caused by Rhizoctonia solani in intensive and high-input rice (Oryza sativa L.) production systems. This study was conducted to determine the varietal difference in ShB development and its association with yield loss across N rates. Two indica inbred and two indica/indica F₁ hybrid varieties were grown under 0 and 90 kg N ha⁻¹ in 2003 wet season (WS) and under 0, 75, 145, and 215 kg N ha⁻¹ in 2004 dry season (DS). Inoculation was done in 3.2 m² in each experiment unit to achieve uniform disease development. Disease intensity was quantified by measuring relative lesion height (RLH) and ShB index (ShBI) of inoculated 10 hills at flowering and 14 days after flowering. Plant traits, grain yield, temperature, and relative humidity inside the canopy were also measured. Consistent and significant varietal differences in ShB intensity were observed across N rates in both WS and DS. Among the four varieties, IR72 and IR75217H had higher RLH and ShBI than PSBRc52 and IR68284H at all N rates. Sheath blight index at 14 days after flowering had the closest correlation with yield loss from ShB. Varieties with taller stature, fewer tillers, and lower leaf N concentration such as IR68284H generally had lower RLH and ShBI, and consequently lower yield loss from the disease. Disease intensity and yield loss from ShB increased with increasing N rates, but the magnitude of yield loss varied among varieties. This suggests that fertilizer N should be managed more precisely and differently for varieties with different plant type in order to reduce the disease development and maximize grain yield in the irrigated rice systems.  相似文献   

Variations in concentrations of N and P forms in leachates from dried soils rewetted at different rates     

Martin S. A. Blackwell  Alison M. Carswell  Roland Bol 《Biology and Fertility of Soils》2013,49(1):79-87

The rate at which dried soils are rewetted can affect the quantities and forms of nutrients in leachates. Both dried and moist replicated (n?=?3) samples of two contrasting grassland soil types (clayey vs brown earth) were irrigated during laboratory experiments with identical total amounts of water, but at different rates, ranging from 0 h, increasing by 30-min increments up to 4 h, and additionally a 24-h rewetting rate. Total P concentrations in leachates from dried samples of both soils generally decreased as rewetting rate increased, ranging from 2,923?±?589 μg P L^?1 (0.5 h rewetting rate) to 731?±?46.0 μg P L^?1 (24 h, clayey soil) and 1,588?±?45.1 μg P L^?1 (0.5 h) to 439?±?25.5 μg P L^?1 (24 h brown earth). Similar patterns in concentrations occurred for molybdate reactive P (MRP), although concentrations were generally an order of magnitude lower, indicating that the majority of the leached P was probably organic. The moist brown earth leached relatively high concentrations of MRP (maximum 232?±?10.6 μg P L^?1, 0.5 h), unlike the moist clayey soil (maximum 20.4?±?10.0 μg P L^?1, 0 h). The total oxidised N concentrations in leachates were less affected by rewetting rate, although longer rewetting rates resulted in decreased concentrations in leachates from the dried samples of both soils. The difference in responses to rewetting rates of the two soils is probably due to differences in the fate of the microbial biomass and adsorption properties in the soils. Results show that soil moisture could be an important factor in regulating nutrient losses and availability, especially under changing patterns of rainfall predicted by future climate change scenarios.  相似文献   

Tenoscopy of the navicular bursa: Endoscopic approach and anatomy     

Fabrice Rossignol DVM  Roland Perrin DVM  Diplomate ECVS 《Journal of Equine Veterinary Science》2003,23(6):258-265

Objectives: Our objectives were to describe an endoscopic technique of the navicular bursa, describe the endoscopic anatomy, assess its feasibility on live horses undergoing an exploratory endoscopy, and assess the usefulness of standard arthroscopic instruments introduced via a contralateral portal.Study design: This was an anatomic study on cadaver limbs and endoscopic observation on clinical cases associated with problems of the navicular bursa and/or navicular bone.Animals or sample population: The sample population was 4 cadaver forelimbs of 2 horses weighing 300 to 450 kg and 8 live horses and one pony weighing 180 to 550 kg with navicular bursa disease.Methods: One cadaver limb was left untouched; the 3 others were dissected in a different way. Dissection and endoscopy of the navicular bursa were performed on the cadaver limbs with 4-mm and 2.7-mm 30° forward oblique arthroscopes. Relative positions of the arthroscope and of various arthroscopic instruments in the bursa were observed. Then, exploratory endoscopy of the navicular bursa was performed on live horses suspected of navicular bursa disease after clinical, radiographic, and/or sonographic examination. Visualization with saline solution and carbon dioxide was compared. Standard arthroscopic instruments were introduced according to the lesions observed. Some lesions were treated and a lavage of the navicular bursa was performed in all horses. Postoperative recovery was followed until 3 months after surgery.Results: Most parts of the anatomic structures of the navicular bursa could be observed with the 4-mm or 2.7-mm arthroscope, and standard arthroscopic instruments could be introduced into the bursa. A lavage of the bursa could be performed in all horses and no iatrogenic damage or postoperative complications were noted.Conclusion: Endoscopy of the navicular bursa with standard arthroscopic instruments is a feasible technique in horses and could be a useful diagnostic modality in suspected disease of this area.Clinical application: Diagnostic endoscopy in horses suspected of navicular bursa disease can be used to complement other diagnostic means. It already is used for treatment of septic bursitis; endoscopy of the navicular bursa could have other therapeutic applications in the future.

Introduction

Arthroscopy of the dorsal aspect of the distal interphalangeal joint in horses was used for removal of extensor process fractures and for diagnosis examination of this joint.¹ Arthroscopy of the palmar (plantar) aspect of the distal interphalangeal joint was described for removal of fibrin, intra-articular lavage in septic arthritis, and to access some fractures of the distal sesamoid (navicular) bone and middle and distal phalanges.²Endoscopy of the bursa podotrochlearis (navicular bursa) was recently described for treatment of septic bursitis.³ In this procedure, the instruments were mostly introduced through the original penetrating wound at the frog and through the flexor digitorum profundus (deep digital flexor tendon). In another study,⁴ the authors observed the navicular bursa in cadaver limbs and compared the endoscopic observation with pathologic findings.Lesions of the navicular bursa and contiguous anatomic structures (deep digital flexor tendon, palmar/plantar fibrocartilaginous facies flexoria [flexor surface] of the navicular bone, ligamentum sesamoideum distale impar [impar ligament], and ligamenta sesamoidea collateralia [collateral sesamoidean ligament]) can be associated with navicular syndrome.^{5, 6 and 7}Conventional radiographs allow evaluation of osseous lesions of the navicular bone (loss of cortico-medullary definition, irregularity of the sagittal ridge of the facies flexoria, and irregularity or thickening of the flexor cortex)^{5, 8 and 9} but are less sensitive for soft tissue evaluation.Ultrasonography allows the evaluation of some soft tissue lesions.¹⁰ It can be performed at the palmar aspect of the pastern or by a transfurcal approach.Scintigraphy is more sensitive than radiography in the evaluation of navicular syndrome, and it can complete an inconclusive radiographic examination.¹¹Magnetic resonance imaging (MRI) and computed tomography (CT) scan are also valuable diagnostic means for navicular syndrome in revealing some osseous abnormalities undetectable with conventional radiographs^{8 and 12} and, for MRI, in providing a reliable evaluation of soft tissues.^{13, 14 and 15}The objectives of this study were to document an endoscopic approach to the navicular bursa, describe the endoscopic anatomy, assess the usefulness of standard surgical instruments introduced via a contralateral portal (which could have potential benefits in diagnosis or treatment of lesions in this area), and finally, to assess the feasibility of this technique in live horses undergoing an exploratory endoscopy.

Instrumentation

The procedure was performed at 2 different clinics with different sets of instruments. Equipment used included two 4-mm (Dyonics or Storz) and one 2.7-mm (Optomed) 30° forward oblique arthroscopes connected to a light cable (Optomed or Storz) and light source (Stryker or Storz). The arthroscope was connected to a camera (Stryker or Storz) and a video system, which allowed recording and printing of endoscopic views. Various surgical instruments were used: a blunt tendon knife for splitting surgery, motorized synovial resector blades (Dyonics), straight and curved curettes (Sontek), Basket type synoviectomy forceps (Acufex), and Ferris-Smith rongeurs (Sontec).

Procedure

Cadaver limbs

Four distal forelimbs from 2 French Warm Blood equine cadavers weighing 300 to 450 kg with no lameness history were examined. Radiographs of the navicular bone were previously performed to document the absence of preexisting lesions. Three views were used: Dorso (60°) proximal-palmarodistal oblique, lateromedial, and palmaro (45°) proximal-palmarodistal oblique.The first limb was partially dissected (skin and subcutaneous tissue were removed) and the navicular bursa was examined by introducing the 4-mm arthroscope lateral to the deep digital flexor tendon.Navicular bursa endoscopy was performed in a similar way on the second undissected limb. The procedure was recorded on videotape and endoscopic photographs were printed. Various instruments were introduced by a medial approach, symmetrically to the arthroscope portal.The third limb was partially dissected like the first and cut in a sagitttal way with a sharp circular saw. The 4-mm arthroscope was introduced into the bursa and its progression from the skin to the bursa was observed by a sagittal view (Figs 1 and 2).