A statistical analysis of the impact of nematode attack symptomatology on the mechanical behaviour of <Emphasis Type="Italic">Pinus pinaster</Emphasis> Ait. wood     

Abel Rodrigues  Miguel Casquilho  Hélène Oliveira  João Bordado 《European Journal of Forest Research》2010,129(2):145-153

An appraisal was made about the impact of pinewood nematode (Bursaphelenchus xylophilus, Nickle) attack symptomatology on the mechanical behaviour of wood from Pinus Pinaster Ait. Two sets of 200 wood specimens were obtained for the study of both mechanical and other physical properties. The specimens, about half of which presented symptoms of nematode, were obtained from a set of 66 wood planks, cut from an equal number of trees, originating from the Setúbal Peninsula (Portugal). Logistic analysis using symptomatology as a binary dependent variable showed adequacy of models containing compression tension to rupture and number of wood rings per unit radial length for the prediction of nematode attack. Analysis of variance revealed that the presence of the disease symptoms was correlated to static bending rupture, modulus of elasticity, work to maximum bending load, and axial compression rupture, causing their decrease at a significance level of 5%.  相似文献   

Sufficiency ranges and crop nutrient removals for peppermint (Mentha X piperita L.) established from field and pot fertilizer experiments     

Margarida Arrobas  Isabel Q. Ferreira  Sandra Afonso  M. Ângelo Rodrigues 《Communications in Soil Science and Plant Analysis》2018,49(14):1719-1730

Peppermint is an important aromatic and medicinal plant used across the world in pharmaceutical, cosmetic and food industries. However, there is a lack of agronomic research on this crop which hinders the implementation of best agricultural practice at farm level. Plant analysis, for instance, cannot be used as a tool to implement a suitable fertilizer recommendation program, since sufficiency ranges and crop nutrient removals have not yet been established. Thus, the main objectives of the present work were to assess the response of peppermint to varying nitrogen (N), phosphorus (P), potassium (K) and boron (B) rates, to establish sufficiency ranges from macro, micronutrients and SPAD-readings and to estimate crop nutrient removals in the aboveground biomass. Field trials and pot experiments were conducted from 2013 to 2015 in a wide range of conditions involving 12 N, P, K or B fertilizer trials and a total of 48 cuts of biomass. Nitrogen fertilization increased dry matter yield of peppermint on the vast majority of sampling dates. In contrast, P, K, or B did not produce a significant effect on dry matter yield in any of the experiments. The sufficiency ranges set for macronutrients N, P, K, Ca and Mg are respectively 32.0 – 42.0, 1.2 – 4.5, 10.0 – 30.0, 7.0 – 23.0, and 4.0 – 10.0 g kg^?1. Those for micronutrients B, copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn) are respectively 20 – 200, 5 – 25, 100 – 600, 25 – 300, and 30 – 200 mg kg^?1. Sufficiency range for SPAD-readings is 45 – 50 SPAD units. All these ranges were established for the commercial harvesting date. The amounts of N, P, K, calcium (Ca), and magnesium (Mg) removed in aboveground biomass are respectively 22.7, 1.6, 26.4, 16.4 and 4.8 kg Mg^?1 of dry biomass.  相似文献   

Relationship between chlorophyll meter readings and nitrogen in poinsettia leaves     

Bruce L. Dunn  Hardeep Singh  Carla Goad 《Journal of plant nutrition》2018,41(12):1566-1575

Chlorophyll meters are used for non-destructive estimation of leaf nitrogen (N). The objective of this study was to evaluate the readings with several chlorophyll meters (SPAD-502, atLEAF, and CCM-300), different sampling sites on leaves, number of leaves used for sampling, and different types of leaf N sampling on estimation of N in leaves of potted poinsettia (Euphorbia pulcherrima) “Prestige Red.” Results showed that all meters gave readings that were correlated for N determination and also were correlated with each other. SPAD and atLEAF showed interaction between different N treatments and different sampling sites on the leaves, while CCM readings were affected by different sampling sites on the leaf. atLEAF readings showed interaction between number of leaves sampled and different N treatments. Thus, during sensor-based leaf N estimation, sampling site on leaf, number of leaves sampled, and stage of plant development should be considered to minimize error.  相似文献   

Sufficiency ranges for lemon balm and nutrient removals in aboveground phytomass     

M. Ângelo Rodrigues  Isabel Q. Ferreira  Sandra Afonso  Margarida Arrobas 《Journal of plant nutrition》2018,41(8):996-1008

A set of fertilizer experiments were conducted during three growing seasons with the aim of establishing sufficiency ranges and crop nutrient removals for Melissa officinalis L. Critical nutrient concentrations were determined by the Cate–Nelson method or by removing 10% of extreme high and low values, respectively if a positive response to a given nutrient was recorded or not. Sufficiency ranges for macro, micronutrients, and SPAD-readings were set as: 27.0–40.0 g N kg^?1; 0.8–2.7 g P kg^?1 (May–August); 1.5–3.8 g P kg^?1 (September–November); 10.0–25.0 g K kg^?1 (May–August); 18.0–32.0 g K kg^?1 (September–November); 5.0–25.0 g Ca kg^?1; 3.5–8.5 g Mg kg^?1; 18–125 mg B kg^?1; 5–25 mg Cu kg^?1; 75–500 mg Fe kg^?1; 20–300 mg Zn kg^?1; 30–250 g Mn kg^?1; 30–45 SPAD-units. These results will allow laboratories to use plant analysis as an important tool in improving the fertilizer recommendations for this species.  相似文献   

Linking sorghum nutrition and production with arbuscular mycorrhizal fungi and alternative soil amendments          下载免费PDF全文

Adam B. Cobb  Gail W. T. Wilson  Carla L. Goad 《植物养料与土壤学杂志》2018,181(2):211-219

Mounting fertilizer costs are disproportionally affecting farmers in developing countries. Alternative soil fertility amendments [worm compost, pyrolyzed carbon (biochar)] and arbuscular mycorrhizal fungi have the potential to reduce these costs while promoting soil health. Our greenhouse study investigated the role of mycorrhizal associations and alternative fertility amendments on the productivity and plant nutrition of grain sorghum. We assessed sorghum (Sorghum bicolor cv. Macia) grown with ten different treatments (combinations of biochar, worm compost, and commercial N and P fertilizers) plus a non‐amended control. An amendment blend containing worm compost, biochar, and 50% of the typically recommended commercial fertilizer rate produced similar plant biomass and protein, similar total tissue mineral contents (Ca, Fe, K, Mg, P, and Zn), and supported ≈ 60% more mycorrhizal fungi in the host plant's roots, compared to sorghum grown with the recommended rate of commercial fertilizer (N and P). Our results indicate the potential of biochar and worm compost to enhance the benefits of mycorrhizal fungi for grain sorghum production and plant nutrition while reducing commercial fertilizer applications.  相似文献   

The cutaneous ecosystem: the roles of the skin microbiome in health and its association with inflammatory skin conditions in humans and animals          下载免费PDF全文

Aline Rodrigues Hoffmann 《Veterinary dermatology》2017,28(1):60-e15

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Anesthesia and anesthetic action mechanism of essential oils of Aloysia triphylla and Cymbopogon flexuosus in silver catfish (Rhamdia quelen)     

Alessandro C. dos Santos  Guerino B. Junior  Daniane C. Zago  Carla C. Zeppenfeld  Daniela T. da Silva  Berta M. Heinzmann  Bernardo Baldisserotto  Mauro A. da Cunha 《Veterinary anaesthesia and analgesia》2017,44(1):106-113

Objectives

To document the time for anesthesia induction and recovery using different concentrations of essential oils (EOs) of Cymbopogon flexuosus and Aloysia triphylla in silver catfish (Rhamdia quelen), and to determine whether the mechanism of action of either EO involves the benzodiazepine (BDZ) site of the GABA_A receptor.

Study design

Experimental study.

Animals

A total of 144 silver catfish, length 7.5 ± 1.1 cm, weighing 3.95 ± 0.85 g.

Methods

Essential oils were evaluated at concentrations of 25, 150 and 300 μL L^?1, and also ethanol alone (seven groups, n = 6 per group). Induction of sedation or anesthesia and recovery were assessed. In a further six groups (n = 6 per group), fish were exposed to both EOs (25, 150 or 300 μL L^?1) with diazepam 150 μm, and also diazepam (10 μm) alone. Flumazenil (5 or 10 μm) was added to the recovery water of fish exposed to diazepam (150 μm) or both EOs (150 and 300 μL L^?1) (total of 10 groups = 60 fish).

Results

Both EOs induced anesthesia at concentrations of 150 and 300 μL L^?1, and sedation at 25 μL L^?1. There was no significant difference between EOs for reaching deep anesthesia; there was a significantly longer recovery time for the EO of C. flexuosus. The addition of diazepam (150 μm) resulted in faster induction of anesthesia with both EOs, with no significant change in recovery times. Flumazenil (10 μm) reversed the diazepam-induced anesthesia, but not the anesthesia induced by EOs.

Conclusions and clinical relevance

The EO of C. flexuosus induced effective sedation (25 μL L^?1) and anesthesia (150 and 300 μL L^?1) without short-term mortality. The modulation of the BDZ site of the GABA_A receptor in the anesthetic action mechanism of both EOs was not demonstrated.  相似文献   

Targeting canine mammary tumours via gold nanoparticles functionalized with promising Co(II) and Zn(II) compounds          下载免费PDF全文

L. R. Raposo  C. Roma‐Rodrigues  J. Jesus  L. M. D. R. S. Martins  A. J. Pombeiro  P. V. Baptista  A. R. Fernandes 《Veterinary and comparative oncology》2017,15(4):1537-1542

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Tumourigenic canine osteosarcoma cell lines associated with frizzled‐6 up‐regulation and enhanced side population cell frequency          下载免费PDF全文

L. C. de Sá Rodrigues  K. E. Holmes  V. Thompson  M. A. Newton  T. J. Stein 《Veterinary and comparative oncology》2017,15(1):78-93

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Biosorption of Toxic Metals by Water Lettuce (<Emphasis Type="Italic">Pistia stratiotes</Emphasis>) Biomass     

Ana Carolina Dornelas Rodrigues  Nelson Moura Brasil do Amaral Sobrinho  Fabiana Soares dos Santos  André Marques dos Santos  Ana Carolina Callegario Pereira  Erica Souto Abreu Lima 《Water, air, and soil pollution》2017,228(4):156

Adsorption isotherms were constructed to evaluate the potential use of water lettuce (Pistia stratiotes) dry biomass for the biosorption of zinc and cadmium. One gram of dry biomass of this plant was treated with five increasing doses of zinc (1.8, 18, 50, 79, and 105 mg L^?1) and four doses of cadmium (0.01, 0.1, 1, and 10 mg L^?1), for nine collection times (1, 3, 6, 12, 24, 36, 48, 60, and 72 h). The levels of these metals were determined by atomic absorption spectrophotometry. To evaluate changes in the surface morphology of the dry biomass, scanning electron microscopy (SEM) images were taken of the samples subjected to the greatest contamination, and these were compared with the images of the samples without zinc and cadmium (control). The ISOFIT software was used to select the isotherm model that best fit the biosorption of metals by water lettuce dry biomass. The linear model was determined to be the best-fitting isotherm model, because it had the lowest corrected Akaike information criterion (AICc) value and a Akaike weight (AICw) value closest to one, which indicates the high affinity of the biosorbent for the adsorbates evaluated. The results for both metals demonstrated greater than 70% reductions in the concentrations of the metals in the contaminated solutions. The SEM images indicated changes in the morphology of the contaminated biomass, thus demonstrating the biosorption mechanisms and confirming the potential of the dry biomass of this plant for use in the remediation of solutions contaminated with zinc and cadmium.  相似文献