Skull base surgery最新文献_第2页

Yield response of African leafy vegetables to combined manure and urea microdosing in West Africa 西非非洲叶菜对有机肥和尿素配施的产量响应

Skull base surgery Pub Date : 2023-01-01 DOI: 10.25518/1780-4507.20248

André Adjogboto, Dagnon Didier Likpètè, C. Sossa-Vihotogbe, P. Akponikpè, A. Djènontin, M. Baco, R. Diogo, K. E. Agbossou

{"title":"Yield response of African leafy vegetables to combined manure and urea microdosing in West Africa","authors":"André Adjogboto, Dagnon Didier Likpètè, C. Sossa-Vihotogbe, P. Akponikpè, A. Djènontin, M. Baco, R. Diogo, K. E. Agbossou","doi":"10.25518/1780-4507.20248","DOIUrl":"https://doi.org/10.25518/1780-4507.20248","url":null,"abstract":"Description of the subject. Fertilizers microdosing was tested for African leafy vegetables (ALVs) production to reduce the high rates of fertilizers usually applied to their production in West Africa. Objectives. This study aims to (i) evaluate the response of three ALVs (Amaranthus cruentus L., Solanum macrocarpon L. and Ocimum gratissimum L.) to cattle manure combined with urea-N microdosing and application timing and (ii) assess their partial factor productivity. Method. On-station trials were carried out over three growing seasons (2015 to 2017) in Northern Benin. Urea-N rates of 0, 10, 20, 30, 40 and 60 kg urea-N·ha-1 combined with 5 t·ha-1 of cattle manure (M5N0, M5N10, M5N20, M5N30, M5N40 and M5N60, respectively) and sole application as control (40 (M0N40) and 80 kg urea-N·ha-1 (M0N80)) and two urea-N application timings (T1 = 0 and T2 = 14 days after transplanting) were tested in a randomized complete block design with four replications. Results. The M5N60 treatment resulted in the highest A. cruentus fresh yield and improved leaf yield by 90 and 151% compared to M5N0, and the average of the two no-manure input treatments M0N40 and M0N80, respectively, while M5N40 treatment improved S. macrocarpon fresh yield the best by 23% compared to M5N0. For O. gratissimum, no significant difference was found between urea-N microdose rates. Besides, urea fertilizer application timing affected neither fresh yields nor partial factor productivity for any studied ALVs species. Conclusions. Reduced combination of urea-N and cattle manure is a promising nutrient management practice for ALVs production in West Africa as it improved yields while saving fertilizer for smallholder vegetable farmers.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"114 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79019545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Technology of a novel conidia-tablet formulation and packaging type to increase Beauveria bassiana (Hypocreales: Ophiocordycipitaceae) shelf life at room temperature 提高球孢白僵菌室温保存期的分生孢子片新配方及包装工艺

Skull base surgery Pub Date : 2023-01-01 DOI: 10.25518/1780-4507.20372

M. G. Almeida, C. Varize, T. S. Santos, Camila S. Rezende, Jorge A. López, M. C. Mendonça

{"title":"Technology of a novel conidia-tablet formulation and packaging type to increase Beauveria bassiana (Hypocreales: Ophiocordycipitaceae) shelf life at room temperature","authors":"M. G. Almeida, C. Varize, T. S. Santos, Camila S. Rezende, Jorge A. López, M. C. Mendonça","doi":"10.25518/1780-4507.20372","DOIUrl":"https://doi.org/10.25518/1780-4507.20372","url":null,"abstract":"Description of the subject. This study describes development of mycoinsecticide formulations containing dry conidia of the entomopathogenic fungus Beauveria bassiana combined with various inert excipients in tablet form to facilitate conidia dispersion in water and to maintain viability during storage. Objectives. This study aimed to evaluate the tablet formation of B. bassiana conidia associated with different inert excipient under direct compression in a hydraulic press. Method. Evaluation and validation of the mechanical and storage properties of conidial tablets in different types of packaging. Results. The tablet formulation containing 30% conidia (active ingredient) and 70% cornstarch (inert excipient) displayed satisfactory results regarding mechanical resistance and dispersion in water. This tablet exhibited hardness and friability of 173.94 N and 0.34%, respectively. The tablet disintegration rate in water occurred in 2 min, presenting a rapid dispersion of 109 conidia∙ml-1. Tablet stored in polyethylene pot with polymerized silica exhibited viability ≥ 80% over 180 days storage (25-28 °C). Conclusions. The formulation-packaging binomial is promising, considering the physical-chemical tablet parameters and the viability data. The conidia:cornstarch tablet type formulation provides a relevant cost-benefit ratio of a simple production process of a bioinsecticide, besides the use of low-cost adjuvant and packaging (polyethylene pot). Considering that most biopesticide products require storage under refrigeration, this work becomes important since the formulation remained viable for 180-days storage under room temperature conditions.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75122558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of year of cultivation on the oil content and fatty acid composition of chia seeds (Salvia hispanica L.) grown in France 栽培年限对法国鼠尾草种子含油量和脂肪酸组成的影响

Skull base surgery Pub Date : 2023-01-01 DOI: 10.25518/1780-4507.20127

Gwendoline Gravé, Z. Mouloungui, M. Cerny, Éric Lacroux, J. Fabre, R. Valentin, O. Merah

{"title":"Effect of year of cultivation on the oil content and fatty acid composition of chia seeds (Salvia hispanica L.) grown in France","authors":"Gwendoline Gravé, Z. Mouloungui, M. Cerny, Éric Lacroux, J. Fabre, R. Valentin, O. Merah","doi":"10.25518/1780-4507.20127","DOIUrl":"https://doi.org/10.25518/1780-4507.20127","url":null,"abstract":"Description of the subject. Spanish sage or chia (Salvia hispanica) has attracted increasing interest over the last decade due to the composition of its seeds. It is now cultivated in several European countries. Objectives. The aims of this study were to investigate the oil content and composition of seeds from chia cultivated over a three-year period in South-West France. Method. The cultivar Oruro (Panam, France) was used for this study. It was cultivated in 2014, 2015 and 2017 at Villemur-sur-Tarn (South-West France). Oil, ash and protein contents (Kjeldahl) was assessed, fatty acids (GC-FID), sterols (GC), tocopherols (HPLC) composition was determined on seeds. Results. Cultivation year affected oil, protein and ash contents, and the content and composition of fatty acid, sterols and tocopherols. Oil (range of 30.6-34.7%) and ash (4.8-5.2%) contents were higher in 2014 and 2015 (higher rainfall than 2017). Protein content was higher in 2017 (21.7%) than in the other two years (17.5-19.9%). This trend was expected, given the negative correlation between oil and protein contents. Polyunsaturated fatty acids predominated, and their levels were highest in 2015 and lowest in 2017. Saturated and monounsaturated fatty acid levels followed the opposite pattern (lowest in 2015 and highest in 2017). Sterols and tocopherols accumulated to higher levels in the seeds in 2014 than in 2017. Conclusions. All the seed quality traits of chia cultivated in France were affected by the climatic conditions of the year of cultivation.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85337257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Cadre conceptuel pour l’étude de la relation société-milieu : attache et insertion au monde 研究社会-环境关系的概念框架:对世界的依恋和插入

Skull base surgery Pub Date : 2023-01-01 DOI: 10.25518/1780-4507.20308

M. Loireau, M. Fargette, M. Dieng, M. Sall

{"title":"Cadre conceptuel pour l’étude de la relation société-milieu : attache et insertion au monde","authors":"M. Loireau, M. Fargette, M. Dieng, M. Sall","doi":"10.25518/1780-4507.20308","DOIUrl":"https://doi.org/10.25518/1780-4507.20308","url":null,"abstract":"Description du sujet. Cet article traite d’une manière d’aborder la relation société-milieu, adaptée au caractère multi-échelle et interdisciplinaire des problématiques socio-écologiques contemporaines complexes. Objectifs. Son objectif est méthodologique : construire un cadre conceptuel, formel et générique, qui ait le potentiel de guider la phase d'observation et rende mieux compte de la relation société-milieu. Méthode. La modélisation conceptuelle utilise un standard de langage formel, des ontologies de domaines de connaissance pour définir un méta-modèle d'observation puis modéliser l'objet d'intérêt, un triplet, lui-même en relation avec son contexte, et la notion de service écosystémique (SE). Elle procède par abstraction croissante. Résultats. Le modèle RESOMI décrit le triplet-SE (une personne - un faisceau de liens en vue de services écosystémiques - un espace géographique) en précisant ses attributs internes et ses relations avec son contexte territorial, puis en abstrait des fonctions ; il distingue les concepts directement observables (1er niveau d'abstraction) de ceux des fonctions, non directement observables (2e niveau d'abstraction). De plus, avec un niveau d'abstraction encore supérieur, le modèle AIM positionne deux nouveaux concepts, attache et insertion au monde, dans une ingénierie territoriale elle-même abstraite à partir de l'organisation des fonctions. Conclusions. Le cadre conceptuel formé de deux modèles opère des ponts entre disciplines et échelles ; il offre des perspectives de modélisation mathématique et informatique. Son potentiel d’observation-description est mis en perspective dans deux expériences de terrain. Il est ensuite discuté de façon générale et pour sa capacité à intégrer plus d'éthique et de durabilité dans les problématiques socio-écologiques pour une meilleure gouvernance.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88676570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Agrometeorological conditions in western Pará compared to agricultural production variables using principal component analysis 利用主成分分析对西部para农业气象条件与农业生产变量进行比较

Skull base surgery Pub Date : 2023-01-01 DOI: 10.25518/1780-4507.20291

Werlleson Nascimento, L. Martorano, L. B. D. Araújo, J. R. D. Sousa, C. Dias

{"title":"Agrometeorological conditions in western Pará compared to agricultural production variables using principal component analysis","authors":"Werlleson Nascimento, L. Martorano, L. B. D. Araújo, J. R. D. Sousa, C. Dias","doi":"10.25518/1780-4507.20291","DOIUrl":"https://doi.org/10.25518/1780-4507.20291","url":null,"abstract":"Description of the subject. Since the beginning of the twenty-first century, soybean cultivation areas have been expanding in the Legal Amazon. Among the factors that contribute to the process of expansion of cultivation of grains in the Amazon, favorable climate conditions are one of the most important, and these include high rainfall indices and good thermal regimes during the cultivation period. Objectives. In this context, the objective of this study was to describe responses of soybean production as a function of climate variables, considering data from an important grain production center in the Amazon. Method. Principal Component Analysis (PCA) was used including the following response variables: rainfall (R), air temperature (T), real evapotranspiration, water stress (WST) and surplus, soybean area harvested (HVA), quantity produced (PD), occurrence of El Niño and La Niña (LAN). Results. Production variables were negatively correlated with precipitation and water surplus. There was also a negative correlation between El Niño, temperature and water stress. The variables that had greater weight in component 1 were R, T and WST. Considering component 2, the variables that most contributed to the variation were HVA, PD and LAN. Conclusions. The strong or severe occurrence of La Niña influences the soybean production in the region of Belterra-PA, due to the high rainfall index causing excess water in the soil, leading the plants to stress. The moderate occurrence of La Niña positively influences soybean production in the region to maintain the water supply at adequate levels for the plants. These results show the importance of monitoring climate variables for agriculture in the region.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90713850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numéro 1 1号

Skull base surgery Pub Date : 2022-01-11 DOI: 10.25518/1780-4507.19411

引用次数: 0

Bioenergy value of seed waste from the Mexican date (Phoenix dactylifera L.) industry 墨西哥枣(Phoenix dactylifera L.)工业种子废弃物的生物能源价值

Skull base surgery Pub Date : 2022-01-01 DOI: 10.25518/1780-4507.20026

C. García-González, R. Salomón-Torres, G. Montero-Alpírez, B. Valdez-Salas, M. A. Coronado-Ortega, M. Curiel-Álvarez, J. R. Ayala-Bautista, R. Krueger, Armando Perez-Sanchez, R. Torres-Ramos, Laura Samaniego-Sandoval

{"title":"Bioenergy value of seed waste from the Mexican date (Phoenix dactylifera L.) industry","authors":"C. García-González, R. Salomón-Torres, G. Montero-Alpírez, B. Valdez-Salas, M. A. Coronado-Ortega, M. Curiel-Álvarez, J. R. Ayala-Bautista, R. Krueger, Armando Perez-Sanchez, R. Torres-Ramos, Laura Samaniego-Sandoval","doi":"10.25518/1780-4507.20026","DOIUrl":"https://doi.org/10.25518/1780-4507.20026","url":null,"abstract":"Description of the subject. Date (Phoenix dactylifera L.) seed waste, from the date industry in Mexico, is an attractive source of biomass for bioenergy due to its renewability, availability, and not being otherwise usable. Objectives. In this research project, we calculated and determined the amount of biofuel that could potentially be used from the thermal energy recovery of raw date seed (RDS) and processed date seed (PDS) through oil extraction. Method. The physicochemical composition and thermal behavior of RDS and PDS was determined to evaluate their usefulness for thermal energy production. Proximate and thermogravimetric analyses, Scanning Electron Microscope imaging, and different fuel properties such as Higher Heating Value (HHV), bulk, and energetic density and Fuel Value Index (FVI), were determined. Furthermore, the potential energy production from seed waste of the Mexican date industry was estimated. Results. The RDS presented better HHV 19.33 MJ·kg-1 and energetic density 14.42 MJ·m-3, however, PDS has lower moisture 5.12% and ash content 5.89%. The FVI of PDS is more favorable than RDS, 363.81 and 208.43 respectively. Conclusions. The potential energy production from date seeds produced in Mexico in 2018 was calculated RDS 10.17 TJ, PDS 8.04 TJ and Biodiesel 2.01 TJ and with a tendency to increase every year.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78979237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Susceptibility of fall armyworm Spodoptera frugiperda (JE Smith) to microbial and botanical bioinsecticides and control failure likelihood estimation 秋粘虫对微生物和植物性生物杀虫剂的敏感性及防治失败可能性估计

Skull base surgery Pub Date : 2022-01-01 DOI: 10.25518/1780-4507.19793

B.R. Ahissou, W.M. Sawadogo, G. Dabiré, F. Kambiré, A. Bokonon-ganta, I. Somda, F. Verheggen

{"title":"Susceptibility of fall armyworm Spodoptera frugiperda (JE Smith) to microbial and botanical bioinsecticides and control failure likelihood estimation","authors":"B.R. Ahissou, W.M. Sawadogo, G. Dabiré, F. Kambiré, A. Bokonon-ganta, I. Somda, F. Verheggen","doi":"10.25518/1780-4507.19793","DOIUrl":"https://doi.org/10.25518/1780-4507.19793","url":null,"abstract":"Description of the subject. The fall armyworm Spodoptera frugiperda (JE Smith) has become one of the most devastating pests of maize and other important economic crops in Africa since 2016. Among the alternatives to chemical insecticides, bioinsecticides are an interesting option that needs to be explored. Objectives. The susceptibility of fall armyworm to seven bioinsecticides available on the West African market was evaluated in Burkina Faso. Method. Bioassays were conducted following the approved IRAC 020 protocol. Results. Spinetoram (LC80 = 85.3 µg·l-1) and spinosad (LC80 = 437.9 µg·l-1) were the most toxic at concentrations below those recommended by the manufacturer, and had control failure likelihoods close to 0%. Bacillus thuringiensis and products based on Azadirachta indica and Carapa procera extracts were less effective (at the manufacturers' recommended doses), even though they showed significant levels of toxicity on young instars. Conclusions. A list of effective bioinsecticides should be communicated for sustainable management of fall armyworm in West Africa.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88735365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Re-authorization of gelatin and collagen of ruminant origin in non-ruminant feed: a new analytical challenge for the control of the feed ban 非反刍动物饲料中反刍动物明胶和胶原蛋白的再授权:对饲料禁令控制的新的分析挑战

Skull base surgery Pub Date : 2022-01-01 DOI: 10.25518/1780-4507.20059

O. Fumière, J. Zagon, M. Lecrenier

{"title":"Re-authorization of gelatin and collagen of ruminant origin in non-ruminant feed: a new analytical challenge for the control of the feed ban","authors":"O. Fumière, J. Zagon, M. Lecrenier","doi":"10.25518/1780-4507.20059","DOIUrl":"https://doi.org/10.25518/1780-4507.20059","url":null,"abstract":"Description of the subject. A recent revision of the feed ban provisions authorizes the use of ruminant collagen and gelatin in feed for non-ruminant farmed animals. This authorization will promote the use of former foodstuffs (FFS) in poultry and pig feed. Objectives. The study aimed to investigate how these ruminant materials could impact the capacity to detect processed animal proteins (PAP) of ruminant origin in feed using the official PCR method and to evaluate the added value of a mass spectrometry protocol in development. Method. Presence of ruminant DNA in samples of collagen hydrolysate, gelatin and FFS collected from the industry was assessed using the official DNA extraction and PCR method. This allowed to evaluate the PCR inhibition properties of gelatin and collagen. The same samples were also submitted to a mass spectrometry-based proteomics (UHPLC-MS/MS) protocol targeting ruminant proteins, including collagen, to distinguish between ruminant by-products (unauthorized or authorized). Results. The results show the complementarity of PCR and UHPLC-MS/MS approaches in the context of the use of former foodstuffs in animal feed. Their combination has allowed to evidence that the presence of ruminant DNA in samples containing FFS was more linked to the presence of milk than to the presence of gelatin. On contrary, some samples have shown an increase of the cycle threshold value (Ct) that could correspond to an inhibitory effect due to gelatin addition. Conclusions. In the context of the circular economy, FFS is an interesting source of nutriment for animal feed. However, due to the presence of dairy ingredients, interference with official methods giving false suspicion of prohibited materials is to be expected. Furthermore, a masking effect of the presence of PAP due to a PCR inhibitory effect by FFS is also possible.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91262240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Determination of urea in compound feed for ruminants: interlaboratory comparison for the validation of the spectrophotometric method in Commission Regulation (EC) No 152/2009 反刍动物配合饲料中尿素的测定:委员会法规(EC) No 152/2009分光光度法验证的实验室间比较

Skull base surgery Pub Date : 2022-01-01 DOI: 10.25518/1780-4507.20069

C. Gonçalves, K. Bouten, H. Emteborg, J. Stroka, C. Holst, U. Vincent

{"title":"Determination of urea in compound feed for ruminants: interlaboratory comparison for the validation of the spectrophotometric method in Commission Regulation (EC) No 152/2009","authors":"C. Gonçalves, K. Bouten, H. Emteborg, J. Stroka, C. Holst, U. Vincent","doi":"10.25518/1780-4507.20069","DOIUrl":"https://doi.org/10.25518/1780-4507.20069","url":null,"abstract":"Description of the subject. Urea is a feed additive authorized in ruminant feedingstuff with a maximum content in compound feed of 8,800 mg·kg-1. Commission Regulation (EC) No 152/2009 displays the official method for the determination of urea in feed but does not specify the type of feed for which the method is applicable. Following reports from Member States stating that the official spectrophotometric method is not fit for purpose for other feed than ruminant feed and given the fact that no method performance characteristics are set, the Joint Research Centre organized an interlaboratory exercise for the validation of this method. Objectives. The objective was to carry out an interlaboratory ring trial for the validation of the official spectrophotometric method for the determination of urea in compound feed for ruminants, under specific request from DG SANTE of the European Commission. Method. A collaborative study was carried out on six different test materials prepared from ruminant compound feeds containing urea at various mass fractions and a blank test material. Nineteen laboratories enrolled for the study and eighteen laboratories from ten EU Member States submitted results. Results. The performance characteristics were established, namely, the validation criterion used in this study (RSDR) was in all cases, except in sheep feed at 3,000 mg·kg-1 measured at 420 nm, achieved (i.e. lower than 20%). Slightly better results in terms of precision and trueness were obtained at 435 nm. Conclusions. Commission Regulation (EC) No 152/2009 should be revised as regards the official spectrophotometric method with a restriction of the scope, which is the determination of urea in ruminant compound feedingstuff at authorized level. Additionally, the selected measurement wavelength, which is either 420 nm or 435 nm, has a minor impact on the performance profile of the method.","PeriodicalId":87455,"journal":{"name":"Skull base surgery","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79763085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3