Evaluation of sample preparation methods and optimization of nickel determination in vegetable tissues

Nickel, although essential to plants, may be toxic to plants and animals. It is mainly assimilated by food ingestion. However, information about the average levels of elements (including Ni) in edible vegetables from different regions is still scarce in Brazil. The objectives of this study were to: (a) evaluate and optimize a method for preparation of vegetable tissue samples for Ni determination; (b) optimize the analytical procedures for determination by Flame Atomic Absorption Spectrometry (FAAS) and by Electrothermal Atomic Absorption (ETAAS) in vegetable samples and (c) determine the Ni concentration in vegetables consumed in the cities of Lorena and Taubaté in the Vale do Paraíba, State of São Paulo, Brazil. By means of the analytical technique for determination by ETAAS or FAAS, the results were validated by the test of analyte addition and recovery. The most viable method tested for quantification of this element was HClO4-HNO3 wet digestion. All samples but carrot tissue collected in Lorena contained Ni levels above the permitted by the Brazilian Ministry of Health. The most disturbing results, requiring more detailed studies, were the Ni concentrations measured in carrot samples from Taubaté, where levels were five times higher than permitted by Brazilian regulations.

Nouvelles méthodes pour le diagnostic des infections liées aux implants [New methods for the diagnosis of implant-associated infections]

For successful treatment of prosthetic joint infection, the identification of the infecting microorganism is crucial. Cultures of synovial fluid and intraoperative periprosthetic tissue represent the standard method for diagnosing prosthetic joint infection. Rapid and accurate diagnostic tools which can detect a broad range of causing microorganisms and their antimicrobial resistance are increasingly needed. With newer diagnostic techniques, such as sonication of removed implants, microcalorimetry, molecular methods and mass spectrometry, the sensitivity has been significantly increased. In this article, we describe the conventional and newer diagnostic techniques with their advantages and potential future applications.

Binding energy and momentum distribution of nuclear matter using Green's functions methods

The influence of hole-hole (h-h) propagation in addition to the conventional particle-particle (p-p) propagation, on the energy per particle and the momentum distribution is investigated for the v2 central interaction which is derived from Reid¿s soft-core potential. The results are compared to Brueckner-Hartree-Fock calculations with a continuous choice for the single-particle (SP) spectrum. Calculation of the energy from a self-consistently determined SP spectrum leads to a lower saturation density. This result is not corroborated by calculating the energy from the hole spectral function, which is, however, not self-consistent. A generalization of previous calculations of the momentum distribution, based on a Goldstone diagram expansion, is introduced that allows the inclusion of h-h contributions to all orders. From this result an alternative calculation of the kinetic energy is obtained. In addition, a direct calculation of the potential energy is presented which is obtained from a solution of the ladder equation containing p-p and h-h propagation to all orders. These results can be considered as the contributions of selected Goldstone diagrams (including p-p and h-h terms on the same footing) to the kinetic and potential energy in which the SP energy is given by the quasiparticle energy. The results for the summation of Goldstone diagrams leads to a different momentum distribution than the one obtained from integrating the hole spectral function which in general gives less depletion of the Fermi sea. Various arguments, based partly on the results that are obtained, are put forward that a self-consistent determination of the spectral functions including the p-p and h-h ladder contributions (using a realistic interaction) will shed light on the question of nuclear saturation at a nonrelativistic level that is consistent with the observed depletion of SP orbitals in finite nuclei.

The impact of navigator timing parameters and navigator spatial resolution on 3D coronary magnetic resonance angiography.

The impact of navigator spatial resolution and navigator evaluation time on image quality in free-breathing navigator-gated 3D coronary magnetic resonance angiography (MRA), including real-time motion correction, was investigated in a moving phantom. Objective image quality parameters signal-to-noise ratio (SNR) and vessel sharpness were compared. It was found that for improved mage quality a short navigator evaluation time is of crucial importance. Navigator spatial resolution showed minimal influence on image quality.

Contribution à la cartographie géomorphologique de la dynamique sédimentaire des petits bassins versants torrentiels

Les laves torrentielles sont l'un des vecteurs majeurs de sédiments en milieu montagneux. Leur comportement hydrogéomorphologique est contrôlé par des facteurs géologique, géomorphologique, topographique, hydrologique, climatique et anthropique. Si, en Europe, la recherche s'est plus focalisée sur les aspects hydrologiques que géomorphologiques de ces phénomènes, l'identification des volumes de sédiments potentiellement mobilisables au sein de petits systèmes torrentiels et des processus responsables de leur transfert est d'une importance très grande en termes d'aménagement du territoire et de gestion des dangers naturels. De plus, une corrélation entre des événements pluviométriques et l'occurrence de laves torrentielles n'est pas toujours établie et de nombreux événements torrentiels semblent se déclencher lorsqu'un seuil géomorphologique intrinsèque (degré de remplissage du chenal) au cours d'eau est atteint.Une méthodologie pragmatique a été développée pour cartographier les stocks sédimentaires constituant une source de matériaux pour les laves torrentielles, comme outil préliminaire à la quantification des volumes transportés par ces phénomènes. La méthode s'appuie sur des données dérivées directement d'analyses en environnement SIG réalisées sur des modèles numériques d'altitude de haute précision, de mesures de terrain et d'interprétation de photographies aériennes. La méthode a été conçue pour évaluer la dynamique des transferts sédimentaires, en prenant en compte le rôle des différents réservoirs sédimentaires, par l'application du concept de cascade sédimentaire sous un angle cartographique.Les processus de transferts sédimentaires ont été étudiés dans deux bassins versants des Alpes suisses (torrent du Bruchi, à Blatten beiNaters et torrent du Meretschibach, à Agarn). La cartographie géomorphologique a été couplée avec des mesures complémentaires permettant d'estimer les flux sédimentaires et les taux d'érosion (traçages de peinture, piquets de dénudation et utilisation du LiDAR terrestre). La méthode proposée se révèle innovatrice en comparaison avec la plupart des systèmes de légendes géomorphologiques existants, qui ne sont souvent pas adaptés pour cartographier de manière satisfaisante les systèmes géomorphologiques complexes et actifs que sont les bassins torrentiels. L'intérêt de cette méthode est qu'elle permet l'établissement d'une cascade sédimentaire, mais uniquement pour des systèmes où l'occurrence d'une lave torrentielle est contrôlé par le degré de remplissage en matériaux du chenal. Par ailleurs, le produit cartographique ne peut être directement utilisé pour la création de cartes de dangers - axées sur les zones de dépôt - mais revêt un intérêt pour la mise en place de mesures de correction et pour l'installation de systèmes de monitoring ou d'alerte.La deuxième partie de ce travail de recherche est consacrée à la cartographie géomorphologique. Une analyse a porté sur un échantillon de 146 cartes ou systèmes de légende datant des années 1950 à 2009 et réalisés dans plus de 40 pays. Cette analyse a permis de mettre en évidence la diversité des applications et des techniques d'élaboration des cartes géomorphologiques. - Debris flows are one of the most important vectors of sediment transfer in mountainous areas. Their hydro-geomorphological behaviour is conditioned by geological, geomorphological, topographical, hydrological, climatic and anthropic factors. European research in torrential systems has focused more on hydrological processes than on geomorphological processes acting as debris flow triggers. Nevertheless, the identification of sediment volumes that have the potential to be mobilised in small torrential systems, as well as the recognition of processes responsible for their mobilisation and transfer within the torrential system, are important in terms of land-use planning and natural hazard management. Moreover, a correlation between rainfall and debris flow occurrence is not always established and a number of debris flows seems to occur when a poorly understood geomorphological threshold is reached.A pragmatic methodology has been developed for mapping sediment storages that may constitute source zone of bed load transport and debris flows as a preliminary tool before quantifying their volumes. It is based on data directly derived from GIS analysis using high resolution DEM's, field measurements and aerial photograph interpretations. It has been conceived to estimate sediment transfer dynamics, taking into account the role of different sediment stores in the torrential system applying the concept of "sediment cascade" in a cartographic point of view.Sediment transfer processes were investigated in two small catchments in the Swiss Alps (Bruchi torrent, Blatten bei Naters and Meretschibach torrent, Agarn). Thorough field geomorphological mapping coupled with complementary measurements were conducted to estimate sediment fluxes and denudation rates, using various methods (reference coloured lines, wooden markers and terrestrial LiDAR). The proposed geomorphological mapping methodology is quite innovative in comparison with most legend systems that are not adequate for mapping active and complex geomorphological systems such as debris flow catchments. The interest of this mapping method is that it allows the concept of sediment cascade to be spatially implemented but only for supply-limited systems. The map cannot be used directly for the creation of hazard maps, focused on the deposition areas, but for the design of correction measures and the implementation of monitoring and warning systems.The second part of this work focuses on geomorphological mapping. An analysis of a sample of 146 (extracts of) maps or legend systems dating from the middle of the 20th century to 2009 - realised in more than 40 different countries - was carried out. Even if this study is not exhaustive, it shows a clear renewed interest for the discipline worldwide. It highlights the diversity of applications, techniques (scale, colours and symbology) used for their conception.

Task-shifting in the delivery of hormonal contraceptive methods: Validation of a questionnaire and preliminary results.

Guilbert ER, Morin D, Guilbert AC, Gagnon H, Robitaille J, Richardson M. International Journal of Nursing Practice 2011; 17: 315-321 Task-shifting in the delivery of hormonal contraceptive methods: Validation of a questionnaire and preliminary results In order to palliate the access problem to effective contraceptive methods in Quebec, Canada, as well as to legitimate nurses' practices in family planning, a collaborative agreement was developed that allow nurses, in conjunction with pharmacists, to give hormonal contraceptives to healthy women of reproductive age for a 6 month period. Training in hormonal contraception was offered to targeted nurses before they could begin this practice. A questionnaire, based on Rogers's theory of diffusion of innovations, was elaborated and validated to specifically evaluate this phenomenon. Preliminary results show that the translation of training into practice might be suboptimal. The validated questionnaire can now be used to fully understand the set of factors influencing this new practice.

Correction of resistance to penetration by pedofunctions and a reference soil water content

The soil penetration resistance is an important indicator of soil compaction and is strongly influenced by soil water content. The objective of this study was to develop mathematical models to normalize soil penetration resistance (SPR), using a reference value of gravimetric soil water content (U). For this purpose, SPR was determined with an impact penetrometer, in an experiment on a Dystroferric Red Latossol (Rhodic Eutrudox), at six levels of soil compaction, induced by mechanical chiseling and additional compaction by the traffic of a harvester (four, eight, 10, and 20 passes); in addition to a control treatment under no-tillage, without chiseling or additional compaction. To broaden the range of U values, SPR was evaluated in different periods. Undisturbed soil cores were sampled to quantify the soil bulk density (BD). Pedotransfer functions were generated correlating the values of U and BD to the SPR values. By these functions, the SPR was adequately corrected for all U and BD data ranges. The method requires only SPR and U as input variables in the models. However, different pedofunctions are needed according to the soil layer evaluated. After adjusting the pedotransfer functions, the differences in the soil compaction levels among the treatments, previously masked by variations of U, became detectable.

The efficiency of different estimation methods of hydro-physical limits

The soil water available to crops is defined by specific values of water potential limits. Underlying the estimation of hydro-physical limits, identified as permanent wilting point (PWP) and field capacity (FC), is the selection of a suitable method based on a multi-criteria analysis that is not always clear and defined. In this kind of analysis, the time required for measurements must be taken into consideration as well as other external measurement factors, e.g., the reliability and suitability of the study area, measurement uncertainty, cost, effort and labour invested. In this paper, the efficiency of different methods for determining hydro-physical limits is evaluated by using indices that allow for the calculation of efficiency in terms of effort and cost. The analysis evaluates both direct determination methods (pressure plate - PP and water activity meter - WAM) and indirect estimation methods (pedotransfer functions - PTFs). The PTFs must be validated for the area of interest before use, but the time and cost associated with this validation are not included in the cost of analysis. Compared to the other methods, the combined use of PP and WAM to determine hydro-physical limits differs significantly in time and cost required and quality of information. For direct methods, increasing sample size significantly reduces cost and time. This paper assesses the effectiveness of combining a general analysis based on efficiency indices and more specific analyses based on the different influencing factors, which were considered separately so as not to mask potential benefits or drawbacks that are not evidenced in efficiency estimation.

Incubation methods for assessing mineralizable nitrogen in soils under sugarcane

Considering nitrogen mineralization (N) of soil organic matter is a key aspect for the efficient management of N fertilizers in agricultural systems. Long-term aerobic incubation is the standard technique for calibrating the chemical extraction methods used to estimate the potentially mineralizable N in soil. However, the technique is laborious, expensive and time-consuming. In this context, the aims of this study were to determine the amount of soil mineralizable N in the 0-60 cm layer and to evaluate the use of short-term anaerobic incubation instead of long-term aerobic incubation for the estimation of net N mineralization rates in soils under sugarcane. Five soils from areas without previous N fertilization were used in the layers 0-20, 20-40 and 40-60 cm. Soil samples were aerobically incubated at 35 ºC for 32 weeks or anaerobically incubated (waterlogged) at 40 ºC for seven days to determine the net soil N mineralization. The sand, silt and clay contents were highly correlated with the indexes used for predicting mineralizable N. The 0-40 cm layer was the best sampling depth for the estimation of soil mineralizable N, while in the 40-60 cm layer net N mineralization was low in both incubation procedures. Anaerobic incubation provided reliable estimates of mineralizable N in the soil that correlated well with the indexes obtained using aerobic incubation. The inclusion of the pre-existing NH4+-N content improved the reliability of the estimate of mineralizable N obtained using anaerobic incubation.

Phosphorus extracted by ion exchange resins and mehlich-1 from oxisols (latosols) treated with different phosphorus rates and sources for varied soil-source contact periods

Despite the large number of studies addressing the quantification of phosphorus (P) availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR) and Mixed Resin (MR), to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2) + 3] x 4 factorial design, with four replications, testing the response of three soils with different texture: a very clayey Red Latosol (LV), a sandy clay loam Red Yellow Latosol (LVA), and a sandy loam Yellow Latosol (LA), to three sources (triple superphosphate, reactive phosphate rock from Gafsa-Tunisia; and natural phosphate from Araxá-Minas Gerais) at two P rates (75 and 150 mg dm-3), plus three control treatments (each soil without P application) after four contact periods (15, 30, 60, and 120 days) of the P sources with soil. The soil acidity of LV and LVA was adjusted by raising base saturation to 60 % with the application of CaCO3 and MgCO3 at a 4:1 molar ratio (LA required no correction). These samples were maintained at field moisture capacity for 30 days. After the contact periods, the samples were collected to quantify the available P concentrations by the three extractants. In general, all three indicated that the available P-content in soils was reduced after longer contact periods with the P sources. Of the three sources, this reduction was most pronounced for triple superphosphate, intermediate for reactive phosphate, while Araxá phosphate was least sensitive to the effect of time. It was observed that AR extracted lower P levels from all three soils when the sources were phosphate rocks, while MR extracted values close to Mehlich-1 in LV (clay) and LVA (medium texture) for reactive phosphate. For Araxá phosphate, much higher P values were determined by Mehlich-1 than by the resins, because of the acidity of the extractor. For triple superphosphate, both resins extracted higher P levels than Mehlich-1, due to the consumption of this extractor, particularly when used for LV and LVA.

Comparison of protection methods of pine stacks against Tomicus piniperda

Summary

Oscar Wilde. 'Camma', a severe and hedonic aesthetic correction of Plutarch's ethics

The aim of this article is to present an accurate analysis of O. Wilde's poem 'Camma' by referring it to its Greek model: that Camma both in Plutarch's Amatorius (Eroticus) and Mulierum Virtutes. It is precisely this accurate reading which permits us to verify how Plutarch's Ethics is corrected from the parameters of the hedonism which is peculiar to O. Wilde's aestheticism, thus turning Camma into a symbol of a pleasant life.

Love in Plutarch: the necessary Platonic correction of Plato

Amb ocasió del simposi internacional dedicat a l'amor a Plutarc, aquest treball fou presentat per mostrar fins a quin punt Plutarc, sobre tot al seu Eròtic i des de paràmetres estrictament platònics, amb l'ajut d'una lògica elemental i alhora rigorosa, es limita a corregir platònicament Plató per tal que éros i philía puguin ser atribuïts també al amor conjugal.