Immobilization of nitrogen from urea and plant residues in a ferrallitic soil: Laboratory experiments and study by size-fractionation

Summary The fate of N when incorporated in a ferrallitic soil was investigated during a 3-month incubation, using either ¹⁵N-labelled urea or ¹⁵N-labelled crop residues (sugarcane roots and leaves). The organic matter was characterized by particle-size fractionation. The urea-derived organic ¹⁵N was mainly found in the clay-sized fractions and was ascribed to biological activity. The plant-derived ¹⁵N was observed both in the sand-sized and in the clay-sized fractions; the former pool was ascribed to the persistence of crops residues, the latter to biological immobilization. The relative proportions of organic ¹⁵N recovered in the various clay fractions (coarse, fine, and very fine) were similar, irrespective of the nature of the added ¹⁵N. The very fine clay fraction (F<0.05 m) showed the highest isotopic excess, and thus gave rise to the highest turnover rate.     

Pig major acute-phase protein and apolipoprotein A-I responses correlate with the clinical course of experimentally induced African Swine Fever and Aujeszky's disease

In the present work, we studied the acute phase protein response after experimental virus infection in pigs. The animals were experimentally infected with African Swine Fever (ASF) or Aujeszky's disease (AD) viruses. The clinical course of ASF infection correlated with increasingly high levels of pig Major Acute-phase Protein (pig-MAP) (mean value of 6 mg/mL on day 6 post infection (p.i.), from 6 to 9 times higher than day 0) and sharp apolipoprotein A-I (apo A-I) decrease (mean value of 0.5 mg/mL, from 4 to 10 times lower than day 0 on day 4 p.i.). AD-clinical signs appeared at day 3 p.i., both in vaccinated (moderate clinical signs) and non-vaccinated pigs (severe outcome within 48 h p.i.). Pig-MAP and apo A-I profiles also followed clinical signs (changing from 0.70 mg/mL to around 3 mg/mL and from around 3 mg/mL to 0.96 mg/mL, respectively in non-vaccinated animals), with minor changes in concentration in the vaccinated group. Haptoglobin levels significantly increased in ASF and AD infected animals (mean maximum values of 2.77 and 3.96 mg/mL, respectively). Minor differences for the C-Reactive Protein in the case of ASF were observed, whereas its concentration increased more than 7 times in AD-infection. The albumin level was not modified in either case. The correlation of clinical signs to our data suggests the potential use of pig-MAP and apo A-I in monitoring infections in swine.     

Application de la CCM à l'étude des produits obtenus dans la démucilagination des huiles de germe de maïs

Résumé Lorsque l'on traite des huiles végétales brutes par de l'eau, de la vapeur d'eau, des solutions salines ou des solutions acides, dans des conditions que la technique industrielle précise, il se sépare une phase aqueuse dite phase de démucilagination. Celle-ci contient des substances dotées de propriétés tensioactives comparables, mais de constitutions chimiques très différentes: des polyholosides qui représentent les mucilages proprement dits, mais aussi des phosphoaminolipides de natures diverses. De plus, des lipides simples: glycérides, acides gras libres et matières insaponifiables peuvent être entraînés dans ce milieu doté de propriétés émulsives.La présente étude est consacrée à l'analyse des produits de démucilagination, obtenus au laboratoire par action d'une quantité d'eau limitée sur l'huile brute extraite du germe de maïs.On sépare d'abord les glucides de l'ensemble lipidique en solubilisant celui-ci par un lavage avec de l'hexane. La solution est séchée, évaporée sous pression réduite et soumise à l'analyse chromatographique sur plaque de Kieselgel de Merck. Après les manipulations d'usage, la mise en évidence des taches pouvait être obtenue au moyen de la vapeur d'iode ou par pulvérisation d'acide sulfurique. Nous avons préféré utiliser la rhodamine B qui nous a permis de mettre en évidence, près de la base, une série de quatre tâches correspondant à des lécithines, (ce fait a été vérifié en soumettant la matière première à l'hydrolyse, ce qui a permis de mettre en évidence la seule choline sans trace d'éthanolamine, constituant caractéristique des céphalines), et près de la ligne de front d'autres dépôts, qui repris, ont été identifiés à des stérols. Il a été vérifié que glycérides et acides gras ne migrent pas dans nos conditions expérimentales.En complément de la chromatographie sur plaques, la chromatographie gazeuse a permis de connaître l'identité des acides gras consituant les lécithines et celle des stérols.

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Summary When raw vegetable oils are treated by water, vapour, solutions of salts or acids, in conditions that are defined by industrial technique, an aqueous phase, called de gumming phase is separated. This phase contains substances possessing compared surface-active properties but differing by their chemical constitutions: poly holosides, which are the gums proper, but also phospho aminolipids of various nature. Furthermore, simple lipids: glycerides, free fatty acids, unsaponifiables may be drawn into this medium endowed with emulsifying properties.The present study is concerned with the analysis of the products of degumming obtained in the laboratory by the action of a limited quantity of water on the raw oil extracted from corn germ.First the carbohydrates are separated from by the complex of lipids by solubilizing it with a washing by hexane. The solution is dried, evaporated under reduced pressure, and chromatographically analyzed on aMerck Kieselgel plate. After the usual manipulations the evidencing of the spots could be obtained with the help of iodine vapours or by spraying with sulphuric acid. We preferred to use Rhodamin B which enabled us to show, near the base, a series of four spots corresponding to lecithins (this fact was verified by the hydrolysis of the raw material which enabled us to isolate only the choline, without any trace of ethanolamine, a characteristic constituant of cephalins), and near the front line, other spots, which, when redissolved, were identified as sterols. It was verified that in our experimental conditions the glycerides and fatty acids do not migrate.As a supplement for plate chromatography, gas-chromatography has enabled us to identify the fatty acids constituting the lecithins, and also to identify the sterols.

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Zusammenfassung Wenn man die rohen Pflanzenöle mit Wasser, Wasserdampf, Salzlösungen oder Säurelösungen unter den Bedingungen der präzisen industriellen Technik behandelt, scheidet sich eine wässerige, sogenannte Entschleimungsphase aus. Diese enthält Stoffe, die vergleichbare tensioaktive Eigenschaften haben, aber deren chemische Beschaffenheit sehr verschieden ist: Polykolloide, welche die eigentlichen Schleime bilden, aber auch Phospho-amino-Lipide verschiedener Natur und auch einfache Lipide: Glyceride, freie Fettsäuren und nicht verseifbare Stoffe, die in diesem mit emulgierenden Eigenschaften ausgestattetem Medium weggespült werden können. Diese Arbeit ist der Analyse der Entschleimungsprodukte gewidmet, die im Laboratorium durch Einwirkung einer beschränkten Menge Wassers auf rohes Öl aus Maiskeimen entstanden ist.Man scheidet zuerst die Kohlenhydrate aus der Gesamtheit der Lipide aus, die durch Waschen mit Hexan lösbar gemacht werden. Die Lösung wird getrocknet, unter reduziertem Druck verdampft und der chromatographischen Analyse auf Kieselgel vonMerck unterworfen. Nach den üblichen Behandlungen wurden die Substanzflecken durch Joddampf oder Besprühen mit Schwefelsäure sichtbar gemacht. Wir bevorzugten Rhodamin B weil wir mit diesem Entwicklungsreagenz eine Reihe von vier Flecken in Startnähe erkennen konnten, die den Lecithinen zugeordnet wurden. (Es handelt sich um Lecithin, da bei der Hydrolyse des Rohmaterials nur Cholin und keine Spur Äthanolamin, dem charakteristischen Bestandteil der Kephaline, gefunden wurde.) In der Nähe der Front lagen Substanzflecken, die sich als Sterole identifizieren ließen. Es konnte nachgewiesen werden, daß Glyceride und Fettsäuren unter den Versuchsbedingungen nicht wandern.Als Ergänzung zur Chromatographie auf Platten hat die Gaschromatographie die Identifizierung der Fettsäuren, welche die Lecithine bilden, und der Sterole ermöglicht.

     

IMAGING DIAGNOSIS—MAGNETIC RESONANCE IMAGING FEATURES OF A CEREBRAL HEMANGIOBLASTOMA IN A DOG

The magnetic resonance (MR) imaging features of a cerebral hemangioblastoma in a 9‐year‐old dog are described. Imaging revealed a well‐defined contrast‐enhancing lesion of the rostral forebrain that appeared extraparenchymal. Histopathology of the excised mass showed clusters of small blood vessels interspersed with interstitial cells staining positive for neuronal specific enolase, features consistent with a cerebral hemangioblastoma; the mass also appeared intraparenchymal after further immunohistochemistry study. This neoplasm should be considered a rare differential diagnosis for intracranial masses in dogs.     

Development and application of an indirect competitive enzyme-linked immunosorbent assay for the detection of p,p'-DDE in human milk and comparison of the results against GC-ECD

1,1-Dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE) is the major metabolite of insecticide 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (p,p'-DDT) and a persistent organic pollutant (POPs) with concerns regarding its bioaccumulation and persistence in the environment and food chain. In the present study, an indirect competitive enzyme-linked immunosorbant assay (ic-ELISA) specific for the detection of p,p'-DDE is described. In hapten synthesis, 2,2'-bis(4-chlorophenyl)ethanol and glutaric anhydride were used as precursor and spacer arm, respectively. The hapten was then conjugated to bovine serum albumin (BSA) as immunogen for mouse immunization and also conjugated to ovalbumin as coating antigen for ELISA. The developed ic-ELISA was used for detecting p,p'-DDE in human milk samples and validated against the results from conventional gas chromatography-electron capture detection (GC-ECD). Coefficients of variation (%CV) of ELISA were 5.7-10.4% for intra-assay and 10.6-19.6% for interassay variations. The Pearson correlation coefficient of p,p'-DDE concentrations between ic-ELISA and GC-ECD was r = 0.766, which was in an acceptable range. The results indicate that the developed assay could be an alternative analytical tool for monitoring p,p'-DDE in lipimic matrices such as human milk.     

Carotenoid diversity in cultivated citrus is highly influenced by genetic factors

Citrus fruits are complex sources of carotenoids with more than 100 kinds of pigments reported in this genus. To understand the origin of the diversity of carotenoid compositions of citrus fruit, 25 genotypes that belong to the 8 cultivated Citrus species were analyzed. Juice extracts of mature fruit were analyzed by high-performance liquid chromatography using a C30 column. The 25 citrus genotypes presented different carotenoid profiles with 25 distinct compounds isolated. Statistical analyses revealed a strong impact of genotype on carotenoid compositions. Two kinds of classifications of genotypes were performed: on qualitative data and on quantitative data, respectively. The results showed that variability in carotenoid compositions was more interspecific than intraspecific. Two carotenoids, cis-violaxanthin and the beta-cryptoxanthin, strongly determined the classification on qualitative data, which was also in agreement with previous citrus variety classifications. These findings provide evidence that, as for other phenotypical traits, the general evolution of cultivated Citrus is the main factor of the organization of carotenoid diversity among citrus varieties. To the authors' knowledge this is the first study that links the diversity of carotenoid composition to the citrus genetic diversity. These results lead to the proposed major biosynthetic steps involved in the differential carotenoid accumulation. Possible regulation mechanisms are also discussed.     

Effects of organic amendment on early growth performance of Jatropha curcas L. on a severely degraded site in the Sub-Sahel of Burkina Faso

The aim of this study was to evaluate the effect of organic amendment on the germination and growth patterns of Jatropha curcas L. on completely barren and degraded land in the Sahelian area of Burkina Faso. Prior to the field trials, laboratory germination tests were undertaken to explore the impact of different pre-treatments on germination of Jatropha seeds. Seeds soaked in water for 24?h had the highest mean rate of germination (86%) while seeds that were pre-treated with sulphuric acid did not germinate. The results of the field experiment showed that plant growth and biomass development were significantly enhanced by organic amendment compared to the control. With direct seeding, 20% of the plants treated with organic manure survived after 2?years, while all seedlings of the control plot perished. In the plantations, 30% of the untreated seedlings remained alive whereas only 5% of the plants survived with amendment. The trials in unfenced plots were decimated by livestock grazing and trampling 2?months after the beginning of the experiment. This emphasizes the need to protect Jatropha plants at an early stage of their development from roaming animals. Organic amendment attracted humivorous termites, which were destructive to the seedlings. The use of pesticides may be necessary to control this problem. When directly seeded, plants of the control plots demonstrated poor growth and became rapidly diseased, further accelerating their decline. The low survival rates (5–30%) and meagre seedling performance, even for the amended plots, may be an indication that Jatropha is unsuited to severely degraded lands like the zippelé, and cannot be expected to give good yields and the claimed environmental and socio-economic benefits. However, we recommend that the performance of Jatropha on the zippelé should be further tested with other soil and water conservation techniques (half-moon, tillage, etc.) that have been shown to enhance crop production and yield on degraded lands in the Sahelo-Sudanian zone of West Africa. The impact of seed provenance on the outcome of this study is unknown. Therefore, further experiments should embrace seeds from different sources, including genotypes that are more adapted to dry conditions and might therefore show improved performance.     

Spatial patterns of Bovine Corona Virus and Bovine Respiratory Syncytial Virus in the Swedish beef cattle population

Background

Both bovine coronavirus (BCV) and bovine respiratory syncytial virus (BRSV) infections are currently wide-spread in the Swedish dairy cattle population. Surveys of antibody levels in bulk tank milk have shown very high nationwide prevalences of both BCV and BRSV, with large variations between regions. In the Swedish beef cattle population however, no investigations have yet been performed regarding the prevalence and geographical distribution of BCV and BRSV. A cross-sectional serological survey for BCV and BRSV was carried out in Swedish beef cattle to explore any geographical patterns of these infections.

Methods

Blood samples were collected from 2,763 animals located in 2,137 herds and analyzed for presence of antibodies to BCV and BRSV. Moran''s I was calculated to assess spatial autocorrelation, and identification of geographical cluster was performed using spatial scan statistics.

Results

Animals detected positive to BCV or BRSV were predominately located in the central-western and some southern parts of Sweden. Moran''s I indicated global spatial autocorrelation. BCV and BRSV appeared to be spatially related: two areas in southern Sweden (Skaraborg and Skåne) had a significantly higher prevalence of BCV (72.5 and 65.5% respectively); almost the same two areas were identified as being high-prevalence clusters for BRSV (69.2 and 66.8% respectively). An area in south-east Sweden (Kronoberg-Blekinge) had lower prevalences for both infections than expected (23.8 and 20.7% for BCV and BRSV respectively). Another area in middle-west Sweden (Värmland-Dalarna) had also a lower prevalence for BRSV (7.9%). Areas with beef herd density > 10 per 100 km² were found to be at significantly higher risk of being part of high-prevalence clusters.

Conclusion

These results form a basis for further investigations of between-herds dynamics and risk factors for these infections in order to design effective control strategies.     

Anthropogenic factors and the risk of highly pathogenic avian influenza H5N1: prospects from a spatial-based model

Beginning in 2003, highly pathogenic avian influenza (HPAI) H5N1 virus spread across Southeast Asia, causing unprecedented epidemics. Thailand was massively infected in 2004 and 2005 and continues today to experience sporadic outbreaks. While research findings suggest that the spread of HPAI H5N1 is influenced primarily by trade patterns, identifying the anthropogenic risk factors involved remains a challenge. In this study, we investigated which anthropogenic factors played a role in the risk of HPAI in Thailand using outbreak data from the “second wave” of the epidemic (3 July 2004 to 5 May 2005) in the country. We first performed a spatial analysis of the relative risk of HPAI H5N1 at the subdistrict level based on a hierarchical Bayesian model. We observed a strong spatial heterogeneity of the relative risk. We then tested a set of potential risk factors in a multivariable linear model. The results confirmed the role of free-grazing ducks and rice-cropping intensity but showed a weak association with fighting cock density. The results also revealed a set of anthropogenic factors significantly linked with the risk of HPAI. High risk was associated strongly with densely populated areas, short distances to a highway junction, and short distances to large cities. These findings highlight a new explanatory pattern for the risk of HPAI and indicate that, in addition to agro-environmental factors, anthropogenic factors play an important role in the spread of H5N1. To limit the spread of future outbreaks, efforts to control the movement of poultry products must be sustained.     

欧洲现代木结构建筑不同的构造技术和成本分析

木材是一种可再生的、同时也是最古老的建筑材料之一。由于其天然美观的纹理、柔和的视觉效果、良好的保温隔热性能以及优良的力学性能,自上古时期的构木为巢开始就和人类生活息息相关,木结构建筑是人类最早兴建的建筑结构之一,积淀着丰厚的建筑文明传统。1欧洲现代木结构建筑发展概况建筑的发展史就是一部科学技术的发展史。技术手段的变革会超越风格流派等文化因素直接对建筑设计产生巨大的影响,并使得设计师的创作观念及设计方法也随之发生变化。这