Central nervous system signs in chickens caused by a new avian reovirus strain: a pathogenesis study

The present study describes the pathogenesis of infection of chicks with a new avian reovirus strain, belonging to the so-called enteric reovirus strains (ERS) that is capable of causing central nervous system signs in SPF white leghorns. After intramuscular (IM) or oral inoculation birds were either observed for clinical signs or sacrificed for macroscopic, histological and virological examination for 21 days. Virus isolation was performed on the brain, leg muscle, hock joint, liver and spleen. For the detection of viral antigen the immunohistochemistry (IHC) technique was performed on the caudal part of the cerebrum, spinal cord including spinal ganglia and right N. Ischiadicus. High mortality (79% in 7 days) was seen in birds that were inoculated IM. Survivors were depressed and stayed small until the end of the experiment. One bird had tremor and showed torticollis at 9 days after IM inoculation. Birds that were inoculated orally were depressed from day 4 and stayed small until the end of the experiment. One bird showed a torticollis at 10 days after inoculation. After both IM and oral inoculation ERS was isolated from the brain between 3 and 10 days after inoculation. Other examined organs were positive for virus isolation from day 1 or 5 until day 21. IHC revealed viral antigen positive cells in the Plexus chorioideus (plexus epithelial cells or cells within the underlying connective tissue) and in a spinal ganglion. The results indicate that the pathogenesis of ERS infection in chickens bears some resemblance with that of the mammalian reoviruses serotype 1 in mice.     

Immunological and gene expression responses to a Salmonella infection in the chicken intestine

Besides infection in humans, Salmonella enteritidis can also cause serious illness in young chickens. However, the genetic and immunological parameters important for the disease in chickens are not well characterized. In this study, processes in the chicken intestine in response to a Salmonella infection were investigated in two different chicken lines. One-day-old chickens were orally infected with Salmonella. T-cell subpopulations, phagocytic properties of intestinal mononuclear cells and RNA expression levels of the jejunum were investigated. The two chicken lines differed in the amount of cfu in the liver and growth retardation after the infection. Differences in phagocytic activity of intestinal mononuclear cells were found between control and Salmonella infected chickens. The number of CD4+ T-cells of the intestine decreased after the Salmonella infection in one chicken line, while the number of CD8+ T-cells increased in both chicken lines, but the time post infection of this increase differed between the lines. In one chicken line the expression levels of the genes carboxypeptidase M and similar to ORF2 decreased after the Salmonella infection, which might be related to a decrease in the amount of macrophages. With the microarray, ten genes were found that were regulated in only one of the chicken lines, while we found six genes regulated in response to the infection in both chicken lines. So differences in genetic background of the chickens influence the intestinal host response of the Salmonella infection as observed by phagocytic activity, gene expression and changes in the number of T-cell subpopulations and macrophages.     

Ethnic differences in 1-year follow-up effect of the Dutch Schoolgruiten Project - promoting fruit and vegetable consumption among primary-school children

OBJECTIVE: To evaluate the effect of a primary school-based intervention providing free fruit and vegetables (F&V), separately for children of Dutch and of non-Western ethnicity. SETTING: Primary schools in two regions (west and east) in The Netherlands. DESIGN AND METHODS: Participating schoolchildren and their parents completed questionnaires at baseline and 1 year later, including questions on usual F&V intake, potential determinants and general demographics. Primary outcomes were the usual fruit intake and the usual vegetable intake as assessed by parent- and child self-reported food frequency measures. Secondary outcome measures were child- or parent-reported taste preference, knowledge of daily recommendations, availability, and accessibility for fruit intake. Multilevel regression analyses were used to assess differences at follow-up adjusted for baseline values between the control and intervention group using both child and parent reports. SUBJECTS: Five hundred and sixty-five children of Dutch ethnicity and 388 children of non-Western ethnicity (mean age 9.9 years at baseline) and their parents. RESULTS: Children of non-Western ethnicity in the intervention group reported a significantly higher vegetable intake (difference = 20.7 g day-1, 95% confidence interval (CI) = 7.6-33.7). A significant positive intervention effect was also found for fruit intake for children of Dutch ethnicity (difference = 0.23 pieces day-1, 95% CI = 0.07-0.39). No significant effects in intake were observed based on parent reports. Significant positive intervention effects were also found for perceived accessibility among children of non-Western ethnicity, as well as for parent-reported taste preference of their child among children of non-Western ethnicity and boys of Dutch ethnicity.CONCLUSION: Providing children with free F&V had some positive effects on child-reported intakes and important correlates of intakes.     

Reservoir sediment characterisation by diffuse reflectance spectroscopy in a semiarid region to support sediment reuse for soil fertilization

Journal of Soils and Sediments - Soil erosion by water yields sediment to surface reservoirs, reducing their storage capacities, changing their geometry, and degrading water quality. Sediment...     

Male sterility and its importance in breeding heterosis varieties

Summary On the basis of data from the literature, a survey of the occurrence and mode of inheritance of male sterility in a large number of plant species is presented (Table 1).The importance of male sterility as a means of breeding heterosis varieties is indicated and the advantages attached to the use of MS, and the problems arising from it, are discussed.It is contented that the rarely occuring types of plasmatically inherited MS offer good possibilities of utilization in the case of cross fertilized plants. The procedure to be adopted in using this type of MS is described in considerable detail in § 5 and 8.It is regretable that, in self-fertilized field crops under conditions of natural pollination, the small seed set obtained presents serious difficulties in breeding hybrids on a scale which is commercially justified. In horticulture, however, where artificial pollination can be made to pay, hybrids have already been created with the aid of MS types possessing a monofactorial recessive system of inheritance and have been put on the market. The procedure adopted is described in § 9.A survey is given of the results already obtained with MS in tomato, onion, sugar beet and maize, and it is anticipated that important increases in yield may also be obtained in other cross fertilized plants and self-fertilized horticultural crops with the aid of MS.

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Samenvatting Aan de hand van literatuurgegevens werd een overzicht gegeven van het voorkomen en de wijze van vererving van mannelijke steriliteit in een groot aantal plantensoorten. (tabel 1).Gewezen werd voorts op de betekenis van mannelijke steriliteit als hylpmiddel bij het kweken van heterosisrassen, terwijl de aan het gebruik van MS verbonden voordelen en de zich daarbij voordoende problemen werden besproken.Betoogd werd dat de schaars voorkomende typen van plasmatisch verervende MS goede toepassingsmogelijkheden bieden voor gebruik in kruisbevsuchters; de bij het benutten van dit type MS te volgen werkwijze werd uitvoerig aangegeven in de paragrafen 5 en 8.Helaas vormt in zelfbevruchtende akkerbouwgewassen bij natuurlijke bestuiving de geringe zaadzetting van MD planten een ernstig beletsel voor het op commericeel verantwoorde wijze kweken van hybriden; in de tuinbouw, waar men veelal kunstmatige bestuiving rendabel kan maken, werden echter met behulp van monofactorieel recessief verervende vormen van MS reeds hybriden verkregen en in het verkeer gebracht. De hierbij gevolgde werkwijze werd beschreven in paragraaf 9.Een overzicht werd gegeven van de reeds met behuop van MS bereikte resultaten bij tomaat, ui, suikerbiet en mais, terwijl de verwachting werd uitgesproken dat ook bij andere kruisbevruchters, zelfbevruchtende tuinbouwgewassen en tabak met behulp van MS nog belangrijke meeropbrengsten in de practijk te behalen zullen zijn.

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The author wishes to thank Prof. Dr R.Prakken for his kind permission to publish this study which has been carried out under his direction, and is grateful to Prof. Dr J. C.Dorst for his helpful criticism.     

Influence of processing on total,monoglutamate and polyglutamate folate contents of leeks,cauliflower, and green beans

Bioavailability of dietary folate might be impaired by the polyglutamate chain to which approximately 70% of dietary folates are bound. This chain must be removed enzymatically in the intestine before folate is absorbed as a monoglutamate. To increase formation of monoglutamate folate in vegetables, the vegetables were subjected to various processing treatments. Treatments included freezing (-18 degrees C, 16 h) and thawing (4 degrees C, 24 h) and hydrostatic high-pressure treatment (200 MPa, 5 min). Both freezing/thawing and high-pressure treatment increased the proportion of folate in the monoglutamate form in leeks, cauliflower, and green beans 2-3-fold. However, loss of total folate after these treatments was >55%. It is concluded that conversion of folate polyglutamate to the monoglutamate form in vegetables is possible by certain processing treatments. Potentially this could lead to vegetables with higher folate bioavailability. However, to prevent folate loss into processing water, processing in a closed system should be applied.     

Volatile flavor analysis and sensory evaluation of custard desserts varying in type and concentration of carboxymethyl cellulose

The influence of type and concentration of carboxymethyl cellulose (CMC) on flavor and textural properties of custard desserts was examined. A synthetic strawberry flavor mixture was used to flavor the custards; it comprised 15 volatile flavor compounds. The viscosity of the custards was determined using rheometric measurements. Static headspace gas chromatography and in-nose proton transfer reaction-mass spectrometry analyses were conducted to determine the custards' volatile flavor properties. Perceived odor, flavor, and textural properties were assessed in sensory analysis experiments using magnitude estimation against a fixed modulus. Both type and concentration of CMC altered the viscosity of the custards. Softer custards had higher static headspace flavor concentrations. On the contrary, firmer custards demonstrated higher in-nose flavor concentrations. In sensory analysis, firmer custards showed higher thickness and lower sweetness intensities than their low-viscosity counterparts. The thickness perception corresponded to the viscosity of the custards. Removal of sucrose from the custards affected sweetness intensity only and not the intensity of other attributes. Therefore, the influence of the viscosity of the custards on the release of sweet-tasting components is held responsible for the effect on perceived sweetness intensity. Odor intensities were generally higher for the low-viscosity custard, whereas fruity flavor intensities were higher for the firmer custards. Odor intensities correlated with static headspace concentrations and flavor intensities related reasonably well with in-nose concentrations. Opening and closing of the nasal cavity is regarded as an important factor determining the discrepancy between static and in-nose measurements.     

A reversibly switching surface

We report the design of surfaces that exhibit dynamic changes in interfacial properties, such as wettability, in response to an electrical potential. The change in wetting behavior was caused by surface-confined, single-layered molecules undergoing conformational transitions between a hydrophilic and a moderately hydrophobic state. Reversible conformational transitions were confirmed at a molecular level with the use of sum-frequency generation spectroscopy and at a macroscopic level with the use of contact angle measurements. This type of surface design enables amplification of molecular-level conformational transitions to macroscopic changes in surface properties without altering the chemical identity of the surface. Such reversibly switching surfaces may open previously unknown opportunities in interfacial engineering.