1,113 research outputs found

    An Ultrasonic Altitude-Velocity Sensor for Airplanes in the Vicinity of the Ground : I. Fundamental Characteristics

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    This paper shows the possibility of an ultrasonic sensor which detects the altitude from the ground and the vertical velocity of an airplane in the vicinity of the ground. The principle of the present technique depends on the measurement of time in which the ultrasonic wave propagates the distance between the airplane and the ground, because the sonic velocity is approximately constant at the usual atmospheric temperature. Furthermore, by differentiating the altitude signal with respect to time, it is possible to detect the vertical velocity of the airplane, too. The fundamental performances of this sensor are investigated with some experiments carried out in our laboratory, and it is shown that the ultrasonic sensor will be useful in place of the radar altimeter, in particular at very low altitude. As an application of this sensor, the automatic control of a VTOL airplane in hovering flight is investigated by analog simulation studies

    Techniques for Arbuscular Mycorrhiza Inoculum Reduction

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    It is well established that arbuscular mycorrhizal (AM) fungi can play a significant role in sustainable crop production and environmental conservation. With the increasing awareness of the ecological significance of mycorrhizas and their diversity, research needs to be directed away from simple records of their occurrence or casual speculation of their function (Smith and Read 1997). Rather, the need is for empirical studies and investigations of the quantitative aspects of the distribution of different types and their contribution to the function of ecosystems. There is no such thing as a fungal effect or a plant effect, but there is an interaction between both symbionts. This results from the AM fungi and plant community size and structure, soil and climatic conditions, and the interplay between all these factors (Kahiluoto et al. 2000). Consequently, it is readily understood that it is the problems associated with methodology that limit our understanding of the functioning and effects of AM fungi within field communities. Given the ubiquous presence of AM fungi, a major constraint to the evaluation of the activity of AM colonisation has been the need to account for the indigenous soil native inoculum. This has to be controlled (i.e. reduced or eliminated) if we are to obtain a true control treatment for analysis of arbuscular mycorrhizas in natural substrates. There are various procedures possible for achieving such an objective, and the purpose of this chapter is to provide details of a number of techniques and present some evaluation of their advantages and disadvantages. Although there have been a large number of experiments to investigated the effectiveness of different sterilization procedures for reducing pathogenic soil fungi, little information is available on their impact on beneficial organisms such as AM fungi. Furthermore, some of the techniques have been shown to affect physical and chemical soil characteristics as well as eliminate soil microorganisms that can interfere with the development of mycorrhizas, and this creates difficulties in the interpretation of results simply in terms of possible mycorrhizal activity. An important subject is the differentiation of methods that involve sterilization from those focussed on indigenous inoculum reduction. Soil sterilization aims to destroy or eliminate microbial cells while maintaining the existing chemical and physical characteristics of the soil (Wolf and Skipper 1994). Consequently, it is often used for experiments focussed on specific AM fungi, or to establish a negative control in some other types of study. In contrast, the purpose of inoculum reduction techniques is to create a perturbation that will interfere with mycorrhizal formation, although not necessarily eliminating any component group within the inoculum. Such an approach allows the establishment of different degrees of mycorrhizal formation between treatments and the study of relative effects. Frequently the basic techniques used to achieve complete sterilization or just an inoculum reduction may be similar but the desired outcome is accomplished by adjustments of the dosage or intensity of the treatment. The ultimate choice of methodology for establishing an adequate non-mycorrhizal control depends on the design of the particular experiments, the facilities available and the amount of soil requiring treatment

    Agronomic Management of Indigenous Mycorrhizas

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    Many of the advantages conferred to plants by arbuscular mycorrhiza (AM) are associated to the ability of AM plants to explore a greater volume of soil through the extraradical mycelium. Sieverding (1991) estimates that for each centimetre of colonized root there is an increase of 15 cm3 on the volume of soil explored, this value can increase to 200 cm3 depending on the circumstances. Due to the enhancement of the volume of soil explored and the ability of the extraradical mycelium to absorb and translocate nutrients to the plant, one of the most obvious and important advantages resulting from mycorrhization is the uptake of nutrients. Among of which the ones that have immobilized forms in soil, such as P, assume particular significance. Besides this, many other benefits are recognized for AM plants (Gupta et al, 2000): water stress alleviation (Augé, 2004; Cho et al, 2006), protection from root pathogens (Graham, 2001), tolerance to toxic heavy metals and phytoremediation (Audet and Charest, 2006; Göhre and Paszkowski, 2006), tolerance to adverse conditions such as very high or low temperature, high salinity (Sannazzaro et al, 2006), high or low pH (Yano and Takaki, 2005) or better performance during transplantation shock (Subhan et al, 1998). The extraradical hyphae also stabilize soil aggregates by both enmeshing soil particles (Miller e Jastrow, 1992) and producing a glycoprotein, golmalin, which may act as a glue-like substance to adhere soil particles together (Wright and Upadhyaya, 1998). Despite the ubiquous distribution of mycorrhizal fungi (Smith and Read, 2000) and only a relative specificity between host plants and fungal isolates (McGonigle and Fitter, 1990), the obligate nature of the symbiosis implies the establishment of a plant propagation system, either under greenhouse conditions or in vitro laboratory propagation. These techniques result in high inoculum production costs, which still remains a serious problem since they are not competitive with production costs of phosphorus fertilizer. Even if farmers understand the significance of sustainable agricultural systems, the reduction of phosphorus inputs by using AM fungal inocula alone cannot be justified except, perhaps, in the case of high value crops (Saioto and Marumoto, 2002). Nurseries, high income horticulture farmers and no-agricultural application such as rehabilitation of degraded or devegetated landscapes are examples of areas where the use of commercial inoculum is current. Another serious problem is quality of commercial available products concerning guarantee of phatogene free content, storage conditions, most effective application methods and what types to use. Besides the information provided by suppliers about its inoculum can be deceiving, as from the usually referred total counts, only a fraction may be effective for a particular plant or in specific soil conditions. Gianinazzi and Vosátka (2004) assume that progress should be made towards registration procedures that stimulate the development of the mycorrhizal industry. Some on-farm inoculum production and application methods have been studied, allowing farmers to produce locally adapted isolates and generate a taxonomically diverse inoculum (Mohandas et al, 2004; Douds et al, 2005). However the inocula produced this way are not readily processed for mechanical application to the fields, being an obstacle to the utilization in large scale agriculture, especially row crops, moreover it would represent an additional mechanical operation with the corresponding economic and soil compaction costs. It is well recognized that inoculation of AM fungi has a potential significance in not only sustainable crop production, but also environmental conservation. However, the status quo of inoculation is far from practical technology that can be widely used in the field. Together a further basic understanding of the biology and diversity of AM fungi is needed (Abbott at al, 1995; Saito and Marumoto, 2002). Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species introductions and the potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. Schwartz et al, (2006) recommend that a careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial. Agricultural practices such as crop rotation, tillage, weed control and fertilizer apllication all produce changes in the chemical, physical and biological soil variables and affect the ecological niches available for occupancy by the soil biota, influencing in different ways the symbiosis performance and consequently the inoculum development, shaping changes and upset balance of native populations. The molecular biology tools developed in the latest years have been very important for our perception of these changes, ensuing awareness of management choice implications in AM development. In this context, for extensive farming systems and regarding environmental and economic costs, the identification of agronomic management practices that allow controlled manipulation of the fungal community and capitalization of AM mutualistic effect making use of local inoculum, seem to be a wise option for mycorrhiza promotion and development of sustainable crop production

    Remarkable effect of bromide ion upon two-dimensional faradaic phase transition of dibenzyl viologen on an HOPG electrode surface: Emergence of two-step transition

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    We found that dibenzyl viologen (dBV) on an HOPG electrode undergoes a two-step first order faradaic phase transition at high concentrations of bromide ion (Br-). Results of voltammetric and electroreflectance measurements were used to describe the mechanism of the two-step transition processes. When [Br-] > 180 mM, the transition step at less negative potential was ascribed to a phase transition between a gas-like adsorption layer of dBV dication (dBV2+) and a mesophase of dBV radical cation (dBV+). Most likely, the mesophase is a two-dimensional (2D) ordered phase composed of co-adsorbed dBV+ and Br- where both are in direct contact with the HOPG surface. The transition step at more negative potential was ascribed to a phase transition between the dBV+ Br- mesophase and a 2D condensed phase of dBV+. In the condensed phase being denser than the mesophase, dBV+ molecules are π-stacked due to face-to-face interaction between bipyridinium radical cations. This transition step involves also a reduction process of dBV2+ to dBV+ followed by its incorporation into the condensed phase. The two-step transition was not observed in KCl solution of any concentration, either in KBr solution of [Br -] < 75 mM. Other viologens examined, including benzyl-heptyl viologen, did not exhibit such a two-step transition but single-step one. The nature of the transition, especially in the [Br-] range from 75 to 180 mM, was closely analyzed

    Alternative uses for co-products: Harnessing the potential of valuable compounds from meat processing chains

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    peer-reviewedOpportunities for exploiting the inherent value of protein-rich meat processing co-products, in the context of increased global demand for protein and for sustainable processing systems, are discussed. While direct consumption maybe the most profitable route for some, this approach is influenced greatly by local and cultural traditions. A more profitable and sustainable approach may be found in recognizing this readily available and under-utilised resource can provide high value components, such as proteins, with targeted high value functionality of relevance to a variety of sectors. Applications in food & beverages, petfood biomedical and nutrition arenas are discussed. Utilization of the raw material in its entirety is a necessary underlying principle in this approach to help maintain minimum waste generation. Understanding consumer attitudes to these products, in particular when used in food or beverage systems, is critical in optimizing commercialization strategies.This work forms part of the ReValueProtein Research Project (Grant Award No. 11/F/043) which is supported by the Irish Department of Agriculture, Food and the Marine (DAFM) and the Food Institutional Research Measure (FIRM) both funded by the Irish Government under the National Development Plan 2007–2013.Department of Agriculture, Food and the Marin

    Bioactive peptides generated from meat industry by products

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    There is a large generation of meat by-products, not only from slaughtering but also in the meat industry from trimming and deboning during further processing. This results in extraordinary volumes of by-products that are primarily used as feeds with low returns or, more recently, to biodiesel generation. The aim of this work was to review the state of the art to generate bioactive peptides from meat industry by-products giving them an added value. Hydrolysis with commercial proteases constitutes the typical process and a variety of peptides result from such extensive proteolysis. This review focuses on the potential of meat by-products for the generation of bioactive peptides through enzymatic hydrolysis. The potential of some of the identified peptides to be used as bioactive supplements in foods has also been considered. (C) 2014 Elsevier Ltd. All rights reserved.Grant AGL2010-16305 from MINECO and FEDER funds are fully acknowledged. JAEDOC-CSIC postdoctoral contract to L.M. is also acknowledged. This work was developed under the Unidad Asociada IAD-UPV/IATA-CSIC framework.Mora, L.; Reig Riera, MM.; Toldra, F. (2014). Bioactive peptides generated from meat industry by products. Food Research International. 65:344-349. https://doi.org/10.1016/j.foodres.2014.09.014S3443496

    Increase in CD14+ HLA-DR−/low myeloid-derived suppressor cells in hepatocellular carcinoma patients and its impact on prognosis

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    13301甲第4291号博士(医学)金沢大学博士論文要旨Abstract 以下に掲載:Cancer Immunology, Immunotherapy 62(3) pp.1421-1430 2013. Springer. 共著者:在原 文教, 水腰 英四郎, 北原 征明, 高田 佳子, 荒井 邦明, 山下 竜也, 中本 安成, 金子 周
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