4,937 research outputs found

    Effect of NaCl on Asparagus Quality, Production and Mineral Leaching

    Get PDF
    Previous research has shown that the incidence of Fusarium oxysporum and F. redolens on asparagus roots was reduced by field applications of NaCl. F. oxysporum and F. redolens are important diseases in asparagus crops causing physiological rust (brown discoloration on the harvested spears), reduced yields, smaller spears, plant losses and may be implicated in asparagus decline. Since 2001 research has been carried out in Lelystad with asparagus plants grown in large wooden containers filled with a typical asparagus replant soil to study the effect of applications of Asparagus Salt (NaCl with addition of Mg) on asparagus quality, production and mineral leaching. In 2003 and 2004 the trial was harvested for a period of 35 days each year. In 2004 spears were graded into standard sizes to identify differences between treatments and to start with an economic evaluation. In both years Asparagus Salt had a positive effect on total yield, marketable yield and number of spears. Field applications of NaCl stimulated earliness in production. The higher loss of Mg due to leaching is compensated by adding Mg to the salt. In this experiment leaching of Mn was also studied in combination with adding Mn to Asparagus Salt

    Effect of NaCl on Asparagus Quality, Production and Mineral Leaching

    Get PDF
    Previous research has shown that the incidence of Fusarium oxysporum and F. redolens on asparagus roots was reduced by field applications of NaCl. F. oxysporum and F. redolens are important diseases in asparagus crops causing physiological rust (brown discoloration on the harvested spears), reduced yields, smaller spears, plant losses and may be implicated in asparagus decline. Since 2001 research has been carried out in Lelystad with asparagus plants grown in large wooden containers filled with a typical asparagus replant soil to study the effect of applications of Asparagus Salt (NaCl with addition of Mg) on asparagus quality, production and mineral leaching. In 2003 and 2004 the trial was harvested for a period of 35 days each year. In 2004 spears were graded into standard sizes to identify differences between treatments and to start with an economic evaluation. In both years Asparagus Salt had a positive effect on total yield, marketable yield and number of spears. Field applications of NaCl stimulated earliness in production. The higher loss of Mg due to leaching is compensated by adding Mg to the salt. In this experiment leaching of Mn was also studied in combination with adding Mn to Asparagus Salt

    Interaction and observation: categorical semantics of reactive systems trough dialgebras

    Full text link
    We use dialgebras, generalising both algebras and coalgebras, as a complement of the standard coalgebraic framework, aimed at describing the semantics of an interactive system by the means of reaction rules. In this model, interaction is built-in, and semantic equivalence arises from it, instead of being determined by a (possibly difficult) understanding of the side effects of a component in isolation. Behavioural equivalence in dialgebras is determined by how a given process interacts with the others, and the obtained observations. We develop a technique to inter-define categories of dialgebras of different functors, that in particular permits us to compare a standard coalgebraic semantics and its dialgebraic counterpart. We exemplify the framework using the CCS and the pi-calculus. Remarkably, the dialgebra giving semantics to the pi-calculus does not require the use of presheaf categories

    Energy-based modelling of adhesive wear in the mixed lubrication regime

    Get PDF
    Adhesive wear in dry contacts is often described using the Archard or Fleischer model. Both provide equations for the determination of a wear volume, taking the load, the sliding path and a set of material parameters into account. While the Fleischer model is based on energetic approaches, the Archard formulation uses an empirical factor-the wear coefficient-describing the intensity of wear. Today, a numerical determination of the wear coefficient is already possible and both approaches can be deduced to a local accumulation of friction energy. The aim of this work is to enhance existing energy-based wear models into the mixed lubrication regime. Therefore, the pressure distribution within the contact area will be determined numerically taking real surface topographies into account. The emerging contact area will be divided into one part of solid and a second part of elastohydrodynamically lubricated (EHL) contacts. Based on the resulting pressure and shear stress distribution, the formation of micro cracks within the loaded volume will be described. Determining a critical number of load cycles for each asperity, a locally resolved wear coefficient will be derived and the local wear depth calculated

    A mechanosensory receptor required for food texture detection in Drosophila.

    Get PDF
    Textural properties provide information on the ingestibility, digestibility and state of ripeness or decay of sources of nutrition. Compared with our understanding of the chemosensory assessment of food, little is known about the mechanisms of texture detection. Here we show that Drosophila melanogaster can discriminate food texture, avoiding substrates that are either too hard or too soft. Manipulations of food substrate properties and flies' chemosensory inputs indicate that texture preferences are revealed only in the presence of an appetitive stimulus, but are not because of changes in nutrient accessibility, suggesting that animals discriminate the substrates' mechanical characteristics. We show that texture preference requires NOMPC, a TRP-family mechanosensory channel. NOMPC localizes to the sensory dendrites of neurons housed within gustatory sensilla, and is essential for their mechanosensory-evoked responses. Our results identify a sensory pathway for texture detection and reveal the behavioural integration of chemical and physical qualities of food

    Classification, diagnosis and potential mechanisms in Pontocerebellar Hypoplasia

    Get PDF
    Pontocerebellar Hypoplasia (PCH) is group of very rare, inherited progressive neurodegenerative disorders with prenatal onset. Up to now seven different subtypes have been reported (PCH1-7). The incidence of each subtype is unknown. All subtypes share common characteristics, including hypoplasia/atrophy of cerebellum and pons, progressive microcephaly, and variable cerebral involvement. Patients have severe cognitive and motor handicaps and seizures are often reported. Treatment is only symptomatic and prognosis is poor, as most patients die during infancy or childhood. The genetic basis of different subtypes has been elucidated, which makes prenatal testing possible in families with mutations. Mutations in three tRNA splicing endonuclease subunit genes were found to be responsible for PCH2, PCH4 and PCH5. Mutations in the nuclear encoded mitochondrial arginyl- tRNA synthetase gene underlie PCH6. The tRNA splicing endonuclease, the mitochondrial arginyl- tRNA synthetase and the vaccinia related kinase1 are mutated in the minority of PCH1 cases. These genes are involved in essential processes in protein synthesis in general and tRNA processing in particular. In this review we describe the neuroradiological, neuropathological, clinical and genetic features of the different PCH subtypes and we report on in vitro and in vivo studies on the tRNA splicing endonuclease and mitochondrial arginyl-tRNA synthetase and discuss their relation to pontocerebellar hypoplasia

    Exploring the relationship among dispositional optimism, health-related quality of life, and CIPN severity among colorectal cancer patients with chronic peripheral neuropathy

    Get PDF
    Purpose. Chemotherapy-induced peripheral neuropathy ((CI)PN) becomes chronic in 30% of cancer patients. Knowledge of predictors of chronic (CI)PN and related impairments in health-related quality of life (HRQoL) is lacking. We examined the role of optimism in chronic (CI)PN severity and associated HRQoL in colorectal cancer (CRC) patients up to two years after diagnosis. Methods. CRC patients from a prospective cohort study participated, with sensory peripheral neuropathy (SPN) 1 year after diagnosis (n = 142). Multivariable regression analyses examined the cross-sectional association between optimism (measured by the LOT-R) and SPN severity/HRQoL (measured by the EORTC QLQ-CIPN20 and QLQ-C30), as well as the prospective association in a subsample that completed measures 2 years after diagnosis and still experienced SPN (n = 86). Results. At 1-year follow-up, higher optimism was associated with better global HRQoL, and better physical, role, emotional, cognitive, and social functioning (all p < .01). Optimism at year one was also prospectively associated with better global HRQoL (p < .05), and emotional and cognitive functioning at 2-year follow-up (both p < .01). Optimism was not related to self-reported SPN severity. Significant associations were retained when controlling for demographic/clinical variables, and became non-significant after controlling for depressive and anxiety symptoms. Conclusions. Optimism and depressive and anxiety symptoms are associated with HRQoL in CRC patients with chronic (CI)PN. Future research may illuminate the mechanisms that these factors share, like the use of (non)adaptive coping styles such as avoidance and acceptance that may inform the design of targeted interventions to help patients to adapt to chronic (CI)PN

    On the Elastohydrodynamic Film-Forming Properties of Metalworking Fluids and Oil-in-Water Emulsions

    Get PDF
    Oil-in-water (O/W) emulsions are water-based lubricants and used as fire-resistant hydraulic fluids and metalworking fluids (MWFs) in industry. The (elasto-)hydrodynamic film-forming properties of O/W emulsions have been studied extensively in literature. Typical elastohydrodynamic lubrication (EHL) behaviors are revealed at low rolling speeds followed by a starved EHL regime at elevated speeds. These emulsions are self-prepared and mostly stable only for a limited time ranging from hours to several days. By contrast, the film-forming behavior of water-miscible commercial MWFs (long-term stable O/W emulsions) has rarely been reported. This restricts the understanding of the lubrication status of many tribological interfaces in manufacturing processes, e.g., the chip-tool contact in cutting. In this work, the (elasto-)hydrodynamic film-forming property of two commercial MWFs is investigated by measuring the film thickness on two ball-on-disc test rigs using different optical interferometry techniques. For comparison, two self-prepared simple O/W emulsions with known formulation have also been investigated. Experimental results from the two test rigs agree well and show that the two self-prepared emulsions have typical EHL behaviors as reported in literature. However, for the two commercial MWFs, there is almost no (elasto-)hydrodynamic film-forming ability over the whole range of speeds used in this study. This could be explained by the cleaning and re-emulsification effects of the MWFs. The lubrication mechanism of the two MWFs is mainly boundary lubrication rather than hydrodynamic lubrication. Graphical Abstract: [Figure not available: see fulltext.]
    corecore