4,719 research outputs found

    Farm Diversification in Relation to Landscape Properties

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    Current European Common Agricultural Policy (CAP) has been moving from production support subsidies to direct decoupled income support. The emergence in policy making of the concept of multifunctional agriculture leads to the recognition that a farmer produces more than food: he produces jointly both commodity and non-commodity goods. Environmental contracts were developed in order to encourage the provision of non-commodity goods such as landscape or biodiversity. Next to these contracts, other activities as for example recreation can be observed. They are the result of farm diversification. The role of location in farmers’ decision making to diversify is pointed out in literature but geographical information is generally reduced to the location within a political delimitation unit the empirical work. Objective of this paper is two-fold. Firstly, it addresses the role of location, in term of site specific natural conditions as well as neighbouring emerging dynamics in farmer’s decision making to diversify. Attention is paid to number of activities as well as the specific types of activities, notably green services, daily recreation and other farm-linked services. Secondly, this paper introduces income from agriculture explicitly allowing testing short term price sensitivity. It was found that attractive landscape is a driver for diversification as these landscape offer more opportunities. Furthermore, diversification is responsive to price. Thirdly, role of density of past multifunctional activities in the neighborhood influences farm diversification: multifunctional activities create an externality effects as new activities emerge next to already existing ones. This dynamic may lead to the emergence of ‘multifunctional hotspots’ in landscape.Farmer diversification, landscape services, location, Farm Management, Land Economics/Use,

    African Land Ecology: Opportunities and Constraints for Agricultural Development

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    Current agriculture in Sub-Sahara Africa is undeveloped and the Green Revolution has left the continent largely untouched. Poor performance is often related to a number of socio-economic factors. In this paper we argue that there are also some specifities of natural resources, namely local homogeneity and spatial diversity of the pre-dominant Basement Complex soils, that imply that simple fertilizer strategies may not produce the yield increases obtained elsewhere. Keywords: Sub-Sahara Africa, Agro-Ecology, Land use, Land resources, Basement Complex, Green Revolution, Micronutrients, Fertilizer Policy

    Environmental monitoring in heterogeneous soil-landscapes; A Dutch case study

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    The spatial heterogeneity of agricultural soil-landscapes is mostly not taken into account in environmental policies. Most environmental goals have been defined at national level or farm level but not at the landscape level. The potential for setting up a regional environmental monitoring network that supports self governance was explored. The research was performed in the Northern Friesian Woodland

    VENUS: A Virtual Environment Network Using Satellites

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    Virtual environment (VE) designs have evolved from text-based to immersive graphical systems. The next logical step of this evolution is to have a fully immersive environment in which thousands of widely distributed users will be able to move around and interact. This requires a VE architecture that can scale well for a large number of participants while providing the necessary support for quality of service, security and flexibility. Current VE architectures are unable to fully meet these requirements and a new network/protocol architecture is needed. The VENUS approach addresses these problems by creating a network architecture which is scalable and flexible. We define a new architecture consisting of a transmit-only satellite/server and bi-directional links which will be capable of sustaining a wide-area virtual environment. We then offer the preliminary results of our experiments

    Reversal of typical multidrug resistance by cyclosporin and its non-immunosuppressive analogue SDZ PSC 833 in Chinese hamster ovary cells expressing the mdr1 phenotype

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    Summary The new non-immunosuppressive cyclosporin derivative SDZ PSC 833 (PSC) is a potent agent used to overcome typical multidrug resistance (MDR) associated with overexpression of themdr1 gene encoding for a P-170 glycoprotein. In the present study, the efficacy of PSC as compared with cyclosporin was determined in Chinese hamster ovary cell lines exhibiting different levels of resistance to colchicine (0, 0.1, 0.2 and 10 μg/ml, respectively). Low concentrations of PSC (8.2nm) increased the cytotoxicity of colchicine in cell lines expressing low levels of drug resistance. The concentration resulting in 50% cell survival (LC50 value) found for colchicine alone or in combination with PSC in the CHO-A3 cell line that was resistant to 100 ng colchicine/ml decreased from >500 to 200 ng/ml at 8.2nm PSC and to 500 ng/ml for colchicine alone to 500 ng/ml for colchicine used in combination with 8.2nm PSC and to <100 ng/ml for colchicine combined with 82 or 820nm PSC. At a concentration of 82nm PSC, the maximal effect in MDR reversal was observed in the cell lines exhibiting moderate resistance. In the highly resistant cell line, PSC (820nm) also reversed colchicine resistance. In drug-accumulation experiments, we obtained a 4-fold increase in intracellular doxorubicin accumulation using 820nm PSC. A comparison of PSC with cyclosporin revealed that a cyclosporin concentration 20-fold that of PSC was required to obtain the same sensitising effect. On the basis of these data, it may be concluded that PSC is a most promising chemosensitiser

    Malignant histiocytosis: A reassessment of cases formerly classified as histiocytic neoplasms and review of the literature

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    Malignant histiocytosis (MH) and true histiocytic lymphoma (THL) are hematopoietic malignancies of the mononuclear phagocytic system distinguished from each other by clinical presentation and presumed cell of origin. THL present as a localized mass derived from the fixed tissue histiocyte which may or may not disseminate. MH originates from the circulating monocyte or tissue macrophage and is characterized by a syndrome of systemic symptoms, pancytopenia, adenopathy, hepatosplenomegaly, and wasting. The distinction between MH and THL is at times arbitrary and overlap exists between these syndromes. The clinicopathologic studies that defined these entities were performed prior to the development of immunophenotyping and other molecular techniques currently used to ensure proper classification of hematopoietic malignancies. Nine patients from the University of Minnesota originally diagnosed with MH were retrospectively analyzed using a panel of antibodies reactive against T cell, B cell, and myelomonocytic antigens. Only one patient was reclassified as a possible histiocytic malignancy after reevaluation. Similar immunophenotyping studies have also shown cases previously diagnosed as MH or THL express lymphoid antigens, and would now be classified as Ki-1 positive anaplastic large cell lymphoma (ALCL) or some other hematopoietic neoplasm. These results indicate true histiocytic neoplasms are extremely rare, and previous concepts concerning clinical presentation and therapeutic outcome of the entities are inaccurate. In this paper we summarize the results of multiple retrospective analyses of cases previously diagnosed as MH or THL, including our experience at University of Minnesota, to illustrate the overall rarity of these entities. The current literature on malignant histiocytic disorders is reviewed, and the clinical presentation of patients determined to have histiocytic malignancies using contemporary analytical techniques is discussed

    Integrating copy number data of 64 iAMP21 BCP-ALL patients narrows the common region of amplification to 1.57 Mb

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    Background and purposeIntrachromosomal amplification of chromosome 21 (iAMP21) is a rare subtype of B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). It is unknown how iAMP21 contributes to leukaemia. The currently known commonly amplified region is 5.1 Mb.MethodsWe aimed to narrow down the common region of amplification by using high resolution techniques. Array comparative genomic hybridization (aCGH) was used to determine copy number aberrations, Affymetrix U133 Plus2 expression arrays were used to determine gene expression. Genome-wide expression correlations were evaluated using Globaltest.ResultsWe narrowed down the common region of amplification by combining copy number data from 12 iAMP21 cases with 52 cases from literature. The combined common region of amplification was 1.57 Mb, located from 36.07 to 37.64 Mb (GRCh38). This region is located telomeric from, but not including, RUNX1, which is the locus commonly used to diagnose iAMP21. This narrow region, which falls inside the Down Syndrome critical region, includes 13 genes of which the expression of eight genes was significantly upregulated compared with 143 non-iAMP21 B-other cases. Among these, transcriptional repressor RIPPLY3 (also known as DSCR6) was the highest overexpressed gene (fold change = 4.2, FDR DiscussionThe more precise definition of the common region of amplification could be beneficial in the diagnosis of iAMP21 based on copy number analysis from DNA sequencing or arrays as well as stimulate functional research into the role of the included genes in iAMP21 biology.</p

    Survival from testicular cancer in England and Wales up to 2001

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    www.bjcancer.com For many years testicular cancer has been the prime example of the tumour that is chemocurable, even when metastatic. The disappointment in oncology is that these results have so far not been replicated in the more common solid tumours. Why this should be is not clear but germ-cell tumours retain sensitivity to chemotherapy in vitro and a number of mechanisms including reduced DNA repair capacity and proneness to apoptosis have been proposed (Mayer et al, 2003). Most patients with testicular cancer present after finding a lump in the testicle that may or may not be painful. A small proportion of patients present with symptoms of metastatic disease. With the exception of some patients with metastatic disease, initial treatment after first assessment is to remove the tumour by inguinal orchidectomy. Patients are staged by tumour marke

    Liver stiffness is associated with excess mortality in the general population driven by heart failure:The Rotterdam Study

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    Background: Elevated liver stiffness reflects hepatic fibrosis but can also be secondary to venous congestion. We aimed to study the association between liver stiffness and mortality in the general population, stratified for heart failure and/or coronary heart disease (CHD). Methods: We analysed individuals enrolled in the ongoing prospective population-based Rotterdam Study who attended a visit between 2009–2014 that included liver stiffness measurement. Exclusion criteria for the primary analysis were incomplete data on heart failure, unreliable liver stiffness, alcohol abuse and viral hepatitis, leaving 4.153 participants (aged 67.5 ± 8.4 years, 44.2% male) for analysis with a median follow-up of 6.0 (interquartile range: 5.1–7.0) years. Secondary analysis included participants with viral hepatitis, alcohol abuse and/or unreliable measurement. The association between liver stiffness and mortality was assessed using Cox regression. Associations between heart failure, CHD, and echocardiographic characteristics and liver stiffness were quantified with linear regression. Results: Liver stiffness ≥8.0 kPa was associated with mortality (aHR: 1.37, 95%CI: 1.00–1.89). However, this was driven by participants with heart failure (aHR: 2.48, 95%CI: 1.15–5.35), since high liver stiffness was not associated with mortality in participants without heart failure and/or CHD (aHR: 1.07, 95%CI: 0.70–1.64). Results were consistent when individuals with viral hepatitis, alcohol abuse or unreliable liver stiffness measurement were not excluded. Several cardiovascular characteristics were significantly associated with higher liver stiffness, e.g. heart failure, moderate/poor diastolic dysfunction, and right atrium diameter &gt; 4.5 cm. Conclusion: In our cohort of community-dwelling elderly, high liver stiffness was associated with excess mortality, primarily explained by participants with heart failure. Moreover, heart failure and its indicators were associated with increased liver stiffness.</p
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