Ciba Foundation symposium最新文献_第8页

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515433.ch5

H Biessmann, M F Walter, J M Mason

引用次数: 21

Spatial variability of soil moisture regimes at different scales: implications in the context of precision agriculture. 不同尺度土壤水分状况的空间变异性:在精准农业背景下的含义。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515419.ch3

M Voltz

{"title":"Spatial variability of soil moisture regimes at different scales: implications in the context of precision agriculture.","authors":"M Voltz","doi":"10.1002/9780470515419.ch3","DOIUrl":"https://doi.org/10.1002/9780470515419.ch3","url":null,"abstract":"Precision agriculture is based on the concept of soil-specific management, which aims to adapt management within a field according to specific site conditions in order to maximize production and minimize environmental damage. This paper examines how the nature and sources of variation in soil moisture regimes affect our ability to simulate soil water behaviour within a field with adequate precision in order to advise optimal soil-specific management. Field examples of variation in soil moisture regimes are described to illustrate the difficulties involved. A discussion identifies three main points. First, it is recognized that the current modelling approaches to soil moisture regimes do not sufficiently account for local heterogeneities in soil and crop characteristics such as soil morphology and rooting patterns. Second, the estimation of within-field variation of soil hydraulic properties is difficult because of large short-range variation of the properties and general lack of observed data; one way to overcome this problem is to seek new measurement techniques or to find easy-to-measure auxiliary variables spatially correlated to the variables of interest. Last, as pollution impacts often become noticeable to society at scales larger than the scale of agricultural management, hydrological modelling can serve for linking both scales and advising agricultural practices that minimize undesirable pollution effects.","PeriodicalId":10218,"journal":{"name":"Ciba Foundation symposium","volume":"210 ","pages":"18-30; discussion 30-7"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20494070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Modelling non-stationary spatial covariance structure from space-time monitoring data. 基于时空监测数据的非平稳空间协方差结构建模。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515419.ch4

P Monestiez, W Meiring, P D Sampson, P Guttorp

{"title":"Modelling non-stationary spatial covariance structure from space-time monitoring data.","authors":"P Monestiez, W Meiring, P D Sampson, P Guttorp","doi":"10.1002/9780470515419.ch4","DOIUrl":"https://doi.org/10.1002/9780470515419.ch4","url":null,"abstract":"Accurate interpolation of soil and climate variables at fine spatial scales is necessary for precise field management. Interpolation is needed to produce the input variables necessary for crop modelling. It is also important when deciding on regulations to limit environmental impacts from processes such as nitrate leaching. Non-stationarity may arise due to many factors, including differences in soil type, or heterogeneity in chemical concentrations. Many geostatistical methods make stationarity assumptions. Substantial improvements in interpolation or in the estimation of standard errors may be obtained by using non-stationary models of spatial covariances. This paper presents recent methodological developments for an approach to modelling non-stationary spatial covariance structure through deformations of the geographic coordinate system. This approach was first introduced by Sampson & Guttorp, although the estimation approach is updated in more recent papers. They compute a deformation of the geographic plane so that the spatial covariance structure can be considered stationary in terms of a new spatial coordinate system. This provides a non-stationary model for the spatial covariances between sampled locations and prediction locations. In this paper, we present a cross-validation procedure to avoid over-fitting of the sample dispersions. Results concerning the variability of the spatial covariance estimates are also presented. An example of the modelling of the spatial correlation field of rainfall at small regional scale is presented. Other directions in methodological development, including modelling temporally varying spatial correlation, and approaches to model temporal and spatial correlation are mentioned. Future directions for methodological development are indicated, including the modelling of multivariate processes and the use of external spatially dense covariables. Such covariates are frequently available in precision agriculture.","PeriodicalId":10218,"journal":{"name":"Ciba Foundation symposium","volume":"210 ","pages":"38-48; discussion 48-51, 68-78"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20494071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Variability and uncertainty in spatial, temporal and spatiotemporal crop-yield and related data. 空间、时间和时空作物产量及相关数据的变异性和不确定性。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515419.ch9

A B McBratney, B M Whelan, T M Shatar

{"title":"Variability and uncertainty in spatial, temporal and spatiotemporal crop-yield and related data.","authors":"A B McBratney, B M Whelan, T M Shatar","doi":"10.1002/9780470515419.ch9","DOIUrl":"https://doi.org/10.1002/9780470515419.ch9","url":null,"abstract":"Application of the theories of precision agriculture to the practicalities of broad-acre farming relies on successful handling of the ramifications of uncertainty in information, i.e. information pertaining to the spatial and temporal variation of those factors which determine yield components and/or environmental losses. This paper discusses the uncertainty of yield and related variables as measured by their spatial and temporal variance. The magnitude of these two components gives a suggestion as to the appropriate scale of management. Simultaneous reporting on spatial and temporal variation is rare and the theory of these types of process is still in its infancy. Some brief theory is presented, followed by several examples from the Rothamsted classic experiments, yield-monitoring experiments in Australia, a long-term barley trial in Denmark, and a soil moisture monitoring network. It is clear that annual temporal variation is much larger than the spatial variation within single fields. This leads to the conclusion that if precision agriculture is to have a sound scientific basis and ultimately a practical outcome then the null hypothesis that still remains to be seriously researched is: 'given the large temporal variation in yields relative to the scale of a single field, then the optimal risk aversion strategy is uniform management.'","PeriodicalId":10218,"journal":{"name":"Ciba Foundation symposium","volume":"210 ","pages":"141-60"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20495247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 31

Molecular evolution of multiply-antibiotic-resistant staphylococci. 多重耐药葡萄球菌的分子进化。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515358.ch11

R A Skurray, N Firth

{"title":"Molecular evolution of multiply-antibiotic-resistant staphylococci.","authors":"R A Skurray, N Firth","doi":"10.1002/9780470515358.ch11","DOIUrl":"https://doi.org/10.1002/9780470515358.ch11","url":null,"abstract":"Methicillin-resistant Staphylococcus aureus (MRSA) is an intractable nosocomial pathogen. The chemotherapeutic intransigence of this organism stems from its predilection to antimicrobial resistance as a consequential response to selective pressures prevailing in the clinical environment. MRSA isolates are frequently resistant to all practicable antimicrobials except the glycopeptide, vancomycin. Although antimicrobial resistance sometimes arises via chromosomal mutation, the emergence of multiply-antibiotic-resistant staphylococci is primarily due to the acquisition of pre-existent resistance genes; such determinants can be encoded chromosomally or by plasmids and are often associated with transposons or insertion sequences. Clinical staphylococci commonly carry one or more plasmids, ranging from small replicons that are phenotypically cryptic or contain only a single resistance gene, to larger episomes that possess several such determinants and sometimes additionally encode systems that mediate their own conjugative transmission and the mobilization of other plasmids. The detection of closely related plasmids, elements and/or genes in other hosts, including coagulase-negative staphylococci and enterococci, attests to interspecific and intergeneric genetic exchange facilitated by mobile genetic elements and DNA transfer mechanisms. The extended genetic reservoir accessible to staphylococci afforded by such horizontal gene flux is fundamental to the acquisition, maintenance and dissemination of staphylococcal antimicrobial resistance in general, and multiresistance in particular.","PeriodicalId":10218,"journal":{"name":"Ciba Foundation symposium","volume":"207 ","pages":"167-83; discussion 183-91"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20135172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 38

Repair and processing events at DNA ends. DNA末端的修复和加工过程。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515433.ch13

T Lindahl, D E Barnes, A Klungland, V J Mackenney, P Schär

引用次数: 5

Controversies in the cellular pharmacology of oligodeoxynucleotides. 寡脱氧核苷酸的细胞药理学争议。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515396.ch7

C. Stein

{"title":"Controversies in the cellular pharmacology of oligodeoxynucleotides.","authors":"C. Stein","doi":"10.1002/9780470515396.ch7","DOIUrl":"https://doi.org/10.1002/9780470515396.ch7","url":null,"abstract":"Phosphodiester and phosphorothioate oligodeoxynucleotides are polyanions that cannot passively diffuse across cell membranes. Instead, the processes of adsorbtive endocytosis and pinocytosis probably account for the great majority of oligodeoxynucleotide internalization in most cell types. Oligodeoxynucleotides can adsorb to heparin-binding, cell surface proteins. An example of such a protein is the integrin Mac-1 (alpha M beta 2; CR3; CD11b/CD18), a receptor for fibrinogen which is found on neutrophils, macrophages and natural killer cells. Up-regulation of neutrophil cell surface Mac-1 expression by interleukin 8, arachidonic acid or tumour necrosis factor alpha leads to increased cell surface oligodeoxynucleotide binding and internalization. Binding and internalization can be blocked by both fibrinogen and by anti-Mac-1 monoclonal antibodies. Subsequent to internalization, oligodeoxynucleotides reside in subcellular vesicular structures, i.e. endosomes and lysosomes. However, in the absence of permeabilizing agents, these compartments may be sites of sequestration and the oligomers may be unavailable for antisense activity. At present, controversy surrounds the use of guanosine-rich phosphorothioate oligodeoxynucleotides as antisense agents. We examined the ability of the 24mer antisense rel A (p65) phosphorothioate oligodeoxynucleotide to inhibit nuclear translocation of NF kappa B in K-BALB murine fibroblasts. 7-Deaza-2'-deoxyguanosine substitution in the 5' guanosine quartet region demonstrated that inhibition of nuclear translocation could not be due to a Watson-Crick antisense effect. Rather, we favour the explanation that the parent molecule may be a sequence-specific, apatameric decoy.","PeriodicalId":10218,"journal":{"name":"Ciba Foundation symposium","volume":"8 1","pages":"79-89; discussion 89-93"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81916316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biological aspects of macrophage-stimulating protein (MSP) and its receptor. 巨噬细胞刺激蛋白(MSP)及其受体的生物学特性。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515457.CH12

E. Leonard

{"title":"Biological aspects of macrophage-stimulating protein (MSP) and its receptor.","authors":"E. Leonard","doi":"10.1002/9780470515457.CH12","DOIUrl":"https://doi.org/10.1002/9780470515457.CH12","url":null,"abstract":"Macrophage-stimulating protein (MSP; also known as HGF-like protein [HGFl]) is a 78 kDa plasma protein that is secreted by the liver into the circulation as single-chain, biologically inactive pro-MSP. The presence of conserved triple disulfide loops (kringles) places pro-MSP in a family of coagulation system serine protease zymogens that are activated by proteolytic cleavage. Although pro-MSP has lost enzymic activity, it has retained the activation mechanism, in that proteolytic cleavage at a single site yields biologically active disulfide-linked alpha beta-chain heterodimeric MSP. The MSP receptor is a transmembrane protein tyrosine kinase. MSP causes phosphorylation of the receptor cytoplasmic domain, association of phosphatidylinositol (PI)-3 kinase with the receptor, and phosphorylation of receptor-bound PI-3 kinase. Inhibition of PI-3 kinase by wortmannin prevents MSP action on cells. MSP stimulates motility of murine resident peritoneal macrophages. However, it does not act on exudate macrophages or blood monocytes, since these earlier maturational stages of the lineage do not express the receptor. MSP also stimulates keratinocyte cell lines, causing either chemotactic responses or increased cell numbers in culture. We suggest that pro-MSP diffuses into local tissue sites, where proteolytic cleavage to MSP results in stimulation of keratinocytes and macrophages. It possibly plays a role in tissue injury or wound healing.","PeriodicalId":10218,"journal":{"name":"Ciba Foundation symposium","volume":"44 1","pages":"183-91; discussion 192-7"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82051321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 18

Oligonucleotide therapeutics for human leukaemia. 人类白血病的寡核苷酸疗法。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1007/978-3-0348-8946-9_9

A. Gewirtz

引用次数: 5

Differentiation and functions of T cell subsets. T细胞亚群的分化和功能。

Ciba Foundation symposium Pub Date : 1997-01-01 DOI: 10.1002/9780470515280.ch10

T R Mosmann, L Li, H Hengartner, D Kagi, W Fu, S Sad

{"title":"Differentiation and functions of T cell subsets.","authors":"T R Mosmann, L Li, H Hengartner, D Kagi, W Fu, S Sad","doi":"10.1002/9780470515280.ch10","DOIUrl":"https://doi.org/10.1002/9780470515280.ch10","url":null,"abstract":"The Tc1 and Tc2 subsets of CD8+ T effector cells secrete different patterns of cytokines, but have similar functions, including perforin- and Fas-dependent cytotoxicity, and induction of delayed type hypersensitivity (DTH) reactions involving oedema and granulocytic infiltration. The characteristic cytokines of Tc1 (gamma-interferon) and Tc2 (interleukins 4 and 5) are expressed in vivo during the DTH reaction. Tc1 cells that are deficient in cytokine synthesis also induce similar levels of DTH, supporting the lack of correlation between CD8+ T cell cytokine patterns and DTH. CD8+ T cells often produce lower cytokine levels than CD4 cells because the CD8 cells kill their antigen-presenting cells before full stimulation can occur. This effect can be counteracted by increasing the frequency of stimulation, or using perforin-deficient T cells. A multiparameter analysis of cytokine effects on CD8+ T cell differentiation has been initiated, on the basis of the principle that normal immune responses involve complex cytokine mixtures. All combinations of seven cytokines were tested. In some combinations, the combined effect could not have been predicted from individual cytokine functions. Conditions were identified in which each of interleukins 4, 10 and 12 could have opposite effects on CD8+ T cell differentiation.","PeriodicalId":10218,"journal":{"name":"Ciba Foundation symposium","volume":"204 ","pages":"148-54; discussion 154-8"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20056846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 61