We develop a nonanticipative calculus for functionals of a continuous semimartingale, using an extension of the Itô formula to path-dependent functionals which possess certain directional ...derivatives. The construction is based on a pathwise derivative, introduced by Dupire, for functionals on the space of right-continuous functions with left limits. We show that this functional derivative admits a suitable extension to the space of square-integrable martingales. This extension defines a weak derivative which is shown to be the inverse of the Itô integral and which may be viewed as a nonanticipative "lifting" of the Malliavin derivative. These results lead to a constructive martingale representation formula for Itô processes. By contrast with the Clark—Haussmann—Ocone formula, this representation only involves nonanticipative quantities which may be computed pathwise.
We derive a change of variable formula for non-anticipative functionals defined on the space of
R
d
-valued right-continuous paths with left limits. The functionals are only required to possess ...certain directional derivatives, which may be computed pathwise. Our results lead to functional extensions of the Itô formula for a large class of stochastic processes, including semimartingales and Dirichlet processes. In particular, we show the stability of the class of semimartingales under certain functional transformations.
Abstract
This article explores datasets curated from the citation evidence in successive editions and revisions of the Oxford English Dictionary (1884–2022), which have been annotated to reflect the ...gender of the authors and other bibliographical metadata. This exploration aims both to supplement the historical account of the dictionary’s uses of female-authored quotation sources, correcting and elaborating some figures which have previously been reported, and to provide a contemporary account of women’s representation in OED Online, using the revision published in June 2022. In seeking to establish a more objective and empirical basis for judging ‘representativeness’, I treat the OED both as a self-contained bibliographical and lexicographical work, and comparatively, against other comprehensive or very large bibliographical corpora, namely the Garside et al. surveys of early English novels, the Library of Congress Catalog, and the HathiTrust Digital Library. The OED data studied here represents a significant (if restricted) subset, rather than a representative sample, of the OED corpus as a whole: modern (post-1700) quotations from books appearing with their author’s name in the OED evidence are considered. While this approach does not claim to make an objectively complete tally of every woman-authored quotation collected in the OED, it does enable a more detailed and accurate account than has previously been possible, and allows for a number of consistent cross-comparisons. A companion document of Supplementary Data & Notes, available at The Review of English Studies online, describes in technical terms how the data was compiled and the processes and principles by which it was annotated.
Abstract
This article discusses the changing ways in which the Oxford English Dictionary has recorded the vocabularies of ‘World English’—English as spoken outside of the British Isles—from the first ...to the present edition. Based on direct analyses of the coded text of multiple editions, it documents and compares the practices of successive editors, taking into account various contextual factors, such as editorial principles and policies, institutional resources, and historical language development. Significant attention is given to labelling practices, including the notorious ‘tramline’ mark of the First Edition and Second Supplement, designating ‘alien’ vocabulary; the evolution of the notion of ‘regional’ English within the dictionary; and the contributions of technology to the art of lexicography. The final section details changes in policy and methods in the current revision and expansion, evaluating both its practices vis-à-vis its predecessors, and the picture it gives us of the current state of World English.
Phytoplankton--the microalgae that populate the upper lit layers of the ocean--fuel the oceanic food web and affect oceanic and atmospheric carbon dioxide levels through photosynthetic carbon ...fixation. Here, we show that multidecadal changes in global phytoplankton abundances are related to basin-scale oscillations of the physical ocean, specifically the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation. This relationship is revealed in approximately 20 years of satellite observations of chlorophyll and sea surface temperature. Interaction between the main pycnocline and the upper ocean seasonal mixed layer is one mechanism behind this correlation. Our findings provide a context for the interpretation of contemporary changes in global phytoplankton and should improve predictions of their future evolution with climate change.
Multiple myeloma (MM) is a currently incurable malignancy of antibody-secreting plasma cells. Long non-coding RNAs (lncRNAs) have been recognised as an important class of regulatory molecules which ...are increasingly implicated in tumorigenesis. While recent studies have demonstrated changes in expression of lncRNAs in MM, the functional significance and molecular pathways downstream of these changes remain poorly characterised. In this study, we have performed CRISPR-mediated deletion of the locus encoding the lncRNA Colorectal Neoplasia Differentially Expressed (CRNDE), a known oncogenic lncRNA that is overexpressed in plasma cells of MM patients and is a marker of poor prognosis. We found that CRISPR-mediated deletion of the CRNDE locus in MM cells decreases proliferation and adhesion properties, increases sensitivity to Dexamethasone and reduces tumour growth in an in vivo xenograft model. Transcriptomic profiling in CRNDE-deleted MM cells demonstrated that CRNDE activates expression of a number of genes previously implicated in the aetiology of MM, including IL6R. We further demonstrate that deletion of the CRNDE locus diminishes IL6 signalling and proliferative responses in MM cells. Altogether this study reveals the IL6 signalling pathway as a novel mechanism by which CRNDE impacts upon MM cell growth and disease progression.
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•Main anion in forest soil solution was NO3− but organic acids in savanna.•Cultivation of forest caused twice more NO3−–N leaching than of savanna.•Forest-derived cropland lost K four ...times more than savanna-derived cropland.•Two-year losses of K and Ca exceeded 5% of soil stocks in forest-derived cropland.
Forest-savanna mosaic is widespread in tropical Africa mainly occurring on nutrient-poor Oxisols. Though sustainable agriculture is a major concern in this region, little is known about the effects of original vegetation (i.e., forest vs savanna) on nutrient losses from cropland. Hence, we evaluated basic cation losses and nutrient balance of Oxisol cropland cultivated over two years in the Cameroonian forest-savanna mosaic. Solute fluxes at 30-cm depth in maize croplands derived from forest (CRFR) and savanna (CRSV) were compared with those in adjacent forest (FR) and savanna (SV) ecosystems. Nutrient inputs by rainfall, outputs from solute leaching and cropland grain removal, and soil nutrient stocks measured at depths between 0 and 30 cm were investigated. The main anion present in FR soil solutions was NO3− (0.16–0.19 mmolc L−1), while it was present in negligible amounts in SV. The 2-year NO3− flux in CRFR (156 kg N ha−1) was double that in CRSV (78 kg N ha−1), leading to greater 2-year K+ leaching in CRFR (118 kg K ha−1) than in CRSV (37 kg K ha−1). The ratio of 2-year nutrient losses to total soil stocks was the greatest for Ca both in CRFR (5%) and CRSV (4%), while K loss also reached 5% in combination with lower solution pH in CRFR. In conclusion, cultivation of former forest land substantially increased NO3− leaching, resulting in depletion of both K and Ca; whereas, cultivation of former savanna results in mainly Ca depletion.
Models based on the multivariate partial least squares (PLS) regression technique are developed for the retrieval of phytoplankton size structure from measured light absorption spectra (BOUSSOLE ...site, northwestern Mediterranean Sea). PLS-models trained with data from the Mediterranean Sea showed good accuracy in retrieving, over the nine-year BOUSSOLE time series, the concentrations of total chlorophyll a Tchl a, of the sum of seven diagnostic pigments and of pigments associated with micro, nano, and picophytoplankton size classes separately. PLS-models trained using either total particle or phytoplankton absorption spectra performed similarly, and both reproduced seasonal variations of biomass and size classes derived by high performance liquid chromatography. Satisfactory retrievals were also obtained using PLS-models trained with a data set including various locations of the world's oceans, with however a lower accuracy. These results open the way to an application of this method to absorption spectra derived from hyperspectral and field satellite radiance measurements.
System Vicarious Calibration (SVC) ensures a relative radiometric calibration to satellite ocean color sensors that minimizes uncertainties in the water-leaving radiance Lw derived from the top of ...atmosphere radiance LT. This is achieved through the application of gain-factors, g-factors, to pre-launch absolute radiometric calibration coefficients of the satellite sensor corrected for temporal changes in radiometric sensitivity. The g-factors are determined by the ratio of simulated to measured spectral LT values where the former are computed using: i. highly accurate in situ Lw reference measurements; and ii. the same atmospheric models and algorithms applied for the atmospheric correction of satellite data. By analyzing basic relations between relative uncertainties of Lw and LT, and g-factors consistently determined for the same satellite mission using different in situ data sources, this work suggests that the creation of ocean color Climate Data Records (CDRs) should ideally rely on: i. one main long-term in situ calibration system (site and radiometry) established and sustained with the objective to maximize accuracy and precision over time of g-factors and thus minimize possible biases among satellite data products from different missions; and additionally ii. unique (i.e., standardized) atmospheric model and algorithms for atmospheric correction to maximize cross-mission consistency of data products at locations different from that supporting SVC. Finally, accounting for results from the study and elements already provided in literature, requirements and recommendations for SVC sites and field radiometric measurements are streamlined.
•System Vicarious Calibration (SVC) for satellite ocean color (OC) sensors.•Uncertainties in SVC correction factors supporting OC Climate Data Records (CDRs).•Recommendations for sites and in situ SVC measurements supporting OC CDRs.
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