1,674 research outputs found
Generic assumptions in utterance interpretation: the case of indirect instructions
This article addresses the role played by genre in the way in which language users interpret âindirectâ directive utterances in the special discourse context of technical instructions. In linguistics, issues of genre have most often been approached from socially oriented frameworks such as systemic functional linguistics and the ethnomethodology of the Swales-Bhatia school. The present article instead adopts the cognitive framework of relevance theory to account for a process of comprehension founded on two modularised cognitive processes, viz. decoding of semantic content and relevance-driven inferential manipulation of resulting representations to which generic assumptions about the discourse provide significant contextual input
The English Possessive Marker in a Framework of Relevance
English nominals constructed with the morpheme {-s} as a so-called possessive marker may be assigned an indeïŹnitely large number of interpretations depending on the context of utterance. This raises interesting questions concerning the interface between semantics and pragmatics, most obviously concerning the more speciïŹc nature of the contextually invariable encoded content of the morpheme as well as the contribution made by that content to the process of comprehension. This article aims brieïŹy to suggest one solution to these problems by proposing an underdetermined procedural semantics feeding into a principled cognitive process of inference as proposed within the framework of relevance theory
Designing and managing multiple pipelines
There is now a growing recognition that supply chains should be designed from
âthe customer backwardsâ rather than from âthe company outwardsâ. If such a view
is accepted then the implication is that since the organisation will likely be
serving multiple markets or segments there will be the need to design and manage
multiple âpipelinesâ to serve those different customers. To assist decision
makers in their choice of appropriate supply chain design a framework is
proposed based upon multiple criteria. A case study is presented which
highlights the benefits of selecting, engineering and operating multiple
pipelines tailored to the needs of th
Volatile hydrocarbons inhibit methanogenic crude oil degradation
Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene, and xylenes) were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34) and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene) were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales) were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 Όmol CH4/g sediment/day) with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34). For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 Όmol CH4/g sediment/day). This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers
Computation of Light Scattering in Young Stellar Objects
A Monte Carlo light scattering code incorporating aligned non-spherical
particles is described. The major effects on the flux distribution, linear
polarisation and circular polarisation are presented, with emphasis on the
application to Young Stellar Objects (YSOs). The need for models with
non-spherical particles in order to successfully model polarisation data is
reviewed. The ability of this type of model to map magnetic field structure in
embedded YSOs is described. The possible application to the question of the
origin of biomolecular homochirality via UV circular polarisation in star
forming regions is also briefly discussed.Comment: Accepted by The Journal of Quantitative Spectroscopy and Radiative
Transfer. Replaced version corrects an error in the definition of the sense
of Cpol in the published version and other minor errors found at the proof
stag
High Resolution Millimeter-Wave Mapping of Linearly Polarized Dust Emission: Magnetic Field Structure in Orion
We present 1.3 and 3.3 mm polarization maps of Orion-KL obtained with the
BIMA array at approximately 4 arcsec resolution. Thermal emission from
magnetically aligned dust grains produces the polarization. Along the Orion
``ridge'' the polarization position angle varies smoothly from about 10 degrees
to 40 degrees, in agreement with previous lower resolution maps. In a small
region south of the Orion ``hot core,'' however, the position angle changes by
90 degrees. This abrupt change in polarization direction is not necessarily the
signpost of a twisted magnetic field. Rather, in this localized region
processes other than the usual Davis-Greenstein mechanism might align the dust
grains with their long axes parallel with the field, orthogonal to their normal
orientation.Comment: AAS preprint:14 pages, 2 figures (3mm.eps and 1mm.eps); requires
aaspp4.sty To be published in Astrophysical Journal Letter
Comparability of surrogate and self-reported information on melanoma risk factors.
Surrogate reports by patients about their relatives, and vice versa, are potentially of great use in studies of the genetic and environmental causes of the familial aggregation of cancer. To assess the quality of such information in a family study of melanoma aetiology in Queensland, Australia, the authors compared surrogate reports with self-reports of standard melanoma risk factors obtained by mailed self-administered questionnaire. There was moderate agreement between surrogate reports provided by the cases and relatives' self-reports for questions on ability to tan (polychoric correlation coefficient (pc) = 0.60), skin colour (pc = 0.57), average propensity to burn (pc = 0.56), and hair colour at age 21 (kappa coefficient = 0.55), although relatives in the extreme risk factor categories were misclassified by surrogates at least half of the time. Agreement was lower for questions on degree of moliness (pc = 0.45), tendency to acute sunburn (pc = 0.42), and number of episodes of painful sunburn (pc = 0.23). The quality of relatives' surrogate reports about cases was similar to that of cases' surrogate reports about relatives. Cases who reported a family history of melanoma provided better surrogate information than did cases who indicated no family history, and female cases provided better surrogate reports than did males. Cases were better able to report for their parents and children than for their siblings. The authors conclude that when the use of surrogate reports of melanoma risk factors is unavoidable, results should be interpreted cautiously in the light of potentially high rates of misclassification. In particular, surrogate reports appear to be a comparatively poor measure of self-assessment of number of moles, the strongest known phenotypic indicator of melanoma risk, and may bias comparisons between families with and without a history of melanoma
DNA lesion bypass and the stochastic dynamics of transcription coupled repair
DNA base damage is a major source of oncogenic mutations and disruption to gene expression. The stalling of RNA polymerase II (RNAP) at sites of DNA damage and the subsequent triggering of repair processes have major roles in shaping the genome-wide distribution of mutations, clearing barriers to transcription, and minimizing the production of miscoded gene products. Despite its importance for genetic integrity, key mechanistic features of this transcription-coupled repair (TCR) process are controversial or unknown. Here, we exploited a well-powered in vivo mammalian model system to explore the mechanistic properties and parameters of TCR for alkylation damage at fine spatial resolution and with discrimination of the damaged DNA strand. For rigorous interpretation, a generalizable mathematical model of DNA damage and TCR was developed. Fitting experimental data to the model and simulation revealed that RNA polymerases frequently bypass lesions without triggering repair, indicating that small alkylation adducts are unlikely to be an efficient barrier to gene expression. Following a burst of damage, the efficiency of transcription-coupled repair gradually decays through gene bodies with implications for the occurrence and accurate inference of driver mutations in cancer. The reinitation of transcription from the repair site is not a general feature of transcription-coupled repair, and the observed data is consistent with reinitiation never taking place. Collectively, these results reveal how the directional but stochastic activity of TCR shapes the distribution of mutations following DNA damage
Data on the concentrations of etoposide, PSC833, BAPTA-AM, and cycloheximide that do not compromise the vitality of mature mouse oocytes, parthenogenetically activated and fertilized embryos
AbstractThese data document the vitality of mature mouse oocytes (Metaphase II (MII)) and early stage embryos (zygotes) following exposure to the genotoxic chemotherapeutic agent, etoposide, in combination with PSC833, a selective inhibitor of permeability glycoprotein. They also illustrate the vitality of parthenogenetically activated and fertilized embryos following incubation with the calcium chelator BAPTA-AM (1,2-Bis(2-aminophenoxy)ethane- N,N,NâČ,NâČ-tetraacetic acid tetrakis (acetoxymethyl ester)), cycloheximide (an antibiotic that is capable of inhibiting protein synthesis), and hydrogen peroxide (a potent reactive oxygen species). Finally, they present evidence that permeability glycoprotein is not represented in the proteome of mouse spermatozoa. Our interpretation and discussion of these data feature in the article âIdentification of a key role for permeability glycoprotein in enhancing the cellular defense mechanisms of fertilized oocytesâ (Martin et al., in press) [1]
Peri- and Postnatal Effects of Prenatal Adenoviral VEGF Gene Therapy in Growth-Restricted Sheep
Uterine artery (UtA) adenovirus vector (Ad)-mediated over-expression of vascular endothelial growth factor (VEGF) enhances uterine blood flow in normal sheep pregnancy and increases fetal growth in the overnourished adolescent sheep model of fetal growth restriction (FGR). Herein we examined its impact on gestation length, neonatal survival, early postnatal growth and metabolism. Singleton-bearing ewes were evenly allocated to receive Ad.VEGF-A165(5 x 10(10)particles/ml, 10 ml, n =17) or Saline (10 ml, n = 16) injected into each UtA at laparotomy (0.6 gestation). Fetal growth was serially monitored (blind) by ultrasound until delivery. Lambs were weighed and blood-sampled weekly and a glucose tolerance test performed (68d postnatal age). Hepatic DNA/RNA was extracted at necropsy (83d postnatal age) to examine methylation status of eight somatotropic axis genes. ITALIC! IGF1mRNA and protein expression were measured by RT-PCR and radioimmunoassay, respectively. All pregnancies remained viable following Ad.VEGF-A165treatment. Fetal abdominal circumference and renal volume were greater in Ad.VEGF-A165versus Saline groups at 21/28 days (p †0.04) post-injection. At delivery, gestation length (p = 0.07), lamb birthweight (p = 0.08), umbilical girth (p = 0.06) and plasma glucose (p=0.09) tended to be greater in Ad.VEGF-A165treated lambs. Levels of neonatal intervention required to ensure survival was equivalent between groups. Absolute postnatal growth rate (p = 0.02), insulin area-under-the-curve (p = 0.04) and carcass weight at necropsy (p = 0.04) were increased by Ad.VEGF-A165treatment. There was no impact on markers of insulin sensitivity or methylation/expression of key genes involved in somatic growth. Ad.VEGF-A165gene therapy increased fetal growth in a sheep FGR model and lambs continued to thrive during the neonatal and early postnatal period
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