3,366 research outputs found
Language comprehension and production
In this chapter, we survey the processes of recognizing and producing words and of understanding and creating sentences. Theory and research on these topics have been shaped by debates about how various sources of information are integrated in these processes, and about the role of language structure, as analyzed in the discipline of linguistics. In this chapter, we describe current views of fluent language users' comprehension of spoken and written language and their production of spoken language. We review what we consider to be the most important findings and theories in psycholinguistics, returning again and again to the questions of modularity and the importance of linguistic knowledge. Although we acknowledge the importance of social factors in language use, our focus is on core processes such as parsing and word retrieval that are not necessarily affected by such factors. We do not have space to say much about the important fields of developmental psycholinguistics, which deals with the acquisition of language by children, or applied psycholinguistics, which encompasses such topics as language disorders and language teaching. Although we recognize that there is burgeoning interest in the measurement of brain activity during language processing and how language is represented in the brain, space permits only occasional pointers to work in neuropsychology and the cognitive neuroscience of language. For treatment of these topics, and others, the interested reader could begin with two recent handbooks of psycholinguistics (Gaskell, 2007; Traxler & Gemsbacher, 2006) and a handbook of cognitive neuroscience (Gazzaniga, 2004)
Patterns, predictors and outcomes of asthma control and exacerbations during pregnancy: a prospective cohort study
There exists a paucity of data for socially disadvantaged populations describing patterns and predictors of asthma control status and exacerbations during pregnancy, and their relationship to adverse perinatal outcomes. Asthmatic women (n=189) were followed prospectively during pregnancy, with visits at 12, 20, 28 and 36 weeks gestation. Data on loss of control, recurrent uncontrolled asthma and moderate/severe exacerbations were collected at each visit and their relationship to perinatal outcomes examined following stratification for fetal sex. 50% of asthmatic women experienced a loss of control or moderate/severe exacerbation during pregnancy, with 22% of women experiencing a moderate/severe exacerbation. Factors associated with an increased risk of women experiencing recurrent uncontrolled asthma during pregnancy included smoking (relative risk 2.92, 95% CI 1.53-5.58), inhaled corticosteroid use at the beginning of pregnancy (relative risk 2.40, 95% CI 1.25-4.60) and increasing maternal age (relative risk 1.06, 95% CI 1.01-1.11). No factors were associated with moderate/severe exacerbations. Asthma control rather than exacerbations during pregnancy appeared to be most strongly correlated with perinatal outcomes. Following stratification by fetal sex, the presence of recurrent uncontrolled asthma was associated with an increased risk of being small for gestational age in women pregnant with females (33.3% versus 9.5%; p=0.018). In contrast, there was a nonsignificant increased risk of preterm birth in women with recurrent uncontrolled asthma that were pregnant with males (25.0% versus 11.8%; p=0.201) These results suggest that the key to improving perinatal outcomes lies in improving asthma control as early as possible in pregnancy and monitoring throughout pregnancy, rather than focusing on preventing exacerbations alone.Luke E. Grzeskowiak, Brian Smith, Anil Roy, Gustaaf A. Dekker and Vicki L. Clifto
Spherically symmetric solutions in f(R)-gravity via Noether Symmetry Approach
We search for spherically symmetric solutions of f(R) theories of gravity via
the Noether Symmetry Approach. A general formalism in the metric framework is
developed considering a point-like f(R)-Lagrangian where spherical symmetry is
required. Examples of exact solutions are given.Comment: 17 pages, to appear in Class. Quant. Gra
Rotationally invariant proof of Bell's theorem without inequalities
The singlet state of two spin-3/2 particles allows a proof of Bell's theorem
without inequalities with two distinguishing features: any local observable can
be regarded as an Einstein-Podolsky-Rosen element of reality, and the
contradiction with local realism occurs not only for some specific local
observables but for any rotation whereof.Comment: REVTeX4, 3 page
Public attitudes towards Chinese medicine in Melbourne, Australia
PURPOSE - To investigate the public attitudes towards Chinese medicine and the impact of the introduction of statutory practitioner registration in Melbourne, Australia. METHOD - A convenience sample of 575 participants (18-45 years of age) from three locations in Melbourne completed a self-administered, 60-question survey in August 2002. RESULTS - In the previous 12 months, Chinese medicine had been used by 30.9% of the respondents and 17.3% had visited a Chinese medicine practitioner. For each of eight common conditions listed in the survey, between 61.2% and 92.7% of participants indicated that western medicine was their preferred therapeutic option, rather than Chinese medicine or combination of Western and Chinese medicine. However, substantial proportions of participants preferred Chinese medicine for stomach or internal problems (28.4%), cold/flu (18.8%) and dizziness (17.6%). Although 78.2% were aware that statutory practitioner registration had recently been introduced in the State, only 29.9% indicated that they would only visit a registered practitioner. IMPLICATION - More stringent surveillance of Chinese medicine service providers and a public education campaign may be necessary to protect against unauthorized Chinese medicine practice
On relativistic elements of reality
Several arguments have been proposed some years ago, attempting to prove the
impossibility of defining Lorentz-invariant elements of reality. I find that a
sufficient condition for the existence of elements of reality, introduced in
these proofs, seems to be used also as a necessary condition. I argue that
Lorentz-invariant elements of reality can be defined but, as Vaidman pointed
out, they won't satisfy the so-called product rule. In so doing I obtain
algebraic constraints on elements of reality associated with a maximal set of
commuting Hermitian operators.Comment: Clarifications, reference added; published versio
Physiologic and therapeutic roles of somatotropin effects in adult animals
12/94.Includes bibliographical references (pages 11-12)
Non-local Correlations are Generic in Infinite-Dimensional Bipartite Systems
It was recently shown that the nonseparable density operators for a bipartite
system are trace norm dense if either factor space has infinite dimension. We
show here that non-local states -- i.e., states whose correlations cannot be
reproduced by any local hidden variable model -- are also dense. Our
constructions distinguish between the cases where both factor spaces are
infinite-dimensional, where we show that states violating the CHSH inequality
are dense, and the case where only one factor space is infinite-dimensional,
where we identify open neighborhoods of nonseparable states that do not violate
the CHSH inequality but show that states with a subtler form of non-locality
(often called "hidden" non-locality) remain dense.Comment: 8 pages, RevTe
Maximum tumor diameter is associated with event-free survival in PET-negative patients with stage I/IIA Hodgkin lymphoma.
Introduction: the high cure rates achieved in early-stage (ES) Hodgkin lymphoma (HL) are one of the great successes of hemato-oncology, but late treatment-related toxicity undermines long-term survival. Improving overall survival and quality of life further will require maintaining disease control while potentially de-escalating chemotherapy and/or omitting radiotherapy to reduce late toxicity. Accurate stratification of patients is required to facilitate individualized treatment approaches. Response assessment using 18F-fluorodeoxyglucose positron emission tomography (PET) is a powerful predictor of outcome in HL,1,2 and has been used in multiple studies, including the United Kingdom National Cancer Research Institute Randomised Phase III Trial to Determine the Role of FDG–PET Imaging in Clinical Stages IA/IIA Hodgkin’s Disease (UK NCRI RAPID) trial, to investigate whether patients achieving complete metabolic remission (CMR) can be treated with chemotherapy alone.3-5 These PET-adapted trials have demonstrated that omitting radiotherapy results in higher relapse rates, but without compromising overall survival.3-5
For the 75% of patients who achieved CMR in RAPID, neither baseline clinical risk stratification (favorable/unfavorable) nor PET (Deauville score 1/2) predicted disease relapse; additional biomarkers are needed.1 Tumor bulk has long been recognized as prognostic in HL,1,6 but there remains uncertainty about the significance and definition of bulk in the era of PET-adapted treatment.7 We performed a subsidiary analysis of RAPID to assess the prognostic value of baseline maximum tumor dimension (MTD) in patients achieving CMR.
Methods: ee have previously reported the RAPID trial design, primary results, and outcomes according to pretreatment risk stratification and PET score.1,3 Patients were aged 16 to 75 years with untreated ES-HL and without B-symptoms or mediastinal bulk (mass > 1/3 internal mediastinal diameter at T5/6).6 Metabolic response after 3 cycles of ABVD chemotherapy (doxorubicin, bleomycin, vinblastine, and dacarbazine) was centrally assessed using PET (N = 562). Patients with CMR (ie, Deauville score 1-2) were randomly assigned to receive involved field radiotherapy (IFRT; n = 208) or no further therapy (NFT; n = 211). PET-positive patients (score, 3-5; n = 143) received a fourth cycle of ABVD and IFRT.
Baseline disease assessment was performed by computed tomography, and bidimensional target lesion measurements were reported by local radiologists in millimeters. The association of baseline MTD with HL-related event-free survival (EFS: progression or HL-related death) and progression-free survival (PFS) (progression or any-cause death) was assessed using Kaplan-Meier and Cox regression analyses. Non-HL deaths were either related to primary treatment toxicity or occurred in HL remission.1
United Kingdom ethical approval for the RAPID trial was via the UK Multicentre Research ethics committee.
Results and discussion: baseline patient characteristics have been previously described.1 Median age was 34 years (range, 16-75 years); 184 (37.4%) of 492 patients had unfavorable risk by European Organisation for Research and Treatment of Cancer criteria, and 155 (32.3%) of 480 by German Hodgkin Study Groupcriteria. Median MTD for patients achieving CMR was 3.0 cm (interquartile range, 2.0-4.0 cm) and 3.0 cm (interquartile range, 1.8-4.5 cm) in the NFT and IFRT groups, respectively, whereas PET-positive patients had a median MTD of 3.9 cm (interquartile range, 2.8-5.1 cm). After a median follow-up of 61.6 m, 44 HL progression events occurred: 21 NFT, 9 IFRT and 14 PET-positive. No patient received salvage treatment without documented progression. Only 5 HL-related deaths occurred (1 IFRT, 4 PET-positive), and 12 non-HL deaths (4 NFT, 6 IFRT, 2 PET-positive).1
For patients with CMR (N = 419), there was a strong association between MTD and EFS (hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.02-1.39; P = .02), adjusting for treatment group, with an approximate 19% increase in HL risk per centimeter increase in MTD. The association was similar in both treatment groups (NFT HR, 1.20 [95% CI, 0.99-1.44; P = .06]; IFRT HR, 1.19 [95% CI, 0.92-1.55; P = .19]). The observed effect sizes did not markedly change after adjusting for baseline clinical risk factors, and similar results were observed for PFS (supplemental Table 1). In contrast, for PET-positive patients, there was no association between MTD and EFS (HR, 0.88; 95% CI, 0.70-1.11; P = .29) or PFS (HR, 0.87; 95% CI, 0.70-1.08; P = .21).
In an exploratory analysis within the NFT group, MTD was dichotomized using increasing 1-cm intervals to investigate the relationship between MTD thresholds and EFS. The largest effect size was observed with an MTD threshold of ≥5 cm (Table 1). Similar results were observed for PFS; this threshold also performed best in time-dependent receiver operating characteristic curve analyses. It was not possible to assess MTD thresholds in the IFRT group with only 9 events. Among all randomized patients, 79 (18.9%) had MTD of ≥5 cm, the majority with mediastinal (n = 43), supraclavicular (n = 17), or cervical (n = 16) locations. Five-year EFS for patients with MTD of ≥5 cm randomly assigned to NFT and IFRT was 79.3% (n = 39; 95% CI, 66.6%-92.0%) and 94.9% (n = 40; 95% CI, 88.0%-100%), respectively (P = .03; Figure 1)
Evolution of a periodic eight-black-hole lattice in numerical relativity
The idea of black-hole lattices as models for the large-scale structure of
the universe has been under scrutiny for several decades, and some of the
properties of these systems have been elucidated recently in the context of the
problem of cosmological backreaction. The complete, three-dimensional and fully
relativistic evolution of these system has, however, never been tackled. We
explicitly construct the first of these solutions by numerically integrating
Einstein's equation in the case of an eight-black-hole lattice with the
topology of S3.Comment: 21 pages, 13 figures. Corrected and clarified discussio
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