323 research outputs found

    The impact of regional jets on air service at selected US airports and markets

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    Regional jets, normally defined as jet aircraft introduced since 1993 with less than 100 seats, have been thought to have significant impacts on air services at airports, for example, in improving service frequency, allowing airlines to exploit niche markets and to feed hubs. Previous studies have focused on regional jet deployment strategy and the overall situation and they suggest that deployment was generally to larger cities first and, in addition, to locations east of the Mississippi. It has also been suggested that smaller airports might lose service when regional jets replace turbo-props and that carrier competition would increase, to the benefit of the consumer. This paper aims to throw more light on these issues from the individual airports’ point of view. Data on changes in schedules from the Official Airline Guide (OAG) at a series of case study airports from 1994 to 2002 is used to examine, the impacts on new route development, market dynamics, carrier competition and concentration and deployment status. In particular, the impact on smaller airports is examined. It is concluded, subject to the usual caveats on sample size, that there is little evidence of a uniform impact on routes or airports. The aggregate picture often described by the industry and government is shown to be a combination of highly dissimilar cases. A spectrum of effects is identified across different types of airports and routes but some of the anticipated trends, such as hub bypassing, are not observed. Some airports reaped significant benefits in terms of improved frequency and services to new destinations, whilst others gained little

    Naturalistic language input is associated with resting-state functional connectivity in infancy

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    The quantity and quality of the language input that infants receive from their caregivers affects their future language abilities; however, it is unclear how variation in this input relates to preverbal brain circuitry. The current study investigated the relation between naturalistic language input and the functional connectivity (FC) of language networks in human infancy using resting-state functional magnetic resonance imaging (rsfMRI). We recorded the naturalistic language environments of five- to eight-month-old male and female infants using the Linguistic ENvironment Analysis (LENA) system and measured the quantity and consistency of their exposure to adult words (AWs) and adult-infant conversational turns (CTs). Infants completed an rsfMRI scan during natural sleep, and we examined FC among regions of interest (ROIs) previously implicated in language comprehension, including the auditory cortex, the left inferior frontal gyrus (IFG), and the bilateral superior temporal gyrus (STG). Consistent with theory of the ontogeny of the cortical language network (Skeide and Friederici, 2016), we identified two subnetworks posited to have distinct developmental trajectories: a posterior temporal network involving connections of the auditory cortex and bilateral STG and a frontotemporal network involving connections of the left IFG. Independent of socioeconomic status (SES), the quantity of CTs was uniquely associated with FC of these networks. Infants who engaged in a larger number of CTs in daily life had lower connectivity in the posterior temporal language network. These results provide evidence for the role of vocal interactions with caregivers, compared with overheard adult speech, in the function of language networks in infancy

    The role of hypothecation in financing transit: lessons from the UK

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    Two hypothecated charges to fund local public transport have recently passed onto the statute books in the UK. The first is road user charging, with the London and Durham the first to be implemented and the second is a workplace parking levy. The use of such local hypothecated (or ‘earmarked’) mechanisms is not new. Indeed a variety of such charges, local taxes and levies have been in use for decades to fund public transport and (less frequently) as a tool for transport demand management in the USA, Germany, Austria, Portugal, Scandinavia, India and Singapore. In the general debate around the two new hypothecated charges in the UK, this international experience has been largely neglected. The aim of this paper is to detail a related and equally neglected area namely the local hypothecation of charges to fund public transport improvements within Britain. Under existing legislation it has been possible for some local authorities to dedicate revenue streams from sources such as parking charges and planning gain to develop and improve public transport services. There is also significant experience of dedicated revenue streams in the private sector, for example at airports. The paper details examples of the British experience of hypothecation and will consider their lessons for the new and more radical measures that are now being considered

    Determining epigenetic memory in kidney proximal tubule cell derived induced pluripotent stem cells using a quadruple transgenic reprogrammable mouse

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    The majority of nucleated somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs). The process of reprogramming involves epigenetic remodelling to turn on pluripotency-associated genes and turn off lineage-specific genes. Some evidence shows that iPSCs retain epigenetic marks of their cell of origin and this epigenetic memory influences their differentiation potential, with a preference towards their cell of origin. Here, we reprogrammed proximal tubule cells (PTC) and tail tip fibroblasts (TTF), from a reprogrammable mouse to iPSCs and differentiated the iPSCs to renal progenitors to understand if epigenetic memory plays a role in renal differentiation. This model allowed us to eliminate experimental variability due to donor genetic differences and transfection of the reprogramming factors such as copy number and integration site. In this study we demonstrated that early passage PTC iPSCs and TTF iPSCs expressed low levels of renal progenitor genes and high levels of pluripotency-associated genes, and the transcriptional levels of these genes were not significantly different between PTC iPSCs and TTF iPSCs. We used ChIP-seq of H3K4me3, H3K27me3, H3K36me3 and global DNA methylation profiles of PTC iPSCs and TTF iPSCs to demonstrate that global epigenetic marks were not different between the cells from the two different sets of tissue samples. There were also no epigenetic differences observed when kidney developmental genes and pluripotency-associated genes were closely examined. We did observe that during differentiation to renal progenitor cells the PTC iPSC-derived renal cells expressed higher levels of three renal progenitor genes compared to progenitors derived from TTF iPSCs but the underlying DNA methylation and histone methylation patterns did not suggest an epigenetic memory basis for this

    Behavioural responses of non-breeding waterbirds to marine traffic in the near-shore environment

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    Capsule: Recording of behavioural responses to ferry traffic for 11 target species showed that Red-throated Diver Gavia stellata, Slavonian Grebe Podiceps auratus, and Black-throated Diver Gavia arctica were most likely to react to passing vessels. Aim: To provide information on how responses to marine traffic vary between waterbird species to inform marine spatial planning and environmental impact assessments in the near-shore environment. Methods: We recorded behavioural responses to ferry traffic for 11 target species in near-shore waters: Common Eider Somateria mollissima, Goldeneye Bucephala clangula, Long-tailed Duck Clangula hyemalis, Velvet Scoter Melanitta fusca, Red-breasted Merganser Mergus serrator, Black-throated Diver, Great Northern Diver Gavia immer, Red-throated Diver, European Shag Gulosus aristotelis, Slavonian Grebe and Black Guillemot Cepphus grylle. Responses were analysed using generalized linear models and mixed models. Results: Red-throated Diver, Black-throated Diver and Slavonian Grebe were the most likely species to exhibit a response to passing vessels. While Red-throated Divers and Slavonian Grebes were highly likely to flush, Black-throated Divers and Great Northern Divers rarely took flight, instead favouring swim or dive responses. In rougher sea conditions birds were more likely to take flight, and the propensity to respond declined across the wintering period. Conclusions: This research provides comparative evidence on the behavioural responses of waterbirds to marine traffic. The results support previous studies which highlighted the high sensitivity of diver species to disturbance and provide new evidence that Slavonian Grebe may also be a high sensitivity species

    Layperson perception of reflux-related symptoms

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    OBJECTIVE: To assess for differences of intended meaning in the description of reflux-related symptoms among otolaryngology patients and clinicians. STUDY DESIGN: Cross-sectional survey-based study. SETTING: Five tertiary, academic otolaryngology practices. METHODS: Between June 2020 and July 2022, a questionnaire consisting of 20 common descriptors of reflux-related symptoms within four domains (throat-, chest-, stomach-, and sensory-related symptoms) was completed by patients. Attending otolaryngologists at five academic medical centers then completed the same survey. The primary outcome was to assess differences in patient and clinician perceptions of reflux-related symptoms. Differences based on geographic location was a secondary outcome. RESULTS: A total of 324 patients and 27 otolaryngologists participated. Patients selected a median of six terms compared with 10.5 for otolaryngologists ( CONCLUSION: There are differences between otolaryngologists and their patients in the interpretation of the symptoms of reflux. Patients tended to have a narrower interpretation of reflux with symptoms primarily limited to classic stomach-related symptoms, while clinicians tended to have a broader definition of reflux that included extra-esophageal manifestations of disease. This has important counseling implications for the clinician, as patients presenting with reflux symptoms may not comprehend the relationship of those symptoms to reflux disease

    A protocol for precise comparisons of small vessel disease lesions between ex vivo magnetic resonance imaging and histopathology

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    pp. 310-32La neuroimagen y los estudios clínicos han definido la enfermedad cerebral de los vasos pequeños humanos, pero la fisiopatología sigue siendo relativamente poco comprendida. Para desarrollar terapias eficaces y estrategias preventivas, debemos comprender mejor la heterogeneidad y el desarrollo de la enfermedad de los vasos pequeños a nivel celular.S

    Acceptable risks of treatments to prevent rheumatoid arthritis among first-degree relatives:demographic and psychological predictors of risk tolerance.

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    Objectives:To quantify tolerance to risks of preventive treatments among first-degree relatives (FDRs) of patients with rheumatoid arthritis (RA).Methods:Preventive treatments for RA are under investigation. In a preference survey, adult FDRs assumed a 60% chance of developing RA within 2 years and made choices between no treatment and hypothetical preventive treatment options with a fixed level of benefit (reduction in chance of developing RA from 60% to 20%) and varying levels of risks. Using a probabilistic threshold technique, each risk was increased or decreased until participants switched their choice. Perceived risk of RA, health literacy, numeracy, Brief Illness Perception Questionnaire and Beliefs about Medicines Questionnaire-General were also assessed. Maximum acceptable risk (MAR) was summarised using descriptive statistics. Associations between MARs and participants’ characteristics were assessed using interval regression with effects coding.Results:289 FDRs (80 male) responded. The mean MAR for a 40% reduction in chance of developing RA was 29.08% risk of mild side effects, 9.09% risk of serious infection and 0.85% risk of a serious side effect. Participants aged over 60 years were less tolerant of serious infection risk (mean MAR ±2.06%) than younger participants. Risk of mild side effects was less acceptable to participants who perceived higher likelihood of developing RA (mean MAR ±3.34%) and more acceptable to those believing that if they developed RA it would last for a long time (mean MAR ±4.44%).Conclusions:Age, perceived chance of developing RA and perceived duration of RA were associated with tolerance to some risks of preventive RA therapy

    A novel grass hybrid to reduce flood generation in temperate regions

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    We report on the evaluation of a novel grass hybrid that provides efficient forage production and could help mitigate flooding. Perennial ryegrass (Lolium perenne) is the grass species of choice for most farmers, but lacks resilience against extremes of climate. We hybridised L. perenne onto a closely related and more stress-resistant grass species, meadow fescue Festuca pratensis. We demonstrate that the L. perenne × F. pratensis cultivar can reduce runoff during the events by 51% compared to a leading UK nationally recommended L. perenne cultivar and by 43% compared to F. pratensis over a two year field experiment. We present evidence that the reduced runoff from this Festulolium cultivar was due to intense initial root growth followed by rapid senescence, especially at depth. Hybrid grasses of this type show potential for reducing the likelihood of flooding, whilst providing food production under conditions of changing climate
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