1,420 research outputs found
Leveraging geospatial statistics for measuring and valuing the urban environment
This thesis looks at emerging uses of geospatial data for analysing the urban environment. As high-dimensional data becomes increasingly available, sophisticated spatial and temporal statistical estimation strategies can assess the minutia of environmental processes in a dynamic urban context.
Each essay focuses on the improved measurement of high-resolution non-market environmental amenities and evaluating them using observed impacts on house prices or transportation networks.
While valuation techniques for each amenity vary depending on context, these works all highlight a set of spatial methodologies for detailed urban analytics with a particular focus on urban greenery, seismic and flood risk, and pollution mitigation
Local Data Spaces: Leveraging trusted research environments for secure location-based policy research in the age of coronavirus disease-2019
This work explores the use of Trusted Research Environments for the secure analysis of sensitive, record-level data on local coronavirus disease-2019 (COVID-19) inequalities and economic vulnerabilities. The Local Data Spaces (LDS) project was a targeted rapid response and cross-disciplinary collaborative initiative using the Office for National Statisticsā Secure Research Service for localized comparison and analysis of health and economic outcomes over the course of the COVID-19 pandemic. Embedded researchers worked on co-producing a range of locally focused insights and reports built on secure secondary data and made appropriately open and available to the public and all local stakeholders for wider use. With secure infrastructure and overall data governance practices in place, accredited researchers were able to access a wealth of detailed data and resources to facilitate more targeted local policy analysis. Working with data within such infrastructure as part of a larger research project involved advanced planning and coordination to be efficient. As new and novel granular data resources become securely available (e.g., record-level administrative digital health records or consumer data), a range of local policy insights can be gained across issues of public health or local economic vitality. Many of these new forms of data however often come with a large degree of sensitivity around issues of personal identifiability and how the data is used for public-facing research and require secure and responsible use. Learning to work appropriately with secure data and research environments can open up many avenues for collaboration and analysis
Pulmonary hypertension in interstitial lung disease: Limitations of echocardiography compared to cardiac catheterization
BACKGROUND AND OBJECTIVE: In interstitial lung disease (ILD), pulmonary hypertension (PH) is a major adverse prognostic determinant. Transthoracic echocardiography (TTE) is the most widely used tool when screening for PH, although discordance between TTE and right heart catheter (RHC) measured pulmonary haemodynamics is increasingly recognized. We evaluated the predictive utility of the updated European Society of Cardiology/European Respiratory Society (ESC/ERS) TTE screening recommendations against RHC testing in a large, well-characterized ILD cohort. METHODS: Two hundred and sixty-five consecutive patients with ILD and suspected PH underwent comprehensive assessment, including RHC, between 2006 and 2012. ESC/ERS recommended tricuspid regurgitation (TR) velocity thresholds for assigning high (>3.4 m/s), intermediate (2.9-3.4 m/s) and low (3.4 m/s, and excluded PH in 60% of ILD subjects with a TR velocity <2.8 m/s. Thus, the ESC/ERS guidelines misclassified 40% of subjects as 'low probability' of PH, when PH was confirmed on subsequent RHC. Evaluating alternative TR velocity thresholds for assigning a low probability of PH did not significantly improve the ability of TR velocity to exclude a diagnosis of PH. CONCLUSION: In patients with ILD and suspected PH, currently recommended ESC/ERS TR velocity screening thresholds were associated with a high positive predictive value (86%) for confirming PH, but were of limited value in excluding PH, with 40% of patients misclassified as low probability when PH was confirmed at subsequent RHC
JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b
We present a JWST/NIRCam transmission spectrum from m of the
recently-validated sub-Earth GJ 341b (
, K) orbiting a nearby bright M1
star ( pc, ). We use three independent
pipelines to reduce the data from the three JWST visits and perform several
tests to check for the significance of an atmosphere. Overall, our analysis
does not uncover evidence of an atmosphere. Our null hypothesis tests find that
none of our pipelines' transmission spectra can rule out a flat line, although
there is weak evidence for a Gaussian feature in two spectra from different
pipelines (at 2.3 and ). However, the candidate features are seen at
different wavelengths (4.3 m vs 4.7 m), and our retrieval analysis
finds that different gas species can explain these features in the two
reductions (CO at compared to O at ), suggesting
that they are not real astrophysical signals. Our forward model analysis rules
out a low mean molecular weight atmosphere ( solar metallicity) to
at least , and disfavors CH-dominated atmospheres at ,
depending on the reduction. Instead, the forward models find our transmission
spectra are consistent with no atmosphere, a hazy atmosphere, or an atmosphere
containing a species that does not have prominent molecular bands across the
NIRCam/F444W bandpass, such as a water-dominated atmosphere. Our results
demonstrate the unequivocal need for two or more transit observations analyzed
with multiple reduction pipelines, alongside rigorous statistical tests, to
determine the robustness of molecular detections for small exoplanet
atmospheres.Comment: 25 pages, 18 figures, 6 tables. Accepted for publication in A
Disease acceptance and adherence to imatinib in Taiwanese chronic myeloid leukaemia outpatients
Background The launch of imatinib has turned chronic myeloid leukaemia (CML) into a chronic illness due to the dramatic improvement in survival. Several recent studies have demonstrated that poor adherence to imatinib may hamper the therapeutic outcomes and result in increased medical expenditures, whilst research on exploring the reasons for non-adherence to imatinib is still limited. Objective This study aimed to explore the experience of patients as they journey through their CML treatments and associated imatinib utilisation in order to understand the perceptions, attitudes and concerns that may influence adherence to imatinib treatment. Setting This study was conducted at oncology outpatient clinics in a medical centre in southern Taiwan. Methods CML patients who regularly attended the oncology outpatient clinics to receive imatinib treatment from October 2011 to March 2012 were invited to participate in the study. Semi-structured face-to-face interviews were used to explore patientsā experiences and views of their treatment, their current CML status and CML-related health conditions, their concerns about imatinib treatment and imatinib-taking behaviours. Patient interviews were recorded, transcribed verbatim and thematically analysed using the constant comparison approach. Main outcome measure Themes related to patientsā views of the disease and health conditions, worries and concerns influencing imatinib utilisation behaviours are reported. Results Forty-two CML patients participated in the interviews. The emerging themes included: acceptance of current disease and health status, misconceptions about disease progression, factors associated with adherence to imatinib, concerns and management of adverse drug effects. Participants regarded CML as a chronic disease but had misconceptions about disease progression, therapeutic monitoring, resistance to imatinib and symptoms of side effects. Participants were generally adherent to imatinib and favoured long-term prescriptions to avoid regular outpatient visits for medication refills. Experiencing adverse effect was the main reason influencing adherence and led to polypharmacy. Most participants altered medicine-taking behaviours to maintain long-term use of imatinib. Conclusion Taiwanese CML patients are adherent to imatinib but report changing their medication-taking behaviour due to adverse drug effects and associated polypharmacy. Patientsā misconceptions of the disease and medication suggests that it is necessary to improve communication between patients and healthcare professionals. Routinely providing updated information as part of the patient counselling process should be considered as a means of improving this communication
Double Trouble: Two Transits of the Super-Earth GJ 1132 b Observed with JWST NIRSpec G395H
The search for rocky planet atmospheres with JWST has focused on planets
transiting M dwarfs. Such planets have favorable planet-to-star size ratios,
enhancing the amplitude of atmospheric features. Since the expected signal
strength of atmospheric features is similar to the single-transit performance
of JWST, multiple observations are required to confirm any detection. Here, we
present two transit observations of the rocky planet GJ 1132 b with JWST
NIRSpec G395H, covering 2.8-5.2 m. Previous HST WFC3 observations of GJ
1132 b were inconclusive, with evidence reported for either an atmosphere or a
featureless spectrum based on analyses of the same dataset. Our JWST data
exhibit substantial differences between the two visits. One transit is
consistent with either a HO-dominated atmosphere containing ~1% CH and
trace NO ( = 1.13) or stellar contamination from unocculted
starspots ( = 1.36). However, the second transit is consistent
with a featureless spectrum. Neither visit is consistent with a previous report
of HCN. Atmospheric variability is unlikely to explain the scale of the
observed differences between the visits. Similarly, our out-of-transit stellar
spectra show no evidence of changing stellar inhomogeneity between the two
visits - observed 8 days apart, only 6.5% of the stellar rotation rate. We
further find no evidence of differing instrumental systematic effects between
visits. The most plausible explanation is an unlucky random noise draw leading
to two significantly discrepant transmission spectra. Our results highlight the
importance of multi-visit repeatability with JWST prior to claiming atmospheric
detections for these small, enigmatic planets.Comment: 22 pages, 10 figures, 2 tables. Accepted for publication in ApJ
Letters. Co-First Authors. Bonus materials and spectral data:
https://doi.org/10.5281/zenodo.1000208
North Pacific twentieth century decadal-scale variability is unique for the past 342 years
Reconstructed sea surface temperatures (SSTs) derived from Mg/Ca measurements in nine encrusting coralline algal skeletons from the Aleutian archipelago in the northernmost Pacific Ocean reveal an overall increase in SST from 1665 to 2007. In the Aleutian SST reconstruction, decadal-scale variability is a transient feature present during the 1700s and early 1800s and then fully emerging post-1950. SSTs vary coherently with available instrument records of cyclone variance and vacillate in and out of coherence with multicentennial Pacific Northwest drought reconstructions as a response to SST-driven alterations of storm tracks reaching North America. These results indicate that an influence of decadal-scale variability on the North Pacific storm tracks only became apparent during the midtwentieth century. Furthermore, what has been assumed as natural variability in the North Pacific, based on twentieth century instrumental data, is not consistent with the long-term natural variability evident in reconstructed SSTs predating the anthropogenic influence
"New" Veneziano amplitudes from "old" Fermat (hyper) surfaces
The history of discovery of bosonic string theory is well documented. This
theory evolved as an attempt to find a multidimensional analogue of Euler's
beta function. Such an analogue had in fact been known in mathematics
literature at least in 1922 and was studied subsequently by mathematicians such
as Selberg, Weil and Deligne among others. The mathematical interpretation of
this multidimensional beta function is markedly different from that described
in physics literature. This paper aims to bridge the gap between the existing
treatments. Preserving all results of conformal field theories intact,
developed formalism employing topological, algebro-geometric, number-theoretic
and combinatorial metods is aimed to provide better understanding of the
Veneziano amplitudes and, thus, of string theories.Comment: 92 pages LaTex, some typos removed, discussion section is added along
with several additional latest reference
Awesome SOSS: Transmission Spectroscopy of WASP-96b with NIRISS/SOSS
The future is now - after its long-awaited launch in December 2021, JWST
began science operations in July 2022 and is already revolutionizing exoplanet
astronomy. The Early Release Observations (ERO) program was designed to provide
the first images and spectra from JWST, covering a multitude of science cases
and using multiple modes of each on-board instrument. Here, we present
transmission spectroscopy observations of the hot-Saturn WASP-96b with the
Single Object Slitless Spectroscopy (SOSS) mode of the Near Infrared Imager and
Slitless Spectrograph, observed as part of the ERO program. As the SOSS mode
presents some unique data reduction challenges, we provide an in-depth
walk-through of the major steps necessary for the reduction of SOSS data:
including background subtraction, correction of 1/f noise, and treatment of the
trace order overlap. We furthermore offer potential routes to correct for field
star contamination, which can occur due to the SOSS mode's slitless nature. By
comparing our extracted transmission spectrum with grids of atmosphere models,
we find an atmosphere metallicity between 1x and 5x solar, and a solar
carbon-to-oxygen ratio. Moreover, our models indicate that no grey cloud deck
is required to fit WASP-96b's transmission spectrum, but find evidence for a
slope shortward of 0.9m, which could either be caused by enhanced Rayleigh
scattering or the red wing of a pressure-broadened Na feature. Our work
demonstrates the unique capabilities of the SOSS mode for exoplanet
transmission spectroscopy and presents a step-by-step reduction guide for this
new and exciting instrument.Comment: MNRAS, in press. Updated to reflect published versio
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