Spatiotemporal Statistical Downscaling for the Fusion of In-lake and Remote Sensing Data

This paper addresses the problem of fusing data from in-lake monitoring programmes with remote sensing data, through statistical downscaling. A Bayesian hierarchical model is developed, in order to fuse the in-lake and remote sensing data using spatially-varying coefficients. The model is applied to an example dataset of log(chlorophyll-a) data for Lake Erie, one of the Great Lakes of North America

Factors that influence treatment seeking expectations in response to infectious intestinal disease: original survey and multinomial regression

Background: Infectious intestinal disease affects 25% of the UK population annually; 1 in 50 affected people consult health professionals about their illness. Aims: We tested if anticipated treatment-seeking decisions for suspected infectious intestinal disease could be related to emotional response, tolerance of symptoms, or beliefs about the consequential benefits and harms of seeking treatment (or not). Methods: Questionnaire survey of adults living in the UK with statistical analysis of responses. A vignette was presented about a hypothetical gastrointestinal illness. People stated their emotional reactions, expected actions in response and beliefs about possible benefits or harms from seeking treatment (or not getting treatment). Multinomial regression looked for predictors of anticipated behaviour. Results: People were inclined to consult a GP when they believed that seeking treatment would be beneficial and that its absence would be harmful. Seeking treatment was less anticipated if the condition was expected to improve quickly. Respondents were also more likely to consult if they strongly disliked fever or headache, and/or if the illness made them feel anxious or angry. Treatment-seeking (or lack of it) was not linked to harms from treatment-seeking, other specific symptoms and emotional responses. Conclusion: It was possible to link anticipated treatment-seeking behaviour to specific factors: expected prognosis, perceived benefits of seeking treatment, some emotions and some specific symptoms. (C) 2019 The Authors. Published by Elsevier Ltd on behalf of King Saud Bin Abdulaziz University for Health Sciences

Spacecraft design project: High latitude communications satellite

The spacecraft design project was part of AE-4871, Advanced Spacecraft Design. The project was intended to provide experience in the design of all major components of a satellite. Each member of the class was given primary responsibility for a subsystem or design support function. Support was requested from the Naval Research Laboratory to augment the Naval Postgraduate School faculty. Analysis and design of each subsystem was done to the extent possible within the constraints of an eleven week quarter and the design facilities (hardware and software) available. The project team chose to evaluate the design of a high latitude communications satellite as representative of the design issues and tradeoffs necessary for a wide range of satellites. The High-Latitude Communications Satellite (HILACS) will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites, i.e., the area above approximately 60 N latitude. HILACS will also provide a communications link to stations below 60 N via a relay Net Control Station (NCS), which is located with access to both the HILACS and geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specified coverage

A population pharmacokinetic model to guide clozapine dose selection, based on age, sex, ethnicity, body weight and smoking status

Aims: Guidance on clozapine dosing in treatment-resistant schizophrenia is based largely on data from White young adult males. This study aimed to investigate the pharmacokinetic profiles of clozapine and Ndesmethylclozapine (norclozapine) across the age range, accounting for sex, ethnicity, smoking status, and body weight. Methods: A population pharmacokinetic model, implemented in Monolix, that linked plasma clozapine and norclozapine via a metabolic rate constant, was used to analyse data from a clozapine therapeutic drug monitoring service, 1993–2017. Results: There were 17,787 measurements from 5960 patients (4315 male) aged 18 to 86 years. The estimated clozapine plasma clearance was reduced from 20.2 to 12.0 L h-1 between 20 and 80 years. Model based dose predictions to attain a pre-dose plasma clozapine concentration of 0.35 mg L-1 was 275 (90% prediction interval 125, 625) mg day-1 in a nonsmoking White male weighing 70 kg and aged 40 years. The corresponding predicted dose was increased by 30% in smokers, decreased by 18% in females and was 10% higher and 14% lower in otherwise analogous Afro-Caribbean and Asian patients, respectively. Overall, the predicted dose decreased by 56% between age 20 and 80 years. Conclusion: The large sample size and wide age range of the patients studied allowed precise estimation of dose requirements to attain a pre-dose plasma clozapine concentration of 0.35 mg L-1. The analysis was however limited by the absence of data on clinical outcome and further studies are required to determine optimal pre-dose concentrations specifically in those aged over 65 years

Developments in Earth observation for the assessment and monitoring of inland, transitional, coastal and shelf-sea waters

The Earth's surface waters are a fundamental resource and encompass a broad range of ecosystems that are core to global biogeochemical cycling and food and energy production. Despite this, the Earth's surface waters are impacted by multiple natural and anthropogenic pressures and drivers of environmental change. The complex interaction between physical, chemical and biological processes in surface waters poses significant challenges for in situ monitoring and assessment and often limits our ability to adequately capture the dynamics of aquatic systems and our understanding of their status, functioning and response to pressures. Here we explore the opportunities that Earth observation (EO) has to offer to basin-scale monitoring of water quality over the surface water continuum comprising inland, transition and coastal water bodies, with a particular focus on the Danube and Black Sea region. This review summarises the technological advances in EO and the opportunities that the next generation satellites offer for water quality monitoring. We provide an overview of algorithms for the retrieval of water quality parameters and demonstrate how such models have been used for the assessment and monitoring of inland, transitional, coastal and shelf-sea systems. Further, we argue that very few studies have investigated the connectivity between these systems especially in large river-sea systems such as the Danube-Black Sea. Subsequently, we describe current capability in operational processing of archive and near real-time satellite data. We conclude that while the operational use of satellites for the assessment and monitoring of surface waters is still developing for inland and coastal waters and more work is required on the development and validation of remote sensing algorithms for these optically complex waters, the potential that these data streams offer for developing an improved, potentially paradigm-shifting understanding of physical and biogeochemical processes across large scale river-sea continuum including the Danube-Black Sea is considerable

Atmospheric Correction Performance of Hyperspectral Airborne Imagery over a Small Eutrophic Lake under Changing Cloud Cover

Atmospheric correction of remotely sensed imagery of inland water bodies is essential to interpret water-leaving radiance signals and for the accurate retrieval of water quality variables. Atmospheric correction is particularly challenging over inhomogeneous water bodies surrounded by comparatively bright land surface. We present results of AisaFENIX airborne hyperspectral imagery collected over a small inland water body under changing cloud cover, presenting challenging but common conditions for atmospheric correction. This is the first evaluation of the performance of the FENIX sensor over water bodies. ATCOR4, which is not specifically designed for atmospheric correction over water and does not make any assumptions on water type, was used to obtain atmospherically corrected reflectance values, which were compared to in situ water-leaving reflectance collected at six stations. Three different atmospheric correction strategies in ATCOR4 was tested. The strategy using fully image-derived and spatially varying atmospheric parameters produced a reflectance accuracy of ±0.002, i.e., a difference of less than 15% compared to the in situ reference reflectance. Amplitude and shape of the remotely sensed reflectance spectra were in general accordance with the in situ data. The spectral angle was better than 4.1° for the best cases, in the spectral range of 450–750 nm. The retrieval of chlorophyll-a (Chl-a) concentration using a popular semi-analytical band ratio algorithm for turbid inland waters gave an accuracy of ~16% or 4.4 mg/m3compared to retrieval of Chl-a from reflectance measured in situ. Using fixed ATCOR4 processing parameters for whole images improved Chl-a retrieval results from ~6 mg/m3difference to reference to approximately 2 mg/m3. We conclude that the AisaFENIX sensor, in combination with ATCOR4 in image-driven parametrization, can be successfully used for inland water quality observations. This implies that the need for in situ reference measurements is not as strict as has been assumed and a high degree of automation in processing is possible

A survey of minimally invasive cardiac surgery during the COVID-19 pandemic

BACKGROUND: Lack of scientific data on the feasibility and safety of minimally invasive cardiac surgery (MICS) during the COVID-19 pandemic has made clinical decision making challenging. This survey aimed to appraise MICS activity in UK cardiac units and establish a consensus amongst front-line MICS surgeons regarding standard best MICS practise during the pandemic. METHODS: An online questionnaire was designed through the ‘googleforms’ platform. Responses were received from 24 out of 28 surgeons approached (85.7%), across 17 cardiac units. RESULTS: There was a strong consensus against a higher risk of conversion from minimally invasive to full sternotomy (92%; n = 22) nor there is increased infection (79%; n = 19) or bleeding (96%; n = 23) with MICS compared to full sternotomy during the pandemic. The majority of respondents (67%; n = 16) felt that it was safe to perform MICS during COVID-19, and that it should not be halted (71%; n = 17). London cardiac units experienced a decrease in MICS (60%; n = 6), whereas non-London units saw no reduction. All London MICS surgeons wore an FP3 mask compared to 62% (n = 8) of non-London MICS surgeons, 23% (n = 3) of which only wore a surgical mask. London MICS surgeons felt that routine double gloving should be done (60%; n = 6) whereas non-London MICS surgeons held a strong consensus that it should not (92%; n = 12). CONCLUSION: Whilst more robust evidence on the effect of COVID-19 on MICS is awaited, this survey provides interesting insights for clinical decision-making regarding MICS and aids to facilitate the development of standardised MICS guidelines for an effective response during future pandemics