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Fast Radio Bursts (FRBs) are millisecond dispersed radio pulses of predominately extra-galactic origin. Although originally discovered at GHz frequencies, most FRBs have been detected between 400 and 800 MHz. Nevertheless, only a handful of FRBs were detected at radio frequencies $\le$400 MHz. Searching for FRBs at low frequencies is computationally challenging due to increased dispersive delay that must be accounted for. Nevertheless, the wide field of view (FoV) of low-frequency telescopes – such as the the Murchison Widefield Array (MWA), and prototype stations of the low-frequency Square Kilometre Array (SKA-Low) – makes them promising instruments to open a low-frequency window on FRB event rates, and constrain FRB emission models. The standard approach, inherited from high-frequencies, is to form multiple tied-array beams to tessellate the entire FoV and perform the search on the resulting time series. This approach, however, may not be optimal for low-frequency interferometers due to their large FoVs and high spatial resolutions leading to a large number of beams. Consequently, there are regions of parameter space in terms of number of antennas and resolution elements (pixels) where interferometric imaging is computationally more efficient. Here we present a new high-time resolution imager BLINK implemented on modern graphical processing units (GPUs) and intended for radio astronomy data. The main goal for this imager is to become part of a fully GPU-accelerated FRB search pipeline. We describe the imager and present its verification on real and simulated data processed to form all-sky and widefield images from the MWA and prototype SKA-Low stations. We also present and compare benchmarks of the GPU and CPU code executed on laptops, desktop computers, and Australian supercomputers. The code is publicly available at https://github.com/PaCER-BLINK-Project/imager and can be applied to data from any radio telescope.
Housing instability is a social determinant of health associated with multiple negative health outcomes including substance use disorders (SUDs). Real-world evidence of housing instability is needed to improve translational research on populations with SUDs.
Methods:
We identified evidence of housing instability by leveraging structured diagnosis codes and unstructured clinical data from electronic health records of 20,556 patients from 2017 to 2021. We applied natural language processing with named-entity recognition and pattern matching to unstructured clinical notes with free-text documentation. Additionally, we analyzed semi-structured addresses containing explicit or implicit housing-related labels. We assessed agreement on identification methods by having three experts review of 300 records.
Results:
Diagnostic codes only identified 58.5% of the population identifiable as having housing instability, whereas 41.5% are identifiable from addresses only (7.1%), clinical notes only (30.4%), or both (4.0%). Reviewers unanimously agreed on 79.7% of cases reviewed; a Fleiss’ Kappa score of 0.35 suggested fair agreement yet emphasized the difficulty of analyzing patients having ambiguous housing situations. Among those with poisoning episodes related to stimulants or opioids, diagnosis codes were only able to identify 63.9% of those with housing instability.
Conclusions:
All three data sources yield valid evidence of housing instability; each has their own inherent practical use and limitations. Translational researchers requiring comprehensive real-world evidence of housing instability should optimize and implement use of structured and unstructured data. Understanding the role of housing instability and temporary housing facilities is salient in populations with SUDs.
In the present chapter we investigate how reward-rich environments can lead to the persistence of (initial) biases. More specifically, we argue that frequent rewards invite the exploitation of a supposedly best option which in turn will reinforce the biased preference. Because feedback is often contingent on the choices made, exploitation will result mostly in the aggregation of information about the exploited option. This, in turn, restricts the extent to which beliefs can be updated, with downstream consequences for further decisions. This dynamic might be responsible for why false beliefs about the outcomes of behavioral options can be maintained even when decision makers are motivated to choose the best choice alternative. We present data from simulations and empirical work to support this argument and conclude that the exploration–exploitation tradeoff serves as a particularly vivid example of the interplay between one’s cognition (goal-directed) behavior, and the sample that is aggregated.
To identify which international health technology assessment (HTA) agencies are undertaking evaluations of medical tests, summarize commonalities and differences in methodological approach, and highlight examples of good practice.
Methods
A methodological review incorporating: systematic identification of HTA guidance documents mentioning evaluation of tests; identification of key contributing organizations and abstraction of approaches to all essential HTA steps; summary of similarities and differences between organizations; and identification of important emergent themes which define the current state of the art and frontiers where further development is needed.
Results
Seven key organizations were identified from 216 screened. The main themes were: elucidation of claims of test benefits; attitude to direct and indirect evidence of clinical effectiveness (including evidence linkage); searching; quality assessment; and health economic evaluation. With the exception of dealing with test accuracy data, approaches were largely based on general approaches to HTA with few test-specific modifications. Elucidation of test claims and attitude to direct and indirect evidence are where we identified the biggest dissimilarities in approach.
Conclusions
There is consensus on some aspects of HTA of tests, such as dealing with test accuracy, and examples of good practice which HTA organizations new to test evaluation can emulate. The focus on test accuracy contrasts with universal acknowledgment that it is not a sufficient evidence base for test evaluation. There are frontiers where methodological development is urgently required, notably integrating direct and indirect evidence and standardizing approaches to evidence linkage.
The appearance of Beaker pottery in Britain and Ireland during the twenty-fifth century bc marks a significant archaeological horizon, being synchronous with the first metal artefacts. The adoption of arsenical copper, mostly from Ireland, was followed by that of tin-bronze around 2200 bc. However, whilst the copper mine of Ross Island in Ireland is securely dated to the Early Bronze Age, and further such mines in the UK have been dated to the Early and Middle Bronze Age, the evidence for the exploitation of tin ores, the other key ingredient to make bronze, has remained circumstantial. This article contains the detailed analyses of seven stone artefacts from securely dated contexts, using a combination of surface pXRF and microwear analysis. The results provide strong evidence that the tools were used in cassiterite processing. The combined analysis of these artefacts documents in detail the exploitation of Cornish tin during this early phase of metal use in Britain and Ireland.
Post-mortem examination of the nervous system is a complex task that culminates in “brain cutting”. It relies on expertise in neuroanatomy, clinical neurosciences, neuroimaging and experience in order to recognise the most subtle abnormalities. Like any specialist examination in medicine, it warrants formal training, a standardised approach and optimal conditions. Revelations of aberrant tissue retention practices of a select few pathologists (e.g. Goudge, Liverpool and Alder Hey inquiries) and a motivated sociopolitical climate led some Canadian jurisdictions to impose broad restrictions on tissue retention. This raised concerns that nervous system examinations for diagnosis, education and research were at risk by limiting examinations to the fresh or incompletely fixed state. Professional experience indicates that cutting an unfixed or partly fixed brain is inferior.
Methods:
To add objectivity and further insight we sought the expert opinion of a group of qualified specialists. Canadian neuropathologists were surveyed for their opinion on the relative merits of examining brains in the fresh or fully fixed state.
Results:
A total of 14 out of 46 Canadian neuropathologists responded (30%). In the pervasive opinion of respondents, cutting and sampling a brain prior to full fixation leads to a loss of diagnostic accuracy, biosafety and academic deliverables.
Conclusions:
Brain cutting in the fresh state is significantly impaired along multiple dimensions of relevance to a pathologist’s professional roles and obligations.
The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.
Research shows high levels of complex co-morbidities within psychiatric populations, and there is an increasing need for mental health practitioners to be able to draw on evidence-based psychological interventions, such as cognitive behavioural therapy (CBT), to work with this population effectively. One way CBT may be utilised when working with complexity or co-morbidity is to target treatment at a particular aspect of an individual’s presentation. This study uses a single-case A-B design to illustrate an example of using targeted diagnosis-specific CBT to address symptoms of a specific phobia of stairs in the context of a long-standing co-morbid diagnosis of schizophrenia. Results show the intervention to have been effective, with a change from a severe to mild phobia by the end of intervention. Clinical implications, limitations and areas for future research are discussed.
Key learning aims
(1) There are high levels of co-morbid, complex mental health problems within psychiatric populations, and an increasing need for mental health practitioners to be able to work with co-morbidity effectively.
(2) Cognitive behavioural therapy (CBT) remains one of the most well-evidenced psychological interventions with a large amount of research highlighting the effectiveness of diagnosis-specific CBT.
(3) One way evidence-based diagnosis-specific CBT approaches could be utilised when working with more complex co-morbidity may be to target an intervention at a specific set of symptoms.
(4) An example of using a targeted CBT intervention (to tackle a specific phobia of stairs in the context of a long-standing co-morbid diagnosis of schizophrenia and ongoing hallucinations) is presented. The outcomes show significant changes in the specific phobia symptoms, suggesting that CBT can be effectively used in this targeted manner within real-world clinical settings. The impact of co-morbid mental health difficulties on therapeutic process and outcomes are highlighted.
(5) The use of cognitive restructuring techniques was identified as key to engagement and therapeutic process, supporting the importance of including cognitive techniques in the treatment of phobias compared with purely behavioural exposure-based interventions.
Criddleite, ideally TlAg2Au3Sb10S10, is a rare constituent within the Hemlo gold deposit, Hemlo, Ontario, Canada. The mineral occurs as 20 to 50 µm-sized lath-like, tabular or anhedral grains usually surrounding or penetrating aurostibite, or associated with native antimony, native gold and stibnite. Criddleite is opaque with a metallic lustre and a black streak. It has been synthesized by reacting TlSbS2 and high purity Ag, Au, Sb and S in an evacuated silica glass tube at 400 °C. The measured density of the synthetic material is 6.86; the calculated density is 6.57 g/cm3. The difference is due to minor admixed aurostibite, native antimony and a dyscrasite-like phase within the charge. VHN25 is 94–129. Mohs hardness (calc.) = 3–3 ½. In reflected plane-polarized light in air, natural criddleite is weakly bireflectant with a discernible reflectance pleochroism from grey-blue to slightly greenish grey-blue. The mineral has a distinct to moderate anisotropy with rotation tints in shades of buff to slate grey. Reflectance spectra and colour values for both natural and synthetic criddleite are given. X-ray study showed that synthetic criddleite is monoclinic (pseudotetragonal) with refined unit-cell parameters a = 20.015(2), b = 8.075(2), c = 7.831(2) Å, β = 92.01(2)°, V = 1264.9 ± 1.0 Å3 and a:b:c = 2.4786: 1:0.9698. The space group choices are A2/m(12), A2(5) or Am(8), diffraction aspect A*/*. The seven strongest lines in the X-ray powder diffraction pattern [d in Å (I) (hkl)] are: 5.63(90) (011), 3.91(50) (002), 3.456(50) (320), 2.860(70) (700), 2.813(100) (022), 2.018(60) (040) and 1.959(70) (004). Electron microprobe analyses are reported of natural criddleite in five polished sections of drill core from four holes. The averaged empirical formulae, based on 26 atoms, are Tl0.92Ag1.99Au2.93Sb9.87S10.28 (natural) and Tl0.94Ag2.03Au2.89Sb9.76S10.38 (synthetic).
The Icelandic crust is characterized by low δ18O values that originate from pervasive high-temperature hydrothermal alteration by 18O-depleted meteoric waters. Igneous rocks in Iceland with δ18O values significantly higher than unaltered oceanic crust (~5.7‰) are therefore rare. Here we report on rhyolitic intra-caldera samples from a cluster of Neogene central volcanoes in Borgarfjörður Eystri, Northeast Iceland, that show whole-rock δ18O values between +2.9 and +17.6‰ (n = 6), placing them among the highest δ18O values thus far recorded for Iceland. Extra-caldera rhyolite samples from the region, in turn, show δ18O whole-rock values between +3.7 and +7.8‰ (n = 6), consistent with the range of previously reported Icelandic rhyolites. Feldspar in the intra-caldera samples (n = 4) show δ18O values between +4.9 and +18.7‰, whereas pyroxene (n = 4) shows overall low δ18O values of +4.0 to +4.2‰, consistent with regional rhyolite values. In combination with the evidence from mineralogy and rock H2O contents, the high whole-rock δ18O values of the intra-caldera rhyolites appear to be the result of pervasive isotopic exchange during subsolidus hydrothermal alteration with 18O-enriched water. This alteration conceivably occurred in a near-surface hot spring environment at the distal end of an intra-caldera hydrothermal system, and was probably fed by waters that had already undergone significant isotope exchange with the country rock. Alternatively, 18O-enriched alteration fluids may have been produced during evaporation and boiling of standing water in former caldera lakes, which then interacted with the intra-caldera rock suites. Irrespective of the exact exchange processes involved, a previously unrecognized and highly localized δ18O-enriched rock composition exists on Iceland and thus probably within the Icelandic crust too.
Tomography produces complex volumetric datasets containing the entire internal structure and density of an object in three dimensions (3D). Interpreting volumetric data requires 3D visualization but needs specialized software distinguishable from more familiar tools used in animation for 3D surface data. This tutorial reviews 3D visualization techniques for volumetric data using the open-source tomviz software package. A suite of tools including two-dimensional (2D) slices, surface contours, and full volume rendering provide quantitative and qualitative analysis of volumetric information. The principles outlined here are applicable to a wide range of 3D tomography techniques and can be applied to volumetric datasets beyond materials characterization.
With manufacturers seeking investment opportunities in Africa, it is timely to explore the interaction of advanced manufacturing technology (AMT) and human resource management approaches there. Because research elsewhere suggests that the effects of the interaction differ across national boundaries, we investigated empowerment approaches and AMT utilisation in Nigeria and New Zealand. Using operational-level survey data from 153 manufacturing managers/CEOs in both countries, we explored the role of national culture on managerial attitudes towards employee empowerment during AMT adoption. Drawing on Hofstede’s cultural dimensions, our results suggest that the observed differences in AMT–empowerment interface are attributable to different national values. The results specifically indicated that during AMT adoption, New Zealand’s liberal culture encourages managers to empower employees more than does Nigeria’s authoritarian one. The results would particularly assist practitioners to recognise the traditional/conservative nature of African values when practicing HR in a country like Nigeria.
We measured the hydrogen and oxygen isotope composition (δ2H and δ18O) of precipitation and stream water from the Soft Plume River at multiple spatiotemporal scales on sub-Antarctic Marion Island, Indian sector of the Southern Ocean. Monthly precipitation δ2H and δ18O values ranged from -43.7‰ to -14.7‰ and from -7.0‰ to -3.3‰ (n=13), respectively. Stream water values ranged from -48.0‰ to -25.4‰ for δ2H and from -7.6‰ to -4.0‰ for δ18O (n=92). The monthly precipitation data yielded a local meteoric water line with the equation δ2H=8.4δ18O+11.4. There was no clear seasonality in isotope composition present in precipitation and stream water. Along the stream, no significant difference was observed between sites. However, δ2H and δ18O values were lower and more variable at the highest site. This is probably the result of the ‘amount effect’, where more precipitation fell at a higher elevation compared with a downstream site in the catchment. The findings illustrate spatiotemporal patterns in precipitation and stream water isotopes and provide insight into mechanisms affecting their composition on sub-Antarctic Marion Island.