A new earthquake catalogue for Bulgaria and the conterminous Balkan high hazard region

A new homogenous earthquake catalogue covering Bulgaria and the surrounding Balkan area has been created with intention of performing a consistent seismic hazard assessment across the region. In keeping with modern requirements of cataloguing seismicity, this catalogue has been made homogenous as far as possible with regards to magnitude, which has been provided on any of four different reported scales for each event; mb, Ms, Mw and ML. A key historical catalogue for the region has been used to represent the early instrumental period of earthquake recording (1900 to 1963), whilst data have been obtained from the International Seismological Centre (ISC), National Earthquake Information Center (NEIC) and National Observatory of Athens (NOA) to cover the instrumental period of earthquake recording (1964 to 2004). ISC data have also been used to develop a new mb→Ms magnitude conversion equation for the catalogued region. Application of this new magnitude conversion relation, in combination with other selected magnitude scale correlations, ensures reported magnitudes can be systematically rendered onto homogenized Ms and Mw scales for all earthquakes. This catalogue contains 3681 events with homogenized magnitudes ≥4.0 Mw, for the time interval 1900 to 2004 (inclusive), located in the region bounded by 39°–45° N, 19°–29° E, at focal depths of 0.0 km to 401.0 km and in a magnitude range 4.0≤Mw≤7.2. Selected large magnitude (M≥6.0 Ms) earthquakes have had their reported magnitudes reassessed – and adjusted if necessary – in light of work by other authors. Applied statistical approaches aimed at determining the lower threshold to magnitude completeness suggest this catalogue is complete down to a homogenized surface-wave magnitude of 4.6 Ms

Assessing the barriers and enablers to the implementation of the diagnostic radiographer musculoskeletal X‑ray reporting service within the NHS in England: a systematic literature review

Introduction The United Kingdom (UK) government’s healthcare policy in the early 1990s paved the way adoption of the skills mix development and implementation of diagnostic radiographers’ X-ray reporting service. Current clinical practice within the public UK healthcare system reflects the same pressures of increased demand in patient imaging and limited capacity of the reporting workforce (radiographers and radiologists) as in the 1990s. This study aimed to identify, define and assess the longitudinal macro, meso, and micro barriers and enablers to the implementation of the diagnostic radiographer musculoskeletal X-ray reporting service in the National Healthcare System (NHS) in England. Methods Multiple independent databases were searched, including PubMed, Ovid MEDLINE; Embase; CINAHL, and Google Scholar, as well as journal databases (Scopus, Wiley), healthcare databases (NHS Evidence Database; Cochrane Library) and grey literature databases (OpenGrey, GreyNet International, and the British Library EthOS depository) and recorded in a PRISMA flow chart. A combination of keywords, Boolean logic, truncation, parentheses and wildcards with inclusion/exclusion criteria and a time frame of 1995–2022 was applied. The literature was assessed against Joanna Briggs Institute’s critical appraisal checklists. With meta-aggregation to synthesize each paper, and coded using NVivo, with context grouped into macro, meso, and micro-level sources and categorised into subgroups of enablers and barriers. Results The wide and diverse range of data (n = 241 papers) identified barriers and enablers of implementation, which were categorised into measures of macro, meso, and micro levels, and thematic categories of context, culture, environment, and leadership. Conclusion The literature since 1995 has reframed the debates on implementation of the radiographer reporting role and has been instrumental in shaping clinical practice. There has been clear influence upon both meso (professional body) and macro-level (governmental/health service) policies and guidance, that have shaped change at micro-level NHS Trust organisations. There is evidence of a shift in culturally intrenched legacy perspectives within and between different meso-level professional bodies around skills mix acceptance and role boundaries. This has helped shape capacity building of the reporting workforce. All of which have contributed to conceptual understandings of the skills mix workforce within modern radiology services

A survey of the NHS reporting radiographer workforce in England

Introduction: At present there is no national register of the population size and scope of reporting radiographers in England. This makes operational workforce and succession planning for sustainable healthcare services in the National Health Service England (NHSE) difficult, affecting implementing NHSE policies and priorities such as 50% of X-rays reported by reporting radiographers and decreasing reporting Turnaround Times (TATs). This survey aimed to establish the workforce population employed as reporting radiographers in NHSE. Methods: An online anonymous seven question survey was distributed on social media and at the UK Imaging and Oncology Congress. Participant criteria included NHSE radiology staff (diagnostic radiographer, reporting radiographer, radiology manager, imaging superintendent modality lead, consultant radiologist, etc.) or a student diagnostic radiographer working within an NHSE trust. The survey recorded the participant's NHSE region (North Western, North Eastern and Yorkshire, Midlands, East of England, London, South Eastern and South Western regions), Integrated Care Systems (ICS), NHSE Trust, hospital, the amount of reporting radiographers and trainees employed, the Agenda for Change (AfC) job banding and imaging modality reported (X-ray, CT, MRI, NM, PET, DEXA). The data analysis applied descriptive statistics for estimating patterns and trends in the distribution of data (English region, AfC banding and imaging modality). Results: Responses were received from all seven of the NHSE regions (n=36/43 ICSs). The data demonstrated a larger workforce in the north of England than in the south, with employment at a range of AfC bandings from 5-8. The imaging modalities reported by radiographers in England demonstrated X-ray (n=34), the most reported imaging examination by region, and Nuclear Medicine (n=3) the least, with evidence of clinical reporting for CT (n=20), MRI (n=18), DEXA (n=16), Mammography (n=13) and fluoroscopy (n=12) being completed by radiographers in England. Conclusion: The findings for England (n=704 reporters; n=142 trainees) provide an estimate based on the response rate of the current reporting radiographer workforce across the NHSE regions, and their contribution to the skills mix radiology reporting service delivery. It is hoped future surveys will provide ongoing workforce estimates for the diagnostic radiographer reporting workforce in NHSE to support workforce transformation and sustainability plans for the radiography profession and to meet government healthcare targets and priorities

Non-metric chaotic inflation

We consider inflation within the context of what is arguably the simplest non-metric extension of Einstein gravity. There non-metricity is described by a single graviscalar field with a non-minimal kinetic coupling to the inflaton field $\Psi$, parameterized by a single parameter $\gamma$. We discuss the implications of non-metricity for chaotic inflation and find that it significantly alters the inflaton dynamics for field values $\Psi \gtrsim M_P/\gamma$, dramatically changing the qualitative behaviour in this regime. For potentials with a positive slope non-metricity imposes an upper bound on the possible number of e-folds. For chaotic inflation with a monomial potential, the spectral index and the tensor-to-scalar ratio receive small corrections dependent on the non-metricity parameter. We also argue that significant post-inflationary non-metricity may be generated.Comment: 7 pages, 1 figur

Multiple Molecular H2 Outflows in AFGL 618

We report high spatial (0.5 arcsec) and high spectral (9 km/s) resolution spectro-imaging of the 2.12 micron H2 1-0 S(1) line in the proto-planetary nebula AFGL 618 using BEAR at the CFHT. The observations reveal the presence of multiple, high-velocity, molecular outflows that align with the remarkable optical jets seen in HST images. The structure and kinematics of the outflows show how jets interact with circumstellar gas and shape the environment in which planetary nebulae form.Comment: 14 pages, 5 figures. To appear in The Astrophysical Journal Letter

The molecular environment of massive star forming cores associated with Class II methanol maser emission

Methanol maser emission has proven to be an excellent signpost of regions undergoing massive star formation (MSF). To investigate their role as an evolutionary tracer, we have recently completed a large observing program with the ATCA to derive the dynamical and physical properties of molecular/ionised gas towards a sample of MSF regions traced by 6.7 GHz methanol maser emission. We find that the molecular gas in many of these regions breaks up into multiple sub-clumps which we separate into groups based on their association with/without methanol maser and cm continuum emission. The temperature and dynamic state of the molecular gas is markedly different between the groups. Based on these differences, we attempt to assess the evolutionary state of the cores in the groups and thus investigate the role of class II methanol masers as a tracer of MSF.Comment: 5 pages, 1 figure, IAU Symposium 242 Conference Proceeding

Quadrilateral-octagon coordinates for almost normal surfaces

Normal and almost normal surfaces are essential tools for algorithmic 3-manifold topology, but to use them requires exponentially slow enumeration algorithms in a high-dimensional vector space. The quadrilateral coordinates of Tollefson alleviate this problem considerably for normal surfaces, by reducing the dimension of this vector space from 7n to 3n (where n is the complexity of the underlying triangulation). Here we develop an analogous theory for octagonal almost normal surfaces, using quadrilateral and octagon coordinates to reduce this dimension from 10n to 6n. As an application, we show that quadrilateral-octagon coordinates can be used exclusively in the streamlined 3-sphere recognition algorithm of Jaco, Rubinstein and Thompson, reducing experimental running times by factors of thousands. We also introduce joint coordinates, a system with only 3n dimensions for octagonal almost normal surfaces that has appealing geometric properties.Comment: 34 pages, 20 figures; v2: Simplified the proof of Theorem 4.5 using cohomology, plus other minor changes; v3: Minor housekeepin

Infrared images of reflection nebulae and Orion's bar: Fluorescent molecular hydrogen and the 3.3 micron feature

Images were obtained of the (fluorescent) molecular hydrogen 1-0 S(1) line, and of the 3.3 micron emission feature, in Orion's Bar and three reflection nebulae. The emission from these species appears to come from the same spatial locations in all sources observed. This suggests that the 3.3 micron feature is excited by the same energetic UV-photons which cause the molecular hydrogen to fluoresce

Rotational quenching rate coefficients for H_2 in collisions with H_2 from 2 to 10,000 K

Rate coefficients for rotational transitions in H_2 induced by H_2 impact are presented. Extensive quantum mechanical coupled-channel calculations based on a recently published (H_2)_2 potential energy surface were performed. The potential energy surface used here is presumed to be more reliable than surfaces used in previous work. Rotational transition cross sections with initial levels J <= 8 were computed for collision energies ranging between 0.0001 and 2.5 eV, and the corresponding rate coefficients were calculated for the temperature range 2 < T <10,000 K. In general, agreement with earlier calculations, which were limited to 100-6000 K, is good though discrepancies are found at the lowest and highest temperatures. Low-density-limit cooling functions due to para- and ortho-H_2 collisions are obtained from the collisional rate coefficients. Implications of the new results for non-thermal H_2 rotational distributions in molecular regions are also investigated

Potential Vorticity Evolution of a Protoplanetary Disk with An Embedded Protoplanet

We present two-dimensional inviscid hydrodynamic simulations of a protoplanetary disk with an embedded planet, emphasizing the evolution of potential vorticity (the ratio of vorticity to density) and its dependence on numerical resolutions. By analyzing the structure of spiral shocks made by the planet, we show that progressive changes of the potential vorticity caused by spiral shocks ultimately lead to the excitation of a secondary instability. We also demonstrate that very high numerical resolution is required to both follow the potential vorticity changes and identify the location where the secondary instability is first excited. Low-resolution results are shown to give the wrong location. We establish the robustness of a secondary instability and its impact on the torque onto the planet. After the saturation of the instability, the disk shows large-scale non-axisymmetry, causing the torque on the planet to oscillate with large amplitude. The impact of the oscillating torque on the protoplanet's migration remains to be investigated.Comment: 17 pages total with 9 figures (Fig.4,5,9 are in .jpg), accepted to Ap