Search

We present the results of a search for associated 21 cm HI absorption at redshift 0.42 < z < 1.00 in radio-loud galaxies from three Galaxy And Mass Assembly (GAMA) survey fields. These observations were carried out as part of a pilot survey for the ASKAP First Large Absorption Survey in HI (FLASH). From a sample of 326 radio sources with 855.5 MHz peak flux density above 10 mJy we detected two associated HI absorption systems, in SDSS J090331+010847 at z= 0.522 and SDSS J113622+004852 at z= 0.563. Both galaxies are massive (stellar mass > 10$^{11}$ M$_{sun}$) and have optical spectra characteristic of luminous red galaxies,though SED fitting implies that SDSS J113622+004852 contains a dust-obscured starburst with SFR ~ 69 M$_{sun}$ yr$^{-1}$. The HI absorption lines have a high optical depth, with $\tau_{pk}$ of 1.77 $\pm$ 0.16 for SDSS J090331+010847 (the highest value for any z > 0.1 associated system found to date) and 0.14 $\pm$ 0.01 for SDSS J113622+004852. In the redshift range probed by our ASKAP observations, the detection rate for associated HI absorption lines (with $\tau_{pk}$ > 0.1 and at least 3$\sigma$ significance) is 2.9 (+9.7 -2.6) percent. Although the current sample is small, this rate is consistent with a trend seen in other studies for a lower detection rate of associated 21 cm HI absorption systems at higher redshift. We also searched for OH absorption lines at 0.67 < z < 1.34, but no detection was made in the 145 radio sources searched., Comment: 26 pages, 15 figures, accepted for publication in MNRAS

We present radio observations of the symbiotic recurrent nova V3890 Sagitarii following the 2019 August eruption obtained with the MeerKAT radio telescope at 1.28 GHz and Karl G. Janksy Very Large Array (VLA) at 1.26 to 5 GHz. The radio light curves span from day 1 to 540 days after eruption and are dominated by synchrotron emission produced by the expanding nova ejecta interacting with the dense wind from an evolved companion in the binary system. The radio emission is detected early on (day 6) and increases rapidly to a peak on day 15. The radio luminosity increases due to a decrease in the opacity of the circumstellar material in front of the shocked material and fades as the density of the surrounding medium decreases and the velocity of the shock decelerates. Modelling the light curve provides an estimated mass-loss rate of $M_{\textrm {wind}} \approx 10^{-8} {\textrm {M}}_\odot~{\textrm {yr}}^{-1}$ from the red giant star and ejecta mass in the range of $M_{\textrm {ej}}=10^{-5}-10^{-6}~{\textrm {M}}_\odot$from the surface of the white dwarf. V3890 Sgr likely hosts a massive white dwarf similar to other symbiotic recurrent novae, thus considered a candidate for supernovae type Ia (SNe Ia) progenitor. However, its radio flux densities compared to upper limits for SNe Ia have ruled it out as a progenitor for SN 2011fe.

We present new upgraded Giant Metrewave Radio Telescope (uGMRT) HI 21-cm observations of the ultra-luminous infrared galaxy IRAS 10565+2448, previously reported to show blueshifted, broad, and shallow HI absorption indicating an outflow. Our higher spatial resolution observations have localised this blueshifted outflow, which is $\sim$ 1.36 kpc southwest of the radio centre and has a blueshifted velocity of $\sim 148\,\rm km\,s^{-1}$ and a full width at half maximum (FWHM) of $\sim 581\,\rm km\,s^{-1}$. The spatial extent and kinematic properties of the HI outflow are consistent with the previously detected cold molecular outflows in IRAS 10565+2448, suggesting that they likely have the same driving mechanism and are tracing the same outflow. By combining the multi-phase gas observations, we estimate a total outflowing mass rate of at least $140\, \rm M_\odot \,yr^{-1}$ and a total energy loss rate of at least $8.9\times10^{42}\,\rm erg\,s^{-1}$, where the contribution from the ionised outflow is negligible, emphasising the importance of including both cold neutral and molecular gas when quantifying the impact of outflows. We present evidence of the presence of a radio jet and argue that this may play a role in driving the observed outflows. The modest radio luminosity $L_{\rm1.4GHz}$ $\sim1.3\times10^{23}\,{\rm W\,Hz^{-1}}$ of the jet in IRAS 10565+2448 implies that the jet contribution to driving outflows should not be ignored in low radio luminosity AGN., Comment: 12 pages, 9 figures, accepted for publication in MNRAS

Dental procedures produce aerosols which may remain suspended and travel significant distances from the source. Dental aerosols and droplets contain oral microbes and there is potential for infectious disease transmission and major disruption to dental services during infectious disease outbreaks. One method to control hazardous aerosols often used in industry is Local Exhaust Ventilation (LEV). The aim of this study was to investigate the effect of LEV on aerosols and droplets produced during dental procedures. Experiments were conducted on dental mannequins in an 825.4 m3 open plan clinic, and a 49.3 m3 single surgery. 10-minute crown preparations were performed with an air-turbine handpiece in the open plan clinic, and 10-minute full mouth ultrasonic scaling in the single surgery. Fluorescein was added to instrument irrigation reservoirs as a tracer. In both settings, Optical Particle Counters (OPCs) were used to measure aerosol particles between 0.3 – 10.0 μm and liquid cyclone air samplers were used to capture aerosolised fluorescein tracer. Additionally, in the open plan setting fluorescein tracer was captured by passive settling onto filter papers in the environment. Tracer was quantified fluorometrically. An LEV device with High Efficiency Particulate Air (HEPA) filtration and a flow rate of 5,000 L/min was used. LEV reduced aerosol production from the air-turbine handpiece by 90% within 0.5 m, and this was 99% for the ultrasonic scaler. OPC particle counts were substantially reduced for both procedures, and air-turbine settled droplet detection reduced by 95% within 0.5 m. The effect of LEV was substantially greater than suction alone for the air-turbine and was similar to the effect of suction for the ultrasonic scaler. LEV reduces aerosol and droplet contamination from dental procedures by at least 90% in the breathing zone of the operator and it is therefore a valuable tool to reduce the dispersion of dental aerosols.

BACKGROUND Persistent oro-facial pain (POFP) is disabling, and patients' treatment outcomes are difficult to predict; psychosocial factors play a role. The West Haven-Yale Multidimensional Pain Inventory (MPI) is a self-report measure, which to our knowledge, has not been studied across primary and secondary care in heterogeneous POFP. OBJECTIVE Assess the MPI's ability to predict clinical outcome in POFP patients across primary and secondary care settings receiving usual care. METHODS About 146 patients receiving usual care for POFP were recruited from primary and secondary care medical and dental practices in north-east England. Participants completed the MPI (v3) and Graded Chronic Pain Scale (GCPS) at recruitment, and after 6, 12, 18 and 24 months. The Patient Health Questionnaire-4 (PHQ-4) was completed at recruitment, 12, and 24 months. 'Good' and 'poor' outcome status was assigned to participants based on their mode dichotomised GCPS score across timepoints. Logistic regression was used with overall GCPS outcome (good/poor) as the dependent variable and MPI subscale scores, demographic variables, and PHQ-4 scores as predictors. RESULTS 110 participants had a 'good', and 36 had a 'poor' outcome. In the 'poor' outcome group, age, mean income, and life control scores were lower; deprivation, months in pain, PHQ-4, pain severity, interference, and affective distress scores were higher. In the 'good' group, MPI scores improved over time. Interference was the only consistent predictor of 'poor' outcome in the logistic regression model (OR: 1.14-1.98, p

Aim This systematic review and meta-analysis aimed to synthesise the current evidence for the association of oral piercings with oral complications.Data sources Research published before January 2022 was identified from the Cochrane Library, Virtual Health Library, Web of Science, Scopus, PubMed, Embase, Google Scholar and OpenGrey databases. Experts in the field were approached via email to request access to relevant ongoing studies and unpublished results.Study design Two independent reviewers determined the eligibility of studies based on the predefined inclusion criteria. Where the outcome was unclear, a third reviewer was consulted to reach consensus. Using the Joanne Briggs institute criteria for critical appraisal, 15 studies achieved good methodological quality.Meta-analysis was conducted to determine the event rate of gingival recession and damage to teeth in participants with oral piercings and to determine odds ratios of these outcomes in participants with oral piercings compared to those without.Results In total, 54 studies published between 2000-2021 met the inclusion criteria, providing a total sample of 27,963 piercings covering various anatomical sites: tongue (39 studies), lip (29 studies) and other sites, such as oral frenula or cheek (11 studies).Meta-analysis showed that there was a 34% prevalence of dental fracture (DF) in participants with oral piercings and this was 34% for tooth wear, 33% for gingival recession (GR), 27% for non-specified dental damage and 22% for tooth chipping. A significant association was found between oral piercings and the presence of GR and DF, with a seven-fold and three-fold increased risk, respectively, when an oral piercing was present. Reporting bias was not observed and evidence certainty for these outcomes was low.Conclusions The presence of oral piercings is associated with an increased risk of gingival recession and dental fracture.

Infection control is critical for the safe delivery of dental care. Infection control practices must be responsive to emerging and re-emerging infectious diseases and outbreaks, as was clearly seen during the peak of the COVID-19 pandemic. An emerging global outbreak of the monkeypox virus has again raised potential challenges for infection control in dentistry. Monkeypox is an infectious disease, characterised by a rash affecting the skin and soft tissues, including the oral cavity. Previously, cases were mostly seen following contact with infected animals in Central and West Africa, with limited human-to-human transmission within and outside of these areas. However, since May 2022, sustained human-to-human transmission has occurred globally. Monkeypox can be transmitted via close contact with an infected person, contaminated objects and surfaces, or by droplets and possibly aerosols, which is therefore of potential importance to dental settings. This article discusses the relevance of monkeypox to dental professionals, the typical presentation of the disease, its potential impact on infection prevention and control practices and the delivery of dental services. The current monkeypox outbreak highlights the need for a more sustained programme of research into dental infection control that can provide a solid evidence base to underpin preparedness planning for future outbreaks and pandemics.

We present HI absorption spectra of the black hole candidate X-ray binary (XRB) MAXI J1348-630 using the Australian Square Kilometre Array Pathfinder (ASKAP) and MeerKAT. The ASKAP HI spectrum shows a maximum negative radial velocity (with respect to the local standard of rest) of $-31\pm4$ km s$^{-1}$ for MAXI J1348-630, as compared to $-50\pm4$ km s$^{-1}$ for a stacked spectrum of several nearby extragalactic sources. This implies a most probable distance of $2.2^{+0.5}_{-0.6}$ kpc for MAXI J1348-630, and a strong upper limit of the tangent point distance at $5.3\pm0.1$ kpc. Our preferred distance implies that MAXI J1348-630 reached $17\pm10$ % of the Eddington luminosity at the peak of its outburst, and that the source transited from the soft to the hard X-ray spectral state at $2.5\pm1.5$ % of the Eddington luminosity. The MeerKAT HI spectrum of MAXI J1348-630 (obtained from the older, low-resolution 4k mode) is consistent with the re-binned ASKAP spectrum, highlighting the potential of the eventual capabilities of MeerKAT for XRB spectral line studies., Comment: Accepted for publication in MNRAS Letters

Background Dental procedures often produce aerosol and splatter which have the potential to transmit pathogens such as SARS‐CoV‐2. The existing literature is limited. Objective(s) To develop a robust, reliable and valid methodology to evaluate distribution and persistence of dental aerosol and splatter, including the evaluation of clinical procedures. Methods Fluorescein was introduced into the irrigation reservoirs of a high‐speed air‐turbine, ultrasonic scaler and 3‐in‐1 spray, and procedures were performed on a mannequin in triplicate. Filter papers were placed in the immediate environment. The impact of dental suction and assistant presence were also evaluated. Samples were analysed using photographic image analysis, and spectrofluorometric analysis. Descriptive statistics were calculated and Pearson’s correlation for comparison of analytic methods. Results All procedures were aerosol and splatter generating. Contamination was highest closest to the source, remaining high to 1–1.5 m. Contamination was detectable at the maximum distance measured (4 m) for high‐speed air‐turbine with maximum relative fluorescence units (RFU) being: 46,091 at 0.5 m, 3,541 at 1.0 m, and 1,695 at 4 m. There was uneven spatial distribution with highest levels of contamination opposite the operator. Very low levels of contamination (≤0.1% of original) were detected at 30 and 60 minutes post procedure. Suction reduced contamination by 67–75% at 0.5–1.5 m. Mannequin and operator were heavily contaminated. The two analytic methods showed good correlation (r=0.930, n=244, p

We have used the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope to search for intervening 21 cm neutral hydrogen (HI) absorption along the line of sight to 53 bright radio continuum sources. Our observations are sensitive to HI column densities typical of Damped Lyman Alpha absorbers (DLAs) in cool gas with an HI spin temperature below about 300-500 K. The six-dish Boolardy Engineering Test Array (BETA) and twelve-antenna Early Science array (ASKAP-12) covered a frequency range corresponding to redshift $0.4, Comment: 21 pages, 11 figures. Accepted for publication in MNRAS

We present early science results from the First Large Absorption Survey in HI (FLASH), a spectroscopically blind survey for 21-cm absorption lines in cold hydrogen HI gas at cosmological distances using the Australian Square Kilometre Array Pathfinder (ASKAP). We have searched for HI absorption towards 1253 radio sources in the GAMA 23 field, covering redshifts between $z = 0.34$ and $0.79$ over a sky area of approximately 50 deg$^{2}$. In a purely blind search we did not obtain any detections of 21-cm absorbers above our reliability threshold. Assuming a fiducial value for the HI spin temperature of $T_{\rm spin}$ = 100 K and source covering fraction $c_{\rm f} = 1$, the total comoving absorption path length sensitive to all Damped Lyman $\alpha$ Absorbers (DLAs; $N_{\rm HI} \geq 2 \times 10^{20}$ cm$^{-2}$) is $\Delta{X} = 6.6 \pm 0.3$ ($\Delta{z} = 3.7 \pm 0.2$) and super-DLAs ($N_{\rm HI} \geq 2 \times 10^{21}$ cm$^{-2}$) is $\Delta{X} = 111 \pm 6$ ($\Delta{z} = 63 \pm 3$). We estimate upper limits on the HI column density frequency distribution function that are consistent with measurements from prior surveys for redshifted optical DLAs, and nearby 21-cm emission and absorption. By cross matching our sample of radio sources with optical spectroscopic identifications of galaxies in the GAMA 23 field, we were able to detect 21-cm absorption at $z = 0.3562$ towards NVSS J224500$-$343030, with a column density of $N_{\rm HI} = (1.2 \pm 0.1) \times 10^{20} (T_{\rm spin}/100~\mathrm{K})$ cm$^{-2}$. The absorber is associated with GAMA J22450.05$-$343031.7, a massive early-type galaxy at an impact parameter of 17 kpc with respect to the radio source and which may contain a massive ($M_{\rm HI} \gtrsim 3 \times 10^{9}$ M$_{\odot}$) gas disc. Such gas-rich early types are rare, but have been detected in the nearby Universe., Comment: 15 pages, 12 figures, accepted for publication in MNRAS

Monthly notices of the Royal Astronomical Society 492(2), 2606 - 2621 (2020). doi:10.1093/mnras/stz3439, We present 1–10 GHz radio continuum flux density, spectral index, polarization, and rotation measure (RM) images of the youngest known Galactic supernova remnant (SNR) G1.9+0.3, using observations from the Australia Telescope Compact Array. We have conducted an expansion study spanning eight epochs between 1984 and 2017, yielding results consistent with previous expansion studies of G1.9+0.3. We find a mean radio continuum expansion rate of (0.78 ± 0.09) per cent yr$^{−1}$ (or ∼8900 km s$^{−1}$ at an assumed distance of 8.5 kpc), although the expansion rate varies across the SNR perimetre. In the case of the most recent epoch between 2016 and 2017, we observe faster-than-expected expansion of the northern region. We find a global spectral index for G1.9+0.3 of −0.81 ± 0.02 (76 MHz–10 GHz). Towards the northern region, however, the radio spectrum is observed to steepen significantly (∼−1). Towards the two so-called (east and west) ‘ears’ of G1.9+0.3, we find very different RM values of 400–600 and 100–200 rad m$^2$, respectively. The fractional polarization of the radio continuum emission reaches (19 ± 2) per cent, consistent with other, slightly older, SNRs such as Cas A., Published by Oxford Univ. Press, Oxford

Objectives To measure mercury release from standardised hydroxyapatite/amalgam constructs during MRI scanning and investigate the impact of static field strength and radiofrequency (RF) power on mercury release. Methods Amalgam was placed into 140 hydroxyapatite disks and matured for 14-days in artificial saliva. The solution was replaced, and samples split into five groups of 28 immediately prior to MRI. One group had no exposure, and the remainder were exposed to either a 3T or 7T MRI scanner, each at high and low RF power. Mercury concentration was measured by inductively coupled plasma mass spectrometry. Groups were compared using one-way ANOVA, and two-way ANOVA for main effects/ interaction of field strength/ RF power. Results Mercury concentration was increased in the 7T groups (high/ low: 15.43/ 11.33 ng mL−1) and 3T high group (3.59) compared to control (2.44). MRI field strength significantly increased mercury release (p < .001) as did RF power (p = .030). At 3T, mercury release was 20.3 times lower than during maturation of dental amalgam, and for the average person an estimated 1.50 ng kg−1 of mercury might be released during one 3T investigation; this is substantially lower than the tolerable weekly intake of 4,000 ng kg−1. Conclusion Mercury release from amalgam shows a measurable increase following MRI, and the magnitude changes with magnetic field strength and RF power. The amount of mercury released is small compared to release during amalgam maturation. Amalgam mercury release during MRI is unlikely to be clinically meaningful and highly likely to remain below safe levels.

We describe the performance of the Boolardy Engineering Test Array (BETA), the prototype for the Australian Square Kilometre Array Pathfinder telescope ASKAP. BETA is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarization beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of BETA's performance: sensitivity, beam characteristics, polarimetric properties and image quality. We summarise the astronomical science that it has produced and draw lessons from operating BETA that will be relevant to the commissioning and operation of the final ASKAP telescope., Accepted for publication in PASA

The Variables and Slow Transients Survey (VAST) on the Australian Square Kilometre Array Pathfinder (ASKAP) is designed to detect highly variable and transient radio sources on timescales from 5 s to$\sim\!5$yr. In this paper, we present the survey description, observation strategy and initial results from the VAST Phase I Pilot Survey. This pilot survey consists of$\sim\!162$h of observations conducted at a central frequency of 888 MHz between 2019 August and 2020 August, with a typical rms sensitivity of$0.24\ \mathrm{mJy\ beam}^{-1}$and angular resolution of$12-20$arcseconds. There are 113 fields, each of which was observed for 12 min integration time, with between 5 and 13 repeats, with cadences between 1 day and 8 months. The total area of the pilot survey footprint is 5 131 square degrees, covering six distinct regions of the sky. An initial search of two of these regions, totalling 1 646 square degrees, revealed 28 highly variable and/or transient sources. Seven of these are known pulsars, including the millisecond pulsar J2039–5617. Another seven are stars, four of which have no previously reported radio detection (SCR J0533–4257, LEHPM 2-783, UCAC3 89–412162 and 2MASS J22414436–6119311). Of the remaining 14 sources, two are active galactic nuclei, six are associated with galaxies and the other six have no multi-wavelength counterparts and are yet to be identified.

Data sources In this systematic review and meta-analysis, Medline, Scopus and Web of Science databases were searched using Medical Subject Headings (MeSH) to identify studies assessing the risk of malignant transformation in oral lichen planus (OLP).Study selection Observational studies published in English between 2003-2020 were independently assessed for inclusion by two blinded investigators.Data extraction and synthesis Data were extracted independently by two investigators followed by discussion to reach consensus. This included: study design and patient characteristics; length of follow-up; risk of bias; method of OLP diagnosis; oral squamous cell carcinoma (OSCC) risk factors; rate of malignant transformation; and individual characteristics of malignant transformation cases. Cases of malignant transformation in the included studies were only included in meta-analysis if: 1) OLP diagnosis met current diagnostic criteria; 2) OSCC developed in the same site as previously diagnosed OLP after at least six months' follow-up; 3) the patient had no history of systemic immunosuppressive therapy, head and neck malignancy, or organ transplantation. Risk of bias was assessed using the modified Newcastle-Ottawa scale, and meta-analysis was conducted to estimate overall risk of OLP malignant transformation using the DerSimonian and Laird method. Pooled univariate odds ratios (OR) for malignant transformation were calculated based on gender, smoking status, alcohol consumption, hepatitis C infection and OLP subtype.Results In total, 593 studies were identified after removal of duplicates and 33 studies were included for data extraction. The included sample comprised 12,838 patients with OLP, and 151 malignant transformation cases were reported in the included studies. The authors excluded 56 malignant transformation cases from the meta-analysis, most commonly because of the absence of pathological OLP diagnosis. Among included malignant transformation cases, the mean (SD) age was 58.1 (12.4) years, and 64% of the sample was female. Random-effects meta-analysis estimated an OLP malignant transformation rate of 0.2% (95%CI: 0.1-0.3%). Heterogeneity was low (I2 = 28.74%, p = 0.065). Malignant transformation was significantly higher among smokers (OR = 4.62, p = 0.001), alcohol consumers (OR = 3.22, p = 0.05), those with hepatitis C (OR = 3.77, p = 0.03) and atrophic or erosive OLP subtypes (OR = 2.70, p = 0.03). Gender was not associated with increased risk of malignant transformation.Conclusions The malignant transformation rate of OLP is likely to be lower than previously reported, possibly as a result of variable diagnostic criteria. Whilst encouraging, clinical vigilance remains necessary, as OLP does carry a small risk of malignant transformation. Smoking, alcohol use, hepatitis C infection and erosive or atrophic subtypes appear to have a greater rate of malignant transformation.

Research question The study aims to investigate spread, distance and spatial distribution of aerosolised microorganisms generated through various endodontic procedures. Study design A case-control study carried out at the University of Maryland, US in 2020. The study investigated the aerosolised microorganisms produced during three endodontic treatments: emergency pulpotomy, emergency pulpectomy and non-surgical root canal therapy (NSRCT), with 15 participants in each group (n = 45). Patients diagnosed with symptomatic apical periodontitis were included. The use of settle plates for passive air sampling was employed, in a 4 x 4 m room with closed doors. The number of colony-forming units (CFUs) and composition of bacterial species were analysed. Variables within the study included: distance of plate to patient's mouth (0.5 m or 2 m), positioning of plate (directly in front of or diagonal to the participant's mouth), type of endodontic treatment performed and the duration of treatment. A baseline sample was collected (room at rest) as a control. All dental treatment was carried out under rubber dam, after patients had undergone a pre-operative 0.12% chlorhexidine digluconate mouth rinse for 60 seconds. An extraoral suction system (ADS EOS Dental System Inc; Ontario, CA, USA) was also placed directly in front of the patient's mouth throughout treatment. Results A significantly greater number of CFUs were recorded after endodontic treatments (all treatments), compared to negative control. CFUs were lower in the emergency pulpotomy group compared to the other two groups. There was a significantly lower number of CFUs found at plates situated 0.5 m, compared to 2 m, away from the patient. There was a positive correlation between the procedure duration and CFU count. The main bacterial species detected were Staphylococcus aureus (48.8%), Staphlococcus epidermidis (42.2%) and oral streptococci (33.1%). Pseudomonas aeruginosa and fungi were not detected. Conclusion Emergency pulpectomy and NSRCT created greater microbial contamination than an emergency pulpotomy. Greater numbers of microorganisms were found after longer treatment times and closer to the patient's mouth.

This special issue of the Kiva is published in honor of Margaret Lyneis, who passed away in 2016 at the age of 78, after a long and influential career as a teacher and scholar. These papers develop...

At the 1988 SAA annual meeting in Phoenix, Margaret Lyneis presented a paper with the title Ceramic Production and Exchange among the Virgin Anasazi. In that paper, she presented evidence that much...

Introduction: Dysfunction of the autonomic nervous system (ANS) is seen in chronic fatigue syndrome (CFS) and temporomandibular disorders (TMDs). Both conditions have poorly understood pathophysiology. Several brain structures that play a role in pain and fatigue, such as the insular cortex and basal ganglia, are also implicated in autonomic function. Objectives: ANS dysfunction may point to common neurophysiologic mechanisms underlying the predominant symptoms for CFS and TMD. No studies to date have investigated the combination of both conditions. Thus, our aim was to test whether patients with CFS with or without TMD show differences in brain responses to autonomic challenges. Methods: In this exploratory functional imaging study, patients with CFS who screened positive for TMD (n = 26), patients who screened negative for TMD (n = 16), and age-matched control participants (n = 10) performed the Valsalva maneuver while in a 3-T magnetic resonance imaging scanner. This maneuver is known to activate the ANS. Results: For all 3 groups, whole-brain F test showed increased brain activation during the maneuver in the superior and inferior frontal gyri, the left and right putamen and thalamus, and the insular cortex. Furthermore, group contrasts with small-volume correction showed that patients with CFS who screened positive for TMD showed greater activity in the left insular cortex as compared with patients who screened negative and in the left caudate nucleus as compared with controls. Conclusion: Our results suggest that increased activity in the cortical and subcortical regions observed during autonomic challenges may be modulated by fatigue and pain. ANS dysfunction may be a contributing factor to these findings, and further work is required to tease apart the complex relationship among CFS, TMD, and autonomic functions. Knowledge Transfer Statement: Brain activity related to activation of the autonomic nervous system in patients with chronic fatigue syndrome who screened positive for painful temporomandibular disorder was greater than in patients who screened negative; activity was seen in brain regions associated with autonomic functions and pain. These findings suggest that autonomic dysfunction may play a role in the pathophysiology of both conditions, explain some of the apparent comorbidity between them, and offer avenues to help with treatment.

Purpose Patients presenting to emergency departments (EDs) following head injury often undergo computed tomography (CT) of the head to exclude traumatic brain injury. In many cases, this does not show the maxillofacial skeleton. A proportion of these patients also sustain facial fractures, and when fractures involve the orbits, CT imaging is useful in diagnosis and management; obtaining a second scan may cause delay, incur greater cost, and increase radiation dose. The aim of this preliminary study was to examine the value of signs and symptoms of orbital fractures in predicting a fracture on CT. Methods The clinical records of 47 patients who underwent CT of the face following facial trauma were retrospectively examined for the presence of signs and symptoms of orbital fractures. Sensitivity, specificity, negative predictive value (NPV) and positive predictive values (PPV) were then calculated for each sign and symptom for the presence of an orbital fracture on CT. We also described a clinical decision instrument and examined the predictive values of this. Results Change in the position of the globe, reduced visual acuity, subconjunctival haemorrhage and change in sensation in the maxillary division of the trigeminal nerve were the most specific signs and symptoms for orbital fracture. Our clinical decision instrument had 80.0% sensitivity, 75.0% specificity, 90.3% PPV and 56.3% NPV for predicting the presence of an orbital fracture on CT in this population. Conclusions Our results demonstrate that signs and symptoms of orbital fractures may be useful for predicting these injuries, and a decision instrument could be used in the ED to identify patients likely to benefit from extending the radiation field to include the orbits where CT of the head is already planned. This work is however exploratory; and further prospective validation is required before a robust instrument can be recommended for clinical use.

We report the results of a survey for HI 21-cm absorption at z < 0.4 in a new sample of radio sources with the Giant Metrewave Radio Telescope. Of the 11 sources for which there are good data, we obtain zero detections, where four are expected upon accounting for the ionising photon rates and sensitivity. Adding these to the previously published values, we confirm that the non-detection of 21-cm absorption in active sources at high redshift is due to photo-ionisation of the gas rather than excitation by 21-cm photons (significant at 6.09 sigma and 2.90 sigma, respectively). We also confirm a strong correlation between the absorption strength and the reddening of the source, suggesting that dust plays a significant role in shielding the gas from the ambient ultra-violet field. An anti-correlation between the 21-cm detection rate and the radio turnover frequency is also found, which runs contrary to what is expected on the basis that the higher the turnover frequency, the more compact the source. It is, however, consistent with the hypothesis that the turnover frequency is related to the electron density, supported by a correlation between the turnover frequency and ionising photon rate., Accepted by MNRAS

Veratrum woodii, a long-lived herbaceous perennial species, has a fragmented distribution with populations scattered in the southeastern and lower midwestern USA. In Georgia, the species has a protection status of rare. This preliminary study focused on verifying historic and/or unvouchered populations in Georgia and characterizing variation and genetic structure within and among all populations in the state. We analyzed AFLP (amplified fragment length polymorphism) data as dominantly inherited markers for 16 populations sampled from Georgia, Florida, and Missouri. Our results suggest that this species overall has relatively low levels of genetic diversity and that differentiation among populations is comparable to species with similar life history traits. Measures of genetic diversity, such as mean He, indicate that variation of populations has some partitioning between disjunct northern and southern Georgia (and Florida) populations. However, our analyses imply that watershed assignment, rather than geographic distance, provides a better explanation for variation and population structure. We hypothesize that southern relict populations in Georgia may have served as refugia during Pleistocene glaciations. We conclude that life-history characteristics, low levels of genetic variation, and suppression of ecological disturbance collectively jeopardize populations of Veratrum woodii in Georgia.

Objectives High-speed dental instruments produce aerosol and droplets. The objective of this study was to evaluate aerosol and droplet production from a novel electric micromotor handpiece (without compressed air coolant) in real world clinical settings. Methods 10-minute upper incisor crown preparations were performed in triplicate in an open-plan clinic with mechanical ventilation providing 3.45 air changes per hour. A 1:5 ratio electric micromotor handpiece which allows water coolant without compressed air (Ti-Max Z95L, NSK) was used at three speeds: 60,000 (60 K), 120,000 (120 K), and 200,000 (200 K) revolutions per minute. Coolant solutions contained fluorescein sodium as a tracer (2.65 mmol L − 1). High-speed air-turbine positive control, and negative control conditions were conducted. Aerosol production was evaluated at 3 locations (0.5 m, 1.5 m, and 1.7 m) using: (1) an optical particle counter (OPC; 3016-IAQ, Lighthouse) to detect all aerosol; and (2) a liquid cyclone air sampler (BioSampler, SKC Ltd.) to detect aerosolised fluorescein, which was quantified by spectrofluorometric analysis. Settled droplets were detected by spectrofluorometric analysis of filter papers placed onto a rig across the open-plan clinic. Results Local (within treatment bay) settled droplet contamination was elevated above negative control for all conditions, with no difference between conditions. Settled droplet contamination was not detected above negative controls outside the treatment bay for any condition. Aerosol detection at 1.5 m and 1.7 m, was only increased for the air-turbine positive control condition. At 0.5 m, aerosol levels were highly elevated for the air-turbine, minimally elevated for 200 K and 120 K, and not elevated for 60 K. Conclusions Electric micromotor handpieces which use water-jet coolant alone without compressed air produce localised (within treatment bay) droplet contamination, but are unlikely to produce aerosol contamination beyond the immediate treatment area (1.5 m), allowing them to be used safely in most open-plan clinic settings.

OH absorption is currently the only viable way to detect OH molecules in non-masing galaxies at cosmological distances. There have been only 6 such detections at z>0.05 to date and so it is hard to put a statistically robust constraint on OH column densities in distant galaxies. We carried out a pilot OH absorption survey towards 8 associated and 1 intervening HI 21-cm absorbers using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We were able to constrain the OH abundance relative to HI ([OH]/[HI]) to be lower than 10^-6 ~ 10^-8 for redshifts z within [0.1919, 0.2241]. Although no individual detection was made, stacking three associated absorbers free of RFI provides a sensitive OH column density 3-sigma upper-limit ~ 1.57 x 10^14 (Tx/10K)(1/fc) cm^-2, which corresponds to a [OH]/[HI] < 5.45 x 10^-8. Combining with archival data, we show that associated absorbers have a slightly lower OH abundance than intervening absorbers. Our results are consistent with a trend of decreasing OH abundance with decreasing redshift., accepted for publication in MNRAS

In this paper we describe the system design and capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope at the conclusion of its construction project and commencement of science operations. ASKAP is one of the first radio telescopes to deploy phased array feed (PAF) technology on a large scale, giving it an instantaneous field of view that covers 31 square degrees at 800 MHz. As a two-dimensional array of 36x12m antennas, with baselines ranging from 22m to 6km, ASKAP also has excellent snapshot imaging capability and 10 arcsecond resolution. This, combined with 288 MHz of instantaneous bandwidth and a unique third axis of rotation on each antenna, gives ASKAP the capability to create high dynamic range images of large sky areas very quickly. It is an excellent telescope for surveys between 700 MHz and 1800 MHz and is expected to facilitate great advances in our understanding of galaxy formation, cosmology and radio transients while opening new parameter space for discovery of the unknown., 38 pages, 24 figures, accepted for publication in PASA

Introduction Dental procedures produce splatter and aerosol which have potential to spread pathogens such as SARS-CoV-2. Mixed evidence exists on the aerosol-generating potential of orthodontic procedures. The aim of this study was to evaluate splatter and/or settled aerosol contamination during orthodontic debonding. Material and methods Fluorescein dye was introduced into the oral cavity of a mannequin. Orthodontic debonding was undertaken with surrounding samples collected. Composite bonding cement was removed using a speed-increasing handpiece with dental suction. A positive control condition included a water-cooled, high-speed air-turbine crown preparation. Samples were analysed using digital image analysis and spectrofluorometric analysis. Results Contamination across the eight-metre experimental rig was 3% of the positive control on spectrofluorometric analysis and 0% on image analysis. Contamination of the operator, assistant and mannequin was 8%, 25% and 28% of the positive control, respectively. Discussion Splatter and settled aerosol from orthodontic debonding is distributed mainly within the immediate locality of the mannequin. Widespread contamination was not observed. Conclusions Orthodontic debonding is unlikely to produce widespread contamination via splatter and settled aerosol, but localised contamination is likely. This highlights the importance of personal protective equipment for the operator, assistant and patient. Further work is required to examine suspended aerosol. Zusatzmaterial online: Zu diesem Beitrag sind unter 10.1038/s41415-020-2503-9 für autorisierte Leser zusätzliche Dateien abrufbar., Key points Orthodontic debonding, including removal of composite using a slow-speed handpiece with dental suction, appears to pose little risk of widespread distribution of settled contamination.Splatter and settled aerosol was produced during the debonding procedure; however, this was mainly localised to the patient, operator and assistant.Further work is required to examine aerosol which remains suspended in the air. Zusatzmaterial online: Zu diesem Beitrag sind unter 10.1038/s41415-020-2503-9 für autorisierte Leser zusätzliche Dateien abrufbar.

Recent studies have shown that both 21cm HI absorption and soft X-ray absorption serve as excellent tracers of the dense and dusty gas near the active nucleus of young radio galaxies, offering new insight into the physical nature of the circumnuclear medium. To date, a correlation between the column densities derived using these absorption processes has been observed within Compact Steep Spectrum (CSS) and Gigahertz-Peaked Spectrum (GPS) radio sources. While it is possible that this correlation exists within the broader radio population, many samples of radio galaxies make this difficult to test due to selection effects. This paper explores the possibility of a correlation in the broader radio population by analysing a historic sample of 168 radio sources compiled from the literature in such a way so as to minimise selection bias. From this historic sample we conclude that there is some evidence for a correlation between HI and soft X-ray absorption outside of peaked spectrum sources, but that the selection bias towards these sources makes further analysis difficult using current samples. We discuss this in the context of the SEAFOG project and how forthcoming data will change the landscape of future absorption studies., Comment: 4 pages, 1 table, 1 figure, to appear in proceedings of "The 6th Workshop on CSS and GPS radio sources"

Evolution of the cosmic star formation rate (SFR) and molecular gas mass density is expected to be matched by a similarly strong evolution of the fraction of atomic hydrogen (HI) in the cold neutral medium (CNM). We use results from a recent commissioning survey for intervening 21-cm absorbers with the Australian Square Kilometre Array Pathfinder (ASKAP) to construct a Bayesian statistical model of the $N_{\rm HI}$-weighted harmonic mean spin temperature ($T_{\rm s}$) at redshifts between $z = 0.37$ and $1.0$. We find that $T_{\rm s} \leq 274$K with 95 per cent probability, suggesting that at these redshifts the typical HI gas in galaxies at equivalent DLA column densities may be colder than the Milky Way interstellar medium ($T_{\rm s, MW} \sim 300$K). This result is consistent with an evolving CNM fraction that mirrors the molecular gas towards the SFR peak at $z \sim 2$. We expect that future surveys for HI 21-cm absorption with the current SKA pathfinder telescopes will provide constraints on the CNM fraction that are an order of magnitude greater than presented here., Comment: 12 pages, 8 figures, accepted for publication in MNRAS

We present a novel 2D flux density model for observed HI emission lines combined with a Bayesian stacking technique to measure the baryonic Tully-Fisher relation below the nominal detection threshold. We simulate a galaxy catalogue, which includes HI lines described either with Gaussian or busy function profiles, and HI data cubes with a range of noise and survey areas similar to the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. With prior knowledge of redshifts, stellar masses and inclinations of spiral galaxies, we find that our model can reconstruct the input baryonic Tully-Fisher parameters (slope and zero point) most accurately in a relatively broad redshift range from the local Universe to $z = 0.3$ for all the considered levels of noise and survey areas, and up to $z = 0.55$ for a nominal noise of $90\,\mu$Jy/channel over 5 deg$^{2}$. Our model can also determine the $M_{\rm HI} - M_{\star}$ relation for spiral galaxies beyond the local Universe, and account for the detailed shape of the HI emission line, which is crucial for understanding the dynamics of spiral galaxies. Thus, we have developed a Bayesian stacking technique for measuring the baryonic Tully-Fisher relation for galaxies at low stellar and/or HI masses and/or those at high redshift, where the direct detection of HI requires prohibitive exposure times., Comment: 13 pages, 9 figures. Accepted for publication in MNRAS

We present results from MUSE observations of a 21-cm HI absorption system detected with the Australian Square Kilometre Array Pathfinder radio telescope at redshift $z = 0.4503$ towards the $z = 1.71$ quasar PKS 1610-771. We identify four galaxies (A, B, X and Y) at the same redshift as the 21-cm H I Damped Lyman-{\alpha} (DLA) absorption system, with impact parameters ranging from less than 10 kpc to almost 200 kpc from the quasar sightline. Ca II and Na I absorption is seen in the MUSE spectrum of the background QSO, with velocities coinciding with the initial HI 21-cm detection, but tracing less dense and warmer gas. This metal-line component aligns with the rotating ionised disc of galaxy B (impact parameter 18 kpc from the QSO) and appears to be co-rotating with the galaxy disc. In contrast, the 21-cm HI absorber is blueshifted relative to the galaxies nearest the absorber and has the opposite sign to the velocity field of galaxy B. Since galaxies A and B are separated by only 17 kpc on the sky and $70$ km s$^{-1}$ in velocity, it appears likely that the 21-cm detection traces extragalactic clouds of gas formed from their interaction. This system reveals that the cold 100 K neutral gas critical for star formation can be associated with complex structures beyond the galaxy disc, and is a first case study made in preparation for future large 21-cm absorption surveys like the ASKAP First Large Absorption Survey in HI., Comment: Accepted. 13 pages, 7 figures

GPS and CSS sources are thought to represent a young and/or confined sub-population of radio-loud active galactic nuclei (AGN) that are yet to evacuate their surrounding ambient interstellar gas. By studying the gaseous environments of these objects we can gain an insight into the inter-dependent relationship between galaxies and their supermassive black holes (SMBHs). The First Large Absorption Survey in HI (FLASH) will build a census of the neutral atomic hydrogen (HI) gas in galaxies at intermediate cosmological redshifts. FLASH is expected to detect at least several hundred HI absorbers associated with GPS and CSS sources. These absorbers provide an important probe of the abundance and kinematics of line-of-sight neutral gas towards radio AGN, in some cases revealing gas associated with infalling clouds and outflows. Observations are now complete for the first phase of the FLASH Pilot Survey and early analysis has already yielded several detections, including the GPS source PKS2311$-$477. Optical imaging of this galaxy reveals an interacting system that could have supplied the neutral gas seen in absorption and triggered the radio-loud AGN. FLASH will provide a statistically significant sample with which the prevalence of such gas-rich interactions amongst compact radio galaxies can be investigated., Comment: 4 pages, 3 figures, to appear in proceedings of "The 6th Workshop on CSS and GPS radio sources"

We report a detailed CO(1-0) survey of a galaxy protocluster field at $z=2.16$, based on 475 hours of observations with the Australia Telescope Compact Array. We constructed a large mosaic of 13 individual pointings, covering an area of 21 arcmin$^2$ and $\pm6500$ km/s range in velocity. We obtain a robust sample of 46 CO(1-0) detections spanning $z=2.09-2.22$, constituting the largest sample of molecular gas measurements in protoclusters to date. The CO emitters show an overdensity at $z=2.12-2.21$, suggesting a galaxy super-protocluster or a protocluster connected to large-scale filaments with ~120 cMpc size. We find that 90% CO emitters have distances $>0'.5-4'$ to the center galaxy, indicating that small area surveys would miss the majority of gas reservoirs in similar structures. Half of the CO emitters have velocities larger than escape velocities, which appears gravitationally unbound to the cluster core. These unbound sources are barely found within the $R_{200}$ radius around the center, which is consistent with a picture in which the cluster core is collapsed while outer regions are still in formation. Compared to other protoclusters, this structure contains relatively more CO emitters with relatively narrow line width and high luminosity, indicating galaxy mergers. We use these CO emitters to place the first constraint on the CO luminosity function and molecular gas density in an overdense environment. The amplitude of the CO luminosity function is 1.6$\pm$0.5 orders of magnitudes higher than observed for field galaxy samples at $z\sim2$, and one order of magnitude higher than predictions for galaxy protoclusters from semi-analytical SHARK models. We derive a high molecular gas density of $0.6-1.3\times10^{9}$ $M_\odot$ cMpc$^{-3}$ for this structure, consistent with predictions for cold gas density of massive structures from hydro-dynamical DIANOGA simulations., 21 pages + Appendices, 9 figures, 6 tables. Accepted for publication in A&A

We present the data and initial results from the first Pilot Survey of the Evolutionary Map of the Universe (EMU), observed at 944 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The survey covers 270 \sqdeg of an area covered by the Dark Energy Survey, reaching a depth of 25--30 \ujybm\ rms at a spatial resolution of $\sim$ 11--18 arcsec, resulting in a catalogue of $\sim$ 220,000 sources, of which $\sim$ 180,000 are single-component sources. Here we present the catalogue of single-component sources, together with (where available) optical and infrared cross-identifications, classifications, and redshifts. This survey explores a new region of parameter space compared to previous surveys. Specifically, the EMU Pilot Survey has a high density of sources, and also a high sensitivity to low surface-brightness emission. These properties result in the detection of types of sources that were rarely seen in or absent from previous surveys. We present some of these new results here., Accepted by PASA

Aim: To identify splatter and aerosol distribution resulting from dental aerosol generating procedures (AGPs) in the open plan clinic environment. A secondary aim is to explore the detailed time course of aerosol settling after an AGP. Methodology: Dental procedures were undertaken on a dental mannequin. Fluorescein dye was placed into the irrigation system of the high-speed air turbine handpiece for the first experimental design, and in the second, fluorescein dye was entered into the mannequin's mouth via artificial salivary ducts. Filter papers were placed at set distances around the open plan clinic environment to collect aerosol and splatter under various mitigating conditions including ventilation and aspiration flow rate. An 8-metre diameter rig was set up to investigate the effect of fallow time. Filter papers were analysed using imaging software and spectrofluorometric analysis. Results: The distribution of fluorescein contamination varied widely across the open plan clinic depending on the experimental conditions. Unmitigated (i.e. no suction) procedures have the potential to deposit contamination at large distances. Medium volume dental suction (159 L/min air) reduced contamination in the AGP bay by 53%, and in adjacent and distant bays/walkways by 81-83%. Low volume suction (40 L/min air) gave similar reductions. Cross-ventilation reduced contamination in adjacent and distant bays/walkways by 80-89%. In the most realistic model (dye in mouth with medium volume suction) the samples in distant bays (≥5 m head-to-head chair distance) either gave zero readings or very low readings (< 0.0016% of the fluorescein introduced into the system during the procedure). Almost all (99.99%) of the splatter detected was retained within the AGP bay/walkway. Time course experiments showed that after 10 minutes, very little additional contaminated aerosol settled. Conclusions: The cross-infection risk from conducting AGPs in an open plan clinic environment appears small, particularly when bays are ≥ 5 m apart. There is a major dilution effect from the instrument water spray and a substantial protective effect from using dental suction. The majority of aerosol settles in the first 10 minutes indicating that environmental cleaning may be appropriate after this time.

IntroductionDental procedures often produce splatter and aerosol which have potential to spread pathogens such as SARS-CoV-2. Mixed guidance exists on the aerosol generating potential of orthodontic procedures. The aim of this study was to evaluate aerosol and/or splatter contamination during an orthodontic debonding procedure.Material and MethodsFluorescein dye was introduced into the oral cavity of a mannequin. Orthodontic debonding was carried out in triplicate with filter papers placed in the immediate environment. Composite bonding cement was removed using a slow-speed handpiece with dental suction. A positive control condition included a high-speed air-turbine crown preparation. Samples were analysed using digital image analysis and spectrofluorometric analysis.ResultsContamination across the 8-metre experimental rig was 3% of the positive control on spectrofluorometric analysis and 0% on image analysis. There was contamination of the operator, assistant, and mannequin, representing 8%, 25%, and 28% of the positive control spectrofluorometric measurements, respectively.DiscussionOrthodontic debonding produces splatter within the immediate locality of the patient. Widespread aerosol generation was not observed.ConclusionsOrthodontic debonding procedures are low risk for aerosol generation, but localised splatter is likely. This highlights the importance of personal protective equipment for the operator, assistant, and patient.Three ‘In brief’ pointsOrthodontic debonding, including removal of composite using a slow speed handpiece with dental suction, appears to be a low risk procedure for aerosol generation.Splatter was produced during the debonding procedure, however this was mainly localised to the patient, operator and assistant.A single positive reading was identified 3.5 meters away from the patient, highlighting the need for suitable distancing and/or barriers in open clinical environments.

Dear Sir, We read with interest a recent article which modelled the risk to dental health care workers of various airborne pathogens [1]. This paper used Carbon Dioxide (CO2) concentration as an indicator of air quality and ventilation, reasoning that CO2 ;levels provide a measure of exposure to exhaled breath [2]. Reassuringly, with high indoor air quality, and a filtering facepiece-2 (FFP2) mask, infection transmission probability was estimated at 0% for severe acute respiratory syndrome coronavirus (SARS-CoV). CO2 concentration (i.e. air quality and ventilation) had the biggest influence on estimated transmission risk, much more so than respiratory protection from masks. With “medium” air quality the estimated transmission probability remained over 20% regardless of respiratory protection (masks) and patient infectivity. It should be noted that these data were based on SARS-CoV-1, but SARS-CoV-2 is expected to behave similarly.Using CO2 concentration is a useful, quick and inexpensive measure to assess air quality in indoor spaces and may be of use to readers. High air quality is defined as < 800 ppm CO2 [3]. We used a calibrated CO2 meter (Extech CO240; Nashua, NH, USA; £200) to assess four indoor environments within Newcastle dental school and hospital, with known air exchange rates. Two people sat (physically distanced) in each space for 30 minutes, allowing CO2 to accumulate, before leaving the area whilst measurement continued. We found that the increase in CO2 was minimal in most environments, with air quality remaining high (i.e. < 800 ppm CO2). In one unventilated, windowless surgery, levels did reach medium quality for a short period. This highlights the potential value of this simple technique in identifying areas with poorer ventilation. We next repeated the measurements with any windows open, and found that air quality and ventilation improved further; this was close to CO2 levels found outdoors. In conclusion, measuring CO2 concentration may be a useful way to measure indoor air quality and opening a window is a powerful and simple way to improve ventilation. Nisha Patel, Ciara Docherty, James Allison, Graham Walton, Ben Cole, Justin Durham, Nick Jakubovics and Richard HollidaySchool of Dental Sciences, Newcastle UniversityNewcastle Hospitals NHS Foundation TrustCorrespondence to richard.holliday@newcastle.ac.ukReferences1.Zemouri C, Awad SF, Volgenant CM, Crielaard W, Laheij AM, de Soet JJ. Modeling of the Transmission of Coronaviruses, Measles Virus, Influenza Virus, Mycobacterium tuberculosis, and Legionella pneumophila in Dental Clinics. J Dent Res 2020; 2:0022034520940288. DOI: https://doi.org/10.1177/0022034520940288. 2.Rudnick SN, Milton DK. Risk of indoor airborne infection transmission estimated from carbon dioxide concentration. Indoor air. 2003; 13(3): 237-45. DOI: https://doi.org/10.1034/j.1600-0668.2003.00189.x3.Kukadia V, Upton S. Ensuring good indoor air quality in buildings. BRE Group. Ensuring Good Indoor Air Quality in Buildings. 2019. Available at https://www.bregroup.com/bretrust/wp-content/uploads/sites/12/2019/03/Ensuring-Good-IAQ-in-Buildings-Trust-report_compressed-2.pdf (accessed July 2020).

BackgroundDental procedures often produce aerosol and splatter which are potentially high risk for spreading pathogens such as SARS-CoV-2. The existing literature is limited.Objective(s)To develop a robust, reliable and valid methodology to evaluate distribution and persistence of dental aerosol and splatter, including the evaluation of clinical procedures.MethodsFluorescein was introduced into the irrigation reservoirs of a high-speed air-turbine, ultrasonic scaler and 3-in-1 spray and procedures performed on a mannequin in triplicate. Filter papers were placed in the immediate environment. The impact of dental suction and assistant presence were also evaluated. Samples were analysed using photographic image analysis, and spectrofluorometric analysis. Descriptive statistics were calculated and Pearson’s correlation for comparison of analytic methods.ResultsAll procedures were aerosol and splatter generating. Contamination was highest closest to the source, remaining high to 1-1.5 m. Contamination was detectable at the maximum distance measured (4 m) for high-speed air-turbine with maximum relative fluorescence units (RFU) being: 46,091 at 0.5 m, 3,541 at 1.0 m, and 1,695 at 4 m. There was uneven spatial distribution with highest levels of contamination opposite the operator. Very low levels of contamination (≤0.1% of original) were detected at 30 and 60 minutes post procedure. Suction reduced contamination by 67-75% at 0.5-1.5 m. Mannequin and operator were heavily contaminated. The two analytic methods showed good correlation (r=0.930, n=244, pConclusionDental procedures have potential to deposit aerosol and splatter at some distance from the source, being effectively cleared by 30 minutes in our setting.

Obscuration of quasars by accreted gas and dust, or dusty intervening galaxies, can cause active galactic nuclei (AGN) to be missed in optically-selected surveys. Radio observations can overcome this dust bias. In particular, radio surveys searching for HI absorption inform us on how the AGN can impact on the cold neutral gas medium within the host galaxy, or the population of intervening galaxies through the observed line of sight gas kinematics. We present the results of a HI absorption line survey at $0.4 < z < 1$ towards 34 obscured quasars with the Australian SKA Pathfinder (ASKAP) commissioning array. We detect three HI absorption lines, with one of these systems previously unknown. Through optical follow-up for two sources, we find that in all detections the HI gas is associated with the AGN, and hence that these AGN are obscured by material within their host galaxies. Most of our sample are compact, and in addition, are either gigahertz peaked spectrum (GPS), or steep spectrum (CSS) sources, both thought to represent young or recently re-triggered radio AGN. The radio spectral energy distribution classifications for our sample agree with galaxy evolution models in which the obscured AGN has only recently become active. Our associated HI detection rate for GPS and compact SS sources matches those of other surveys towards such sources. We also find shallow and asymmetric HI absorption features, which agrees with previous findings that the cold neutral medium in compact radio galaxies is typically kinematically disturbed by the AGN., Accepted for publication in MNRAS. 19 pages, 8 figures

Twenty-seven species, new to the flora of Georgia, are reported here and validated by cited voucher specimens at the University of Georgia (GA) and Valdosta State University (VSC) herbaria, the two largest herbaria in the state. Reassessment and comparison of these collections data have been greatly facilitated by specimen digitization efforts, especially those fostered among herbaria by the GA–VSC Herbaria Collaborative and by the Southeast Regional Network of Expertise and Collections (SERNEC). Four species (Chelone lyonii, Prunus hortulana, Sporobolus arcuatus, and Symphyotrichum simmondsii) are likely native to Georgia and represent range extensions from nearby states. Chelone lyonii and Sporobolus arcuatus are rare and state-ranked critically imperiled (S1) by the Georgia Department of Natural Resources. The 23 exotic species are more or less naturalized or have potential to naturalize in the state. These nonnatives are escapes from cultivation (15 species) or weedy plants (eight species) t...

Many radio galaxies show the presence of dense and dusty gas near the active nucleus. This can be traced by both 21cm HI absorption and soft X-ray absorption, offering new insight into the physical nature of the circumnuclear medium of these distant galaxies. To better understand this relationship, we investigate soft X-ray absorption as an indicator for the detection of associated HI absorption, as part of preparation for the First Large Absorption Survey in HI (FLASH) to be undertaken with the Australian Square Kilometre Array Pathfinder (ASKAP). We present the results of our pilot study using the Boolardy Engineering Test Array, a precursor to ASKAP, to search for new absorption detections in radio sources brighter than 1 Jy that also feature soft X-ray absorption. Based on this pilot survey, we detected HI absorption towards the radio source PKS 1657-298 at a redshift of z = 0.42. This source also features the highest X-ray absorption ratio of our pilot sample by a factor of 3, which is consistent with our general findings that X-ray absorption predicates the presence of dense neutral gas. By comparing the X-ray properties of AGN with and without detection of HI absorption at radio wavelengths, we find that X-ray hardness ratio and HI absorption optical depth are correlated at a statistical significance of 4.71{\sigma}. We conclude by considering the impact of these findings on future radio and X-ray absorption studies., Comment: 22 pages, 20 figures, accepted for publication in MNRAS