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Paleosols formed in direct contact with the Earth's atmosphere, so they can record the composition of the atmosphere through weathering processes and products. Herein we critically review a variety of different approaches for reconstructing atmospheric O2 and CO2 over the past three billion years. Paleosols indicate relatively low CO2 over that time, requiring additional greenhouse forcing to overcome the 'faint young Sun' paradox in the Archean and Mesoproterozoic, as well as low O2 levels until the Neoproterozoic. Emerging techniques will revise the history of Earth's atmosphere further and may provide a window into atmospheric evolution on other planets.
The aim of this study is to determine the species of parasite that infected the population of Brussels during the Medieval and Renaissance periods, and determine if there was notable variation between different households within the city. We compared multiple sediment layers from cesspits beneath three different latrines dating from the 14th–17th centuries. Helminths and protozoa were detected using microscopy and enzyme-linked immunosorbent assay (ELISA). We identified Ascaris sp., Capillaria sp., Dicrocoelium dendriticum, Entamoeba histolytica, Fasciola hepatica, Giardia duodenalis, Taenia sp. and Trichuris sp. in Medieval samples, and continuing presence of Ascaris sp., D. dendriticum, F. hepatica, G. duodenalis and Trichuris sp. into the Renaissance. While some variation existed between households, there was a broadly consistent pattern with the domination of species spread by fecal contamination of food and drink (whipworm, roundworm and protozoa that cause dysentery). These data allow us to explore diet and hygiene, together with routes for the spread of fecal–oral parasites. Key factors explaining our findings are manuring practices with human excrement in market gardens, and flooding of the polluted River Senne during the 14th–17th centuries.
To make a power spectrum (PS) detection of the 21-cm signal from the Epoch of Reionisation (EoR), one must avoid/subtract bright foreground sources. Sources such as Fornax A present a modelling challenge due to spatial structures spanning from arc seconds up to a degree. We compare modelling with multi-scale (MS) CLEAN components to ‘shapelets’, an alternative set of basis functions. We introduce a new image-based shapelet modelling package, SHAMFI. We also introduce a new CUDA simulation code (WODEN) to generate point source, Gaussian, and shapelet components into visibilities. We test performance by modelling a simulation of Fornax A, peeling the model from simulated visibilities, and producing a residual PS. We find the shapelet method consistently subtracts large-angular-scale emission well, even when the angular resolution of the data is changed. We find that when increasing the angular resolution of the data, the MS CLEAN model worsens at large angular scales. When testing on real Murchison Widefield Array data, the expected improvement is not seen in real data because of the other dominating systematics still present. Through further simulation, we find the expected differences to be lower than obtainable through current processing pipelines. We conclude shapelets are worthwhile for subtracting extended galaxies, and may prove essential for an EoR detection in the future, once other systematics have been addressed.
Little is known about the types of intestinal parasites that infected people living in prehistoric Britain. The Late Bronze Age archaeological site of Must Farm was a pile-dwelling settlement located in a wetland, consisting of stilted timber structures constructed over a slow-moving freshwater channel. At excavation, sediment samples were collected from occupation deposits around the timber structures. Fifteen coprolites were also hand-recovered from the occupation deposits; four were identified as human and seven as canine, using fecal lipid biomarkers. Digital light microscopy was used to identify preserved helminth eggs in the sediment and coprolites. Eggs of fish tapeworm (Diphyllobothrium latum and Diphyllobothrium dendriticum), Echinostoma sp., giant kidney worm (Dioctophyma renale), probable pig whipworm (Trichuris suis) and Capillaria sp. were found. This is the earliest evidence for fish tapeworm, Echinostoma worm, Capillaria worm and the giant kidney worm so far identified in Britain. It appears that the wetland environment of the settlement contributed to establishing parasite diversity and put the inhabitants at risk of infection by helminth species spread by eating raw fish, frogs or molluscs that flourish in freshwater aquatic environments, conversely the wetland may also have protected them from infection by certain geohelminths.
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
The early village at Çatalhöyük (7100–6150 BC) provides important evidence for the Neolithic and Chalcolithic people of central Anatolia. This article reports on the use of lipid biomarker analysis to identify human coprolites from midden deposits, and microscopy to analyse these coprolites and soil samples from human burials. Whipworm (Trichuris trichiura) eggs are identified in two coprolites, but the pelvic soil samples are negative for parasites. Çatalhöyük is one of the earliest Eurasian sites to undergo palaeoparasitological analysis to date. The results inform how intestinal parasitic infection changed as humans modified their subsistence strategies from hunting and gathering to settled farming.
To evaluate the relationships between maternal fish consumption and pregnancy outcomes in a large, population-based sample of women in the USA.
We collected average fish consumption prior to pregnancy using a modified version of the semi-quantitative Willett FFQ. We estimated adjusted OR (aOR) and 95 % CI for associations between different levels of fish consumption and preterm birth (<37 weeks), early preterm birth (<32 and <35 weeks) and small-for-gestational-age infants (SGA; <10th percentile).
The National Birth Defects Prevention Study (NBDPS).
Control mother–infant pairs with estimated delivery dates between 1997 and 2011 (n 10 919).
No significant associations were observed between fish consumption and preterm birth or early preterm birth (aOR = 0·7–1·0 and 0·7–0·9, respectively). The odds of having an SGA infant were elevated (aOR = 2·1; 95 % CI 1·2, 3·4) among women with daily fish consumption compared with women consuming fish less than once per month. No associations were observed between other levels of fish consumption and SGA (aOR = 0·8–1·0).
High intake of fish was associated with twofold higher odds of having an SGA infant, while moderate fish consumption prior to pregnancy was not associated with preterm or SGA. Our study, like many other studies in this area, lacked information regarding preparation methods and the specific types of fish consumed. Future studies should incorporate information on nutrient and contaminant contents, preparation methods and biomarkers to assess these relationships.
Introduction: The ECG diagnosis of acute coronary occlusion (ACO) in the setting of ventricular paced rhythm (VPR) is purported to be impossible. However, VPR has a similar ECG morphology to LBBB. The validated Smith-modified Sgarbossa criteria (MSC) have high sensitivity (Sens) and specificity (Spec) for ACO in LBBB. MSC consist of 1 of the following in 1 lead: concordant ST Elevation (STE) 1 mm, concordant ST depression 1 mm in V1-V3, or ST/S ratio <−0.25 (in leads with 1 mm STE). We hypothesized that the MSC will have higher Sens for diagnosis of ACO in VPR when compared to the original Sgarbossa criteria. We report preliminary findings of the Paced Electrocardiogram Requiring Fast Emergency Coronary Therapy (PERFECT) study Methods: The PERFECT study is a retrospective, multicenter, international investigation of ED patients from 1/2008 - 12/2016 with VPR on the ECG and symptoms suggestive of acute coronary syndrome (e.g. chest pain or shortness of breath). Data from four sites are presented. Acute myocardial infarction (AMI) was defined by the Third Universal Definition of AMI. A blinded cardiologist adjudicated ACO, defined as thrombolysis in myocardial infarction score 0 or 1 on coronary angiography; a pre-defined subgroup of ACO patients with peak cardiac troponin (cTn) >100 times the 99% upper reference limit (URL) of the cTn assay was also analyzed. Another blinded physician measured all ECGs. Statistics were by Mann Whitney U, Chi-square, and McNemars test. Results: The ACO and No-AMI groups consisted of 15 and 79 encounters, respectively. For the ACO and No-AMI groups, median age was 78 [IQR 72-82] vs. 70 [61-75] and 13 (86%) vs. 48 (61%) patients were male. The median peak cTn ratio (cTn/URL) was 260 [33-663] and 0.5 [0-1.3] for ACO vs. no-AMI. The Sens and Spec for the MSC and the original Sgarbossa criteria were 67% (95%CI 39-87) vs. 46% (22-72; p=0.25) and 99% (92-100) vs. 99% (92-100; p=0.5). In pre-defined subgroup analysis of ACO patients with peak cTn >100 times the URL (n=10), the Sens was 90% (54-100) for the MSC vs. 60% (27- 86) for original Sgarbossa criteria (p=0.25). Conclusion: ACO in VPR is an uncommon condition. The MSC showed good Sens for diagnosis of ACO in the presence of VPR, especially among patients with high peak cTn, and Spec was excellent. These methods and results are consistent with studies that have used the MSC to diagnose ACO in LBBB.
Many women experience both vasomotor menopausal symptoms (VMS) and depressed mood at midlife, but little is known regarding the prospective bi-directional relationships between VMS and depressed mood and the role of sleep difficulties in both directions.
A pooled analysis was conducted using data from 21 312 women (median: 50 years, interquartile range 49−51) in eight studies from the InterLACE consortium. The degree of VMS, sleep difficulties, and depressed mood was self-reported and categorised as never, rarely, sometimes, and often (if reporting frequency) or never, mild, moderate, and severe (if reporting severity). Multivariable logistic regression models were used to examine the bi-directional associations adjusted for within-study correlation.
At baseline, the prevalence of VMS (40%, range 13–62%) and depressed mood (26%, 8–41%) varied substantially across studies, and a strong dose-dependent association between VMS and likelihood of depressed mood was found. Over 3 years of follow-up, women with often/severe VMS at baseline were more likely to have subsequent depressed mood compared with those without VMS (odds ratios (OR) 1.56, 1.27–1.92). Women with often/severe depressed mood at baseline were also more likely to have subsequent VMS than those without depressed mood (OR 1.89, 1.47–2.44). With further adjustment for the degree of sleep difficulties at baseline, the OR of having a subsequent depressed mood associated with often/severe VMS was attenuated and no longer significant (OR 1.13, 0.90–1.40). Conversely, often/severe depressed mood remained significantly associated with subsequent VMS (OR 1.80, 1.38–2.34).
Difficulty in sleeping largely explained the relationship between VMS and subsequent depressed mood, but it had little impact on the relationship between depressed mood and subsequent VMS.
We present techniques developed to calibrate and correct Murchison Widefield Array low-frequency (72–300 MHz) radio observations for polarimetry. The extremely wide field-of-view, excellent instantaneous (u, v)-coverage and sensitivity to degree-scale structure that the Murchison Widefield Array provides enable instrumental calibration, removal of instrumental artefacts, and correction for ionospheric Faraday rotation through imaging techniques. With the demonstrated polarimetric capabilities of the Murchison Widefield Array, we discuss future directions for polarimetric science at low frequencies to answer outstanding questions relating to polarised source counts, source depolarisation, pulsar science, low-mass stars, exoplanets, the nature of the interstellar and intergalactic media, and the solar environment.
The current generation of experiments aiming to detect the neutral hydrogen signal from the Epoch of Reionisation (EoR) is likely to be limited by systematic effects associated with removing foreground sources from target fields. In this paper, we develop a model for the compact foreground sources in one of the target fields of the MWA’s EoR key science experiment: the ‘EoR1’ field. The model is based on both the MWA’s GLEAM survey and GMRT 150 MHz data from the TGSS survey, the latter providing higher angular resolution and better astrometric accuracy for compact sources than is available from the MWA alone. The model contains 5 049 sources, some of which have complicated morphology in MWA data, Fornax A being the most complex. The higher resolution data show that 13% of sources that appear point-like to the MWA have complicated morphology such as double and quad structure, with a typical separation of 33 arcsec. We derive an analytic expression for the error introduced into the EoR two-dimensional power spectrum due to peeling close double sources as single point sources and show that for the measured source properties, the error in the power spectrum is confined to high k⊥ modes that do not affect the overall result for the large-scale cosmological signal of interest. The brightest 10 mis-modelled sources in the field contribute 90% of the power bias in the data, suggesting that it is most critical to improve the models of the brightest sources. With this hybrid model, we reprocess data from the EoR1 field and show a maximum of 8% improved calibration accuracy and a factor of two reduction in residual power in k-space from peeling these sources. Implications for future EoR experiments including the SKA are discussed in relation to the improvements obtained.
Functional neurological disorders (FNDs), also known as conversion disorder, are unexplained neurological symptoms unrelated to a neurological cause. The disorder is common, yet poorly understood. The symptoms are experienced as involuntary but have similarities to voluntary processes. Here we studied intention awareness in FND.
A total of 26 FND patients and 25 healthy volunteers participated in this functional magnetic resonance study using Libet's clock.
FND is characterized by delayed awareness of the intention to move relative to the movement itself. The reporting of intention was more precise, suggesting that these findings are reliable and unrelated to non-specific attentional deficits. That these findings were more prominent with aberrant positive functional movement symptoms rather than negative symptoms may be relevant to impairments in timing for an inhibitory veto process. Attention towards intention relative to movement was associated with lower right inferior parietal cortex activity in FND, a region early in the processing of intention. During rest, aberrant functional connectivity was observed with the right inferior parietal cortex and other motor intention regions.
The results converge with observations of low inferior parietal activity comparing involuntary with voluntary movement in FND, emphasizing core deficiencies in intention. Heightened precision of this impaired intention is consistent with Bayesian theories of impaired top-down priors that might influence the sense of involuntariness. A primary impairment in voluntary motor intention at an early processing stage might explain clinical observations of slowed effortful voluntary movement, heightened self-directed attention and underlie functional movements. These findings further suggest novel therapeutic targets.
We present new software to cross-match low-frequency radio catalogues: the Positional Update and Matching Algorithm. The Positional Update and Matching Algorithm combines a positional Bayesian probabilistic approach with spectral matching criteria, allowing for confusing sources in the matching process. We go on to create a radio sky model using Positional Update and Matching Algorithm based on the Murchison Widefield Array Commissioning Survey, and are able to automatically cross-match ~ 98.5% of sources. Using the characteristics of this sky model, we create simple simulated mock catalogues on which to test the Positional Update and Matching Algorithm, and find that Positional Update and Matching Algorithm can reliably find the correct spectral indices of sources, along with being able to recover ionospheric offsets. Finally, we use this sky model to calibrate and remove foreground sources from simulated interferometric data, generated using OSKAR (the Oxford University visibility generator). We demonstrate that there is a substantial improvement in foreground source removal when using higher frequency and higher resolution source positions, even when correcting positions by an average of 0.3 arcmin given a synthesised beam-width of ~ 2.3 arcmin.
We evaluated the QX200 Droplet Digital PCR (ddPCR™, Bio-Rad) system and protocols for the detection of the tick-borne pathogens Borrelia burgdorferi and Borrelia miyamotoi in Ixodes scapularis nymphs and adults collected from North Truro, Massachusetts. Preliminary screening by nested PCR determined positive infection levels of 60% for B. burgdorferi in these ticks. To investigate the utility of ddPCR as a screening tool and to calculate the absolute number of bacterial genome copies in an infected tick, we adapted previously reported TaqMan®-based qPCR assays for ddPCR. ddPCR proved to be a reliable means for detection and absolute quantification of control bacterial DNA with precision as low as ten spirochetes in an individual sample. Application of this method revealed the average carriage level of B. burgdorferi in infected I. scapularis nymphs to be 2291 spirochetes per nymph (range: 230–5268 spirochetes) and 51 179 spirochetes on average in infected adults (range: 5647–115 797). No ticks naturally infected with B. miyamotoi were detected. The ddPCR protocols were at least as sensitive to conventional qPCR assays but required fewer overall reactions and are potentially less subject to inhibition. Moreover, the approach can provide insight on carriage levels of parasites within vectors.
We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation 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 Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.
We have compiled a catalogue of H ii regions detected with the Murchison Widefield Array between 72 and 231 MHz. The multiple frequency bands provided by the Murchison Widefield Array allow us identify the characteristic spectrum generated by the thermal Bremsstrahlung process in H ii regions. We detect 306 H ii regions between 260° < l < 340° and report on the positions, sizes, peak, integrated flux density, and spectral indices of these H ii regions. By identifying the point at which H ii regions transition from the optically thin to thick regime, we derive the physical properties including the electron density, ionised gas mass, and ionising photon flux, towards 61 H ii regions. This catalogue of H ii regions represents the most extensive and uniform low frequency survey of H ii regions in the Galaxy to date.