Two new eurypterids, a pterygotid Pterygotus wanggaii n. sp. and an adelophthalmoid Parahughmilleria fuea n. sp., are described from the Early Devonian (Lochkovian) Xiaxishancun Formation of Yunnan province, southwest China. This discovery represents the first record of Parahughmilleria from Gondwana and the first Pterygotus from China. Pterygotus wanggaii n. sp. is characterized by the first primary denticles (d1,d1′) being located on the middle part of the cheliceral ramus and third primary denticles (d3,d3′) elongate, even longer than the first primary denticles. Parahughmilleria fuea n. sp. is differentiated by being a large Parahughmilleria with strongly developed lateral epimera from tergites T4 to T12. These discoveries not only extend the geographical extent of the genera Pterygotus and Parahughmilleria from Euramerica to SW China, but also give insight into the similarity of ecosystem structures across the Early Devonian world. In addition, based on previous studies, the new discoveries further support the hypothesis that eurypterids underwent a crisis during the Silurian–Devonian boundary interval.

Two new eurypterids, a pterygotid Erettopterus qujingensis n. sp., and a slimoniid, Slimonia sp., are described from the upper Silurian (Pridolian) Yulongsi Formation of Yunnan Province, China. Erettopterus qujingensis n. sp. is characterized by several inversely curved ramus denticles and a metastoma with a deep notch in the center. The discovery not only extends the geographic extent of the genus Erettopterus and Slimonia from Euramerica to southwest China, but also gives insight into the similarity of ecosystem structures across the Silurian world.

UUID: http://zoobank.org/939e82cd-58fc-415b-9209-514aecef2267

The impact of influenza and pneumonia on individuals in clinical risk groups in England has not previously been well characterized. Using nationally representative linked databases (Clinical Practice Research Database (CPRD), Hospital Episode Statistics (HES) and Office for National Statistics (ONS)), we conducted a retrospective cohort study among adults (≥ 18 years) during the 2010/2011–2019/2020 influenza seasons to estimate the incidence of influenza- and pneumonia-diagnosed medical events (general practitioner (GP) diagnoses, hospitalisations and deaths), stratified by age and risk conditions. The study population included a seasonal average of 7.2 million individuals; approximately 32% had ≥1 risk condition, 42% of whom received seasonal influenza vaccines. Medical event incidence rates increased with age, with ~1% of adults aged ≥75 years hospitalized for influenza/pneumonia annually. Among individuals with vs. without risk conditions, GP diagnoses occurred 2–5-fold more frequently and hospitalisations were 7–10-fold more common. Among those with obesity, respiratory, kidney or cardiovascular disorders, hospitalisation were 5–40-fold more common than in individuals with no risk conditions. Though these findings likely underestimate the full burden of influenza, they emphasize the concentration of disease burden in specific age and risk groups and support existing recommendations for influenza vaccination.

Non-typhoidal Salmonella (NTS) serovars, sequences types and antimicrobial susceptibility profiles have specific associations with animal and human infections in Vietnam. Antimicrobial resistance may have an effect on the manifestation of human NTS infections, with isolates from asymptomatic individuals being more susceptible to antimicrobials than those associated with animals and human diarrhoea.

Introduction: Very low concentrations of high-sensitivity cardiac troponin can rule-out myocardial infarction (MI) at ED arrival in patients with chest pain. However, this single troponin rule-out strategy works poorly in patients with renal impairment and elevated baseline troponin levels. The objective of this study was to develop and validate a troponin adjustment strategy to accurately rule-out MI with a single hs-cTnTmeasurement in patients with kidney dysfunction. Methods: We used data from three cohorts of ED chest pain patients to develop an adjustment score for a high-sensitivity troponin T (hs-cTnT) assay in patients with kidney dysfunction. The derivation cohort (n = 8846) used administrative and registry data. Two validation cohorts (n = 1187 and 1092) were prospectively-collected. The score assigned points for increasing hs-cTnT levels and subtracted points for lower estimated glomerular filtration rate (eGFR). In the derivation cohort, hs-cTnT concentrations achieving 98.5% sensitivity in of patients with eGFR ≥60, 45-59, 30-44, 15-29 and <15 were assigned ascending positive integer values. Negative integer values were assigned to eGFR values 45-59, 30-44, 15-29 and <15. The scpres for troponin and eGFR were summed for each patient, with scores ranging from −4 to +5. The proportion of patients with 7-day MI ruled out by a score ≤0, sensitivity, NPV, negative likelihood ratio (LR-) and area under the curve (AUC) were quantified in each study cohort. Results: The derivation and validation cohorts had 7-day MI rates of 5.7, 8.6 and 9.1%. In the derivation cohort, a score ≤0 ruled out MI in 35% of patients, with a sensitivity for 7-day MI of 99.5% (95% CI 98-100), NPV of 99.9% (95% CI 98.4-99.9), LR- of 0.02 (95% CI 0.01-0.05) and AUC of 0.88. In the first validation cohort, a score ≤0 ruled out MI in 45% of patients, with a sensitivity for 7-day MI of 97% (95% CI 90-100%), NPV of 99% (95% CI 98-100%), LR- 0.06 (0.02-0.18) and AUC of 0.89. In the second validation cohort, a score ≤0 ruled out MI in 20% of patients, with a sensitivity for 7-day MI of 96% (95% CI 93-99%), NPV of 98% (95% CI 96-100%), LR- of 0.16 (95% CI 0.07-0.39) and AUC of 0.78. Conclusion: We developed and validated a simple scoring system to adjust hs-cTnT concentrations for a patient's kidney function that enables MI to be ruled out in a large proportion of chest pain patients using a single measurement on ED presentation.

The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.

The Yellow Sea region is of high global importance for waterbird populations, but recent systematic bird count data enabling identification of the most important sites are relatively sparse for some areas. Surveys of waterbirds at three sites on the coast of southern Jiangsu Province, China, in 2014 and 2015 produced peak counts of international importance for 24 species, including seven globally threatened and six Near Threatened species. The area is of particular global importance for the ‘Critically Endangered’ Spoon-billed Sandpiper Calidris pygmaea (peak count across all three study sites: 62 in spring [2015] and 225 in autumn [2014] and ‘Endangered’ Spotted Greenshank Tringa guttifer (peak count across all three study sites: 210 in spring [2014] and 1,110 in autumn [2015]). The southern Jiangsu coast is therefore currently the most important migratory stopover area in the world, in both spring and autumn, for both species. Several serious and acute threats to waterbirds were recorded at these study sites. Paramount is the threat of large-scale land claim which would completely destroy intertidal mudflats of critical importance to waterbirds. Degradation of intertidal mudflat habitats through the spread of invasive Spartina, and mortality of waterbirds by entrapment in nets or deliberate poisoning are also real and present serious threats here. Collisions with, and displacement by, wind turbines and other structures, and industrial chemical pollution may represent additional potential threats. We recommend the rapid establishment of effective protected areas for waterbirds in the study area, maintaining large areas of open intertidal mudflat, and the urgent removal of all serious threats currently faced by waterbirds here.

Differential response of three weed species to prosulfuron was examined through studies of acetolactate synthase (ALS) sensitivity, uptake, translocation, and metabolism of the herbicide. Sensitivity of common cocklebur, common lambsquarters, and sicklepod ALS to prosulfuron was similar with I50 values of 3.3, 4.5, and 8.8 nM, respectively. Absorption of the herbicide increased with time for all three weed species. Percent absorption 2 d after application for common cocklebur, common lambsquarters, and sicklepod was 8, 33, and 26%, respectively. An average of 53% of the absorbed herbicide remained in the treated leaves of common cocklebur, 80% in common lambsquarters, and 93% in sicklepod. Approximately 33, 15, and 5% of the absorbed herbicide was translocated into the upper shoots of common cocklebur, common lambsquarters, and sicklepod, respectively. Metabolism of 14C-prosulfuron 1, 2, and 4 d after application was greater in sicklepod than in common lambsquarters or common cocklebur. The results suggest a combination of differential rates of translocation and metabolism may account for the differing sensitivity of these weeds at the whole plant level.

Small, irregular terraces on hillslopes, or terracettes, are common landscape features throughout west central China. Despite their prevalence, there is limited understanding of the nature of these topographic features, the processes that form them, and the role humans played in their formation. We used an interdisciplinary approach to investigate the geology, ecology, and cultural history of terracette development within Jiuzhaigou National Park, Sichuan Province, China. Terracettes occur on south facing, 20° slopes at 2500 m elevation, which appears to coincide with places people historically preferred to build villages. Ethnographic interviews suggest that traditional swidden agricultural cycles removed tree roots, causing the loess sediments to lose cohesion, slump, and the terrace risers to retreat uphill over time. This evidence is supported by landslide debris at terracette faces. Archaeological analysis of terracette sites reveal remains of rammed spread soil structures, bones, stone tools, and ceramics dating from at least 2200 years before present within a distinct paleosol layer. Radiocarbon and optically stimulated luminescence dating of terracette sediments ranged in age from between 1500 and 2000 14C yr BP and between 16 and 0.30"ka, respectively. These multiple lines of evidence indicate a long history of human habitation within Jiuzhaigou National Park and taken together, suggest strong links between terracette formation and human-landuse interactions.

Students in rural China are dropping out of secondary school at troubling rates. While there is considerable quantitative research on this issue, no systematic effort has been made to assess the deeper reasons behind student decision making through a mixed-methods approach. This article seeks to explore the prevalence, correlates and potential reasons for rural dropout throughout the secondary education process. It brings together results from eight large-scale survey studies covering 24,931 rural secondary students across four provinces, as well as analysis of extensive interviews with 52 students from these same study sites. The results show that the cumulative dropout rate across all windows of secondary education may be as high as 63 per cent. Dropping out is significantly correlated with low academic performance, high opportunity cost, low socio-economic status and poor mental health. A model is developed to suggest that rural dropout is primarily driven by two mechanisms: rational cost-benefit analysis or impulsive, stress-induced decision making.

Coxsackievirus A6 (CV-A6), coxsackievirus A16 (CV-A16) and enterovirus 71 (EV-A71) were the major enteroviruses causing nationwide hand, foot and mouth disease (HFMD) epidemics in Singapore in the last decade. We estimated the basic reproduction number (R0) of these enteroviruses to obtain a better understanding of their transmission dynamics. We merged records of cases from HFMD outbreaks reported between 2007 and 2012 with laboratory results from virological surveillance. R0 was estimated based on the cumulative number of reported cases in the initial growth phase of each outbreak associated with the particular enterovirus type. A total of 33 HFMD outbreaks were selected based on the inclusion criteria specified for our study, of which five were associated with CV-A6, 13 with CV-A16, and 15 with EV-A71. The median R0 was estimated to be 5·04 [interquartile range (IQR) 3·57–5·16] for CV-A6, 2·42 (IQR 1·85–3·36) for CV-A16, and 3·50 (IQR 2·36–4·53) for EV-A71. R0 was not significantly associated with number of infected children (P = 0·86), number of exposed children (P = 0·94), and duration of the outbreak (P = 0·05). These enterovirus-specific R0 estimates will be helpful in providing insights into the potential growth of future HFMD epidemics and outbreaks for timely implementation of disease control measures, together with disease dynamics such as severity of the cases.

We examine the impact of rigorous trade suppression during 1550–1567 on the sharp rise of piracy in this period of Ming China. By analyzing a uniquely constructed historical data set, we find that the enforcement of a “sea (trade) ban” policy led to a rise in pirate attacks that was 1.3 times greater among the coastal prefectures more suitable for silk manufactures—our proxy for greater trade potential. Our study illuminates the conflicts in which China subsequently engaged with the Western powers, conflicts that eventually resulted in the forced abandonment of its long upheld autarkic principle.

Recently, the detection of non-bulk superconductivity with unexpectedly high onset-Tcs up to 49 K in Pr-doped CaFe2As2 [(Ca,Pr)122] single crystals and the report of a Tc up to 65 K in one-unit-cell (1UC) FeSe epi-films, offer an unusual opportunity to seek an answer to the question posed in the title. Through systematic compositional, structural, resistive, and magnetic investigations on (Ca,Pr)122 single crystals, we have observed a doping-level-independent Tc, the simultaneous appearance of superparamagnetism and superconductivity, large magnetic anisotropy, and the existence of mesoscopic-2D structures in these crystals, thus providing clear evidence consistent with the proposed interface-enhanced Tc in these naturally occurring rareearth-doped Fe-based superconductors, (Ca,R)122. Similar resistive and magnetic measurements were also made on the 3–4UC FeSe ultrathin epi-films. We have detected weak links in the Meissner state below 20 K, weakly coupled small superconducting patches between 20–45 K, and collective excitations of spin and/or superconducting nature between 45–80 K. The unusual frequency dependences of the diamagnetic moment observed in the films in different temperature ranges will be presented and their implications discussed.

Molecules such as dithiols are of significant interest for potential molecular electronics applications. To investigate their properties, an efficient method for measuring their electrical conductance is crucial. This research focuses on the time domain measurement, a novel technique capable of measuring hundreds of molecules within a matter of seconds. Measurements were conducted using STM with the tip positioned within tunneling distance over a SAM of 1,8-octanedithiol on Au(111)-mica substrate submerged in toluene. Bonding/debonding events between the tops of molecules and the tip were observed through jumps in the time domain current waveform. A new time-spent histogram data analysis technique was developed to extract conductance values from complex waveforms. Conductance of 2.6 nS was obtained for a single 1,8-octanedithiol molecule, consistent with results obtained from wellestablished but time consuming break junction technique, validating the new STM based time domain technique for fast measurement of molecular conductance.

We investigate the ray-length distributions for two different rectangular versions of Gilbert's tessellation (see Gilbert (1967)). In the full rectangular version, lines extend either horizontally (east- and west-growing rays) or vertically (north- and south-growing rays) from seed points which form a Poisson point process, each ray stopping when another ray is met. In the half rectangular version, east- and south-growing rays do not interact with west and north rays. For the half rectangular tessellation, we compute analytically, via recursion, a series expansion for the ray-length distribution, whilst, for the full rectangular version, we develop an accurate simulation technique, based in part on the stopping-set theory for Poisson processes (see Zuyev (1999)), to accomplish the same. We demonstrate the remarkable fact that plots of the two distributions appear to be identical when the intensity of seeds in the half model is twice that in the full model. In this paper we explore this coincidence, mindful of the fact that, for one model, our results are from a simulation (with inherent sampling error). We go on to develop further analytic theory for the half-Gilbert model using stopping-set ideas once again, with some novel features. Using our theory, we obtain exact expressions for the first and second moments of the ray length in the half-Gilbert model. For all practical purposes, these results can be applied to the full-Gilbert model—as much better approximations than those provided by Mackisack and Miles (1996).