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Background This study investigated changes over time in the epidemiology of extended-spectrum β-lactamase (ESBL) producing Escherichia coli within a single equine referral hospital in the UK. Faecal samples were collected from hospitalised horses in 2008 and 2017, processed using selective media and standard susceptibility laboratory methods. A novel real-time PCR with high resolution melt analysis was used to distinguish bla CTX-M-1 and bla CTX-M-15 within CTX-M-1 group. Results In 2008, 457 faecal samples from 103 horses were collected, with ESBL-producing E. coli identified in 131 samples (28.7, 95% CI 24.6–33.1). In 2017, 314 faecal samples were collected from 74 horses with ESBL-producing E. coli identified in 157 samples (50.0, 95% CI 44.5–55.5). There were 135 and 187 non-duplicate ESBL-producing isolates from 2008 and 2017, respectively. In 2008, 12.6% of isolates belonged to CTX-M-1 group, all carrying bla CTX-M-1 , whilst in 2017, 94.1% of isolates were CTX-M-1 group positive and of these 39.2 and 60.8% of isolates carried bla CTX-M-1 and bla CTX-M-15 , respectively. In addition, the prevalence of doxycycline, gentamicin and 3rd generation cephalosporin resistance increased significantly from 2008 to 2017 while a decreased prevalence of phenotypic resistance to potentiated sulphonamides was observed. Conclusions The real-time PCR proved a reliable and high throughput method to distinguish between bla CTX-M-1 and bla CTX-M-15 . Furthermore, its use in this study demonstrated the emergence of faecal carriage of CTX-M-15 in hospitalised horses, with an increase in prevalence of ESBL-producing E. coli as well as increased antimicrobial resistance to frequently used antimicrobials.

A second look at KBO 55636 Kuiper belt objects (KBOs), small icy bodies orbiting in the Solar System beyond Neptune, are difficult observational targets. Occasionally one is spotted causing a stellar occultation, when data relevant to its structure can be obtained and a few properties deduced. But the stellar occultation of 9 October 2009, involving KBO 55636, a member of the water-ice rich Haumea collisional family, was a landmark event taking the observational astronomy of KBOs to a new level. Following several years of tracking of bright KBOs, it was possible to predict an imminent occultation, and to train a number of telescopes in its direction. Despite the vagaries of weather and other observational hazards, more than one (in fact two) separate telescopes were able to make the observation. With two different angles of view to work with, more accurate figures can be calculated: KBO 55636's mean radius of 143 ± 5 km, and its geometric albedo of about 0.9 in the V band, reveal it to be smaller than previously thought and, like its parent body, highly reflective. The dynamical age implies either that KBO 55636 has an active resurfacing mechanism, or that fresh water ice can persist for billions of years in the outer reaches of the Solar System. KBO 55636 (2002 TX 300 ) is one of the Kuiper belt objects — specifically, a member of the water-ice-rich Haumea KBO collisional family. Here, observations are reported of a multi-chord stellar occultation by KBO 55636. Calculations show that KBO 55636 is smaller than previously thought and, like its parent body, is highly reflective. The dynamical age implies either that it has an active resurfacing mechanism, or that fresh water-ice in the outer Solar System can persist for gigayear timescales. The Kuiper belt is a collection of small bodies (Kuiper belt objects, KBOs) that lie beyond the orbit of Neptune and which are believed to have formed contemporaneously with the planets. Their small size and great distance make them difficult to study. KBO 55636 (2002 TX 300 ) is a member of the water-ice-rich Haumea KBO collisional family 1 . The Haumea family are among the most highly reflective objects in the Solar System. Dynamical calculations indicate that the collision that created KBO 55636 occurred at least 1 Gyr ago 2 , 3 . Here we report observations of a multi-chord stellar occultation by KBO 55636, which occurred on 9 October 2009 ut . We find that it has a mean radius of 143 ± 5 km (assuming a circular solution). Allowing for possible elliptical shapes, we find a geometric albedo of in the V photometric band, which establishes that KBO 55636 is smaller than previously thought and that, like its parent body, it is highly reflective. The dynamical age implies either that KBO 55636 has an active resurfacing mechanism, or that fresh water-ice in the outer Solar System can persist for gigayear timescales.

We present a high-speed, visible-wavelength imaging instrument: MORIS (the MIT Optical Rapid Imaging System). MORIS is mounted on the 3 m Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. Its primary component is an Andor iXon camera, a nearly 60\" square field of view with high quantum efficiency, low read noise, low dark current, and full-frame readout rates ranging from as slow as desired to a maximum of between 3.5 Hz and 35 Hz (depending on the mode; read noise of6 e - pixel-1 6     e -     pixe l - 1 and49 e - pixel-1 49     e -     pixe l - 1 with electron-multiplyinggain = 1 gain = 1 , respectively). User-selectable binning and subframing can increase the cadence to a few hundred hertz. An electron-multiplying mode can be employed for photon counting, effectively reducing the read noise to subelectron levels at the expense of dynamic range. Data cubes, or individual frames, can be triggered to several-nanosecond accuracy using the Global Positioning System. MORIS is mounted on the side-facing exit window of SpeX, allowing simultaneous near-infrared and visible observations. Here, we describe the components, setup, and measured characteristics of MORIS. We also report results from the first science observations: the 2008 June 24 stellar occultation by Pluto and an extrasolar planetary transit by XO-2b. The Pluto occultation of a15.8R 15.8 R magnitude star has a signal-to-noise ratio of 35 per atmospheric scale height and a midtime error of 0.32 s. The XO-2b transit reaches photometric precision of 0.5 mmag in 2 minutes and has a midtime timing precision of 23 s.

Background. This study assessed the relationship of early adolescent marijuana use to performance of developmental tasks integral to the transition to young adulthood. The tasks concerned intimacy, education, and work and social conformity. Methods. African American (N = 617) and Puerto Rican (N = 531) youths completed questionnaires in their classrooms. Five years later they were individually interviewed. Logistic regression analysis estimated the increased likelihood that early marijuana users would make an inadequate transition to young adult social roles. Results. Analyses examining the association between early marijuana use and 20 outcome variables found significant relationships for 10 of them: (a) having lower educational and occupational expectations; (b) being suspended or expelled from school, fired from jobs, ‘high’ at school or work, collecting welfare; and (c) rebelliousness, not participating in productive activities, not attending church, and being an unmarried parent. Marijuana use was not related to any of the intimate relationship measures. These finding emerged with controls on gender, ethnicity, age and mother's education. Conclusions. Among African Americans and Puerto Ricans, early marijuana use predicts less adequate performance on some developmental tasks integral to becoming an independent young adult. Marijuana is not a benign drug and is associated with future risks for the individual and society at large.

Background. This paper examines the association between exposure to the Chornobyl nuclear power plant explosion and the psychological and physical well-being of mothers with young children. The study also examines whether exposure to Chornobyl increased the vulnerability of mothers to subsequent economic and social stress, and thus represents a unique test of the stress–vulnerability model in a non-Western setting. Method. The sample consisted of mothers evacuated from the contamination zone surrounding the plant (evacuees) and mothers who had never lived in a radiation-contaminated area (controls). In addition to exposure status, the interview obtained data on perceived economic stress, social stress and stress moderators. The dependent variables were measured by the SCL-90 global severity index (GSI), perceived physical health and number of days unable to work due to illness. Results. Overall, evacuees reported fewer stressors and greater personal and social resources than control mothers. Nevertheless, evacuees scored higher on the GSI, reported lower perceived physical health and took more sick days relative to control mothers, even after controlling for demographic factors, stressors and stress moderators. Tests of interaction effects were not statistically significant. Conclusions. The findings confirmed that married women with young children evacuated to Kyiv following the Chornobyl nuclear power plant explosion reported significantly poorer psychological and perceived physical health than controls 11 years later. Although perceived social and economic adversities also affected these outcomes, there was no evidence that exposure to the Chornobyl accident increased the vulnerability of mothers to these stressors, giving support to the additive burden model of stress.

Salivarian trypanosomes pose a substantial threat to livestock, but their full diversity is not known. To survey trypanosomes carried by tsetse in Tanzania, DNA samples from infected proboscides of Glossina pallidipes and G. swynnertoni were identified using fluorescent fragment length barcoding (FFLB), which discriminates species by size polymorphisms in multiple regions of the ribosomal RNA locus. FFLB identified the trypanosomes in 65 of 105 (61·9%) infected proboscides, revealing 9 mixed infections. Of 7 different FFLB profiles, 2 were similar but not identical to reference West African Trypanosoma vivax; 5 other profiles belonged to known species also identified in fly midguts. Phylogenetic analysis of the glycosomal glyceraldehyde phosphate dehydrogenase gene revealed that the Tanzanian T. vivax samples fell into 2 distinct groups, both outside the main clade of African and South American T. vivax. These new T. vivax genotypes were common and widespread in tsetse in Tanzania. The T. brucei-like trypanosome previously described from tsetse midguts was also found in 2 proboscides, demonstrating a salivarian transmission route. Investigation of mammalian host range and pathogenicity will reveal the importance of these new trypanosomes for the epidemiology and control of animal trypanosomiasis in East Africa.

The coronavirus disease 2019 (COVID-19) pandemic has caused disruption to professional and recreational sports across the world. The SARS-CoV-2 virus can be transmitted by relatively large respiratory droplets that behave ballistically, and exhaled aerosol droplets, which potentially pose a greater risk. This review provides a summary of end-to-end SARS-CoV-2 transmission risk factors for sport and an overview of transmission mechanisms to be considered by all stakeholders. The risk of SARS-CoV-2 transmission is greatest indoors, and primarily influenced by the ventilation of the environment and the close proximity of individuals. The SARS-CoV-2 transmission risks outdoors, e.g. via water, and from fomites, appear less than initially thought. Mitigation strategies include good end-to-end scenario planning of activities to optimise physical distancing, face mask wearing and hygiene practice of individuals, the environment and equipment. The identification and removal of infectious individuals should be undertaken by means of the taking of temperature and COVID-19 symptom screening, and the use of diagnostic monitoring tests to identify asymptomatic individuals. Using adequate video footage, data from proximity technology and subject interviews, the identification and isolation of ‘close contacts’ should also be undertaken to limit SARS-CoV-2 transmission within sporting environments and into the wider community. Sports should aim to undertake activities outdoors where possible, given the lower SARS-CoV-2 transmission risk, in comparison to indoor environments.

Charon among the stars Stellar occultations, when a Solar System object passes between us and a star and blocks its light, are eagerly awaited by astronomers as they provide a chance to make measurements that are not normally possible. It had been 25 years since a solitary observation of a stellar occultation by Pluto's moon Charon. But on 11 July 2005 another occurred and this time observatories across South America were ideally placed to track it. The resulting haul of data has been used to obtain an accurate measure of Charon's radius, of close to 605 km, and to establish an upper limit (a rather low one) on the density of its atmosphere. Visit tinyurl.com/9c56s for a QuickTime movie of the event. The physical characteristics of Pluto and its moon, Charon, provide insight into the evolution of the outer Solar System. Although previous measurements have constrained the masses of these bodies 1 , 2 , their radii and densities have remained uncertain. The observation of a stellar occultation by Charon in 1980 established a lower limit on its radius of 600 km (ref. 3 ) (later refined to 601.5 km; ref. 4 ) and suggested a possible atmosphere 4 . Subsequent, mutual event modelling yielded a range of 600–650 km (ref. 5 ), corresponding to a density of 1.56 ± 0.22 g cm -3 (refs 2 , 5 ). Here we report multiple-station observations of a stellar occultation by Charon. From these data, we find a mean radius of 606 ± 8 km, a bulk density of 1.72 ± 0.15 g cm -3 , and rock-mass fraction 0.63 ± 0.05. We do not detect a significant atmosphere and place 3 σ upper limits on atmospheric number densities for candidate gases. These results seem to be consistent with collisional formation for the Pluto–Charon system in which the precursor objects may have been differentiated 6 , and they leave open the possibility of atmospheric retention by the largest objects in the outer Solar System.

Trypanosomes are the causative agents of many diseases of medical and veterinary importance, including sleeping sickness and nagana in Africa, and Chagas disease in South America. Accurate identification of trypanosome species is essential, as some species are morphologically indistinguishable, yet differ greatly in their pathogenicity. A range of molecular tools has been developed for identification of species and strains of trypanosomes. PCR, using primer sets designed to amplify a specific DNA fragment from each trypanosome species, is frequently used. More recently, generic systems have been developed that can potentially recognize all trypanosome species, such as amplification of the internal transcribed spacer and fluorescent fragment length barcoding, both of which use interspecies size variation in PCR fragments amplified from the ribosomal RNA locus. Loop-mediated isothermal amplification is a promising technique and is able to detect trypanosomes in blood, serum and cerebrospinal fluid. The advantages of these techniques for high-throughput and sensitive molecular identification will be discussed.

A zone of hypoperfusion surrounding acute intracerebral hemorrhage (ICH) has been interpreted as regional ischemia. To determine if ischemia is present in the periclot area, the authors measured cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and oxygen extraction fraction (OEF) with positron emission tomography (PET) in 19 patients 5 to 22 hours after hemorrhage onset. Periclot CBF, CMRO2, and OEF were determined in a 1-cm-wide area around the clot. In the 16 patients without midline shift, periclot data were compared with mirror contralateral regions. All PET images were masked to exclude noncerebral structures, and all PET measurements were corrected for partial volume effect due to clot and ventricles. Both periclot CBF and CMRO2 were significantly reduced compared with contralateral values (CBF: 20.9 ± 7.6 vs. 37.0 ± 13.9 mL 100 g−1 min−1, P = 0.0004; CMRO2: 1.4 ± 0.5 vs. 2.9 ± 0.9 mL 100 g−1 min−1, P = 0.00001). Periclot OEF was less than both hemispheric OEF (0.42 ± 0.15 vs. 0.47 ± 0.13, P = 0.05; n = 19) and contralateral regional OEF (0.44 ± 0.16 vs. 0.51 ± 0.13, P = 0.05; n = 16). In conclusion, CMRO2 was reduced to a greater degree than CBF in the periclot region in acute ICH, resulting in reduced OEF rather than the increased OEF that occurs in ischemia. Thus, the authors found no evidence for ischemia in the periclot zone of hypoperfusion in acute ICH patients studied 5 to 22 hours after hemorrhage onset.