Microwave observations reveal the deep extent and structure of Jupiter's atmospheric vortices.

Jupiter's atmosphere has a system of zones and belts punctuated by small and large vortices, the largest being the Great Red Spot. How these features change with depth is unknown, with theories of their structure ranging from shallow meteorological features to surface expressions of deep-seated convection. We present observations of atmospheric vortices using the Juno spacecraft's Microwave Radiometer. We found vortex roots that extend deeper than the altitude at which water is expected to condense, and we identified density inversion layers. Our results constrain the three-dimensional structure of Jupiter's vortices and their extension below the clouds.

Dominant Bacterial Phyla from the Human Gut Show Widespread Ability To Transform and Conjugate Bile Acids.

Gut bacteria influence human physiology by chemically modifying host-synthesized primary bile acids. These modified bile acids, known as secondary bile acids, can act as signaling molecules that modulate host lipid, glucose, and energy metabolism and affect gut microbiota composition via selective antimicrobial properties. However, knowledge regarding the bile acid-transforming capabilities of individual gut microbes remains limited. To help address this knowledge gap, we screened 72 bacterial isolates, spanning seven major phyla commonly found in the human gut, for their ability to chemically modify unconjugated bile acids. We found that 43 isolates, representing 41 species, were capable of in vitro modification of one or more of the three most abundant unconjugated bile acids in humans: cholic acid, chenodeoxycholic acid, and deoxycholic acid. Of these, 32 species have not been previously described as bile acid transformers. The most prevalent bile acid transformations detected were oxidation of 3α-, 7α-, or 12α-hydroxyl groups on the steroid core, a reaction catalyzed by hydroxysteroid dehydrogenases. In addition, we found 7α-dehydroxylation activity to be distributed across various bacterial genera, and we observed several other complex bile acid transformations. Finally, our screen revealed widespread bacterial conjugation of primary and secondary bile acids to glycine, a process that was thought to only occur in the liver, and to 15 other amino acids, resulting in the discovery of 44 novel microbially conjugated bile acids. IMPORTANCE Our current knowledge regarding microbial bile acid transformations comes primarily from biochemical studies on a relatively small number of species or from bioinformatic predictions that rely on homology to known bile acid-transforming enzyme sequences. Therefore, much remains to be learned regarding the variety of bile acid transformations and their representation across gut microbial species. By carrying out a systematic investigation of bacterial species commonly found in the human intestinal tract, this study helps better define the gut bacteria that impact composition of the bile acid pool, which has implications in the context of metabolic disorders and cancers of the digestive tract. Our results greatly expand upon the list of bacterial species known to perform different types of bile acid transformations. This knowledge will be vital for assessing the causal connections between the microbiome, bile acid pool composition, and human health.

Detection of SARS-CoV-2 within the healthcare environment: a multi-centre study conducted during the first wave of the COVID-19 outbreak in England.

BACKGROUND: Understanding how severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is spread within the hospital setting is essential in order to protect staff, implement effective infection control measures, and prevent nosocomial transmission. METHODS: The presence of SARS-CoV-2 in the air and on environmental surfaces around hospitalized patients, with and without respiratory symptoms, was investigated. Environmental sampling was undertaken within eight hospitals in England during the first wave of the coronavirus disease 2019 outbreak. Samples were analysed using reverse transcription polymerase chain reaction (PCR) and virus isolation assays. FINDINGS: SARS-CoV-2 RNA was detected on 30 (8.9%) of 336 environmental surfaces. Cycle threshold values ranged from 28.8 to 39.1, equating to 2.2 x 105 to 59 genomic copies/swab. Concomitant bacterial counts were low, suggesting that the cleaning performed by nursing and domestic staff across all eight hospitals was effective. SARS-CoV-2 RNA was detected in four of 55 air samples taken <1 m from four different patients. In all cases, the concentration of viral RNA was low and ranged from <10 to 460 genomic copies/m3 air. Infectious virus was not recovered from any of the PCR-positive samples analysed. CONCLUSIONS: Effective cleaning can reduce the risk of fomite (contact) transmission, but some surface types may facilitate the survival, persistence and/or dispersal of SARS-CoV-2. The presence of low or undetectable concentrations of viral RNA in the air supports current guidance on the use of specific personal protective equipment for aerosol-generating and non-aerosol-generating procedures.

Platelet function testing in patients with post-operative tonsillectomy bleeding may be a useful early identifier of inherited platelet function disorders.

BACKGROUND: Post-tonsillectomy bleeding is the most frequent complication of tonsillectomy. Inherited platelet function disorders have an estimated prevalence of 1 per cent. Any association between post-tonsillectomy bleeds and undiagnosed inherited platelet function disorders has not been investigated before. OBJECTIVES: To assess the prevalence of inherited platelet function disorders in a cohort of post-tonsillectomy bleed patients. METHODS: An observational cohort study was conducted using hospital digital records. Platelet function analyser 100 ('PFA-100') closure time was tested on post-tonsillectomy bleed patients who presented to hospital. RESULTS: Between 2013 and 2017, 9 of 91 post-tonsillectomy bleed patients who underwent platelet function analyser 100 testing (9.89 per cent) had positive results. Five patients (5.49 per cent) had undiagnosed inherited platelet function disorders. Four patients had false positive results secondary to a non-steroidal anti-inflammatory drug effect (specificity of 95.3 per cent) proven by repeat testing six weeks later, off medication. The false negative rate was 0 per cent. CONCLUSION: The prevalence of inherited platelet function disorders in our post-tonsillectomy bleed cohort is five-fold higher than in the general population. Platelet function analyser 100 testing when patients present with a post-tonsillectomy bleed allows management of their inherited platelet function disorder.

Disease burden in offspring is associated with changing paternal demographics in the United States.

BACKGROUND: Average paternal age in the United States has increased substantially in the last few decades. Children of advanced age fathers have a higher incidence of early onset cancer and neuropsychiatric disease. OBJECTIVES: To quantify the number of population adjusted cases of early-onset cancer and neuropsychiatric disease in children attributable to increasing paternal age in the United States. METHODS: Paternal age in the United States from 1972 to 2015 was collected using the National Vital Statistics System (NVSS). Population attributable fraction and paternal age-specific cumulative incidence rates of several cancers and neuropsychiatric disorders were obtained from peer-reviewed publications. Paternal age-specific birth rates were correlated with paternal age-specific cumulative incidence rates to determine the number of attributable cases of disease caused by advancing age of fathers in the United States. RESULTS: The 2015 birth cohort in the United States is estimated to expect 9.2% more cases of acute lymphoblastic leukemia (ALL) diagnosed before 16 years of age (157 additional cases), 13.2% more cases of embryonal tumors in children <5 years of age (209 additional cases), and 13.0% more cases of breast cancer in females younger than 40 years old (424 additional cases) compared to the 1972 birth cohort. We can estimate to expect 10.5% more cases of schizophrenia diagnosed before 21 years of age (2864 additional cases), 6.3% more cases of autism spectrum disorder (ASD) in adolescents <17 years of age (2934 additional cases), 4.5% more cases of anorexia nervosa (AN) in females 8-30 years old (620 additional cases), and 9.2% more cases of bipolar disorder in young patients 16-25 years old (252 additional cases) in the 2015 birth cohort compared to the 1972 birth cohort. CONCLUSION: Increasing paternal age in the United States is associated with a substantial increase in the number of cases of early-onset cancer and neuropsychiatric disease in offspring.

Preterm birth phenotypes in women with autoimmune rheumatic diseases: a population-based cohort study.

OBJECTIVE: To investigate preterm birth (PTB) phenotypes in women with different autoimmune rheumatic diseases in a large population-based cohort. DESIGN: Retrospective cohort study. SETTING: California, USA. POPULATION: All live singleton births in California between 2007 and 2011 were analysed. Patients with autoimmune disease at delivery were identified by International Classification of Diseases, Ninth Revision , Clinical Modification (ICD-9-CM), codes for systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis (RA), polymyositis/dermatomyositis (DM/PM), and juvenile idiopathic arthritis (JIA). METHODS: Maternally linked hospital and birth certificate records of 2 481 516 deliveries were assessed (SLE n = 2272, RA n = 1501, SSc n = 88, JIA n = 187, DM/PM n = 38). Multivariable Poisson regression models estimated the risk ratios (RRs) for different PTB phenotypes (relative to term deliveries) for each autoimmune disease compared with the general obstetric population, adjusting for maternal age, race/ethnicity, body mass index, smoking, education, payer, parity, and prenatal care. MAIN OUTCOME MEASURES: Preterm birth (PTB) was assessed overall (20-36 weeks of gestation) and by subphenotype: preterm prelabour rupture of membranes (PPROM), spontaneous birth, or medically indicated PTB. The risk of PTB overall and for each phenotype was partitioned by gestational age: early (20-31 weeks of gestation) and late (32-36 weeks of gestation). RESULTS: Risks for PTB were elevated for each autoimmune disease evaluated: SLE (RR 3.27, 95% CI 3.01-3.56), RA (RR 2.04, 95% CI 1.79-2.33), SSc (RR 3.74, 95% CI 2.51-5.58), JIA (RR 2.23, 95% CI 1.54-3.23), and DM/PM (RR 5.26, 95% CI 3.12-8.89). These elevated risks were observed for the majority of PTB phenotypes as well. CONCLUSIONS: Women with systemic autoimmune diseases appear to have an elevated risk of various PTB phenotypes. Therefore, preconception counselling and close monitoring during pregnancy is crucial. TWEETABLE ABSTRACT: This study found that women with systemic autoimmune diseases have an elevated risk of preterm birth phenotypes.

Development and validation of a machine-learning model for prediction of shoulder dystocia.

OBJECTIVES: To develop a machine-learning (ML) model for prediction of shoulder dystocia (ShD) and to externally validate the model's predictive accuracy and potential clinical efficacy in optimizing the use of Cesarean delivery in the context of suspected macrosomia. METHODS: We used electronic health records (EHR) from the Sheba Medical Center in Israel to develop the model (derivation cohort) and EHR from the University of California San Francisco Medical Center to validate the model's accuracy and clinical efficacy (validation cohort). Subsequent to application of inclusion and exclusion criteria, the derivation cohort included 686 singleton vaginal deliveries, of which 131 were complicated by ShD, and the validation cohort included 2584 deliveries, of which 31 were complicated by ShD. For each of these deliveries, we collected maternal and neonatal delivery outcomes coupled with maternal demographics, obstetric clinical data and sonographic fetal biometry. Biometric measurements and their derived estimated fetal weight were adjusted (aEFW) according to gestational age at delivery. A ML pipeline was utilized to develop the model. RESULTS: In the derivation cohort, the ML model provided significantly better prediction than did the current clinical paradigm based on fetal weight and maternal diabetes: using nested cross-validation, the area under the receiver-operating-characteristics curve (AUC) of the model was 0.793 ± 0.041, outperforming aEFW combined with diabetes (AUC = 0.745 ± 0.044, P = 1e-16 ). The following risk modifiers had a positive beta that was > 0.02, i.e. they increased the risk of ShD: aEFW (beta = 0.164), pregestational diabetes (beta = 0.047), prior ShD (beta = 0.04), female fetal sex (beta = 0.04) and adjusted abdominal circumference (beta = 0.03). The following risk modifiers had a negative beta that was < -0.02, i.e. they were protective of ShD: adjusted biparietal diameter (beta = -0.08) and maternal height (beta = -0.03). In the validation cohort, the model outperformed aEFW combined with diabetes (AUC = 0.866 vs 0.784, P = 0.00007). Additionally, in the validation cohort, among the subgroup of 273 women carrying a fetus with aEFW ≥ 4000 g, the aEFW had no predictive power (AUC = 0.548), and the model performed significantly better (0.775, P = 0.0002). A risk-score threshold of 0.5 stratified 42.9% of deliveries to the high-risk group, which included 90.9% of ShD cases and all cases accompanied by maternal or newborn complications. A more specific threshold of 0.7 stratified only 27.5% of the deliveries to the high-risk group, which included 63.6% of ShD cases and all those accompanied by newborn complications. CONCLUSION: We developed a ML model for prediction of ShD and, in a different cohort, externally validated its performance. The model predicted ShD better than did estimated fetal weight either alone or combined with maternal diabetes, and was able to stratify the risk of ShD and neonatal injury in the context of suspected macrosomia. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Neuro-inflammatory effects of photodegradative products of bilirubin.

Phototherapy was introduced in the early 1950's, and is the primary treatment of severe neonatal jaundice or Crigler-Najjar syndrome. Nevertheless, the potential biological effects of the products generated from the photodegradation of bilirubin during phototherapy remain unknown. This is very relevant in light of recent clinical observations demonstrating that the use of aggressive phototherapy can increase morbidity or even mortality, in extremely low birthweight (ELBW) infants. The aim of our study was to investigate the effects of bilirubin, lumirubin (LR, its major photo-oxidative product), and BOX A and B (its monopyrrolic oxidative products) on the central nervous system (CNS) using in vitro and ex vivo experimental models. The effects of bilirubin photoproducts on cell viability and expression of selected genes were tested in human fibroblasts, three human CNS cell lines (neuroblastoma SH-SY5Y, microglial HMC3, and glioblastoma U-87 cell lines), and organotypic rat hippocampal slices. Neither bilirubin nor its photo-oxidative products affected cell viability in any of our models. In contrast, LR in biologically-relevant concentrations (25 µM) significantly increased gene expression of several pro-inflammatory genes as well as production of TNF-α in organotypic rat hippocampal slices. These findings might underlie the adverse outcomes observed in ELBW infants undergoing aggressive phototherapy.

Jupiter's atmospheric jet streams extend thousands of kilometres deep.

The depth to which Jupiter's observed east-west jet streams extend has been a long-standing question. Resolving this puzzle has been a primary goal for the Juno spacecraft, which has been in orbit around the gas giant since July 2016. Juno's gravitational measurements have revealed that Jupiter's gravitational field is north-south asymmetric, which is a signature of the planet's atmospheric and interior flows. Here we report that the measured odd gravitational harmonics J3, J5, J7 and J9 indicate that the observed jet streams, as they appear at the cloud level, extend down to depths of thousands of kilometres beneath the cloud level, probably to the region of magnetic dissipation at a depth of about 3,000 kilometres. By inverting the measured gravity values into a wind field, we calculate the most likely vertical profile of the deep atmospheric and interior flow, and the latitudinal dependence of its depth. Furthermore, the even gravity harmonics J8 and J10 resulting from this flow profile also match the measurements, when taking into account the contribution of the interior structure. These results indicate that the mass of the dynamical atmosphere is about one per cent of Jupiter's total mass.

A suppression of differential rotation in Jupiter's deep interior.

Jupiter's atmosphere is rotating differentially, with zones and belts rotating at speeds that differ by up to 100 metres per second. Whether this is also true of the gas giant's interior has been unknown, limiting our ability to probe the structure and composition of the planet. The discovery by the Juno spacecraft that Jupiter's gravity field is north-south asymmetric and the determination of its non-zero odd gravitational harmonics J3, J5, J7 and J9 demonstrates that the observed zonal cloud flow must persist to a depth of about 3,000 kilometres from the cloud tops. Here we report an analysis of Jupiter's even gravitational harmonics J4, J6, J8 and J10 as observed by Juno and compared to the predictions of interior models. We find that the deep interior of the planet rotates nearly as a rigid body, with differential rotation decreasing by at least an order of magnitude compared to the atmosphere. Moreover, we find that the atmospheric zonal flow extends to more than 2,000 kilometres and to less than 3,500 kilometres, making it fully consistent with the constraints obtained independently from the odd gravitational harmonics. This depth corresponds to the point at which the electric conductivity becomes large and magnetic drag should suppress differential rotation. Given that electric conductivity is dependent on planetary mass, we expect the outer, differentially rotating region to be at least three times deeper in Saturn and to be shallower in massive giant planets and brown dwarfs.

Measurement of Jupiter's asymmetric gravity field.

The gravity harmonics of a fluid, rotating planet can be decomposed into static components arising from solid-body rotation and dynamic components arising from flows. In the absence of internal dynamics, the gravity field is axially and hemispherically symmetric and is dominated by even zonal gravity harmonics J2n that are approximately proportional to qn, where q is the ratio between centrifugal acceleration and gravity at the planet's equator. Any asymmetry in the gravity field is attributed to differential rotation and deep atmospheric flows. The odd harmonics, J3, J5, J7, J9 and higher, are a measure of the depth of the winds in the different zones of the atmosphere. Here we report measurements of Jupiter's gravity harmonics (both even and odd) through precise Doppler tracking of the Juno spacecraft in its polar orbit around Jupiter. We find a north-south asymmetry, which is a signature of atmospheric and interior flows. Analysis of the harmonics, described in two accompanying papers, provides the vertical profile of the winds and precise constraints for the depth of Jupiter's dynamical atmosphere.

Out-of-hospital births in California 1991-2011.

OBJECTIVE: We investigated the frequencies and characteristics of out-of-hospital births in a 20-year period in California, where 1 of every 7 births in the United States occurs. STUDY DESIGN: Birth certificate records of deliveries in California between 1991 and 2011 were analyzed. Out-of-hospital births were assessed by year, parity, gestational age and maternal race/ethnicity. RESULTS: In the 20-year period there were 10 593,904 deliveries, of which 46 243 occurred out of hospital (0.44%). Out-of-hospital births decreased from 0.54 to 0.38% per year between 1991 and 2004, and increased from 0.41% in 2005 to 0.61% in 2011. In contrast, preterm out-of-hospital births declined from 7.2% in 2006 to 5.0% in 2011. The frequency of vaginal birth after cesarean in the out-of-hospital birth cohort increased from 1.2% (n=19) in 1996 to 4.2% (n=82) in 2011. CONCLUSION: California birth records from a 20-year period show an increase in out-of-hospital births from years 2005 to 2011, following a period of decline from 1991 to 2004.

'The obesity paradox': a reconsideration of obesity and the risk of preterm birth.

OBJECTIVE: The association between obesity and spontaneous preterm births (sPTBs) has been shown to be influenced by obesity-attendant comorbidities. Our objective was to better understand the complex relationship of obesity and its attendant comorbidities with sPTBs. STUDY DESIGN: A retrospective analysis utilizing maternally linked hospital and birth certificate records of 2 049 196 singleton California deliveries from 2007 to 2011. Adjusted relative risks (aRRs) for sPTBs were estimated using multivariate Poisson regression modeling. RESULTS: Obese women had higher aRRs for sPTBs than their normal body mass index (BMI) controls. aRRs (95% confidence interval) increased with increasing BMI category: Obese I=1.10 (1.08 to 1.12); Obese II=1.15 (1.12 to 1.18); and Obese III=1.26 (1.22 to 1.30). When comparing only obese women without comorbidities to their normal BMI controls, aRRs reversed, that is, obese women had lower aRRs of sPTBs: Obese I=0.96 (0.94 to 0.98), Obese II=0.95 (0.91 to 0.98); and Obese III=0.98 (0.94 to 1.03). This same reversal of aRR direction was also observed among women with comorbidities: 0.92 (0.89 to 0.96); 0.89 (0.85 to 0.93); and 0.89 (0.85 to 0.93), respectively. Increasing BMI increased the aRRs for sPTBs among patients with gestational diabetes (P<0.05), while decreasing the risk among patients with chronic hypertension and pregnancy-related hypertensive disease (P<0.05). CONCLUSIONS: The obesity and preterm birth paradox is an example of what has been described as 'Simpson's Paradox'. Unmeasured confounding factors mediated by comorbidities may explain the observed protective effect of obesity upon conditioning on the presence or absence of comorbidities and thus resolve the paradox.

Jupiter's interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft.

On 27 August 2016, the Juno spacecraft acquired science observations of Jupiter, passing less than 5000 kilometers above the equatorial cloud tops. Images of Jupiter's poles show a chaotic scene, unlike Saturn's poles. Microwave sounding reveals weather features at pressures deeper than 100 bars, dominated by an ammonia-rich, narrow low-latitude plume resembling a deeper, wider version of Earth's Hadley cell. Near-infrared mapping reveals the relative humidity within prominent downwelling regions. Juno's measured gravity field differs substantially from the last available estimate and is one order of magnitude more precise. This has implications for the distribution of heavy elements in the interior, including the existence and mass of Jupiter's core. The observed magnetic field exhibits smaller spatial variations than expected, indicative of a rich harmonic content.

Evaluation of Legionella real-time PCR against traditional culture for routine and public health testing of water samples.

AIMS: To evaluate the usefulness of Legionella qPCR alongside traditional culture for enumeration of Legionella from water samples as part of both routine and public health investigation testing. METHODS AND RESULTS: Routine water samples (n = 2002) and samples from public health investigations (n = 215) were analysed by culture and qPCR for Legionella spp., Legionella pneumophila and L. pneumophila sg-1. A negative qPCR result was highly predictive of a negative culture result for all water systems (negative predictive values, NPV from 97·4 to 100%). Positive predictive values (PPV) were lower (0-50%). Results for qPCR were generally larger than culture with average log10 differences of 1·1 for Legionella spp. and 1·2 for L. pneumophila. Alert and action levels of 1000 and 10 000 GU per litre, respectively, are proposed for Legionella qPCR for hot and cold water systems (HCWS). The use of qPCR significantly reduced the time to results for public health investigations by rapidly identifying potential sources and ruling out others, thus enabling a more rapid and efficient response. CONCLUSIONS: The high NPV of qPCR supports its use to rapidly screen out negative samples without culture. Alert and action levels for Legionella qPCR for HCWS are proposed. Quantitative PCR will be a valuable tool for both routine and public health testing. SIGNIFICANCE AND IMPACT OF THE STUDY: This study generated comparative data of >2000 water samples by qPCR and culture. Action and alert levels have been recommended that could enable duty holders to interpret qPCR results to facilitate timely Legionella control and public health protection.

Heme oxygenase-1 promoter polymorphisms: do they modulate neonatal hyperbilirubinemia?

The role of genetic factors in the modulation of serum bilirubin levels and the pathophysiology of neonatal hyperbilirubinemia is being increasingly recognized. Heme oxygenase-1 (HO-1) is the rate-limiting enzyme by which heme is catabolized to biliverdin and thence to bilirubin, with the simultaneous release of equimolar quantities of ferrous iron (Fe3+) and carbon monoxide. Polymorphisms of the HO-1 gene promoter may modulate transcriptional activity, thereby augmenting or attenuating HO-1 expression with resultant modulation of the production of bilirubin. Few studies have related these polymorphisms to neonatal bilirubin metabolism and have reported conflicting results. In this clinical review, we surveyed the role of HO-1 gene promoter polymorphisms in the control of bilirubin production and further considered their role, if any, in the pathophysiology of neonatal hyperbilirubinemia.

Skin-to-skin contact after birth and the natural course of neurosteroid levels in healthy term newborns.

OBJECTIVE: To determine the postnatal course of neurosteroid levels in relation to gender, mode of delivery and the extent of skin-to-skin (STS) contact during the first days of life in healthy term newborns. STUDY DESIGN: Prospective observational study of 39 neonates in which parents recorded total duration of STS in the first 2 days and nine neurosteroids (dehydroepiandrosterone-sulfate, progesterone, pregnenolone, pregnenolone-sulfate, allopregnanolone, isopregnanolone, epipregnanolone, pregnanolone and pregnanolone-sulfate) were assayed from blood samples at birth and at 1-2 days of age. RESULTS: All nine neurosteroid levels declined significantly during the first 2 days of life. Gender did not significantly affect the change in neurosteroid levels. The decline in neurosteroid levels was generally more pronounced in vaginal deliveries, and there was a trend toward a larger decline with more exposure to STS. CONCLUSION: Ongoing studies may better characterize the role of neurosteroids and the influence of STS in more critically ill and premature neonates.

High prevalence of Legionella in non-passenger merchant vessels.

There is a paucity of information on the risk from potable water in non-passenger merchant vessels (NPMVs) particularly with regard to Legionella and other bacteria. This retrospective study examined water samples from 550 NPMVs docked in eight UK ports. A total of 1027 samples from 412 NPMVs were examined for total aerobic colony counts (ACC), coliforms, Escherichia coli and enterococci; 41% of samples yielded ACC above the action level (>1 × 103 c.f.u./ml) and 4·5% contained actionable levels (>1 c.f.u./100 ml) of faecal indicator bacteria. Eight hundred and three samples from 360 NPMVs were cultured specifically for Legionella and 58% of vessels proved positive for these organisms with 27% of samples showing levels greater than the UK upper action limit of 1 × 103 c.f.u./l. Cabin showers (49%) and hospital shower (45%) were frequently positive. A subset of 106 samples was analysed by quantitative polymerase chain reaction for Legionella and identified a further 11 Legionella-positive NPMVs, returning a negative predictive value of 100%. There was no correlation between NPMV age or size and any microbial parameters (P > 0·05). Legionella pneumophila serogroup 1 was isolated from 46% of NPMVs and sequence-based typing of 17 isolates revealed four sequence types (STs) previously associated with human disease. These data raise significant concerns regarding the management of microbial and Legionella risks on board NPMVs and suggest that better guidance and compliance are required to improve control.

The Evolution of HD2 Proteins in Green Plants.

In eukaryotes, protein deacetylation is carried out by two well-conserved histone deacetylase (HDAC) families: RPD3/HDA1 and SIR2. Intriguingly, model plants such as Arabidopsis express an additional plant-specific HDAC family, termed type-2 HDACs (HD2s). Transcriptomic analyses from more than 1300 green plants generated by the 1000 plants (1KP) consortium showed that HD2s appeared early in green plant evolution, the first members being detected in several streptophyte green alga. The HD2 family has expanded via several rounds of successive duplication; members are expressed in all major green plant clades. Interestingly, angiosperm species express new HD2 genes devoid of a zinc-finger domain, one of the main structural features of HD2s. These variants may have been associated with the origin and/or the biology of the ovule/seed.