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Recent comparisons between classical Wagner theory for the impact of two liquid droplets and direct numerical simulations in Cimpeanu & Moore (J. Fluid Mech., vol. 856, 2018, pp. 764–796) show that, in some regimes, the inviscid theory over-predicts the thickness of the root of the splash jet that forms in the impact, while also struggling to predict the angle at which the jet is emitted. The effect of capillary and viscous perturbations to Helmholtz flows was investigated in a previous study, see Moore et al. (J. Fluid Mech., vol. 742, 2014, R1). However, the paper in question ignored a term in the second-order perturbation analysis, which needs to be included in order to predict the displacement of the inviscid free boundary to lowest order. In this paper, we derive a singular integro-differential equation for the free-surface perturbations caused by viscosity in Helmholtz flows and discuss its application both in the context of Wagner theory and more generally. In particular, viscosity can induce non-monotonic behaviour in the free boundary profiles near points of maximum curvature.
With the recent discovery of a dozen dusty star-forming galaxies and around 30 quasars at z > 5 that are hyper-luminous in the infrared (μ LIR > 1013 L⊙, where μ is a lensing magnification factor), the possibility has opened up for SPICA, the proposed ESA M5 mid-/far-infrared mission, to extend its spectroscopic studies toward the epoch of reionisation and beyond. In this paper, we examine the feasibility and scientific potential of such observations with SPICA’s far-infrared spectrometer SAFARI, which will probe a spectral range (35–230 μm) that will be unexplored by ALMA and JWST. Our simulations show that SAFARI is capable of delivering good-quality spectra for hyper-luminous infrared galaxies at z = 5 − 10, allowing us to sample spectral features in the rest-frame mid-infrared and to investigate a host of key scientific issues, such as the relative importance of star formation versus AGN, the hardness of the radiation field, the level of chemical enrichment, and the properties of the molecular gas. From a broader perspective, SAFARI offers the potential to open up a new frontier in the study of the early Universe, providing access to uniquely powerful spectral features for probing first-generation objects, such as the key cooling lines of low-metallicity or metal-free forming galaxies (fine-structure and H2 lines) and emission features of solid compounds freshly synthesised by Population III supernovae. Ultimately, SAFARI’s ability to explore the high-redshift Universe will be determined by the availability of sufficiently bright targets (whether intrinsically luminous or gravitationally lensed). With its launch expected around 2030, SPICA is ideally positioned to take full advantage of upcoming wide-field surveys such as LSST, SKA, Euclid, and WFIRST, which are likely to provide extraordinary targets for SAFARI.
Our current global food system – from food production to consumption, including manufacture, packaging, transport, retail and associated businesses – is responsible for extensive negative social and environmental impacts which threaten the long-term well-being of society. This has led to increasing calls from science–policy organizations for major reform and transformation of the global food system. However, our knowledge regarding food system transformations is fragmented and this is hindering the development of co-ordinated solutions. Here, we collate recent research across several academic disciplines and sectors in order to better understand the mechanisms that ‘lock-in’ food systems in unsustainable states.
Background: Continuous video-EEG (cvEEG) monitoring is the standard of care for diagnosis and management of neonatal seizures. However, it is labour-intensive. We aimed to establish consistency in monitoring of newborns utilising NICU nurses. Methods: Neonatal nurses were trained to apply scalp electrodes, troubleshoot technical issues. Guidelines, checklists and visual training modules were developed. A central network system allowed remote access to the cvEEGs by the epileptologist for timely interpretation and feedback. We compared 100 infants with moderate to severe HIE before and after the training program. Results: 192 cvEEGs were performed. Of the 100 infants compared; time to initiate brain monitoring decreased by average of 31.5 hours, in electrographic seizure detection increased(20% compared to 34% a), seizure clinical misdiagnosis decreased (65% compared to 36% ), and Anti-Seizure burden decreased. Conclusions: Training experienced NICU nurses to set-up, start and monitor cvEEG can decrease the time to initiate cvEEG which may lead to better seizure diagnosis and management.
Background: Despite advances in neonatal care, neonates with moderate to severe HIE are at high risk of mortality and morbidity. we report the impact of a dedicated NNCC team on short term mortality and morbidities. Methods: A retrospective cohort study on neonates with moderate to serve HIE between July 1st 2008 and December 31st 2017. primary outcome : a composite of death and/or brain injury on MRI. Secondary outcomes: rate of cooling, length of hospital stay, anti-seizure medication burden, and use of inotropes. A regression analysis was done adjusting for gestational age, birth weight, gender, out-born status, Apgar score at 10 minutes, cord blood pH, and HIE clinical staging Results: 216 neonates were included, 109 before NNCC implementation, and 107 thereafter. NNCC program resulted in reduction in the primary outcome (AOR: 0.28, CI: 0.14-0.54, p<0.001) and brain injury (AOR: 0.28, CI: 0.14-0.55, p<0.001). It decreased average length of stay/infants by 5 days (p=0.03), improved cooling rate (73% compared to 93% , p <0.001), reduced: seizure misdiagnosis (71% compared to 23%, P <0.001), anti-seizure medication burden (P = 0.001), and inotrope use (34% compared to 53%, p=0.004) Conclusions: NNCC program decreased mortality and brain injury , shortened the length of hospital stay and improved care of neonates with significant HIE.
Tidal flexure in ice shelf grounding zones has been used extensively in the past to determine grounding line position and ice properties. Although the rheology of ice is viscoelastic at tidal loading frequencies, most modelling studies have assumed some form of linear elastic beam approximation to match observed flexure profiles. Here we use density, radar and DInSAR measurements in combination with full-Stokes viscoelastic modelling to investigate a range of additional controls on the flexure of the Southern McMurdo Ice Shelf. We find that inclusion of observed basal crevasses and density dependent ice stiffness can greatly alter the flexure profile and yet fitting a simple elastic beam model to that profile will still produce an excellent fit. Estimates of the effective Young's modulus derived by fitting flexure profiles are shown to vary by over 200% depending on whether these factors are included, even when the local thickness is well constrained. Conversely, estimates of the grounding line position are relatively insensitive to these considerations for the case of a steep bed slope in our study region. By fitting tidal amplitudes only, and ignoring phase information, elastic beam theory can provide a good fit to observations in a wide variety of situations. This should, however, not be taken as an indication that the underlying rheological assumptions are correct.
The perinatal environment has a major influence on long-term health and disease risk. Preterm birth alters early-life environment and is associated with altered metabolic function in adulthood. Whether preterm birth per se or the early nutritional interventions used to support growth in preterm infants underpins this association is unknown. Lambs born preterm, following dexamethasone induction of labour, or spontaneously at term were randomised to receive nutrient supplementation, analogous to the milk fortifier used clinically or water as a control for the first 2 weeks after birth. Thereafter, nutrition was not different between groups. Growth was monitored, and the glucose–insulin axis function was assessed in juvenile (4 months) and adult life (14 months). Early nutrition influenced adult metabolic function and body composition to a greater extent than preterm birth. In supplemented females, arginine-stimulated insulin secretion was increased in preterm but reduced in term-born juveniles compared with controls (repeated-measures ANOVA P<0·01). In supplemented preterm males, adult weight, ponderal index (PI) and fasting insulin concentrations were elevated compared with preterm controls (weight, 75 (sem 3) v. 69 (sem 2) kg; PI, 48·0 (sem 2·1) v. 43·7 (sem 1·7) kg/m3; fasting insulin, 0·19 (sem 0·02) v. 0·10 (sem 0·02) ng/ml). Conversely, supplemented term-born males had reduced adult weight, PI and fasting insulin concentrations compared with term-born controls (weight, 64 (sem 2) v. 70 (sem 2) kg; PI, 44·4 (sem 1·8) v. 48·2 (sem 1·7) kg/m3; fasting insulin, 0·09 (sem 0·02) v. 0·14 (sem 0·02) ng/ml; all group×supplement interactions P<0·05). Adult metabolic health may reflect both gestational age at birth and early nutrition. Human studies are urgently needed to investigate the adult sex-specific health implications of neonatal nutritional strategies.
Africa is experiencing a rapid increase in adult obesity and associated cardiometabolic diseases (CMDs). The H3Africa AWI-Gen Collaborative Centre was established to examine genomic and environmental factors that influence body composition, body fat distribution and CMD risk, with the aim to provide insights towards effective treatment and intervention strategies. It provides a research platform of over 10 500 participants, 40–60 years old, from Burkina Faso, Ghana, Kenya and South Africa. Following a process that involved community engagement, training of project staff and participant informed consent, participants were administered detailed questionnaires, anthropometric measurements were taken and biospecimens collected. This generated a wealth of demographic, health history, environmental, behavioural and biomarker data. The H3Africa SNP array will be used for genome-wide association studies. AWI-Gen is building capacity to perform large epidemiological, genomic and epigenomic studies across several African counties and strives to become a valuable resource for research collaborations in Africa.
Far-infrared (FIR), ultraviolet (UV), and soft X-ray observations are easily degraded by dust and gas between the source and the telescope. They must be made from space, where they are still affected by the interstellar medium (ISM) of our Galaxy. Fortunately the ISM is quite patchy, with several “cosmic windows” covering ∼ 100 deg2 of sky having exceptionally low interstellar extinction and cirrus emission. Since the universe is nearly isotropic, these windows contain representative samples of cosmologically distant sources and will be the targets of deep multiwavelength studies including SWIRE, GALEX/DIS, and XMM-LSS. Overlapping optical and radio surveys provide essential source identifications, redshifts, morphologies, and continuum spectra. The prototype VLA survey (see http://www.cv.nrao.edu/sirtf_fls/) covers the 5 deg2 SIRTF First-Look Survey (FLS) and is being used to identify the expected FIR sources in advance. Most will be star-forming galaxies obeying the very tight far-infrared/radio correlation and thus continuum radio sources stronger than S ≈ 100 μJy at 1.4 GHz. Proposed VLA surveys covering the remaining “cosmic windows” will be useful for studying the evolution of obscured AGNs, clusters, and other uncommon objects.
The variations in the incidence of mastitis and infection with stage in lactation of dairy cattle have been the subject of a number of investigations (Oliver, 1955) but until recent years the udder health of dry cows has been given little attention. This is surprising, because many cows are dry for almost three months in each year and the dry period is immediately followed by a few weeks when the incidence of mastitis is high (Oliver et al .,1956a).
During the last ten years a study has been made at this Institute of the importance of the dry period to the control of mastitis in dairy cattle. The object of this article is to review the progress made.
D. R. Viete, G. J. H. Oliver and S. A. Wilde comment: First, we would like to commend Aoki et al. (2013) on a careful study and thought-provoking manuscript. Their interpretation of the Barrovian metamorphism as a fundamentally retrograde feature offers a refreshing alternative to the more conventional ‘peak-metamorphic’ models.
Inspired by recent calculations by Thoraval et al. (Phys. Rev. Lett., vol. 108, 2012, p. 264506) relating to droplet impact, this paper presents an analysis of the perturbations to the free surface caused by small surface tension and viscosity in steady Helmholtz flows. In particular, we identify the regimes in which appreciable vorticity can be shed from the boundary layer to the bulk flow.
Maternal undernutrition during pregnancy increases offspring obesity and metabolic disease risk. We hypothesized that periconceptional undernutrition in sheep from 60 days before conception through to day 30 of gestation (UN) would decrease voluntary locomotor activity in adult offspring. Distance travelled was measured at 18 months of age for ∼48 h in the paddock. Data were analysed using multiple regression analysis, with explanatory variables including sex, nutrition group, birth weight, average time between GPS measurements and percentage of time during the measurement period spent in daylight. Mean (±s.e.) distance walked (m/h) was greater for control (CON) than UN animals, and greater for females than males [110.2 (6.5), CON females; 110.7 (6.3), CON males; 105.1 (5.3), UN females and 95.5 (5.8), UN males; P = 0.02 for nutrition group effect and for sex effect]. Periconceptional undernutrition may lead to a significant decrease in voluntary physical activity in adult offspring.
Single layer regions of MoS2 on SiO2 and SrTiO3 were identified by Raman spectroscopy and μ-photoluminescence before Kelvin probe force microscopy was performed. For the already known system MoS2/SiO2 we find 1.839 eV for the direct bandgap, in good agreement with earlier results. On MoS2/SrTiO3 the direct bandgap was determined to be 1.829 eV. From our Kelvin probe data we infer that the SrTiO3 substrate leads to a dipole layer at the interface of the MoS2 single layer. The corresponding μ-PL measurements however show no significant decrease of the bandgap. This shows, that in the case of MoS2 the carrier type as well as concentration is not significantly influenced by the choice of SrTiO3 as the substrate compared to SiO2.
Atomic force microscopy (AFM) can be combined with fluorescence microscopy to measure the changes in intracellular calcium levels (indicated by fluorescence of Ca2+ sensitive dye fluo-4) in response to mechanical stimulation performed by AFM. Mechanical stimulation using AFM is associated with cantilever movement, which may interfere with the fluorescence signal. The motion of the AFM cantilever with respect to the sample resulted in changes of the reflection of light back to the sample and a subsequent variation in the fluorescence intensity, which was not related to changes in intracellular Ca2+ levels. When global Ca2+ responses to a single stimulation were assessed, the interference of reflected light with the fluorescent signal was minimal. However, in experiments where local repetitive stimulations were performed, reflection artifacts, correlated with cantilever motion, represented a significant component of the fluorescent signal. We developed a protocol to correct the fluorescence traces for reflection artifacts, as well as photobleaching. An added benefit of our method is that the cantilever reflection in the fluorescence recordings can be used for precise temporal correlation of the AFM and fluorescence measurements.