To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Maternal nutrition is critical in mammalian development, influencing the epigenetic reprogramming of gametes, embryos, and fetal programming. We evaluated the effects of different levels of sulfur (S) and cobalt (Co) in the maternal diet throughout the pre- and periconceptional periods on the biochemical and reproductive parameters of the donors and the DNA methylome of the progeny in Bos indicus cattle. The low-S/Co group differed from the control with respect to homocysteine, folic acid, B12, insulin growth factor 1, and glucose. The oocyte yield was lower in heifers from the low S/Co group than that in the control heifers. Embryos from the low-S/Co group exhibited 2320 differentially methylated regions (DMRs) across the genome compared with the control embryos. We also characterized candidate DMRs linked to the DNMT1 and DNMT3B genes in the blood and sperm cells of the adult progeny. A DMR located in DNMT1 that was identified in embryos remained differentially methylated in the sperm of the progeny from the low-S/Co group. Therefore, we associated changes in specific compounds in the maternal diet with DNA methylation modifications in the progeny. Our results help to elucidate the impact of maternal nutrition on epigenetic reprogramming in livestock, opening new avenues of research to study the effect of disturbed epigenetic patterns in early life on health and fertility in adulthood. Considering that cattle are physiologically similar to humans with respect to gestational length, our study may serve as a model for studies related to the developmental origin of health and disease in humans.
The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
The objective of this study was to investigate the impact of the most commonly cited factors that may have influenced infants’ gut microbiota profiles at one year of age: mode of delivery, breastfeeding duration and antibiotic exposure. Barcoded V3/V4 amplicons of bacterial 16S-rRNA gene were prepared from the stool samples of 52 healthy 1-year-old Australian children and sequenced using the Illumina MiSeq platform. Following the quality checks, the data were processed using the Quantitative Insights Into Microbial Ecology pipeline and analysed using the Calypso package for microbiome data analysis. The stool microbiota profiles of children still breastfed were significantly different from that of children weaned earlier (P<0.05), independent of the age of solid food introduction. Among children still breastfed, Veillonella spp. abundance was higher. Children no longer breastfed possessed a more ‘mature’ microbiota, with notable increases of Firmicutes. The microbiota profiles of the children could not be differentiated by delivery mode or antibiotic exposure. Further analysis based on children’s feeding patterns found children who were breastfed alongside solid food had significantly different microbiota profiles compared to that of children who were receiving both breastmilk and formula milk alongside solid food. This study provided evidence that breastfeeding continues to influence gut microbial community even at late infancy when these children are also consuming table foods. At this age, any impacts from mode of delivery or antibiotic exposure did not appear to be discernible imprints on the microbial community profiles of these healthy children.
We conducted a prospective cohort study between 1 January 2010 and 31 December 2012 at five adult and paediatric academic medical centres to identify factors associated with persistent methicillin-resistant Staphylococcus aureus (MRSA) colonisation. Adults and children presenting to ambulatory settings with a MRSA skin and soft tissue infection (i.e. index cases), along with household members, performed self-sampling for MRSA colonisation every 2 weeks for 6 months. Clearance of colonisation was defined as two consecutive negative sampling periods. Subjects without clearance by the end of the study were considered persistently colonised and compared with those who cleared colonisation. Of 243 index cases, 48 (19·8%) had persistent colonisation and 110 (45·3%) cleared colonisation without recurrence. Persistent colonisation was associated with white race (odds ratio (OR), 4·90; 95% confidence interval (CI), 1·38–17·40), prior MRSA infection (OR 3·59; 95% CI 1·05–12·35), colonisation of multiple sites (OR 32·7; 95% CI 6·7–159·3). Conversely, subjects with persistent colonisation were less likely to have been treated with clindamycin (OR 0·28; 95% CI 0·08–0·99). Colonisation at multiple sites is a risk factor for persistent colonisation and may require more targeted decolonisation efforts. The specific effect of clindamycin on MRSA colonisation needs to be elucidated.
Effects of soil tillage systems and nitrogen (N) fertilizer management on spring wheat yield components, grain yield and N-use efficiency (NUE) were evaluated in contrasting weather of 2013 and 2014 on a clay soil at the Royal Agricultural University's Harnhill Manor Farm, Cirencester, UK. Three tillage systems – conventional plough tillage (CT), high intensity non-inversion tillage (HINiT) and low intensity non-inversion tillage (LINiT) for seedbed preparation – were compared at four rates of N fertilizer (0, 70, 140 and 210 kg N/ha). Responses to the effects of the management practices were strongly influenced by weather conditions and varied across seasons. Grain yields were similar between LINiT and CT in 2013, while CT produced higher yields in 2014. Nitrogen fertilization effects also varied across the years with no significant effects observed on grain yield in 2013, while in 2014 applications up to 140 kg N/ha increased yield. Grain protein ranged from 10·1 to 14·5% and increased with N rate in both years. Nitrogen-use efficiency ranged from 12·6 to 49·1 kg grain per kg N fertilizer and decreased as N fertilization rate increased in both years. There was no tillage effect on NUE in 2013, while in 2014 NUE under CT was similar to LINiT and higher than HINiT. The effect of tillage and N fertilization on soil moisture and soil mineral N (SMN) fluctuated across years. In 2013, LINiT showed significantly higher soil moisture than CT, while soil moisture did not differ between tillage systems in 2014. Conventional tillage had significantly higher SMN at harvest time in 2014, while no significant differences on SMN were observed between tillage systems in 2013. These results indicate that LINiT can be used to produce similar spring wheat yield to CT on this particular soil type, if a dry cropping season is expected. Crop response to N fertilization is limited when soil residual N is higher, while in conditions of lower residual SMN, a higher N supply is needed to increase yield and improve grain protein content.
There are now significant data to support the hypothesis that early life nutrition in the fetus, infant and young child can have profound effects on long-term health. This review considers some of this evidence with specific reference to the current burden of disease in Australia and New Zealand. As the findings of further research become available, recommendations on optimizing early life nutrition should be formulated and made widely available as part of the preventative health policy agenda in both Australia and New Zealand.
This paper presents our experience of managing children with a tracheostomy in a multidisciplinary team clinic consisting of an ENT consultant, paediatric respiratory consultant, a nurse specialist, and speech and language therapist.
A retrospective case note review was conducted of all children seen in the multidisciplinary team tracheostomy clinic (at a tertiary paediatric hospital) between February 2009 and September 2014.
Ninety-seven patients were examined. The most common indications for tracheostomy were: lower airway and respiratory problems (66 per cent), upper airway obstruction (64 per cent), and neurodevelopmental problems (60.8 per cent).
Children with a tracheostomy are a diverse group of patients. The most common indications for paediatric tracheostomy have changed from infective causes to airway obstruction and anomalies, long-term ventilation requirement, and underlying neuromuscular or respiratory problems. Our unified approach empowers the carers and patient, as a home management plan, long-term plan and goals are generated at the end of each appointment.
We conducted infrared spectroscopic observations of bright stars in the direction of the molecular clouds W33 and GMC G23.3 − 0.3. We compared stellar spectro-photometric distances with parallactic distances to these regions, and we were able to assess the association of the detected massive stars with these molecular complexes. The spatial and temporal distributions of the detected stars enabled us to locate sources of ionizing radiation and to gather precise information on the star formation history of these clouds. The studied clouds present different distributions of massive stars.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
New angular diameter determinations for the bright southern F8 supergiant δ CMa enable the bolometric emergent flux and effective temperature of the star to be determined with improved accuracy. The spectral flux distribution and bolometric flux have been determined from published photometry and spectrophotometry and combined with the angular diameter to derive the bolometric emergent flux ℱ = (6.50 ± 0.24) × 107 Wm−2 and the effective temperature Teff = 5818 ± 53 K. The new value for the effective temperature is compared with previous interferometric and infrared flux method determinations. The accuracy of the effective temperature is now limited by the uncertainty in the bolometric flux rather than by the uncertainty in the angular diameter.
A new beam-combination and detection system has been installed in the Sydney University Stellar Interferometer working at the red end of the visual spectrum (λλ 500–950 nm) to complement the existing blue-sensitive system (λλ 430–520 nm) and to provide an increase in sensitivity. Dichroic beam-splitters have been introduced to allow simultaneous observations with both spectral systems, albeit with some restriction on the spectral range of the longer wavelength system (λλ 550–760 nm). The blue system has been upgraded to allow remote selection of wavelength and spectral bandpass, and to enable simultaneous operation with the red system with the latter providing fringe-envelope tracking. The new system and upgrades are described and examples of commissioning tests presented. As an illustration of the improvement in performance the measurement of the angular diameter of the southern F supergiant δ CMa is described and compared with previous determinations.
A compact spectrometer-on-a-chip featuring a plasmonic molecular interaction region has been conceived, designed, modeled, and partially fabricated. The silicon-on-insulator (SOI) system is the chosen platform for the integration. The low loss of both silicon and SiO2 between 3 and 4 μm wavelengths enables silicon waveguides on SiO2 as the basis for molecular sensors at these wavelengths. Important characteristic molecular vibrations occur in this range, namely the bond stretching modes C-H (Alkynes), O-H (monomeric alcohols, phenols) and N-H (Amines), as well as CO double bonds, NH2, and CN. The device consists of a broad-band infrared LED, photonic waveguides, photon-to-plasmon transformers, a molecular interaction region, dispersive structures, and detectors. Photonic waveguide modes are adiabatically converted into SPPs on a neighboring metal surface by a tapered waveguide. The plasmonic interaction region enhances optical intensity, which allows a reduction of the overall device size without a reduction of the interaction length, in comparison to ordinary optical methods. After the SPPs propagate through the interaction region, they are converted back into photonic waveguide modes by a second taper. The dispersing region consists of a series of micro-ring resonators with photodetectors coupled to each resonator. Design parameters were optimized via electro-dynamic simulations. Fabrication was performed using a combination of photo- and electron-beam-lithography together with standard silicon processing techniques.
It is known that freckles form at the sidewalls of directionally solidified materials. We present a weakly nonlinear analysis of the effects of a weak and slowly varying background flow formed by non-axial thermal gradients on convection near onset in a mushy layer. We find that in the two-dimensional case, the onset of mush convection occurs away from the walls. However if three-dimensional disturbances are allowed, the onset occurs near the walls of the container confining the mush. We derive amplitude equations governing this behaviour and simulate their evolution numerically.