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 firstname.lastname@example.org
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.
Three-dimensional numerical simulations of canonical statistically steady, statistically planar turbulent flames have been used in an attempt to produce distributed burning in lean methane and hydrogen flames. Dilatation across the flame means that extremely large Karlovitz numbers are required; even at the extreme levels of turbulence studied (up to a Karlovitz number of 8767) distributed burning was only achieved in the hydrogen case. In this case, turbulence was found to broaden the reaction zone visually by around an order of magnitude, and thermodiffusive effects (typically present for lean hydrogen flames) were not observed. In the preheat zone, the species compositions differ considerably from those of one-dimensional flames based a number of different transport models (mixture averaged, unity Lewis number and a turbulent eddy viscosity model). The behaviour is a characteristic of turbulence dominating non-unity Lewis number species transport, and the distinct limit is again attributed to dilatation and its effect on the turbulence. Peak local reaction rates are found to be lower in the distributed case than in the lower Karlovitz cases but higher than in the laminar flame, which is attributed to effects that arise from the modified fuel-temperature distribution that results from turbulent mixing dominating low Lewis number thermodiffusive effects. Finally, approaches to achieve distributed burning at realisable conditions are discussed; factors that increase the likelihood of realising distributed burning are higher pressure, lower equivalence ratio, higher Lewis number and lower reactant temperature.
The aim of the study was to investigate any association between extrauterine growth restriction (EUGR) and intestinal flora of <30-week-old preterm infants. A total of 59 preterm infants were assigned to EUGR (n=23) and non-EUGR (n=36) groups. Intestinal bacteria were compared by using high-throughput sequencing of bacterial rRNA. The total abundance of bacteria in 344 genera (7568 v. 13,760; P<0.0001) and 456 species (10,032 v. 18,240; P<0.0001) was significantly decreased in the EUGR group compared with the non-EUGR group. After application of a multivariate logistic model and adjusting for potential confounding factors, as well as false-discovery rate corrections, we found four bacterial genera with higher and one bacterial genus with lower abundance in the EUGR group compared with the control group. In addition, the EUGR group showed significantly increased abundances of six species (Streptococcus parasanguinis, Bacterium RB5FF6, two Klebsiella species and Microbacterium), but decreased frequencies of three species (one Acinetobacter species, Endosymbiont_of_Sphenophorus_lev and one Enterobacter_species) compared with the non-EUGR group. Taken together, there were significant changes in the intestinal microflora of preterm infants with EUGR compared to preterm infants without EUGR.
The Main Karoo Basin of South Africa contains a near-continuous sequence of continental deposition spanning ~80 Myr from the mid-Permian to the Early Jurassic. The terrestrial vertebrates of this sequence provide a high-resolution stratigraphic record of regional origination and extinction, especially for the mid–late Permian. Until now, data have only been surveyed at coarse stratigraphic resolution using methods that are biased by nonuniform sampling rates, limiting our understanding of the dynamics of diversification through this important time period. Here, we apply robust methods (gap-filler and modified gap-filler rates) for the inference of patterns of species richness, origination rates, and extinction rates to a subset of 1321 reliably-identified fossil occurrences resolved to approximately 50 m stratigraphic intervals. This data set provides an approximate time resolution of 0.3–0.6 Myr and shows that extinction rates increased considerably in the upper 100 m of the mid-Permian Abrahamskraal Formation, corresponding to the latest part of the Tapinocephalus Assemblage Zone (AZ). Origination rates were only weakly elevated in the same interval and were not sufficient to compensate for these extinctions. Subsampled species richness estimates for the lower part of the overlying Teekloof Formation (corresponding to the Pristerognathus and Tropidostoma AZs) are low, showing that species richness remained low for at least 1.5–3 million years after the main extinction pulse. A high unevenness of the taxon abundance–frequency distribution, which is classically associated with trophically unstable postextinction faunas, in fact developed shortly before the acme of elevated extinction rates due to the appearance and proliferation of the dicynodont Diictodon. Our findings provide strong support for a Capitanian (“end-Guadalupian”) extinction event among terrestrial vertebrates and suggest that further high-resolution quantitative studies may help resolve the lack of consensus among paleobiologists regarding this event.
Brandãoite, [BeAl2(PO4)2(OH)2(H2O)4](H2O), is a new Be–Al phosphate mineral from the João Firmino mine, Pomarolli farm region, Divino das Laranjeiras County, Minas Gerais State, Brazil, where it occurs in an albite pocket with other secondary phosphates, including beryllonite, atencioite and zanazziite, in a granitic pegmatite. It occurs as colourless acicular crystals <10 µm wide and <100 µm long that form compact radiating spherical aggregates up to 1.0–1.5 mm across. It is colourless and transparent in single crystals and white in aggregates, has a white streak and a vitreous lustre, is brittle and has conchoidal fracture. Mohs hardness is 6, and the calculated density is 2.353 g/cm3. Brandãoite is biaxial (+), α = 1.544, β = 1.552 and γ = 1.568, all ± 0.002; 2Vobs = 69.7(10)° and 2Vcalc = 71.2°. No pleochroism was observed. Brandãoite is triclinic, space group P
, a = 6.100(4), b = 8.616(4), c = 10.261(5) Å, α = 93.191(11), β = 95.120(11), γ = 96.863(11)°, V = 532.1(8) Å3 and Z = 2. Chemical analysis of a 4 µm wide needle-shaped crystal by electron microprobe and secondary-ion mass spectrometry gave P2O5 = 28.42, Al2O3 = 20.15, BeO = 4.85, H2O = 21.47 and sum = 74.89 wt.%. The empirical formula, normalised on the basis of 15 anions pfu with (OH) = 2 and (H2O) = 5 apfu (from the crystal structure) is Be0.98Al1.99P2.02H12O15. The crystal structure was solved by direct methods and refined to an R1 index of 7.0%. There are two P sites occupied by P5+, two Al sites occupied by octahedrally coordinated Al3+, and one Be site occupied by tetrahedrally coordinated Be2+. There are fifteen anions, two of which are (OH) groups and five of which are (H2O) groups. The simplified ideal formula is thus [BeAl2(PO4)2(OH)2(H2O)4](H2O) with Z = 2. Beryllium and P tetrahedra share corners to form a four-membered ring. Aluminium octahedra share a common vertex to form an [Al2φ11] dimer, and these dimers are cross-linked by P tetrahedra to form a complex slab of polyhedra parallel to (001). These slabs are cross-linked by BeO2(OH)(H2O) tetrahedra, with interstitial (H2O) groups in channels that extend along .
Background: A need exists to characterise the long-term cognitive outcomes in patients who recovered from autoimmune encephalitis and to identify the modifiable factors associated with improved outcomes. Methods: We retrospectively analysed data from patients diagnosed with autoimmune encephalitis in our outpatient autoimmune encephalitis clinic over a 5-year period, where the Montreal Cognitive Assessment (MoCA) is routinely administered. Results: In total, 21 patients met the inclusion criteria, of whom 52% had persistent cognitive impairment at their latest follow-up (median delay to testing=20 months, range 13-182). Visuospatial and executive abilities, language, attention, and delayed recall were predominantly affected. Patients with status epilepticus at presentation had lower total MoCA scores at their last follow-up (median total score 21, range 15-29) compared with patients without status epilepticus at presentation (median total score 27.5, range 21-30; r2=0.366, p=0.004). Patients who experienced delays of more than 60 days from symptom onset to initiation of treatment (either immunosuppression or tumour removal) were more likely to have a MoCA score compatible with cognitive impairment at their last follow-up (r2=0.253, p=0.0239; z-score=−2.01, p=0.044). Conclusions: Our study suggests that the MoCA may be used to evaluate cognition in recovering patients with autoimmune encephalitis. Delays to treatment shorter than 60 days and absence of status epilepticus at onset were associated with better performance on the MoCA obtained more than 1 year after symptom onset, and may predict better long-term cognitive outcomes.
In vivo and in vitro trials were conducted to assess the effects of tributyrin (TB) supplementation on short-chain fatty acid (SFCA) concentrations, fibrolytic enzyme activity, nutrient digestibility and methanogenesis in adult sheep. Nine 12-month-old ruminally cannulated Small Tail ewes (initial body weight 55 ± 5.0 kg) without pregnancy were used for the in vitro trial. In vitro substrate made to offer TB at 0, 2, 4, 6 and 8 g/kg on a dry matter (DM) basis was incubated by ruminal microbes for 72 h at 39°C. Forty-five adult Small Tail ewes used for the in vivo trial were randomly assigned to five treatments with nine animals each for an 18-d period according to body weight (55 ± 5.0 kg). Total mixed ration fed to ewes was also used to offer TB at 0, 2, 4, 6 and 8 g/kg on a DM basis. The in vitro trial showed that TB supplementation linearly increased apparent digestibility of DM, crude protein, neutral detergent fibre and acid detergent fibre, and enhanced gas production and methane emissions. The in vivo trial showed that TB supplementation decreased DM intake, but enhanced ruminal fermentation efficiency. Both in vitro and in vivo trials showed that TB supplementation enhanced total SFCA concentrations and carboxymethyl cellulase activity. The results indicate that TB supplementation might exert advantage effects on rumen microbial metabolism, despite having an enhancing effect on methanogenesis.
We investigate the class of bipartite Borel graphs organized by the order of Borel homomorphism. We show that this class is unbounded by finding a jump operator for Borel graphs analogous to a jump operator of Louveau for Borel equivalence relations. The proof relies on a nonseparation result for iterated Fréchet ideals and filters due to Debs and Saint Raymond. We give a new proof of this fact using effective descriptive set theory. We also investigate an analogue of the Friedman-Stanley jump for Borel graphs. This analogue does not yield a jump operator for bipartite Borel graphs. However, we use it to answer a question of Kechris and Marks by showing that there is a Borel graph with no Borel homomorphism to a locally countable Borel graph, but each of whose connected components has a countable Borel coloring.
The development of adverse behaviour in group–housed growing/ finishing pigs with intact tails was studied in a straw–flow housing system and in a part–slatted system with a commercial enrichment object. Food intake, body weight and behaviour were monitored over the finishing period, with tail biting outbreaks defined as an occasion where three or more pigs within a group had freshly damaged tails and tail biting behaviour was ongoing. Data from the two systems were analysed to identify tail–biting outbreaks and behavioural changes over time. Levels of pig manipulation were higher in the part–slatted system. Over time, pigs in both systems showed reduced interest in the enrichment provided, but not in each other. Despite the presence of the enrichment device, tail biting occurred in all groups in the part–slatted system, but only 1/12 groups in the straw–flow system. The amount of time occupied by manipulation of the enrichment provided was very significantly higher for straw than for the commercial object. Better design of enrichment strategies is therefore needed and should be based on species–relevant requirements.
The Chinese Solar and Geophysical Data (CSGD) was first issued at the Beijing Astronomical Observatory, Chinese Academy of Sciences (now the headquarter of the National Astronomical Observatories, Chinese Academy of Sciences) in 1971, when China’s satellite-industry was booming. CSGD covers the observational data (observations of the sunspots, solar flares, solar radio bursts, ionospheric storm and geomagnetic storm) from a couple of domestic observatories and the forecast data. The compiler of CSGD still keeps the data exchange with other institutes worldwide. The type of the dataset includes texts, tables, figures and so on. Up to now, we have electronized all the historic archives, making them easily accessible to people who are interested in them.
Animal science research is important in relation to our understanding of animals, their function and performance, and their relationships with their social and physical environments. Animal science research covers a wide range of disciplines and so can lead to the use of a variety of experimental techniques on animals for many different purposes. This has the potential to lead to a multitude of diverse ethical issues. Members of the British Society of Animal Science and authors of papers submitted to the Society for publication come from countries around the world and therefore are subject to differences in legislative requirements and recommendations regarding animal experimentation. These legal requirements, along with the ethical implications of the research must be fully considered before any experimental work is undertaken.
UK legislation dictates that all pigs shall have access to straw or other material or object suitable to satisfy their behavioural needs (Welfare of Livestock Regulations, 1994). However, it is unknown how much straw must be provided to be behaviourally rewarding, and whether pigs’ prior experience of straw can impact upon their subsequent behavioural needs. Therefore, the aim of the current experiment was to investigate these issues by exposing pigs which did, or did not, have prior experience of straw to four levels of straw bed depth.
Providing environmental enrichment to farmed animals such as pigs is very important to safeguard their welfare. Current legislation specifies that all pigs must have permanent access to a sufficient quantity of material to enable proper investigation and manipulation activities. Straw has always been regarded as a functional form of enrichment for pigs, but can be difficult to use in slatted housing systems. Alternative enrichment objects might be acceptable substitutes, provided they are designed according to characteristics which pigs find important (Van de Weerd et al., 2003), as pigs may lose interest in simple devices. Most enrichment studies have focussed on immediate effects on behaviour, but it is also important to find out whether there are critical periods where providing enrichment will have effects later in life. The aim of the present study was to investigate whether early life enrichment had an effect on the behavioural development of pigs. To assess this, pigs were tested on an Elevated Plus Maze (EPM) at 10 weeks of age. The EPM is a well-validated anxiety model in rodents, which has more recently been used in pigs. It provides a way to separate fear of novelty (avoidance of open arms) and activity-related elements (entries into closed arms) (Anderson et al., 2000).
Legislation in the United Kingdom states that all pigs should have access to straw or other material or object suitable to satisfy their behavioural needs (Welfare of Livestock Regulations, 1994). However, the use of straw bedding has not been universally adopted as its use is incompatible with housing systems which contain perforated flooring, and 76% of pig producers in the UK currently employ fully- or part-slatted finishing housing systems. The aim of this study was to investigate whether different lengths of chopped straw would achieve enhancements in pig welfare, by exploring the possibility that small quantities of chopped straw, in preference to unchopped straw, could constitute adequate provision in part- and fully-slatted systems, thus avoiding the blockage of perforated flooring.
Previous research into free-farrowing systems for pigs has found that although sow welfare is better than in crated systems, piglet mortality levels are often unacceptably high. Whilst on-going research programmes are investigating methods to address this problem, the effect of alternative farrowing systems on piglet behaviour and welfare post-weaning is largely unknown. A recent study found that the increased social contact between piglets reared outdoors prior to weaning resulted in welfare benefits post-weaning (Cox and Cooper, 1999). The aim of this experiment was to investigate whether offering different degrees of social contact in an indoor community-lactation system would confer similar enhancements to piglet welfare post-weaning.
The general well-being of growing pigs is known to be affected by both the quantity/quality of stockperson input invested and the complexity of their housing environment (Pearce et. al., 1989). However, the nature of the interactions which exist between these two factors is still largely unknown. The aim of this experiment was to investigate the separate and interactive effects of handling and environmental enrichment on the welfare and performance of growing pigs.
Nose ringing is widely used in conventional outdoor pig production as the only reliable method of preventing sows destroying pasture by rooting (Edwards et al., 1998), but is prohibited by some organic sector bodies as it inhibits the sows’ behaviour. Some organic producers use a rotation policy in which the sows are moved to fresh pasture about three times a year, after green cover has been destroyed. As well as limiting nutrient leaching, frequent movement also limits parasite build-up in a system which prohibits the routine use of anthelmintics. However, it has a high labour demand. An alternative strategy is to maintain the sows on a larger area for the whole year. This abstract presents initial data on comparison of the two systems regarding annual pattern of pasture damage by sows.
The excretory behaviour of outdoor lactating sows has important implications for sow and piglet health, especially in organic systems, where use of anthelmintics and other medication is restricted. It is also important in determining the environmental impact of the system. If foraging and excretion are spatially separated this limits risk of parasite infection, but may lead to nutrient “hotspot” formation with potential for leaching and poor nutrient cycling to subsequent crops. Where nose-ringing of organic sows is not permitted by the certification scheme, pasture will be destroyed by foraging activity, further promoting nutrient losses. This study aimed to investigate the spatial distribution of excretory behaviour and patterns of pasture loss during the period from farrowing to weaning.
This paper provides a contextual summary of a diachronic analysis of ceramic vessels and hunter-gatherer societies from the final Pleistocene to the later Holocene in a remote corner of the Vitim Basin in Eastern Siberia. An integrated programme of ceramic analysis, raw materials survey, and archaeological investigation is drawn into new models of group mobility and social behaviour. The results challenge widespread assumptions about the relationship between ceramics, sedentarisation, and social complexity. Evidence of these transformations, though potentially identifiable in the archaeological record, could not be associated with the adoption of pottery.
Methanesulfonate was investigated as a potential contributor to the sulfur budget, based on analysis of a firn core from Collins Ice Cap, King George Island, Antarctica (62°10′ S, 58°50′ W). The anion was found to be present at a mean concentration of 0.17 μeq L−1, with a maximum of 0.73 μeq L−1. Dating based on the δ18O profile suggests that the principal peaks of methanesulfonate are associated with snow deposited in summer and autumn. A careful examination of MSA, SO42− and nssSO42− profiles indicates that two of the three peaks in the MSA profile may result mainly from migration and relocation of MSA. The mechanism responsible for this might be similar to that for deep cores from other Antarctic glaciers, supporting the migration hypothesis proposed by prior researchers and extending it to near-temperate ice. Due to the post-depositional modification, the main part of the MSA profile of the firn is no longer indicative of the seasonal pattern of MSA in the atmosphere, and the basis for calculation of the MSA/nssSO42− ratio should be changed. The MSA/nssS042 ratio obtained by a new computation is 0.22, 10% higher than that ignoring the effect of MSA migration.