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This paper considers the timing and mechanisms of deforestation in the Western Isles of Scotland, focusing in particular on the landscape around the Calanais stone circles, one of the best preserved late Neolithic/early Bronze Age monumental landscapes in north-west Europe. We present new archaeological and palaeoenvironmental evidence from a soil and peat sequence at the site of Aird Calanais, which spans the main period of use of the Calanais circles. We then draw on a new synthesis of archaeobotanical and palynological evidence from across the Western Isles and a review of comparable data from the wider North Atlantic zone, before assessing the role of early farming communities in clearing the wooded landscapes of the region. Pollen and radiocarbon dating at the site of Aird Calanais reveal that a layer of birch branches, dating to the late Neolithic (2912–2881 cal bc), was contemporaneous with a decline in woodland at the site, as well as with the major phase of Neolithic activity at the Calanais stone circle complex. However, our synthesis of the pollen and plant macrofossil evidence from across the Western Isles suggests that the picture across these islands was altogether more complex: woodlands declined both before, as well as during, the Neolithic and deciduous woodlands remained sufficiently abundant for Neolithic fuel procurement. Finally, we consider the implications of the results for understanding the interactions between first farmers and woodlands in the wider North Atlantic region.
Bovine tuberculosis (bTB) is an important disease of cattle caused by infection with Mycobacterium bovis, a pathogen that may be extremely difficult to eradicate in the presence of a true wildlife reservoir. Our objective was to identify and review relevant literature and provide a succinct summary of current knowledge of risk factors for transmission of infection of cattle. Search strings were developed to identify publications from electronic databases to February 2015. Abstracts of 4255 papers identified were reviewed by three reviewers to determine whether the entire article was likely to contain relevant information. Risk factors could be broadly grouped as follows: animal (including nutrition and genetics), herd (including bTB and testing history), environment, wildlife and social factors. Many risk factors are inter-related and study designs often do not enable differentiation between cause and consequence of infection. Despite differences in study design and location, some risk factors are consistently identified, e.g. herd size, bTB history, presence of infected wildlife, whereas the evidence for others is less consistent and coherent, e.g. nutrition, local cattle movements. We have identified knowledge gaps where further research may result in an improved understanding of bTB transmission dynamics. The application of targeted, multifactorial disease control regimens that address a range of risk factors simultaneously is likely to be a key to effective, evidence-informed control strategies.
The incidence of recreational water-associated outbreaks in the United States has significantly increased, driven, at least in part, by outbreaks both caused by Cryptosporidium and associated with treated recreational water venues. Because of the parasite's extreme chlorine tolerance, transmission can occur even in well-maintained treated recreational water venues (e.g. pools) and a focal cryptosporidiosis outbreak can evolve into a community-wide outbreak associated with multiple recreational water venues and settings (e.g. childcare facilities). In August 2004 in Auglaize County, Ohio, multiple cryptosporidiosis cases were identified and anecdotally linked to pool A. Within 5 days of the first case being reported, pool A was hyperchlorinated to achieve 99·9% Cryptosporidium inactivition. A case-control study was launched to epidemiologically ascertain the outbreak source 11 days later. A total of 150 confirmed and probable cases were identified; the temporal distribution of illness onset was peaked, indicating a point-source exposure. Cryptosporidiosis was significantly associated with swimming in pool A (matched odds ratio 121·7, 95% confidence interval 27·4–∞) but not with another venue or setting. The findings of this investigation suggest that proactive implementation of control measures, when increased Cryptosporidium transmission is detected but before an outbreak source is epidemiologically ascertained, might prevent a focal cryptosporidiosis outbreak from evolving into a community-wide outbreak.
The 2013 multistate outbreaks contributed to the largest annual number of reported US cases of cyclosporiasis since 1997. In this paper we focus on investigations in Texas. We defined an outbreak-associated case as laboratory-confirmed cyclosporiasis in a person with illness onset between 1 June and 31 August 2013, with no history of international travel in the previous 14 days. Epidemiological, environmental, and traceback investigations were conducted. Of the 631 cases reported in the multistate outbreaks, Texas reported the greatest number of cases, 270 (43%). More than 70 clusters were identified in Texas, four of which were further investigated. One restaurant-associated cluster of 25 case-patients was selected for a case-control study. Consumption of cilantro was most strongly associated with illness on meal date-matched analysis (matched odds ratio 19·8, 95% confidence interval 4·0–∞). All case-patients in the other three clusters investigated also ate cilantro. Traceback investigations converged on three suppliers in Puebla, Mexico. Cilantro was the vehicle of infection in the four clusters investigated; the temporal association of these clusters with the large overall increase in cyclosporiasis cases in Texas suggests cilantro was the vehicle of infection for many other cases. However, the paucity of epidemiological and traceback information does not allow for a conclusive determination; moreover, molecular epidemiological tools for cyclosporiasis that could provide more definitive linkage between case clusters are needed.
US public health laboratories began reporting Escherichia coli O157 isolates to CDC in 1996. We describe temporal and geographical patterns of isolates reported from 1996 to 2011 and demographics of persons whose specimens yielded isolates. We calculated annual E. coli O157 isolation rates/100 000 persons by patient's state of residence, county of residence, age, and sex using census data. The average annual isolation rate was 0·84. The average isolation rate in northern states (1·52) was higher than in southern states (0·43). Counties with ⩾76% rural population had a lower isolation rate (0·67) than counties with ⩽25%, 26–50%, and 51–75% rural populations (0·81, 0·92, and 0·81, respectively). The highest isolation rate (3·19) was in children aged 1–4 years. Infections were seasonal with 49% of isolates collected during July to September. Research into reasons for higher incidence in northern states and for seasonality could guide strategies to prevent illnesses.
In August 2008 an outbreak of Salmonella Typhimurium DT104 occurred in South West London. Sixteen cases were identified with a particular multilocus variable number tandem repeat analysis (MLVA) pattern. In a matched case-control study 14 primary cases were included. These were defined as individuals with gastrointestinal symptoms and Salmonella Typhimurium DT104 isolated from a stool specimen, with a characteristic antibiotic resistance profile and MLVA pattern, and diagnosed in a local laboratory. Four controls per case were matched on age, gender and area of residence. Cases were 26 times more likely than controls to have eaten beef biltong, a South African speciality meat product (odds ratio 25·83, 95% confidence interval 4·92–135·59, P < 0·01). Although environmental investigation failed to identify Salmonella in the food product we conclude that beef biltong consumption led to this outbreak. This conclusion has importance in informing the ongoing risk assessment relating to uncontrolled foodstuffs.
In this work, we report on the use ion of implantation to synthesize resistive memory oxides. The surface of copper thin films was converted to copper oxide using oxygen implantation. Devices fabricated from the copper oxide (CuxO) layers exhibited unipolar switching behavior without the need for a forming voltage. Technology scaling was demonstrated by oxygen implanting copper damascene vias. Unipolar switching was observed in via-based devices down to 48 nm. The current-voltage data of devices scaled from 100 μm to 48 nm suggests that the RESET transition is related to localized Joule heating. Tantalum oxide (TaxOy) was also created by oxygen implantation but exhibited bipolar resistive switching. Analysis of the conduction suggests that the difference between the two resistance states in these devices is largely due to a lowering of the Pt-TaxOy Schottky barrier.
In nano-crystalline ceramics, the grain boundary volume fraction is large relative to that in micro-crystalline materials and can therefore become the dominant factor in determining its electrical, chemical, and mechanical properties. Reduced enthalpies of defect formation for nanocrystalline Pr0.1Ce0.9O2-δ , derived from thermo-gravimetric and impedance spectroscopy measurements, are reported. In addition, observations of cerium carbonate formation on nanoporous materials and implications for thermo-gravimetric analysis are discussed.
Progress in achieving improved performance in the generation and utilization of hydrogen depends on our ability to identify materials with optimized electrical and (photo)- electrochemical performance. Given their high volume fraction of interfaces, high chemical stability and versatility (ionic, electronic, optical property control), nanocrystalline electroceramic materials are of growing interest for advanced energy conversion and storage technologies. As grain size decreases towards the Debye length and grain boundaries come in closer proximity, space charge properties begin to dominate, resulting in modified charge transport. Through systematic variation of grain boundary properties by heterogeneous indiffusion of cations, the electronic and ionic carrier profiles in the space charge region may be altered. The relationships between space charge potential and defect profiles in the space charge regions are quantitatively analyzed, and implications for nano-ionic materials in thin film solid oxide fuel cells are discussed. From the standpoint of photoelectrochemical water splitting for hydrogen generation, optimizing the band gap, band alignments, and transport properties while retaining stability has remained a challenging objective. Novel nanocrystalline composite structures are discussed which exhibit features amenable to optimization of required properties and electrical measurements to determine key transport properties of titanium dioxide nanopowder, a photoanode material are introduced.
In this paper, we describe improvements to the in situ cosmogenic radiocarbon extraction system at SUERC made since 2004, highlighting the factors that potentially control the reduction of analytical variability. We also present new results on system blanks and of measurements of in situ14C in shielded quartz and a surface quartz sample used at the University of Arizona as an in situ14C standard (PP-4). The SUERC in situ14C extraction system was built in 2001 and is based on a combustion technique following the design of the extraction system at the University of Arizona. Our preliminary results suggest that the continuous running of the extraction system and the monitoring of gas collecting time and of the temperature of the cryogenic traps used in the gas cleaning steps are key to maintaining low and stable system blanks. Our latest average system blank is 2.02 ± 0.23 x 10514C atoms. This is consistent with those recently published by the University of Arizona and ETH in situ14C labs. Measurements of in situ14C concentrations in sample PP-4 yield an average of 3.82 ± 0.23 x 105 atoms g–1 quartz, again consistent with published values.
Sensory traits, such as juiciness and tenderness, are known to be important to the consumer and thus will influence their consumption of meat, specifically beef. These traits are difficult to measure and often require the use of taste panels to assess the complex parameters involved in the eating experience. Such panels are potentially a large source of measurement error, which may reduce the effectiveness of breeding programmes based on the data they generate. The aim of this study was to assess the quality of such taste panel-derived sensory traits as well as calculating genetic parameters and residual correlations for these traits along with a further set of traditional carcass quality traits. The study examined a sample of 443 Aberdeen Angus-cross animals collected from 14 breeder–finisher farms throughout Scotland. To assess the quality of the taste panel measurements, three consistency statistics were calculated: (i) panel-member consistency, i.e. the extent to which an individual panel member varied in their scoring for a given trait over the period of the experiment; (ii) repeatability, i.e. the consistency with which an individual panel member was able to score a trait on repeated samples from the same animal; and (iii) reproducibility, i.e. the extent to which taste panel members agreed with each other when scoring a trait. These consistency statistics were moderately high, particularly for panel-member consistency and reproducibility, with values ranging from 0.48 to 0.81 and 0.43 to 0.73 respectively. Estimated heritabilities were low for most of the sensory taste-panel-evaluated traits where the maximum value was 0.16 for overall liking. Residual correlations were high between many of the closely related sensory traits, although few significant correlations were found between the carcass quality data and meat quality traits.
We investigated an outbreak of Shigella sonnei infections in Denmark and Australia associated with imported baby corn from one packing shed in Thailand. We reviewed nationwide surveillance and undertook case finding, food trace-back and microbiological investigation of human, food and environmental samples. A recall of baby corn and sugar snaps was based on descriptive epidemiological evidence. In Denmark, we undertook a retrospective cohort study in one workplace. In total, 215 cases were laboratory-confirmed in Denmark, and 12 in Australia. In a multivariable analysis, baby corn was the only independent risk factor. Antibiotic resistance and PFGE outbreak profiles in Denmark and Australia were indistinguishable, linking the outbreaks. Although we did not detect S. sonnei in baby corn, we isolated high levels of other enteric pathogens. We identified a packing shed in Thailand that supplied baby corn to Denmark and Australia, and uncovered unhygienic practices in the supply chain. This outbreak highlights the importance of international communication in linking outbreaks and pinpointing the source.
We have been developing noble metal nanoparticles and nanocomposites for large scale application to glass surfaces. The novel functionality of the nanocomposites is attributed to the properties of both the metal nanoparticles and host matrix. Here a single-process route to nanocomposite thin films by spray deposition technique has been investigated. Preformed gold nanoparticles have been incorporated into several different transition metal oxides (TiO2, SnO2, ZnO). The nanocomposite films showed intense coloration due to the surface plasmon resonance effects of gold nanoparticles embedded in the host matrix. The gold nanoparticles were found well embedded into the host metal oxides homogeneously. This film deposition method can easily be scaled up and is compatible with current industrial on-line processes.
Footrot is a highly contagious bacterial disease of sheep affecting the interdigital skin and surrounding soft and hard horn of a hoof, often resulting in severe lameness. This study was aimed at estimating the effect of footrot on weight gain of affected animals, and characterising the variation between animals in terms of phenotypic, environmental and genetic components. A general approach was developed describing the relationship between the disease and weight gain, defining new traits such as the maximum weight loss as a result of disease and the time after infection that this occurs. In two trials, 1267 Merino sheep were artificially challenged with footrot when 10 months old and re-infected through exposure to footrot on pasture 33 weeks later. Their feet were scored for footrot and live weights were measured approximately every 3 weeks. From data on animals that were not affected by footrot throughout each trial, normal growth curves were calculated and applied to affected animals to predict their growth had they remained healthy, so that weight loss as a result of footrot could be predicted. Animals with average footrot severity in the two trials suffered weight losses of 0.5 to 2.5 kg live weight, but most animals regained lost live weight later in the trials as footrot healed following vaccination. The estimates of the heritabilities of weight loss, adjusted for the severity of footrot, were about 0.30 and 0.15 in the experimental and natural challenge groups, respectively. Animals with higher genotypic values for weights at the start of each trial appeared to cope better with infections, in terms of lower weight losses. The time of highest footrot score and the time of maximum weight loss after infection had only very small genetic components.
Mineralogy and Remote Sensing of Rocks, Soil, Dust, and Ices
W. H. Farrand, Space Science Institute 4750 Walnut Street, # 205 Boulder, CO 80301, USA,
J. F. Bell, Cornell University, Department of Astronomy, 402 Space Sciences Building, Ithaca, NY 14853-6801, USA,
J. R. Johnson, Cold Regions Research & Engineering Laboratory Alaska Office PO Box 35170 Ft. Wainwright, AK 99703, USA,
J. L. Bishop, SETI Institute 515 N. Whisman Road Mountain View, CA 94034, USA,
R. V. Morris, NASA/JSC Cose KR, Building 31, Room 120 2101 NASA Road 1 Houston, TX 77058, USA
The Imager for Mars Pathfinder (IMP) was a mast-mounted instrument on the Mars Pathfinder (MPF) lander which landed on Mars' Ares Vallis floodplain on July 4, 1997. During the 83 sols of MPF landed operations, the IMP collected over 16 600 images. Multispectral images were collected using 12 narrowband filters at wavelengths between 400 and 1000 nm in the visible and near-infrared (VNIR) range. The IMP provided VNIR spectra of the materials surrounding the lander including rocks, bright soils, dark soils, and atmospheric observations. During the primary mission, only a single primary rock spectral class, “Gray Rock,” was recognized; since then, “Black Rock” has been identified. The Black Rock spectra have a stronger absorption at longer wavelengths than do Gray Rock spectra. A number of coated rocks have also been described, the Red and Maroon Rock classes, and perhaps indurated soils in the form of the Pink Rock class. A number of different soil types were also recognized with the primary ones being Bright Red Drift, Dark Soil, Brown Soil, and Disturbed Soil. Examination of spectral parameter plots indicated two trends which were interpreted as representing alteration products formed in at least two different environmental epochs of the Ares Vallis area. Subsequent analysis of the data and comparison with terrestrial analogs have supported the interpretation that the rock coatings provide evidence of earlier Martian environments.
Material collected during surveys of the Atlantic Frontier Margin (north-east Atlantic) in 1996, 1998, 2000 and 2002 includes ten species of the cumacean family Lampropidae belonging to three genera. A new species of the genus Hemilamprops, H. pterini, is described. Hemilamprops cristatus is partially re-illustrated from specimens sent to A.M. Norman by G.O. Sars. A key to the North Atlantic species of Hemilamprops is provided. A new species of the genus Mesolamprops, M. hartleyi, is described from the Atlantic Frontier Margin and the North Sea. The first record of Mesolamprops denticulatus from the Atlantic is reported. A key to the species of Mesolamprops is provided. Two species of the genus Platysympus were also found. A list of other lampropid species found in the Atlantic Frontier Margin is given.
Feeding regimens for horses are usually based on perceived workload (PW) together with body condition. This can lead to inappropriate energy intake and, in particular, excess weight. Therefore, a more detailed understanding of the factors influencing individual energy needs under practical field conditions would be valuable. The purpose of this study was to evaluate to what extent the variations in actual versus PW may influence the estimated energy intake required to maintain body weight (BW) in individual animals. Eight mature, experienced riding school horses, chosen at random and maintaining a constant BW, were observed in standard flat work lessons with four different instructors at an equine training college. Heart rate (HR) and the structure of the lessons were recorded. Relative workload (RW) was determined for each horse by dividing its average HR per lesson by its estimated maximum HR (HRmax). PW was estimated by each instructor for each horse using a scale of 1–5. One-way ANOVA and t-test were used to determine the differences and Spearman's and Pearson's correlations were used to determine the correlations. The mean estimated RW was 39.1% of the estimated HRmax ( ± 5.7%) and was not significantly different between instructors (P>0.05). Rider weight as a percentage of BW showed a weak but statistically significant positive correlation with mean HR (r2 = 0.14, P < 0.05). Estimated energy intake was negatively correlated with BCS (r2 = 0.65, P < 0.001) and differed significantly (P < 0.05) between light (BW = 455–532 kg) horses (mean 0.18 ± 0.04 MJ kg− 1 BW) and heavy (BW = 622–660 kg) horses (mean 0.15 ± 0.03 MJ kg− 1 BW). No difference was found in estimated energy intake between different workloads (flat work only or flat work and jumping) (P>0.05). When BW was compared with estimated energy intake, no relation was found either (P>0.05). These results suggest that the amount of energy needed to maintain BW in individual horses cannot necessarily be estimated simply on the basis of the intensity and the duration of structured exercise. Other factors including age, individual digestive and metabolic efficiency, body condition and possibly the energy utilized through non-structured activity (e.g. box walking) may need to be taken into account.