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The morphology of englacial drainage networks and their temporal evolution are poorly characterised, particularly within cold ice masses. At present, direct observations of englacial channels are restricted in both spatial and temporal resolution. Through novel use of a terrestrial laser scanning (TLS) system, the interior geometry of an englacial channel in Austre Brøggerbreen, Svalbard, was reconstructed and mapped. Twenty-eight laser scan surveys were conducted in March 2016, capturing the glacier surface around a moulin entrance and the uppermost 122 m reach of the adjoining conduit. The resulting point clouds provide detailed 3-D visualisation of the channel with point accuracy of 6.54 mm, despite low (<60%) overall laser returns as a result of the physical and optical properties of the clean ice, snow, hoar frost and sediment surfaces forming the conduit interior. These point clouds are used to map the conduit morphology, enabling extraction of millimetre-to-centimetre scale geometric measurements. The conduit meanders at a depth of 48 m, with a sinuosity of 2.7, exhibiting teardrop shaped cross-section morphology. This improvement upon traditional surveying techniques demonstrates the potential of TLS as an investigative tool to elucidate the nature of glacier hydrological networks, through reconstruction of channel geometry and wall composition.
Out of hours, there is only one on-site junior doctor. First year psychiatry trainees (CT1s) and GP trainees may have no prior experience in psychiatry. On-call shifts are therefore potentially daunting for new trainees.
Expand the resources available for trainees when on-call.
We issued questionnaires to CT1s asking if they would have appreciated more information about on-call scenarios and in what format.
Based on the questionnaire results we implemented some changes. These were:
– a printed “pocket-guide” summarising common on-call scenarios;
– a training video on common on-call scenarios.
The handout was given to new trainees in February 2016 and in August 2016. The video was shown to new trainees in August 2016. Trainees provided feedback on the resources.
Of 24 CT1s, 15 (63%) were “neutral” or “disagreed” that they had felt prepared for on-calls.
CT1s wanted additional resources, especially a paper handout or phone download.
Feedback on the “pocket-guide” from trainees in February 2016 (n = 8) was positive (62.5% reported increased confidence in on-call situations). Feedback is also being collected from trainees who received the guide in August 2016.
Trainees in August 2016 (n = 36) liked the video – no trainees “disagreed” with statements asking if the video had been useful.
The video improved the confidence of trainees about on-call situations by an average of 2.8 points.
We have expanded available resources relating to on-calls and improved confidence. Further improvements would include making resources more easily available in downloadable formats.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Impetigo is common in remote Indigenous children of northern Australia, with the primary driver in this context being Streptococcus pyogenes [or group A Streptococcus (GAS)]. To reduce the high burden of impetigo, the transmission dynamics of GAS must be more clearly elucidated. We performed whole genome sequencing on 31 GAS isolates collected in a single community from children in 11 households with ⩾2 GAS-infected children. We aimed to determine whether transmission was occurring principally within households or across the community. The 31 isolates were represented by nine multilocus sequence types and isolates within each sequence type differed from one another by only 0–3 single nucleotide polymorphisms. There was evidence of extensive transmission both within households and across the community. Our findings suggest that strategies to reduce the burden of impetigo in this setting will need to extend beyond individual households, and incorporate multi-faceted, community-wide approaches.
Although the incidence of invasive group A streptococcal disease in northern Australia is very high, little is known of the regional epidemiology and molecular characteristics. We conducted a case series of Northern Territory residents reported between 2011 and 2013 with Streptococcus pyogenes isolates from a normally sterile site. Of the 128 reported episodes, the incidence was disproportionately high in the Indigenous population at 69·7/100 000 compared to 8·8/100 000 in the non-Indigenous population. Novel to the Northern Territory is the extremely high incidence in haemodialysis patients of 2205·9/100 000 population; and for whom targeted infection control measures could prevent transmission. The incidences in the tropical north and semi-arid Central Australian regions were similar. Case fatality was 8% (10/128) and streptococcal toxic shock syndrome occurred in 14 (11%) episodes. Molecular typing of 82 isolates identified 28 emm types, of which 63 (77%) were represented by four emm clusters. Typing confirmed transmission between infant twins. While the diverse range of emm types presents a challenge for effective coverage by vaccine formulations, the limited number of emm clusters raises optimism should cluster-specific cross-protection prove efficacious. Further studies are required to determine effectiveness of chemoprophylaxis for contacts and to inform public health response.
Mentalizing deficits are a hallmark of the autism spectrum condition (ASC) and a potential endophenotype for atypical social cognition in ASC. Differences in performance and neural activation on the ‘Reading the Mind in the Eyes’ task (the Eyes task) have been identified in individuals with ASC in previous studies.
Performance on the Eyes task along with the associated neural activation was examined in adolescents with ASC (n = 50), their unaffected siblings (n = 40) and typically developing controls (n = 40). Based on prior literature that males and females with ASC display different cognitive and associated neural characteristics, analyses were stratified by sex. Three strategies were applied to test for endophenotypes at the level of neural activation: (1) identifying and locating conjunctions of ASC–control and sibling–control differences; (2) examining whether the sibling group is comparable to the ASC or intermediate between the ASC and control groups; and (3) examining spatial overlaps between ASC–control and sibling–control differences across multiple thresholds.
Impaired behavioural performance on the Eyes task was observed in males with ASC compared to controls, but only at trend level in females; and no difference in performance was identified between sibling and same-sex control groups in both sexes. Neural activation showed a substantial endophenotype effect in the female groups but this was only modest in the male groups.
Behavioural impairment on complex emotion recognition associated with mental state attribution is a phenotypic, rather than an endophenotypic, marker of ASC. However, the neural response during the Eyes task is a potential endophenotypic marker for ASC, particularly in females.
Phenotypic plasticity is a ubiquitous phenomenon in nature, and provides a basis for trait-mediated indirect interactions (TMIIs) among species in ecological communities. Since trait-mediated indirect effects (TMIEs) are replete across a wide range of ecosystems, it is becoming increasingly apparent that phenotypic plasticity in response to interacting species can play an important role in determining community organization and dynamics. Below we highlight the major findings of community consequences of TMIIs in this volume.
TMIIs are common and can determine trophic structure in marine pelagic and insect host–parasitoid systems, both of which have been little explored (Chapters 3 and 4).
TMIEs in prey–predator systems should be taken into consideration in terms of non-trophic links (Chapter 2), size- and age-structure of a population (Chapter 5) and density-dependence (Chapter 6).
Herbivore-caused phenotypic plasticity and/or genetic variations of plants have significant, indirect impacts on diversity and abundance of predators, and prey–predator interactions by bottom-up cascading effects (Chapters 7 and 9).
Community ecology is experiencing a resurgence, driven in part by its central importance in addressing critical applied problems, ranging from the control of pest and invasive species, to the wise harvest of natural resources, to projecting the impact of global climate change. A fundamental tenet of community ecology is that species do not exist in isolation: they are directly, and more importantly, indirectly interconnected with myriad other species. The essential ‘glue’ that holds communities together and that makes them more than the haphazard sum of individual species is the nexus of indirect interactions among three or more species that emerges from direct interactions such as predation, competition and mutualism between pairs of species. The recognition of indirect effects has triggered a rapid growth of empirical and theoretical research that aims to predict community-level dynamics under different contexts.
Indirect effects occur when the impacts of one species on another are influenced by one or more intermediate species. Indirect effects are diverse, but can be classified broadly as either (1) density-mediated or (2) trait-mediated. Density-mediated indirect effects (DMIEs) result from numerical responses of species to each other. For instance, a fox may kill rabbits, reducing rabbit population size, and so relaxing herbivory upon herbaceous plants. Hence, the fox’s indirect effect on plants is mediated by density changes in rabbits; this is known as a trophic cascade. DMIEs, such as depicted by this trophic cascade, and other mechanisms such as apparent competition between prey mediated by the numerical response of a shared predator, have been well studied and have contributed to our understanding of community organization and ecosystem functioning in both terrestrial and aquatic systems (Holt and Lawton 1994; Polis et al. 2000; Terborgh and Estes 2010). However, the fox may not only kill rabbits, it may alter their behaviour and other traits. For instance, rabbits may hide more in the presence of foxes and so have less opportunity to feed on herbs. This indirect effect of the fox upon the plants could be strong, even though rabbit abundance remains high in the presence of foxes. In this case, it is a change in a rabbit’s trait – altered behaviour to avoid predation – that determines the outcome of the predator–prey direct interaction and the nature of the indirect effect of foxes on plants.
Previous studies have suggested that motivational aspects of executive functioning, which may be disrupted in schizophrenia patients with negative symptoms, are mediated in part by the striatum. Negative symptoms have been linked to impaired recruitment of both the striatum and the dorsolateral prefrontal cortex (DLPFC). Here we tested the hypothesis that negative symptoms are associated primarily with striatal dysfunction, using functional magnetic resonance imaging (fMRI).
Working-memory load-dependent activation and gray matter volumes of the striatum and DLPFC were measured using a region-of-interest (ROI) approach, in 147 schizophrenia patients and 160 healthy controls. In addition to testing for a linear relationships between striatal function and negative symptoms, we chose a second, categorical analytic strategy in which we compared three demographically and behaviorally matched subgroups: patients with a high burden of negative symptoms, patients with minimal negative symptoms, and healthy subjects.
There were no differences in striatal response magnitudes between schizophrenia patients and healthy controls, but right DLPFC activity was higher in patients than in controls. Negative symptoms were inversely associated with striatal, but not DLPFC, activity. In addition, patients with a high burden of negative symptoms exhibited significantly lower bilateral striatal, but not DLPFC, activation than schizophrenia patients with minimal negative symptoms. Working memory performance, antipsychotic exposure and changes in gray matter volumes did not account for these differences.
These data provide further evidence for a robust association between negative symptoms and diminished striatal activity. Future work will determine whether low striatal activity in schizophrenia patients could serve as a reliable biomarker for negative symptoms.
Detectable allelic variation at the Gpi-1 loci on the short arms of the homoeologous group 1 chromsomes in wheat is not common. However, a variant null allele at the Gpi-D1 locus is present in some stocks of Chinese Spring. This has allowed the locus to be mapped between the ω-gliadin locus carried distally on the short arm of chromosome 1D, Gli-D1 (34·5%) and the high-molecular-weight glutenin subunit locus carried near the centromere on the long arm, Glu-D1 (36·2%). The origin of this isoenzyme polymorphism in Chinese Spring stocks is described and its potential significance is discussed in relation to quantitative analysis of aneuploids, alien chromosome addition and substitution lines and intervarietal chromosome substitution lines involving Chinese Spring.
Recent work suggests that heavy use of cannabis is associated with an increased risk of schizophrenia-like psychosis. However, there is a dearth of experimental studies of the effects of the constituents of cannabis, such as Δ9-tetrahydrocannabinol (THC). In a study of intravenous (i.v.) synthetic THC in healthy humans, we aimed to study the relationship of the psychotic symptoms induced by THC to the consequent anxiety and neuropsychological impairment.
Twenty-two healthy adult males aged 28±6 years (mean±s.d.) participated in experimental sessions in which i.v. THC (2.5 mg) was administered under double-blind, placebo-controlled conditions. Self-rated and investigator-rated measurements of mood and psychosis [the University of Wales Institute of Science and Technology Mood Adjective Checklist (UMACL), the Positive and Negative Syndrome Scale (PANSS) and the Community Assessment of Psychic Experiences (CAPE)] were made at baseline and at 30, 80 and 120 min post-injection. Participants also completed a series of neuropsychological tests [the Rey Auditory Verbal Learning Task (RAVLT), Digit Span, Verbal Fluency and the Baddeley Reasoning Task] within 45 min of injection.
THC-induced positive psychotic symptoms, and participant- and investigator-rated measurements of these were highly correlated. Participants showed an increase in anxiety ratings but there was no relationship between either self- or investigator-rated positive psychotic symptoms and anxiety. THC also impaired neuropsychological performance but once again there was no relationship between THC-induced positive psychotic symptoms and deficits in working memory/executive function.
These findings confirm that THC can induce a transient, acute psychotic reaction in psychiatrically well individuals. The extent of the psychotic reaction was not related to the degree of anxiety or cognitive impairment.
We have identified and partially sequenced 8 ABC transporters from an EST dataset of Sarcoptes scabiei var. hominis, the causative agent of scabies. Analysis confirmed that most of the known ABC subfamilies are represented in the EST dataset including several members of the multidrug resistance protein subfamily (ABC-C). Although P-glycoprotein (ABC-B) sequences were not found in the EST dataset, a partial P-glycoprotein sequence was subsequently obtained using a degenerate PCR strategy and library screening. Thus a total of 9 potential S. scabiei ABC transporters representing the subfamilies A, B, C, E, F and H have been identified. Ivermectin is currently used in the treatment of hyper-infested (crusted) scabies, and has also been identified as a potentially effective acaricide for mass treatment programmes in scabies-endemic communities. The observation of clinical and in vitro ivermectin resistance in 2 crusted scabies patients who received multiple treatments has raised serious concerns regarding the sustainability of such programmes. One possible mechanism for ivermectin resistance is through ABC transporters such as P-glycoprotein. This work forms an important foundation for further studies to elucidate the potential role of ABC transporters in ivermectin resistance of S. scabiei.
Giardiasis surveillance data as well as drinking water, socioeconomic and land-use data were used in spatial regression models to investigate determinants of the geographic distribution of endemic giardiasis in southern Ontario. Higher giardiasis rates were observed in areas using surface water [rate ratio (RR) 2·36, 95% CI 1·38–4·05] and in rural areas (RR 1·79, 95% CI 1·32–2·37). Lower rates were observed in areas using filtered water (RR 0·55, 95% CI 0·42–0·94) and in those with high median income (RR 0·62, 95% CI 0·42–0·92). Chlorination of drinking water, cattle density and intensity of manure application on farmland were not significant determinants. The study shows that waterborne transmission plays an important role in giardiasis distribution in southern Ontario and that well-collected routine surveillance data could be useful for investigation of disease determinants and identification of high-risk communities. This information is useful in guiding decisions on control strategies.
Many people take dietary supplements, but information on characteristics associated with their use is lacking. The relationship between lifestyle behaviours, morbidity and use of dietary supplements has not been examined and earlier studies have limited applicability to a general population. These issues were addressed in the current study. Information was obtained by postal questionnaire sent to a sample of the general population. The questionnaire was completed by 70·5% of the sample (15465 from a total sample of 21923), with at least one-third (35·5%) taking dietary supplements. In adjusted analyses, supplement users were more likely to be women, white, home-owners, non-smokers and physically active. Use of vitamin, mineral and/or antioxidant supplements was associated with eating more fruits and vegetables, and taking fish-oil supplements was associated with eating oil-rich fish. A history of CVD or risk factors for CVD reduced the risk of taking vitamins, minerals and/or antioxidants or fish-oil supplements. Those reporting musculoskeletal disorders such as arthritis were more likely to take fish-oil supplements For the first time, we have shown that dietary supplement use is related to different types of morbidity. In particular, people at risk of primary or secondary CVD seem less likely to use dietary supplements, despite possible benefits shown in clinical trials. Public health organisations need to develop guidelines for the public and health professionals regarding the uncontrolled use of dietary supplements in the community.
A membrane of multiwall carbon nanotubes embedded in a silicon nitride matrix was fabricated for use in studying fluid mechanics on the nanometer scale. Characterization by fluorescent tracer diffusion and scanning electron microscopy suggests that the membrane is void-free near the silicon substrate on which it rests, implying that the hollow core of the nanotube is the only conduction path for molecular transport. Assuming Knudsen diffusion through this nanotube membrane, a maximum helium transport rate (for a pressure drop of 1 atm) of 0.25 cc/sec is predicted. Helium flow measurements of a nanoporous silicon nitride membrane, fabricated by sacrificial removal of carbon, give a flow rate greater than 1×10-6 cc/sec. For viscous, laminar flow conditions, water is estimated to flow across the nanotube membrane (under a 1 atm pressure drop) at up to 2.8×10-5 cc/sec (1.7 μL/min).
The Foot and Mouth Disease (FMD) epidemic of 2001 clearly illustrated the fragility of the UK's farm animal genetic resources. In particular, millions of sheep were killed by the disease and by the ‘stamping out’ policy chosen for disease control. Loss of genetic resources was not evenly spread throughout the UK, nor throughout the many different sheep breeds that are native to the UK and for which the UK has a formal responsibility for protection to the United Nations. In fact, the FMD epidemic demonstrated for the first time that sheep breeds comprising large numbers of individuals which are commercially farmed, can nevertheless be at considerable risk of extinction. The breeds most affected were those restricted to geographical regions of the UK into which the FMD spread. These regionally important breeds are adapted to their particular regional environments, represent an important living heritage for the UK and are a key component in sustaining the rural economies of sheep farming communities.
The events of 2001 provided clear proof that there are two components of the UK's farm animal genetic resources demanding protection. One component is already recognised as a priority and is composed of the numerically rare breeds of all domesticated species: these are already under the protection of the Rare Breeds Survival Trust (RBST). The second component has not previously been recognised as a priority for protection. The FMD crisis proved that sheep breeds could exist as large numbers of individuals, but nevertheless face extinction due to their regional location. Urgent attention must be focussed on our Heritage Breeds of sheep. The UK has one of the greatest number of native sheep breeds of any country in the world. The Heritage Breeds provide potentially valuable genetic resources for environmental, low-input farming systems.
Heritage GeneBank was founded during the FMD epidemic specifically to protect sheep breeds at threat of extinction from the disease. A group of academic research scientists established a genetic salvage programme: collecting semen and embryos for protection in a gene bank. Germplasm from seven breeds is in long-term storage. Following the crisis, the scientists involved in the gene bank made a commitment to continue their conservation work in recognition that the Heritage Breeds of sheep in the UK continue to require protection.
This paper describes: (1) the work of Heritage GeneBank (HGB); (2) the threefold mission of The Sheep Trust, the new national charity that evolved from HGB (http://www.thesheeptrust.org); and (3) the ongoing urgent need for conservation of the UK's Heritage Breeds of sheep threatened by genetic erosion.