ABSTRACT
Sambar (Rusa unicolor) are the most numerous and rapidly expanding of Australia's six introduced deer species, however, there is little information about the reproductive biology of sambar deer in their natural habitat. To better predict and manage wild sambar populations in Australia it is important to understand their reproductive seasonality and rate of population growth. From results of the present study, there is reporting of field estimates of age at first breeding, reproductive lifespan, juvenile survival, adult bodyweights and fecundity to derive estimates of the current and intrinsic rates of increase for sambar in Victoria, Australia. Mean age of first reproduction was estimated to be 1.8 years, approximately 80 % of hinds calved between April and August, juvenile survival was estimated as 0.81 and age of last reproduction 12.75 years. Seasonality of reproduction is apparently compressed at 36° latitude compared to sambar at the equator indicating a response to photoperiod. Demographic data were used to estimate the current rate of growth of the Victorian population using the two stage Lotke-Euler equation and age-specific schedules of survival and fecundity in a lifetable. These estimates of r were 0.21 and 0.14, respectively, inferring annual rates of population increase of 24 % and 15 %. These data are in the context of a population which, even though there is a marked harvesting, is reportedly growing and dispersing northwards. Suggestions for how this information can inform management decisions directed at the conservation for sustainable use and/or population reduction in Australia are made.
Subject(s)
Deer/physiology , Parturition/physiology , Seasons , Aging , Animals , Environment , Female , Lactation/physiology , Male , Population Growth , Time Factors , VictoriaABSTRACT
For livestock production systems to play a positive role in global food security, the balance between their benefits and disbenefits to society must be appropriately managed. Based on the evidence provided by field-scale randomised controlled trials around the world, this debate has traditionally centred on the concept of economic-environmental trade-offs, of which existence is theoretically assured when resource allocation is perfect on the farm. Recent research conducted on commercial farms indicates, however, that the economic-environmental nexus is not nearly as straightforward in the real world, with environmental performances of enterprises often positively correlated with their economic profitability. Using high-resolution primary data from the North Wyke Farm Platform, an intensively instrumented farm-scale ruminant research facility located in southwest United Kingdom, this paper proposes a novel, information-driven approach to carry out comprehensive assessments of economic-environmental trade-offs inherent within pasture-based cattle and sheep production systems. The results of a data-mining exercise suggest that a potentially systematic interaction exists between 'soil health', ecological surroundings and livestock grazing, whereby a higher level of soil organic carbon (SOC) stock is associated with a better animal performance and less nutrient losses into watercourses, and a higher stocking density with greater botanical diversity and elevated SOC. We contend that a combination of farming system-wide trials and environmental instrumentation provides an ideal setting for enrolling scientifically sound and biologically informative metrics for agricultural sustainability, through which agricultural producers could obtain guidance to manage soils, water, pasture and livestock in an economically and environmentally acceptable manner. Priority areas for future farm-scale research to ensure long-term sustainability are also discussed.
ABSTRACT
Breast cancer is the most commonly diagnosed cancer in women with a lifetime risk of 1 in 8 in the UK. The disease is associated with considerable morbidity and mortality. The UK breast screening program has been in place for almost 30 years and has evolved with improved diagnostic imaging. The overall benefits of the screening program are subject to continued heated debate with multiple potential harms. The aim of this review is to provide the non-breast specialist health-care professional an overview of the evolution of the breast screening program, a summary of the evidence of the benefits, and a description of the harms. In addition, the diagnostic methods currently employed as well as potential future changes to the screening program and imaging techniques will be covered.
Subject(s)
Breast Neoplasms/diagnostic imaging , Mass Screening/methods , Adult , Age Factors , Aged , BRCA2 Protein/genetics , Breast Neoplasms/genetics , Breast Neoplasms/mortality , Early Detection of Cancer/adverse effects , Early Detection of Cancer/methods , False Positive Reactions , Female , Humans , Mammography , Mass Screening/psychology , Menopause , Middle Aged , Mutation , Risk Assessment , Risk Factors , Ubiquitin-Protein Ligases/genetics , Ultrasonography , United KingdomABSTRACT
OBJECTIVE: Magnetic resonance imaging (MRI) texture analysis is a method of analyzing subchondral bone alterations in osteoarthritis (OA). The objective of this study was to evaluate the association between MR texture analysis and ground-truth subchondral bone histomorphometry at the tibial plateau. DESIGN: The local research ethics committee approved the study. All subjects provided written, informed consent. This was a cross-sectional study carried out at our institution between February and August 2014. Ten participants aged 57-84 with knee OA scheduled for total knee arthroplasty (TKA) underwent pre-operative MRI of the symptomatic knee at 3T using a high spatial-resolution coronal T1 weighted sequence. Tibial plateau explants obtained at the time of TKA underwent histological preparation to allow calculation of bone volume fraction (BV.TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp) and trabecular number (Tb.N). Texture analysis was performed on the tibial subchondral bone of MRI images matched to the histological sections. Regression models were created to assess the association of texture analysis features with BV.TV, Tb.Th, Tb.Sp and Tb.N. RESULTS: MRI texture features were significantly associated with BV.TV (R2 = 0.76), Tb.Th (R2 = 0.47), Tb.Sp (R2 = 0.75) and Tb.N (R2 = 0.60, all P < 0.001). Simple gray-value histogram based texture features demonstrated the highest standardized regression coefficients for each model. CONCLUSION: MRI texture analysis features were significantly associated with ground-truth subchondral bone histomorphometry at the tibial plateau.
Subject(s)
Magnetic Resonance Imaging/methods , Menisci, Tibial/diagnostic imaging , Menisci, Tibial/pathology , Osteoarthritis, Knee/diagnostic imaging , Osteoarthritis, Knee/pathology , Aged , Aged, 80 and over , Analysis of Variance , Arthroplasty, Replacement, Knee/methods , Biopsy, Needle , Cartilage, Articular/diagnostic imaging , Cartilage, Articular/pathology , Cross-Sectional Studies , Female , Humans , Immunohistochemistry , Male , Middle Aged , Observer Variation , Osteoarthritis, Knee/surgery , Prognosis , Risk Assessment , Severity of Illness Index , Treatment Outcome , United KingdomABSTRACT
The North Wyke Farm Platform was established as a United Kingdom national capability for collaborative research, training and knowledge exchange in agro-environmental sciences. Its remit is to research agricultural productivity and ecosystem responses to different management practices for beef and sheep production in lowland grasslands. A system based on permanent pasture was implemented on three 21-ha farmlets to obtain baseline data on hydrology, nutrient cycling and productivity for 2 years. Since then two farmlets have been modified by either (i) planned reseeding with grasses that have been bred for enhanced sugar content or deep-rooting traits or (ii) sowing grass and legume mixtures to reduce nitrogen fertilizer inputs. The quantities of nutrients that enter, cycle within and leave the farmlets were evaluated with data recorded from sensor technologies coupled with more traditional field study methods. We demonstrate the potential of the farm platform approach with a case study in which we investigate the effects of the weather, field topography and farm management activity on surface runoff and associated pollutant or nutrient loss from soil. We have the opportunity to do a full nutrient cycling analysis, taking account of nutrient transformations in soil, and flows to water and losses to air. The NWFP monitoring system is unique in both scale and scope for a managed land-based capability that brings together several technologies that allow the effect of temperate grassland farming systems on soil moisture levels, runoff and associated water quality dynamics to be studied in detail. HIGHLIGHTS: Can meat production systems be developed that are productive yet minimize losses to the environment?The data are from an intensively instrumented capability, which is globally unique and topical.We use sensing technologies and surveys to show the effect of pasture renewal on nutrient losses.Platforms provide evidence of the effect of meteorology, topography and farm activity on nutrient loss.
ABSTRACT
One of the major challenges for agriculture is to understand the effects of agricultural practices on soil properties and diffuse pollution, to support practical farm-scale land management. Three conventionally managed grassland fields with similar short-term management, but different ploughing histories, were studied on a long-term research platform: the North Wyke Farm Platform. The aims were to (i) quantify the between-field and within-field spatial variation in soil properties by geostatistical analysis, (ii) understand the effects of soil condition (in terms of nitrogen, phosphorus and carbon contents) on the quality of discharge water and (iii) establish robust baseline data before the implementation of various grassland management scenarios. Although the fields sampled had experienced the same land use and similar management for at least 6 years, there were differences in their mean soil properties. They showed different patterns of soil spatial variation and different rates of diffuse nutrient losses to water. The oldest permanent pasture field had the largest soil macronutrient concentrations and the greatest diffuse nutrient losses. We show that management histories affect soil properties and diffuse losses. Potential gains in herbage yield or benefits in water quality might be achieved by characterizing every field or by area-specific management within fields (a form of precision agriculture for grasslands). Permanent pasture per se cannot be considered a mitigation measure for diffuse pollution. The between- and within-field soil spatial variation emphasizes the importance of baseline characterization and will enable the reliable identification of any effects of future management change on the Farm Platform. HIGHLIGHTS: Quantification of soil and water quality in grassland fields with contrasting management histories.Considerable spatial variation in soil properties and diffuse losses between and within fields.Contrasting management histories within and between fields strongly affected soil and water quality.Careful pasture management needed: the oldest pasture transferred the most nutrients from soil to water.
ABSTRACT
A dynamic and innovative approach to managing the blood-consuming nematode Haemonchus contortus in goats is critical to crack dependence on veterinary anthelmintics. H. contortus management strategies have been the subject of intense research for decades, and must be selected to create a tailored, individualized program for goat farms. Through the selection and combination of strategies from the Toolbox, an effective management program for H. contortus can be designed according to the unique conditions of each particular farm. This Toolbox investigates strategies including vaccines, bioactive forages, pasture/grazing management, behavioural management, natural immunity, FAMACHA, Refugia and strategic drenching, mineral/vitamin supplementation, copper Oxide Wire Particles (COWPs), breeding and selection/selecting resistant and resilient individuals, biological control and anthelmintic drugs. Barbervax(®), the ground-breaking Haemonchus vaccine developed and currently commercially available on a pilot scale for sheep, is prime for trialling in goats and would be an invaluable inclusion to this Toolbox. The specialised behaviours of goats, specifically their preferences to browse a variety of plants and accompanying physiological adaptations to the consumption of secondary compounds contained in browse, have long been unappreciated and thus overlooked as a valuable, sustainable strategy for Haemonchus management. These strategies are discussed in this review as to their value for inclusion into the 'Toolbox' currently, and the future implications of ongoing research for goat producers. Combining and manipulating strategies such as browsing behaviour, pasture management, bioactive forages and identifying and treating individual animals for haemonchosis, in addition to continuous evaluation of strategy effectiveness, is conducted using a model farm scenario. Selecting strategies from the Toolbox, with regard to their current availability, feasibility, economical cost and potential ease of implementation depending on the systems of production and their complementary nature, is the future of managing H. contortus in farmed goats internationally and maintaining the remaining efficacy of veterinary anthelmintics.
Subject(s)
Anthelmintics/therapeutic use , Goat Diseases/drug therapy , Haemonchiasis/veterinary , Animal Husbandry/trends , Animals , Anthelmintics/economics , Disease Management , Goat Diseases/economics , Goats , Haemonchiasis/drug therapy , Haemonchiasis/economics , Haemonchus , Models, TheoreticalABSTRACT
A gene regulatory network may be defined as a collection of DNA segments which interact with each other indirectly through their RNA and protein products. Such a network is said to contain a negative feedback loop if its products inhibit gene transcription, and a positive feedback loop if a gene product promotes its own production. Negative feedback loops can create oscillations in mRNA and protein levels while positive feedback loops are primarily responsible for signal amplification. It is often the case in real biological systems that both negative and positive feedback loops operate in parameter regimes that result in low copy numbers of gene products. In this paper we investigate the spatio-temporal dynamics of a single feedback loop in a eukaryotic cell. We first develop a simplified spatial stochastic model of a canonical feedback system (either positive or negative). Using a Gillespie's algorithm, we compute sample trajectories and analyse their corresponding statistics. We then derive a system of equations that describe the spatio-temporal evolution of the stochastic means. Subsequently, we examine the spatially homogeneous case and compare the results of numerical simulations with the spatially explicit case. Finally, using a combination of steady-state analysis and data clustering techniques, we explore model behaviour across a subregion of the parameter space that is difficult to access experimentally and compare the parameter landscape of our spatio-temporal and spatially-homogeneous models.
Subject(s)
Gene Regulatory Networks , Models, Genetic , Algorithms , Computer Simulation , Feedback, Physiological , Mathematical Concepts , Signal Transduction , Stochastic ProcessesABSTRACT
Mammals are coinfected by multiple pathogens that interact through unknown mechanisms. We found that helminth infection, characterized by the induction of the cytokine interleukin-4 (IL-4) and the activation of the transcription factor Stat6, reactivated murine γ-herpesvirus infection in vivo. IL-4 promoted viral replication and blocked the antiviral effects of interferon-γ (IFNγ) by inducing Stat6 binding to the promoter for an important viral transcriptional transactivator. IL-4 also reactivated human Kaposi's sarcoma-associated herpesvirus from latency in cultured cells. Exogenous IL-4 plus blockade of IFNγ reactivated latent murine γ-herpesvirus infection in vivo, suggesting a "two-signal" model for viral reactivation. Thus, chronic herpesvirus infection, a component of the mammalian virome, is regulated by the counterpoised actions of multiple cytokines on viral promoters that have evolved to sense host immune status.
Subject(s)
Gammaherpesvirinae/physiology , Herpesvirus 8, Human/physiology , Interferon-gamma/immunology , Interleukin-4/metabolism , STAT6 Transcription Factor/metabolism , Schistosoma mansoni/immunology , Schistosomiasis mansoni/immunology , Virus Activation/physiology , Animals , Gammaherpesvirinae/genetics , Gene Expression Regulation, Viral , Herpesvirus 8, Human/genetics , Humans , Interferon-gamma/pharmacology , Interleukin-4/pharmacology , Macrophages/immunology , Mice , Mice, Inbred C57BL , Nematospiroides dubius/immunology , Ovum/immunology , Promoter Regions, Genetic , Strongylida Infections/immunology , Virus Activation/drug effects , Virus Activation/genetics , Virus Latency/physiology , Virus Replication/physiologyABSTRACT
A best evidence topic in vascular surgery was written according to a structured protocol. The question addressed whether endovascular treatment improved peri-operative outcomes when compared to an open approach to restore arterial perfusion in acute mesenteric occlusive disease. Four hundred and ninety seven papers were identified using the reported search; of which 4 represented the best evidence to answer the question and are discussed. The evidence on this subject is limited, comprising largely of non-randomised retrospective cohort studies. The evidence suggests that endovascular treatment is associated with reduced mortality and has better short-term peri-operative outcomes, as well as longer-term survival - however many endovascular cases require subsequent open surgery. There is also conflicting evidence to suggest endovascular therapy is associated with longer ICU stays. Aside from procedural complications, factors such as patient status, time delay to diagnosis and treatment may play a greater role in determining mortality rates. In summary, endovascular therapy appears to be a feasible treatment option with post-operative complications and inpatient mortality rates lower than those seen in open surgery.
Subject(s)
Mesenteric Vascular Occlusion/surgery , Vascular Surgical Procedures/methods , Acute Disease , Aged , Endovascular Procedures/adverse effects , Endovascular Procedures/methods , Endovascular Procedures/statistics & numerical data , Female , Humans , Male , Middle Aged , Retrospective Studies , Vascular Surgical Procedures/adverse effects , Vascular Surgical Procedures/statistics & numerical dataABSTRACT
OBJECTIVE: To discuss international aspects as they relate to the convergence of disciplines in health informatics. METHOD: A group of international experts was invited at a symposium to present and discuss their perspectives on this topic. These have been collated in a single manuscript. RESULTS AND CONCLUSIONS: Significant challenges, as well as opportunities, appear when cumulating the intrinsic multidisciplinary nature of health informatics interventions with the diversity of contexts at the global level, in particular when considered in the perspective of a confluence, i.e., the mixing of different waters and their merging into a new, stronger entity. Health informatics experts reflect on key issues such as collaborative software development and distributed knowledge sourcing, social media and mobile technologies, the evolutions of the discipline from an historical perspective, as well as examples of challenges for implementing ubiquitous healthcare or for supporting disaster situations when infrastructures get disrupted.
Subject(s)
Biological Science Disciplines , Internationality , Medical Informatics , Congresses as Topic , Global Health , Republic of Korea , Social Media , Software , TelemedicineABSTRACT
Many studies utilise enrichment of stable isotopes as tracers to follow the interactions occurring within soil food webs and methods have been developed to enrich bacteria, soil fauna and plant litter, Here for the first time we attempt to enrich a soil fungus to 99 atom% with (13)C and (15)N stable isotopes. In this study our objectives were to (a) assess whether the saprotrophic zygomycete fungus Absidia cylindrospora could grow on a medium enriched to 99 atom% with (13)C-glucose and (15)N-ammonium chloride, (b) to determine the level of enrichment obtained, and (c) to examine the change in growth rate of this fungus while it was growing on the dually enriched medium. To achieve this, the fungus was grown on agar enriched with (13)C and (15)N to 99 atom% and its growth rate monitored. The results showed that A. cylindrospora would grow on the highly labelled growth medium, but that its rate of growth was affected compared with the rate on either natural abundance media or media highly enriched with a single isotope ((13)C or (15)N). The implications of these results is that although the fungus is able to utilise these heavier isotopes, the biochemical processes involved in growth are affected, and consideration should be given to these differences when using stable isotope tracers in, for example, soil food web studies.
Subject(s)
Absidia/growth & development , Carbon Isotopes/metabolism , Nitrogen Isotopes/metabolism , Absidia/chemistry , Absidia/metabolism , Carbon Isotopes/analysis , Culture Media/chemistry , Data Interpretation, Statistical , Microbiological Phenomena , Nitrogen Isotopes/analysisABSTRACT
The soil food web has been referred to as a 'black box', a 'poor man's tropical rainforest' and an 'enigma', due to its opacity, diversity and the limited insight into feeding specificity. Here we investigate the flow of C and N through the soil food web as a way to gain understanding of the feeding interactions occurring. A bacterium, Pseudomonas lurida, was introduced to soil cores from two different habitats, a grassland and a woodland with the same soil type, enriched to 99 atom% in (13)C and (15)N, to trace the flow of bacterial C and N through the soil food web. Throughout the experiment the soil remained enriched in (13)C and (15)N. Almost all the invertebrates tested gained C and N enrichment indicative of the labelled bacteria, implying that bacterial feeding is a common mechanism within the soil. Only three groups were significantly enriched in both (13)C and (15)N in both habitats. These were Collembola (Entomobryomorpha), Acari (Oribatida), and Nematoda, indicating that these organisms are consuming the most bacteria within both systems. When the invertebrates were grouped into hypothesised trophic levels, those considered secondary decomposers were gaining the most enrichment across all invertebrates tested. This enrichment was also high in the micro-predators within the soil, implying that their main food source was the secondary decomposers, particularly the Collembola. Using an enriched bacterium to track the trophic transfer between organisms within the soil food web is a novel way of empirically showing that interactions are occurring, which normally cannot be seen.
Subject(s)
Biomass , Carbon Isotopes/analysis , Food Chain , Nitrogen Isotopes/analysis , Soil Microbiology , Soil/chemistry , Animals , Carbon Isotopes/chemistry , Carbon Isotopes/metabolism , Invertebrates , Nitrogen Isotopes/chemistry , Nitrogen Isotopes/metabolism , Poaceae , Pseudomonas/metabolismABSTRACT
Alternatively activated macrophages (AAMs) have key roles in the immune response to a variety of gastrointestinal helminths such as Heligmosomoides bakeri and Nippostrongylus brasiliensis. In addition, AAMs have been implicated in the resolution of infection-induced pathology in Schistosoma mansoni infection. AAMs exert their activity in part via the enzyme arginase-1 (Arg1), which hydrolyses L-arginine into urea and ornithine, and can supply precursor substrate for proline and polyamine production. Trichuris muris is a worm that resides in the large intestine with resistance being characterized by a Th2 T-cell response, which drives alternatively activated macrophage production in the local environment of the infection. To investigate the role of AAMs in T. muris infection, we used independent genetic and pharmacologic models of arginase deficiency. In acute infection and Th2-dominated immunity, arginase-deficient models expelled worms normally. Macrophage-Arg1-deficient mice showed cytokine and antibody levels comparable to wild-type animals in acute and chronic infection. We also found no role for AAMs and Arg1 in infection-induced pathology in the response to T. muris in either chronic (Th1 dominated) or acute (Th2 dominated) infections. Our data demonstrate that, unlike other gastrointestinal helminths, Arg1 expression in AAMs is not essential for resistance to T. muris in effective resolution of helminth-induced inflammation.
Subject(s)
Arginase/metabolism , Macrophages/enzymology , Macrophages/immunology , Trichuriasis/immunology , Trichuris/immunology , Animals , Antibodies, Helminth/blood , Arginase/genetics , Cytokines/metabolism , Disease Models, Animal , Histocytochemistry , Intestinal Mucosa/immunology , Intestinal Mucosa/pathology , Lymph Nodes/immunology , Male , Mice , Mice, Knockout , Rodent Diseases/immunology , Rodent Diseases/parasitology , Trichuriasis/parasitologyABSTRACT
During gaseous exchange the lungs are exposed to a vast variety of pathogens, allergens, and innocuous particles. A feature of the lung immune response to lung-tropic aerosol-transmitted bacteria such as Mycobacterium tuberculosis (Mtb) is a balanced immune response that serves to restrict pathogen growth while not leading to host-mediated collateral damage of the delicate lung tissues. One immune-limiting mechanism is the inhibitory and anti-inflammatory cytokine interleukin (IL)-10. IL-10 is made by many hematopoietic cells and a major role is to suppress macrophage and dendritic cell (DC) functions, which are required for the capture, control, and initiation of immune responses to pathogens such as Mtb. Here, we review the role of IL-10 on bacterial control during the course of Mtb infection, from early innate to adaptive immune responses. We propose that IL-10 is linked with the ability of Mtb to evade immune responses and mediate long-term infections in the lung.
Subject(s)
CD4-Positive T-Lymphocytes/immunology , Interleukin-10/immunology , Lung/immunology , Mycobacterium tuberculosis/immunology , Tuberculosis, Pulmonary/immunology , Adaptive Immunity , Animals , Disease Progression , Host-Pathogen Interactions , Humans , Immune Evasion , Immune Tolerance , Immunity, Mucosal , Mycobacterium tuberculosis/pathogenicity , VirulenceABSTRACT
BACKGROUND: Education has long been, and continues to be, one of the major thematic areas of the activities of IMIA, the International Medical Informatics Association. OBJECTIVE: To report on IMIA's past activities and to discuss possible future perspectives on IMIA's role on biomedical and health informatics education. METHODS: Summarizing past activities by searching in reports and publications. Making suggestions for wider discussion on possible future activities. RESULTS: Since its inception, IMIA has been active in the field of education, mainly through its working group on education. Among other activities, nine working conferences have been held, many of which have resulted in publications as outcomes, which have helped to exchange knowledge on the development of high-quality health and biomedical informatics education. Recommendations on education in health and medical informatics were endorsed by IMIA in 1999, and a revised version is currently in preparation. CONCLUSIONS: IMIA should continue to stimulate the exchange of knowledge on a range of aspects of health and biomedical informatics education in the countries and regions of the world, with IMIA's academic institutional members playing an increasing role. Establishing procedures for the international accreditation of high-level programs in health and biomedical informatics through IMIA is one of several areas that need to be discussed as IMIA plans and develops its future activities.
Subject(s)
Internationality , Medical Informatics/education , Societies , HumansABSTRACT
One of the key processes that drives rhizosphere microbial activity is the exudation of soluble organic carbon (C) by plant roots. We describe an experiment designed to determine the impact of defoliation on the partitioning and movement of C in grass (Lolium perenne L.), soil and grass-sterile sand microcosms, using a (13)CO(2) pulse-labelling method. The pulse-derived (13)C in the shoots declined over time, but that of the roots remained stable throughout the experiment. There were peaks in the atom% (13)C of rhizosphere CO(2) in the first few hours after labelling probably due to root respiration, and again at around 100 h. The second peak was only seen in the soil microcosms and not in those with sterilised sand as the growth medium, indicating possible microbial activity. Incorporation of the (13)C label into the microbial biomass increased at 100 h when incorporation into replicating cells, as indicated by the amounts of the label in the microbial DNA, started to increase. These results indicate that the rhizosphere environment is conducive to bacterial growth and replication. The results also show that defoliation had no impact on the pattern of movement of (13)C from plant roots into the microbial population in the rhizosphere.
Subject(s)
Carbon Isotopes/metabolism , DNA, Bacterial/metabolism , DNA, Fungal/metabolism , Lolium/metabolism , Lolium/microbiology , Analysis of Variance , Carbon Isotopes/analysis , DNA, Bacterial/chemistry , DNA, Fungal/chemistry , Glucose/analysis , Mass Spectrometry/methods , Plant Components, Aerial/metabolism , Plant Extracts/chemistry , Plant Roots/metabolism , Plant Roots/microbiology , Soil/analysisABSTRACT
Variations in natural abundance of carbon (C) and nitrogen (N) stable isotopes are widely used as tools for many aspects of scientific research. By examining variations in the ratios of heavy to light stable isotopes, information can be obtained as to what physical, chemical and biological processes may be occurring. The spatial heterogeneity of soil delta(15)N- and delta(13)C-values across a range of scales and under different land use have been described by a number of researchers and the natural abundances of the C and N stable isotopes in soils have been found to be correlated with many factors including hydrology, topography, land use, vegetation cover and climate. In this study the Latin square sampling +1 (LSS+1) sampling method was compared with a simple grid sampling approach for delta(13)C and delta(15)N measurement at the field scale. A set of 144 samples was collected and analysed for delta(15)N and delta(13)C from a 12 x 12 grid (in a 1 ha improved grassland field in south-west England). The dimension of each cell of the grid was approximately 11 x 6 m. The 12 x 12 grid was divided into four 6 x 6 grids and the LSS+1 sampling technique was applied to these and the main 12 x 12 grid for a comparison of sample means and variation. The LSS+1 means from the 12 x 12 grid and the four 6 x 6 grids compared well with the overall grid mean because of the low variation within the field. The LSS+1 strategy (13 samples) generated representative samples from the 12 x 12 grid, and hence would be an acceptable method for sampling similar plots for the measurement of mean isotopic composition.
Subject(s)
Carbon Isotopes/analysis , Nitrogen Isotopes/analysis , Soil/analysis , Data Interpretation, Statistical , Mass Spectrometry/methods , Sample SizeABSTRACT
Chelonid corneal fibropapillomatosis has not previously been recorded in Australian waters. During 2008, 724 green sea turtles (Chelonia mydas) were examined in Queensland, Australia at two sites, Moreton Bay (n=155) and Shoalwater Bay (n=569), during annual monitoring. In the same calendar year, 63 turtles were submitted from various sites in southern Queensland for post-mortem examination at the University of Queensland. Four of the 787 animals (0.5%) were found to have corneal fibropapillomas of varying size, with similar gross and microscopical features to those reported in other parts of the world. Two animals with corneal fibropapillomas also had cutaneous fibropapillomas. Clinical assessment indicated that these lesions had detrimental effects on the vision of the turtles and therefore their potential ability to source food, avoid predators and interact with conspecifics. Importantly, these findings represent an emergence of this manifestation of fibropapillomatosis in green sea turtle populations in the southern Pacific Ocean.
Subject(s)
Turtles/virology , Animals , Australia , Cornea/pathology , Female , Male , Pacific Ocean , Queensland/epidemiology , Skin/pathologyABSTRACT
OBJECTIVES: To describe the experience of, and lessons learned from, a collaborative project developing and delivering an MSc in Health Informatics in South Africa. METHODS: The description and discussion is based on the experiences of the staff delivering the course, and formal and informal evaluations, the former conducted as part of the University of Winchester's quality assurance processes. RESULTS: Some of the lessons learned from adapting the course to meet local needs are described and discussed. CONCLUSIONS: Simply attempting to transpose a successful course from one country and culture to another is not a guarantee of success. Educational staff delivering such courses need to take account of local context and culture, be flexible and prepared to adapt to students' needs and circumstances, which may be beyond anyone's control. However, by meeting real identified needs, success can contribute to sustaining capacity building and the development of the local health informatics workforce.