Detection of Helicobacter pullorum in meat chickens in Australia

The bacterial genus Helicobacter is a member of the Campylobacteriales in the Epsilonproteobacteria subphylum, and is comprised of organisms that are morphologically similar to Campylobacter. The term ‘campylobacteria’ is used to encompass the genera Campylobacter, Arcobacter, Helicobacter and Anaerobiospirillum. Helicobacter was separated from the genus Campylobacter in 1989. Helicobacter spp have been isolated from gastric tissue or intestinal contents of humans and a wide range of animal species, with some associated with disease...

Molecular and serological detection of A. centrale- and A. marginale-infected cattle grazing within an endemic area

A reverse line blot hybridization (RLB) one-stage nested PCR (nPCR) for Anaplasma centrale and a nested PCR for Anaplasma marginale were used to detect infected cattle grazing within an endemic region in Israel. A novel set of PCR primers and oligonucleotide probes based on a 16S ribosomal RNA gene was designed for RLB detection of both Anaplasma species, and the performance of the molecular assays compared. The immunofluorescent antibody test (IFA) was used to detect antibodies to both Anaplasma species, whereas, a highly sensitive and specific competitive enzyme-linked immunosorbent assay (cELISA) was used to detect antibodies in A. centrale-vaccinated cattle. The RLB and the nested PCR procedures showed bacteremia with sensitivity of 50 infected erythrocytes per milliliter. Up to 93% of the A. centrale vaccinates carried specific antibodies that were detected by cELISA, and up to 71% of the vaccinated cattle were found to be naturally infected with A. marginale according to the PCR and the RLB assays. Nevertheless, no severe outbreaks of A. marginale infection occurred among vaccinated herds in this endemic region. It appears that both, molecular tools and serology are useful for evaluation of the vaccine efficacy. In the light of wide natural field infection with A. marginale, strong recommendations to continue the A. centrale vaccination program regime will continue until a new generation of non-blood-based vaccine will be developed.

Spinel-Corundum Phase Equilibria in the Systems Mn-Cr-Al-O and Co-Cr-Al-O at 1373 K

The tie lines delineating ion-exchange equilibria between MCr2O4-MAl2O4 spinel solid solution, where M is either Mn or Co, and Cr2O3-Al2O3 solid solution with the corundum structure were determined at 1373 K by electron microprobe and E0AX point count analysis of the oxide phases equilibrated with metallic Co and Au-5% Mn. The component activities in the spinel solid solutions are derived from the tie lines and the thernodynamic data for Cr2O3-Al2O3 soiid solutions available hi the literature. The Gibbs free energies of mixing calculated from the experimental data are discussed in relation to the values derived from the cation distribution a.odel based on the site preference energies and assuming random mixing on both tetrahedral and octahedral sites. Positive deviations from ideality observed in this study suggest a miscibility gap for both series of spinel solid solutions at low temperatures in the absence of oxidation.

Detection and characterisation of strong resistance to phosphine in Brazilian Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae)

As failure to control Rhyzopertha dominica (F.) with phosphine is a common problem in the grain-growing regions of Brazil, a study was undertaken to investigate the frequency, distribution and strength of phosphine resistance in R. dominica in Brazil. Nineteen samples of R. dominica were collected between 1991 and 2003 from central storages where phosphine fumigation had failed to control this species. Insects were cultured without selection until testing in 2005. Each sample was tested for resistance to phosphine on the basis of the response of adults to discriminating concentrations of phosphine (20 and 48 h exposures) and full dose-response assays (48 h exposure). Responses of the Brazilian R. dominica samples were compared with reference susceptible, weak-resistance and strong-resistance strains from Australia in parallel assays. All Brazilian population samples showed resistance to phosphine: five were diagnosed with weak resistance and 14 with strong resistance. Five samples showed levels of resistance similar to the reference strong-resistance strain. A representative highly resistant sample was characterised by exposing mixed-age cultures to a range of constant concentrations of phosphine for various exposure periods. Time to population extinction (TPE) and time to 99.9% suppression of population (LT99.9) values of this sample were generally similar to those of the reference strong-resistance strain. For example, at 0.1, 0.5 and 1.0 mg L-1, LT99.9 values for BR33 and the reference strong-resistance strain were respectively 21, 6.4 and 3.7 days and 17, 6.2 and 3.8 days. With both strains, doubling phosphine concentrations to 2 mg L -1 resulted in increased LT99.9 and TPE. High level and frequency of resistance in all population samples, some of which had been cultured without selection for up to 12 years, suggest little or no fitness deficit associated with phosphine resistance. The present research indicates that widespread phosphine resistance may be developing in Brazil. Fumigation practices should be monitored and resistance management plans implemented to alleviate further resistance development.

The assessment of TGGE for the detection of interspecific and intergeneric DNA-marker polymorphism within Solanaceae

RFLP markers are currently the most appropriate marker system for the identification of uncharacterised polymorphism at the interspecific and intergeneric level. Given the benefits of a PCR-based marker system and the availability of sequence information for many Solanaceous cDNA clones, it is now possible to target conserved fragments, for primer development, that flank sequences possessing interspecific polymorphism. The potential outcome is the development of a suite of markers that amplify widely in Solanaceae. Temperature gradient gel electrophoresis (TGGE) is a relatively inexpensive gel-based system that is suitable for the detection of most single-base changes. TGGE can be used to screen for both known and unknown polymorphisms, and has been assessed here, for the development of PCR-based markers that are useful for the detection of interspecific variation within Solanaceae. Fifteen markers are presented where differences between Lycopersicon esculentum and L. pennellii have been detected by TGGE. The markers were assessed on a wider selection of plant species and found to be potentially useful for the identification of interspecific and intergeneric polymorphism in Solanaceous plants.

Learning challenges of NGOs in development : Co-operation of Finnish NGOs in Morogoro, Tanzania

Non-governmental organisations (NGOs) have gained an important role in development co-operation during the last two decades. The development funding channelled through NGOs has increased and the number of NGOs engaged in development activities, both North and South, has been growing. Supporting NGOs has been seen as one way to strengthen civil society in the South and to provide potential for enhancing more effective development than the state, and to exercise participatory development and partnership in their North-South relationships. This study focuses on learning in the co-operation practices of small Finnish NGOs in Morogoro, Tanzania. Drawing on the cultural-historical activity theory and the theory of expansive learning, in this study I understand learning as a qualitative change in the actual co-operation practices. The qualitative change, for its part, emerges out of attempts to deal with the contradictions in the present activity. I use the concept of developmental contradiction in exploring the co-operation of the small Finnish NGOs with their Tanzanian counterparts. Developmental contradiction connects learning to actual practice and its historical development. By history, in this study I refer to multiple developmental trajectories, such as trajectories of individual participants, organisations, co-operation practices and the institutional system in which the NGO-development co-operation is embedded. In the empirical chapters I explore the co-operation both in the development co-operation projects and in micro-level interaction between partners taking place within the projects. I analyse the perceptions of the Finnish participants about the different developmental trajectories, the tensions, inclusions and exclusions in the evolving object of co-operation in one project, the construction of power relations in project meetings in three projects, and the collision of explicated partnership with the emerging practice of trusteeship in one project. On the basis of the empirical analyses I elaborate four developmental contradictions and learning challenges for the co-operation. The developmental contradictions include: 1) implementing a ready-made Finnish project idea vs. taking the current activities of Tanzanian NGO as a starting point; 2) gaining experiences and cultural interaction vs. access to outside funding; 3) promoting the official tools of development co-operation in training vs. use of tools and procedures taken from the prior activities of both partners in actual practice; and 4) asymmetric relations between the partners vs. rhetoric of equal partnership. Consequently, on the basis of developmental contradictions four learning challenges are suggested: a shift from legitimation of Finnish ideas to negotiation, transcending the separate objects and finding a partly joint object, developing locally shared tools for the co-operation, and identification and reflection of the power relations in the practice of co-operation. Keywords: activity theory; expansive learning; NGO development co-operation; partnership; power

In quest of a reliable and efficient computational test for detection of isomorphism in kinematic chains

The test based on comparison of the characteristic coefficients of the adjancency matrices of the corresponding graphs for detection of isomorphism in kinematic chains has been shown to fail in the case of two pairs of ten-link, simple-jointed chains, one pair corresponding to single-freedom chains and the other pair corresponding to three-freedom chains. An assessment of the merits and demerits of available methods for detection of isomorphism in graphs and kinematic chains is presented, keeping in view the suitability of the methods for use in computerized structural synthesis of kinematic chains. A new test based on the characteristic coefficients of the “degree” matrix of the corresponding graph is proposed for detection of isomorphism in kinematic chains. The new test is found to be successful in the case of a number of examples of graphs where the test based on characteristic coefficients of adjancency matrix fails. It has also been found to be successful in distinguishing the structures of all known simple-jointed kinematic chains in the categories of (a) single-freedom chains with up to 10 links, (b) two-freedom chains with up to 9 links and (c) three-freedom chains with up to 10 links.

Structural Damage Detection Using Modal Curvature and Fuzzy Logic

A fuzzy logic system (FLS) with a new sliding window defuzzifier is proposed for structural damage detection using modal curvatures. Changes in the modal curvatures due to damage are fuzzified using Gaussian fuzzy sets and mapped to damage location and size using the FLS. The first four modal vectors obtained from finite element simulations of a cantilever beam are used for identifying the location and size of damage. Parametric studies show that modal curvatures can be used to accurately locate the damage; however, quantifying the size of damage is difficult. Tests with noisy simulated data show that the method detects damage very accurately at different noise levels and when some modal data are missing.

A one-tube fluorescent assay for the quarantine detection and identification of Tilletia indica and other grass bunts in wheat

A molecular assay with enhanced specificity and sensitivity has been developed to assist in the surveillance of Karnal bunt, a quarantineable disease with a significant impact on international trade. The protocol involves the release of DNA from spores, PCR amplification to enrich Tilletia-specific templates from released DNA and a five-plex, real-time PCR assay to detect, identify and distinguish T. indica and other Tilletia species (T. walkeri, T. ehrhartae, T. horrida and a group comprising T. caries, T. laevis, T. contraversa, T. bromi and T. fusca) in wheat grains. This fluorescent molecular tool has a detection sensitivity of one spore and thus bypasses the germination step, which in the current protocol is required for confirmation when only a few spores have been found in grain samples. The assay contains five dual-labelled, species-specific probes and associated species-specific primer pairs in a PCR mix in one tube. The different amplification products are detected simultaneously by five different fluorescence spectra. This specific and sensitive assay with reduced labour and reagent requirements makes it an effective and economically sustainable tool to be used in a Karnal bunt surveillance program. This protocol will also be valuable for the identification of some contaminant Tilletia sp. in wheat grains.

Processes leading to the detection of tropical weed infestations during an eradication program.

The authors identify and track processes that have resulted in the detection of six tropical weeds targeted for eradication. The habitats and distributions of these species make detection by field officers and members of the public more likely than targeted searches. The eradication program is increasing the scope of detection processes by conducting and documenting activities to improve weed recognition amongst public, government and industry stakeholders.

Co-evolution of wild rabbits (Oryctolagus cuniculus) and RHDV: resistance and virulence

Rabbit Haemorrhagic Disease Virus (RHDV) was introduced to Australia in 1995 for the control of wild rabbits. Initial outbreaks greatly reduced rabbit numbers and the virus has continued to control rabbits to varying degrees in different parts of Australia. However, recent field evidence suggests that the virus may be becoming less effective in those areas that have previously experienced repeated epizootics causing high mortality. There are also reports of rabbits returning to pre-1995 density levels, Virus and host can be expected to co-evolve. The host will develop resistance to the virus with the virus subsequently changing to overcome that resistance. It has been 12 years since the release of RHDV and it is an opportune time to examine where the dynamic currently stands between RHDV and rabbits. Laboratory challenge tests have indicated that resistance to RHDV has developed to different degrees in populations throughout Australia. In one population a low dose (1:25 dilution) of Czech strain RHDV failed to infect a single susceptible rabbit, yet infected a low to high (up to 73%) percentage across other populations tested. Different selection pressures are present in these populations and will be driving the level of resistance being seen. The mechanisms and genetics behind the development of resistance are also important as the on-going use of RHDV as a control tool in the management of rabbits relies on our understanding of factors influencing the efficacy of the virus. Understanding how resistance has developed may provide clues on how best to use the virus to circumvent these mechanisms. Similarly, it will help in managing populations that have yet to develop high levels of resistance.

Can feral pig harvesting and co-ordinated control reduce damage to grain crops?

Commercial and recreational harvesting of pigs is often encouraged by pest managers because it is essentially a ‘free’ reduction in pest density. However, the reduction in numbers may provide minimal damage mitigation and may be inappropriately allocated in space and time. Additionally, more effective control (e.g. baiting) may not occur because of the incorrect perception that harvesting is effective or because pigs are valued for recreational use.

Direct electrochemical formation of nanostructured amorphous Co(OH)2 on gold electrodes with enhanced activity for the oxygen evolution reaction.

The oxides of cobalt have recently been shown to be highly effective electrocatalysts for the oxygen evolution reaction (OER) under alkaline conditions. In general species such as Co3O4 and CoOOH have been investigated that often require an elevated temperature step during their synthesis to create crystalline materials. In this work we investigate the rapid and direct electrochemical formation of amorphous nanostructured Co(OH)2 on gold electrodes under room temperture conditions which is a highly active precursor for the OER. During the OER some conversion to crystalline Co3O4 occurs at the surface, but the bulk of the material remains amorphous. It is found that the underlying gold electrode is crucial to the materials enhanced performance and provides higher current density than can be achieved using carbon, palladium or copper support electrodes. This catalyst exhibits excellent activity with a current density of 10 mA cm-2 at an overpotential of 360 mV with a high turnover frequency of 2.1 s-1 in 1 M NaOH. A Tafel slope of 56 mV dec-1 at low overpotentials and a slope of 122 mV dec-1 at high overpotentials is consistent with the dual barrier model for the electrocatalytic evolution of oxygen. Significantly, the catalyst maintains excellent activity for up to 24 hr of continuous operation and this approach offers a facile way to create a highly effective and stable material.

Teledermatology: Its use in the detection and management of actinic keratosis

Teledermatology can profoundly improve access to medical services for those who may have limited access to dermatology due to workforce shortages, distance to providers, or limitations in their mobility. Two common ways of teledermatology are differentiated: life synchronous, where patient and doctor communicate directly, or store and forward asynchronous methods, where the patient and doctor provide and assess the medical information independently. Teledermatology has been tested for its safety, feasibility and accuracy for a number of dermatological conditions, including the early detection of skin cancer and is usually safe, feasible and accurate. Studies reported somewhat better results for synchronous than asynchronous methods, possibly because of loss of information if no direct patient doctor contact is feasible. However asynchronous methods are easier to organize, require less sophisticated technology and are more widely accessible, and are more convenient for both patients and doctors. No study to date focused solely on teledermatology of actinic keratosis, but such lesions are typically found during teledermatology examinations for other main target lesions. In studies where such results were reported, actinic keratoses seemed to be readily identifiable for teledermatologists and adequate management and treatment can be suggested within remote consultations.