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Introduction: Cognitive processing theories postulate that decision making depends on both fast and slow thinking. Experienced physicians (EPs) make diagnoses quickly and with less effort by using fast, intuitive thinking, whereas inexperienced medical students rely on slow, analytical thinking. This study used a cognitive task analysis to examine EPs cognitive processes and ability to provide knowledge translation to learners. Methods: A novel mind mapping approach was used to examine how EPs translate their clinical reasoning to learners, when evaluating a patient for a possible venous thromboembolism (VTE). Nine EPs were interviewed and shown two different videos of a medical student patient interview (randomized from six possible videos). Results: EPs were asked to demonstrate their clinical approach to the scenario using a mind map, assuming they were teaching a learner in the Emergency Department. EPs were later re-interviewed to examine response stability, and given the opportunity to make clarifying or substantive mind map modifications. Maps were broken into component pieces and analyzed using mixed-methods techniques. A mean of 15.7 component pieces were identified within each mind map (standard deviation (SD) 7.8). Maps were qualitatively coded, with a mean of 2.8 clarifying amendments (e.g. adding a time course caveat) (SD 1.5-5.75) and 4.4 substantive modifications (e.g. changing the flow of the map) (SD 2-5). Conclusion: Resulting mind maps displayed significant heterogeneity in teaching points and the degree to which EPs used slow thinking. EPs frequently made fast thinking jumps, although learners could prompt slow thinking by questioning unclear points. This is particularly important as learners engage in cognitive apprenticeship throughout their training. An improved understanding of EPs cognitive processes through mind mapping will allow learners to improve their own clinical reasoning (Merrit et al., 2017). Educating EPs on these processes will allow modification of their teaching styles to better suit learners.
The evidence underpinning the developmental origins of health and disease (DOHaD) is overwhelming. As the emphasis shifts more towards interventions and the translational strategies for disease prevention, it is important to capitalize on collaboration and knowledge sharing to maximize opportunities for discovery and replication. DOHaD meetings are facilitating this interaction. However, strategies to perpetuate focussed discussions and collaborations around and between conferences are more likely to facilitate the development of DOHaD research. For this reason, the DOHaD Society of Australia and New Zealand (DOHaD ANZ) has initiated themed Working Groups, which convened at the 2014–2015 conferences. This report introduces the DOHaD ANZ Working Groups and summarizes their plans and activities. One of the first Working Groups to form was the ActEarly birth cohort group, which is moving towards more translational goals. Reflecting growing emphasis on the impact of early life biodiversity – even before birth – we also have a Working Group titled Infection, inflammation and the microbiome. We have several Working Groups exploring other major non-cancerous disease outcomes over the lifespan, including Brain, behaviour and development and Obesity, cardiovascular and metabolic health. The Epigenetics and Animal Models Working Groups cut across all these areas and seeks to ensure interaction between researchers. Finally, we have a group focussed on ‘Translation, policy and communication’ which focusses on how we can best take the evidence we produce into the community to effect change. By coordinating and perpetuating DOHaD discussions in this way we aim to enhance DOHaD research in our region.
Driving cessation in later life is associated with depression. This study examines if social support can buffer the negative effects of driving cessation on older women's mental health.
Participants were drawn from the 1921–1926 cohort of the Australian Longitudinal Study on Women's Health (ALSWH) and included 4,075 older women (aged 76–87 years) who drove at baseline, following them for three years to assess driving cessation. The outcome variable was mental health, measured by the mental health index (MHI) of the SF-36. The explanatory variables were social support factors, including social interaction, whether the women were living alone or with others, and engagement in social activities. Control variables included age, country of birth, area of residence, ability to manage on income, marital status, and general health.
Main effect results showed that poor mental health was predicted by driving cessation, low levels of social interaction, and non-engagement in social activities. There was a significant interaction effect of driving status by social activities engagement on mental health. Women who remained active in their engagement of social activities were able to maintain a good level of mental health despite driving cessation.
Engagement and participation in social activities can help older women who stopped driving maintain a good level of mental health.
We assessed vascular programming in genetically identical monochorionic twin pairs with twin-to-twin transfusion syndrome (TTTS) treated differently in utero by serial amnioreduction or fetal laser arterial photocoagulation. This case–control study re-assessed four twin groups at median 11 years comprising 20 pairs of monochorionic diamniotic twins: nine treated by amnioreduction (TTTS-amnio) and eleven by laser (TTTS-laser) with seven monochorionic and six dichorionic control pairs. Outcome measures were current blood pressure (BP), brachio-radial arterial stiffness derived from pulse wave velocity (PWV), resting microcirculation (Flux) and response to heating and post-occlusive reactive hyperaemia measured using laser Doppler. Potential confounders [PWV and BP at first study, current height, weight, heart rate and twin type (ex-recipient, ex-donor or heavier/lighter of pair)] were accounted for by Mixed Linear Models statistical methodology. PWV dichorionic > monochorionic (P = 0.024); systolic and diastolic BP dichorionic > TTTS-amnio and TTTS-laser (P = 0.004, P = 0.02 and P = 0.005, P = 0.02, respectively). Within-twin pair pattern of PWV discordance was similar in laser treated and dichorionic controls (heavier-born > lighter), opposite to TTTS-amnio and monochorionic controls. Flux monochorionic > dichorionic (P = 0.044) and heavier > lighter-born (P = 0.024). TTTS-laser and dichorionic diamniotic showed greatest hyperaemic responses (dichorionic > TTTS-amnio or monochorionic controls (P = 0.007, P = 0.025). Hyperaemic responses were slower in heavier-born twins (P = 0.005). In summary, monochorionic twins had lower BP, arterial stiffness and increased resting vasodilatation than dichorionic twins implying shared fetal circulation affects vascular development. Vascular responses in laser-TTTS were similar to dichorionic and opposite to TTTS-amnio suggesting a lasting effect of fetal therapy on vascular health.
Basic fibroblast growth factor (bFGF), a protein, plays a key role in wound healing and blood vessel regeneration. However, most negative effects in vivo, or in vitro result from the over dosage of bFGF. Furthermore, it needs to keep the bFGF from protein denaturant. Thus, this study aims to develop a new delivery system based on silica nanoparticles (SiO2 NPs) dispersed in collagen patch for delivery of the bFGF in a local and prolonged manner. In this research, SiO2 NPs are used to encapsulate bFGF through a modified water-in-oil micro-emulsion. The bFGF-loaded nanoparticles afterwards are dispersed in the collagen-based matrix through a EDC cross-linking step. The in vitro release kinetics of SiO2 NPs - encapsulated bFGF with and without collagen matrix have been monitored through ELISA. In addition, the cytotoxicity of SiO2 NPs is investigated by studying the viability of Human Umbilical Vein Endothelial Cells (HUVEC) under the different concentrations of SiO2 NPs. It has found the average diameter (d) for SiO2 NPs encapsulating bFGF is 45 ± 8 nm with a loading efficiency of 72.5±3%. The maximum concentration of bFGF locally released from SiO2 NPs impregnated collagen matrix can be monitored after 30 days, while bFGF released from SiO2 NPs can be detected in 20 days. The further prolonged releasing after the nanoparticle-encapsulated bFGF laden collagen matrix is possibly due to the interaction between the nanoparticles and collagen matrix. In addition, the biocompatibility of the SiO2 NP has been investigated. We found that SiO2 NPs at the concentration of 50 μg/ml can still keep the cell alive. The results indicate that the nanoparticle-laden collagen matrix can locally deliver growth factor in a prolonged manner. This new delivery system may benefit to blood vessel regeneration and potentiate greater angiogenesis.
Ferroelectric materials such as BaTiO3 are notable for their nonlinear optical and electrical properties. Optical frequency doubling in thin films integrated with compact semiconductor laser pumped solid state lasers is an attractive candidate for high efficiency generation of blue light. Chemical vapor deposition (CVD) using a single liquid source has been used to grow BaTiO3 films on MgO. X-ray diffraction in the pole figure configuration indicates the films to be epitaxial, and rocking curves had FWHM ≈ 0.7°. An optical scatterometer (λ = 633 nm.) has been used to identify deposition conditions that result in the lowest scatter losses. This paper describes these results as well as waveguide designs to enhance the second harmonic generation efficiency in epitaxial BaTiO3 films on MgO.
Le comportement atypique des fissures courtes peut être, pour une large part, expliqué
par l’effet de la fermeture. Toutefois, la détection du niveau de contrainte correspondant
à l’ouverture s’avère généralement difficile sinon impossible pour les fissures de petite
dimension. Cette étude porte sur la fermeture des fissures courtes 2D dans un acier
inoxydable 304L. Pour optimiser la détection des variations de complaisance, une méthode
automatique a été développée pour analyser les signaux numériques grâce à des méthodes de
filtrage. Il est montré que cet outil permet d’obtenir une mesure précise de la charge
d’ouverture même pour des fissures ayant une profondeur de l’ordre de 0,1 mm. Les
résultats obtenus permettent de définir l’évolution de la contribution de la fermeture en
fonction de la profondeur de la fissure.
An appropriate foetal cardiovascular (CV) response to reduced substrate supply (e.g. oxygen or other nutrients) is vital for growth and development, and may impact on CV control. The prevailing nutritional environment and associated CV changes may influence subsequent CV responses to challenges during late gestation, for example, umbilical cord occlusion (UCO). We investigated the effect of low-circulating glucose on foetal CV control mechanisms and response to UCO. Under general anaesthesia, late gestation foetal sheep (n = 7, 119 days gestational age (dGA), term ∼147 days) were implanted with vascular catheters, a bladder catheter, electrocardiogram electrodes and an umbilical cord occluder. Mean arterial pressure (MAP), heart rate (HR) and kidney function were monitored during maternal saline (MSAL, 125dGA) and insulin (MINS, 126dGA) infusion, and foetal CV responses were assessed during incremental doses of angiotensin II, a 90-s total UCO, and administration of phenylephrine to assess baroreflex function. During MINS infusion, the decrease in maternal and foetal blood glucose was associated with a small but significant decrease in foetal HR and reduced foetal baroreflex sensitivity (P < 0.05). The increase in foetal MAP during a 90-s UCO was greater during hypoglycaemia (P < 0.05). The MAP response to angiotensin II was not affected by hypoglycaemia. Decreased foetal HR and baroreflex sensitivity and increased CV responsiveness to UCO during hypoglycaemia indicates altered CV homoestatic mechanisms. The combination of altered nutrition and a CV challenge, such as UCO, during late gestation may have a cumulative effect on foetal CV function.
Most agricultural production systems harbor many species of herbivorous arthropods capable of damaging crops. However, the vast majority of these species do not reach damaging levels. In this chapter we explore the role of predators and parasitoids in suppressing pest abundance and damage. In particular, we focus on factors that influence the abundance of beneficial arthropods in agricultural landscapes. Finally, we address ways to manage these systems to increase the effectiveness of beneficial arthropods.
There are three primary means by which managers influence biological control of insects. Importation of natural enemies against pests of exotic origin is sometimes referred to as classical biological control, while augmentation is the rearing and release of natural enemies already present to increase their effectiveness. Conservation of natural enemies involves improving conditions for existing natural enemies by reducing factors which interfere with natural enemies or increasing access to resources that they require to be successful (Ehler, 1998). Habitat management is considered a subset of conservation practices that focus on manipulating habitats within agricultural landscapes to provide resources to enhance natural enemies (Landis et al., 2000).
Managing agricultural landscapes to improve biological control relies on a detailed understanding of factors that influence both pest and natural enemy abundance (Fig. 12.1). We begin by examining landscape processes that influence pests and beneficial insects at larger spatial scales. Next we focus on processes that influence these organisms and their interactions at local scales.
A finite volume computer model of the continuous casting
process for steel flat products has been developed. In this first
stage, the model concentrates on the hydrodynamic aspects
of the process and in particular the dynamic behavior of
the metal/slag interface. The model was validated against
experimental measurements obtained in a water model apparatus.
Endoscopic sinus surgery (ESS) has undergone exponential growth worldwide in the last decade. It is now accepted as a safe and effective means of treating sinonasal disease. The purpose of this study was to determine whether post-operative debridement is necessary after ESS. Seventeen patients undergoing bilateral primary ESS were randomized to receive debridement of either the left or right ethmoid cavity. All patients included in the study had symmetrical disease. Saline douches and all other concomitant treatments were delivered bilaterally. Outcome measures were based on regular symptom scores and surgeons’ semi-quantitative assessment of the debrided and non-debrided cavities, over a three-month period. Analysis of adhesion rates, healing and symptom scores showed no statistically significant difference between the two groups. In conclusion, this study did not demonstrate significant benefit from post-operative ESS cavity debridement, at least with regard to cavity healing. This should be considered a pilot study and therefore limited conclusions can be drawn. Further work is needed to determine the optimum post-operative care for ESS.
Attempts were made to immunize goats by infection with large numbers of metacyclic trypanosomes of a clone of Trypanosoma vivax, followed by chemotherapy. Five groups of 6 goats each were infected intradermally with 5 different doses of cultured metacyclics of T. vivax, ranging from 102 to 106 trypanosomes/goat. Four weeks after infection, the goats were treated with 10 mg/kg diminazene aceturate (Berenil, Hoechst A.G.). Three weeks after treatment, 3 goats in each group were challenged intradermally with 104 homologous metacyclics derived from culture. The remaining 3 goats in each group were challenged by 20 tsetse infected with the homologous clone. Five out of 30 goats were resistant to homologous challenge; 4 of the goats that had been challenged with cultured parasites, and 1 that had been challenged by tsetse. In each group 1 goat was protected. Protection was therefore not apparently influenced by the number of trypanosomes used to establish the primary infection. In another experiment, 6 goats were each infected by feeding 100 tsetse on the goats for 15 consecutive days. Three weeks after infection the goats were treated with Berenil and 3 weeks later challenged by 20 tsetse infected with the homologous clone. Three out of the 6 goats resisted challenge. The susceptible goats in both experiments, however, showed a reduction in the peak of parasitaemia following challenge compared with both challenge controls and the initial infections. Lytic antibodies to cultured metacyclics of T. vivax were detected in goats that resisted challenge after a primary infection with cultured metacyclics, and in resistant and susceptible goats after a primary infection by tsetse. All infected goats produced lytic antibodies to live bloodstream forms, as well as antibodies to bloodstream form lysates (demonstrated by ELISA). It is suggested that the immunity that had been induced in some of the experimental animals is due to antibody responses to both metacyclic and bloodstream variable antigen types (VATs) expressed during infection.
To determine if, as is the case with Trypanosoma brucei and T. congolense, serodemes of T. vivax could be distinguished on the basis of immunity to the metacyclic stages of the parasite, attempts were made to immunize goats by infection with infected tsetse, followed by chemotherapy or eventual ‘self-cure’. Thirty goats were infected by tsetse with either clones or stocks of T. vivax from East or West Africa. Twenty-four goats were treated with diminazene aceturate (Berenil, Hoechst A.G.) 2–6 weeks after infection and 6 goats were allowed to self-cure. Infection, followed by treatment, induced immunity to a first homologous challenge by infected tsetse in only 2 of 24 goats (one immune to the East African stock, and the other to a clone of the West African stock). Immunity to a clone of the East African stock was induced in 3 or 4 animals after a second infection and treatment and in the fourth animal of the group following a third infection and treatment. One of 2 goats infected with the clone of the East African stock was immune to challenge at 16 weeks, following self-cure without treatment, and 1 of 4 goats infected with the parent stock was similarly immune when challenged at 40 weeks post-infection. Goats susceptible to infection with East African T. vivax showed evidence of partial immunity by delayed pre-patent periods and depressed parasitaemias after challenge. Goats infected with the relatively more virulent West African T. vivax were, however, completely susceptible to infection after homologous challenge, and showed only a slight delay in pre-patent period. A similar result was obtained in a further 8 goats primed and challenged by large numbers of tsetse (20 or 100 infected tsetse/goat) with the West African T. vivax. In further experiments using a very short treatment interval, infections following challenge were clearly shown to be the result of a lack of immunity rather than relapse following treatment. Lytic antibody activity to cultured metacyclic trypanosomes could not be detected during infection but such activity against bloodstream forms was detected after 2 weeks of infection. It is suggested that the primary reason for the erratic induction of immunity to T. vivax employing this methodology is the low number of metacyclics transmitted by infected tsetse, and thus poor antigenic stimulus encountered by goats upon tsetse challenge.
The laws observed among Orthodox Jews regulating coital activity according to menstrual cycle phase (the laws of Taharat HaMishpacha), in a population that generally does not use contraception, have potentially important effects on fertility. Analysis of these effects based on menstrual cycle and ovulatory phase lengths for women in the childbearing years shows that the majority of cycles are potentially exposed to coital activity during a fertile period and the increased likelihood of coitus following abstinence has potentially fertility-enhancing effects. For the individual woman with a predominance of short cycles, delays in conception are probable.
Antigenic variation in the ILDar 1 serodeme of the naturally rodent-infective stock of West African Trypanosoma vivax has been investigated following cyclical transmission. The immunofluorescent and immune lysis tests were employed with a panel of 39 variant-specific mouse antisera. When antigenically homogeneous, or mixed, populations were transmitted by tsetse flies to goats, the first peak parasitaemias arising in the goats were antigenic mixtures (up to 9 major, and several minor variants being recognized in some cases) from which the ingested variant was absent. Although first peak parasitaemias in similarly infected goats showed some variants in common, there was no obvious relationship between the VAT profiles in different goats. When these populations were expanded in irradiated mice, VAT heterogeneity was maintained with a tendency towards the development of predominant variants in some, but not all, instances. Six additional variants, derived following the growth of bloodstream form ILDat 1·9 in 37°C culture, were also represented in goat and mouse populations. Two further variants, isolated after cyclical development of ILDat 1·9-derived trypanosomes in vitro, were not present in the early parasitaemias in goats and mice.
Coated metacyclics of Trypanosoma vivax exist in the hypopharynges of infected tsetse flies and are extruded in low numbers when the flies are induced to probe onto warm slides or into medium. After extensive searching of T. vivax-infected proboscides, and resort to a process for the examination of single, extruded, metacyclic trypanosomes, electron micro scopic evidence is presented that, contrary to an earlier report, metacyclic T. vivaxacquire a surface coat before contact with the mammalian host. Since T. vivax exhibits antigenic variation, the role of the surface coat in this species is likely to be functionally equivalent to the surface coat of the other tsetse-transmitted trypanosome species, T. brucei and T. congolense.