Le médecin de famille et le patient suicidaire

Comme base de discussion, nous survolons rapidement les études portant sur les possibilités d'intervention et de prévention du suicide et des tentatives de suicide dans un contexte de pratique générale. L'objectif principal du présent article est de discuter des différentes façons d'améliorer la capacité des médecins de famille à reconnaître et à intervenir face à des signes suicidaires chez le patient. Un résumé des articles importants déjà publiés en Suède par Rutz et son équipe démontre clairement l'importance de la formation sur les désordres dépressifs et sur les problèmes connexes. L'importance des habiletés communicationnelles du médecin dans cette situation clinique ne fait aucun doute mais cet aspect n'a jamais fait l'objet d'études approfondies et nous en touchons brièvement.As a background for the discussion, a minor literary survey points out the potentiality for intervention and prevention of suicide and suicide attempts in the primary care setting. The main purpose of this paper is to discuss what options this implicates when it comes to improve the family physicians' ability to recognize and to handle suicidal signals from the patient. A summary of the important papers already published by Rutz and his group in Sweden clearly demonstrates the importance of education concerning depressive disorders and other immediate matters. The significance of communicative skills of the doctor in this clinical situation in undoubted but still mostly unexplored and finally this is shortly discussed

Arboreality increases reptile community resistance to disturbance from livestock grazing

1. Domestic livestock grazing directly alters ground-level habitat but its effects on arboreal habitat are poorly known. Similarly, the response to grazing of ground-dwelling fauna has been examined, but there are few studies of arboreal fauna. Globally, grazing has been implicated in the decline of vertebrate fauna species, but some species appear resistant to the effects of grazing, either benefiting from the structural changes at ground level or avoiding them, as may be the case with arboreal species. Here we examine arboreal and terrestrial habitat responses and reptile community responses to grazing, to determine whether arboreal reptile species are more resistant than terrestrial reptile species. 2. We conducted arboreal and terrestrial reptile surveys on four different grazing treatments, at a 19-year experimental grazing trial in northern Australia. To compare the grazing response of arboreal and terrestrial reptile assemblages, we used community, functional group and individual species-level analyses. Species responses were modelled in relation to landscape-scale and microhabitat variables. 3. Arboreal reptile species were resistant to the impact of grazing, whereas terrestrial reptiles were negatively affected by heavy grazing. Terrestrial reptiles were positively associated with complex ground structures, which were greatly reduced in heavily grazed areas. Arboreal lizards responded positively to microhabitat features such as tree hollows. 4. Synthesis and applications. Arboreal and terrestrial reptiles have different responses to the impact of livestock grazing. This has implications for rangeland management, particularly if management objectives include goals relating to conserving certain species or functional groups. Arboreal reptiles showed resistance in a landscape that is grazed, but where trees have not been cleared. We highlight the importance of retaining trees in rangelands for both terrestrial and arboreal microhabitats

Problems and needs for improving primary care of osteoarthritis patients: the views of patients, general practitioners and practice nurses

BACKGROUND: Osteoarthritis (OA) is highly prevalent and has substantial impact on quality of life as well as on healthcare costs. The general practitioner (GP) often is the first care provider for patients with this chronic disease. The aim of this study was to identify health care needs of patients with OA and to reveal possible obstacles for improvements in primary care management of OA patients. METHODS: We performed semi-structured interviews with a stratified sample of 20 patients, 20 GPs and 20 practice nurses. RESULTS: Diagnosing OA posed no major problem, but during the course of OA, GPs found it difficult to distinguish between complaints resulting from the affection of the joints and complaints related to a concomitant depression. Patients felt to be well informed about the degenerative nature of the disease and possible side effects of medications, but they lacked information on individual consequences of the disease. Therefore, the most important concerns of many patients were pain and fear of disability which they felt to be addressed by GPs only marginally. Regarding pain treatment, physicians and patients had an ambivalent attitude towards NSAIDs and opiates. Therefore, pain treatment was not performed according to prevailing guidelines. GPs felt frustrated about the impact of counselling regarding life style changes but on the other hand admitted to have no systematic approach to it. Patients stated to be aware of the impact of life style on OA but lacked detailed information e.g. on how to exercise. Several suggestions were made concerning improvement. CONCLUSION: GPs should focus more on disability and pain and on giving information about treatment since these topics are inadequately addressed. Advanced approaches are needed to increase GPs impact on patients' life style. Being aware of the problem of labelling patients as chronically ill, a more proactive, patient-centred care is needed

The impact of weeds and prescribed fire on faunal diversity

Human mediated transport has allowed some species to extend their range beyond their natural ability to disperse. Many exotic annual grasses are highly adaptable and can establish population in their introduced ranges because they can tolerate high variability in local climatic conditions, annual rainfall, and nutrient availability. The most successful invader grasses transform the ecosystems they invade. Invasive grasses can alter the natural fire frequency by increasing local fuel load, and then they flourish under the new conditions they create. This thesis examines the impacts of the introduced weed grader grass (Themeda quadrivalvis) and fire on vertebrate assemblages in tropical savannahs in northern Queensland, Australia. To determine the effects of weeds and fire, and their interaction, on savannah vertebrates, I conducted a two-year vertebrate fauna survey in tropical savannah woodland at Undara Lava Tubes National Park. My survey sites were carefully chosen to provide me with plots that were not spatially auto correlated, and that included either native grasses, or native grasslands invaded by grader grass. After one year examining the influence of the presence of the weed on vertebrate fauna (reptiles), my sites were burned. I expanded my survey to include more recently burned sites, and continued to survey these through their recovery for 15 months. This allowed me to monitor the recovery of reptile and mammal assemblages after fire. Finally, I conducted an experiment to determine the influence of predation on foraging in mice, using giving-up density experiments. To conduct these experiments, I offered native and introduced mice food items in known quantities in trays, in open and closed environments, and determined the amount of time they were willing to forage in these trays, using the amount of food remaining in the trays as a measure of willingness to forage. Invasive grasses are among the worst threats to native biodiversity, but the mechanisms causing negative effects are poorly understood. To investigate the impact of an invasive grass on reptiles, I compared the reptile assemblages that used native kangaroo grass (Themeda triandra), and black spear grass (Heteropogon contortus), to those using habitats invaded by grader grass (Themeda quadrivalvis). There were significantly more reptile species, in greater abundances, in native kangaroo and black spear grass than in invasive grader grass. To understand the sources of negative responses of reptile assemblages to the weed, I compared habitat characteristics, temperatures within grass clumps, food availability and predator abundance among these three grass habitats. Environmental temperatures in grass, invertebrate food availability, and avian predator abundances did not differ among the habitats, and there were fewer reptiles that fed on other reptiles in the invaded than in the native grass sites. Thus, native grass sites did not provide better available thermal environments within the grass, food, or lower predator abundance. Instead I suggest that habitat structure was the critical factor driving weed avoidance by reptiles in this system, and recommend that the maintenance of heterogeneous habitat structure, including clumping native grasses, with interspersed bare ground, and leaf litter are critical to reptile biodiversity. Land managers often use fire as a management tool, to reduce accumulation of fuel, and by extension, the impact of wildfires on flora, fauna and the built environment. Many grassy weeds are tall, and grow in dense stands with high biomass. Grassy weeds often burn at a higher intensity than native grasses, which may alter the influence of fires on fauna. Thus, the response of fauna to fire in weedy environments may be complex. Here I examined reptile and mammal responses to fire in savannah open woodland habitats in native kangaroo and black spear grass habitats, and in habitats invaded by grader grass. I compared reptile richness, abundance and assemblage composition in a group of replicated habitats that had not been burnt for 2 years, directly after they were burned, and up to 15 months after burning, when grasses had regrown. Reptiles are excellent model systems to examine the influence of fire on fauna, because they respond strongly to habitat structural features, and are only moderately vagile. I found that reptile abundance and richness were highest in unburnt habitats (2 years after burning), and greatly reduced in all habitats immediately after burning, most strongly in grader grass. Abundance and richness recovered in all three habitats one year after burning, but assemblage composition had changed. Three skinks and one monitor lizard were present only in the longest unburnt kangaroo grass sites, and their populations did not recover 15 months after burning. In weedy habitats, reptile abundance was more strongly reduced immediately after fire than in other habitats. Even in fire-prone, often burnt habitats such as these, in which richness and abundance were not strongly influenced by fire, assemblage composition was. As above, I also examined mammal richness and abundance in replicated unburnt, burnt, and revegetated native and weedy sites. Mammal abundances were higher in unburnt native grasses than in unburnt weedy sites. The lowest mammal abundances occurred in sites revegetated after fire. All mammals, except rufous bettongs (Aepyprymnus rufescens) and tropical short-tailed mice (Leggadina lakedownensis) were reduced in abundance following fire. Eastern chestnut mice (Pseudomys gracilicaudatus) and common planigales (Planigale maculata) returned with returning grass cover. Over the course of my study, I detected a gradual decline in northern brown bandicoots (Isoodon macrourus). Mammal responses to fire in weeds were idiosyncratic, some species were more abundant in weedy habitats following fire, some less, and some returned to their prior abundance. My study indicated that in, tropical savannahs, a naturally fire-prone habitat, overall mammal abundance, but not richness, decreased with frequent fires (≤ 2 years), in both weeds and native grass, whereas individual species responses varied greatly. Differential predation risk among habitats, or 'the landscape of fear' can have profound impacts on foraging strategies of prey. Few studies, however, have described the landscape of fear in the wild, in relation to actual predator densities. Using giving up density experiments, and vertebrate surveys, I described the landscape of fear of two rodent species in relation to predator abundances in open savannah woodland. I offered native eastern chestnut (Pseudomys gracilicaudatus) and introduced house mice (Mus musculus) food in the open, and under the cover of grass. When eastern brown snakes (Pseudonaja textilis) were absent, both eastern chestnut and house mice consumed more food items under cover. When snakes were present, eastern chestnut mice consumed more food items in the open than under cover. House mice, on the other hand reduced their foraging activity undercover, but did not increase foraging in the open in the presence of snakes. The abundance of other predators did not correlate with food intake in different habitats. Native mice apparently can adjust their antipredator behaviour to remain successful in the presence of native predators. In conclusion, my study provides the first insights into the responses of reptile and mammal assemblages to native savannah invaded by grader grass, and the interaction between fire and the presence of grader grass. I describe how fauna respond to habitat modifications after fire, and after vegetation cover had returned to levels similar to prefire. My study found that reptiles and mammal community composition in these naturally fire-prone savannah systems were sensitive to the presence of the weed, and to frequent fires (≤ 2 years), especially in the weedy parts of the habitat. I suggest managers leave longer intervals between prescribed fire in tropical savannahs, which burn frequently anyway, and suggest that fewer fires might help to maintain faunal biodiversity in fire-prone habitats. I also suggest that decisions to burn weeds should include an awareness of the likelihood of enhancing certain species while discouraging others, and conservation decisions should be based on fire sensitive species given a multi-species response

The influence of higher order incident modes on the performance of a hybrid reactive-dissipative splitter silencer

© 2017 Acoustical Society of America. A hybrid reactive-dissipative splitter silencer offers the potential to attenuate turbomachinery noise over a wide frequency range, including the problematic low to medium frequencies. This article uses a theoretical model to investigate the performance of a hybrid parallel baffle silencer for different complex incident sound fields. This includes an incident sound field with equal modal energy density, as well as the excitation of individual higher order modes. It is shown that provided horizontal and vertical partitions are used in the reactive element, the sound attenuation performance of the reactive chamber under complex incident sound fields is equivalent to that obtained using plane wave excitation over the frequency range of interest. Furthermore, it is demonstrated that the reactive elements work at frequencies above the first cut-on mode in the inlet duct, and so they are capable of extending sound attenuation into the low to medium frequency range. This delivers an efficient hybrid silencer design that is suitable for use in power generation applications, such as gas turbine exhaust systems

Portfolio Construction Using Systematic Risk in an Emerging Market: A Study based on the Nairobi Stock Exchange(NSE)

Project submitted to the School of Business in partial fulfillment of the requirement for the Degree of Masters in Business Administrations (MBA).The general objective of this study was to construct a portfolio of securities in the Nairobi stock exchange (NSE), which have high excess return to beta ratios delivered from the sharpe single index model. The specific objectives of the study were to: • Determine how the alpha of individual securities affects the expected security return. • Determine how the beta of individual securities affects the expected security return. • Determine how market index return affects the expected security return. • Construct an excess return to beta ratio portfolio by combining the expected security return and betas derived from the sharpe single index model. The study used correlation reseach to dertermine the direction and strength of relationship between the independent variables, namely alpha, beta and market return with the dependent variable, the expected stock return. The study used the entire population of stocks listed and traded in NSE. Data was collected using the observation guide and the relevant data collected, were the end of month stocks prices, cash dividends, stock dividends, stock splits and market index values for the period January 2000 to December 2004. security and market returns were derived and regression analysis used to obtain alpha and beta coefficients, which were used in sharpe single index model to calculate the expected return of each security. All the securities were then ranked in descending order of excess return to beta ratio and all stocks, which were above a predetermined cut off point, were selected in the excess return to beta portfolio. The research findings revealed that alphas were strongly positively correlated with expected returns, with high alpha stocks providing the highest stocks levels of expected stock return. Alphas were found to be a good measure of unsystematic returns and abnormal returns not related to the returns on the benchmark index. The study reveled that betas are positively correlated with expected stock returns and also with systematic risks and R2. The study also reveled that market returns are positively correlated with expected stock returns and with those macroeconomics variables like GDP growth and inflation. Interest rates were however negatively correlated with market returns and expected security returns. The research also revealed that the construction of the ER: BR portfolio gave a portfolio with high expected returns but low total and systematic risks, that was lower than that of any single security in the portfolio. The excess return to beta ratio portfolio formation was successful in reducing total risk and unsystematic risk of the portfolio it was unable to substantially increase the R2, the portion of portfolio variance attributable to markets variance. The expected returns of the excess return to beta ratio portfolio were a quite accurate compared to the actual portfolio return. The study recommended the selection of high alpha stocks to provide for unsystematic returns. The study further recommended the selection of high betas stocks to provide high returns during periods of high forecast economic growth and the selection of low beta stocks to minimize risks during periods when macroeconomic turbulence is forecast. The formation of excess returns to beta ratio portfolios was recommended because it provides investors with a technique that allows for high weighting of those securities, which have the highest amount of expected returns and highly systematic risk and/ or low unsystematic risks. The study further recommended that further research be carried out to test the accuracy of expected returns derived from the Sharpe single index model by comparing the means of actual monthly security returns for the next 24 months to the expected monthly returns

Differential behavioural flexibility in response to predation risk in native and introduced tropical savannah rodents

Differential predation risk between habitats, or 'the landscape of fear', can have profound impacts on foraging strategies of prey. Few studies, however, have described the landscape of fear in the wild, in relation to predator densities. Using giving-up density experiments, and vertebrate surveys, we described the landscape of fear for two rodent species in relation to actual predator abundances in a tropical savannah. We offered native eastern chestnut mice, Pseudomys gracilicaudatus, and introduced house mice, Mus musculus domesticus, food in the open, and under the cover of grass. When eastern brown snakes, Pseudonaja textilis, were absent, both eastern chestnut and house mice consumed more food items under grass. In habitats where snakes were abundant, however, eastern chestnut mice changed their foraging behaviour, and consumed more food items in the open than under grass. In contrast, non-native house mice reduced their foraging activity under cover, but showed no increase in foraging in the open in the presence of snakes. Thus, native eastern chestnut mice have the ability to change their foraging tactics to adjust their antipredator behaviour to remain successful in the presence of native eastern brown snakes, whereas introduced house mice did not exhibit this behaviour

Short-term responses of reptile assemblages to fire in native and weedy tropical savannah

Fire is frequently used as a management tool to reduce the cover of weeds, to reduce the amount of fuel available for future fires, and to create succession mosaics that may enhance biodiversity. We determined the influence of fire on wildlife, by quantifying reptile assemblage composition in response to fire in a weedy environment characterised by very short-term fire return intervals (<2 years). We used reptiles because they are often understudied, and are only moderately vagile compared to other vertebrates, and they respond strongly to changes in vegetation structure. We repeatedly sampled 24 replicate sampling sites after they had been unburned for two years, just prior to burning (pre-burnt), just after burning (post-burnt), and up to 15 months after burning (revegetated) and monitored vegetation structure and reptile richness, abundance and assemblage composition. Our sites were not spatially auto-correlated, and were covered by native kangaroo grass (Themeda triandra), black spear grass (Heteropogon contortus), or an invasive weed (grader grass, Themeda quadrivalvis). Reptile abundance and richness were highest when sites had been unburned for 2 years, and greatly reduced in all areas post burning. The lowest reptile abundances occurred in sites dominated by the weed. Reptile abundance and richness had recovered in all grass types 15 months after burning, but assemblage composition changed. Some species were present only in before our focus fire in native grass, and their populations did not recover even 15 months post-burning. Even in fire-prone, often-burnt habitats such as our study sites, in which faunal richness and abundance were not strongly influenced by fire, reptile assemblage composition was altered. To maintain faunal biodiversity in fire-prone systems, we suggest reducing the frequency of prescribed fires, and (if possible) excluding fire from weedy invasions if it allows native grasses to return

Decoupled diversification dynamics of feeding morphology following a major functional innovation in marine butterflyfishes

The diversity of fishes on coral reefs is influenced by the evolution of feeding innovations. For instance, the evolution of an intramandibular jaw joint has aided shifts to corallivory in Chaetodon butterflyfishes following their Miocene colonization of coral reefs. Today, over half of all Chaetodon species consume coral, easily the largest concentration of corallivores in any reef fish family. In contrast with Chaetodon, other chaetodontids, including the long-jawed bannerfishes, remain less intimately associated with coral and mainly consume other invertebrate prey. Here, we test (i) if intramandibular joint (IMJ) evolution in Chaetodon has accelerated feeding morphological diversification, and (ii) if cranial and post-cranial traits were affected similarly. We measured 19 cranial functional morphological traits, gut length and body elongation for 33 Indo-Pacific species. Comparisons of Brownian motion rate parameters revealed that cranial diversification was about four times slower in Chaetodon butterflyfishes with the IMJ than in other chaetodontids. However, the rate of gut length evolution was significantly faster in Chaetodon, with no group-differences for body elongation. The contrasting patterns of cranial and post-cranial morphological evolution stress the importance of comprehensive datasets in ecomorphology. The IMJ appears to enhance coral feeding ability in Chaetodon and represents a design breakthrough that facilitates this trophic strategy. Meanwhile, variation in gut anatomy probably reflects diversity in how coral tissues are procured and assimilated. Bannerfishes, by contrast, retain a relatively unspecialized gut for processing invertebrate prey, but have evolved some of the most extreme cranial mechanical innovations among bony fishes for procuring elusive prey