Characterizing the dual mixed volume via additive functionals

Integral representations are obtained of positive additive functionals on finite products of the space of continuous functions (or of bounded Borel functions) on a compact Hausdorff space. These are shown to yield characterizations of the dual mixed volume, the fundamental concept in the dual Brunn-Minkowski theory. The characterizations are shown to be best possible in the sense that none of the assumptions can be omitted. The results obtained are in the spirit of a similar characterization of the mixed volume in the classical Brunn-Minkowski theory, obtained recently by Milman and Schneider, but the methods employed are completely different

Use of Medicines by Community Dwelling Elderly in Ontario

OBJECTIVE: Prescription medicine use by the elderly is of growing concern as indicated by a large literature focused on rising costs, patient compliance and the appropriateness of use. However, prescriptions account for only a portion of medicines used by the elderly, who have increasing access to non-prescription medicines and natural health products. The objective of this paper is to describe overall medicine use among the elderly in Ontario. METHODS: Using the National Population Health Survey (1996/97), we describe self-reported use of prescription, non-prescription and alternative medicines among elderly Ontarians aged 65+, and we compare use among four age sub-groups and by gender. Analysis is focused on the prevalence of, and the relative balance of use of different types of medicines. RESULTS: About one quarter of the respondents reported using no prescription or non-prescription medicines in the two days prior to being surveyed; a large majority reported using two or fewer medicines only, and use of non- prescription medicines was reported more often than prescription medicines (56% vs 48%). Use of natural health products by seniors is relatively low, but we observe a trend toward increased use in younger age groups. DISCUSSION: The findings place the consumption of prescription medicines by the elderly into a broader context that reveals that much of medicine use by the elderly involves non-prescribed products. We highlight the need to better understand seniors' decision-making regarding the different types of medicines available, and the financial costs and health risks of the medicine regimes of elderly persons.elderly, medicine-use, prescription medicines, over-the-counter medicines, natural health products, NPHS

Egg parasitoid exploitation of plant volatiles induced by single or concurrent attack of a zoophytophagous predator and an invasive phytophagous pest

Zoophytophagous insect predators can induce physiological responses in plants by activating defence signalling pathways, but whether plants can respond to facultative phytophagy by recruiting natural enemies remains to be investigated. In Y-tube olfactometer bioassays, using a system including a Vicia faba plant, the zoophytophagous predator Podisus maculiventris and the egg parasitoid Telenomus podisi, we first demonstrated that T. podisi females are attracted by broad bean plants damaged by feeding activity of P. maculiventris and on which host egg masses had been laid, while they are not attracted by undamaged plants or plants damaged by feeding activity alone. In a second experiment, we evaluated the impact of the invasive phytophagous pest Halyomorpha halys on this plant volatile-mediated tritrophic communication. Results showed that the invasive herbivorous adults do not induce plants to recruit the native egg parasitoid, but they can disrupt the local infochemical network. In fact, T. podisi females are not attracted by volatiles emitted by plants damaged by H. halys feeding alone or combined with oviposition activity, nor are they attracted by plants concurrently infested by P. maculiventris and H. halys, indicating the specificity in the parasitoid response and the ability of the invasive herbivore in interrupting the semiochemical communication between plants and native egg parasitoids. To the best of our knowledge, this is the first study showing that zoophytophagous predator attacks induce indirect plant defences similarly to those defence strategies adopted by plants as a consequence of single or concurrent infestations of herbivorous insects

Evidence of non-thermal X-ray emission from HH 80

Protostellar jets appear at all stages of star formation when the accretion process is still at work. Jets travel at velocities of hundreds of km/s, creating strong shocks when interacting with interstellar medium. Several cases of jets have been detected in X-rays, typically showing soft emission. For the first time, we report evidence of hard X-ray emission possibly related to non-thermal processes not explained by previous models of the post-shock emission predicted in the jet/ambient interaction scenario. HH 80 is located at the south head of the jet associated to the massive protostar IRAS 18162-2048. It shows soft and hard X-ray emission in regions that are spatially separated, with the soft X-ray emission region situated behind the region of hard X-ray emission. We propose a scenario for HH 80 where soft X-ray emission is associated to thermal processes from the interaction of the jet with denser ambient matter and the hard X-ray emission is produced by synchrotron radiation at the front shock.Comment: Accepted for publication in ApJ

Detection of nonthermal emission from the bow shock of a massive runaway star

The environs of massive, early-type stars have been inspected in recent years in the search for sites where particles can be accelerated up to relativistic energies. Wind regions of massive binaries that collide have already been established as sources of high-energy emission; however, there is a different scenario for massive stars where strong shocks can also be produced: the bow-shaped region of matter piled up by the action of the stellar strong wind of a runaway star interacting with the interstellar medium. We study the bow-shock region produced by a very massive runaway star, BD+43 3654, to look for nonthermal radio emission as evidence of a relativistic particle population. We observed the field of BD+43 3654 at two frequencies, 1.42 and 4.86 GHz, with the Very Large Array (VLA), and obtained a spectral index map of the radio emission. We have detected, for the first time, nonthermal radio emission from the bow shock of a massive runaway star. After analyzing the radiative mechanisms that can be at work, we conclude that the region under study could produce enough relativistic particles whose radiation might be detectable by forthcoming gamma-ray instruments, like CTA North.Comment: Accepted in Astronomy and Astrophysics Letter

Just a different place to graze? An unusual occurrence of the echinoid feeding trace Gnathichnus pentax on a marine vertebrate coprolite (Miocene, Italy) and its palaeoethological implications

Faeces produced by marine vertebrates and macro-invertebrates contain sufficient organic matter to represent a usable food source for a wide array of macroscopic animals. In some extant marine environments, coprophagy even represents a crucial trophic interaction in food webs. In ancient ecosystems, coprophagy by macroscopic animals is occasionally exemplified by coprolites that exhibit biting traces or burrows. Here, we report Gnathichnus pentax on an exquisitely preserved vertebrate-bitten vertebrate coprolite from the marine calcareous deposits of the Pietra leccese (Miocene, southern Italy). This unusual occurrence is interpreted as evidence of the feeding activity of a regular echi-noid; in particular, it may represent either exploratory coprophagy or the browsing of an algal (microbial) film that locally developed on the exterior of the faeces. Strengthening the former interpretation, the development of microbial communities on submerged faeces often leads to their destruction; furthermore, some extant Antarctic echinoderms are well known to ordinarily feed on vertebrate faeces, and coprophagy is believed to be fairly widespread among sea urchins. Supporting the algal browsing hypothesis, in turn, only a limited area of the external surface of the faeces was subject to grazing, and the resulting trace is neatly defined, which suggest that the feeding sea urchin targeted a precise location on the dung's exterior when the latter was already rather firm. To our knowledge, the G. pentax specimen studied here represents the first published record of this ichnotaxon on a coprolite

Prediction of Canopy Photosynthesis for Cocksfoot Pastures Grown Under Different Light Regimes

Plants in field environments can experience frequent fluctuations in irradiance from full sun to shade caused by cloud cover, overstory shading (e.g. silvopastoral systems) and within canopy shading. Research with widely spaced radiata pine (Pinus radiata D. Don) has suggested that due to its shade tolerance cocksfoot (Dactylis glomerata L.) is a suitable grass for silvopastoral systems. However, there is limited explanation of the physiological basis for the responses, and consequently no predictive capacity. This limits the application of results to environments, sites and seasons outside of those in which they were measured. The objectives of this study were to simulate net daily canopy photosynthesis rates incorporating the leaf photosynthesis models into a canopy photosynthesis model when only shade was limiting, and to determine the optimum net canopy photosynthesis and LAI for each light regime

The environs of the massive runaway star BD+43 3654

The very massive runaway star BD+43° 3654 (O4 If) seems to be related with a bow shock detected by the MSX mission, that would be the result of the interaction of the strong stellar wind with the ambient matter. Shock-accelerated electrons will cool through synchrotron radiation producing a non-thermal radio source, yet never detected in such scenario. While new Very Large Array observations are carried out, we have examined archive data and present here the findings.Fil: Peri, Cintia Soledad. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Benaglia, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto Argentino de Radioastronomia (i); Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Romero, Gustavo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto Argentino de Radioastronomia (i); Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Martí, J.. Universidad de Jaén; Españ

Social-psychological and Structural Factors Influencing the Experience of Chronic Disease: A focus on Individuals with Severe Arthritis

In-depth personal interviews were conducted with 29 men and women with severe arthritis of the hip or knee. All respondents had been identified by medical experts as having demonstrable need for total joint arthroplasty, but in assessment in another study, had stated an unwillingness to consider the procedure. In interviews, we explored 1) current self reported health status and co-morbidities; 2) features and functions of the informal and formal support network; and 3) general orientations to aging, illness and independence, to examine the influence of these on participants' strategies for coping with severe arthritis and their views of treatment options. We present a multi-level model of the social-interactional and social-structural features of lives in which the experience of arthritis and responses to it are contextualized. Interviews reveal a complex set of experiences and responses: participants frequently reject the medicalization of their arthritis; they normalize the experience of functional decline (ie: they modify expectations to fit their capacity), or define it as age normative; they draw on a broad set of previous experiences from the lay health care system as well as from the formal medical care system to define an appropriate strategy of coping for the "here and now". The discussion focuses on the distinction between objectively assessed disease and subjectively experienced illness, and the implications of this distinction for medical practice.illness experience, lay perspectives, social context, decision-making, chronic illness, arthritis