5,584 research outputs found

    870 micron continuum observations of the bubble-shaped nebula Gum 31

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    We are presenting here a study of the cold dust in the infrared ring nebula Gum 31. We aim at deriving the physical properties of the molecular gas and dust associated with the nebula, and investigating its correlation with the star formation in the region, that was probably triggered by the expansion of the ionization front. We use 870 micron data obtained with LABOCA to map the dust emission. The obtained LABOCA image was compared to archival IR,radio continuum, and optical images. The 870 micron emission follows the 8 micron (Spitzer), 250 micron, and 500 micron (Herschel) emission distributions showing the classical morphology of a spherical shell. We use the 870 micron and 250 micron images to identify 60 dust clumps in the collected layers of molecular gas using the Gaussclumps algorithm. The clumps have effective deconvolved radii between 0.16 pc and 1.35 pc, masses between 70 Mo and 2800 Mo, and volume densities between 1.1x10^3 cm^-3 and 2.04x10^5 cm^-3. The total mass of the clumps is 37600 Mo. The dust temperature of the clumps is in the range from 21 K to 32 K, while inside the HII region reaches ~ 40 K. The clump mass distribution is well-fitted by a power law dN/dlog(M/Mo) proportional to M^(-alpha), with alpha=0.93+/-0.28. The slope differs from those obtained for the stellar IMF in the solar neighborhood, suggesting that the clumps are not direct progenitors of single stars/protostars. The mass-radius relationship for the 41 clumps detected in the 870 microns emission shows that only 37% of them lie in or above the high-mass star formation threshold, most of them having candidate YSOs projected inside. A comparison of the dynamical age of the HII region with the fragmentation time, allowed us to conclude that the collect and collapse mechanism may be important for the star formation at the edge of Gum 31, although other processes may also be acting.Comment: 15 pages, 10 figures. Accepted for publication in A&

    Dissipative Dynamics of Collisionless Nonlinear Alfven Wave Trains

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    The nonlinear dynamics of collisionless Alfven trains, including resonant particle effects is studied using the kinetic nonlinear Schroedinger (KNLS) equation model. Numerical solutions of the KNLS reveal the dynamics of Alfven waves to be sensitive to the sense of polarization as well as the angle of propagation with respect to the ambient magnetic field. The combined effects of both wave nonlinearity and Landau damping result in the evolutionary formation of stationaryOA S- and arc-polarized directional and rotational discontinuities. These waveforms are freqently observed in the interplanetary plasma.Comment: REVTeX, 6 pages (including 5 figures). This and other papers may be found at http://sdphpd.ucsd.edu/~medvedev/papers.htm

    Teaching Functionally Equivalent Replacement Behaviors to Students with Problem Behavior: What? How? Why?

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    Twisted topological structures related to M-branes

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    Studying the M-branes leads us naturally to new structures that we call Membrane-, Membrane^c-, String^K(Z,3)- and Fivebrane^K(Z,4)-structures, which we show can also have twisted counterparts. We study some of their basic properties, highlight analogies with structures associated with lower levels of the Whitehead tower of the orthogonal group, and demonstrate the relations to M-branes.Comment: 17 pages, title changed on referee's request, minor changes to improve presentation, typos correcte

    Chemotherapy induced peripheral neuropathy: the modified total neuropathy score in clinical practice.

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    BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common, potentially reversible side effect of some chemotherapeutic agents. CIPN is associated with decreased balance, function and quality of life (QoL). This association has to date been under-investigated. AIMS: To profile patients presenting with CIPN using the modified Total Neuropathy Score (mTNS) in this cross-sectional study and to examine the relationship between CIPN (measured by mTNS) and indices of balance, quality of life (QoL) and function. METHODS: Patients receiving neurotoxic chemotherapy regimens were identified using hospital databases. Those who did not have a pre-existing neuropathy were invited to complete mTNS, Berg Balance Scale (BBS), timed up and go (TUG), and FACT-G QoL questionnaire. mTNS scores were profiled and also correlated with BBS, TUG and FACT-G using Spearmans correlation coefficient. RESULTS: A total of 29 patients undergoing neurotoxic chemotherapy regimens were tested. The patients mTNS scores ranged between 1 and 12 (median = 5), indicating that all patients had clinical evidence of neuropathy on mTNS. No significant correlations were found between mTNS and BERG (r = -0.29), TUG (r = 0.14), or FACT-G (r = 0.05). CONCLUSIONS: This study found a high prevalence of CIPN in patients treated with neurotoxic chemotherapy regimens. The mTNS provided a clinically applicable, sensitive screening tool for CIPN which could prove useful in clinical practice. mTNS did not correlate with BBS, TUG or FACT-G in this sample, possibly due to relatively mild levels of CIPN and consequent subtle impairments which were not adequately captured by gross functional assessments

    Prevalencia de factores de riesgo cardiovascular clásicos en población adulta de Talca, Chile, 2005

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    Departamento de Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud, Universidad de Talca, Talca, Chile. Instituto de Matemática y Física, Universidad de Talca, Talca, Chile. Departamento de Salud Pública, Facultad de Ciencias de la Salud, Universidad de Talca, Talca, Chile. Escuela de Psicología, Universidad de Talca, Talca, Chile.Background: Cardiovascular disease (CVD) has several traditional risk factors (RF), and some of them are potentially modifiable. Aim: To determine the prevalence of most common risk factors in adult population in Talca in Central Chile. Subjects and methods: We studied 1007 subjects aged 18 to 74 years (66% women), living in Talca, selected by a probability sampling. They answered a questionnaire and anthropometry, blood pressure, lipid profile and blood glucose were measured. Results: Thirty seven percent of subjects smoked, 70.1% had a body mass index over 25 kg/m2 and 41% had an abnormally high circumference. High blood pressure was found in 37% (36% of these subjects were unaware of this condition), 44.5% had hypercholesterolemia, 21.5% had low HDL cholesterol, 40.1% had hypertriglyceridemia and 26.3% had high blood glucose levels. Conclusions: There is a high prevalence of risk factors for CVD in adult population from Talca. The prevalence of risk factors is higher than that reported by the 2003 National Health Survery

    Patrón de comportamiento tipo A, ira y enfermedades cardiovasculares (ECV) en población urbana chilena

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    Diaz, EM (Moyano Diaz, Emilio)1; Icaza, G (Icaza, Gloria); Mujica, V (Mujica, Veronica); Nunez, L (Nunez, Loreto); Leiva, E (Leiva, Elba); Vasquez, M (Vasquez, Marcela); Palomo, I (Palomo, Ivan)A worldwide raise in the number of cardiovascular disease (CVD) and the existence of a higher percentage in Maule (Chile) than the national media, and increased attention in the analysis of psychological factors motivate to analyze the Type A Behavior Pattern (TABP) and anger in relation to CVD. The sample was 1007 adults between 18 and 74 years old (citizens of Talca, Chile), mostly women. They provided information about their demographic details, eating habits and lifestyle, answered the Novaco's Anger inventory and the Retiro Scale of Type A Behavior (RSTAB), and also were taken measurements like weight, body mass index and blood pressure and blood tests related to risk factors to traditional cardiovascular diseases. The results show Overall, that the participants appear highly sedentary (79.9%) with relatively high levels of tabaquism (53.6%), and hypercholesterolemia (44.5%), overweight (40.7%) and obesity (32.6%). A quarter of the sample also presents hyperglycemic indexes, hypertension and TABP unequally distributed by sex. The absence of PCTA (or PCTB presence) appeared mostly associated with traditional cardiovascular risk factors (CRF). Regarding anger, women present more high than men (2.1% against 0.3%; c(2)(3) = 27.99,p<.0001), decreasing for both sexes with age, while also befall stroke by sex

    Integrating hydraulic modelling and GIS for wastewater systems management: a case study

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    The increasing costs related to operation and maintenance of urban wastewater systems has led to a special attention of utilities in promoting studies to address the key problem of water infiltration, inflow and improper connections entering the separate drainage networks. This is a common and hard to predict operational situation that needs to be identified and minimized as it negatively affects the managerial conditions of the network and the downstream wastewater treatment plant (WWTP) efficiency. Management difficulties in separate drainage networks seldom occur when unexpected groundwater inflow, stormwater infiltration, and flows from improper connections enter into the dedicated sanitary sewer systems. Although the consequences that improper flows may have on wastewater systems are known, the problem is difficult to locate and quantify. The use of modelling tools is of special relevance to the planning, management and rehabilitation of these types of systems, which can be very useful for: (i) evaluating the capacity of existing systems in real time; (ii) testing alternative solutions to solve problems detected; or testing different procedures to operate the systems in extreme events scenarios. The implementation of mathematical models for determining the hydrodynamics behaviour of dry-weather and wet-weather flows in sewers was applied in a small urban wastewater network of the city of Braga in Portugal (Figure 1). The free user program US EPA SWMM was applied with the integration of GIS InterAqua information related to the wastewater collection system

    Thirty Meter Telescope Site Testing I: Overview

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    As part of the conceptual and preliminary design processes of the Thirty Meter Telescope (TMT), the TMT site testing team has spent the last five years measuring the atmospheric properties of five candidate mountains in North and South America with an unprecedented array of instrumentation. The site testing period was preceded by several years of analyses selecting the five candidates, Cerros Tolar, Armazones and Tolonchar in northern Chile; San Pedro Martir in Baja California, Mexico and the 13 North (13N) site on Mauna Kea, Hawaii. Site testing was concluded by the selection of two remaining sites for further consideration, Armazones and Mauna Kea 13N. It showed that all five candidates are excellent sites for an extremely large astronomical observatory and that none of the sites stands out as the obvious and only logical choice based on its combined properties. This is the first article in a series discussing the TMT site testing project.Comment: Accepted for publication in PASP, April 2009 issu
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