11,366 research outputs found
Rotation curves and metallicity gradients from HII regions in spiral galaxies
In this paper we study long slit spectra in the region of H emission
line of a sample of 111 spiral galaxies with recognizable and well defined
spiral morphology and with a well determined environmental status, ranging from
isolation to non-disruptive interaction with satellites or companions. The form
and properties of the rotation curves are considered as a function of the
isolation degree, morphological type and luminosity. The line ratios are used
to estimate the metallicity of all the detected HII regions, thus producing a
composite metallicity profile for different types of spirals. We have found
that isolated galaxies tend to be of later types and lower luminosity than the
interacting galaxies. The outer parts of the rotation curves of isolated
galaxies tend to be flatter than in interacting galaxies, but they show similar
relations between global parameters. The scatter of the Tully-Fisher relation
defined by isolated galaxies is significantly lower than that of interacting
galaxies. The [NII]/H ratios, used as metallicity indicator, show a
clear trend between Z and morphological type, t, with earlier spirals showing
larger ratios; this trend is tighter when instead of t the gradient of the
inner rotation curve, G, is used; no trend is found with the interaction
status. The Z-gradient of the disks depends on the type, being almost flat for
early spirals, and increasing for later types. The [NII]/H ratios
measured for disk HII regions of interacting galaxies are higher than for
normal/isolated objects, even if all the galaxy families present similar
distributions of H Equivalent Width.Comment: accepted for publication in A&A (tables for HII region parameters
incomplete, contact [email protected] for the whole set of tables
The Cauchy-Schlomilch transformation
The Cauchy-Schl\"omilch transformation states that for a function and , the integral of and over the
interval are the same. This elementary result is used to evaluate
many non-elementary definite integrals, most of which cannot be obtained by
symbolic packages. Applications to probability distributions is also given
Collaborative and intelligent networks and decision systems and services for supporting engineering and production management
Collaborative networks and systems (CNS) have received much attention in recent decades to reach a competitive advantage [...]This work was supported by national funds through the FCT-Fundacao para a Ciencia e Tecnologia, through the R&D Units Project Scopes: UIDB/00319/2020, UIDB/50014/2020, and EXPL/EME-SIS/1224/2021
Neutral perfect fluids of Majumdar-type in general relativity
We consider the extension of the Majumdar-type class of static solutions for
the Einstein-Maxwell equations, proposed by Ida to include charged perfect
fluid sources. We impose the equation of state and discuss
spherically symmetric solutions for the linear potential equation satisfied by
the metric. In this particular case the fluid charge density vanishes and we
locate the arising neutral perfect fluid in the intermediate region defined by
two thin shells with respective charges and . With its innermost flat
and external (Schwarzschild) asymptotically flat spacetime regions, the
resultant condenser-like geometries resemble solutions discussed by Cohen and
Cohen in a different context. We explore this relationship and point out an
exotic gravitational property of our neutral perfect fluid. We mention possible
continuations of this study to embrace non-spherically symmetric situations and
higher dimensional spacetimes.Comment: 9 page
Runoff at the micro-plot and slope scale following wildfire, central Portugal
Through their effects on soil properties and vegetation/litter cover, wildfires can strongly enhance overland flow generation and accelerate soil erosion [1] and, thereby, negatively affect land-use sustainability as well as downstream aquatic and flood zones. Wildfires are a common phenomenon in present-day Portugal, devastating in an average year some 100.000 ha of forest and woodlands and in an exceptional year like 2003 over 400.000 ha. There therefore exists a clear need in Portugal for a tool that can provide guidance to post-fire land management by predicting soil erosion risk, on the one hand, and, on the other, the mitigation effectiveness of soil conservation measures. Such a tool has recently been developed for the Western U.S.A. [3: ERMiT] but its suitability for Portuguese forests will need to be corroborated by field observations.
Testing the suitability of existing erosion models in recently burned forest areas in Portugal is, in a nutshell, the aim of the EROSFIRE projects. In the first EROSFIRE project the emphasis was on the prediction of erosion at the scale of individual hill slopes. In the ongoing EROSFIRE-II project the spatial scope is extended to include the catchment scale, so that also the connectivity between hill slopes as well as channel and road processes are being addressed. Besides ERMiT, the principal models under evaluation for slope-scale erosion prediction are: (i) the variant of USLE [4] applied by the Portuguese Water Institute after the wildfires of 2003; (ii) the Morgan–Morgan–Finney model (MMF) [5]; (iii) MEFIDIS [6]. From these models, MEFIDIS and perhaps MMF will, after successful calibration at the slope scale, also be applied for predicting catchment-scale sediment yields of extreme events
Development of a novel scheme for long-term body temperature monitoring: a review of benefits and applications
Body temperature is a health or disease marker that has been in clinical use for centuries. The threshold currently applied to define fever, with small variations, is 38 °C. However, current approaches do not provide a full picture of the thermoregulation process and its correlation with disease. This paper describes a new non-invasive body temperature device that improves the understanding of the pathophysiology of diseases by integrating a variety of temperature data from different body locations. This device enables to gain a deeper insight into fever, endogenous rhythms, subject activity and ambient temperature to provide anticipatory and more efficient treatments. Its clinical use would be a big step in the overcoming of the anachronistic febrile/afebrile dichotomy and walking towards a system medicine approach to certain diseases. This device has already been used in some clinical applications successfully. Other possible applications based on the device features and clinical requirements are also described in this paper.Cuesta Frau, D.; Varela Entrecanales, M.; Valor Pérez, R.; Vargas, B. (2015). Development of a novel scheme for long-term body temperature monitoring: a review of benefits and applications. Journal of Medical Systems. 39(4):1-7. doi:10.1007/s10916-015-0209-3S17394Gai, M., Merlo, I., Dellepiane, S., Cantaluppi, V., Leonardi, G., Fop, F., Guarena, C., Grassi, G., and Biancore, L., Glycemic pattern in diabetic patients on hemodialysis: Continuous Glucose Monitoring (CGM) analysis. Blood Purif. 38(1):68–73 , 2014.Kondziella, D., Friberg, C.K., Wellwood, I., Reiffurth, C., Fabricius, M., and Dreier, J.P.: Continuous EEG monitoring in aneurysmal subarachnoid hemorrhage: A systematic review. Neurocrit. Care (2014)Ciccone, A., Celani, M.G., Chiaramonte, R., Rossi, C., and Righetti, E., Continuous versus intermittent physiological monitoring for acute stroke. 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Care, 14, 2010.Sund-Levander, M., and Grodzinsky, E., Time for a change to assess and evaluate body temperature in clinical practice. Int. J. Nurs. Pract. 15:241–249, 2009.Cuesta-Frau, D., Varela, M., Aboy, M., and Miro, P., Description of a portable wireless device for body temperature acquisition and analysis. Sensors 9(10):7648–7663, 2009.Varela, M., Cuesta-Frau, D., Madrid, J.A., Churruca, J., Miro-Matinez, P., Ruiz, R., and Marinez, C., Holter monitoring of central peripheral temperature: Possible uses and feasibility study in outpatient settings. J. Clin. Monit. Comput. 4(23):209–216, 2009.Jordan, J., Miro, P., Cuesta-Frau, D., Varela, M., and Vargas B.: Aplicacion de analisis multivariante para la deteccion de estados prefebriles en pacientes ingresados (in Spanish), XXXIV Congreso Nacional de Estadistica e Investigacion Operativa, Castellon (Spain) (2013)Richman, J., and Moorman, J.R., Physiological time-series analysis using approximate entropy and sample entropy. Am. J. Physiol. Heart Circ. Physiol. 278(6):H2039–2049, 2000.Young, P., Saxena, M., Eastwood, G.M., Bellomo, R., and Beasley, R., Fever and fever management among intensive care patients with known or suspected infection: A multicentre prospective cohort study. Crit. Care Resusc. 13:97–102 , 2011.Drewry, A.M., Fuller, B.M., Bailey, T.C., and Hotchkiss, R.S., Body temperature patterns as a predictor of hospital-acquired sepsis in afebrile adult intensive care unit patients: A case-control study. Crit. Care,17, 2013.Musher, D., Fainstein, V., Young, E., and Pruett, T., Fever patterns. Their lack of significance. Arch. Intern. Med. 139(11):1225–8, 1979.Varela, M., Calvo, M., Chana, M., Gomez-Mestre, I., Asensio, R., and Galdos, P., Clinical implications of temperature curve complexity in critically ill patients. Crit. Care Med. 33(12):2764–2771, 2005.Varela, M., Churruca, J., Gonzalez, A., Martin, A., Ode, J., and Galdos, P., Temperature curve complexity predicts survival in critically ill patients. Am. J. Respir. Crit. Care Med. 174(3):290–298, 2006.Cuesta-Frau, D., Varela, M., Miro, P., Galdos, P., Abasolo, D., Hornero, R., and Aboy, M., Predicting survival in critical patients by use of body temperature regularity measurement based on Approximate Entropy. Med. Biol. Eng. Computing 45:671–678, 2007.Mackiowak, P. Temperature regulation and the pathogenesis of fever, Principles and Practice of Infectious Diseases, pp. 765–778. New York: Churchill Livingston Elsevier, 2010.Cherbuin N., and Brinkman C., Cognition is cool: Can hemispheric activation be assessed by tympanic membrane thermometry? Brain Cogn. 54:228–231, 2004
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