oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

匹配条件: “Navajas” ,找到相关结果约95条。
列表显示的所有文章,均可免费获取
第1页/共95条
每页显示
Forced oscillation assessment of respiratory mechanics in ventilated patients
Daniel Navajas, Ramon Farré
Critical Care , 2001, DOI: 10.1186/cc972
Abstract: The mechanical properties of the respiratory system in paralysed and mechanically ventilated patients are commonly measured by means of occlusion techniques [1] or by multilinear regression analysis [2]. Respiratory resistance and elastance are computed from pressure and flow recorded at the airway opening under the assumption that the contribution of the patient's respiratory muscles is nil, so that airway pressure coincides with transpulmonary pressure. Although these measurements can readily be performed on paralysed patients, their application during assisted ventilation in patients with active inspiratory muscles is not possible. The only conventional procedure for assessing respiratory mechanics when the patient's respiratory muscles are active is to employ an oesophageal balloon catheter. However, the use of an oesophageal balloon is not practicable in applications during mechanical ventilation such as noninvasive ventilation or weaning.FOT is a method for noninvasively assessing respiratory mechanics during mechanical ventilation [3] and is applicable both in paralysed [4,5,6,7] and nonparalysed patients [8,9,10]. FOT is based on the application of a small pressure oscillation (about 2 cmH2O) at the airway opening by means of an external generator, and on recording the oscillation pressure and flow [11]. When employed in non-paralysed patients, forced oscillation is applied at a frequency (more than 2 Hz) that is much higher than the patient's breathing rate. At such high frequencies the activity of the muscle pump, which operates at the breathing frequency and its first harmonics, is negligible. Under this assumption the only driving pressure at the forced oscillation frequency is the pressure applied at the mouth by the external generator. Consequently, FOT applied at a sufficiently high frequency allows the noninvasive assessment of respiratory mechanics in patients with artificial respiratory support regardless of the degree of activity of their respirat
Macrozoobentos da Praia do Codó (Ubatuba, SP) e a presen?a de Halodule wrightii Ascherson
Corbisier, Thais Navajas;
Boletim do Instituto Oceanográfico , 1994, DOI: 10.1590/S0373-55241994000100008
Abstract: a year's survey conducted at a seagrass (halodule wrightii ascherson) bed and an adjacent bare sand area, on codó beach, ubatuba, southern brazil, showed that the macrobenthic species composition was different at the two habitats. surface deposit feeder infaunal polychaetes were the dominant species in the halodule site and omnivorous/carnivorous and filter feeder polychaetes, in the bare sand. these differences could be explained mainly by the characteristics of the sediment and the stability of the bottom and, secondly, by the presence of halodule. the presence of vegetation has no effect on density of macrobenthos, probably due to the small size of halodule plants, which do not support an abundant epifauna. despite that fact, both number and diversity of species were higher in the seagrass area than in the unvegetated site, as was epifaunal abundance. significant patterns of temporal fluctuations of macrobenthos abundance and species diversity were not observed, but diversity was the highest in spring at both habitats. the temporal fluctuations of abundance differed in the two habitats. at the unvegetated site instability of the substrate seems to be responsible for the observed fluctuations in densities. at the halodule site only light fluctuations occurred, though they did not follow those of macrophyte biomass. macropredator effects are suggested to be one of the controling factors of macrobenthos density at the vegetated habitat.
Benthic macrofauna of sandy intertidal zone at Santos estuarine system, S?o Paulo, Brazil
Corbisier, Thais Navajas;
Boletim do Instituto Oceanográfico , 1991, DOI: 10.1590/S0373-55241991000100001
Abstract: species composition, faunal density, species diversity and zonation patterns of benthic macrofauna, as well as its relation to sediment characteristics were examined and compared in three sandy beaches on the polyhaline area at santos estuarine system in the state of s?o paulo. samples were collected quarterly during one year (july/1977 - may/1978). low, mean and high intertidal levels were sampled. polyehaetes dominated the fauna, both in terms of numbers of species and numbers of individuals. the community structure of ponta da praia beach was characterized by high density, low diversity (h') and evenness (j'), due to the dominance of the spionid scolelepis squamata. at vicente de carvalho the fauna was characterized by the dominance of the polyehaetes laeonereis acuta and capitella capitata and presented low density, high diversity and evenness. at bertioga channel, intermediate values were observed and the fauna was dominated by scololepis squamata andlaeonereis acuta. the sediment texture was responsible for those figures, although some differences in diversity may be explained by differences in wave energy. the low number of crustaceans and molluscs suggests the effect of the estuarine pollution upon the fauna. the zonation pattern of both species distribution and community structure differed at the studied sites; it was not correlated with sediment characteristics which were relatively uniform down shore; however, the lowest diversity was observed at the high level in all sites.
Macrozoobentos da praia do Codó (Ubatuba, SP) e a presen?a de Halodule wrightii Ascherson
Corbisier, Thais Navajas;
Brazilian Journal of Oceanography , 1994, DOI: 10.1590/S1679-87591994000100008
Abstract: a year's survey conducted at a seagrass (halodule wrightii ascherson) bed and an adjacent bare sand area, on codó beach, ubatuba, southern brazil, showed that the macrobenthic species composition was different at the two habitats. surface deposit feeder infaunal polychaetes were the dominant species in the halodule site and omnivorous/carnivorous and filter feeder polychaetes, in the bare sand. these differences could be explained mainly by the characteristics of the sediment and the stability of the bottom and, secondly, by the presence of halodule. the presence of vegetation has no effect on density of macrobenthos, probably due to the small size of halodule plants, which do not support an abundant epifauna. despite that fact, both number and diversity of species were higher in the seagrass area than in the unvegetated site, as was epifaunal abundance. significant patterns of temporal fluctuations of macrobenthos abundance and species diversity were not observed, but diversity was the highest in spring at both habitats. the temporal fluctuations of abundance differed in the two habitats. at the unvegetated site instability of the substrate seems to be responsible for the observed fluctuations in densities. at the halodule site only light fluctuations occurred, though they did not follow those of macrophyte biomass. macropredator effects are suggested to be one of the controling factors of macrobenthos density at the vegetated habitat.
La conflictividad política en la década de 1860: disputas regionales y tensiones locales (Tucumán, Santiago y Salta)
Navajas,María José;
Poblaci?3n y sociedad , 2012,
Abstract: we analyze the obstacles and resistances generated by the process of political unification which stressed the relationship between the provinces and the central government, also affecting the frameworks of local and regional powers. it is intended to nuance the established notion of the nation-state's formation as a unidirectional process of penetration and subordination of the peripheries to the center. for this, we review various conflicts that affected the northern argentinean provinces. such conflicts were expressed through material actions, but also provoked ongoing controversies. in these controversies the political identities inherited from the previous decade had a prominent place.
Tarifas P oblicas y Distribuci 3n del Ingreso: Teor -a y Medici 3n Preliminar para la Argentina Tarifas P oblicas y Distribuci 3n del Ingreso: Teor -a y Medici 3n Preliminar para la Argentina
Alberto Porto,Fernando Navajas
Revista de Análisis Económico (RAE) , 1989,
Abstract: This article makes an effort in integrating the theory of public tariffs which considers aspect on income distribution with empirical evidence for the Argentinean economy. A theoretical framework is developed in order to relate these aspects which have been historically divorced for the argentinean case. It is then shown that some commonly used criteria to measure the impact of public tariffs on income distribution are mistaken. Finally, an attempt is made in measuring the presence of distributive considerations for Argentinean public tariffs. Tarifas Públicas y Distribución del Ingreso: Teoría y Medición Preliminar para la Argentina
On Managerial Incentives, Performance Indicators and Efficiency Audits in Public Enterprises On Managerial Incentives, Performance Indicators and Efficiency Audits in Public Enterprises
Fernando H. Navajas
Revista de Análisis Económico (RAE) , 1987,
Abstract: On Managerial Incentives, Performance Indicators and Efficiency Audits in Public Enterprises This article discusses the issues of the selection of performance indicators and the design of efficiency audits in public enterprises following a standar principal-agent model. First, using a well known proposition on the value of information we argue that there must exist a limit to the number of performance indicators employed and that some broadly advocated measures such as productivity indices may be redundant if a well defined (ourcomebosed) bonus incentive scheme is already in use. Second, following recent theoretical research on managerial accounting we interpret efficiency audits as condition of information mechanisms or costly investigations that are triggered only in specific circumstances, which depend on the extreme realisations of the outcome used to evaluate managerial performance.
Environmental Resources, Public Inputs and Fiscal Constraints Environmental Resources, Public Inputs and Fiscal Constraints
Omar Chissari,Fernando Navajas
Revista de Análisis Económico (RAE) , 1990,
Abstract: We study the consequences of a binding constraint on the level of public expenditures directed at sustaining an environmental resource, which enters as a public input (alongside capital) into the economy-wide production function. As expected, the long run stock of that resource is reduced: however, we also find that the long run capital stock is reduced in a larger proportion. Also, the capital-environmental resource ratio becomes sensitive to changes in the rate of interest. Environmental Resources, Public Inputs and Fiscal Constraints
LOS TRABAJADORES Y LA MOVILIZACIóN POLíTICA DE 1909-1910. UN ACERCAMIENTO A LA SOCIABILIDAD POPULAR
María José Navajas
Tzintzun. Revista de Estudios Históricos , 2008,
Abstract: El texto revisa la participación política de las clases trabajadoras del Distrito Federal a través de algunos espacios formales de sociabilidad a finales del porfiriato. En particular se busca determinar la manera como se vincularon los sectores trabajadores urbanos en el conflicto que dividía a las élites, cuáles fueron los canales y consignas utilizados, y evaluar su capacidad para apropiarse de estas consignas creadas por los grupos dirigentes. Se abordará el estudio de las clases trabajadoras a través de la sociedad mutualista y moralizadora de obreros, y las agrupaciones políticas que organizaron a los trabajadores durante la campa a electoral de 1909- 1910.
The Location of ICT activities in EU regions. Implications for regional policies
Salvador Barrios,Elena Navajas Cawood
Investigaciones Regionales , 2008,
Abstract: The location of ICT producing industries does matter for global competitivenessand long-run growth potential. For instance, the differing contribution ofICT to economic growth between the US and the EU is often mentioned as one of themain cause explaining the diverging growth performance of these two areas since themid-1990s. In turn, since the mid-1990s, countries with especially dynamic economicgrowth have tended to be highly specialized in ICT-producing and ICT-using industries,see van Ark and Inkaar (2005). More generally, ICT producing sectors, tendto promote technological change and innovative capability which are seen to be at thecore of economic growth and competitiveness. When considering the EU economy,ICT industries appear to be concentrated in a limited number of regions, see Koski etal. (2002) for empirical evidence. Afirst objective of the present paper is to documentthe location of ICT producing industries in European regions in order to map existingEU clusters as well as to analyze recent changes in these industries using recent dataon employment and firm location, especially in relation to the EU enlargement thathas taken place in May 2004. The location of the ICT-producing sectors is not the endof the story however. A crucial aspect concerns the nature of activities that are beingundertaken in different regions. Importantly, ICT industries do have different characteristicsin terms of human capital, skill requirement, and knowledge content. In particular,because of the positive association between human capital, knowledge andlong-run growth, it is important to analyze to what extent EU regional ICT clustersdiffer in according to these characteristics. The second question addressed in the paperconcerns the nature of ICT activities undertaken in EU regions. Finally, the paperprovides econometric estimates of the location of firms in ICT industries across EUregions. The paper considers more specifically the case of multinationals’ location.Results on the determinants of firms’ location appear to differ widely depending on the ICT sector considered as well as the type of companies considered. A number ofpolicy implications are derived from these results.
第1页/共95条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.