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Una tortuga Chelidae (Testudines: Pleurodira) de cuello largo en el Grupo Neuquén, Río Negro, Argentina: Significado cronológico y paleobiogeográfico
de la Fuente,Marcelo S; Barbieri,Rubén; Chafrat,Pablo;
Andean geology , 2010,
Abstract: a long necked chelid turtle species from the anacleto formation (late santonian-early campanian) cropping out at valle de la luna rojo, río negro province, argentina, is assigned to yaminuechelys cf. gasparinii de la fuente, de lapparent de broin and manera de bianco, 2001 and it represents the oldest record of a long-necked chelid. we suggest that the common ancestor of yaminuechelys and hydromedusa lived in southern gondwana before the separation of australia from the remaining southern gondwanan landmasses. the presence of this chelid taxon in the late cretaceous of patagonia and some previous phylogenetic analyses support the hypothesis of an early differentiation and diversification of chelids on southern gondwana.
Una tortuga Chelidae (Testudines: Pleurodira) de cuello largo en el Grupo Neuquén, Río Negro, Argentina: Significado cronológico y paleobiogeográfico A long-necked Chelidae turtle (Testudines: Pleurodira) from the Neuquén Group, Río Negro, Argentina: Chronological and paleobiogeographical significance
Marcelo S de la Fuente,Rubén Barbieri,Pablo Chafrat
Andean Geology , 2010,
Abstract: Diferentes restos de una tortuga Chelidae cuellilarga de la Formación Anacleto (Santoniano tardío-Campaniano temprano), aflorante en la localidad de Valle de la Luna Rojo, Provincia de Río Negro, Argentina, son conferidos a la especie Yaminuechelys cf. gasparinii De la Fuente, De Lapparent de Broin y Manera de Bianco, 2001. Ellos representan el registro más antiguo para el género y los Chelidae de cuello largo. Se sugiere que el ancestro común de Yaminuechelys e Hydromedusa habitó en Gondwana meridional con anterioridad a la separación de Australia. La presencia de este taxón en el Cretácico Tardío en Patagonia y algunos de los resultados de los análisis filogenéticos previos apoyan la hipótesis sobre una temprana diferenciación y diversificación de los quélidos en dicha región de Gondwana. A long necked chelid turtle species from the Anacleto Formation (late Santonian-early Campanian) cropping out at Valle de La Luna Rojo, Río Negro Province, Argentina, is assigned to Yaminuechelys cf. gasparinii De la Fuente, De Lapparent de Broin and Manera de Bianco, 2001 and it represents the oldest record of a long-necked chelid. We suggest that the common ancestor of Yaminuechelys and Hydromedusa lived in Southern Gondwana before the separation of Australia from the remaining Southern Gondwanan landmasses. The presence of this chelid taxon in the Late Cretaceous of Patagonia and some previous phylogenetic analyses support the hypothesis of an early differentiation and diversification of chelids on Southern Gondwana.
Environmental stress upon hepatopancreatic cells of freshwater prawns (Decapoda: Caridea) from the floodplain of Paraná River  [PDF]
Pablo Collins
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.27094
Abstract: In order to evaluate the influence of stressed environments on hepatopancreatic cells of fre- shwater prawns, Macrobachium borellii Nobili, 1896 and Palaemonetes argentinus Nobili 1901, (Crustacea, Decapoda, Palaemonidae) were collected at three different aquatic environments with different relationship to urban development in Argentina. Furthermore the effects of several cypermethryn concentration on hepa- topancreatic cell of M. borellii and P. argentinus were evaluated in a laboratory assays. The “N° 1” lake (Santa Fe Argentina) which is more affected by the anthropogenic pressure and “Don Felipe” lake which is still not strongly by human activities were the studied sites from the floodplain of Paraná river. While Alejandra lake was the intermedia effects sites. Different damaged ultra-structures were found in F- and R-cells of prawns in the stressed lake. The predominant features were: disrupted the microvillous border, swelled mitochondria, reduction of endoplasmic reticulum, dyctiosomes, glycoproteins, desna-turalization of vacuole membrane and premature autolysis. Moreover the F-cell number was higher in the environment near to city than in the others sites. Similar effects were observed in the cypermethryn assays. The observations clearly indicate that the ultrastructure of midgut gland in the both palaemonids varies depending on the site from which animals are collected and the biocid presence. So, in this case it can be stated that the hepatopancreas histology of fre- shwater prawns is a good tool to monitor the impact of a stressed environment upon freshwater prawns.
A Note on Price Asymmetry Using a Monetary Model  [PDF]
Pablo L. Schiaffino, Juan Pablo Pinasco
Theoretical Economics Letters (TEL) , 2014, DOI: 10.4236/tel.2014.48088
Abstract: In this paper we present a macroeconomic foundation of downward money price inflexibility based on classical Monetary Economics. We show that under the principle of risk aversion and the neutral money axiom, our model derives an endogenous asymmetric price response as prices adjust more rapidly when they go upward than downward. This asymmetry does not disappear; on the contrary, it is increasing in time.
Influenza epidemics and Spanish climatic domains  [PDF]
Pablo Fdez-Arroyabe
Health (Health) , 2012, DOI: 10.4236/health.2012.430144
Abstract: The present article proposes a climatic approach to the study of the interaction between influenza spreading and climatic and meteorological factors in different climatic domains of the Iberian Peninsula. This association can be used to help in the prevention and mitigation of influenza epidemics. A biometeorological index has been defined and applied to the epidemic periods that took place in the Iberian Peninsula between 2000 and 2009 considering its climatic domains.
An Iterative Method for Solving Two Special Cases of Lane-Emden Type Equation  [PDF]
Pedro Pablo Cárdenas Alzate
American Journal of Computational Mathematics (AJCM) , 2014, DOI: 10.4236/ajcm.2014.43021
Abstract:

In this work we apply the differential transformation method or DTM for solving some classes of Lane-Emden type equations as a model for the dimensionless density distribution in an isothermal gas sphere \"\" and as a study of the gravitational potential of (white-dwarf) stars ,\"\" which are nonlinear ordinary differential equations on the semi-infinite domain [1] [2]. The efficiency of the DTM is illustrated by investigating the convergence results for this type of the Lane-Emden equations. The numerical results show the reliability and accuracy of this method.

A Survey of the Implementation of Numerical Schemes for Linear Advection Equation  [PDF]
Pedro Pablo Cárdenas Alzate
Advances in Pure Mathematics (APM) , 2014, DOI: 10.4236/apm.2014.48052
Abstract:

The interpolation method in a semi-Lagrangian scheme is decisive to its performance. Given the number of grid points one is considering to use for the interpolation, it does not necessarily follow that maximum formal accuracy should give the best results. For the advection equation, the driving force of this method is the method of the characteristics, which accounts for the flow of information in the model equation. This leads naturally to an interpolation problem since the foot point is not in general located on a grid point. We use another interpolation scheme that will allow achieving the high order for the box initial condition.

A Survey of the Implementation of Numerical Schemes for the Heat Equation Using Forward Euler in Time  [PDF]
Pedro Pablo Cárdenas Alzate
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.213135
Abstract: We establish the conditions for the compute of the Global Truncation Error (GTE), stability restriction on the time step and we prove the consistency using forward Euler in time and a fourth order discretization in space for Heat Equation with smooth initial conditions and Dirichlet boundary conditions.
A Special Case of Variational Formulation for Two-Point Boundary Value Problem in L2(Ω)  [PDF]
Pedro Pablo Cárdenas Alzate
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.64065
Abstract: We consider the nonlinear boundary value problems for elliptic partial differential equations and using a maximum principle for this problem we show uniqueness and continuous dependence on data. We use the strong version of the maximum principle to prove that all solutions of two-point BVP are positives and we also show a numerical example by applying finite difference method for a two-point BVP in one dimension based on discrete version of the maximum principle.
REDD+ and the Indigenous Question: A Case Study from Ecuador
Pablo Reed
Forests , 2011, DOI: 10.3390/f2020525
Abstract: One of the main issues regarding the implementation of REDD+ in Latin America has been the growing concern that such projects may infringe upon the rights and negatively affect the livelihoods of forest-dependent communities. Various indigenous and civil society organizations are ardently opposed to the initiative. Such is the case in Ecuador, where indigenous opposition to REDD+ represents a considerable obstacle in the creation of a national strategy since more than 60% of the country’s remaining forest cover is on indigenous land or under indigenous occupation. Thus one of the most critical challenges remaining for Ecuador will be the construction of a strong legal, financial, and institutional framework—one that the greater indigenous community might be willing to accept. Closer examination of this topic however, reveals just how difficult this may become. Lack of information, a recent political split between national authorities and the indigenous sector, and the dissimilar organizational capacity levels of indigenous communities make the feasibility of carrying out REDD+ projects on these lands extremely complex. However, the biggest obstacle may be ideological. Many indigenous groups view REDD+, with its possible emphasis on international markets and neoliberal mechanisms, as a continuation of the type of policies that have impeded their quest for sovereignty and self determination. As such, indigenous people are only willing to consider such projects if they clearly see preconditions in place that would safeguard their cultures, territories, and autonomy.
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