1,098 research outputs found
Las nuevas excavaciones (1995-2006) en el yacimiento del Mioceno final de Venta del Moro, Valencia
Se presenta una síntesis preliminar de la metodología y de los principales resultados obtenidos en
las nuevas campañas de excavación (1995-2006) en la localidad clásica de vertebrados del Mioceno
final (Turoliense superior, MN13) de Venta del Moro (Valencia, España). Destaca la actualización de la
lista faunística, con la incorporación de más de una decena de taxones de vertebrados no citados anteriormente
en el yacimiento. Así, si consideramos sólo la asociación de mamíferos, el listado se compone,
por el momento, de 43 taxones. Además, se presentan las listas provisionales de otros grupos,
como los moluscos, y se cita por vez primera el hallazgo de foraminíferos.From 1995 until 2006 new paleontological excavations were carried out at Venta del Moro (Valencia,
Spain), one of the classical Uppermost Miocene (Upper Turolian, MN 13) vertebrate locality of Spain. In
the present paper a preliminary synthesis of the methods and main results are presented. Abundant faunal
remains were recovered including ten vertebrate taxa no previously recorded from the site. Up to
now 43 mammalian species are known from the site. Preliminary list of others groups, as mollusc, are
given. The occurrence of foraminifera is reported for the first [email protected] [email protected] [email protected] [email protected] [email protected]
Bose-Einstein condensate dark matter phase transition from finite temperature symmetry breaking of Klein-Gordon fields
In this paper the thermal evolution of scalar field dark matter particles at
finite cosmological temperatures is studied. Starting with a real scalar field
in a thermal bath and using the one loop quantum corrections potential, we
rewrite Klein-Gordon's (KG) equation in its hydrodynamical representation and
study the phase transition of this scalar field due to a Z_2 symmetry breaking
of its potential. A very general version of a nonlinear Schr\"odinger equation
is obtained. When introducing Madelung's representation, the continuity and
momentum equations for a non-ideal SFDM fluid are formulated, and the
cosmological scenario with the SFDM described in analogy to an imperfect fluid
is then considered where dissipative contributions are obtained in a natural
way.Additional terms appear compared to those obtained in the classical version
commonly used to describe the \LambdaCDM model, i.e., the ideal fluid. The
equations and parameters that characterize the physical properties of the
system such as its energy, momentum and viscous flow are related to the
temperature of the system, scale factor, Hubble's expansion parameter and the
matter energy density. Finally, some details on how galaxy halos and smaller
structures might be able to form by condensation of this SF are given.Comment: Substantial changes have been made to the paper, following the
referees recommendations. 16 pages. Published in Classical and Quantum
Gravit
Las nuevas excavaciones (1995-2006) en el yacimiento del Mioceno final de Venta del Moro, Valencia
From 1995 until 2006 new paleontological excavations were carried out at Venta del Moro (Valencia, Spain), one of the classical Uppermost Miocene (Upper Turolian, MN 13) vertebrate locality of Spain. In the present paper a preliminary synthesis of the methods and main results are presented. Abundant faunal remains were recovered including ten vertebrate taxa no previously recorded from the site. Up to now 43 mammalian species are known from the site. Preliminary list of others groups, as mollusc, are given. The occurrence of foraminifera is reported for the first time.Se presenta una síntesis preliminar de la metodología y de los principales resultados obtenidos en las nuevas campañas de excavación (1995-2006) en la localidad clásica de vertebrados del Mioceno final (Turoliense superior, MN13) de Venta del Moro (Valencia, España). Destaca la actualización de la lista faunística, con la incorporación de más de una decena de taxones de vertebrados no citados anteriormente en el yacimiento. Así, si consideramos sólo la asociación de mamíferos, el listado se compone, por el momento, de 43 taxones. Además, se presentan las listas provisionales de otros grupos, como los moluscos, y se cita por vez primera el hallazgo de foraminíferos
Presence of Mammuthus sp. from Caravaca (Murcia)
In Rambla del Pizcalejo (Caravaca, Murcia, Spain) new Proboscidea fossil remains were found. In this paper are
described all postcranial bones belonging to a 2-4 years old Mammuthus.
Stratigraphycal and mollusc data confirm the lacustrine paleoenvironment. The remains shouldn’t have suffered
a hard transport; neither should their time of exposure have been long.
The date of the remains is not precise due to the lack of chronostratigraphic and biostratigraphic data. It is only
the assignment of the remains to the genus Mammuthus that allows to surmise a period about Plio-Pleistocen
La fauna del pleistoceno inferior de la sierra de Quibas (Abanilla, Murcia)
El yacimiento kárstico cuaternario de la Sierra de Quibas (Abanilla, Murcia) ha proporcionado
una amplia lista faunística constituida por 53 especies repartidas entre gasterópodos,
miriápodos, anfibios, reptiles, aves y mamíferos. En el conjunto de los gasterópodos
destaca Palaeoglandina, un género que se extingue en el resto de Europa durante el Plioceno
y que se mantiene como relicto en el Pleistoceno de la Península Ibérica. Dos de las
especies de aves determinadas, Gypaetus barbatus y Gerontieus eremita, y una de las serpientes,
Elaphe cf. E. sealaris, apenas se hallan representadas en el registro fósil. Hay además
varias especies de aves cuya aparición en Quibas supone la primera cita en el Pleistoceno
inferior de la Península Ibérica. Entre los mamíferos posee una especial relevancia la
presencia del cercopitécido Macaca sylvanus. La asociación de los taxones Arvieola deuealíon,
Castillomys rivas rivas, Elíomys intermedius, Equus altidens y Capra sp. aff. C.
alba permite la correlación con Plines 1, Orce 3 y Venta Micena, entre otros. El yacimiento
de Quibas puede situarse, por tanto, antes del final del Pleistoceno inferior, con una antigüedad
entre 1.3 y 1 Ma. Por lo que se refiere a las condiciones paleoclimáticas, podemos
inferir a partir de la asociación faunística un régimen xerófilo, muy semejante al actual en
el área geográfica, aunque quizás con valores de humedad y temperatura algo superiores.
El entorno de la cavidad kárstica estaba formado por roquedo calcáreo con áreas abiertas
de matorral, pero en las proximidades se desarrollaron humedales y zonas arboladas, como
así lo atestigua la presencia de aves y micromamíferos típicos de estos hábitats.The Quaternary karstic site of Sierra de Quibas (Abanilla, Murcia, Spain) has provided
a wide faunallist with 53 species distributed among gastropods, myriapods, amphibians,
reptiles, birds and mammals. Especially interesting among the gastropods is
Palaeoglandina that became extinct in Europe during the Pliocene. It remains as a relict
genus in the Pleistocene of the Iberian Peninsula. Two of the birds, Gypaetus barbatus
and Geronticus eremita, and a snake, Elaphe cf. E. sealaris, are scarcely represented in the fossil record. For several birds, it is the first record in the Lower Pleistocene of the
Iberian Peninsula. Among the mammals, the presence of the Cercopithecine Macaca sylvanus
is especially relevant. The assemblage of the taxa Arvicola deucalion, Castillomys
rivas rivas, Eliomys intermedius, Equus altidens and Capra sp. aff. C. alba allows the
correlation with Plines 1, Orce 3 and Venta Micena, among other sites. Therefore Quibas
can be clated before the end of Lower Pleistocene, between 1.3 and 1 Ma. A dry paleoclimatic
regime, very similar to the current climate in the geographical area, though perhaps
slightly wetter and warmer, can be inferred from the faunal assemblage. The environment
of the karstic cavity was a rocky place with open brushwood areas, but in the
proximities there were wetlands and woodlands, as can be inferred from the presence of
birds and micromammals characteristic of these [email protected] [email protected]
Kretzoiarctos gen. nov., the Oldest Member of the Giant Panda Clade
The phylogenetic position of the giant panda, Ailuropoda melanoleuca (Carnivora: Ursidae: Ailuropodinae), has been one of the most hotly debated topics by mammalian biologists and paleontologists during the last century. Based on molecular data, it is currently recognized as a true ursid, sister-taxon of the remaining extant bears, from which it would have diverged by the Early Miocene. However, from a paleobiogeographic and chronological perspective, the origin of the giant panda lineage has remained elusive due to the scarcity of the available Miocene fossil record. Until recently, the genus Ailurarctos from the Late Miocene of China (ca. 8–7 mya) was recognized as the oldest undoubted member of the Ailuropodinae, suggesting that the panda lineage might have originated from an Ursavus ancestor. The role of the purported ailuropodine Agriarctos, from the Miocene of Europe, in the origins of this clade has been generally dismissed due to the paucity of the available material. Here, we describe a new ailuropodine genus, Kretzoiarctos gen. nov., based on remains from two Middle Miocene (ca. 12–11 Ma) Spanish localities. A cladistic analysis of fossil and extant members of the Ursoidea confirms the inclusion of the new genus into the Ailuropodinae. Moreover, Kretzoiarctos precedes in time the previously-known, Late Miocene members of the giant panda clade from Eurasia (Agriarctos and Ailurarctos). The former can be therefore considered the oldest recorded member of the giant panda lineage, which has significant implications for understanding the origins of this clade from a paleobiogeographic viewpoint
PP-239 Ancylostoma spp. in soil of public recreative areas of Culiacan and Navolato Sinaloa, Mexico
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV
A search for new physics is presented based on an event signature of at least
three jets accompanied by large missing transverse momentum, using a data
sample corresponding to an integrated luminosity of 36 inverse picobarns
collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector
at the LHC. No excess of events is observed above the expected standard model
backgrounds, which are all estimated from the data. Exclusion limits are
presented for the constrained minimal supersymmetric extension of the standard
model. Cross section limits are also presented using simplified models with new
particles decaying to an undetected particle and one or two jets
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