Reconnaissance of prehistoric rock-avalanches and rock blocks slides in the Andean area of Neuquén (37°15′-37°30′S)

Five prehistoric rock-avalanches are described in the northern cordilleran region of Neuquén Province, between 37°15′ and 37°30′S and between 70°55′ and 71°05′W. These slides and their deposits were not previously identified and moreover they were classified as glacial and glaciofluvial in origin. All of them are developed on volcanic-sedimentary deposits. They are named after local places: Cerro Piche Moncol, Cerro Guañaco, Cerro Coronal, Laguna Negra and Laguna Lauquen Mallin avalanches. The first three form a group of avalanches situated north of Reñileuvú creek, in the vicinity of the previously described Moncol rock-avalanche. Their break-away zones are located on the lateral slopes of a pre-existing deep glacial valley. The biggest rock-avalanche is the Cerro Piche Moncol and its deposits are due to the collapse of the southern flank of a volcanic edifice with a small caldera. The Cerro Guañaco, Cerro Coronal and Laguna Negra rock-avalanches began as a slump slide to evolving distally into a flow. The slides of Laguna Lauquen Mallín are big rock-block slides. Some local factors, principally contrasting lithology and physical properties, structural factors and more humid conditions during postglacial times favourable conditions for the loss of slope equilibrium. The authors suggest that these gravitational movements triggered by seismic shock. The age of these rock-avalanches is unknown but they must be younger than last local glaciation. © 2005 Asociación Geológica Argentina.Fil:Folguera, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

The cosmic flow in the Local Supercluster: Tracing PSCz tidal influence through optimized Least Action Principle

We assess the extent to which the flux-limited PSCz redshift sample is capable of accounting for the major share of mass concentrations inducing the external tidal forces affecting the peculiar velocities within the Local Supercluster (LS). The investigation is based upon a comparison of the ``true'' velocities in 2 large N-body simulations and their reconstruction from ``observation-mimicking'' mock catalogues. The mildly nonlinear ``mock'' LS and PSCz velocities are analyzed by means of the Least Action Principle technique in its highly optimized implementation of Nusser & Branchini's Fast Action Method (FAM). For both model N-body Universes, we conclude that the dipolar and quadrupolar force field implied by the PSCz galaxy distribution would indeed be sufficiently representing the full external tidal force field.Comment: 2 pages, 1 figure, contribution to ``Where's the Matter? Tracing Dark and Bright Matter with the New Generation of Large Scale Surveys'', June 2001, Treyer & Tresse Eds, Frontier Grou

Fiabilidad y validez de constructo del test MUNSH para medir felicidad, en población de adultos mayores chilenos

Diaz, EM (reprint author), Univ Talca, Fac Psicol, Casilla 747, Talca, Chile.The goal was to adapt and to conduct the preliminary validation of the Scale of Happiness of the Memorial University of Newfounland (MUNSH). Three hundred elderly (Maule, Chile) of more than 65 years (M = 72,8; DS = 5,71), answered the MUNSH, the Life Satisfaction Scale of Diener (ESV), and the Abbreviated Geriatric Depression Scale of Yesavage (EGADY). The MUNSH reached a Cronbach's alpha consistency of 0.90, and correlated positively with the ESV (r = 0.623) and negatively with the EGADY (r = -0.746), demonstrating appropriate convergent validity. A factor analysis revealed a multifactorial structure for the MUNSH with a single factor explaining 31,7 % of the variance. The data collected with the MUNSH are analyzed in terms of age and sex differences and separate normative scores are provided. Accession Number: WOS:00029970900002

Rock avalanche of Potrero de Levés" southern Sierras Pampeanas, Sierra Grande of San Luis, Argentina (32° 30'S lot.)

The first rock avalanche to be identified in the southern Sierras Pampeanas is described here and its origin analysed. It is located in the northern sector (Cordon El Realito) of the San Luis fault scarp, which marks the western slope of the Sierra Grande de San Luis. It is suggested that the avalanche was triggered by seismic schock, a hypothesis supported by the seismotectonic and geologic conditions of the region as well as by the records of historical seismicity and by the recognition of modern fractures, scarplets and springwater spots in the piedmont area. Several other geological factors also support this suggestion, such as joint density, main shear zone location, attitude of the internal structure of granitoids and other nearby gravitational movements. The primary landforms of the avalanche landscape strongly suggest that the event was a recent one. The estimated speed is about 190 km/hour. © 1997 Asociacón Geológica Argentina.Fil:Fauque, L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Costa, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Pereyra, F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Effect of continuum couplings in fusion of halo 11^{11}Be on 208^{208}Pb around the Coulomb barrier

The effect of continuum couplings in the fusion of the halo nucleus $^{11}$Be on $^{208}$Pb around the Coulomb barrier is studied using a three-body model within a coupled discretised continuum channels (CDCC) formalism. We investigate in particular the role of continuum-continuum couplings. These are found to hinder total, complete and incomplete fusion processes. Couplings to the projectile $1p_{1/2}$ bound excited state redistribute the complete and incomplete fusion cross sections, but the total fusion cross section remains nearly constant. Results show that continuum-continuum couplings enhance the irreversibility of breakup and reduce the flux that penetrates the Coulomb barrier. Converged total fusion cross sections agree with the experimental ones for energies around the Coulomb barrier, but underestimate those for energies well above the Coulomb barrier.Comment: 15 pages, 7 figures, accepted in Phys. Rev.

Quark Hadron Phase Transition and Hybrid Stars

We investigate the properties of hybrid stars consisting of quark matter in the core and hadron matter in outer region. The hadronic and quark matter equations of state are calculated by using nonlinear Walecka model and chiral colour dielectric (CCD) model respectively. We find that the phase transition from hadron to quark matter is possible in a narrow range of the parameters of nonlinear Walecka and CCD models. The transition is strong or weak first order depending on the parameters used. The EOS thus obtained, is used to study the properties of hybrid stars. We find that the calculated hybrid star properties are similar to those of pure neutron stars.Comment: 25 pages in LaTex and 9 figures available on request, IP/BBSR/94-3

Grain Surface Models and Data for Astrochemistry

AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions

Recent experimental results in sub- and near-barrier heavy ion fusion reactions

Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus will be mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations over-predict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars.Comment: 40 pages, 63 figures, review paper accepted for EPJ

Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology

notes: As the primary author, O’Malley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. ‘Macrobe’ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes – the dominant life form on the planet, both now and throughout evolutionary history – will transform some of the philosophy of biology’s standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology – including biofilm formation, chemotaxis, quorum sensing and gene transfer – that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations