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10.1371/journal.pone.0103634 The first arrivals of hominin populations into Eurasia during the Early Pleistocene are currently considered to have occurred as short and poorly dated biological dispersions. Questions as to the tempo and mode of these early prehistoric settlements have given rise to debates concerning the taxonomic significance of the lithic assemblages, as trace fossils, and the geographical distribution of the technological traditions found in the Lower Palaeolithic record. Here, we report on the Barranc de la Boella site which has yielded a lithic assemblage dating to ~1 million years ago that includes large cutting tools (LCT). We argue that distinct technological traditions coexisted in the Iberian archaeological repertoires of the late Early Pleistocene age in a similar way to the earliest sub-Saharan African artefact assemblages. These differences between stone tool assemblages may be attributed to the different chronologies of hominin dispersal events. The archaeological record of Barranc de la Boella completes the geographical distribution of LCT assemblages across southern Eurasia during the EMPT (Early-Middle Pleistocene Transition, circa 942 to 641 kyr). Up to now, chronology of the earliest European LCT assemblages is based on the abundant Palaeolithic record found in terrace river sequences which have been dated to the end of the EMPT and later. However, the findings at Barranc de la Boella suggest that early LCT lithic assemblages appeared in the SW of Europe during earlier hominin dispersal episodes before the definitive colonization of temperate Eurasia took place.

Muchos cálculos de transporte para estudiar los datos del dispositivo TJ-II se realizan con el sistema de transporte ASTRA. Sin embargo, ingredientes fundamentales en estos cálculos tales como las fuentes de partículas o de energía se obtienen mediante complicados códigos independientes. Éstos son accesibles desde ASTRA mediante los procedimientos que se explican.

El barranc de la Boella de la Canonja és un jaciment descobert en el primer terç del segle XX. Cinquanta anys després de la seva descoberta, la publicació d'aquest jaciment pels senyors R. Capdevila i S. Vilaseca va permetre actualitzar l'escàs coneixement de la bioestratigrafia del quaternari del Camp de Tarragona (Vilaseca, 1973). Tal com assenyala el mateix S. Vilaseca, la presència de fòssils de mamífers en el barranc va ser donada a conèixer per J. R. Bataller en la memòria explicativa del segon mapa geològic del full 473 de l'IGME corresponent a Tarragona (Bataller, 1935). El mateix S. Vilaseca apunta altres descobertes de mamífers ressenyades en el Camp de Tarragona, com la nota de Faura i Sans sobre un fragment de molar de proboscidi que Harlé determinaria com Elephas meridionalis el mateix any (Faura i Sans, 1920; Harlé, 1920). Aquesta resta va ser enviada per A. Romaní, aleshores director del Museu Balaguer de Vilanova i la Geltrú, a qui li van fer arribar des d'unes pedreres del Port de Tarragona. Els treballs geològics de M. Faura i Sans, J.R. Bataller i S. Vilaseca durant el primer quart del segle XX protagonitzaren el desenvolupament de la geologia, la paleontologia i la prehistòria en el marc del Servei del Mapa de la Mancomunitat de Catalunya.

Critical stability issues involving magnetic reconnection that are likely to influence the successful operation of burning plasma experiments are addressed. In particular, we discuss: (1) the stabilization of drift-tearing modes in weakly collisional regimes, with particular reference to nonlinear stability, including neo-classical effects; (2) the present understanding of sawtooth oscillations, in particular the interpretation of peculiar sawtooth features in FTU experiments with pellet injection; (3) reconnection near the X-points of magnetic separatrices.

Proceedings of tile 1" R.C.A.N.S. Congress, Lisboa, October 1992 The studied marine Neogene-Quaternary of NE Venezuela outcrop in the localities of the Araya peninsula and in the Cubagua and Margarita islands discordant upon a basementof metamorphic rocks and pre-rniocenic sediments. These neogene-quaternary sections belong principally to the Cubagua Formation, which is composed of a lower clayish interval (Cerro Verde Member) and an upper one of calcareous nature (Cerro Negro Member), and to La Tejita and Tortuga formations. The age of this sedimentary interval, based upon analysis of planktonic foraminifera, ranges from the lower part of Late Miocene to Holocene. According to the calcareous nannoflora, in the Cubagua Formation a floral assemblage was identified which goes from the Zone NN10 until the limit of NN16-NN17 zones. The fauna of benthic foraminifera allowed one to establish that the paleoenvironmental evolution of the Cubagua Formation varied from bathial to neritic depths during the Early Pliocene. After a period of elevation an erosion during the greater part of the Pleistocene, water invading the eroded surface depositing upon it the calcareous sequence of the Tortuga Formation.

To determine the incidence and results of the treatment offered to acute thrombotic obstructions of mechanical valvular prostheses, we have reviewed a series of 3,637 consecutive hospital survivors who, between January 1970 and September 1990, underwent single mitral or aortic and double mitroaortic valve replacements (MVR, AVR, and DVR, respectively). The cumulative follow-up in these patients was 22,783 years (mean, 7.2 years; range, 0.6-19 years). Sixty-five patients (24 MVR, 13 AVR, and 28 DVR) experienced 72 thrombotic prosthetic obstructions (42 mitral and 41 aortic prostheses) at a mean interval of 3.4 years (range, 0.6-14 years) after the operation. The actuarial prosthetic thrombosis free estimates were 96 +/- 0.9% for MVR, 97 +/- 0.9% for AVR, and 96 +/- 0.8% for DVR (all NS). Mortality associated with prosthetic thrombosis was 25% (four in the MVR group, five in the AVR group, and seven in the DVR group). Fifty-seven patients (22 MVR, 12 AVR, and 23 DVR) underwent a total of 62 reoperations, with a hospital mortality of 17% (two MVR, four AVR, and four DVR). In 37 of the latter patients (20 MVR, three AVR, and 14 DVR), we performed valve replacement (31 mitral prostheses and 14 aortic prostheses), with a hospital mortality of 16% (six of 37) and only one case of subsequent rethrombosis (actuarial rethrombosis free estimate, 96 +/- 3.6%). Conversely, five of the 27 patients (actuarial rethrombosis free estimate, 41 +/- 20%) (two MVR, 11 AVR, and 14 DVR) (seven mitral prostheses and 21 aortic prostheses) whose prosthetic valves were debrided developed rethrombosis during follow-up (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)