Benthic foraminiferal assemblages and epifaunal isotope record of the Agulhas Plateau

Benthic foraminiferal assemblages and the carbon isotope composition of the epifaunal benthic foraminifera Epistominella exigua and Fontbotia wuellerstorfi have been investigated along core MD02-2589 located at the southern Agulhas Plateau (41°26.03'S, 25°15.30'E, 2660 m water depth). This study aims to evaluate changes in the benthic paleoenvironment and its influence on benthic d13C with a notable focus on E. exigua, a species associated with phytodetritus deposits and poorly studied in isotope paleoceanographic reconstructions. The benthic foraminiferal assemblages (>63 µm) show large fluctuations in species composition suggesting significant changes in the pattern of ocean surface productivity conceivably related to migrations of the Subtropical Convergence (STC) and Subantarctic Front (SAF). Low to moderate seasonality and relatively higher food supply to the seafloor are indicated during glacial marine isotope stages (MIS) 6, 4, and 2 and during MIS 3, probably associated with the northward migration of the SAF and confluence with the more stationary STC above the southern flank of the Agulhas Plateau. The lowest organic carbon supply to the seafloor is indicated from late MIS 5b to MIS 4 as a consequence of increased influence of the Agulhas Front (AF) and/or weakening of the influence of the STC over the region. Episodic delivery of fresh organic matter, similar to modern conditions at the core location, is indicated during MIS 5c-MIS 5e and at Termination I. Comparison of this paleoenvironmental information with the paired d13C records of E. exigua and F. wuellerstorfi suggests that organic carbon offsets d13C of E. exigua from ambient bottom water d13CDIC, while its d13C amplitude, on glacial-interglacial timescales, does not seem affected by changes of organic carbon supply to the seafloor. This suggests that this species calcifies preferentially during the short time span of the year when productivity peaks and phytodetritus is delivered to the seafloor. Therefore E. exigua, while offset from d13CDIC, potentially more faithfully records the amplitude of ambient bottom water d13CDIC changes than F. wuellerstorfi, notably in settings such as the Southern Ocean that experienced substantial changes through time in the organic carbon supply to the seafloor.

Late Eocene to Early Oligocene magnetostratigraphic chron boundaries of ODP Hole 119-744A (Table 1)

The earliest Oligocene (~33.5 Ma) is marked by a major step in the long-term transition from an ice-free to glaciated world. The transition, characterized by both cooling and ice-sheet growth, triggered a transient but extreme glacial period designated Oi-1. High-resolution isotope records suggest that Oi-1 lasted for roughly 400,000 yr (the duration of magnetochron 13N) before partially abating, and that it was accompanied by an ocean-wide carbon isotope anomaly of 0.75?. One hypothesis relates the carbon isotope anomaly to enhanced export production brought about by climate-induced intensification of wind stress and upwelling, particularly in the Southern Ocean. To understand how this climatic event affected export production in the Southern Ocean, biogenic silica (opal) and carbonate accumulation rates were computed for the sub-polar Indian Ocean using deep-sea cores from ODP Site 744, Kerguelen Plateau. Our findings suggest that net productivity in this region increased by several fold in response to the Oi-1 glaciation. In addition, calcareous primary producers dominant in the Late Eocene were partially replaced by opaline organisms suggesting a trend toward seasonally greater surface divergence and upwelling in this sector of the Southern Ocean. We attribute these changes to intensification of atmospheric=oceanic circulation brought about by high-latitude cooling and the appearance of a full-scale continental ice-sheet on East Antarctica. Higher terrigenous sediment accumulation rates support the idea that wind-induced changes in regional productivity were augmented by an increased supply of glacial dust and debris that provided limiting micro-nutrients (e.g., iron-rich dust particles). We speculate that the rapid changes in biogenic sediment accumulation in the Southern Ocean and other upwelling-dominated regions contributed to the ocean-wide positive carbon isotope anomaly by temporarily increasing the burial rate of organic carbon relative to carbonate carbon. The changes in burial rates, in turn, may have produced a positive feedback on climate by briefly drawing down atmospheric pCO2 .

(Table 2) Ice rafted debris abundance and accumulation rate, sedimentation rate and dry bulk density of bottom sediments from the Sea of Okhotsk

Oxygen isotope records, radiocarbon AMS data, carbonate and opal stratigraphy, sediment magnetic susceptibility, tephrachronology, and paleontological results were used to obtain detailed sediment stratigraphy and an age model for the studied cores. For studying sea-ice sedimentation an analysis of lithogenic grain number in >0.15 mm grain size fraction of bottom sediments was carried out. For quantitative estimation of intensity ice-rafting debris sedimentation number of IRD particles per sq cm per ka was calculated. Obtained results allowed to plot IRD AR distribution for the first oxygen isotope stage (0-12.5 14C ka, 14C) and for the second stage (12.5-24 14C ka). The first stage was subdivided into the latest deglaciation and the beginning of Holocene (6-12.5 14C ka) (transitive period), when the sea level was changing significantly, and the second part of Holocene (0-6 14C ka), when climate conditions and the sea level were similar to modern estimates. Data clearly show strong increase in ice formation in the glacial Sea of Okhotsk and its extent in the middle part of the sea. Average annual duration of ice coverage during glaciation was longer than that for interglaciation. However the sea ice cover was not continuous all the year round and disappeared in summer time except the far northwestern part of the sea.

Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic

A high-resolution (10-20 kyr) record of variations in CaCO3 content and dissolution was established for latest Cretaceous (last 0.7 Myr) deep-sea sediments from the South Atlantic Ocean (DSDP Site 516 from the Rio Grande Rise, and sites 525 and 527 from the Walvis Ridge). The degree of fragmentation of planktonic foraminifera (DFP) was used as a measure of calcite dissolution. High negative correlations between DFP and other independent measures of carbonate dissolution (percentage of sand fraction, absolute abundance of planktonic foraminifera, and planktonic/benthic foraminiferal ratio) validate its use as a sensitive index of calcite dissolution in upper Maastrichtian deep-sea sediments. Very high DFP and a significant negative correlation between DFP and CaCO 3 content suggest that Site 516 was located below the foraminiferal lysocline during the entire interval studied. Such a shallow position of the lysocline (paleodepth of Site 516 was 1.2 km) may be explained by "upwelling" of corrosive deep waters along the southern margin of the Rio Grande Rise. Sites 525 and 527 were located above the foraminiferal lysocline; however, three short periods of enhanced dissolution were recognised at Site 525 (paleodepth 1 km) and one interval of strong dissolution was identified at Site 527 (paleodepth 2.7 km). The lack of correspondence between the dissolution regimes at sites from the Walvis Ridge suggests limited deep-water communication across this physiographic barrier. Two of the dissolution maxima recognised at Site 525 correspond to carbonate maxima at Site 527. Variations in "upwelling" intensity along the Walvis Ridge, resulting in fluctuations in primary productivity in this area, may be the proximal cause of both carbonate cycles at Site 527 and dissolution cycles at Site 525. We suggest that development of the bottom Ekman layer between a hypothetical westward geostrophic current and the topographical height of the Rio Grande Rise-Walvis Ridge system may be a plausible hydrodynamical explanation for the proposed "'upwelling" along the southern margin of this topographical structure.

Geochemistry and stable isotope record of black shales and inoceramids from the Demerara Rise

The bulk rock geochemistry and inoceramid isotopic composition from Cenomanian to Santonian, finely laminated, organic-rich black shales, recovered during Ocean Drilling Program Leg 207 on Demerara Rise (western tropical North Atlantic), suggest persistent anoxic (free H2S) conditions within the sediments and short-term variations within a narrow range of anoxic to episodically dysoxic bottom waters over a ~15 Ma time interval. In addition to being organic-rich, the 50-90 m thick sections examined exhibit substantial bulk rock enrichments of Si, P, Ba, Cu, Mo, Ni, and Zn relative to World Average Shale. These observations point to high organic burial fluxes, likely driven by high primary production rates, which led to the establishment of intensely sulfidic pore waters and possibly bottom waters, as well as to the enrichments of Cr, Mo, U, and V in the sediments. At the same time, the irregular presence of benthic inoceramids and foraminifera in this facies demonstrates that the benthic environment could not have been continuously anoxic. The d13C and d15N values of the inoceramid shell organics provide no evidence of chemosymbiosis and are consistent with pelagic rain as being a significant food source. Demerara Rise inoceramids also exhibit well-defined, regularly spaced growth lines that are tracked by d13C and d18O variations in shell carbonate that cannot be simply explained by diagenesis. Instead, productivity variations in surface waters may have paced the growth of the shells during brief oxygenation events suitable for benthic inoceramid settlement. These inferences imply tight benthopelagic coupling and more dynamic benthic conditions than generally portrayed during black shale deposition. By invoking different temporal scales for geochemical and paleontological data, this study resolves recent contradictory conclusions (e.g., sulfidic sedimentary conditions versus dysoxic to suboxic benthic waters) drawn from studies of either sediment geochemistry or fossil distributions alone on Demerara Rise. This variability may be relevant for discussions of black shales in general.

Intracranial EEG correlates of implicit relational inference within the hippocampus

Drawing inferences from past experiences enables adaptive behavior in future situations. Inference has been shown to depend on hippocampal processes. Usually, inference is considered a deliberate and effortful mental act which happens during retrieval, and requires the focus of our awareness. Recent fMRI studies hint at the possibility that some forms of hippocampus-dependent inference can also occur during encoding and possibly also outside of awareness. Here, we sought to further explore the feasibility of hippocampal implicit inference, and specifically address the temporal evolution of implicit inference using intracranial EEG. Presurgical epilepsy patients with hippocampal depth electrodes viewed a sequence of word pairs, and judged the semantic fit between two words in each pair. Some of the word pairs entailed a common word (e.g.,‘winter - red’, ‘red - cat’) such that an indirect relation was established in following word pairs (e.g, ‘winter - cat’). The behavioral results suggested that drawing inference implicitly from past experience is feasible because indirect relations seemed to foster ‘fit’ judgments while the absence of indirect relations fostered 'do not fit' judgments, even though the participants were unaware of the indirect relations. A event-related potential (ERP) difference emerging 400 ms post-stimulus was evident in the hippocampus during encoding, suggesting that indirect relations were already established automatically during encoding of the overlapping word pairs. Further ERP differences emerged later post-stimulus (1500 ms), were modulated by the participants' responses and were evident during encoding and test. Furthermore, response-locked ERP effects were evident at test. These ERP effects could hence be a correlate of the interaction of implicit memory with decision-making. Together, the data map out a time-course in which the hippocampus automatically integrates memories from discrete but related episodes to implicitly influence future decision making.

Should I Stay or Should I Go? Career Choice Intentions of Students with Family Business Background

Personal and motivational patterns of intentional founders have been researched in great depth; however, antecedents to career choices of intentional successors have been conspicuously missing in entrepreneurship research. By drawing on theory of planned behavior, we investigate how intentional founders, successors, and employees differ in terms of locus of control and entrepreneurial self-efficacy as well as independence and innovation motives. We find that transitive likelihood of career intent depends on degree of entrepreneurial self-efficacy and the independence motive. Unexpectedly, we see that high levels of internal locus of control lead to a preference of employment, which challenges traditional entrepreneurship research and suggests that the feasibility of an entrepreneurial career path does not automatically make it desirable. Our findings suggest that students with family business background are pessimistic about being in control in an entrepreneurial career, but optimistic about their efficacy to pursue an entrepreneurial career.

Some things that matter,/

How to concentrate -- How to deserve -- How to read -- The art of public speaking -- Maxims for speakers -- The use of the dictionary -- The fly-wheel of civilization : importance of habit -- How to think -- How to judge things -- Circumstantial evidence -- Facts and inferences --Hearsay and what is relevant -- How to find things out -- The laws of thought -- Legal maxims -- The moral duty of belief.

A history of trade unionism in the United States,

"Part I ... is based on the History of labour in the United States by Commons and associates ..."

Causación y ergatividad en la semántica relacional

En el marco de la gramática contrastiva entre inglés y castellano, asumimos la perspectiva generativista, según la cual la sintaxis humana resulta de procesos derivacionales que combinan, por medio de mecanismos innatos, elementos capaces de codificar significados primitivos. Trabajamos con datos, ya sea reales o inventados, que ilustran los distintos tipos de oraciones ?gramaticales? posibles en una lengua natural. Nos centramos en la noción de ?ergatividad?, utilizada por distintas teorías para explicar fenómenos sintácticos y semánticos no siempre coincidentes. Desde el Funcionalismo/Cognitivismo norteamericano, Scott DeLancey (2001) compara distintas lenguas y distingue morfológicamente los sujetos ?agentivos? en estructuras causadas de los sujetos ?afectados? en estructuras no causadas. Según la Lingüística Sistémica Funcional (Halliday 1985, 2004), la ergatividad abarca, no sólo la presencia o ausencia de Causa en un proceso particular, sino también la relación causal que vincula distintos procesos entre sí. El esquema ergativo de Halliday incluye, además de pares constituidos por eventos de cambio de estado no causados y de causa externa, eventos inergativos de causa externa, y eventos transitivos instigados por otro proceso, expresado lingüísticamente o bien inferido. Desde la perspectiva de la Semántica Relacional (Mateu, 2002), reducimos el número de ?constructos primitivos? disponibles de tres a dos. Consideramos dos alternancias: la ergativo-transitiva y la causa interna/externa con inergativos. No vinculamos ni sintáctica ni derivacionalmente las construcciones transitivas con los eventos inferidos que las instigan. Justificamos la relación derivacional que vincula las construcciones pasivas estáticas con las construcciones ergativas de verbos naturalmente alternantes, por un lado, y, con las construcciones transitivas de verbos de ?locatum? y de inergativos, por el otro. Reanalizamos, respecto de la bibliografía canónica, la naturaleza del clítico ?se? en las construcciones ergativas españolas. Este análisis orienta de manera teórica el abordaje de las construcciones pertinentes, y ofrece equivalencias posibles que pueden resultar útiles para la traducción

Causación y ergatividad en la semántica relacional

En el marco de la gramática contrastiva entre inglés y castellano, asumimos la perspectiva generativista, según la cual la sintaxis humana resulta de procesos derivacionales que combinan, por medio de mecanismos innatos, elementos capaces de codificar significados primitivos. Trabajamos con datos, ya sea reales o inventados, que ilustran los distintos tipos de oraciones ?gramaticales? posibles en una lengua natural. Nos centramos en la noción de ?ergatividad?, utilizada por distintas teorías para explicar fenómenos sintácticos y semánticos no siempre coincidentes. Desde el Funcionalismo/Cognitivismo norteamericano, Scott DeLancey (2001) compara distintas lenguas y distingue morfológicamente los sujetos ?agentivos? en estructuras causadas de los sujetos ?afectados? en estructuras no causadas. Según la Lingüística Sistémica Funcional (Halliday 1985, 2004), la ergatividad abarca, no sólo la presencia o ausencia de Causa en un proceso particular, sino también la relación causal que vincula distintos procesos entre sí. El esquema ergativo de Halliday incluye, además de pares constituidos por eventos de cambio de estado no causados y de causa externa, eventos inergativos de causa externa, y eventos transitivos instigados por otro proceso, expresado lingüísticamente o bien inferido. Desde la perspectiva de la Semántica Relacional (Mateu, 2002), reducimos el número de ?constructos primitivos? disponibles de tres a dos. Consideramos dos alternancias: la ergativo-transitiva y la causa interna/externa con inergativos. No vinculamos ni sintáctica ni derivacionalmente las construcciones transitivas con los eventos inferidos que las instigan. Justificamos la relación derivacional que vincula las construcciones pasivas estáticas con las construcciones ergativas de verbos naturalmente alternantes, por un lado, y, con las construcciones transitivas de verbos de ?locatum? y de inergativos, por el otro. Reanalizamos, respecto de la bibliografía canónica, la naturaleza del clítico ?se? en las construcciones ergativas españolas. Este análisis orienta de manera teórica el abordaje de las construcciones pertinentes, y ofrece equivalencias posibles que pueden resultar útiles para la traducción

Causación y ergatividad en la semántica relacional

En el marco de la gramática contrastiva entre inglés y castellano, asumimos la perspectiva generativista, según la cual la sintaxis humana resulta de procesos derivacionales que combinan, por medio de mecanismos innatos, elementos capaces de codificar significados primitivos. Trabajamos con datos, ya sea reales o inventados, que ilustran los distintos tipos de oraciones ?gramaticales? posibles en una lengua natural. Nos centramos en la noción de ?ergatividad?, utilizada por distintas teorías para explicar fenómenos sintácticos y semánticos no siempre coincidentes. Desde el Funcionalismo/Cognitivismo norteamericano, Scott DeLancey (2001) compara distintas lenguas y distingue morfológicamente los sujetos ?agentivos? en estructuras causadas de los sujetos ?afectados? en estructuras no causadas. Según la Lingüística Sistémica Funcional (Halliday 1985, 2004), la ergatividad abarca, no sólo la presencia o ausencia de Causa en un proceso particular, sino también la relación causal que vincula distintos procesos entre sí. El esquema ergativo de Halliday incluye, además de pares constituidos por eventos de cambio de estado no causados y de causa externa, eventos inergativos de causa externa, y eventos transitivos instigados por otro proceso, expresado lingüísticamente o bien inferido. Desde la perspectiva de la Semántica Relacional (Mateu, 2002), reducimos el número de ?constructos primitivos? disponibles de tres a dos. Consideramos dos alternancias: la ergativo-transitiva y la causa interna/externa con inergativos. No vinculamos ni sintáctica ni derivacionalmente las construcciones transitivas con los eventos inferidos que las instigan. Justificamos la relación derivacional que vincula las construcciones pasivas estáticas con las construcciones ergativas de verbos naturalmente alternantes, por un lado, y, con las construcciones transitivas de verbos de ?locatum? y de inergativos, por el otro. Reanalizamos, respecto de la bibliografía canónica, la naturaleza del clítico ?se? en las construcciones ergativas españolas. Este análisis orienta de manera teórica el abordaje de las construcciones pertinentes, y ofrece equivalencias posibles que pueden resultar útiles para la traducción