1,752,376 research outputs found
Miocene Biomarker Temperature and CO2 Estimates from DSDP Site 94-608
No full textClimate proxies indicate coupling between changes in atmospheric pCO2, global temperatures and ice volume over much of the Cenozoic. Evidence has been presented for decoupling of these factors in the Miocene, though the cause of the apparent decoupling was uncertain. Here, we revisit Deep Sea Drilling Program (DSDP) Site 608 (24-9 Ma) in the North Atlantic, to provide improved constraints on sea surface temperatures (SSTs) using the TEX86 and Uk'37 proxies, and use these to recalculate atmospheric pCO2. From the Oligocene/Miocene boundary to the middle Miocene Climatic Optimum (MCO, ~23.03 to ~14.5 Ma), SSTs at Site 608 were upwards of 30°C, nearly 15 °C warmer than modern. During the Middle Miocene Climatic Transition (MMCT), starting at ~14.5 Ma, SSTs cooled by ~ 6 °C These lower SSTs persisted until the end of our record (9 Ma). Our organic proxy derived SST estimates are considerably higher than those previously calculated from planktonic foraminiferal oxygen isotope data, leading to reassessed pCO2 estimates from alkenones ~65 to ~175 ppm higher than previously calculated, with other assumptions held constant. A pCO2 decrease from an average of ~430 ppm in MCO to ~305 ppm after the MMCT, in step with the ~6 °C SST cooling, demonstrates coupling of climate and the carbon cycle, as well as a highly sensitive climate system
Strontium isotope record of Miocene sediments from DSDP Hole 94-608
No full textWe developed an isotope (87Sr/86Sr, delta18O) reference section for the uppermost Oligocene to lower upper Miocene (ca. 25-8 Ma) at Site 608 in the northeastern North Atlantic. This site contains the least ambiguous magnetostratigraphic record of Miocene polarity changes available, providing direct correlations to the Geomagnetic Polarity Time Scale (GPTS). We integrate biostratigraphic, magnetostratigraphic, Sr isotope, and stable isotope data to provide a reference section for Miocene isotope fluctuations. The direct correlation of isotopes and biostratigraphy to the Geomagnetic Polarity Time Scale (GPTS) provides relatively precise age estimates. We use these age estimates to evaluate the timing of first and last occurrences of planktonic foraminifera, and conclude that many of these are synchronous within a 0.5 m.y. resolution between subtropical Site 563 (33°N) and high-latitude Site 608 (43°N). In addition, we use this chronology to estimate the ages of previously established Miocene oxygen isotope Zones Mi 1 through Mi 7 and to compare the Sr isotope record at Site 608 with previously published 87Sr/86Sr records. We approximate latest Oligocene to early late Miocene (25-8 Ma) Sr isotope changes with two linear regressions. The rate of increase of 87Sr/86Sr was high from the latest Oligocene (~25 Ma) to earliest middle Miocene (~15 Ma), with an estimated rate of 0.000059/m.y. Our ability to reproduce Sr isotope measurements is +/-0.000030 or better, yielding a stratigraphic resolution of as good as +/-0.5 m.y. for this interval. The rate of change was much lower from about 15 to 8 Ma (on average, 0.000013/m.y.), yielding Sr isotope stratigraphic resolution of worse than +/-2.3 m.y. The causes of the late Eocene to Miocene 87Sr/86Sr increases are not known. We speculate that a moderate 87Sr/86Sr increase (0.000030/m.y) which occurred during the late Eocene-latest Oligocene can be explained by intermittent glaciations and deglaciations of the Antarctic continent. These pulse-like changes in the input of glacial weathering products yield what appears to be a monotonic, linear increase. The increase in the frequency of glaciations during the latest Oligocene-early Miocene can explain the higher rate of change of 87Sr/86Sr at this time. We speculate that by the middle Miocene, the development of a permanent east Antarctica ice sheet resulted in decreased input of glacial weathering products and a lower rate of 87Sr/86Sr change
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
608 and 606 Adams Street
No full textA black and white snapshot of the upper floors of 608 and 606 Adams Street in downtown Toledo, Ohio. At the time this photo was taken 606 Adams was the Town Club restaurant and 608 was vacant. Today 606 Adams is an office building and 608 is the Adams Street Cafe. Photo was taken by Howard Mackenzie in September of 1974
El Tlacuache Núm. 608 (2014). 608 Año 13 (2014) febrero. El Tlacuache
No full textCuerpos para Xinula. La presencia de la Sirena entre los tepehuas de la huasteca hidalguense por Karina Munguí Ochoa. - La invención de la frontera: territorialidades novohispanas por Israel Lazcarro Salgado
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Verlustliste Nr. 608. (Nr. 608. /1917)
No full textVERLUSTLISTE NR. 608.
Verlustliste (-)
Verlustliste Nr. 608. (Nr. 608. /1917) ([1])
Belehrung. (2)
Offiziere. (3)
A, B, C, D, E, F, G, H, J (3)
K (3)
L, M, N, P, R (4)
S (4)
T, U, V, W, Z (5)
Einjährig-Freiwillige. (5)
Mannschaft. (6)
A (6)
B (6)
C (9)
D (10)
E (12)
F (12)
G (13)
H (14)
I (16)
J (16)
K (17)
L (21)
M (22)
N (25)
O (26)
P (27)
R (29)
S (31)
T (39)
U (41)
V (42)
W (43)
Z (44)
Ergänzungen zu den Verlustlisten: (45)
Nr. 40. Nr. 46. Nr. 546. (45)
Berichtigungen zu den Verlustlisten: (45)
Nr. 104. Nr. 119. Nr. 148. Nr. 157. Nr. 190. Nr. 222. Nr. 234. Nr. 239. Nr. 309. Nr. 326. Nr. 336. Nr. 349. Nr. 356. Nr. 382. Nr. 385. Nr. 405. (45)
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Ergänzungen und Berichtigungen zu den Verlustlisten: (46)
Nr. 23. Nr. 25. Nr. 97. Nr. 122. Nr. 170. Nr. 199. Nr. 280. Nr. 351. Nr. 521. (46)
Berichtigungen bereits veröffentlichter, jedoch nicht legal nachweisbarer Todesfälle. (46)
Nr. 379. Nr. 446. (46
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
(Table 1) Calcium and magnesium in porewater at DSDP Hole 94-608
No full textThe suggestion that nuclear waste material might be buried within the sediments of the deep ocean has increased interest in possible ways that vertical pore-water movement might be detected and measured. A heat-flow station (Discovery 10335) previously occupied near Kings Trough indicated nonlinear temperature-depth profiles in the surficial sediments, which could be interpreted in terms of a very high upward pore-water velocity. The calcium and magnesium pore-water profiles at Site 608, however, prove to be unusually linear and show a strong inverse correlation with each other. In these circumstances it is very unlikely that vertical pore-water movements have occurred, and the application of a simple model indicates that, given the assumptions of this model, the vertical pore-water advection velocity has been zero ± 0.006 cm yr**-1. for a substantial fraction of the recent sedimentological history of this area
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