TY  - JOUR
A1  - Quirico, E.
A1  - Moroz, Liubov V.
A1  - Schmitt, B.
A1  - Arnold, Gabriele
A1  - Faure, M.
A1  - Beck, P.
A1  - Bonal, L.
A1  - Ciarniello, M.
A1  - Capaccioni, F.
A1  - Filacchione, G.
A1  - Erard, S.
A1  - Leyrat, C.
A1  - Bockelee-Morvan, D.
A1  - Zinzi, A.
A1  - Palomba, E.
A1  - Drossart, P.
A1  - Tosi, F.
A1  - Capria, M. T.
A1  - De Sanctis, M. C.
A1  - Raponi, A.
A1  - Fonti, S.
A1  - Mancarella, F.
A1  - Orofino, V.
A1  - Barucci, A.
A1  - Blecka, M. I.
A1  - Carlson, R.
A1  - Despan, D.
A1  - Faure, A.
A1  - Fornasier, S.
A1  - Gudipati, M. S.
A1  - Longobardo, A.
A1  - Markus, K.
A1  - Mennella, V.
A1  - Merlin, F.
A1  - Piccioni, G.
A1  - Rousseau, B.
A1  - Taylor, F.
T1  - Refractory and semi-volatile organics at the surface of comet 67P/Churyumov-Gerasimenko: Insights from the VIRTIS/Rosetta imaging spectrometer
JF  - Icarus : international journal of solar system studies
N2  - The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument aboard the Rosetta spacecraft has performed extensive spectral mapping of the surface of comet 67P/Churyumov-Gerasimenko in the range 0.3-5 mu m. The reflectance spectra collected across the surface display a low reflectance factor over the whole spectral range, two spectral slopes in the visible and near-infrared ranges and a broad absorption band centered at 3.2 mu m. The first two of these characteristics are typical of dark small bodies of the Solar System and are difficult to interpret in terms of composition. Moreover, solar wind irradiation may modify the structure and composition of surface materials and there is no unequivocal interpretation of these spectra devoid of vibrational bands. To circumvent these problems, we consider the composition of cometary grains analyzed in the laboratory to constrain the nature of the cometary materials and consider results on surface rejuvenation and solar wind processing provided by the OSIRIS and ROSINA instruments, respectively. Our results lead to five main conclusions: (i) The low albedo of comet 67P/CG is accounted for by a dark refractory polyaromatic carbonaceous component mixed with opaque minerals. VIRTIS data do not provide direct insights into the nature of these opaque minerals. However, according to the composition of cometary grains analyzed in the laboratory, we infer that they consist of Fe-Ni alloys and FeS sulfides. (ii) A semi-volatile component, consisting of a complex mix of low weight molecular species not volatilized at T similar to 220 K, is likely a major carrier of the 3.2 p.m band. Water ice contributes significantly to this feature in the neck region but not in other regions of the comet. COOH in carboxylic acids is the only chemical group that encompasses the broad width of this feature. It appears as a highly plausible candidate along with the NH4+ ion. (iii) Photolytic/thermal residues, produced in the laboratory from interstellar ice analogs, are potentially good spectral analogs. (iv) No hydrated minerals were identified and our data support the lack of genetic links with the CI, CR and CM primitive chondrites. This concerns in particular the Orgueil chondrite, previously suspected to have been of cometary origin. (v) The comparison between fresh and aged terrains revealed no effect of solar wind irradiation on the 3.2 mu m band. This is consistent with the presence of efficient resurfacing processes such as dust transport from the interior to the surface, as revealed by the OSIRIS camera. (C) 2016 Elsevier Inc. All rights reserved.
KW  - Comets
KW  - Organic chemistry
KW  - Infrared observations
KW  - Meteorites
KW  - Spectrophotometry
Y1  - 2016
U6  - https://doi.org/10.1016/j.icarus.2016.02.028
SN  - 0019-1035
SN  - 1090-2643
VL  - 272
SP  - 32
EP  - 47
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - JOUR
A1  - Cohen, Andrew
A1  - Campisano, C.
A1  - Arrowsmith, J. Ramón
A1  - Asrat, Asfawossen
A1  - Behrensmeyer, A. K.
A1  - Deino, A.
A1  - Feibel, C.
A1  - Hill, A.
A1  - Johnson, R.
A1  - Kingston, J.
A1  - Lamb, Henry F.
A1  - Lowenstein, T.
A1  - Noren, A.
A1  - Olago, D.
A1  - Owen, R. B.
A1  - Potts, R.
A1  - Reed, Kate
A1  - Renaut, R.
A1  - Schäbitz, Frank
A1  - Tiercelin, J. -J.
A1  - Trauth, Martin H.
A1  - Wynn, J.
A1  - Ivory, S.
A1  - Brady, K.
A1  - Rodysill, J.
A1  - Githiri, J.
A1  - Russell, J.
A1  - Förster, Verena
A1  - Dommain, René
A1  - Rucina, S.
A1  - Deocampo, D.
A1  - Russell, J.
A1  - Billingsley, A.
A1  - Beck, C.
A1  - Dorenbeck, G.
A1  - Dullo, L.
A1  - Feary, D.
A1  - Garello, D.
A1  - Gromig, R.
A1  - Johnson, T.
A1  - Junginger, A.
A1  - Karanja, M.
A1  - Kimburi, E.
A1  - Mbuthia, A.
A1  - McCartney, T.
A1  - McNulty, E.
A1  - Muiruri, V.
A1  - Nambiro, E.
A1  - Negash, E. W.
A1  - Njagi, D.
A1  - Wilson, J. N.
A1  - Rabideaux, N.
A1  - Raub, T.
A1  - Sier, M. J.
A1  - Smith, P.
A1  - Urban, J.
A1  - Warren, M.
A1  - Yadeta, M.
A1  - Yost, C.
A1  - Zinaye, B.
T1  - The Hominin Sites and Paleolakes Drilling Project: inferring the environmental context of human evolution from eastern African rift lake deposits
JF  - Scientific Drilling
N2  - The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.
Y1  - 2016
U6  - https://doi.org/10.5194/sd-21-1-2016
SN  - 1816-8957
SN  - 1816-3459
VL  - 21
SP  - 1
EP  - 16
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - GEN
A1  - Cohen, Abby
A1  - Campisano, Christopher
A1  - Arrowsmith, J. Ramon
A1  - Asrat, Asfawossen
A1  - Behrensmeyer, A. K.
A1  - Deino, A.
A1  - Feibel, C.
A1  - Hill, A.
A1  - Johnson, R.
A1  - Kingston, J.
A1  - Lamb, Henry F.
A1  - Lowenstein, T.
A1  - Noren, A.
A1  - Olago, D.
A1  - Owen, Richard Bernhart
A1  - Potts, R.
A1  - Reed, Kate
A1  - Renaut, R.
A1  - Schäbitz, F.
A1  - Tiercelin, J.-J.
A1  - Trauth, Martin  H.
A1  - Wynn, J.
A1  - Ivory, S.
A1  - Brady, K.
A1  - O’Grady, R.
A1  - Rodysill, J.
A1  - Githiri, J.
A1  - Russell, Joellen
A1  - Foerster, Verena
A1  - Dommain, René
A1  - Rucina, J. S.
A1  - Deocampo, D.
A1  - Russell, J.
A1  - Billingsley, A.
A1  - Beck, C.
A1  - Dorenbeck, G.
A1  - Dullo, L.
A1  - Feary, D.
A1  - Garello, D.
A1  - Gromig, R.
A1  - Johnson, T.
A1  - Junginger, Annett
A1  - Karanja, M.
A1  - Kimburi, E.
A1  - Mbuthia, A.
A1  - McCartney, Tannis
A1  - McNulty, E.
A1  - Muiruri, V.
A1  - Nambiro, E.
A1  - Negash, E. W.
A1  - Njagi, D.
A1  - Wilson, J. N.
A1  - Rabideaux, N.
A1  - Raub, Timothy
A1  - Sier, Mark Jan
A1  - Smith, P.
A1  - Urban, J.
A1  - Warren, M.
A1  - Yadeta, M.
A1  - Yost, Chad
A1  - Zinaye, B.
T1  - The Hominin Sites and Paleolakes Drilling Project
BT  - inferring the environmental context of human evolution from eastern African rift lake deposits
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 611 
KW  - Turkana-Basin
KW  - Adar formation
KW  - climate-change
KW  - olorgesailie formation
KW  - Southern Ethiopia
KW  - global climate
KW  - Kenya Rift
KW  - Pleistocene
KW  - variability
KW  - patterns
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-412498
IS  - 611
ER  - 
TY  - JOUR
A1  - Yuan, X. H
A1  - Sobolev, Stephan Vladimir
A1  - Kind, Rainer
A1  - Oncken, Onno
A1  - Bock, Günter
A1  - Asch, Günter
A1  - Schurr, B.
A1  - Gräber, F.
A1  - Rudloff, Alexander
A1  - Hanka, W.
A1  - Wylegalla, Kurt
A1  - Tibi, R.
A1  - Haberland, Christian
A1  - Rietbrock, Andreas
A1  - Giese, Peter
A1  - Wigger, Peter
A1  - Rower, P.
A1  - Zandt, G.
A1  - Beck, S.
A1  - Wallace, T.
A1  - Pardo, M.
A1  - Comte, D.
T1  - Subduction and collision processes in the Central Andes constrained by converted seismic phases
Y1  - 2000
ER  - 
TY  - JOUR
A1  - van der Lubbe, H. J. L.
A1  - Krause-Nehring, J.
A1  - Junginger, A.
A1  - Garcin, Yannick
A1  - Joordens, J. C. A.
A1  - Davies, G. R.
A1  - Beck, C.
A1  - Feibel, C. S.
A1  - Johnson, T. C.
A1  - Vonhof, H. B.
T1  - Gradual or abrupt? Changes in water source of Lake Turkana (Kenya) during the African Humid Period inferred from Sr isotope ratios
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
Y1  - 2017
U6  - https://doi.org/10.1016/j.quascirev.2017.08.010
SN  - 0277-3791
VL  - 174
SP  - 1
EP  - 12
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Schad, Daniel
A1  - Garbusow, Maria
A1  - Friedel, Eva
A1  - Sommer, Christian
A1  - Sebold, Miriam
A1  - Hägele, Claudia
A1  - Bernhardt, Nadine
A1  - Nebe, Stephan
A1  - Kuitunen-Paul, Sören
A1  - Liu, Shuyan
A1  - Eichmann, Uta
A1  - Beck, Anne
A1  - Wittchen, Hans-Ulrich
A1  - Walter, Henrik
A1  - Sterzer, Philipp
A1  - Zimmermann, Ulrich S.
A1  - Smolka, Michael N.
A1  - Schlagenhauf, Florian
A1  - Huys, Quentin J. M.
A1  - Heinz, Andreas
A1  - Rapp, Michael A.
T1  - Neural correlates of instrumental responding in the context of alcohol-related cues index disorder severity and relapse risk
JF  - European archives of psychiatry and clinical neuroscience : official organ of the German Society for Biological Psychiatry
N2  - The influence of Pavlovian conditioned stimuli on ongoing behavior may contribute to explaining how alcohol cues stimulate drug seeking and intake. Using a Pavlovian-instrumental transfer task, we investigated the effects of alcohol-related cues on approach behavior (i.e., instrumental response behavior) and its neural correlates, and related both to the relapse after detoxification in alcohol-dependent patients. Thirty-one recently detoxified alcohol-dependent patients and 24 healthy controls underwent instrumental training, where approach or non-approach towards initially neutral stimuli was reinforced by monetary incentives. Approach behavior was tested during extinction with either alcohol-related or neutral stimuli (as Pavlovian cues) presented in the background during functional magnetic resonance imaging (fMRI). Patients were subsequently followed up for 6 months. We observed that alcohol-related background stimuli inhibited the approach behavior in detoxified alcohol-dependent patients (t = -3.86, p < .001), but not in healthy controls (t = -0.92, p = .36). This behavioral inhibition was associated with neural activation in the nucleus accumbens (NAcc) (t((30)) = 2.06, p < .05). Interestingly, both the effects were only present in subsequent abstainers, but not relapsers and in those with mild but not severe dependence. Our data show that alcohol-related cues can acquire inhibitory behavioral features typical of aversive stimuli despite being accompanied by a stronger NAcc activation, suggesting salience attribution. The fact that these findings are restricted to abstinence and milder illness suggests that they may be potential resilience factors.
KW  - Alcohol dependence
KW  - Human neuroimaging
KW  - Nucleus accumbens
KW  - Pavlovian-instrumental transfer
KW  - Relapse
Y1  - 2018
U6  - https://doi.org/10.1007/s00406-017-0860-4
SN  - 0940-1334
SN  - 1433-8491
VL  - 269
IS  - 3
SP  - 295
EP  - 308
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Sebold, Miriam
A1  - Nebe, Stephan
A1  - Garbusow, Maria
A1  - Guggenmos, Matthias
A1  - Schad, Daniel
A1  - Beck, Anne
A1  - Kuitunen-Paul, Sören
A1  - Sommer, Christian
A1  - Frank, Robin
A1  - Neu, Peter
A1  - Zimmermann, Ulrich S.
A1  - Rapp, Michael A.
A1  - Smolka, Michael N.
A1  - Huys, Quentin J. M.
A1  - Schlagenhauf, Florian
A1  - Heinz, Andreas
T1  - When Habits Are Dangerous: Alcohol Expectancies and Habitual Decision Making Predict Relapse in Alcohol Dependence
JF  - Biological psychiatry : a journal of psychiatric neuroscience and therapeutics ; a publication of the Society of Biological Psychiatry
N2  - BACKGROUND: Addiction is supposedly characterized by a shift from goal-directed to habitual decision making, thus facilitating automatic drug intake. The two-step task allows distinguishing between these mechanisms by computationally modeling goal-directed and habitual behavior as model-based and model-free control. In addicted patients, decision making may also strongly depend upon drug-associated expectations. Therefore, we investigated model-based versus model-free decision making and its neural correlates as well as alcohol expectancies in alcohol-dependent patients and healthy controls and assessed treatment outcome in patients. METHODS: Ninety detoxified, medication-free, alcohol-dependent patients and 96 age-and gender-matched control subjects underwent functional magnetic resonance imaging during the two-step task. Alcohol expectancies were measured with the Alcohol Expectancy Questionnaire. Over a follow-up period of 48 weeks, 37 patients remained abstinent and 53 patients relapsed as indicated by the Alcohol Timeline Followback method. RESULTS: Patients who relapsed displayed reduced medial prefrontal cortex activation during model-based decision making. Furthermore, high alcohol expectancies were associated with low model-based control in relapsers, while the opposite was observed in abstainers and healthy control subjects. However, reduced model-based control per se was not associated with subsequent relapse. CONCLUSIONS: These findings suggest that poor treatment outcome in alcohol dependence does not simply result from a shift from model-based to model-free control but is instead dependent on the interaction between high drug expectancies and low model-based decision making. Reduced model-based medial prefrontal cortex signatures in those who relapse point to a neural correlate of relapse risk. These observations suggest that therapeutic interventions should target subjective alcohol expectancies.
KW  - Alcohol dependence
KW  - Alcohol expectancy
KW  - Goal-directed control
KW  - Medial prefrontal cortex
KW  - Reinforcement learning
KW  - Treatment outcome
Y1  - 2017
U6  - https://doi.org/10.1016/j.biopsych.2017.04.019
SN  - 0006-3223
SN  - 1873-2402
VL  - 82
SP  - 847
EP  - 856
PB  - Elsevier
CY  - New York
ER  - 
TY  - JOUR
A1  - Sier, Mark J.
A1  - Langereis, Cor G.
A1  - Dupont-Nivet, Guillaume
A1  - Feibel, Craig S.
A1  - Joordens, Josephine C. A.
A1  - van der Lubbe, Jeroen Fiji.
A1  - Beck, Catherine C.
A1  - Olago, Daniel
A1  - Cohen, Andrew
T1  - The top of the Olduvai Subchron in a high-resolution magnetostratigraphy from the West Turkana core WTK13, hominin sites and Paleolakes Drilling Project (HSPDP)
JF  - Quaternary geochronology : the international research and review journal on advances in quaternary dating techniques
N2  - One of the major challenges in understanding the evolution of our own species is identifying the role climate change has played in the evolution of hominin species. To clarify the influence of climate, we need long and continuous high-resolution paleoclimate records, preferably obtained from hominin-bearing sediments, that are well-dated by tephro- and magnetostratigraphy and other methods. This is hindered, however, by the fact that fossil-bearing outcrop sediments are often discontinuous, and subject to weathering, which may lead to oxidation and remagnetization. To obtain fresh, unweathered sediments, the Hominin Sites and Paleolakes Drilling Project (HSPDP) collected a &#8764;216-meter core (WTK13) in 2013 from Early Pleistocene Paleolake Lorenyang deposits in the western Turkana Basin (Kenya). Here, we present the magnetostratigraphy of the WTK13 core, providing a first age model for upcoming HSPDP paleoclimate and paleoenvrionmental studies on the core sediments. Rock magnetic analyses reveal the presence of iron sulfides carrying the remanent magnetizations. To recover polarity orientation from the near-equatorial WTK13 core drilled at 5°N, we developed and successfully applied two independent drill-core reorientation methods taking advantage of (1) the sedimentary fabric as expressed in the Anisotropy of Magnetic Susceptibility (AMS) and (2) the occurrence of a viscous component oriented in the present day field. The reoriented directions reveal a normal to reversed polarity reversal identified as the top of the Olduvai Subchron. From this excellent record, we find no evidence for the ‘Vrica Subchron’ previously reported in the area. We suggest that outcrop-based interpretations supporting the presence of the Vrica Subchron have been affected by the oxidation of iron sulfides initially present in the sediments -as evident in the core record- and by subsequent remagnetization. We discuss the implications of the observed geomagnetic record for human evolution studies.
KW  - Paleolake Lorenyang
KW  - Magnetostratigraphy
KW  - Olduvai Subchron
KW  - Vrica Subchron
KW  - Drill-core reorientation
KW  - ICDP
KW  - Paleoclimate
KW  - Hominin evolution
Y1  - 2017
U6  - https://doi.org/10.1016/j.quageo.2017.08.004
SN  - 1871-1014
SN  - 1878-0350
VL  - 42
SP  - 117
EP  - 129
PB  - Elsevier
CY  - Oxford
ER  -