Biometry of Upper Cretaceous (Cenomanian-Maastrichtian) coccoliths - a record of long-term stability and interspecies size shifts

Biometric measurements of Mesozoic coccoliths (coccolith length and width) have been used in short-term biostratigraphic, taxonomic and palaeoecologic studies, but until now, not over longer time scales. Here, we present a long time-series study (∼ 30 million years) for the Upper Cretaceous, which aims to identify broad trends in coccolith size and to understand the factors governing coccolith size change over long time scales. We have generated biometric data for the dominant Upper Cretaceous coccolith groups, Broinsonia/Arkhangelskiella, Prediscosphaera, Retecapsa and Watznaueria, from 36 Cenomanian–Maastrichtian (100.5–66 Ma) samples from Goban Spur in the northeast Atlantic (DSDP Site 549). These data show that the coccolith sizes within Prediscosphaera, Retecapsa and Watznaueria were relatively stable through the Late Cretaceous, with mean size variation less than 0.7 μm. Within the Broinsonia/Arkhangelskiella group there was more pronounced variation, with a mean size increase from ∼ 6 μm in the Cenomanian to ∼ 10 μm in the Campanian. This significant change in mean size was largely driven by evolutionary turnover (species origination and extinctions), and, in particular, the appearance of larger species/subspecies (Broinsonia parca parca, Broinsonia parca constricta, Arkhangelskiella cymbiformis) in the early Campanian, replacing smaller species, such as Broinsonia signata and Broinsonia enormis. Shorter-term size fluctuations within Broinsonia/Arkhangelskiella, observed across the Late Cenomanian–Turonian and Late Campanian–Maastrichtian intervals, may, however, reflect changing palaeoenvironmental conditions, such as sea surface temperature and nutrient availability. / Les dimensions des coccolithes du Mésozoïque (longueur et largeur) ont été utilisées dans des études biostratigraphiques, taxonomiques et paléoécologiques sur le court-terme mais jusqu’à présent, jamais sur le long-terme. Ici, nous présentons l’étude d’une série chronologique à échelle de temps longue (∼ 30 millions d’années) du Crétacé supérieur, visant à identifier les tendances générales de leur taille et de comprendre les facteurs gouvernant les changements de taille des coccolithes sur une échelle de temps longue. Nous avons généré des données biométriques pour les groupes de coccolithes dominants au Crétacé supérieur, Broinsonia/Arkhangelskiella, Prediscosphaera, Retecapsa et Watznaueria, sur 36 échantillons du Cénomanien–Maastrichtien (100,5–66 Ma) provenant du Goban Spur dans l’Atlantique Nord-Est (DSDP Site 549). Ces données montrent que la taille des coccolithes appartenant aux groupes Prediscosphaera, Retecapsa et Watznaueria fut relativement stable durant tout le Crétacé supérieur, avec une variation de la taille moyenne inférieure à 0,7 μm. Au sein du groupe Broinsonia/Arkhangelskiella, les variations furent plus prononcées, avec une augmentation de la taille moyenne de ∼ 6 μm au Cénomanien jusqu’à ∼ 10 μm au Campanien. Ce changement significatif de la taille moyenne fut largement dû aux processus évolutifs (spéciations et extinctions), et en particulier à l’apparition d’espèces/sous-espèces plus larges (Broinsonia parca parca, Broinsonia parca constricta, Arkhangelskiella cymbiformis) au Campanien inférieur, remplaçant des espèces plus petites, telles que Broinsonia signata et Broinsonia enormis. Cependant, les fluctuations à court-terme au sein du groupe Broinsonia/Arkhangelskiella, observées aux transitions Cénomanien–Turonien et Campanien–Maastrichtien, pourraient refléter un changement des conditions paléoenvironnementales, telles que la température superficielle des eaux océaniques et la disponibilité en nutriment

Characterization and extent of expansive soils in the Las Vegas Valley

Expansive soils have been documented in the Las Vegas Valley for many years; however, the extent of these soils horizontally and vertically was relatively unknown. This study investigates the extent and expansivity of soils in the Las Vegas Valley. It is an attempt to present an empirical model predicting areas where expansive soils may be encountered. A correlation between swell test results and plasticity index was evaluated for two datasets, and results compare favorably with relationships established for other areas. Analyses were conducted to evaluate correlations between expansion potential and topographic slope, soil classification, and locations of subsidence-related faults and earth fissures. Results show that expansion potential generally increases with decreasing slope, finer grain-size and increasing plasticity. Over ninety-four percent by length of mapped subsidence-related faults are located within areas having some expansion potential. Eighty-eight percent of earth fissures are found in areas exhibiting moderate to critical expansion

Evidence for global cooling in the Late Cretaceous

PublishedArticleThe Late Cretaceous ‘greenhouse’ world witnessed a transition from one of the warmest climates of the past 140 million years to cooler conditions, yet still without significant continental ice. Low-latitude sea surface temperature (SST) records are a vital piece of evidence required to unravel the cause of Late Cretaceous cooling, but high-quality data remain illusive. Here, using an organic geochemical palaeothermometer (TEX86), we present a record of SSTs for the Campanian–Maastrichtian interval (~83–66 Ma) from hemipelagic sediments deposited on the western North Atlantic shelf. Our record reveals that the North Atlantic at 35 °N was relatively warm in the earliest Campanian, with maximum SSTs of ~35 °C, but experienced significant cooling (~7 °C) after this to <~28 °C during the Maastrichtian. The overall stratigraphic trend is remarkably similar to records of high-latitude SSTs and bottom-water temperatures, suggesting that the cooling pattern was global rather than regional and, therefore, driven predominantly by declining atmospheric pCO2 levels.We gratefully acknowledge funding from the German Science Foundation (DFG Research Stipend Li 2177/1-1 to C.L.), a Royal Society (UK) URF (S.A.R.), a NERC (UK) grant (J.A.L.), a NERC (UK) studentship (K.L.), The Curry Fund of UCL (C.L.), the Cushman Foundation for Foraminiferal Research (J.M. Resig Fellowship to F.F.) and the Spanish Ministerio de Ciencia e Innovación project CGL2011-22912, co-financed by the European Regional Development Fund (I.P.-R., J.A.A., J.A.L.). We thank T. Dunkley-Jones and J. Young for assistance in collecting the samples and S. Schouten for providing TEX86L data from Demerara Rise. This paper is dedicated to Ernie Russell, who sadly died after submission of the manuscript

Structure of the TPR Domain of AIP: Lack of Client Protein Interaction with the C-Terminal alpha-7 Helix of the TPR Domain of AIP Is Sufficient for Pituitary Adenoma Predisposition

PMCID: PMC3534021This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

TWISTED DWARF1 mediates the action of auxin transport inhibitors on actin cytoskeleton dynamics

Plant growth and architecture is regulated by the polar distribution of the hormone auxin. Polarity and flexibility of this process is provided by constant cycling of auxin transporter vesicles along actin filaments, coordinated by a positive auxin-actin feedback loop. Both polar auxin transport and vesicle cycling are inhibited by synthetic auxin transport inhibitors, such as 1-N-naphthylphthalamic acid (NPA), counteracting the effect of auxin; however, underlying targets and mechanisms are unclear. Using NMR, we map the NPA binding surface on the Arabidopsis thaliana ABCB chaperone TWISTED DWARF1 (TWD1). We identify ACTIN7 as a relevant, although likely indirect, TWD1 interactor, and show TWD1-dependent regulation of actin filament organization and dynamics and that TWD1 is required for NPA-mediated actin cytoskeleton remodeling. The TWD1-ACTIN7 axis controls plasma membrane presence of efflux transporters, and as a consequence act7 and twd1 share developmental and physiological phenotypes indicative of defects in auxin transport. These can be phenocopied by NPA treatment or by chemical actin (de)stabilization. We provide evidence that TWD1 determines downstream locations of auxin efflux transporters by adjusting actin filament debundling and dynamizing processes and mediating NPA action on the latter. This function appears to be evolutionary conserved since TWD1 expression in budding yeast alters actin polarization and cell polarity and provides NPA sensitivity

Struktur und Funktion der Peptidyl-Prolyl-cis/trans-Isomerase-Domäne des humanen FK506-bindenden Proteins 37.7

Für das humane FK506-bindende Protein 37.7 wurde eine N-terminal lokalisierte PPIase-Domäne vom FKBP-Typ und eine C-terminal lokalisierte TPR-Domäne vorhergesagt. Während für die TPR-Domäne zahlreiche Protein-Protein-Interaktionen bekannt sind ist über die Funktion der PPIase-Domäne nur wenig bekannt. Im Rahmen der vorliegenden Arbeit konnte gezeigt werden, dass FKBP37.7 weder eine PPIase-Aktivität besitzt noch an FK506 bindet. Ein Sequenzvergleich der PPIase-Domäne mit dem prototypischen FKBP12 offenbarte neben Homologien auch Unterschiede. Daher wurde die Proteinstruktur der PPIase-Domäne mittels NMR-Spektroskopie aufgeklärt. FKBP37.7 besitzt eine typische FKBP-Faltung mit fünf antiparallel verlaufenden -Faltblattsträngen gewunden um eine zentrale -Helix und zwei ungewöhnliche Strukturelemente, eine N-terminale -Helix und einen langen Einschub. Weiterhin wurde Hsp90 als Interaktionspartner von FKBP37.7 identifiziert mit ungewöhnlichen Bindungskontakten an der PPIase-Domäne.The human FK506 binding protein 37.7 has been predicted to consist of a N-terminal FKBP-type PPIase domain and a C-terminal TPR domain. While for the TPR domain several protein protein interactions are known nearly nothing is known about the function of the PPIase domain. During the investigation FKBP37.7 showed no inherent FK506 binding or PPIase activity as other FKBP. An alignment of the FKBP37.7 PPIase domain with the prototypic FKBP12 showed a high sequence homology but indicated also inconsistencies. To find the reason for the inactivity of the protein the NMR-based structure of the PPIase domain was determined. This structure revealed a typical FKBP fold with five antiparallel -strands wrapped around a central -helix and additional two unusual structure elements, a N-terminal -helix and a rather long insert. Additionally Hsp90 was identified as an interaction partner of FKBP37.7, which revealed binding contacts next to the TPR domain and uncommonly also to the PPIase domain.von Miriam Linner

Pirosabb-e a Ferrari a papagájnál? - a színek hatásának vizsgálata vizuális kategorizációban a kiváltott potenciálokra

A szín fontos szereplője vizuális világunknak, de nem elengedhetetlen tárgyak felismeréséhez. Látórendszerünk a felismeréshez szükséges alak- és felszíni információkat ugyanazon a pályán dolgozza fel, mint a színinformációt, a ventrális vizuális kérgi pályarendszeren. Az irodalomban ellentmondásos adatokat találunk azzal kapcsolatban, hogy alak és szín feldolgozása együtt vagy elkülönülve történik a magasabb kérgi területeken. Vizsgálatunkban humán alanyokon végeztünk elektrofiziológiai méréseket a kérdés megközelítésére. Egyetemünk Vizuális Laboratóriumában folytatott nem-humán főemlős vizsgálatokhoz kapcsolódik kísérletünk, mely a makákó ventrális vizuális pályájának utolsó unimodális területén robosztus színfüggetlen alakfeldolgozást mutatott ki. Jelen vizsgálatban humán alanyokon a szín kivonásának hatását vizsgáltuk összetett vizuális ingerekkel végzett kategorizációs feladatban, miközben vizuális eseményfüggő potenciálokat regisztráltunk. A makákó inferotemporális kérgi (IT) területének megfelelő humán oldalsó tarkólebenyi komplexum (laterális okcipitális komplex (LOC)) fölül elvezetettvizuális kiváltott potenciálokat (N170-es komponens) hasonlítottuk össze színes és akromatikus vizuális ingerekre két kategóriában (autó és madár), valamint felismerhetetlen kontrollkondícióban. Eredményeink megerősítették a makákók esetében tapasztaltakat, azaz a vizsgált területen az N170-es kiváltott potenciálra az inger színessége nem volt hatással a felismerhető 'képek esetében. Kontrollkondícióban, amikor a kategóriák felismerhetetlenek voltak, ám színességük megmaradt, az N170 amplitúdójában különbség mutatkozott a színes és az akromatikus változatok között, a tesztkondícióval összehasonlítva. Emellettkimutattunk erőteljes kategóriahatást a kiváltott potenciálokra, valamint megmutattuk a féltekék feldolgozási sebességének különbségét. Eredményeink alapján elmondhatjuk, hogy, jól felismerhető ingerek esetén a szín nem befolyásolja a perceptuális kategorizációhoz köthető elektrofiziológiai jelenségeket a tárgyfelismerésért felelős területek fölött. Ha azonban a felismeréshez nem áll elegendő formai információ rendelkezésre, akkor a szín hatása mérhető. There are ambiguities in the literature derived from primate studies concerning the role of IT (inferior temporal) cortex in color processing. We investigated the human homologue of IT, the LOC (lateral occipital complex) by recording EEG activity and analyzing the evoked potential component NI70. Subjects were performing a two alternative forced choice categorization task on car and bird categories, both presented in coloured and grayscale versions. According to our results, color does not influence the electrophysiological phenomena related to perceptual categorization above the LOC in the case of easily recognizable stimuli. However, color seems to affect recorded waves when shape information is removed from the stimuli

Politisierung durch Konflikt – Zu den Auswirkungen sozialer Konflikte auf die Politisierung von Freiwilligen in der Geflüchtetenarbeit

POLITISIERUNG DURCH KONFLIKT – ZU DEN AUSWIRKUNGEN SOZIALER KONFLIKTE AUF DIE POLITISIERUNG VON FREIWILLIGEN IN DER GEFLÜCHTETENARBEIT Politisierung durch Konflikt – Zu den Auswirkungen sozialer Konflikte auf die Politisierung von Freiwilligen in der Geflüchtetenarbeit / Linnert, Julius (Rights reserved) ( -

Toward a Dynamic Allocation Strategy for Deadline-Oriented Resource and Job Management in HPC Systems

As high-performance computing (HPC) becomes a tool used in many different workflows, quality of service (QoS) becomes increasingly important. In many cases, this includes the reliable execution of an HPC job and the generation of the results by a certain deadline. The resource and job management system (RJMS) or simply RMS is responsible for receiving the job requests and executing the jobs with a deadline-oriented policy to support the workflows. In this article, we evaluate how well static resource management policies cope with deadline-constrained HPC jobs and explore two variations of a dynamic policy in this context. As the Hilbert curve-based approach used by the SLURM workload manager represents the state-of-the-art in production environments, it was selected as one of the static allocation strategies. The Manhattan median approach as a second allocation strategy was introduced as a research work that aims to minimize the communication overhead of the parallel programs by providing compact partitions more than the Hilbert curve approach. In contrast to the static partitions provided by the Hilbert curve approach and the Manhattan median approach, the leak approach focuses on supporting dynamic runtime behavior of the jobs and assigning nodes of the HPC system on demand at runtime. Since the contiguous leak version also relies on a compact set of nodes, the noncontiguous leak can provide additional nodes at a greater distance from the nodes already used by the job. Our preliminary results clearly show that a dynamic policy is needed to meet the requirements of a modern deadline-oriented RMS scenario