FOZO, HIMU, and the rest of the mantle zoo

Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 6 (2005): Q05007, doi:10.1029/2004GC000824.The parameter μ describes the 238U/204Pb ratio of an Earth reservoir. Mantle domains labeled HIMU (high μ) originally defined reservoirs with highly radiogenic Pb isotope ratios observed in basalts from a select number of ocean islands, St. Helena in the Atlantic Ocean and the Cook-Austral islands in the South Pacific Ocean. While some authors use the term HIMU in this original sense, others refer to HIMU as a widespread component in many mid-ocean ridge and ocean island basalt (MORB and OIB) sources. Here we show that highly radiogenic Pb isotope signatures in MORB and OIB originate from two different sources. In addition to the classical HIMU component observed at St. Helena and the South Pacific (named HIMU in the following), we define a component with slightly less radiogenic Pb but significantly more radiogenic Sr isotope signatures. This component lies at the extension of the (Atlantic and Pacific) MORB array in a Sr-Pb isotope ratio diagram and is argued to be a ubiquitous component in MORB and many OIB sources. The inferred role of this component in the mantle and its inferred genetic origin closely resemble those originally suggested for a mantle component termed FOZO by Hart and coworkers. By redefining the composition, the origin, and the role of FOZO in the mantle, we establish a simple conceptual framework that explains the isotopic variability in both MORB and OIB with the lowest number of components. OIB are grouped into HIMU-type OIB and basalts from islands that diverge from the MORB-FOZO array toward various isotopically “enriched” compositions (EM). The apparent ubiquity of FOZO in the mantle and the calculated isotopic evolution of compositionally diverse MORB suggest that normal mantle melting and continuous subduction and aging of that crust during recycling through the mantle are the dominant causes of the MORB-FOZO array. In contrast to FOZO, HIMU-type OIB are quite rare, and if an origin by recycling of oceanic crust is also postulated, the production of HIMU sources has to be a special and rare combination of age and composition of subduction-modified recycled oceanic crust.This work is partially supported by the Deutsche Forschungsgmeinschaft (DFG grant STR853/1 to A.S)

Petrogenesis of synorogenic high-temperature leucogranites (Damara orogen, Namibia): Constraints from U–Pb monazite ages and Nd, Sr and Pb isotopes

Highlights: • Geochemical data from high-T leucogranites imply pure crustal melting. • New U–Pb monazite ages constrain intrusion time close to peak metamorphism. • Updated Sr–Nd–Pb isotope data imply metasedimentary sources. Two suites of leucogranites were emplaced at 508 ± 5.9 Ma in the Okombahe District of the Damara belt (Namibia) synchronous with the peak of regional high-temperature metamorphism. The Sr (87Sr/86Srinit: 0.707 to 0.711), Nd (εNdinit: − 4.5 to − 6.6), and Pb isotopic (206Pb/204Pb: 18.51–19.13; 207Pb/204Pb: 15.63–15.69; 208Pb/204Pb: 38.08–38.66) compositions indicate that these peraluminous S-type granites were derived from mid- to lower-crustal rocks, which are slightly different to the metapelitic rocks into which they intruded. Since the leucogranites are unfractionated and show no evidence for assimilation or contamination, they constrain the temperature and pressure conditions of their formation. Calculated Zr and LREE saturation temperatures of ca. 850 °C indicate high-temperature crustal melts. High Rb/Sr and low Sr/Ba ratios are consistent with biotite dehydration melting of pelitic source rocks. Qz–Ab–Or systematics reveal that melting and segregation for the least fractionated samples occurred at ca. 7 kbar corresponding to a mid-crustal level of ca. 26 km. However, there is no evidence for a mantle component that could have served as a local heat source for crustal melting. Therefore, the hot felsic magmas that formed close to the time of peak metamorphism are the result of long-lasting high temperature regional metamorphic conditions and intra-crustal collision

Natural variation in flavonol accumulation in Arabidopsis is determined by the flavonol glucosyltransferase BGLU6.

Ishihara H, Tohge T, Viehöver P, Fernie AR, Weisshaar B, Stracke R. Natural variation in flavonol accumulation in Arabidopsis is determined by the flavonol glucosyltransferase BGLU6. Journal of Experimental Botany. 2016;67(5):1505-1517

Domains of depleted mantle : new evidence from hafnium and neodymium isotopes

Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 12 (2011): Q08001, doi:10.1029/2011GC003617.Isotope systematics of basalts provide information on the distribution of mantle components and the length scale of mantle heterogeneity. To obtain this information, high data and sampling density are crucial. We present hafnium and neodymium isotope data on more than 400 oceanic volcanics. Over length scales of several hundred to over one thousand kilometers hafnium and neodymium isotopes of mid-ocean ridge basalts are correlated and form an array of parallel trends on a global scale. On a larger scale these domains differ in the amount of highly depleted mantle material with radiogenic hafnium and neodymium isotope ratios. Compared to the Atlantic and Indian Ocean basins the asthenosphere of the Pacific basin seems to have a more uniform and a less radiogenic Hf isotopic composition for a given Nd isotopic composition. The parallel arrays of mid-ocean ridge basalts provide strong constraints on the makeup of the MORB mantle and are evidence for the presence of a highly depleted and highly radiogenic neodymium and hafnium component. This component, because of its highly depleted character, is unrecognized in the strontium-neodymium-lead isotope systems alone. Alternatively, the parallel arrays can have an ancient origin of systematic variations in the degree of depletion. Each array then represents the variations in this fossil melting regime. Individual ocean island basalt suites display different slopes in hafnium-neodymium isotope space, which are also best explained by varying amounts of highly residual mantle rather than isotopic differences in enriched mantle components as previously invoked. The ocean island basalt arrays diverge at the depleted end and project to radiogenic compositions that are similar to those of the asthenosphere through which they travel. This is strong evidence that the plume material interacts with its surrounding mantle as it ascends. The isotopic compositions of the ocean island and ridge basalts suggest that their systematics are influenced by a heretofore unrecognized depleted component.This work was supported by NSF grants EAR 0635864 and OCE0648484 to V.S. and OCE0351437 to S.H

Are competitors forward looking in strategic interactions? : evidence from the field

This paper investigates empirically whether decision makers are forward looking in dynamic strategic interactions. In particular, we test whether decision makers in multistage tournaments take heterogeneity induced changes of continuation values and the ability of their immediate opponent into account when choosing effort. Using data from professional and semi-professional basketball tournaments, we find that effort is negatively affected by the ability of the current opponent, consistent with the theoretical prediction and previous evidence. More importantly, the results indicate that the expected relative strength in future interactions does affect behavior in earlier stages, which provides support for the 'standard’ view that decision makers are forward looking in dynamic strategic interactions

Deep Learning-Based Tracking of Multiple Objects in the Context of Farm Animal Ethology

Automatic detection and tracking of individual animals is important to enhance their welfare and to improve our understanding of their behaviour. Due to methodological difficulties, especially in the context of poultry tracking, it is a challenging task to automatically recognise and track individual animals. Those difficulties can be, for example, the similarity of animals of the same species which makes distinguishing between them harder, or sudden changes in their body shape which may happen due to putting on or spreading out the wings in a very short period of time. In this paper, an automatic poultry tracking algorithm is proposed. This algorithm is based on the well-known tracktor approach and tackles multi-object tracking by exploiting the regression head of the Faster R-CNN model to perform temporal realignment of object bounding boxes. Additionally, we use a multi-scale re-identification model to improve the re-association of the detected animals. For evaluating the performance of the proposed method in this study, a novel dataset consisting of seven image sequences that show chicks in an average pen farm in different stages of growth is used

Разработка информационно-измерительного комплекса для учета расхода электроэнергии в многоквартирном доме

Объектом исследования является автоматизированная система учета расхода электроэнергии в многоквартирном доме. Цель работы – разработать автоматизированную систему учета расхода электроэнергии в многоквартирном доме, с передачей данных на центральный сервер ресурсоснабжающей организации. В процессе исследования проводился сбор данных, систематизация и анализ информации по теме данного дипломного проекта, проектирование АСКУЭ. Область применения: учет расхода энергоресурсов бытовых потребителей.The object of research is automated system of metering of electricity consumption in an apartment building. Purpose - to develop an automated electricity metering system in an apartment building, with the transfer of data to a central server power company. The study was conducted to collect data, organize and analyze information on the subject of the degree project, the design of AMR. Scope: Accounting consumption of household energy consumers

Genetic dissection of photoperiod response based on GWAS of pre-anthesis phase duration in spring barley

Heading time is a complex trait, and natural variation in photoperiod responses is a major factor controlling time to heading, adaptation and grain yield. In barley, previous heading time studies have been mainly conducted under field conditions to measure total days to heading. We followed a novel approach and studied the natural variation of time to heading in a world-wide spring barley collection (218 accessions), comprising of 95 photoperiod-sensitive (Ppd-H1) and 123 accessions with reduced photoperiod sensitivity (ppd-H1) to long-day (LD) through dissecting pre-anthesis development into four major stages and sub-phases. The study was conducted under greenhouse (GH) conditions (LD; 16/8 h; ∼20/∼16°C day/night). Genotyping was performed using a genome-wide high density 9K single nucleotide polymorphisms (SNPs) chip which assayed 7842 SNPs. We used the barley physical map to identify candidate genes underlying genome-wide association scans (GWAS). GWAS for pre-anthesis stages/sub-phases in each photoperiod group provided great power for partitioning genetic effects on floral initiation and heading time. In addition to major genes known to regulate heading time under field conditions, several novel QTL with medium to high effects, including new QTL having major effects on developmental stages/sub-phases were found to be associated in this study. For example, highly associated SNPs tagged the physical regions around HvCO1 (barley CONSTANS1) and BFL (BARLEY FLORICAULA/LEAFY) genes. Based upon our GWAS analysis, we propose a new genetic network model for each photoperiod group, which includes several newly identified genes, such as several HvCO-like genes, belonging to different heading time pathways in barley