A Reference Section for the Otavi Group (Damara Supergroup) in Eastern Kaoko Zone near Ongongo, Namibia

A reference section for the Otavi Group (Damara Supergroup) in the East Kaoko Zone near Ongongo is proposed and described. The section is easily accessible, well exposed, suitable for field excursions, and well documented in terms of carbonate lithofacies, depositional sequences and stableisotope chemostratigraphy. The late Tonian Ombombo Subgroup is 355 m thick above the basal Beesvlakte Formation, which is not included in the section due to poor outcrop and complex structure. The earlymiddle Cryogenian Abenab Subgroup is 636 m thick and the early Ediacaran Tsumeb Subgroup is 1020 m thick. While the section is complete in terms of formations represented, the Ombombo and lower Abenab subgroups have defined gaps due to intermittent uplift of the northward-sloping Makalani rift shoulder. The upper Abenab and Tsumeb subgroups are relatively thin due to erosion of a broad shallow trough during late Cryogenian glaciation and flexural arching during post-rift thermal subsidence of the carbonate platform

Not so non-marine? Revisiting the Stoer Group and the Mesoproterozoic biosphere

Funding for this project was provided by the NASA postdoctoral program (EES), the Lewis and Clark Fund (EES), an NSERC PGS-D grant (EJB), the NSF ELT (TWL, NJP) and FESD (TWL) programs, and the NASA Astrobiology Institute (TWL, NJP).The Poll a’Mhuilt Member of the Stoer Group (Torridonian Supergroup) in Scotland has been heralded as a rare window into the ecology of Mesoproterozoic terrestrial environments. Its unusually high molybdenum concentrations and large sulphur isotope fractionations have been used as evidence to suggest that lakes 1.2 billion years ago were better oxygenated and enriched in key nutrients relative to contemporaneous oceans, making them ideal habitats for the evolution of eukaryotes. Here we show with new Sr and Mo isotope data, supported by sedimentological evidence, that the depositional setting of this unit was likely connected to the ocean and that the elevated Mo and S contents can be explained by evapo-concentration of seawater. Thus, it remains unresolved if Mesoproterozoic lakes were important habitats for early eukaryotic life.Publisher PDFPeer reviewe

The Doublesex-related Dmrta2 safeguards neural progenitor maintenance involving transcriptional regulation of Hes1

The mechanisms that determine whether a neural progenitor cell (NPC) re-enters the cell cycle or exits and differentiates are pivotal for generating cells in correct numbers and diverse types, and hence dictate proper brain development. Combining gain-of-function and loss-of-function approaches in an embryonic stem cell-derived cortical differentiation model, we report that Dmrta2 plays an important role in maintaining NPCs in the cell cycle. Temporally controlled expression of transgenic Dmrta2 in NPCs suppresses differentiation without affecting their neurogenic competence. In contrast, Dmrta2 knockout accelerates the cell cycle exit and differentiation into post-mitotic neurons of NPCs derived from embryonic stem cells and in Emx1-cre conditional mutant mice. Dmrta2 function was linked to the regulation of Hes1 and other proneural genes as demonstrated by genome wide RNAseq and direct binding of Dmrta2 to the Hes1 genomic locus. Moreover, transient Hes1 expression rescues precocious neurogenesis in Dmrta2 knockout NPCs. Our study therefore establishes a novel link between Dmrta2 modulation of Hes1 expression and the maintenance of NPCs during cortical development.

Tuinarcheologisch onderzoek in de binnentuin van het kasteel van Gaasbeek te Lennik (Vl.- Brabant). Eindverslag van een opgraving vanuit wetenschappelijke vraagstelling

De opgraving met wetenschappelijke vraagstelling in de in de late 19de eeuw aangelegde neorenaissance binnentuin van het kasteel van Gaasbeek had tot doel na te gaan of er nog sporen aanwezig waren van de oorspronkelijke aanleg. Hiervoor werden in samenspraak met collegas vijf werkputjes op cruciale plaatsen uitgezet en opgegraven en gerichte onderzoeksvragen opgesteld

LED's Buy Greener: Shedding Light on Sustainable Procurement

In last decade, the lighting industry significantly changed with the development of light emitting diodes (LEDs) and their corresponding penetration of the market. The new technology increases energy efficiency and longevity compared to other types of lamps. As a result, LEDs can improve the sustainability performance of cities and towns, contributing to the mitigation of climate change and cutting costs over the long term. This report reviews LED procurement from multiple perspectives, formulated as a guide to help public and private stakeholders make more effective and sustainable decisions when buying lighting products. This publication is the collective work of students involved in the Masters of Environmental Science, Policy and Management (MESPOM) programme, currently enrolled at International Institute for Industrial Environmental Economics (IIIEE). The research has been performed for the European Union Inter-reg Lighting Metropolis Project, which involves institutions, designers and producers, and municipalities in the Öresund (or Greater Copenhagen) Region of Denmark and Sweden. The first two chapters of the report dive into the initial and final stages of the life cycle of LEDs. These chapters connect the impacts and risks of raw material extraction and supply chains to lighting procurement, and provide recommendations for the integration of end-of-life considerations into the procurement process. Chapter three analyses various national policies that contribute to promoting LEDs in public procurement. Chapter four examines the drivers and barriers for implementing innovative business models through the mapping various actors and their relationships. Finally, chapter five explores the decision-making process and the drivers and barriers of municipalities when procuring lighting solutions. Together, these five chapters provide a comprehensive set of recommendations to improve decision making for sustainable lighting solutions

A lithium-isotope perspective on the evolution of carbon and silicon cycles

The evolution of the global carbon and silicon cycles is thought to have contributed to the long-term stability of Earth's climate. Many questions remain, however, regarding the feedback mechanisms at play, and there are limited quantitative constraints on the sources and sinks of these elements in Earth's surface environments. Here we argue that the lithium-isotope record can be used to track the processes controlling the long-term carbon and silicon cycles. By analysing more than 600 shallow-water marine carbonate samples from more than 100 stratigraphic units, we construct a new carbonate-based lithium-isotope record spanning the past 3 billion years. The data suggest an increase in the carbonate lithium-isotope values over time, which we propose was driven by long-term changes in the lithium-isotopic conditions of sea water, rather than by changes in the sedimentary alterations of older samples. Using a mass-balance modelling approach, we propose that the observed trend in lithium-isotope values reflects a transition from Precambrian carbon and silicon cycles to those characteristic of the modern. We speculate that this transition was linked to a gradual shift to a biologically controlled marine silicon cycle and the evolutionary radiation of land plants

Designing Inter- and Transdisciplinary Research on Mountains: What Place for the Unexpected?

In recent decades, research on mountains has become more inter- and transdisciplinary, but a greater effort is needed if such research is to contribute to a societal transformation toward sustainability. Mountain research centers are a crucial actor in this endeavor. Yet, the literature has not paid sufficient attention to how these centers should (re-)design inter- and transdisciplinary research. In this study, we explored this question with a self-reflexive approach. We analyzed the first 15 months of the Interdisciplinary Centre for Mountain Research (CIRM) of the University of Lausanne (Switzerland) through qualitative data collected via interviews and observation. We used a simple model of inter- and transdisciplinarity at the organizational level of a research center. Special attention was devoted to the individual and collective ability to exploit the unexpected (serendipity). Our results indicate an interdependency between the coconstruction of research objects and the creation of integrative partnerships. They also shed light on the types of institutional resources and integrative methodologies that enhance inter- and transdisciplinary research, as well as their challenges. Our experience shows that implementing inter- and transdisciplinarity requires deep changes in research evaluation procedures, research funding policies, and researchers themselves. Serendipity is in turn shown to play an important role in inter- and transdisciplinarity due to its potential to change the research process in creative ways. We speculate that serendipity offers unique opportunities to capitalize on hidden resources that can catalyze a radical transformation of mountain researchers, research organizations, and society in the face of unprecedented global change

Ascl1 coordinately regulates gene expression and the chromatin landscape during neurogenesis

The proneural transcription factor Ascl1 coordinates gene expression in both proliferating and differentiating progenitors along the neuronal lineage. Here, we used a cellular model of neurogenesis to investigate how Ascl1 interacts with the chromatin landscape to regulate gene expression when promoting neuronal differentiation. We find that Ascl1 binding occurs mostly at distal enhancers and is associated with activation of gene transcription. Surprisingly, the accessibility of Ascl1 to its binding sites in neural stem/progenitor cells remains largely unchanged throughout their differentiation, as Ascl1 targets regions of both readily accessible and closed chromatin in proliferating cells. Moreover, binding of Ascl1 often precedes an increase in chromatin accessibility and the appearance of new regions of open chromatin, associated with de novo gene expression during differentiation. Our results reveal a function of Ascl1 in promoting chromatin accessibility during neurogenesis, linking the chromatin landscape at Ascl1 target regions with the temporal progression of its transcriptional program

Predictive Thermal Management for Energy-Efficient Execution of Concurrent Applications on Heterogeneous Multicores

Current multicore platforms contain different types of cores, organized in clusters (e.g., ARM's big.LITTLE). These platforms deal with concurrently executing applications, having varying workload profiles and performance requirements. Runtime management is imperative for adapting to such performance requirements and workload variabilities and to increase energy and temperature efficiency. Temperature has also become a critical parameter since it affects reliability, power consumption, and performance and, hence, must be managed. This paper proposes an accurate temperature prediction scheme coupled with a runtime energy management approach to proactively avoid exceeding temperature thresholds while maintaining performance targets. Experiments show up to 20% energy savings while maintaining high-temperature averages and peaks below the threshold. Compared with state-of-the-art temperature predictors, this paper predicts 35% faster and reduces the mean absolute error from 3.25 to 1.15 °C for the evaluated applications' scenarios