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Rano Raraku, the crater lake constrained by basaltic tuff that served as the primary quarry used to construct themoaistatues on Rapa Nui (Easter Island), has experienced fluctuations in lake level over the past centuries. As one of the only freshwater sources on the island, understanding the present and past geochemical characteristics of the lake water is critical to understand if the lake could have been a viable freshwater source for Rapa Nui. At the time of sampling in September 2017, the maximum lake depth was ~1 m. The lake level has substantially declined in the subsequent years, with the lake drying almost completely in January 2018. The lake is currently characterized by highly anoxic conditions, with a predominance of ammonium ions on nitrates, a high concentration of organic carbon in the water-sediment interface and reducing conditions of the lake, as evidenced by Mn/Fe and Cr/V ratios. Our estimates of past salinity inferred from the chloride mass balance indicates that it was unlikely that Rano Raraku provided a viable freshwater source for early Rapa Nui people. The installation of an outlet pipe around 1950 that was active until the late 1970s, as well as grazing of horses on the lake margins appear to have significantly impacted the geochemical conditions of Rano Raraku sediments and lake water in recent decades. Such impacts are distinct from natural environmental changes and highlight the need to consider the sensitivity of the lake geochemistry to human activities.

We determined the specific biomass burning biomarker levoglucosan in an ice core from the TALos Dome Ice CorE drilling project (TALDICE) during the mid- to late Holocene (6000–750 BP). The levoglucosan record is characterized by a long-term increase with higher rates starting at ∼ 4000 BP and peaks between 2500 and 1500 BP. The anomalous increase in levoglucosan centered at ∼ 2000 BP is consistent with other Antarctic biomass burning records. Multiple atmospheric phenomena affect the coastal Antarctic Talos Dome drilling site, where the Southern Annular Mode (SAM) is the most prominent as the Southern Annular Mode Index (SAMA) correlates with stable isotopes in precipitation throughout the most recent 1000 years of the ice core. If this connection remains throughout the mid- to late Holocene, then our results demonstrate that changes in biomass burning, rather than changes in atmospheric transport, are the major influence on the TALDICE levoglucosan record. Comparisons with charcoal syntheses help evaluate fire sources, showing a greater contribution from southern South American fires than from Australian biomass burning. The levoglucosan peak centered at ∼ 2000 BP occurs during a cool period throughout the Southern Hemisphere, yet during a time of increased fire activity in both northern and southern Patagonia. This peak in biomass burning is influenced by increased vegetation in southern South America from a preceding humid period, in which the vegetation desiccated during the following cool, dry period. The Talos Dome ice core record from 6000 to ∼ 750 BP currently does not provide clear evidence that the fire record may be strongly affected by anthropogenic activities during the mid- to late Holocene, although we cannot exclude at least a partial influence.

AbstractImage texture extraction and analysis are fundamental steps in computer vision. In particular, considering the biomedical field, quantitative imaging methods are increasingly gaining importance because they convey scientifically and clinically relevant information for prediction, prognosis, and treatment response assessment. In this context, radiomic approaches are fostering large-scale studies that can have a significant impact in the clinical practice. In this work, we present a novel method, called CHASM (Cuda, HAralick & SoM), which is accelerated on the graphics processing unit (GPU) for quantitative imaging analyses based on Haralick features and on the self-organizing map (SOM). The Haralick features extraction step relies upon the gray-level co-occurrence matrix, which is computationally burdensome on medical images characterized by a high bit depth. The downstream analyses exploit the SOM with the goal of identifying the underlying clusters of pixels in an unsupervised manner. CHASM is conceived to leverage the parallel computation capabilities of modern GPUs. Analyzing ovarian cancer computed tomography images, CHASM achieved up to $$\sim 19.5\times $$ ∼ 19.5 × and $$\sim 37\times $$ ∼ 37 × speed-up factors for the Haralick feature extraction and for the SOM execution, respectively, compared to the corresponding C++ coded sequential versions. Such computational results point out the potential of GPUs in the clinical research. Funder: Università degli Studi di Milano - Bicocca

Nanomaterials are handled in global value chains for many different products, albeit not always recognisable as nanoproducts. The global market for nanomaterials faces an uncertain future, as the international dialogue on regulating nanomaterials is still ongoing and risk assessment data are being collected. At the same time, regulators and civil society organisations complain about a lack of transparency about the presence of nanomaterials on the market. In the project on Sustainable Nanotechnologies (SUN, ), a Decision Support System (SUNDS) has been developed, primarily for confidential use by risk and sustainability managers inside a company or consortium. In this article, we formulate a scenario concerning a potential role for an open access decision support system in negotiations on international agreements regulating trade in nanomaterials. The scenario includes design rules for decision support systems as well as procedures for use of such a system in stakeholder dialogue and policy-making on governance of these and other emerging technologies. This article incorporates analysis of results of stakeholder engagement on nanomaterials as well as literature and internet sources suggested by these stakeholders.

This paper addresses the topic of acquisitive modals grammaticalized from the etyma meaning “come to have” (Enfield 2001), as Mandarin dĕi/dé/de 得, Cantonese dàk 得, Lao daj4 and Vietnamese được. The goal of the investigation is twofold. It is argued that (i) the polyfunctionality covered by the MSEA acquisitive modals, in Mandarin, tends to be displayed by the core modal néng, which functions as a sort of umbrella accommodating different modal meanings, whereas the acquisitive morphemes are highly specialized in conveying a unique modal meaning. Moreover, evidence is provided showing that, (ii) when co-occurring with potential contributions, néng contributes to conferring an agentive reading. To this end, a comparison is provided between the expression of possibility via the core modal néng versus the acquisitive modals, also with reference to their stacked occurrences. Examples are provided showing that néng is a modal “reinforcement” of the potential construction (Cheng and Sybesma 2004), wherein the latter is characterized by reduced agentivity. Different types of double occurrences are singled out, also with reference to the degree of grammatical acceptability by different informants. The contexts in which the ‘néng de-construction’ is fully accepted are mainly interrogatives and rhetorical questions. This modal stacking is considered very natural in epistemic multimodal constructions and is perceived as mandatory in the relative clauses wherein the nominal head is the object of the potential construction. In these cases, for the head to be interpreted as the object, there must be either the subject or a full-fledged modal, like néng, (or both). Finally, it is also highlighted that méi néng can occur as a suppletive form of negative potential constructions. The former expresses actuality entailment, therefore displaying the implicative feature which is common to many acquisitive modals, such as 'get'.