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Excluding the large ice sheets of Greenland and Antarctica, glaciers in South America are large contributors to sea-level rise1. Their rates of mass loss, however, are poorly known. Here, using repeat bi-static synthetic aperture radar interferometry over the years 2000 to 2011/2015, we compute continent-wide, glacier-specific elevation and mass changes for 85% of the glacierized area of South America. Mass loss rate is calculated to be 19.43 ± 0.60 Gt a−1from elevation changes above ground, sea or lake level, with an additional 3.06 ± 1.24 Gt a−1from subaqueous ice mass loss not contributing to sea-level rise. The largest contributions come from the Patagonian icefields, where 83% mass loss occurs, largely from dynamic adjustments of large glaciers. These changes contribute 0.054 ± 0.002 mm a−1to sea-level rise. In comparison with previous studies2, tropical and out-tropical glaciers — as well as those in Tierra del Fuego — show considerably less ice loss. These results provide basic information to calibrate and validate glacier-climate models and also for decision-makers in water resource management3.

Understanding changes in glacier mass balances is essential for investigating climate changes. However, glacier‐wide mass balances determined from geodetic observations do not provide a relevant climatic signal as they depend on the dynamic response of the glaciers. In situ point mass balance measurements provide a direct signal but show a strong spatial variability that is difficult to assess from heterogeneous in situ measurements over several decades. To address this issue, we propose a nonlinear statistical model that takes into account the spatial and temporal changes in point mass balances. To test this model, we selected four glaciers in different climatic regimes (France, Bolivia, India, and Norway) for which detailed point annual mass balance measurements were available over a large elevation range. The model extracted a robust and consistent signal for each glacier. We obtained explained variances of 87.5, 90.2, 91.3, and 75.5% on Argentière, Zongo, Chhota Shigri, and Nigardsbreen glaciers, respectively. The standard deviations of the model residuals are close to measurement uncertainties. The model can also be used to detect measurement errors. Combined with geodetic data, this method can provide a consistent glacier‐wide annual mass balance series from a heterogeneous network. This model, available to the whole community, can be used to assess the impact of climate change in different regions of the world from long‐term mass balance series. We propose a nonlinear statistical model to extract a robust and consistent climatic signal for each glacierOur method has been tested from glacier mass balance observations for four glaciers located in very different climatic regimesThis model, available for the whole community, can be used to assess the impact of climate change in different regions of the world

ABSTRACTWord-list learning tasks are among the most important and frequently used tests for declarative memory evaluation. For example, the California Verbal Learning Test-Children’s Version (CVLT-C) and Rey Auditory Verbal Learning Test provide important information about different cognitive-neuropsychological processes. However, the impact of test length (i.e., number of words) and semantic organization (i.e., type of words) on children’s and adolescents’ memory performance remains to be clarified, especially during this developmental stage. To explore whether a medium-length non-semantically organized test can produce the typical curvilinear performance that semantically organized tests produce, reflecting executive control, we studied and compared the cognitive performance of normal children and adolescents by utilizing mathematical modeling. The model is based on the first-order system transfer function and has been successfully applied to learning curves for the CVLT-C (15 words, semantically organized paradigm). Results indicate that learning nine semantically unrelated words produces typical curvilinear (executive function) performance in children and younger adolescents and that performance could be effectively analyzed with the mathematical model. This indicates that the exponential increase (curvilinear performance) of correctly learned words does not solely depend on semantic and/or length features. This type of test controls semantic and length effects and may represent complementary tools for executive function evaluation in clinical populations in which semantic and/or length processing are affected.

A study polling 76 educators who head academic public relations programs, about whether they support the idea that students in public relations should take core mass media communication classes, reveals that educators support core mass media course requirements, even if the courses are created from a traditional news-editorial-journalism viewpoint. Results also indicate that 46% of the public relations faculty feel that public relations theories and concepts are not being treated adequately and fairly by textbooks that are used in core classes.

The Linc-p21locus, encoding a long non-coding RNA, plays an important role in p53 signaling, cell-cycle regulation, and tumor suppression. However, despite extensive study, confusion exists regarding its mechanism of action: is activity driven by the transcript acting in trans, in cis, or by an underlying functional enhancer? Here, using a knockout mouse model and a massively parallel enhancer assay, we delineate the functional elements at this locus. We observe that, even in tissues with no detectable Linc-p21transcript, deletion of the locus significantly affects local gene expression, including of the cell-cycle regulator Cdkn1a. To characterize this RNA-independent regulatory effect, we systematically interrogated the underlying DNA sequence for enhancer activity at nucleotide resolution and confirmed the existence of multiple enhancer elements. Together, these data suggest that, in vivo, the cis-regulatory effects mediated by Linc-p21, in the presence or absence of transcription, are due to DNA enhancer elements.

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In this article, we argue that relationships between key actors in extractive industries – in our case, mining cooperatives and the state in Bolivia – develop not only on the basis of calculated interest-perceptions and advocacy of rationally understood concerns and goals in policy negotiations, but also on the basis of histories and memories. These influence attitudes and negotiation or confrontation strategies on both sides. The relationship between, on the one hand, individual mining cooperatives and a national federation of cooperative mining organizations, and on the other hand, the Bolivian state, demonstrates that it is crucially important to take into account the specific historical, regional and intra-organizational aspects and memories. More specifically, we show that there is a contrast between the strategy of the national mining cooperatives federation FENCOMIN and a local mining cooperative (ASOBAL), and that to understand this contrast we need to introduce a historical and cultural dimension. After sketching more general conceptual and regional matters, we move on to the current position of cooperative mining in the country and the strategies deployed by FENCOMIN, and subsequently address the situation of a case-study cooperative called ASOBAL. We connect stands and negotiation strategies to issues of identity, memory and place.

The application of a distributed energy balance model over nine years at an hourly time step to a 20 × 20 m grid cell over Glacier Zongo (Bolivia, 16°S) enabled assessment of the climate factors that control the interseasonal and interannual variability of its surface mass balance. The model was validated by comparing the measured and simulated discharge at the outlet, albedo at the Automatic Weather Station, surface state and annual mass balance both glacier‐wide and as a function of altitude. Analysis of the mean monthly energy fluxes highlighted the importance of the meteorological conditions over October and November on the variability of the annual surface mass balance. Two sensitivity analyses are presented, one of the distribution of precipitation over time which maintains a physical coherence between the different meteorological variables and one of the impact of prolonged periods of intense cloud radiative forcing on the surface mass balance. The distribution of precipitation events over time and their associated amounts are the main drivers of the interannual variability of the surface mass balance via an albedo feedback effect. Additionally, prolonged periods of negative cloud radiative forcing, specifically over the month of November, notably reduce the melt rate. This study aimed at identifying the meteorological variables which control the seasonal and annual melt rates of a tropical glacier in Bolivia considering nine years of measurements at the hourly timescale. The analysis of the energy fluxes at the weather station has shown that the period between the austral winter and summer is the period during which most melt can be generated making it key in defining the annual melt rates. The analysis of the impact of measured meteorological variables on the melt rate has shown that it is the solar energy that controls most of it. The amount of solar energy available for melt is defined by the state of the glacier surface (snow, ice, debris) which controls the amount of reflected energy. In this context, the frequency of the snowfall events plays a key role in controlling the melt as frequent events imply a whiter glacier which is able to reflect most of the incoming solar energy. Similarly, because clouds can block large portions of solar energy, sustained cloud periods can play an important role in reducing the melt rate. Seasons over Zongo Glacier can be identified using the distribution of the cloud radiative forcingOctober and November play a strong control on the interannual surface mass balance variability of Zongo GlacierDistribution of the precipitation events in time is key in controlling the melt rate Seasons over Zongo Glacier can be identified using the distribution of the cloud radiative forcing October and November play a strong control on the interannual surface mass balance variability of Zongo Glacier Distribution of the precipitation events in time is key in controlling the melt rate

Abstract:  The X-ray structure of recombinant horse L-chain (rL) apoferritin, solved at 2.0 � resolution with a final R factor of 17.9%, gives evidence that the residue at position 93 in the sequence is a proline and not a leucine, as found in earlier sequencing studies. The structure is isomorphous with other apoferritin structures, and we thus draw particular attention to those structural features which can be related to the stability and function of the protein. Analysis of hydrogen bonding and salt bridge interactions shows that dimers and tetramers are the most stable molecular entities within the protein shell: a result confirming earlier biophysical experiments. The stability of horse rL apoferritin to both dissociation into subunits at acidic pH values and to complete unfolding in guanidine chloride solutions is compared with that of other apoferritins. This emphasizes the role played by the salt bridge in the stability of this protein family. The horse rL apoferritin is significantly more resistant to denaturation than horse spleen ferritin, which in turn is more resistant than any human rH apoferritins, even those for which a salt bridge is restored. Finally, this structure determination not only establishes that a preformed pocket exists in L-chain apoferritin, at a site known to be able to bind porphyrin, but also underlines the particular function of a cluster of glutamic acids (E53, E56, E57 and E60) located at the entrance of this porphyrin-binding pocket.

Patients with kidney failure who are receiving maintenance dialysis have a higher risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and worse clinical outcomes after coronavirus disease 2019 (COVID-19) than the general population. Therefore, immunization against SARS-CoV-2 with effective vaccines is an important component of health-maintenance strategies for these patients. This study evaluated the humoral and cellular responses to messenger RNA (mRNA) SARS-CoV-2 vaccines in this population.

The article discusses the significance of network neutrality for small businesses.

The article discusses some factors businesses should consider when using a solar energy to reduce energy costs including financial incentives, policies and financing.