Ice core records of atmospheric CO2 around the last three glacial terminations

Air trapped in bubbles in polar ice cores constitutes an archive for the reconstruction of the global carbon cycle and the relation between greenhouse gases and climate in the past. High-resolution records from Antarctic ice cores show that carbon dioxide concentrations increased by 80 to 100 parts per million by volume 600 ± 400 years after the warming of the last three deglaciations. Despite strongly decreasing temperatures, high carbon dioxide concentrations can be sustained for thousands of years during glaciations; the size of this phase lag is probably connected to the duration of the preceding warm period, which controls the change in land ice coverage and the buildup of the terrestrial biosphere.</jats:p

Novel sulfur and selenium containing bis-α-amino acids from 4-hydroxyproline

The synthesis of new substituted prolines carrying at C-4 a second α-amino acid residue is reported. The amino acid, l-cysteine or l-selenocysteine, is linked to the proline ring through the sulfur or the selenium atom, respectively. The products were prepared with different stereochemistry at C-4, in few and clean high-yielding steps, with suitable protections for solid phase applications. The introduction of both sulfur and selenium atoms at C-4 of the proline ring seems to enhance significantly the cis geometry at the prolyl amide bond

Reducing the operational cost of cloud data centers through renewable energy

The success of cloud computing services has led to big computing infrastructures that are complex to manage and very costly to operate. In particular, power supply dominates the operational costs of big infrastructures, and several solutions have to be put in place to alleviate these operational costs and make the whole infrastructure more sustainable. In this paper, we investigate the case of a complex infrastructure composed of data centers (DCs) located in different geographical areas in which renewable energy generators are installed, co-located with the data centers, to reduce the amount of energy that must be purchased by the power grid. Since renewable energy generators are intermittent, the load management strategies of the infrastructure have to be adapted to the intermittent nature of the sources. In particular, we consider EcoMultiCloud, a load management strategy already proposed in the literature for multi-objective load management strategies, and we adapt it to the presence of renewable energy sources. Hence, cost reduction is achieved in the load allocation process, when virtual machines (VMs) are assigned to a data center of the considered infrastructure, by considering both energy cost variations and the presence of renewable energy production. Performance is analyzed for a specific infrastructure composed of four data centers. Results show that, despite being intermittent and highly variable, renewable energy can be effectively exploited in geographical data centers when a smart load allocation strategy is implemented. In addition, the results confirm that EcoMultiCloud is very flexible and is suited to the considered scenario

L’aerofotointerpretazione archeologica per una nuova ipotesi ricostruttiva della città romana di Telesia (Benevento, Campania)

The author illustrates a research project aimed at making an important contribution to the topographical knowledge of the urban area inside the city walls of Roman ‘Telesia’, located near Benevento (S. Salvatore Telesino). The urban survey has involved topographical and archaeological research and a selected coverage of the western area of the city, near Porta Volturno, using satellite images and low altitude aerial photography. A Geographical Information System, based on the integration of aerial data, maps and the digitization of several negative cropmarks, has allowed the author to develop a database for the visualization and comprehension of the complex ancient site of Telesia and to interpret the urban planning of the Roman city

Falerii Novi: spunti per un update topografico vettorializzato della città romana. Nuovi dati dall’area meridionale urbana ed extraurbana

The city of Falerii Novi is situated on the lowest eastern slopes of Monti Cimini, in the volcanic area on the western side of Tiber Valley, in the district of Fabrica di Roma (VT). The ancient Roman town was founded in 241 BC, the same year of the occupation and destruction of the ancient Faliscan town of Falerii Veteres (now Civita Castellana). Recent geophysical and lidar surveys, conducted between 1998 and 2008 by S. Keay and R. Opitz, allowed the reconstruction of the ancient city plan characterized by an orthogonal grid that was organized into 69 insulae. Thanks to geophysical surveys in 2008, along with the study of aerial photographs by G. Scardozzi in 2004, it was possible to identify a large Roman domus with slightly different orientation to the northern walls of the ancient city. These data validated the information from the excavation campaigns conducted between 1821 and 1830 and between 1969 and 1975. The research aims at integrating the data from the landscape surveys in the area of Civita Castellana in 1994, which were carried out by the Soprintendenza per i Beni Archeologici dell’Etruria Meridionale, with data derived from the analysis of aerial photointerpretation. The objective was to define, with precision, new elements for the reconstruction of the ancient topography of Falerii Novi

Load Management with Predictions of Solar Energy Production for Cloud Data Centers

Power supply of big infrastructures is today a tremendous operational cost for providers and the expected growth of Internet traffic and services will lead to a further expansion of the computing and networking infrastructures and this, in its turn, raises also concerns in terms of sustainability. In this context, renewable energy generators can help to both reduce costs and alleviate the concerns of sustainability of big infrastructures. In this paper, we consider the case of Data Centers (DCs) composed of a few sites located in different geographical positions and powered with solar energy. Due to the intermittent nature of solar energy, different time zones and price of electricity in different locations, load management strategies are fundamental. We consider predictions of the solar energy production performed through Artificial Neural Networks and we assess the impact of predictions on load management decisions and, ultimately, on the DC performance

General and Intensive Care Outcomes for Hospitalized Patients With Solid Organ Transplants With COVID-19

© The Author(s) 2020. Purpose: COVID-19 has been associated with a dysregulated inflammatory response. Patients who have received solid-organ transplants are more susceptible to infections in general due to the use of immunosuppressants. We investigated factors associated with mechanical ventilation and outcomes in solid-organ transplant recipients with COVID-19. Materials and Methods: We conducted a retrospective cohort study of all solid-organ transplant recipients admitted with a diagnosis of COVID-19 in our 23-hospital health system over a 1-month period. Descriptive statistics were used to describe hospital course and laboratory results and bivariate comparisons were performed on variables to determine differences. Results: Twenty-two patients with solid-organ transplants and COVID-19 were identified. Eight patients were admitted to the ICU, of which 7 were intubated. Admission values of CRP (p = 0.045) and N/L ratio (p = 0.047) were associated with the need for mechanical ventilation. Seven patients (32%) died during admission, including 86% (n = 6) of patients who received mechanical ventilation. Conclusions: In solid-organ transplant recipients with COVID-19, initial CRP and N/L ratio were associated with need for mechanical ventilation

Altered lipid acyl chain length controls energy dissipation in light-harvesting complex II proteoliposomes by hydrophobic mismatch.

In plants, the major light-harvesting antenna complex (LHCII) is vital for both light harvesting and photoprotection in photosystem II. Previously, we proposed that the thylakoid membrane itself could switch LHCII into the photoprotective state, qE, via a process known as hydrophobic mismatch. The decrease in the membrane thickness that followed the formation of ΔpH was a key fact that prompted this idea. To test this, we made proteoliposomes from lipids with altered acyl chain length (ACL). Here, we show that ACL regulates the average chlorophyll fluorescence lifetime of LHCII. For liposomes made of lipids with an ACL of 18 carbons, the lifetime was ∼2 ns, like that for the thylakoid membrane. Furthermore, LHCII appears to be quenched in proteoliposomes with an ACL both shorter and longer than 18 carbons. The proteoliposomes made of short ACL lipids display structural heterogeneity revealing two quenched conformations of LHCII, each having characteristic 77 K fluorescence spectra. One conformation spectrally resembles isolated LHCII aggregates, whilst the other resembles LHCII immobilized in polyacrylamide gels. Overall, the decrease in the ACL appears to produce quenched conformations of LHCII, which renders plausible the idea that the trigger of qE is the hydrophobic mismatch

Holocene carbon-cycle dynamics based on CO2 trapped in ice at Taylor Dome, Antarctica

A high-resolution ice-core record of atmospheric CO2 concentration over the Holocene epoch shows that the global carbon cycle has not been in steady state during the past 11,000 years. Analysis of the CO2 concentration and carbon stable-isotope records, using a one-dimensional carbon-cycle model,uggests that changes in terrestrial biomass and sea surface temperature were largely responsible for the observed millennial-scale changes of atmospheric CO2 concentrations