Peptides from chiral Calpha,alpha-disubstituted glycines : crystallographic characterization of conformation of Calpha-methyl, Calpha-isopropylglycine [(alphaMe)Val] in simple derivatives and model peptides

The mol. and crystal structures of R-L-(aMe)Val-R1 [R = ClCH2CO, R1 = OH; R = Z, R1 = Ala-Ala-OMe (I); R = Ac-Aib-Aib, Z-Aib, R1 = Aib-Aib-OCMe3; (aMe)Val = NHCMe(CHMe2)CO; Z = PhCH2O2C; Aib = NHCMe2CO] were detd. by x-ray diffraction. Tripeptide I adopts a type-I b-turn conformation stabilized by a

The effects of new 2030 scenario: Reduction of short-circuit power and widening of voltage dips

In Italy, 80% of PV installations are at MV and LV levels, which makes it particularly challenging to control them from the national dispatch centre; this leads to an increase of the reverse power flow in the primary and secondary substations, increasing pressure on the existing measuring and protection systems and on voltage control. The National Strategic Plan, approved on November 10 th , 2017 by the Ministry of Economic Development and the Ministry of the Environment, has launched an ambitious challenge, e.g., phasing-out of coal and the increase of electricity from renewable sources: more than 55% by 2030 of gross final consumption. The power system must be able to withstand unplanned events and manage their impacts on the network, thus reducing the risk of cascading effects and maintaining suitable quality of supply. During operation with a high percentage of RES connected to the network through inverters, the system is weaker (lower short circuit power) and, with currently adopted controls, less able to react to emerging faults. With the increase of PV installations, also due to reduction of rotating synchronous machines connected to transmission grid, there is lower Short-circuit-Power available and therefore voltage dips generated at transmission level have larger impact (c.g. area impacting supply quality widens hundreds of kilometers away from the event). This paper summarizes the main challenges in terms of impacting supply quality for the Italian Power system in a new scenario with more than 50% RES by 2030 of gross final consumption and suggests some computation procedures to investigate the phenomenon

HERASE: monitorare l’erosione del suolo nelle Alpi con tecniche Geomatiche

In Italia ci sono circa 4 milioni di ettari di terreno agricolo e forestale a rischio di erosione o frana e recenti stime del Ministero dell’Ambiente (2013) indicano che sarebbero necessari 40 miliardi di Euro per ridurre il rischio dovuto alla perdita di suolo sul territorio nazionale. Il progetto Hydrogeological modeling for Erosion Risk Assessment from SpacE (HERASE), finanziato da Fondazione Cariplo (Grant Nr.2016-0768), affronta questo tema nel bacino camuno del fiume Oglio, un’area alpina dell’Italia settentrionale. Scopo di HERASE è mettere a punto una metodologia di analisi basato sul Revised Universal Soil Loss Equation (RUSLE), reso dinamico dall’uso di mappe di copertura del suolo multi-temporali, per evidenziare le zone potenzialmente soggette a fenomeni erosivi e le dinamiche dei cambiamenti del territorio capaci di influenzarne l’entità. Misure in situ di erosione realizzate con un simulatore di pioggia permetteranno la caratterizzazione idrologica di zone rappresentative e la taratura del modello. Infine, le previsioni restituite dai modelli climatici saranno utilizzate per delineare possibili scenari di rischio futuro, in un contesto che vede il territorio montano, e quello alpino in particolare, soggetto a sempre più evidenti cambiamenti climatici. Il presente lavoro riporta alcuni risultati preliminari del progetto HERASE ottenuti sul sotto-bacino del torrente Arcanello (circa 21 km2), dove la stima preliminare dell’erosione è pari a 7,61 [t ha-1 a-1]. Tale risultato è concorde con il valore medio annuo a livello nazionale

Impact of climate change on agricultural productivity and food security in the Himalayas: A case study in Nepal

The paradigmatic Dudh Koshi basin laid at the toe of Mt. Everest is largely visited by tourists every year, and yet agricultural productivity and food security therein are at stake under climate change. Agricultural yield in the area recently decreased, and the question arose whether cropping at higher altitudes may help adaptation. We investigated here the present, and future (until 2100) patterns of productivity of three main rain-fed crops in the catchment (wheat Triticum L., rice Oryza L., and maize Zea Mais L.). We explored food security using a nutritional index, given by the ratio of the caloric content from our target cereals, to daily caloric demand. We preliminary investigated whether vertical extension of the cropped area may increase food security. We did so by (i) mapping crops area using remote sensing, (ii) setting up the agronomic model Poly-Crop, (iii) feeding Poly-Crop with downscaled outputs from global climate models, and (iv) projecting vertical land occupation for cropping, population projections, and nutritional requirements. We estimated crop yield and food security at half century (2040–2050), and end of century (2090–2100), against a control run decade CR (2003−2013), under constant land use, and projected land occupation. On average, specific wheat yield would decrease against CR by −25% (rice −42%, maize −46%) at 2100, with largely yearly variability for unchanged land use scenario. Under modified land use scenario, wheat yield would decrease by −38%, while rice and maize yield would improve, maize very slightly (−22%, and −45%, against CR) in response to occupation of higher altitudes than now. Our food security index would decrease under all scenarios (111% in 2010, 49% on average at 2050, under a population peak, and 51% at 2100), and become more variable, however with potential for adaptation by colonization of higher lands (75%, 62%, at 2050, 2100). Very large expansion of one cereal (i.e. maize), may make food security more unstable, as mostly depending on erratic yield of that cereal only

Automatic Co-registration of Copernicus Time Series via Synchronization

This paper presents a satellite image co-registration procedure aiming at simultaneously estimating multiple affine transformations between a set of multi-temporal or multi-source satellite images, reducing error accumulation and improving metric precision. The approach is based on synchronization, a method that seeks to infer the unknown states of a network of nodes, where only the ratio (or difference) between node pairs can be measured. In our case states represent affine transformations. The proposed method globally combines via synchronization pairwise transformations computed for all the image combinations of the multi-temporal sequence, beyond the traditional image-to-base approach available in remote sensing and GIS packages. Results obtained with Landsat and Sentinel-2 images reveal that the algorithm can be used not only to perform the actual co-registration, but also as a diagnostic tool to evaluate the quality of transformation parameters through a comparison with basic co-registration methods, as well as with global least squares adjustment