Non-adiabatic generation of a pure spin current in a 1D quantum ring with spin-orbit interaction

We demonstrate the theoretical possibility of obtaining a pure spin current in a 1D ring with spin-orbit interaction by irradiation with a non-adiabatic, two-component terahertz laser pulse, whose spatial asymmetry is reflected by an internal dephasing angle $\phi$. The stationary solutions of the equation of motion for the density operator are obtained for a spin-orbit coupling linear in the electron momentum (Rashba) and used to calculate the time-dependent charge and spin currents. We find that there are critical values of $\phi$ at which the charge current disappears, while the spin current reaches a maximum or a minimum value.Comment: 8 pages, 5 figure

Gridovi fine prostorne rezolucije dnevnih visina snijega za Rumunjsku (2005.–2015.)

This study presents the spatial interpolation procedure from snow depth measurements at weather stations implying the following stages: (1) Spatial interpolation at 1 km × 1 km resolution of the mean multiannual values (2005-2015) corresponding to each month, computed from the data extracted from the climatological database; (2) Computation of the daily deviations against the multiannual monthly mean for every day and year over 2005–2015 and their spatial interpolation; (3) Spatio-temporal datasets were obtained through merging the two surfaces obtained in stages 1 and 2. The anomalies were considered to be the ratio between the daily snow depth values and the climatology. The spatial variability of the data used in the first stage was accounted for through the use of a series of predictors derived from the digital elevation model (DEM). To plot the maps with the climatological normals (multiannual means), the Regression-Kriging (RK) spatial interpolation method was used. In order to choose the optimum method applied in spatializing deviations, four interpolation methods were tested using a cross-validation procedure: Multiquadratic, Ordinary Kriging (separated and pooled variograms) and 3d Kriging.Ova studija prikazuje proceduru prostorne interpolacije mjerenja dubine snijega na meteorološkim postajama koja podrazumijeva sljedeće faze: (1) prostorna interpolacija pri rezoluciji od 1 km x 1 km srednjih višegodišnjih vrijednosti (2005.–2015.), koja se provodi s podacima iz klimatološke baze; (2) izračunavanje dnevnih odstupanja od višegodišnjeg mjesečnog srednjaka za svaki dan i godinu tijekom razdoblja od 2005. do 2015. i njihova prostorna interpolacija; (3) prostorno-vremenski skup podataka dobiven je združivanjem procjena dobivenih u fazi 1 i 2. Odstupanja su definirana kao omjeri dnevnih vrijednosti dubine snijeg i klimatološkog srednjaka. Prostorna varijabilnost podataka korištenih u prvoj fazi objašnjena je korištenjem niza prediktora izvedenih iz digitalnog modela visina (DEM). Karte klimatoloških normala (višegodišnji srednjaci) izrađene su metodom prostorne interpolacije zvanom regresijski kriging (RK). Za odabir optimalne metode za prostornu interpolaciju odstupanja, testirane su četiri metode interpolacije i ocijenjene pomoću postupka poprečne validacije: multikvadratična, obični kriging (razdvojeni i skupni variogrami) i 3D kriging

Electrical Characterization of Circulation Weather Types in Northern Spain Based on Atmospheric Nanoparticles Measurements: A Pilot Study

The electrical component of the atmosphere is a key element to understand bio-effects of atmospheric processes. In this paper an attempt was made to find possible interactions between air masses arriving in Santander, Northern Spain, and electrical properties of nanoparticles measured in this zone. A methodological approach is proposed to characterize electrically the predominant weather types in the study area. An electrical low pressure impactor device (ELPI +) was used to measure atmospheric particles net charge and particle net charge distribution in real time in July 2018, among other parameters. Data from two specific channels [0.054?0.071 lm] and [2.5?3.0 lm] has been initially used. Atmospheric circulation was defined attending to two, subjective and objective, weather type classifications. Back trajectories of nanoparticles were also computed by the Hybrid Single-Particle Lagrangian Integrated Trajectory model. Results confirm that atmospheric nanoparticles charge varies according to their size. The highest mean absolute charge is associated with local circulation in Santander for both channels. The studied nanoparticles show a quicker reaction to weather conditions than microparticles. They also have a significant correlation with meteorological variables for 18 synoptic groups found, but humidity. Microparticles [2.5?3.0 lm] are negatively related with air humidity, mainly with S-SE circulation pattern.Authors would like to thank Dekati Ltd. for providing the instrument used in this study through the company SOLMA Environmental Solutions SLU. Authors would like to thank NOAA Air researches Laboratory (ARL) for the provision of FNL-HYSPLIT data, the Hysplit transport and dispersion Model, and, the READY web site used in this publication. Also authors acknowledge Cost Action 15211, Atmospheric Electricity Network: coupling with the Earth System, climate and biological systems, for funding a STSM of Prof. P. Kassomenos at the Geobiomet research group at the University of Cantabria, Santander. Authors would like to thank to support from the Spanish National Research Agency – Project CSO2016-75154-R and the European Funds for Regional Development (FEDER)

Variability and Change in Water Cycle at the Catchment Level

This study proposes a simple methodology for assessing future-projected evolution of water cycle components (precipitation, potential evapotranspiration, and potential runoff) based on the two-level Palmer model of the soil and their impact on drought conditions at basin level. The Palmer Drought Severity Index (PDSI) is used as drought metric. The catchments of rivers Arges, Mures, Prut, Siret and Somes (mid- and lower Danube basin) have been chosen as case studies. The present climate data consist of Romanian gridded dataset, monthly precipitation and values of streamflow from Romania and Republic of Moldova and potential evapotranspiration-related data from the Climate Research Unit (University of East Anglia). We used as future projections five numerical experiments with regional models obtained through the EURO-CORDEX initiative, under two Representative Concentration Pathway scenarios. The correlations between observed streamflow at the river basin outlets and PDSI-related components of the water cycle show that PDSI represents reasonably well processes taking place in the selected catchments. Depending on the specific scenario and catchment, droughts that in the Palmer classification were deemed as incipient, mild or severe under present climate will become a normal summer feature toward the end of this century, especially over catchments situated in the lower Danube basin

A unifying modelling of multiple land degradation pathways in Europe

Land degradation is a complex socio-environmental threat, which generally occurs as multiple concurrent pathways that remain largely unexplored in Europe. Here we present an unprecedented analysis of land multi-degradation in 40 continental countries, using twelve dataset-based processes that were modelled as land degradation convergence and combination pathways in Europe’s agricultural (and arable) environments. Using a Land Multi-degradation Index, we find that up to 27%, 35% and 22% of continental agricultural (~2 million km2) and arable (~1.1 million km2) lands are currently threatened by one, two, and three drivers of degradation, while 10–11% of pan-European agricultural/arable landscapes are cumulatively affected by four and at least five concurrent processes. We also explore the complex pattern of spatially interacting processes, emphasizing the major combinations of land degradation pathways across continental and national boundaries. Our results will enable policymakers to develop knowledge-based strategies for land degradation mitigation and other critical European sustainable development goals

IL-1β Processing in Host Defense: Beyond the Inflammasomes

Stimulation and release of proinflammatory cytokines is an essential step for the activation of an effective innate host defense, and subsequently for the modulation of adaptive immune responses. Interleukin-1β (IL-1β) and IL-18 are important proinflammatory cytokines that on the one hand activate monocytes, macropages, and neutrophils, and on the other hand induce Th1 and Th17 adaptive cellular responses. They are secreted as inactive precursors, and the processing of pro-IL-1β and pro-IL-18 depends on cleavage by proteases. One of the most important of these enzymes is caspase-1, which in turn is activated by several protein platforms called the inflammasomes. Inflammasome activation differs in various cell types, and knock-out mice defective in either caspase-1 or inflammasome components have an increased susceptibility to several types of infections. However, in other infections and in models of sterile inflammation, caspase-1 seems to be less important, and alternative mechanisms such as neutrophil-derived serine proteases or proteases released from microbial pathogens can process and activate IL-1β. In conclusion, IL-1β/IL-18 processing during infection is a complex process in which the inflammasomes are only one of several activation mechanisms

Vegetation and climate variability during the Last Interglacial evidenced in the pollen record from Lake Baikal

A high-resolution pollen record from the core sediments collected in the northern part of Lake Baikal represents the latest stage of the Taz (Saale) Glaciation, Kazantsevo (Eemian) Interglacial (namely the Last Interglacial), and the earliest stage of the Zyryanka (Weichselian) Glaciation. According to the palaeomagnetic-based age model applied to the core, the Last Interglacial in the Lake Baikal record lasted about 10.6 kyrs from 128 kyr to 117.4 kyr BP, being more or less synchronous with the Marine Isotope Stage 5e. The reconstructed changes in the south Siberian vegetation and climate are following. A major spread of shrub alder (Duschekia fruticosa = Alnus fruticosa) and shrub birches (Betula sect. Nanae/Fruticosae) in the study area was a characteristic feature during the late glacial phase of the Taz Glaciation. Boreal trees e.g. spruce (Picea obovata) and birch (Betula sect. Albae) started to play an important role in the regional vegetation with the onset of the interglacial conditions. Optimal conditions for Abies sibirica-Picea obovata taiga development occurred ca. 126.3 kyr BP. The maximum spread of birch forest-steppe communities took place at the low altitudes ca. 126.5-125.5 kyr BP and Pinus sylvestris started to form forests in the northern Baikal area after ca. 124.4 kyr BP. Re-expansion of the steppe communities, as well as shrubby alder and willow communities and the disappearance of forest vegetation occurred at about 117.4 kyr BP, suggesting the end of the interglacial succession. The changes in the pollen assemblages recorded in the sediments from northern Baikal point to a certain instability of the interglacial climate. Three phases of climate deterioration have been distinguished: 126-125.5, 121.5-120, and 119.5-119 kyr BP. The penultimate cooling signal may be correlated with the cool oscillation recorded in European pollen records. However, such far distant correlation requires more careful investigation

Global warming or global cooling?

Nicolae Testemianu State University of Medicine and Pharmacy, Republic of MoldovaIntroduction. Although nowadays multiple scientific organisations have shown solid evidence that Earth is going through global warming, some stories prove vice-versa, their main argument being those 2 years studies shown by NASA in data. However, you can’t state the fact that our planet is going through global cooling based on such a short period. Studies have shown that on a larger time scale, atmosphere temperature can be explained using the Keeling Curve, which is a long-term study of CO2 concentrations-the higher the concentration, the higher the temperature. And even if this curve is constantly jiggling up and down, meaning that the temperature during short periods such as a few years is either increasing or decreasing, the overall direction is an increase, meaning that slowly but steadily, Earth is warming on a global scale. Material and methods. This research analysed the major aspects of global warming, using data provided by trustworthy scientific organisations, such as the Natural Resources Defence Council, National Geographic, NASA and others which have studied this field for a prolonged time. There have been avoided platforms that offered information without any reference to sources. Results. Scientists generally regard the second half of the 19th century as the starting point of humanity influencing the global climate. How much of the warming since 1850 can be attributed to human emissions? Almost all of it. The intergovernmental Panel on Climate Change stated that greenhouse gas emissions are at an unprecedented level in the last 800.000 years, and the ones at fault are none other than humans. The interdependence between carbonic acid gas and global temperatures have been confirmed during Earth’s history. During the last 800.000 years, there have been CO2 fluctuations, which were periodically higher or lower and the main cause were the changes of Earth’s orbit around the sun, also known as Milankovitch Cycles. However, during this long-time frame, the concentrations of carbon dioxide have not been higher than 300 parts per million. Studies also have shown that this index began to grow since Industrial Revolution. Thus, in just less than 200 centuries humanity raised concentrations to more than 400 ppm. Global warming has been a hot topic between highly developed countries, as it is already a worldwide problem. With current policies, by 2050 global temperature will be higher with 1.5°C. 20% of the people living in regions have already seen warming greater at least with 1.5 degrees Celsius in one of the seasons. That means that at least once every 5 years Earth’s population will be exposed to severe heatwaves, and if the temperature will continuously rise by 0.5 degrees, the percentage of the victims will be doubled. This ‘’insignificant growth’’ may cause annually deadly heatwaves like in Pakistan during 2015 with temperatures as high as 49°C, which caused 2000 deaths from dehydration and heatstroke, severe damage to livestock as well as agriculture. Conclusions. To sum up, Earth periodically is passing through short term cooling, but overall, the temperature is steadily growing, and the reason is humanity. In just 2 centuries, the concentrations of carbon dioxide increased to about 1.3 of the norms. The effects of global warming look as follows: more greenhouse gasses->higher temperature->calamities->destruction and death

Nonadiabatic Generation of a Pure Spin Current in a One-Dimensional Quantum Ring with Spin-Orbit Interaction

We demonstrate the theoretical possibility of obtaining a pure spin current in a 1D ring with spin-orbit interaction by irradiation with a nonadiabatic, two-component terahertz laser pulse, whose spatial asymmetry is reflected by an internal phase difference φ. The solutions of the equation of motion for the density operator are obtained for a spin-orbit coupling linear in the electron momentum (Rashba) and they are used to calculate the time-dependent charge and spin currents. We find that there are critical values of φ at which the charge current disappears, while the spin current reaches a maximum or a minimum value

SPON: Enabling Resilient Inter-Ledgers Payments with an Intrusion-Tolerant Overlay

Payment systems are a critical component of everyday life in our society. While in many situations payments are still slow, opaque, siloed, expensive or even fail, users expect them to be fast, transparent, cheap, reliable and global. Recent technologies such as distributed ledgers create opportunities for near-real-time, cheaper and more transparent payments. However, in order to achieve a global payment system, payments should be possible not only within one ledger, but also across different ledgers and geographies.In this paper we propose Secure Payments with Overlay Networks (SPON), a service that enables global payments across multiple ledgers by combining the transaction exchange provided by the Interledger protocol with an intrusion-tolerant overlay of relay nodes to achieve (1) improved payment latency, (2) fault-tolerance to benign failures such as node failures and network partitions, and (3) resilience to BGP hijacking attacks. We discuss the design goals and present an implementation based on the Interledger protocol and Spines overlay network. We analyze the resilience of SPON and demonstrate through experimental evaluation that it is able to improve payment latency, recover from path outages, withstand network partition attacks, and disseminate payments fairly across multiple ledgers. We also show how SPON can be deployed to make the communication between different ledgers resilient to BGP hijacking attacks