Thermal entanglement in a triple quantum dot system

We present studies of thermal entanglement of a three-spin system in triangular symmetry. Spin correlations are described within an effective Heisenberg Hamiltonian, derived from the Hubbard Hamiltonian, with super-exchange couplings modulated by an effective electric field. Additionally a homogenous magnetic field is applied to completely break the degeneracy of the system. We show that entanglement is generated in the subspace of doublet states with different pairwise spin correlations for the ground and excited states. At low temperatures thermal mixing between the doublets with the same spin destroys entanglement, however one can observe its restoration at higher temperatures due to the mixing of the states with an opposite spin orientation or with quadruplets (unentangled states) always destroys entanglement. Pairwise entanglement is quantified using concurrence for which analytical formulae are derived in various thermal mixing scenarios. The electric field plays a specific role -- it breaks the symmetry of the system and changes spin correlations. Rotating the electric field can create maximally entangled qubit pairs together with a separate spin (monogamy) that survives in a relatively wide temperature range providing robust pairwise entanglement generation at elevated temperatures.Comment: 9 pages, 5 figures, accepted in Eur. Phys. J.

Spatial distribution and reduction of PCDD/PCDF Toxic Equivalents along three shallow lowland reservoirs

Reservoirs situated along a river continuum are ecosystems where rates of transfer of suspended matter and associated micropollutants are reduced due to sedimentation, accumulation, and biological and physical transformation processes. Among the micropollutants, PCDDs and PCDFs are substances that are highly toxic and carcinogenic for humans and animals. They are emitted and dispersed in the environment throughout the whole catchment area and may accumulate in aquatic and terrestrial food chains, creating a risk for human health. A wealth of data exists indicating the increase in the concentrations of pollutants along a river continuum. A comparative analysis of total, individual, and TEQ PCDD/PCDF concentrations in large lowland, shallow reservoirs located in different catchments (“I”—industrial/urban/ agricultural, “U”—urban/agricultural, and “A”—agricultural/ rural) showed decreases of the TEQ concentrations in bottom sediments along a gradient from the middle sections to the dam walls. Moreover, penta-, hexa-, and heptachlorinated CDD/CDF congeners were reduced from 28.8 up to 93.6 % in all three types of reservoirs. A further analysis of water samples from the inlets and outlets of the “A” reservoir confirmed this tendency.The authors wish to express their sincere appreciation to Prof. Konrad Rydzyński from the Nofer Institute of Occupational Medicine in Lodz, Prof. Richard Robarts from the UNEP Global Environment Monitoring System (GEMS)/Water Programme, Prof. Paul DuBowy from the U.S. Army Corps of Engineers, and Prof. David Harper from the Department of Biology, the University of Leicester for their constructive comments on an earlier version of this paper. The authors also wish to acknowledge the research team of the Nofer Institute of Occupational Medicine in Lodz: Dr Danuta Ligocka and Dr Wiktor Wesołowski for their assistance during the laboratory processes. The research was supported by the following projects of the Polish Ministry of Science and Higher Education: – N N305 365738 “Analysis of point sources pollution of nutrients, dioxins and dioxin-like compounds in the Pilica River catchment and draw up of reclamation methods”; – 2PO4 G08830 “Accumulation of dioxins and dioxin-like pollutants in the food chain of the Sulejowski and Włocławski Reservoirs: chemometric analysis and toxicological estimation”

Analiza interwencji z przyczyn kardiologicznych podejmowanych przez zespoły ratownictwa medycznego w powiecie brzeskim w roku 2010 i 2011

Wstęp. Częstą przyczyną wezwań zespołów ratownictwa medycznego są choroby układu krążenia. Celem pracy była analiza interwencji z przyczyn kardiologicznych podejmowanych przez zespoły ratownictwa medycznego w powiecie brzeskim. Materiał i metody: Analizą objęto 10 208 kart wyjazdów zespołów ratownictwa medycznego i medycznych czynności ratunkowych z roku 2010 i 2011, w tym 1082 z przyczyn kardiologicznych. Kryterium wyboru było rozpoznanie na podstawie procedur ICD-10: I20-I25 choroba niedokrwienna serca, I30-I52 inne choroby serca. Do analizy zastosowano statystykę opisową oraz nieparametryczny test zgodności χ2. Wyniki: Przyczyny kardiologiczne stanowiły 10,6 % wszystkich wyjazdów. W roku 2011 zanotowano o 56 mniej wyjazdów z przyczyn kardiologicznych w porównaniu z rokiem 2010. Ponad dwukrotnie częściej do wezwań wysyłany był zespół specjalistyczny. Mediana czasu dojazdu mieściła się w wymogach określonych w ustawie. Przyczyny wezwania zespołu ratownictwa medycznego były zróżnicowane, przeważały: bóle w klatce piersiowej i duszność. Większość interwencji dotyczyła obszarów wiejskich i osób po 61 roku życia. Odnotowano wzrost zgonów o 24 % w przypadku nagłego zatrzymania krążenia w roku 2011. Zdecydowanie częściej niektóre procedury i leki były stosowane przez zespoły specjalistyczne. Wnioski: Interwencje z przyczyn kardiologicznych nadal są częstą przyczyną wezwania zespołu ratownictwa medycznego. Właściwe rozmieszczenie ambulansów umożliwia dostosowanie me-diany czasu dojazdu zespołów do wymogów określonych w ustawie. Rodzaj podejmowanych interwencji jest zależny od rodzaju zespołu, a kwalifikacje ich członków nie mają wpływu rezultat końcowy.Introduction. Frequent paramedical emergency dispatch calls are caused by cardiovascular diseases. The aim of the study was to analyse medical intervention for cardiological causes undertaken by medical rescue teams in the Brzesko area. Materials and methods. The analysis covered 10,208 medical emergencies by medical rescue teams in 2010 and 2011, includ-ing 1,082 undertaken for cardiological reasons. The choice of criterion was a diagnosis based on ICD-10 procedures: I20-I25 - ischemic heart disease and I30-I52 - other heart diseases. Descriptive statistics and the nonparametric compliance χ2 test were used for the analysis. Results. Cardiovascular causes accounted for 10.6% of all ambulance departures. In 2011, there were 56 fewer dispatches due to cardiological reasons than in 2010. There were more than twice as many specialist team dispatches sent on call. The average travel time was within the requirements set forth in the Act. The reasons for calling for a medical rescue team varied, but mostly in-cluded chest pain and dyspnoea. Most of the interventions concerned rural areas and people over 61 years of age. There was an increase in deaths by 24% in the case of sudden cardiac arrest in 2011. Specialist teams used more procedures and medications than the basic teams. Conclusions. Cardiac interventions are still a frequent cause for calling for an emergency medical team. Properly locating ambulances allows the mediating time of arrival of the units to meet the requirements specified by regulations. The type of intervention is dependent on the type of the team and the qualifications of their members do not affect the final outcome

Colloidal topological insulators

Topological insulators insulate in the bulk but exhibit robust conducting edge states protected by the topology of the bulk material. Here, we design a colloidal topological insulator and demonstrate experimentally the occurrence of edge states in a classical particle system. Magnetic colloidal particles travel along the edge of two distinct magnetic lattices. We drive the colloids with a uniform external magnetic field that performs a topologically non-trivial modulation loop. The loop induces closed orbits in the bulk of the magnetic lattices. At the edge, where both lattices merge, the colloids perform skipping orbits trajectories and hence edge-transport. We also observe paramagnetic and diamagnetic colloids moving in opposite directions along the edge between two inverted patterns; the analogue of a quantum spin Hall effect in topological insulators. We present a new, robust, and versatile way of transporting colloidal particles, enabling new pathways towards lab on a chip applications