154 research outputs found

    Effect of a skin-deep surface zone on formation of two-dimensional electron gas at a semiconductor surface

    Full text link
    Two dimensional electron gases (2DEGs) at surfaces and interfaces of semiconductors are described straightforwardly with a 1D self-consistent Poisson-Schr\"{o}dinger scheme. However, their band energies have not been modeled correctly in this way. Using angle-resolved photoelectron spectroscopy we study the band structures of 2DEGs formed at sulfur-passivated surfaces of InAs(001) as a model system. Electronic properties of these surfaces are tuned by changing the S coverage, while keeping a high-quality interface, free of defects and with a constant doping density. In contrast to earlier studies we show that the Poisson-Schr\"{o}dinger scheme predicts the 2DEG bands energies correctly but it is indispensable to take into account the existence of the physical surface. The surface substantially influences the band energies beyond simple electrostatics, by setting nontrivial boundary conditions for 2DEG wavefunctions.Comment: 9 pages, 7 figures, 2 table

    Improving animal health and welfare in organic cattle milk production through breeding and management

    Get PDF
    Overall summary of main results, discussion and conclusions WP1 The aim in WP1 was to map the performance of local breeds compared to commercial dairy breeds on organic farms in Austria, Switzerland, Sweden, Poland and Germany with regard to health associated traits, fertility and production traits. In a study covering the whole population of the selected breeds, managed under organic conditions during the period 1.7.2011 to 30.6.2014, we found lower milk yields for local breeds. In general we found better fertility performance (less days open, shorter calving intervals, lower number of inseminations) for at least one of the local breeds involved in each country. We also detected lower proportions of milk records with somatic cell counts above 100.000 cells/ ml milk for in at least one of the local breeds in Austria, Switzerland and Sweden, but not so for Poland where the commercial breed performed best. Moreover, we found a lower proportion of test day records with a fat: protein ratio above 1.5 in the first 100 days in milk for many local breeds (Grey Cattle (AL) and Original Braunvieh (OB) in Switzerland. AL by trend in Austria, Swedish Red (SRB) in Sweden and Polish Red and White (ZR) in Poland) hinting at a lower risk of subclinical ketosis for some of the local breeds compared to the respective commercial breed. We could not find breed differences regarding overall occurrence of veterinary treatments or those due to fertility or leg/ claw problems in Austrian data, but found that AL had less treatments due to udder problems than the commercial Braunvieh (BV). In Sweden, the local breed SRB had less overall treatments, fewer treatments due to fertility or udder disorders and also showed less remarks on claw or leg disorders than the commercial breed. We did not find breed differences regarding treatments due to metabolic disorders in Swedish data. We analyzed Austrian and Swiss data from culled cows on productive life span and detected a superiority of local breeds for this trait, but higher lifetime production (kg ECM) in the commercial breed. The second study on cows managed under very similar conditions in Sweden (period: 1.7.2011 to 30.6.2014) and Germany (period 1.7.2011 to 30.6.2015) revealed no significant breed differences in total ECM yield in German data, while we found higher milk fat and milk protein contents for the local breed Original Red Angler Cattle breed (AAZ). In Sweden, we found the highest ECM yield in the commercial breed Swedish Holstein (SH). The local breed Swedish Polled (SKB) had the highest fat and protein contents, followed by the second local breed Swedish Red (SRB), both differed significantly from the respective commercial breed SH and also among each other. We could not detect significant breed differences in the German data set with regard to fertility traits, although the local AAZ tended to have fewer days open than the commercial breed HO. In Sweden, we did not find breed differences for calving interval, but both local breeds had fewer days open, and SKB needed fewer inseminations compared to SH. No breed differences in any of the two countries regarding the proportion of test day records with a SCC content of over 100.000 cells per ml milk was found. We assessed the risk of subclinical ketosis during the first 100 days in milk by comparing fat protein ratios (FPR), applying differing thresholds in Germany (AAZ >1.7, HO >1.5) per breed, without detecting breed differences. However, in Sweden (with a threshold of >1.5) where the local SRB performed best, SKB showed an intermedium position, while SH had the highest proportion of FPR >1.5. Occurrence of veterinary treatments and those due to fertility problems did not differ between German breeds. Data on treatment due to metabolic disorders and leg or claw problems had low incidences, but models did not converge. In Sweden, we found the lowest incidence of overall veterinary treatments and treatments due to mastitis in the local breed SRB, but the local breed SKB did not differ from the commercial SH in neither of the two traits. We did not find breed differences regarding veterinary treatments due to fertility problems or diagnosis of claw/leg problems during claw trimming in the Swedish data set. Incidences of treatments due to metabolic disorders were low in all Swedish breeds, but models for this trait failed to converge. From our finding’s we conclude that local breeds partly have advantages with regard to many functional traits studied and that their potential should be better exploited in future, especially on farms with a medium production level (most clearly shown in the small study on German and Swedish farms). We also found overall high proportions of test day records with elevated SCC in Germany and even more so in Poland from which we deduct a great potential for further overall management improvement regardless of the involved breeds in these countries

    Combined garnet and zircon geochronology of the ultra-high temperature metamorphism: Constraints on the rise of the Orlica-Śnieżnik Dome, NE Bohemian Massif, SW Poland

    Get PDF
    Garnet and zircon geochronology combined with trace element partitioning and petrological studies provide tight constraints on evolution of the UHT-(U)HP terrain of the Orlica-Śnieżnik Dome (OSD) in the NE Bohemian massif. Lu-Hf dating of peritectic garnet from two mesocratic granulites constrained the time of its initial growth at 346.9 ± 1.2 and 348.3 ± 2.0 Ma recording peak 2.5 GPa pressure and 950 °C temperature. In situ, U-Pb SHRIMP dating of zircon from the same granulite gave a younger age of 341.9 ± 3.4 Ma. Ti-in-zircon thermometry indicates crystallization at 810–860 °C pointing to zircon formation on the retrograde path. Lu partitioning between garnet rim and zircon suggest equilibrium growth and thus U-Pb zircon age constrain the terminal phase of garnet crystallization which lasted about 6 Ma. All Sm-Nd garnet ages obtained for mesocratic and mafic granulites are identical and consistently younger than the corresponding Lu-Hf dates. They are interpreted as reflecting cooling of granulites through the Sm-Nd closure temperature at about 337 Ma. The estimated PTt path documents the ca. 10 Ma evolution cycle of the OSD characterized by two distinct periods: (1) 347 - > 342 Ma period corresponds to nearly isothermal decompression resulting from crustal scale folding and vertical extrusion of granulites, and (2) at > 342–337 Ma which corresponds to a fast, nearly isobaric cooling.This study was financed by Polish Ministry of Science and Higher Education grant No. N N307 057734 and financially supported by Polish Academy of Sciences, Institute of Geological Sciences grant No. HPT. R. Anczkiewicz acknowledges funding from internal IGS PAS grant. The research of J. Szczepanski was funded by the University of Wroclaw grant 1017/S/ING

    NIEOCZYWISTA ROLA RUIN POPRZEMYSŁOWYCH W KRAJOBRAZIE KULTUROWYM POLSKI

    Get PDF
    The paper deals with the issues related to protection of industrial heritage. Authors focused on the problem of derelict industrial objects in the state of disrepair, which might be considered as historic ruins. The discussed subject was settled in the historical and socio-cultural context. The importance of perception and identity was underlined as crucial factors for successful heritage protection, including former industrial sites. This is followed by the critical analysis of selected cases of ruined factories. Various approaches to the post-industrial ruins ware identified. The location type as well as local society approach to the industrial pasts were identified as the most important aspects determining adopted heritage protection scenarios. The role of contemporary pop- and digital cultures was also identified in respect of experience authenticity.Artykuł zajmuje się zagadnieniami związanymi z ochroną dziedzictwa przemysłowego. Autorzy skupili się na problemie zaniedbanych obiektów przemysłowych w stanie ruiny, które można uznać za historyczne. Omawiany temat został rozstrzygnięty w kontekście historycznym i społeczno-kulturowym. Znaczenie percepcji i tożsamości podkreśla się jako kluczowe czynniki skutecznej ochrony dziedzictwa, w tym dawnych terenów przemysłowych. Sporządzono krytyczną analizę wybranych przypadków fabryk znajdujących się w stanie ruiny. Podano różne podejścia do ruin poprzemysłowych. Lokalizacja oraz podejście społeczności lokalnej do przeszłości przemysłowej to najważniejsze aspekty określające przyjęte scenariusze ochrony dziedzictwa. Rola współczesnej popkultur i cyfryzacji została zidentyfikowana w odniesieniu do autentyczności doświadczeni

    Morphological reassessment of the movable calcar of delphacid planthoppers (Hemiptera: Fulgoromorpha: Delphacidae)

    Get PDF
    This study presents the morphology of calcar in adult Delphacidae based on representatives of the genera Ugyops Guérin-Meneville, 1834, Notuchus Fennah, 1969 (Ugyopini), Asiraca Latreille, 1798 (Asiracini), Kelisia Fieber, 1866, (Kelisini), Stenocranus Fieber, 1866 (Stenocranini), Chloriona Fieber, 1866, Megadelphax Wagner, 1963, Muellerianella Wagner, 1963, Javesella Fennah, 1963, Conomelus Fieber, 1866, Euconomelus Haupt, 1929, Hyledelphax Vilbaste, 1968, Stiroma Fieber, 1866, Struebingianella Wagner, 1963 and Xanthodelphax Wagner, 1963 (Delphacini). We used SEM electron microscopy, to define seven types of calcar structure (Types 1, 2, 5, 6, 7, 8, and 9) based on combinations of characters including shape, number of teeth and differentiation of sensory structures in species from fifteen genera. Additionally, two other types (Types 3 and 4) were determined based on the calcar descriptions from previous studies. Similarities and differences in calcar structure and function were discussed and emerging relationships between planthopper species and their particular habitats were indicated

    Molecular contamination of an animal facility during and after African swine fever virus infection

    Get PDF
    The molecular contamination of an animal facility was investigated during and after an infection with highly pathogenic African swine fever virus (ASFV) among domestic pigs. The investigation evaluated the risk of indirect transmission of the disease and indicated points that may facilitate cleaning and disinfection processes. Material and Methods: Six domestic pigs were infected oronasally with the highly pathogenic Georgia 2007 strain. Environmental samples from the floors, walls, rubber floor mats, feeders, drinkers, high-efficiency particulate-absorbing filter covers and doors were collected 7 days post infection (dpi), 7 days later and 24 h after disinfection of the facility. The samples were investigated by real-time PCR and in vitro assays to find genetic traces of ASFV and infectious virus. Results: Typical clinical outcomes for ASF (i.e. fever, apathy, recumbency and bloody diarrhoea) were observed, and all animals died or required euthanasia before or at 9 dpi. No infectious virus was found in environmental samples at the sampling time points. Genetic traces of ASFV were found in all locations except the doors. The initial virus load was calculated using real-time PCR threshold cycle values and was the highest at the drain. A statistically significant decrease of virus load over time was found on non-porous surfaces mechanically cleaned by water (the floor and drain). Conclusion: The gathered data confirmed different routes of virus excretion (oral and nasal, faeces and urine, and aerosol) and showed virus locations and different initial concentrations in the animal facility. Maintaining the facility with mechanical cleaning and using personal protection (gloves) and hand disinfection may efficiently minimise the risk of further virus spread. Together with the results of previously published studies, the present investigations’ failure to isolate infectious virus may suggest that if stable environmental conditions are assured, the time needed before the introduction of new herds into previously ASF-affected farm facilities could be shortened and in this way the economic losses caused by the disease outbreak mitigated.info:eu-repo/semantics/publishedVersio

    Recommendations on the use of innovative medical technologies in cardiology and cardiac surgery and solutions leading to increased availability for Polish patients

    Get PDF
    There is a great need for innovative technologies that will improve the health and quality of life (QoL) of Polish patients with cardiac problems. It is important that the safety and effectiveness of the technology are confirmed by scientific evidence on which guidelines and clinical recommendations are based. Scientific evidence for medical devices is also increasingly important for decision-making in finance approval from public funds. New technologies in cardiology and cardiac surgery contribute to improved patient QoL, increased treatment effectiveness and facilitated diagnosis. Hence, it is necessary to increase accessibility to such technologies, primarily through the development of clinical recommendations, and education of medical personnel in conjunction with public funding. The aim of this publication is to present the recommendations of leading experts in the field of cardiology and cardiosurgery, supported by clinical research results, regarding the use of the cited innovative medical technologies and solutions leading to their increased availability for Polish patients.
    corecore