348 research outputs found

    Ochrona zasobów biosfery w produkcji roślinnej

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    The article analyzes the impact of plant production on the protection of biosphere resources. Agriculture significantly affects the quality of resources and natural environment assets and shapes their character. The quality of environmental resources determines the size and directions of agricultural production, and agriculture changes ecosystems, shapes the landscape, affects the quality and quantity of natural resources. European integration has influenced the relationship between agriculture and the environment in many directions. EU legislation and the formulation of development strategies and economic programs contribute to the greening of agricultural land use and the protection of biosphere resources. The assessment of these activities is definitely positive due to the creation of conditions for conflict-free coexistence of the protective function and the agricultural function.Artykuł zawiera analizę wpływu produkcji roślinnej na ochronę zasobów biosfery. Rolnictwo w istotny sposób wpływa na jakość zasobów i walorów środowiska przyrodniczego oraz kształtuje ich charakter. Jakość zasobów środowiskowych determinuje wielkość i kierunki produkcji rolniczej, a gospodarka rolna zmienia ekosystemy, kształtuje krajobraz, wpływa na jakość i ilość zasobów naturalnych. Integracja europejska wielokierunkowo wpłynęła na relację rolnictwo – środowisko. Legislacja unijna oraz konstruowanie strategii rozwojowych i programów gospodarczych przyczyniają się do ekologizacji użytkowania gruntów rolnych i ochrony zasobów biosfery. Ocena tych działań jest zdecydowanie pozytywna ze względu na tworzenie warunków do bezkonfliktowego współistnienia funkcji ochronnej i funkcji rolniczej

    Rare quantum metastable states in the strongly dispersive Jaynes-Cummings oscillator

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    We present evidence of metastable rare quantum-fluctuation switching for the driven dissipative Jaynes-Cummings oscillator coupled to a zero-temperature bath in the strongly dispersive regime. We show that single-atom complex amplitude bistability is accompanied by the appearance of a low-amplitude long-lived transient state, hereinafter called `dark state', having a distribution with quasi-Poissonian statistics both for the coupled qubit and cavity mode. We find that the dark state is linked to a spontaneous flipping of the qubit state, detuning the cavity to a low-photon response. The appearance of the dark state is correlated with the participation of the two metastable states in the dispersive bistability, as evidenced by the solution of the Master Equation and single quantum trajectories.Comment: Extensively revised text, 18 revised figures (16 in main and 2 in appendix), 38(+1) references, appendi

    Condensation in hybrid superconducting-cavity–microscopic-spins systems with finite-bandwidth drive

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    Using Keldysh field theory, we find conditions for nonequilibrium condensation in the open Tavis-Cummings model under a direct finite-bandwidth incoherent cavity drive. Experimentally, we expect the condensation transition to be easily accessible to hybrid superconducting systems coupled to microscopic spins, as well as to many other incoherently driven light-matter systems. In our theoretical analysis, we explicitly incorporate the drive's spectral distribution into the saddle-point description. We show that the injected incoherent photons create a drive-dependent effective coupling between spin-1/2 particles. The condensation transition arises at a critical regime of driving which we can now accurately predict. Our results also provide important guidelines for future quantum simulation experiments of nonequilibrium phases with hybrid devices

    Thermodynamics and Excitations of Condensed Polaritons in Disordered Microcavities

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    We study the thermodynamic condensation of microcavity polaritons using a realistic model of disorder in semiconductor quantum wells. This approach correctly describes the polariton inhomogeneous broadening in the low density limit, and treats scattering by disorder to all orders in the condensed regime. While the weak disorder changes the thermodynamic properties of the transition little, the effects of disorder in the condensed state are prominent in the excitations and can be seen in resonant Rayleigh scattering.Comment: 5 pages, 3 eps figures (published version

    Non-paraganglioma tumors of the jugular foramen – Growth patterns, radiological presentation, differential diagnosis

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    Objective Most common tumors of the jugular foramen are paragangliomas. However, other lesions, also malignant, may involve the jugular foramen and mimic radiographic presentation of paragangliomas. Therefore, a correct preoperative diagnosis is crucial for best treatment planning. This study analyzes imaging characteristics of non-paraganglioma neoplasms involving the jugular foramen, with attention given to features helpful in differential diagnosis. Study design A retrospective chart search. Setting Teritary referral university centre. Subjects and methods During the years 1997–2010, 11 cases of jugular foramen tumors other than paragangliomas, with available imaging studies, were identified. Histopathology revealed: 3 schwannomas, 1 malignant schwannoma, 2 meningiomas, 1 hemangiopericytoma, 1 ependymoma, 1 endolymphatic sac carcinoma (ELST) and 2 nasopharyngeal carcinoma metastases. CT, MRI and angiography were assessed to determine tumor growth directions, bone involvement, tumor morphology and vascular composition. Results Schwannomas were characterized by parapharyngeal space involvement, jugular foramen expansion, preservation of cortical margins, irregular contrast enhancement. Meningiomas presented diffuse bone infiltration, sclerotic changes, erosion of the cortical bone. Ependymoma showed diffuse skull base infiltration, permeative erosion, heterogeneity, abundant vascularization. Hemangiopericytoma radiologically imitated paraganglioma. ELST showed permeative/geographic bony destruction, heterogeneity, intratumoral bony fragments. Metastases were lytic, solid lesions characterized by circumferential growth, internal carotid artery encasement and stenosis. Conclusions A combination of certain radiological features including tumor epicenter, growth vectors, skull base infiltration, bony changes and tumor morphology help establish correct preoperative diagnosis and differentiate less common jugular foramen tumors, from most common paragangliomas. Hemangiopericytoma may radiologically mimic paraganglioma

    POLISH TOWNS AND THE CHANGES IN THEIR AREAS AND POPULATION DENSITIES

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    DOI: 10.2478 Available on-line at: http://www.bulletinofgeography.umk.pl http://versita.com/bgssThis article presents the spatial and population density changes in Polish towns in the years 1960–2003. The assumed time frame allowed identifying area changes for a complete set of towns in different socio-economic conditions: the period of intense industrialisation, the economic crisis of the 1980s, the period of economic transition and finally in the years of a market economy. The investigation revealed that the trend shown by changes and the size of a town as measured by the number of its population are distinctly interrelated. It also demonstrated a much stronger dynamics of changes in the first subperiod, i.e. years 1960–1985, followed by a phase of relative stabilization (compared with the previous period) after the year 1980 (mainly of the spatial changes). Moreover, change intensity and change trends observed for the urban areas and population densities vary considerably in terms of space

    Simultaneous bistability of qubit and resonator in circuit quantum electrodynamics

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    We explore the joint activated dynamics exhibited by two quantum degrees of freedom: a cavity mode oscillator which is strongly coupled to a superconducting qubit in the strongly coherently driven dispersive regime. Dynamical simulations and complementary measurements show a range of parameters where both the cavity and the qubit exhibit sudden simultaneous switching between two metastable states. This manifests in ensemble averaged amplitudes of both the cavity and qubit exhibiting a partial coherent cancellation. Transmission measurements of driven microwave cavities coupled to transmon qubits show detailed features which agree with the theory in the regime of simultaneous switching

    Adiabatic Phase Diagram of an Ultracold Atomic Fermi Gas with a Feshbach Resonance

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    We determine the adiabatic phase diagram of a resonantly-coupled system of Fermi atoms and Bose molecules confined in the harmonic trap by using the local density approximation. The adiabatic phase diagram shows the fermionic condensate fraction composed of condensed molecules and Cooper pair atoms. The key idea of our work is conservation of entropy through the adiabatic process, extending the study of Williams et al. [Williams et al., New J. Phys. 6, 123 (2004)] for an ideal gas mixture to include the resonant interaction in a mean-field theory. We also calculate the molecular conversion efficiency as a function of initial temperature. Our work helps to understand recent experiments on the BCS-BEC crossover, in terms of the initial temperature measured before a sweep of the magnetic field.Comment: 13 pages, 8 figures. In press, "Journal of the Physical Society of Japan", Vol.76, No.

    Związek układu serotoninergicznego i układu sercowo-naczyniowego

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    Serotonin plays an important role in regulating the cardiovascular system. Drugs widely used in the treatment of depression, migraine, Parkinson’s disease or obesity affect the serotonergic system. The use of these compounds causes both acute and chronic effects, depending on the type of activated 5-HT receptor and its location. An acute cardiac response to 5-HT, known as Bezold-Jarisch reflex, leads to bradycardia and hypotension. The chronic contribution of serotonin may be associated with fibrosis and cardiac valve degeneration. This article analyses the impact of 5-HT receptors activation on the cardiovascular system and describes side effects of this activation and new therapies targeting this system.Serotonina (5-HT) odgrywa istotną rolę w regulacji układu sercowo-naczyniowego. Leki wpływające na układ serotoninergiczny powszechnie stosuje się w terapii depresji, migreny, choroby Parkinsona czy otyłości. W zależności od rodzaju aktywowanego receptora 5-HT i jego lokalizacji przyjmowanie tych związków może prowadzić do ostrych i przewlekłych skutków. Przykładem takiego oddziaływania jest ostra odpowiedź kardiologiczna na serotoninę, zwana odruchem Bezolda-Jarisha, która prowadzi do bradykardii i hipotonii. Przewlekła ekspozycja na nadmiar serotoniny może natomiast łączyć się z włóknieniem i zwyrodnieniem zastawek serca. W artykule omówiono wpływ aktywacji poszczególnychreceptorów 5-HT na układ sercowo-naczyniowy, działania niepożądane stosowanych leków, a także wskazano nowemożliwości terapii

    Halophyte–Endophyte Interactions: Linking Microbiome Community Distribution and Functionality to Salinity

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    Many plants are unable to adapt to rapid environmental changes (e.g., salinity, drought, or limited nutrients) and may acquire assistance from microbes that have the capacity to increase tolerance of host-plants in stress conditions. By having the right microbes, the plants are more resilient! Such microbes include endophytes that inhabit inner tissues of the plant without causing symptoms of disease in their host. However, this plant–endophytic association exists only when chemical equilibrium is maintained between both, therefore making this mutualistic interaction even more unique. Therefore it is interesting to decode the endophytic community composition in halophytes specifically in the most salt-tolerant halophyte species Salicornia europaea, and further determine the factors that could affect this association. Moreover, understanding the endophytes potential plant growth-promoting activities in association with host (S. europaea) and non-host plant (non-halophytes) are the focus of this chapter
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