2,502 research outputs found

    Yang-Mills Equations of Motion for the Higgs Sector of SU(3)-Equivariant Quiver Gauge Theories

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    We consider SU(3)-equivariant dimensional reduction of Yang-Mills theory on spaces of the form R x SU(3)/H, with H equals either SU(2) x U(1) or U(1) x U(1). For the corresponding quiver gauge theory we derive the equations of motion and construct some specific solutions for the Higgs fields using different gauge groups. Specifically we choose the gauge groups U(6) and U(8) for the space R x CP^2 as well as the gauge group U(3) for the space R x SU(3)/U(1)xU(1), and derive Yang-Mills equations for the latter one using a spin connection endowed with a non-vanishing torsion. We find that a specific value for the torsion is necessary in order to obtain non-trivial solutions of Yang-Mills equations. Finally, we take the space R x CP^1 x CP^2 and derive the equations of motion for the Higgs sector for a U(3m+3) gauge theory.Comment: 21 pages, 4 figures; v2: figures added, references updated, published version (JMP

    Improved efficiency of nutrient and water use for high quality field vegetable production using fertigation

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    Drip-based fertigation may improve the application efficiency of water and nutrients while maintaining or improving marketable yield and quality at harvest and post-harvest. Two plantings of lettuce (Lactuca sativa) were grown in the UK, with six N treatments and two methods of irrigation and N application. The conventional overhead irrigated treatments had all N applied in the base dressing with irrigation scheduled from SMD calculations. The closed loop treatments had nitrogen and irrigation delivered via drip automatically controlled by a sensor and logger system. The work established that water content in the root zone can be monitored in real time using horizontally oriented soil moisture sensors linked to data logging and telemetry, and that these data can be used to automatically trigger drip irrigation for commercially grown field vegetables. When the closed loop irrigation control was combined with fertigation treatments, lettuce crops were grown with savings of up to 60% and 75% of water and nitrogen respectively, compared to standard UK production systems. However, excess supply of N through fertigation rather than solid fertiliser was more detrimental to marketable yield and post harvest quality highlighting that care is needed when selecting N rates for fertigation

    Physical Layer Discrimination of Electronic Control Units Using Wired Signal Distinct Native Attribute (WS-DNDA)

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    The Controller Area Network (CAN) bus is a communication system used in automobiles to connect the electronic components required for critical vehicle operations. These components are called Electronic Control Units (ECU) and each one exercises one or more functions within the vehicle. ECUs can provide autonomous safety features and increased comfort to drivers but these advancements may come at the expense of vehicle security. Researchers have shown that the CAN bus can be hacked by compromising authorized ECUs or by physically connecting unauthorized devices to the bus. Physical layer (PHY) device fingerprinting has emerged as one of the accepted approaches to establishing vehicle security. This paper uses a fingerprinting method called Wired Signal Distinct Native Attribute (WS-DNA) and classification algorithm called Multiple Discriminant Analysis Maximum Likelihood (MDA/ML) to achieve ECU discrimination which includes device classification and verification

    Maternal fluoxetine exposure alters cortical hemodynamic and calcium response of offspring to somatosensory stimuli

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    Epidemiological studies have found an increased incidence of neurodevelopmental disorders in populations prenatally exposed to selective serotonin reuptake inhibitors (SSRIs). Optical imaging provides a minimally invasive way to determine if perinatal SSRI exposure has long-term effects on cortical function. Herein we probed the functional neuroimaging effects of perinatal SSRI exposure in a fluoxetine (FLX)-exposed mouse model. While resting-state homotopic contralateral functional connectivity was unperturbed, the evoked cortical response to forepaw stimulation was altered in FLX mice. The stimulated cortex showed decreased activity for FLX versus controls, by both hemodynamic responses [oxyhemoglobin (Hb

    Entry pathways of herpes simplex virus type 1 into human keratinocytes are dynamin- and cholesterol-dependent

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    Herpes simplex virus type 1 (HSV-1) can enter cells via endocytic pathways or direct fusion at the plasma membrane depending on the cell line and receptor(s). Most studies into virus entry have used cultured fibroblasts but since keratinocytes represent the primary entry site for HSV-1 infection in its human host, we initiated studies to characterize the entry pathway of HSV-1 into human keratinocytes. Electron microscopy studies visualized free capsids in the cytoplasm and enveloped virus particles in vesicles suggesting viral uptake both by direct fusion at the plasma membrane and by endocytic vesicles. The ratio of the two entry modes differed in primary human keratinocytes and in the keratinocyte cell line HaCaT. Inhibitor studies further support a role for endocytosis during HSV-1 entry. Infection was inhibited by the cholesterol-sequestering drug methyl-beta-cyclodextrin, which demonstrates the requirement for host cholesterol during virus entry. Since the dynamin-specific inhibitor dynasore and overexpression of a dominant-negative dynamin mutant blocked infection, we conclude that the entry pathways into keratinocytes are dynamin-mediated. Electron microscopy studies confirmed that virus uptake is completely blocked when the GTPase activity of dynamin is inhibited. Ex vivo infection of murine epidermis that was treated with dynasore further supports the essential role of dynamin during entry into the epithelium. Thus, we conclude that HSV-1 can enter human keratinocytes by alternative entry pathways that require dynamin and host cholesterol

    Strong (π,0)(\pi,0) spin fluctuations in β\beta-FeSe observed by neutron spectroscopy

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    We have performed powder inelastic neutron scattering measurements on the unconventional superconductor β\beta-FeSe (Tc≃8 KT_{\rm c} \simeq 8\,\mathrm{K}). The spectra reveal highly dispersive paramagnetic fluctuations emerging from the square-lattice wave vector (π,0)(\pi,0) extending beyond 80 meV in energy. Measurements as a function of temperature at an energy of ∼13 meV\sim 13\,\mathrm{meV} did not show any variation from TcT_{\rm c} to 104 K104\,\mathrm{K}. The results show that FeSe is close to an instability towards (π,0)(\pi,0) antiferromagnetism characteristic of the parent phases of the high-TcT_{\rm c} iron arsenide superconductors, and that the iron paramagnetic moment is neither affected by the orthorhombic-to-tetragonal structural transition at Ts≃90 KT_{\rm s} \simeq 90\,\mathrm{K} nor does it undergo a change in spin state over the temperature range studied.Comment: Revised version, includes Supplementary Materia
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