Graded Lie algebras and q-commutative and r-associative parameters

We study graded Lie algebras whose transformation parameters are graded q-commutativive and r-associative. We study first some graded algebras over a field, with no zero divisors at the level of monomials in their graded algebra generators. These generators are q-commutative and r-associative. We address the cohomology of the q-function and r-functions, in particular we study quaternions and octonions. We then define algebras whose transformation parameters are q-commutative and r-associative. We address a generalization of a theorem by Scheunert on its relation to Lie (super)algebras. We show finally that for the cases studied by Scheunert there is always a real and faithful transformation parameter basis with the required q-commutativity. We use this basis to perform a transformation on the graded Lie algebra that relates it to a plain Lie (super)algebra while respecting the self-adjoint character of generators and preserving the group grading. Keywords: Graded Lie (super)algebras, Color Lie (super)algebras, noncommutative algebras, nonassociative algebras, cohomology of deformation parameters, perfect algebra. AMS-MSC: 17B70, 17B75, 22E60, 17A99, 17D99, 13D03, 20J06

Topological defects and misfit strain in magnetic stripe domains of lateral multilayers with perpendicular magnetic anisotropy

Stripe domains are studied in perpendicular magnetic anisotropy films nanostructured with a periodic thickness modulation that induces the lateral modulation of both stripe periods and inplane magnetization. The resulting system is the 2D equivalent of a strained superlattice with properties controlled by interfacial misfit strain within the magnetic stripe structure and shape anisotropy. This allows us to observe, experimentally for the first time, the continuous structural transformation of a grain boundary in this 2D magnetic crystal in the whole angular range. The magnetization reversal process can be tailored through the effect of misfit strain due to the coupling between disclinations in the magnetic stripe pattern and domain walls in the in-plane magnetization configuration

EPITRAGUS AURULENTUS (KIRSCH) (COLEOPTERA: TENEBRIONIDAE): A NEW RECORD AND REPORT FOR PUERTO RICO

EPITRAGUS AURULENTUS (KIRSCH) (COLEOPTERA: TENEBRIONIDAE): A NEW RECORD AND REPORT FOR PUERTO RIC

Crossed-ratchet effects and domain wall geometrical pinning

The motion of a domain wall in a two dimensional medium is studied taking into account the internal elastic degrees of freedom of the wall and geometrical pinning produced both by holes and sample boundaries. This study is used to analyze the geometrical conditions needed for optimizing crossed ratchet effects in periodic rectangular arrays of asymmetric holes, recently observed experimentally in patterned ferromagnetic films. Geometrical calculations and numerical simulations have been used to obtain the anisotropic critical fields for depinning flat and kinked walls in rectangular arrays of triangles. The aim is to show with a generic elastic model for interfaces how to build a rectifier able to display crossed ratchet effects or effective potential landscapes for controlling the motion of interfaces or invasion fronts.Comment: 13 pages, 18 figure

Osmium- And Iridium-Promoted C-H Bond Activation of 2, 2'-Bipyridines and Related Heterocycles: Kinetic and Thermodynamic Preferences

The d2-hexahydride complex OsH6(PiPr3)2 (1) promotes the activation of C-H bonds of 2, 2'-bipyridines and related heterocycles. The study of the same reactions with the deuteride counterpart OsD6(PiPr3)2 (1-d) reveals that the activation of the C-H bonds situated in the sterically less hindered positions is kinetically preferred. However, the isolated products are the result of the thermodynamic control of the reactions. Thus, reactions of 1 with 2, 2'-bipyridine, 6-phenyl-2, 2'-bipyridine, and 6-methyl-2, 2'-bipyridine give the "rollover cyclometalation" products OsH3{¿2-C, N-[C5(R)H2N-py]}(PiPr3)2 (R = H (2), Ph (3), Me (4)), whereas 3, 5-dimethyl-6-phenyl-2, 2'-bipyridine affords OsH2{¿3-C, N, C-[C5H3N-(Me)2py-C5H4]}(PiPr3)2 (5), containing a dianionic C, N, C-pincer ligand. The behavior of substrates pyridyl-benzimidazolium and -imidazolium is similar. Reaction of 1 with 3-methyl-1-(6-phenylpyridin-2-yl)-1H-benzimidazolium tetrafluoroborate leads to OsH3{¿2-C, C-[MeBzim-C5(Ph)H2N]}(PiPr3)2 (6), bearing an anionic Cpy, CNHC-chelate. On the other hand, 3-methyl-1-(6-phenylpyridin-2-yl)-1H-imidazolium tetrafluoroborate yields [OsH2{¿3-C, N, C-(MeIm-py-C6H4)}(PiPr3)2]BF4 (7), containing a monoanionic C, N, C-pincer with a NHC-unit coordinated in an abnormal fashion. The reactivity pattern of these substrates is also observed with the d4-iridium-pentahydride IrH5(PiPr3)2 (8), which has generated IrH2{¿2-C, N-[C5(R)H2N-py]}(PiPr3)2 (R = H, (9), Ph (10)) and IrH{¿3-C, N, C-[C5H3N-(Me2)py-C5H4]}(PiPr3)2 (11). The osmium(IV)-carbon bonds display a higher degree of covalency than the iridium(III)-carbon bonds. In contrast to 2, the metalated carbon atom of 9 undergoes the addition of a proton of methanol to give [IrH2{¿2-N, N-(bipy)}(PiPr3)2]BF4 (12)

Un marco conceptual y analítico para estimar la integridad ecológica a escala de paisaje

A conceptual and analytical framework to assess ecological integrity at a landscape level. A concep tual and methodological approach for the ecological integrity analysis at landscape level is presented. The aim is providing a tool for land planning and nature conservation. With this purpose the meaning of integrity and related concepts are discussed, and a model to evaluate landscape integrity by a comprehensive scheme is proposed. The first index is based in metrics of landscape ecology theory (connectivity, cover of both conservation areas and human managed land, etc.) to evaluate the different ecosystem fragments pattern. The second one, an ecosystems integrity index, is focused to evaluate remnants with a structure close to maturity and evaluates the mathematical distance to a reference hypothetical composition. Finally, the agricultural area is evaluated by a coherence index, with emphasis in ecological processes but also including the natural structures with conservation functions. These indexes are combined in a model that facilitates the joint consideration of their values and the comparison with theoretical scenarios. The model allows us to develop a concurrent management of relevant variables that usually are associated to different environmental qualities. Because of its characteristics and the intermediate scale of application, the model constitutes an important tool for matching ecosystem integrity and land planning. Both are actions and concept and relevant for nature conservation and landscape management, but in general independently considered.El trabajo constituye una aproximación conceptual y metodológica para el análisis de la integridad ecológica, como instrumento aplicable a la planificación del territorio y la conservación de la naturaleza a escala de paisaje. Con dicho fin se discuten las acepciones de integridad y conceptos próximos y se presenta un modelo de evaluación que considera la integridad del paisaje como resultado de la interacción de tres índices. El primero (integridad espacial) utiliza métricas de la ecología del paisaje (conectividad y cobertura de áreas naturales y áreas de uso humano) y evalúa la distribución de los fragmentos de los distintos tipos de ecosistemas existentes en el territorio. El segundo, un índice de integridad ecosistémica, se centra en los fragmentos con estructura más próxima a la madurez y valora su distancia numérica a ecosistemas de referencia. Por último, en el área sometida a usos agrícolas, se aplica un índice de coherencia ecológica de los usos del suelo que tiene en los elementos naturales con funciones de conservación. Estos índices son articulados mediante un modelo que facilita una visión simultánea de sus valores, así como su comparación con escenarios teóricos. El modelo permite manejar de forma simultánea variables relevantes que comúnmente se presentan como asociadas a aspectos diferentes de la calidad del entorno. Por sus características y escala intermedia de aplicación puede constituir una herramienta importante para enlazar conceptos y actuaciones, relevantes para la conservación de la naturaleza, pero que suelen manejarse por separado, en concreto la integridad ecosistémica y con la planificación del territorio

Pulmonary thromboembolism and alveolar hemorrhage as initial manifestations of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organs. SLE can affect the lung, the pulmonary vasculature, and the pleura. A 38-year-old female with limb pain and ecchymosis who later developed pulmonary thromboembolism and alveolar hemorrhage is presented here. Clinical, imaging, laboratory, and histopathological evidence is presented. The patient met the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) criteria for SLE. Furthermore, the patient had a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of 35; thus, indicating severe disease. This case is an example of concomitant venous and arterial lung complications in an SLE patient

The role of temperature in the magnetic irreversibility of type-I Pb superconductors

Evidence of how temperature takes part in the magnetic irreversibility in the intermediate state of a cylinder and various disks of pure type-I superconducting lead is presented. Isothermal measurements of first magnetization curves and magnetic hysteresis cycles are analyzed in a reduced representation that defines an equilibrium state for flux penetration in all the samples and reveals that flux expulsion depends on temperature in the disks but not in the cylinder. The magnetic field at which irreversibility sets in along the descending branch of the hysteresis cycle and the remnant magnetization at zero field are found to decrease with temperature in the disks. The contributions to irreversibility of the geometrical barrier and the energy minima associated to stress defects that act as pinning centers on normal-superconductor interfaces are discussed. The differences observed among the disks are ascribed to the diverse nature of the stress defects in each sample. The pinning barriers are suggested to decrease with the magnetic field to account for these results

The Hazards of Monitoring Ecosystem Ocean Health in the Gulf of Mexico: A Mexican Perspective

Ecological services provided by the Gulf of Mexico constitute vital assets for the socioeconomic development of the USA, Mexico, and Cuba. This ecosystem houses vast biodiversity and significant fossil fuel reserves. However, its ecological stability and resilience have been jeopardized by anthropogenic disturbances. Massive oil spills (Ixtoc-I, 1979; Deepwater Horizon, 2010) caused severe environmental injuries and unveiled the vulnerability of coastal and deep-sea habitats. Baseline and monitoring studies are actions implemented by the Gulf stakeholders to cope with such disturbances. The 3-year monitoring program implemented by Mexico in 2010 to assess the environmental damage caused by the Deepwater Horizon (DWH) event confirmed the void of knowledge on the complexity of physical and biological processes susceptible of being altered by oil spills. Between the pelagic and benthic compartments, the latter proved to be a better option in establishing the baseline concentration and trends of oil compounds. Surficial sediments exhibited an increasing concentration trend of PAH, AH, and trace metals throughout the 3-year monitoring. The macroinfauna and selected biomarkers experienced interannual variability attributed to critical hydrocarbon and trace metal thresholds. Sediment toxicity bioassays added support to the distribution and potential sources of oil contaminants dispersed from the northern gulf toward Mexican waters

Order in driven vortex lattices in superconducting Nb films with nanostructured pinning potentials

Driven vortex lattices have been studied in a material with strong pinning, such as Nb films. Samples in which natural random pinning coexists with artificial ordered arrays of defects (submicrometric Ni dots) have been fabricated with different geometries (square, triangular and rectangular). Three different dynamic regimes are found: for low vortex velocities, there is a plastic regime in which random defects frustrate the effect of the ordered array; then, for vortex velocities in the range 1-100 m/s, there is a sudden increase in the interaction between the vortex lattice and the ordered dot array, independent on the geometry. This effect is associated to the onset of quasi long range order in the vortex lattice leading to an increase in the overlap between the vortex lattice and the magnetic dots array. Finally, at larger velocities the ordered array-vortex lattice interaction is suppresed again, in agreement with the behavior found in numerical simulations.Comment: 8 text pages + 4 figure