939 research outputs found
On F-theory Quiver Models and Kac-Moody Algebras
We discuss quiver gauge models with bi-fundamental and fundamental matter
obtained from F-theory compactified on ALE spaces over a four dimensional base
space. We focus on the base geometry which consists of intersecting F0=CP1xCP1
Hirzebruch complex surfaces arranged as Dynkin graphs classified by three kinds
of Kac-Moody (KM) algebras: ordinary, i.e finite dimensional, affine and
indefinite, in particular hyperbolic. We interpret the equations defining these
three classes of generalized Lie algebras as the anomaly cancelation condition
of the corresponding N =1 F-theory quivers in four dimensions. We analyze in
some detail hyperbolic geometries obtained from the affine A base geometry by
adding a node, and we find that it can be used to incorporate fundamental
fields to a product of SU-type gauge groups and fields.Comment: 13 pages; new equations added in section 3, one reference added and
typos correcte
National Transonic Facility Fan Blade prepreg material characterization tests
The test program for the basic prepreg materials used in process development work and planned fabrication of the national transonic facility fan blade is presented. The basic prepreg materials and the design laminate are characterized at 89 K, room temperature, and 366 K. Characterization tests, test equipment, and test data are discussed. Material tests results in the warp direction are given for tensile, compressive, fatigue (tension-tension), interlaminar shear and thermal expansion
Developing an integrated approach to understanding the effects of climate change and other environmental alterations at a flyway level
The environmental consequences of global climate change are predicted to have their greatest effect at high latitudes and have great potential to impact fragile tundra ecosystems. The Arctic tundra is a vast biodiversity resource and provides breeding areas for many migratory geese. Importantly, tundra ecosystems
also currently act as a global carbon âsinkâ, buffering carbon emissions from human activities. In January 2003, a new three year project was implemented to understand and model the interrelationships between goose population dynamics, conservation, European land use/agriculture and climate change. A range of potential future climate and land-use scenarios will be applied to the models and combined with information from field experiments on grazing and climate change in the Arctic. This paper describes the content of the research programme as well as issues in relation to engaging stakeholders with the project
Developing an integrated approach to understanding the effects of climate change and other environmental alterations at a flyway level
The environmental consequences of global climate change are predicted to have their greatest effect at high latitudes and have great potential to impact fragile tundra ecosystems. The Arctic tundra is a vast biodiversity resource and provides breeding areas for many migratory geese. Importantly, tundra ecosystems
also currently act as a global carbon âsinkâ, buffering carbon emissions from human activities. In January 2003, a new three year project was implemented to understand and model the interrelationships between goose population dynamics, conservation, European land use/agriculture and climate change. A range of potential future climate and land-use scenarios will be applied to the models and combined with information from field experiments on grazing and climate change in the Arctic. This paper describes the content of the research programme as well as issues in relation to engaging stakeholders with the project
On Local F-theory Geometries and Intersecting D7-branes
We discuss local F-theory geometries and theirs gauge theory dualities in
terms of intersecting D7-branes wrapped four-cycles in Type IIB superstring.
The manifolds are built as elliptic K3 surface fibrations over intersecting
F_0=CP^1 \times CP^1 base geometry according to ADE Dynkin Diagrams. The base
is obtained by blowing up the extended ADE hyper-Kahler singularities of eight
dimensional manifolds considered as sigma model target spaces with eight
supercharges. The resulting gauge theory of such local F-theory models are
given in terms of Type IIB D7-branes wrapped intersecting F_0. The four
dimensional N=1 anomaly cancelation requirement translates into a condition on
the associated affine Lie algebras.Comment: 16 pages, 1 figure, Reference added, published in IJGMMP (2009
Tyrosine protonation changes in bacteriorhodopsin: a Fourier transform infrared study of BR548 and its primary photoproduct
Bio-organic Synthesi
Invasive disease caused by Haemophilus influenzae in Sweden 1997â2009; evidence of increasing incidence and clinical burden of nonâtype b strains
Introduction of a conjugated vaccine against encapsulated Haemophilus influenzae type b (Hib) has led to a dramatic reduction of invasive Hib disease. However, an increasing incidence of invasive disease by H. influenzae nonâtype b has recently been reported. Nonâtype b strains have been suggested to be opportunists in an invasive context, but information on clinical consequences and related medical conditions is scarce. In this retrospective study, all H. influenzae isolates ( nâ = â 410) from blood and cerebrospinal fluid in three metropolitan Swedish regions between 1997 and 2009 from a population of approximately 3âmillion individuals were identified. All available isolates were serotyped by PCR ( nâ = â 250). We observed a statistically significant increase in the incidence of invasive H. influenzae disease, ascribed to nonâtypeable H. influenzae (NTHi) and encapsulated strains type f (Hif) in mainly individuals >60âyears of age. The medical reports from a subset of 136 cases of invasive Haemophilus disease revealed that 48% of invasive NTHi cases and 59% of invasive Hif cases, respectively, met the criteria of severe sepsis or septic shock according to the ACCP/SCCM classification of sepsis grading. Oneâfifth of invasive NTHi cases and more than oneâthird of invasive Hif cases were admitted to intensive care units. Only 37% of patients with invasive nonâtype b disease had evidence of immunocompromise, of which conditions related to impaired humoral immunity was the most common. The clinical burden of invasive nonâtype b H. influenzae disease, measured as days of hospitalization/100â000 individuals at risk and year, increased significantly throughout the study period.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87052/1/j.1469-0691.2010.03417.x.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/87052/2/CLM_3417_sm_FigS1.pd
- âŠ