19,619 research outputs found
Higgs Limit and b->s gamma Constraints in Minimal Supersymmetry
New limits on the Higgs mass from LEP and new calculations on the radiative
(penguin) decay of the b->s gamma branching ratio restrict the parameter space
of the Constrained Minimal Supersymmetric Standard Model (CMSSM).
We find that for the low tan(beta) scenario only one sign of the Higgs mixing
parameter is allowed, while the high tan(beta scenario is practically excluded,
if one requires all sparticles to be below 1 TeV and imposes radiative
electroweak symmetry breaking as well as gauge and Yukawa coupling unification.
For squarks between 1 and 2 TeV high tan(beta) scenarios are allowed. We
consider especially a new high tan(beta)=64 scenario with triple unification of
all Yukawa couplings of the third generation, which show an infrared fixed
point behaviour.
The upper limit on the mass of the lightest Higgs in the low (high) tan(beta)
scenarios is 97+-6~(120+-2) GeV, where the errors originate predominantly from
the uncertainty in the top mass.Comment: latex + 6 eps figs, 10 pages, IEKP-KA/98-08; References updated in
replacement + 1 figure concerning triple Yukawa unification added for final
publication in Phys. Let
Black Hole Meiosis
The enumeration of BPS bound states in string theory needs refinement.
Studying partition functions of particles made from D-branes wrapped on
algebraic Calabi-Yau 3-folds, and classifying states using split attractor flow
trees, we extend the method for computing a refined BPS index, arXiv:0810.4301.
For certain D-particles, a finite number of microstates, namely polar states,
exclusively realized as bound states, determine an entire partition function
(elliptic genus). This underlines their crucial importance: one might call them
the `chromosomes' of a D-particle or a black hole. As polar states also can be
affected by our refinement, previous predictions on elliptic genera are
modified. This can be metaphorically interpreted as `crossing-over in the
meiosis of a D-particle'. Our results improve on hep-th/0702012, provide
non-trivial evidence for a strong split attractor flow tree conjecture, and
thus suggest that we indeed exhaust the BPS spectrum. In the D-brane
description of a bound state, the necessity for refinement results from the
fact that tachyonic strings split up constituent states into `generic' and
`special' states. These are enumerated separately by topological invariants,
which turn out to be partitions of Donaldson-Thomas invariants. As modular
predictions provide a check on many of our results, we have compelling evidence
that our computations are correct.Comment: 46 pages, 8 figures. v2: minor changes. v3: minor changes and
reference adde
Highly sensitive micro coriolis mass flow sensor
We have realized a micromachined micro Coriolis mass flow sensor consisting of a silicon nitride resonant tube of 40 ?m diameter and 1.2 μm wall thickness. Actuation of the sensor in resonance mode is achieved by Lorentz forces. First measurements with both gas and liquid flow have demonstrated a resolution in the order of 10 milligram per hour. The sensor can simultaneously be used as a density sensor
HISTOLOGÍA DE HUESOS HUMANOS SECOS (UNA REVISIÓN)
Despite archaeological preservation conditions, the histomorphology of human dry bone still contains useful information on the physiological and pathological status of deceased individuals. Histology can therefore be a helpful addition to routine archaeological methods. But practice has shown that, for many archaeologists, unfamiliarity with this technique shaped a pointless obstacle to add it to their tool box. Thus, after having addressed the restrictions associated with histological analysis in general, we will show that the preparation of sections/slides does not need to be diff icult, expensive or time-consuming. Then we will provide an introduction to the histological application of assessing age at death of the deceased. It’s must be its theoretical basis, its value in comparison to other methods and its limits are discussed. Finally, we will elaborate on the effectiveness of histology as an indicator of pathological processes, and explain that only a small number of disorders have distinct ‘pathognonomic’ microscopic features. In all other cases, the histological findings must be combined with gross anatomical and radiological findings from the same individual to come to a conclusive diagnosis or to a shortened list of differential (alternative) diagnoses.Independientemente de las condiciones de conservación arqueológica, la histomorfología de hueso seco humano conserva información útil sobre el estado f isiológico y patológico de las personas fallecidas. Por lo tanto la utilización del análisis histológico puede ser una adición útil a los métodos arqueológicos de rutina. No obstante, en la práctica se ha demostrado, que para muchos arqueólogos la falta de familiaridad con esta técnica constituye un obstáculo para su utilización. Por lo tanto, después de haber abordado las restricciones asociadas al análisis histológico en general, vamos a demostrar que la preparación de secciones / diapositivas no tiene por qué ser difícil, costoso o requerir mucho tiempo para su utilización. En este trabajo se expone una intro- ducción a la aplicación de la evaluación histológica para poder determinar la edad de la persona fallecida. Se discute su base teórica, su valor en comparación con otros métodos y sus límites. Por último, vamos a tratar la ef icacia de la histología como indicador de procesos patológicos y mostrar que sólo un pequeño número de trastornos tienen características microscópicas ‘patognonomicas’ diferenciadas. En todos los demás casos los datos histológicos deben ser combinados con los resultados anatómicos macroscópicos y radiológicos del mismo individuo para obtener un diagnóstico concluyente o una lista abreviada de diferentes (alternativos) diagnósticos
Can we cut out the meat of the dish? Constructing consumer-oriented pathways toward meat substitution
The shift towards a more sustainable diet necessitates less reliance on foods of animal origin. This study presents data from a representative survey of Dutch consumers on their practices related to meat, meat substitution and meat reduction. The practices reflected a cultural gradient of meat substitution options running from other products of animal origin and conventional meat free meals to real vegetarian meals. To investigate feasible substitution options, a variety of meals without meat were presented using photos, which were rated by the participants in terms of attractiveness and chances that they would prepare a similar meal at home. The results demonstrated the influence of meal formats, product familiarity, cooking skills, preferences for plant-based foods and motivational orientations towards food. In particular, a lack of familiarity and skill hampered the preparation of real vegetarian meals. Based on the findings we propose a diversified understanding of meat substitution and we specify four policy-relevant pathways for a transition towards a more plant-based diet, including an incremental change towards more health-conscious vegetarian meals, a pathway that utilizes the trend towards convenience, a pathway of reduced portion size, and practice-oriented change towards vegetarian meals. © 2011 Elsevier Ltd
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