777 research outputs found
On the Spontaneous CP Breaking in the Higgs Sector of the Minimal Supersymmetric Standard Model
We revise a recently proposed mechanism for spontaneous CP breaking at finite
temperature in the Higgs sector of the Minimal Supersymmetric Standard Model,
based on the contribution of squarks, charginos and neutralinos to the one-loop
effective potential. We have included plasma effects for all bosons and added
the contribution of neutral scalar and charged Higgses. While the former have
little effect, the latter provides very strong extra constraints on the
parameter space and change drastically the previous results. We find that CP
can be spontaneously broken at the critical temperature of the electroweak
phase transition without any fine-tuning in the parameter space.Comment: 9 pages, LATEX, 3 appended postscript figures, IEM-FT-76/9
The Higgs as a Portal to Plasmon-like Unparticle Excitations
A renormalizable coupling between the Higgs and a scalar unparticle operator
O_U of non-integer dimension d_U<2 triggers, after electroweak symmetry
breaking, an infrared divergent vacuum expectation value for O_U. Such IR
divergence should be tamed before any phenomenological implications of the
Higgs-unparticle interplay can be drawn. In this paper we present a novel
mechanism to cure that IR divergence through (scale-invariant) unparticle
self-interactions, which has properties qualitatively different from the
mechanism considered previously. Besides finding a mass gap in the unparticle
continuum we also find an unparticle pole reminiscent of a plasmon resonance.
Such unparticle features could be explored experimentally through their mixing
with the Higgs boson.Comment: 12 LaTeX pages, 2 figure
Surco en cabeza femoral como signo de inestabilidad de cadera en pacientes con Síndrome de Down.
La inestabilidad de cadera en pacientes afectos de síndrome de Down es una entidad poco frecuente,
en la actualidad todavía existe controversia sobre las anomalías anatómicas asociadas. El objetivo de este trabajo es
describir los cambios anatómicos en las caderas de pacientes con inestabilidad en el síndrome de Down (SD). Hemos
revisado las tomografías computarizadas (TC) de los pacientes afectos de luxación de cadera con SD. A tres de los 7
pacientes intervenidos en nuestro centro, se les había realizado TC de caderas. En todas las TC mostraban la presen
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cia de lesión lineal vertical (surco) localizada en región epifisaria, atravesando la fisis, de localización antero-interna.
Creemos que la posición adoptada cuando duermen (flexión, aducto y rotación interna) puede producir hiperpresión
de la cabeza femoral sobre la ceja acetabular posterior, produciendo un surco vertical. La presencia de esta lesión
puede ser sugestiva de inestabilidad subclínica de cadera en ausencia de episodio de luxación.Hip instability in patients with Down syndrome is a rare entity, currently there is still controversy
about the associated anatomical anomalies. The aim of the study is to describe the anatomical changes in the hips of
patients with instability in Down syndrome (DS). We have reviewed the computed tomography (CT) of patients with
hip dislocation with SD. Three of the 7 patients treated in our center are performed CT had hips. All CT showed the
presence of vertical linear lesion (groove) located in epiphyseal region, crossing the physis, antero-internal location.
We believe that the position taken when sleeping (flexion, adduction and internal rotation) can produce overpressure
of the femoral head over the posterior acetabular rim, producing a vertical groove. The presence of this lesion can be
suggestive of subclinical instability in the absence of hip dislocation
New analytical method for determination of phthalates in wastewater by on line lc-gc-ms using the totad interface and fraction collector
There is an increasing demand for automatic, reliable and sensitive analytical methods for determining trace levels of phthalic acid esters (PAEs) in environmental samples. While on line coupled liquid chromatography-gas chromatography (LC-GC) has been proof to be a powerful tool for trace-level analyses in complex matrices, the present work presents a new totally automated on line LC-GC method, using the Through Oven Transfer Adsorption Desorption (TOTAD) interface, for the analysis of four of the main phthalates, dibuthyl phthalate (DBP), diethyl phthalate (DEP), dimethyl phthalate (DMP) and diethylhexyl phthalate (DEHP), in a matrix as complex as leachate. The sample is directly injected into the LC injector valve with no sample pretreatment other than simple filtration. The LC step separates the target analytes from matrix interference. Two different LC fractions are collected in a purposely designed fraction collector and then transferred to the TOTAD interface, which concentrates the analytes, totally eliminates the solvent and transfers the analytes to the GC-MS system, where the analysis is carried out. The LOD of the method varied from 0.1 µg/L (DEHP) to 1.4 µg/L (DMP), RSD for retention time below 0.14% and for absolute peak areas below 12% and linearity from 1 µg/L to 1000 µg/L (R2 > 0.99), except in the case of DEHP (linearity from 1 to 250 µg/L, R2 = 0.94). The method was applied to the analysis of the target analytes in samples collected from a municipal solid waste (MSW) landfill in Rosario (Argentina).Fil: Espinosa, F.J.. Universidad de Castilla-La Mancha; EspañaFil: Toledano, R.M.. Universidad de Castilla-La Mancha; EspañaFil: Andini, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Cortés, J.M.. Universidad de Castilla-La Mancha; EspañaFil: Vázquez, A.M.. Universidad de Castilla-La Mancha; Españ
Inestabilidad patelofemoral en niños con Síndrome de Down
La inestabilidad patelofemoral en el síndrome de Down se presenta en el contexto de hiperlaxitud
e inmadurez esquelética suponiendo un reto en el tratamiento. Nuestro objetivo es valorar el resultado clínico-funcional
de la cirugía de partes blandas, en estos pacientes hiperlaxos e inmaduros esqueléticamente. Hemos
revisado retrospectivamente a los pacientes con síndrome de Down e inmadurez esquelética intervenidos por
inestabilidad patelofemoral con seguimiento hasta el cierre fisario. Seis pacientes (9 rodillas) con media de edad
de 12,4 años fueron incluidos. El grado de inestabilidad patelofemoral prequirúrgica (clasificación de Dugdale)
mostró 1 (11,1%) caso grado 2; 2 (22,2%) casos grado 3 y 6 (66,6%) casos grado 4. El grado de función patelar
(según Insall) al alcanzar la madurez esquelética fue malo en un caso (recidiva de la luxación), bueno en 2 y
excelente en 6. En definitiva, los procedimientos sobre partes blandas pueden ser suficientes en pacientes con
síndrome de Down.Patelofemoral instability in Down syndrome´s patients appears in hiperlaxity and open physis
context. Our aim is to make a retrospective clinical-functional assessment of the soft tissue procedure treatment
of patellofemoral instability in patients with Down Syndrome skeletally immature (open physeal), following
them until the physeal closure. We have included six patients (9 knees) with a mean age of 12.4 years old. Patellar
instability (Dugdale´s classification) distribution was 1 (11.1%) cases degree ll; 2 (22.2%) cases degree lll and 6
(66.6%) cases degree IV. Patellar function assessed by Insall score at follow up was excellent in 6 of the cases,
good in 2 cases and bad in one case (recurrent dislocation). In summary, a proximal soft tissues procedure in
Down syndrome patients could be enough for patellar instability treatment
Hydrodynamic obstruction to bubble expansion
We discuss a hydrodynamic obstruction to bubble wall acceleration during a
cosmological first-order phase transition. The obstruction results from the
heating of the plasma in the compression wave in front of the phase transition
boundary. We provide a simple criterion for the occurrence of the obstruction
at subsonic bubble wall velocity in terms of the critical temperature, the
phase transition temperature, and the latent heat of the model under
consideration. The criterion serves as a sufficient condition of subsonic
bubble wall velocities as required by electroweak baryogenesis.Comment: 18 pages, 4 figures; comments and reference added, published versio
Forest landscape restoration in the drylands of Latin America
Forest Landscape Restoration (FLR) involves the ecological restoration of degraded forest landscapes, with the aim of benefiting both biodiversity and human well-being. We first identify four fundamental principles of FLR, based on previous definitions. We then critically evaluate the application of these principles in practice, based on the experience gained during an international, collaborative research project conducted in six dry forest landscapes of Latin America. Research highlighted the potential for FLR; tree species of high socioeconomic value were identified in all study areas, and strong dependence of local communities on forest resources was widely encountered, particularly for fuelwood. We demonstrated that FLR can be achieved through both passive and active restoration approaches, and can be cost-effective if the increased provision of ecosystem services is taken into account. These results therefore highlight the potential for FLR, and the positive contribution that it could make to sustainable development. However, we also encountered a number of challenges to FLR implementation, including the difficulty of achieving strong engagement in FLR activities among local stakeholders, lack of capacity for community-led initiatives, and the lack of an appropriate institutional and regulatory environment to support restoration activities. Successful implementation of FLR will require new collaborative alliances among stakeholders, empowerment and capacity building of local communities to enable them to fully engage with restoration activities, and an enabling public policy context to enable local people to be active participants in the decision making process. © 2012 by the author(s). Published here under license by the Resilience Alliance
Inferior lateral genicular artery injury during anterior cruciate ligament reconstruction surgery
We report a case of inferior lateral genicular artery (ILG) injury during anterior cruciate ligament (ACL) reconstruction surgery with lateral partial meniscectomy. This is a rare arthroscopy complication. A review of the literature has been made with the aim to define the anatomy of ILG across the lateral articular line and the risk of lesion during knee arthroscopy. We propose embolization as a good treatment option for this type of injurie
Resummation Methods at Finite Temperature: The Tadpole Way
We examine several resummation methods for computing higher order corrections
to the finite temperature effective potential, in the context of a scalar
theory. We show by explicit calculation to four loops that dressing
the propagator, not the vertex, of the one-loop tadpole correctly counts
``daisy'' and ``super-daisy'' diagrams.Comment: 18 pages, LaTeX, CALT-68-1858, HUTP-93-A011, EFI-93-2
Energy Budget of Cosmological First-order Phase Transitions
The study of the hydrodynamics of bubble growth in first-order phase
transitions is very relevant for electroweak baryogenesis, as the baryon
asymmetry depends sensitively on the bubble wall velocity, and also for
predicting the size of the gravity wave signal resulting from bubble
collisions, which depends on both the bubble wall velocity and the plasma fluid
velocity. We perform such study in different bubble expansion regimes, namely
deflagrations, detonations, hybrids (steady states) and runaway solutions
(accelerating wall), without relying on a specific particle physics model. We
compute the efficiency of the transfer of vacuum energy to the bubble wall and
the plasma in all regimes. We clarify the condition determining the runaway
regime and stress that in most models of strong first-order phase transitions
this will modify expectations for the gravity wave signal. Indeed, in this
case, most of the kinetic energy is concentrated in the wall and almost no
turbulent fluid motions are expected since the surrounding fluid is kept mostly
at rest.Comment: 36 pages, 14 figure
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