The light CP-even MSSM Higgs mass resummed to fourth logarithmic order

We present the calculation of the light neutral CP-even Higgs mass in the MSSM for a heavy SUSY spectrum by resumming enhanced terms through fourth logarithmic order (N$^3$LL), keeping terms of leading order in the top Yukawa coupling $\alpha_t$, and NNLO in the strong coupling $\alpha_s$. To this goal, the three-loop matching coefficient for the quartic Higgs coupling of the SM to the MSSM is derived to order $\alpha_t^2\alpha_s^2$ by comparing the perturbative EFT to the fixed-order expression for the Higgs mass. The new matching coefficient is made available through an updated version of the program Himalaya. Numerical effects of the higher-order resummation are studied using specific examples, and sources of theoretical uncertainty on this result are discussed.Comment: 26 pages, 3 figures, matches version published in EPJ

Modelación matemática del consumo de presas y el flujo de energía asociado a la reproducción de Rostrhamus sociabilis (Aves, Falconiformes)

El gavilán caracolero (Rostrhamus sociabilis) es un ave rapaz, residente permanente y común en Cuba, clasificada como de alto interés conservacionista en el Plan de Conservación de las Aves Acuáticas de Norteamérica, en parte debido a su dieta altamente especializada en caracoles acuáticos del género Pomacea. En el presente estudio se elabora un modelo matemático en el programa Stella para analizar el consumo y la movilización de energía durante la reproducción del gavilán caracolero, y se aplica con parámetros determinados en una colonia de nidificación del Gran Humedal del Norte de Ciego de Ávila, en Cuba. La estructura básica del modelo incluye variables morfométricas de los adultos, los huevos y los pichones; elementos conductuales; parámetros tróficos y otros parámetros reproductivos, algunos de los cuales se midieron en la colonia estudiada; el resto se tomaron de fuentes bibliográficas. El modelo tuvo como variables principales de salida el consumo energético por individuo, el consumo diario y total por estación y el número de presas a que esta equivale. Para probar el modelo, se simuló el comportamiento de una colonia de 100 nidos con una producción media de 158 ± 7,1 huevos y entre 106 y 125 pichones. El consumo energético diario por adulto se estimó entre 110,32 y 118,47 kcal, que puede obtenerse con la ingesta de alrededor de 28 caracoles diarios. Se calcula que para mantener una colonia de este tamaño, se requiere una energía total de 1.893.103 kcal, que se extrae de 5.933 ± 59 kg de biomasa de caracoles, lo que equivale a entre 419 y 552 mil pomáceas consumidas en tres meses y medio. El análisis de sensibilidad muestra que las variables cuyos cambios influyen más en el consumo de energía de las colonias son las relacionadas con el éxito reproductivo, el tamaño de los adultos y los vuelos de alimentación. El modelo resultante de este trabajo permite simular y evaluar el efecto que las alteraciones futuras del hábitat pueden tener en la cría de esta especie.El gavilán caracolero (Rostrhamus sociabilis) es un ave rapaz, residente permanente y común en Cuba, clasificada como de alto interés conservacionista en el Plan de Conservación de las Aves Acuáticas de Norteamérica, en parte debido a su dieta altamente especializada en caracoles acuáticos del género Pomacea. En el presente estudio se elabora un modelo matemático en el programa Stella para analizar el consumo y la movilización de energía durante la reproducción del gavilán caracolero, y se aplica con parámetros determinados en una colonia de nidificación del Gran Humedal del Norte de Ciego de Ávila, en Cuba. La estructura básica del modelo incluye variables morfométricas de los adultos, los huevos y los pichones; elementos conductuales; parámetros tróficos y otros parámetros reproductivos, algunos de los cuales se midieron en la colonia estudiada; el resto se tomaron de fuentes bibliográficas. El modelo tuvo como variables principales de salida el consumo energético por individuo, el consumo diario y total por estación y el número de presas a que esta equivale. Para probar el modelo, se simuló el comportamiento de una colonia de 100 nidos con una producción media de 158 ± 7,1 huevos y entre 106 y 125 pichones. El consumo energético diario por adulto se estimó entre 110,32 y 118,47 kcal, que puede obtenerse con la ingesta de alrededor de 28 caracoles diarios. Se calcula que para mantener una colonia de este tamaño, se requiere una energía total de 1.893.103 kcal, que se extrae de 5.933 ± 59 kg de biomasa de caracoles, lo que equivale a entre 419 y 552 mil pomáceas consumidas en tres meses y medio. El análisis de sensibilidad muestra que las variables cuyos cambios influyen más en el consumo de energía de las colonias son las relacionadas con el éxito reproductivo, el tamaño de los adultos y los vuelos de alimentación. El modelo resultante de este trabajo permite simular y evaluar el efecto que las alteraciones futuras del hábitat pueden tener en la cría de esta especie.Mathematical model of prey consumption and energy flow associated with breeding in Rostrhamus sociabilis (Aves, Falconiformes) The snail kite (Rostrhamus sociabilis) is a bird of prey that has permanent populations and is fairly common in Cuba. It is classified as High Concern in the North American Water Bird Conservation Plan, partially due to a highly specialized diet, preying only on water snail of the genus i>Pomacea. In the current paper we developed a mathematical model in Stella software to analyze consumption and mobilization of energy during reproduction of this species. The model was calibrated with reproductive parameters determined in a nesting colony of the Great Wetland of North Ciego de Ávila, Cuba. Variables included in the basic model were adults, eggs and nestling morphometry, behavioral aspects, trophic elements and other reproductive parameters; some were measured in the field and the rest were taken from literature sources. The main outcomes of the model were: energy consumption per individual, daily and total season consumption, and the number of prey it represented. To test the model we simulated the behaviour of a 100–nest colony that resulted in the production of an average of 158 ± 7.1 eggs and between 106 and 125 nestlings. Daily adult energy consumption was estimated between 110.32 and 118.47 kcal, which can be achieved by consuming around 28 snails each day. A colony of this size has an estimated requirement of 1,893,103 kcal of total energy per season, driven by 5,933 ± 59 kg of snail biomass, equivalent to between 419 and 552 thousand snails in three and half months. Sensitivity analysis of the model showed that the variables that most influenced energy consumption were those related to reproductive success, adult body size and flying behavior. The resulting model will allow to simulate and assess the potential impact of future habitat modifications on the species breeding

Constraining the Noncommutative Spectral Action via Astrophysical Observations

The noncommutative spectral action extends our familiar notion of commutative spaces, using the data encoded in a spectral triple on an almost commutative space. Varying a rather simple action, one can derive all of the standard model of particle physics in this setting, in addition to a modified version of Einstein-Hilbert gravity. Thus, noncommutative geometry provides a geometric interpretation of particle physics coupled to curvature. In this letter we use observations of pulsar timings, assuming that no deviation from General Relativity has been observed, to constrain the gravitational sector of this theory. Thus, we directly constrain noncommutative geometry, a potential grand unified theory of physics, via astrophysical observations. Whilst the bounds on the coupling constants remain rather weak, they are comparable to existing bounds on deviations from General Relativity in other settings and are likely to be further constrained by future observations.Comment: 5 pages; slightly shorter version to match the one will appear in Phys. Rev. Let

Black-body radiation induced photodissociation and population redistribution of weakly bound states in H2+_2^+

Molecular hydrogen ions in weakly bound states close to the first dissociation threshold are attractive quantum sensors for measuring the proton-to-electron mass ratio and hyperfine-induced ortho-para mixing. The experimental accuracy of previous spectroscopic studies relying on fast ion beams could be improved by using state-of-the-art ion trap setups. With the electric dipole moment vanishing in H$_2^+$ and preventing fast spontaneous emission, radiative lifetimes of the order of weeks are found. We include the effect of black-body radiation that can lead to photodissociation and rovibronic state redistribution to obtain effective lifetimes for trapped ion experiments. Rate coefficients for bound-bound and bound-continuum processes were calculated using adiabatic nuclear wave functions and nonadiabatic energies, including relativistic and radiative corrections. Effective lifetimes for the weakly bound states were obtained by solving a rate equation model and lifetimes in the range of 4 to 523~ms and $>$215~ms were found at room temperature and liquid nitrogen temperature, respectively. Black-body induced photodissociation was identified as the lifetime-limiting effect, which guarantees the purity of state-selectively generated molecular ion ensembles. The role of hyperfine-induced $g/u$-mixing, which allows pure rovibrational transitions, was found to be negligible.Comment: 13 pages, 5 figure

Geostrophy via potential vorticity inversion in the Yucatan Channel

It has become common practice to measure ocean current velocities together with the hydrography by lowering an ADCP on typical CTD casts. The velocities and densities thus observed are considered to consist mostly of a background contribution in geostrophic balance, plus internal waves and tides. A method to infer the geostrophic component by inverting the linearized potential vorticity (Pv) provides plausible geostrophic density and velocity distributions. The method extracts the geostrophic balance closest to the measurements by minimizing the energy involved in the difference, supposed to consist of Pv-free anomalies. The boundary conditions and the retention of Pv by the geostrophic estimates follow directly from the optimization, which is based on simple linear dynamics and avoids both the use of the thermal wind equation on the measured density, and the classical problem of a reference velocity. By construction, the transport in geostrophic balance equals the measured one. Tides are the largest source of error in the calculation. The method is applied to six ADCP/CTD surveys made across the Yucatan Channel in the springs of 1997 and 1998 and in the winter of 1998-1999. Although the time interval between sections is sometimes close to one inertial period, large variations on the order of 10 percent are found from one section to the next. Transports range from 20 to 31 Sv with a net average close to 25 Sv, consisting of 33 Sv of inflow into the Gulf of Mexico and 8 Sv of outflow into the Caribbean Sea. The highest velocities are 2.0 m sec-1 into the Gulf of Mexico near the surface on the western side of the channel, decreasing to 0.1 m sec-1 by 400 to 500 m depth. Beneath the core of the Yucatan Current a countercurrent, with speeds close to 0.2 m sec-1 and an average transport of 2 Sv, hugs the slopes of the channel from 500 to 1500 m depth. Our data show an additional 6 Sv of return flow within the same depth range over the abrupt slope near Cuba, which is likely to be the recirculating fraction of the Yucatan Current deep extention, unable to outflow through the Florida Straits. The most significant southerly flows do not occur in the deepest portion of the channel, but at depths around 1000 m

Prevalence and risk factors for asthma, rhinitis, eczema, and atopy among preschool children in an Andean city.

BACKGROUND: Limited data are available on prevalence and associated risk factors for atopy and allergic diseases from high-altitude urban settings in Latin America. OBJECTIVE: To estimate the prevalence of atopy, asthma, rhinitis, and eczema, and associations with relevant risk factors in preschool children in the Andean city of Cuenca. METHODS: A cross-sectional study was undertaken using a representative sample of 535 children aged 3-5 years attending 30 nursery schools in the city of Cuenca, Ecuador. Data on allergic diseases and risk factors were collected by parental questionnaire. Atopy was measured by skin prick test (SPT) reactivity to a panel of relevant aeroallergens. Associations between risk factors and the prevalence of atopy and allergic diseases were estimated using multivariable logistic regression. RESULTS: Asthma symptoms were reported for 18% of children, rhinitis for 48%, and eczema for 28%, while SPT reactivity was present in 33%. Population fractions of asthma, rhinitis, and eczema attributable to SPT were 3.4%, 7.9%, and 2.9%, respectively. In multivariable models, an increased risk of asthma was observed among children with a maternal history of rhinitis (OR 1.85); rhinitis was significantly increased in children of high compared to low socioeconomic level (OR 2.09), among children with a maternal history of rhinitis (OR 2.29) or paternal history of eczema (OR 2.07), but reduced among children attending daycare (OR 0.64); eczema was associated with a paternal history of eczema (OR 3.73), and SPT was associated with having a dog inside the house (OR 1.67). CONCLUSIONS: A high prevalence of asthma, rhinitis, and eczema symptoms were observed among preschool children in a high-altitude Andean setting. Despite a high prevalence of atopy, only a small fraction of symptoms was associated with atopy. Parental history of allergic diseases was the most consistent risk factor for symptoms in preschool children

Influence of MWCNT/surfactant dispersions on the mechanical properties of Portland cement pastes

This work studies the reinforcing effect of Multi Walled Carbon Nanotubes (MWCNT) on cement pastes. A 0.35% solid concentration of MWCNT in powder was dispersed in deionized water with sodium dodecyl sulfate (cationic surfactant), cetylpyridinium chloride (anionic surfactant) and triton X-100 (amphoteric surfactant) using an ultrasonic tip processor. Three concentrations of each surfactant (1mM, 10mM and 100mM) were tested, and all samples were sonicated until an adequate dispersion degree was obtained. Cement pastes with additions of carbon nanotubes of 0.15% by mass of cement were produced in two steps; first the dispersions of MWCNT were combined with the mixing water using an ultrasonic tip processor to guarantee homogeneity, and then cement was added and mixed until a homogeneous paste was obtained. Direct tensile strength, apparent density and open porosity of the pastes were measured after 7 days of curing. It was found that the MWCNT/surfactants dispersions decrease the mechanical properties of the cement based matrix due to an increased porosity caused by the presence of surfactants. © Published under licence by IOP Publishing Ltd