Vacuum decay in an interacting multiverse

We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of "true" vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behaviour that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation.Comment: 9 pages, 5 figure

Baja presión en aspersores de impacto en coberturas de riego: análisis técnico y agronómico

La eficiencia energética en riego presurizado se ha abordado desde la gestión hidráulica de las infraestructuras de red y la eficiencia en los bombeos, sin embargo, es necesario analizar los ahorros que pueden realizarse a escala de parcela. Resultados preliminares indican que la reducción de la presión de funcionamiento de un aspersor de impacto de 300 kPa a 200 kPa ligeramente reduce la uniformidad del riego. En este trabajo se evalúa en campo la calidad del riego y los resultados agronómicos de tres configuraciones aspersor+presión: 1) un aspersor de impacto convencional trabajando a 300 kPa (AC 300), 2) un aspersor convencional trabajando a 200 kPa (AC 200) y 3) un aspersor modificado con una pequeña placa deflectora sobre el brazo de impacto trabajando a 200 kPa (APD 200). En una parcela experimental de cobertura total formada por 12 subparcelas, se realizó un ensayo en bloques al azar sobre un cultivo de maíz durante la campaña 2015. Se caracterizaron las condiciones meteorológicas (velocidad y dirección del viento) de los riegos aplicados al maíz. Para cada tratamiento se realizaron ensayos de uniformidad, evaluaciones agronómicas, cosecha manual de biomasa aérea y cosecha de grano. Los resultados indican que la uniformidad media evaluada no fue significativamente diferente entre tratamientos. La biomasa y producción de grano del tratamiento de 300 kPa resultaron menores que las de los tratamientos a 200 kPa (AC 200 y APD 200), no resultando significativas las diferencias entre ambos tratamientos de 200 kPa. Se detectó un problema en el crecimiento de cultivo que afectó principalmente a las subparcelas de 300 kPa, por lo que los resultados deben de considerarse con cuidado y realizar el ensayo en una o dos temporadas más.Ministerio de Economía y Competitivida

Development of a portable leaf photosynthesis and volatile organic compounds emission system.

Understanding how plant carbon metabolism responds to environmental variables such as light is central to understanding ecosystem carbon cycling and the production of food, biofuels, and biomaterials. Here, we couple a portable leaf photosynthesis system to an autosampler for volatile organic compounds (VOCs) to enable field observations of net photosynthesis simultaneously with emissions of VOCs as a function of light. Following sample collection, VOCs are analyzed using automated thermal desorption-gas chromatograph-mass spectrometry (TD-GC-MS). An example is presented from a banana plant in the central Amazon with a focus on the response of photosynthesis and the emissions of eight individual monoterpenes to light intensity. Our observations reveal that banana leaf emissions represent a 1.1 +/- 0.1% loss of photosynthesis by carbon. Monoterpene emissions from banana are dominated by trans-β-ocimene, which accounts for up to 57% of total monoterpene emissions at high light. We conclude that the developed system is ideal for the identification and quantification of VOC emissions from leaves in parallel with CO2 and water fluxes.The system therefore permits the analysis of biological and environmental sensitivities of carbon metabolism in leaves in remote field locations, resulting in the emission of hydrocarbons to the atmosphere.•A field-portable system is developed for the identification and quantification of VOCs from leaves in parallel with leaf physiological measurements including photosynthesis and transpiration.•The system will enable the characterization of carbon and energy allocation to the biosynthesis and emission of VOCs linked with photosynthesis (e.g. isoprene and monoterpenes) and their biological and environmental sensitivities (e.g. light, temperature, CO2).•Allow the development of more accurate mechanistic global VOC emission models linked with photosynthesis, improving our ability to predict how forests will respond to climate change. It is our hope that the presented system will contribute with critical data towards these goals across Earth's diverse tropical forests

Sudden death in patients without structural heart disease

AbstractSudden unexpected cardiac death generally occurs in persons with known or previously unrecognized heart disease. However, it has become evident that it occurs often enough in patients without any identifiable structural abnormality to warrant the cardiologist's attention. Mostly, it concerns young, active, and otherwise healthy individuals. This paper focuses on various categories of patients with life-threatening events considered to have occurred on a solely “electrical” basis. Currently, several entities are recognized with distinct electrophysiological abnormalities, including Wolff-Parkinson-White syndrome, long QT syndrome, the Brugada syndrome, short-coupled torsade de pointes, and catecholamine-induced polymorphic ventricular tachyarrhythmia. The remaining patients without such distinct abnormalities are categorized as having idiopathic ventricular fibrillation. Although mechanical cardiac function may seem normal, such patients might have certain discrete anatomic abnormalities, unidentifiable with current investigational tools. Possibly in the future, with development of newer and more sophisticated tools (magnetic resonance imaging, positron emission tomography, genetic testing), some or all cases of idiopathic ventricular fibrillation must be redefined as having specific genetic and/or anatomic bases. All patients successfully resuscitated from cardiac arrest due to ventricular tachyarrhythmia without clear precipitating factors (acute myocardial infarction, severe electrolyte or metabolic disturbances) are at high risk of recurrences. Long-term prophylactic therapy is indicated. Contrasting with older belief, survivors of idiopathic ventricular fibrillation are now also considered high-risk patients. The implantable cardioverter-defibrillator appears to be the safest and most effective therapy

Ultra-ductile and low friction epoxy matrix composites

We present the results of an effective reinforcement of epoxy resin matrix with fullerene carbon soot. The optimal carbon soot addition of 1 wt. % results in a toughness improvement of almost 20 times. The optimized soot-epoxy composites also show an increase in tensile elongation of more than 13 %, thus indicating a change of the failure mechanism in tension from brittle to ductile. Additionally, the coefficient of friction is reduced from its 0.91 value in plain epoxy resin to 0.15 in the optimized composite. In the optimized composite, the lateral forces during nanoscratching decrease as much as 80 % with enhancement of the elastic modulus and hardness by 43 % and 94%, respectively. The optimized epoxy resin fullerene soot composite can be a strong candidate for coating applications where toughness, low friction, ductility and light weight are important.Comment: 24 pages, 7 Figures, 1 Table in Polymer Testing (2015

Vacuum decay in an interacting multiverse

8 págs.; 5 figs.; Open Access funded by Creative Commons Atribution Licence 4.0We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of “true” vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behavior that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation. ©2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY licenseA. A.-S. was partially supported by the Marsden grant “Topics in mathematical general relativity and theoretical cosmology”admin-istered by the Royal Society of New Zealand. The work of C.B. was supported by the FCT (Portugal) grant SFRH/BPD/62861/2009. S. R.-P. and A.A.-S.were partially supported by the project FIS2012-38816, from the Spanish Ministerio de Economía y CompetitividadPeer Reviewe

Interacting universes and the cosmological constant

In this Letter it is studied the effects that an interaction scheme among universes can have in the values of their cosmological constants. In the case of two interacting universes, the value of the cosmological constant of one of the universes becomes very close to zero at the expense of an increasing value of the cosmological constant of the partner universe. In the more general case of a chain of N interacting universes with periodic boundary conditions, the spectrum of the Hamiltonian splits into a large number of levels, each of them associated with a particular value of the cosmological constant, that can be occupied by single universes revealing a collective behavior that plainly shows that the multiverse is much more than the mere sum of its parts. © 2013 Elsevier B.V.Peer Reviewe

How do the movement patterns of homeless youth affect their information seeking behaviors within the systems provided to them

This work provides a reflection on the relationship between movement patterns, homeless youth, and their information seeking behaviors within the information systems they have access to in order to find help. While understudied, the relationship between the movement patterns of the homeless youth population could be used to build information systems that are customized to the way this population looks for and uses resources. We propose a two phase user study focused on homeless youth that consists of a semi-structured interview as well as a user study on a tool they use to locate resources for help