470 research outputs found
Berry Phase Quantum Thermometer
We show how Berry phase can be used to construct an ultra-high precision
quantum thermometer. An important advantage of our scheme is that there is no
need for the thermometer to acquire thermal equilibrium with the sample. This
reduces measurement times and avoids precision limitations.Comment: Updated to published version. I. Fuentes previously published as I.
Fuentes-Guridi and I. Fuentes-Schulle
The entangling side of the Unruh-Hawking effect
We show that the Unruh effect can create net quantum entanglement between
inertial and accelerated observers depending on the choice of the inertial
state. This striking result banishes the extended belief that the Unruh effect
can only destroy entanglement and furthermore provides a new and unexpected
source for finding experimental evidence of the Unruh and Hawking effects.Comment: 4 pages, 4 figures. Added Journal referenc
Effect of small-sided games on football players
El objetivo ha sido analizar cómo influyen los juegos reducidos o SSGs sobre la condición física, técnica y los cambios de dirección (CODA) en jugadoras alevines de fútbol femenino. Participan 12 jugadoras de fútbol femenino. Realizaron 14 sesiones de entrenamiento basado en juegos reducidos de fútbol. La muestra presenta valores normales en la prueba de Saphiro-Wilk, además, en la prueba de t de Student muestra que existen diferencias estadísticamente muy significativas (p ≤0,00) en todas las variables físicas analizadas, menos en el caso de la fuerza explosiva. En las variables de técnica nos muestra que existen diferencias significativas en todas las variables analizadas (p ≤0,00). Por último existen correlaciones positivas y estadísticamente significativas entre las distintas variables analizadas. De esta forma podemos considerar los juegos reducidos son un método adecuado y muy ventajoso para el entrenamiento en las etapas iniciales o de formación en jugadoras de fútbolThe objective has been to analyze how small-sided games or SSGs affect physical, technical and changes of direction (CODA) in U12 female soccer players. 12 female soccer players participate. They conducted 14 training sessions based on reduced soccer games. The sample has normal values in the Saphiro-Wilk test, and in the Student's t test it shows that there are statistically very significant differences (p ≤0,00) in all the analyzed physical variables, less in the case of the explosive force. In the technique variables we show that there are significant differences in all variables analyzed (p ≤0,00). Finally, there are positive and statistically significant correlations between the different variables analyzed. In this way we can consider reduced games are a suitable and very advantageous method for training in the initial stages or training in soccer player
Programa de rehabilitación cardíaca mediante un entrenamiento de tenis adaptado
The aims of this study were to determine the effect of a cardiac rehabilitation program, based on the adjustment of a sports modality (tennis), on differentes laboratory analysis variables (triglycerides, cholesterol,cholesterol LDL, cholesterol HDL and glucose ) And and on an exercise stress test (metabolics equivalent-METs-, time of effort, systolic pressure, dyastolic pressure, maximum cardiac frecuencia and double product). The study involved 7 patients with low risk myocardial heart attack. The ages was include between 48 and 63 years old. By the end of the program, which has lasted 3 months, triglycerides, cholesterol, exercise capacity and double product had improved significantly (p<.005 for all).Los objetivos de este estudio son evaluar los efectos de nuestro programa de rehabilitación cardiaca, basado en la adaptación de una modalidad deportiva (tenis), sobre diferentes variables del perfil lipídico (triglicéridos, colesterol, cLDL, cHDL, y glucosa) así como en la prueba de esfuerzo (MET, tiempo de esfuerzo, presión sistólica, presión diastólica, frecuencia cardíaca máxima y doble producto). Analizamos a 7 pacientes con infarto agudo de miocardio de bajo riesgo. Las edades estaban comprendidas entre los 48 y 63 años. Tras la realización del programa, que ha tenido 3 meses de duración, se han producido mejoras significativas a nivel de triglicéridos, colesterol, capacidad funcional valorada en equivalentes metabólicos y doble producto (p<.005 para todos)
Can solid body destruction explain abundance discrepancies in planetary nebulae?
In planetary nebulae, abundances of oxygen and other heavy elements derived
from optical recombination lines are systematically higher than those derived
from collisionally excited lines. We investigate the hypothesis that the
destruction of solid bodies may produce pockets of cool, high-metallicity gas
that could explain these abundance discrepancies. Under the assumption of
maximally efficient radiative ablation, we derive two fundamental constraints
that the solid bodies must satisfy in order that their evaporation during the
planetary nebula phase should generate a high enough gas phase metallicity. A
local constraint implies that the bodies must be larger than tens of meters,
while a global constraint implies that the total mass of the solid body
reservoir must exceed a few hundredths of a solar mass. This mass greatly
exceeds the mass of any population of comets or large debris particles expected
to be found orbiting evolved low- to intermediate-mass stars. We therefore
conclude that contemporaneous solid body destruction cannot explain the
observed abundance discrepancies in planetary nebulae. However, similar
arguments applied to the sublimation of solid bodies during the preceding
asymptotic giant branch (AGB) phase do not lead to such a clear-cut conclusion.
In this case, the required reservoir of volatile solids is only one
ten-thousandth of a solar mass, which is comparable to the most massive debris
disks observed around solar-type stars, implying that this mechanism may
contribute to abundance discrepancies in at least some planetary nebulae, so
long as mixing of the high metallicity gas is inefficient.Comment: 8 pages, no figures, ApJ in pres
High-pT signatures in vector–leptoquark models
We present a detailed analysis of the collider signatures of TeV-scale massive vector bosons motivated by the hints of lepton flavour non-universality observed in B-meson decays. We analyse three representations that necessarily appear together in a large class of ultraviolet-complete models: a colour-singlet (Z′), a colour-triplet (the U1 leptoquark), and a colour octet (G′). Under general assumptions for the interactions of these exotic states with Standard Model fields, including in particular possible right-handed and flavour off-diagonal couplings for the U1, we derive a series of stringent bounds on masses and couplings that constrain a wide range of explicit new-physics models
Mitochondrial activity is modulated by TNFα and IL-1β in normal human chondrocyte cells
SummaryObjectivePro-inflammatory cytokines play an important role in osteoarthritis (OA). In osteoarthritic cartilage, chondrocytes exhibit an alteration in mitochondrial activity. This study analyzes the effect of tumor necrosis factor-α (TNFα) and interleukin-1β (IL-1β) on the mitochondrial activity of normal human chondrocytes.Materials and methodsMitochondrial function was evaluated by analyzing the activities of respiratory chain enzyme complexes and citrate synthase, as well as by mitochondrial membrane potential (Δψm) and adenosine triphosphate (ATP) synthesis. Bcl-2 family mRNA expression and protein synthesis were analyzed by RNase protection assay (RPA) and Western-blot, respectively. Cell viability was analyzed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and apoptosis by 4′, 6-diamidino-2-phenylindole dihydrochloride (DAPI) stain. Glycosaminoglycans were quantified in supernatant by a dimethyl-methylene blue binding assay.ResultsCompared to basal cells, stimulation with TNFα (10ng/ml) and IL-1β (5ng/ml) for 48h significantly decreased the activity of complex I (TNFα=35% and IL-1β=35%) and the production of ATP (TNFα=18% and IL-1β=19%). Both TNFα and IL-1β caused a definitive time-dependent decrease in the red/green fluorescence ratio in chondrocytes, indicating depolarization of the mitochondria. Both cytokines induced mRNA expression and protein synthesis of the Bcl-2 family. Rotenone, an inhibitor of complex I, caused a significant reduction of the red/green ratio, but it did not reduce the viability of the chondrocytes. Rotenone also increased Bcl-2 mRNA expression and protein synthesis. Finally, rotenone as well as TNFα and IL-1β, reduced the content of proteoglycans in the extracellular matrix of normal cartilage.ConclusionThese results show that both TNFα and IL-1β regulate mitochondrial function in human articular chondrocytes. Furthermore, the inhibition of complex I by both cytokines could play a key role in cartilage degradation induced by TNFα and IL-1β. These data could be important for understanding of the OA pathogenesis
MicroRNA-200 Family Modulation in Distinct Breast Cancer Phenotypes
The epithelial to mesenchymal transition (EMT) contributes to tumor invasion and metastasis in a variety of cancer types. In human breast cancer, gene expression studies have determined that basal-B/claudin-low and metaplastic cancers exhibit EMT-related characteristics, but the molecular mechanisms underlying this observation are unknown. As the family of miR-200 microRNAs has been shown to regulate EMT in normal tissues and cancer, here we evaluated whether the expression of the miR-200 family (miR-200f) and their epigenetic state correlate with EMT features in human breast carcinomas. We analyzed by qRT-PCR the expression of miR-200f members and various EMT-transcriptional inducers in a series of 70 breast cancers comprising an array of phenotypic subtypes: estrogen receptor positive (ER+), HER2 positive (HER2+), and triple negative (TN), including a subset of metaplastic breast carcinomas (MBCs) with sarcomatous (homologous or heterologous) differentiation. No MBCs with squamous differentiation were included. The DNA methylation status of miR-200f loci in tumor samples were inspected using Sequenom MassArray® MALDI-TOF platform. We also used two non-tumorigenic breast basal cell lines that spontaneously undergo EMT to study the modulation of miR-200f expression during EMT in vitro. We demonstrate that miR-200f is strongly decreased in MBCs compared with other cancer types. TN and HER2+ breast cancers also exhibited lower miR-200f expression than ER+ tumors. Significantly, the decreased miR-200f expression found in MBCs is accompanied by an increase in the expression levels of EMT-transcriptional inducers, and hypermethylation of the miR-200c-141 locus. Similar to tumor samples, we demonstrated that downregulation of miR-200f and hypermethylation of the miR-200c-141 locus, together with upregulation of EMT-transcriptional inducers also occur in an in vitro cellular model of spontaneous EMT. Thus, the expression and methylation status of miR-200f could be used as hypothetical biomarkers to assess the occurrence of EMT in breast cancer. © 2012 Castilla et al.This work was supported by grants from: the Instituto de Salud Carlos III (ISCIII; Grant Nos PI07/90324 and PI080971) and the Ministerio de Ciencia e Innovación (MCINN), co-financed by the European Development Regional Fund, “A way to achieve Europe” EDRF (Grant No. RD06/0020/0013); the Junta de Andalucía (Consejería de Salud, Grant No.PI-0384/2007, PI0581/2009); the Consejería de Innovación (Proyecto de Excelencia, Grant No. P07-CVI-03100); and Sandra Ibarra Foundation (Grant No. 2011/088) to JP. MAC and JDM are PhD researchers funded by the ISCIII (Grant No. RD06/0020/0013) and the Consejería de Salud, Junta de Andalucía (PI0581/2009), respectively. DS was funded by an EU Marie Curie Intra-European Fellowship (PIEF-GA-2008-221083) and by Breakthrough Breast Cancer. LRP is a PhD student recipient of a PFIS fellowship (Grant No. F109/00193). MB is a researcher funded by the ISCIII-Red de Biobancos RD09/0076/00085. SR works as a lab technician supported by the ISCIII (PI080971). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe
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