8,246 research outputs found
A discriminating microscopy technique for the measurement of ice crystals and air bubbles size distribution in sorbets
24ième Congrès International du Froid ICR 2015, Yokohama, JPN, 16-/08/2015 - 22/08/2015International audienceIn this work, a technique capable to distinguish between ice crystals and air bubbles in sorbets was developed in order to characterize the effect of operating conditions on their size distributions at the exit of the freezer. A pilot freezer was used to crystallize and aerate a commercial lemon sorbet mix. Crystals and bubbles sizes were measured using a light microscope technique under low temperature in a refrigerated glove box developed in the lab for that purpose. Results showed that the developed microscope technique allowed to distinguish them and to quantify their size distributions. Measurements showed that ice crystals size decreases with air flow rate while air bubbles size increases. The latter also increases with the cylinder pressure inside the scraped surface heat exchanger (SSHE)
A Case for Context-Free Grammar
System administrators agree that permutable methodologies are an interesting new topic in the field of programming languages, and electrical engineers concur. In this paper, authors demonstrate the study of DHCP, demonstrates the natural importance of machine learning. Our focus in our research is not on whether object-oriented languages and replication are often incompatible, but rather on constructing a psychoacoustic tool for evaluating I/O automata (Outlier)
Coherent exciton-vibrational dynamics and energy transfer in conjugated organics
Coherence, signifying concurrent electron-vibrational dynamics in complex natural and man-made systems, is currently a subject of intense study. Understanding this phenomenon is important when designing carrier transport in optoelectronic materials. Here, excited state dynamics simulations reveal a ubiquitous pattern in the evolution of photoexcitations for a broad range of molecular systems. Symmetries of the wavefunctions define a specific form of the non-adiabatic coupling that drives quantum transitions between excited states, leading to a collective asymmetric vibrational excitation coupled to the electronic system. This promotes periodic oscillatory evolution of the wavefunctions, preserving specific phase and amplitude relations across the ensemble of trajectories. The simple model proposed here explains the appearance of coherent exciton-vibrational dynamics due to non-adiabatic transitions, which is universal across multiple molecular systems. The observed relationships between electronic wavefunctions and the resulting functionalities allows us to understand, and potentially manipulate, excited state dynamics and energy transfer in molecular materials.Fil: Nelson, Tammie R.. Los Alamos National Laboratory; Estados UnidosFil: Ondarse Alvarez, Dianelys. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Oldani, Andres Nicolas. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez Hernández, Beatriz. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alfonso Hernandez, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Galindo, Johan F.. Universidad Nacional de Colombia; ColombiaFil: Kleiman, Valeria D.. University of Florida; Estados UnidosFil: Fernández Alberti, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Roitberg, Adrián. University of Florida; Estados UnidosFil: Tretiak, Sergei. Los Alamos National Laboratory; Estados Unido
Enhancement of Electrical Conduction and Phonon Scattering in Ga2O3(ZnO)9-In2O3(ZnO)9 Compounds by Modification of Interfaces at the Nanoscale
The Ga2O3(ZnO)9 and In2O3(ZnO)9 homologous phases have attracted attention as thermoelectric (TE) oxides due to their layered structures. Ga2O3(ZnO)9 exhibits low thermal conductivity, while In2O3(ZnO)9 possesses higher electrical conductivity. The TE properties of the solid solution of Ga2O3(ZnO)9-In2O3(ZnO)9 were explored and correlated with changes in the crystal structure. High-quality (1−x)Ga2O3(ZnO)9-(ZnO)9 (x = 0.0 to 1.0) ceramics were prepared by the solid-state route using B2O3 and Nd2O3 as additives. The crystal structures were analysed by x-ray diffraction, high-resolution transmission electron microscopy and atomic resolution scanning transmission electron microscopy–high-angle annular dark field imaging–energy dispersive x-ray spectroscopy (STEM–HAADF–EDS) techniques. A layered superstructure with compositional modulations was observed in all samples in the (1−x)Ga2O3(ZnO)9-xIn2O3(ZnO)9 system. All the ceramics exhibited nanoscale structural features identified as Ga- and In-rich inversion boundaries (IBs). Substitution of 20 mol.% In (x = 0.2) in the Ga2O3(ZnO)9 compounds generated basal and pyramidal indium IBs typically found in the In2O3(ZnO)m system. The (Ga0.8In0.2)2O3(ZnO)9 compound does not exhibit the structural features of the Cmcm Ga2O3(ZnO)9 compound, which is formed by a stacking of Ga-rich IBs along the pyramidal plane of the wurtzite ZnO, but features that resemble the crystal structure exhibited by the R3¯¯¯m In2O3(ZnO)m with basal and pyramidal indium IBs. The structural changes led to improved TE performance. For example, (Ga0.8In0.2)2O3(ZnO)9 showed a low thermal conductivity of 2 W/m K and a high power factor of 150 μW/m K2 giving a figure of merit (ZT) of 0.07 at 900 K. This is the highest ZT for Ga2O3(ZnO)9-based homologous compounds and is comparable with the highest ZT reported for In2O3(ZnO)9 homologous compounds
A Multi-Isotope Approach Reveals Seasonal Variation in the Reliance on Marine Resources, Production of Metabolic Water, and Ingestion of Seawater by Two Species of Coastal Passerine to Maintain Water Balance
Tracing how free-ranging organisms interact with their environment to maintain water balance is a difficult topic to study for logistical and methodological reasons. We use a novel combination of triple-oxygen stable isotope analyses of water extracted from plasma (δ16O, δ17O, δ18O) and bulk tissue carbon (δ13C) and nitrogen (δ15N) isotopes of feathers and blood to estimate the proportional contribution of marine resources, seawater, and metabolic water used by two species of unique songbirds (genus Cinclodes) to maintain their water balance in a seasonal coastal environment. We also assessed the physiological adjustments that these birds use to maintain their water balance. In agreement with previous work on these species, δ13C and δ15N data show that the coastal resident and invertivore C. nigrofumosus consumes a diet rich in marine resources, while the diet of migratory C. oustaleti shifts seasonally between marine (winter) to freshwater aquatic resources (summer). Triple-oxygen isotope analysis (Δ17O) of blood plasma, basal metabolic rate (BMR), and total evaporative water loss (TEWL) revealed that ~25% of the body water pool of both species originated from metabolic water, while the rest originated from a mix of seawater and fresh water. Δ17O measurements suggest that the contribution of metabolic water tends to increase in summer in C. nigrofumosus, which is coupled with a significant increase in BMR and TEWL. The two species had similar BMR and TEWL during the austral winter when they occur sympatrically in coastal environments. We also found a positive and significant association between the use of marine resources as measured by δ13C and δ15N values and the estimated δ18O values of ingested (pre-formed) water in both species, which indicates that Cinclodes do not directly drink seawater but rather passively ingest when consuming marine invertebrates. Finally, results obtained from physiological parameters and the isotope-based estimates of marine (food and water) resource use are consistent, supporting the use of the triple-oxygen isotopes to quantify the contribution of water sources to the total water balance of free-ranging birds
Arteriovenous uterine malformation: case report
The case of a 49-year-old patient is reported, with a particular history of obstetric risk, who presented with severe transvaginal hemorrhage, was performed doppler arteriography and ultrasound, finding data suggestive of arteriovenous uterine malformation, surgery was decided due to heavy menstrual bleeding with anemia, the pathology report shows characteristics of an arteriovenous uterine malformation
Polimorfismos del gen BoLA-DRB3.2* en ganado criollo colombiano
Objetivo Caracterizar el polimorfismo del gen BoLA-DRB3.2* en las razas bovinas criollas y colombianas. Materiales y métodos En 360 muestras de ADN de ocho razas bovinas criollas (Blanco Orejinegro, Casanareño, Costeño con Cuernos, Chino Santandereano, Caqueteño, Hartón del Valle, Romosinuano y San Martinero), dos razas sintéticas Colombianas (Lucerna y Velásquez) y dos razas foráneas (Brahman y Holstein) se evaluó el polimorfismo del gen BoLA-DRB3.2 mediante técnicas moleculares (PCR-RFLP); se calculó el número promedio de alelos (NPA), las frecuencias, la heterocigocidad esperada (He) y observada (Ho), el equilibrio de Hardy-Weinberg, la estructura genética y los valores de FST y FIS. Resultados El NPA fue 14.6 ± 3.8 siendo Caqueteño la raza con mayor NPA (25) y el menor el Chino Santandereano (10). Se encontraron 41 alelos BoLA-DRB3.2* los más frecuentes fueron *28, *37, *24, *23, *20, *27, *8, *16, *39 (0.17, 0.11, 0.10, 0.09, 0.09, 0.07, 0.07 y 0.06 respectivamente). Se encontró alta diversidad genética (He = 0.878) con mayor valor en Caqueteño (0.96) y menor en San Martinero (0.81). Todas las razas se encontraron en equilibrio de Hardy-Weinberg, se encontraron valores altamente significativos de diferenciación genética (FST= 0.044) y de coeficiente de endogamia (FIS = 0.249). Conclusiones El ganado criollo colombiano posee alto polimorfismo del gen BoLA-DRB3.2* representado en los altos valores de NPA y diversidad genética.Objective To characterize BoLA-DRB3.2*gen polymorphism in Colombian Creole breeds. Materials and methods. Using 360 DNA samples from eight Creole bovine breeds (Blanco Orejinegro, Casanareño, Costeño con Cuernos, Chino Santandereano, Caqueteño, Hartón del Valle, Romosinuano and San Martinero), two synthetic Colombian breeds (Lucerna and Velásquez) and two introduced breeds (Brahmán and Holstein), polymorphism of BoLA-DRB3.2* was evaluated using molecular techniques (PCR-RFLP). Allele average number (AAN), expected (He) and observed (Ho) allele frequencies, heterozygosity, Hardy-Weinberg equilibrium (HW), genetic structure and FST and FIS values were estimated. Results. AAN was 14.6 ± 3.8, Caqueteño breed displayed the highest AAN value (25) and Chino Santandereano the lowest (10). 41 alleles of BoLA-DRB3.2* were detected. The most frequent were *28, *37, *24, *23, *20, *27, *8, *16 and *39 (0.17, 0.11, 0.10, 0.09, 0.09, 0.07, 0.07 and 0.06 respectively). High genetic diversity was found (He=0.878) with the highest value for Caqueteño (0.96) and lowest for San Martinero (0.81). All breeds were in HW, and highly significant values of genetic differentiation (FST=0.044) and inbreeding coefficient (FIS=0.249) were found. Conclusions The Colombian Creole breeds have a high BoLA-DRB3.2*gen polymorphism represented by the high AAN and genetic diversity valuesInstituto de Genética Veterinari
Subjects With Early-Onset Type 2 Diabetes Show Defective Activation of the Skeletal Muscle PGC-1α/Mitofusin-2 Regulatory Pathway in Response to Physical Activity
Objective: Type 2 diabetes is associated with insulin resistance and skeletal muscle mitochondrial dysfunction. We have found that subjects with early-onset type 2 diabetes show incapacity to increase Vo2max in response to chronic exercise. This suggests a defect in muscle mitochondrial response to exercise. Here, we have explored the nature of the mechanisms involved. Research design and methods: Muscle biopsies were collected from young type 2 diabetic subjects and obese control subjects before and after acute or chronic exercise protocols, and the expression of genes and/or proteins relevant to mitochondrial function was measured. In particular, the regulatory pathway peroxisome proliferator-activated receptor gamma coactivator (PGC)-1alpha/mitofusin-2 (Mfn2) was analyzed. Results: At baseline, subjects with diabetes showed reduced expression (by 26%) of the mitochondrial fusion protein Mfn2 and a 39% reduction of the alpha-subunit of ATP synthase. Porin expression was unchanged, consistent with normal mitochondrial mass. Chronic exercise led to a 2.8-fold increase in Mfn2, as well as increases in porin, and the alpha-subunit of ATP synthase in muscle from control subjects. However, Mfn2 was unchanged after chronic exercise in individuals with diabetes, whereas porin and alpha-subunit of ATP synthase were increased. Acute exercise caused a fourfold increase in PGC-1alpha expression in muscle from control subjects but not in subjects with diabetes. Conclusions: Our results demonstrate alterations in the regulatory pathway that controls PGC-1alpha expression and induction of Mfn2 in muscle from patients with early-onset type 2 diabetes. Patients with early-onset type 2 diabetes display abnormalities in the exercise-dependent pathway that regulates the expression of PGC-1alpha and Mfn2.</p
The nuclear lamina couples mechanical forces to cell fate in the preimplantation embryo via actin organization
During preimplantation development, contractile forces generated at the apical cortex segregate cells into inner and outer positions of the embryo, establishing the inner cell mass (ICM) and trophectoderm. To which extent these forces influence ICM-trophectoderm fate remains unresolved. Here, we found that the nuclear lamina is coupled to the cortex via an F-actin meshwork in mouse and human embryos. Actomyosin contractility increases during development, upregulating Lamin-A levels, but upon internalization cells lose their apical cortex and downregulate Lamin-A. Low Lamin-A shifts the localization of actin nucleators from nucleus to cytoplasm increasing cytoplasmic F-actin abundance. This results in stabilization of Amot, Yap phosphorylation and acquisition of ICM over trophectoderm fate. By contrast, in outer cells, Lamin-A levels increase with contractility. This prevents Yap phosphorylation enabling Cdx2 to specify the trophectoderm. Thus, forces transmitted to the nuclear lamina control actin organization to differentially regulate the factors specifying lineage identity
Methods to Determine Neutrino Flux at Low Energies:Investigation of the Low Method
We investigate the "low-" method (developed by the CCFR/NUTEV
collaborations) to determine the neutrino flux in a wide band neutrino beam at
very low energies, a region of interest to neutrino oscillations experiments.
Events with low hadronic final state energy (of 1, 2 and 5 GeV)
were used by the MINOS collaboration to determine the neutrino flux in their
measurements of neutrino () and antineutrino (\nub_\mu) total cross
sections. The lowest energy for which the method was used in MINOS is
3.5 GeV, and the lowest \nub_\mu energy is 6 GeV. At these energies, the
cross sections are dominated by inelastic processes. We investigate the
application of the method to determine the neutrino flux for ,
\nub_\mu energies as low as 0.7 GeV where the cross sections are dominated by
quasielastic scattering and (1232) resonance production. We find that
the method can be extended to low energies by using values of 0.25
and 0.50 GeV, which is feasible in fully active neutrino detectors such as
MINERvA.Comment: 25 pages, 32 figures, to be published in European Physics Journal
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