1,989 research outputs found
spl(2,1) dynamical supersymmetry and suppression of ferromagnetism in flat band double-exchange models
The low energy spectrum of the ferromagnetic Kondo lattice model on a N-site
complete graph extended with on-site repulsion is obtained from the underlying
spl(2,1) algebra properties in the strong coupling limit. The ferromagnetic
ground state is realized for 1 and N+1 electrons only. We identify the large
density of states to be responsible for the suppression of the ferromagnetic
state and argue that a similar situation is encountered in the Kagome,
pyrochlore, and other lattices with flat bands in their one-particle density of
states.Comment: 7 pages, 1 figur
CuisineNet: Food Attributes Classification using Multi-scale Convolution Network
Diversity of food and its attributes represents the culinary habits of
peoples from different countries. Thus, this paper addresses the problem of
identifying food culture of people around the world and its flavor by
classifying two main food attributes, cuisine and flavor. A deep learning model
based on multi-scale convotuional networks is proposed for extracting more
accurate features from input images. The aggregation of multi-scale convolution
layers with different kernel size is also used for weighting the features
results from different scales. In addition, a joint loss function based on
Negative Log Likelihood (NLL) is used to fit the model probability to multi
labeled classes for multi-modal classification task. Furthermore, this work
provides a new dataset for food attributes, so-called Yummly48K, extracted from
the popular food website, Yummly. Our model is assessed on the constructed
Yummly48K dataset. The experimental results show that our proposed method
yields 65% and 62% average F1 score on validation and test set which
outperforming the state-of-the-art models.Comment: 8 pages, Submitted in CCIA 201
Temperature dependence of the resistivity in the double-exchange model
The resistivity around the ferromagnetic transition temperature in the double
exchange model is studied by the Schwinger boson approach. The spatial spin
correlation responsible for scattering of conduction electrons are taken into
account by adopting the memory function formalism. Although the correlation
shows a peak lower than the transition temperature, the resistivity in the
ferromagnetic state monotonically increases with increasing temperature due to
a variation of the electronic state of the conduction electron. In the
paramagnetic state, the resistivity is dominated by the short range correlation
of scattering and is almost independent of the temperature. It is attributed to
a cancellation between the nearest-neighbor spin correlation, the fermion
bandwidth, and the fermion kinetic energy. This result implies the importance
of the temperature dependence of the electronic states of the conduction
electron as well as the localized spin states in both ferromagnetic and
paramagnetic phases.Comment: RevTex, 4 pages, 4 PostScript figures, To appear in Phys. Rev.
Effect of Fly Ash on the Durability Properties of High Strength Concrete
Utilization of fly ash as a supplementary cementitious material adds sustainability to concrete by reducing the CO2 emission of cement production. The positive effects of fly ash as a partial replacement of cement on the durability of concrete are recognized through numerous researches; however, the extent of improvement depends on the properties of fly ash. In this study, durability properties of high strength concrete utilizing high volume Class F fly ash sourced from Western Australia have been investigated. Concrete mixtures with fly ash as 30% and 40% of total binder wereused to cast the test specimens. The compressive strength, drying shrinkage, sorptivity and rapid chloride permeability of the fly ash and control concrete specimens were determined. The 28-day compressive strength of the concrete mixtures varied from 65 to 85 MPa. The fly ash concrete samples showed less drying shrinkage than the control concrete samples when designed for the same 28-day compressive strength of the control concrete. Inclusion of fly ash reduced sorptivity and chloride ion permeation significantly at 28 days and reduced further at 6 months. In general, incorporation of fly ash as partial replacement of cement improved the durability properties of concrete
Acute Pancreatitis Secondary to a Perivaterian Duodenal Diverticular Abscess
A 46-year-old previously fit lady was admitted with acute pancreatitis. She had no history of gallstones. She was not on any medications and consumed minimal amounts of alcohol. On subsequent investigations as to the causative factor, she was found at ultrasound to have an air-fluid filled cystic structure posterior to the head of pancreas which was compressing the common bile duct. Further magnetic resonance imaging and computer tomography scans showed that this cystic lesion was located around the ampulla of Vater. A diagnosis of a perivaterian abscess was made. At endoscopy, a large contained abscess was seen which was successfully drained. She made a full and uneventful recovery
Actividad antibacteriana y antioxidante de los extractos de Piper cubeba (Piperaceae)
Piper cubeba L. (Piperaceae), commonly known as ‘cubeb’, is native to Indonesia, and also found in many other countriesof the South-East Asia, and in some African countries. This plant has been used as a popular food additive, andin folklore medicine to treat various ailments, particularly bacterial infections. The n-hexane, dichloromethane (DCM)and methanol (MeOH) extracts of the dried berries (fruit) of this plant were assessed for their antioxidant (free radicalscavenging) and antibacterial activities using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and the micro titre basedantimicrobial assay incorporating resazurin as an indicator of cell growth, respectively. While all extracts showed antioxidantactivity in the qualitative assay, the most prominent antioxidant activity was observed with the MeOH extract inthe quantitative assay with a RC50 value of 2.71 x 10-1 mg/mL. The antioxidant potency of the DCM extract was about3 fold less (RC50 = 6.50 x 10-1 mg/mL) than that of the MeOH extract. None of the extracts showed any antibacterialproperty against Bacillus subtilis, Escherichia coli, and ampicillin resistant Escherichia coli. While both the n-hexaneand the DCM extracts inhibited the growth of Bacillus cereus, Pseudomonas aeruginosa and Staphylococcus aureus, theMeOH extract was active only against B. cereus and P. aeruginosa. The most potent antibacterial activity was displayedby the n-hexane extract against B. cereus with an MIC value of 1.56 mg/mL. All antibacterial activities of the extractswere found to be bacteriostatic rather than bactericidal.Piper cubeba L. (Piperaceae), conocida comúnmente como ‘cubeb’, es autóctona de Indonesia y también se encuentraen muchos otros países del sureste de Asia, así como en algunos países africanos.Esta planta se ha utilizado como un popular aditivo alimentario y, en la medicina tradicional, para tratar diversasdolencias, especialmente infecciones bacterianas. Para evaluar la actividad antioxidante (barrido de radicales libres)y la actividad antibacteriana de los extractos de n-hexano, diclorometano (DCM) y metanol (MeOH) de las bayassecas (fruto) de esta planta, se llevó a cabo un ensayo 2,2-difenil-1-picrilhidracil (DPPH) y un ensayo antimicrobianobasado en microtitulación que incorporaba resazurina como indicador del crecimiento celular, respectivamente. Aunquetodos los extractos mostraron actividad antioxidante en el ensayo cualitativo, la actividad antioxidante más destacadase observó con el extracto de MeOH en el ensayo cuantitativo con un valor de RC50 de 2,71 x 10-1 mg/mL.La potencia antioxidante del extracto de DCM fue aproximadamente 3 veces menor (RC50 = 6,50 x 10-1 mg/mL)que la del extracto de MeOH.Ninguno de los extractos mostró propiedades antibacterianas frente a Bacillus subtilis, Escherichia coli y Escherichiacoli resistente a la ampicilina. Aunque ambos extractos, el n-hexano y el DCM, inhibieron el crecimiento de Bacilluscereus, Pseudomonas aeruginosa y Staphylococcus aureus, el extracto de MeOH sólo mostró actividad frente a B.cereus y P. aeruginosa. El extracto de n-hexano fue el que mostró mayor potencia antibacteriana frente a B. cereus,con un valor de concentración inhibitoria mínima (CIM) de 1,56 mg/mL. Se observó que todas las actividades antibacterianasde los extractos resultaron más bacteriostáticas que bactericidas
Ab Initio No Core Shell Model with Leadership-Class Supercomputers
Nuclear structure and reaction theory is undergoing a major renaissance with
advances in many-body methods, strong interactions with greatly improved links
to Quantum Chromodynamics (QCD), the advent of high performance computing, and
improved computational algorithms. Predictive power, with well-quantified
uncertainty, is emerging from non-perturbative approaches along with the
potential for guiding experiments to new discoveries. We present an overview of
some of our recent developments and discuss challenges that lie ahead. Our foci
include: (1) strong interactions derived from chiral effective field theory;
(2) advances in solving the large sparse matrix eigenvalue problem on
leadership-class supercomputers; (3) selected observables in light nuclei with
the JISP16 interaction; (4) effective electroweak operators consistent with the
Hamiltonian; and, (5) discussion of A=48 system as an opportunity for the
no-core approach with the reintroduction of the core.Comment: 23 pages, 7 figures, Conference Proceedings online at
http://ntse.khb.ru/files/uploads/2016/proceedings/Vary.pd
Comparative Study of Monosex Tilapia (Oreochromis niloticus) Production under Different Stocking Density in Ponds
A field experiment was conducted to study the effect of stocking density on the growth and production of monosex male tilapia (Oreochromis niloticus L.) conducted in six ponds commencing from 7th July to 4th November, 2012. Feeding frequency were two times in a day. The mean initial weight of fry in all the treatments were 5.7±0.04 g and after completion of the experiment the mean final weight of tilapia was 321.62±1.11 g for T1, 300.12±0.87 g for T2 and 256.25±2.38 g for T3. The mean weight gain of 315.92±1.11, 294.42±0.87 and 250.552.38g and mean percent weight gain of 5542.40, 5165.20 and 4395.61% and mean FCR was 1.41±0.00, 1.46±0.01 and 1.59±0.00and mean SGRof 3.36, 3.30 and 3.17% and the survival rate was 97.67, 94.25 and 93.40% were recorded in T1, T2 and T3, respectively. The highest weight gain, percent weight gain, SGR and survival rate were found in T1 and lowest were found in T3. The production was observed to be 47.12±0.52, 56.57±0.80 and 59.84±1.10 kg/dec/4 months in T1, T2 and T3, respectively. The significant (P?0.01) highest fish production and FCR was obtained 59.84 kg/dec/4 months and 1.59 respectively in T3 under stocking density was 250 fish/decimal and production, FCR was found to be decreased significantly with the decrease in stocking density. The lowest fish production 47.12 kg/dec/4 months were observed in T1. Although higher production was obtained in T3 but individually growth performance of monosex tilapia was higher in T1. Keywords: Monosex tilapia, growth performance, stocking density, tilapia production
AMP-activated protein kinase is a key regulator of acute neurovascular permeability
Many neuronal and retinal disorders are associated with pathological hyperpermeability of the microvasculature. We have used explants of rodent retinae to study acute neurovascular permeability and signal transduction and the role of AMP-activated protein kinase (AMPK). Following stimulation with either vascular endothelial growth factor (VEGF-A) or bradykinin (BK), AMPK was rapidly and strongly phosphorylated and acted as a key mediator of permeability downstream of Ca2+ Accordingly, AMPK agonists potently induced acute retinal vascular leakage. AMPK activation led to phosphorylation of endothelial nitric oxide synthase (eNOS), which in turn increased VE-cadherin phosphorylation on Y685. In parallel, AMPK also mediated phosphorylation of p38 MAP kinase and HSP27, indicating that it regulated paracellular junctions and cellular contractility, both previously associated with endothelial permeability. Endothelial AMPK provided a missing link in neurovascular permeability, connecting Ca2+ transients to the activation of eNOS and p38, irrespective of the permeability-inducing factor used. Collectively, we find that, due to its compatibility with small molecule antagonists/agonists and siRNA, the ex-vivo retina model constitutes a reliable tool to identify and study regulators and mechanism of acute neurovascular permeability
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