4,977 research outputs found
Bulk viscosity of the massive Gross-Neveu model
A calculation of the bulk viscosity for the massive Gross-Neveu model at zero
fermion chemical potential is presented in the large- limit. This model
resembles QCD in many important aspects: it is asymptotically free, has a
dynamically generated mass gap, and for zero bare fermion mass it is scale
invariant at the classical level (broken through the trace anomaly at the
quantum level). For our purposes, the introduction of a bare fermion mass is
necessary to break the integrability of the model, and thus to be able to study
momentum transport. The main motivation is, by decreasing the bare mass, to
analyze whether there is a correlation between the maximum in the trace anomaly
and a possible maximum in the bulk viscosity, as recently conjectured. After
numerical analysis, I find that there is no direct correlation between these
two quantities: the bulk viscosity of the model is a monotonously decreasing
function of the temperature. I also comment on the sum rule for the spectral
density in the bulk channel, as well as on implications of this analysis for
other systems.Comment: v2: 3->3 processes included, conclusions unchanged. Comments and
references added. Typos corrected. To appear in Phys. Rev.
A multienzyme response is involved in the phenomenon of resistance to triclabendazole on Fasciola
The trematode Fasciola hepatica is the producer of a parasitic zoonosis known as fasciolosis. Triclabendazole (TCBZ) is the most widely used fasciolicide anthelmintic. Today, its indiscriminate use has led to the expression of anthelmintic resistance. Our previous studies over the Sligo strain (TCBZ-R) confirmed in the Phase I of detoxification, an overexpression of Flavin-Monooxygenases. This phenomenon should not be the only response that the trematode has and should not rule out the involvement of other processes of detoxification of Phase I or II. In the processes of detoxification in Phase I, the Carboxylesterase (CE) is a serine esterase-dependent with broad substrate specificity. This family of enzymes are involved in many metabolic functions including detoxification of xenobiotics. In Phase II exists a system using the Glutathione (GSH). It is a sequence of certain enzymes that culminate adding reduced GSH to xenobiotic increasing its water solubility and facilitatingtheir excretion. Glutathione addition plays an important role in antioxidant defense in different tissues catalyze the reduction of oxidized to reduced GSH which will be utilized by GST to reduce the peroxide and lipoperoxide, which they are reactive oxygen species. This process involves Glutathione Peroxidase (GPx), Glutathione Reductase (GSR) and Glutathione S-Transferase (GST). In the present work, we evaluate, in vitro, the cytosolic activity of different xenobiotic metabolizing enzymes of Phase I: CE and Phase II: GST, GPx and GSR in adults of F. hepatica TCBZ susceptible (TCBZ-S) and TCBZ resistant (TCBZ-R),respectively Cullompton strain and Sligo and Oberon strains. In the TCBZ-R Sligo and Oberon strains, the GST activity was 1277±32 and 1216±16 nmol/min/mg protein, respectively, higher than that in the TCBZ-S Cullompton strain 800±60 nmol/ min/mg protein. Regarding the GPx activity in the Sligo and Oberon strains, TCBZ-R was 83±3.41 and 81±2.45 nmol/min/ mg protein, respectively, higher than that in the TCBZ-S Cullompton strain 49±2.58 nmol/min/mg protein. The GSR activity in Sligo and Oberon strains was 38±2.07 and 41±1.25 nmol/min/mg protein, respectively, higher than that in the TCBZ-S Cullompton strain 29±1.22 nmol/min/mg protein, whereas CE activity did not differ between the different strains tested. In this work, a multienzyme response involving at all the family of enzymes GSH dependent is detected. Carboxylesterase expressed no significant differences not being involved in the resistance phenomenon. These results contribute to the understanding of the mechanisms referred to the phenomenon of resistance to TCBZ.Fil: Fernandez, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Acevedo, Maria E.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Laboratorio de Biología Celular y Molecular; ArgentinaFil: Solana, Hugo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Laboratorio de Biología Celular y Molecular; ArgentinaInternational Conference on ParasitologyPhiladelphiaEstados UnidosOMICS Publishing Grou
An optical coherence microscope for 3-dimensional imaging in developmental biology
An optical coherence microscope (OCM) has been designed and constructed to acquire 3-dimensional images of highly scattering biological tissue. Volume-rendering software is used to enhance 3-D visualization of the data sets. Lateral resolution of the OCM is 5 mm (FWHM), and the depth resolution is 10 mm (FWHM) in tissue. The design trade-offs for a 3-D OCM are discussed, and the fundamental photon noise limitation is measured and compared with theory. A rotating 3-D image of a frog embryo is presented to illustrate the capabilities of the instrument
Mapping Wind Direction with HF Radar
The article of record as published may be found at https://www.jstor.org/stable/43924806Office of Naval ResearchH.C. Graber acknowledges the sup- port by the Office of Naval Research through grant N00014-94-1-1016 (DUCK94)
NGcGM3 Ganglioside: A Privileged Target for Cancer Vaccines
Active specific immunotherapy is a promising field in cancer research. N-glycolyl (NGc) gangliosides, and particularly NGcGM3, have received attention as a privileged target for cancer therapy. Many clinical trials have been performed with the anti-NGc-containing gangliosides anti-idiotype monoclonal antibody racotumomab (formerly known as 1E10) and the conjugated NGcGM3/VSSP vaccine for immunotherapy of melanoma, breast, and lung cancer. The present paper examines the role of NGc-gangliosides in tumor biology as well as the available preclinical and clinical data on these vaccine products. A brief discussion on the relevance of prioritization of cancer antigens in vaccine development is also included
Bayesian spatio-temporal models for stream networks
Spatio-temporal models are widely used in many research areas including
ecology. The recent proliferation of the use of in-situ sensors in streams and
rivers supports space-time water quality modelling and monitoring in near
real-time. In this paper, we introduce a new family of dynamic spatio-temporal
models, in which spatial dependence is established based on stream distance and
temporal autocorrelation is incorporated using vector autoregression
approaches. We propose several variations of these novel models using a
Bayesian framework. Our results show that our proposed models perform well
using spatio-temporal data collected from real stream networks, particularly in
terms of out-of-sample RMSPE. This is illustrated considering a case study of
water temperature data in the northwestern United States.Comment: 26 pages, 10 fig
Multiphase progenetic development shaped the brain of flying archosaurs
The growing availability of virtual cranial endocasts of extinct and extant vertebrates has fueled the quest for endocranial characters that discriminate between phylogenetic groups and resolve their neural significances. We used geometric morphometrics to compare a phylogenetically and ecologically comprehensive data set of archosaurian endocasts along the deep evolutionary history of modern birds and found that this lineage experienced progressive elevation of encephalisation through several chapters of increased endocranial doming that we demonstrate to result from progenetic developments. Elevated encephalisation associated with progressive size reduction within Maniraptoriformes was secondarily exapted for flight by stem avialans. Within Mesozoic Avialae, endocranial doming increased in at least some Ornithurae, yet remained relatively modest in early Neornithes. During the Paleogene, volant non-neoavian birds retained ancestral levels of endocast doming where a broad neoavian niche diversification experienced heterochronic brain shape radiation, as did non-volant Palaeognathae. We infer comparable developments underlying the establishment of pterosaurian brain shapes
Erratum: Dynamics of Energy Transfer in a Conjugated Dendrimer Driven by Ultrafast Localization of Excitations (Journal of the American Chemical Society (2015) 137 (11637-11644) DOI: 10.1021/jacs.5b04075)
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