4,032 research outputs found
Myocardial Dysfunction in an Animal Model of Cancer Cachexia
Aims Fatigue is a common occurrence in cancer patients regardless of tumor type or anti-tumor therapies and is an especially problematic symptom in persons with incurable tumor disease. In rodents, tumor-induced fatigue is associated with a progressive loss of skeletal muscle mass and increased expression of biomarkers of muscle protein degradation. The purpose of the present study was to determine if muscle wasting and expression of biomarkers of muscle protein degradation occur in the hearts of tumor-bearing mice, and if these effects of tumor growth are associated with changes in cardiac function. Main methods The colon26 adenocarcinoma cell line was implanted into female CD2F1 mice and skeletal muscle wasting, in vivo heart function, in vitro cardiomyocyte function, and biomarkers of muscle protein degradation were determined. Key findings Expression of biomarkers of protein degradation were increased in both the gastrocnemius and heart muscle of tumor-bearing mice and caused systolic dysfunction in vivo. Cardiomyocyte function was significantly depressed during both cellular contraction and relaxation. Significance These results suggest that heart muscle is directly affected by tumor growth, with myocardial function more severely compromised at the cellular level than what is observed using echocardiography
Comparison of Two Trap Net Designs for Sampling Muskellunge
Sampling adequate numbers of muskellunge (Esox masquinongy) is necessary to evaluate stocking success and to collect information on various population metrics (e.g., growth, condition, relative abundance). However, muskellunge are often difficult to sample with standard fish sampling gears. We collected muskellunge in trap nets of two different designs (large trap nets [1.5-m × 1.8-m frames, 1.5-m diameter hoops, double throated, single 1.5-m × 30.5-m lead and 19-mm knotless mesh] and small trap nets [0.9-m × 1.5-m frames, 0.9-m diameter hoops, single throat, single 0.9-m × 15.2-m lead and 19-mm knotted mesh]. We also estimated abundance of muskellunge (\u3e600 mm total length) in three eastern South Dakota waters using marked and recaptured fish collected from the trap net comparisons. Sampling with both large and small trap nets was completed during thespring of 2013 and 2014 soon after ice-out. More muskellunge were collected in large than small trap nets at all three lakes. Mean total lengths of muskellunge did not differ significantly between large and small trap nets; however, length-frequency distribu- tions did differ between net designs. Regardless of trap net design, a small number of muskellunge were collected, likely due to low abundance (population range = 0.10 fish/ha to 0.47 fish/ha) in these populations. Thus, long-term monitoring is necessary to accurately assess populations and associated trends. Sampling with large trap nets during the spring combined with population estimates may improve the ability to monitor and manage muskellunge when compared to sampling with small trap nets
An Algebraic Criterion for the Ultraviolet Finiteness of Quantum Field Theories
An algebraic criterion for the vanishing of the beta function for
renormalizable quantum field theories is presented. Use is made of the descent
equations following from the Wess-Zumino consistency condition. In some cases,
these equations relate the fully quantized action to a local gauge invariant
polynomial. The vanishing of the anomalous dimension of this polynomial enables
us to establish a nonrenormalization theorem for the beta function ,
stating that if the one-loop order contribution vanishes, then will
vanish to all orders of perturbation theory. As a by-product, the special case
in which is only of one-loop order, without further corrections, is
also covered. The examples of the N=2,4 supersymmetric Yang-Mills theories are
worked out in detail.Comment: 1+32 pages, LaTeX2e, typos correcte
Dynamic of Mutational Events in Variable Number Tandem Repeats of Escherichia coli O157:H7
VNTRs regions have been successfully used for bacterial subtyping; however, the hypervariability in VNTR loci is problematic when trying to predict the relationships among isolates. Since few studies have examined the mutation rate of these markers, our aim was to estimate mutation rates of VNTRs specific for verotoxigenic E. coli O157:H7. The knowledge of VNTR mutational rates and the factors affecting them would make MLVA more effective for epidemiological or microbial forensic investigations. For this purpose, we analyzed nine loci performing parallel, serial passage experiments (PSPEs) on 9 O157:H7 strains. The combined 9 PSPE population rates for the 8 mutating loci ranged from 4.4 × 10−05 to 1.8 × 10−03 mutations/generation, and the combined 8-loci mutation rate was of 2.5 × 10−03 mutations/generation. Mutations involved complete repeat units, with only one point mutation detected. A similar proportion between single and multiple repeat changes was detected. Of the 56 repeat mutations, 59% were insertions and 41% were deletions, and 72% of the mutation events corresponded to O157-10 locus. For alleles with up to 13 UR, a constant and low mutation rate was observed; meanwhile longer alleles were associated with higher and variable mutation rates. Our results are useful to interpret data from microevolution and population epidemiology studies and particularly point out that the inclusion or not of O157-10 locus or, alternatively, a differential weighting data according to the mutation rates of loci must be evaluated in relation with the objectives of the proposed study.Fil: Bustamante, Ana Victoria. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Sanso, Andrea Mariel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Segura, D. O.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Parma, Alberto Ernesto. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Lucchesi, Paula Maria Alejandra. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentin
South Dakota Fisheries: An Evaluation of a Chemical Immersion Marking Technique for Juvenile Yellow Perch and Application to a Stocking Assessment of Marsh-Reared Yellow Perch into Eastern South Dakota Lakes
Currently, yellow perch Perca flavescens stocking needs in South Dakota are met by intensive trap and transfer of juvenile and adult perch. The success of these stocking efforts is largely undocumented, primarily due to problems in distinguishing yellow perch produced within the recipient water body and stocked perch. We first developed a transfer-tank marking protocol to determine immersion duration and optimal concentration of oxytetracycline (OTC) hydrochloride needed to produce an effective mark. Then we validated the protocol for adult yellow perch and determined the persistence of OTC in edible muscle tissue. Marking results indicated that satisfactory OTC marks may be obtained in juvenile yellow perch using 600- to 700-ppm OTC for an immersion period of 6 to 8 h. OTC marks were evident in juvenile yellow perch otoliths and dorsal spines checked at 3 months post-immersion. Mark quality was observed to be slightly better in juvenile dorsal spines than otoliths. OTC marks in adult yellow perch were detectable at otolith margins at 9 d post-immersion. Adult muscle tissues were analyzed with high pressure liquid chromatography to quantify OTC residues. A nonlinear model (In epi-OTC [~g g-I] = 0.960 - 0.389*In time [h]; r\u27- = 0.99) describing the combined OTC base/epi residue relation to time indicated that no more than 0.5 ~g OTC g-I should be present at 73 h following immersion
Diacilglicerol induce la reacción acrosomal en espermatozoides humanos mediante la activación de RASGRP1 en ausencia de calcio y AMPc
El espermatozoide contiene un gran gránulo secretorio (acrosoma) que exocita frente a diferentes estÃmulos. Este proceso se denomina reacción acrosomal y es requerido para que ocurra la fertilización.
Nuestro laboratorio demostró que el diacilglicerol (DAG) estimula la exocitosis acrosomal induciendo un ciclo de retroalimentación positiva dependiente de PKC y fosfolipasa D1 (PLD1) que provee continuamente fosfatidilinositol 4,5-bifosfato (PIP2). Llamativamente, DAG es capaz de inducir la exocitosis en ausencia de calcio extracelular activando dos vÃas de señalización, una que conduce a la sÃntesis de IP3 y salida de calcio del reservorio acrosomal, y otra que conduce a la activación de Rab3A y ensamble de las SNAREs.Fil: Altamirano, K. .
Consejo Nacional de Investigaciones CientÃficas y TécnicasFil: Lucchesi, O..
Consejo Nacional de Investigaciones CientÃficas y TécnicasFil: Ruete. M.
Consejo Nacional de Investigaciones CientÃficas y TécnicasFil: Belmonte, S..
Consejo Nacional de Investigaciones CientÃficas y Técnica
Reduction of Couplings in Quantum Field Theories with applications in Finite Theories and the MSSM
We apply the method of reduction of couplings in a Finite Unified Theory and
in the MSSM. The method consists on searching for renormalization group
invariant relations among couplings of a renormalizable theory holding to all
orders in perturbation theory. It has a remarkable predictive power since, at
the unification scale, it leads to relations between gauge and Yukawa couplings
in the dimensionless sectors and relations involving the trilinear terms and
the Yukawa couplings, as well as a sum rule among the scalar masses and the
unified gaugino mass in the soft breaking sector. In both the MSSM and the FUT
model we predict the masses of the top and bottom quarks and the light Higgs in
remarkable agreement with the experiment. Furthermore we also predict the
masses of the other Higgses, as well as the supersymmetric spectrum, both being
in very confortable agreement with the LHC bounds on Higgs and supersymmetric
particles.Comment: 18 pages, 4 figures. To appear in the proceedings of LT-10, Varna.
Based on invited talks given at: LT-10, Varna; PACT-2013, Madrid; SQS'2013,
Dubna; CORFU 2013, Corfu, and in several invited seminar
Constraints from orbital motions around the Earth of the environmental fifth-force hypothesis for the OPERA superluminal neutrino phenomenology
It has been recently suggested by Dvali and Vikman that the superluminal
neutrino phenomenology of the OPERA experiment may be due to an environmental
feature of the Earth, naturally yielding a long-range fifth force of
gravitational origin whose coupling with the neutrino is set by the scale M_*,
in units of reduced Planck mass. Its characteristic length lambda should not be
smaller than one Earth's radius R_e, while its upper bound is expected to be
slightly smaller than the Earth-Moon distance (60 R_e). We analytically work
out some orbital effects of a Yukawa-type fifth force for a test particle
moving in the modified field of a central body. Our results are quite general
since they are not restricted to any particular size of lambda; moreover, they
are valid for an arbitrary orbital configuration of the particle, i.e. for any
value of its eccentricity . We find that the dimensionless strength coupling
parameter alpha is constrained to |alpha| <= 1 10^-10-4 10^-9 for 1 R_e <=
lambda <= 10 R_e by the laser data of the Earth's artificial satellite LAGEOS
II, corresponding to M_* >= 4 10^9 -1.6 10^10. The Moon perigee allows to
obtain |alpha| <= 3 10^-11 for the Earth-Moon pair in the range 15 R_e <=
lambda = 3 10^10 - 4.5 10^10. Our results
are neither necessarily limited to the superluminal OPERA scenario nor to the
Dvali-Vikman model, in which it is M_* = 10^-6 at lambda = 1 R_e, in contrast
with our bounds: they generally extend to any theoretical scenario implying a
fifth-force of Yukawa-type.Comment: LaTex2e, 18 pages, 4 figures, 1 table, 81 reference
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