4,792 research outputs found
Rice Field Fish Farming Integrated with Rodent Pest Management in Cambodia
The effect of integrating rice field fish culture with rodent pest management was examined. The use of rodent pest management was effective for controlling rodent pests as well as containing fish within the rice field while potentially providing a free source of dietary protein (captured rats) to feed fish. The growth of fed (captured rats or dried fish) walking catfish hybrids (Clarias batrachus x Clarias macrocephalus) in the rice field over 3 months was significantly higher (51.5g, 7.8cm) than a treatment of unfed walking catfish hybrids (26.4g, 4.5cm) in the same rice fields. Fish culture was shown to contribute to a farmer's income (68,800 Riel) and provided a source of protein for the family's consumption. Both the fed and unfed products were found to be palatable and accepted by a test group with 24% of the test group selecting fed fish and 21% selecting unfed fish as their first choice from 5 fish products. This pilot study and a preliminary survey in Kampong Cham province indicate that this technology will be useful for farmers to improve rodent management practices while supplementing income through fish sale and providing a high protein diet for their families
Viability of competing field theories for the driven lattice gas
It has recently been suggested that the driven lattice gas should be
described by a novel field theory in the limit of infinite drive. We review the
original and the new field theory, invoking several well-documented key
features of the microscopics. Since the new field theory fails to reproduce
these characteristics, we argue that it cannot serve as a viable description of
the driven lattice gas. Recent results, for the critical exponents associated
with this theory, are re-analyzed and shown to be incorrect.Comment: 4 pages, revtex, no figure
Methods for 3-D vector microcavity problems involving a planar dielectric mirror
We develop and demonstrate two numerical methods for solving the class of
open cavity problems which involve a curved, cylindrically symmetric conducting
mirror facing a planar dielectric stack. Such dome-shaped cavities are useful
due to their tight focusing of light onto the flat surface. The first method
uses the Bessel wave basis. From this method evolves a two-basis method, which
ultimately uses a multipole basis. Each method is developed for both the scalar
field and the electromagnetic vector field and explicit ``end user'' formulas
are given. All of these methods characterize the arbitrary dielectric stack
mirror entirely by its 2\times2 transfer matrices for s- and p-polarization. We
explain both theoretical and practical limitations to our method. Non-trivial
demonstrations are given, including one of a stack-induced effect (the mixing
of near-degenerate Laguerre-Gaussian modes) that may persist arbitrarily far
into the paraxial limit. Cavities as large as 50 \lambda are treated, far
exceeding any vectorial solutions previously reported.Comment: For high-quality figures, visit
http://darkwing.uoregon.edu/~noeckel/papers.ph
Spatial stochastic resonance in 1D Ising systems
The 1D Ising model is analytically studied in a spatially periodic and
oscillatory external magnetic field using the transfer-matrix method. For low
enough magnetic field intensities the correlation between the external magnetic
field and the response in magnetization presents a maximum for a given
temperature. The phenomenon can be interpreted as a resonance phenomenon
induced by the stochastic heatbath. This novel "spatial stochastic resonance"
has a different origin from the classical stochastic resonance phenomenon.Comment: REVTex, 5 pages, 3 figure
The cap-snatching SFTSV endonuclease domain is an antiviral target
Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tick-borne virus with 12%-30% case mortality rates and is related to the Heartland virus (HRTV) identified in the United States. Together, SFTSV and HRTV are emerging segmented, negative-sense RNA viral (sNSV) pathogens with potential global health impact. Here, we characterize the amino-terminal cap-snatching endonuclease domain of SFTSV polymerase (L) and solve a 2.4-Å X-ray crystal structure. While the overall structure is similar to those of other cap-snatching sNSV endonucleases, differences near the C terminus of the SFTSV endonuclease suggest divergence in regulation. Influenza virus endonuclease inhibitors, including the US Food and Drug Administration (FDA) approved Baloxavir (BXA), inhibit the endonuclease activity in in vitro enzymatic assays and in cell-based studies. BXA displays potent activity with a half maximal inhibitory concentration (I
Growth suppressive effect of pegylated arginase in malignant pleural mesothelioma xenografts
BACKGROUND: Malignant pleural mesothelioma (MPM) is a difficult-to-treat global disease. Pegylated arginase (BCT-100) has recently shown anti-tumor effects in hepatocellular carcinoma, acute myeloid leukemia and melanoma. This study aims to investigate the effects of PEG-BCT-100 in MPM. METHODS: A panel of 5 mesothelioma cell lines (H28, 211H, H226, H2052 and H2452) was used to study the in vitro effects of BCT-100 by crystal violet staining. The in vivo effects of BCT-100 were studied using 211H and H226 nude mice xenografts. Protein expression (argininosuccinate synthetase, ornithine transcarbamylase, cleaved PARP, cleaved caspase 3, cyclins (A2, D3, E1 and H), CDK4 and Ki67) and arginine concentration were evaluated by Western blot and ELISA respectively. Cellular localization of BCT-100 was detected by immunohistochemistry and immunoflorescence. TUNEL assay was used to identify cellular apoptotic events. RESULTS: Argininosuccinate synthetase was expressed in H28, H226, and H2452 cells as well as 211H and H266 xenografts. Ornithine transcarbamylase was undetectable in all cell lines and xenograft models. BCT-100 reduced in vitro cell viability (IC50 values at 13-24 mU/ml, 72 h) across different cell lines and suppressed tumor growth in both 211H and H226 xenograft models. BCT-100 (60 mg/kg) significantly suppressed tumor growth (p < 0.01) with prolonged median survival (p < 0.01) in both xenograft models. Combining BCT-100 with pemetrexed or cisplatin conferred no additional benefits over single agents. Serum and intratumoral arginine levels were effectively decreased by BCT-100, associated with cytosolic accumulation of BCT-100 within tumor cells. Apoptosis (PARP cleavage in 211H xenografts; Bcl-2 downregulation, and cleavage of PARP and caspase 3 in H226 xenografts; positive TUNEL staining in both) and G1 arrest (downregulation of cyclin A2, D3, E1 and CDK4 in 211H xenografts; suppression of cyclin A2, E1, H and CDK4 in H226 xenografts) were evident with BCT-100 treatment. Furthermore, proliferative factor Ki67 was downregulated in BCT-100 treatments arms. CONCLUSIONS: BCT-100 suppressed tumor growth with prolonged median survival partially mediated by intratumoral arginine depletion resulting in apoptosis and G1 arrest in mesothelioma xenograft models. The findings provide scientific evidence to support further clinical development of BCT-100 in treatment of MPM.published_or_final_versio
Renormalization Flow of Bound States
A renormalization group flow equation with a scale-dependent transformation
of field variables gives a unified description of fundamental and composite
degrees of freedom. In the context of the effective average action, we study
the renormalization flow of scalar bound states which are formed out of
fundamental fermions. We use the gauged Nambu--Jona-Lasinio model at weak gauge
coupling as an example. Thereby, the notions of bound state or fundamental
particle become scale dependent, being classified by the fixed-point structure
of the flow of effective couplings.Comment: 25 pages, 3 figures, v2: minor corrections, version to appear in PR
Effects of differential mobility on biased diffusion of two species
Using simulations and a simple mean-field theory, we investigate jamming
transitions in a two-species lattice gas under non-equilibrium steady-state
conditions. The two types of particles diffuse with different mobilities on a
square lattice, subject to an excluded volume constraint and biased in opposite
directions. Varying filling fraction, differential mobility, and drive, we map
out the phase diagram, identifying first order and continuous transitions
between a free-flowing disordered and a spatially inhomogeneous jammed phase.
Ordered structures are observed to drift, with a characteristic velocity, in
the direction of the more mobile species.Comment: 15 pages, 4 figure
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