1,270 research outputs found
THE DECOMPOSITION OF CELLULOSE IN LAKE SOYANG, KOREA
For elucidating the degradation rates of phytoplankton, part of carbon cycle, the rates of cellulose breakdown were investigated at two sites in Lake Soyang. Cellulose films stained with Rmazol brilliant blue R were used as the substrate. The degradation rates were ranged betweeen 0.1-100 %. In summer and autumn, the cellulose films were completely decomposed in epilimnion of fish farm site, but only about 30 % of the dam site. The perfect degradation of cellulose at the fish farm site were due to the fish feed, which contains phosphate, and showed the possibility of new indicator of eutrophication. At the metalimnion, the rates were higher than other depth in summer and autumn.Article信州大学理学部付属諏訪臨湖実験所報告 7: 73-80(1991)departmental bulletin pape
International collaboration in science: The global map and the network
The network of international co-authorship relations has been dominated by
certain European nations and the USA, but this network is rapidly expanding at
the global level. Between 40 and 50 countries appear in the center of the
international network in 2011, and almost all (201) nations are nowadays
involved in international collaboration. In this brief communication, we
present both a global map with the functionality of a Google Map (zooming,
etc.) and network maps based on normalized relations. These maps reveal
complementary aspects of the network. International collaboration in the
generation of knowledge claims (that is, the context of discovery) changes the
structural layering of the sciences. Previously, validation was at the global
level and discovery more dependent on local contexts. This changing
relationship between the geographical and intellectual dimensions of the
sciences also has implications for national science policies.Comment: El Profesional de la Informaci\'on (2013, in press
Warm needle acupuncture for osteoarthritis: A systematic review and meta-analysis.
Warm needle acupuncture (WA) is considered a potential intervention in the treatment of osteoarthritis (OA). To systematically evaluate the clinical efficacy and safety of WA in the treatment of OA. Systematic review and meta-analysis METHODS: Fourteen databases were searched from their inception until May 2022. Randomized controlled trials (RCTs) of WA for treating OA were identified. Study selection and data extraction were performed by two independent reviewers. The Cochrane risk of bias tool and the Grading of Recommendations Assessment, Development and Evaluation program were used to assess all included RCTs. A total of 66 RCTs met the inclusion criteria for this review. Most of the included studies had an unclear risk of bias, and the certainty of the evidence was very low. Twenty-four RCTs compared the effects of WA with those of oral drug therapies. Meta-analysis showed superior effects of WA for the total effective rate (risk ratio (RR): 1.22, 95% confidence interval (CI): 1.17 to 1.27, I = 26%, p < 0.001, 24 studies, n = 2278), pain, and function. Eight RCTs compared the effects of WA+drug therapy, and meta-analysis showed favorable effects for the total effective rate (RR: 1.27, 95% CI: 1.18 to 1.35, I =0%, p < 0.001, 8 studies, n = 646). Eight RCTs compared the effects of WA and intra-articular sodium hyaluronate (IASH) injection on OA and found equivalent effects of WA on the symptoms of OA. Twenty-eight RCTs compared the effects of WA+IASH injection with those of IASH injection, and meta-analysis showed superior effects of WA+IASH in terms of the total effective rate (RR: 1.15, 95% CI: 1.11 to 1.19, I =27.3%, p < 0.001, 25 studies, n = 2208), pain, and function. None of the RCTs reported serious adverse events. WA may have some distinct advantages in the treatment of OA. However, well-designed RCTs with larger sample sizes are needed. [Abstract copyright: Copyright © 2022 The Author(s). Published by Elsevier GmbH.. All rights reserved.
Pathogenicity of the H1N1 influenza virus enhanced by functional synergy between the NPV100I and NAD248N pair
By comparing and measuring covariations of viral protein sequences from isolates of the 2009 pH1N1 influenza A virus (IAV), specific substitutions that co-occur in the NP-NA pair were identified. To investigate the effect of these co-occurring substitution pairs, the V100I substitution in NP and the D248N substitution in NA were introduced into laboratory-adapted WSN IAVs. The recombinant WSN with the covarying NPV100I-NAD248N pair exhibited enhanced pathogenicity, as characterized by increased viral production, increased death and inflammation of host cells, and high mortality in infected mice. Although direct interactions between the NPV100I and NAD248N proteins were not detected, the RNA-binding ability of NPV100I was increased, which was further strengthened by NAD248N, in expression-plasmid- transfected cells. Additionally, the NAD248N protein was frequently recruited within lipid rafts, indirectly affecting the RNA-binding ability of NP as well as viral release. Altogether, our data indicate that the covarying NPV100I-NAD248N pair obtained from 2009 pH1N1 IAV sequence information function together to synergistically augment viral assembly and release, which may explain the observed enhanced viral pathogenicity. © 2019 Kim et al.11Ysciescopu
Formation of Low-Molecular-Weight Dissolved Organic Nitrogen in Predenitrification Biological Nutrient Removal Systems and Its Impact on Eutrophication in Coastal Waters
To alleviate eutrophication in coastal waters, reducing nitrogen (N) discharge from wastewater treatment plants (WWTPs) by upgrading conventional activated sludge (CAS) to biological nutrient removal (BNR) processes is commonplace. However, despite numerous upgrades and successful reduction of N discharge from WWTPs, eutrophication problems persist. These unexpected observations raise the possibility that some aspects of BNR yield environmental responses as yet overlooked. Here, we report that one of the most common BNR processes, predenitrification, is prone to the production of low-molecular-weight dissolved organic N (LMW-DON), which is highly bioavailable and stimulates phytoplankton blooms. We found that in predenitrification BNR, LMW-DON is released during the post-aerobic step following the preanoxic step, which does not occur in CAS. Consequently, predenitrification systems produced larger amount of LMW-DON than CAS. In estuarine bioassays, predenitrification BNR effluents produced more phytoplankton biomass than CAS effluents despite lower N concentrations. This was also supported by stronger correlations found between phytoplankton biomass and LMW-DON than other N forms. These findings suggest that WWTPs upgraded to predenitrification BNR reduce inorganic N discharge but introduce larger quantities of potent LMW-DON into coastal systems. We suggest reassessing the N-removal strategy for WWTPs to minimize the eutrophication effects of effluents
The absence of the Kerr black hole in the Ho\v{r}ava-Lifshitz gravity
We show that the Kerr metric does not exist as a fully rotating black hole
solution to the modified Ho\v{r}ava-Lifshitz (HL) gravity with
and case. We perform it by showing that the Kerr metric does not
satisfy full equations derived from the modified HL gravity.Comment: 35 pages, no figure
Nonpropagation of massive mode on AdS2 in topologically massive gravity
Making use of Achucarro-Ortiz (AO) type of dimensional reduction, we study
the topologically massive gravity with a negative cosmological constant on AdS2
spacetimes. For a constant dilaton, this two-dimensional model also admits
three AdS2 vacuum solutions, which are related to two AdS3 and warped AdS3
backgrounds with an identification upon uplifting three dimensions. We carry
out the perturbation analysis around these backgrounds to find what is a
physically propagating field. However, it turns out that there is no
propagating massive mode on AdS2 background, in contrast to the Kaluza-Klein
(KK) type of dimensional reduction. We note that two dimensionally reduced
actions are different and thus, the non-equivalence of their on-shell
amplitudes is obtained.Comment: 19 pages, version to appear in EPJ
Dynamical Behavior of dilaton in de Sitter space
We study the dynamical behavior of the dilaton in the background of
three-dimensional Kerr-de Sitter space which is inspired from the low-energy
string effective action. The perturbation analysis around the cosmological
horizon of Kerr-de Sitter space reveals a mixing between the dilaton and other
fields. Introducing a gauge (dilaton gauge), we can disentangle this mixing
completely and obtain one decoupled dilaton equation. However it turns out that
this belongs to the tachyon. The stability of de Sitter solution with J=0 is
discussed. Finally we compute the dilaton absorption cross section to extract
information on the cosmological horizon of de Sitter space.Comment: 11 pages, reference added and a version to appear in PL
Polarons with a twist
We consider a polaron model where molecular \emph{rotations} are important.
Here, the usual hopping between neighboring sites is affected directly by the
electron-phonon interaction via a {\em twist-dependent} hopping amplitude. This
model may be of relevance for electronic transport in complex molecules and
polymers with torsional degrees of freedom, such as DNA, as well as in
molecular electronics experiments where molecular twist motion is significant.
We use a tight-binding representation and find that very different polaronic
properties are already exhibited by a two-site model -- these are due to the
nonlinearity of the restoring force of the twist excitations, and of the
electron-phonon interaction in the model. In the adiabatic regime, where
electrons move in a {\em low}-frequency field of twisting-phonons, the
effective splitting of the energy levels increases with coupling strength. The
bandwidth in a long chain shows a power-law suppression with coupling, unlike
the typical exponential dependence due to linear phonons.Comment: revtex4 source and one eps figur
The Volume of the Past Light-Cone and the Paneitz Operator
We study a conjecture involving the invariant volume of the past light-cone
from an arbitrary observation point back to a fixed initial value surface. The
conjecture is that a 4th order differential operator which occurs in the theory
of conformal anomalies gives when acted upon the invariant volume of the
past light-cone. We show that an extended version of the conjecture is valid
for an arbitrary homogeneous and isotropic geometry. First order perturbation
theory about flat spacetime reveals a violation of the conjecture which,
however, vanishes for any vacuum solution of the Einstein equation. These
results may be significant for constructing quantum gravitational observables,
for quantifying the back-reaction on spacetime expansion and for alternate
gravity models which feature a timelike vector field.Comment: 22 pages, no figures, 5 tables. Version 2 substantially extended to
cover nonzero spatial curvature, and with simplified derivation
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