1,026 research outputs found
Bioremediation of n-alkanes and the formation of biofloccules by Rhodococcus erythropolis NTU-1 under various saline conditions and sea water
No full text
Population Genetic Structure among Intra-Annual Arrival Waves of the Japanese Eel Anguilla japonica in Northern Taiwan
No full textPopulation genetic structure among intraannual
arrival waves of the Japanese eel Anguilla japonica in northern Taiwan. Zoological Studies 46(5): 583-
590. A previous study showed that the Japanese eel Anguilla japonica Temminck and Schlegel is not a panmictic
species, as it is divided into low- and high-latitude groups, but it shows no significant genetic differentiation
among year cohorts in the same habitat. However, based on hatching dates back-calculated from otolith of
elvers recruited in Taiwan in the winter, the arrival waves of elvers are from different intra-annual cohorts with
separate spawning times. To test if temporal genetic differentiation exists within intra-annual cohorts, 7 polymorphic
microsatellite DNA loci were examined. Four arrival waves of Japanese eel elvers were collected from
a single location in northern Taiwan from Nov. 2000 to Mar. 2001. Deviations from Hardy-Weinberg equilibrium
were found in three of the 7 loci after the Bonferroni correction, and five of the 7 loci were used for a genetic
variation test. No significant genetic differentiation was observed among the overall sample (FST = 0.0029, p =
0.173), and subtle, but significant, differentiation was only found between temporal cohorts of Nov. and Dec.
2000 (FST = 0.0111, p = 0.008). The phylogenetic tree indicates patchiness among elver waves with samples of
Nov. 2000 significantly separated from the others. The assignment test, however, showed a high mixing rate
among each cohorts. These results indicate that arrival waves of elvers in consecutive months at the same
habitat exhibit subtle genetic patchiness but overall lack significant temporal genetic variations
Vero cell-derived inactivated West Nile (WN) vaccine induces protective immunity against lethal WN virus infection in mice and shows a facilitated neutralizing antibody response in mice previously immunized with Japanese encephalitis vaccine
No full textAbstractA novel Vero cell-derived inactivated WN vaccine (WN-VAX) was prepared from virus strain NY99-35262. Two immunizations with WN-VAX induced high levels of neutralizing antibody to WN virus. All immunized mice were protected against challenge with a lethal dose of WN virus. No WN viremia was detected, and the level of WN virus-neutralizing antibody increased rapidly. WN-VAX was then examined for immunogenicity in mice previously immunized with Japanese encephalitis vaccine (JE-VAX). Immunization with WN-VAX induced WN virus-neutralizing antibody in all mice previously immunized with JE-VAX but in only half of the control mice at 10 weeks. These results indicate that WN-VAX induced complete protective immunity against lethal WN infection and that the WN-VAX-induced antibody response is facilitated in JE-VAX-immunized mice. This WN-VAX is thus a candidate WN vaccine for humans
The Oxidation of Carbon Monoxide on W(111) surface and Wn (n=10\ue215) nanoparticles
No full textThis dissertation employs the density functional theory (DFT) to investigate the oxidation of carbon monoxide (CO) on the W(111) surface and on the surface of Wn (n=10\ue215) nanoparticles. Since the properties of materials are significantly dependent on material size, we look into the influence of both the size and surface structure of tungsten catalysts on the CO oxidation process. The work contains two parts.
Part 1: The adsorption and dissociation of O2 and CO on W(111) surface and Wn (n=10\ue215) nanoparticles. The chemical adsorption of O2 and CO on solid catalysts plays a very important role in heterogeneous catalysis for the CO oxidation reaction. The configurations, adsorption energies, vibration frequencies and electronic structures of adsorbates on W(111) and Wn (n=10\ue215) nanoparticles have been calculated to investigate their surface activity. The results indicate that adsorption of O2 and CO on Wn (n=10\ue215) nanoparticles are more stable compared to on the W(111) surface. The minimum energy pathways and transition states of chemical reaction processes on metal surfaces were also studied by the nudged elastic band (NEB) method. The dissociation barriers of O2 chemisorbed on Wn (n=10\ue215) nanoparticles are smaller those for the W(111) surface. Our results demonstrate that both the surface structure and size of metal significantly influence the adsorption and dissociation properties of adsorbates. Density functional theory-molecular dynamics (DFT-MD) simulation was also adapted to clarify the mechanism of O2 deposition on the W(111) surface. Observations of the variations of energy and bond lengths as a function of time show that the interaction between O2 and W atoms weakens the O\ue2O bond, giving rise to the dissociation process. We conclude that the dissociation probability of an O2 molecule is affected by chemisorbed O2 coverage in the vicinity.
Part 2: The mechanism of CO oxidation on W(111) and Wn nanoparticles.
The oxidation of the CO molecule on transition metals usually follows two reaction pathways, either the Eley-Rideal (ER) mechanism or the Langmuir-Hinshelwood (LH) mechanism. In the ER mechanism, the CO molecule in the gas phase reacts directly with activated O2. The LH mechanism generally involves a few elementary steps, namely the co-adsorption of the O2 and CO molecules, O2 dissociation to form atomic oxygen, diffusion of atomic oxygen, and desorption of CO2. The oxidation of CO on a W10 nanoparticle surface and the W(111) surface are investigated by DFT calculations. Three pathways were studied in this dissertation: (i) CO + O2\ue2CO2 + O, (ii) CO + O2\ue2CO + O + O\ue2CO2 + O and (iii) CO + O\ue2CO2 via both LH and ER mechanisms. The calculated results show that CO oxidation on both the W10 nanoparticle and W(111) surfaces follow the ER rather than the LH mechanism. The CO oxidation on the W10 nanoparticle and W(111) surfaces occurs most easily via pathway (i) as compared to other two
The association between telomerase activity and expression of its RNA component (hTR) in breast cancer patients: the importance of DNase treatment
Full text linkTelomerase is a ribonucleoprotein enzyme that compensates for the telomere length shortening
which occurs during the cell cycle. Telomerase activity has been detected in most tumours but not
in somatic cells. However, hTR; the RNA component of telomerase; has been reported to be
universally expressed in both cancerous and non-cancerous tissues. Tumour samples from 50
patients with primary invasive breast cancer were collected. The TRAP assay was used to detect
telomerase activity. RT-PCR on cDNA and DNased cDNA samples and control groups was used
to detect the expression of hTR, GAPDH and PGM1 genes. Seventy-two percent of samples
showed telomerase activity. DNA contamination was detected in 36 (72%) of RNA samples.
Without performing DNase treatment, 49 (98%) of all samples showed hTR expression, but with
the application of this strategy, hTR expression decreased from 98% to 64%. A significant
association (p < 0.001) between hTR expression and telomerase activity was observed. Among the
32 hTR positive samples, 30 had telomerase activity and among the 18 hTR negative samples,
telomerase activity was observed in 6 cases. Thus the application of this strategy could provide an
applicable tool to use instead of the TRAP assay thus facilitating telomerase research in cancer
genetic investigations
Toward monitoring and estimating the size of the HFO-contaminated seabed around a shipwreck using MBES backscatter data
No full textFunding Information: The authors are grateful to three anonymous reviewers for their constructive criticism and valuable comments. The authors express their gratitude to the Maritime Institute in Gdansk for making the final version of the report (Maritime Institute in Gdansk, 2016) available. The second author appreciates the support of the Gdynia Maritime University in funding this research through internal grant WN/PZ/2021/02. Funding Information: The second author appreciates the support of the Gdynia Maritime University in funding this research through internal grant WN/PZ/2021/02 . Publisher Copyright: © 2021Despite a progressive reduction of oil spills caused by the activity of maritime transportation, the latent sources of pollution still exist. Although the harmful impact of heavy fuel oil (HFO) on the marine environment is widely known, many shipwrecks cause contamination of the surrounding areas. In this paper, an approach to monitor the area of the HFO spill around a shipwreck is made using a bottom backscattering strength (BBS) obtained by a multibeam echosounder (MBES). As a case study, the s/s Stuttgart wreck located in the Gulf of Gdansk (Poland) is verified. Two different measurement campaigns have been carried out in shallow waters using low (190 kHz) and high (420 kHz) MBES frequency. The results indicate that the polluted area around s/s Stuttgart was estimated at 49.1 ha, which is around 18.3% more in comparison to the geological surveys made four years earlier.Peer reviewe
A scale invariant surface curvature estimator
No full textIn this paper we introduce a new scale invariant curvature measure, similarity curvature. We define a similarity curvature space which consists of the set of all possible similarity curvature values. An estimator for the similarity curvature of digital surface points is developed. Experiments and results applying similarity curvature to synthetic data are also presented. © 2006 Springer-Verlag
The Weight and Hopcount of the Shortest Path in the Complete Graph with Exponential Weights
No full textBoth the hopcount HN (the number of links) and the weight WN (the sum of the weights on links) of the shortest path between two arbitrary nodes in the complete graph KN with i.i.d. exponential link weights is computed. We consider the joint distribution of the pair (HN,WN) and derive, after proper scaling, the joint limiting distribution. One of the results is that HN and WN, properly scaled, are asymptotically independent.Delft Institute of Applied MathematicsElectrical Engineering, Mathematics and Computer Scienc
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