• Journal of Microbiology
• /
• v.43 no.5
• /
• pp.391-397
• /
• 2005

Escherichia coli is a common inhabitant of the intestinal tracts of animals and humans. The intestines of animals also represent an ideal environment for the selection and transfer of antimicrobial resistance genes. The aim of this study was to investigate the resistance of E. coli isolated from chicken fecal samples to fluoroquinolones and to analyze the characterization of mutations in its gyrA and parC gene related resistance. One hundred and twenty-eight E. coil isolates showed a high resistance to ciprofloxacin (CIP; $60.2\%$), enrofloxacin (ENO; $73.4\%$) and norfloxacin (NOR; $60.2\%$). Missense mutation in gyrA was only found in the amino acid codons of Ser-83 or Asp-87. A high percentage of isolates ($60.2\%$) showed mutations at both amino acid codons. Missense mutation in parC was found in the amino acid codon of Ser-80 or Glu-84, and seven isolates showed mutations at both amino acid codons. Isolates with a single mutation in gyrA showed minimal inhibitory concentrations (MIC) for CIP (${\le}0.5\;to\;0.75{\mu}g/ml$), ENO (1 to $4{\mu}g/ml$) and NOR (0.75 to $4{\mu}g/ml$). These MIC were level compared to isolates with two mutations, one in gyrA and one in parC, and three mutations, one in gyrA and two in parC (CIP, ${\le}0.5\;to\;3{\mu}g/ml;\;ENO,\;2\;to\;32<{\mu}g/ml;\;NOR,\;1.5\;to\;6\;{\mu}g/ml$). However, the isolates with two mutation in gyrA regardless of whether there was a mutation in parC showed high MIC for the three fluoroquinolones (CIP, 0.75 to $32{\le}{\mu}g/ml;\;ENO,\;3\;to\;32{\le}{\mu}g/ml;\;NOR,\;3\;to\;32{\le}{\mu}g/ml$). Interestingly, although the E. coil used in this study was isolated from normal flora of chicken, not clinical specimens, a high percentage of isolates showed resistance to fluoroquinolones and possessed mutations at gyrA and parC associated with fluoroquinolone resistance.

• Journal of Ecology and Environment
• /
• v.47 no.3
• /
• pp.85-102
• /
• 2023

Background: Ecophysiological characteristics of Rosa rugosa were analyzed under different environmental factors from May to October 2022. Photosynthesis, chlorophyll fluorescence, chlorophyll content, leaf water content (LWC), osmolality, carbohydrate content, and total ion content were measured to compare the physiological characteristics of R. rugosa at two study sites (i.e., in large pots and in the Goraebul coastal sand dune area). Results: When R. rugosa was exposed to high temperatures, photosynthetic parameters including net photosynthetic rate (P_N) and stomatal conductance (g_s) in both experiment areas declined. In addition, severe photoinhibition occurs when R. rugosa is continuously exposed to high photosynthetically active radiation (PAR), and because of this, relatively low Y(II) (i.e., the quantum yield of photochemical energy conversion in photosystem II [PSII]) and high Y(NO) (i.e., the quantum yield of non-regulated, non-photochemical energy loss in PSII) in the R. rugosa of the pot were observed. As the high Y(NPQ) (i.e., the quantum yield of regulated non-photochemical energy loss in PSII) of R. rugosa in the coastal sand dune, they dissipated the excessed photon energy through the non-photochemical quenching (NPQ) mechanism when they were exposed to relatively low PAR and low temperature. Rosa rugosa in the coastal sand dune has higher chlorophyll a and carotenoid content. The high chlorophyll a + b and low chlorophyll a/b ratios seemed to optimize light absorption in response to low PAR. High carotenoid content played an important role in NPQ. As a part of the osmotic regulation in response to low LWCs, R. rugosa exposed to high temperatures and continuously high PAR used soluble carbohydrates and ions to maintain high osmolality. Conclusions: We found that F_v/F_m was lower in the potted plants than in the coastal sand dune plants, indicating the vulnerability of R. rugosa to high temperatures and PAR levels. We expect that the suitable habitat range for R. rugosa will shrink and move to north under climate change conditions.

• Journal of Satellite, Information and Communications
• /
• v.4 no.1
• /
• pp.28-35
• /
• 2009

We investigate the adaptive channel attenuation compensation of satellite OFDMA downlink users for minimum PAR (Peak to Average power Ratio), which is one of the main challenging issues in satellite OFDMA application. First, we analyze and compare PAR performances of two main different channel attenuation compensation schemes for OFDMA, i.e., PC-OFDMA (power control OFDMA) and AMC-OFDMA (Adaptive Modulation and Coding). While AMC-OFDMA maintains the constant transmission powers through entire user data subcarriers, PC-OFDMA has non-uniform subcarrier transmission powers because subcarrier powers are separately controlled to compensate each user's sub-channel attenuation. We newly found the fact that non-uniform subcarrier power in PC-OFDMA achieves rather reduced PAR compared to AMC-OFDMA and the amount of reduction becomes larger as the power differences among subcarriers increase. Also, there is an additional PAR reduction in PC-OFDMA by optimizing subcarrier grouping scheme for user's sub-channelization.

• Ocean Science Journal
• /
• v.41 no.4
• /
• pp.235-244
• /
• 2006

Determining 'photosynthetically active radiation' (PAR) is a key part of calculating phytoplankton productivity in a biogeochemical model. We explore the daily and seasonal variability in the ratio of PAR irradiance to total irradiance that occurred at Ieodo Ocean Research Station (IORS) in the East China Sea under clear-sky conditions in 2004 using a simple radiative transfer model (RTM). Meteorological data observed at IORS and aerosol optical properties derived from Aerosol Robotic Network observations at Gosan are used for the RTM. Preliminary results suggest that the use of simple PAR irradiance-ratio values is appropriate in calculating phytoplankton productivity as follows: an average of $0.44\;({\pm}0.01)$ in January to an average of $0.48\;({\pm}0.01)$ in July, with average daily variabilities over these periods of about $0.016\;({\pm}0.008)$ and $0.025\;({\pm}0.008)$, respectively. The model experiments demonstrate that variations in the major controlling input parameters (i.e. solar zenith angle, precipitable water vapor and aerosol optical thickness) cause PAR irradiance ratio variation at daily and seasonal timescales. Further, increases (>0.012) in the PAR irradiance ratio just below the sea-surface are positively correlated with high solar zenith angles and strong wind stresses relative to those just above the sea-surface.

• The Journal of Art Theory & Practice
• /
• no.6
• /
• pp.51-76
• /
• 2008

Nous obserbons dans le champs de l'art aujourd' hui, le changement radical provoquant $\'{e}$tant donn$\'{e}$ que le pouvoir du march$\'{e}$ de l'art s'augmente de plus en plus. C'est pour cela que le champ du discours de l'art n'est actuellement plus form$\'{e}$ par des notions esth$\`{e}$tiques artistiques, mais par celles qui sont r$\'{e}$serv$\'{e}$es au domaine de l'$\'{e}$conomie et du march$\'{e}$. Il n'est plus significatif de croire la valeur esth$\`{e}$tique de l'oeuvre d'art, puisque l'esth$\`{e}$tique elle-m$\^{e}$me ne fonctionne plus. Par contre, le syst$\`{e}$me de donner le prix $\`{a}$ l'oeuvre d'art fonctionne rigoureusement. En plus, cette situation s'aggrave $\'{e}$tant donn$\'{e}$ que la mondialisation du march$\'{e}$ de l'art s'installe avec rapidit$\'{e}$. Malgr$\'{e}$ la mondialisation de l'art, des gens qui habitent par exemple $\`{a}$ S$\'{e}$oul ne peuvent pas s' approcher facilement de ce qui se passe $\`{a}$ New York, le vrai centre de l'art contemporain. Dans cette situation, le champ de discours de l'art n'a pas d'autre solution de se r$\'{e}$tr$\'{e}$cir remaquablement et le sujet de discussion sur le grand art est remplac$\'{e}$ par celui du success de l'art. Cette recherche est arriv$\'{e}$e $\`{a}$ remarquer que le syst$\`{e}$me du foire internationale de l'art fonctionne comme une locomotive dans le march$\'{e}$ de l'art qui est le vrai dominateur de l'art contemporain. Aujourd'hui les grands clients du monde de l'art et les jeunes sp$\'{e}$ctateurs, les clients de l'avenir s'assemblent autour de quelques foires internationales r$\'{e}$put$\'{e}$s qui ont de l'autorit$\'{e}$. C'est ainsi que l'achat et la vante de l'oeuvres d'art est suffisamment mondialis$\'{e}$ et que le syst$\`{e}$me local du march$\'{e}$ est d$\'{e}$rang$\'{e}$ et s'$\'{e}$ffondr$\'{e}$gravement. Malgr$\'{e}$ la diff$\'{e}$rence significative, la majorit$\'{e}$ des galeries d'art lacaux s'oblige de suivre $\`{a}$ la suite du style du foire internationale de l'art. C'est la raison pour laquelle que cette recherche se fait une id$\'{e}$e nette que la prosp$\'{e}$rit$\'{e}$ actuelle du march$\'{e}$ de l'art n'est que la situation $\'{e}$conomique ou financi$\`{e}$re. A ce stade de la r$\'{e}$flexion, cette recherche arrivera $\`{a}$ poser une question primordiale ci-dessous: "Si l'art qu'on $\`{a}$ l'intention de proclamer ne serai plus possible de faire r$\'{e}$fl$\'{e}$chir sur la libert$\'{e}$ et la solidarit$\'{e}$ humain, la dignit$\'{e}$ de l'homme, cet art n'est plus autre chose que l'insignifiance. Au lieu de parcourir divers ph$\'{e}$nom$\`{e}$ne du march$\'{e}$ de l'art aujourd'hui, cette recherche fixera son attention sur la r$\'{e}$alit$\'{e}$ du foire internationales de l'art. Dans ce context, cette recherche sera compos$\'{e}$e par trois chapitres donc le premi$\`{e}$re essayera de r$\'{e}$pondre $\'{a}$ la question de son influence extraodinairement puissante. Le deuxi$\`{e}$me chapitre essayera d'analiser la r$\'{e}$alit$\'{e}$ et la source du pouvoir du foire internationale de l'art. Nous essayeront au troisi$\`{e}$me chapitre de configurer le point de vue critique qui permettra de bien comprendre notre sujet.

• Journal of Korean Philosophical Society
• /
• v.131
• /
• pp.303-330
• /
• 2014

Les avis des philosophes sur la mort sont $diff{\acute{e}}rentes$ selon leurs visions du monde. Certains essaient de surmonter la peur sur la mort, en $n{\acute{e}}gligeant$ la mort, et certains essaient de vivre le vraie vie par la $m{\acute{e}}ditation$ de la mort. Chez Kierkegaard la notion de la mort se $pr{\acute{e}}sente$ comme key-world $tr{\grave{e}}s$ important, et cela signifie qu'il parle par la mort une vie $s{\acute{e}}rieuse$ et vraie. Pour Kierkegaard la mort signifie d'abord la mort de la vie mondaine ou la $n{\acute{e}}gation$ de soi, cela est en faveur de sa conception de la nature humaine $o{\grave{u}}$ l'homme est fondamentalement un ${\hat{e}}tre$ $probl{\grave{e}}matique$ et ${\grave{a}}$ la fois ceuli qui a un rapport avec $l^{\prime}{\acute{e}}ternel$. Le $d{\acute{e}}sespoir$ de l'homme sur la vie $pr{\acute{e}}sente$ peut devenir 'la maladie qui entraîne la mort' c'est-${\grave{a}}$-dire la mort spirituelle, mais il peut donner aussi une chemin par laquelle l'homme se dirige en tant qu'individu vers l'Absolu. Chez lui ${\hat{e}}tre$ $s{\acute{e}}rieux$ signifie devenir existentiellement par la $n{\acute{e}}gation$ de soi. Et l'absence de la $sinc{\acute{e}}rit{\acute{e}}$ signifie l'absence de soi en tnat $qu^{\prime}{\hat{e}}tre$ spirituel. Ainsi la $pens{\acute{e}}e$ $s{\acute{e}}rieuse$ sur la mort $n^{\prime}{\acute{e}}tant$ autre chose que de penser la mort comme la partie de $l^{\prime}{\hat{e}}tre$ $pr{\acute{e}}sent$, elle devient la source ${\acute{e}}nergique$ qui permet de vivre pleinement le $pr{\acute{e}}sent$ comme $r{\acute{e}}alit{\acute{e}}$ $li{\acute{e}}$ ${\acute{a}}$ $l^{\prime}{\acute{e}}ternit{\acute{e}}$. Sa $pens{\acute{e}}e$ $s{\acute{e}}rieuse$ sur la mort permet d'avoir une conviction religieuse par laquelle l'homme peut penser la mort corporelle comme aventure $li{\acute{e}}e$ ${\grave{a}}$ $l^{\prime}{\acute{e}}ternit{\acute{e}}$ et par laquelle l'homme peut penser aussi la vie $apr{\grave{e}}s$ la mort comme vraie vie que les justes avaient $d{\acute{e}}sir{\acute{e}}s$. Cette $pens{\acute{e}}e$ de Kierkegaard sur la mort signifie le sens $m{\acute{e}}taphysique$ sur la mort au sens $o{\grave{u}}$ elle est une $r{\acute{e}}alit{\acute{e}}$ $v{\acute{e}}cue$, et aussi la $pens{\acute{e}}e$ qui ${\acute{e}}claircit$ la sagesse des philosophes antiques ${\grave{a}}$ la perspective $chr{\acute{e}}tienne$ qui dit philosopher, c'est apprendre ${\grave{a}}$ mourir.

• Biomedical Science Letters
• /
• v.26 no.2
• /
• pp.120-126
• /
• 2020

Fluoroquinolone (FQ) resistant uropathogenic Escherichia coli (UPEC) have become a major problem in urinary tract infections (UTIs). The purpose of this study was to compare the quinolone resistance-determining region (QRDR) and plasmid mediated quinolone resistance (PMQR) determinants of FQ resistant UPEC between 1989 and 2010-2014. A total of 681 strains of UPEC clinical isolates was collected from Korean healthcare facility in 1989 (123 strains) and in 2010-2014 (558 strains). The minimum inhibitory concentrations (MICs) of FQs were determined by agar dilution method. QRDRs (gyrA, gyrB, parC and parE) and PMQR determinants (qnrA, qnrB, qnrS, aac(6')-Ib-cr and qepA) were analyzed polymerase chain reaction and sequencing method. Among 681 isolates, FQ resistant UPEC were 3 strains (2.4%) in 1989 isolates and 220 strains (39.4%) in 2010-2014 isolates. The rate of the FQ resistant UPEC strains in 2010-2014 isolates was increased than that of in 1989 isolates. UPEC isolates from 1989 and 2010-2014 were shown to carry mutations in gyrA (Ser83 and Asp87), gyrB (Ser464 and Thr469), parC (Ser80 and Glu84) and parE (Glu460, Ser458, Ile464 and Leu445). The most common mutations of QRDRs in 1989 isolates were Ser83Leu and Asp87Gly in gyrA and Ser80Ile in parC (2 strains: 66.7%) while those in 2010-2014 isolates were Ser83Leu and Asp87Asn in gyrA and Ser80Il2 and Glu84Val in parC (88 strains: 40.0%). PMQR determinants were detected only in 2010-2014 UPEC strains (47 strains: 21.4%).

• Korean Journal of Microbiology
• /
• v.50 no.3
• /
• pp.185-190
• /
• 2014

The aim of this study was to investigate the prevalence of quinolone resistant E. coli from raw bulk milk and to characterize the resistance determinants. In this study, the gyrA, gyrB, parC, and parE quinolone resistance determining regions (QRDR) were sequenced from quinolone resistant E. coli isolates. Also, the presence of plasmid-mediated quinolone resistance (PMQR) and the expression of efflux pump genes based on quantitative real-time PCR (qRT-PCR) were investigated. Of the 487 coliform bacteria, 9 strains showed nalidixic acid resistance, and 6 of the 9 nalidixic acid resistant isolates were also ciprofloxacin resistant. These 9 strains had a single mutation at codon 83 (S83L) in gyrA, 2 of them had double mutations at codon 83 and 87 (S83L and D87N) in gyrA and 3 of the 9 isolates had single mutations at codon 80 (S80I) in parC. None of the 9 isolates harbored PMQR determinants. Compared with wild-type E. coli ATCC 25922, an over-expression of the acrB gene (2.15-5.74 fold), encoding the pump component of the AcrAB-TolC efflux pump was observed in 4 of 6 ciprofloxacin resistant isolates. This study identified the quinolone resistance mechanism of E. coli isolated from raw milk samples in Gyeonggi-do.

• YAKHAK HOEJI
• /
• v.60 no.1
• /
• pp.1-7
• /
• 2016

The aim of this study was to investigate the prevalence of quinolone resistant E. coli from retail meat and to characterize the resistant determinants. Determination of minimum inhibitory concentration, the sequence analysis of gyrA, gyrB, parC, and parE quinolone resistance determining regions (QRDR), the presences of plasmid mediated quinolone resistance (PMQR) and the expression of efflux pump genes were investigated. Of the total 277 retail meat samples, 67 coli form bacteria were isolated. 15 of 67 isolates showed nalidixic acid resistance and 7 of 15 nalidixic acid resistant isolates were also resistant to ciprofloxacin, moxifloxacin and levofloxacin. 11 of 15 nalidixic acid resistant strains were isolated from chicken, 2 of 15 were isolated from beef and 2 of 15 were isolated from pork samples. 11 of 15 nalidixic acid resistant strains have single mutation at codon 87 (D87N or D87G) in gyrA, 2 of 11 gyrA mutants have double mutations at codon 86 and 87 (L86A and L87I) in parC with mutations at codon 434+445+465 or 429 in gyrB. 2 of 15 resistant isolates harbored qnrS, a PMQR determinant. Over expression of the acrB gene, efflux pump gene (3.93~16.53 fold), was observed in 10 of 15 resistant isolates.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.3
• /
• pp.247-254
• /
• 2014

To investigate the acquisition of quinolone resistance, we examined mutations in the quinolone resistance-determining region (QRDR) of type II topoisomerase genes in ciprofloxacin (CIP)-resistant clinical isolates and in vitro mutants of Streptococcus parauberis. The CIP-resistant clinical isolates had one base change responsible for a Ser-79${\rightarrow}$Thr in the QRDR of parC. However, the CIP-resistant in vitro mutants had an altered QRDR of parC (Ser-79${\rightarrow}$Ile) that differed from that of the isolates. None of the CIP-resistant S. parauberis clinical isolates or in vitro mutants exhibited amino acid changes in gyrA or gyrB. However, even though involvement in the increased resistance was not clear, an Arg-449${\rightarrow}$Ser mutation outside of the QRDR of parE was detected in CIP-resistant mutant 2P1. These results suggest that the topoisomerase IV gene, parC (and possibly parE, as well), is the primary ciprofloxacin target in S. parauberis. Additionally we established a high-resolution melting (HRM) assay capable of detecting the dominant mutation in four type II topoisomerase genes conferring ciprofloxacin resistance. These rapid and reliable assays may provide a convenient method of surveillance for genetic mutations conferring antibiotic resistance.