Co-trimoxazole susceptibility tests improved with separate trimethoprim and sulfamethoxazole disks.

OpenAIRE

Amyes, S G

1981-01-01

It is impossible to test accurately bacterial susceptibility to the trimethoprim-sulfamethoxazole combination co-trimoxazole with a single combined susceptibility disk. However, a variety of factors still affect the result even when separate trimethoprim and sulfamethoxazole disks are used. Experiments with separate disks showed that the optimum conditions for testing the susceptibilities of enterobacteria to these drugs were to flood-seed an agar plate with an inoculum of 10(4) to 10(5) orga...

Disruption of the GDP-mannose synthesis pathway in Streptomyces coelicolor results in antibiotic hyper-susceptible phenotypes.

Science.gov (United States)

Howlett, Robert; Anttonen, Katri; Read, Nicholas; Smith, Margaret C M

2018-04-01

Actinomycete bacteria use polyprenol phosphate mannose as a lipid linked sugar donor for extra-cytoplasmic glycosyl transferases that transfer mannose to cell envelope polymers, including glycoproteins and glycolipids. We showed recently that strains of Streptomyces coelicolor with mutations in the gene ppm1 encoding polyprenol phosphate mannose synthase were both resistant to phage φC31 and have greatly increased susceptibility to antibiotics that mostly act on cell wall biogenesis. Here we show that mutations in the genes encoding enzymes that act upstream of Ppm1 in the polyprenol phosphate mannose synthesis pathway can also confer phage resistance and antibiotic hyper-susceptibility. GDP-mannose is a substrate for Ppm1 and is synthesised by GDP-mannose pyrophosphorylase (GMP; ManC) which uses GTP and mannose-1-phosphate as substrates. Phosphomannomutase (PMM; ManB) converts mannose-6-phosphate to mannose-1-phosphate. S. coelicolor strains with knocked down GMP activity or with a mutation in sco3028 encoding PMM acquire phenotypes that resemble those of the ppm1 - mutants i.e. φC31 resistant and susceptible to antibiotics. Differences in the phenotypes of the strains were observed, however. While the ppm1 - strains have a small colony phenotype, the sco3028 :: Tn5062 mutants had an extremely small colony phenotype indicative of an even greater growth defect. Moreover we were unable to generate a strain in which GMP activity encoded by sco3039 and sco4238 is completely knocked out, indicating that GMP is also an important enzyme for growth. Possibly GDP-mannose is at a metabolic branch point that supplies alternative nucleotide sugar donors.

Study of the magnetic susceptibilities of some plutonium derivatives

International Nuclear Information System (INIS)

Raphael, G.

1969-06-01

We present a detailed description of an automatic recording apparatus for magnetic susceptibility measurement of radioactive samples in the temperature range 4 K - 1200 K. We have measured the magnetic susceptibility of various plutonium compounds: - PuO 2 , Pu 2 O 3 , PuO 2-x , - PuS, Pu 2 S 3 , Pu 3 S 4 , (U x Pu 1-x )S - PuN - PuC 1-x (N,O,H,vacancy), Pu 2 C 3 , (U 0.85 Pu 0.15 )C. The curves of susceptibilities versus temperature show many magnetic transitions. The interpretation of these results shows the existence of magnetic moments carried by the 5 f electrons and localized on the metallic sites as well as the great influence of the 'crystal field' in all these compounds. (author) [fr

Mean magnetic susceptibility regularized susceptibility tensor imaging (MMSR-STI) for estimating orientations of white matter fibers in human brain.

Science.gov (United States)

Li, Xu; van Zijl, Peter C M

2014-09-01

An increasing number of studies show that magnetic susceptibility in white matter fibers is anisotropic and may be described by a tensor. However, the limited head rotation possible for in vivo human studies leads to an ill-conditioned inverse problem in susceptibility tensor imaging (STI). Here we suggest the combined use of limiting the susceptibility anisotropy to white matter and imposing morphology constraints on the mean magnetic susceptibility (MMS) for regularizing the STI inverse problem. The proposed MMS regularized STI (MMSR-STI) method was tested using computer simulations and in vivo human data collected at 3T. The fiber orientation estimated from both the STI and MMSR-STI methods was compared to that from diffusion tensor imaging (DTI). Computer simulations show that the MMSR-STI method provides a more accurate estimation of the susceptibility tensor than the conventional STI approach. Similarly, in vivo data show that use of the MMSR-STI method leads to a smaller difference between the fiber orientation estimated from STI and DTI for most selected white matter fibers. The proposed regularization strategy for STI can improve estimation of the susceptibility tensor in white matter. © 2014 Wiley Periodicals, Inc.

Quark number density and susceptibility calculation with one correction in mean field potential

International Nuclear Information System (INIS)

Singh, S. Somorendro

2016-01-01

We calculate quark number density and susceptibility of a model which has one loop correction in mean field potential. The calculation shows continuous increasing in the number density and susceptibility up to the temperature T = 0.4 GeV. Then the value of number density and susceptibility approach to the lattice result for higher value of temperature. The result indicates that the calculated values of the model fit well and the result increase the temperature to reach the lattice data with the one loop correction in the mean field potential. (author)

Insecticide susceptibility of the dengue vector Aedes aegypti (Diptera: culicidae in Makkah City, Saudi Arabia

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Al Thbiani Aziz

2011-06-01

Full Text Available Objective: To examine the insecticide susceptibility of Aedes aegypti (Ae. aegypti from various sites in Makkah City, Saudi Arabia. Methods: This was examined based on WHO standard procedures. Results: The larvae of Ae. aegypti were susceptible to all larvicides examined, but this susceptibility was more pronounced in wild populations, which tended to show tolerance to icon. Icon was the most effective larvicide with LC 50 values of 0.007 ppm and 0.012 ppm for the laboratory and field strains, respectively. Ae. aegypti adults exposed to lambda-cyhalothrin showed a low mortality rate in comparison with those exposed to deltamethrin and cyfluthrin. Conclusions: The results of the present study indicate differential susceptibility between field and laboratory larval populations. Wild larvae are less susceptible to insecticide treatments than their laboratory-bred counterparts. Taken together, these results suggest that tolerance and the tendency toward resistance to commonly used insecticides are present in Ae. aegypti populations throughout Makkah City, Saudi Arabia.

Magnetic susceptibility of molecular carbon: nanotubes and fullerite

Energy Technology Data Exchange (ETDEWEB)

Ramirez, A P; Haddon, R C; Zhou, O; Fleming, R M; Zhang, J; McClure, S M; Smalley, R E [AT T Bell Laboratories, Murray Hill, NJ (United States)

1994-07-01

Elemental carbon can be synthesized in a variety of geometrical forms, from three-dimensional extended structures (diamond) to finite molecules (C[sub 60] fullerite). Results are presented here on the magnetic susceptibility of the least well-understood members of this family, nanotubes and C[sub 60] fullerite. (1) Nanotubes represent the cylindrical form of carbon, intermediate between graphite and fullerite. They are found to have significantly larger orientation-averaged susceptibility, on a per carbon basis, than any other form of elemental carbon. This susceptibility implies an average band structure among nanotubes similar to that of graphite. (2) High-resolution magnetic susceptibility data on C[sub 60] fullerite near the molecular orientational-ordering transition at 259 K show a sharp jump corresponding to 2.5 centimeter-gram-second parts per million per mole of C[sub 60]. This jump directly demonstrates the effect of an intermolecular cooperative transition on an intramolecular electronic property, where the susceptibility jump may be ascribed to a change in the shape of the molecule due to lattice forces.

Preliminary soil-slip susceptibility maps, southwestern California

Science.gov (United States)

Morton, Douglas M.; Alvarez, Rachel M.; Campbell, Russell H.; Digital preparation by Bovard, Kelly R.; Brown, D.T.; Corriea, K.M.; Lesser, J.N.

2003-01-01

This group of maps shows relative susceptibility of hill slopes to the initiation sites of rainfall-triggered soil slip-debris flows in southwestern California. As such, the maps offer a partial answer to one part of the three parts necessary to predict the soil-slip/debris-flow process. A complete prediction of the process would include assessments of “where”, “when”, and “how big”. These maps empirically show part of the “where” of prediction (i.e., relative susceptibility to sites of initiation of the soil slips) but do not attempt to show the extent of run out of the resultant debris flows. Some information pertinent to “when” the process might begin is developed. “When” is determined mostly by dynamic factors such as rainfall rate and duration, for which local variations are not amenable to long-term prediction. “When” information is not provided on the maps but is described later in this narrative. The prediction of “how big” is addressed indirectly by restricting the maps to a single type of landslide process—soil slip-debris flows. The susceptibility maps were created through an iterative process from two kinds of information. First, locations of sites of past soil slips were obtained from inventory maps of past events. Aerial photographs, taken during six rainy seasons that produced abundant soil slips, were used as the basis for soil slip-debris flow inventory. Second, digital elevation models (DEM) of the areas that were inventoried were used to analyze the spatial characteristics of soil slip locations. These data were supplemented by observations made on the ground. Certain physical attributes of the locations of the soil-slip debris flows were found to be important and others were not. The most important attribute was the mapped bedrock formation at the site of initiation of the soil slip. However, because the soil slips occur in surficial materials overlying the bedrocks units, the bedrock formation can only serve as

The relationship of motion sickness susceptibility to learned autonomic control for symptom suppression

Science.gov (United States)

Cowings, P. S.; Toscano, W. B.

1982-01-01

Twenty-four men were randomly assigned to four equal groups matched in terms of their Coriolis Sickness Susceptibility Index (CSSI). Two groups of subjects were highly susceptible to motion sickness, and two groups were moderately susceptible. All subjects were given six C551 tests at 5-d intervals. Treatment Groups I (highly susceptible) and II (moderately susceptible) were taught to control their autonomic responses, using a training method called autogenic-feedback training (AFT) before the third, fourth, and fifth CSSI tests. Control groups III (highly susceptible) and IV (moderately susceptible) received no treatment. Results showed that both treatment groups significantly improved performance on CSSI tests after training; neither of the control groups changed significantly. Highly and moderately susceptible subjects in the two treatment groups improved at comparable rates. Highly susceptible control group subjects did not habituate across tests as readily as the moderately susceptible controls.

Genome-wide high-density SNP linkage search for glioma susceptibility loci: results from the Gliogene Consortium

DEFF Research Database (Denmark)

Shete, Sanjay; Lau, Ching C; Houlston, Richard S

2011-01-01

.S. families and obtained a maximum NPL score of 1.26 (P = 0.008) and the Z-score of 1.47 (P = 0.035). Accounting for the genetic heterogeneity using the ordered subset analysis approach, the combined analyses of 75 families resulted in a maximum NPL score of 3.81 (P = 0.00001). The genomic regions we have...... implicated in this study may offer novel insights into glioma susceptibility, focusing future work to identify genes that cause familial glioma.......-fold increased risk of glioma, the search for susceptibility loci in familial forms of the disease has been challenging because the disease is relatively rare, fatal, and heterogeneous, making it difficult to collect sufficient biosamples from families for statistical power. To address this challenge...

Apparent competition in canopy trees determined by pathogen transmission rather than susceptibility.

Science.gov (United States)

Richard Cobb; Ross Meentemeyer; David Rizzo

2010-01-01

Epidemiological theory predicts that asymmetric transmission, susceptibility, and mortality within a community will drive pathogen and disease dynamics. These epidemiological asymmetries can result in apparent competition, where a highly infectious host reduces the abundance of less infectious or more susceptible members in a community via a shared pathogen. We show...

Magnetic susceptibility of scandium-hydrogen and lutetium-hydrogen solid-solution alloys from 2 to 3000K

International Nuclear Information System (INIS)

Stierman, R.J.

1982-12-01

Results for pure Sc show that the maximum and minimum in the susceptibility discovered earlier are enhanced as the impurity level of iron in scandium decreases. The Stoner enhancement factor, calculated from low-temperature heat capacity data, susceptibility data, and band-structure calculations show Sc to be a strongly enhanced paramagnet. Below 2 0 K, the magnetic anisotropy between the hard and easy directions of scandium decreases linearly with decreasing temperature, tending toward zero at 0 K. The large increase in the susceptibility of Sc at lower temperatures indicates magnetic ordering. Pure Lu and Lu-H alloys showed an anisotropy in susceptibility vs orientation; thus the samples were not random polycrystalline samples. Pure Lu shows the shallow maximum and minimum, but the increase in susceptibility at low temperatures is larger than previously observed. The susceptibility-composition dependence of the Lu-H alloys also did not match other data. The susceptibility-composition dependence does not match the composition dependence of the electronic specific heat constant below 150 K, showing the electronic specific heat is being affected by terms other than phonon-electron and pure electron-electron interactions

Susceptibility to hypoxia and breathing control changes after short-term cold exposures

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Lyudmila T. Kovtun

2013-08-01

Full Text Available Background . Hypoxia is the reduction of oxygen availability due to external or internal causes. There is large individual variability of response to hypoxia. Objective . The aim of this study was to define individual and typological features in susceptibility to hypoxia, its interrelation with hypoxic and hypercapnic ventilatory responses (HVR and HCVR, respectively and their changes after cold acclimation. Design . Twenty-four healthy men were tested. HVR and HCVR were measured by the rebreathing method during hypoxic and hypercapnic tests, respectively. These tests were carried out in thermoneutral conditions before and after cold exposures (nude, at 13°C, 2 h daily, for 10 days. Susceptibility to hypoxia (sSaO2 was determined as haemoglobin saturation slope during hypoxic test. Results . It was found that HVR and HCVR significantly increased and susceptibility to hypoxia (sSaO2 tended to decrease after cold acclimation. According to sSaO2 results before cold exposures, the group was divided into 3: Group 1 – with high susceptibility to hypoxia, Group 2 – medium and Group 3 – low susceptibility. Analysis of variances (MANOVA shows the key role of susceptibility to hypoxia and cold exposures and their interrelation. Posterior analysis (Fisher LSD showed significant difference in susceptibility to hypoxia between the groups prior to cold acclimation, while HVR and HCVR did not differ between the groups. After cold acclimation, susceptibility to hypoxia was not significantly different between the groups, while HCVR significantly increased in Groups 1 and 3, HVR significantly increased in Group 3 and HCVR, HVR did not change in Group 2. Conclusions . Short-term cold exposures caused an increase in functional reserves and improved oxygen supply of tissues in Group 1. Cold exposure hypoxia has caused energy loss in Group 3. Group 2 showed the most appropriate energy conservation reaction mode to cold exposures. No relation was found between

Incidence and Antibiotic Susceptibility Pattern of Bacterial Isolates ...

African Journals Online (AJOL)

In vitro antibiotic susceptibility tests showed that Pseudomonas aeruginosa was susceptible to ceftazidime, ciprofloxacin and gentamicin while the enteric bacteria were generally more resistant to ceftazidime, gentamicin and ciprofloxacin. Conclusion: The findings show that there is a high rate of wound infection in Kano, ...

[Susceptibility and resistence of Pseudomonas aeruginosa to antimicrobial agents].

Science.gov (United States)

Gamero Delgado, M C; García-Mayorgas, A D; Rodríguez, F; Ibarra, A; Casal, M

2007-06-01

Pseudomonas aeruginosa is an opportunistic microorganism that is frequently the cause of nosocomial infections. Multiple mechanisms are involved in its natural and acquired resistance to many of the antimicrobial agents commonly used in clinical practice. The objective of this study was to assess the susceptibility and resistance patterns of P. aeruginosa strains isolated in Hospital Reina Sofia between 2000 and 2005, as well as to analyze the differences between intrahospital and extrahospital isolates in 2005 and to compare the results with those obtained in other studies. A total of 3,019 strains of P. aeruginosa from different hospitals and nonhospital settings were evaluated, taking into consideration their degree of sensitivity to different antibiotics. The MICs were determined by means of the Wider I automated system (Soria Melguizo), taking into consideration the criteria of susceptibility and resistance recommended by MENSURA. Results of the analysis showed that P. aeruginosa maintained similar levels of antimicrobial susceptibility during the period 2000-2005, with increased susceptibility to amikacin, gentamicin and tobramycin. There were also important differences in the degree of susceptibility between intrahospital and extrahospital strains, except for imipenem and fosfomycin. The intrahospital difference in susceptibility was also evaluated, emphasizing the importance of periodically studying susceptibility and resistance patterns of P. aeruginosa in each setting in order to evaluate different therapeutic guidelines, as it is not always advisable to extrapolate data from different regions. These differences can be explained by the different use of antibiotics in each center and the geographic variations of the resistance mechanisms of P. aeruginosa.

ANFIS modeling for the assessment of landslide susceptibility for the Cameron Highland (Malaysia)

Science.gov (United States)

Pradhan, Biswajeet; Sezer, Ebru; Gokceoglu, Candan; Buchroithner, Manfred F.

2010-05-01

Landslides are one of the recurrent natural hazard problems throughout most of Malaysia. In landslide literature, there are several approaches such as probabilistic, bivariate and multivariate statistical models, fuzzy and artificial neural network models etc. However, a neuro-fuzzy application on the landslide susceptibility assessment has not been encountered in the literature. For this reason, this study presents the results of an adaptive neuro-fuzzy inference system (ANFIS) using remote sensing data and GIS for landslide susceptibility analysis in a part of the Cameron Highland areas in Malaysia. Landslide locations in the study area were identified by interpreting aerial photographs and satellite images, supported by extensive field surveys. Landsat TM satellite imagery was used to map vegetation index. Maps of topography, lineaments, NDVI and land cover were constructed from the spatial datasets. Seven landslide conditioning factors such as altitude, slope angle, curvature, distance from drainage, lithology, distance from faults and NDVI were extracted from the spatial database. These factors were analyzed using an ANFIS to produce the landslide susceptibility maps. During the model development works, total 5 landslide susceptibility models were constructed. For verification, the results of the analyses were then compared with the field-verified landslide locations. Additionally, the ROC curves for all landslide susceptibility models were drawn and the area under curve values were calculated. Landslide locations were used to validate results of the landslide susceptibility map and the verification results showed 97% accuracy for the model 5 employing all parameters produced in the present study as the landslide conditioning factors. The validation results showed sufficient agreement between the obtained susceptibility map and the existing data on landslide areas. Qualitatively, the model yields reasonable results which can be used for preliminary land

Defense response of susceptible and resistant Biomphalaria alexandrina snails against Schistosoma mansoni infection

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Iman F. Abou-El-Naga

2012-09-01

Full Text Available In Egypt, Biomphalaria alexandrina is the intermediate host for Schistosoma mansoni. The fates of Schistosoma miracidia in the snails varies between different species of Biomphalaria. The internal defense system is one of the factors that influence the susceptibility pattern of the snails. The interaction between Biomphalaria snails and S. mansoni needs to be identified for each species, and even between the members of the same species with different degrees of susceptibility. In the present study, the first generation of susceptible and resistant parents of B. alexandrina was examined histologically at the 30th day post exposure. The study includes the characterization of the immune response, as expressed by tissue reactions, of susceptible and resistant B. alexandrina snails against S. mansoni. It was also designed to determine the impact of the resistance increase in parent snails, on the mechanisms of interaction of their offspring against infection. The results showed that the infection rate of the offspring from the susceptible parents was 92%. No susceptible offspring was produced from the resistant parents. When the parents were of equal number of susceptible and resistant snails, they gave an offspring with an infection rate of 20%. Susceptible snails that had susceptible parents showed a higher degree of susceptibility than those that had both susceptible and resistant parents. A common feature of the resistant snails was the absence of any viable parasites. The tissue reactions of the resistant snails having only resistant parents occurred at the site of miracidial penetration. In resistant snails for which susceptible ones were included in their parents, the reactions occurred in the deep tissues. These results characterized the immune response of B. alexandrina snails against Schistosoma infection which was found to occur by two different mechanisms. One type of defense occurs in highly resistant snails, and employs direct

Studies on maize inbred lines susceptibility to herbicides

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Stefanović Lidija

2010-01-01

Full Text Available This paper presents the analysis of results obtained during long- term studies on the response of maize inbred lines to herbicides. Under the agroecological conditions of Zemun Polje the response (reaction of maize inbred lines to herbicides of different classes was investigated. Biological tests were performed and some agronomic, morphological, physiological and biochemical parameters were determined when the response of maize inbred lines to herbicides was estimated. The use of active ingredients of herbicides from triazine, acetanilide, thiocarbamate to new chemical groups (sulfonylurea etc., have been resulted in changes in weed suppression and susceptibility of inbred lines. Obtained results show that effects of herbicides on susceptible maize genotypes can be different: they can slowdown the growth and development and affect the plant height; they can also affect the stages of the tassel and ear development and at the end they can reduced grain yield of the tested inbreds. Numerous studies confirmed the existence of differences in susceptibility level of maize genotypes in relation to herbicides. According to gained results the recommendations for growers are made on the possibility of the application of new herbicides in the hybrid seed production.

Influence of deformation on SCC susceptibility of austenitic stainless steel in PWR primary water

Energy Technology Data Exchange (ETDEWEB)

Kaneshima, Yoshiari; Totsuka, Nobuo; Nakajima, Nobuo [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

2001-09-01

Slow strain rate tests (SSRT) were carried out to evaluate the SCC susceptibility of four types of austenitic stainless steels (SUS304, SUS316, SUS304L and SUS316L) in PWR primary water. The influence of deformation on SCC susceptibility of SUS316 was studied. All types of stainless steel were susceptible to SCC, and the SCC susceptibility varied depending on the steel type. The comparison of the SSRT results and tensile test in air based on the reduction of area measurement showed that the SCC susceptibility increased with increasing the degree of deformation. For explaining the influence of deformation on SCC susceptibility, it is necessary to evaluate both intergranular and transgranular fractures. (author)

In Vitro Susceptibility Test of Different Clinical Isolates against Ceftriaxone

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Syed Hakim Masood

2010-06-01

Full Text Available Objectives: Because of the prevailing penicillin resistance in microorganisms, broad spectrum cephalosporins are used empirically specially in developing countries. The aim of this study is to determine the susceptibility pattern of different gram positive and gram negative pathogens against third generation cephalosporin-ceftriaxone to explore the existing effectiveness of this antibiotic.Methods: 180 clinical isolates of different gram positive and gram negative pathogens including P.mirabilis, S. typhi P.aeruginosa, E. coli, S. aureus and Klebsiella were collected from blood and urine samples of in-patients. 30 isolates of all species were tested against each of six brands of ceftriaxone using in vitro sensitivity tests by disc diffusion method (NCCLS criteria. The susceptibility limit was ≥21 mm zone of inhibition, while moderately susceptible was considered at 20-14 mm, and those isolates which showed >13 mm or no zone of inhibition were resistant to this antibacterial drug.Results: Ceftriaxone was found most effective against S. aureus. While 96.1% of the isolates showed susceptibility towards ceftriaxone, followed by E. coli (95%, P. aeruginosa (92.7%, K. pneumonia (89.4% and S. typhi (87.2%. P. mirabilis showed lowest susceptibility amongst all the test organisms (83.8%.Conclusion: Ceftriaxone can be used as a drug of choice in infections caused by S. aureus, E. coli, P. aurigenosa, K. pneumonia and S. typhi. However, it should be used with other antimicrobial agents in order to increase its effectiveness against P. mirabilis.

Antimicrobial Susceptibility Patterns of Brachyspira Species Isolated in Taiwan.

Science.gov (United States)

Yeh, Jih-Ching; Lo, Dan-Yuan; Chang, Shao-Kuang; Kuo, Hung-Chih

2018-03-13

Some members of the Brachyspira genus cause diseases such as swine dysentery (SD) and porcine intestinal (or colonic) spirochetosis. Severe economic losses are caused by decreased feed intake and increased feed conversion ratio, as well as costs associated with treatment and death. A loss of clinical efficacy of some antimicrobial agents authorized for treating SD has been observed in many countries. The aim of this study was to analyze the antimicrobial susceptibility of Brachyspira isolated from Taiwan and to investigate the mechanism of decreased susceptibility to macrolides. A total of 55 Brachyspira isolates obtained from the grower-finisher period were evaluated in this study. These isolates included B. hyodysenteriae (n = 37), B. murdochii (n = 11), B. pilosicoli (n = 5), B. intermedia (n = 1), and B. innocens (n = 1). Antimicrobial susceptibility testing was performed to examine 12 selected antimicrobial agents. The results showed that the 50% and 90% minimum inhibitory concentration (MIC) values of the tested macrolides were all >256 μg/ml. The MIC 50 of lincomycin, tiamulin, carbadox, olaquindox, ampicillin, amoxicillin, doxycycline, oxytetracycline, and gentamicin were 32, 1, ≤0.125, ≤0.125, 0.5, 0.25, 2, 2, and 2 μg/ml. The genetic basis of the decreased susceptibility to tylosin and lincomycin in Brachyspira spp. was investigated and the results showed a possible connection to the mutations at position A2058 and G2032 of the 23S rRNA gene. These findings demonstrated that, in Taiwan, there may be a decrease in susceptibility of Brachyspira spp. to antimicrobials commonly used for the treatment of SD.

Susceptibility Tensor Imaging (STI) of the Brain

Science.gov (United States)

Li, Wei; Liu, Chunlei; Duong, Timothy Q.; van Zijl, Peter C.M.; Li, Xu

2016-01-01

Susceptibility tensor imaging (STI) is a recently developed MRI technique that allows quantitative determination of orientation-independent magnetic susceptibility parameters from the dependence of gradient echo signal phase on the orientation of biological tissues with respect to the main magnetic field. By modeling the magnetic susceptibility of each voxel as a symmetric rank-2 tensor, individual magnetic susceptibility tensor elements as well as the mean magnetic susceptibility (MMS) and magnetic susceptibility anisotropy (MSA) can be determined for brain tissues that would still show orientation dependence after conventional scalar-based quantitative susceptibility mapping (QSM) to remove such dependence. Similar to diffusion tensor imaging (DTI), STI allows mapping of brain white matter fiber orientations and reconstruction of 3D white matter pathways using the principal eigenvectors of the susceptibility tensor. In contrast to diffusion anisotropy, the main determinant factor of susceptibility anisotropy in brain white matter is myelin. Another unique feature of susceptibility anisotropy of white matter is its sensitivity to gadolinium-based contrast agents. Mechanistically, MRI-observed susceptibility anisotropy is mainly attributed to the highly ordered lipid molecules in myelin sheath. STI provides a consistent interpretation of the dependence of phase and susceptibility on orientation at multiple scales. This article reviews the key experimental findings and physical theories that led to the development of STI, its practical implementations, and its applications for brain research. PMID:27120169

Quantitative susceptibility mapping of human brain at 3T: a multisite reproducibility study.

Science.gov (United States)

Lin, P-Y; Chao, T-C; Wu, M-L

2015-03-01

Quantitative susceptibility mapping of the human brain has demonstrated strong potential in examining iron deposition, which may help in investigating possible brain pathology. This study assesses the reproducibility of quantitative susceptibility mapping across different imaging sites. In this study, the susceptibility values of 5 regions of interest in the human brain were measured on 9 healthy subjects following calibration by using phantom experiments. Each of the subjects was imaged 5 times on 1 scanner with the same procedure repeated on 3 different 3T systems so that both within-site and cross-site quantitative susceptibility mapping precision levels could be assessed. Two quantitative susceptibility mapping algorithms, similar in principle, one by using iterative regularization (iterative quantitative susceptibility mapping) and the other with analytic optimal solutions (deterministic quantitative susceptibility mapping), were implemented, and their performances were compared. Results show that while deterministic quantitative susceptibility mapping had nearly 700 times faster computation speed, residual streaking artifacts seem to be more prominent compared with iterative quantitative susceptibility mapping. With quantitative susceptibility mapping, the putamen, globus pallidus, and caudate nucleus showed smaller imprecision on the order of 0.005 ppm, whereas the red nucleus and substantia nigra, closer to the skull base, had a somewhat larger imprecision of approximately 0.01 ppm. Cross-site errors were not significantly larger than within-site errors. Possible sources of estimation errors are discussed. The reproducibility of quantitative susceptibility mapping in the human brain in vivo is regionally dependent, and the precision levels achieved with quantitative susceptibility mapping should allow longitudinal and multisite studies such as aging-related changes in brain tissue magnetic susceptibility. © 2015 by American Journal of Neuroradiology.

Effects of o-aminoazotoluene on liver regeneration and p53 activation in mice susceptible and resistant to hepatocarcinogenesis

International Nuclear Information System (INIS)

Timofeeva, Olga A.; Eremeev, Artem V.; Goloshchapov, Andrey; Kalashnikova, Eugenia; Ilnitskaya, Svetlana; Setkov, Nikolai A.; Kobzev, Victor; Buzard, Gregory S.; Filipenko, Maxim L.; Kaledin, Vasily I.; Merkulova, Tatyana I.

2008-01-01

The susceptibility to hepatocellular carcinoma (HCC) varies greatly within human populations in response to environmental risk agents. The mechanisms underlying differential susceptibility are still largely unknown and need to be clarified to improve HCC chemoprevention and therapeutic treatment. Inbred rodent strains with established predispositions for hepatocarcinogenesis offer the opportunity to identify intrinsic susceptibility and resistance factors. Previously, we have characterized mouse strains showing differential susceptibility to o-aminoazotoluene (OAT) and established that susceptibility does not result from OAT metabolism or genotoxicity in the livers of resistant and susceptible mice. In this study we have found that OAT differently affects hepatocyte proliferation in mice after partial hepatectomy (PH). OAT inhibited hepatocyte proliferation by 60-80% in the livers of susceptible mice, whereas resistant mice showed less than 15% inhibition. The inhibition resulted in significant delay of hepatic mass recovery in susceptible mice. OAT induced p53 stabilization and transcriptional activation in response to carcinogen treatment to the same degree in both, susceptible and resistant mice. Taken together, our data support inhibition of hepatocyte proliferation as a major cause for increased mouse susceptibility to hepatocarcinogenesis, and acceleration of functional liver recovery may offer a way to increase resistance to hepatic neoplasms. These results may have relevance to clinical observations of HCCs and implications for HCC chemoprevention and treatment

Immunogenetics and genetic susceptibility in the pathogenesis of autoimmune hepatitis

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Das Anup K

2014-11-01

Full Text Available vAutoimmune hepatitis is a progressive liver disease. Its pathogenesis is unclear, but needs a ‘trigger’ to initiate the disease in a genetically susceptible person. The susceptibility is partly related to MHCII class genes, and more so with human leukocyte antigen (HLA. Several mechanisms have been proposed which, however, cannot fully explain the immunologic findings in autoimmune hepatitis. The susceptibility to any autoimmune disease is determined by several factors where genetic and immunological alterations, along with, environmental factor are active. MHCII antigens as a marker for AIH, or a predictor of treatment response and prognosis has been investigated. Since MHCII antigens show significant ethnic heterogeneity, mutations in MHCII may merely act as only precursors of the surface markers of immune cells, which can be of significance, because the changes in HLA and MHC are missing in certain populations. One such marker is the CTLA-4 (CD152 gene mutation, reported in the phenotypes representing susceptibility to AIH. Other candidate genes of cytokines, TNF, TGF-beta1 etc, have also been investigated but with unvalidated results. Paediatric AIH show differences in genetic susceptibility. Genetic susceptibility or resistance to AIH may be associated with polypeptides in DRB1 with certain amino-acid sequences. Understanding which genes are implicated in genesis and/or disease progression will obviously help to identify key pathways in AIH and provide better insights into its pathogenesis. But studies to identify responsible genes are complex because of the complex trait of AIH.

In vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and the correlation between triazoles susceptibility: Results from a five-year study.

Science.gov (United States)

Lei, J; Xu, J; Wang, T

2018-06-01

Candida spp. is a common cause of invasive fungal disease. The aim of this study was to examine the susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and explore the correlation between triazoles susceptibility. The antifungal susceptibility in the present study was measured by ATB Fungus 3 method, and the potential relationship was examined by obtaining the correlation of measured minimal inhibitory concentrations (MICs) of Candida spp. isolates. A total of 2099 clinical isolates of Candida spp. from 1441 patients were analyzed. The organisms included 1435 isolates of Candida albicans, 207 isolates of Candida glabrata, 65 isolates of Candida parapsilosis, 31 isolates of Candida krusei, 268 isolates of Candida tropicalis. Voriconazole and itraconazole were more active than fluconazole and against Candida spp. in vitro. The fluconazole, itraconazole and voriconazole MIC 90 (MIC for 90% of the isolates) for all Candida spp. isolates was 4mg/L, 1mg/L and 0.25mg/L, respectively. There was a moderate correlation between the fluconazole MIC s for Candida spp. isolates and this for voriconazole (R 2 =0.475; P<0.01) and itraconazole (R 2 =0.431; P<0.01). Voriconazole MICs for the Candida spp. isolates also correlated with those for itraconazole (R 2 =0.401; P<0.01). These observations suggest that the in vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole exhibits a moderate correlation. Published by Elsevier Masson SAS.

An application of adaptive neuro-fuzzy inference system to landslide susceptibility mapping (Klang valley, Malaysia)

Science.gov (United States)

Sezer, Ebru; Pradhan, Biswajeet; Gokceoglu, Candan

2010-05-01

Landslides are one of the recurrent natural hazard problems throughout most of Malaysia. Recently, the Klang Valley area of Selangor state has faced numerous landslide and mudflow events and much damage occurred in these areas. However, only little effort has been made to assess or predict these events which resulted in serious damages. Through scientific analyses of these landslides, one can assess and predict landslide-susceptible areas and even the events as such, and thus reduce landslide damages through proper preparation and/or mitigation. For this reason , the purpose of the present paper is to produce landslide susceptibility maps of a part of the Klang Valley areas in Malaysia by employing the results of the adaptive neuro-fuzzy inference system (ANFIS) analyses. Landslide locations in the study area were identified by interpreting aerial photographs and satellite images, supported by extensive field surveys. Landsat TM satellite imagery was used to map vegetation index. Maps of topography, lineaments and NDVI were constructed from the spatial datasets. Seven landslide conditioning factors such as altitude, slope angle, plan curvature, distance from drainage, soil type, distance from faults and NDVI were extracted from the spatial database. These factors were analyzed using an ANFIS to construct the landslide susceptibility maps. During the model development works, total 5 landslide susceptibility models were obtained by using ANFIS results. For verification, the results of the analyses were then compared with the field-verified landslide locations. Additionally, the ROC curves for all landslide susceptibility models were drawn and the area under curve values was calculated. Landslide locations were used to validate results of the landslide susceptibility map and the verification results showed 98% accuracy for the model 5 employing all parameters produced in the present study as the landslide conditioning factors. The validation results showed sufficient

Susceptibility tensor imaging (STI) of the brain.

Science.gov (United States)

Li, Wei; Liu, Chunlei; Duong, Timothy Q; van Zijl, Peter C M; Li, Xu

2017-04-01

Susceptibility tensor imaging (STI) is a recently developed MRI technique that allows quantitative determination of orientation-independent magnetic susceptibility parameters from the dependence of gradient echo signal phase on the orientation of biological tissues with respect to the main magnetic field. By modeling the magnetic susceptibility of each voxel as a symmetric rank-2 tensor, individual magnetic susceptibility tensor elements as well as the mean magnetic susceptibility and magnetic susceptibility anisotropy can be determined for brain tissues that would still show orientation dependence after conventional scalar-based quantitative susceptibility mapping to remove such dependence. Similar to diffusion tensor imaging, STI allows mapping of brain white matter fiber orientations and reconstruction of 3D white matter pathways using the principal eigenvectors of the susceptibility tensor. In contrast to diffusion anisotropy, the main determinant factor of the susceptibility anisotropy in brain white matter is myelin. Another unique feature of the susceptibility anisotropy of white matter is its sensitivity to gadolinium-based contrast agents. Mechanistically, MRI-observed susceptibility anisotropy is mainly attributed to the highly ordered lipid molecules in the myelin sheath. STI provides a consistent interpretation of the dependence of phase and susceptibility on orientation at multiple scales. This article reviews the key experimental findings and physical theories that led to the development of STI, its practical implementations, and its applications for brain research. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Non-susceptible landslide areas in Italy and in the Mediterranean region

Science.gov (United States)

Marchesini, I.; Ardizzone, F.; Alvioli, M.; Rossi, M.; Guzzetti, F.

2014-08-01

We used landslide information for 13 study areas in Italy and morphometric information obtained from the 3-arcseconds shuttle radar topography mission digital elevation model (SRTM DEM) to determine areas where landslide susceptibility is expected to be negligible in Italy and in the landmasses surrounding the Mediterranean Sea. The morphometric information consisted of the local terrain slope which was computed in a square 3 × 3-cell moving window, and in the regional relative relief computed in a circular 15 × 15-cell moving window. We tested three different models to classify the "non-susceptible" landslide areas, including a linear model (LNR), a quantile linear model (QLR), and a quantile, non-linear model (QNL). We tested the performance of the three models using independent landslide information presented by the Italian Landslide Inventory (Inventario Fenomeni Franosi in Italia - IFFI). Best results were obtained using the QNL model. The corresponding zonation of non-susceptible landslide areas was intersected in a geographic information system (GIS) with geographical census data for Italy. The result determined that 57.5% of the population of Italy (in 2001) was located in areas where landslide susceptibility is expected to be negligible. We applied the QNL model to the landmasses surrounding the Mediterranean Sea, and we tested the synoptic non-susceptibility zonation using independent landslide information for three study areas in Spain. Results showed that the QNL model was capable of determining where landslide susceptibility is expected to be negligible in the validation areas in Spain. We expect our results to be applicable in similar study areas, facilitating the identification of non-susceptible landslide areas, at the synoptic scale.

Grey matter correlates of susceptibility to scams in community-dwelling older adults.

Science.gov (United States)

Duke Han, S; Boyle, Patricia A; Yu, Lei; Arfanakis, Konstantinos; James, Bryan D; Fleischman, Debra A; Bennett, David A

2016-06-01

Susceptibility to scams is a significant issue among older adults, even among those with intact cognition. Age-related changes in brain macrostructure may be associated with susceptibility to scams; however, this has yet to be explored. Based on previous work implicating frontal and temporal lobe functioning as important in decision making, we tested the hypothesis that susceptibility to scams is associated with smaller grey matter volume in frontal and temporal lobe regions in a large community-dwelling cohort of non-demented older adults. Participants (N = 327, mean age = 81.55, mean education = 15.30, 78.9 % female) completed a self-report measure used to assess susceptibility to scams and an MRI brain scan. Results indicated an inverse association between overall grey matter and susceptibility to scams in models adjusted for age, education, and sex; and in models further adjusted for cognitive function. No significant associations were observed for white matter, cerebrospinal fluid, or total brain volume. Models adjusted for age, education, and sex revealed seven clusters showing smaller grey matter in the right parahippocampal/hippocampal/fusiform, left middle temporal, left orbitofrontal, right ventromedial prefrontal, right middle temporal, right precuneus, and right dorsolateral prefrontal regions. In models further adjusted for cognitive function, results revealed three significant clusters showing smaller grey matter in the right parahippocampal/hippocampal/fusiform, right hippocampal, and right middle temporal regions. Lower grey matter concentration in specific brain regions may be associated with susceptibility to scams, even after adjusting for cognitive ability. Future research is needed to determine whether grey matter reductions in these regions may be a biomarker for susceptibility to scams in old age.

A two-hour antibiotic susceptibility test by ATP-bioluminescence.

Science.gov (United States)

March Rosselló, Gabriel Alberto; García-Loygorri Jordán de Urries, María Cristina; Gutiérrez Rodríguez, María Purificación; Simarro Grande, María; Orduña Domingo, Antonio; Bratos Pérez, Miguel Ángel

2016-01-01

The antibiotic susceptibility test (AST) in Clinical Microbiology laboratories is still time-consuming, and most procedures take 24h to yield results. In this study, a rapid antimicrobial susceptibility test using ATP-bioluminescence has been developed. The design of method was performed using five ATCC collection strains of known susceptibility. This procedure was then validated against standard commercial methods on 10 strains of enterococci, 10 staphylococci, 10 non-fermenting gram negative bacilli, and 13 Enterobacteriaceae from patients. The agreement obtained in the sensitivity between the ATP-bioluminescence method and commercial methods (E-test, MicroScan and VITEK2) was 100%. In summary, the preliminary results obtained in this work show that the ATP-bioluminescence method could provide a fast and reliable AST in two hours. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Distribution and antibiotic susceptibility pattern of methicillin ...

African Journals Online (AJOL)

Distribution and antibiotic susceptibility pattern of methicillin-resistant Staphylococcus aureus isolates in a university Teaching hospital in Nigeria. ... Amoxycillin clavunanic acid and ciprofloxacin were most active with MRSA isolates showing 97% and 93.9% susceptibility to the two drugs respectively. Eighteen (54.5%) ...

Assessing MRI susceptibility artefact through an indicator of image distortion

Directory of Open Access Journals (Sweden)

Illanes Alfredo

2016-09-01

Full Text Available Susceptibility artefacts in magnetic resonance imaging (MRI caused by medical devices can result in a severe degradation of the MR image quality. The quantification of susceptibility artefacts is regulated by the ASTM standard which defines a manual method to assess the size of an artefact. This means that the estimated artefact size can be user dependent. To cope with this problem, we propose an algorithm to automatically quantify the size of such susceptibility artefacts. The algorithm is based on the analysis of a 3D surface generated from the 2D MR images. The results obtained by the automatic algorithm were compared to the manual measurements performed by study participants. The results show that the automatic and manual measurements follow the same trend. The clear advantage of the automated algorithm is the absence of the inter- and intra-observer variability. In addition, the algorithm also detects the slice containing the largest artefact which was not the case for the manual measurements.

Penicillin-susceptible Staphylococcus aureus: susceptibility testing, resistance rates and outcome of infection.

Science.gov (United States)

Hagstrand Aldman, Malin; Skovby, Annette; I Påhlman, Lisa

2017-06-01

Staphylococcus aureus (SA) is an important human pathogen that causes both superficial and invasive infections. Penicillin is now rarely used in the treatment of SA infections due to widespread resistance and a concern about the accuracy of existing methods for penicillin susceptibility testing. The aims of the present study were to determine the frequency of penicillin-susceptible SA isolates from blood and wound cultures in Lund, Sweden, and to evaluate methods for penicillin testing in SA. We also wanted to investigate if penicillin-susceptible isolates are associated with higher mortality. Hundred blood culture isolates collected 2008/2009, 140 blood culture isolates from 2014/2015, and 141 superficial wound culture strains from 2015 were examined. Penicillin susceptibility was tested with disk diffusion according to EUCAST guidelines, and results were confirmed with a cloverleaf assay and PCR amplification of the BlaZ gene. Patient data for all bacteraemia cases were extracted from medical records. The disk diffusion method with assessment of both zone size and zone edge appearance had high accuracy in our study. About 57% of bacteraemia isolates from 2008/2009 were sensitive to penicillin compared to 29% in 2014/2015 (p penicillin susceptible. There was no difference in co-morbidity or mortality rates between patients with penicillin resistant and penicillin sensitive SA bacteraemia. Disk-diffusion is a simple and reliable method to detect penicillin resistance in SA, and susceptibility rates are significant. Penicillin has many theoretical advantages and should be considered in the treatment of SA bacteraemia when susceptible.

Embryonic development of human lice: rearing conditions and susceptibility to spinosad

Directory of Open Access Journals (Sweden)

Gastón Mougabure Cueto

2006-05-01

Full Text Available The embryonic development of human lice was evaluated according to the changes in the morphology of the embryo observed through the transparent chorion. Based on ocular and appendage development, three stages of embryogenesis were established: early, medium, and late. Influence of temperature and relative humidity (RH on the laboratory rearing of Pediculus humanus capitis eggs was assessed. The optimal ranges for temperature and RH were 27-31°C and 45-75%. The susceptibility of human louse eggs to insecticide spinosad (a macrocyclic lactone was assessed by immersion method. The results showed similar susceptibility to spinosad in early, medium, and late stages of head lice eggs. In addition, this study showed similar susceptibility of head and body lice eggs to spinosad, an insecticide that has not been used as pediculicide in Argentina (lethal concentration 50: 0.01%.

A laboratory study of susceptibility of methicillin resistant staphylococcus aureus (MRSA)

International Nuclear Information System (INIS)

Bukhari, M.H.; Iqbal, N.; Naeem, S.; Qureshi, G.R.; Naveed, I.A.; Iqbal, A.; Khatoon, N.

2004-01-01

Objective: To study the mode of infection, incidence of methicillin resistant staphylococcus aureus (MRSA) and their susceptibility against glycopeptides and fucidic acid, so that awareness may be created for consultants against such notorious rapidly spreading bacteria and recommendation can be made for their prevention and control. Methods: The specimens from various infections suspected on clinical ground were processed by standard methods and antibiotic susceptibility testing of all the 350 S. aureus and 135 MRSA isolates was done by using modified Kirby Bauer Disc diffusion technique. Results: Of 350 positive S.aureus cultures, 135 were found to be Methicillin resistant (38.5%) which showed susceptibility 96%, 94% and 86% to Vancomycin, Teicoplanin and Fucidic acid respectively. Conclusion: This study showed a high incidence of MRSA at Mayo Hospital Lahore, Glycopeptides and Fucidic acid were found to be valuable antibiotics against MRSA. (author)

Topological susceptibility from the twisted mass Dirac operator spectrum

Energy Technology Data Exchange (ETDEWEB)

Cichy, Krzysztof [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Poznan Univ. (Poland). Faculty of Physics; Garcia-Ramos, Elena [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Humboldt-Universitaet, Berlin (Germany); Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Collaboration: European Twisted Mass Collaboration

2013-12-15

We present results of our computation of the topological susceptibility with N{sub f}=2 and N{sub f}= +1+1 flavours of maximally twisted mass fermions, using the method of spectral projectors. We perform a detailed study of the quark mass dependence and discretization effects. We make an attempt to confront our data with chiral perturbation theory and extract the chiral condensate from the quark mass dependence of the topological susceptibility. We compare the value with the results of our direct computation from the slope of the mode number. We emphasize the role of autocorrelations and the necessity of long Monte Carlo runs to obtain results with good precision. We also show our results for the spectral projector computation of the ratio of renormalization constants Z{sub P}/Z{sub S}.

Topological susceptibility from the twisted mass Dirac operator spectrum

International Nuclear Information System (INIS)

Cichy, Krzysztof; Jansen, Karl; Cyprus Univ., Nicosia

2013-12-01

We present results of our computation of the topological susceptibility with N f =2 and N f = +1+1 flavours of maximally twisted mass fermions, using the method of spectral projectors. We perform a detailed study of the quark mass dependence and discretization effects. We make an attempt to confront our data with chiral perturbation theory and extract the chiral condensate from the quark mass dependence of the topological susceptibility. We compare the value with the results of our direct computation from the slope of the mode number. We emphasize the role of autocorrelations and the necessity of long Monte Carlo runs to obtain results with good precision. We also show our results for the spectral projector computation of the ratio of renormalization constants Z P /Z S .

Susceptibility of Eikenella corrodens to Newer Beta-Lactam Antibiotics

OpenAIRE

1981-01-01

In vitro susceptibility testing of 28 strains of Eikenella corrodens by the agar dilution technique showed that all strains were uniformly susceptible to penicillin, ticarcillin, cefoxitin, cefotaxime, N-formimidoyl thienamycin, and moxalactam and resistant to clindamycin and cefadroxil. Cefoperazone, piperacillin, and mezlocillin showed good activity, with some strains relatively resistant. Bacampicillin and cefamandole showed relatively poor activity.

Temporal percolation of the susceptible network in an epidemic spreading.

Science.gov (United States)

Valdez, Lucas Daniel; Macri, Pablo Alejandro; Braunstein, Lidia Adriana

2012-01-01

In this work, we study the evolution of the susceptible individuals during the spread of an epidemic modeled by the susceptible-infected-recovered (SIR) process spreading on the top of complex networks. Using an edge-based compartmental approach and percolation tools, we find that a time-dependent quantity ΦS(t), namely, the probability that a given neighbor of a node is susceptible at time t, is the control parameter of a node void percolation process involving those nodes on the network not-reached by the disease. We show that there exists a critical time t(c) above which the giant susceptible component is destroyed. As a consequence, in order to preserve a macroscopic connected fraction of the network composed by healthy individuals which guarantee its functionality, any mitigation strategy should be implemented before this critical time t(c). Our theoretical results are confirmed by extensive simulations of the SIR process.

Assessing landslide susceptibility by applying fuzzy sets, possibility evidence-based theories

Directory of Open Access Journals (Sweden)

Ibsen Chivatá Cárdenas

2008-01-01

Full Text Available A landslide susceptibility model was developed for the city of Manizales, Colombia; landslides have been the city’s main environmental problem. Fuzzy sets and possibility and evidence-based theories were used to construct the mo-del due to the set of circumstances and uncertainty involved in the modelling; uncertainty particularly concerned the lack of representative data and the need for systematically coordinating subjective information. Susceptibility and the uncertainty were estimated via data processing; the model contained data concerning mass vulnerability and uncer-tainty. Output data was expressed on a map defined by linguistic categories or uncertain labels as having low, me-dium, high and very high susceptibility; this was considered appropriate for representing susceptibility. A fuzzy spec-trum was developed for classifying susceptibility levels according to perception and expert opinion. The model sho-wed levels of susceptibility in the study area, ranging from low to high susceptibility (medium susceptibility being mo-re frequent. This article shows the details concerning systematic data processing by presenting theories and tools regarding uncertainty. The concept of fuzzy parameters is introduced; this is useful in modelling phenomena regar-ding uncertainty, complexity and nonlinear performance, showing that susceptibility modelling can be feasible. The paper also shows the great convenience of incorporating uncertainty into modelling and decision-making. However, quantifying susceptibility is not suitable when modelling identified uncertainty because incorporating model output information cannot be reduced into exact or real numerical quantities when the nature of the variables is particularly uncertain. The latter concept is applicable to risk assessment.

Susceptible-infected-recovered and susceptible-exposed-infected models

International Nuclear Information System (INIS)

Tome, Tania; De Oliveira, Mario J

2011-01-01

Two stochastic epidemic lattice models, the susceptible-infected-recovered and the susceptible-exposed-infected models, are studied on a Cayley tree of coordination number k. The spreading of the disease in the former is found to occur when the infection probability b is larger than b c = k/2(k - 1). In the latter, which is equivalent to a dynamic site percolation model, the spreading occurs when the infection probability p is greater than p c = 1/(k - 1). We set up and solve the time evolution equations for both models and determine the final and time-dependent properties, including the epidemic curve. We show that the two models are closely related by revealing that their relevant properties are exactly mapped into each other when p = b/[k - (k - 1)b]. These include the cluster size distribution and the density of individuals of each type, quantities that have been determined in closed forms.

Extended biofilm susceptibility assay for Staphylococcus aureus bovine mastitis isolates: evidence for association between genetic makeup and biofilm susceptibility.

Science.gov (United States)

Melchior, M B; van Osch, M H J; Lam, T J G M; Vernooij, J C M; Gaastra, W; Fink-Gremmels, J

2011-12-01

Staphylococcus aureus is one of the most prevalent causes of bovine mastitis. The antimicrobial treatment of this disease is currently based on antimicrobial susceptibility tests according to Clinical and Laboratory Standards Institute standards. However, various authors have shown a discrepancy between the results of this standard susceptibility test and the actual cure rate of the applied antimicrobial treatment. Increasing evidence suggests that in vivo biofilm formation by Staph. aureus, which is not assessed in the antimicrobial susceptibility tests, is associated with this problem, resulting in disappointing cure rates, especially for infections of longer duration. Previous data obtained with a limited number of strains showed that the extended biofilm antimicrobial susceptibility (EBS) assay reveals differences between strains, which cannot be derived from a standard susceptibility test or from a 24-h biofilm susceptibility test. The objective of this study was to test a collection of Staph. aureus bovine mastitis strains in the EBS assay and to model the effect of antimicrobial exposure, duration of antimicrobial exposure, and genotype profile of the strains on antimicrobial susceptibility. With the results from a previous study with the same collection of strains, the effect of genotype represented by accessory gene regulator gene (agr-type), the presence of insertional sequence 257 (IS257), intercellular adhesion (ica), and the β-lactamase (blaZ) gene were entered as explanatory factors in a logistic regression model. The agr locus of Staph. aureus controls the expression of most of the virulence factors, represses the transcription of several cell wall-associated proteins, and activates several exoproteins during the post-exponential phase. The IS257 gene has been related to biofilm formation in vitro and was found earlier in 50% of the agr-type 2 strains. The ica gene cluster encodes for the production of an extracellular polysaccharide adhesin, termed

Susceptibility of various cell lines to Neospora caninum tachyzoites cultivation

Directory of Open Access Journals (Sweden)

Khordadmehr, M.,

2014-05-01

Full Text Available Neospora caninum is a coccidian protozoan parasite which is a major cause of bovine abortions and neonatal mortality in cattle, sheep, goat and horse. Occasionally, cultured cells are used for isolation and multiplication of the agent in vitro with several purposes. In this study the tachyzoite yields of N. caninum were compared in various cell cultures as the host cell lines. Among the cell cultures tested, two presented good susceptibility to the agent: cell lines Vero and MA-104. SW742 and TLI (in vitro suspension culture of lymphoid cells infected with Theileria lestoquardi showed moderate sensitivity. No viable tachyzoite were detected in the culture of MDCK and McCoy cell lines. These results demonstrate that MA-104 and SW742 cells present adequate susceptibility to N. caninum compared to Vero cells, which have been largely used to multiply the parasite in vitro. Moreover, these have easy manipulation, fast multiplication and relatively low nutritional requirements. In addition, the result of this study showed that TLI cell line as a suspension cell culture is susceptible to Nc-1 tachyzoites infection and could be used as an alternative host cell line for tachyzoites culture in vitro studies.

Selective reporting of antibiotic susceptibility test results in European countries: an ESCMID cross-sectional survey.

Science.gov (United States)

Pulcini, Céline; Tebano, Gianpiero; Mutters, Nico T; Tacconelli, Evelina; Cambau, Emmanuelle; Kahlmeter, Gunnar; Jarlier, Vincent

2017-02-01

Selective reporting of antibiotic susceptibility test (AST) results is one possible laboratory-based antibiotic stewardship intervention. The primary aim of this study was to identify where and how selective reporting of AST results is implemented in Europe both in inpatient and in outpatient settings. An ESCMID cross-sectional, self-administered, internet-based survey was conducted among all EUCIC (European Committee on Infection Control) or EUCAST (European Committee on Antimicrobial Susceptibility Testing) national representatives in Europe and Israel. Of 38 countries, 36 chose to participate in the survey. Selective reporting of AST results was implemented in 11/36 countries (31%), was partially implemented in 4/36 (11%) and was limited to local initiatives or was not adopted in 21/36 (58%). It was endorsed as standard of care by health authorities in only three countries. The organisation of selective reporting was everywhere discretionally managed by each laboratory, with a pronounced intra- and inter-country variability. The most frequent application was in uncomplicated community-acquired infections, particularly urinary tract and skin and soft-tissue infections. The list of reported antibiotics ranged from a few first-line options, to longer reports where only last-resort antibiotics were hidden. Several barriers to implementation were reported, mainly lack of guidelines, poor system support, insufficient resources, and lack of professionals' capability. In conclusion, selective reporting of AST results is poorly implemented in Europe and is applied with a huge heterogeneity of practices. Development of an international framework, based on existing initiatives and identified barriers, could favour its dissemination as one important element of antibiotic stewardship programmes. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Magnetic Susceptibility and Heavy Metals in Guano from South Sulawesi Caves

Science.gov (United States)

Rifai, H.; Putra, R.; Fadila, M. R.; Erni, E.; Wurster, C. M.

2018-04-01

Measurement of some magnetic properties have been performed on vertical profile from South Sulawesi caves (Mampu and Bubau) by using low cost, rapid, sensitive and non destructive magnetic method. The aim is to attempt to use magnetic characters as a fingerprint for anthropogenic pollution in the caves. Guano samples were collected every 5 cm at a certain section of Mampu and Bubau cave, South Sulawesi, starting from surface through 300 cm in depth of mampu Cave and 30 cm of Bubau Cave. The magnetic parameters such as magnetic susceptibility and percentage frequency dependence susceptibility were measured using the Bartington MS2-MS2B instruments and supported by X-Ray Fluoroscence (XRF) to know their element composition. The results show that the samples had variations in magnetic susceptibility from 3.5 to 242.6 x 10‑8 m3/kg for Mampu Cave and from 8.6 to 106.5 x 10‑8 m3/kg for Bubau Cave and also magnetic domain. Then, the XRF results show that the caves contain several heavy metals. Magnetic and heavy metal analyses showing that the magnetic minerals in caves are lithogenic (Fe-bearing minerals) in origin and anthropogenic (Zn content) in the caves.

Brief report: personality correlates of susceptibility to peer influence in adolescence.

Science.gov (United States)

Stautz, Kaidy; Cooper, Andrew

2014-06-01

Adolescents show a heightened susceptibility to peer influence compared to adults. Individual differences in this susceptibility exist, yet there has been little effort to link these with broader personality processes. Reward sensitivity and impulsive behaviour are also heightened in adolescence and could affect the tendency to be influenced by peers. This study examined associations between self-reported resistance to peer influence, facets of reward sensitivity and impulsivity, and subjective social status in a sample of 269 British sixth form students (mean age 16.79). Multiple regression analyses showed that negative and positive urgency were significantly negatively associated with resistance to peer influence. The relationship between negative urgency and resistance was moderated by subjective social status, such that individuals reporting low status showed a stronger negative relationship. Results suggest that a susceptibility to peer influence is linked with a tendency to act impulsively when in heightened emotional states. Adolescents high in negative urgency who feel lower in their social hierarchy may be particularly vulnerable. Copyright © 2014 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Prevalence and Antibiotic susceptibility pattern of Panton-Valentine ...

African Journals Online (AJOL)

Staphylococcal cassette chromosome mec typing by two standard multiplex PCR assay, revealed an uncharacterized resistance element. Overall antibiotic susceptibility pattern showed relatively high degree of susceptibility,however 1 isolate demostrated multidrug resistant pattern, 37(74.0%)resistant to only penicillin, 5 to ...

Antimicrobial susceptibility of clinical isolates of anaerobic bacteria in Ontario, 2010-2011.

Science.gov (United States)

Marchand-Austin, Alex; Rawte, Prasad; Toye, Baldwin; Jamieson, Frances B; Farrell, David J; Patel, Samir N

2014-08-01

The local epidemiology of antimicrobial susceptibility patterns in anaerobic bacteria is important in guiding the empiric treatment of infections. However, susceptibility data are very limited on anaerobic organisms, particularly among non-Bacteroides organisms. To determine susceptibility profiles of clinically-significant anaerobic bacteria in Ontario Canada, anaerobic isolates from sterile sites submitted to Public Health Ontario Laboratory (PHOL) for identification and susceptibility testing were included in this study. Using the E-test method, isolates were tested for various antimicrobials including, penicillin, cefoxitin, clindamycin, meropenem, piperacillin-tazobactam and metronidazole. The MIC results were interpreted based on guidelines published by Clinical and Laboratory Standards Institute. Of 2527 anaerobic isolates submitted to PHOL, 1412 were either from sterile sites or bronchial lavage, and underwent susceptibility testing. Among Bacteroides fragilis, 98.2%, 24.7%, 1.6%, and 1.2% were resistant to penicillin, clindamycin, piperacillin-tazobactam, and metronidazole, respectively. Clostridium perfringens was universally susceptible to penicillin, piperacillin-tazobactam, and meropenem, whereas 14.2% of other Clostridium spp. were resistant to penicillin. Among Gram-positive anaerobes, Actinomyces spp., Parvimonas micra and Propionibacterium spp. were universally susceptible to β-lactams. Eggerthella spp., Collinsella spp., and Eubacterium spp. showed variable resistance to penicillin. Among Gram-negative anaerobes, Fusobacterium spp., Prevotella spp., and Veillonella spp. showed high resistance to penicillin but were universally susceptible to meropenem and piperacillin-tazobactam. The detection of metronidazole resistant B. fragilis is concerning as occurrence of these isolates is extremely rare. These data highlight the importance of ongoing surveillance to provide clinically relevant information to clinicians for empiric management of

Susceptibility-Weighted Imaging and Quantitative Susceptibility Mapping in the Brain

Science.gov (United States)

Liu, Chunlei; Li, Wei; Tong, Karen A.; Yeom, Kristen W.; Kuzminski, Samuel

2015-01-01

Susceptibility-weighted imaging (SWI) is a magnetic resonance imaging (MRI) technique that enhances image contrast by using the susceptibility differences between tissues. It is created by combining both magnitude and phase in the gradient echo data. SWI is sensitive to both paramagnetic and diamagnetic substances which generate different phase shift in MRI data. SWI images can be displayed as a minimum intensity projection that provides high resolution delineation of the cerebral venous architecture, a feature that is not available in other MRI techniques. As such, SWI has been widely applied to diagnose various venous abnormalities. SWI is especially sensitive to deoxygenated blood and intracranial mineral deposition and, for that reason, has been applied to image various pathologies including intracranial hemorrhage, traumatic brain injury, stroke, neoplasm, and multiple sclerosis. SWI, however, does not provide quantitative measures of magnetic susceptibility. This limitation is currently being addressed with the development of quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI). While QSM treats susceptibility as isotropic, STI treats susceptibility as generally anisotropic characterized by a tensor quantity. This article reviews the basic principles of SWI, its clinical and research applications, the mechanisms governing brain susceptibility properties, and its practical implementation, with a focus on brain imaging. PMID:25270052

Susceptibility-weighted imaging and quantitative susceptibility mapping in the brain.

Science.gov (United States)

Liu, Chunlei; Li, Wei; Tong, Karen A; Yeom, Kristen W; Kuzminski, Samuel

2015-07-01

Susceptibility-weighted imaging (SWI) is a magnetic resonance imaging (MRI) technique that enhances image contrast by using the susceptibility differences between tissues. It is created by combining both magnitude and phase in the gradient echo data. SWI is sensitive to both paramagnetic and diamagnetic substances which generate different phase shift in MRI data. SWI images can be displayed as a minimum intensity projection that provides high resolution delineation of the cerebral venous architecture, a feature that is not available in other MRI techniques. As such, SWI has been widely applied to diagnose various venous abnormalities. SWI is especially sensitive to deoxygenated blood and intracranial mineral deposition and, for that reason, has been applied to image various pathologies including intracranial hemorrhage, traumatic brain injury, stroke, neoplasm, and multiple sclerosis. SWI, however, does not provide quantitative measures of magnetic susceptibility. This limitation is currently being addressed with the development of quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI). While QSM treats susceptibility as isotropic, STI treats susceptibility as generally anisotropic characterized by a tensor quantity. This article reviews the basic principles of SWI, its clinical and research applications, the mechanisms governing brain susceptibility properties, and its practical implementation, with a focus on brain imaging. © 2014 Wiley Periodicals, Inc.

Possible origins of the susceptibility contrast in the brain. Presidential award proceedings

International Nuclear Information System (INIS)

Fukunaga, Masaki; Li, T.Q.; Lee, J.; Matsuura, Eiji; Gelderen, P.V.; Zwart, J.A. de; Merkle, H.; Duyn, J.H.

2011-01-01

The magnetic susceptibility contrast derived from high resolution T 2 *-weighted magnetic resonance (MR) imaging at ultra high field strength has been used to reveal laminar contrast in the gray matter (GM) and fiber bundle-like structure in the white matter (WM) of the human brain. This contrast has been attributed to subtle variations in the magnetic properties of brain tissue, which possibly reflect varying iron and myelin content and haemoglobin in the microvasculature. To investigate the origin of this contrast, MRI data from postmortem brain samples were compared with histological staining for iron and myelin. The laminar susceptibility variations in GM strongly correlate with local iron content, which generally co-localized with myelin. On the other hand, fiber bundles in white matter, shows strong susceptibility contrast in the absence of iron while myelin is high. The results suggest that iron contributes significantly to susceptibility contrast across the cortical GM, but myelin is the dominant source of susceptibility in WM bundles. (author)

Nature of the magnetic susceptibility of dysprosium. Paramagnetic susceptibility of dysprosium - yttrium alloys

International Nuclear Information System (INIS)

Demidov, V.G.; Levitin, R.Z.; Chistyakov, O.D.

1976-01-01

The paramagnetic susceptibility of single crystals of dysprosium-yttirum alloys is measured in the basal plane and along the hexagonal axis. It is shown that the susceptibility of the alloys obeys the Curie-Weiss law, the effective magnetic moments allong the different directions being the same and the paramagnetic Curie temperatures being different. The difference between the paramagnetic Curie temperatures in the basal plane and along the hexagonal axis is independent of the dysprosium concentration in the alloy. As a comparison with the theoretical models of magnetic anisotropy shows, this is an indication that the magnetic anisotropy of dysprosium - yttrium alloys is of a single-ion nature

Susceptibility of Some Stone and Pome Fruit Rootstocks to Crown Gall

Directory of Open Access Journals (Sweden)

A. Rhouma

2005-12-01

Full Text Available The susceptibility of different fruit rootstocks to crown gall disease was investigated in greenhouse and field experiments with numerous strains of Agrobacterium tumefaciens over three years. Plants were inoculated in the roots and shoots for pot experiments. Field experiments were performed in a naturally contaminated nursery plot. The genotypes Prunus dulcis and P. persica showed a high level of susceptibility to A. tumefaciens. Among the stone rootstocks, bitter almond was highly susceptible in all experiments. Apricot and Cadaman rootstocks displayed low susceptibility but larger galls, showing that there was no relation between rootstock susceptibility and gall size. Among pome rootstocks, quince BA29 was resistant to the disease, while MM106 was susceptible in potted trials; however, in the field essays, pome rootstocks did not become galled, possibly because the strains had selected for and adapted to stone rootstocks.

Mapping Landslides Susceptibility in a Traditional Northern Nigerian City

Science.gov (United States)

Oluwafemi, Olawale A.; Yakubu, Tahir A.; Muhammad, Mahmud U.; Shitta, Nyofo; Akinwumiju, Akinola S.

2018-05-01

As a result of dearth of relevant information about Landslides Susceptibility in Nigeria, the monitoring and assessment appears intractable. Hence, the study developed a Remote Sensing approach to mapping landslides susceptibility, landuse and landcover analysis in Jos South LGA, Plateau State, Nigeria. Field Observation, SPOT 5 2009 and 2012, ASTER DEM 2009, Geological Map 2006, Topographical Map 1966 were used to map Landslide Susceptibility and Landuse /Lancover Analysis in the study area. Geospatial Analytical Operations employed using ArcGIS 10.3 and Erdas Imagine 2014 include Spatial Modeling, Vectorization, Pre-lineament Extraction, Image Processing among others. Result showed that 72.38 % of the study area is underlain by granitic rocks. The landuse/cover types delineated for the study area include floodplain (29.27 %), farmland (23.96 %), sparsely vegetated land (15.43 %), built up area (13.65 %), vegetated outcrop (8.48 %), light vegetation (5.37 %), thick vegetation (2.39 %), water body (0.58 %), plantation (0.50 %) and mining pond (0.37 %). Landslide Susceptibility Analysis also revealed that 87 % of the study area is relatively at low to very low risk of landslide event. While only 13 % of the study area is at high to very high risk of landslide event. The study revealed that the susceptibility of landslide event is very low in the study area. However, possible landslide event in the hot spots could be pronounced and could destabilize the natural and man-made environmental systems of the study area.

Antimicrobial susceptibility of anaerobic bacteria in New Zealand: 1999-2003.

Science.gov (United States)

Roberts, Sally A; Shore, Keith P; Paviour, Susan D; Holland, David; Morris, Arthur J

2006-05-01

Routine susceptibility testing of all anaerobic organisms is not advocated, but it is useful for laboratories to test periodically for anaerobic organisms and provide local susceptibility data to guide therapy. This study reports the national trend of antibiotic susceptibility of clinically significant anaerobes in New Zealand. Clinical isolates were tested using standardized methods against a range of antibiotics commonly used to treat anaerobic infections. Susceptibility was determined using NCCLS criteria. The change in susceptibility trends between this study and earlier studies was measured by comparing the geometric mean of the MIC. A total of 364 anaerobes were tested. Penicillin had poor activity against Bacteroides spp., Prevotella spp., Eubacterium spp., Clostridium tertium and Veillonella spp. In general, Fusobacterium spp., Bacteroides ureolyticus, Propionibacterium spp., Clostridium perfringens and anaerobic streptococci isolates, with the exception of Peptostreptococcus anaerobius, were penicillin susceptible. Amoxicillin/clavulanate showed good activity against most anaerobes, but resistance was seen with Bacteroides fragilis group and P. anaerobius isolates. Cefoxitin was more active than cefotetan, particularly against non-B. fragilis species, Eubacterium spp. and P. anaerobius. Meropenem and imipenem showed good activity against all anaerobes, with only 2 and 4% of Bacteroides spp., respectively, showing resistance. With the exception of Propionibacterium acnes isolates, which are predictably resistant, metronidazole was active against all anaerobes tested. There has been little change in susceptibility since 1997. Metronidazole, cefoxitin, piperacillin/tazobactam and amoxicillin/clavulanate remain good empirical choices when anaerobes are expected in our setting. No clinically relevant changes in susceptibility over time were found.

Implementation of landslide susceptibility maps in Lower Austria as part of risk governance

Science.gov (United States)

Bell, Rainer; Petschko, Helene; Bauer, Christian; Glade, Thomas; Granica, Klaus; Heiss, Gerhard; Leopold, Philip; Pomaroli, Gilbert; Proske, Herwig; Schweigl, Joachim

2013-04-01

, the number of susceptibility classes, their colour and naming, as well as on the instructions for actions referring to each susceptibility class respectively. All susceptibility maps showed very good validation results. Both, the WofE and the GAM slide susceptibility map showed high median AUROC values of 0.9 and the geomorphological plausibility proved to be very good in both cases. Due to these results it was concluded the stakeholders should take the decision which of the two slide susceptibility maps should be used. This decision was performed as a blind test providing resulting maps and their respective performance measures but coded with a color so that the stakeholders did not know which maps were produced by whom and with which method. This presentation is thus focusing on a detailed description of all these aspects and it is discussed how this participative approach led to a high acceptance of the final landslide susceptibility maps by the stakeholders. Consequently these maps are going to be implemented in the spatial planning strategies soon.

Genetic control of susceptibility to apoptosis of thymocytes

International Nuclear Information System (INIS)

Mori, N.; Okumoto, M.; Morimoto, J.; Imai, S.; Matsuyama, T.; Takamori, Y.; Yagasaki, O.

1992-01-01

Genetic control of the susceptibility of thymocytes to radiation-induced apoptosis in mice was investigated by counting dead cells in a selected area of thymic cortex on histological specimens after whole-body X-irradiation. The number of dead cells increased almost linearly with doses in BALB/cHeA and STS/A mice. However, dead cell counts in BALB/cHeA mice were more than twice those in STS/A mice at each dose. C57BL/6N and B10.BR mice exhibited a sensitive phenotype similar to BALB/cHeA mice, while C3H/HeMsNrs and NFS/N mice showed a resistant phenotype similar to STS/A mice. Sex difference in the susceptibility of thymocytes to cell death was not recognized in BALB/cHeA and STS/A mice. Resistance was dominant over susceptibility in the progenies of reciprocal crosses between the two strains, indicating an autosomal inheritance. The segregation ratio of susceptible to resistant phenotype in the backcrosses of (BALB/cHeA X STS/A)F 1 with BALB/cHeA was not significantly different from 1 : 1 and all backcrosses of (BALB/cHeA X STS/A)F 1 with STS/A exhibited a resistant phenotype. The results demonstrated that the difference in the susceptibility of thymocytes to radiation-induced apoptosis in the two strains of mice is due to one major autosomal allele. (author)

Antimicrobial Susceptibility Monitoring of Bacterial Pathogens Isolated from Urinary Tract Infections in Dogs and Cats Across Europe: ComPath Results.

Science.gov (United States)

Moyaert, Hilde; Morrissey, Ian; de Jong, Anno; El Garch, Farid; Klein, Ulrich; Ludwig, Carolin; Thiry, Julien; Youala, Myriam

2017-04-01

ComPath is a pan-European antimicrobial surveillance program collecting bacterial pathogens from dogs and cats not recently exposed to antimicrobials. We present minimum inhibitory concentration data obtained using Clinical and Laboratory Standards Institute methodology for 616 urinary tract infection (UTI) isolates collected between 2008 and 2010. In both dogs and cats, the most common pathogen was Escherichia coli (59.8% and 46.7%, respectively). Antimicrobial activity against E. coli in dogs and cats was similar with fluoroquinolone and trimethoprim/sulfamethoxazole susceptibility >90%. Ampicillin susceptibility was ∼80%. Staphylococcus intermedius Group isolates from dogs (67/437, 15.3%) had high antimicrobial susceptibility (>90%) toward beta-lactams, fluoroquinolones, and trimethoprim/sulfamethoxazole. Four canine isolates (6%) were oxacillin resistant, and harbored mecA. Proteus mirabilis from dogs (48/437, 11.0%) had high antimicrobial susceptibility (∼90%) to amoxicillin/clavulanic acid, enrofloxacin, and marbofloxacin and slightly lower susceptibility (∼80-85%) to ampicillin and orbifloxacin. Streptococcus canis isolates (35/437, 8.0%) from dogs were all susceptible to ampicillin and amoxicillin/clavulanic acid and >90% susceptible to marbofloxacin. Although resistance was not observed, high intermediate susceptibility was seen for both enrofloxacin (28.6%) and orbifloxacin (85.7%). Overall, antimicrobial in vitro activity appears to be high in UTI pathogens from dogs and cats with low multidrug resistance, although a lack of specific dog and cat breakpoints for important antimicrobials such as cefovecin, cephalexin, and ibafloxacin prevents analysis of susceptibility for these agents.

Antimicrobial susceptibility pattern of bacterial isolates from surgical ...

African Journals Online (AJOL)

S. aureus and Streptococcus spp. showed maximum susceptibility (100%) to linezolid and vancomycin. Maximum susceptibility of E. coli was observed to ciprofloxacin (75.7%), followed by gentamicin (54.5%); of Klebsiella spp. to ceftriaxone and gentamicin (66.6% each), of Proteus spp. to gentamicin (70%) followed by ...

Frequency and antimicrobial susceptibility of acinetobacter species isolated from blood samples of paediatric patients

International Nuclear Information System (INIS)

Javed, A.; Zafar, A.; Ejaz, H.; Zubair, M.

2012-01-01

Objective: Acinetobacter species is a major nosocomial pathogen causing serious infections in immuno-compromised and hospitalized patients. The aim of this study was to determine the frequency and antimicrobial susceptibility pattern of Acinetobacter species in blood samples of paediatric patients. Methodology: This cross sectional observational study was conducted during January to October, 2011 at The Children's Hospital and Institute of Child Health, Lahore. A total number of 12,032 blood samples were analysed during the study period. Acinetobacter species were Bauer disc diffusion method. Results: The blood cultures showed growth in 1,141 cultures out of which 46 (4.0%) were Acinetobacter species. The gender distribution of Acinetobacter species was 29 (63.0%) in males and 17 (37.0%) in females. A good antimicrobial susceptibility pattern of Acinetobacter species was seen with sulbactam-cefoperazone (93.0%), imepenem and meropenem (82.6% (30.4%) was poor. Conclusion: The results of the present study shows high rate of resistance of Acinetobacter species with cephalosporins in nosocomial infections. The sulbactam-cefoperazone, carbapenems and piperacillin-tazobactam showed effective antimicrobial susceptibility against Acinetobacter species. (author)

Quantitative Susceptibility Mapping: Contrast Mechanisms and Clinical Applications

Science.gov (United States)

Liu, Chunlei; Wei, Hongjiang; Gong, Nan-Jie; Cronin, Matthew; Dibb, Russel; Decker, Kyle

2016-01-01

Quantitative susceptibility mapping (QSM) is a recently developed MRI technique for quantifying the spatial distribution of magnetic susceptibility within biological tissues. It first uses the frequency shift in the MRI signal to map the magnetic field profile within the tissue. The resulting field map is then used to determine the spatial distribution of the underlying magnetic susceptibility by solving an inverse problem. The solution is achieved by deconvolving the field map with a dipole field, under the assumption that the magnetic field is a result of the superposition of the dipole fields generated by all voxels and that each voxel has its unique magnetic susceptibility. QSM provides improved contrast to noise ratio for certain tissues and structures compared to its magnitude counterpart. More importantly, magnetic susceptibility is a direct reflection of the molecular composition and cellular architecture of the tissue. Consequently, by quantifying magnetic susceptibility, QSM is becoming a quantitative imaging approach for characterizing normal and pathological tissue properties. This article reviews the mechanism generating susceptibility contrast within tissues and some associated applications. PMID:26844301

Genetic architecture for susceptibility to gout in the KARE cohort study.

Science.gov (United States)

Shin, Jimin; Kim, Younyoung; Kong, Minyoung; Lee, Chaeyoung

2012-06-01

This study aimed to identify functional associations of cis-regulatory regions with gout susceptibility using data resulted from a genome-wide association study (GWAS), and to show a genetic architecture for gout with interaction effects among genes within each of the identified functions. The GWAS was conducted with 8314 control subjects and 520 patients with gout in the Korea Association REsource cohort. However, genetic associations with any individual nucleotide variants were not discovered by Bonferroni multiple testing in the GWAS (P>1.42 × 10(-7)). Genomic regions enrichment analysis was employed to identify functional associations of cis-regulatory regions. This analysis revealed several biological processes associated with gout susceptibility, and they were quite different from those with serum uric acid level. Epistasis for susceptibility to gout was estimated using entropy decomposition with selected genes within each biological process identified by the genomic regions enrichment analysis. Some epistases among nucleotide sequence variants for gout susceptibility were found to be larger than their individual effects. This study provided the first evidence that genetic factors for gout susceptibility greatly differed from those for serum uric acid level, which may suggest that research endeavors for identifying genetic factors for gout susceptibility should not be heavily dependent on pathogenesis of uric acid. Interaction effects between genes should be examined to explain a large portion of phenotypic variability for gout susceptibility.

AC susceptibility and NQR measurements on CeCu6 below 5 mK

International Nuclear Information System (INIS)

Jin, C.; Lee, D.M.; Pollack, L.; Smith, E.N.; Markert, J.T.; Maple, M.B.; Hinks, D.G.

1994-01-01

We have measured the zero field ac magnetic susceptibility of single and polycrystalline CeCu 6 samples down to 100 μK. For the single crystal sample, the susceptibility shows pronounced anisotropic behavior with respect to the crystal orientation. At ∼3 mK the susceptibility along two different crystal orientations shows a broad peak, and at 500 μK the susceptibility shows a second peak along one orientation and a plateau along the other. The susceptibility of the polycrystalline sample has a similar peak at 3 mK. NQR measurements are under way to study the Cu nuclear spin system in this compound in order to gain additional information about the nature of the peaks. (orig.)

Genetic susceptibility markers for a breast-colorectal cancer phenotype: Exploratory results from genome-wide association studies

Science.gov (United States)

Joon, Aron; Brewster, Abenaa M.; Chen, Wei V.; Eng, Cathy; Shete, Sanjay; Casey, Graham; Schumacher, Fredrick; Lin, Yi; Harrison, Tabitha A.; White, Emily; Ahsan, Habibul; Andrulis, Irene L.; Whittemore, Alice S.; Ko Win, Aung; Schmidt, Daniel F.; Kapuscinski, Miroslaw K.; Ochs-Balcom, Heather M.; Gallinger, Steven; Jenkins, Mark A.; Newcomb, Polly A.; Lindor, Noralane M.; Peters, Ulrike; Amos, Christopher I.; Lynch, Patrick M.

2018-01-01

Background Clustering of breast and colorectal cancer has been observed within some families and cannot be explained by chance or known high-risk mutations in major susceptibility genes. Potential shared genetic susceptibility between breast and colorectal cancer, not explained by high-penetrance genes, has been postulated. We hypothesized that yet undiscovered genetic variants predispose to a breast-colorectal cancer phenotype. Methods To identify variants associated with a breast-colorectal cancer phenotype, we analyzed genome-wide association study (GWAS) data from cases and controls that met the following criteria: cases (n = 985) were women with breast cancer who had one or more first- or second-degree relatives with colorectal cancer, men/women with colorectal cancer who had one or more first- or second-degree relatives with breast cancer, and women diagnosed with both breast and colorectal cancer. Controls (n = 1769), were unrelated, breast and colorectal cancer-free, and age- and sex- frequency-matched to cases. After imputation, 6,220,060 variants were analyzed using the discovery set and variants associated with the breast-colorectal cancer phenotype at Pcolorectal cancer phenotype in the discovery and replication data (most significant; rs7430339, Pdiscovery = 1.2E-04; rs7429100, Preplication = 2.8E-03). In meta-analysis of the discovery and replication data, the most significant association remained at rs7429100 (P = 1.84E-06). Conclusion The results of this exploratory analysis did not find clear evidence for a susceptibility locus with a pleiotropic effect on hereditary breast and colorectal cancer risk, although the suggestive association of genetic variation in the region of ROBO1, a potential tumor suppressor gene, merits further investigation. PMID:29698419

Discussion of Various Susceptibilities within Thermal and Dense Quantum Chromodynamics

International Nuclear Information System (INIS)

Xu Shu-Sheng; Shi Yuan-Mei; Yang You-Chang; Cui Zhu-Fang; Zong Hong-Shi

2015-01-01

It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to understand the nature of strong interacting matters of quantum chromodynamics (QCD). Since at present there is no exact order of parameters of the phase transitions beyond the chiral limit, QCD susceptibilities are widely used as indicators. In this work various susceptibilities are discussed in the framework of Dyson–Schwinger equations. The results show that different kinds of susceptibilities give the same critical end point, which is the bifurcation point of the crossover region and the first order phase transition line of QCD. Nevertheless, different pseudocritical points are found in the temperature axis. We think that defining a critical band is more suitable in the crossover region. (paper)

Real-Time Optical Antimicrobial Susceptibility Testing

DEFF Research Database (Denmark)

Fredborg, Marlene; Andersen, Klaus R; Jørgensen, Erik

2013-01-01

Rapid antibiotic susceptibility testing is in highly demand in health-care fields as antimicrobial resistant bacterial strains emerge and spread. Here we describe an optical screening system (oCelloScope), which based on time-lapse imaging of 96 bacteria-antibiotic combinations at a time......, introduces real-time detection of bacterial growth and antimicrobial susceptibility, with imaging material to support the automatically generated graphs. Automated antibiotic susceptibility tests of a monoculture showed statistically significant antibiotic effect within 6 minutes and within 30 minutes...... from multidrug-resistant pathogenic bacteria. The oCelloScope system can be employed for a broad range of applications within bacteriology and may present new vistas as a point-of-care instrument in both clinical and veterinarian settings....

Finite perturbation studies of magnetic susceptibility and shielding with GIAO

International Nuclear Information System (INIS)

Zaucer, M.; Pumpernik, D.; Hladnik, M.; Azman, A.

1977-01-01

The magnetic susceptibility tensor and proton and fluorine magnetic shielding tensors are calculated for F 2 and (FHF) - using an ab initio finite perturbation method with gauge-invariant atomic orbitals (GIAO). The discussion of the basis set deficiency shows that the calculated values for the susceptibilities are reliable. Simple additivity (Pascal rule) for the susceptibility is confirmed. (orig.) [de

Susceptibility to emotional contagion for negative emotions improves detection of smile authenticity.

Science.gov (United States)

Manera, Valeria; Grandi, Elisa; Colle, Livia

2013-01-01

A smile is a context-dependent emotional expression. A smiling face can signal the experience of enjoyable emotions, but people can also smile to convince another person that enjoyment is occurring when it is not. For this reason, the ability to discriminate between felt and faked enjoyment expressions is a crucial social skill. Despite its importance, adults show remarkable individual variation in this ability. Revealing the factors responsible for these huge individual differences is a key challenge in this domain. Here we investigated, on a large sample of participants, whether individual differences in smile authenticity recognition are accounted for by differences in the predisposition to experience other people's emotions, i.e., by susceptibility to emotional contagion. Results showed that susceptibility to emotional contagion for negative emotions increased smile authenticity detection, while susceptibility to emotional contagion for positive emotions worsened detection performance, because it leaded to categorize most of the faked smiles as sincere. These findings suggest that susceptibility to emotional contagion plays a key role in complex emotion recognition, and point out the importance of analyzing the tendency to experience other people's positive and negative emotions as separate abilities.

Effectiveness of clean-up procedures on stain susceptibility of different orthodontic adhesives

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Swati Pundlik Mane

2014-01-01

Conclusion: Chemical-cure adhesive showed higher stain susceptibility than light-cure adhesive in all clean-up procedures. Both adhesives would show less stain susceptibility with polishing step with rubber cup and pumice.

Magnetic susceptibility in the edged topological disordered nanoscopic cylinder

International Nuclear Information System (INIS)

Faizabadi, Edris; Omidi, Mahboubeh

2011-01-01

The effects of edged topological disorder on magnetic susceptibility are investigated in a nanoscopic cylinder threaded by a magnetic flux. Persistent current versus even or odd number of electrons shows different signs in ordered and disordered cylinders and also in short or long ones. In addition, temperature-averaged susceptibility has only diamagnetic signs in strong regimes and it is associated with paramagnetic signs in ordered and weak disordered ones. Besides, in an edged topological disordered cylinder, the temperature-averaged susceptibility decreases by raising the temperature somewhat and then increasing initiates and finally at high temperature tends to zero as the ordered one. - Research highlights: → Magnetic susceptibility in one-dimensional topological disordered quantum ring. → Edged topological disorder effect on magnetic susceptibility in nanoscopic cylinder. → Edged topological disorder effect on temperature-averaged susceptibility in cylinder.

Real-time and quantitative isotropic spatial resolution susceptibility imaging for magnetic nanoparticles

Science.gov (United States)

Pi, Shiqiang; Liu, Wenzhong; Jiang, Tao

2018-03-01

The magnetic transparency of biological tissue allows the magnetic nanoparticle (MNP) to be a promising functional sensor and contrast agent. The complex susceptibility of MNPs, strongly influenced by particle concentration, excitation magnetic field and their surrounding microenvironment, provides significant implications for biomedical applications. Therefore, magnetic susceptibility imaging of high spatial resolution will give more detailed information during the process of MNP-aided diagnosis and therapy. In this study, we present a novel spatial magnetic susceptibility extraction method for MNPs under a gradient magnetic field, a low-frequency drive magnetic field, and a weak strength high-frequency magnetic field. Based on this novel method, a magnetic particle susceptibility imaging (MPSI) of millimeter-level spatial resolution (<3 mm) was achieved using our homemade imaging system. Corroborated by the experimental results, the MPSI shows real-time (1 s per frame acquisition) and quantitative abilities, and isotropic high resolution.

Nanotoxicity overview: nano-threat to susceptible populations.

Science.gov (United States)

Li, Yang; Zhang, Yi; Yan, Bing

2014-02-28

Due to the increasing applications of nanomaterials and nanotechnology, potential danger of nanoparticle exposure has become a critical issue. However, recent nanotoxicity studies have mainly focused on the health risks to healthy adult population. The nanotoxicity effects on susceptible populations (such as pregnant, neonate, diseased, and aged populations) have been overlooked. Due to the alterations in physiological structures and functions in susceptible populations, they often suffer more damage from the same exposure. Thus, it is urgent to understand the effects of nanoparticle exposure on these populations. In order to fill this gap, the potential effects of nanoparticles to pregnant females, neonate, diseased, and aged population, as well as the possible underlying mechanisms are reviewed in this article. Investigations show that responses from susceptible population to nanoparticle exposure are often more severe. Reduced protection mechanism, compromised immunity, and impaired self-repair ability in these susceptible populations may contribute to the aggravated toxicity effects. This review will help minimize adverse effects of nanoparticles to susceptible population in future nanotechnology applications.

Nanotoxicity Overview: Nano-Threat to Susceptible Populations

Directory of Open Access Journals (Sweden)

Yang Li

2014-02-01

Full Text Available Due to the increasing applications of nanomaterials and nanotechnology, potential danger of nanoparticle exposure has become a critical issue. However, recent nanotoxicity studies have mainly focused on the health risks to healthy adult population. The nanotoxicity effects on susceptible populations (such as pregnant, neonate, diseased, and aged populations have been overlooked. Due to the alterations in physiological structures and functions in susceptible populations, they often suffer more damage from the same exposure. Thus, it is urgent to understand the effects of nanoparticle exposure on these populations. In order to fill this gap, the potential effects of nanoparticles to pregnant females, neonate, diseased, and aged population, as well as the possible underlying mechanisms are reviewed in this article. Investigations show that responses from susceptible population to nanoparticle exposure are often more severe. Reduced protection mechanism, compromised immunity, and impaired self-repair ability in these susceptible populations may contribute to the aggravated toxicity effects. This review will help minimize adverse effects of nanoparticles to susceptible population in future nanotechnology applications.

Female Nur77-deficient mice show increased susceptibility to diet-induced obesity.

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Sonia Perez-Sieira

Full Text Available Adipose tissue is essential in the regulation of body weight. The key process in fat catabolism and the provision of energy substrate during times of nutrient deprivation or enhanced energy demand is the hydrolysis of triglycerides and the release of fatty acids and glycerol. Nur77 is a member of the NR4A subfamily of nuclear receptors that plays an important metabolic role, modulating hepatic glucose metabolism and lipolysis in muscle. However, its endogenous role on white adipose tissue, as well as the gender dependency of these mechanisms, remains largely unknown. Male and female wild type and Nur77 deficient mice were fed with a high fat diet (45% calories from fat for 4 months. Mice were analyzed in vivo with the indirect calorimetry system, and tissues were analyzed by real-time PCR and Western blot analysis. Female, but not male Nur77 deficient mice, gained more weight and fat mass when compared to wild type mice fed with high fat diet, which can be explained by decreased energy expenditure. The lack of Nur77 also led to a decreased pHSL/HSL ratio in white adipose tissue and increased expression of CIDEA in brown adipose tissue of female Nur77 deficient mice. Overall, these findings suggest that Nur77 is an important physiological modulator of lipid metabolism in adipose tissue and that there are gender differences in the sensitivity to deletion of the Nur77 signaling. The decreased energy expenditure and the actions of Nur77 on liver, muscle, brown and white adipose tissue contribute to the increased susceptibility to diet-induced obesity in females lacking Nur77.

Absolute method of measuring magnetic susceptibility

Science.gov (United States)

Thorpe, A.; Senftle, F.E.

1959-01-01

An absolute method of standardization and measurement of the magnetic susceptibility of small samples is presented which can be applied to most techniques based on the Faraday method. The fact that the susceptibility is a function of the area under the curve of sample displacement versus distance of the magnet from the sample, offers a simple method of measuring the susceptibility without recourse to a standard sample. Typical results on a few substances are compared with reported values, and an error of less than 2% can be achieved. ?? 1959 The American Institute of Physics.

In Vitro Antibiotic Susceptibility Studies Of Bacteria Associated With ...

African Journals Online (AJOL)

In vitro tests of the susceptibility of isolates of bacterial keratitis pathogens to antibiotics were carried out in this study. Staphylococcus aureus was the most frequently isolated organisms followed by Pseudomonas aeruginosa and Streptococcus pneumoniae. Antibiotic sensitivity testing showed a high susceptibility to ...

Antimicrobial Susceptibility and Genetic Characterisation of Burkholderia pseudomallei Isolated from Malaysian Patients

Directory of Open Access Journals (Sweden)

Yalda Khosravi

2014-01-01

Full Text Available Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to many antibiotics. Ceftazidime (CAZ, the synthetic β-lactam, is normally used as the first-line antibiotic therapy for treatment of melioidosis. However, acquired CAZ resistance can develop in vivo during treatment with CAZ, leading to mortality if therapy is not switched to a different antibiotic(s in a timely manner. In this study, susceptibilities of 81 B. pseudomallei isolates to nine different antimicrobial agents were determined using the disk diffusion method, broth microdilution test and Etest. Highest percentage of susceptibility was demonstrated to CAZ, amoxicillin/clavulanic acid, meropenem, imipenem, and trimethoprim/sulfamethoxazole. Although these drugs demonstrated the highest percentage of susceptibility in B. pseudomallei, the overall results underline the importance of the emergence of resistance in this organism. PCR results showed that, of the 81 B. pseudomallei, six multidrug resistant (MDR isolates carried bpeB, amrB, and BPSS1119 and penA genes. Genotyping of the isolates using random amplified polymorphic DNA analysis showed six different PCR fingerprinting patterns generated from the six MDR isolates clusters (A and eight PCR fingerprinting patterns generated for the remaining 75 non-MDR isolates clusters (B.

The study of past damaging hydrogeological events for damage susceptibility zonation

Directory of Open Access Journals (Sweden)

O. Petrucci

2008-08-01

Full Text Available Damaging Hydrogeological Events are defined as periods during which phenomena, such as landslides, floods and secondary floods, cause damage to people and the environment.

A Damaging Hydrogeological Event which heavily damaged Calabria (Southern Italy between December 1972, and January 1973, has been used to test a procedure to be utilised in the zonation of a province according to damage susceptibility during DHEs. In particular, we analyzed the province of Catanzaro (2391 km², an administrative district composed of 80 municipalities, with about 370 000 inhabitants.

Damage, defined in relation to the reimbursement requests sent to the Department of Public Works, has been quantified using a procedure based on a Local Damage Index. The latter, representing classified losses, has been obtained by multiplying the value of the damaged element and the percentage of damage affecting it.

Rainfall has been described by the Maximum Return Period of cumulative rainfall, for both short (1, 3, 5, 7, 10 consecutive days and long duration (30, 60, 90, 180 consecutive days, recorded during the event.

Damage index and population density, presumed to represent the location of vulnerable elements, have been referred to Thiessen polygons associated to rain gauges working at the time of the event.

The procedure allowed us to carry out a preliminary classification of the polygons composing the province according to their susceptibility to damage during DHEs. In high susceptibility polygons, severe damage occurs during rainfall characterised by low return periods; in medium susceptibility polygons maximum return period rainfall and induced damage show equal levels of exceptionality; in low susceptibility polygons, high return period rainfall induces a low level of damage.

The east and west sectors of the province show the highest susceptibility, while polygons of the N-NE sector show the lowest

A major genetic component of BSE susceptibility

Science.gov (United States)

Juling, Katrin; Schwarzenbacher, Hermann; Williams, John L; Fries, Ruedi

2006-01-01

Background Coding variants of the prion protein gene (PRNP) have been shown to be major determinants for the susceptibility to transmitted prion diseases in humans, mice and sheep. However, to date, the effects of polymorphisms in the coding and regulatory regions of bovine PRNP on bovine spongiform encephalopathy (BSE) susceptibility have been considered marginal or non-existent. Here we analysed two insertion/deletion (indel) polymorphisms in the regulatory region of bovine PRNP in BSE affected animals and controls of four independent cattle populations from UK and Germany. Results In the present report, we show that two previously reported 23- and 12-bp insertion/deletion (indel) polymorphisms in the regulatory region of bovine PRNP are strongly associated with BSE incidence in cattle. Genotyping of BSE-affected and control animals of UK Holstein, German Holstein, German Brown and German Fleckvieh breeds revealed a significant overrepresentation of the deletion alleles at both polymorphic sites in diseased animals (P = 2.01 × 10-3 and P = 8.66 × 10-5, respectively). The main effect on susceptibility is associated with the 12-bp indel polymorphism. Compared with non-carriers, heterozygous and homozygous carriers of the 12-bp deletion allele possess relatively higher risks of having BSE, ranging from 1.32 to 4.01 and 1.74 to 3.65 in the different breeds. These values correspond to population attributable risks ranging from 35% to 53%. Conclusion Our results demonstrate a substantial genetic PRNP associated component for BSE susceptibility in cattle. Although the BSE risk conferred by the deletion allele of the 12-bp indel in the regulatory region of PRNP is substantial, the main risk factor for BSE in cattle is environmental, i.e. exposure to feedstuffs contaminated with the infectious agent. PMID:17014722

A major genetic component of BSE susceptibility

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Williams John L

2006-10-01

Full Text Available Abstract Background Coding variants of the prion protein gene (PRNP have been shown to be major determinants for the susceptibility to transmitted prion diseases in humans, mice and sheep. However, to date, the effects of polymorphisms in the coding and regulatory regions of bovine PRNP on bovine spongiform encephalopathy (BSE susceptibility have been considered marginal or non-existent. Here we analysed two insertion/deletion (indel polymorphisms in the regulatory region of bovine PRNP in BSE affected animals and controls of four independent cattle populations from UK and Germany. Results In the present report, we show that two previously reported 23- and 12-bp insertion/deletion (indel polymorphisms in the regulatory region of bovine PRNP are strongly associated with BSE incidence in cattle. Genotyping of BSE-affected and control animals of UK Holstein, German Holstein, German Brown and German Fleckvieh breeds revealed a significant overrepresentation of the deletion alleles at both polymorphic sites in diseased animals (P = 2.01 × 10-3 and P = 8.66 × 10-5, respectively. The main effect on susceptibility is associated with the 12-bp indel polymorphism. Compared with non-carriers, heterozygous and homozygous carriers of the 12-bp deletion allele possess relatively higher risks of having BSE, ranging from 1.32 to 4.01 and 1.74 to 3.65 in the different breeds. These values correspond to population attributable risks ranging from 35% to 53%. Conclusion Our results demonstrate a substantial genetic PRNP associated component for BSE susceptibility in cattle. Although the BSE risk conferred by the deletion allele of the 12-bp indel in the regulatory region of PRNP is substantial, the main risk factor for BSE in cattle is environmental, i.e. exposure to feedstuffs contaminated with the infectious agent.

Effects of Inventory Bias on Landslide Susceptibility Calculations

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Stanley, T. A.; Kirschbaum, D. B.

2017-01-01

Many landslide inventories are known to be biased, especially inventories for large regions such as Oregon's SLIDO or NASA's Global Landslide Catalog. These biases must affect the results of empirically derived susceptibility models to some degree. We evaluated the strength of the susceptibility model distortion from postulated biases by truncating an unbiased inventory. We generated a synthetic inventory from an existing landslide susceptibility map of Oregon, then removed landslides from this inventory to simulate the effects of reporting biases likely to affect inventories in this region, namely population and infrastructure effects. Logistic regression models were fitted to the modified inventories. Then the process of biasing a susceptibility model was repeated with SLIDO data. We evaluated each susceptibility model with qualitative and quantitative methods. Results suggest that the effects of landslide inventory bias on empirical models should not be ignored, even if those models are, in some cases, useful. We suggest fitting models in well-documented areas and extrapolating across the study region as a possible approach to modeling landslide susceptibility with heavily biased inventories.

Influence of Radiation Damage and Isochronal Annealing on the Magnetic Susceptibility of Pu1-xAmx Alloys

International Nuclear Information System (INIS)

McCall, Scott K.; Fluss, Michael J.; Chung, Brandon W.; Haire, Richard G.

2008-01-01

Results of radiation damage in Pu and Pu 1-x Am x alloys studied with magnetic susceptibility, χ(T), and resistivity are presented. Damage accumulated at low temperatures increases χ(T) for all measured alloys, with the trend generally enhanced as the lattice expands. There is a trend towards saturation observable in the damage induced magnetic susceptibility data. that is not evident in similar damage induced resistivity data taken on the same specimen. A comparison of isochronal annealing curves measured by both resistivity and magnetic susceptibility on a 4.3 at% Ga stabilized δ-Pu specimen show that Stage I annealing, where interstitials begin to move, is largely transparent to the magnetic measurement. This indicates that interstitials have little impact on the damage induced increase in the magnetic susceptibility. The isochronal annealing curves of the Pu 1-x Am x alloys do not show distinct annealing stages as expected for alloys. However, samples near 20% Am concentration show an unexpected increase in magnetization beginning when specimens are annealed to 35 K. This behavior is also reflected in a time dependent increase in the magnetic susceptibility of damaged specimens indicative of first order kinetics. These results suggest there may be a metastable phase induced by radiation damage and annealing in Pu 1-x Am x alloys. (authors)

Ertapenem susceptibility of extended spectrum beta-lactamase-producing organisms

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Selby Edward B

2007-06-01

Full Text Available Abstract Background Infections caused by multiply drug resistant organisms such as extended spectrum beta-lactamase (ESBL-producing Escherichia coli and Klebsiella pneumoniae are increasing. Carbapenems (imipenem and meropenem are the antibiotics commonly used to treat these agents. There is limited clinical data regarding the efficacy of the newest carbapenem, ertapenem, against these organisms. Ertapenem susceptibility of ESBL-producing E. coli and K. pneumoniae clinical isolates were evaluated and compared to imipenem to determine if imipenem susceptibility could be used as a surrogate for ertapenem susceptibility. Methods 100 ESBL isolates (n = 34 E. coli and n = 66 K. pneumoniae collected from 2005–2006 clinical specimens at WRAMC were identified and tested for susceptibility by Vitek Legacy [bioMerieux, Durham, NC]. Ertapenem susceptibility was performed via epsilometer test (E-test [AB Biodisk, Solna, Sweden]. Results 100% of ESBL isolates tested were susceptible to ertapenem. 100% of the same isolates were also susceptible to imipenem. Conclusion These results, based on 100% susceptibility, suggest that ertapenem may be an alternative to other carbapenems for the treatment of infections caused by ESBL-producing E. coli and K. pneumoniae. Clinical outcomes studies are needed to determine if ertapenem is effective for the treatment of infection caused by these organisms. However, due to lack of resistant isolates, we are unable to conclude whether imipenem susceptibility accurately predicts ertapenem susceptibility.

Measurement of weak electric currents in copper wire phantoms using MRI: influence of susceptibility enhancement.

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Huang, Ruiwang; Posnansky, Oleg; Celik, Abdullah; Oros-Peusquens, Ana-Maria; Ermer, Veronika; Irkens, Marco; Wegener, H-Peter; Shah, N Jon

2006-08-01

The use of magnetic resonance imaging (MRI)-based methods for the direct detection of neuronal currents is a topic of intense investigation. Much experimental work has been carried out with the express aim of establishing detection thresholds and sensitivity to flowing currents. However, in most of these experiments, magnetic susceptibility enhancement was ignored. In this work, we present results that show the influence of a susceptibility artefact on the detection threshold and sensitivity. For this purpose, a novel phantom, consisting of a water-filled cylinder with two wires of different materials connected in series, was constructed. Magnitude MR images were acquired from a single slice using a gradient-echo echo planar imaging (EPI) sequence. The data show that the time course of the detected MR signal magnitude correlates very well with the waveform of the input current. The effect of the susceptibility artefacts arising from the two different wires was examined by comparing the magnitudes of the MR signals at different voxel locations. Our results indicate the following: (1) MR signal enhancement arising from the magnetic susceptibility effect influences the detection sensitivity of weak current; (2) the detection threshold and sensitivity are phantom-wire dependent; (3) sub-mu A electric current detection in a phantom is possible on a 1.5-T MR scanner in the presence of susceptibility enhancement.

Prevalence and bacterial susceptibility of hospital acquired urinary tract infection

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Dias Neto José Anastácio

2003-01-01

Full Text Available PURPOSE: Urinary tract infection is the most common nosocomially acquired infection. It is important to know the etiology and antibiotic susceptibility infectious agents to guide the initial empirical treatment. OBJECTIVE: To determine the prevalence of bacterial strains and their antibiotic susceptibility in nosocomially acquired urinary tract infection in a university hospital between January and June 2003. METHODS: We analyzed the data of 188 patients with positive urine culture (= 10(5 colony-forming units/mL following a period of 48 hours after admission. RESULTS: Half of patients were male. Mean age was 50.26 ± 22.7 (SD, range 3 months to 88 years. Gram-negative bacteria were the agent in approximately 80% of cases. The most common pathogens were E. coli (26%, Klebsiella sp. (15%, P. aeruginosa (15% and Enterococcus sp. (11%. The overall bacteria susceptibility showed that the pathogens were more sensible to imipenem (83%, second or third generation cephalosporin and aminoglycosides; and were highly resistant to ampicillin (27% and cefalothin (30%. It is important to note the low susceptibility to ciprofloxacin (42% and norfloxacin (43%. CONCLUSION: This study suggests that if one can not wait the results of urine culture, the best choices to begin empiric treatment are imipenem, second or third generation cephalosporin and aminoglycosides. Cefalothin and ampicillin are quite ineffective to treat these infections.

Magnetic susceptibility of YbN

International Nuclear Information System (INIS)

Zhou, Y.; Bowen, S.P.; Koelling, D.D.; Monnier, R.

1991-01-01

Applying the Zwicknagl, Zevin, and Fulde (ZZF) approximation for the spectral densities of the occupied and empty f states resulting from a degenerate-Anderson-impurity model, which incorporates crystal fields, we compute the low-temperature magnetic susceptibility of YbN. The model, in which each crystal-field level couples to the band states with its own hybridization function, has previously been successfully applied without the ZZF approximation to explain the specific-heat structure at low temperatures. The ZZF approximation removes the spurious zero-temperature behavior of the parent noncrossing approximation for the susceptibility. Surprisingly, even at the low crystal-field degeneracy (N=2) of YbN, the Shiba relation is very nearly satisfied. The appropriate experimental impurity susceptibility for comparison is extracted from the measurement by removing an empirical exchange interaction. The resultant Kondo temperature (T 0 =8.49 K) is consistent with previous specific-heat estimates (10--11 K), and the agreement with experiment is good

Anisotropy of susceptibility in rocks which are magnetically nonlinear even in low fields

Science.gov (United States)

Hrouda, František; Chadima, Martin; Ježek, Josef

2018-06-01

Theory of the low-field anisotropy of magnetic susceptibility (AMS) assumes a linear relationship between magnetization and magnetizing field, resulting in field-independent susceptibility. This is valid for diamagnetic and paramagnetic minerals by definition and also for pure magnetite, while in titanomagnetite, pyrrhotite and hematite the susceptibility may be clearly field-dependent even in low fields used in common AMS meter. Consequently, the use of the linear AMS theory is fully legitimate in the former minerals, but in principle incorrect in the latter ones. Automated measurement of susceptibility in 320 directions in variable low-fields ranging from 5 to 700 A m-1 was applied to more than 100 specimens of various pyrrhotite-bearing and titanomagnetite-bearing rocks. Data analysis showed that the anisotropic susceptibility remains well represented by an ellipsoid in the entire low-field span even though the ellipsoid increases its volume and eccentricity. The principal directions do not change their orientations with low-field in most specimens. Expressions for susceptibility as a function of field were found in the form of diagonal tensor whose elements are polynomials of low order. In a large proportion of samples, the susceptibility expressions can be further simplified to have one common skeleton polynomial.

Improving the quark number susceptibilities for staggered fermions

International Nuclear Information System (INIS)

Gavai, Rajiv V.

2003-01-01

Quark number susceptibilities approach their ideal gas limit at sufficiently high temperatures. As in the case of other thermodynamic quantities, this limit itself is altered substantially on lattices with small temporal extent, N t = 4-8, making it thus difficult to check the validity of perturbation theory. Unlike other observables, improving susceptibilities or number densities is subject to constraints of current conservation and absence of chemical potential (μ) dependent divergences. We construct such an improved number density and susceptibility for staggered fermions and show that they approximate the continuum ideal gas limit better on small temporal lattices

Intersite interactions and susceptibility in mixed valence systems

International Nuclear Information System (INIS)

Xiaoqian Wang; Gao Lin; Bingjian Ni; Fusui Liu.

1985-10-01

This paper considers the effect of intersite processes on the susceptibility in mixed valence system. The method of thermodynamical perturbation used in this paper can also be generalized to study other properties of mixed valence system. The general formula of partition function of two-site interactions for the mixed valence system is given. The numerical calculations show that the intersite interaction is large enough to explain the minimum of susceptibility discovered in experiments. The different types of our theoretical curves predict that the susceptibility should exhibit a rich variety of behaviour at low temperature for various materials. (author)

Changes in bacillus thuringiensis tolerance levels due to hybridization of Bt-tolerant and susceptible silkworm populations

International Nuclear Information System (INIS)

Begumad, H.A.; Hassana, E.; Dingleb, J.; Alshehic, A.A.

2012-01-01

Males and females of a Bt-tolerant mulberry silkworm (Bombyx mori L.) population were crossed with females and males of a Bt-susceptible population, to produce Bt-tolerant silkworm hybrids, and to determine the expression of the Bt-tolerance pattern in the F 1 hybrids. It was observed that when a Bt-tolerant (42% larval mortality) female (BtT ) silkworm was crossed with a Bt-susceptible (85% larval mortality) male (BtS ), the resultant F 1 offspring showed lower levels of Bt-tolerance (87% larval mortality). On the other hand, when a Bt-tolerant male (BtT ) was crossed with a Bt-susceptible female (BtS ), the F 1 hybrid showed higher levels of Bt-tolerance (35% larval mortality) characteristic. The probit statistics showed that both hybrids expressed Bt-tolerance or susceptible levels similar to their male parents. These different patterns of Bt-tolerance in F 1 hybrids might be due to the transferring of a Bt-tolerant gene, from the parents to offspring, through the homozygotic male (ZZ) silkworm. (author)

Landslide susceptibility map: from research to application

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Fiorucci, Federica; Reichenbach, Paola; Ardizzone, Francesca; Rossi, Mauro; Felicioni, Giulia; Antonini, Guendalina

2014-05-01

Susceptibility map is an important and essential tool in environmental planning, to evaluate landslide hazard and risk and for a correct and responsible management of the territory. Landslide susceptibility is the likelihood of a landslide occurring in an area on the basis of local terrain conditions. Can be expressed as the probability that any given region will be affected by landslides, i.e. an estimate of "where" landslides are likely to occur. In this work we present two examples of landslide susceptibility map prepared for the Umbria Region and for the Perugia Municipality. These two maps were realized following official request from the Regional and Municipal government to the Research Institute for the Hydrogeological Protection (CNR-IRPI). The susceptibility map prepared for the Umbria Region represents the development of previous agreements focused to prepare: i) a landslide inventory map that was included in the Urban Territorial Planning (PUT) and ii) a series of maps for the Regional Plan for Multi-risk Prevention. The activities carried out for the Umbria Region were focused to define and apply methods and techniques for landslide susceptibility zonation. Susceptibility maps were prepared exploiting a multivariate statistical model (linear discriminant analysis) for the five Civil Protection Alert Zones defined in the regional territory. The five resulting maps were tested and validated using the spatial distribution of recent landslide events that occurred in the region. The susceptibility map for the Perugia Municipality was prepared to be integrated as one of the cartographic product in the Municipal development plan (PRG - Piano Regolatore Generale) as required by the existing legislation. At strategic level, one of the main objectives of the PRG, is to establish a framework of knowledge and legal aspects for the management of geo-hydrological risk. At national level most of the susceptibility maps prepared for the PRG, were and still are obtained

Multidisciplinary approach to evaluate landslide susceptibility along highway in northern Calabria, Italy

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Muto, Francesco; Conforti, Massimo; Critelli, Salvatore; Fabbricatore, Davide; Filomena, Luciana; Rago, Valeria; Robustelli, Gaetano; Scarciglia, Fabio; Versace, Pasquale

2014-05-01

), that are a unique combination of the predisposing factors. Subsequently, the landslide area is determined within each UCU and the landslide density is computed. The outcome of the study was a classification of the study area into four susceptibility classes, ranked from low to very high. The results showed that the 33% of the study area is characterized by a high to very high degree of susceptibility. The validation procedure results, obtained by crossing the group of the landslide of validation set with the susceptibility map, showed that the predictive model is generally satisfactory; therefore, over 75% of the landslide of validation set is correctly classified falling in high and very high susceptibility classes. The consistency of the model is also suggested by computing the seed cell area index (SCAI) because the high and very high susceptibility classes have very low SCAI values, whereas the SCAI values of the very low and low susceptibility classes are very high. Finally, the landslide susceptibility map provides the baseline information for further evaluations of landslide hazards and related risks.

Susceptible-infected-susceptible epidemics on networks with general infection and cure times

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Cator, E.; van de Bovenkamp, R.; Van Mieghem, P.

2013-06-01

The classical, continuous-time susceptible-infected-susceptible (SIS) Markov epidemic model on an arbitrary network is extended to incorporate infection and curing or recovery times each characterized by a general distribution (rather than an exponential distribution as in Markov processes). This extension, called the generalized SIS (GSIS) model, is believed to have a much larger applicability to real-world epidemics (such as information spread in online social networks, real diseases, malware spread in computer networks, etc.) that likely do not feature exponential times. While the exact governing equations for the GSIS model are difficult to deduce due to their non-Markovian nature, accurate mean-field equations are derived that resemble our previous N-intertwined mean-field approximation (NIMFA) and so allow us to transfer the whole analytic machinery of the NIMFA to the GSIS model. In particular, we establish the criterion to compute the epidemic threshold in the GSIS model. Moreover, we show that the average number of infection attempts during a recovery time is the more natural key parameter, instead of the effective infection rate in the classical, continuous-time SIS Markov model. The relative simplicity of our mean-field results enables us to treat more general types of SIS epidemics, while offering an easier key parameter to measure the average activity of those general viral agents.

The BTNL2 G16071A gene polymorphism increases granulomatous disease susceptibility

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Tong, Xiang; Ma, Yao; Niu, Xundong; Yan, Zhipeng; Liu, Sitong; Peng, Bo; Peng, Shifeng; Fan, Hong

2016-01-01

Abstract Objective: The butyrophilin-like 2 (BTNL2) G16071A gene polymorphism has been implicated in the susceptibility to granulomatous diseases, but the results were inconclusive. The objective of the current study was to precisely explore the relationship between BTNL2 G16071A gene polymorphism and granulomatous disease susceptibility by the meta-analysis including false-positive report probability (FPRP) test. Methods: A systematic literature search in the PubMed, Embase, and Wanfang databases, China National Knowledge Internet, and commercial Internet search engines was conducted to identify studies published up to April 1, 2016. The odds ratio (OR) with 95% confidence interval (CI) was used to assess the effect size. Statistical analysis was conducted using the STATA 12.0 software and FPRP test sheet. Results: In total, all 4324 cases and 4386 controls from 14 eligible studies were included in the current meta-analysis. By the overall meta-analysis, we found a significant association between BTNL2 G16071A gene polymorphism and granulomatous disease susceptibility (A vs G: OR = 1.25, 95% CI = 1.07–1.45, P = 0.005). The meta-regression analyses showed that a large proportion of the between-study heterogeneity was significantly attributed to the ethnicity (A vs G, P = 0.013) and the types of granulomatous diseases (A vs G, P = 0.002). By the subgroup meta-analysis, the BTNL2 G16071A gene polymorphism was associated with granulomatous disease susceptibility in Caucasians (A vs G: OR = 1.37, 95% CI = 1.18–1.58, P susceptibility (A vs G: OR = 1.52, 95% CI = 1.39–1.66, P susceptibility (A vs G, FPRP susceptibility among Caucasians (A vs G, FPRP susceptibility, especially increasing the sarcoidosis susceptibility. In addition, the polymorphism may be greatly associated with likelihood of granulomatous diseases among Caucasians. PMID:27472712

Hot tearing susceptibility of binary Mg–Y alloy castings

International Nuclear Information System (INIS)

Wang, Zhi; Huang, Yuanding; Srinivasan, Amirthalingam; Liu, Zheng; Beckmann, Felix; Kainer, Karl Ulrich; Hort, Norbert

2013-01-01

Highlights: ► Quantitatively and qualitatively assessing hot tearing susceptibility for different alloys. ► Monitoring the hot tearing propagation process. ► Detecting the hot tearing initiation/onset temperature. ► Recording the stress and strain evolution during the casting solidification and the subsequent cooling. - Abstract: The influence of Y content on the hot tearing susceptibility (HTS) of binary Mg–Y alloys has been predicted using thermodynamic calculations based on Clyne and Davies model. The calculated results are compared with experimental results determined using a constrained rod casting (CRC) apparatus with a load cell and data acquisition system. Both thermodynamic calculations and experimental measurements indicate that the hot tearing susceptibility as a function of Y content follows the “λ” shape. The experimental results show that HTS first increases with increase in Y content, reaches the maximum at about 0.9 wt.%Y and then decreases with further increase the Y content. The maximum susceptibility observed in Mg–0.9 wt.%Y alloy is attributed to its coarsened columnar microstructure, large solidification range and small amount of eutectic at the time of hot tearing. The initiation of hot cracks is monitored during CRC experiments. It corresponds to a drop in load increment on the force curves. The critical solid fractions at which the hot cracks are initiated are in the range from 0.9 to 0.99. It is also found that it decreases with increasing the content of Y. The hot cracks propagate along the dendritic or grain boundaries through the interdendritic separation or tearing of interconnected dendrites. Some of the formed cracks are possible to be healed by the subsequent refilling of the remained liquids

Magnetic susceptibility characterisation of superparamagnetic microspheres

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Grob, David Tim; Wise, Naomi; Oduwole, Olayinka; Sheard, Steve

2018-04-01

The separation of magnetic materials in microsystems using magnetophoresis has increased in popularity. The wide variety and availability of magnetic beads has fuelled this drive. It is important to know the magnetic characteristics of the microspheres in order to accurately use them in separation processes integrated on a lab-on-a-chip device. To investigate the magnetic susceptibility of magnetic microspheres, the magnetic responsiveness of three types of Dynabeads microspheres were tested using two different approaches. The magnetophoretic mobility of individual microspheres is studied using a particle tracking system and the magnetization of each type of Dynabeads microsphere is measured using SQUID relaxometry. The magnetic beads' susceptibility is obtained at four different applied magnetic fields in the range of 38-70 mT for both the mobility and SQUID measurements. The susceptibility values in both approaches show a consistent magnetic field dependence.

Sensory Processing Sensitivity as a Marker of Differential Susceptibility to Parenting

Science.gov (United States)

Slagt, Meike; Dubas, Judith Semon; van Aken, Marcel A. G.; Ellis, Bruce J.; Dekovic, Maja

2018-01-01

In this longitudinal multiinformant study negative emotionality and sensory processing sensitivity were compared as susceptibility markers among kindergartners. Participating children (N = 264, 52.9% boys) were Dutch kindergartners (M[subscript age] = 4.77, SD = 0.60), followed across three waves, spaced seven months apart. Results show that…

Carbapenem susceptibilities and non-susceptibility concordance to different carbapenems amongst clinically important Gram-negative bacteria isolated from intensive care units in Taiwan: results from the Surveillance of Multicentre Antimicrobial Resistance in Taiwan (SMART) in 2009.

Science.gov (United States)

Jean, Shio-Shin; Hsueh, Po-Ren; Lee, Wen-Sen; Yu, Kwok-Woon; Liao, Chun-Hsing; Chang, Feng-Yi; Ko, Wen-Chien; Wu, Jiunn-Jong; Chen, Yen-Hsu; Chen, Yao-Shen; Liu, Jien-Wei; Lu, Min-Chi; Liu, Cheng-Yi; Lam, Carlos; Chen, Ray-Jade

2013-05-01

To investigate the in vitro susceptibilities to various carbapenems amongst clinical Gram-negative bacteria isolated from patients in intensive care units of ten major teaching hospitals in Taiwan in 2009, a survey was conducted to determine the minimum inhibitory concentrations (MICs) of ertapenem, imipenem, meropenem and doripenem against isolates of Enterobacteriaceae (n = 594), Pseudomonas aeruginosa (n = 185), Acinetobacter baumannii (n = 192) and Burkholderia cepacia (n = 23) using the agar dilution method. Susceptibilities were determined according to 2009, 2011 and 2012 MIC breakpoints recommended by the CLSI as well as 2012 MIC breakpoints recommended by EUCAST. Based on CLSI 2012 criteria, the ertapenem susceptible rate was 93%, 81%, 68% and 92% for Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae and Serratia marcescens, respectively. All Proteus mirabilis and Morganella morganii isolates were susceptible to ertapenem; however, 64% of P. mirabilis and all M. morganii isolates were non-susceptible to imipenem. Meropenem and doripenem had better activities than imipenem against ertapenem-non-susceptible Enterobacteriaceae isolates. E. coli, K. pneumoniae and E. cloacae with ertapenem MICs≥4 mg/L were synchronously not susceptible to imipenem, meropenem and doripenem. Imipenem susceptibility was 65% and 29% for P. aeruginosa and A. baumannii, respectively. Additionally, P. aeruginosa and A. baumannii isolates with imipenem MICs≥8 mg/L were also not susceptible to meropenem and doripenem. These data provide a better understanding of choosing appropriate carbapenem agents to treat infections caused by ertapenem-non-susceptible Enterobacteriaceae as well as P. aeruginosa and A. baumannii isolates with imipenem MICs≥4 mg/L. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Rapid, radiolabeled-microculture method that uses macrophages for in vitro evaluation of Mycobacterium leprae viability and drug susceptibility.

Science.gov (United States)

Mittal, A; Sathish, M; Seshadri, P S; Nath, I

1983-04-01

This paper describes a microculture rapid assay using radiolabeling and mouse macrophages to determine the viability and the drug susceptibility or resistance of Mycobacterium leprae. Comparison of M. leprae resident macrophage cultures maintained in 96-well flat-bottomed plates showed results for viability and susceptibility or resistance to dapsone that were similar to results for concurrent cultures in Leighton tubes with greater numbers of bacilli and macrophages.

Rapid, Radiolabeled-Microculture Method That Uses Macrophages for In Vitro Evaluation of Mycobacterium leprae Viability and Drug Susceptibility

OpenAIRE

Mittal, A.; Sathish, M.; Seshadri, P. S.; Nath, Indira

1983-01-01

This paper describes a microculture rapid assay using radiolabeling and mouse macrophages to determine the viability and the drug susceptibility or resistance of Mycobacterium leprae. Comparison of M. leprae resident macrophage cultures maintained in 96-well flat-bottomed plates showed results for viability and susceptibility or resistance to dapsone that were similar to results for concurrent cultures in Leighton tubes with greater numbers of bacilli and macrophages.

CISH and Susceptibility to Infectious Diseases

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Khor, Chiea C.; Vannberg, Fredrik O.; Chapman, Stephen J.; Guo, Haiyan; Wong, Sunny H.; Walley, Andrew J.; Vukcevic, Damjan; Rautanen, Anna; Mills, Tara C.; Chang, Kwok-Chiu; Kam, Kai-Man; Crampin, Amelia C.; Ngwira, Bagrey; Leung, Chi-Chiu; Tam, Cheuk-Ming; Chan, Chiu-Yeung; Sung, Joseph J.Y.; Yew, Wing-Wai; Toh, Kai-Yee; Tay, Stacey K.H.; Kwiatkowski, Dominic; Lienhardt, Christian; Hien, Tran-Tinh; Day, Nicholas P.; Peshu, Nobert; Marsh, Kevin; Maitland, Kathryn; Scott, J. Anthony; Williams, Thomas N.; Berkley, James A.; Floyd, Sian; Tang, Nelson L.S.; Fine, Paul E.M.; Goh, Denise L.M.; Hill, Adrian V.S.

2013-01-01

Background The interleukin-2 (IL2)-mediated immune response is critical for host defence against infectious pathogens. CISH, a suppressor of cytokine signalling, controls IL2 signalling. Methods We tested for association between CISH polymorphisms and susceptibility to major infectious diseases (bacteremia, tuberculosis and severe malaria) in 8402 persons from the Gambia, Hong Kong, Kenya, Malawi, and Vietnam using a case-control design. We have previously tested twenty other immune-related genes in one or more of these sample collections. Results We observed associations between variant alleles of multiple CISH polymorphisms and increased susceptibility to each infectious disease in each of the study populations. When all five SNPs (CISH −639, −292, −163, +1320 and +3415) within the CISH-associated locus were considered together in a multi-SNP score, we found substantial support for an effect of CISH genetic variants on susceptibility to bacteremia, malaria, and tuberculosis (overall P=3.8 × 10−11) with CISH −292 being “responsible” for the majority of the association signal (P=4.58×10−7). Peripheral blood mononuclear cells of adult volunteers carrying the CISH −292 variant showed a muted response to IL2 stimulation — in the form of 25-40% less CISH — when compared with “control” cells lacking the −292 variant. Conclusions Variants of CISH are associated with susceptibility to diseases caused by diverse infectious pathogens, suggesting that negative regulators of cytokine signalling may play a major role in immunity against various infectious diseases. The overall risk of having one of these infectious diseases was found to be increased by at least 18 percent in individuals carrying the variant CISH alleles. PMID:20484391

Antimicrobial susceptibility determined by the E test, Löwenstein-Jensen proportion, and DNA sequencing methods among Mycobacterium tuberculosis isolates discrepancies, preliminary results

Directory of Open Access Journals (Sweden)

Maria Inês Moura Freixo

2004-02-01

Full Text Available Mycobacterium tuberculosis strains resistant to streptomycin (SM, isoniazid (INH, and/or rifampin (RIF as determined by the conventional Löwenstein-Jensen proportion method (LJPM were compared with the E test, a minimum inhibitory concentration susceptibility method. Discrepant isolates were further evaluated by BACTEC and by DNA sequence analyses for mutations in genes most often associated with resistance to these drugs (rpsL, katG, inhA, and rpoB. Preliminary discordant E test results were seen in 75% of isolates resistant to SM and in 11% to INH. Discordance improved for these two drugs (63% for SM and none for INH when isolates were re-tested but worsened for RIF (30%. Despite good agreement between phenotypic results and sequencing analyses, wild type profiles were detected on resistant strains mainly for SM and INH. It should be aware that susceptible isolates according to molecular methods might contain other mechanisms of resistance. Although reproducibility of the LJPM susceptibility method has been established, variable E test results for some M. tuberculosis isolates poses questions regarding its reproducibility particularly the impact of E test performance which may vary among laboratories despite adherence to recommended protocols. Further studies must be done to enlarge the evaluated samples and looked possible mutations outside of the hot spot sequenced gene among discrepant strains.

Ciprofloxacin susceptibility of Pseudomonas aeruginosa isolates from keratitis

DEFF Research Database (Denmark)

Lomholt, JA; Kilian, Mogens

2003-01-01

keratitis, endophthalmitis, contact lens associated red eye (CLARE), and contact lens storage cases showed MIC values below 1 mg/l. Several allelic forms of gyrA and a single variation in the mexR gene product were detected in 10 ciprofloxacin susceptible strains. CONCLUSIONS: The vast majority of eye......AIM: To examine the ciprofloxacin susceptibility of 106 Pseudomonas aeruginosa eye isolates from the United Kingdom, Denmark, India, the United States, and Australia, and to determine the molecular mechanisms of resistance. METHODS: Ciprofloxacin susceptibility was tested by an agar dilution method...... isolates of P aeruginosa from European countries are fully susceptible to ciprofloxacin and the concentration of ciprofloxacin eye drops used for local treatment (3000 mg/l) exceeds MIC values for strains recorded as resistant. Mutations in more than one target gene were associated with higher MIC values....

Ciprofloxacin susceptibility of Pseudomonas aeruginosa isolates from keratitis

DEFF Research Database (Denmark)

Lomholt, JA; Kilian, Mogens

2003-01-01

AIM: To examine the ciprofloxacin susceptibility of 106 Pseudomonas aeruginosa eye isolates from the United Kingdom, Denmark, India, the United States, and Australia, and to determine the molecular mechanisms of resistance. METHODS: Ciprofloxacin susceptibility was tested by an agar dilution method...... keratitis, endophthalmitis, contact lens associated red eye (CLARE), and contact lens storage cases showed MIC values below 1 mg/l. Several allelic forms of gyrA and a single variation in the mexR gene product were detected in 10 ciprofloxacin susceptible strains. CONCLUSIONS: The vast majority of eye...... isolates of P aeruginosa from European countries are fully susceptible to ciprofloxacin and the concentration of ciprofloxacin eye drops used for local treatment (3000 mg/l) exceeds MIC values for strains recorded as resistant. Mutations in more than one target gene were associated with higher MIC values....

Antimicrobial susceptibility pattern of bacteria isolated from patients with urinary tract infection

International Nuclear Information System (INIS)

Khan, I.U.; Mirza, I.A.; Ikram, A.; Afzal, A.; Ali, S.; Hussain, A.; Ghafoor, T.

2014-01-01

To determine the antimicrobial susceptibility pattern of bacterial pathogens in the patients of urinary tract infection reporting at a tertiary care hospital. Study Design: Laboratory based study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from January to December 2012. Methodology: A total of 440 culture positive bacterial isolates from 1110 urine samples; submitted over a period of one year were included in this study. Identification of bacterial isolates was done by standard biochemical profile of the organisms. The antimicrobial susceptibility of culture positive bacterial isolates was performed by disk diffusion method as recommended by Clinical Laboratory Standard Institute guidelines (CLSI). Results: Out of the 440 culture positive urine samples, 152 (34.6%) were from indoor patients whereas 288 (65.4%) from outdoor patients. Gram negative bacteria accounted for 414 (94%) of the total isolates while rest of the 26 (6%) were Gram positive bacteria. The most prevalent bacterial isolate was Escherichia (E.) coli 270 (61.3%) followed by Pseudomonas (P.) aeruginosa 52 (12%) and Klebsiella (K.) pneumoniae 42 (9.5%). The susceptibility pattern of E. coli showed that 96.2% of the bacterial isolates were sensitive to imipenem, 85.1% to amikacin, 80.7% to piperacillin/tazobactam and 72.6% to nitrofurantoin. In case of P. aeruginsosa, 73% bacterial isolates were sensitive to tazobactam/piperacillin, 69.2% to sulbactam/cefoperazone and 65.38% to imipenem. The antibiogram of K. pneumoniae has revealed that 76.1% of the bacterial isolates were sensitive to imipenem and 52.3% to piperacillin/tazobactam. Nitrofurantoin and imipenem were the most effective antimicrobials amongst the Enterococcus spp. as 92.3% showed susceptibility to this bacterial isolate. Conclusion: Majority of the bacterial isolates were sensitive to imipenem and piperacillin/tazobactam while susceptibility to most of the commonly used oral

Low-field susceptibilities of rare earth spin glass alloys

International Nuclear Information System (INIS)

Sarkissian, B.V.B.

1977-01-01

Static susceptibility in various applied fields and AC susceptibility data on Sc 13% Gd and Sc 4.5% Tb spin glass alloys are reported. The data show that the sharp peak at the freezing temperature, Tsub(g), normally observed in the low-field susceptibility of spin glasses containing 3d magnetic impurities is observed here in the case of Gd, which is an S state solute, but not for Tb. On the contrary, for the Sc-Tb alloy a rather rounded maximum is observed which becomes slightly sharper with increasing applied magnetic fields. (author)

Multifractal magnetic susceptibility distribution models of hydrothermally altered rocks in the Needle Creek Igneous Center of the Absaroka Mountains, Wyoming

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M. E. Gettings

2005-01-01

Full Text Available Magnetic susceptibility was measured for 700 samples of drill core from thirteen drill holes in the porphyry copper-molybdenum deposit of the Stinkingwater mining district in the Absaroka Mountains, Wyoming. The magnetic susceptibility measurements, chemical analyses, and alteration class provided a database for study of magnetic susceptibility in these altered rocks. The distribution of the magnetic susceptibilities for all samples is multi-modal, with overlapping peaked distributions for samples in the propylitic and phyllic alteration class, a tail of higher susceptibilities for potassic alteration, and an approximately uniform distribution over a narrow range at the highest susceptibilities for unaltered rocks. Samples from all alteration and mineralization classes show susceptibilities across a wide range of values. Samples with secondary (supergene alteration due to oxidation or enrichment show lower susceptibilities than primary (hypogene alteration rock. Observed magnetic susceptibility variations and the monolithological character of the host rock suggest that the variations are due to varying degrees of alteration of blocks of rock between fractures that conducted hydrothermal fluids. Alteration of rock from the fractures inward progressively reduces the bulk magnetic susceptibility of the rock. The model introduced in this paper consists of a simulation of the fracture pattern and a simulation of the alteration of the rock between fractures. A multifractal model generated from multiplicative cascades with unequal ratios produces distributions statistically similar to the observed distributions. The reduction in susceptibility in the altered rocks was modelled as a diffusion process operating on the fracture distribution support. The average magnetic susceptibility was then computed for each block. For the purpose of comparing the model results with observation, the simulated magnetic susceptibilities were then averaged over the same

Multifractal magnetic susceptibility distribution models of hydrothermally altered rocks in the Needle Creek Igneous Center of the Absaroka Mountains, Wyoming

Science.gov (United States)

Gettings, M.E.

2005-01-01

Magnetic susceptibility was measured for 700 samples of drill core from thirteen drill holes in the porphyry copper-molybdenum deposit of the Stinkingwater mining district in the Absaroka Mountains, Wyoming. The magnetic susceptibility measurements, chemical analyses, and alteration class provided a database for study of magnetic susceptibility in these altered rocks. The distribution of the magnetic susceptibilities for all samples is multi-modal, with overlapping peaked distributions for samples in the propylitic and phyllic alteration class, a tail of higher susceptibilities for potassic alteration, and an approximately uniform distribution over a narrow range at the highest susceptibilities for unaltered rocks. Samples from all alteration and mineralization classes show susceptibilities across a wide range of values. Samples with secondary (supergene) alteration due to oxidation or enrichment show lower susceptibilities than primary (hypogene) alteration rock. Observed magnetic susceptibility variations and the monolithological character of the host rock suggest that the variations are due to varying degrees of alteration of blocks of rock between fractures that conducted hydrothermal fluids. Alteration of rock from the fractures inward progressively reduces the bulk magnetic susceptibility of the rock. The model introduced in this paper consists of a simulation of the fracture pattern and a simulation of the alteration of the rock between fractures. A multifractal model generated from multiplicative cascades with unequal ratios produces distributions statistically similar to the observed distributions. The reduction in susceptibility in the altered rocks was modelled as a diffusion process operating on the fracture distribution support. The average magnetic susceptibility was then computed for each block. For the purpose of comparing the model results with observation, the simulated magnetic susceptibilities were then averaged over the same interval as the

Burst of virus infection and a possibly largest epidemic threshold of non-Markovian susceptible-infected-susceptible processes on networks

Science.gov (United States)

Liu, Qiang; Van Mieghem, Piet

2018-02-01

Since a real epidemic process is not necessarily Markovian, the epidemic threshold obtained under the Markovian assumption may be not realistic. To understand general non-Markovian epidemic processes on networks, we study the Weibullian susceptible-infected-susceptible (SIS) process in which the infection process is a renewal process with a Weibull time distribution. We find that, if the infection rate exceeds 1 /ln(λ1+1 ) , where λ1 is the largest eigenvalue of the network's adjacency matrix, then the infection will persist on the network under the mean-field approximation. Thus, 1 /ln(λ1+1 ) is possibly the largest epidemic threshold for a general non-Markovian SIS process with a Poisson curing process under the mean-field approximation. Furthermore, non-Markovian SIS processes may result in a multimodal prevalence. As a byproduct, we show that a limiting Weibullian SIS process has the potential to model bursts of a synchronized infection.

Spectroscopic AC susceptibility imaging (sASI) of magnetic nanoparticles

International Nuclear Information System (INIS)

Ficko, Bradley W.; Nadar, Priyanka M.; Diamond, Solomon G.

2015-01-01

This study demonstrates a method for alternating current (AC) susceptibility imaging (ASI) of magnetic nanoparticles (mNPs) using low cost instrumentation. The ASI method uses AC magnetic susceptibility measurements to create tomographic images using an array of drive coils, compensation coils and fluxgate magnetometers. Using a spectroscopic approach in conjunction with ASI, a series of tomographic images can be created for each frequency measurement set and is termed sASI. The advantage of sASI is that mNPs can be simultaneously characterized and imaged in a biological medium. System calibration was performed by fitting the in-phase and out-of-phase susceptibility measurements of an mNP sample with a hydrodynamic diameter of 100 nm to a Brownian relaxation model (R 2 =0.96). Samples of mNPs with core diameters of 10 and 40 nm and a sample of 100 nm hydrodynamic diameter were prepared in 0.5 ml tubes. Three mNP samples were arranged in a randomized array and then scanned using sASI with six frequencies between 425 and 925 Hz. The sASI scans showed the location and quantity of the mNP samples (R 2 =0.97). Biological compatibility of the sASI method was demonstrated by scanning mNPs that were injected into a pork sausage. The mNP response in the biological medium was found to correlate with a calibration sample (R 2 =0.97, p<0.001). These results demonstrate the concept of ASI and advantages of sASI. - Highlights: • Development of an AC susceptibility imaging model. • Comparison of AC susceptibility imaging (ASI) and susceptibility magnitude imaging (SMI). • Demonstration of ASI and spectroscopic ASI (sASI) using three different magnetic nanoparticle types. • SASI scan separation of three different magnetic nanoparticles samples using 5 spectroscopic frequencies. • Demonstration of biological feasibility of sASI

Pre-Use Susceptibility to Ceftaroline in Clinical Staphylococcus aureus Isolates from Germany: Is There a Non-Susceptible Pool to be Selected?

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Birgit Strommenger

Full Text Available Ceftaroline is a new cephalosporin active against Methicillin-resistant Staphylococcus aureus (MRSA. Based on a representative collection of clinical S. aureus isolates from Germany, supplemented with isolates of clonal lineages ST228 and ST239, we demonstrate the in-vitro susceptibility towards ceftaroline prior to its introduction into clinical use for a total of 219 isolates. Susceptibility testing was performed by broth microdilution, disc diffusion and Etest, respectively. Results were interpreted according to EUCAST guidelines and showed considerable variance in dependence on clonal affiliation of the isolates tested. Among isolates of widespread hospital-associated lineages we found a high proportion of clinical isolates with MICs close to the EUCAST breakpoint (MIC50/90 1.0/1.5 mg/L; currently, interpretation of these "borderline" MICs is complicated by a lack of concordant susceptibility testing methods and reasonable breakpoint determination. Isolates of clonal lineages ST228 and ST239 demonstrated increased MIC50/90 values of 2.5/3.33 mg/L. Sequencing of mecA revealed no association of resistance to a specific mecA polymorphism, but rather reveals two regions in the non-penicillin-binding domain of PbP2a which displayed different combinations of mutations putatively involved in resistance development. This study provides national baseline data to (i adjust susceptibility testing methods and current breakpoints to clinical and epidemiological requirements, (ii evaluate current breakpoints with respect to therapeutic outcome and (iii monitor further resistance evolution.

Magnetic susceptibilities of integrable quantum ladders

International Nuclear Information System (INIS)

Park, Soo A; Lee, K.

2001-01-01

As an extension of previous studies, we consider the magnetic susceptibilities of a coupled spin chain model at low temperature and of a more realistic model at low temperature and of a more realistic model having a t-J ladder structure at zero temperature. The magnetic susceptibilities for both models are obtained numerically when the coupling constant is greater than its critical value. In this region, the ladders behave as a single chain for H c and as two independent chains for H>H c , showing a divergence at H c . This divergence is expected to smear out at a finite temperature

Fidelity susceptibility and long-range correlation in the Kitaev honeycomb model

Science.gov (United States)

Yang, Shuo; Gu, Shi-Jian; Sun, Chang-Pu; Lin, Hai-Qing

2008-07-01

We study exactly both the ground-state fidelity susceptibility and bond-bond correlation function in the Kitaev honeycomb model. Our results show that the fidelity susceptibility can be used to identify the topological phase transition from a gapped A phase with Abelian anyon excitations to a gapless B phase with non-Abelian anyon excitations. We also find that the bond-bond correlation function decays exponentially in the gapped phase, but algebraically in the gapless phase. For the former case, the correlation length is found to be 1/ξ=2sinh-1[2Jz-1/(1-Jz)] , which diverges around the critical point Jz=(1/2)+ .

Susceptibility of Agrilus planipennis (Coleoptera: Buprestidae) to Beauveria bassiana and Metarhizium anisopliae

Science.gov (United States)

Houping Lui; Leah S. Bauer

2006-01-01

The susceptibility of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) to selected strains of the entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metschnikoff) Sorokin was evaluated through bioassays with direct immersion or foliar exposure under laboratory conditions. Results showed that A. planipennis adults were...

Effects of electron transitions on the susceptibility of Cd3Mg

International Nuclear Information System (INIS)

Sereda, Yu.P.

1988-01-01

The monotone susceptibility component has been examined at 4.2-420 K for Cd 1-x Mg x ordering single crystals for 0.18 < x < 0.33. The temperature and concentration curves for the susceptibility components show features related to structural and electronic topological transitions. The susceptibility anomalies at the electron-transition points are correlated with the boundaries to the existence of the allotropic forms

The susceptible-infected-recovered (SIR) model for viral marketing

Science.gov (United States)

Ismail, Siti Suhaila; Akil, Ku Azlina Ku; Chulan, Majdah; Sharif, Noorzila

2017-11-01

Viral marketing is a marketing strategy utilizes social media to spread information about a product or services provided. It is the most powerful way to share information in a short amount of time. The objective of this study is to investigate the dynamic of viral marketing within a time duration in the point of view of mathematics. This study used the epidemiological model known as Susceptible-Infected-Recovered (SIR). The model consists of a system of three differential equations with three state variables namely susceptible (S), infected (I) and recovered (R). It considers a case of SIR model with demography. Numerical experiments have been performed. The results show that viral marketing reaches its peak within two days. The online messages shared will become higher if the initial number of the infected individual has been increased.

Definition of a magnetic susceptibility of conglomerates with magnetite particles. Particularities of defining single particle susceptibility

Science.gov (United States)

Sandulyak, A. A.; Sandulyak, A. V.; Ershova, V.; Pamme, N.; Ngmasom, B.; Iles, A.

2017-11-01

Data of a magnetic susceptibility of ferro-and the ferrimagnetic particles of many technogenic, natural, special media are especially demanded for the solution of various tasks connected with purposeful magnetic impact on these particles. One of productive approaches to definition of a magnetic susceptibility χ of these particles consists in receiving experimental data of a susceptibility of disperse samples 〈 χ 〉 with a disperse phase of these particles. The paper expounds and analyses the results of experiments on defining (by Faraday method in a magnetic field with intensity H = 90-730 kA/m) the magnetic susceptibility 〈 χ 〉 of disperse samples (conglomerates) with a given volume ratio γ of magnetite particles (γ = 0.0065-0.25). The corresponding families of concentration and field dependences are provided alongside with discussing the applicability of linear and exponential functions to describe these dependences. We consider the possibility of defining single particles susceptibility χ (with simultaneous obtaining field dependence of this susceptibility) by the commonly used relation χ = 〈 χ 〉 /γ both at relatively small (preferable for accuracy reasons) values γ - to γ = 0.02…0.025, as well as at increased values γ - up to γ = 0.25. The data χ are provided depending on H and correlating with known data at H matter magnetic susceptibility χm (for the case when the particles are traditionally likened to balls with the characteristic for them demagnetising factor equalling 1/3) complies with the anticipated inverse function χm ∼ 1/H in the studied area H (where magnetization M expressed as M = χH reaches saturation M = Const).

Taxonomy and antifungal susceptibility of clinically important Rasamsonia species

DEFF Research Database (Denmark)

Houbraken, J.; Giraud, S.; Meijer, M.

2013-01-01

In recent years, Geosmithia argillacea has been increasingly reported in humans and animals and can be considered an emerging pathogen. The taxonomy of Geosmithia was recently studied, and Geosmithia argillacea and related species were transferred to the new genus Rasamsonia. The diversity among...... reported clinical isolates from animal or human patients. Susceptibility tests showed that the antifungal susceptibility profiles of the four members of the R. argillacea complex are similar, and caspofungin showed significant activity in vitro, followed by amphotericin B and posaconazole. Voriconazole...

Topological susceptibility from the overlap

DEFF Research Database (Denmark)

Del Debbio, Luigi; Pica, Claudio

2003-01-01

The chiral symmetry at finite lattice spacing of Ginsparg-Wilson fermionic actions constrains the renormalization of the lattice operators; in particular, the topological susceptibility does not require any renormalization, when using a fermionic estimator to define the topological charge....... Therefore, the overlap formalism appears as an appealing candidate to study the continuum limit of the topological susceptibility while keeping the systematic errors under theoretical control. We present results for the SU(3) pure gauge theory using the index of the overlap Dirac operator to study...

Susceptibility to chemical insecticides of two Brazilian populations of the visceral leishmaniasis vector Lutzomyia longipalpis (Diptera: Psychodidae).

Science.gov (United States)

Alexander, B; Barros, V C; de Souza, S F; Barros, S S; Teodoro, L P; Soares, Z R; Gontijo, N F; Reithinger, R

2009-10-01

To investigate the insecticide susceptibility of two geographically separated Lutzomyia longipalpis populations (Lapinha and Montes Claros) with different histories of insecticide exposure (i.e. no exposure and repeated exposure, respectively). (i) Bioassay monitoring of sand fly survival over time when exposed to a range of insecticides; and (ii) analysis of the level of insecticide detoxification enzymes in individual sand flies caught at both study sites. Insecticides tested were the organophosphates malathion and fenitrothion and the pyrethroids lambda-cyhalothrin, permethrin and deltamethrin. Survival analyses showed that whilst there was no overall significant difference in susceptibility of both populations to organophosphates, Lapinha sand flies were significantly more susceptible to pyrethroids than those from Montes Claros. Multiple regression analyses also showed that insecticide susceptibility in both locations varied with sand fly sex. The relative susceptibilities of the two sand fly populations to tested insecticides were also compared. Thus, Montes Claros sand flies were most susceptible to malathion, followed by fenitrothion, deltamethrin and permethrin. Those from Lapinha were most susceptible to lambda-cyhalothrin, followed by malathion, permethrin, deltamethrin and fenitrothion. Biochemical analyses demonstrated that Montes Claros sand flies had significantly lower insecticide detoxification enzyme activity than Lapinha sand flies. Our results are the first record of significantly reduced susceptibility to the insecticides used in control of wild populations of Lu. longipalpis. They demonstrate the importance of evaluating chemicals against this species by conventional bioassay and microplate assays before and during spraying programmes.

Effects of different aging statuses and strain rate on the adiabatic shear susceptibility of 2195 aluminum–lithium alloy

International Nuclear Information System (INIS)

Yang, Y.; Tan, G.Y.; Chen, P.X.; Zhang, Q.M.

2012-01-01

The adiabatic shear susceptibility of 2195 aluminum–lithium alloy was investigated by means of split Hopkinson pressure bar. The stress collapse in true stress–true strain curves and true stress–time curves was observed. The adiabatic shear susceptibility of different aging statuses and strain rate were discussed by means of metallography observation. The critical strain, stress collapse time and formation energy of adiabatic shear bands were compared. The results show that different aging statuses and strain rate have significant influences on adiabatic shear behaviors of 2195 aluminum–lithium alloy. The peak-aged specimen has the highest adiabatic shearing susceptibility, while the under-aged specimen has the least adiabatic shear susceptibility. The susceptibility of adiabatic shearing increases with the increases of strain rate.

Effects of different aging statuses and strain rate on the adiabatic shear susceptibility of 2195 aluminum-lithium alloy

Energy Technology Data Exchange (ETDEWEB)

Yang, Y. [School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan (China); State Key Laboratory of Explosion Science and Technology, Beijing 100081 (China); Tan, G.Y., E-mail: yangyanggroup@163.com [School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan (China); Chen, P.X. [School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan (China); Zhang, Q.M. [State Key Laboratory of Explosion Science and Technology, Beijing 100081 (China)

2012-06-01

The adiabatic shear susceptibility of 2195 aluminum-lithium alloy was investigated by means of split Hopkinson pressure bar. The stress collapse in true stress-true strain curves and true stress-time curves was observed. The adiabatic shear susceptibility of different aging statuses and strain rate were discussed by means of metallography observation. The critical strain, stress collapse time and formation energy of adiabatic shear bands were compared. The results show that different aging statuses and strain rate have significant influences on adiabatic shear behaviors of 2195 aluminum-lithium alloy. The peak-aged specimen has the highest adiabatic shearing susceptibility, while the under-aged specimen has the least adiabatic shear susceptibility. The susceptibility of adiabatic shearing increases with the increases of strain rate.

Intergranular corrosion susceptibility in supermartensitic stainless steel weldments

Energy Technology Data Exchange (ETDEWEB)

Aquino, J.M. [Sao Carlos Federal University (UFSCar), Materials Engineering Department, Rodovia Washington Luis, km 235, CEP 13565-905, Sao Carlos, SP (Brazil)], E-mail: dsek@power.ufscar.br; Della Rovere, C.A.; Kuri, S.E. [Sao Carlos Federal University (UFSCar), Materials Engineering Department, Rodovia Washington Luis, km 235, CEP 13565-905, Sao Carlos, SP (Brazil)

2009-10-15

The intergranular corrosion susceptibility in supermartensitic stainless steel (SMSS) weldments was investigated by the double loop - electrochemical potentiokinetic reactivation (DL-EPR) technique through the degree of sensitization (DOS). The results showed that the DOS decreased from the base metal (BM) to the weld metal (WM). The heat affected zone (HAZ) presented lower levels of DOS, despite of its complex precipitation mechanism along the HAZ length. Chromium carbide precipitate redissolution is likely to occur due to the attained temperature at certain regions of the HAZ during the electron beam welding (EBW). Scanning electron microscopy (SEM) images showed preferential oxidation sites in the BM microstructure.

Harmonic and static susceptibilities of YBa2Cu3O7

International Nuclear Information System (INIS)

Ishida, T.; Goldfarb, R.B.; Okayasu, S.; Kazumata, Y.; Franz, J.; Arndt, T.; Schauer, W.

1993-01-01

Intergranular properties of the sintered superconductor YBa 2 Cu 3 O 7 have been studied in terms of complex harmonic magnetic susceptibility χ n χ n ' - iχ n '' (n integer) as well as DC susceptibility χ dc . As functions of temperature T, χ 1 ' and χ 1 '' depend on both the AC magnetic-field amplitude H ac and the magnitude of a superimposed DC field H dc . Only odd-harmonic susceptibilities are observed below the critical temperature, T c , for zero H dc while both odd and even harmonics are observed for nonzero H dc . With T constant, odd-harmonic susceptibilities are even functions of H dc , whereas even-harmonic susceptibilities are odd functions of H dc . Experimental intergranular characteristics of χ n ' and χ n '' are in good agreement with theoretical predictions from a simplified Kim model of magnetization. In contrast, even-harmonic susceptibilities measured for a GdBa 2 Cu 3 O 7 thin film and an YBa 2 Cu 3 O 7 single crystal are not prominent due to missing weak links, whereas odd-harmonic susceptibilities are remarkable. A survey of several models for the harmonic response of superconductors is presented. The DC susceptibility curve for the zero-field-cooled YBa 2 Cu 3 O 7 sample, χ ZFC (T), has a two-step structure arising from intra- and inter-granular components, similar to χ 1 '. DC susceptibility measured upon warming, χ FCW (T), shows a negative peak near T c for the sample cooled rapidly in small DC fields. DC susceptibility measured upon cooling, χ FCC (T), does not show a peak. A negative peak is not seen in measurements on a powdered sample. The negative peak can be explained by intergranular flux depinning upon warming. (orig.)

Landslide susceptibility mapping using a neuro-fuzzy

Science.gov (United States)

Lee, S.; Choi, J.; Oh, H.

2009-12-01

This paper develops and applied an adaptive neuro-fuzzy inference system (ANFIS) based on a geographic information system (GIS) environment using landslide-related factors and location for landslide susceptibility mapping. A neuro-fuzzy system is based on a fuzzy system that is trained by a learning algorithm derived from the neural network theory. The learning procedure operates on local information, and causes only local modifications in the underlying fuzzy system. The study area, Boun, suffered much damage following heavy rain in 1998 and was selected as a suitable site for the evaluation of the frequency and distribution of landslides. Boun is located in the central part of Korea. Landslide-related factors such as slope, soil texture, wood type, lithology, and density of lineament were extracted from topographic, soil, forest, and lineament maps. Landslide locations were identified from interpretation of aerial photographs and field surveys. Landslide-susceptible areas were analyzed by the ANFIS method and mapped using occurrence factors. In particular, we applied various membership functions (MFs) and analysis results were verified using the landslide location data. The predictive maps using triangular, trapezoidal, and polynomial MFs were the best individual MFs for modeling landslide susceptibility maps (84.96% accuracy), proving that ANFIS could be very effective in modeling landslide susceptibility mapping. Various MFs were used in this study, and after verification, the difference in accuracy according to the MFs was small, between 84.81% and 84.96%. The difference was just 0.15% and therefore the choice of MFs was not important in the study. Also, compared with the likelihood ratio model, which showed 84.94%, the accuracy was similar. Thus, the ANFIS could be applied to other study areas with different data and other study methods such as cross-validation. The developed ANFIS learns the if-then rules between landslide-related factors and landslide

Evaluating Susceptibility to Commercial Fungicide of Endophytic Fungi Isolated from Roses (Rosa hybrida

Directory of Open Access Journals (Sweden)

Ingrid Carolina Corredor Perilla

2007-01-01

Full Text Available Fungal endophytes have shown their potential as biocontrol agents; however, their application in commercial fields remains limited. Continuously applying fungicides to crops (specifically to roses may have harmful effects on endophyte growth. Endophytic fungi were isolated from R. hybrida and their susceptibility to fungicides regularly used for controlling important pathogens was analysed. This was performed in vitro, mixing several fungicide concentrations with standard medium for fungal endophytes; growth inhibition was then measured. The susceptibility of Botrytis cinerea (3015 strain, one of the most important pathogens affecting roses in Colombia, was also assessed using the same protocols. Active ingredients, such as boscalid, captan, iprodione and pyrimethanyl, showed susceptibility ranging from not sensitive (³73.75% to regularly sensitive (³48.75% - <61.25% for 45.45% of the fungal endophytes assessed. Endophytic fungi were highly susceptible to fungicides such as pyrimethanyl, carboxin plus thiram, fludioxonyl plus ciprodinyl and prochloraz. B. cinerea (3015 strain presented high susceptibility (<23.75% to fungicides such as pyrimethanyl, carboxin and thiram, fludioxonil and ciprodinyl, prochloraz. Although B. cinerea showed the greatest growth in controls, the endophytic fungi being assessed grew better in different media with fungicides. The results revealed some of these fungal endophytes’ potential for integrated pest management (IPM in roses in Colombia (3002, 3003, 3004, 3005 and 3006 strains, taking into account correct application time, application frequency and both fungal endophyte and fungicide dosage which may greatly limit fungal endophyte growth.

High-frequency, transient magnetic susceptibility of ferroelectrics

Science.gov (United States)

Grimes, Craig A.

1996-10-01

A significant high-frequency magnetic susceptibility was measured both in weakly polarized and nonpolarized samples of barium titanate, lead zirconate titanate, and carnauba wax. Magnetic susceptibility measurements were made from 10 to 500 MHz using a thin film permeameter at room temperature; initial susceptibilities ranged from 0.1 to 2.5. These values are larger than expected for paramagnets and smaller than expected for ferromagnets. It was found that the magnetic susceptibility decreases rapidly with exposure to the exciting field. The origin of the magnetic susceptibility is thought to originate with the applied time varying electric field associated with the susceptibility measurements. An electric field acts to rotate an electric dipole, creating a magnetic quadrupole if the two moments are balanced, and a net magnetic dipole moment if imbalanced. It is thought that local electrostatic fields created at ferroelectric domain discontinuities associated with grain boundaries create an imbalance in the anion rotation that results in a net, measurable, magnetic moment. The origin of the magnetic aftereffect may be due to the local heating of the material through the moving charges associated with the magnetic moment.

Susceptibility of Sogatella furcifera and Laodelphax striatellus (Hemiptera: Delphacidae) to Six Insecticides in China.

Science.gov (United States)

Zhang, Kai; Zhang, Wei; Zhang, Shuai; Wu, Shun-Fan; Ban, Lan-Feng; Su, Jian-Ya; Gao, Cong-Fen

2014-10-01

The whitebacked planthopper, Sogatella furcifera (Horváth), and small brown planthopper, Laodelphax striatellus (Fallén), both are important crop pests throughout China, especially in rice. Application of chemical insecticides is the major control practice. Consequently, insecticide resistance has become an urgent issue. In this study, resistance levels to six conventional insecticides were evaluated for these two species collected from major occurring areas of China. Additionally, imidacloprid- (resistance ratio [RR] = 10.4-fold) and buprofezin (RR = 15.1-fold)-resistant strains of whitebacked planthopper were obtained through laboratory selections for cross-resistance profiling and synergism assessment to understand resistance mechanisms. The results showed that all tested populations of both species exhibited low to high levels of resistance to chlorpyrifos, while remaining susceptible to thiamethoxam. Three of the 14 whitebacked planthopper populations showed low to moderate resistance to imidacloprid, while all small brown planthopper populations reminded susceptible. All small brown planthopper and whitebacked planthopper (except one) populations showed at least moderate resistance (RR = 10.1-271.1) to buprofezin. All small brown planthopper populations remained susceptible to pymetrozine and nitenpyram, and all whitebacked planthopper populations remained susceptible to isoprocarb. The imidacloprid-resistant whitebacked planthopper strain showed no significant cross-resistance to other tested insecticides. However, the buprofezin-resistant strain exhibited a low-level cross-resistance (CR = 3.1) to imidacloprid. Piperonyl butoxide, triphenyl phosphate, and diethylmaleate displayed no synergism effect on the resistant whitebacked planthopper strains. © 2014 Entomological Society of America.

Topological susceptibility from twisted mass fermions using spectral projectors and the gradient flow

Science.gov (United States)

Alexandrou, Constantia; Athenodorou, Andreas; Cichy, Krzysztof; Constantinou, Martha; Horkel, Derek P.; Jansen, Karl; Koutsou, Giannis; Larkin, Conor

2018-04-01

We compare lattice QCD determinations of topological susceptibility using a gluonic definition from the gradient flow and a fermionic definition from the spectral-projector method. We use ensembles with dynamical light, strange and charm flavors of maximally twisted mass fermions. For both definitions of the susceptibility we employ ensembles at three values of the lattice spacing and several quark masses at each spacing. The data are fitted to chiral perturbation theory predictions with a discretization term to determine the continuum chiral condensate in the massless limit and estimate the overall discretization errors. We find that both approaches lead to compatible results in the continuum limit, but the gluonic ones are much more affected by cutoff effects. This finally yields a much smaller total error in the spectral-projector results. We show that there exists, in principle, a value of the spectral cutoff which would completely eliminate discretization effects in the topological susceptibility.

Review of magnetic susceptibility logging and its application to uranium exploration

International Nuclear Information System (INIS)

George, D.C.; Scott, J.H.

1982-01-01

Borehole measurement of magnetic susceptibility can show anomalies associated with mineralization or alteration. The detection of small anomalies is necessary, so efforts have been made in recent years to improve the sensitivity and the stability of magnetic susceptibility logging tools. Typical tools contain a single coil constructed as a solenoid wound on ferrite rods about 30cm long. The coil is heated to a constant temperature to reduce drift, and careful design is necessary to optimize temperature control and to maximize sensitivity. Measurements of coil resistance and inductance, which indicate conductivity and susceptibility, are made using a Maxwell bridge circuit. Circuit analysis shows that conductivity measurements are difficult and that stringent requirements are placed on phase stability of measurement circuitry. Corrections to the observed log are necessary to account for borehole size. The response of the tool to a thin zones of anomalous susceptibility is double peaked and a set of curves has been developed for interpretation. Calibrations of the tools are made by measuring the tool's response in models of known susceptibility

Severity and Susceptibility Beliefs Associated with Urban Air Pollution: Results of a Qualitative Study

International Nuclear Information System (INIS)

Oltra, C.; Sala, R.

2015-01-01

In this report we present the results of a qualitative study based on recombined focus groups with lay citizens. The main objective is to analyze individuals’ beliefs on urban air pollution and perceived benefits and barriers of some self-protective actions, such as using special masks, avoidance of polluted streets, etc. The analytical framework on which the study is based is the Health Belief Model, whose basic idea is that it is more likely that individuals take actions to protect themselves if they think they are potentially susceptible to a serious threat to your health, if they think adopting certain actions has advantages, and if they think there are no significant barriers for such conduct. A secondary objective is to explore the perception of different existing materials to inform the public about air pollution. The results of the study are intended to contribute to the design of interventions aimed at reducing health impacts of urban air pollution and, specifically, to the design of messages in the context of information campaigns on health and environmental risk.

Frequency in-vitro antibiotic susceptibility pattern of aerobic isolated from PUS at IIMCT-Railway Hospital Rawalpindi

International Nuclear Information System (INIS)

Khan, A. B.; Hassan, M. U.; Rehman, M. U.; Muzaffar, M.

2006-01-01

A total of 302 samples of pus/pus swabs were cultured aerobically on routine media. One hundred and seventy two bacteria isolated from the samples showing positive growth were identified by standard methods and their antibiotic susceptibility pattern was determined using Kirby-Bauer disk diffusion method. Out of 302 processed samples, 162 samples showed positive result on culture revealing the growth of 172 microorganism of different genera. The spectrum of these isolated bacteria included staphylococcus aureus (51.11%), Escherichia coli (22.9%) pseudomonas aeruginosa (20.93%) and miscellaneous gram negative bacilli (5.81%). The staphylococcus aureus in our study revealed relatively good susceptibility to cloxacillin, flucloxacillin and first generation cephalosporins. In this study 9% of the S. aureus were methicillin resistant. Susceptibility to ampicillin, erythromycin and co-trimoxazole was low. Aminoglycosides and quinolones also showed reasonably good activity against staphylococci. Against Escherichia coli and pseudomonas aeruginosa the activity of quinolones was relatively low when compared with amikacin. Piperacillin+ tazobactam and impepenem/ meropenem revealed a better activity. (author)

Assessments on landslide susceptibility in the Tseng-wen reservoir watershed, Taiwan

Science.gov (United States)

Chen, Yu-Chin; Chen, Yung-Chau; Chen, Wen-Fu

2014-05-01

(high human development). Among considered factors, slope, distance to river, NDVI, and maximum hourly rainfall are the major influence factors for landslide susceptibility. The results show that the accuracy of predicted landslide area is 74.74% and AUC is 0.82 corresponding to typhoon Morakot. Comparing model predicted with actual landslide areas, it shows that the predicted accuracy is 93% for high or high-intermediate level landslide area. It suggests that a landslide susceptibility map, depicted by this assessment model, is applicable on landslide prediction.

Antifungal susceptibility testing method for resource constrained laboratories

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Khan S

2006-01-01

Full Text Available Purpose: In resource-constrained laboratories of developing countries determination of antifungal susceptibility testing by NCCLS/CLSI method is not always feasible. We describe herein a simple yet comparable method for antifungal susceptibility testing. Methods: Reference MICs of 72 fungal isolates including two quality control strains were determined by NCCLS/CLSI methods against fluconazole, itraconazole, voriconazole, amphotericin B and cancidas. Dermatophytes were also tested against terbinafine. Subsequently, on selection of optimum conditions, MIC was determined for all the fungal isolates by semisolid antifungal agar susceptibility method in Brain heart infusion broth supplemented with 0.5% agar (BHIA without oil overlay and results were compared with those obtained by reference NCCLS/CLSI methods. Results: Comparable results were obtained by NCCLS/CLSI and semisolid agar susceptibility (SAAS methods against quality control strains. MICs for 72 isolates did not differ by more than one dilution for all drugs by SAAS. Conclusions: SAAS using BHIA without oil overlay provides a simple and reproducible method for obtaining MICs against yeast, filamentous fungi and dermatophytes in resource-constrained laboratories.

The effect of nitrogen fertilization and irradiation on barley susceptibility to net blotch disease

International Nuclear Information System (INIS)

Arabi, M.I.E.; Al-safadi, B.; Charbaji, T.

2000-11-01

Isolates of Drechslera teres f. sp. teres that cause net blotch symptoms on barley were collected from fields in different regions of Syria. there virulence spectra were determined using 11 barley cultivars. Cultivars exhibited a continuos range of response from very susceptible to moderately resistant. Isolate Raqa 13 had the highest mean virulence, then Halap 2, whereas ICARDA 3 was the lowest virulent. The effect of three concentrations (1000, 1500, 2000 ppm) of nitrogen (Urea 45%) fertilizer, and two doses of gamma ray (10 and 20 Gy), on susceptibility to infection by Drechslera teres were studied. Two barley cultivars (Thibaut and Furia) were used in this study. Results showed that 1000 ppm (N) and 15 Gy dose treatment had a positive effect on decreasing the susceptibility. (author)

Reactivating dynamics for the susceptible-infected-susceptible model: a simple method to simulate the absorbing phase

Science.gov (United States)

Macedo-Filho, A.; Alves, G. A.; Costa Filho, R. N.; Alves, T. F. A.

2018-04-01

We investigated the susceptible-infected-susceptible model on a square lattice in the presence of a conjugated field based on recently proposed reactivating dynamics. Reactivating dynamics consists of reactivating the infection by adding one infected site, chosen randomly when the infection dies out, avoiding the dynamics being trapped in the absorbing state. We show that the reactivating dynamics can be interpreted as the usual dynamics performed in the presence of an effective conjugated field, named the reactivating field. The reactivating field scales as the inverse of the lattice number of vertices n, which vanishes at the thermodynamic limit and does not affect any scaling properties including ones related to the conjugated field.

Bile anaerobic bacteria detection and antibiotic susceptibility in patients with gallstone.

Science.gov (United States)

Lu, Yun; Xiang, Ting-Hai; Shi, Jing-Sen; Zhang, Bing-Yuan

2003-08-01

To detect bile anaerobic bacteria and antibiotic susceptibility in 59 patients with gallstones who had had cholecystectomy. BACT/ALERT 120 microbe detection system and SCEPTOR microbe detection system were used to detect bile anaerobic bacteria, antibiotic susceptibility. The ratio of anaerobic bacteria to the patients examined was 52.5% (31/59). Obligate anaerobe bile culture showed positive results in 4 patients. B. fragilis (37.8%) was the major type of anaerobic bacteria in bile. Most (81.8%) of anaerobic bacteria were sensitive to metronidazole, and imipenem was suitable for beta-lactamase bacteria. Culture of anaerobic bacteria in logarithmic phase can improve the positive rate of the culture. There are some relations between anaerobic infection and gallstone formation.

Clinical Presentation and Antibiotic Susceptibility of Contact Lens Associated Microbial Keratitis

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Hesam Hedayati

2015-01-01

Full Text Available Introduction. In recent years, the number of contact lens wearers has dramatically increased in Iran, particularly in youngsters. The purpose of current study was to assess the clinical presentation and antibiotic susceptibility of contact lens related microbial keratitis in Ahvaz, southwest of Iran. Methodology. A cross-sectional investigation of 26 patients (33 eyes with contact lens induced corneal ulcers who were admitted to Imam Khomeini Hospital, Ahwaz City, from June 2012 to June 2013 was done. In order to study microbial culture and susceptibility of corneal ulcers, all of them were scraped. Results. Eight samples were reported as sterile. Pseudomonas aeruginosa (80% in positive cultures was the most widely recognized causative organism isolated. This is followed by Staphylococcus aureus 12% and Enterobacter 8%. The results showed that 84% of the microorganism cases were sensitive to ciprofloxacin, while imipenem, meropenem, and ceftazidime were the second most effective antibiotics (76%. Conclusion. Results of current study show the importance of referring all contact lens wearers with suspected corneal infection to ophthalmologists for more cure. The corneal scraping culture and contact lens solution should be performed to guide antibiotic therapy.

Secondhand smoke exposure and other correlates of susceptibility to smoking: a propensity score matching approach.

Science.gov (United States)

McIntire, Russell K; Nelson, Ashlyn A; Macy, Jonathan T; Seo, Dong-Chul; Kolbe, Lloyd J

2015-09-01

Secondhand smoke (SHS) exposure is responsible for numerous diseases of the lungs and other bodily systems among children. In addition to the adverse health effects of SHS exposure, studies show that children exposed to SHS are more likely to smoke in adolescence. Susceptibility to smoking is a measure used to identify adolescent never-smokers who are at risk for smoking. Limited research has been conducted on the influence of SHS on susceptibility to smoking. The purpose of this study was to determine a robust measure of the strength of correlation between SHS exposure and susceptibility to smoking among never-smoking U.S. adolescents. This study used data from the 2009 National Youth Tobacco Survey to identify predictors of susceptibility to smoking in the full (pre-match) sample of adolescents and a smaller (post-match) sample created by propensity score matching. Results showed a significant association between SHS exposure and susceptibility to smoking among never-smoking adolescents in the pre-match (OR=1.47) and post-match (OR=1.52) samples. The odds ratio increase after matching suggests that the strength of the relationship was underestimated in the pre-match sample. Other significant correlates of susceptibility to smoking identified include: gender, race/ethnicity, personal income, smoke-free home rules, number of smoking friends, perception of SHS harm, perceived benefits of smoking, and exposure to pro-tobacco media messages. The use of propensity score matching procedures reduced bias in the post-match sample, and provided a more robust estimate of the influence of SHS exposure on susceptibility to smoking, compared to the pre-match sample estimates. Copyright © 2015 Elsevier Ltd. All rights reserved.

Manifestation of a neuro-fuzzy model to produce landslide susceptibility map using remote sensing data derived parameters

Science.gov (United States)

Pradhan, Biswajeet; Lee, Saro; Buchroithner, Manfred

Landslides are the most common natural hazards in Malaysia. Preparation of landslide suscep-tibility maps is important for engineering geologists and geomorphologists. However, due to complex nature of landslides, producing a reliable susceptibility map is not easy. In this study, a new attempt is tried to produce landslide susceptibility map of a part of Cameron Valley of Malaysia. This paper develops an adaptive neuro-fuzzy inference system (ANFIS) based on a geographic information system (GIS) environment for landslide susceptibility mapping. To ob-tain the neuro-fuzzy relations for producing the landslide susceptibility map, landslide locations were identified from interpretation of aerial photographs and high resolution satellite images, field surveys and historical inventory reports. Landslide conditioning factors such as slope, plan curvature, distance to drainage lines, soil texture, lithology, and distance to lineament were extracted from topographic, soil, and lineament maps. Landslide susceptible areas were analyzed by the ANFIS model and mapped using the conditioning factors. Furthermore, we applied various membership functions (MFs) and fuzzy relations to produce landslide suscep-tibility maps. The prediction performance of the susceptibility map is checked by considering actual landslides in the study area. Results show that, triangular, trapezoidal, and polynomial MFs were the best individual MFs for modelling landslide susceptibility maps (86

Effect of fuel rod design on SCC susceptibility

International Nuclear Information System (INIS)

Wilson, H.W.; Yoon, K.K.; Baty, D.L.

1979-01-01

Laboratory tests were conducted to compare the relative susceptibility of three different zircaloy cladding types to iodine stress corrosion cracking. Two types of tests were conducted which had different characteristics. A substantial dependency of failure susceptibility on cladding type was noted. The differences in behavior were attributed to one or a combination of three cladding characteristics: cladding crystallographic texture, stress relaxation rates, and cladding inner diameter surface condition. The failure susceptibility was qualitatively consistent with the theoretical predictions of crystallographic texture dependencies. A separate series of tests were performed to quantify the differences in stress relaxation between the material types. Results of an analytical calculation are presented which evaluates the applicability of the test results to in-reactor performance

Susceptibility of Seven Termite Species (Isoptera) to the Entomopathogenic Fungus Metarhizium anisopliae

OpenAIRE

Chouvenc , Thomas; Su , Nan-Yao; Robert , Alain

2009-01-01

Seven termite species (Isoptera) from five families were tested for disease susceptibility against the entomopathogenic fungus Metarhizium anisopliae using a standard protocol: Mastotermes darwiniensis (Mastotermitidae), Hodotermopsis sjoestedti (Termopsidae), Hodotermes mossambicus (Hodotermitidae), Kalotermes flavicollis (Kalotermitidae), Reticulitermes flavipes and Prorhinotermes canalifrons (Rhinotermitidae), and Nasutitermes voeltzkowi (Termitidae). Our results showed a large diversity i...

Rapid Antimicrobial Susceptibility Testing Using Forward Laser Light Scatter Technology.

Science.gov (United States)

Hayden, Randall T; Clinton, Lani K; Hewitt, Carolyn; Koyamatsu, Terri; Sun, Yilun; Jamison, Ginger; Perkins, Rosalie; Tang, Li; Pounds, Stanley; Bankowski, Matthew J

2016-11-01

The delayed reporting of antimicrobial susceptibility testing remains a limiting factor in clinical decision-making in the treatment of bacterial infection. This study evaluates the use of forward laser light scatter (FLLS) to measure bacterial growth for the early determination of antimicrobial susceptibility. Three isolates each (two clinical isolates and one reference strain) of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were tested in triplicate using two commercial antimicrobial testing systems, the Vitek2 and the MicroScan MIC panel, to challenge the BacterioScan FLLS. The BacterioScan FLLS showed a high degree of categorical concordance with the commercial methods. Pairwise comparison with each commercial system serving as a reference standard showed 88.9% agreement with MicroScan (two minor errors) and 72.2% agreement with Vitek (five minor errors). FLLS using the BacterioScan system shows promise as a novel method for the rapid and accurate determination of antimicrobial susceptibility. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Low signal-to-noise FDEM in-phase data: Practical potential for magnetic susceptibility modelling

Science.gov (United States)

Delefortrie, Samuël; Hanssens, Daan; De Smedt, Philippe

2018-05-01

test case whereby the in-phase responses of a multi-receiver FDEM instrument are calibrated through downhole susceptibility data. Our results show that, while it is possible to derive approximate susceptibility profiles from FDEM data, robust quantitative analysis hinges on appropriate calibration of the responses.

Increased LDL susceptibility to oxidation accelerates future carotid artery atherosclerosis

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Aoki Toshinari

2012-01-01

Full Text Available Abstract Background We analyzed the causal relationship between LDL susceptibility to oxidation and the development of new carotid artery atherosclerosis over a period of 5 years. We previously described the determinants related to a risk of cardiovascular changes determined in a Japanese population participating in the Niigata Study, which is an ongoing epidemiological investigation of the prevention of cardiovascular diseases. Methods We selected 394 individuals (169 males and 225 females who underwent a second carotid artery ultrasonographic examination in 2001 - 2002 for the present study. The susceptibility of LDL to oxidation was determined as the photometric absorbance and electrophoretic mobility of samples that had been collected in 1996 - 1997. The measurements were compared with ultrasonographic findings obtained in 2001 - 2002. Results The multivariate-adjusted model showed that age (odds ratio (OR, 1.034; 95% confidence interval (95%CI, 1.010 - 1.059, HbA1c (OR, 1.477; 95%CI, 0.980 - 2.225, and photometric O/N (OR, 2.012; 95%CI, 1.000 - 4.051 were significant variables that could independently predict the risk of new carotid artery atherosclerosis. Conclusion The susceptibility of LDL to oxidation was a significant parameter that could predict new carotid artery atherosclerosis over a 5-year period, and higher susceptibility was associated with a higher incidence of new carotid artery atherosclerosis.

Rapid antibiotic susceptibility testing of Mycobacterium tuberculosis : Its utility in resource poor settings

Directory of Open Access Journals (Sweden)

Poojary A

2006-01-01

Full Text Available Purpose: To compare the rapid colorimetric nitrate reductase based antibiotic susceptibility (CONRAS test performed on Mycobacterium tuberculosis isolates with the conventional method i.e., the proportion method. Methods: One hundred clinical isolates of M. tuberculosis were tested for susceptibility to isoniazid (INH and rifampicin (RIF by the conventional proportion method and CONRAS in Middlebrook 7H9 liquid medium enriched with growth supplements (MB7H9S. Results: The performance of the CONRAS test was evaluated using proportion method as the gold standard. The sensitivity (ability to detect true drug resistance and specificity (ability to detect true drug susceptibility of the CONRAS test to INH was 93.75 and 98.52% and for RIF it was 96.10 and 100% respectively. The mean time for reporting was 6.3 days and the test showed excellent reproducibility. The kappa (k value for INH was 0.92 and for RIF was 0.99, indicating excellent agreement between the two methods. Conclusions: CONRAS test is a rapid and reliable method of drug susceptibility for M. tuberculosis.

The association between miR-499 polymorphism and cancer susceptibility: a meta-analysis.

Science.gov (United States)

Xu, Zhongfei; Zhang, Enjiao; Duan, Weiyi; Sun, Changfu; Bai, Shuang; Tan, Xuexin

2015-01-01

MicroRNAs are a class of new noncoding RNA that play important roles in the pathogenesis of tumor. Rs3746444 in miR-499 is suggested to be associated with cancer susceptibility. In the present study, we assess the association between miR-499 rs3746444 polymorphism and cancer susceptibility through a meta-analysis. We searched relevant articles from the PubMed and Embase databases. We screened all the resulting articles for adherence to the inclusion and exclusion criteria. The associations between miR-499 polymorphism and cancer susceptibility were estimated by computing the odds ratios (ORs) and 95% confidence intervals (CIs). All analyses were performed using Stata software. There are 18 datasets included in the analysis. Statistically significant associations were found between the miR-499 rs3746444 polymorphism and susceptibility to cancer (GG versus AA: OR =1.24, 95% CI: 1.01-1.52; G versus A: OR =1.11, 95% CI: 1.01-1.23). A subsequent analysis, on the basis of ethnicity for the population characteristic, showed that Asians had increased susceptibility to cancer (GG versus AA: OR =1.32, 95% CI: 1.09-1.59; GG + AG versus AA: OR = 1.17, 95% CI: 1.01-1.37). In the subgroup analysis of tumor type, none of the genetic models had statistically significant results. The meta-regression suggested that race and cancer types are not the source of heterogeneity in the present meta-analysis. No publication bias was detected by either the inverted funnel plot or Egger's test. Rs3746444 in miR-499 might be related to susceptibility to cancer.

Suitable reference tissues for quantitative susceptibility mapping of the brain.

Science.gov (United States)

Straub, Sina; Schneider, Till M; Emmerich, Julian; Freitag, Martin T; Ziener, Christian H; Schlemmer, Heinz-Peter; Ladd, Mark E; Laun, Frederik B

2017-07-01

Since quantitative susceptibility mapping (QSM) quantifies magnetic susceptibility relative to a reference value, a suitable reference tissue has to be available to compare different subjects and stages of disease. To find such a suitable reference tissue for QSM of the brain, melanoma patients with and without brain metastases were measured. Twelve reference regions were chosen and assessed for stability of susceptibility values with respect to multiple intra-individual and inter-individual measurements, age, and stage of disease. Cerebrospinal fluid (CSF), the internal capsule and one region in the splenium of the corpus callosum are the regions with the smallest standard deviations of the mean susceptibility value. The mean susceptibility is 0.010 ± 0.014 ppm for CSF in the atrium of the lateral ventricles (csf post ), -0.060 ± 0.019 ppm for the posterior limb of the internal capsule (ci2), and -0.008 ± 0.019 ppm for the splenium of the corpus callosum. csf post and ci2 show nearly no dependence on age or stage of disease, whereas some other regions, e.g., the red nucleus, show moderate dependence on age or disease. The internal capsule and CSF appear to be the most suitable reference regions for QSM of the brain in the melanoma patients studied. Both showed virtually no dependence on age or disease and small variations among patients. Magn Reson Med 78:204-214, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

[Susceptibility of natural populations of dengue vector to insecticides in Colombia].

Science.gov (United States)

Santacoloma, Liliana; Chaves, Bernardo; Brochero, Helena Luisa

2012-09-01

Physiological resistance of natural population of Aedes aegypti to insecticides contribute to the decreased efficacy of chemical control as a main control strategy during dengue outbreaks. The susceptibility status of Ae. aegypti was assessed for the carbamate propoxur, the adulticide malathion and the larvicide temephos on 13 natural populations of Ae. aegypti immature forms were taken from 8 Colombian localities. These included the following: Bucaramanga (1), Sabana de Torres (2), Girardot (2), La Mesa (2), Villavicencio (2), Puerto López (2), San José del Guaviare (1) and Florencia (1). Susceptibility tests mainly consisted of the standardized bioassay outlined by WHO (1981) and CDC bottles (1998). Colorimetric tests were undertaken to determine enzyme levels possibly responsible for the reduction of susceptibility to organophosphate and carbamate insecticides. All specimens demonstrated susceptibility to malathion and propoxur insecticides. Four of the 13 populations revealed susceptibility to the temephos larvicide. Seven of 11 populations showed a limited increase in values for nonspecific esterase enzymes. The Bucaramanga population was the only one which showed an increase in the cytochrome P450 monooxygenases enzymes. Neither population was found with modified acetilcolinesterase. The widespread susceptibility to organophosphates used as adulticides indicated that malathion, the most used insecticide in Colombia, remains effective in interrupting the transmission of dengue. Physiological resistance to insecticides occurring in communities of a single township proved to be a localized phenomenon.

Influence of edge effects on single event upset susceptibility of SOI SRAMs

International Nuclear Information System (INIS)

Gu, Song; Liu, Jie; Zhao, Fazhan; Zhang, Zhangang; Bi, Jinshun; Geng, Chao; Hou, Mingdong; Liu, Gang; Liu, Tianqi; Xi, Kai

2015-01-01

An experimental investigation of the single event upset (SEU) susceptibility for heavy ions at tilted incidence was performed. The differences of SEU cross-sections between tilted incidence and normal incidence at equivalent effective linear energy transfer were 21% and 57% for the silicon-on-insulator (SOI) static random access memories (SRAMs) of 0.5 μm and 0.18 μm feature size, respectively. The difference of SEU cross-section raised dramatically with increasing tilt angle for SOI SRAM of deep-submicron technology. The result of CRÈME-MC simulation for tilted irradiation of the sensitive volume indicates that the energy deposition spectrum has a substantial tail extending into the low energy region. The experimental results show that the influence of edge effects on SEU susceptibility cannot be ignored in particular with device scaling down

Allele-specific DNA methylation of disease susceptibility genes in Japanese patients with inflammatory bowel disease

Science.gov (United States)

Chiba, Hirofumi; Kakuta, Yoichi; Kinouchi, Yoshitaka; Kawai, Yosuke; Watanabe, Kazuhiro; Nagao, Munenori; Naito, Takeo; Onodera, Motoyuki; Moroi, Rintaro; Kuroha, Masatake; Kanazawa, Yoshitake; Kimura, Tomoya; Shiga, Hisashi; Endo, Katsuya; Negoro, Kenichi; Nagasaki, Masao; Unno, Michiaki; Shimosegawa, Tooru

2018-01-01

Background Inflammatory bowel disease (IBD) has an unknown etiology; however, accumulating evidence suggests that IBD is a multifactorial disease influenced by a combination of genetic and environmental factors. The influence of genetic variants on DNA methylation in cis and cis effects on expression have been demonstrated. We hypothesized that IBD susceptibility single-nucleotide polymorphisms (SNPs) regulate susceptibility gene expressions in cis by regulating DNA methylation around SNPs. For this, we determined cis-regulated allele-specific DNA methylation (ASM) around IBD susceptibility genes in CD4+ effector/memory T cells (Tem) in lamina propria mononuclear cells (LPMCs) in patients with IBD and examined the association between the ASM SNP genotype and neighboring susceptibility gene expressions. Methods CD4+ effector/memory T cells (Tem) were isolated from LPMCs in 15 Japanese IBD patients (ten Crohn's disease [CD] and five ulcerative colitis [UC] patients). ASM analysis was performed by methylation-sensitive SNP array analysis. We defined ASM as a changing average relative allele score (ΔRAS¯) >0.1 after digestion by methylation-sensitive restriction enzymes. Among SNPs showing ΔRAS¯ >0.1, we extracted the probes located on tag-SNPs of 200 IBD susceptibility loci and around IBD susceptibility genes as candidate ASM SNPs. To validate ASM, bisulfite-pyrosequencing was performed. Transcriptome analysis was examined in 11 IBD patients (seven CD and four UC patients). The relation between rs36221701 genotype and neighboring gene expressions were analyzed. Results We extracted six candidate ASM SNPs around IBD susceptibility genes. The top of ΔRAS¯ (0.23) was rs1130368 located on HLA-DQB1. ASM around rs36221701 (ΔRAS¯ = 0.14) located near SMAD3 was validated using bisulfite pyrosequencing. The SMAD3 expression was significantly associated with the rs36221701 genotype (p = 0.016). Conclusions We confirmed the existence of cis-regulated ASM around IBD

Effect of centrifugation on dynamic susceptibility of magnetic fluids

International Nuclear Information System (INIS)

Pshenichnikov, Alexander; Lebedev, Alexander; Lakhtina, Ekaterina; Kuznetsov, Andrey

2017-01-01

Highlights: • Six samples of magnetic fluid were obtained by centrifuging two base ferrocolloids. • Aggregates in magnetic fluids are main reason of dynamic susceptibility dispersion. • Centrifugation is an effective way of changing the dynamic susceptibility. - Abstract: The dispersive composition, dynamic susceptibility and spectrum of times of magnetization relaxation for six samples of magnetic fluid obtained by centrifuging two base colloidal solutions of the magnetite in kerosene was investigated experimentally. The base solutions differed by the concentration of the magnetic phase and the width of the particle size distribution. The procedure of cluster analysis allowing one to estimate the characteristic sizes of aggregates with uncompensated magnetic moments was described. The results of the magnetogranulometric and cluster analyses were discussed. It was shown that centrifugation has a strong effect on the physical properties of the separated fractions, which is related to the spatial redistribution of particles and multi-particle aggregates. The presence of aggregates in magnetic fluids is interpreted as the main reason of low-frequency (0.1–10 kHz) dispersion of the dynamic susceptibility. The obtained results count in favor of using centrifugation as an effective means of changing the dynamic susceptibility over wide limits and obtaining fluids with the specified type of susceptibility dispersion.

Effect of centrifugation on dynamic susceptibility of magnetic fluids

Energy Technology Data Exchange (ETDEWEB)

Pshenichnikov, Alexander, E-mail: pshenichnikov@icmm.ru; Lebedev, Alexander; Lakhtina, Ekaterina; Kuznetsov, Andrey

2017-06-15

Highlights: • Six samples of magnetic fluid were obtained by centrifuging two base ferrocolloids. • Aggregates in magnetic fluids are main reason of dynamic susceptibility dispersion. • Centrifugation is an effective way of changing the dynamic susceptibility. - Abstract: The dispersive composition, dynamic susceptibility and spectrum of times of magnetization relaxation for six samples of magnetic fluid obtained by centrifuging two base colloidal solutions of the magnetite in kerosene was investigated experimentally. The base solutions differed by the concentration of the magnetic phase and the width of the particle size distribution. The procedure of cluster analysis allowing one to estimate the characteristic sizes of aggregates with uncompensated magnetic moments was described. The results of the magnetogranulometric and cluster analyses were discussed. It was shown that centrifugation has a strong effect on the physical properties of the separated fractions, which is related to the spatial redistribution of particles and multi-particle aggregates. The presence of aggregates in magnetic fluids is interpreted as the main reason of low-frequency (0.1–10 kHz) dispersion of the dynamic susceptibility. The obtained results count in favor of using centrifugation as an effective means of changing the dynamic susceptibility over wide limits and obtaining fluids with the specified type of susceptibility dispersion.

Nodal infection in Markovian susceptible-infected-susceptible and susceptible-infected-removed epidemics on networks are non-negatively correlated.

Science.gov (United States)

Cator, E; Van Mieghem, P

2014-05-01

By invoking the famous Fortuin, Kasteleyn, and Ginibre (FKG) inequality, we prove the conjecture that the correlation of infection at the same time between any pair of nodes in a network cannot be negative for (exact) Markovian susceptible-infected-susceptible (SIS) and susceptible-infected-removed (SIR) epidemics on networks. The truth of the conjecture establishes that the N-intertwined mean-field approximation (NIMFA) upper bounds the infection probability in any graph so that network design based on NIMFA always leads to safe protections against malware spread. However, when the infection or/and curing are not Poisson processes, the infection correlation between two nodes can be negative.

Nodal infection in Markovian susceptible-infected-susceptible and susceptible-infected-removed epidemics on networks are non-negatively correlated

Science.gov (United States)

Cator, E.; Van Mieghem, P.

2014-05-01

By invoking the famous Fortuin, Kasteleyn, and Ginibre (FKG) inequality, we prove the conjecture that the correlation of infection at the same time between any pair of nodes in a network cannot be negative for (exact) Markovian susceptible-infected-susceptible (SIS) and susceptible-infected-removed (SIR) epidemics on networks. The truth of the conjecture establishes that the N-intertwined mean-field approximation (NIMFA) upper bounds the infection probability in any graph so that network design based on NIMFA always leads to safe protections against malware spread. However, when the infection or/and curing are not Poisson processes, the infection correlation between two nodes can be negative.

Assessment of Groundwater Susceptibility to Non-Point Source Contaminants Using Three-Dimensional Transient Indexes.

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Zhang, Yong; Weissmann, Gary S; Fogg, Graham E; Lu, Bingqing; Sun, HongGuang; Zheng, Chunmiao

2018-06-05

Groundwater susceptibility to non-point source contamination is typically quantified by stable indexes, while groundwater quality evolution (or deterioration globally) can be a long-term process that may last for decades and exhibit strong temporal variations. This study proposes a three-dimensional (3- d ), transient index map built upon physical models to characterize the complete temporal evolution of deep aquifer susceptibility. For illustration purposes, the previous travel time probability density (BTTPD) approach is extended to assess the 3- d deep groundwater susceptibility to non-point source contamination within a sequence stratigraphic framework observed in the Kings River fluvial fan (KRFF) aquifer. The BTTPD, which represents complete age distributions underlying a single groundwater sample in a regional-scale aquifer, is used as a quantitative, transient measure of aquifer susceptibility. The resultant 3- d imaging of susceptibility using the simulated BTTPDs in KRFF reveals the strong influence of regional-scale heterogeneity on susceptibility. The regional-scale incised-valley fill deposits increase the susceptibility of aquifers by enhancing rapid downward solute movement and displaying relatively narrow and young age distributions. In contrast, the regional-scale sequence-boundary paleosols within the open-fan deposits "protect" deep aquifers by slowing downward solute movement and displaying a relatively broad and old age distribution. Further comparison of the simulated susceptibility index maps to known contaminant distributions shows that these maps are generally consistent with the high concentration and quick evolution of 1,2-dibromo-3-chloropropane (DBCP) in groundwater around the incised-valley fill since the 1970s'. This application demonstrates that the BTTPDs can be used as quantitative and transient measures of deep aquifer susceptibility to non-point source contamination.

Carbapenem non-susceptible enterobacteriaceae in Quebec, Canada: results of a laboratory surveillance program (2010-2012.

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Brigitte Lefebvre

Full Text Available The emergence and spread of carbapenemase-producing Enterobacteriaceae (CPE represent a major public health concern because these bacteria are usually extensively resistant to most antibiotics. In order to evaluate their dissemination in Quebec, a surveillance program was introduced in 2010. We report the molecular and epidemiological profiles of CPE isolates collected. Between August 2010 and December 2012, a total of 742 non-duplicate isolates non-susceptible to carbapenems were analysed. AmpC β-lactamase and metallo-β-lactamase production were detected by Etest and carbapenemase production by the modified Hodge test (MHT. Antibiotic susceptibility profiles were determined using broth microdilution or Etest. Clonality of Klebsiella pneumoniae carbapenemase (KPC strains was analyzed by pulsed-field gel electrophoresis (PFGE. The presence of genes encoding carbapenemases as well as other β-lactamases was detected using PCR. Of the 742 isolates tested, 169 (22.8% were CPE. Of these 169 isolates, 151 (89.3% harboured a blaKPC gene while the remaining isolates carried blaSME (n = 9, blaOXA-48 (n = 5, blaNDM (n = 3, and blaNMC (n = 1 genes. Among the 93 KPC strains presenting with a unique pattern (unique PFGE pattern and/or unique antibiotics susceptibility profile, 99% were resistant to ertapenem, 95% to imipenem, 87% to meropenem, 97% to aztreonam, 31% to colistin and 2% to tigecycline. In 19 patients, 2 to 5 KPC strains from different species or with a different PFGE pattern were isolated. CPE strains were present in the province of Quebec with the majority of strains harbouring KPC. Alternately, SME, OXA-48 and NMC containing strains were rarely found.

Effects of white matter microstructure on phase and susceptibility maps.

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Wharton, Samuel; Bowtell, Richard

2015-03-01

To investigate the effects on quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI) of the frequency variation produced by the microstructure of white matter (WM). The frequency offsets in a WM tissue sample that are not explained by the effect of bulk isotropic or anisotropic magnetic susceptibility, but rather result from the local microstructure, were characterized for the first time. QSM and STI were then applied to simulated frequency maps that were calculated using a digitized whole-brain, WM model formed from anatomical and diffusion tensor imaging data acquired from a volunteer. In this model, the magnitudes of the frequency contributions due to anisotropy and microstructure were derived from the results of the tissue experiments. The simulations suggest that the frequency contribution of microstructure is much larger than that due to bulk effects of anisotropic magnetic susceptibility. In QSM, the microstructure contribution introduced artificial WM heterogeneity. For the STI processing, the microstructure contribution caused the susceptibility anisotropy to be significantly overestimated. Microstructure-related phase offsets in WM yield artifacts in the calculated susceptibility maps. If susceptibility mapping is to become a robust MRI technique, further research should be carried out to reduce the confounding effects of microstructure-related frequency contributions. © 2014 Wiley Periodicals, Inc.

Effect of algal growth phase on Aureococcus anophagefferens susceptibility to hydrogen peroxide

International Nuclear Information System (INIS)

Randhawa, Varunpreet; Thakkar, Megha; Wei, Liping

2013-01-01

Highlights: •Brown tide alga's susceptibility to H 2 O 2 was examined via growth and physiology responses. •The study was designed equalizing the influence of the media and cell density in test cultures. •Stationary cells was more sensitive to H 2 O 2 than exponential cells. •Stationary cells showed weaker non-protein thiol up-regulation than exponential cells. •Stationary cells mediated greater H 2 O 2 decomposition than exponential cells did. -- Abstract: A cell's growth phase could affect its susceptibility to a biocide in microbial control. This study examines the growth phase dependent susceptibility of a brown tide bloom alga Aureococcus anophagefferens to microbial biocide hydrogen peroxide (H 2 O 2 ). Test cultures of A. anophagefferens cells in exponential and stationary growth phase and similar initial cell density (1.6 × 10 6 cells mL −1 ) were exposed to 0.4–1.6 mg L −1 H 2 O 2 . Changes in algal growth (in vivo fluorescence, total chlorophyll a, and cell density), cell physiology (maximum quantum yield of photosystem II, and total intracellular non-protein thiols), and H 2 O 2 decomposition were quantified. Results show that the stationary phase cells are more susceptible to H 2 O 2 than the exponential phase cells, and this is attributed to the weaker ROS (reactive oxygen species) scavenging system and consequently greater cell damage in stationary phase cells. The stationary phase cells potentially require 30–40% less H 2 O 2 to reach 90% removal within 12 h of treatment as compared to the exponential phase cells. The results have practical implications in brown tide bloom control with respect to the timing and the dosage of H 2 O 2 application

Frequency and antimicrobial susceptibility of Staphylococcus pseudintermedius in dogs with otitis externa

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Carolina Boesel Scherer

2018-05-01

Full Text Available ABSTRACT: Infections by Staphyloccocus pseudintermedius in the skin of dogs have been object of studies, since such microorganisms often present multiple resistance to antibiotics. This study aimed to identify and evaluate the antimicrobial susceptibility of Staphylococcus pseudintermedius (SP strains isolated from dogs with otitis. Swabs from both ears of 52 dogs with otitis (n=104 were included. Bacteria were cultured using Muller-Hinton agar (supplemented with 5% equine blood and incubated at 37°C for 24 to 48 hours. All colonies underwent biochemical evaluation for identification of staphylococci. The identity of colonies as SP was confirmed by polymerase chain reaction. The antimicrobial susceptibility of SP strains was evaluated by disk diffusion. The presence of the gene mecA was evaluated in all SP isolates by PCR. Forty-four SP strains were isolated from swabs of 31 dogs (31/52, 59.6%. Seventy-five percent of the strains were susceptible to cephalexin and 93.2% to amoxicillin plus clavulanic acid. Less than 23% of the strains were susceptible to penicillin. For non-beta-lactam antimicrobials, 63.6% of the strains showed resistance to sulfamethoxazole-trimethoprim, 61.4% to tetracycline, and 38, 64% to enrofloxacin. Aminoglycoside resistance rate was 27.3% for gentamicin. Resistance to oxacillin in vitro was detected in 13 of the 44 strains (29, 55%. A total of 12 strains (27.3% were positive for mecA gene and five of these 12 strains were susceptible to in vitro oxacillin. Twenty-six (59, 1% strains were resistant to three or more classes of antimicrobials, and classified as multi resistant. Our results showed high frequency of SP and multi resistant isolates to antimicrobials commonly used in veterinary.

Methicillin-resistant Staphylococcus aureus isolates with SCCmec type V and spa types t437 or t1081 associated to discordant susceptibility results between oxacillin and cefoxitin, Central Taiwan.

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Ho, Cheng-Mao; Lin, Chien-Yu; Ho, Mao-Wang; Lin, Hsiao-Chuan; Chen, Chao-Jung; Lin, Lee-Chung; Lu, Jang-Jih

2016-12-01

Staphylococcus aureus isolates with discordant susceptibility results between oxacillin and cefoxitin obtained using automated microbiology systems are infrequently observed. From April 2013 to December 2014, 1956 methicillin-resistant S. aureus (MRSA) and 1761 methicillin-susceptible S. aureus isolates were obtained from different patients. Forty isolates (1.1% and 2% in case of S. aureus and MRSA, respectively) with discordant susceptibility results (oxacillin susceptible and cefoxitin resistant) and carrying mecA gene were obtained. Except 2 SCCmec type IV isolates, 38 MRSA isolates were all SCCmec type V (V T or non-V T ), which were further divided into V T (n=22) and non-V T (n=16). The most common spa type in V T and non-V T isolates were t437 (n=19) and t1081 (n=13), respectively. Only 55% of patients received effective antimicrobial agents; 2 mortalities were not attributable to MRSA infection. Using standard agar dilution, 17 MRSA isolates (0.46% and 0.87% in case of S. aureus and MRSA, respectively) had oxacillin MIC in the susceptible ranges (oxacillin-susceptible MRSA [OS-MRSA]); all carried SCCmec type V (V T , n=8; non-V T , n=9). The most common spa-MLST types of OS-MRSA in V T and non-V T were t437-ST59 (n=4) and t1081-ST45 (n=7), respectively. Concomitant testing by both cefoxitin- and oxacillin-based methods is a practical strategy for OS-MRSA detection in the clinical laboratories. Continuous monitoring of OS-MRSA isolates is necessary to elucidate their impact in clinical infectious diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Occurrence and antimicrobial susceptibility of enteric rods and pseudomonads isolated from the dental prostheses biofilm

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Sanrrangers Sales Silva

Full Text Available ABSTRACT Aspiration of oral bacteria leads to cardiac and respiratory infectious diseases and dentures can act as a reservoir for pathogenic microorganisms. Objective: To determine the occurrence and the in vitro antimicrobial susceptibility of enteric rods and pseudomonads from the denture biofilm of 52 subjects at the Center for Dental Specialties of Sobral/ Ceara, Brazil. Material and Methods: Denture biofilm was collected and samples plated on MacConkey agar. The isolated bacterial colonies were identified using the BBL Crystal enteric/non-fermenter system. Antibiotic bacterial susceptibility was assessed by the disc diffusion method of amoxicillin, amoxicillin/clavulanic acid, doxycycline, tetracycline, tobramycin, imipenem, cefotaxime, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC of cefotaxime, tobramycin, doxycycline, imipenem, and ciprofloxacin was determined for 40 species by E-test. Results: 34 subjects (65.4% harbored enteric rods in their prostheses. Klebsiella pneumoniae (26.5%, Escherichia coli (23.5%, and Enterobacter aerogenes (23.5% were the most prevalent species. All organisms were susceptible to ciprofloxacin and most species were resistant to amoxicillin or amoxicillin/clavulanic acid, demonstrating variable sensitivity patterns to other antimicrobials. However, the MIC showed the emergence of strains with reduced sensitivity to ciprofloxacin (MIC90≥3 μg/ mL and cefotaxime (MIC90≥2 μg/mL. Conclusion: The findings show high prevalence of nosocomial diseases-related bacterial species and low susceptibility to antimicrobial drugs. Therefore, these results imply caution against the indiscriminate use of broad spectrum antibiotics in dental practice.

Heterozygote loss of ACE2 is sufficient to increase the susceptibility to heart disease.

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Wang, Wang; Patel, Vaibhav B; Parajuli, Nirmal; Fan, Dong; Basu, Ratnadeep; Wang, Zuocheng; Ramprasath, Tharmarajan; Kassiri, Zamaneh; Penninger, Josef M; Oudit, Gavin Y

2014-08-01

Angiotensin-converting enzyme 2 (ACE2) metabolizes Ang II into Ang 1-7 thereby negatively regulating the renin-angiotensin system. However, heart disease in humans and in animal models is associated with only a partial loss of ACE2. ACE2 is an X-linked gene; and as such, we tested the clinical relevance of a partial loss of ACE2 by using female ACE2(+/+) (wildtype) and ACE2(+/-) (heterozygote) mice. Pressure overload in ACE2(+/-) mice resulted in greater LV dilation and worsening systolic and diastolic dysfunction. These changes were associated with increased myocardial fibrosis, hypertrophy, and upregulation of pathological gene expression. In response to Ang II infusion, there was increased NADPH oxidase activity and myocardial fibrosis resulting in the worsening of Ang II-induced diastolic dysfunction with a preserved systolic function. Ang II-mediated cellular effects in cultured adult ACE2(+/-) cardiomyocytes and cardiofibroblasts were exacerbated. Ang II-mediated pathological signaling worsened in ACE2(+/-) hearts characterized by an increase in the phosphorylation of ERK1/2 and JNK1/2 and STAT-3 pathways. The ACE2(+/-) mice showed an exacerbated pressor response with increased vascular fibrosis and stiffness. Vascular superoxide and nitrotyrosine levels were increased in ACE2(+/-) vessels consistent with increased vascular oxidative stress. These changes occurred with increased renal fibrosis and superoxide production. Partial heterozygote loss of ACE2 is sufficient to increase the susceptibility to heart disease secondary to pressure overload and Ang II infusion. Heart disease in humans with idiopathic dilated cardiomyopathy is associated with a partial loss of ACE2. Heterozygote female ACE2 mutant mice showed enhanced susceptibility to pressure overload-induced heart disease. Heterozygote female ACE2 mutant mice showed enhanced susceptibility to Ang II-induced heart and vascular diseases. Partial loss of ACE2 is sufficient to enhance the susceptibility to

Landslide susceptibility mapping at Hoa Binh province (Vietnam) using an adaptive neuro-fuzzy inference system and GIS

Science.gov (United States)

Tien Bui, Dieu; Pradhan, Biswajeet; Lofman, Owe; Revhaug, Inge; Dick, Oystein B.

2012-08-01

The objective of this study is to investigate a potential application of the Adaptive Neuro-Fuzzy Inference System (ANFIS) and the Geographic Information System (GIS) as a relatively new approach for landslide susceptibility mapping in the Hoa Binh province of Vietnam. Firstly, a landslide inventory map with a total of 118 landslide locations was constructed from various sources. Then the landslide inventory was randomly split into a testing dataset 70% (82 landslide locations) for training the models and the remaining 30% (36 landslides locations) was used for validation purpose. Ten landslide conditioning factors such as slope, aspect, curvature, lithology, land use, soil type, rainfall, distance to roads, distance to rivers, and distance to faults were considered in the analysis. The hybrid learning algorithm and six different membership functions (Gaussmf, Gauss2mf, Gbellmf, Sigmf, Dsigmf, Psigmf) were applied to generate the landslide susceptibility maps. The validation dataset, which was not considered in the ANFIS modeling process, was used to validate the landslide susceptibility maps using the prediction rate method. The validation results showed that the area under the curve (AUC) for six ANFIS models vary from 0.739 to 0.848. It indicates that the prediction capability depends on the membership functions used in the ANFIS. The models with Sigmf (0.848) and Gaussmf (0.825) have shown the highest prediction capability. The results of this study show that landslide susceptibility mapping in the Hoa Binh province of Vietnam using the ANFIS approach is viable. As far as the performance of the ANFIS approach is concerned, the results appeared to be quite satisfactory, the zones determined on the map being zones of relative susceptibility.

The mediational pathway among parenting styles, attachment styles and self-regulation with addiction susceptibility of adolescents*

Science.gov (United States)

Zeinali, Ali; Sharifi, Hassanpasha; Enayati, Mirsalahadine; Asgari, Parviz; Pasha, Gohlamreza

2011-01-01

BACKGROUND: The purpose of present study was to create and test a model that illustrates variables that influence the development of addiction susceptibility and determine how different styles of parenting may indirectly influence the addiction susceptibility of children through the mediators of attachment style and self-regulation. METHODS: Using random cluster sampling, 508 adolescent high school boys and girls aged 14-19 years were enrolled. Data were analyzed using structural equations modeling (path analysis). RESULTS: The results showed that authoritative and permissive parenting styles were associated with secure attachment whereas authoritarian and neglectful parenting styles were associated with insecure attachment. Insecure attachment was associated with a low level of self-regulation whereas secure attachment was associated with a high level of self-regulation. We found that a low level of self-regulation increased the adolescent's addiction susceptibility whereas a high level of self-regulation decreased their addiction susceptibility. CONCLUSIONS: The findings of present study suggest the authoritative and permissive parenting styles as the most efficient styles and authoritarian and neglectful parenting styles as the most inefficient styles in terms of addiction susceptibility. Accordingly, efficient parenting style training to parents should be the main goal of drug demand reduction program. PMID:22973379

A Systematic Review on Sasang Constitutional Type-Associated Susceptibility to Disorders in Korea.

Science.gov (United States)

Lee, Hyun-Yong; Lee, Woo-Jin; Kim, Hae-Won; Jang, Eun-Su; Ahn, Yo-Chan; Ku, Bon-Cho; Kang, Weechang; Lee, Si-Woo; Son, Chang-Gue

2016-12-01

Sasang constitutional medicine is a component of traditional Korean medicine that classifies individuals into four Sasang constitutional types (SCTs) by their physical and psychological traits. Each SCT is known to show different susceptibilities to disorders. This systematic review investigated the effect of SCT as a risk factor for various disorders. A systematic literature survey was conducted by searching seven databases for all articles on the prevalence rates of disorders according to SCT and sex. From 14,272 relevant articles, 15 studies (13 disorders) were ultimately identified to verify different prevalence rates by SCT. Of the 13 disorders, 6 (prehypertension, general obesity, abdominal obesity, metabolic syndrome, diabetes mellitus, and irritable bowel syndrome [IBS]) had a significantly different prevalence by SCT. Metabolic syndrome and its associated disorders showed the highest prevalence in Taeumin-type individuals, whereas IBS was most prevalent in Soeumin-type individuals. In general, these findings were consistent with the results obtained in an analysis of male and female participants. This study revealed that susceptibility to disorders was affected by SCT to some extent. Further studies are needed to determine the concrete features of SCT-related susceptibility, which may be helpful in preventive medicine with Sasang constitutional practice.

GIS-Based Integration of Subjective and Objective Weighting Methods for Regional Landslides Susceptibility Mapping

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Suhua Zhou

2016-04-01

Full Text Available The development of landslide susceptibility maps is of great importance due to rapid urbanization. The purpose of this study is to present a method to integrate the subjective weight with objective weight for regional landslide susceptibility mapping on the geographical information system (GIS platform. The analytical hierarchy process (AHP, which is subjective, was employed to weight predictive factors’ contribution to landslide occurrence. The frequency ratio (FR method, which is objective, was used to derive subclasses’ frequency ratio with respect to landslides that indicate the relative importance of a subclass within each predictive factor. A case study was carried out at Tsushima Island, Japan, using a historical inventory of 534 landslides and seven predictive factors: elevation, slope, aspect, terrain roughness index (TRI, lithology, land cover and mean annual precipitation (MAP. The landslide susceptibility index (LSI was calculated using the weighted linear combination of factors’ weights and subclasses’ weights. The study area was classified into five susceptibility zones according to the LSI. In addition, the produced susceptibility map was compared with maps generated using the conventional FR and AHP method and validated using the relative landslide index (RLI. The validation result showed that the proposed method performed better than the conventional application of the FR method and AHP method. The obtained landslide susceptibility maps could serve as a scientific basis for urban planning and landslide hazard management.

Retrieval of high-order susceptibilities of nonlinear metamaterials

International Nuclear Information System (INIS)

Wang Zhi-Yu; Qiu Jin-Peng; Chen Hua; Mo Jiong-Jiong; Yu Fa-Xin

2017-01-01

Active metamaterials embedded with nonlinear elements are able to exhibit strong nonlinearity in microwave regime. However, existing S -parameter based parameter retrieval approaches developed for linear metamaterials do not apply in nonlinear cases. In this paper, a retrieval algorithm of high-order susceptibilities for nonlinear metamaterials is derived. Experimental demonstration shows that, by measuring the power level of each harmonic while sweeping the incident power, high-order susceptibilities of a thin-layer nonlinear metamaterial can be effectively retrieved. The proposedapproach can be widely used in the research of active metamaterials. (paper)

Nonlinear electromagnetic susceptibilities of unmagnetized plasmas

International Nuclear Information System (INIS)

Yoon, Peter H.

2005-01-01

Fully electromagnetic nonlinear susceptibilities of unmagnetized plasmas are analyzed in detail. Concrete expressions of the second-order nonlinear susceptibility are found in various forms in the literature, usually in connection with the discussions of various three-wave decay processes, but the third-order susceptibilities are rarely discussed. The second-order susceptibility is pertinent to nonlinear wave-wave interactions (i.e., the decay/coalescence), whereas the third-order susceptibilities affect nonlinear wave-particle interactions (i.e., the induced scattering). In the present article useful approximate analytical expressions of these nonlinear susceptibilities that can be readily utilized in various situations are derived

Landslide susceptibility mapping by comparing weight of evidence, fuzzy logic, and frequency ratio methods

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V. Vakhshoori

2016-09-01

Full Text Available A regional scale basin susceptible to landslide located in Qaemshahr area in northern Iran was chosen for comparing the reliability of weight of evidence (WofE, fuzzy logic, and frequency ratio (FR methods for landslide susceptibility mapping. The locations of 157 landslides were identified using Google Earth® or extracted from archived data, from which, 22 rockslides were eliminated from the data-set due to their different conditions. The 135 remaining landslides were randomly divided into two groups of modelling (70% and validation (30% data-sets. Elevation, slope degree, slope aspect, lithology, land use/cover, normalized difference vegetation index, rainfall, distance to drainage network, roads, and faults were considered as landslide causative factors. The landslide susceptibility maps were prepared using the three mentioned methods. The validation process was measured by the success and prediction rates calculated by area under receiver operating characteristic curve. The ‘OR’, ‘AND’, ‘SUM’, and ‘PRODUCT’ operators of the fuzzy logic method were unacceptable because these operators classify the target area into either very high or very low susceptible zones that are inconsistent with the physical conditions of the study area. The results of fuzzy ‘GAMMA’ operators were relatively reliable while, FR and WofE methods showed results that are more reliable.

Gun Shows and Gun Violence: Fatally Flawed Study Yields Misleading Results

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Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A.

2010-01-01

A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled “The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas” outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors’ prior research. The study should not be used as evidence in formulating gun policy. PMID:20724672

The association between miR-499 polymorphism and cancer susceptibility: a meta-analysis

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Xu Z

2015-08-01

Full Text Available Zhongfei Xu, Enjiao Zhang, Weiyi Duan, Changfu Sun, Shuang Bai, Xuexin Tan Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University, Shenyang, People’s Republic of China Background: MicroRNAs are a class of new noncoding RNA that play important roles in the pathogenesis of tumor. Rs3746444 in miR-499 is suggested to be associated with cancer susceptibility. In the present study, we assess the association between miR-499 rs3746444 polymorphism and cancer susceptibility through a meta-analysis. Methods: We searched relevant articles from the PubMed and Embase databases. We screened all the resulting articles for adherence to the inclusion and exclusion criteria. The associations between miR-499 polymorphism and cancer susceptibility were estimated by computing the odds ratios (ORs and 95% confidence intervals (CIs. All analyses were performed using Stata software. Results: There are 18 datasets included in the analysis. Statistically significant associations were found between the miR-499 rs3746444 polymorphism and susceptibility to cancer (GG versus AA: OR =1.24, 95% CI: 1.01–1.52; G versus A: OR =1.11, 95% CI: 1.01–1.23. A subsequent analysis, on the basis of ethnicity for the population characteristic, showed that Asians had increased susceptibility to cancer (GG versus AA: OR =1.32, 95% CI: 1.09–1.59; GG + AG versus AA: OR = 1.17, 95% CI: 1.01–1.37. In the subgroup analysis of tumor type, none of the genetic models had statistically significant results. The meta-regression suggested that race and cancer types are not the source of heterogeneity in the present meta-analysis. No publication bias was detected by either the inverted funnel plot or Egger’s test. Conclusion: Rs3746444 in miR-499 might be related to susceptibility to cancer. Keywords: microRNA, single-nucleotide polymorphism, tumor, risk factor

Soil susceptibility to compaction under use conditions in southern Brazil

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Michael Mazurana

Full Text Available ABSTRACT The degree of soil compaction is intensified by its inadequate management, compaction being variable depending on soil type since even under identical management conditions, different types have different abilities to withstand load. The objective of this study was to evaluate the susceptibility to compaction of different classes of soils under no-tillage (NT croping system compared to the original condition. Thus, i soils with the same source material have distinct resistance to compression with increased NT adoption time; ii the most sensitive indicators of this change are the ratios mass:volume and volume:volume and; iii there is a relationship between resistance and compaction susceptibility with the amount and type of oxide. Soil samples were collected in areas under NT and under natural condition in order to assess the impact imposed by the NT on the attributes density and porosity, precompression stress and compressibility index and relate them to the oxide type of, and content in, the soils under study. The results show that the density and macroporosity were those most affected by the NT agricultural use, regardless of soil type, that is, its dynamic is related more to soil use and less to mineralogical characteristics. The soil resistance and compaction susceptibility were higher in soil developed in basalt, followed by those developed in sandstone and granite. Both the organic matter content and type and concentration of iron oxides were related to the soil resistance and susceptibility to compaction.

Antibiotic susceptibility of Atopobium vaginae

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Verschraegen Gerda

2006-03-01

Full Text Available Abstract Background Previous studies have indicated that a recently described anaerobic bacterium, Atopobium vaginae is associated with bacterial vaginosis (BV. Thus far the four isolates of this fastidious micro-organism were found to be highly resistant to metronidazole and susceptible for clindamycin, two antibiotics preferred for the treatment of BV. Methods Nine strains of Atopobium vaginae, four strains of Gardnerella vaginalis, two strains of Lactobacillus iners and one strain each of Bifidobacterium breve, B. longum, L. crispatus, L. gasseri and L. jensenii were tested against 15 antimicrobial agents using the Etest. Results All nine strains of A. vaginae were highly resistant to nalidixic acid and colistin while being inhibited by low concentrations of clindamycin (range: G. vaginalis strains were also susceptible for clindamycin ( 256 μg/ml but susceptible to clindamycin (0.023 – 0.125 μg/ml. Conclusion Clindamycin has higher activity against G. vaginalis and A. vaginae than metronidazole, but not all A. vaginae isolates are metronidazole resistant, as seemed to be a straightforward conclusion from previous studies on a more limited number of strains.

A Specific Autistic Trait that Modulates Visuospatial Illusion Susceptibility

Science.gov (United States)

Walter, Elizabeth; Dassonville, Paul; Bochsler, Tiana M.

2009-01-01

Although several accounts of autism have predicted that the disorder should be associated with a decreased susceptibility to visual illusions, previous experimental results have been mixed. This study examined whether a link between autism and illusion susceptibility can be more convincingly demonstrated by assessing the relationships between…

Wave Vector Dependent Susceptibility at T>Tc in a Dipolar Ising Ferromagnet

DEFF Research Database (Denmark)

Als-Nielsen, Jens Aage; Holmes, L. M:; Guggenheim, H. J.

1974-01-01

The wave-vector-dependent susceptibility of LiTbF4 has been investigated by means of neutron scattering. The observations show a singularity of the susceptibility near wave vector Q=0 which is characteristic of the dipolar Coulomb interaction and good agreement with theory is obtained...

Collapse susceptibility mapping in karstified gypsum terrain (Sivas basin - Turkey) by conditional probability, logistic regression, artificial neural network models

Science.gov (United States)

Yilmaz, Isik; Keskin, Inan; Marschalko, Marian; Bednarik, Martin

2010-05-01

This study compares the GIS based collapse susceptibility mapping methods such as; conditional probability (CP), logistic regression (LR) and artificial neural networks (ANN) applied in gypsum rock masses in Sivas basin (Turkey). Digital Elevation Model (DEM) was first constructed using GIS software. Collapse-related factors, directly or indirectly related to the causes of collapse occurrence, such as distance from faults, slope angle and aspect, topographical elevation, distance from drainage, topographic wetness index- TWI, stream power index- SPI, Normalized Difference Vegetation Index (NDVI) by means of vegetation cover, distance from roads and settlements were used in the collapse susceptibility analyses. In the last stage of the analyses, collapse susceptibility maps were produced from CP, LR and ANN models, and they were then compared by means of their validations. Area Under Curve (AUC) values obtained from all three methodologies showed that the map obtained from ANN model looks like more accurate than the other models, and the results also showed that the artificial neural networks is a usefull tool in preparation of collapse susceptibility map and highly compatible with GIS operating features. Key words: Collapse; doline; susceptibility map; gypsum; GIS; conditional probability; logistic regression; artificial neural networks.

Susceptibility profiles of Nocardia isolates based on current taxonomy.

Science.gov (United States)

Schlaberg, Robert; Fisher, Mark A; Hanson, Kimberley E

2014-01-01

The genus Nocardia has undergone rapid taxonomic expansion in recent years, and an increasing number of species are recognized as human pathogens. Many established species have predictable antimicrobial susceptibility profiles, but sufficient information is often not available for recently described organisms. Additionally, the effectiveness of sulfonamides as first-line drugs for Nocardia has recently been questioned. This led us to review antimicrobial susceptibility patterns for a large number of molecularly identified clinical isolates. Susceptibility results were available for 1,299 isolates representing 39 different species or complexes, including 11 that were newly described, during a 6-year study period. All tested isolates were susceptible to linezolid. Resistance to trimethoprim-sulfamethoxazole (TMP-SMX) was rare (2%) except among Nocardia pseudobrasiliensis (31%) strains and strains of the N. transvalensis complex (19%). Imipenem susceptibility varied for N. cyriacigeorgica and N. farcinica, as did ceftriaxone susceptibility of the N. nova complex. Resistance to more than one of the most commonly used drugs (amikacin, ceftriaxone, TMP-SMX, and imipenem) was highest for N. pseudobrasiliensis (100%), N. transvalensis complex (83%), N. farcinica (68%), N. puris (57%), N. brasiliensis (51%), N. aobensis (50%), and N. amikacinitolerans (43%). Thus, while antimicrobial resistance can often be predicted, susceptibility testing should still be considered when combination therapy is warranted, for less well characterized species or those with variable susceptibility profiles, and for patients with TMP-SMX intolerance.

Experimental infection of Aphanomyces invadans and susceptibility in seven species of tropical fish

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Seyedeh F. Afzali

2015-09-01

Full Text Available Aim: Epizootic ulcerative syndrome (EUS causes by aquatic oomycete fungus, Aphanomyces invadans is a dangerous fish disease of a wide range of fresh and brackish water, wild and farmed fish throughout the world. The objective of the present study was to determine the susceptibility of a number of tropical fish species to the EUS and compare the severity of infection between experimental groups. Materials and Methods: Snakehead, Channa striata (Bloch, 1793; snakeskin gourami, Trichopodus pectoralis (Regan, 1910; koi carp, Cyprinus carpio (Linnaeus, 1758; broadhead catfish, Clarias macrocephalus (Günther, 1864; goldfish, Carassius auratus (Linnaeus, 1758; climbing perch, Anabas testudineus (Bloch, 1792; and Nile tilapia, Oreochromis niloticus (Linnaeus, 1758 were challenged by intramuscular injection using zoospores of Aphanomyces invadans (NJM9701. The infected fish skins and muscles were examined for EUS histopathological characteristics, and the results on the severity of lesions and mortality were analyzed using SPSS program. Results: All zoospore-injected fish were shown to be susceptible to the EUS infection except Nile tilapia. Although, the general histopathological pattern was similar in the zoospore-injected group, but there were some variation in granulomatous reaction, that is the presence or absence of giant cells, and time of mortality were detected. The result of statistical analysis showed that there was a significant difference between species, (c2=145.11 and p<0.01. Conclusion: Gourami, koi carp, and catfish were demonstrated to be highly susceptible while goldfish and climbing perch were found to be moderately susceptible to the EUS infection. These findings suggested that the cellular response of fish to mycotic infection and granulomatous reaction varied in different fish species, which could not be an indicator of susceptibility or resistant to the EUS itself, although it was shown that the granulation rate and the level of

Antimicrobial Effects of β-Lactams on Imipenem-Resistant Ceftazidime-Susceptible Pseudomonas aeruginosa.

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Wi, Yu Mi; Choi, Ji-Young; Lee, Ji-Young; Kang, Cheol-In; Chung, Doo Ryeon; Peck, Kyong Ran; Song, Jae-Hoon; Ko, Kwan Soo

2017-06-01

We studied the resistance mechanism and antimicrobial effects of β-lactams on imipenem-resistant Pseudomonas aeruginosa isolates that were susceptible to ceftazidime as detected by time-kill curve methods. Among 215 P. aeruginosa isolates from hospitalized patients in eight hospitals in the Republic of Korea, 18 isolates (23.4% of 77 imipenem-resistant isolates) were imipenem resistant and ceftazidime susceptible. Multilocus sequence typing revealed diverse genotypes, which indicated independent emergence. These 18 isolates were negative for carbapenemase genes. All 18 imipenem-resistant ceftazidime-susceptible isolates showed decreased mRNA expression of oprD , and overexpression of mexB was observed in 13 isolates. In contrast, overexpression of ampC , mexD , mexF , or mexY was rarely found. Time-kill curve methods were applied to three selected imipenem-resistant ceftazidime-susceptible isolates at a standard inoculum (5 × 10 5 CFU/ml) or at a high inoculum (5 × 10 7 CFU/ml) to evaluate the antimicrobial effects of β-lactams. Inoculum effects were detected for all three β-lactam antibiotics, ceftazidime, cefepime, and piperacillin-tazobactam, against all three isolates. The antibiotics had significant killing effects in the standard inoculum, but no effects in the high inoculum were observed. Our results suggest that β-lactam antibiotics should be used with caution in patients with imipenem-resistant ceftazidime-susceptible P. aeruginosa infection, especially in high-inoculum infections such as endocarditis and osteomyelitis. Copyright © 2017 American Society for Microbiology.

[Bacterial diversity in the oral cavity of adolescents with different caries susceptibilities].

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Yangyang, Zhang; Jinzhi, He; Xin, Xu; Xuedong, Zhou

2015-12-01

To analyze the differences between the bacterial diversities in the saliva of caries-free and caries-susceptible adolescents through polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). Twenty adolescent subjects aged 12-18 years were recruited and subdivided into two groups: caries-free adolescents (n = 10) and caries-susceptible adolescents (n = 10). Saliva samples were collected. Total DNA was isolated directly from each sample. A portion of the 16S rRNA gene locus was PCR-amplified by using universal primers. Microbial diversity was analyzed through PCR-DGGE. Analyzing the DGGE profile, we found that the composition of the saliva microbiome exhibited great intra-individual differences; the average band numbers of the caries-free adolescent group and the caries-susceptible adolescent group were 32.5 ± 3.7 and 27.3 ± 3.4, respectively. The differences between the groups were statistically significant (P = 0.008). Shannon-Wiener's indexes of the caries-susceptible adolescent group and the caries-free adolescent group were 2.5 ± 0.2 and 2.6 ± 0.2, respectively, but the differences between the groups were not significant (P = 0.405). Clustering analysis results suggested that most of the samples in the same group clustered together; this observation showed a high community structure similarity. The microbial diversity and complexity of bacteria in saliva are significantly higher in caries-free adolescents than in caries-susceptible adolescents. During caries development, bacterial diversity in the saliva likely decreases.

Determination of antifungal susceptibility patterns among the clinical isolates of Candida species

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Kamiar Zomorodian

2011-01-01

Full Text Available Context: Candida species are opportunistic yeasts that cause infections ranging from simple dermatosis to potentially life-threatening fungemia. The emergence of resistance to antifungal drugs has been increased in the past two decades. Aim: the present study we determined to find out the susceptibility profiles of clinical isolates of Candida species against four antifungal drugs, including amphotericin B, ketoconazole, fluconazole and itraconazole. Materials and Methods: Antifungal susceptibility testing of the yeasts was done in accordance with the proposed guidelines for antifungal disk diffusion susceptibility testing of yeasts based on the CLSI document M44-A. Results: A total of 206 yeast isolates were assessed. Among the evaluated Candida species, the highest rates of resistance to ketoconazole were seen in Candida glabrata (16.6% and Candida albicans (3.2%. Susceptibility and intermediate response to fluconazole were seen in 96.6% and 3.4% of the Candida isolates, respectively. A total of 19 (9.2% yeast isolates showed petite phenomenon including 11 C. glabrata, 3 C. albicans, 2 Candida dubliniensis and one isolate of each Candida krusei and Candida parapsilosis. Conclusion: The high number of petite mutation in the isolated yeasts should be seriously considered since it may be one of the reasons of antifungal treatment failure.

Defense response of susceptible and resistant Biomphalaria alexandrina snails against Schistosoma mansoni infection

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Iman F. Abou-El-Naga

2012-09-01

Full Text Available In Egypt, Biomphalaria alexandrina is the intermediate host for Schistosoma mansoni. The fates of Schistosoma miracidia in the snails varies between different species of Biomphalaria. The internal defense system is one of the factors that influence the susceptibility pattern of the snails. The interaction between Biomphalaria snails and S. mansoni needs to be identified for each species, and even between the members of the same species with different degrees of susceptibility. In the present study, the first generation of susceptible and resistant parents of B. alexandrina was examined histologically at the 30th day post exposure. The study includes the characterization of the immune response, as expressed by tissue reactions, of susceptible and resistant B. alexandrina snails against S. mansoni. It was also designed to determine the impact of the resistance increase in parent snails, on the mechanisms of interaction of their offspring against infection. The results showed that the infection rate of the offspring from the susceptible parents was 92%. No susceptible offspring was produced from the resistant parents. When the parents were of equal number of susceptible and resistant snails, they gave an offspring with an infection rate of 20%. Susceptible snails that had susceptible parents showed a higher degree of susceptibility than those that had both susceptible and resistant parents. A common feature of the resistant snails was the absence of any viable parasites. The tissue reactions of the resistant snails having only resistant parents occurred at the site of miracidial penetration. In resistant snails for which susceptible ones were included in their parents, the reactions occurred in the deep tissues. These results characterized the immune response of B. alexandrina snails against Schistosoma infection which was found to occur by two different mechanisms. One type of defense occurs in highly resistant snails, and employs direct

Results of Use of WHO Global Salm-Surv External Quality Assurance System for Antimicrobial Susceptibility Testing of Salmonella Isolates from 2000 to 2007

DEFF Research Database (Denmark)

Hendriksen, Rene S.; Seyfarth, Anne Mette; Jensen, Arne Bent

2009-01-01

laboratories in 102 countries participated in at least one EQAS iteration. A large number of laboratories reported results for the E. coli ATCC 25922 reference strain which were outside the quality control ranges. Critical deviations for susceptibility testing of the Salmonella isolates varied from 4% in 2000......An international External Quality Assurance System (EQAS) for antimicrobial susceptibility testing of Salmonella was initiated in 2000 by the World Health Organization (WHO) Global Salm-Surv in order to enhance the capacities of national reference laboratories to obtain reliable data....... In particular, further training and dissemination of information on quality control, appropriate interpretive criteria (breakpoints), and harmonization of the methodology worldwide through WHO Global Salm-Surv and other programs will contribute to the generation of comparable and reliable antimicrobial...

Genetic Susceptibility to Vitiligo: GWAS Approaches for Identifying Vitiligo Susceptibility Genes and Loci

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Shen, Changbing; Gao, Jing; Sheng, Yujun; Dou, Jinfa; Zhou, Fusheng; Zheng, Xiaodong; Ko, Randy; Tang, Xianfa; Zhu, Caihong; Yin, Xianyong; Sun, Liangdan; Cui, Yong; Zhang, Xuejun

2016-01-01

Vitiligo is an autoimmune disease with a strong genetic component, characterized by areas of depigmented skin resulting from loss of epidermal melanocytes. Genetic factors are known to play key roles in vitiligo through discoveries in association studies and family studies. Previously, vitiligo susceptibility genes were mainly revealed through linkage analysis and candidate gene studies. Recently, our understanding of the genetic basis of vitiligo has been rapidly advancing through genome-wide association study (GWAS). More than 40 robust susceptible loci have been identified and confirmed to be associated with vitiligo by using GWAS. Most of these associated genes participate in important pathways involved in the pathogenesis of vitiligo. Many susceptible loci with unknown functions in the pathogenesis of vitiligo have also been identified, indicating that additional molecular mechanisms may contribute to the risk of developing vitiligo. In this review, we summarize the key loci that are of genome-wide significance, which have been shown to influence vitiligo risk. These genetic loci may help build the foundation for genetic diagnosis and personalize treatment for patients with vitiligo in the future. However, substantial additional studies, including gene-targeted and functional studies, are required to confirm the causality of the genetic variants and their biological relevance in the development of vitiligo. PMID:26870082

Susceptibility pattern of extended spectrum beta-lactamase producing isolates in various clinical specimens

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Roshan, M.

2011-01-01

Objective: To determine the susceptibility pattern of extended spectrum beta-lactamase (ESBL) producing Gram negative isolates from various clinical specimens. Study Design: Descriptive study. Place and Duration of Study: Microbiology Department, Armed Forces Institute of Pathology, Rawalpindi, from January 2008 to January 2009. Methodology: A total of 308 ESBL producing isolates from various clinical specimens sent to AFIP for culture and sensitivity were identified using standard microbiological techniques and tested for antimicrobial susceptibility. At the same time screening for ESBL production was also done. ESBL production was confirmed by combination disc synergy method. The susceptibility pattern of isolates was then recorded in frequency percentages. Results: Out of the 308 ESBL producing isolates more than 99% were susceptible to carbapenems, 84% to tazobactam/ piperacillin, 81% to sulbactam/cefoperazone, 12% to fluoroquinolones, 13% to cotrimoxazole, 59% to amikacin and 18% to gentamicin. Among the urinary isolates 49% were susceptible to Nitrofurontoin and only 5% to Pipemidic acid. Conclusion: Antibiotic choices in case of ESBL producing isolates are limited and at present only carbapenems can be regarded as treatment of choice. As empirical agents, beta-lactam/beta lactamase inhibitor combinations should be used cautiously for serious infections. Fluoroquinolones showed very poor efficacy. Amikacin can be used alternatively in such cases. Nitrofurantoin is still a good oral agent for treating UTI. (author)

Possible Association of IL-4 VNTR Polymorphism with Susceptibility to Preeclampsia

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Saeedeh Salimi

2014-01-01

Full Text Available Preeclampsia (PE is a pregnancy-specific disorder that results in maternal mortality and morbidity. Growing evidence indicated that cytokines are involved in the pathogenesis of PE and interleukin-4 VNTR polymorphism could be implicated in altering the PE risk. The aim of this study was to evaluate the possible association between IL-4 VNTR polymorphism and susceptibility to PE in Iranian population for the first time. Genetic polymorphism was evaluated in 192 PE and 186 healthy control women by polymerase chain reaction method. We found that the VNTR polymorphism of IL-4 gene has significantly increased the risk of preeclampsia (RP2/RP1 versus RP1/RP1, OR, 2.8 [95% CI, 1.7 to 8.8]; P=0.0001 and RP2/RP2 versus RP1/RP1; P=0.002. The results showed that carriage of IL-4 VNTR RP2 allele has positive association with preeclampsia susceptibility.

Antimicrobial susceptibility of quinupristin/dalfopristin tested against gram-positive cocci from Latin America: results from the Global SMART (GSMART surveillance study

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Sader Helio S.

2001-01-01

active against many of these isolates as well as having potency against nearly all staphylococci and streptococci tested at or = 16 mm. Comparisons to GSMART results from other continents show nearly identical quinupristin/dalfopristin activity for each Gram-positive species tested. These results define the role of quinupristin/dalfopristin in Latin American medical centers and provide a benchmark for future in vitro comparisons.

Susceptibility and triggering scenarios at a regional scale for shallow landslides

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Gullà, G.; Antronico, L.; Iaquinta, P.; Terranova, O.

2008-07-01

The work aims at identifying susceptible areas and pluviometric triggering scenarios at a regional scale in Calabria (Italy), with reference to shallow landsliding events. The proposed methodology follows a statistical approach and uses a database linked to a GIS that has been created to support the various steps of spatial data management and manipulation. The shallow landslide predisposing factors taken into account are derived from (i) the 40-m digital terrain model of the region, an ˜ 15,075 km 2 extension; (ii) outcropping lithology; (iii) soils; and (iv) land use. More precisely, a map of the slopes has been drawn from the digital terrain model. Two kinds of covers [prevalently coarse-grained (CG cover) or fine-grained (FG cover)] were identified, referring to the geotechnical characteristics of geomaterial covers and to the lithology map; soilscapes were drawn from soil maps; and finally, the land use map was employed without any prior processing. Subsequently, the inventory maps of some shallow landsliding events, totaling more than 30,000 instabilities of the past and detected by field surveys and photo aerial restitution, were employed to calibrate the relative importance of these predisposing factors. The use of single factors (first level analysis) therefore provides three different susceptibility maps. Second level analysis, however, enables better location of areas susceptible to shallow landsliding events by crossing the single susceptibility maps. On the basis of the susceptibility map obtained by the second level analysis, five different classes of susceptibility to shallow landsliding events have been outlined over the regional territory: 8.9% of the regional territory shows very high susceptibility, 14.3% high susceptibility, 15% moderate susceptibility, 3.6% low susceptibility, and finally, about 58% very low susceptibility. Finally, the maps of two significant shallow landsliding events of the past and their related rainfalls have been

Personality traits as potential susceptibility markers : Differential susceptibility to support among parents

NARCIS (Netherlands)

Slagt, M.; Dubas, J.S.; Denissen, J.J.A.; Deković, M.; van Aken, M.A.G.

2015-01-01

In this study, we examined whether parents are differentially susceptible to support from their spouse and adolescent child depending on their personality traits, and whether differences in susceptibility to support among parents, in turn, are linked to the quality of support parents give to their

Evaluation of semisolid agar method for antifungal susceptibility test of T. rubrum

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Sultana Razia

2016-08-01

Full Text Available Background: With increasing fungal disease many newer antifungal drugs are available with different spectrum of activ­ity. Antifungal susceptibility test will help clinicians for selection of effective drug and thereby treatment of patient. Objective: The study was undertaken to perform a simple screening drug susceptibility test of T. rnbrum by Semi Solid Agar Antifungal Susceptibility (SAAS Method: Perfonnance of susceptibility method was assessed by comparing the MICs of three commonly prescribed antifungal agents namely- tluconazole (FCZ, itraconazole (ITZ and terbinafine (TER to the CLSI (Clinical and Laboratory Standard Institute recommended M-38, a broth microdilution method. Results: In SAAS method, among twenty nine T. rubrum, twenty five (86.2% were susceptible (MIC range 0.5-64 µg/ml to Fluconazole (FCZ and four (13.7% were resistant (MIC value >64 µg/ml. In broth microdilution method, among twenty nine T. rubrum, twenty six (89.6% were susceptible (MIC range 0.3-64 µg/ml to FCZ and three (10.3% were resistant (MIC value >64 µg/ml. In case of both ITZ and TER, all were susceptible (MIC range 0.3-64 µg/ml to both methods. The SAAS method demonstrated the susceptibility pattern of T. rubrum against FCZ, ITZ and TER usually within 72 to 96 hours after organism isolation and results were concordance with the results of CLSI broth microdilution method. Conclusion: Though it is a newer method with proper standardization of the test method, SAAS method is simple and easily applicable screening method for susceptibility testing of antifungal agents against dermatophytes in any microbiology laboratories.

Antimicrobial susceptibility and glycopeptide-resistance of enterococci in vegetables

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Ida Torre

2010-03-01

Full Text Available

Background: Vancomycin-resistant enterococci (VRE, often responsible for nosocomial infections, have frequently been isolated from animal and vegetable foods. In our study we evaluated the antibiotic susceptibility of enterococci isolated from eight types of vegetables randomly selected from grocery stores in Naples.

Methods: From July to November 2008, we analyzed 150 samples: the bacteria were isolated with standardized methods and antibiotic susceptibility was determined using the disc diffusion method. The resistance to vancomycin versus other antibiotics was assessed by the Kappa test.

Results: 70% of the samples, mainly parsley (96.2%, showed enterococci. Of these, 59.1% belonged to the species Enterococcus faecium. Strains resistant to vancomycin and teicoplanin were isolated respectively in 47.6% and 49.5% of the samples: the first one mainly in curly endive (72.7% and the second one in parsley (76.9%. Almost all the isolated strains showed resistance to methicillin (89%, kanamycin (82% and cephalothin (68%. The Kappa test showed statistically significant associations between resistance to vancomycin and resistance to teicoplanin, erythromycin, methicillin, tetracycline and chloramphenicol.

Conclusions: Because of the possible involvement of food in the transmission of resistant micro-organisms to human intestinal microbiota, our data may provide the basis for future studies.

Static quadrupolar susceptibility for a Blume–Emery–Griffiths model based on the mean-field approximation

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Pawlak, A., E-mail: pawlak@amu.edu.pl [Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61–614 Poznań (Poland); Gülpınar, G. [Department of Physics, Dokuz Eylül University, 35160 İzmir (Turkey); Erdem, R. [Department of Physics, Akdeniz University, 07058 Antalya (Turkey); Ağartıoğlu, M. [Institute of Science, Dokuz Eylül University, 35160 İzmir (Turkey)

2015-12-01

The expressions for the dipolar and quadrupolar susceptibilities are obtained within the mean-field approximation in the Blume–Emery–Griffiths model. Temperature as well as crystal field dependences of the susceptibilities are investigated for two different phase diagram topologies which take place for K/J=3 and K/J=5.0.Their behavior near the second and first order transition points as well as multi-critical points such as tricritical, triple and critical endpoint is presented. It is found that in addition to the jumps connected with the phase transitions there are broad peaks in the quadrupolar susceptibility. It is indicated that these broad peaks lie on a prolongation of the first-order line from a triple point to a critical point ending the line of first-order transitions between two distinct paramagnetic phases. It is argued that the broad peaks are a reminiscence of very strong quadrupolar fluctuations at the critical point. The results reveal the fact that near ferromagnetic–paramagnetic phase transitions the quadrupolar susceptibility generally shows a jump whereas near the phase transition between two distinct paramagnetic phases it is an edge-like. - Highlights: • MFA calculation of the quadrupolar and dipolar susceptibility in BEG model is given • The crystal-field variation of susceptibilities near the multi-critical points is examined • There are broad peaks in the quadrupolar susceptibility in the vicinity of CP • These maxima are remembrances of the very strong quadrupolar Fluctuations.

Kohn anomalies in momentum dependence of magnetic susceptibility of some three-dimensional systems

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Stepanenko, A. A.; Volkova, D. O.; Igoshev, P. A.; Katanin, A. A.

2017-11-01

We study a question of the presence of Kohn points, yielding at low temperatures nonanalytic momentum dependence of magnetic susceptibility near its maximum, in electronic spectra of some threedimensional systems. In particular, we consider a one-band model on face-centered cubic lattice with hopping between the nearest and next-nearest neighbors, which models some aspects of the dispersion of ZrZn2, and the two-band model on body-centered cubic lattice, modeling the dispersion of chromium. For the former model, it is shown that Kohn points yielding maxima of susceptibility exist in a certain (sufficiently wide) region of electronic concentrations; the dependence of the wave vectors, corresponding to the maxima, on the chemical potential is investigated. For the two-band model, we show the existence of the lines of Kohn points, yielding maximum susceptibility, whose position agrees with the results of band structure calculations and experimental data on the wave vector of antiferromagnetism of chromium.

An assessment on the use of bivariate, multivariate and soft computing techniques for collapse susceptibility in GIS environ

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Yilmaz, Işik; Marschalko, Marian; Bednarik, Martin

2013-04-01

The paper presented herein compares and discusses the use of bivariate, multivariate and soft computing techniques for collapse susceptibility modelling. Conditional probability (CP), logistic regression (LR) and artificial neural networks (ANN) models representing the bivariate, multivariate and soft computing techniques were used in GIS based collapse susceptibility mapping in an area from Sivas basin (Turkey). Collapse-related factors, directly or indirectly related to the causes of collapse occurrence, such as distance from faults, slope angle and aspect, topographical elevation, distance from drainage, topographic wetness index (TWI), stream power index (SPI), Normalized Difference Vegetation Index (NDVI) by means of vegetation cover, distance from roads and settlements were used in the collapse susceptibility analyses. In the last stage of the analyses, collapse susceptibility maps were produced from the models, and they were then compared by means of their validations. However, Area Under Curve (AUC) values obtained from all three models showed that the map obtained from soft computing (ANN) model looks like more accurate than the other models, accuracies of all three models can be evaluated relatively similar. The results also showed that the conditional probability is an essential method in preparation of collapse susceptibility map and highly compatible with GIS operating features.

Adolescent Susceptibility to Peer Influence in Sexual Situations.

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Widman, Laura; Choukas-Bradley, Sophia; Helms, Sarah W; Prinstein, Mitchell J

2016-03-01

One consistent predictor of adolescents' engagement in sexual risk behavior is their belief that peers are engaging in similar behavior; however, not all youth are equally susceptible to these peer influence effects. Understanding individual differences in susceptibility to peer influence is critical to identifying adolescents at risk for negative health outcomes. The purpose of this project was to identify predictors of susceptibility to peer influence using a novel performance-based measure of sexual risk taking. Participants were 300 early adolescents (Mage = 12.6 years; 53% female; 44% Caucasian) who completed (1) a pretest assessment of demographics, sexual attitudes, and hypothetical scenarios measuring the likelihood of engaging in sexual risk behavior and (2) a subsequent experimental procedure that simulated an Internet chat room in which youth believed that they were communicating with peers regarding these same hypothetical scenarios. In reality, these "peers" were computer-programmed e-confederates. Changes in responses to the sexual scenarios in the private pretest versus during the public chat room provided a performance-based measure of peer influence susceptibility. In total, 78% of youth provided more risky responses in the chat room than those in pretest. The most robust predictor of this change was gender, with boys significantly more susceptible to peer influence than girls. Significant interactions also were noted, with greater susceptibility among boys with later pubertal development and African-American boys. Results confirm that not all youth are equally susceptible to peer influence. Consistent with sexual script theory, boys evidence greater susceptibility to social pressure regarding sexual behavior than girls. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Glutathione maintenance mitigates age-related susceptibility to redox cycling agents

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Nicholas O. Thomas

2016-12-01

Full Text Available Isolated hepatocytes from young (4–6 mo and old (24–26 mo F344 rats were exposed to increasing concentrations of menadione, a vitamin K derivative and redox cycling agent, to determine whether the age-related decline in Nrf2-mediated detoxification defenses resulted in heightened susceptibility to xenobiotic insult. An LC50 for each age group was established, which showed that aging resulted in a nearly 2-fold increase in susceptibility to menadione (LC50 for young: 405 μM; LC50 for old: 275 μM. Examination of the known Nrf2-regulated pathways associated with menadione detoxification revealed, surprisingly, that NAD(PH: quinone oxido-reductase 1 (NQO1 protein levels and activity were induced 9-fold and 4-fold with age, respectively (p=0.0019 and p=0.018; N=3, but glutathione peroxidase 4 (GPX4 declined by 70% (p=0.0043; N=3. These results indicate toxicity may stem from vulnerability to lipid peroxidation instead of inadequate reduction of menadione semi-quinone. Lipid peroxidation was 2-fold higher, and GSH declined by a 3-fold greater margin in old versus young rat cells given 300 µM menadione (p2-fold reduction in cell death, suggesting that the age-related increase in menadione susceptibility likely stems from attenuated GSH-dependent defenses. This data identifies cellular targets for intervention in order to limit age-related toxicological insults to menadione and potentially other redox cycling compounds.

LANDSLIDE SUSCEPTIBILITY ASSESSMENT THROUGH FUZZY LOGIC INFERENCE SYSTEM (FLIS

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T. Bibi

2016-09-01

Full Text Available Landslide is among one of the most important natural hazards that lead to modification of the environment. It is a regular feature of a rapidly growing district Mansehra, Pakistan. This caused extensive loss of life and property in the district located at the foothills of Himalaya. Keeping in view the situation it is concluded that besides structural approaches the non-structural approaches such as hazard and risk assessment maps are effective tools to reduce the intensity of damage. A landslide susceptibility map is base for engineering geologists and geomorphologists. However, it is not easy to produce a reliable susceptibility map due to complex nature of landslides. Since 1980s, several mathematical models have been developed to map landslide susceptibility and hazard. Among various models this paper is discussing the effectiveness of fuzzy logic approach for landslide susceptibility mapping in District Mansehra, Pakistan. The factor maps were modified as landslide susceptibility and fuzzy membership functions were assessed for each class. Likelihood ratios are obtained for each class of contributing factors by considering the expert opinion. The fuzzy operators are applied to generate landslide susceptibility maps. According to this map, 17% of the study area is classified as high susceptibility, 32% as moderate susceptibility, 51% as low susceptibility and areas. From the results it is found that the fuzzy model can integrate effectively with various spatial data for landslide hazard mapping, suggestions in this study are hope to be helpful to improve the applications including interpretation, and integration phases in order to obtain an accurate decision supporting layer.

Association of breast cancer risk with genetic variants showing differential allelic expression: Identification of a novel breast cancer susceptibility locus at 4q21

Science.gov (United States)

Adoue, Véronique; Michailidou, Kyriaki; Canisius, Sander; Lemaçon, Audrey; Droit, Arnaud; Andrulis, Irene L; Anton-Culver, Hoda; Arndt, Volker; Baynes, Caroline; Blomqvist, Carl; Bogdanova, Natalia V.; Bojesen, Stig E.; Bolla, Manjeet K.; Bonanni, Bernardo; Borresen-Dale, Anne-Lise; Brand, Judith S.; Brauch, Hiltrud; Brenner, Hermann; Broeks, Annegien; Burwinkel, Barbara; Chang-Claude, Jenny; Couch, Fergus J.; Cox, Angela; Cross, Simon S.; Czene, Kamila; Darabi, Hatef; Dennis, Joe; Devilee, Peter; Dörk, Thilo; Dos-Santos-Silva, Isabel; Eriksson, Mikael; Fasching, Peter A.; Figueroa, Jonine; Flyger, Henrik; García-Closas, Montserrat; Giles, Graham G.; Goldberg, Mark S.; González-Neira, Anna; Grenaker-Alnæs, Grethe; Guénel, Pascal; Haeberle, Lothar; Haiman, Christopher A.; Hamann, Ute; Hallberg, Emily; Hooning, Maartje J.; Hopper, John L.; Jakubowska, Anna; Jones, Michael; Kabisch, Maria; Kataja, Vesa; Lambrechts, Diether; Marchand, Loic Le; Lindblom, Annika; Lubinski, Jan; Mannermaa, Arto; Maranian, Mel; Margolin, Sara; Marme, Frederik; Milne, Roger L.; Neuhausen, Susan L.; Nevanlinna, Heli; Neven, Patrick; Olswold, Curtis; Peto, Julian; Plaseska-Karanfilska, Dijana; Pylkäs, Katri; Radice, Paolo; Rudolph, Anja; Sawyer, Elinor J.; Schmidt, Marjanka K.; Shu, Xiao-Ou; Southey, Melissa C.; Swerdlow, Anthony; Tollenaar, Rob A.E.M.; Tomlinson, Ian; Torres, Diana; Truong, Thérèse; Vachon, Celine; Van Den Ouweland, Ans M. W.; Wang, Qin; Winqvist, Robert; Investigators, kConFab/AOCS; Zheng, Wei; Benitez, Javier; Chenevix-Trench, Georgia; Dunning, Alison M.; Pharoah, Paul D. P.; Kristensen, Vessela; Hall, Per; Easton, Douglas F.; Pastinen, Tomi; Nord, Silje; Simard, Jacques

2016-01-01

There are significant inter-individual differences in the levels of gene expression. Through modulation of gene expression, cis-acting variants represent an important source of phenotypic variation. Consequently, cis-regulatory SNPs associated with differential allelic expression are functional candidates for further investigation as disease-causing variants. To investigate whether common variants associated with differential allelic expression were involved in breast cancer susceptibility, a list of genes was established on the basis of their involvement in cancer related pathways and/or mechanisms. Thereafter, using data from a genome-wide map of allelic expression associated SNPs, 313 genetic variants were selected and their association with breast cancer risk was then evaluated in 46,451 breast cancer cases and 42,599 controls of European ancestry ascertained from 41 studies participating in the Breast Cancer Association Consortium. The associations were evaluated with overall breast cancer risk and with estrogen receptor negative and positive disease. One novel breast cancer susceptibility locus on 4q21 (rs11099601) was identified (OR = 1.05, P = 5.6x10-6). rs11099601 lies in a 135 kb linkage disequilibrium block containing several genes, including, HELQ, encoding the protein HEL308 a DNA dependant ATPase and DNA Helicase involved in DNA repair, MRPS18C encoding the Mitochondrial Ribosomal Protein S18C and FAM175A (ABRAXAS), encoding a BRCA1 BRCT domain-interacting protein involved in DNA damage response and double-strand break (DSB) repair. Expression QTL analysis in breast cancer tissue showed rs11099601 to be associated with HELQ (P = 8.28x10-14), MRPS18C (P = 1.94x10-27) and FAM175A (P = 3.83x10-3), explaining about 20%, 14% and 1%, respectively of the variance inexpression of these genes in breast carcinomas. PMID:27792995

Association of breast cancer risk with genetic variants showing differential allelic expression: Identification of a novel breast cancer susceptibility locus at 4q21.

Science.gov (United States)

Hamdi, Yosr; Soucy, Penny; Adoue, Véronique; Michailidou, Kyriaki; Canisius, Sander; Lemaçon, Audrey; Droit, Arnaud; Andrulis, Irene L; Anton-Culver, Hoda; Arndt, Volker; Baynes, Caroline; Blomqvist, Carl; Bogdanova, Natalia V; Bojesen, Stig E; Bolla, Manjeet K; Bonanni, Bernardo; Borresen-Dale, Anne-Lise; Brand, Judith S; Brauch, Hiltrud; Brenner, Hermann; Broeks, Annegien; Burwinkel, Barbara; Chang-Claude, Jenny; Couch, Fergus J; Cox, Angela; Cross, Simon S; Czene, Kamila; Darabi, Hatef; Dennis, Joe; Devilee, Peter; Dörk, Thilo; Dos-Santos-Silva, Isabel; Eriksson, Mikael; Fasching, Peter A; Figueroa, Jonine; Flyger, Henrik; García-Closas, Montserrat; Giles, Graham G; Goldberg, Mark S; González-Neira, Anna; Grenaker-Alnæs, Grethe; Guénel, Pascal; Haeberle, Lothar; Haiman, Christopher A; Hamann, Ute; Hallberg, Emily; Hooning, Maartje J; Hopper, John L; Jakubowska, Anna; Jones, Michael; Kabisch, Maria; Kataja, Vesa; Lambrechts, Diether; Le Marchand, Loic; Lindblom, Annika; Lubinski, Jan; Mannermaa, Arto; Maranian, Mel; Margolin, Sara; Marme, Frederik; Milne, Roger L; Neuhausen, Susan L; Nevanlinna, Heli; Neven, Patrick; Olswold, Curtis; Peto, Julian; Plaseska-Karanfilska, Dijana; Pylkäs, Katri; Radice, Paolo; Rudolph, Anja; Sawyer, Elinor J; Schmidt, Marjanka K; Shu, Xiao-Ou; Southey, Melissa C; Swerdlow, Anthony; Tollenaar, Rob A E M; Tomlinson, Ian; Torres, Diana; Truong, Thérèse; Vachon, Celine; Van Den Ouweland, Ans M W; Wang, Qin; Winqvist, Robert; Zheng, Wei; Benitez, Javier; Chenevix-Trench, Georgia; Dunning, Alison M; Pharoah, Paul D P; Kristensen, Vessela; Hall, Per; Easton, Douglas F; Pastinen, Tomi; Nord, Silje; Simard, Jacques

2016-12-06

There are significant inter-individual differences in the levels of gene expression. Through modulation of gene expression, cis-acting variants represent an important source of phenotypic variation. Consequently, cis-regulatory SNPs associated with differential allelic expression are functional candidates for further investigation as disease-causing variants. To investigate whether common variants associated with differential allelic expression were involved in breast cancer susceptibility, a list of genes was established on the basis of their involvement in cancer related pathways and/or mechanisms. Thereafter, using data from a genome-wide map of allelic expression associated SNPs, 313 genetic variants were selected and their association with breast cancer risk was then evaluated in 46,451 breast cancer cases and 42,599 controls of European ancestry ascertained from 41 studies participating in the Breast Cancer Association Consortium. The associations were evaluated with overall breast cancer risk and with estrogen receptor negative and positive disease. One novel breast cancer susceptibility locus on 4q21 (rs11099601) was identified (OR = 1.05, P = 5.6x10-6). rs11099601 lies in a 135 kb linkage disequilibrium block containing several genes, including, HELQ, encoding the protein HEL308 a DNA dependant ATPase and DNA Helicase involved in DNA repair, MRPS18C encoding the Mitochondrial Ribosomal Protein S18C and FAM175A (ABRAXAS), encoding a BRCA1 BRCT domain-interacting protein involved in DNA damage response and double-strand break (DSB) repair. Expression QTL analysis in breast cancer tissue showed rs11099601 to be associated with HELQ (P = 8.28x10-14), MRPS18C (P = 1.94x10-27) and FAM175A (P = 3.83x10-3), explaining about 20%, 14% and 1%, respectively of the variance inexpression of these genes in breast carcinomas.

Cracking susceptibility of stainless steel subjected to plasma disruption

International Nuclear Information System (INIS)

Madarame, H.

1995-01-01

The similarities and differences in the cracking susceptibility between welding and resolidification after plasma disruption were examined experimentally using a number of primary candidate alloy samples with different chemical compositions. The product of the number density and the average depth of the cracks was measured after simulated disruption, employing a hydrogen ion beam as the heat source, and was compared with the Varestraint test result. An adequate correlation was observed between them, which indicates that the cracking susceptibility during plasma disruption can be well estimated from the welding cracking susceptibility. (orig.)

Comparison of the landslide susceptibility models in Taipei Water Source Domain, Taiwan

Science.gov (United States)

WU, C. Y.; Yeh, Y. C.; Chou, T. H.

2017-12-01

Taipei Water Source Domain, locating at the southeast of Taipei Metropolis, is the main source of water resource in this region. Recently, the downstream turbidity often soared significantly during the typhoon period because of the upstream landslides. The landslide susceptibilities should be analysed to assess the influence zones caused by different rainfall events, and to ensure the abilities of this domain to serve enough and quality water resource. Generally, the landslide susceptibility models can be established based on either a long-term landslide inventory or a specified landslide event. Sometimes, there is no long-term landslide inventory in some areas. Thus, the event-based landslide susceptibility models are established widely. However, the inventory-based and event-based landslide susceptibility models may result in dissimilar susceptibility maps in the same area. So the purposes of this study were to compare the landslide susceptibility maps derived from the inventory-based and event-based models, and to interpret how to select a representative event to be included in the susceptibility model. The landslide inventory from Typhoon Tim in July, 1994 and Typhoon Soudelor in August, 2015 was collected, and used to establish the inventory-based landslide susceptibility model. The landslides caused by Typhoon Nari and rainfall data were used to establish the event-based model. The results indicated the high susceptibility slope-units were located at middle upstream Nan-Shih Stream basin.

The magnetic susceptibility of soils in Krakow, southern Poland

Science.gov (United States)

Wojas, Anna

2017-06-01

Studies into the magnetic susceptibility have been used to assess the soils contamination in the Krakow area. The results of topsoil (over a 2 × 2 km grid), subsoil (37 shallow holes) and soil samples (112) measurements were presented as maps of soil magnetic susceptibility (both volume and mass) illustrating the distribution of parameters in topsoil horizon (0-10 cm) and differential magnetic susceptibility maps between topsoil horizon and subsoil (40-60 cm). All evidence leads to the finding that the highest values of magnetic susceptibility of soil are found exclusively in industrial areas. Taking into consideration the type of land use, the high median value (89.8 × 10-8 m3kg-1) was obtained for samples of cultivated soils and is likely to be connected with occurrence of fertile soil (chernozem). Moreover, enrichment of soils with Pb and Zn accompanies magnetic susceptibility anomalies in the vicinity of the high roads and in the steelworks area, respectively.

Speciation and antibiotic susceptibility patterns of coagulase-negative staphylococci.

Science.gov (United States)

Smith, D J; Kaplan, R L; Landau, W; Trenholme, G M

1982-08-01

During a six month period, 191 isolates of coagulase-negative staphylococci from blood, urine, cerebrospinal fluid and heart valves were identified to species level and tested for antimicrobial susceptibility. Seventy-one percent of isolates were Staphylococcus epidermidis, 8% Staphylococcus warneri, 7% Staphylococcus hominis, 7% Staphylococcus haemolyticus, 4% Staphylococcus capitis, 2% Staphylococcus saprophyticus and 1% Staphylococcus cohnii. Approximately 4% of isolates were felt to be associated with infection. Overall, 18% of isolates were susceptible to penicillin G, 61% oxacillin, 98% cephalothin, 98% cefamandole, 72% cefotaxime, 95% cefsulodin, 76% gentamicin, 64% clindamycin and 98% rifampicin. All isolates were susceptible to vancomycin. Vancomycin, rifampicin, cephalothin and cefamandole showed excellent activity against oxacillin-resistant isolates. With one exception, speciation was not helpful in determining whether or not an isolate was associated with infection.

Polymyxins: Antimicrobial susceptibility concerns and therapeutic options

Directory of Open Access Journals (Sweden)

V Balaji

2011-01-01

Full Text Available The increasing prevalence of multidrug-resistant nosocomial pathogens such as Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae poses a great challenge to the treating physicians. The paucity of newer effective antimicrobials has led to renewed interest in the polymyxin group of drugs, as a last resort for treatment of gram-negative bacterial infections. There is a dearth of information on the pharmacological properties of colistin, leading to difficulties in selecting the right dose, dosing interval, and route of administration for treatment, especially in critically-ill patients. The increasing use of colistin over the last few years necessitates the need for accurate and reliable in vitro susceptibility testing methods. Development of heteroresistant strains as a result of colistin monotherapy is also a growing concern. There is a compelling need from the clinicians to provide options for probable and possible colistin combination therapy for multidrug-resistant bacterial infections in the ICU setting. Newer combination drug synergy determination tests are being developed and reported. There are no standardized recommendations from antimicrobial susceptibility testing reference agencies for the testing and interpretation of these drug combinations. Comparison and analysis of these reported methodologies may help to understand and assist the microbiologist to choose the best method that produces accurate results at the earliest. This will help clinicians to select the appropriate combination therapy. In this era of multidrug resistance it is important for the microbiology laboratory to be prepared, by default, to provide timely synergistic susceptibility results in addition to routine susceptibility, if warranted. Not as a favour or at request, but as a responsibility.

Migraine aura: retracting particle-like waves in weakly susceptible cortex.

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Markus A Dahlem

Full Text Available Cortical spreading depression (SD has been suggested to underlie migraine aura. Despite a precise match in speed, the spatio-temporal patterns of SD observed in animal cortex and aura symptoms mapped to the cortical surface ordinarily differ in aspects of size and shape. We show that this mismatch is reconciled by utilizing that both pattern types bifurcate from an instability point of generic reaction-diffusion models. To classify these spatio-temporal pattern we suggest a susceptibility scale having the value sigma = 1 at the instability point. We predict that human cortex is only weakly susceptible to SD (sigma1, and potentially silent aura occurring below a second bifurcation point at sigma = 0 on the susceptible scale.

Shallow Landslide Susceptibility Modeling Using the Data Mining Models Artificial Neural Network and Boosted Tree

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Hyun-Joo Oh

2017-09-01

Full Text Available The main purpose of this paper is to present some potential applications of sophisticated data mining techniques, such as artificial neural network (ANN and boosted tree (BT, for landslide susceptibility modeling in the Yongin area, Korea. Initially, landslide inventory was detected from visual interpretation using digital aerial photographic maps with a high resolution of 50 cm taken before and after the occurrence of landslides. The debris flows were randomly divided into two groups: training and validation sets with a 50:50 proportion. Additionally, 18 environmental factors related to landslide occurrence were derived from the topography, soil, and forest maps. Subsequently, the data mining techniques were applied to identify the influence of environmental factors on landslide occurrence of the training set and assess landslide susceptibility. Finally, the landslide susceptibility indexes from ANN and BT were compared with a validation set using a receiver operating characteristics curve. The slope gradient, topographic wetness index, and timber age appear to be important factors in landslide occurrence from both models. The validation result of ANN and BT showed 82.25% and 90.79%, which had reasonably good performance. The study shows the benefit of selecting optimal data mining techniques in landslide susceptibility modeling. This approach could be used as a guideline for choosing environmental factors on landslide occurrence and add influencing factors into landslide monitoring systems. Furthermore, this method can rank landslide susceptibility in urban areas, thus providing helpful information when selecting a landslide monitoring site and planning land-use.

Landslide susceptibility mapping & prediction using Support Vector Machine for Mandakini River Basin, Garhwal Himalaya, India

Science.gov (United States)

Kumar, Deepak; Thakur, Manoj; Dubey, Chandra S.; Shukla, Dericks P.

2017-10-01

In recent years, various machine learning techniques have been applied for landslide susceptibility mapping. In this study, three different variants of support vector machine viz., SVM, Proximal Support Vector Machine (PSVM) and L2-Support Vector Machine - Modified Finite Newton (L2-SVM-MFN) have been applied on the Mandakini River Basin in Uttarakhand, India to carry out the landslide susceptibility mapping. Eight thematic layers such as elevation, slope, aspect, drainages, geology/lithology, buffer of thrusts/faults, buffer of streams and soil along with the past landslide data were mapped in GIS environment and used for landslide susceptibility mapping in MATLAB. The study area covering 1625 km2 has merely 0.11% of area under landslides. There are 2009 pixels for past landslides out of which 50% (1000) landslides were considered as training set while remaining 50% as testing set. The performance of these techniques has been evaluated and the computational results show that L2-SVM-MFN obtains higher prediction values (0.829) of receiver operating characteristic curve (AUC-area under the curve) as compared to 0.807 for PSVM model and 0.79 for SVM. The results obtained from L2-SVM-MFN model are found to be superior than other SVM prediction models and suggest the usefulness of this technique to problem of landslide susceptibility mapping where training data is very less. However, these techniques can be used for satisfactory determination of susceptible zones with these inputs.

[Comparison of microdilution and disk diffusion methods for the detection of fluconazole and voriconazole susceptibility against clinical Candida glabrata isolates and determination of changing susceptibility with new CLSI breakpoints].

Science.gov (United States)

Hazırolan, Gülşen; Sarıbaş, Zeynep; Arıkan Akdağlı, Sevtap

2016-07-01

Candida albicans is the most frequently isolated species as the causative agent of Candida infections. However, in recent years, the isolation rate of non-albicans Candida species have increased. In many centers, Candida glabrata is one of the commonly isolated non-albicans species of C.glabrata infections which are difficult-to-treat due to decreased susceptibility to fluconazole and cross-resistance to other azoles. The aims of this study were to determine the in vitro susceptibility profiles of clinical C.glabrata isolates against fluconazole and voriconazole by microdilution and disk diffusion methods and to evaluate the results with both the previous (CLSI) and current species-specific CLSI (Clinical and Laboratory Standards Institute) clinical breakpoints. A total of 70 C.glabrata strains isolated from clinical samples were included in the study. The identification of the isolates was performed by morphologic examination on cornmeal Tween 80 agar and assimilation profiles obtained by using ID32C (BioMérieux, France). Broth microdilution and disk diffusion methods were performed according to CLSI M27-A3 and CLSI M44-A2 documents, respectively. The results were evaluated according to CLSI M27-A3 and M44-A2 documents and new vs. species-specific CLSI breakpoints. By using both previous and new CLSI breakpoints, broth microdilution test results showed that voriconazole has greater in vitro activity than fluconazole against C.glabrata isolates. For the two drugs tested, very major error was not observed with disk diffusion method when microdilution method was considered as the reference method. Since "susceptible" category no more exists for fluconazole vs. C.glabrata, the isolates that were interpreted as susceptible by previous breakpoints were evaluated as susceptible-dose dependent by current CLSI breakpoints. Since species-specific breakpoints remain yet undetermined for voriconazole, comparative analysis was not possible for this agent. The results obtained

Toxicological and biochemical characterizations of AChE in phosalone-susceptible and resistant populations of the common pistachio psyllid, Agonoscena pistaciae

Science.gov (United States)

Alizadeh, Ali; Talebi-Jahromi, Khalil; Hosseininaveh, Vahid; Ghadamyari, Mohammad

2014-01-01

Abstract The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in nine populations of the common pistachio psyllid, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), were investigated in Kerman Province, Iran. Nine A. pistaciae populations were collected from pistachio orchards, Pistacia vera L. (Sapindales: Anacardiaceae), located in Rafsanjan, Anar, Bam, Kerman, Shahrbabak, Herat, Sirjan, Pariz, and Paghaleh regions of Kerman province. The previous bioassay results showed these populations were susceptible or resistant to phosalone, and the Rafsanjan population was most resistant, with a resistance ratio of 11.3. The specific activity of AChE in the Rafsanjan population was significantly higher than in the susceptible population (Bam). The affinity ( KM ) and hydrolyzing efficiency ( Vmax ) of AChE on acetylthiocholine iodide, butyrylthiocholine iodide, and propionylthiocholine odide as artificial substrates were clearly lower in the Bam population than that in the Rafsanjan population. These results indicated that the AChE of the Rafsanjan population had lower affinity to these substrates than that of the susceptible population. The higher Vmax value in the Rafsanjan population compared to the susceptible population suggests a possible over expression of AChE in the Rafsanjan population. The in vitro inhibitory effect of several organophosphates and carbamates on AChE of the Rafsanjan and Bam populations was determined. Based on I50, the results showed that the ratios of AChE insensitivity of the resistant to susceptible populations were 23 and 21.7-fold to monocrotophos and phosphamidon, respectively. Whereas, the insensitivity ratios for Rafsanjan population were 0.86, 0.8, 0.78, 0.46, and 0.43 for carbaryl, eserine, propoxur, m-tolyl methyl carbamate, and carbofuran, respectively, suggesting negatively correlated sensitivity to organophosphate-insensitive AChE. Therefore, AChE from the Rafsanjan population showed

Calculation of the magnetic susceptibilities of transition metal monocarbides, mononitrides and monoxides

International Nuclear Information System (INIS)

Eibler, R.; Neckel, A.

1975-01-01

Results of Augmented Plane Wave (APW) band structure calculations are used to determine the magnetic susceptibilities of some transition metal monocarbides, mononitrides and monoxides (TiC, TiN, TiO, VC, VN, VO, NbC, NbN) assuming stoichiometric composition. Contributions to the susceptibility arising from the orbital para- and diamagnetism and the spin paramagnetism are determined separately. The orbital susceptibility terms are calculated by means of the model of Kubo and Obata. The calculated susceptibilities are compared with measured values. The approximations in the calculation of the orbital susceptibility terms are discussed especially with regard to the agreement between calculated and measured susceptibilities for the individual compounds. Similar calculations are performed for the susceptibilities of non-stoichiometric VCsub(x)-phase, for which APR-Virtual Crystal Approximation (VCA) band structure calculations are available. (author)

Effects of thermal aging and stress triaxiality on PWSCC initiation susceptibility of nickel-based Alloy 600

Energy Technology Data Exchange (ETDEWEB)

Yoo, Seung Chang; Choi, Kyoung Joon; Kim, Tae Ho; Kim, Ji Hyun [Dept. of Nuclear Science and Engineering, School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2016-10-15

In present study, effects of thermal aging and triaxial stress were investigated in terms of primary water stress corrosion cracking susceptibility. The thermal aging was applied via heat treatment at 400°C and triaxial stress was applied via notched tensile test specimen. The crack initiation time of each specimen were then measured by direct current potential drop method during slow strain rate test at primary water environment. Alloys with 10 years thermal aging exhibited the highest susceptibility to stress corrosion cracking and asreceived specimen shows lowest susceptibility. The trend was different with triaxial stress applied; 20 years thermal aging specimen shows highest susceptibility and as-received specimen shows lowest. It would be owing to change of precipitate morphology during thermal aging and different activated slip system in triaxial stress state.

Weights of evidence method for landslide susceptibility mapping in Tangier, Morocco

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Bousta Mahfoud

2018-01-01

Full Text Available Tangier region is known by a high density of mass movements which cause several human and economic losses. The goal of this paper is to assess the landslide susceptibility of Tangier using the Weight of Evidence method (WofE. The method is founded on the principle that an event (landslide is more likely to occur based on the relationship between the presence or absence of a predictive variable (predisposing factors and the occurrence of this event. The inventory, description and analysis of mass movements were prepared. Then the main factors governing their occurrence (lithology, fault, slope, elevation, exposure, drainage and land use were mapped before applying WofE. Finally, the ROC curves were established and the areas under curves (AUC were calculated to evaluate the degree of fit of the model and to choose the best landslide susceptibility zonation. The prediction accuracy was found to be 70%. Obtained susceptibility map shows that 60% of inventoried landslides are in the high to very high susceptibility zones, which is very satisfactory for the validation of the adopted model and the obtained results. These zones are mainly located in the N-E and E part of the Tangier region in the soft and fragile facies of the marls and clays of the Tangier unit, where landuse is characterized by dominance of arable and agricultural land (lack of forest cover. From a purely spatial point of view, the localization of these two classes of susceptibility is completely corresponding to the ground truth data, that is to say that all the environmental and anthropogenic conditions are in place for making this area prone to landslide hazards. The obtained map is a decision-making tool for presenting, comparing and discussing development and urban scenarios in Tangier. These results fall within the context of sustainable development and will help to mitigate the socio-economic impacts usually observed when landslides are triggered.

Antimicrobial susceptibility pattern and plasmid-mediated ...

African Journals Online (AJOL)

negative Staphylococci (CoNS) were isolated from clinical samples and isolates subjected to antibiotic susceptibility testing, plasmid curing and plasmid DNA isolation. Result: The highest percentages isolates were recovered from urine samples and ...

Association of STAT4 rs7574865 with susceptibility to systemic lupus erythematosus in Iranian population.

Science.gov (United States)

Mirkazemi, Sedigheh; Akbarian, Mahmoud; Jamshidi, Ahmad Reza; Mansouri, Reza; Ghoroghi, Shima; Salimi, Yahya; Tahmasebi, Zahra; Mahmoudi, Mahdi

2013-12-01

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease with complex genetic inheritance that affecting different organs and systems. STAT4 has been newly identified as a susceptible gene in the development of SLE. According to recent studies, STAT4 has been associated with SLE in various populations. We investigated whether STAT4 single nucleotide polymorphisms (SNPs) were associated with susceptibility and clinical features of SLE in Iranian patients. The study group comprised 280 patients with SLE and 281 sex-, age-, and ethnicity-matched healthy controls of Iranian ancestry. Two SNPs (rs7574865 and rs7601754) were genotyped using the TaqMan MGB Allelic Discrimination method. Our results showed a significant association between rs7574865 T allele (odds ratio (OR) = 1.50, 95 % CI = 1.18-1.92, P = 0.002) and susceptibility to SLE. The rs7574865TT genotype (P = 0.02, OR = 1.94, 95 % CI = 1.74-3.19) and GT genotype (P = 0.008, OR = 1.71, 95 % CI = 1.19-2.45) showed a significant association with the risk of SLE in the Iranian population. We concluded that STAT4 rs7574865 is associated with SLE susceptibility in the Iranian population and this SNP might be a factor in the pathogenesis of SLE. However, further studies are required to investigate the mechanism by which polymorphisms in this gene lead to SLE.

Effect of centrifugation on dynamic susceptibility of magnetic fluids

Science.gov (United States)

Pshenichnikov, Alexander; Lebedev, Alexander; Lakhtina, Ekaterina; Kuznetsov, Andrey

2017-06-01

The dispersive composition, dynamic susceptibility and spectrum of times of magnetization relaxation for six samples of magnetic fluid obtained by centrifuging two base colloidal solutions of the magnetite in kerosene was investigated experimentally. The base solutions differed by the concentration of the magnetic phase and the width of the particle size distribution. The procedure of cluster analysis allowing one to estimate the characteristic sizes of aggregates with uncompensated magnetic moments was described. The results of the magnetogranulometric and cluster analyses were discussed. It was shown that centrifugation has a strong effect on the physical properties of the separated fractions, which is related to the spatial redistribution of particles and multi-particle aggregates. The presence of aggregates in magnetic fluids is interpreted as the main reason of low-frequency (0.1-10 kHz) dispersion of the dynamic susceptibility. The obtained results count in favor of using centrifugation as an effective means of changing the dynamic susceptibility over wide limits and obtaining fluids with the specified type of susceptibility dispersion.

Evaluation of Local Wheat Cultivars Susceptibility to infection with Black Stem Rust

International Nuclear Information System (INIS)

Batta, Y.A.

2007-01-01

The present study was conducted to assess the susceptibility of seven local wheat cultivars from Palestine to infection with black stem rust caused by Puccinia graminis f. sp. tritici. Two techniques of disease inoculation were applied during bioassays: global inoculation of entire wheat plants with urediospores and localized inoculation with urediospores and localized inoculation with urediospores on wheat leaf-pieces incubated under humid conditions. Susceptibility of tested cultivars was evaluated according to disease scale based on number and size of typical unredial pustules that appeared after inoculation on entire plants or leaf pieces. Results obtained on bioassay of susceptibility and disease rating on entire plants indicated that Anbar, Kamata and Hetiya safra cultivars were the least susceptible to P. g. tritici infection, whereas Debiya beda cultivar was the most susceptible. The other tested cultivars such as Nab-El-Jama, sawda and Senf 870 were moderately susceptible. On leaf-pieces, Anbar and Kamatat were the least susceptible cultivars, whereas Debiya beda and Nab-El-Jamal were the most susceptible cultivars. The other tested cultivars such as Debiya swada, Senf 870 and Hetiya safra were moderately susceptible. Significant reductions were obtained for the size of unredial postules formed on leaf-pieces when inoculated in an unwounded state compared to the wounded indicating the importance of wounds during inoculation. The global results indicated the possibility of using above method of disease inoculating, scaling and rating for evaluation of wheat cultivars susceptibility for the eventual use in breeding program for resistant varieties in Palestine. (author)

The mediational pathway among parenting styles, attachment styles and self-regulation with addiction susceptibility of adolescents.

Science.gov (United States)

Zeinali, Ali; Sharifi, Hassanpasha; Enayati, Mirsalahadine; Asgari, Parviz; Pasha, Gohlamreza

2011-09-01

The purpose of present study was to create and test a model that illustrates variables that influence the development of addiction susceptibility and determine how different styles of parenting may indirectly influence the addiction susceptibility of children through the mediators of attachment style and self-regulation. Using random cluster sampling, 508 adolescent high school boys and girls aged 14-19 years were enrolled. Data were analyzed using structural equations modeling (path analysis). The results showed that authoritative and permissive parenting styles were associated with secure attachment whereas authoritarian and neglectful parenting styles were associated with insecure attachment. Insecure attachment was associated with a low level of self-regulation whereas secure attachment was associated with a high level of self-regulation. We found that a low level of self-regulation increased the adolescent's addiction susceptibility whereas a high level of self-regulation decreased their addiction susceptibility. The findings of present study suggest the authoritative and permissive parenting styles as the most efficient styles and authoritarian and neglectful parenting styles as the most inefficient styles in terms of addiction susceptibility. Accordingly, efficient parenting style training to parents should be the main goal of drug demand reduction program.

Mitochondrial genetic background modulates bioenergetics and susceptibility to acute cardiac volume overload.

Science.gov (United States)

Fetterman, Jessica L; Zelickson, Blake R; Johnson, Larry W; Moellering, Douglas R; Westbrook, David G; Pompilius, Melissa; Sammy, Melissa J; Johnson, Michelle; Dunham-Snary, Kimberly J; Cao, Xuemei; Bradley, Wayne E; Zhang, Jinju; Wei, Chih-Chang; Chacko, Balu; Schurr, Theodore G; Kesterson, Robert A; Dell'italia, Louis J; Darley-Usmar, Victor M; Welch, Danny R; Ballinger, Scott W

2013-10-15

Dysfunctional bioenergetics has emerged as a key feature in many chronic pathologies such as diabetes and cardiovascular disease. This has led to the mitochondrial paradigm in which it has been proposed that mtDNA sequence variation contributes to disease susceptibility. In the present study we show a novel animal model of mtDNA polymorphisms, the MNX (mitochondrial-nuclear exchange) mouse, in which the mtDNA from the C3H/HeN mouse has been inserted on to the C57/BL6 nuclear background and vice versa to test this concept. Our data show a major contribution of the C57/BL6 mtDNA to the susceptibility to the pathological stress of cardiac volume overload which is independent of the nuclear background. Mitochondria harbouring the C57/BL6J mtDNA generate more ROS (reactive oxygen species) and have a higher mitochondrial membrane potential relative to those with C3H/HeN mtDNA, independent of nuclear background. We propose this is the primary mechanism associated with increased bioenergetic dysfunction in response to volume overload. In summary, these studies support the 'mitochondrial paradigm' for the development of disease susceptibility, and show that the mtDNA modulates cellular bioenergetics, mitochondrial ROS generation and susceptibility to cardiac stress.

Field-impressed anisotropy of susceptibility in iron-terbium thin films

International Nuclear Information System (INIS)

Stephenson, A.; Booth, N.A.

1995-01-01

Two thin films of Fe 1-x Tb x where x=0.17 and 0.23 are shown to exhibit the effect of field-impressed anisotropy. After application of a direct field of 80 mT, which gives them an isothermal remanent magnetization (IRM) in their plane, the anisotropy of initial susceptibility differs from that measured after the films have been tumble-demagnetized. By subtracting the susceptibility results of the tumble-demagnetized state from those obtained after the application of the 80 mT direct field, it is shown that the effect of this field is to decrease the susceptibility measured along the former applied field direction and to increase the susceptibility at right angles to this. The effect is almost certainly due to changes in domain alignment. Even though these films contain many domains, the above results are similar to those previously obtained for single-domain γFe 2 O 3 and magnetite particles. The sense of the effect is opposite to that for multi-domain magnetite particles where the susceptibility has been found to increase along the previously applied field direction. ((orig.))

Effect of feeding broilers diets differing in susceptible phytate content

Directory of Open Access Journals (Sweden)

Natalie K. Morgan

2016-03-01

Full Text Available Measurements of total phytate phosphorus content of diets may be deceptive as they do not indicate substrate availability for phytase; it may be that measurements of phytate susceptible to phytase effects are a more accurate measure of phosphorus (P availability to the bird. To verify this hypothesis, an experiment was conducted to compare diets formulated to contain either high or low susceptible phytate, supplemented with either 0 or 500 FTU/kg phytase. Susceptible phytate was determined by exposing the feed samples to conditions that mimicked the average pH of the proximal gastrointestinal tract (pH 4.5 and the optimum temperature for phytase activity (37 °C and then measuring phytate dissolved. Ross 308 birds (n = 240 were fed one of 4 dietary treatments in a 2 × 2 factorial design; 2 diets with high (8.54 g/kg, 57.90% of total phytate or low (5.77 g/kg, 46.33% of total phytate susceptible phytate, containing 0 or 500 FTU/kg phytase. Diets were fed to broilers (12 replicate pens of 5 birds per pen from d 0 to 28 post hatch. Birds fed diets high in susceptible phytate had greater phytate hydrolysis in the gizzard (P < 0.001, jejunum (P < 0.001 and ileum (P < 0.001 and resulting greater body weight gain (BWG (P = 0.015 and lower FCR (P = 0.003 than birds fed the low susceptible phytate diets, irrespective of phytase presence. Birds fed the high susceptible diets also had greater P solubility in the gizzard and Ca and P solubility in the jejunum and ileum (P < 0.05 and resulting greater tibia and femur Ca and P (P < 0.05 content than those fed the low susceptible diets. All the susceptible phytate was fully degraded in the tract in the absence of added phytase, suggesting the assay used in this study was able to successfully estimate the amount of total dietary phytate that was susceptible to the effects of phytase when used at standard levels. No interactions were observed between susceptible phytate and phytase on

Effect of algal growth phase on Aureococcus anophagefferens susceptibility to hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Randhawa, Varunpreet; Thakkar, Megha; Wei, Liping, E-mail: liping.wei@njit.edu

2013-10-15

Highlights: •Brown tide alga's susceptibility to H{sub 2}O{sub 2} was examined via growth and physiology responses. •The study was designed equalizing the influence of the media and cell density in test cultures. •Stationary cells was more sensitive to H{sub 2}O{sub 2} than exponential cells. •Stationary cells showed weaker non-protein thiol up-regulation than exponential cells. •Stationary cells mediated greater H{sub 2}O{sub 2} decomposition than exponential cells did. -- Abstract: A cell's growth phase could affect its susceptibility to a biocide in microbial control. This study examines the growth phase dependent susceptibility of a brown tide bloom alga Aureococcus anophagefferens to microbial biocide hydrogen peroxide (H{sub 2}O{sub 2}). Test cultures of A. anophagefferens cells in exponential and stationary growth phase and similar initial cell density (1.6 × 10{sup 6} cells mL{sup −1}) were exposed to 0.4–1.6 mg L{sup −1} H{sub 2}O{sub 2}. Changes in algal growth (in vivo fluorescence, total chlorophyll a, and cell density), cell physiology (maximum quantum yield of photosystem II, and total intracellular non-protein thiols), and H{sub 2}O{sub 2} decomposition were quantified. Results show that the stationary phase cells are more susceptible to H{sub 2}O{sub 2} than the exponential phase cells, and this is attributed to the weaker ROS (reactive oxygen species) scavenging system and consequently greater cell damage in stationary phase cells. The stationary phase cells potentially require 30–40% less H{sub 2}O{sub 2} to reach 90% removal within 12 h of treatment as compared to the exponential phase cells. The results have practical implications in brown tide bloom control with respect to the timing and the dosage of H{sub 2}O{sub 2} application.

Use of Satellite Remote Sensing Data in the Mapping of Global Landslide Susceptibility

Science.gov (United States)

Hong, Yang; Adler, Robert F.; Huffman, George J.

2007-01-01

Satellite remote sensing data has significant potential use in analysis of natural hazards such as landslides. Relying on the recent advances in satellite remote sensing and geographic information system (GIS) techniques, this paper aims to map landslide susceptibility over most of the globe using a GIs-based weighted linear combination method. First , six relevant landslide-controlling factors are derived from geospatial remote sensing data and coded into a GIS system. Next, continuous susceptibility values from low to high are assigned to each of the six factors. Second, a continuous scale of a global landslide susceptibility index is derived using GIS weighted linear combination based on each factor's relative significance to the process of landslide occurrence (e.g., slope is the most important factor, soil types and soil texture are also primary-level parameters, while elevation, land cover types, and drainage density are secondary in importance). Finally, the continuous index map is further classified into six susceptibility categories. Results show the hot spots of landslide-prone regions include the Pacific Rim, the Himalayas and South Asia, Rocky Mountains, Appalachian Mountains, Alps, and parts of the Middle East and Africa. India, China, Nepal, Japan, the USA, and Peru are shown to have landslide-prone areas. This first-cut global landslide susceptibility map forms a starting point to provide a global view of landslide risks and may be used in conjunction with satellite-based precipitation information to potentially detect areas with significant landslide potential due to heavy rainfall. 1

Combined analysis of 19 common validated type 2 diabetes susceptibility gene variants shows moderate discriminative value and no evidence of gene-gene interaction

DEFF Research Database (Denmark)

Sparsø, T; Grarup, N; Andreasen, C.

2009-01-01

study; and additional type 2 diabetic patients and glucose-tolerant individuals. The case-control studies involved 4,093 type 2 diabetic patients and 5,302 glucose-tolerant individuals. RESULTS: Single-variant analyses demonstrated allelic odds ratios ranging from 1.04 (95% CI 0.98-1.11) to 1.33 (95% CI...... analysis of the 19 validated variants enables detection of subgroups at substantially increased risk of type 2 diabetes; however, the discrimination between glucose-tolerant and type 2 diabetes individuals is still too inaccurate to achieve clinical value.......AIMS/HYPOTHESIS: The list of validated type 2 diabetes susceptibility variants has recently been expanded from three to 19. The variants identified are common and have low penetrance in the general population. The aim of the study is to investigate the combined effect of the 19 variants by applying...

Assessment of earthquake-triggered landslide susceptibility in El Salvador based on an Artificial Neural Network model

Science.gov (United States)

García-Rodríguez, M. J.; Malpica, J. A.

2010-06-01

This paper presents an approach for assessing earthquake-triggered landslide susceptibility using artificial neural networks (ANNs). The computational method used for the training process is a back-propagation learning algorithm. It is applied to El Salvador, one of the most seismically active regions in Central America, where the last severe destructive earthquakes occurred on 13 January 2001 (Mw 7.7) and 13 February 2001 (Mw 6.6). The first one triggered more than 600 landslides (including the most tragic, Las Colinas landslide) and killed at least 844 people. The ANN is designed and programmed to develop landslide susceptibility analysis techniques at a regional scale. This approach uses an inventory of landslides and different parameters of slope instability: slope gradient, elevation, aspect, mean annual precipitation, lithology, land use, and terrain roughness. The information obtained from ANN is then used by a Geographic Information System (GIS) to map the landslide susceptibility. In a previous work, a Logistic Regression (LR) was analysed with the same parameters considered in the ANN as independent variables and the occurrence or non-occurrence of landslides as dependent variables. As a result, the logistic approach determined the importance of terrain roughness and soil type as key factors within the model. The results of the landslide susceptibility analysis with ANN are checked using landslide location data. These results show a high concordance between the landslide inventory and the high susceptibility estimated zone. Finally, a comparative analysis of the ANN and LR models are made. The advantages and disadvantages of both approaches are discussed using Receiver Operating Characteristic (ROC) curves.

Effects of phase constitution of Zr-Nb alloys on their magnetic susceptibilities

International Nuclear Information System (INIS)

Nomura, Naoyuki; Tanaka, Yuko; Suyalatu; Kondo, Ryota; Doi, Hisashi; Tsutsumi, Yusuke; Hanawa, Takao

2009-01-01

The magnetic susceptibilities and microstructures of Zr-Nb binary alloys were investigated to develop a new metallic biomaterial with a low magnetic susceptibility for magnetic resonance imaging (MRI). The magnetic susceptibility was measured with a magnetic susceptibility balance, and the microstructure was evaluated with an X-ray diffractometer (XRD), an optical microscope (OM), and a transmission electron microscope (TEM). Zr-Nb alloys as-cast showed a minimum value of magnetic susceptibility between 3 and 9 mass% Nb, and the value abruptly increased up to 20 mass% Nb, followed by a gradual increase with the increase of the Nb content. XRD, OM, and TEM revealed that the minimum value of the susceptibility was closely related to the appearance of the athermal ω phase in the β phase. Since the magnetic susceptibility of Zr-3Nb alloy consisting of an α' phase was as low as that of Zr-9Nb alloy consisting of the β and ω phases, that of the ω phase was lower than that of the α' and β phases. When Zr-16Nb alloy was heat-treated, the isothermal ω phase appeared, and, simultaneously, the magnetic susceptibility decreased. Therefore, the ω phase contributes to the decrease of the magnetic susceptibility, independently of the formation process of the ω phase. The magnetic susceptibility of the Zr-3Nb alloy as-cast was almost one-third that of Ti-6Al-4V alloy, which is commonly used for medical implant devices. Zr-Nb alloys are useful for medical devices used under MRI. (author)

Children's differential susceptibility to parenting: An experimental test of "for better and for worse".

Science.gov (United States)

Slagt, Meike; Dubas, Judith Semon; van Aken, Marcel A G; Ellis, Bruce J; Deković, Maja

2017-02-01

Differential susceptibility theory proposes that a subset of individuals exist who display enhanced susceptibility to both negative (risk-promoting) and positive (development-enhancing) environments. This experiment represents the first attempt to directly test this assumption by exposing children in the experimental group to both negative and positive feedback using puppet role-plays. It thereby serves as an empirical test as well as a methodological primer for testing differential susceptibility. Dutch children (N=190, 45.3% girls) between the ages of 4 and 6years participated. We examined whether negative and positive feedback would differentially affect changes in positive and negative affect, in prosocial and antisocial intentions and behavior, depending on children's negative emotionality. Results show that on hearing negative feedback, children in the experimental group increased in negative affect and decreased in positive affect more strongly than children in the control group. On hearing positive feedback, children in the experimental group tended to increase in positive affect and decrease in prosocial behavior. However, changes in response to negative or positive feedback did not depend on children's negative emotionality. Moreover, using reliable change scores, we found support for a subset of "vulnerable" children but not for a subset of "susceptible" children. The findings offer suggestions to guide future differential susceptibility experiments. Copyright © 2016 Elsevier Inc. All rights reserved.

Antifungal susceptibility profiles of 1698 yeast reference strains revealing potential emerging human pathogens.

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Marie Desnos-Ollivier

Full Text Available New molecular identification techniques and the increased number of patients with various immune defects or underlying conditions lead to the emergence and/or the description of novel species of human and animal fungal opportunistic pathogens. Antifungal susceptibility provides important information for ecological, epidemiological and therapeutic issues. The aim of this study was to assess the potential risk of the various species based on their antifungal drug resistance, keeping in mind the methodological limitations. Antifungal susceptibility profiles to the five classes of antifungal drugs (polyens, azoles, echinocandins, allylamines and antimetabolites were determined for 1698 yeast reference strains belonging to 992 species (634 Ascomycetes and 358 Basidiomycetes. Interestingly, geometric mean minimum inhibitory concentrations (MICs of all antifungal drugs tested were significantly higher for Basidiomycetes compared to Ascomycetes (p<0.001. Twenty four strains belonging to 23 species of which 19 were Basidiomycetes seem to be intrinsically "resistant" to all drugs. Comparison of the antifungal susceptibility profiles of the 4240 clinical isolates and the 315 reference strains belonging to 53 shared species showed similar results. Even in the absence of demonstrated in vitro/in vivo correlation, knowing the in vitro susceptibility to systemic antifungal agents and the putative intrinsic resistance of yeast species present in the environment is important because they could become opportunistic pathogens.

Prioritising watersheds on the basis of regional flood susceptibility and vulnerability in mountainous areas through the use of indicators

Science.gov (United States)

Rogelis, Carolina; Werner, Micha

2013-04-01

Settlements in peri-urban areas of many cities in mountainous areas such as in the Andes are susceptible to hazards such as flash floods and debris flows. Additionally these settlements are in many cases informal and thus vulnerable to such hazards, resulting in significant risk. Such watersheds are often quiet small, and generally there is little or no information from gauges to help characterise risk. To help identify watersheds in which flood management measures are to be targeted, a rapid assessment of risk is required. In this paper a novel approach is presented where indicators of susceptibility and vulnerability to flash floods were used to prioritize 106 mountain watersheds in Bogotá (Colombia). Variables recognized in literature to determine the dominant processes both in susceptibility and vulnerability to flash floods were used to construct the indicators. Susceptibility was considered to increase with flashiness and the possibility of debris flow events occurring. This was assessed through the use of an indicator composed of a morphometric indicator and a land use indicator. The former was constructed using morphological variables recognized in literature to significantly influence flashiness and occurrence of debris flows; the latter was constructed in terms of percentage of vegetation cover, urban area and bare soil. The morphometric indicator was compared with the results of a debris flow propagation algorithm to assess its capacity in indentifying the morphological conditions of a watershed that make it able to transport debris flows. Propagation was carried out through the use of the Modified Single Flow Direction algorithm, following previous identification of source areas by applying thresholds identified in the area-slope curve of the watersheds and empirical thresholds. Results show that the morphometric variables can be grouped in four categories: size, shape, hypsometry and energy, with the energy the component found to best explain the

Landslide Susceptibility Assessment Using Spatial Multi-Criteria Evaluation Model in Rwanda

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Jean Baptiste Nsengiyumva

2018-01-01

Full Text Available Landslides susceptibility assessment has to be conducted to identify prone areas and guide risk management. Landslides in Rwanda are very deadly disasters. The current research aimed to conduct landslide susceptibility assessment by applying Spatial Multi-Criteria Evaluation Model with eight layers of causal factors including: slope, distance to roads, lithology, precipitation, soil texture, soil depth, altitude and land cover. In total, 980 past landslide locations were mapped. The relationship between landslide factors and inventory map was calculated using the Spatial Multi-Criteria Evaluation. The results revealed that susceptibility is spatially distributed countrywide with 42.3% of the region classified from moderate to very high susceptibility, and this is inhabited by 49.3% of the total population. In addition, Provinces with high to very high susceptibility are West, North and South (40.4%, 22.8% and 21.5%, respectively. Subsequently, the Eastern Province becomes the peak under low susceptibility category (87.8% with no very high susceptibility (0%. Based on these findings, the employed model produced accurate and reliable outcome in terms of susceptibility, since 49.5% of past landslides fell within the very high susceptibility category, which confirms the model’s performance. The outcomes of this study will be useful for future initiatives related to landslide risk reduction and management.

Landslide Susceptibility Assessment Using Spatial Multi-Criteria Evaluation Model in Rwanda

Science.gov (United States)

Nsengiyumva, Jean Baptiste; Luo, Geping; Nahayo, Lamek; Huang, Xiaotao; Cai, Peng

2018-01-01

Landslides susceptibility assessment has to be conducted to identify prone areas and guide risk management. Landslides in Rwanda are very deadly disasters. The current research aimed to conduct landslide susceptibility assessment by applying Spatial Multi-Criteria Evaluation Model with eight layers of causal factors including: slope, distance to roads, lithology, precipitation, soil texture, soil depth, altitude and land cover. In total, 980 past landslide locations were mapped. The relationship between landslide factors and inventory map was calculated using the Spatial Multi-Criteria Evaluation. The results revealed that susceptibility is spatially distributed countrywide with 42.3% of the region classified from moderate to very high susceptibility, and this is inhabited by 49.3% of the total population. In addition, Provinces with high to very high susceptibility are West, North and South (40.4%, 22.8% and 21.5%, respectively). Subsequently, the Eastern Province becomes the peak under low susceptibility category (87.8%) with no very high susceptibility (0%). Based on these findings, the employed model produced accurate and reliable outcome in terms of susceptibility, since 49.5% of past landslides fell within the very high susceptibility category, which confirms the model’s performance. The outcomes of this study will be useful for future initiatives related to landslide risk reduction and management. PMID:29385096

Seasonal fluctuation in susceptibility to insecticides within natural populations of Drosophila melanogaster. II. Features of genetic variation in susceptibility to organophosphate insecticides within natural populations of D. melanogaster.

Science.gov (United States)

Miyo, Takahiro; Oguma, Yuzuru; Charlesworth, Brian

2006-08-01

To elucidate genetic variation in susceptibility to organophosphate insecticides within natural populations of Drosophila melanogaster, we conducted an analysis of variance for mortality data sets of isofemale lines (10-286 lines) used in the previous studies. Susceptibility of isofemale lines to the three organophosphate insecticides was continuously distributed within each natural population, ranging from susceptible to resistant. Analysis of variance showed highly significant variation among isofemale lines in susceptibility to each insecticide for each natural population. Significant genetic variances in susceptibility to the three chemicals were estimated for the Katsunuma population; 0.0529-0.2722 for malathion, 0.0492-0.1603 for prothiophos, and 0.0469-0.1696 for fenitrothion. Contrary to the consistent seasonal tendency towards an increase in mean susceptibility in the fall, reported in the previous study, genetic variances in susceptibility to the three organophosphates did not change significantly in 1997 but tended to increase by 2- to 5-times in 1998. We tested whether both the observed situations, maintenance and increase in genetic variance in organophosphate resistance, can be generated under circumstances in which the levels of resistance to the three organophosphates tended to decrease, by conducting a simulation analysis, based on the hypothesis that resistant genotypes have lower fitnesses than susceptible ones under the density-independent condition. The simulation analysis generally explained the pattern in the mean susceptibility and genetic variances in susceptibility to the three organophosphates, observed in the Katsunuma population of D. melanogaster. It was suggested that the differences in the frequencies of resistance genes in the summer population could affect the patterns in genetic variance in organophosphate resistance in the fall population.

Combined value of susceptibility weighted imaging and dynamic susceptibility-weighted contrast-enhanced MR perfusion-weighted imaging in brain astrocytoma grading

International Nuclear Information System (INIS)

Wang Xiaochun; Zhang Hui; Qin Jiangbo; Wang Le; Wu Xiaofeng

2012-01-01

Objective: To assess the value of combination of susceptibility weighted imaging (SWI) and dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion-weighted magnetic resonance imaging in astrocytoma grading. Methods: SWI and DSC scans were performed in 82 patients with pathologically confirmed astrocytoma. The patient group consisted of grade Ⅱ (15), grade Ⅲ (10), and grade Ⅳ (57). The intratumoral susceptibility signal intensity (ITSS) and relative cerebral blood volume (rCBV) max were used to determine the grade of astrocytomas by Kruskal Wallis test, Welch test, Spearman correlation coefficients, Pearson correlation coefficients, and receiver operating characteristic curve (ROC)statistic methods. Results: There were no ITSS in 14 cases of low-grade astrocytomas, the degree of ITSS were grade 1 to 3 in anaplastic astrocytomas, the degree of ITSS were grade 3 in all of the glioblastomas, the degree of ITSS were significant difference in all grades (H=71.96, P<0.01). rCBV max in grade Ⅱ, grade Ⅲ and grade Ⅳ astrocytomas were 1.26 ± 0.42, 3.59 ± 2.09 and 8.34 ± 1.16 respectively, rCBV max were significant difference in all grades (F'=681.72, P<0.01). ITSS showed significant correlation with rCBV max (r=0.72, P<0.01) and tumor grades (r=0.89, P<0.01), and rCBV and tumor grades showed significant correlation (r=0.78, P<0.01). Area under the ROC curve application SWI, DSC, SWI and DSC in differentiation of the grade Ⅱ and grade Ⅲ astrocytomas were 0.99, 0.93, 1.00, differentiate grade Ⅲ from grade Ⅳ were 0.70, 0.94, 0.94, and differentiate high-grade from low-grade astrocytomas were 1.00, 0.99, 1.00. Conclusions: ITSS is helpful to determine the grade of astrocytomas. The use of SWI in combination with DSC may improve the diagnostic accuracy of astrocytoma grading. (authors)

Materials with low DC magnetic susceptibility for sensitive magnetic measurements

International Nuclear Information System (INIS)

Khatiwada, R; Kendrick, R; Khosravi, M; Peters, M; Smith, E; Snow, W M; Dennis, L

2016-01-01

Materials with very low DC magnetic susceptibility have many scientific applications. To our knowledge however, relatively little research has been conducted with the goal to produce a totally nonmagnetic material. This phrase in our case means after spatially averaging over macroscopic volumes, it possesses an average zero DC magnetic susceptibility. We report measurements of the DC magnetic susceptibility of three different types of nonmagnetic materials at room temperature: (I) solutions of paramagnetic salts and diamagnetic liquids, (II) liquid gallium–indium alloys and (III) pressed powder mixtures of tungsten and bismuth. The lowest measured magnetic susceptibility among these candidate materials is in the order of 10 −9 cgs volume susceptibility units, about two orders of magnitude smaller than distilled water. In all cases, the measured concentration dependence of the magnetic susceptibility is consistent with that expected for the weighted sum of the susceptibilities of the separate components within experimental error. These results verify the well-known Wiedemann additivity law for the magnetic susceptibility of inert mixtures of materials and thereby realize the ability to produce materials with small but tunable magnetic susceptibility. For our particular scientific application, we are also looking for materials with the largest possible number of neutrons and protons per unit volume. The gallium–indium alloys fabricated and measured in this work possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature liquid, and the tungsten-bismuth pressed powder mixtures possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature solid. This ratio is a figure of merit for a certain class of precision experiments that search for possible exotic spin-dependent forces of Nature. (paper)

Allele-specific DNA methylation of disease susceptibility genes in Japanese patients with inflammatory bowel disease.

Science.gov (United States)

Chiba, Hirofumi; Kakuta, Yoichi; Kinouchi, Yoshitaka; Kawai, Yosuke; Watanabe, Kazuhiro; Nagao, Munenori; Naito, Takeo; Onodera, Motoyuki; Moroi, Rintaro; Kuroha, Masatake; Kanazawa, Yoshitake; Kimura, Tomoya; Shiga, Hisashi; Endo, Katsuya; Negoro, Kenichi; Nagasaki, Masao; Unno, Michiaki; Shimosegawa, Tooru

2018-01-01

Inflammatory bowel disease (IBD) has an unknown etiology; however, accumulating evidence suggests that IBD is a multifactorial disease influenced by a combination of genetic and environmental factors. The influence of genetic variants on DNA methylation in cis and cis effects on expression have been demonstrated. We hypothesized that IBD susceptibility single-nucleotide polymorphisms (SNPs) regulate susceptibility gene expressions in cis by regulating DNA methylation around SNPs. For this, we determined cis-regulated allele-specific DNA methylation (ASM) around IBD susceptibility genes in CD4+ effector/memory T cells (Tem) in lamina propria mononuclear cells (LPMCs) in patients with IBD and examined the association between the ASM SNP genotype and neighboring susceptibility gene expressions. CD4+ effector/memory T cells (Tem) were isolated from LPMCs in 15 Japanese IBD patients (ten Crohn's disease [CD] and five ulcerative colitis [UC] patients). ASM analysis was performed by methylation-sensitive SNP array analysis. We defined ASM as a changing average relative allele score ([Formula: see text]) >0.1 after digestion by methylation-sensitive restriction enzymes. Among SNPs showing [Formula: see text] >0.1, we extracted the probes located on tag-SNPs of 200 IBD susceptibility loci and around IBD susceptibility genes as candidate ASM SNPs. To validate ASM, bisulfite-pyrosequencing was performed. Transcriptome analysis was examined in 11 IBD patients (seven CD and four UC patients). The relation between rs36221701 genotype and neighboring gene expressions were analyzed. We extracted six candidate ASM SNPs around IBD susceptibility genes. The top of [Formula: see text] (0.23) was rs1130368 located on HLA-DQB1. ASM around rs36221701 ([Formula: see text] = 0.14) located near SMAD3 was validated using bisulfite pyrosequencing. The SMAD3 expression was significantly associated with the rs36221701 genotype (p = 0.016). We confirmed the existence of cis-regulated ASM around

CISH and susceptibility to infectious diseases.

Science.gov (United States)

Khor, Chiea C; Vannberg, Fredrik O; Chapman, Stephen J; Guo, Haiyan; Wong, Sunny H; Walley, Andrew J; Vukcevic, Damjan; Rautanen, Anna; Mills, Tara C; Chang, Kwok-Chiu; Kam, Kai-Man; Crampin, Amelia C; Ngwira, Bagrey; Leung, Chi-Chiu; Tam, Cheuk-Ming; Chan, Chiu-Yeung; Sung, Joseph J Y; Yew, Wing-Wai; Toh, Kai-Yee; Tay, Stacey K H; Kwiatkowski, Dominic; Lienhardt, Christian; Hien, Tran-Tinh; Day, Nicholas P; Peshu, Nobert; Marsh, Kevin; Maitland, Kathryn; Scott, J Anthony; Williams, Thomas N; Berkley, James A; Floyd, Sian; Tang, Nelson L S; Fine, Paul E M; Goh, Denise L M; Hill, Adrian V S

2010-06-03

The interleukin-2-mediated immune response is critical for host defense against infectious pathogens. Cytokine-inducible SRC homology 2 (SH2) domain protein (CISH), a suppressor of cytokine signaling, controls interleukin-2 signaling. Using a case-control design, we tested for an association between CISH polymorphisms and susceptibility to major infectious diseases (bacteremia, tuberculosis, and severe malaria) in blood samples from 8402 persons in Gambia, Hong Kong, Kenya, Malawi, and Vietnam. We had previously tested 20 other immune-related genes in one or more of these sample collections. We observed associations between variant alleles of multiple CISH polymorphisms and increased susceptibility to each infectious disease in each of the study populations. When all five single-nucleotide polymorphisms (SNPs) (at positions -639, -292, -163, +1320, and +3415 [all relative to CISH]) within the CISH-associated locus were considered together in a multiple-SNP score, we found an association between CISH genetic variants and susceptibility to bacteremia, malaria, and tuberculosis (P=3.8x10(-11) for all comparisons), with -292 accounting for most of the association signal (P=4.58x10(-7)). Peripheral-blood mononuclear cells obtained from adult subjects carrying the -292 variant, as compared with wild-type cells, showed a muted response to the stimulation of interleukin-2 production--that is, 25 to 40% less CISH expression. Variants of CISH are associated with susceptibility to diseases caused by diverse infectious pathogens, suggesting that negative regulators of cytokine signaling have a role in immunity against various infectious diseases. The overall risk of one of these infectious diseases was increased by at least 18% among persons carrying the variant CISH alleles. 2010 Massachusetts Medical Society

Vector Susceptibility of QCD Vacuum from an Effective Quark-Quark Interaction

Institute of Scientific and Technical Information of China (English)

ZONG Hong-Shi; QI Shi; CHEN Wei; WU Xiao-Hua

2003-01-01

.A new approach for calculating vacuum susceptibilities from an effective quark-quark interaction model is derived. As a special case, the vector vacuum susceptibility is calculated. A comparison with the results of the previous approaches is given.

Evaluation of landslide susceptibility mapping techniques using lidar-derived conditioning factors (Oregon case study

Directory of Open Access Journals (Sweden)

Rubini Mahalingam

2016-11-01

Full Text Available Landslides are a significant geohazard, which frequently result in significant human, infrastructure, and economic losses. Landslide susceptibility mapping using GIS and remote sensing can help communities prepare for these damaging events. Current mapping efforts utilize a wide variety of techniques and consider multiple factors. Unfortunately, each study is relatively independent of others in the applied technique and factors considered, resulting in inconsistencies. Further, input data quality often varies in terms of source, data collection, and generation, leading to uncertainty. This paper investigates if lidar-derived data-sets (slope, slope roughness, terrain roughness, stream power index, and compound topographic index can be used for predictive mapping without other landslide conditioning factors. This paper also assesses the differences in landslide susceptibility mapping using several, widely used statistical techniques. Landslide susceptibility maps were produced from the aforementioned lidar-derived data-sets for a small study area in Oregon using six representative statistical techniques. Most notably, results show that only a few factors were necessary to produce satisfactory maps with high predictive capability (area under the curve >0.7. The sole use of lidar digital elevation models and their derivatives can be used for landslide mapping using most statistical techniques without requiring additional detailed data-sets that are often difficult to obtain or of lower quality.

Density-independent population projection trajectories of chromosome-substituted lines resistant and susceptible to organophosphate insecticides in Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Miyo Takahiro

2004-11-01

Full Text Available Abstract Background Seasonal fluctuations in susceptibility to organophosphate insecticides were observed in the Katsunuma population of Drosophila melanogaster for two consecutive years; susceptibility to three organophosphates tended to increase in the fall. To examine the hypothesis that variation in fitness among resistant and susceptible genotypes could trigger the change of genetic constitution within the fall population, we investigated density-independent population projection trajectories starting from single adult females with characteristics of chromosome-substituted lines resistant and susceptible to the three organophosphates. Results Density-independent population projection trajectories, expressed as the ratios of the number of each chromosome-substituted line to that of line SSS, for which all chromosomes were derived from the susceptible line, showed significant declines in numbers with time for all the resistant chromosome-substituted lines. Conclusion The declining tendency in the density-independent population projection trajectories of the resistant chromosome-substituted lines could explain the simultaneous decline in the levels of resistance to the three organophosphates, observed in the Katsunuma population in the fall.

Decrease in Hydrogen Embrittlement Susceptibility of 10B21 Screws by Bake Aging

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Kuan-Jen Chen

2016-08-01

Full Text Available The effects of baking on the mechanical properties and fracture characteristics of low-carbon boron (10B21 steel screws were investigated. Fracture torque tests and hydrogen content analysis were performed on baked screws to evaluate hydrogen embrittlement (HE susceptibility. The diffusible hydrogen content within 10B21 steel dominated the fracture behavior of the screws. The fracture torque of 10B21 screws baked for a long duration was affected by released hydrogen. Secondary ion mass spectroscopy (SIMS result showed that hydrogen content decreased with increasing baking duration, and thus the HE susceptibility of 10B21 screws improved. Diffusible hydrogen promoted crack propagation in high-stress region. The HE of 10B21 screws can be prevented by long-duration baking.

Antifungal susceptibility and phylogeny of opportunistic members of the order mucorales.

Science.gov (United States)

Vitale, Roxana G; de Hoog, G Sybren; Schwarz, Patrick; Dannaoui, Eric; Deng, Shuwen; Machouart, Marie; Voigt, Kerstin; van de Sande, Wendy W J; Dolatabadi, Somayeh; Meis, Jacques F; Walther, Grit

2012-01-01

The in vitro susceptibilities of 66 molecularly identified strains of the Mucorales to eight antifungals (amphotericin B, terbinafine, itraconazole, posaconazole, voriconazole, caspofungin, micafungin, and 5-fluorocytosine) were tested. Molecular phylogeny was reconstructed based on the nuclear ribosomal large subunit to reveal taxon-specific susceptibility profiles. The impressive phylogenetic diversity of the Mucorales was reflected in susceptibilities differing at family, genus, and species levels. Amphotericin B was the most active drug, though somewhat less against Rhizopus and Cunninghamella species. Posaconazole was the second most effective antifungal agent but showed reduced activity in Mucor and Cunninghamella strains, while voriconazole lacked in vitro activity for most strains. Genera attributed to the Mucoraceae exhibited a wide range of MICs for posaconazole, itraconazole, and terbinafine and included resistant strains. Cunninghamella also comprised strains resistant to all azoles tested but was fully susceptible to terbinafine. In contrast, the Lichtheimiaceae completely lacked strains with reduced susceptibility for these antifungals. Syncephalastrum species exhibited susceptibility profiles similar to those of the Lichtheimiaceae. Mucor species were more resistant to azoles than Rhizopus species. Species-specific responses were obtained for terbinafine where only Rhizopus arrhizus and Mucor circinelloides were resistant. Complete or vast resistance was observed for 5-fluorocytosine, caspofungin, and micafungin. Intraspecific variability of in vitro susceptibility was found in all genera tested but was especially high in Mucor and Rhizopus for azoles and terbinafine. Accurate molecular identification of etiologic agents is compulsory to predict therapy outcome. For species of critical genera such as Mucor and Rhizopus, exhibiting high intraspecific variation, susceptibility testing before the onset of therapy is recommended.

SU-F-I-24: Feasibility of Magnetic Susceptibility to Relative Electron Density Conversion Method for Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Ito, K; Kadoya, N; Chiba, M; Matsushita, H; Jingu, K [Tohoku University Graduate School of Medicine, Sendai, Miyagi (Japan); Sato, K; Nagasaka, T; Yamanaka, K [Tohoku University Hospital, Sendai, Miyagi (Japan); Dobashi, S; Takeda, K [Tohoku University, Sendai, Miyagi (Japan)

2016-06-15

Purpose: The aim of this study is to develop radiation treatment planning using magnetic susceptibility obtained from quantitative susceptibility mapping (QSM) via MR imaging. This study demonstrates the feasibility of a method for generating a substitute for a CT image from an MRI. Methods: The head of a healthy volunteer was scanned using a CT scanner and a 3.0 T MRI scanner. The CT imaging was performed with a slice thickness of 2.5 mm at 80 and 120 kV (dual-energy scan). These CT images were converted to relative electron density (rED) using the CT-rED conversion table generated by a previous dual-energy CT scan. The CT-rED conversion table was generated using the conversion of the energy-subtracted CT number to rED via a single linear relationship. One T2 star-weighted 3D gradient echo-based sequence with four different echo times images was acquired using the MRI scanner. These T2 star-weighted images were used to estimate the phase data. To estimate the local field map, a Laplacian unwrapping of the phase and background field removal algorithm were implemented to process phase data. To generate a magnetic susceptibility map from the local field map, we used morphology enabled dipole inversion method. The rED map was resampled to the same resolution as magnetic susceptibility, and the magnetic susceptibility-rED conversion table was obtained via voxel-by-voxel mapping between the magnetic susceptibility and rED maps. Results: A correlation between magnetic susceptibility and rED is not observed through our method. Conclusion: Our results show that the correlation between magnetic susceptibility and rED is not observed. As the next step, we assume that the voxel of the magnetic susceptibility map comprises two materials, such as water (0 ppm) and bone (-2.2 ppm) or water and marrow (0.81ppm). The elements of each voxel were estimated from the ratio of the two materials.

Antimicrobial susceptibility patterns of Brazilian Haemophilus parasuis field isolates

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Michela Miani

Full Text Available ABSTRACT: Haemophilus parasuis is the etiological agent of Glässer’s disease (GD, an ubiquitous infection of swine characterized by systemic fibrinous polyserositis, polyarthritis and meningitis. Intensive use of antimicrobial agents in swine husbandries during the last years triggered the development of antibiotic resistances in bacterial pathogens. Thus, regular susceptibility testing is crucial to ensure efficacy of different antimicrobial agents to this porcine pathogen. In this study, 50 clinical isolates from South Brazilian pig herds were characterized and analyzed for their susceptibility to commonly used antibiotic. The identification and typing of clinical isolates was carried out by a modified indirect hemagglutination assay combined with a multiplex PCR. The susceptibility of each isolate was analyzed by broth microdilution method against a panel of 21 antimicrobial compounds. We found that field isolates are highly resistance to gentamycin, bacitracin, lincomycin and tiamulin, but sensitive to ampicillin, clindamycin, neomycin, penicillin, danofloxacin and enrofloxacin. Furthermore, an individual susceptibility analysis indicated that enrofloxacin is effective to treat clinical isolates with the exception of those classified as serovar 1. The results presented here firstly demonstrate the susceptibility of Brazilian clinical isolates of H. parasuis to antimicrobials widely used by swine veterinary practitioners and strengthen the need to perform susceptibility test prior to antibiotic therapy during GD outbreaks. In addition, because only six antimicrobial drugs (28.6% were found effective against field isolates, a continuous surveillance of the susceptibility profile should be of major concern to the swine industry.

Azasordarins: Susceptibility of Fluconazole-Susceptible and Fluconazole-Resistant Clinical Isolates of Candida spp. to GW 471558

OpenAIRE

Cuenca-Estrella, Manuel; Mellado, Emilia; Díaz-Guerra, Teresa M.; Monzón, Araceli; Rodríguez-Tudela, Juan L.

2001-01-01

The in vitro activity of the azasordarin GW 471558 was compared with those of amphotericin B, flucytosine, itraconazole, and ketoconazole against 177 clinical isolates of Candida spp. GW 471558 showed potent activity against Candida albicans, Candida glabrata, and Candida tropicalis, even against isolates with decreased susceptibility to azoles. Candida krusei, Candida parapsilosis, Candida lusitaniae, and Candida guilliermondii are resistant to GW 471558 in vitro (MICs, >128 μg/ml).

In vitro susceptibility of Helicobacter pullorum strains to different antimicrobial agents.

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Ceelen, Liesbeth; Decostere, Annemie; Devriese, Luc A; Ducatelle, Richard; Haesebrouck, Freddy

2005-01-01

The in vitro activity of 13 antimicrobial agents against 23 Helicobacter pullorum strains from poultry (21) and human (two) origin, and one human H. canadensis strain was tested by the agar dilution method. With the H. pullorum strains, monomodal distributions of Minimum Inhibitory Concentrations (MICs) were seen with lincomycin, doxycycline, gentamicin, tobramycin, erythromycin, tylosin, metronidazole, and enrofloxacin in concentration ranges considered as indicating susceptibility in other bacteria. The normal susceptibility level for nalidixic acid was situated at or slightly above the MIC breakpoints proposed for Campylobacteriaceae. Ampicillin, ceftriaxone, and sulphamethoxazole-trimethoprim showed poor activity against H. pullorum. For the H. canadensis strain, a similar susceptibility pattern was seen, except for nalidixic acid and enrofloxacin, whose MIC of >512 and 8 microg/ml, respectively, indicated resistance of this agent. With spectinomycin, a bimodal distribution of the MICs was noted for the tested strains; eight H. pullorum isolates originating from one flock showed acquired resistance (MIC>512 microg/ml).

TGF-b2 induction regulates invasiveness of Theileria-transformed leukocytes and disease susceptibility.

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Marie Chaussepied

2010-11-01

Full Text Available Theileria parasites invade and transform bovine leukocytes causing either East Coast fever (T. parva, or tropical theileriosis (T. annulata. Susceptible animals usually die within weeks of infection, but indigenous infected cattle show markedly reduced pathology, suggesting that host genetic factors may cause disease susceptibility. Attenuated live vaccines are widely used to control tropical theileriosis and attenuation is associated with reduced invasiveness of infected macrophages in vitro. Disease pathogenesis is therefore linked to aggressive invasiveness, rather than uncontrolled proliferation of Theileria-infected leukocytes. We show that the invasive potential of Theileria-transformed leukocytes involves TGF-b signalling. Attenuated live vaccine lines express reduced TGF-b2 and their invasiveness can be rescued with exogenous TGF-b. Importantly, infected macrophages from disease susceptible Holstein-Friesian (HF cows express more TGF-b2 and traverse Matrigel with great efficiency compared to those from disease-resistant Sahiwal cattle. Thus, TGF-b2 levels correlate with disease susceptibility. Using fluorescence and time-lapse video microscopy we show that Theileria-infected, disease-susceptible HF macrophages exhibit increased actin dynamics in their lamellipodia and podosomal adhesion structures and develop more membrane blebs. TGF-b2-associated invasiveness in HF macrophages has a transcription-independent element that relies on cytoskeleton remodelling via activation of Rho kinase (ROCK. We propose that a TGF-b autocrine loop confers an amoeboid-like motility on Theileria-infected leukocytes, which combines with MMP-dependent motility to drive invasiveness and virulence.

Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation

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Glenn P. Morlock

2017-01-01

Full Text Available The primary platform used for pyrazinamide (PZA susceptibility testing of Mycobacterium tuberculosis is the MGIT culture system (Becton Dickinson. Since false-resistant results have been associated with the use of this system, we conducted a multicenter evaluation to determine the effect of using a reduced cell density inoculum on the rate of false resistance. Two reduced inoculum densities were compared with that prescribed by the manufacturer (designated as “BD” method. The reduced inoculum methods (designated as “A” and “C” were identical to the manufacturer’s protocol in all aspects with the exception of the cell density of the inoculum. Twenty genetically and phenotypically characterized M. tuberculosis isolates were tested in duplicate by ten independent laboratories using the three inoculum methods. False-resistant results declined from 21.1% using the standard “BD” method to 5.7% using the intermediate (“A” inoculum and further declined to 2.8% using the most dilute (“C” inoculum method. The percentages of the resistant results that were false-resistant declined from 55.2% for the “BD” test to 28.8% and 16.0% for the “A” and “C” tests, respectively. These results represent compelling evidence that the occurrence of false-resistant MGIT PZA susceptibility test results can be mitigated through the use of reduced inoculum densities.

Antimicrobial susceptibility of Brachyspira hyodysenteriae isolated from 21 Polish farms.

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Zmudzki, J; Szczotka, A; Nowak, A; Strzelecka, H; Grzesiak, A; Pejsak, Z

2012-01-01

Swine dysentery (SD) is a common disease among pigs worldwide, which contributes to major production losses. Antimicrobial susceptibility testing of B. hyodysenteriae, the etiological agent of SD, is mainly performed by the agar dilution method. This method has certain limitations due to difficulties in interpretation of results. The aim of this study was the analysis of antimicrobial susceptibility of Brachyspira hyodysenteriae (B. hyodysenteriae) Polish field isolates by broth microdilution procedure. The study was performed on 21 isolates of B. hyodysenteriae, collected between January 2006 to December 2010 from cases of swine dysentery. VetMIC Brachyspira panels with antimicrobial agents (tiamulin, valnemulin, doxycycline, lincomycin, tylosin and ampicillin) were used for susceptibility testing of B. hyodysenteriae. The minimal inhibitory concentration (MIC) was determined by the broth dilution procedure. The lowest antimicrobial activity was demonstrated for tylosin and lincomycin, with inhibition of bacterial growth using concentrations > 128 microg/ml and 32 microg/ml, respectively. In the case of doxycycline, the MIC values were < or = 2.0 microg/ml. No decreased susceptibility to tiamulin was found among the Polish isolates and MIC values for this antibiotic did not exceed 1.0 microg/ml. The results of the present study confirmed that Polish B. hyodysenteriae isolates were susceptible to the main antibiotics (tiamulin and valnemulin) used in treatment of swine dysentery. Further studies are necessary to evaluate a possible slow decrease in susceptibility to tiamulin and valnemulin of B. hyodysenteriae strains in Poland.

In vitro susceptibilities of Brucella melitensis isolates to eleven antibiotics

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Loukaides Feidias

2006-10-01

Full Text Available Abstract Background Brucellosis is an endemic disease present in many countries worldwide, but it is rare in Europe and North America. Nevertheless brucella is included in the bacteria potentially used for bioterrorism. The aim of this study was the investigation of the antibiotic susceptibility profile of brucella isolates from areas of the eastern Mediterranean where it has been endemic. Methods The susceptibilities of 74 Brucella melitensis isolates derived from clinical samples (57 and animal products (17 were tested in vitro. The strains originate from Crete (59, Cyprus (10, and Syria (5. MICs of tetracycline, rifampicin, streptomycin, gentamicin, norfloxacin, ciprofloxacin, levofloxacin, trimethoprim/sulfamethoxazole, ampicillin, amoxicillin/clavulanic acid, and erythromycin were detected by E-test method. The NCCLS criteria for slow growing bacteria were considered to interpret the results. Results All the isolates were susceptible to tetracycline, streptomycin, gentamicin, ciprofloxacin, norfloxacin, and levofloxacin. Two isolates presented reduced susceptibility to rifampicin (MIC value: 1.5 mg/l and eight to SXT (MIC values: 0.75–1.5 mg/l. Erythromycin had the highest (4 mg/l MIC90value and both norfloxacin and erythromycin the highest (1.5 mg/l MIC50 value. Conclusion Brucella isolates remain susceptible in vitro to most antibiotics used for treatment of brucellosis. The establishment of a standardized antibiotic susceptibility method for Brucella spp would be useful for resistance determination in these bacteria and possible evaluation of bioterorism risks.

Change of antibiotic susceptibility testing guidelines from CLSI to EUCAST: influence on cumulative hospital antibiograms.

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Aline Wolfensberger

Full Text Available OBJECTIVE: We studied whether the change in antibiotic susceptibility testing (AST guidelines from CLSI to EUCAST influenced cumulative antibiograms in a tertiary care hospital in Switzerland. METHODS: Antibiotic susceptibilities of non-duplicate isolates collected within a one-year period before (period A and after (period B changing AST interpretation from CLSI 2009 to EUCAST 1.3 (2011 guidelines were analysed. In addition, period B isolates were reinterpreted according to the CLSI 2009, CLSI 2013 and EUCAST 3.1 (2013 guidelines. RESULTS: The majority of species/drug combinations showed no differences in susceptibility rates comparing periods A and B. However, in some gram-negative bacilli, decreased susceptibility rates were observed when comparing CLSI 2009 with EUCAST 1.3 within period B: Escherichia coli / cefepime, 95.8% (CLSI 2009 vs. 93.1% (EUCAST 1.3, P=0.005; Enterobacter cloacae / cefepime, 97.0 (CLSI 2009 vs. 90.5% (EUCAST 1.3, P=0.012; Pseudomonas aeruginosa / meropenem, 88.1% (CLSI 2009 vs. 78.3% (EUCAST 1.3, P=0.002. These differences were still evident when comparing susceptibility rates according to the CLSI 2013 guideline with EUCAST 3.1 guideline. For P. aeruginosa and imipenem, a trend towards a lower antibiotic susceptibility rate in ICUs compared to general wards turned into a significant difference after the change to EUCAST: 87.9% vs. 79.8%, P=0.08 (CLSI 2009 and 86.3% vs. 76.8%, P=0.048 (EUCAST 1.3. CONCLUSIONS: The change of AST guidelines from CLSI to EUCAST led to a clinically relevant decrease of susceptibility rates in cumulative antibiograms for defined species/drug combinations, particularly in those with considerable differences in clinical susceptibility breakpoints between the two guidelines.

Identification of highly susceptible individuals in complex networks

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Tang, Shaoting; Teng, Xian; Pei, Sen; Yan, Shu; Zheng, Zhiming

2015-08-01

Identifying highly susceptible individuals in spreading processes is of great significance in controlling outbreaks. In this paper, we explore the susceptibility of people in susceptible-infectious-recovered (SIR) and rumor spreading dynamics. We first study the impact of community structure on people's susceptibility. Although the community structure can reduce the number of infected people for same infection rate, it will not significantly affect nodes' susceptibility. We find the susceptibility of individuals is sensitive to the choice of spreading dynamics. For SIR spreading, since the susceptibility is highly correlated to nodes' influence, the topological indicator k-shell can better identify highly susceptible individuals, outperforming degree, betweenness centrality and PageRank. In contrast, in rumor spreading model, where nodes' susceptibility and influence have no clear correlation, degree performs the best among considered topological measures. Our finding highlights the significance of both topological features and spreading mechanisms in identifying highly susceptible population.

An in-depth characterization of the major psoriasis susceptibility locus identifies candidate susceptibility alleles within an HLA-C enhancer element.

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Alex Clop

Full Text Available Psoriasis is an immune-mediated skin disorder that is inherited as a complex genetic trait. Although genome-wide association scans (GWAS have identified 36 disease susceptibility regions, more than 50% of the genetic variance can be attributed to a single Major Histocompatibility Complex (MHC locus, known as PSORS1. Genetic studies indicate that HLA-C is the strongest PSORS1 candidate gene, since markers tagging HLA-Cw*0602 consistently generate the most significant association signals in GWAS. However, it is unclear whether HLA-Cw*0602 is itself the causal PSORS1 allele, especially as the role of SNPs that may affect its expression has not been investigated. Here, we have undertaken an in-depth molecular characterization of the PSORS1 interval, with a view to identifying regulatory variants that may contribute to disease susceptibility. By analysing high-density SNP data, we refined PSORS1 to a 179 kb region encompassing HLA-C and the neighbouring HCG27 pseudogene. We compared multiple MHC sequences spanning this refined locus and identified 144 candidate susceptibility variants, which are unique to chromosomes bearing HLA-Cw*0602. In parallel, we investigated the epigenetic profile of the critical PSORS1 interval and uncovered three enhancer elements likely to be active in T lymphocytes. Finally we showed that nine candidate susceptibility SNPs map within a HLA-C enhancer and that three of these variants co-localise with binding sites for immune-related transcription factors. These data indicate that SNPs affecting HLA-Cw*0602 expression are likely to contribute to psoriasis susceptibility and highlight the importance of integrating multiple experimental approaches in the investigation of complex genomic regions such as the MHC.

Susceptibility of different subsets of immature thymocytes to apoptosis induced by anti-TCRmAb

International Nuclear Information System (INIS)

Li Hongmei; Zhong Renqian; Yu Jiaping; Kong Xiantao; Chen Weifeng

2003-01-01

To analysis the susceptibility of different subsets of immature mice thymocytes to apoptosis induced by anti-TCRmAbs in vitro apoptosis was induced in unfractionated mice thymocytes by anti-TCRmAb. In Vivo apoptosis was induced in BALB/c mice by anti-TCR mAb, and thymocytes were examined by FACS. Results showed that CD4 + CD8 + DP thymocytes and CD4 - CD8 + CD3 - thymocytes were equally sensitive to apoptosis after treatment with the anti-TCR mAb. In sharp contrast, the early migrants or precursor containing thymocytes which are CD4 - CD8 - CD3 - TN have a lower spontaneous apoptosis rate and were relatively resistant to the anti-TCR mAb. The findings showed a breakpoint in thymocyte sensitivity to apoptosis which occurs after the onset of CD4 - CD8 + CD3 expression, suggesting that susceptibility of thymocytes to apoptosis is developmentally regulated

Tensor Susceptibilities of the Vacuum from Constituent Quarks

International Nuclear Information System (INIS)

Broniowski, W.; Polyakov, M.; Goeke, K.; Hyun-Chul Kim

1998-01-01

We show that the constituent quark model leads to simple expression for the isoscalar and isovector tensor susceptibilities of the vacuum. The found values are negative and of magnitude compatible with QCD-sum-rule parametrizations of spectral densities in appropriate L=1-meson channels. (author)

Tensor Susceptibilities of the Vacuum from Constituent Quarks

Energy Technology Data Exchange (ETDEWEB)

Broniowski, W [The H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland); Polyakov, M; Goeke, K [Institute for Theoretical Physics II, Ruhr-Universitaet-Bochum, Bochum (Germany); Kim, Hyun-Chul [Pusan National University, Department of Physics, Pusan (Korea, Republic of)

1998-05-15

We show that the constituent quark model leads to simple expression for the isoscalar and isovector tensor susceptibilities of the vacuum. The found values are negative and of magnitude compatible with QCD-sum-rule parametrizations of spectral densities in appropriate L=1-meson channels. (author)

Variation of the dynamic susceptibility along an isochrone

DEFF Research Database (Denmark)

Bailey, Nicholas; Schrøder, Thomas; Dyre, J. C.

2014-01-01

Koperwas et al. showed in a recent paper [Phys. Rev. Lett. 111, 125701 (2013)] that the dynamic susceptibility χ4 as estimated by dielectric measurements for certain glass-forming liquids decreases substantially with increasing pressure along a curve of constant relaxation time. This observation...

Canine susceptibility to visceral leishmaniasis: A systematic review upon genetic aspects, considering breed factors and immunological concepts.

Science.gov (United States)

de Vasconcelos, Tassia Cristina Bello; Furtado, Marina Carvalho; Belo, Vínicus Silva; Morgado, Fernanda Nazaré; Figueiredo, Fabiano Borges

2017-10-05

Dogs have different susceptibility degrees to leishmaniasis; however, genetic research on this theme is scarce, manly on visceral form. The aims of this systematic review were to describe and discuss the existing scientific findings on genetic susceptibility to canine leishmaniasis, as well as to show the gaps of the existing knowledge. Twelve articles were selected, including breed immunological studies, genome wide associations or other gene polymorphism or gene sequencing studies, and transcription approaches. As main results of literature, there was a suggestion of genetic clinical resistance background for Ibizan Hound dogs, and alleles associated with protection or susceptibility to visceral leishmaniasis in Boxer dogs. Genetic markers can explain phenotypic variance in both pro- and anti-inflammatory cytokines and in cellular immune responses, including antigen presentation. Many gene segments are involved in canine visceral leishmaniasis phenotype, with Natural Resistance Associated Macrophage Protein 1 (NRAMP1) as the most studied. This was related to both protection and susceptibility. In comparison with murine and human genetic approaches, lack of knowledge in dogs is notorious, with many possibilities for new studies, revealing a wide field to be assessed on canine leishmaniasis susceptibility research. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in Amino Acid Profile in Roots of Glyphosate Resistant and Susceptible Soybean (Glycine max) Induced by Foliar Glyphosate Application.

Science.gov (United States)

Moldes, Carlos Alberto; Cantarelli, Miguel Angel; Camiña, José Manuel; Tsai, Siu Mui; Azevedo, Ricardo Antunes

2017-10-11

Amino acid profiles are useful to analyze the responses to glyphosate in susceptible and resistant soybean lines. Comparisons of profiles for 10 amino acids (Asp, Asn, Glu, Gln, Ser, His, Gly, Thr, Tyr, Leu) by HPLC in soybean roots were performed in two near isogenic pairs (four varieties). Foliar application of glyphosate was made to soybean plants after 5 weeks of seeding. Roots of four varieties were collected at 0 and 72 h after glyphosate application (AGA) for amino acid analysis by HPLC. Univariate analysis showed a significant increase of several amino acids in susceptible as well as resistant soybean lines; however, amino acids from the major pathways of carbon (C) and nitrogen (N) metabolism, such as Asp, Asn, Glu and Gln, and Ser, increased significantly in susceptible varieties at 72 h AGA. Multivariate analysis using principal component analysis (2D PCA and 3D PCA) allowed different groups to be identified and discriminated based on the soybean genetic origin, showing the amino acid responses on susceptible and resistant varieties. Based on the results, it is possible to infer that the increase of Asn, Asp, Glu, Gln, and Ser in susceptible varieties would be related to the deregulation of C and N metabolism, as well as changes in the growth mechanisms regulated by Ser.

Effect of water content on the stress corrosion cracking susceptibility of Zircaloy-4 in iodine-alcoholic solutions

International Nuclear Information System (INIS)

Gomez Sanchez, Andrea; Farina, Silvia B.; Duffo, Gustavo S.

2005-01-01

The stress corrosion cracking (SCC) susceptibility of Zircaloy-4 (UNS R60804) was studied in 10 g/L iodine dissolved in various alcohols: methanol, ethanol, 1 propanol, 1-butanol, 1-pentanol and 1-octanol. SCC was observed in all the systems studied and it was found that the higher the size of alcohol molecule, the lower the SCC susceptibility. The existence of intergranular attack -controlled by the diffusion of the active species- is a condition for the SCC process to occur. In the present work the inhibiting effect of water on the SCC susceptibility of Zircaloy-4 in iodine-alcoholic solutions was also investigated and the results showed that the minimum water content to inhibit the SCC process depends on the type of alcohol used as a solvent. (author) [es

Audiovisual sentence recognition not predicted by susceptibility to the McGurk effect.

Science.gov (United States)

Van Engen, Kristin J; Xie, Zilong; Chandrasekaran, Bharath

2017-02-01

In noisy situations, visual information plays a critical role in the success of speech communication: listeners are better able to understand speech when they can see the speaker. Visual influence on auditory speech perception is also observed in the McGurk effect, in which discrepant visual information alters listeners' auditory perception of a spoken syllable. When hearing /ba/ while seeing a person saying /ga/, for example, listeners may report hearing /da/. Because these two phenomena have been assumed to arise from a common integration mechanism, the McGurk effect has often been used as a measure of audiovisual integration in speech perception. In this study, we test whether this assumed relationship exists within individual listeners. We measured participants' susceptibility to the McGurk illusion as well as their ability to identify sentences in noise across a range of signal-to-noise ratios in audio-only and audiovisual modalities. Our results do not show a relationship between listeners' McGurk susceptibility and their ability to use visual cues to understand spoken sentences in noise, suggesting that McGurk susceptibility may not be a valid measure of audiovisual integration in everyday speech processing.

Evaluation of the routine antimicrobial susceptibility testing results of clinically significant anaerobic bacteria in a Slovenian tertiary-care hospital in 2015.

Science.gov (United States)

Jeverica, Samo; Kolenc, Urša; Mueller-Premru, Manica; Papst, Lea

2017-10-01

The aim of our study was to determined antimicrobial susceptibility profiles of 2673 clinically significant anaerobic bacteria belonging to the major genera, isolated in 2015 in a large tertiary-care hospital in Slovenia. The species identification was performed by MALDI-TOF mass spectrometry. Antimicrobial susceptibility was determined immediately at the isolation of the strains against: penicillin, co-amoxiclav, imipenem, clindamycin and metronidazole, using gradient diffusion methodology and EUCAST breakpoints. The most frequent anaerobes were Bacteroides fragilis group with 31% (n = 817), Gram positive anaerobic cocci (GPACs) with 22% (n = 589), Prevotella with 14% (n = 313) and Propionibacterium with 8% (n = 225). Metronidazole has retained full activity (100%) against all groups of anaerobic bacteria intrinsically susceptible to it. Co-amoxiclav and imipenem were active against most tested anaerobes with zero or low resistance rates. However, observed resistance to co-amoxiclav (8%) and imipenem (1%) is worrying especially among B. fragilis group isolates. High overall resistance (23%) to clindamycin was detected in our study and was highest among the genera Prevotella, Bacteroides, Parabacteroides, GPACs and Clostridium. Routine testing of antimicrobial susceptibility of clinically relevant anaerobic bacteria is feasible and provides good surveillance data. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Hybridism between Biomphalaria cousini and Biomphalaria amazonica and its susceptibility to Schistosoma mansoni

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Tatiana Maria Teodoro

2011-11-01

Full Text Available Molecular techniques can aid in the classification of Biomphalaria species because morphological differentiation between these species is difficult. Previous studies using phylogeny, morphological and molecular taxonomy showed that some populations studied were Biomphalaria cousini instead of Biomphalaria amazonica. Three different molecular profiles were observed that enabled the separation of B. amazonica from B. cousini. The third profile showed an association between the two and suggested the possibility of hybrids between them. Therefore, the aim of this work was to investigate the hybridism between B. cousini and B. amazonica and to verify if the hybrids are susceptible to Schistosoma mansoni. Crosses using the albinism factor as a genetic marker were performed, with pigmented B. cousini and albino B. amazonica snails identified by polymerase chain reaction-restriction fragment length polymorphism. This procedure was conducted using B. cousini and B. amazonica of the type locality accordingly to Paraense, 1966. In addition, susceptibility studies were performed using snails obtained from the crosses (hybrids and three S. mansoni strains (LE, SJ, AL. The crosses between B. amazonica and B. cousini confirmed the occurrence of hybrids. Moreover, hybrids can be considered potential hosts of S. mansoni because they are susceptible to LE, SJ and AL strains (4.4%, 5.6% and 2.2%, respectively. These results indicate that there is a risk of introducing schistosomiasis mansoni into new areas.

Antifungal susceptibility testing of vaginal candida isolates: the broth microdilution method

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Mahmoudi Rad M

2010-02-01

Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Vulvovaginal candidiasis is a common mucosal infection among immunocompetent, healthy women, and is caused by opportunistic yeasts that belong to genus Candida. In this study, we isolated and identified the Candida species in the vagina of patients who admitted in Gynecology Department of Mahdieh Hospital in Tehran, Iran to evaluate the in vitro activities of fluconazole, miconazole, itraconazole and flucytosine against 191 clinical Candida isolates by the NCCLS microdilution method."n"nMethods: 191 Candida were isolated from vaginal secretions and identified with conventional mycological methods in the diagnosis of Candida species. The identity of all strains was confirmed genotypically by multiplex PCR. In vitro susceptibility testing of vaginal Candida isolates was performed by the NCCLS broth microdilution method. The results were read at 48 h."n"nResults: Most C. albicans isolates (>90% were sensitive in vitro to the antifungal agents tested. Most C. glabrata isolates showed sensitivity to miconazole and then flucytosine while they were more resistant to Itraconazole and fluconazole. Many isolates of C. tropicalis were susceptible to miconazole and then fluconazole. They showed a little resistance to

Wound-induced pectin methylesterases enhance banana (Musa spp. AAA) susceptibility to Fusarium oxysporum f. sp. cubense.

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Ma, Li; Jiang, Shuang; Lin, Guimei; Cai, Jianghua; Ye, Xiaoxi; Chen, Houbin; Li, Minhui; Li, Huaping; Takác, Tomás; Samaj, Jozef; Xu, Chunxiang

2013-05-01

Recent studies suggest that plant pectin methylesterases (PMEs) are directly involved in plant defence besides their roles in plant development. However, the molecular mechanisms of PME action on pectins are not well understood. In order to understand how PMEs modify pectins during banana (Musa spp.)-Fusarium interaction, the expression and enzyme activities of PMEs in two banana cultivars, highly resistant or susceptible to Fusarium, were compared with each other. Furthermore, the spatial distribution of PMEs and their effect on pectin methylesterification of 10 individual homogalacturonan (HG) epitopes with different degrees of methylesterification (DMs) were also examined. The results showed that, before pathogen treatment, the resistant cultivar displayed higher PME activity than the susceptible cultivar, corresponding well to the lower level of pectin DM. A significant increase in PME expression and activity and a decrease in pectin DM were observed in the susceptible cultivar but not in the resistant cultivar when plants were wounded, which was necessary for successful infection. With the increase of PME in the wounded susceptible cultivar, the JIM5 antigen (low methyestrified HGs) increased. Forty-eight hours after pathogen infection, the PME activity and expression in the susceptible cultivar were higher than those in the resistant cultivar, while the DM was lower. In conclusion, the resistant and the susceptible cultivars differ significantly in their response to wounding. Increased PMEs and thereafter decreased DMs acompanied by increased low methylesterified HGs in the root vascular cylinder appear to play a key role in determination of banana susceptibility to Fusarium.

Assessment of earthquake-triggered landslide susceptibility in El Salvador based on an Artificial Neural Network model

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M. J. García-Rodríguez

2010-06-01

Full Text Available This paper presents an approach for assessing earthquake-triggered landslide susceptibility using artificial neural networks (ANNs. The computational method used for the training process is a back-propagation learning algorithm. It is applied to El Salvador, one of the most seismically active regions in Central America, where the last severe destructive earthquakes occurred on 13 January 2001 (M_w 7.7 and 13 February 2001 (M_w 6.6. The first one triggered more than 600 landslides (including the most tragic, Las Colinas landslide and killed at least 844 people.

The ANN is designed and programmed to develop landslide susceptibility analysis techniques at a regional scale. This approach uses an inventory of landslides and different parameters of slope instability: slope gradient, elevation, aspect, mean annual precipitation, lithology, land use, and terrain roughness. The information obtained from ANN is then used by a Geographic Information System (GIS to map the landslide susceptibility. In a previous work, a Logistic Regression (LR was analysed with the same parameters considered in the ANN as independent variables and the occurrence or non-occurrence of landslides as dependent variables. As a result, the logistic approach determined the importance of terrain roughness and soil type as key factors within the model. The results of the landslide susceptibility analysis with ANN are checked using landslide location data. These results show a high concordance between the landslide inventory and the high susceptibility estimated zone. Finally, a comparative analysis of the ANN and LR models are made. The advantages and disadvantages of both approaches are discussed using Receiver Operating Characteristic (ROC curves.

Mapping of murine radiation-induced acute myeloid leukaemia susceptibility loci

International Nuclear Information System (INIS)

Darakhshan, F.

2001-01-01

Studies on radiation-induced AML have shown characteristic phenotypic variation in susceptibility amongst inbred mouse strains, suggesting the involvement of genetic factors in determining the development of AML post-irradiation exposure. The main objective of the present study therefore was to identify and map markers in linkage disequilibrium with gene variants associated with influencing susceptibility to radiation induced AML in mice. Given Chr 2 abnormalities are characteristic of AML in mice, this feature was exploited in an effort to overcome the long latency for AML development. Analysis of Chr 2 aberrations at 24 and 48 h following irradiation established a positive correlation between Chr 2 radiosensitivity and radiation-AML susceptibility thus validating the choice of substitute assay. The analysis also resulted in the identification of a further trait, additional to Chr 2 radiosensitivity, termed overall chromosome radiosensitivity. Genetic mapping of Chr 2 radiosensitivity using public domain microsatellite database information resulted in the definition of cluster regions on 7 different chromosomes. Further genotyping reduced the candidate regions to 3 specific regions of interest. A test of allelic association could not ascertain a conclusive link between markers at these regions and the Chr 2 radiosensitivity/radiation-AML susceptibility phenotype. However, a region on Chr 4 around D4Mit221 appears to be most strongly associated. Similar studies identified three chromosomal regions of interest (on Chrs 4, 8 and 16) associated with overall chromosome radiosensitivity trait. An independent mapping strategy using F3 RCS confirmed the likely involvement of two of the candidate Chr 2 radiosensitivity regions identified by the inbred analysis including that on Chr 4 and also highlighted phenotypic heterogeneity amongst resistant RC strains, suggesting the influence of multiple alleles in specific phenotypes. RFLP analysis of candidate genes, localised on

CovR Regulates Streptococcus mutans Susceptibility To Complement Immunity and Survival in Blood

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Alves, Lívia A.; Nomura, Ryota; Mariano, Flávia S.; Harth-Chu, Erika N.; Stipp, Rafael N.; Nakano, Kazuhiko

2016-01-01

Streptococcus mutans, a major pathogen of dental caries, may promote systemic infections after accessing the bloodstream from oral niches. In this study, we investigate pathways of complement immunity against S. mutans and show that the orphan regulator CovR (CovRSm) modulates susceptibility to complement opsonization and survival in blood. S. mutans blood isolates showed reduced susceptibility to C3b deposition compared to oral isolates. Reduced expression of covRSm in blood strains was associated with increased transcription of CovRSm-repressed genes required for S. mutans interactions with glucans (gbpC, gbpB, and epsC), sucrose-derived exopolysaccharides (EPS). Consistently, blood strains showed an increased capacity to bind glucan in vitro. Deletion of covRSm in strain UA159 (UAcov) impaired C3b deposition and binding to serum IgG and C-reactive protein (CRP) as well as phagocytosis through C3b/iC3b receptors and killing by neutrophils. Opposite effects were observed in mutants of gbpC, epsC, or gtfBCD (required for glucan synthesis). C3b deposition on UA159 was abolished in C1q-depleted serum, implying that the classical pathway is essential for complement activation on S. mutans. Growth in sucrose-containing medium impaired the binding of C3b and IgG to UA159, UAcov, and blood isolates but had absent or reduced effects on C3b deposition in gtfBCD, gbpC, and epsC mutants. UAcov further showed increased ex vivo survival in human blood in an EPS-dependent way. Consistently, reduced survival was observed for the gbpC and epsC mutants. Finally, UAcov showed an increased ability to cause bacteremia in a rat model. These results reveal that CovRSm modulates systemic virulence by regulating functions affecting S. mutans susceptibility to complement opsonization. PMID:27572331

Pauli Paramagnetic Susceptibility of an Ideal Anyon Gas within Haldane Fractional Exclusion Statistics

International Nuclear Information System (INIS)

Qin Fang; Chen Jisheng

2012-01-01

The finite-temperature Pauli paramagnetic susceptibility of a three-dimensional ideal anyon gas obeying Haldane fractional exclusion statistics is studied analytically. Different from the result of an ideal Fermi gas, the susceptibility of an ideal anyon gas depends on a statistical factor g in Haldane statistics model. The low-temperature and high-temperature behaviors of the susceptibility are investigated in detail. The Pauli paramagnetic susceptibility of the two-dimensional ideal anyons is also derived. It is found that the reciprocal of the susceptibility has the similar factorizable property which is exhibited in some thermodynamic quantities in two dimensions.

GIS-based landslide susceptibility mapping for the 2005 Kashmir earthquake region

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Kamp, Ulrich; Growley, Benjamin J.; Khattak, Ghazanfar A.; Owen, Lewis A.

2008-11-01

The Mw 7.6 October 8, 2005 Kashmir earthquake triggered several thousand landslides throughout the Himalaya of northern Pakistan and India. These were concentrated in six different geomorphic-geologic-anthropogenic settings. A spatial database, which included 2252 landslides, was developed and analyzed using ASTER satellite imagery and geographical information system (GIS) technology. A multi-criterion evaluation was applied to determine the significance of event-controlling parameters in triggering the landslides. The parameters included lithology, faults, slope gradient, slope aspect, elevation, land cover, rivers and roads. The results showed four classes of landslide susceptibility. Furthermore, they indicated that lithology had the strongest influence on landsliding, particularly when the rock is highly fractured, such as in shale, slate, clastic sediments, and limestone and dolomite. Moreover, the proximity of the landslides to faults, rivers, and roads was also an important factor in helping to initiate failures. In addition, landslides occurred particularly in moderate elevations on south facing slopes. Shrub land, grassland, and also agricultural land were highly susceptible to failures, while forested slopes had few landslides. One-third of the study area was highly or very highly susceptible to future landsliding and requires immediate mitigation action. The rest of the region had a low or moderate susceptibility to landsliding and remains relatively stable. This study supports the view that (1) earthquake-triggered landslides are concentrated in specific zones associated with event-controlling parameters; and (2) in the western Himalaya deforestation and road construction contributed significantly to landsliding during and shortly after earthquakes.

The Influence of Alloy Composition on the Hot Tear Susceptibility of the Al-Zn-Mg-Cu Alloy System

International Nuclear Information System (INIS)

Kim, Jee-Hun; Jo, Jae-Sub; Sim, Woo-Jeong; Im, Hang-Joon

2012-01-01

Hot tearing was the most significant casting defect when the castability evaluation of the Al- Zn-Mg-Cu alloy system was conducted. It was related to the solidification range of the alloy. Therefore, the hot tear susceptibility of the AA7075 alloy, whose solidification range is the widest, was evaluated. The hot tear susceptibility was evaluated by using a mold for a hot tearing test designed to create the condition for the occurrence of hot tear in 8 steps. According to the tearing location and shape, a hot tear susceptibility index (HTS) score was measured. The solidification range of each alloy and hot tear susceptibility was compared and thereafter the microstructure of a near tear defect was observed. As a result, the HTS of the AA7075 alloy was found to be 67. Also, the HTS in relation to a change in Zn, Mg, Cu composition showed a difference of about 6-11% compared to the AA7075 alloy.

Lack of Correlation Between β-Lactamase Production and Susceptibility to Cefamandole or Cefoxitin Among Spontaneous Mutants of Enterobacteriaceae

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Ott, John L.; Turner, J. R.; Mahoney, David F.

1979-01-01

A large number of cultures of gram-negative bacteria were examined for their susceptibility to various concentrations of cefamandole, cefoxitin, carbenicillin, and nalidixic acid. Heterogeneity of susceptibility was demonstrated in individual cultures to all of these antibiotics. Resistant clones isolated from cefamandole or cefoxitin plates were examined for β-lactamase production. Approximately 13% of 262 resistant clones acquired the ability to produce a β-lactamase. Examination of the substrate profile of the β-lactamases from some of these clones revealed no change in the specific activity of these enzymes for cefamandole, cephaloridine, or compound 87/312 as compared with their parental enzymes. This study clearly shows that some resistant clones do not produce β-lactamases, whereas some susceptible strains produced significant amounts of these enzymes. We conclude from these findings that little correlation exists between β-lactamase production and decreased susceptibility to cefamandole or cefoxitin. The results suggest the possibility that characteristics other than β-lactamase production may be responsible for resistance in Enterobacteriaceae. PMID:311615

[Microbial etiology and susceptibility of community urinary tract infections during pregnancy in the south of Brazil].

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Schenkel, Daniela Fraguas; Dallé, Jessica; Antonello, Vicente Sperb

2014-03-01

Urinary tract infection (UTI) is one of the most common conditions during pregnancy. The aim of this study was to assess the prevalence of germs and the antimicrobial susceptibility profile in urine culture isolates from pregnant patients treated at a tertiary maternity hospital in Porto Alegre, Brazil. A cross-sectional, retrospective and descriptive study was carried out at Hospital Fêmina, a leading institution in prenatal, birth and postnatal healthcare in the city of Porto Alegre, Brazil. A total of 482 microbial community results were analyzed out of 1,558 positive urine cultures of pregnant women in all gestational ages treated at Fêmina Hospital between January 2007 and July 2013. The susceptibility pattern presented in this research shows that the choice for UTI treatment during pregnancy should be nitrofurantoin (for uncomplicated infections) or second-generation cephalosporins such as cefuroxime (for uncomplicated and complicated infections), over ampicillin, first-generation cephalosporins and sulfamethoxazole/trimethoprim. Empirical treatment for UTI in pregnancy should be started according to the susceptibility patterns described in the literature and re-analyzed after the results of the urine culture.

Brain Injury Lesion Imaging Using Preconditioned Quantitative Susceptibility Mapping without Skull Stripping.

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Soman, S; Liu, Z; Kim, G; Nemec, U; Holdsworth, S J; Main, K; Lee, B; Kolakowsky-Hayner, S; Selim, M; Furst, A J; Massaband, P; Yesavage, J; Adamson, M M; Spincemallie, P; Moseley, M; Wang, Y

2018-04-01

Identifying cerebral microhemorrhage burden can aid in the diagnosis and management of traumatic brain injury, stroke, hypertension, and cerebral amyloid angiopathy. MR imaging susceptibility-based methods are more sensitive than CT for detecting cerebral microhemorrhage, but methods other than quantitative susceptibility mapping provide results that vary with field strength and TE, require additional phase maps to distinguish blood from calcification, and depict cerebral microhemorrhages as bloom artifacts. Quantitative susceptibility mapping provides universal quantification of tissue magnetic property without these constraints but traditionally requires a mask generated by skull-stripping, which can pose challenges at tissue interphases. We evaluated the preconditioned quantitative susceptibility mapping MR imaging method, which does not require skull-stripping, for improved depiction of brain parenchyma and pathology. Fifty-six subjects underwent brain MR imaging with a 3D multiecho gradient recalled echo acquisition. Mask-based quantitative susceptibility mapping images were created using a commonly used mask-based quantitative susceptibility mapping method, and preconditioned quantitative susceptibility images were made using precondition-based total field inversion. All images were reviewed by a neuroradiologist and a radiology resident. Ten subjects (18%), all with traumatic brain injury, demonstrated blood products on 3D gradient recalled echo imaging. All lesions were visible on preconditioned quantitative susceptibility mapping, while 6 were not visible on mask-based quantitative susceptibility mapping. Thirty-one subjects (55%) demonstrated brain parenchyma and/or lesions that were visible on preconditioned quantitative susceptibility mapping but not on mask-based quantitative susceptibility mapping. Six subjects (11%) demonstrated pons artifacts on preconditioned quantitative susceptibility mapping and mask-based quantitative susceptibility mapping

Low-temperature susceptibility of concentrated magnetic fluids

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Pshenichnikov, Alexander F.; Lebedev, Alexander V.

2004-09-01

The initial susceptibility of concentrated magnetic fluids (ferrocolloids) has been experimentally investigated at low temperatures. The results obtained indicate that the interparticle dipole-dipole interactions can increase the susceptibility by several times as compared to the Langevin value. It is shown that good agreement between recent theoretical models and experimental observations can be achieved by introducing a correction for coefficients in the series expansion of susceptibility in powers of density and aggregation parameter. A modified equation for equilibrium susceptibility is offered to sum over corrections made by Kalikmanov (Statistical Physics of Fluids, Springer-Verlag, Berlin, 2001) and by B. Huke and M. Lücke (Phys. Rev. E 67, 051403, 2003). The equation gives good quantitative agreement with the experimental data in the wide range of temperature and magnetic particles concentration. It has been found that in some cases the magnetic fluid solidification occurs at temperature several tens of kelvins higher than the crystallization temperature of the carrier liquid. The solidification temperature of magnetic fluids is independent of particle concentration (i.e., magneto-dipole interparticle interactions) and dependent on the surfactant type and carrier liquid. This finding allows us to suggest that molecular interactions and generation of some large-scale structure from colloidal particles in magnetic fluids are responsible for magnetic fluid solidification. If the magnetic fluid contains the particles with the Brownian relaxation mechanism of the magnetic moment, the solidification manifests itself as the peak on the "susceptibility-temperature" curve. This fact proves the dynamic nature of the observed peak: it arises from blocking the Brownian mechanism of the magnetization relaxation.

Susceptibilidade de Aedes aegypti aos inseticidas temephos e cipermetrina, Brasil Susceptibility of Aedes aegypti to temephos and cypermethrin insecticides, Brazil

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Jonny E Duque Luna

2004-12-01

Full Text Available Realizaram-se bioensaios para detectar a susceptibilidade de Aedes aegypti aos inseticidas químicos, temefós e cipermetrina. Os resultados mostraram que esta espécie é suscetível a temefós e apresenta resistência a cipermetrinae.Bioassays were performed in order to detect the susceptibility of Aedes aegypti to the chemical insecticides temephos and cypermethrin. The results showed that this species is susceptible to temephos and presents resistance to cypermethrin.

Health Psychological Constructs as Predictors of Doping Susceptibility in Adolescent Athletes

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Blank, Cornelia; Schobersberger, Wolfgang; Leichtfried, Veronika; Duschek, Stefan

2016-01-01

Background Doping is a highly relevant problem in sport, even in adolescent athletes. Knowledge of the psychological factors that influence doping susceptibility in young elite athletes remains sparse. Objectives This study investigated the predictive potential of different health-psychological constructs and well-being on doping susceptibility. The main hypotheses to be tested were positive associations of fear of failure, external locus of control, and ego-oriented goal orientation as well as negative associations of confidence of success, task orientation, internal locus of control, and performance motivation with doping susceptibility. Low levels of well-being are furthermore expected to be associated with doping susceptibility. Methods Within this cross-sectional study, 1,265 Austrian junior athletes aged between 14 and 19 years responded to a paper-pencil questionnaire. Results Performance motivation was a negative, while depressive mood, self-esteem, fear of failure and ego-oriented goal orientation were positive predictors of doping susceptibility. In addition, participants who were offered performance enhancing substances in the past were particularly susceptible to doping. Conclusions The study corroborates the predictive value of classical psychological constructs in doping research, initially analyzed in view of adult athletes, also for adolescents’ doping susceptibility. PMID:28144408

Insecticide susceptibility of Anopheles mosquitoes changes in response to variations in the larval environment.

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Owusu, Henry F; Chitnis, Nakul; Müller, Pie

2017-06-16

Insecticide resistance threatens the success achieved through vector control in reducing the burden of malaria. An understanding of insecticide resistance mechanisms would help to develop novel tools and strategies to restore the efficacy of insecticides. Although we have substantially improved our understanding of the genetic basis of insecticide resistance over the last decade, we still know little of how environmental variations influence the mosquito phenotype. Here, we measured how variations in larval rearing conditions change the insecticide susceptibility phenotype of adult Anopheles mosquitoes. Anopheles gambiae and A. stephensi larvae were bred under different combinations of temperature, population density and nutrition, and the emerging adults were exposed to permethrin. Mosquitoes bred under different conditions showed considerable changes in mortality rates and body weight, with nutrition being the major factor. Weight is a strong predictor of insecticide susceptibility and bigger mosquitoes are more likely to survive insecticide treatment. The changes can be substantial, such that the same mosquito colony may be considered fully susceptible or highly resistant when judged by World Health Organization discriminatory concentrations. The results shown here emphasise the importance of the environmental background in developing insecticide resistance phenotypes, and caution for the interpretation of data generated by insecticide susceptibility assays.

Susceptible-infected-recovered epidemics in random networks with population awareness

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Wu, Qingchu; Chen, Shufang

2017-10-01

The influence of epidemic information-based awareness on the spread of infectious diseases on networks cannot be ignored. Within the effective degree modeling framework, we discuss the susceptible-infected-recovered model in complex networks with general awareness and general degree distribution. By performing the linear stability analysis, the conditions of epidemic outbreak can be deduced and the results of the previous research can be further expanded. Results show that the local awareness can suppress significantly the epidemic spreading on complex networks via raising the epidemic threshold and such effects are closely related to the formulation of awareness functions. In addition, our results suggest that the recovered information-based awareness has no effect on the critical condition of epidemic outbreak.

Desertification Susceptibility Mapping Using Logistic Regression Analysis in the Djelfa Area, Algeria

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Farid Djeddaoui

2017-10-01

Full Text Available The main goal of this work was to identify the areas that are most susceptible to desertification in a part of the Algerian steppe, and to quantitatively assess the key factors that contribute to this desertification. In total, 139 desertified zones were mapped using field surveys and photo-interpretation. We selected 16 spectral and geomorphic predictive factors, which a priori play a significant role in desertification. They were mainly derived from Landsat 8 imagery and Shuttle Radar Topographic Mission digital elevation model (SRTM DEM. Some factors, such as the topographic position index (TPI and curvature, were used for the first time in this kind of study. For this purpose, we adapted the logistic regression algorithm for desertification susceptibility mapping, which has been widely used for landslide susceptibility mapping. The logistic model was evaluated using the area under the receiver operating characteristic (ROC curve. The model accuracy was 87.8%. We estimated the model uncertainties using a bootstrap method. Our analysis suggests that the predictive model is robust and stable. Our results indicate that land cover factors, including normalized difference vegetation index (NDVI and rangeland classes, play a major role in determining desertification occurrence, while geomorphological factors have a limited impact. The predictive map shows that 44.57% of the area is classified as highly to very highly susceptible to desertification. The developed approach can be used to assess desertification in areas with similar characteristics and to guide possible actions to combat desertification.

Effect of microstructure on the sulphide stress cracking susceptibility of a high strength pipeline steel

Energy Technology Data Exchange (ETDEWEB)

Ramirez, E. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, 62209-Cuernavaca, Mor. (Mexico); Gonzalez-Rodriguez, J.G. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, 62209-Cuernavaca, Mor. (Mexico)], E-mail: ggonzalez@uaem.mx; Torres-Islas, A.; Serna, S. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, 62209-Cuernavaca, Mor. (Mexico); Campillo, B. [Intituto de Ciencias Fisicas-Facultad de Quimicas-Universidad Nacional Autonoma de Mexico Cuernavaca, Mor. (Mexico); Dominguez-Patino, G. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas-UAEM, Av. Universidad 1001, 62209-Cuernavaca, Mor. (Mexico); Juarez-Islas, J.A. [Instituto de Investigaciones en Materiales-Universidad Nacional Autonoma de Mexico, Circuito Exterior S/N, Cd. Universitaria, C.P. 04510, Mexico, D.F. (Mexico)

2008-12-15

The sulphide stress cracking (SSC) susceptibility of a newly developed high strength microalloyed steel with three different microstructures has been evaluated using the slow strain rate testing (SSRT) technique. Studies were complemented with potentiodynamic polarization curves and hydrogen permeation measurements. Material included a C-Mn steel having Ni, Cu, and Mo as main microalloying elements with three microstructures: martensitic, ferritic and ferritic + bainitic. Testing temperatures included 25, 50, 70 and 90 deg. C. Detailed SEM observations of the microstructure and fracture surfaces were done to identify possible degradation mechanisms. The results showed that in all cases, the corrosion rate, number of hydrogen atoms at the surface and the percentage reduction in area increased with temperature. The steel with a martensitic microstructure had the highest SSC susceptibility at all temperatures, whereas the ferritic steels were susceptible only at 25 deg. C, and the most likely mechanism is hydrogen embrittlement assisted by anodic dissolution.

Susceptibility Genes in Thyroid Autoimmunity

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Yoshiyuki Ban

2005-01-01

Full Text Available The autoimmune thyroid diseases (AITD are complex diseases which are caused by an interaction between susceptibility genes and environmental triggers. Genetic susceptibility in combination with external factors (e.g. dietary iodine is believed to initiate the autoimmune response to thyroid antigens. Abundant epidemiological data, including family and twin studies, point to a strong genetic influence on the development of AITD. Various techniques have been employed to identify the genes contributing to the etiology of AITD, including candidate gene analysis and whole genome screening. These studies have enabled the identification of several loci (genetic regions that are linked with AITD, and in some of these loci, putative AITD susceptibility genes have been identified. Some of these genes/loci are unique to Graves' disease (GD and Hashimoto's thyroiditis (HT and some are common to both the diseases, indicating that there is a shared genetic susceptibility to GD and HT. The putative GD and HT susceptibility genes include both immune modifying genes (e.g. HLA, CTLA-4 and thyroid specific genes (e.g. TSHR, Tg. Most likely, these loci interact and their interactions may influence disease phenotype and severity.

Antimicrobial susceptibility of Haemophilus parasuis and Histophilus somni from pigs and cattle in Denmark

DEFF Research Database (Denmark)

Aarestrup, Frank Møller; Seyfarth, Anne Mette; Angen, Øystein

2004-01-01

A total of 52 Haemophilus parasuis and 80 Histophilus somni isolates were tested for antimicrobial susceptibility by MIC-determinations. None of the isolates were resistant to ampicillin, ceftiofur, ciprofloxacin, erythromycin, florphenicol, penicillin, spectinomycin, tetracycline, tiamulin......, or tilmicosin. Two H. parasuis isolates were resistant to trimethoprim + sulfamethoxazole. Six H. parasuis isolates had reduced susceptibility (0.06-0.5 mug/ml) to ciprofloxacin and 10 reduced susceptibility to TMP + sulfamethoxazole (1-2 mug/ml). This study showed that Danish isolates of H. parasuis and H...

Sex-specific differences in pathogen susceptibility in honey bees (Apis mellifera).

Science.gov (United States)

Retschnig, Gina; Williams, Geoffrey R; Mehmann, Marion M; Yañez, Orlando; de Miranda, Joachim R; Neumann, Peter

2014-01-01

Sex-related differences in susceptibility to pathogens are a common phenomenon in animals. In the eusocial Hymenoptera the two female castes, workers and queens, are diploid and males are haploid. The haploid susceptibility hypothesis predicts that haploid males are more susceptible to pathogen infections compared to females. Here we test this hypothesis using adult male (drone) and female (worker) honey bees (Apis mellifera), inoculated with the gut endoparasite Nosema ceranae and/or black queen cell virus (BQCV). These pathogens were chosen due to previously reported synergistic interactions between Nosema apis and BQCV. Our data do not support synergistic interactions between N. ceranae and BQCV and also suggest that BQCV has limited effect on both drone and worker health, regardless of the infection level. However, the data clearly show that, despite lower levels of N. ceranae spores in drones than in workers, Nosema-infected drones had both a higher mortality and a lower body mass than non-infected drones, across all treatment groups, while the mortality and body mass of worker bees were largely unaffected by N. ceranae infection, suggesting that drones are more susceptible to this pathogen than workers. In conclusion, the data reveal considerable sex-specific differences in pathogen susceptibility in honey bees and highlight the importance of ultimate measures for determining susceptibility, such as mortality and body quality, rather than mere infection levels.

Frequency of Reduced Vancomycin Susceptibility among Clinical Staphylococcus aureus Isolated in Ahvaz Iran

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Mojtaba Moosavian

2015-11-01

Full Text Available Introduction:   One   of   the   most   important   agents   in   hospital-acquired   infections   is Staphylococcus aureus. Treatment of methicillin-resistant S. aureus (MRSA infections with decreased susceptibility to vancomycin has recently been more difficult. The aim of this study was to evaluate the possible presence of vancomycin intermediate S. aureus (VISA and vancomycin- resistant S. aureus (VRSA and also to determine the frequency of MRSA in clinical specimens.Methods: In this study, 195 S. aureus isolates were collected from the patients were examined. All of the isolates were identified using standard biochemical tests.  Susceptibility of S. aureus isolates against 10 antibiotics was detected by disk diffusion method and was followed by E-test and vancomycin screen agar methods. Minimum inhibitory concentration (MIC of vancomycin was determined according to the CLSI guidelines.  Also, detection of mecA gene was performed by PCR and finally, the results were compared.Results: All of the isolates were susceptible to vancomycin (i.e. MIC range of vancomycin was between 0.25-2 µg/ml. Out of 195 S. aureus isolates, 99 isolates (50.8% were resistant to methicillin, and mecA gene was detected in 96 isolates. These results also showed that the highest and lowest resistance rate of isolates was to penicillin (96.9% and chloramphenicol (0%, respectively.Conclusion: Our findings showed that vancomycin can still be used as a valuable drug for treatment of S. aureus infections in our region. However, periodic evaluation of vancomycin MIC of S. aureus isolates is critical for monitoring MRSA and preventing the spread of VISA or VRSA among patients.

Using online databases for landslide susceptibility assessment: an example from the Veneto Region (northeastern Italy

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M. Floris

2011-07-01

Full Text Available In this paper, spatial data available in the Italian portals was used to evaluate the landslide susceptibility of the Euganean Hills Regional Park, located SW of Padua (northeastern Italy. Quality, applicability and possible analysis scales of the online data were investigated.

After a brief overview on the WebGIS portals around the world, their contents and tools for natural risk analyses, a susceptibility analysis of the study area was carried out using a simple probabilistic approach that compared landslide distribution and influencing factors. The input factors used in the analysis depended on available data and included landslides, morphometric data (elevation, slope, curvature, profile and plan Curvature and non-morphometric data (land use, distance to roads and distance to rivers. Great attention was paid to the pre-processing step, in particular the re-classification of continuous data that was performed following objective, geologic and geomorphologic criteria.

The results of the study show that the simple probabilistic approach used for the susceptibility evaluation showed quite good accuracy and precision (repeatability. However, heuristic, statistical or deterministic methods could be applied to the online data to improve the prediction.

The data available online for the Italian territory allows susceptibility assessment at medium and large scales. Morphometric factors, such as elevation and slope angle, are important because they implicitly include information that is not available, such as lithologic and structural data. The main drawback of the Italian online databases is the lack of information on the frequency of landslides; thus, a complete hazard analysis is not possible.

Despite the good results achieved to date, collection and sharing of data on natural risks must be improved in Italy and around the world. The creation of spatial data infrastructure and more WebGIS portals is desirable.

Dynamic insecticide susceptibility changes in Florida populations of Diaphorina citri (Hemiptera: Psyllidae).

Science.gov (United States)

Tiwari, Siddharth; Killiny, Nabil; Stelinski, Lukasz L

2013-02-01

Five field populations of Diaphorina citri Kuwayama from various regions of Florida were evaluated in 2011 for resistance to commonly used insecticides. Three diagnostic doses (LD50, LD75, and LD95), developed in 2009 using a laboratory susceptible population, were used to measure changes in susceptibility levels of field-collected populations as compared with a susceptible laboratory population. Further reductions in the susceptibility levels of D. citri to chlorpyriphos and fenpropathrin were determined, compared with results obtained in 2010. Mean percent mortality obtained from all five locations was significantly lower than observed with the laboratory susceptible population for all insecticides tested. Previously, expression of five CYP4 genes was implicated in contributing to insecticide metabolism in D. citri. In the current study, we compared the relative expression of these five CYP4 genes and their associated levels of protein expression among field-collected and laboratory susceptible populations. Expression of all CYP4 genes investigated was higher in field-collected populations when normalized against the laboratory susceptible population. There was an increased signal of a band corresponding to a 45 kDa protein in four of the five field populations as measured by the Western blot assay, which suggests increased production of cytochrome P450 enzymes. The current results indicate that insecticide resistance continues to increase in Florida populations ofD. citri, particularly to chlorpyriphos and fenpropathrin. However, there was no further decrease in susceptibility of Florida populations of D. citri to neonicotinoid insecticides in 2011 as compared with previous years.

Simple Sample Preparation Method for Direct Microbial Identification and Susceptibility Testing From Positive Blood Cultures.

Science.gov (United States)

Pan, Hong-Wei; Li, Wei; Li, Rong-Guo; Li, Yong; Zhang, Yi; Sun, En-Hua

2018-01-01

Rapid identification and determination of the antibiotic susceptibility profiles of the infectious agents in patients with bloodstream infections are critical steps in choosing an effective targeted antibiotic for treatment. However, there has been minimal effort focused on developing combined methods for the simultaneous direct identification and antibiotic susceptibility determination of bacteria in positive blood cultures. In this study, we constructed a lysis-centrifugation-wash procedure to prepare a bacterial pellet from positive blood cultures, which can be used directly for identification by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and antibiotic susceptibility testing by the Vitek 2 system. The method was evaluated using a total of 129 clinical bacteria-positive blood cultures. The whole sample preparation process could be completed in identification was 96.49% for gram-negative bacteria and 97.22% for gram-positive bacteria. Vitek 2 antimicrobial susceptibility testing of gram-negative bacteria showed an agreement rate of antimicrobial categories of 96.89% with a minor error, major error, and very major error rate of 2.63, 0.24, and 0.24%, respectively. Category agreement of antimicrobials against gram-positive bacteria was 92.81%, with a minor error, major error, and very major error rate of 4.51, 1.22, and 1.46%, respectively. These results indicated that our direct antibiotic susceptibility analysis method worked well compared to the conventional culture-dependent laboratory method. Overall, this fast, easy, and accurate method can facilitate the direct identification and antibiotic susceptibility testing of bacteria in positive blood cultures.

Susceptibility of Phelipanche and Orobanche species to AAL-toxin.

Science.gov (United States)

de Zélicourt, Axel; Montiel, Grégory; Pouvreau, Jean-Bernard; Thoiron, Séverine; Delgrange, Sabine; Simier, Philippe; Delavault, Philippe

2009-10-01

Fusarium and Alternaria spp. are phytopathogenic fungi which are known to be virulent on broomrapes and to produce sphinganine-analog mycotoxins (SAMs). AAL-toxin is a SAM produced by Alternaria alternata which causes the inhibition of sphinganine N-acyltransferase, a key enzyme in sphingolipid biosynthesis, leading to accumulation of sphingoid bases. These long chain bases (LCBs) are determinant in the occurrence of programmed cell death (PCD) in susceptible plants. We showed that broomrapes are sensitive to AAL-toxin, which is not common plant behavior, and that AAL-toxin triggers cell death at the apex of the radicle as well as LCB accumulation and DNA laddering. We also demonstrated that three Lag1 homologs, encoding components of sphinganine N-acyltransferase in yeast, are present in the Orobanche cumana genome and two of them are mutated leading to an enhanced susceptibility to AAL-toxin. We therefore propose a model for the molecular mechanism governing broomrape susceptibility to the fungus Alternaria alternata.

Landslide susceptibility mapping using logistic statistical regression in Babaheydar Watershed, Chaharmahal Va Bakhtiari Province, Iran

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Ebrahim Karimi Sangchini

2015-01-01

Full Text Available Landslides are amongst the most damaging natural hazards in mountainous regions. Every year, hundreds of people all over the world lose their lives in landslides; furthermore, there are large impacts on the local and global economy from these events. In this study, landslide hazard zonation in Babaheydar watershed using logistic regression was conducted to determine landslide hazard areas. At first, the landslide inventory map was prepared using aerial photograph interpretations and field surveys. The next step, ten landslide conditioning factors such as altitude, slope percentage, slope aspect, lithology, distance from faults, rivers, settlement and roads, land use, and precipitation were chosen as effective factors on landsliding in the study area. Subsequently, landslide susceptibility map was constructed using the logistic regression model in Geographic Information System (GIS. The ROC and Pseudo-R2 indexes were used for model assessment. Results showed that the logistic regression model provided slightly high prediction accuracy of landslide susceptibility maps in the Babaheydar Watershed with ROC equal to 0.876. Furthermore, the results revealed that about 44% of the watershed areas were located in high and very high hazard classes. The resultant landslide susceptibility maps can be useful in appropriate watershed management practices and for sustainable development in the region.

Behavioural Susceptibility Theory: Professor Jane Wardle and the Role of Appetite in Genetic Risk of Obesity.

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Llewellyn, Clare H; Fildes, Alison

2017-03-01

There is considerable variability in human body weight, despite the ubiquity of the 'obesogenic' environment. Human body weight has a strong genetic basis and it has been hypothesised that genetic susceptibility to the environment explains variation in human body weight, with differences in appetite being implicated as the mediating mechanism; so-called 'behavioural susceptibility theory' (BST), first described by Professor Jane Wardle. This review summarises the evidence for the role of appetite as a mediator of genetic risk of obesity. Variation in appetitive traits is observable from infancy, drives early weight gain and is highly heritable in infancy and childhood. Obesity-related common genetic variants identified through genome-wide association studies show associations with appetitive traits, and appetite mediates part of the observed association between genetic risk and adiposity. Obesity results from an interaction between genetic susceptibility to overeating and exposure to an 'obesogenic' food environment.

Effects of disruption of heat shock genes on susceptibility of Escherichia coli to fluoroquinolones

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Morioka Mizue

2003-08-01

Full Text Available Abstract Background It is well known that expression of certain bacterial genes responds rapidly to such stimuli as exposure to toxic chemicals and physical agents. It is generally believed that the proteins encoded in these genes are important for successful survival of the organism under the hostile conditions. Analogously, the proteins induced in bacterial cells exposed to antibiotics are believed to affect the organisms' susceptibility to these agents. Results We demonstrated that Escherichia coli cells exposed to levofloxacin (LVFX, a fluoroquinolone (FQ, induce the syntheses of heat shock proteins and RecA. To examine whether the heat shock proteins affect the bactericidal action of FQs, we constructed E. coli strains with mutations in various heat shock genes and tested their susceptibility to FQs. Mutations in dnaK, groEL, and lon increased this susceptibility; the lon mutant exhibited the greatest effects. The increased susceptibility of the lon mutant was corroborated by experiments in which the gene encoding the cell division inhibitor, SulA, was subsequently disrupted. SulA is induced by the SOS response and degraded by the Lon protease. The findings suggest that the hypersusceptibility of the lon mutant to FQs could be due to abnormally high levels of SulA protein resulting from the depletion of Lon and the continuous induction of the SOS response in the presence of FQs. Conclusion The present results show that the bactericidal action of FQs is moderately affected by the DnaK and GroEL chaperones and strongly affected by the Lon protease. FQs have contributed successfully to the treatment of various bacterial infections, but their widespread use and often misuse, coupled with emerging resistance, have gradually compromised their utility. Our results suggest that agents capable of inhibiting the Lon protease have potential for combination therapy with FQs.

Changes in the antibiotic susceptibility of anaerobic bacteria from 2007-2009 to 2010-2012 based on the CLSI methodology.

Science.gov (United States)

Hastey, Christine J; Boyd, Halsey; Schuetz, Audrey N; Anderson, Karen; Citron, Diane M; Dzink-Fox, Jody; Hackel, Meredith; Hecht, David W; Jacobus, Nilda V; Jenkins, Stephen G; Karlsson, Maria; Knapp, Cynthia C; Koeth, Laura M; Wexler, Hannah; Roe-Carpenter, Darcie E

2016-12-01

Antimicrobial susceptibility testing of anaerobic isolates was conducted at four independent sites from 2010 to 2012 and compared to results from three sites during the period of 2007-2009. This data comparison shows significant changes in antimicrobial resistance in some anaerobic groups. Therefore, we continue to recommend institutions regularly perform susceptibility testing when anaerobes are cultured from pertinent sites. Annual generation of an institutional-specific antibiogram is recommended for tracking of resistance trends over time. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selection of media for antimicrobial susceptibility testing of fish pathogenic bacteria

DEFF Research Database (Denmark)

Dalsgaard, Inger

2001-01-01

3, Diagnostic Sensitivity Test Agar) have been used in addition to media (Brain Heart Infusion Agar, Heart Infusion Agar, Columbia Blood Agar) normally utilized for cultivating fastidious bacteria. When testing marine pathogens, sodium chloride or seawater has been included in the media. Media...... pattern in fish pathogenic bacteria. The American guideline from The National Committee for Clinical Laboratory Standards (NCCLS) recommends Mueller-Hinton Agar for susceptibility testing of human pathogens and this validated medium appears to be adequate for the rapidly growing fish pathogens. Following......The available data concerning antimicrobial susceptibility testing of fish pathogens showed that there is no consensus to the basal medium currently being employed. Different media recommended for susceptibility testing of human pathogens (Mueller-Hinton Agar, Tryptone Soya Agar, Antibiotic Medium...

Selection of media for antimicrobial susceptibility testing of fish pathogenic bacteria

DEFF Research Database (Denmark)

Dalsgaard, Inger

2001-01-01

The available data concerning antimicrobial susceptibility testing of fish pathogens showed that there is no consensus to the basal medium currently being employed. Different media recommended for susceptibility testing of human pathogens (Mueller-Hinton Agar, Tryptone Soya Agar, Antibiotic Medium...... 3, Diagnostic Sensitivity Test Agar) have been used in addition to media (Brain Heart Infusion Agar, Heart Infusion Agar, Columbia Blood Agar) normally utilized for cultivating fastidious bacteria. When testing marine pathogens, sodium chloride or seawater has been included in the media. Media...... normally used for cultivation of pathogens with specific growth requirements like Flavobacterium species and Renibacterium salmoninarum have been used for susceptibility testing. The Mueller-Hinton Agar and different modifications of this medium was used most frequently in published studies on resistant...

Low-temperature magnetic susceptibility of the solid solutions (ErxY1-x)3Al5O12

International Nuclear Information System (INIS)

Bagdasarov, Kh.S.; Dodokin, A.P.; Sorokin, A.A.

1988-01-01

Measurements of magnetic susceptibility of erbium-yttrium alumogarnets in the 0.04-4.2 K temperature range are carried out. (Er x I 1-x ) 3 Al 5 O 12 monocrystals were grown by the method of vertical directed crystallization. The specimens were produced as 5 cm high cylinders 0.63 cm in diameter; the axis of the cylinders coincided with the (100) direction of the crystals. Magnetic susceptibility was measured by the Harsthorn bridge method at the frequency of 33 Hz. The analysis of measurement results shows that susceptibility of the investigated crystals at T >or approx. 2T N is well described by the Curie-Weiss law. Existence of threshold concentration of the magnetic component testifies to an essential role of exchange interactions in establishment of the magnetic order in Er 3 Al 5 O 12

A Microfluidic Channel Method for Rapid Drug-Susceptibility Testing of Pseudomonas aeruginosa.

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Yoshimi Matsumoto

Full Text Available The recent global increase in the prevalence of antibiotic-resistant bacteria and lack of development of new therapeutic agents emphasize the importance of selecting appropriate antimicrobials for the treatment of infections. However, to date, the development of completely accelerated drug susceptibility testing methods has not been achieved despite the availability of a rapid identification method. We proposed an innovative rapid method for drug susceptibility testing for Pseudomonas aeruginosa that provides results within 3 h. The drug susceptibility testing microfluidic (DSTM device was prepared using soft lithography. It consisted of five sets of four microfluidic channels sharing one inlet slot, and the four channels are gathered in a small area, permitting simultaneous microscopic observation. Antimicrobials were pre-introduced into each channel and dried before use. Bacterial suspensions in cation-adjusted Mueller-Hinton broth were introduced from the inlet slot and incubated for 3 h. Susceptibilities were microscopically evaluated on the basis of differences in cell numbers and shapes between drug-treated and control cells, using dedicated software. The results of 101 clinically isolated strains of P. aeruginosa obtained using the DSTM method strongly correlated with results obtained using the ordinary microbroth dilution method. Ciprofloxacin, meropenem, ceftazidime, and piperacillin caused elongation in susceptible cells, while meropenem also induced spheroplast and bulge formation. Morphological observation could alternatively be used to determine the susceptibility of P. aeruginosa to these drugs, although amikacin had little effect on cell shape. The rapid determination of bacterial drug susceptibility using the DSTM method could also be applicable to other pathogenic species, and it could easily be introduced into clinical laboratories without the need for expensive instrumentation.

Characteristics of Japanese inflammatory bowel disease susceptibility loci.

Science.gov (United States)

Arimura, Yoshiaki; Isshiki, Hiroyuki; Onodera, Kei; Nagaishi, Kanna; Yamashita, Kentaro; Sonoda, Tomoko; Matsumoto, Takayuki; Takahashi, Atsushi; Takazoe, Masakazu; Yamazaki, Keiko; Kubo, Michiaki; Fujimiya, Mineko; Imai, Kohzoh; Shinomura, Yasuhisa

2014-08-01

There are substantial differences in inflammatory bowel disease (IBD) genetics depending on the populations examined. We aimed to identify Japanese population-specific or true culprit susceptibility genes through a meta-analysis of past genetic studies of Japanese IBD. For this study, we reviewed 2,703 articles. The review process consisted of three screening stages: we initially searched for relevant studies and then relevant single nucleotide polymorphisms (SNPs). Finally, we adjusted them for the meta-analysis. To maximize our chances of analysis, we introduced proxy SNPs during the first stage. To minimize publication bias, no significant SNPs and solitary SNPs without pairs were combined to be reconsidered during the third stage. Additionally, two SNPs were newly genotyped. Finally, we conducted a meta-analysis of 37 published studies in 50 SNPs located at 22 loci corresponding to the total number of 4,853 Crohn's disease (CD), 5,612 ulcerative colitis (UC) patients, and 14,239 healthy controls. We confirmed that the NKX2-3 polymorphism is associated with common susceptibility to IBD and that HLA-DRB1*0450 alleles increase susceptibility to CD but reduce risk for UC while HLA-DRB1*1502 alleles increase susceptibility to UC but reduce CD risk. Moreover, we found individual disease risk loci: TNFSF15 and TNFα to CD and HLA-B*5201, and NFKBIL1 to UC. The genetic risk of HLA was substantially high (odds ratios ranged from 1.54 to 2.69) while that of common susceptibility loci to IBD was modest (odds ratio ranged from 1.13 to 1.24). Results indicate that Japanese IBD susceptibility loci identified by the meta-analysis are closely associated with the HLA regions.

School bullying and susceptibility to smoking among never-tried cigarette smoking students.

Science.gov (United States)

Azagba, Sunday

2016-04-01

Bullying involvement has been linked with substance use; however, less is known about its relationship with pre-initiation stages of adolescent cigarette smoking behavior. This study examined the association between bullying involvement and smoking susceptibility among never tried or experimented with cigarette smoking students. Susceptibility to cigarette smoking in adolescence is a strong predictor of subsequent smoking initiation. A cross-sectional data on Canadian adolescent and youth were drawn from the 2012/2013 Youth Smoking Survey (n=28,843). Logistic regression analysis was used to examine the association between bullying and smoking susceptibility among never-smoking students. About 21% self-reported involvement in bullying (as a bully, victim or both). Middle school students (grades 6-8) reported more involvement in bullying (24%) than those in grades 9-12 (16%). The multivariable analyses showed that the association between bullying and smoking susceptibility was significantly different by grade level. Middle school students involved in bullying had higher odds of smoking susceptibility compared to uninvolved students (bully, adjusted odds ratio [AOR]=2.54, 95% CI=1.73-3.74; victim, AOR=1.29, 95% CI=1.11-1.48; bully-victim, AOR=2.19, 95% CI=1.75-2.74). There were no significant associations between all subgroups of bullying and smoking susceptibility for grades 9-12 students. Students involved in bullying were more susceptible to smoking, although patterns of association varied by grade level. In particular, the findings highlight that non-smoking middle school students involved in bullying were susceptible to future smoking. Copyright © 2016 Elsevier Inc. All rights reserved.

Allele-specific deletions in mouse tumors identify Fbxw7 as germline modifier of tumor susceptibility.

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Jesus Perez-Losada

Full Text Available Genome-wide association studies (GWAS have been successful in finding associations between specific genetic variants and cancer susceptibility in human populations. These studies have identified a range of highly statistically significant associations between single nucleotide polymorphisms (SNPs and susceptibility to development of a range of human tumors. However, the effect of each SNP in isolation is very small, and all of the SNPs combined only account for a relatively minor proportion of the total genetic risk (5-10%. There is therefore a major requirement for alternative routes to the discovery of genetic risk factors for cancer. We have previously shown using mouse models that chromosomal regions harboring susceptibility genes identified by linkage analysis frequently exhibit allele-specific genetic alterations in tumors. We demonstrate here that the Fbxw7 gene, a commonly mutated gene in a wide range of mouse and human cancers, shows allele-specific deletions in mouse lymphomas and skin tumors. Lymphomas from three different F1 hybrids show 100% allele-specificity in the patterns of allelic loss. Parental alleles from 129/Sv or Spretus/Gla mice are lost in tumors from F1 hybrids with C57BL/6 animals, due to the presence of a specific non-synonymous coding sequence polymorphism at the N-terminal portion of the gene. A specific genetic test of association between this SNP and lymphoma susceptibility in interspecific backcross mice showed a significant linkage (p = 0.001, but only in animals with a functional p53 gene. These data therefore identify Fbxw7 as a p53-dependent tumor susceptibility gene. Increased p53-dependent tumor susceptibility and allele-specific losses were also seen in a mouse skin model of skin tumor development. We propose that analysis of preferential allelic imbalances in tumors may provide an efficient means of uncovering genetic variants that affect mouse and human tumor susceptibility.

Nonlinear AC susceptibility, surface and bulk shielding

Science.gov (United States)

van der Beek, C. J.; Indenbom, M. V.; D'Anna, G.; Benoit, W.

1996-02-01

We calculate the nonlinear AC response of a thin superconducting strip in perpendicular field, shielded by an edge current due to the geometrical barrier. A comparison with the results for infinite samples in parallel field, screened by a surface barrier, and with those for screening by a bulk current in the critical state, shows that the AC response due to a barrier has general features that are independent of geometry, and that are significantly different from those for screening by a bulk current in the critical state. By consequence, the nonlinear (global) AC susceptibility can be used to determine the origin of magnetic irreversibility. A comparison with experiments on a Bi 2Sr 2CaCu 2O 8+δ crystal shows that in this material, the low-frequency AC screening at high temperature is mainly due to the screening by an edge current, and that this is the unique source of the nonlinear magnetic response at temperatures above 40 K.

Accuracy of magnetic resonance based susceptibility measurements

Science.gov (United States)

Erdevig, Hannah E.; Russek, Stephen E.; Carnicka, Slavka; Stupic, Karl F.; Keenan, Kathryn E.

2017-05-01

Magnetic Resonance Imaging (MRI) is increasingly used to map the magnetic susceptibility of tissue to identify cerebral microbleeds associated with traumatic brain injury and pathological iron deposits associated with neurodegenerative diseases such as Parkinson's and Alzheimer's disease. Accurate measurements of susceptibility are important for determining oxygen and iron content in blood vessels and brain tissue for use in noninvasive clinical diagnosis and treatment assessments. Induced magnetic fields with amplitude on the order of 100 nT, can be detected using MRI phase images. The induced field distributions can then be inverted to obtain quantitative susceptibility maps. The focus of this research was to determine the accuracy of MRI-based susceptibility measurements using simple phantom geometries and to compare the susceptibility measurements with magnetometry measurements where SI-traceable standards are available. The susceptibilities of paramagnetic salt solutions in cylindrical containers were measured as a function of orientation relative to the static MRI field. The observed induced fields as a function of orientation of the cylinder were in good agreement with simple models. The MRI susceptibility measurements were compared with SQUID magnetometry using NIST-traceable standards. MRI can accurately measure relative magnetic susceptibilities while SQUID magnetometry measures absolute magnetic susceptibility. Given the accuracy of moment measurements of tissue mimicking samples, and the need to look at small differences in tissue properties, the use of existing NIST standard reference materials to calibrate MRI reference structures is problematic and better reference materials are required.

Meta-analysis and genome-wide interpretation of genetic susceptibility to drug addiction

Science.gov (United States)

2011-01-01

Background Classical genetic studies provide strong evidence for heritable contributions to susceptibility to developing dependence on addictive substances. Candidate gene and genome-wide association studies (GWAS) have sought genes, chromosomal regions and allelic variants likely to contribute to susceptibility to drug addiction. Results Here, we performed a meta-analysis of addiction candidate gene association studies and GWAS to investigate possible functional mechanisms associated with addiction susceptibility. From meta-data retrieved from 212 publications on candidate gene association studies and 5 GWAS reports, we linked a total of 843 haplotypes to addiction susceptibility. We mapped the SNPs in these haplotypes to functional and regulatory elements in the genome and estimated the magnitude of the contributions of different molecular mechanisms to their effects on addiction susceptibility. In addition to SNPs in coding regions, these data suggest that haplotypes in gene regulatory regions may also contribute to addiction susceptibility. When we compared the lists of genes identified by association studies and those identified by molecular biological studies of drug-regulated genes, we observed significantly higher participation in the same gene interaction networks than expected by chance, despite little overlap between the two gene lists. Conclusions These results appear to offer new insights into the genetic factors underlying drug addiction. PMID:21999673

Susceptibility and resistance to deltamethrin of wild and domestic populations of Triatoma infestans (Reduviidae: Triatominae in Bolivia: new discoveries

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Stéphanie Depickère

2012-12-01

Full Text Available Bolivia is a high-endemic country for Chagas disease, for which the principal vector is Triatoma infestans (Triatominae. This is a mainly domestic species that is also found in the wild environment. Recently, an increasing number of studies have shown the importance of Triatominae resistance to insecticides, especially in Bolivia. Data regarding the susceptibility/resistance of wild and domestic populations of T. infestans to deltamethrin are presented. For the first time, domestic populations of the department of Santa Cruz were tested, showing low resistance. Although most of the wild populations were found to be susceptible to deltamethrin, three populations from three departments showed a mortality rate of less than 100%. This result is emphasised here.

Susceptibility tensor imaging and tractography of collagen fibrils in the articular cartilage.

Science.gov (United States)

Wei, Hongjiang; Gibbs, Eric; Zhao, Peida; Wang, Nian; Cofer, Gary P; Zhang, Yuyao; Johnson, G Allan; Liu, Chunlei

2017-11-01

To investigate the B 0 orientation-dependent magnetic susceptibility of collagen fibrils within the articular cartilage and to determine whether susceptibility tensor imaging (STI) can detect the 3D collagen network within cartilage. Multiecho gradient echo datasets (100-μm isotropic resolution) were acquired from fixed porcine articular cartilage specimens at 9.4 T. The susceptibility tensor was calculated using phase images acquired at 12 or 15 different orientations relative to B 0 . The susceptibility anisotropy of the collagen fibril was quantified and diffusion tensor imaging (DTI) was compared against STI. 3D tractography was performed to visualize and track the collagen fibrils with DTI and STI. STI experiments showed the distinct and significant anisotropic magnetic susceptibility of collagen fibrils within the articular cartilage. STI can be used to measure and quantify susceptibility anisotropy maps. Furthermore, STI provides orientation information of the underlying collagen network via 3D tractography. The findings of this study demonstrate that STI can characterize the orientation variation of collagen fibrils where diffusion anisotropy fails. We believe that STI could serve as a sensitive and noninvasive marker to study the collagen fibrils microstructure. Magn Reson Med 78:1683-1690, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Detection of superparamagnetic particles in soils developed on basalts using frequency- and amplitude-dependent magnetic susceptibility

Science.gov (United States)

Grison, H.; Petrovsky, E.; Kapicka, A.

2016-12-01

In rock, soil and environmental studies dealing with magnetic methods, the frequency-dependent magnetic susceptibility (κFD%) is parameter generally accepted as a tool for identification of ultrafine superparamagnetic (SP) particles. This parameter became an indicator of pedogenic magnetic fraction (increased pedogenesis). Despite the number of studies using this parameter, knowledge about threshold values of κFD% is not clear enough and this parameter may be misinterpreted. Moreover, in strongly magnetic soils, magnetic signal of the SP (mostly pedogenic) minerals may be masked by dominant lithological signal, carried by coarse-grain mineral fraction; therefore, influence of pedogenesis is hard to detect. The aim of this contribution is to compare results in determination of ultrafine SP magnetic particles in soils determined using different instruments: (a) Bartington MS2B dual-frequency meter, and (b) more sensitive AGICO Kappameter MFK1-FA. The values of the κFD % obtained by the Bartington MS2B varied from 0.9 to 5.8% (mass-specific magnetic susceptibility from 119 to 1533 × 10-8 m3/kg) while the AGICO MFK1-FA varied from 3.7 to 8.2% (mass-specific magnetic susceptibility from 295 to 1843 × 10-8 m3/kg). Although both instruments suggest significant portion of SP magnetic particles, the results can't be interpreted using the generally accepted threshold values based on Bartington data. However, our results suggest that relation between the mass-specific magnetic susceptibility and κFD% along whole soil profile may serve as suitable tool in discriminating between lithogenic and pedogenic control of magnetic fraction in the soil profile. Moreover, we propose new concept of identification of SP particles, based on field-dependent magnetic susceptibility. Its behaviour shows distinct features with significant change at amplitudes of about 100 A/m. Below this value, susceptibility decreases with increasing amplitude, reflecting saturation of magnetization due

Understanding the susceptibility to HIV of female and male students case study of LAMS school in Benin

NARCIS (Netherlands)

Kissezounnon, M.S.

2008-01-01

This research project aims to understand the factors that influence susceptibility to HIV for female and male students in LAMS (Lycee Agricole Meidji o Sekou in Benin), in order to contribute to the reduction of the phenomenon. The results of questionnaires, group discussions and interviews show the

Magnetic susceptibility as a method of investigation of short-range order in strongly nonstoichiometric carbides

International Nuclear Information System (INIS)

Nazarova, S.Z.; Gusev, A.I.

2001-01-01

Magnetic susceptibility in disordered and ordered carbides of transition metals (M = Ti, Zr, Hf, Nb, Ta) was studied, the results are generalized. It was ascertained that the change in carbide susceptibility induced by deviation from stoichiometry stems from specific features of electronic spectra of the compounds. The use of magnetic susceptibility for determining structural disorder-order transitions is discussed. It is shown that change in the contribution made by orbital paramagnetism, resulting from short-range order formation, is the reason of decrease in susceptibility of nonstoichiometric carbides during the ordering. Experimentally obtained data on susceptibility permitted evaluating short- and far-range order parameters in NbC y , TaC y , TiC y and HfC y carbides [ru

Susceptibility Testing

Science.gov (United States)

... Marker Bicarbonate (Total CO2) Bilirubin Blood Culture Blood Gases Blood Ketones Blood Smear Blood Typing Blood Urea ... hours depending on the method used. There are commercial tests available that offer rapid susceptibility testing and ...

Investigation of irradiation induced inter-granular stress corrosion cracking susceptibility on austenitic stainless steels for PWR by simulated radiation induced segregation materials

Energy Technology Data Exchange (ETDEWEB)

Yonezawa, Toshio; Fujimoto, Koji; Kanasaki, Hiroshi; Iwamura, Toshihiko [Mitsubishi Heavy Industries Ltd., Takasago R and D Center, Takasago, Hyogo (Japan); Nakada, Shizuo; Ajiki, Kazuhide [Mitsubishi Heavy Industries Ltd., Kobe Shipyard and Machinery Works, Kobe, Hyogo (Japan); Urata, Sigeru [General Office of Nuclear and Fossil Power Production, Kansai Electric Power Co., Inc., Osaka (Japan)

2000-07-01

An Irradiation Assisted Stress Corrosion Cracking (IASCC) has not been found in Pressurized Water Reactors (PWRs). However, the authors have investigated on the possibility of IASCC so as to be able to estimate the degradation of PWR plants up to the end of their lifetime. In this study, the authors melted the test alloys whose bulk compositions simulated the grain boundary compositions of irradiated Type 304 and Type 316 CW stainless steels. Low chromium, high nickel and silicon (12%Cr-28%Ni-3%Si) steel showed high susceptibility to PWSCC (Primary Water Stress Corrosion Cracking) by SSRT (Slow Strain Rate Tensile) test in simulated PWR primary water. PWSCC susceptibility of the test steels increases with a decrease of chromium content and a increase of nickel and silicon contents. The aged test steel included coherent M{sub 23}C{sub 6} carbides with matrices at the grain boundaries showed low PWSCC susceptibility. This tendency is in very good agreement with that of the PWSCC susceptibility of nickel based alloys X-750 and 690. From these results, if there is the possibility of IASCC for austenitic stainless steels in PWRs, in the future, the IASCC shall be caused by the PWSCC as a result of irradiation induced grain boundary segregation. (author)

Integration of landslide susceptibility products in the environmental plans

Science.gov (United States)

Fiorucci, Federica; Reichenbach, Paola; Rossi, Mauro; Cardinali, Mauro; Guzzetti, Fausto

2015-04-01

Landslides are one of the most destructive natural hazard that causes damages to urban area worldwide. The knowledge of where a landslide could occur is essential for the strategic management of the territory and for a good urban planning . In this contest landslide susceptibility zoning (LSZ) is crucial to provide information on the degree to which an area can be affected by future slope movements. Despite landslide susceptibility maps have been prepared extensively during the last decades, there are few examples of application is in the environmental plans (EP). In this work we present a proposal for the integration of the landslide inventory map with the following landslide susceptibility products: (i) landslide susceptibility zonation , (ii) the associated error map and (iii) the susceptibility uncertainty map. Moreover we proposed to incorporate detailed morphological studies for the evaluation of landslide risk associated to local parceling plan. The integration of all this information is crucial for the management of landslide risk in urban expansions forecasts. Municipality, province and regional administration are often not able to support the costs of landslide risk evaluation for extensive areas but should concentrate their financial resources to specific hazardous and unsafe situations defined by the result of the integration of landslide susceptibility products. Zonation and detail morphological analysis should be performed taking into account the existing laws and regulations, and could become a starting point to discuss new regulations for the landslide risk management.

Monitoring of antimicrobial susceptibility of respiratory tract pathogens isolated from diseased cattle and pigs across Europe, 2009-2012: VetPath results.

Science.gov (United States)

El Garch, Farid; de Jong, Anno; Simjee, Shabbir; Moyaert, Hilde; Klein, Ulrich; Ludwig, Carolin; Marion, Hervé; Haag-Diergarten, Silke; Richard-Mazet, Alexandra; Thomas, Valérie; Siegwart, Ed

2016-10-15

VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme that collects pathogens from diseased cattle, pigs and poultry. In the current study, 996 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 10 countries during 2009-2012. Pasteurella multocida, Mannheimia haemolytica and Histophilus somni from cattle and P. multocida, Actinobacillus pleuropneumoniae, Haemophilus parasuis, Bordetella bronchiseptica and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MIC values of 16 or 17 antibiotics were assessed centrally by broth microdilution following CLSI standards. Results were interpreted using CLSI breakpoints where available. Cattle isolates were generally highly susceptible to most antibiotics, except to tetracycline (3.0-12.0% resistance). Low levels of resistance (0-4.0%) were observed for the macrolide antibiotics. Resistance to spectinomycin varied from 0 to 6.0%. In pig isolates similar observations were made. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tulathromycin, tiamulin and tilmicosin was absent or <2%. Trimethoprim/sulfamethoxazole resistance varied from 1.9 to 5.3%, but tetracycline resistance varied from 20.4% in P. multocida to 88.1% in S. suis. For most antibiotics and pathogens the percentage resistance remained unchanged or only increased numerically as compared to that of the period 2002-2006. In conclusion, absence or low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from livestock. Comparison of all antibiotics and organisms was hampered since for almost half of the antibiotics no CLSI-defined breakpoints were available. Copyright © 2016

Glioblastomas vs. lymphomas. More diagnostic certainty by using susceptibility-weighted imaging (SWI)

Energy Technology Data Exchange (ETDEWEB)

Peters, S.; Knoess, N.; Wodarg, F.; Cnyrim, C.; Jansen, O. [Universitaetsklinikum Schleswig-Holstein, Kiel (Germany). Inst. fuer Neuroradiologie

2012-08-15

Purpose: It can be difficult to differentiate glioblastomas from lymphomas using only standard MR images. There are references suggesting that it might be possible to differentiate these tumors using susceptibility-weighted imaging (SWI). The purpose of this study is to prove the diagnostic benefit using susceptibility-weighted images. Material and Methods: Three neuroradiologists tried to differentiate 4 histologically verified lymphomas from 11 glioblastomas in retrospect. They first viewed the conventional MR images and declared a diagnosis with a grade of certainty. Afterwards they additionally reviewed the susceptibility-weighted images. Results: Glioblastomas have a clearly higher grade of susceptibility signals than lymphomas. By additionally using susceptibility-weighted images, the radiologists determined the correct diagnosis in 82.2 % of the cases. Without susceptibility-weighted images, the diagnosis was correct in 75.5 % of the cases. The subjective gain of certainty was 16.5 %. If there were no intratumoral susceptibility signals (ITSS) (grade 1), the sensitivity for diagnosing a lymphoma was 70 % and the specificity was 100 %. The sensitivity for diagnosing a glioblastoma was 90.5 % and the specificity was 100 % if there was a high rate of intratumoral susceptibility signals (grade 3). Conclusion: Susceptibility-weighted images are an additional tool in clinical practice for determining the correct diagnosis. The differentiation between glioblastomas and lymphomas and the certainty of the determined diagnosis are better. Therefore, we recommend adding susceptibility-weighted imaging to the clinical MR tumor protocol. (orig.)

Glioblastomas vs. lymphomas. More diagnostic certainty by using susceptibility-weighted imaging (SWI)

International Nuclear Information System (INIS)

Peters, S.; Knoess, N.; Wodarg, F.; Cnyrim, C.; Jansen, O.

2012-01-01

Purpose: It can be difficult to differentiate glioblastomas from lymphomas using only standard MR images. There are references suggesting that it might be possible to differentiate these tumors using susceptibility-weighted imaging (SWI). The purpose of this study is to prove the diagnostic benefit using susceptibility-weighted images. Material and Methods: Three neuroradiologists tried to differentiate 4 histologically verified lymphomas from 11 glioblastomas in retrospect. They first viewed the conventional MR images and declared a diagnosis with a grade of certainty. Afterwards they additionally reviewed the susceptibility-weighted images. Results: Glioblastomas have a clearly higher grade of susceptibility signals than lymphomas. By additionally using susceptibility-weighted images, the radiologists determined the correct diagnosis in 82.2 % of the cases. Without susceptibility-weighted images, the diagnosis was correct in 75.5 % of the cases. The subjective gain of certainty was 16.5 %. If there were no intratumoral susceptibility signals (ITSS) (grade 1), the sensitivity for diagnosing a lymphoma was 70 % and the specificity was 100 %. The sensitivity for diagnosing a glioblastoma was 90.5 % and the specificity was 100 % if there was a high rate of intratumoral susceptibility signals (grade 3). Conclusion: Susceptibility-weighted images are an additional tool in clinical practice for determining the correct diagnosis. The differentiation between glioblastomas and lymphomas and the certainty of the determined diagnosis are better. Therefore, we recommend adding susceptibility-weighted imaging to the clinical MR tumor protocol. (orig.)

MULTI-CRITERIA ANALYSIS APPLIED TO LANDSLIDE SUSCEPTIBILITY MAPPING

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Mariana Madruga de Brito

2017-10-01

Full Text Available This paper presents the application of a multi-criteria analysis (MCA tool for landslide susceptibility assessment in Porto Alegre municipality, southern Brazil. A knowledge driven approach was used, aiming to ensure an optimal use of the available information. The landslide conditioning factors considered were slope, lithology, flow accumulation and distance from lineaments. Standardization of these factors was done through fuzzy membership functions, and evaluation of their relative importance for landslide predisposition was supported by the analytic hierarchy process (AHP, based on local expert knowledge. Finally, factors were integrated in a GIS environment using the weighted linear combination (WLC method. For validation, an inventory, including 107 landslide points recorded between 2007 and 2013 was used. Results indicated that 8.2% (39.40 km² of the study area are highly and very highly susceptible to landslides. An overall accuracy of 95% was found, with an area under the receiver operating characteristic (ROC curve of 0.960. Therefore, the resulting map can be regarded as useful for monitoring landslide-prone areas. Based on the findings, it is concluded that the proposed method is effective for susceptibility assessment since it yielded meaningful results and does not require extensive input data.

New perspectives to the enterotoxigenic E. coli F4 porcine infection model: Susceptibility genotypes in relation to performance, diarrhoea and bacterial shedding.

Science.gov (United States)

Roubos-van den Hil, Petra J; Litjens, Ralph; Oudshoorn, Anna-Katharina; Resink, Jan Willem; Smits, Coen H M

2017-04-01

Enterotoxigenic E. coli (ETEC), causing post-weaning diarrhoea, is a major problem in weaned piglets. Individual animal responses to ETEC infection show high variability in animal experiments. Two studies were designed to optimize the ETEC F4ac infection model in piglets by combining the genotype susceptibility with performance, diarrhoea incidence and bacterial shedding. The studies were performed with respectively 120 and 80 male piglets that were tested for susceptibility or resistance towards ETEC O149:F4ac by a DNA marker based test. Three different genotypes were observed; resistant (RR), susceptible heterozygote (RS) and susceptible homozygote (SS). Piglets, were orally infected with an inoculum suspension (containing 1.5E8 CFU/ml ETEC F4ac) at day 0, 1 and 2 of the study. Performance, diarrhoea incidence and bacterial shedding were followed for 21days. In the first week after challenge a difference in average daily gain was observed between resistant and susceptible piglets in both studies. For the complete study period no significant differences were observed. Diarrhoea incidence was significantly higher in susceptible pigs compared to the resistant pigs in the first week after challenge. Bacterial shedding was much higher in the susceptible pigs and ETEC excretion lasted longer. ETEC was hardly detected in the faecal material of the resistant pigs. In conclusion, susceptible pigs showed higher diarrhoea incidence and higher numbers of faecal ETEC shedding in the first week after challenge compared to resistant pigs. The DNA marker based test can be used to select pigs that are susceptible for ETEC for inclusion in ETEC infection model, resulting in less animals needed to perform infection studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Magnon heat capacity and magnetic susceptibility of the spin Lieb lattice

Energy Technology Data Exchange (ETDEWEB)

Yarmohammadi, Mohsen, E-mail: m.yarmohammadi69@gamil.com

2016-11-01

Using linear response theory, Heisenberg model Hamiltonian and Green's function technique, the influences of Dzyaloshinskii–Moriya interaction (DMI), external magnetic field and next-nearest-neighbor (NNN) coupling on the density of magnon modes (DMM), the magnetic susceptibility (MS) and the magnon heat capacity (MHC) of a spin Lieb lattice, a face-centered square lattice, are investigated. The results reveal a band gap in the DMM and we witness an extension in the bandwidth and an increase in the number of van-Hove singularities as well. As a notable point, besides the magnetic nature which includes ferromagnetism in spin Lieb-based nanosystems, MS is investigated. Further, we report a Schottky anomaly in the MHC. The results show that the effects of the magnetic field on the MHC and MS have different behaviors in two temperature regions. In the low temperature region, MHC and MS increase when the magnetic field strength increases. On the other hand, the MHC and MS reduce with increasing the magnetic field strength in the high temperature region. Also comprehensive numerical modelling of the DMM, the MS and the MHC of a spin Lieb lattice yields excellent qualitative agreement with the experimental data. - Highlights: • Theoretical calculation of density of states of the spin Lieb lattice. • The investigation of the effect of external magnetic field on the magnon heat capacity and magnetic susceptibility. • The investigation of the effect of NNN coupling and the DMI strength on the magnon heat capacity and magnetic susceptibility.

Relationship between antimicrobial susceptibility of clinical mastitis pathogens and treatment outcome in cows.

Science.gov (United States)

Hoe, Fernanda G H; Ruegg, Pamela L

2005-11-01

To determine whether there was any association between results of in vitro antimicrobial susceptibility testing of pathogens isolated from cows with mild or moderate clinical mastitis and outcome of treatment. Observational study. 133 cows with mild or moderate mastitis in a single quarter. Cows were treated by means of intramammary infusion of pirlimycin (50 mg) in the affected quarter once daily for 2 days; additional intramammary treatments with the same product were administered if the milk continued to appear abnormal. Duration of treatment and days until clinical cure were recorded. Bacterial isolates were tested for antimicrobial susceptibility by means of a broth micro-dilution technique. Environmental streptococci, coliforms, and coagulase-negative Staphylococcus spp were the most commonly isolated pathogens. Duration of treatment and days until clinical cure were not significantly different for cows from which pathogens that were susceptible or resistant to pirlimycin were isolated. Bacteriologic cure rates 14 and 21 days after treatment were not significantly different for cows with mastitis caused by susceptible or resistant bacteria. Similar results were found when data only from cows with mastitis caused by gram-positive isolates were analyzed. In the present study, differences in clinical outcome for cows with mild or moderate mastitis that could be attributed to differences in results of in vitro susceptibility testing were not identified. The use of in vitro susceptibility testing to guide intramammary mastitis treatment cannot be recommended on the basis of results of this study.

Susceptibility of pathogenic and nonpathogenic Naegleria ssp

International Nuclear Information System (INIS)

Whiteman, L.Y.

1988-01-01

The susceptibility of four species of Naegleria amoebae to complement-mediated lysis was determined. The amoebicidal activity of normal human serum (NHS) and normal guinea pig serum (NGPS) for Naegleria amoebae was measured by an in vitro cytotoxicity assay. Release of radioactivity from amoebae labeled with 3 H-uridine and visual observation with a compound microscope were used as indices of lysis. Susceptibility or resistance to complement-mediated lysis in vitro correlated with the in vivo pathogenic potential. Nonpathogenic Naegleria amoebae were lysed at a faster rate and at higher cell concentrations than were pathogenic amoebae. Electrophoretic analysis of NHS incubated with pathogenic or nonpathogenic Naegleria spp. demonstrated that amoebae activate the complement cascade resulting in the production of C3 and C5 complement cleavage products. Treatment with papain or trypsin for 1 h, but not with sialidase, increase the susceptibility of highly pathogenic, mouse-passaged N. fowleri to lysis. Treatment with actinomycin D, cycloheximide or various protease inhibitors for 4 h did not increase susceptibility to lysis. Neither a repair process involving de novo protein synthesis nor a complement-inactivating protease appear to account for the increase resistance of N. fowleri amoebae to complement-mediated lysis. A binding study with 125 I radiolabeled C9 indicated that the terminal complement component does not remain stably bound to the membrane of pathogenic amoebae

A fast, simple method for screening radiation susceptibility genes by RNA interference

International Nuclear Information System (INIS)

Tsuji, Atsushi B.; Sudo, Hitomi; Sugyo, Aya; Otsuki, Marika; Miyagishi, Makoto; Taira, Kazunari; Imai, Takashi; Harada, Yoshi-nobu

2005-01-01

Radiotherapy can cause unacceptable levels of damage to normal tissues in some cancer patients. To understand the molecular mechanisms underlying radiation-induced physiological responses, and to be able to predict the radiation susceptibility of normal tissues in individual patients, it is important to identify a comprehensive set of genes responsible for radiation susceptibility. We have developed a simple and rapid 96-well screening protocol using cell proliferation assays and RNA interference to identify genes associated with radiation susceptibility. We evaluated the performance of alamarBlue-, BrdU-, and sulforhodamine B-based cell proliferation assays using the 96-well format. Each proliferation assay detected the known radiation susceptibility gene, PRKDC. In a trial screen using 28 shRNA vectors, another known gene, CDKN1A, and one new radiation susceptibility gene, ATP5G3, were identified. Our results indicate that this method may be useful for large-scale screens designed to identify novel radiation susceptibility genes

Influence of delta ferrite on corrosion susceptibility of AISI 304 austenitic stainless steel

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Lawrence O. Osoba

2016-12-01

Full Text Available In the current study, the influence of delta (δ ferrite on the corrosion susceptibility of AISI 304 austenitic stainless steel was evaluated in 1Molar concentration of sulphuric acid (H2SO4 and 1Molar concentration of sodium chloride (NaCl. The study was performed at ambient temperature using electrochemical technique—Tafel plots to evaluate the corrosive tendencies of the austenitic stainless steel sample. The as-received (stainless steel specimen and 60% cold-worked (stainless steel specimens were isothermally annealed at 1,100°C for 2 h and 1 h, respectively, and quenched in water. The results obtained show that the heat-treated specimen and the 60% cold-worked plus heat-treated specimen exhibited higher corrosion susceptibility than the as-received specimen, which invariably contained the highest fraction of δ ferrite particles. The finding shows that the presence of δ ferrite, in which chromium (Cr, the main corrosion inhibitor segregates, does not degrade and or reduces the resistance to aqueous corrosion of the austenitic stainless steel material.

antimicrobial susceptibility pattern of urinary pathogens isolated ...

African Journals Online (AJOL)

boaz

Conclusion: This study justifies the necessity to treat patients with UTI based on antimicrobial susceptibility test result in order ... colonization of the urine and symptomatic infection ... indicated a high incidence of UTIs (54%) in pregnant women ...

A multiplex single nucleotide polymorphism typing assay for detecting mutations that result in decreased fluoroquinolone susceptibility in Salmonella enterica serovars Typhi and Paratyphi A.

LENUS (Irish Health Repository)

Song, Yajun

2010-08-01

OBJECTIVES: Decreased susceptibility to fluoroquinolones has become a major problem for the successful therapy of human infections caused by Salmonella enterica, especially the life-threatening typhoid and paratyphoid fevers. METHODS: By using Luminex xTAG beads, we developed a rapid, reliable and cost-effective multiplexed genotyping assay for simultaneously detecting 11 mutations in gyrA, gyrB and parE of S. enterica serovars Typhi and Paratyphi A that result in nalidixic acid resistance (Nal(R)) and\\/or decreased susceptibility to fluoroquinolones. RESULTS: This assay yielded unambiguous single nucleotide polymorphism calls on extracted DNA from 292 isolates of Salmonella Typhi (Nal(R) = 223 and Nal(S) = 69) and 106 isolates of Salmonella Paratyphi A (Nal(R) = 24 and Nal(S) = 82). All of the 247 Nal(R) Salmonella Typhi and Salmonella Paratyphi A isolates were found to harbour at least one of the target mutations, with GyrA Phe-83 as the most common one (143\\/223 for Salmonella Typhi and 18\\/24 for Salmonella Paratyphi A). We also identified three GyrB mutations in eight Nal(S) Salmonella Typhi isolates (six for GyrB Phe-464, one for GyrB Leu-465 and one for GyrB Asp-466), and mutations GyrB Phe-464 and GyrB Asp-466 seem to be related to the decreased ciprofloxacin susceptibility phenotype in Salmonella Typhi. This assay can also be used directly on boiled single colonies. CONCLUSIONS: The assay presented here would be useful for clinical and reference laboratories to rapidly screen quinolone-resistant isolates of Salmonella Typhi and Salmonella Paratyphi A, and decipher the underlying genetic changes for epidemiological purposes.

Methylation of 23S rRNA nucleotide G748 by RlmAII methyltransferase renders Streptococcus pneumoniae telithromycin susceptible.

Science.gov (United States)

Takaya, Akiko; Sato, Yoshiharu; Shoji, Tatsuma; Yamamoto, Tomoko

2013-08-01

Several posttranscriptional modifications of bacterial rRNAs are important in determining antibiotic resistance or sensitivity. In all Gram-positive bacteria, dimethylation of nucleotide A2058, located in domain V of 23S rRNA, by the dimethyltransferase Erm(B) results in low susceptibility and resistance to telithromycin (TEL). However, this is insufficient to produce high-level resistance to TEL in Streptococcus pneumoniae. Inactivation of the methyltransferase RlmA(II), which methylates the N-1 position of nucleotide G748, located in hairpin 35 of domain II of 23S rRNA, results in increased resistance to TEL in erm(B)-carrying S. pneumoniae. Sixteen TEL-resistant mutants (MICs, 16 to 32 μg/ml) were obtained from a clinically isolated S. pneumoniae strain showing low TEL susceptibility (MIC, 2 μg/ml), with mutation resulting in constitutive dimethylation of A2058 because of nucleotide differences in the regulatory region of erm(B) mRNA. Primer extension analysis showed that the degree of methylation at G748 in all TEL-resistant mutants was significantly reduced by a mutation in the gene encoding RlmA(II) to create a stop codon or change an amino acid residue. Furthermore, RNA footprinting with dimethyl sulfate and a molecular modeling study suggested that methylation of G748 may contribute to the stable interaction of TEL with domain II of 23S rRNA, even after dimethylation of A2058 by Erm(B). This novel finding shows that methylation of G748 by RlmA(II) renders S. pneumoniae TEL susceptible.

Magnetic susceptibility of sodium disilicate glasses containing PuO2

International Nuclear Information System (INIS)

Aldred, A.T.

1979-01-01

A solubility limit of approx. 6 mol % PuO 2 in sodium disilicate (Na 2 O.2SiO 2 ) glass has been determined. Magnetic susceptibility measurements on these glasses yield approximate Curie-Weiss behavior, in contrast to the temperature-independent susceptibility of crystalline PuO 2 . This result is interpreted to indicate that the local site symmetry around the Pu ion in the sodium disilicate glass is much different than in crystalline PuO 2 . The effective paramagnetic moments determined from the temperature dependence of the susceptibility are found to be consistent with calculated free-ion values based on the most likely 5f electron configurations

Risk of leukemia in susceptible children exposed to preconception, in utero, and postnatal radiation

International Nuclear Information System (INIS)

Bross, I.D.J.; Natarajan, N.

1974-01-01

Further statistical analysis has clarified the hypothesis that there exists a susceptible subgroup of children who are prone to develop leukemia after exposure to low doses of diagnostic radiation which have no effect on normal insusceptible children. The susceptible group does not show marked increase in relative risk when there is no report of exposure. The risk of developing leukemia among the susceptible children with any of the three types of radiation exposure is markedly increased in the appropriate age groups. The data are concordant with a latent period of 4 to 7 years. (auth)

Bacteriology of diabetic foot in tertiary care hospital; frequency, antibiotic susceptibility and risk factors

International Nuclear Information System (INIS)

Amjad, S.S.; Shams, N.

2017-01-01

Diabetic foot being one of the frequent and disabling complications of diabetes. In view of widespread regional variation in causative organisms and antimicrobial susceptibility, the current study aimed to determine frequency of causative organisms, their antimicrobial susceptibility and associated risk factors. Methods: This descriptive cross-sectional study was conducted in 6 months' duration at dept. of Medicine; PIMS Hospital Islamabad. Type 2 Diabetes mellitus patients with diabetic foot ulcer were enrolled after informed consent. Patients already receiving antibiotics, having no growth on culture and >3 weeks' duration of ulcer were excluded. Sample from wound was sent for culture and sensitivity. Antibiotic susceptibility testing identified the susceptible and resistant strains of organisms. Results: Among 114 patients (66.67% males and 33.33% females); mean age was 55.11+-11.96 years. Staphylococcus aureus was identified in 46%, E. coli in 28%, Pseudomonas in 6%, Klebsiella in 3.5% and other organisms in 17%. 92% of S. aureus was sensitive to Vancomycin and 67% to Clindamycin. Amongst E. coli, 81% showed sensitivity to Imipenem, 69% to Aminoglycosides and 31% to Quinolones. Glycaemic control was unsatisfactory in 65.8%. Peripheral vascular disease was found in 46% patients and sensory neuropathy in 94%. Conclusion: Staphylococcus aureus was the most frequent isolate amongst gram positive organisms while E. coli amongst gram-negatives. Vancomycin is suggested to be the drug of choice for gram positive and Imipenem for gram negative organisms. Appropriate antimicrobial therapy according to susceptibility patterns would reduce the morbidity and emergence of multidrug resistant organisms in diabetic foot infections. (author)

Multisite reproducibility of the broth microdilution method for susceptibility testing of Nocardia species.

Science.gov (United States)

Conville, Patricia S; Brown-Elliott, Barbara A; Wallace, Richard J; Witebsky, Frank G; Koziol, Deloris; Hall, Geraldine S; Killian, Scott B; Knapp, Cindy C; Warshauer, David; Van, Tam; Wengenack, Nancy L; Deml, Sharon; Woods, Gail L

2012-04-01

Antimicrobial susceptibility testing (AST) of clinical isolates of Nocardia is recommended to detect resistance to commonly used antimicrobial agents; such testing is complicated by difficulties in inoculum preparation and test interpretation. In this study, six laboratories performed repetitive broth microdilution testing on single strains of Nocardia brasiliensis, Nocardia cyriacigeorgica, Nocardia farcinica, Nocardia nova, and Nocardia wallacei. For each isolate, a total of 30 microdilution panels from three different lots were tested at most sites. The goal of the study was to determine the inter- and intralaboratory reproducibility of susceptibility testing of this group of isolates. Acceptable agreement (>90% agreement at ±1 dilution of the MIC mode) was found for amikacin, ciprofloxacin, clarithromycin, and moxifloxacin. After eliminating MIC values from single laboratories whose results showed the greatest deviation from those of the remaining laboratories, acceptable agreement was also found for amoxicillin-clavulanic acid, linezolid, minocycline, and tobramycin. Results showed unsatisfactory reproducibility of broth microdilution testing of ceftriaxone with N. cyriacigeorgica and N. wallacei, tigecycline with N. brasiliensis and N. cyriacigeorgica, and sulfonamides with N. farcinica and N. wallacei. N. nova ATCC BAA-2227 is proposed as a quality control organism for AST of Nocardia sp., and the use of a disk diffusion test for sulfisoxazole is proposed as a check of the adequacy of the inoculum and to confirm sulfonamide MIC results.

On the susceptibility of adaptive memory to false memory illusions.

Science.gov (United States)

Howe, Mark L; Derbish, Mary H

2010-05-01

Previous research has shown that survival-related processing of word lists enhances retention for that material. However, the claim that survival-related memories are more accurate has only been examined when true recall and recognition of neutral material has been measured. In the current experiments, we examined the adaptive memory superiority effect for different types of processing and material, measuring accuracy more directly by comparing true and false recollection rates. Survival-related information and processing was examined using word lists containing backward associates of neutral, negative, and survival-related critical lures and type of processing (pleasantness, moving, survival) was varied using an incidental memory paradigm. Across four experiments, results showed that survival-related words were more susceptible than negative and neutral words to the false memory illusion and that processing information in terms of its relevance to survival independently increased this susceptibility to the false memory illusion. Overall, although survival-related processing and survival-related information resulted in poorer, not more accurate, memory, such inaccuracies may have adaptive significance. These findings are discussed in the context of false memory research and recent theories concerning the importance of survival processing and the nature of adaptive memory. Copyright 2009 Elsevier B.V. All rights reserved.

Biofilm antifungal susceptibility of Candida urine isolated from ambulatory patients

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Débora da Luz Becker

2016-07-01

Full Text Available Background and Objectives: the association between the biofilm formations an antifungal resistance has been suggested to be an important factor in the pathogenesis of several Candida species. Besides, studies have included invasive candidiasis from hospitalized patients; however there are few studies that evaluated the species distribution, antifungal susceptibility and biofilm formation of Candida species isolated from ambulatory patients. Thus, the aim of this study was to evaluate whether biofilm producing contributes to antifungal resistance in Candida isolates from urine sample obtained from ambulatory patients. Methods: During one year, 25 urine samples positive for yeast were collected, stored and plated on agar supplemented with chloramphenicol and Sabouread left at room temperature for 5 days for subsequent: 52% (13/25 were C. albicans, 36% (9/25 C. tropicalis, 8% (2/25 C. krusei and 4% (1/25 C. parapsilosis. Results: The ability to form biofilm was detected in 23 (92% of the yeast studied and 15.4% (2/13 of C. albicans were fluconazole (FLU and ketoconazole (KET resistant, while 11.1% (1/9 of C. tropicalis were ketoconazole resistant and were anidulafungin (ANI non-susceptible. Conclusion: our results showed the high capacity for biofilm formation among Candida isolates from ambulatory patients.

Insecticide susceptibility status and major detoxifying enzymes' activity in Aedes albopictus (Skuse), vector of dengue and chikungunya in Northern part of West Bengal, India.

Science.gov (United States)

Bharati, Minu; Saha, Dhiraj

2017-06-01

Mosquitoes belonging to Aedes genus, Aedes aegypti and Aedes albopictus transmit many globally important arboviruses including Dengue (DENV) and Chikungunya (CHIKV). Vector control with the use of insecticide remains the suitable method of choice to stop the transmission of these diseases. However, vector control throughout the world is failing to achieve its target results because of the worldwide development of insecticide resistance in mosquitoes. To assess the insecticide susceptibility status of Aedes albopictus from northern part of West Bengal, the susceptibility of eight different Aedes albopictus populations were tested against a commonly used larvicide (temephos) and some adulticides (malathion, deltamethrin and lambda cyhalothrin) along with the major insecticide detoxifying enzymes' activity in them. Through this study, it was revealed that most of the populations were found susceptible to temephos except Nagrakata (NGK) and Siliguri (SLG), which showed both a higher resistance ratio (RR 99 ) and a lower susceptibility, thereby reflecting the development of resistance against temephos in them. However, all tested adulticides caused 100% mortality in all the population implying their potency in control of this mosquito in this region of India. Through the study of carboxylesterase activity, it was revealed that the NGK population showed a 9.6 fold higher level of activity than susceptible population. The same population also showed a lower level of susceptibility and a higher resistance ratio (RR 99 ), indicating a clear correlation between susceptibility to temephos and carboxylesterase enzymes' activity in this population. This preliminary data reflects that the NGK population is showing a trend towards resistance development and with time, there is possibility that this resistance phenomenon will spread to other populations. With the recurrence of dengue and chikungunya, this data on insecticide susceptibility status of Aedes albopictus could help the

Scalar and pseudoscalar susceptibilities in nuclei

International Nuclear Information System (INIS)

Ericson, Magda; Chanfray, Guy; Chanfray, Guy

2003-01-01

We study the two QCD susceptibilities of the nuclear medium in the linear σ model. The magnitude of the scalar one increases due to the mixing with the softer modes of the nucleon-hole excitations. The pseudoscalar susceptibility, follows the density evolution of the quark condensate and thus decreases in magnitude. At normal nuclear matter density the two susceptibilities become much close than in the vacuum, a consequence of the partial chiral symmetry restoration. (author)

Differential Susceptibility Experiments: Going beyond Correlational Evidence--Comment on beyond Mental Health, Differential Susceptibility Articles

Science.gov (United States)

van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.

2012-01-01

Reviewing the studies on differential susceptibility presented in this section, we argue that the time is ripe to go beyond correlational designs to differential susceptibility experiments. In such experiments, randomization prevents hidden moderator effects on the environment and guarantees the independence of moderator and outcome, while the…

Susceptibility of Aeromonas Hydophila Isolates to Antimicrobial Drugs

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Igor Stojanov

2010-05-01

Full Text Available Aeromonas hydrophila is a microorganism widely distributed in nature: in water, soil, food. It is also part of the normal bacterial flora of many animals. As an opportune microorganism it is a secondary biological agent that contributes to the occurrence of a fish disease and its deterioration. Frequently, its presence is an indication of bad zoohygiene and zootechnical conditions in fish ponds. Reduced quality and quantity of feed, mechanical injuries, parasitosis, seasonal oscillation in temperature present some of the factors that produce favorable conditions for bacterial proliferation of aeromonas in fish ponds, so clinical symptoms of the disease occur. Aeromonas is almost always present in clinical isolates and may be unjustly accused for bad health of fish. Antibiotic therapy is applied even when the clinical findings are clear, what certainly effects the susceptibility to chemotherapeutics. The subject of our work was bacteriological examination of the material obtained from the carps with the observed skin changes and the carps without these changes. Also, antimicrobial susceptibility of Aeromonas hydrophila was tested. The aim of this research was to determined the presence of Aeromonas hydrophilia in the carp ponds and to test antibiotic susceptibility. The material consisted of the samples from the fish ponds where the carps were with and without changed skin. The method the isolation of Aeromonas hydrophila was used. The diffusion disk technique was used for testing antibiotic susceptibility. The isolates were tested for their susceptibility to Florephenikol, Flumequine, Olaqindox and Oxitetracycline. The obtained results point that antimicrobial susceptibility was the same regardless of the origin of the samples, i.e. the resistance was the same for both groups of samples (the strains isolated from the fish with skin changes and the strains from fish without changes on skin. The strains were highly resistant: 35% were resistant to

Simple Sample Preparation Method for Direct Microbial Identification and Susceptibility Testing From Positive Blood Cultures

Directory of Open Access Journals (Sweden)

Hong-wei Pan

2018-03-01

Full Text Available Rapid identification and determination of the antibiotic susceptibility profiles of the infectious agents in patients with bloodstream infections are critical steps in choosing an effective targeted antibiotic for treatment. However, there has been minimal effort focused on developing combined methods for the simultaneous direct identification and antibiotic susceptibility determination of bacteria in positive blood cultures. In this study, we constructed a lysis-centrifugation-wash procedure to prepare a bacterial pellet from positive blood cultures, which can be used directly for identification by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS and antibiotic susceptibility testing by the Vitek 2 system. The method was evaluated using a total of 129 clinical bacteria-positive blood cultures. The whole sample preparation process could be completed in <15 min. The correct rate of direct MALDI-TOF MS identification was 96.49% for gram-negative bacteria and 97.22% for gram-positive bacteria. Vitek 2 antimicrobial susceptibility testing of gram-negative bacteria showed an agreement rate of antimicrobial categories of 96.89% with a minor error, major error, and very major error rate of 2.63, 0.24, and 0.24%, respectively. Category agreement of antimicrobials against gram-positive bacteria was 92.81%, with a minor error, major error, and very major error rate of 4.51, 1.22, and 1.46%, respectively. These results indicated that our direct antibiotic susceptibility analysis method worked well compared to the conventional culture-dependent laboratory method. Overall, this fast, easy, and accurate method can facilitate the direct identification and antibiotic susceptibility testing of bacteria in positive blood cultures.

Mapping Magnetic Susceptibility Anisotropies of White Matter in vivo in the Human Brain at 7 Tesla

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Li, Xu; Vikram, Deepti S; Lim, Issel Anne L; Jones, Craig K; Farrell, Jonathan A.D.; van Zijl, Peter C. M.

2012-01-01

High-resolution magnetic resonance phase- or frequency- shift images acquired at high field show contrast related to magnetic susceptibility differences between tissues. Such contrast varies with the orientation of the organ in the field, but the development of quantitative susceptibility mapping (QSM) has made it possible to reproducibly image the intrinsic tissue susceptibility contrast. However, recent studies indicate that magnetic susceptibility is anisotropic in brain white matter and, as such, needs to be described by a symmetric second-rank tensor (χ¯¯). To fully determine the elements of this tensor, it would be necessary to acquire frequency data at six or more orientations. Assuming cylindrical symmetry of the susceptibility tensor in myelinated white matter fibers, we propose a simplified method to reconstruct the susceptibility tensor in terms of a mean magnetic susceptibility, MMS = (χ∥ + 2χ⊥)/3 and a magnetic susceptibility anisotropy, MSA = χ∥ − χ⊥, where χ∥ and χ⊥ are susceptibility parallel and perpendicular to the white matter fiber direction, respectively. Computer simulations show that with a practical head rotation angle of around 20°–30°, four head orientations suffice to reproducibly reconstruct the tensor with good accuracy. We tested this approach on whole brain 1×1×1 mm3 frequency data acquired from five healthy subjects at 7 T. The frequency information from phase images collected at four head orientations was combined with the fiber direction information extracted from diffusion tensor imaging (DTI) to map the white matter susceptibility tensor. The MMS and MSA were quantified for regions in several large white matter fiber structures, including the corona radiata, posterior thalamic radiation and corpus callosum. MMS ranged from −0.037 to −0.053 ppm (referenced to CSF being about zero). MSA values could be quantified without the need for a reference and ranged between 0.004 and 0.029 ppm, in line with

Phosphorylcholine impairs susceptibility to biofilm formation of hydrogel contact lenses.

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Selan, Laura; Palma, Stefano; Scoarughi, Gian Luca; Papa, Rosanna; Veeh, Richard; Di Clemente, Daniele; Artini, Marco

2009-01-01

To compare silicone-hydrogel, poly(2-hydroxyethyl methacrylate) (pHEMA), and phosphorylcholine-coated (PC-C) contact lenses in terms of their susceptibility to biofilm formation by Staphylococcus epidermidis and Pseudomonas aeruginosa. Laboratory investigation. Biofilm formation on colonized test lenses was evaluated with confocal microscopy and in vitro antibiotic susceptibility assays. The results of the latter assays were compared with those performed on planktonic cultures of the same organism. For both microorganisms, sessile colonies on silicone-hydrogel and pHEMA lenses displayed lower antibiotic susceptibility than their planktonic counterparts. In contrast, the susceptibility of cultures growing on PC-C lenses was comparable with that for planktonic cultures. In particular, minimum inhibitory concentration for Tazocin (piperacillin plus tazobactam; Wyeth Pharmaceuticals, Aprilia, Italy; S. epidermidis) and gentamicin (P. aeruginosa) was identical, either in the presence of PC-C support or in planktonic cultures (Tazocin, aeruginosa) was two-fold higher for PC-C lenses (0.4 mug/ml) with respect to planktonic cultures (0.2 mug/ml). Confocal microscopy of lenses colonized for 24 hours with P. aeruginosa green fluorescent protein-expressing cells revealed a sessile colonization on silicone-hydrogel lens and a few isolated bacterial cells scattered widely over the surface of the PC-C lens. An increase in antibiotic susceptibility of bacterial cultures was associated with diminished bacterial adhesion. Our results indicate that PC-C lenses seem to be more resistant than silicone-hydrogel and pHEMA lenses to bacterial adhesion and colonization. This feature may facilitate their disinfection.

Landslide susceptibility assessment using logistic regression and its comparison with a rock mass classification system, along a road section in the northern Himalayas (India)

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Das, Iswar; Sahoo, Sashikant; van Westen, Cees; Stein, Alfred; Hack, Robert

2010-02-01

Landslide studies are commonly guided by ground knowledge and field measurements of rock strength and slope failure criteria. With increasing sophistication of GIS-based statistical methods, however, landslide susceptibility studies benefit from the integration of data collected from various sources and methods at different scales. This study presents a logistic regression method for landslide susceptibility mapping and verifies the result by comparing it with the geotechnical-based slope stability probability classification (SSPC) methodology. The study was carried out in a landslide-prone national highway road section in the northern Himalayas, India. Logistic regression model performance was assessed by the receiver operator characteristics (ROC) curve, showing an area under the curve equal to 0.83. Field validation of the SSPC results showed a correspondence of 72% between the high and very high susceptibility classes with present landslide occurrences. A spatial comparison of the two susceptibility maps revealed the significance of the geotechnical-based SSPC method as 90% of the area classified as high and very high susceptible zones by the logistic regression method corresponds to the high and very high class in the SSPC method. On the other hand, only 34% of the area classified as high and very high by the SSPC method falls in the high and very high classes of the logistic regression method. The underestimation by the logistic regression method can be attributed to the generalisation made by the statistical methods, so that a number of slopes existing in critical equilibrium condition might not be classified as high or very high susceptible zones.

[Antimicrobial susceptibility in Chile 2012].

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Cifuentes-D, Marcela; Silva, Francisco; García, Patricia; Bello, Helia; Briceño, Isabel; Calvo-A, Mario; Labarca, Jaime

2014-04-01

Bacteria antimicrobial resistance is an uncontrolled public health problem that progressively increases its magnitude and complexity. The Grupo Colaborativo de Resistencia, formed by a join of experts that represent 39 Chilean health institutions has been concerned with bacteria antimicrobial susceptibility in our country since 2008. In this document we present in vitro bacterial susceptibility accumulated during year 2012 belonging to 28 national health institutions that represent about 36% of hospital discharges in Chile. We consider of major importance to report periodically bacteria susceptibility so to keep the medical community updated to achieve target the empirical antimicrobial therapies and the control measures and prevention of the dissemination of multiresistant strains.

Involvement of salicylic acid, ethylene and jasmonic acid signalling pathways in the susceptibility of tomato to Fusarium oxysporum.

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Di, Xiaotang; Gomila, Jo; Takken, Frank L W

2017-09-01

Phytohormones, such as salicylic acid (SA), ethylene (ET) and jasmonic acid (JA), play key roles in plant defence following pathogen attack. The involvement of these hormones in susceptibility following Fusarium oxysporum (Fo) infection has mostly been studied in Arabidopsis thaliana. However, Fo causes vascular wilt disease in a broad range of crops, including tomato (Solanum lycopersicum). Surprisingly little is known about the involvement of these phytohormones in the susceptibility of tomato towards Fo f. sp. lycopersici (Fol). Here, we investigate their involvement by the analysis of the expression of ET, JA and SA marker genes following Fol infection, and by bioassays of tomato mutants affected in either hormone production or perception. Fol inoculation triggered the expression of SA and ET marker genes, showing the activation of these pathways. NahG tomato, in which SA is degraded, became hypersusceptible to Fol infection and showed stronger disease symptoms than wild-type. In contrast, ACD and Never ripe (Nr) mutants, in which ET biosynthesis and perception, respectively, are impaired, showed decreased disease symptoms and reduced fungal colonization on infection. The susceptibility of the def1 tomato mutant, and a prosystemin over-expressing line, in which JA signalling is compromised or constitutively activated, respectively, was unaltered. Our results show that SA is a negative and ET a positive regulator of Fol susceptibility. The SA and ET signalling pathways appear to act synergistically, as an intact ET pathway is required for the induction of an SA marker gene, and vice versa. © 2017 THE AUTHORS. MOLECULAR PLANT PATHOLOGY PUBLISHED BY BRITISH SOCIETY FOR PLANT PATHOLOGY AND JOHN WILEY & SONS LTD.

Evaluating performance of simplified physically based models for shallow landslide susceptibility

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G. Formetta

2016-11-01

Full Text Available Rainfall-induced shallow landslides can lead to loss of life and significant damage to private and public properties, transportation systems, etc. Predicting locations that might be susceptible to shallow landslides is a complex task and involves many disciplines: hydrology, geotechnical science, geology, hydrogeology, geomorphology, and statistics. Two main approaches are commonly used: statistical or physically based models. Reliable model applications involve automatic parameter calibration, objective quantification of the quality of susceptibility maps, and model sensitivity analyses. This paper presents a methodology to systemically and objectively calibrate, verify, and compare different models and model performance indicators in order to identify and select the models whose behavior is the most reliable for particular case studies.The procedure was implemented in a package of models for landslide susceptibility analysis and integrated in the NewAge-JGrass hydrological model. The package includes three simplified physically based models for landslide susceptibility analysis (M1, M2, and M3 and a component for model verification. It computes eight goodness-of-fit indices by comparing pixel-by-pixel model results and measurement data. The integration of the package in NewAge-JGrass uses other components, such as geographic information system tools, to manage input–output processes, and automatic calibration algorithms to estimate model parameters. The system was applied for a case study in Calabria (Italy along the Salerno–Reggio Calabria highway, between Cosenza and Altilia. The area is extensively subject to rainfall-induced shallow landslides mainly because of its complex geology and climatology. The analysis was carried out considering all the combinations of the eight optimized indices and the three models. Parameter calibration, verification, and model performance assessment were performed by a comparison with a detailed landslide

Xenopsylla cheopis (Siphonaptera: Pulicidae susceptibility to Deltamethrin in Madagascar.

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Sebastien Boyer

Full Text Available The incidence of bubonic plague in Madagascar is high. This study reports the susceptibility of 32 different populations of a vector, the flea Xenopsylla cheopis (Siphonaptera: Pulicidae, to the insecticide Deltamethrin. Despite the use of Deltamethrin against fleas, plague epidemics have re-emerged in Madagascar. The majority of the study sites were located in the Malagasy highlands where most plague cases have occurred over the last 10 years. X. cheopis fleas were tested for susceptibility to Deltamethrin (0.05%: only two populations were susceptible to Deltamethrin, four populations were tolerant and 26 populations were resistant. KD50 (50% Knock-Down and KD90 (90% Knock-Down times were determined, and differed substantially from 9.4 to 592.4 minutes for KD50 and 10.4 min to 854.3 minutes for KD90. Susceptibility was correlated with latitude, but not with longitude, history of insecticide use nor date of sampling. Combined with the number of bubonic plague cases, our results suggest that an immediate switch to an insecticide other than Deltamethrin is required for plague vector control in Madagascar.

Van Vleck temperature independent susceptibilities in the rare earth double nitrates

International Nuclear Information System (INIS)

Commander, R.J.; Finn, C.B.P.

1978-01-01

Measurements of the magnetic susceptibilities between 4.2 and 1.1 K of the rare earth zinc nitrates are reported. It is shown that the results for the Van Vleck temperature independent susceptibilities for cerium magnesium nitrate and cerium zinc nitrate are consistent with the published low lying level schemes for these two salts. (author)

Serological Susceptibility to Varicella Among U.S. Immigration and Customs Enforcement Detainees.

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Varan, Aiden K; Lederman, Edith R; Stous, Shanon S; Elson, Diana; Freiman, Jennifer L; Marin, Mona; Lopez, Adriana S; Stauffer, William M; Joseph, Rachael H; Waterman, Stephen H

2018-01-01

U.S. Immigration and Customs Enforcement (ICE) is responsible for detaining unauthorized aliens during immigration proceedings. During 2014 to 2015, adult ICE detainees at a California facility were invited to complete a survey concerning self-reported varicella history and risk factors. Participants underwent serological testing for varicella-zoster virus (VZV) IgG; susceptible individuals were offered varicella vaccination. Among 400 detainees with available serology results, 48 (12%) were susceptible to varicella. Self-reported varicella history was negatively associated with susceptibility (adjusted odds ratio = 0.16; 95% confidence interval [0.07, 0.35]). Among 196 detainees reporting a positive history, 95% had VZV IgG levels suggestive of varicella immunity. Among 44 susceptible detainees offered vaccination, 86% accepted. Given relatively high varicella susceptibility, targeted screening and vaccination among ICE detainees lacking a positive history might reduce varicella transmission risks.

Differential fipronil susceptibility and metabolism in two rice stem borers from China.

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Fang, Qi; Huang, Cheng-Hua; Ye, Gong-Yin; Yao, Hong-Wei; Cheng, Jia-An; Akhtar, Zunnu-Raen

2008-08-01

The susceptibilities of larvae of two rice stem borers, namely, Chilo suppressalis (Walker) (Lepidoptera: Crambidae) and Sesamia inferens (Walker) (Lepidoptera: Nocutidae) to fipronil and its metabolites were investigated, and then the activities of microsomal O-demethylase, and glutathione transferase (GST) in two species were measured. The metabolism of fipronil in both stem borers was determined in vivo and in vitro. The LD50 value of fipronil to S. inferens was 118.5-fold higher than that of C. suppressalis. The bioassay results offipronil metabolites showed that the toxicities of sulfone and sulfide were higher than fipronil for both species, and the differential toxicity between sulfone and fipronil was remarkable. Alternatively, the activities of microsomal O-demethylase and GST of C. suppressalis were 1.35- and 2.06-fold higher than S. inferens, respectively. The in vivo and in vitro studies on metabolism of fipronil showed that all of fipronil, sulfone, and sulfide were detected and the content of sulfone was higher than sulfide in both stem borers. The residue of sulfone in C. suppressalis was significantly higher than that in S. inferens. These results suggest that the higher activity of mixed function oxidases may cause the higher capacity of C. suppressalis to produce fipronil-sulfone, which is more toxic than fipronil leading to the higher susceptibility of this species.

Susceptibility to Eating Disorders Among Collegiate Female Student–Athletes

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McLester, Cherilyn N.; Hardin, Robin; Hoppe, Stephanie

2014-01-01

Context: Research has suggested that the prevalence of young women with eating disorders (EDs) is increasing, but determining the exact prevalence of EDs within the female student–athlete (FS-A) population is difficult. Looking at certain traits may help us to identify their level of susceptibility to developing an ED. Objective: To determine the susceptibility of FS-As to EDs in relation to self-concept, including self-esteem and body image. Design: Cross-sectional study. Setting: Athletic training and health centers at National Collegiate Athletic Association Division I, II, and III institutions via e-mail questionnaire correspondence. Patients or Other Participants: A total of 439 FS-As from 17 participating institutions completed the questionnaires. The sample was primarily white (83.1%) and underclass (61.8%). Main Outcome Measure(s): The questionnaire consisted of 4 parts: 3 subscales of the Eating Disorder Inventory-2, the Rosenberg Self-Esteem Scale, the Body Cathexis Scale, and demographic items. Results: A total of 6.8% of FS-As were susceptible to anorexia and 1.8% were susceptible to bulimia. The majority of FS-As (61%) reported normal self-esteem levels, whereas 29.4% had high self-esteem. Overall, 64.5% were satisfied and 23% were very satisfied with their body image. Conclusions: These results are generally positive in that they suggest FS-As have high levels of self-concept and are at low risk to develop EDs. However, these findings do not mean that all concerns should be dismissed. Although more than 90% of the respondents were not susceptible to an ED, there are still FS-As who may be. Athletic departments should evaluate their FS-As' levels of self-concept so that their susceptibility to EDs can be addressed. The emotional aspect of health care should be included in providing holistic care for student–athletes. Athletic trainers often are the primary health care providers for FS-As, so they should be made aware of this concern. PMID:24762233

In Vitro Antimicrobial Susceptibility of Pathogenic Leptospira Biofilm.

Science.gov (United States)

Vinod Kumar, Kirubakaran; Lall, Chandan; Raj, Ratchagadasse Vimal; Vedhagiri, Kumaresan; Sunish, Ittoop Pulikkottil; Vijayachari, Paluru

2016-10-01

Pathogenic Leptospira spp. are the causative agent of leptospirosis. Biofilm formation in leptospires is a new area of study, and its role in pathogenesis is not fully explored. As in other biofilm-forming bacteria, Leptospira biofilm may play a significant role in antibiotic resistance. In this study, the antimicrobial susceptibility of Leptospira biofilm was investigated by 96-well plate assay using Alamar Blue. Leptospira biofilm showed five to sixfold increase in resistance in all the strains used. The range of minimal bactericidal concentrations for penicillin G, ampicillin, tetracycline, and doxycycline was 1,600 U/ml, 800-1,600 μg/ml, 800-1,600 μg/ml, and 800-1,600 μg/ml, respectively. In agar substrate, the biofilm showed six- to sevenfold increase in resistance to antibiotics compared to planktonic cell. The present study emphasizes the importance of biofilm formation and its antibiotic susceptibility patterns. This could pave the way for devising appropriate strategy to prevent the occurrence of potential chronic leptospirosis in endemic areas and also during an outbreak situation.

A GIS-based extended fuzzy multi-criteria evaluation for landslide susceptibility mapping.

Science.gov (United States)

Feizizadeh, Bakhtiar; Shadman Roodposhti, Majid; Jankowski, Piotr; Blaschke, Thomas

2014-12-01

Landslide susceptibility mapping (LSM) is making increasing use of GIS-based spatial analysis in combination with multi-criteria evaluation (MCE) methods. We have developed a new multi-criteria decision analysis (MCDA) method for LSM and applied it to the Izeh River basin in south-western Iran. Our method is based on fuzzy membership functions (FMFs) derived from GIS analysis. It makes use of nine causal landslide factors identified by local landslide experts. Fuzzy set theory was first integrated with an analytical hierarchy process (AHP) in order to use pairwise comparisons to compare LSM criteria for ranking purposes. FMFs were then applied in order to determine the criteria weights to be used in the development of a landslide susceptibility map. Finally, a landslide inventory database was used to validate the LSM map by comparing it with known landslides within the study area. Results indicated that the integration of fuzzy set theory with AHP produced significantly improved accuracies and a high level of reliability in the resulting landslide susceptibility map. Approximately 53% of known landslides within our study area fell within zones classified as having "very high susceptibility", with the further 31% falling into zones classified as having "high susceptibility".

Mannose-binding lectin genotypes: lack of association with susceptibility to thoracic empyema

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Moore Catrin E

2010-01-01

Full Text Available Abstract Background The role of the innate immune protein mannose-binding lectin (MBL in host defence against severe respiratory infection remains controversial. Thoracic empyema is a suppurative lung infection that arises as a major complication of pneumonia and is associated with a significant mortality. Although the pathogenesis of thoracic empyema is poorly understood, genetic susceptibility loci for this condition have recently been identified. The possible role of MBL genotypic deficiency in susceptibility to thoracic empyema has not previously been reported. Methods To investigate this further we compared the frequencies of the six functional MBL polymorphisms in 170 European individuals with thoracic empyema and 225 healthy control individuals. Results No overall association was observed between MBL genotypic deficiency and susceptibility to thoracic empyema (2 × 2 Chi square = 0.02, P = 0.87. Furthermore, no association was seen between MBL deficiency and susceptibility to the Gram-positive or pneumococcal empyema subgroups. MBL genotypic deficiency did not associate with progression to death or requirement for surgery. Conclusions Our results suggest that MBL genotypic deficiency does not associate with susceptibility to thoracic empyema in humans.

Toxicogenetics: In Search of Host Susceptibility to Environmental Toxicants

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Gelareh eAlam

2014-09-01

Full Text Available Heavy metals, various pesticide and herbicides are implicated as risk factors for human health. Paraquat, maneb, and rotenone, carbamate and organophospherous insecticides are examples of toxicants for which acute and chronic exposure are associated with multiple neurological disorders including Parkinson’s disease (PD. Nevertheless, the role of pesticide exposure in neurodegenerative diseases is not clear-cut, as there are inconsistencies in both the epidemiological and preclinical research. The aim of this short review is to show that the inconsistencies are related to individual differences in susceptibility to the effects of neurotoxicants, individual differences that can be traced to the genetic constitution of the individuals and animals studies, i.e., host-based susceptibility.

Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

DEFF Research Database (Denmark)

Rostrup, Egill; Larsson, H B; Toft, P B

1996-01-01

PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...... to be in accordance with results obtained by other methods. Noncontrast functional MR (fMR) imaging showed signal increases in gray matter, but also inconsistent changes in some white matter regions. CONCLUSION: In this experiment, contrast-enhanced imaging seemed to show a somewhat higher sensitivity towards changes...

Reduction in soil loss from erosion-susceptible soils amended with humic substances from oxidized coal

International Nuclear Information System (INIS)

Piccolo, A.; Pietramellara, G.; Mbagwu, J.S.C.

1997-01-01

Soils that pose high risk of erosion require amendment with either natural or synthetic soil conditioners to reduce soil loss hazards. The objective of this study was to evaluate the potential of using coal-derived humic substances (as soil conditioners) to reduce runoff erosion on erosion-susceptible soils. Surface samples of severely degraded soils from Principina in Tuscany and Bovolone in Venice in Italy were used to assess the effects of five rates (0, 0.05, 0.01, 0.50 and 1.00 g/kg) of humic acids (HA) on soil loss and other hydrological parameters. The results showed that amending erosion-susceptible soils with low rates of coal-derived humic substances is a potentially effective soil management practice for reducing erosion rates

Clay mineralogy and magnetic susceptibility of Oxisols in geomorphic surfaces

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Livia Arantes Camargo

2014-06-01

Full Text Available Studies analyzing the variability of clay minerals and magnetic susceptibility provide data for the delineation of site-specific management areas since many of their attributes are important to agronomy and the environment. This study aimed to evaluate the spatial variability of clay minerals, magnetic susceptibility, adsorbed phosphorus and physical attributes in Oxisols of sandstones in different geomorphic surfaces. For that purpose, soil samples were collected every 25 m along a transect located within the area where the geomorphic surfaces were identified and mapped. The transect occupied the central portion of 500 ha, where it was also sampled for density purposes with one sample per six hectares. Soil samples were collected at a depth of 0.0-0.2 m. The results of the physical, chemical, mineralogical and magnetic susceptibility analyses were subjected to statistical and geostatistical analyses. The nature of the clay minerals and magnetic susceptibility was dependent on the variation of the soil parent material. High values of magnetic susceptibility were associated with the presence of maghemite and magnetite of coarse size. The spatial variability of crystallinity and the content of Fe oxides, as well as magnetic susceptibility, were dependent on the age of the geomorphic surfaces. The youngest surface had greater spatial variability of these attributes. The iron (goethite and hematite and aluminum (gibbsite oxides in the youngest geomorphic surface influenced the low values of soil density and high values of total pore volume, micropores and P adsorption. The characterization of the spatial variability of Fe oxides and susceptibility allowed for the delineation of homogeneous areas.

Polymyxin susceptibility testing, interpretative breakpoints and resistance mechanisms: An update.

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Bakthavatchalam, Yamuna Devi; Pragasam, Agila Kumari; Biswas, Indranil; Veeraraghavan, Balaji

2018-03-01

Emerging multidrug-resistant (MDR) nosocomial pathogens are a great threat. Polymyxins, an old class of cationic polypeptide antibiotic, are considered as last-resort drugs in treating infections caused by MDR Gram-negative bacteria. Increased use of polymyxins in treating critically ill patients necessitates routine polymyxin susceptibility testing. However, susceptibility testing both of colistin and polymyxin B (PMB) is challenging. In this review, currently available susceptibility testing methods are briefly discussed. The multicomponent composition of colistin and PMB significantly influences susceptibility testing. In addition, poor diffusion in the agar medium, adsorption to microtitre plates and the synergistic effect of the surfactant polysorbate 80 with polymyxins have a great impact on the performance of susceptibility testing methods This review also describes recently identified chromosomal resistance mechanisms, including modification of lipopolysaccharide (LPS) with 4-amino-4-deoxy-l-arabinose (L-Ara4-N) and phosphoethanolamine (pEtN) resulting in alteration of the negative charge, as well as the plasmid-mediated colistin resistance determinants mcr-1, mcr-1.2, mcr-2 and mcr-3. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Investigation of odd-order nonlinear susceptibilities in atomic vapors

Energy Technology Data Exchange (ETDEWEB)

Yan, Yaqi [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi’an Jiaotong University, Xi’an 710049 (China); Shaanxi Key Laboratory of Information Photonic Technique, Xi’an Jiaotong University, Xi’an 710049 (China); Teaching and Research Section of Maths and Physics, Guangzhou Commanding Academy of Chinese People’s Armed Police Force, Guangzhou, 510440 (China); Wu, Zhenkun; Si, Jinhai; Yan, Lihe; Zhang, Yiqi; Yuan, Chenzhi; Sun, Jia [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi’an Jiaotong University, Xi’an 710049 (China); Shaanxi Key Laboratory of Information Photonic Technique, Xi’an Jiaotong University, Xi’an 710049 (China); Zhang, Yanpeng, E-mail: ypzhang@mail.xjtu.edu.cn [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi’an Jiaotong University, Xi’an 710049 (China); Shaanxi Key Laboratory of Information Photonic Technique, Xi’an Jiaotong University, Xi’an 710049 (China)

2013-06-15

We theoretically deduce the macroscopic symmetry constraints for arbitrary odd-order nonlinear susceptibilities in homogeneous media including atomic vapors for the first time. After theoretically calculating the expressions using a semiclassical method, we demonstrate that the expressions for third- and fifth-order nonlinear susceptibilities for undressed and dressed four- and six-wave mixing (FWM and SWM) in atomic vapors satisfy the macroscopic symmetry constraints. We experimentally demonstrate consistence between the macroscopic symmetry constraints and the semiclassical expressions for atomic vapors by observing polarization control of FWM and SWM processes. The experimental results are in reasonable agreement with our theoretical calculations. -- Highlights: •The macroscopic symmetry constraints are deduced for homogeneous media including atomic vapors. •We demonstrate that odd-order nonlinear susceptibilities satisfy the constraints. •We experimentally demonstrate the deduction in part.

High susceptibility prevalence for F4+ and F18+Escherichia coli in Flemish pigs.

Science.gov (United States)

Nguyen, Ut V; Coddens, Annelies; Melkebeek, Vesna; Devriendt, Bert; Goetstouwers, Tiphanie; Poucke, Mario Van; Peelman, Luc; Cox, Eric

2017-04-01

F4 and/or F18 enterotoxigenic Escherichia coli (F4 + /F18 + ETEC) are responsible for diarrhea while F18 + verotoxigenic E. coli (F18 + VTEC) cause edema disease in pigs. Both infections can result in severe economic losses, which are mainly the result of the medication, growth retardation and mortality. The susceptibility of piglets to these pathogens is determined by the presence of F4 and F18 receptors (F4R and F18R). Understanding the composition of the susceptibility phenotypes of pigs is useful for animal health and breeding management. This study aimed to determine the prevalence of the F4 ETEC susceptibility phenotypes and F18 + E. coli susceptibility among Flemish pig breeds by using the in vitro villous adhesion assay. In this study, seven F4 ETEC susceptibility phenotypes were found, namely A (F4 ab R + , ac R + , ad R + ; 59.16%), B (F4 ab R + , ac R + , ad R - ; 6.28%), C (F4 ab R + , ac R - , ad R + ; 2.62%), D (F4 ab R - , ac R - , ad R + ; 6.28%), E (F4 ab R - , ac R - , ad R - ; 24.08%), F (F4 ab R + , ac R - , ad R - ; 1.05%) and G (F4 ab R - , ac R + , ad R - ; 0.52%). F4ab and F4ac E. coli showed a stronger degree of adhesion to the intestinal villi (53.40% and 52.88% strong adhesion, respectively), compared to F4ad E. coli (43.46% strong adhesion). Furthermore, the correlation between F4ac and F4ab adhesion was higher (r=0.78) than between F4ac and F4ad adhesion (r=0.41) and between F4ab and F4ad adhesion (r=0.57). For F18 + E. coli susceptibility, seven out of 82 pigs were F18R negative (8.54%), but only two of these seven pigs (2.44%) were also negative for F4R. As such, the chance to identify a pig that is positive for a F4 ETEC variant or F18 + E. coli is 97.56%. Therefore, significant economic losses will arise due to F4 + and/or F18 + E. coli infections in the Flemish pig population due to the high susceptibility prevalence. Copyright © 2016 Elsevier B.V. All rights reserved.

Cyclopentanoid analogs of phosphatidylcholine: susceptibility to phospholipase A2.

Science.gov (United States)

Lister, M D; Hancock, A J

1988-10-01

Six isomers of dipalmitoylcyclopentanetriol phosphocholine (cyclopentano-lecithin) were tested as potential substrates for phospholipase A2. Since each of these analogs possesses a configuration that mimics a narrow range of conformations of a glycerophospholipid molecule, the analogs were used to assess the enzyme's conformational requirements. Studies showed that all of the analogs containing the phosphocholine at the C-1 (or C-3) position could be hydrolyzed, while only one of the three analogs that contains the polar head group at the C-2 position was susceptible. Kinetic studies, however, revealed that only the all-trans-(1,3/2-1P)-cyclopentano-lecithin gave initial rates of hydrolysis that were measurable by pH-stat. Acyl group specificity of the enzyme towards the all-trans isomer was determined with an analog was acyl groups were distinguishable. The synthesis of this mixed-acid-cyclopentano-PC is described herein. When this analog was enzymatically assayed, results unequivocally showed the enzyme to be specific for C-2 acyl hydrolysis. This specificity, and data showing that the all-trans analog is stereospecifically hydrolyzed, indicate that it is acted on in an analogous manner to dipalmitoylphosphatidylcholine. These studies indicate that although the configuration of the analog is not necessarily a prerequisite for hydrolysis, there does appear to be an optimal spatial orientation for enzymatic activity. The analogy between the susceptibilities of all-trans-(1,3/2-1P)-cyclopentano-lecithin and glycero-lecithin suggests that the conformation of the glycero-lecithin during phospholipase A2-mediated hydrolysis may be best simulated by the all-trans orientation of C-O bonds in the artificial substrate.

Landslide susceptibility assessment of SE Bartin (West Black Sea region, Turkey by artificial neural networks

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M. Ercanoglu

2005-01-01

Full Text Available Landslides are significant natural hazards in Turkey, second only to earthquakes with respect to economic losses and casualties. The West Black Sea region of Turkey is known as one of the most landslide-prone regions in the country. The work presented in this paper is aimed at evaluating landslide susceptibility in a selected area in the West Black Sea region using Artificial Neural Network (ANN method. A total of 317 landslides were identified and mapped in the area by extensive field work and by use of air photo interpretations to build a landslide inventory map. A landslide database was then derived automatically from the landslide inventory map. To evaluate landslide susceptibility, six input parameters (slope angle, slope aspect, topographical elevation, topographical shape, wetness index, and vegetation index were used. To obtain maps of these parameters, Digital Elevation Model (DEM and ASTER satellite imagery of the study area were used. At the first stage, all data were normalized in [0, 1] interval, and parameter effects on landslide occurrence were expressed using Statistical Index values (Wi. Then, landslide susceptibility analyses were performed using an ANN. Finally, performance of the resulting map and the applied methodology is discussed relative to performance indicators, such as predicted areal extent of landslides and the strength of relation (rij value. Much of the areal extents of the landslides (87.2% were classified as susceptible to landsliding, and rij value of 0.85 showed a high degree of similarity. In addition to these, at the final stage, an independent validation strategy was followed by dividing the landslide data set into two parts and 82.5% of the validation data set was found to be correctly classified as landslide susceptible areas. According to these results, it is concluded that the map produced by the ANN is reliable and methodology applied in the study produced high performance, and satisfactory results.

Antimicrobial susceptibility patterns of Haemophilus parasuis from pigs in the United Kingdom and Spain.

Science.gov (United States)

de la Fuente, A J Martín; Tucker, A W; Navas, J; Blanco, M; Morris, S J; Gutiérrez-Martín, C B

2007-02-25

A total of 30 British and 30 Spanish Haemophilus parasuis isolates were tested for their susceptibility to 19 of the antimicrobials currently used in swine practice with a broth microdilution method in order to know the emergence of resistance against these compounds in this porcine pathogen. All the British isolates were susceptible to penicillin, ceftiofur, erythromycin, tilmicosin, enrofloxacin, and florfenicol, and most of them were susceptible to the remaining antimicrobials (the highest resistance rate found was of 20% to neomycin). In contrast, all the Spanish isolates were susceptible exclusively to florfenicol, and high proportions of resistance were encountered for penicillin, ampicillin, oxytetracycline, erythromycin, tilmicosin, tiamulin and trimethoprim+sulphamethoxazole; in addition, a bimodal or multimodal distribution, or tailing of Spanish isolates over the MIC range was observed for clindamycin, sulphonamides and tylosine tartrate, suggesting the development of acquired resistance. In addition, several multiresistance patterns were found among the Spanish isolates, 23.3% of them being resistant to at least eight antimicrobials, the same rate as that encountered for those being susceptible to all antimicrobials tested. This study showed that in general British H. parasuis isolates are susceptible to antimicrobial agents routinely used for treatment of porcine respiratory diseases; however, the Spanish isolates need a more continuous surveillance of their susceptibility patterns.

Object-based Classification for Detecting Landslides and Stochastic Procedure to landslide susceptibility maps - A Case at Baolai Village, SW Taiwan

Science.gov (United States)

Lin, Ying-Tong; Chang, Kuo-Chen; Yang, Ci-Jian

2017-04-01

As the result of global warming in the past decades, Taiwan has experienced more and more extreme typhoons with hazardous massive landslides. In this study, we use object-oriented analysis method to classify landslide area at Baolai village by using Formosat-2 satellite images. We used for multiresolution segmented to generate the blocks, and used hierarchical logic to classified 5 different kinds of features. After that, classification the landslide into different type of landslide. Beside, we use stochastic procedure to integrate landslide susceptibility maps. This study assumed that in the extreme event, 2009 Typhoon Morakot, which precipitation goes to 1991.5mm in 5 days, and the highest landslide susceptible area. The results show that study area's landslide area was greatly changes, most of landslide was erosion by gully and made dip slope slide, or erosion by the stream, especially at undercut bank. From the landslide susceptibility maps, we know that the old landslide area have high potential to occur landslides in the extreme event. This study demonstrates the changing of landslide area and the landslide susceptible area. Keywords: Formosat-2, object-oriented, segmentation, classification, landslide, Baolai Village, SW Taiwan, FS

Dielectric susceptibility of classical Coulomb systems. II

International Nuclear Information System (INIS)

Choquard, Ph.; Piller, B.; Rentsch, R.

1987-01-01

This paper deals with the shape dependence of the dielectric susceptibility (equivalently defined, in a canonical ensemble, by the mean square fluctuation of the electric polarization or by the second moment of the charge-charge correlation function) of classical Coulomb systems. The concept of partial second moment is introduced with the aim of analyzing the contributions to the total susceptibility of pairs of particles of increasing separation. For a disk-shaped one-component plasma with coupling parameter γ=2 it is shown, numerically and algebraically for small and large systems, that (1) the correlation function of two particles close to the edge of the disk decays as the inverse of the square of their distance, and (2) the susceptibility is made up of a bulk contribution, which saturates rapidly toward the Stillinger-Lovett value, and of surface contribution, which varies on the scale of the disk diameter and is described by a new law called the arc sine law. It is also shown that electrostatics and statistical mechanics with shape-dependent thermodynamic limits are consistent for the same model in a strip geometry, whereas the Stillinger-Lovett sum rule is verified for a boundary-free geometry such as the surface of a sphere. Some results of extensive computer simulations of one- and two-component plasmas in circular and elliptic geometries are shown. Anisotropy effects on the susceptibilities are clearly demonstrated and the arc sine law for a circular plasma is well confirmed

Susceptibility of Spodoptera frugiperda and S. exigua to Bacillus thuringiensis Vip3Aa insecticidal protein.

Science.gov (United States)

Chakroun, Maissa; Bel, Yolanda; Caccia, Silvia; Abdelkefi-Mesrati, Lobna; Escriche, Baltasar; Ferré, Juan

2012-07-01

The Vip3Aa protein is an insecticidal protein secreted by Bacillus thuringiensis during the vegetative stage of growth. The activity of this protein has been tested after different steps/protocols of purification using Spodoptera frugiperda as a control insect. The results showed that the Vip3Aa protoxin was stable and retained full toxicity after being subjected to common biochemical steps used in protein purification. Bioassays with the protoxin in S. frugiperda and S. exigua showed pronounced differences in LC(50) values when mortality was measured at 7 vs. 10d. At 7d most live larvae were arrested in their development. LC(50) values of "functional mortality" (dead larvae plus larvae remaining in the first instar), measured at 7d, were similar or even lower than the LC(50) values of mortality at 10d. This strong growth inhibition was not observed when testing the trypsin-activated protein (62 kDa) in either species. S. exigua was less susceptible than S. frugiperda to the protoxin form, with LC(50) values around 10-fold higher. However, both species were equally susceptible to the trypsin-activated form. Processing of Vip3Aa protoxin to the activated form was faster with S. frugiperda midgut juice than with S. exigua midgut juice. The results strongly suggest that the differences in the rate of activation of the Vip3Aa protoxin between both species are the basis for the differences in susceptibility towards the protoxin form. Copyright © 2012 Elsevier Inc. All rights reserved.

Hydrogen embrittlement susceptibility of laser-hardened 4140 steel

Energy Technology Data Exchange (ETDEWEB)

Tsay, L.W.; Lin, Z.W. [Nat. Taiwan Ocean Univ., Keelung (Taiwan). Inst. of Mater. Eng.; Shiue, R.K. [Institute of Materials Sciences and Engineering, National Dong Hwa University, Hualien, Taiwan (Taiwan); Chen, C. [Institute of Materials Sciences and Engineering, National Taiwan University, Taipei, Taiwan (Taiwan)

2000-10-15

Slow strain rate tensile (SSRT) tests were performed to investigate the susceptibility to hydrogen embrittlement of laser-hardened AISI 4140 specimens in air, gaseous hydrogen and saturated H{sub 2}S solution. Experimental results indicated that round bar specimens with two parallel hardened bands on opposite sides along the loading axis (i.e. the PH specimens), exhibited a huge reduction in tensile ductility for all test environments. While circular-hardened (CH) specimens with 1 mm hardened depth and 6 mm wide within the gauge length were resistant to gaseous hydrogen embrittlement. However, fully hardened CH specimens became susceptible to hydrogen embrittlement for testing in air at a lower strain rate. The strength of CH specimens increased with decreasing the depth of hardened zones in a saturated H{sub 2}S solution. The premature failure of hardened zones in a susceptible environment caused the formation of brittle intergranular fracture and the decrease in tensile ductility. (orig.)

Application of an advanced fuzzy logic model for landslide susceptibility analysis

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Biswajeet Pradhan

2010-09-01

Full Text Available The aim of this study is to evaluate the susceptibility of landslides at Klang valley area, Malaysia, using a Geographic Information System (GIS and remote sensing. Landslide locations were identified in the study area from interpretation of aerial photographs and from field surveys. Topographical and geological data and satellite images were collected, processed, and constructed into a spatial database using GIS and image processing. A data derived model (frequency ratio and a knowledge-derived model (fuzzy operator were combined for landslide susceptibility analysis. The nine factors that influence landslide occurrence were extracted from the database and the frequency ratio coefficient for each factor was computed. Using the factors and the identified landslide, the fuzzy membership values were calculated. Then fuzzy algebraic operators were applied to the fuzzy membership values for landslide susceptibility mapping. Finally, the produced map was verified by comparing with existing landslide locations for calculating prediction accuracy. Among the fuzzy operators, in the case in which the gamma operator (l = 0.8 showed the best accuracy (91% while the case in which the fuzzy algebraic product was applied showed the worst accuracy (79%.

A comparative study on the predictive ability of the decision tree, support vector machine and neuro-fuzzy models in landslide susceptibility mapping using GIS

Science.gov (United States)

Pradhan, Biswajeet

2013-02-01

The purpose of the present study is to compare the prediction performances of three different approaches such as decision tree (DT), support vector machine (SVM) and adaptive neuro-fuzzy inference system (ANFIS) for landslide susceptibility mapping at Penang Hill area, Malaysia. The necessary input parameters for the landslide susceptibility assessments were obtained from various sources. At first, landslide locations were identified by aerial photographs and field surveys and a total of 113 landslide locations were constructed. The study area contains 340,608 pixels while total 8403 pixels include landslides. The landslide inventory was randomly partitioned into two subsets: (1) part 1 that contains 50% (4000 landslide grid cells) was used in the training phase of the models; (2) part 2 is a validation dataset 50% (4000 landslide grid cells) for validation of three models and to confirm its accuracy. The digitally processed images of input parameters were combined in GIS. Finally, landslide susceptibility maps were produced, and the performances were assessed and discussed. Total fifteen landslide susceptibility maps were produced using DT, SVM and ANFIS based models, and the resultant maps were validated using the landslide locations. Prediction performances of these maps were checked by receiver operating characteristics (ROC) by using both success rate curve and prediction rate curve. The validation results showed that, area under the ROC curve for the fifteen models produced using DT, SVM and ANFIS varied from 0.8204 to 0.9421 for success rate curve and 0.7580 to 0.8307 for prediction rate curves, respectively. Moreover, the prediction curves revealed that model 5 of DT has slightly higher prediction performance (83.07), whereas the success rate showed that model 5 of ANFIS has better prediction (94.21) capability among all models. The results of this study showed that landslide susceptibility mapping in the Penang Hill area using the three approaches (e

[Susceptibility of yeasts to antifungal agents in Kaunas University of Medicine Hospital].

Science.gov (United States)

Skrodeniene, Erika; Dambrauskiene, Asta; Vitkauskiene, Astra

2006-01-01

The aim of this study was to determine the species of yeast and their susceptibility to antifungal agents isolated from clinical specimens of patients treated in Kaunas University of Medicine Hospital. A total of 142 yeasts isolated from various clinical specimens of patients hospitalized in Kaunas University of Medicine Hospital were included in this study. All yeasts were cultivated on Sabouraud dextrose agar and identified using either CHROM agar or API 20C AUX system. The minimum inhibitory concentrations of fluconazole, itraconazole, and amphotericin B were determined by the ATB FUNGUS 2 agar microdilution test. In all clinical specimens except blood, Candida albicans was the most frequently isolated yeast (65.5%, pyeast strains showed resistance to fluconazole. Nearly one-fourth of Candida albicans strains (24.7%) and 23.2% of all isolated yeast strains showed resistance to itraconazole. Almost all of fluconazole-resistant (93.3%) and 12.6% of fluconazole-susceptible yeast were found to be resistant to itraconazole (pyeast strains were susceptible to amphotericin B. Candida albicans strains were significantly frequently resistant to fluconazole than non-albicans Candida species (15.1% and 4.1%, respectively, pyeast isolated in Kaunas University of Medicine Hospital. There was determined that yeasts resistant to fluconazole were commonly resistant to itraconazole too. All isolated yeast strains were susceptible to amphotericin B.

A prospective study on evaluation of pathogenesis, biofilm formation, antibiotic susceptibility of microbial community in urinary catheter

Science.gov (United States)

Younis, Khansa Mohammed; Usup, Gires; Ahmad, Asmat

2015-09-01

This study is aimed to isolate, detect biofilm formation ability and antibiotic susceptibility of urinary catheter adherent microorganisms from elderly hospitalized patient at the Universiti Kebangsaan Malaysia Medical Center. Microorganisms were isolated from three samples of urinary catheters (UC) surface; one of the acute vascular rejection patient (UCB) and two from benign prostate hyperplasia patients (UCC and UCD). A total of 100 isolates was isolated with 35 from UCB, 38 (UCC) and 28 (UCD). Ninety six were identified as Gram-negative bacilli, one Gram-positive bacilli and three yeasts. Results of biofilm forming on sterile foley catheter showed that all the isolates can form biofilm at different degrees; strong biofilm forming: 32% from the 35 isolates (UCB), 25% out of 38 isolates (UCC), 26% out of 28 isolates (UCD). As for moderate biofilm forming; 3% from UCB, 10% from UCC and 2% from UCD. Weak biofilm forming in UCC (3%). The antibiotic susceptibility for (UCB) isolates showed highly resistant to ampicillin, novobiocin and penicillin 100 (%), kanamycin (97%), tetracycline (94%), chloramphenicol (91%), streptomycin (77%) and showed low level of resistance to gentamycin (17%), while all the isolates from (UCC-D) showed high resistant towards ampicillin and penicillin, novobiocin (94%), tetracycline (61%), streptomycin (53%), gentamycin (50%) and low level of resistance to kanamycin (48%), chloramphenicol (47%). The findings indicate that these isolates can spread within the community on urinary catheters surface and produce strong biofilm, therefore, monitoring antibiotic susceptibility of bacteria isolated in the aggregation is recommended.

An Improved Information Value Model Based on Gray Clustering for Landslide Susceptibility Mapping

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Qianqian Ba

2017-01-01

Full Text Available Landslides, as geological hazards, cause significant casualties and economic losses. Therefore, it is necessary to identify areas prone to landslides for prevention work. This paper proposes an improved information value model based on gray clustering (IVM-GC for landslide susceptibility mapping. This method uses the information value derived from an information value model to achieve susceptibility classification and weight determination of landslide predisposing factors and, hence, obtain the landslide susceptibility of each study unit based on the clustering analysis. Using a landslide inventory of Chongqing, China, which contains 8435 landslides, three landslide susceptibility maps were generated based on the common information value model (IVM, an information value model improved by an analytic hierarchy process (IVM-AHP and our new improved model. Approximately 70% (5905 of the inventory landslides were used to generate the susceptibility maps, while the remaining 30% (2530 were used to validate the results. The training accuracies of the IVM, IVM-AHP and IVM-GC were 81.8%, 78.7% and 85.2%, respectively, and the prediction accuracies were 82.0%, 78.7% and 85.4%, respectively. The results demonstrate that all three methods perform well in evaluating landslide susceptibility. Among them, IVM-GC has the best performance.

Application of Physically based landslide susceptibility models in Brazil

Science.gov (United States)

Carvalho Vieira, Bianca; Martins, Tiago D.

2017-04-01

Shallow landslides and floods are the processes responsible for most material and environmental damages in Brazil. In the last decades, some landslides events induce a high number of deaths (e.g. Over 1000 deaths in one event) and incalculable social and economic losses. Therefore, the prediction of those processes is considered an important tool for land use planning tools. Among different methods the physically based landslide susceptibility models having been widely used in many countries, but in Brazil it is still incipient when compared to other ones, like statistical tools and frequency analyses. Thus, the main objective of this research was to assess the application of some Physically based landslide susceptibility models in Brazil, identifying their main results, the efficiency of susceptibility mapping, parameters used and limitations of the tropical humid environment. In order to achieve that, it was evaluated SHALSTAB, SINMAP and TRIGRS models in some studies in Brazil along with the Geotechnical values, scales, DEM grid resolution and the results based on the analysis of the agreement between predicted susceptibility and the landslide scar's map. Most of the studies in Brazil applied SHALSTAB, SINMAP and to a lesser extent the TRIGRS model. The majority researches are concentrated in the Serra do Mar mountain range, that is a system of escarpments and rugged mountains that extends more than 1,500 km along the southern and southeastern Brazilian coast, and regularly affected by heavy rainfall that generates widespread mass movements. Most part of these studies used conventional topographic maps with scales ranging from 1:2000 to 1:50000 and DEM-grid resolution between 2 and 20m. Regarding the Geotechnical and hydrological values, a few studies use field collected data which could produce more efficient results, as indicated by international literature. Therefore, even though they have enormous potential in the susceptibility mapping, even for comparison

Genome-wide local ancestry approach identifies genes and variants associated with chemotherapeutic susceptibility in African Americans.

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Heather E Wheeler

Full Text Available Chemotherapeutic agents are used in the treatment of many cancers, yet variable resistance and toxicities among individuals limit successful outcomes. Several studies have indicated outcome differences associated with ancestry among patients with various cancer types. Using both traditional SNP-based and newly developed gene-based genome-wide approaches, we investigated the genetics of chemotherapeutic susceptibility in lymphoblastoid cell lines derived from 83 African Americans, a population for which there is a disparity in the number of genome-wide studies performed. To account for population structure in this admixed population, we incorporated local ancestry information into our association model. We tested over 2 million SNPs and identified 325, 176, 240, and 190 SNPs that were suggestively associated with cytarabine-, 5'-deoxyfluorouridine (5'-DFUR-, carboplatin-, and cisplatin-induced cytotoxicity, respectively (p≤10(-4. Importantly, some of these variants are found only in populations of African descent. We also show that cisplatin-susceptibility SNPs are enriched for carboplatin-susceptibility SNPs. Using a gene-based genome-wide association approach, we identified 26, 11, 20, and 41 suggestive candidate genes for association with cytarabine-, 5'-DFUR-, carboplatin-, and cisplatin-induced cytotoxicity, respectively (p≤10(-3. Fourteen of these genes showed evidence of association with their respective chemotherapeutic phenotypes in the Yoruba from Ibadan, Nigeria (p<0.05, including TP53I11, COPS5 and GAS8, which are known to be involved in tumorigenesis. Although our results require further study, we have identified variants and genes associated with chemotherapeutic susceptibility in African Americans by using an approach that incorporates local ancestry information.

Pregnancy and Susceptibility to Infectious Diseases

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Elisabeth Sappenfield

2013-01-01

Full Text Available To summarize the literature regarding susceptibility of pregnant women to infectious diseases and severity of resulting disease, we conducted a review using a PubMed search and other strategies. Studies were included if they reported information on infection risk or disease outcome in pregnant women. In all, 1454 abstracts were reviewed, and a total of 85 studies were included. Data were extracted regarding number of cases in pregnant women, rates of infection, risk factors for disease severity or complications, and maternal outcomes. The evidence indicates that pregnancy is associated with increased severity of some infectious diseases, such as influenza, malaria, hepatitis E, and herpes simplex virus (HSV infection (risk for dissemination/hepatitis; there is also some evidence for increased severity of measles and smallpox. Disease severity seems higher with advanced pregnancy. Pregnant women may be more susceptible to acquisition of malaria, HIV infection, and listeriosis, although the evidence is limited. These results reinforce the importance of infection prevention as well as of early identification and treatment of suspected influenza, malaria, hepatitis E, and HSV disease during pregnancy.

Microbicide excipients can greatly increase susceptibility to genital herpes transmission in the mouse

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Sun Mianmian

2010-11-01

Full Text Available Abstract Background Several active ingredients proposed as vaginal microbicides have been shown paradoxically to increase susceptibility to infection in mouse genital herpes (HSV-2 vaginal susceptibility models and in clinical trials. In addition, "inactive ingredients" (or excipients used in topical products to formulate and deliver the active ingredient might also cause epithelial toxicities that increase viral susceptibility. However, excipients have not previously been tested in susceptibility models. Methods Excipients commonly used in topical products were formulated in a non-toxic vehicle (the "HEC universal placebo", or other formulations as specified. Twelve hours after exposure to the excipient or a control treatment, mice were challenged with a vaginal dose of HSV-2, and three days later were assessed for infection by vaginal lavage culture to assess susceptibility. Results The following excipients markedly increased susceptibility to HSV-2 after a single exposure: 5% glycerol monolaurate (GML formulated in K-Y® Warming Jelly, 5% GML as a colloidal suspension in phosphate buffered saline, K-Y Warming Jelly alone, and both of its humectant/solvent ingredients (neat propylene glycol and neat PEG-8. For excipients formulated in the HEC vehicle, 30% glycerin significantly increased susceptibility, and a trend toward increased HSV-2 susceptibility was observed after 10% glycerin, and 0.1% disodium EDTA, but not after 0.0186% disodium EDTA. The following excipients did not increase susceptibility: 10% propylene glycol, 0.18%, methylparaben plus 0.02% propylparaben, and 1% benzyl alcohol. Conclusions As reported with other surfactants, the surfactant/emulsifier GML markedly increased susceptibility to HSV-2. Glycerin at 30% significantly increased susceptibility, and, undiluted propylene glycol and PEG-8 greatly increased susceptibility.

Genome-wide association studies on HIV susceptibility, pathogenesis and pharmacogenomics

NARCIS (Netherlands)

van Manen, Daniëlle; van 't Wout, Angélique B.; Schuitemaker, Hanneke

2012-01-01

Susceptibility to HIV-1 and the clinical course after infection show a substantial heterogeneity between individuals. Part of this variability can be attributed to host genetic variation. Initial candidate gene studies have revealed interesting host factors that influence HIV infection, replication

Presynaptic plasticity as a hallmark of rat stress susceptibility and antidepressant response.

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Jose Luis Nieto-Gonzalez

Full Text Available Two main questions are important for understanding and treating affective disorders: why are certain individuals susceptible or resilient to stress, and what are the features of treatment response and resistance? To address these questions, we used a chronic mild stress (CMS rat model of depression. When exposed to stress, a fraction of rats develops anhedonic-like behavior, a core symptom of major depression, while another subgroup of rats is resilient to CMS. Furthermore, the anhedonic-like state is reversed in about half the animals in response to chronic escitalopram treatment (responders, while the remaining animals are resistant (non-responder animals. Electrophysiology in hippocampal brain slices was used to identify a synaptic hallmark characterizing these groups of animals. Presynaptic properties were investigated at GABAergic synapses onto single dentate gyrus granule cells. Stress-susceptible rats displayed a reduced probability of GABA release judged by an altered paired-pulse ratio of evoked inhibitory postsynaptic currents (IPSCs (1.48 ± 0.25 compared with control (0.81 ± 0.05 and stress-resilient rats (0.78 ± 0.03. Spontaneous IPSCs (sIPSCs occurred less frequently in stress-susceptible rats compared with control and resilient rats. Finally, a subset of stress-susceptible rats responding to selective serotonin reuptake inhibitor (SSRI treatment showed a normalization of the paired-pulse ratio (0.73 ± 0.06 whereas non-responder rats showed no normalization (1.2 ± 0.2. No changes in the number of parvalbumin-positive interneurons were observed. Thus, we provide evidence for a distinct GABAergic synaptopathy which associates closely with stress-susceptibility and treatment-resistance in an animal model of depression.

Quark-number susceptibility, thermodynamic sum rule, and the hard thermal loop approximation

International Nuclear Information System (INIS)

Chakraborty, Purnendu; Mustafa, Munshi G.; Thoma, Markus H.

2003-01-01

The quark number susceptibility, associated with the conserved quark number density, is closely related to the baryon and charge fluctuations in the quark-gluon plasma, which might serve as signature for the quark-gluon plasma formation in ultrarelativistic heavy-ion collisions. In addition to QCD lattice simulations, the quark number susceptibility has been calculated recently using a resummed perturbation theory (hard thermal loop resummation). In the present work we show, based on general arguments, that the computation of this quantity neglecting hard thermal loop vertices contradicts the Ward identity and violates the thermodynamic sum rule following from quark number conservation. We further show that the hard thermal loop perturbation theory is consistent with the thermodynamic sum rule

Host Phenology and Leaf Effects on Susceptibility of California Bay Laurel to Phytophthora ramorum.

Science.gov (United States)

Johnston, Steven F; Cohen, Michael F; Torok, Tamas; Meentemeyer, Ross K; Rank, Nathan E

2016-01-01

Spread of the plant pathogen Phytophthora ramorum, causal agent of the forest disease sudden oak death, is driven by a few competent hosts that support spore production from foliar lesions. The relationship between traits of a principal foliar host, California bay laurel (Umbellularia californica), and susceptibility to P. ramorum infection were investigated with multiple P. ramorum isolates and leaves collected from multiple trees in leaf-droplet assays. We examined whether susceptibility varies with season, leaf age, or inoculum position. Bay laurel susceptibility was highest during spring and summer and lowest in winter. Older leaves (>1 year) were more susceptible than younger ones (8 to 11 months). Susceptibility was greater at leaf tips and edges than the middle of the leaf. Leaf surfaces wiped with 70% ethanol were more susceptible to P. ramorum infection than untreated leaf surfaces. Our results indicate that seasonal changes in susceptibility of U. californica significantly influence P. ramorum infection levels. Thus, in addition to environmental variables such as temperature and moisture, variability in host plant susceptibility contributes to disease establishment of P. ramorum.

Susceptibility of central Red Sea corals during a major bleaching event

KAUST Repository

Furby, Kathryn A.

2013-01-04

A major coral bleaching event occurred in the central Red Sea near Thuwal, Saudi Arabia, in the summer of 2010, when the region experienced up to 10-11 degree heating weeks. We documented the susceptibility of various coral taxa to bleaching at eight reefs during the peak of this thermal stress. Oculinids and agaricids were most susceptible to bleaching, with up to 100 and 80 % of colonies of these families, respectively, bleaching at some reefs. In contrast, some families, such as mussids, pocilloporids, and pectinids showed low levels of bleaching (<20 % on average). We resurveyed the reefs 7 months later to estimate subsequent mortality. Mortality was highly variable among taxa, with some taxa showing evidence of full recovery and some (e. g., acroporids) apparently suffering nearly complete mortality. The unequal mortality among families resulted in significant change in community composition following the bleaching. Significant factors in the likelihood of coral bleaching during this event were depth of the reef and distance of the reef from shore. Shallow reefs and inshore reefs had a higher prevalence of bleaching. This bleaching event shows that Red Sea reefs are subject to the same increasing pressures that reefs face worldwide. This study provides a quantitative, genus-level assessment of the vulnerability of various coral groups from within the Red Sea to bleaching and estimates subsequent mortality. As such, it can provide valuable insights into the future for reef communities in the Red Sea. © 2013 Springer-Verlag Berlin Heidelberg.

Identification of Heavy Metal Pollution Derived From Traffic in Roadside Soil Using Magnetic Susceptibility.

Science.gov (United States)

Yang, Pingguo; Ge, Jing; Yang, Miao

2017-06-01

The study integrates surface and vertical distribution of magnetic susceptibility and heavy metal contents (Pb, Cu, Zn and Fe) to characterize the signature of vehicle pollutants in roadside soils at Linfen city, China. Sites with reforestation and without vegetation cover were investigated. The results showed that magnetic susceptibility and heavy metal contents were higher at the roadside without trees than in the reforest belt. The variations of magnetic susceptibility and heavy metal contents decreased both with distance and with depth. The maximum value was observed at 5-10 m away from the roadside edge. The vertical distribution in soil revealed accumulation of pollutants in 0-5 cm topsoils. The average contents were higher than the background values and in the order Fe (107.21 g kg -1 ), Zn (99.72 mg kg -1 ), Pb (90.99 mg kg -1 ), Cu (36.14 mg kg -1 ). Coarse multi domain grains were identified as the dominating magnetic particles. Multivariate statistical and SEM/EDX analyses suggested that the heavy metals derived from traffic sources. Trees act as efficient receptors and green barrier, which can reduce vehicle derived pollution.

Enhanced pairing susceptibility in a photodoped two-orbital Hubbard model

Science.gov (United States)

Werner, Philipp; Strand, Hugo U. R.; Hoshino, Shintaro; Murakami, Yuta; Eckstein, Martin

2018-04-01

Local spin fluctuations provide the glue for orbital-singlet spin-triplet pairing in the doped Mott insulating regime of multiorbital Hubbard models. At large Hubbard repulsion U , the pairing susceptibility is nevertheless tiny because the pairing interaction cannot overcome the suppression of charge fluctuations. Using nonequilibrium dynamical mean field simulations of the two-orbital Hubbard model, we show that out of equilibrium the pairing susceptibility in this large-U regime can be strongly enhanced by creating a photoinduced population of the relevant charge states. This enhancement is supported by the long lifetime of photodoped charge carriers and a built-in cooling mechanism in multiorbital Hubbard systems.

Comparative drug susceptibility study of five clonal strains of Trichomonas vaginalis in vitro

Institute of Scientific and Technical Information of China (English)

Hemantkumar Somabhai Chaudhari; Prati Pal Singh

2011-01-01

Objective: To produce comparative data on a group of Trichomonas vaginalis clonal strains with varied drug responses using identical methods and materials. Methods: Five clonal strains of Trichomonas vaginalis were isolated from reference strain using agar plate technique. The variability of growth kinetic and susceptibility of clonal strain to metronidazole, tinidazole, satranidazole and nitazoxanide were observed in 96 well microtitre plate. Results: Among these clonal strains there was a good correlation between rates of growth with the relative susceptibility of the strains to drugs in vitro. Regarding metronidazole, tinidazole and satranidazole susceptibility, different degrees of susceptibility were determined. However, no difference in nitazoxanide susceptibility was found between the clonal strain tested and a reference strain.Conclusions: This is the first description of biological variability in clonal stock of Trichomonas vaginalis. Different degrees of drug susceptibility were determined among clonal strains tested. Further studies will be necessary to ascertain the importance of this variability in clinical infection.

Antimicrobial resistance in methicillin susceptible and methicillin resistant Staphylococcus pseudintermedius of canine origin

DEFF Research Database (Denmark)

Moodley, Arshnee; Damborg, Peter Panduro; Nielsen, Søren Saxmose

2014-01-01

and enrofloxacin amongst MSSP. The review highlights inconsistencies between studies as a result of several factors, for example the use of different antimicrobial susceptibility testing methods and interpretation criteria. We recommend that data on susceptibility in important companion animal pathogens...

Magnetic susceptibility of functional groups

International Nuclear Information System (INIS)

Herr, T.; Ferraro, M.B.; Contreras, R.H.

1990-01-01

Proceeding with a series of works where new criteria are applied to the the calculation of the contribution of molecular fragments to certain properties, results are presented for a group of 1-X-benzenes and 1-X-naphtalenes for the magnetic susceptibility constant. Both the diamagnetic and paramagnetic parts are taken into account. To reduce the problems associated with the Gauge dependence originated in the approximations made, Gauge independent atomic orbitals (GIAO) orbitals are used in the atomic orbital basis. Results are discussed in terms of functional groups. (Author). 17 refs., 1 fig., 3 tabs

Insecticide susceptibility of Aedes aegypti populations from Senegal and Cape Verde Archipelago.

Science.gov (United States)

Dia, Ibrahima; Diagne, Cheikh Tidiane; Ba, Yamar; Diallo, Diawo; Konate, Lassana; Diallo, Mawlouth

2012-10-22

Two concomitant dengue 3 (DEN-3) epidemics occurred in Cape Verde Archipelago and Senegal between September and October 2009. Aedes aegypti was identified as the vector of these epidemics as several DEN-3 virus strains were isolated from this species in both countries. The susceptibility to pyrethroids, organochlorine, organophosphates and carbamate was investigated in two field strains of Aedes aegypti from both countries using WHO diagnostic bioassay kits in order to monitor their the current status of insecticide susceptibility. The two tested strains were highly resistant to DDT. The Cape Verde strain was found to be susceptible to all others tested insecticides except for propoxur 0.1%, which needs further investigation. The Dakar strain was susceptible to fenitrothion 1% and permethrin 0.75%, but displayed reduced susceptibility to deltamethrin, lambda-cyhalothrin and propoxur. As base-line results, our observations stress a careful management of insecticide use for the control of Ae. aegypti. Indeed, they indicate that DDT is no longer efficient for the control of Ae. aegypti populations in Cape Verde and Dakar and further suggest a thorough follow-up of propoxur susceptibility status in both sites and that of deltamethrin and lambda-cyhalothrin in Ae. aegypti populations in Dakar. Thus, regular monitoring of susceptibility is greatly needed as well as the knowing if this observed resistance/susceptibility is focal or not and for observed resistance, the use of biochemical methods is needed with detailed comparison of resistance levels over a large geographic area. Aedes aegypti, Insecticides, Susceptibility, Cape Verde, Senegal.

Antimicrobial Susceptibility/Resistance of Streptococcus Pneumoniae

Science.gov (United States)

Karcic, Emina; Aljicevic, Mufida; Bektas, Sabaheta; Karcic, Bekir

2015-01-01

Introduction: Pneumococcal infections are a major cause of morbidity and mortality worldwide, whose treatment is threatened with an increase in the number of strains resistant to antibiotic therapy. Goal: The main goal of this research was to investigate the presence of antimicrobial susceptibility/resistance of S. pneumoniae. Material and methods: Taken are swabs of the nose and nasopharynx, eye and ear. In vitro tests that were made in order to study the antimicrobial resistance of pneumococci are: disk diffusion method and E-test. Results: The resistance to inhibitors of cell wall synthesis was recorded at 39.17%, protein synthesis inhibitors 19.67%, folate antagonists 47.78% and quinolone in 1.11%. S. pneumoniae has shown drug resistance to erythromycin in 45%, clindamycin in 45%, chloramphenicol–0.56%, rifampicin–6.11%, tetracycline–4.67%, penicillin-G in 4.44%, oxacillin in 73.89%, ciprofloxacin in 1.11% and trimethoprim-sulfamethoxazole in 5.34% of cases. Conclusion: The highest resistance pneumococcus showed to erythromycin, clindamycin and trimethoprim-sulfamethoxazole and these should be avoided in the treatment. The least resistance pneumococcus showed to tetracycline, rifampicin, chloramphenicol, penicillin-G and ciprofloxacin. PMID:26236165

Magnetic susceptibility of 244Cm metal and 249Cf metal

International Nuclear Information System (INIS)

Fujita, D.K.; Parsons, T.C.; Edelstein, N.; Noe, M.; Peterson, J.R.

1975-07-01

The first magnetic susceptibility measurements made on the expanded fcc phase of 249 Cf metal are reported. Further measurements are needed on other Cf metal phases. Another measurement of the magnetic susceptibility of 244 Cm metal in a limited temperature range has been reported. The result does not agree with previously reported values. Further work is continuing on the synthesis of 244 Cm metal and 248 Cm metal and magnetic measurements on these samples. (auth)

Tricking the guard: exploiting plant defense for disease susceptibility.

Science.gov (United States)

Lorang, J; Kidarsa, T; Bradford, C S; Gilbert, B; Curtis, M; Tzeng, S-C; Maier, C S; Wolpert, T J

2012-11-02

Typically, pathogens deploy virulence effectors to disable defense. Plants defeat effectors with resistance proteins that guard effector targets. We found that a pathogen exploits a resistance protein by activating it to confer susceptibility in Arabidopsis. The guard mechanism of plant defense is recapitulated by interactions among victorin (an effector produced by the necrotrophic fungus Cochliobolus victoriae), TRX-h5 (a defense-associated thioredoxin), and LOV1 (an Arabidopsis susceptibility protein). In LOV1's absence, victorin inhibits TRX-h5, resulting in compromised defense but not disease by C. victoriae. In LOV1's presence, victorin binding to TRX-h5 activates LOV1 and elicits a resistance-like response that confers disease susceptibility. We propose that victorin is, or mimics, a conventional pathogen virulence effector that was defeated by LOV1 and confers virulence to C. victoriae solely because it incites defense.

Antianaerobic Antimicrobials: Spectrum and Susceptibility Testing

Science.gov (United States)

Wexler, Hannah M.; Goldstein, Ellie J. C.

2013-01-01

SUMMARY Susceptibility testing of anaerobic bacteria recovered from selected cases can influence the choice of antimicrobial therapy. The Clinical and Laboratory Standards Institute (CLSI) has standardized many laboratory procedures, including anaerobic susceptibility testing (AST), and has published documents for AST. The standardization of testing methods by the CLSI allows comparisons of resistance trends among various laboratories. Susceptibility testing should be performed on organisms recovered from sterile body sites, those that are isolated in pure culture, or those that are clinically important and have variable or unique susceptibility patterns. Organisms that should be considered for individual isolate testing include highly virulent pathogens for which susceptibility cannot be predicted, such as Bacteroides, Prevotella, Fusobacterium, and Clostridium spp.; Bilophila wadsworthia; and Sutterella wadsworthensis. This review describes the current methods for AST in research and reference laboratories. These methods include the use of agar dilution, broth microdilution, Etest, and the spiral gradient endpoint system. The antimicrobials potentially effective against anaerobic bacteria include beta-lactams, combinations of beta-lactams and beta-lactamase inhibitors, metronidazole, chloramphenicol, clindamycin, macrolides, tetracyclines, and fluoroquinolones. The spectrum of efficacy, antimicrobial resistance mechanisms, and resistance patterns against these agents are described. PMID:23824372

In Vitro Antifungal Susceptibility of Neoscytalidium dimidiatum Clinical Isolates from Malaysia.

Science.gov (United States)

James, Jasper Elvin; Santhanam, Jacinta; Lee, Mei Chen; Wong, Choon Xian; Sabaratnam, Parameswari; Yusoff, Hamidah; Tzar, Mohd Nizam; Razak, Mohd Fuat Abdul

2017-04-01

Neoscytalidium dimidiatum is an opportunistic fungus causing cutaneous infections mostly, which are difficult to treat due to antifungal resistance. In Malaysia, N. dimidiatum is associated with skin and nail infections, especially in the elderly. These infections may be mistaken for dermatophyte infections due to similar clinical appearance. In this study, Neoscytalidium isolates from cutaneous specimens, identified using morphological and molecular methods (28 Neoscytalidium dimidiatum and 1 Neoscytalidium sp.), were evaluated for susceptibility towards antifungal agents using the CLSI broth microdilution (M38-A2) and Etest methods. Amphotericin B, voriconazole, miconazole and clotrimazole showed high in vitro activity against all isolates with MIC ranging from 0.0313 to 1 µg/mL. Susceptibility towards fluconazole and itraconazole was noted in up to 10% of isolates, while ketoconazole was inactive against all isolates. Clinical breakpoints for antifungal drugs are not yet available for most filamentous fungi, including Neoscytalidium species. However, the results indicate that clinical isolates of N. dimidiatum in Malaysia were sensitive towards miconazole, clotrimazole, voriconazole and amphotericin B, in vitro.

Measurements of temperature dependence of 'localized susceptibility'

CERN Document Server

Shiozawa, H; Ishii, H; Takayama, Y; Obu, K; Muro, T; Saitoh, Y; Matsuda, T D; Sugawara, H; Sato, H

2003-01-01

The magnetic susceptibility of some rare-earth compounds is estimated by measuring magnetic circular dichroism (MCD) of rare-earth 3d-4f absorption spectra. The temperature dependence of the magnetic susceptibility obtained by the MCD measurement is remarkably different from the bulk susceptibility in most samples, which is attributed to the strong site selectivity of the core MCD measurement.

Studies on the Identification of Constituents in Ethanol Extract of Radix Glycyrrhizae and Their Anti-Primary Hepatoma Cell Susceptibility

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Jie Liu

2014-01-01

Full Text Available The objective of this paper is to study the chemical constituents of Radix Glycyrrhizae and to apply the resulting natural products in the study of drug susceptibility of hepatoma cells so as to provide a scientific basis for quality standards and clinical application of medicinal Radix Glycyrrhizae. Chromatographic materials were used for isolation and purification; structural identification was performed based on physicochemical properties and spectral data. MTT colorimetry was used to detect the proliferation inhibition rate against primary hepatoma cells by natural products, and flow cytometry was used to detect the changes in cell cycle progression. Five compounds were isolated and identified, namely, liquiritigenin (1, liquiritin (2, isoliquiritigenin (3, betulinic acid (4, and oleanolic acid (5. In the study, 5-FU (5-fluorouracil is used as a positive control to the hepatoma cells. Primary hepatoma cells were highly susceptible to 5-FU and liquiritigenin, both of which markedly inhibited the proliferation of hepatoma cells; flow cytometry results showed an increase in G0/G1 phase cells, a decrease in S phase cells, and a relative increase in G2/M phase cells. Primary hepatoma cells are highly susceptible to liquiritigenin, a natural product; the testing of tumor cell susceptibility is of important significance to the improvement of therapeutic effect of cancer.

ORCHIDS: an Observational Randomized Controlled Trial on Childhood Differential Susceptibility

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Chhangur Rabia R

2012-10-01

Full Text Available Abstract Background A central tenet in developmental psychopathology is that childhood rearing experiences have a major impact on children’s development. Recently, candidate genes have been identified that may cause children to be differentially susceptible to these experiences (i.e., susceptibility genes. However, our understanding of the differential impact of parenting is limited at best. Specifically, more experimental research is needed. The ORCHIDS study will investigate gene-(gene-environment interactions to obtain more insight into a moderating effects of polymorphisms on the link between parenting and child behavior, and b behavioral mechanisms that underlie these gene-(gene-environment interactions in an experimental design. Methods/Design The ORCHIDS study is a randomized controlled trial, in which the environment will be manipulated with an intervention (i.e., Incredible Years parent training. In a screening, families with children aged 4–8 who show mild to (subclinical behavior problems will be targeted through community records via two Dutch regional healthcare organizations. Assessments in both the intervention and control condition will be conducted at baseline (i.e., pretest, after 6 months (i.e., posttest, and after 10 months (i.e., follow-up. Discussion This study protocol describes the design of a randomized controlled trial that investigates gene-(gene-environment interactions in the development of child behavior. Two hypotheses will be tested. First, we expect that children in the intervention condition who carry one or more susceptibility genes will show significantly lower levels of problem behavior and higher levels of prosocial behavior after their parent(s received the Incredible Years training, compared to children without these genes, or children in the control group. Second, we expect that children carrying one or more susceptibility genes will show a heightened sensitivity to changes in parenting behaviors, and

Virulence properties of methicillin-susceptible Staphylococcus aureus food isolates encoding Panton-Valentine Leukocidin gene.

Science.gov (United States)

Sudagidan, Mert; Aydin, Ali

2010-04-15

In this study, three Panton-Valentine Leukocidin gene carrying methicillin-susceptible Staphylococcus aureus (MSSA) strains (M1-AAG42B, PY30C-b and YF1B-b) were isolated from different food samples in Kesan-Edirne, Turkey. These strains were characterized on the basis of MLST type, spa type, virulence factor gene contents, antibiotic susceptibilities against 21 antibiotics and biofilm formation. The genetic relatedness of the strains was determined by PFGE. In addition, the complete gene sequences of lukS-PV and lukF-PV were also investigated. All strains were found to be susceptible to tested antibiotics and they were mecA negative. Three strains showed the same PFGE band pattern, ST152 clonal type and t355 spa type. In the detection of virulence factor genes, sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq, seu, eta, etb, set1, geh and tst genes were not detected. All strains showed the positive results for alpha- and beta-haemolysin genes (hla and hlb), protease encoding genes (sspA, sspB and aur), lukE and lukD leukocidin genes (lukED). The strains were found to be non-biofilm formers. By this study, the virulence properties of the strains were described and this is one of the first reports regarding PVL-positive MSSA strains from food. (c) 2010 Elsevier B.V. All rights reserved.

TRIGRS Application for landslide susceptibility mapping

Science.gov (United States)

Sugiarti, K.; Sukristiyanti, S.

2018-02-01

Research on landslide susceptibility has been carried out using several different methods. TRIGRS is a modeling program for landslide susceptibility by considering pore water pressure changes due to infiltration of rainfall. This paper aims to present a current state-of-the-art science on the development and application of TRIGRS. Some limitations of TRIGRS, some developments of it to improve its modeling capability, and some examples of the applications of some versions of it to model the effect of rainfall variation on landslide susceptibility are reviewed and discussed.

Susceptibility weighted imaging: differentiating between calcification and hemosiderin

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Jeam Haroldo Oliveira; Salmon, Carlos Ernesto Garrido, E-mail: jeamharoldo@hotmail.com [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras; Santos, Antonio Carlos [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina

2015-03-15

Objective: to present a detailed explanation on the processing of magnetic susceptibility weighted imaging (SWI), demonstrating the effects of echo time and sensitive mask on the differentiation between calcification and hemosiderin. Materials and methods: computed tomography and magnetic resonance (magnitude and phase) images of six patients (age range 41-54 years; four men) were retrospectively selected. The SWI images processing was performed using the Matlab's own routine. Results: four out of the six patients showed calcifications at computed tomography images and their SWI images demonstrated hyperintense signal at the calcification regions. The other patients did not show any calcifications at computed tomography, and SWI revealed the presence of hemosiderin deposits with hypointense signal. Conclusion: the selection of echo time and of the mask may change all the information on SWI images, and compromise the diagnostic reliability. Amongst the possible masks, the authors highlight that the sigmoid mask allows for contrasting calcifications and hemosiderin on a single SWI image. (author)

Inhibition or knockdown of ABC transporters enhances susceptibility of adult and juvenile schistosomes to Praziquantel.

Directory of Open Access Journals (Sweden)

Ravi S Kasinathan

2014-10-01

Full Text Available Parasitic flatworms of the genus Schistosoma cause schistosomiasis, a neglected tropical disease that affects hundreds of millions. Treatment of schistosomiasis depends almost entirely on the drug praziquantel (PZQ. Though essential to treating and controlling schistosomiasis, a major limitation of PZQ is that it is not active against immature mammalian-stage schistosomes. Furthermore, there are reports of field isolates with heritable reductions in PZQ susceptibility, and researchers have selected for PZQ-resistant schistosomes in the laboratory. P-glycoprotein (Pgp; ABCB1 and other ATP binding cassette (ABC transporters remove a wide variety of toxins and xenobiotics from cells, and have been implicated in multidrug resistance (MDR. Changes in ABC transporter structure or expression levels are also associated with reduced drug susceptibility in parasitic helminths, including schistosomes. Here, we show that the activity of PZQ against schistosome adults and juveniles ex vivo is potentiated by co-administration of either the highly potent Pgp inhibitor tariquidar or combinations of inhibitors targeting multiple ABC multidrug transporters. Adult worms exposed to sublethal PZQ concentrations remain active, but co-administration of ABC transporter inhibitors results in complete loss of motility and disruption of the tegument. Notably, juvenile schistosomes (3-4 weeks post infection, normally refractory to 2 µM PZQ, become paralyzed when transporter inhibitors are added in combination with the PZQ. Experiments using the fluorescent PZQ derivative (R-PZQ-BODIPY are consistent with the transporter inhibitors increasing effective intraworm concentrations of PZQ. Adult worms in which expression of ABC transporters has been suppressed by RNA interference show increased responsiveness to PZQ and increased retention of (R-PZQ-BODIPY consistent with an important role for these proteins in setting levels of PZQ susceptibility. These results indicate that

Rainfall and earthquake-induced landslide susceptibility assessment using GIS and Artificial Neural Network

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Y. Li

2012-08-01

Full Text Available A GIS-based method for the assessment of landslide susceptibility in a selected area of Qingchuan County in China is proposed by using the back-propagation Artificial Neural Network model (ANN. Landslide inventory was derived from field investigation and aerial photo interpretation. 473 landslides occurred before the Wenchuan earthquake (which were thought as rainfall-induced landslides (RIL in this study, and 885 earthquake-induced landslides (EIL were recorded into the landslide inventory map. To understand the different impacts of rainfall and earthquake on landslide occurrence, we first compared the variations between landslide spatial distribution and conditioning factors. Then, we compared the weight variation of each conditioning factor derived by adjusting ANN structure and factors combination respectively. Last, the weight of each factor derived from the best prediction model was applied to the entire study area to produce landslide susceptibility maps.

Results show that slope gradient has the highest weight for landslide susceptibility mapping for both RIL and EIL. The RIL model built with four different factors (slope gradient, elevation, slope height and distance to the stream shows the best success rate of 93%; the EIL model built with five different factors (slope gradient, elevation, slope height, distance to the stream and distance to the fault has the best success rate of 98%. Furthermore, the EIL data was used to verify the RIL model and the success rate is 92%; the RIL data was used to verify the EIL model and the success rate is 53%.

Antimicrobial susceptibility of porcine Brachyspira hyodysenteriae and Brachyspira pilosicoli isolated in Sweden between 1990 and 2010

Science.gov (United States)

2012-01-01

Background The anaerobic spirochetes Brachyspira hyodysenteriae and Brachyspira pilosicoli cause diarrheal diseases in pigs. Their fastidious nature has hampered standardization of methods for antimicrobial susceptibility testing. For monitoring of antimicrobial susceptibility wild type cutoff values are needed to define where the wild type distribution of MICs ends and no approved cutoffs are available for Brachyspira spp. In this study antimicrobial susceptibility data for both species (in total 906 isolates) were compiled and analyzed and wild type cut off values for B. hyodysenteriae proposed. Methods The MICs of tiamulin, valnemulin, tylosin, tylvalosin, doxycycline and lincomycin were determined by broth dilution in brain heart infusion broth supplemented with 10% fetal calf serum. Results The compiled MICs from the broth dilution tests of the B. hyodysenteriae type strain, B78T (ATCC® 27164T), showed that the method yields reproducible results. In an international perspective the frequencies of isolates with decreased antimicrobial susceptibility were low among both B. hyodysenteriae and B. pilosicoli. However, in B. pilosicoli a constant level of 10-15% isolates with tiamulin MICs >4 μg/ml was detected between 2002 and 2010 and in B. hyodysenteriae a gradual increase in tiamulin MICs was seen between 1990 and 2003 although this increase has ceased during the last years. The wild type cutoff values proposed for B. hyodysenteriae are: tiamulin >0.25 μg/ml, valnemulin >0.125 μg/ml, tylosin >16 μg/ml, tylvalosin >1 μg/ml, lincomycin >1 μg/ml and doxycycline >0.5 μg/ml. Conclusions The broth dilution method used in this study has over the years generated tightly grouped MIC populations for the field isolates and reproducible results for the control strain B78T and is therefore a suitable antimicrobial susceptibility test method for monitoring of Brachyspira spp. Here we propose wild type cutoff values for six antimicrobial agents for B. hyodysenteriae

Antimicrobial susceptibility of porcine Brachyspira hyodysenteriae and Brachyspira pilosicoli isolated in Sweden between 1990 and 2010

Directory of Open Access Journals (Sweden)

Pringle Märit

2012-09-01

Full Text Available Abstract Background The anaerobic spirochetes Brachyspira hyodysenteriae and Brachyspira pilosicoli cause diarrheal diseases in pigs. Their fastidious nature has hampered standardization of methods for antimicrobial susceptibility testing. For monitoring of antimicrobial susceptibility wild type cutoff values are needed to define where the wild type distribution of MICs ends and no approved cutoffs are available for Brachyspira spp. In this study antimicrobial susceptibility data for both species (in total 906 isolates were compiled and analyzed and wild type cut off values for B. hyodysenteriae proposed. Methods The MICs of tiamulin, valnemulin, tylosin, tylvalosin, doxycycline and lincomycin were determined by broth dilution in brain heart infusion broth supplemented with 10% fetal calf serum. Results The compiled MICs from the broth dilution tests of the B. hyodysenteriae type strain, B78T (ATCC® 27164T, showed that the method yields reproducible results. In an international perspective the frequencies of isolates with decreased antimicrobial susceptibility were low among both B. hyodysenteriae and B. pilosicoli. However, in B. pilosicoli a constant level of 10-15% isolates with tiamulin MICs >4 μg/ml was detected between 2002 and 2010 and in B. hyodysenteriae a gradual increase in tiamulin MICs was seen between 1990 and 2003 although this increase has ceased during the last years. The wild type cutoff values proposed for B. hyodysenteriae are: tiamulin >0.25 μg/ml, valnemulin >0.125 μg/ml, tylosin >16 μg/ml, tylvalosin >1 μg/ml, lincomycin >1 μg/ml and doxycycline >0.5 μg/ml. Conclusions The broth dilution method used in this study has over the years generated tightly grouped MIC populations for the field isolates and reproducible results for the control strain B78T and is therefore a suitable antimicrobial susceptibility test method for monitoring of Brachyspira spp. Here we propose wild type cutoff values for six antimicrobial

Susceptibility of Staphylococcus species and subspecies to teicoplanin.

Science.gov (United States)

Bannerman, T L; Wadiak, D L; Kloos, W E

1991-01-01

Twenty-four Staphylococcus species and their subspecies were examined for their susceptibilities to teicoplanin by disk diffusion (30-micrograms disk) and agar dilution for the determination of MICs. Moderately susceptible and resistant clinical strains were further tested for their susceptibilities to oxacillin and vancomycin. Teicoplanin resistance was not observed in the reference strains of the various Staphylococcus species isolated from healthy volunteers or animals. However, the novobiocin-resistant species Staphylococcus saprophyticus, Staphylococcus cohnii, Staphylococcus xylosus, Staphylococcus arlettae, Staphylococcus kloosii, and Staphylococcus gallinarum were less susceptible to teicoplanin (MIC, 2 to 8 micrograms/ml) than most of the novobiocin-susceptible species were (MIC, 0.5 to 4 micrograms/ml). Clinical isolates of coagulase-negative species were generally less susceptible to teicoplanin than were reference strains. Seven percent of the Staphylococcus epidermidis clinical strains were moderately susceptible (MIC, 16 micrograms/ml) to teicoplanin. Of these strains, 70% were oxacillin resistant. For Staphylococcus haemolyticus strains, 11% were resistant (MIC, greater than 16 micrograms/ml) and 21% were moderately susceptible to teicoplanin. Of these strains, 95% were oxacillin resistant, No strains of S. epidermidis or S. haemolyticus were intermediate or resistant to vancomycin. Teicoplanin appears to be less active in vitro against oxacillin-resistant S. haemolyticus. However, teicoplanin is an effective antimicrobial agent against many Staphylococcus species. PMID:1835340

Evaluation of SCC susceptibility of alloy 800 under CANDU SG secondary-side conditions

International Nuclear Information System (INIS)

Liu, S.; Lu, Y.

2006-01-01

As part of a coordinated program, AECL is developing a set of tools to aid with the prediction and management of steam generator performance. Although stress corrosion cracking (of Alloy 800) has not been detected in any operating steam generator, for life management it is necessary to develop mechanistic models to predict the conditions under which stress corrosion cracking is plausible. Therefore, constant extension rate tests were carried out for Alloy 800 under various steam generator crevice chemistry conditions at applied potentials. These tests were designed to evaluate the stress corrosion cracking susceptibility of Alloy 800 under CANDU( steam generator operating conditions. Based on the experimental results, the recommended electrochemical corrosion potential/pH zone for Alloy 800 determined by electrochemical polarization measurements was verified with the respect of stress corrosion cracking susceptibility. The effects of lead contamination on the stress corrosion cracking susceptibility of Alloy 800 tubing were also evaluated. The experimental results from constant extension rate tests obtained under applied potentials suggest that Alloy 800 has good performance inside much of a previously recommended electrochemical corrosion potential/pH zone determined by electrochemical analysis. Alloy 800 is not susceptible to stress corrosion cracking under normal CANDU steam generator operating conditions. However, Alloy 800 may be susceptible to stress corrosion cracking under near-neutral crevice chemistry conditions in the presence of oxidants. In addition, stress corrosion cracking susceptibility is increased by lead contamination. This observation suggests that the previously defined electrochemical corrosion potential limit under near-neutral crevice conditions could be modified to minimize stress corrosion cracking of Alloy 800. The test results from this work also suggest that the pH dependency of the stress corrosion cracking susceptibility of Alloy 800