Science.gov

Sample records for aberration ca test

  1. [In vitro chromosome aberration test and in vivo micronucleus test of Ca-type Garcinia extract].

    PubMed

    Ono, Hiromi; Tamura, Hideyuki; Yamashita, Yasuhiro; Tamura, Kouichi; Iwakura, Keiko

    2006-04-01

    The induction of chromosome aberration of Ca-type Garcinia cambogia extract containing about 65% (-)-hydroxycitric acid was investigated by use of the chromosome aberration test in cultured Chinese hamster lung cells (CHL/IU) and the micronucleus test in mice. In the chromosome aberration test, Ca-type Garcinia cambogia extract did not increase the number of cells with structural aberration and/or numerical aberrations. The micronucleus test was carried out with bone marrow cells of Slc : ddY male mice after single oral administration of up to 2,000 microg/kg. There was no significant increase in the frequency of micronucleated polychromatic erythrocytes. These results indicate that Ca-type Garcinia cambogia extract does not induce chromosome aberration. PMID:16729669

  2. Modified Matching Ronchi Test to Visualize Lens Aberrations

    ERIC Educational Resources Information Center

    Hassani, Kh; Ziafi, H. Hooshmand

    2011-01-01

    We introduce a modification to the matching Ronchi test to visualize lens aberrations with simple and inexpensive equipment available in educational optics labs. This method can help instructors and students to observe and estimate lens aberrations in real time. It is also a semi-quantitative tool for primary tests in research labs. In this work…

  3. Modified matching Ronchi test to visualize lens aberrations

    NASA Astrophysics Data System (ADS)

    Hassani, Kh; Hooshmand Ziafi, H.

    2011-09-01

    We introduce a modification to the matching Ronchi test to visualize lens aberrations with simple and inexpensive equipment available in educational optics labs. This method can help instructors and students to observe and estimate lens aberrations in real time. It is also a semi-quantitative tool for primary tests in research labs. In this work by comparing a single lens with a doublet, we can clearly demonstrate the superior quality of the doublet over the single lens, and estimate their conic constants.

  4. Comparative evaluation of the in vitro micronucleus test and the in vitro chromosome aberration test: industrial experience.

    PubMed

    Miller, B; Albertini, S; Locher, F; Thybaud, V; Lorge, E

    1997-08-01

    Because of its rapidness, simplicity and potential for automation, the measurement of micronucleated cells in vivo is not only equivalent to the analysis of chromosome aberrations, but often even preferred within routine genotoxicity testing. In order to evaluate the correlation between the in vitro micronucleus assay (MNT) and the in vitro chromosome aberration test (CA), we collected data from four pharmaceutical companies obtained either in Chinese hamster cell lines (CHO-K5, CHO-K1, V79) or in human peripheral blood lymphocytes. Among the 57 compounds included in this comparison, 45 compounds gave rise to concordant results in both assays (26 compounds negative in both assays; 19 compounds positive in both assays). The high percentage of concordance, i.e. about 79% is very promising and can be even increased to about 88% by omitting the 3 aneugenic compounds and 2 compounds inducing endoreduplicated chromosomes which were found positive only in the in vitro MNT. The results are remarkable in particular considering that most of the compounds evaluated are 'standard' pharmaceutical compounds and thus are at most weak inducers of chromosome damage. Our comparison strongly supports that the in vitro micronucleus test is a suitable alternative to the in vitro chromosome aberration assay. Moreover, the MNT has the potential of not only detecting clastogens but additionally aneuploidy inducing chemicals.

  5. Bayesian Procedures for Identifying Aberrant Response-Time Patterns in Adaptive Testing

    ERIC Educational Resources Information Center

    van der Linden, Wim J.; Guo, Fanmin

    2008-01-01

    In order to identify aberrant response-time patterns on educational and psychological tests, it is important to be able to separate the speed at which the test taker operates from the time the items require. A lognormal model for response times with this feature was used to derive a Bayesian procedure for detecting aberrant response times.…

  6. Freshwater planarians as novel organisms for genotoxicity testing: Analysis of chromosome aberrations.

    PubMed

    Lau, Adriana Helena; Knakievicz, Tanise; Prá, Daniel; Erdtmann, Bernardo

    2007-07-01

    Two freshwater species of planarians, Girardia schubarti Marcus and G. tigrina Girard, were used for measuring chromosome aberration (CA) induction under laboratory conditions. Three genotoxicants were tested: methyl methanesulfonate (MMS), a direct-acting genotoxicant; cyclophosphamide, a metabolism-dependent genotoxicant; and gamma-radiation, a clastogenic agent. All three agents produced positive responses in both species. The strongest dose-responses were detected with MMS, and, in general, G. tigrina was somewhat more sensitive to the genotoxicity of the agents than G. schubarti. This difference in sensitivity may be due to: (a) the smaller body mass of G. tigrina; (b) differences in DNA repair, which may be reflected in the marginally higher background CA frequency of G. tigrina; and/or (c) the greater number of chromosomes in G. tigrina (2N = 16) as compared with G. schubarti (2N = 8). The responses induced by gamma-radiation in the planarians were similar to or higher than those induced in cultured human lymphocytes. The CA-planarian assay has advantages for monitoring environmental genotoxicity in natural water resources or urban and industrial wastewater since planarians are characterized by (a) a relatively low number of easily analyzable chromosomes; (b) high regenerating capacity, allowing exposure of replicating cells from different parts of the same organism to different doses; (c) easy maintenance under laboratory conditions; and (d) worldwide distribution, making them available for genotoxicity tests using either in situ or controlled laboratory exposure conditions.

  7. 40 CFR 799.9538 - TSCA mammalian bone marrow chromosomal aberration test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... as a dose-related increase in the relative number of cells with chromosome aberrations or a clear increase in the number of cells with aberrations in a single dose group at a single sampling time... study. (D) Stability of the test substance, if known. (ii) Solvent/vehicle: (A) Justification for...

  8. 10. "TEST STAND 15, AIR FORCE FLIGHT TEST CENTER." ca. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. "TEST STAND 1-5, AIR FORCE FLIGHT TEST CENTER." ca. 1958. Test Area 1-115. Original is a color print, showing Test Stand 1-5 from below, also showing the superstructure of TS1-4 at left. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Leuhman Ridge near Highways 58 & 395, Boron, Kern County, CA

  9. Aberrant activation of CaMKIIγ accelerates chronic myeloid leukemia blast crisis.

    PubMed

    Gu, Y; Zheng, W; Zhang, J; Gan, X; Ma, X; Meng, Z; Chen, T; Lu, X; Wu, Z; Huang, W; Xu, R

    2016-06-01

    Blast crisis (BC) is the final deadly phase of chronic myeloid leukemia (CML), but its molecular basis remains poorly understood. Here, we show that CML BC is regulated by calcium-calmodulin-dependent kinase IIγ (CaMKIIγ). Genetic deletion of CaMKIIγ greatly inhibits disease progression via selectively impairing the self-renewal of leukemia stem cells (LSCs) in mouse models, whereas overexpression of CaMKIIγ has the opposite effects. In human CML, phosphorylated CaMKIIγ abundance is significantly associated with BC. Moreover, CaMKIIγ phosphorylates and reduces the nuclear cyclin-dependent kinase inhibitor p27Kip1, a critical brake that maintains LSC quiescence. These findings suggest that CaMKIIγ might be an important switch for the transition of CML BC and identify a unique mechanism by which CaMKIIγ promotes the self-renewal of LSCs by deceasing nuclear p27Kip1 to wake up dormant LSCs. Therefore, CaMKIIγ may provide a new therapeutic target to treat CML BC.

  10. Aberrant activation of CaMKIIγ accelerates chronic myeloid leukemia blast crisis.

    PubMed

    Gu, Y; Zheng, W; Zhang, J; Gan, X; Ma, X; Meng, Z; Chen, T; Lu, X; Wu, Z; Huang, W; Xu, R

    2016-06-01

    Blast crisis (BC) is the final deadly phase of chronic myeloid leukemia (CML), but its molecular basis remains poorly understood. Here, we show that CML BC is regulated by calcium-calmodulin-dependent kinase IIγ (CaMKIIγ). Genetic deletion of CaMKIIγ greatly inhibits disease progression via selectively impairing the self-renewal of leukemia stem cells (LSCs) in mouse models, whereas overexpression of CaMKIIγ has the opposite effects. In human CML, phosphorylated CaMKIIγ abundance is significantly associated with BC. Moreover, CaMKIIγ phosphorylates and reduces the nuclear cyclin-dependent kinase inhibitor p27Kip1, a critical brake that maintains LSC quiescence. These findings suggest that CaMKIIγ might be an important switch for the transition of CML BC and identify a unique mechanism by which CaMKIIγ promotes the self-renewal of LSCs by deceasing nuclear p27Kip1 to wake up dormant LSCs. Therefore, CaMKIIγ may provide a new therapeutic target to treat CML BC. PMID:27012864

  11. Testing for Aberrant Behavior in Response Time Modeling

    ERIC Educational Resources Information Center

    Marianti, Sukaesi; Fox, Jean-Paul; Avetisyan, Marianna; Veldkamp, Bernard P.; Tijmstra, Jesper

    2014-01-01

    Many standardized tests are now administered via computer rather than paper-and-pencil format. In a computer-based testing environment, it is possible to record not only the test taker's response to each question (item) but also the amount of time spent by the test taker in considering and answering each item. Response times (RTs) provide…

  12. Cryogenic Pupil Alignment Test Architecture for Aberrated Pupil Images

    NASA Technical Reports Server (NTRS)

    Bos, Brent; Kubalak, David A.; Antonille, Scott; Ohl, Raymond; Hagopian, John G.

    2009-01-01

    A document describes cryogenic test architecture for the James Webb Space Telescope (JWST) integrated science instrument module (ISIM). The ISIM element primarily consists of a mechanical metering structure, three science instruments, and a fine guidance sensor. One of the critical optomechanical alignments is the co-registration of the optical telescope element (OTE) exit pupil with the entrance pupils of the ISIM instruments. The test architecture has been developed to verify that the ISIM element will be properly aligned with the nominal OTE exit pupil when the two elements come together. The architecture measures three of the most critical pupil degrees-of-freedom during optical testing of the ISIM element. The pupil measurement scheme makes use of specularly reflective pupil alignment references located inside the JWST instruments, ground support equipment that contains a pupil imaging module, an OTE simulator, and pupil viewing channels in two of the JWST flight instruments. Pupil alignment references (PARs) are introduced into the instrument, and their reflections are checked using the instrument's mirrors. After the pupil imaging module (PIM) captures a reflected PAR image, the image will be analyzed to determine the relative alignment offset. The instrument pupil alignment preferences are specularly reflective mirrors with non-reflective fiducials, which makes the test architecture feasible. The instrument channels have fairly large fields of view, allowing PAR tip/tilt tolerances on the order of 0.5deg.

  13. Evaluation of genotoxicity of Trois through Ames and in vitro chromosomal aberration tests

    PubMed Central

    Chaudhary, Manu; Payasi, Anurag

    2013-01-01

    Objective To investigate the mutagenic potential of Trois using the bacterial reverse mutation assay (Ames test) and in vitro chromosomal aberration test. Methods The ability of Trois to induce reverse mutations was evaluated in Salmonella typhimurium (TA 98, TA100, TA1535 and TA1537) and Escherichia coli (WP2 uvrA) with and without metabolic activation system (S9 mix) at the dose range of 313 to 5000 µg/plate. Chromosomal aberrations were evaluated in Chinese hamster lung (CHL) cell line at the dose levels of 15, 7.5, 3.7, 1.9 and 0.9 mg/mL in the absence and presence of S9 mix. Results There were no increases in the number of revertant colonies at any concentrations of Trois used in the study with and without S9 mix in all tester strains. Trois did not produce any structural aberration in CHL cells in the presence or absence of S9 mix. Conclusions Results of this study suggest that Trois is non-mutagenic.

  14. Field applications of the piscine anaphase aberration test: lessons from the Exxon Valdez oil spill.

    PubMed

    Hose, J E; Brown, E D

    1998-03-20

    Several large-scale genotoxicity assessments have been performed in coastal marine areas that have demonstrated either localized or widespread genetic effects resulting from human activity. One common assessment method is the anaphase aberration test, a measurement of abnormal chromosome division, using embryolarval fishes. It can be used to detect the presence of mutagens within a poorly characterized complex mixture or monitor specific genotoxins and is easily adapted for laboratory screening. One comprehensive marine genotoxicity assessment was conducted using Pacific herring (Clupea pallasi) following the Exxon Valdez oil spill (EVOS) in Prince William Sound (PWS), AK in late March 1989. In early May, genetic damage was detected at many sites within the oil trajectory and was correlated with concentrations of polycyclic aromatic hydrocarbons characteristic of Exxon Valdez oil (EVO) in intertidal mussels. Effects were related spatially and temporally to oil exposure. Anaphase aberration rates decreased throughout May and June 1989, and by 1991, genotoxicity was undetectable. The abundance of the 1989 herring year class in PWS is significantly reduced; this is the first reported example linking genotoxicity to subsequent population level effects. This review describes the methodology for the anaphase aberration test using fish eggs, its applications for large-scale assessments and supportive laboratory studies, and its limitations for prediction of higher level effects on populations. PMID:9672658

  15. Field applications of the piscine anaphase aberration test: lessons from the Exxon Valdez oil spill.

    PubMed

    Hose, J E; Brown, E D

    1998-03-20

    Several large-scale genotoxicity assessments have been performed in coastal marine areas that have demonstrated either localized or widespread genetic effects resulting from human activity. One common assessment method is the anaphase aberration test, a measurement of abnormal chromosome division, using embryolarval fishes. It can be used to detect the presence of mutagens within a poorly characterized complex mixture or monitor specific genotoxins and is easily adapted for laboratory screening. One comprehensive marine genotoxicity assessment was conducted using Pacific herring (Clupea pallasi) following the Exxon Valdez oil spill (EVOS) in Prince William Sound (PWS), AK in late March 1989. In early May, genetic damage was detected at many sites within the oil trajectory and was correlated with concentrations of polycyclic aromatic hydrocarbons characteristic of Exxon Valdez oil (EVO) in intertidal mussels. Effects were related spatially and temporally to oil exposure. Anaphase aberration rates decreased throughout May and June 1989, and by 1991, genotoxicity was undetectable. The abundance of the 1989 herring year class in PWS is significantly reduced; this is the first reported example linking genotoxicity to subsequent population level effects. This review describes the methodology for the anaphase aberration test using fish eggs, its applications for large-scale assessments and supportive laboratory studies, and its limitations for prediction of higher level effects on populations.

  16. Using aberration test patterns to optimize the performance of EUV aerial imaging microscopes

    SciTech Connect

    Mochi, Iacopo; Goldberg, Kenneth A.; Miyakawa, Ryan; Naulleau, Patrick; Han, Hak-Seung; Huh, Sungmin

    2009-06-16

    The SEMATECH Berkeley Actinic Inspection Tool (AIT) is a prototype EUV-wavelength zoneplate microscope that provides high quality aerial image measurements of EUV reticles. To simplify and improve the alignment procedure we have created and tested arrays of aberration-sensitive patterns on EUV reticles and we have compared their images collected with the AIT to the expected shapes obtained by simulating the theoretical wavefront of the system. We obtained a consistent measure of coma and astigmatism in the center of the field of view using two different patterns, revealing a misalignment condition in the optics.

  17. Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test

    NASA Astrophysics Data System (ADS)

    Musa, Marahaini; Thirumulu Ponnuraj, Kannan; Mohamad, Dasmawati; Rahman, Ismail Ab

    2013-01-01

    Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions.

  18. Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test.

    PubMed

    Musa, Marahaini; Ponnuraj, Kannan Thirumulu; Mohamad, Dasmawati; Rahman, Ismail Ab

    2013-01-11

    Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions.

  19. Recombinant Atrial Natriuretic Peptide Prevents Aberrant Ca2+ Leakage through the Ryanodine Receptor by Suppressing Mitochondrial Reactive Oxygen Species Production Induced by Isoproterenol in Failing Cardiomyocytes

    PubMed Central

    Susa, Takehisa; Nanno, Takuma; Ishiguchi, Hironori; Myoren, Takeki; Nishimura, Shigehiko; Kato, Takayoshi; Hino, Akihiro; Oda, Tetsuro; Okuda, Shinichi; Yamamoto, Takeshi; Yano, Masafumi

    2016-01-01

    Catecholamines induce intracellular reactive oxygen species (ROS), thus enhancing diastolic Ca2+ leakage through the ryanodine receptor during heart failure (HF). However, little is known regarding the effect of atrial natriuretic peptide (ANP) on ROS generation and Ca2+ handling in failing cardiomyocytes. The aim of the present study was to clarify the mechanism by which an exogenous ANP exerts cardioprotective effects during HF. Cardiomyocytes were isolated from the left ventricles of a canine tachycardia-induced HF model and sham-operated vehicle controls. The degree of mitochondrial oxidized DNA was evaluated by double immunohistochemical (IHC) staining using an anti-VDAC antibody for the mitochondria and an anti-8-hydroxy-2′-deoxyguanosine antibody for oxidized DNA. The effect of ANP on ROS was investigated using 2,7-dichlorofluorescin diacetate, diastolic Ca2+ sparks assessed by confocal microscopy using Fluo 4-AM, and the survival rate of myocytes after 48 h. The double IHC study revealed that isoproterenol (ISO) markedly increased oxidized DNA in the mitochondria in HF and that the ISO-induced DNA damage was markedly inhibited by the co-presence of ANP. ROS production and Ca2+ spark frequency (CaSF) were increased in HF compared to normal controls, and were further increased in the presence of ISO. Notably, ANP significantly suppressed both ISO-induced ROS and CaSF without changing sarcoplasmic reticulum Ca2+ content in HF (p<0.01, respectively). The survival rate after 48 h in HF was significantly decreased in the presence of ISO compared with baseline (p<0.01), whereas it was significantly improved by the co-presence of ANP (p<0.01). Together, our results suggest that ANP strongly suppresses ISO-induced mitochondrial ROS generation, which might correct aberrant diastolic Ca2+ sparks, eventually contributing to the improvement of cardiomyocyte survival in HF. PMID:27657534

  20. Aberrant Splicing Promotes Proteasomal Degradation of L-type CaV1.2 Calcium Channels by Competitive Binding for CaVβ Subunits in Cardiac Hypertrophy

    PubMed Central

    Hu, Zhenyu; Wang, Jiong-Wei; Yu, Dejie; Soon, Jia Lin; de Kleijn, Dominique P. V.; Foo, Roger; Liao, Ping; Colecraft, Henry M.; Soong, Tuck Wah

    2016-01-01

    Decreased expression and activity of CaV1.2 calcium channels has been reported in pressure overload-induced cardiac hypertrophy and heart failure. However, the underlying mechanisms remain unknown. Here we identified in rodents a splice variant of CaV1.2 channel, named CaV1.2e21+22, that contained the pair of mutually exclusive exons 21 and 22. This variant was highly expressed in neonatal hearts. The abundance of this variant was gradually increased by 12.5-folds within 14 days of transverse aortic banding that induced cardiac hypertrophy in adult mouse hearts and was also elevated in left ventricles from patients with dilated cardiomyopathy. Although this variant did not conduct Ca2+ ions, it reduced the cell-surface expression of wild-type CaV1.2 channels and consequently decreased the whole-cell Ca2+ influx via the CaV1.2 channels. In addition, the CaV1.2e21+22 variant interacted with CaVβ subunits significantly more than wild-type CaV1.2 channels, and competition of CaVβ subunits by CaV1.2e21+22 consequently enhanced ubiquitination and subsequent proteasomal degradation of the wild-type CaV1.2 channels. Our findings show that the resurgence of a specific neonatal splice variant of CaV1.2 channels in adult heart under stress may contribute to heart failure. PMID:27731386

  1. Comprehensive retrospective evaluation of existing in vitro chromosomal aberration test data by cytotoxicity index transformation.

    PubMed

    Fujita, Yurika; Morita, Takeshi; Matsumura, Shoji; Kawamoto, Taisuke; Ito, Yuichi; Nishiyama, Naohiro; Honda, Hiroshi

    2016-05-01

    New OECD test guidelines have been issued, in which the cytotoxicity index relative cell count (RCC) is replaced with a new index, RICC or RPD (relative increase in cell count/relative population doubling), with the goal of reducing the high proportion of false positive results in in vitro chromosomal aberration tests. Using a mathematical approach to estimate new indices from the RCC, we constructed an evaluation flow that quantitatively estimates how often the previous test conclusions change when applying the updated cytotoxicity criteria. The new evaluation flow was applied to a retrospective evaluation of 285 chemicals in two databases. The effects of the employment of new cytotoxicity indices are investigated at a large scale. Using the new evaluation flow, 90 chemicals were estimated as positive, 39 were designated as estimated negative (13 probably negative and 26 possibly negative), and 140 were designated as negative. Moreover, we also applied a prioritization index to indicate the likelihood of a chemical being re-evaluated as negative and assigned priorities for testing. Most of the chemicals that were designated as estimated negative and had negative results in the in vivo micronucleus tests were considered as false-positives that would be correctly judged under the new test guideline. Furthermore, statistical analysis of the frequency of estimated negatives revealed that the results for Ames-positive chemicals, especially those with a strong response, are unlikely to change. Therefore, we concluded that the new indices would likely reduce the proportion of false positive results and not increase the proportion of false negative results. This study is the first report of a comprehensive re-evaluation of test results in terms of new cytotoxicity indices. The evaluation flow we have developed facilitates efficient retrospective evaluation of genotoxicity.

  2. Allium cepa chromosome aberration and micronucleus tests applied to study genotoxicity of extracts from pesticide-treated vegetables and grapes.

    PubMed

    Feretti, D; Zerbini, I; Zani, C; Ceretti, E; Moretti, M; Monarca, S

    2007-06-01

    The Allium cepa assay is an efficient test for chemical screening and in situ monitoring for genotoxicity of environmental contaminants. The test has been used widely to study genotoxicity of many pesticides revealing that these compounds can induce chromosomal aberrations in root meristems of A. cepa. Pesticide residues can be present in fruit and vegetables and represent a risk for human health. The mutagenic and carcinogenic action of herbicides, insecticides and fungicides on experimental animals is well known. Several studies have shown that chronic exposure to low levels of pesticides can cause birth defects and that prenatal exposure is associated with carcinogenicity. This study evaluated the potential application of plant genotoxicity tests for monitoring mutagens in edible vegetables. The presence of pesticides and genotoxic compounds extracted from 21 treated vegetables and eight types of grapes sampled from several markets in Campania, a region in Southern Italy, was monitored concurrently. The extracts were analysed for pesticides by gas chromatography and high-performance liquid chromatography, and for genotoxicity using two plant tests: the micronucleus test and the chromosomal aberration test in A. cepa roots. Thirty-three pesticides were detected, some of which are not approved. Genotoxicity was found in some of the vegetables and grapes tested. Allium cepa tests proved to be sensitive in monitoring genotoxicity in food extracts. The micronucleus test in interphase cells gave a much higher mutagenicity than the chromosomal aberration test in anaphase-telophase cells. PMID:17487597

  3. A comparative biomonitoring study of populations residing in regions with low and high risk of lung cancer using the chromosome aberration and the micronucleus tests.

    PubMed

    Heepchantree, Worapa; Paratasilpin, Thipmani; Kangwanpong, Daoroong

    2005-11-10

    Chromosome aberration (CA) and micronucleus (MN) tests were performed in peripheral blood lymphocytes from people residing in two districts of Chiang Mai, Thailand, a high-risk area, Saraphi (n=107), where the lung cancer incidence is three-fold higher than in a low-risk area, Chom Thong (n=118). The percentage of cells with CAs was significantly lower in the Saraphi population than in the Chom Thong population (0.47+/-0.91 versus 1.04+/-1.18, P=0.0001) as was the percentage of CAs (0.49+/-0.91 versus 1.08+/-1.21, P<0.0001) and the mitotic indices (1.25+/-0.44 versus 1.33+/-0.33, P=0.025). The frequency of MN in binucleated (BN) cells, however, was significantly higher in the Saraphi population (12.01+/-3.57 versus 9.99+/-3.11, P<0.0001) as was the percentage of BN cells with MN (1.14+/-0.31 versus 0.93+/-0.23, P<0.0001). There was no difference in the nuclear division indices (1.49+/-0.07 versus 1.47+/-0.11, P=0.1759) between the two populations. With regard to the effect of confounding factors, it was found that cigarette smoking influenced both CA and MN frequencies, and that the chewing of fermented tea leaves or betel nuts affected CA and sex affected MN frequencies. An increasing of CA and MN frequencies were seen in smokers and chewers over non-smokers and non-chewers, with CA frequencies being higher in Chom Thong smokers and chewers and MN frequency being higher in Saraphi smokers. However, pesticide exposure and alcohol consumption had no impact on CA and MN frequencies. Due to the conflicting results obtained in the two tests, we cannot make a clear statement regarding the potential effects of the environmental exposures in the two study populations. PMID:16185913

  4. RESEM-CA: Validation and testing

    SciTech Connect

    Pal, Vineeta; Carroll, William L.; Bourassa, Norman

    2002-09-01

    This report documents the results of an extended comparison of RESEM-CA energy and economic performance predictions with the recognized benchmark tool DOE2.1E to determine the validity and effectiveness of this tool for retrofit design and analysis. The analysis was a two part comparison of patterns of (1) monthly and annual energy consumption of a simple base-case building and controlled variations in it to explore the predictions of load components of each program, and (2) a simplified life-cycle cost analysis of the predicted effects of selected Energy Conservation Measures (ECMs). The study tries to analyze and/or explain the differences that were observed. On the whole, this validation study indicates that RESEM is a promising tool for retrofit analysis. As a result of this study some factors (incident solar radiation, outside air film coefficient, IR radiation) have been identified where there is a possibility of algorithmic improvements. These would have to be made in a way that does not sacrifice the speed of the tool, necessary for extensive parametric search of optimum ECM measures.

  5. Report from the working group on the in vivo mammalian bone marrow chromosomal aberration test.

    PubMed

    Tice, R R; Hayashi, M; MacGregor, J T; Anderson, D; Blakey, D H; Holden, H E; Kirsch-Volders, M; Oleson, F B; Pacchierotti, F; Preston, R J

    1994-06-01

    The following summary represents a consensus of the working group, except where noted. The goal of this working group was to identify the minimal requirements needed to conduct a scientifically valid and practical in vivo chromosomal aberration assay. For easy reference, the items discussed are listed in the order in which they appear in OECD guideline 475. Specific disagreement with the current and/or proposed OECD guideline is presented in the text. Introduction, purpose, scope, relevance, application, and limits of test: This test would not be appropriate in situations where there was sufficient evidence to indicate that the test article or reactive metabolites could not reach the bone marrow. Test substances: Solid and liquid test substances should be dissolved, if possible, in water or isotonic saline. If insoluble in water/saline, the test substance should be dissolved or homogeneously suspended in an appropriate vehicle (e.g., vegetable oil). A suspension was not considered suitable for an intravenous injection. The use of dimethyl sulfoxide as an organic solvent was not recommended. The use of any uncommonly used solvent/vehicle should be justified. Freshly prepared solutions or suspensions of the test substance should be employed unless stability data demonstrate the acceptability of storage. Selection of species: Any commonly used rodent species was deemed acceptable but rats or mice were preferred, with no strain preference. Number and sex: A consensus could not be reached as to the requirement for both sexes versus one sex in this assay. It was suggested that a single sex should be used unless pharmacokinetic and/or toxicity data indicated a difference in metabolism and/or sensitivity between males and females. The size of the experiment (i.e., number of cells per animal, number of animals per treatment group) should be based on statistical considerations. Lacking a formal analysis, it was agreed that at least 100 metaphase cells should be scored per

  6. 40 CFR 799.9537 - TSCA in vitro mammalian chromosome aberration test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... equally divided amongst the duplicates, if applicable. This number can be reduced when high numbers of... or a reproducible increase in the number of cells with chromosome aberrations. Biological relevance... not be the only determining factor for a positive response. (ii) An increase in the number......

  7. 40 CFR 799.9537 - TSCA in vitro mammalian chromosome aberration test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... equally divided amongst the duplicates, if applicable. This number can be reduced when high numbers of... or a reproducible increase in the number of cells with chromosome aberrations. Biological relevance... not be the only determining factor for a positive response. (ii) An increase in the number......

  8. [Genotoxic effects of pesticide-treated vegetable extracts using the Allium cepa chromosome aberration and micronucleus tests].

    PubMed

    Biscardi, D; De Fusco, R; Feretti, D; Zerbini, I; Izzo, C; Esposito, V; Nardi, G; Monarca, S

    2003-01-01

    The presence of chemical residues in vegetables and fruit is a source of human exposure to toxic and genotoxic chemicals. The mutagenic and carcinogenic action of herbicides, insecticides and fungicides on experimental animals is already known. Several studies have shown that chronic exposure to low levels of pesticides can cause adverse health effects and that many pesticides are mutagenic/carcinogenic. In the present research we monitored concurrently the presence of pesticides and genotoxic compounds extracted from 21 treated vegetables and 8 types of grapes sampled from the markets of a region in Southern Italy. The extracts were analysed for pesticides by gas-chromatography and HPLC, and for genotoxicity with two plant tests in Allium cepa roots: the micronucleus test and the chromosomal aberration test. We found 33 pesticides, some of which are outlawed. Genotoxicity was found in some of the vegetables and grapes tested. Allium cepa tests were sensitive for monitoring genotoxicity in food extracts. The micronucleus test in interphase cells gave much higher mutagenicity than the chromosomal aberration test in anaphase-telophase cells. PMID:15049565

  9. ANALOG I/O MODULE TEST SYSTEM BASED ON EPICS CA PROTOCOL AND ACTIVEX CA INTERFACE

    SciTech Connect

    YENG,YHOFF,L.

    2003-10-13

    Analog input (ADC) and output (DAC) modules play a substantial role in device level control of accelerator and large experiment physics control system. In order to get the best performance some features of analog modules including linearity, accuracy, crosstalk, thermal drift and so on have to be evaluated during the preliminary design phase. Gain and offset error calibration and thermal drift compensation (if needed) may have to be done in the implementation phase as well. A natural technique for performing these tasks is to interface the analog VO modules and GPIB interface programmable test instruments with a computer, which can complete measurements or calibration automatically. A difficulty is that drivers of analog modules and test instruments usually work on totally different platforms (vxworks VS Windows). Developing new test routines and drivers for testing instruments under VxWorks (or any other RTOS) platform is not a good solution because such systems have relatively poor user interface and developing such software requires substantial effort. EPICS CA protocol and ActiveX CA interface provide another choice, a PC and LabVIEW based test system. Analog 110 module can be interfaced from LabVIEW test routines via ActiveX CA interface. Test instruments can be controlled via LabVIEW drivers, most of which are provided by instrument vendors or by National Instruments. Labview also provides extensive data analysis and process functions. Using these functions, users can generate powerful test routines very easily. Several applications built for Spallation Neutron Source (SNS) Beam Loss Monitor (BLM) system are described in this paper.

  10. TEST REACTOR AREA PLOT PLAN CA. 1968. MTR AND ETR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TEST REACTOR AREA PLOT PLAN CA. 1968. MTR AND ETR AREAS SOUTH OF PERCH AVENUE. "COLD" SERVICES NORTH OF PERCH. ADVANCED TEST REACTOR IN NEW SECTION WEST OF COLD SERVICES SECTION. NEW PERIMETER FENCE ENCLOSES BETA RAY SPECTROMETER, TRA-669, AN ATR SUPPORT FACILITY, AND ATR STACK. UTM LOCATORS HAVE BEEN DELETED. IDAHO NUCLEAR CORPORATION, FROM A BLAW-KNOX DRAWING, 3/1968. INL INDEX NO. 530-0100-00-400-011646, REV. 0. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  11. Lack of Mutagenicity Potential of Periploca sepium Bge. in Bacterial Reverse Mutation (Ames) Test, Chromosomal Aberration and Micronucleus Test in Mice

    PubMed Central

    Zhang, Mei-Shu; Bang, In-Seok

    2012-01-01

    Objectives The root barks of Periploca sepium Bge. (P. sepium) has been used in traditional Chinese medicine for healing wounds and treating rheumatoid arthritis. However, toxicity in high-doses was often diagnosed by the presence of many glycosides. The potential mutagenicity of P. sepium was investigated both in vitro and in vivo. Methods This was examined by the bacterial reverse mutation (Ames) test using Escherichia coli WP2uvrA and Salmonella typhimurium strains, such as TA98, TA100, TA1535, and TA1537. Chromosomal aberrations were investigated using Chinese hamster lung cells, and the micronucleus test using mice. Results P. sepium did not induce mutagenicity in the bacterial test or chromosomal aberrations in Chinese hamster lung cells, although metabolic activation and micronucleated polychromatic erythrocytes were seen in the mice bone marrow cells. Conclusions Considering these results, it is suggested that P. sepium does not have mutagenic potential under the conditions examined in each study. PMID:22888473

  12. Chromosome aberration and sister chromatid exchange tests in Chinese hamster ovary cells in vitro III: Results with 27 chemicals

    SciTech Connect

    Gulati, D.K. ); Witt, K.; Anderson, B.; Zeiger, E.; Shelby, M.D. )

    1989-01-01

    Twenty-seven chemicals previously tested in rodent carcinogenicity assays were tested for induction of chromosomal aberrations (ABS) and sister chromatid exchanges (SCE) in Chinese hamster ovary (CHO) cells as part of a larger analysis of the correlation between results of in vitro genetic toxicity assays and carcinogenicity bioassays. Chemicals were tested up to toxic doses with and without exogenous metabolic activation. Seventeen of the chemicals tested were carcinogens; only two of these were negative for both ABS and SCE. Of the eight noncarcinogens tested, four were negative for both endpoints and four gave a positive response for at least one endpoint. Of the remaining two chemicals, one, diallylphthalate, gave an equivocal response in the bioassay and a positive response in these CHO cell cytogenetics tests. The other chemical, 2,4-toluene diisocyanate, was tested for carcinogenicity as a mixture with the 2,6-isomer; the mixture was carinogenic, but the cytogenetic test results for the 2,4-isomer were negative. Experiments with unsynchronized CHO cells demonstrated that mean SCE frequency increased with increasing culture time, and this may have been a factor in the positive results obtained for five chemicals in the SCE test under conditions of delayed harvest.

  13. Late-occurring chromosome aberrations and global DNA methylation in hematopoietic stem/progenitor cells of CBA/CaJ mice exposed to silicon ((28)Si) ions.

    PubMed

    Rithidech, Kanokporn Noy; Honikel, Louise M; Reungpathanaphong, Paiboon; Tungjai, Montree; Jangiam, Witawat; Whorton, Elbert B

    2015-11-01

    Although myeloid leukemia (ML) is one of the major health concerns from exposure to space radiation, the risk prediction for developing ML is unsatisfactory. To increase the reliability of predicting ML risk, a much improved understanding of space radiation-induced changes in the target cells, i.e. hematopoietic stem/progenitor cells (HSPCs), is important. We focused on the in vivo induction of late-occurring damage in HSPCs of mice exposed to (28)Si ions since such damage is associated with radiation-induced genomic instability (a key event of carcinogenesis). We gave adult male CBA/CaJ mice, known to be sensitive to radiation-induced ML, a whole-body exposure (2 fractionated exposures, 15 days apart, that totaled each selected dose, delivered at the dose-rate of 1 cGy/min) to various doses of 300 MeV/n (28)Si ions, i.e. 0 (sham controls), 0.1, 0.25, or 0.5 Gy. At 6 months post-irradiation, we collected bone marrow cells from each mouse (five mice per treatment-group) for obtaining the myeloid-lineage of HSPC-derived clones for analyses. We measured the frequencies of late-occurring chromosome aberrations (CAs), using the genome-wide multicolor fluorescence in situ hybridization method. The measurement of CAs was coupled with the characterization of the global DNA methylation patterns, i.e. 5-methylcytosine (5 mC) and 5-hydroxymethylcytosine (5 hmC). A dose-dependent increase in the frequencies of CAs was detected (Analysis of Variance or ANOVA, p<0.01), indicating the induction of genomic instability after exposure of mice to 300 MeV/n (28)Si ions. Slight increases in the levels of 5 mC were observed in all treatment groups, as compared to the sham-control level. In contrast, there was a significant reduction in levels of 5 hmC (ANOVA, p<0.01). Since these endpoints were evaluated in the same mouse, our data suggested for the first time a link between a reduction in 5 hmC and genomic instability in HSPC-derived myeloid colonies of CBA/CaJ mice exposed to 300 Me

  14. Nicotine derived genotoxic effects in human primary parotid gland cells as assessed in vitro by comet assay, cytokinesis-block micronucleus test and chromosome aberrations test.

    PubMed

    Ginzkey, Christian; Steussloff, Gudrun; Koehler, Christian; Burghartz, Marc; Scherzed, Agmal; Hackenberg, Stephan; Hagen, Rudolf; Kleinsasser, Norbert H

    2014-08-01

    Genotoxic effects of nicotine were described in different human cells including salivary gland cells. Based on the high nicotine concentration in saliva of smokers or patients using therapeutic nicotine patches, the current study was performed to evaluate the genotoxic potential of nicotine in human salivary gland cells. Therefore, primary salivary gland cells from 10 patients undergoing parotid gland surgery were exposed to nicotine concentrations between 1 μM and 1000 μM for 1 h in the absence of exogenous metabolic activation. The acinar phenotype was proven by immunofluorescent staining of alpha-amylase. Genotoxic effects were evaluated using the Comet assay, the micronucleus test and the chromosome aberration test. Cytotoxicity and apoptosis were determined by trypan blue exclusion test and Caspase-3 assay. Nicotine was able to induce genotoxic effects in all three assays. The chromosome aberration test was the most sensitive and increases in numerical and structural (chromatid-type and chromosome-type) aberrations were seen at ≥1 μM, whereas increases in micronuclei frequency were detected at 10 μM and DNA damage as measured in the Comet assay was noted at >100 μM. No cytotoxic damage or influence of apoptosis could be demonstrated. Nicotine as a possible risk factor for tumor initiation in salivary glands is still discussed controversially. Our results demonstrated the potential of nicotine to induce genotoxic effects in salivary gland cells. These results were observed at saliva nicotine levels similar to those found after oral or transdermal exposure to nicotine and suggest the necessity of careful monitoring of the use of nicotine in humans. PMID:24698733

  15. Quantal release of Ca2+ from intracellular stores by InsP3: tests of the concept of control of Ca2+ release by intraluminal Ca2+.

    PubMed

    Tregear, R T; Dawson, A P; Irvine, R F

    1991-03-22

    A possible mechanism for the generation of 'quantal' release of intracellular Ca2+ by InsP3 (Muallem et al., J. biol. Chem. 264, 205-212 (1989)) has been put forward in which intraluminal Ca2+ levels modulate InsP3 receptor structure (Irvine, FEBS Lett. 263, 5-9 (1990)). Here we have modelled such a steady-state mechanism, with an InsP3-sensitive store plus an InsP3-insensitive one, to test its ability to mimic published data. We have also performed experiments on InsP3-stimulated rat liver microsomes to test whether the model is consistent with one-way Ca2+ fluxes at a steady state. The model can simulate quantal release, in that InsP3 produces a release of part of the stored Ca2+ which is initially rapid relative to the one-way flux. In the original form of the model, in which InsP3-modulated Ca2+ binding to the intraluminal site opens the Ca2+ channel, the range of InsP3 concentrations needed to release Ca2+ is greater than that observed. When the model is changed so that Ca2(+)-modulated InsP3 binding opens the channels, the effective InsP3 range is shortened, but the quantal release effect is reduced. Other published data on one-way fluxes, and our own data on microsomes, can be simulated when leakage from the InsP3-insensitive store is adjusted to fit the observations; these data therefore do not test the existence of a steady state in the InsP3-sensitive store. We conclude that sensitivity of Ca2+ release to intraluminal Ca2+ provides a steady-state explanation of most, but not all, current quantal release observations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1675803

  16. 40 CFR 799.9538 - TSCA mammalian bone marrow chromosomal aberration test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... sequence being 12 hrs light, 12 hrs dark. For feeding, conventional laboratory diets may be used with an... in this test. (iv) Although most experiments will give clearly positive or negative results, in rare.... Results may remain equivocal or questionable regardless of the number of experiments performed....

  17. 40 CFR 799.9538 - TSCA mammalian bone marrow chromosomal aberration test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sequence being 12 hrs light, 12 hrs dark. For feeding, conventional laboratory diets may be used with an... in this test. (iv) Although most experiments will give clearly positive or negative results, in rare.... Results may remain equivocal or questionable regardless of the number of experiments performed....

  18. 40 CFR 799.9538 - TSCA mammalian bone marrow chromosomal aberration test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sequence being 12 hrs light, 12 hrs dark. For feeding, conventional laboratory diets may be used with an... in this test. (iv) Although most experiments will give clearly positive or negative results, in rare.... Results may remain equivocal or questionable regardless of the number of experiments performed....

  19. 40 CFR 799.9537 - TSCA in vitro mammalian chromosome aberration test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... The definitions in section 3 of TSCA and in 40 CFR Part 792—Good Laboratory Practice Standards apply... after an S period of DNA replication, the nucleus does not go into mitosis but starts another S period... other than direct DNA damage. (e) Principle of the test method. Cell cultures are exposed to the...

  20. The Effect of Test and Examinee Characteristics on the Occurrence of Aberrant Response Patterns in a Computerized Adaptive Test

    ERIC Educational Resources Information Center

    Rizavi, Saba; Hariharan, Swaminathan

    2001-01-01

    The advantages that computer adaptive testing offers over linear tests have been well documented. The Computer Adaptive Test (CAT) design is more efficient than the Linear test design as fewer items are needed to estimate an examinee's proficiency to a desired level of precision. In the ideal situation, a CAT will result in examinees answering…

  1. [239Pu and chromosomal aberrations in human peripheral blood lymphocytes].

    PubMed

    Okladnikova, N D; Osovets, S V; Kudriavtseva, T I

    2009-01-01

    The genome status in somatic cells was assessed using the chromosomal aberration (CA) test in peripheral blood lymphocytes from 194 plutonium workers exposed to occupational radiation mainly from low-transportable compounds of airborne 230Pu. Pu body burden at the time of cytogenetic study varied from values close to the method sensitivity to values multiply exceeding the permissible level. Standard (routine) methods of peripheral blood lymphocytes cultivation were applied. Chromatid- and chromosomal-type structural changes were estimated. Aberrations were estimated per 100 examined metaphase cells. The quantitative relationship between the CA frequency and Pu body burden and the absorbed dose to the lung was found. Mathematical processing of results was carried out based on the phenomenological model. The results were shown as theoretical and experimental curves. The threshold of the CA yield was 0.43 +/- 0.03 kBq (Pu body burden) and 6.12 +/- 1.20 cGy (absorbed dose to the lung).

  2. The Great Spherical Aberration Fiasco of 1902 and Its Aftermath: Testing a New Big Telescope in San Diego

    NASA Astrophysics Data System (ADS)

    Osterbrock, D. E.

    1998-05-01

    In 1901, W. W. Campbell, the new director of Lick Observatory, planned to build a "big" (0.9-m) new reflecting telescope, to be erected in the Southern Hemisphere. His aim was complete sky coverage for statistical studies of stellar radial velocities. Campbell designed it as a reflector rather than a refractor to save money; when completed it would be the largest professional-quality silver-on-glass reflector in the world. It would be more effective in collecting light, especially photographic light, than any of the big refractors of that era. The 37-inch primary mirror, when delivered on Mount Hamilton, proved to be afflicted with severe spherical aberration. Like the HST nine decades later, it was not usable. How this happened will be described. Unlike the HST, this "Mills reflector" was still on the ground in America. The optics were returned to the maker, John A. Brashear, in Allegheny, Pa., and were refigured there. To save time, the final testing and touch-ups of the figure, in January 1903, were moved to San Diego, the clearest accessible site in the United States. The dome, mounting, and other equipment were waiting in a warehouse near the pier in San Francisco, boxed for shipment to Chile. Campbell was badly injured during the testing process, but his assistant, William H. Wright, completed it. James McDowell of the Brashear firm did the final figuring at San Diego, and in February 1903, Wright and Harold K. Palmer (who passed his final Ph.D. oral exam the afternoon before their ship sailed) took the telescope to Santiago and put it into operation there. It proved higly successful for a quarter of a century, in obtaining the observational data for which it was designed.

  3. Theoretical and experimental tests of a chromosomal fingerprint for densely ionizing radiation based on F ratios calculated from stable and unstable chromosome aberrations

    NASA Technical Reports Server (NTRS)

    Lucas, J. N.; Deng, W.; Oram, S. W.; Hill, F. S.; Durante, M.; George, K.; Wu, H.; Owens, C. L.; Yang, T.

    1999-01-01

    In the present study, F ratios for both stable chromosome aberrations, i.e. ratios of translocations to pericentric inversions, and unstable aberrations, i.e. dicentrics and centric rings, were measured using fluorescence in situ hybridization. F ratios for stable aberrations measured after exposure to low (2.89 Gy 60Co gamma rays) and high-LET (0.25 Gy 56Fe ions; 1.25 Gy 56Fe ions; 3.0 Gy 12C ions) radiation were 6.5 +/- 1.5, 4.7 +/- 1.6, 9.3 +/- 2.5 and 10.4 +/- 3.0, respectively. F ratios for unstable aberrations measured after low (2.89 Gy 60Co gamma rays) and high-LET (0.25 Gy 56Fe ions; 3.0 Gy 12C ions) radiations were 6.5 +/- 1.6, 6.3 +/- 2.3 and 11.1 +/- 3.7, respectively. No significant difference between the F ratios for low- and high-LET radiation was found. Further tests on the models for calculation of the F ratio proposed by Brenner and Sachs (Radiat. Res. 140, 134-142, 1994) showed that the F ratio may not be straightforward as a practical fingerprint for densely ionizing radiation.

  4. Determination of aberration center of Ronchigram for automated aberration correctors in scanning transmission electron microscopy.

    PubMed

    Sannomiya, Takumi; Sawada, Hidetaka; Nakamichi, Tomohiro; Hosokawa, Fumio; Nakamura, Yoshio; Tanishiro, Yasumasa; Takayanagi, Kunio

    2013-12-01

    A generic method to determine the aberration center is established, which can be utilized for aberration calculation and axis alignment for aberration corrected electron microscopes. In this method, decentering induced secondary aberrations from inherent primary aberrations are minimized to find the appropriate axis center. The fitness function to find the optimal decentering vector for the axis was defined as a sum of decentering induced secondary aberrations with properly distributed weight values according to the aberration order. Since the appropriate decentering vector is determined from the aberration values calculated at an arbitrary center axis, only one aberration measurement is in principle required to find the center, resulting in /very fast center search. This approach was tested for the Ronchigram based aberration calculation method for aberration corrected scanning transmission electron microscopy. Both in simulation and in experiments, the center search was confirmed to work well although the convergence to find the best axis becomes slower with larger primary aberrations. Such aberration center determination is expected to fully automatize the aberration correction procedures, which used to require pre-alignment of experienced users. This approach is also applicable to automated aperture positioning.

  5. Genotoxicity evaluation of Guibi-Tang extract using an in vitro bacterial reverse mutation assay, chromosome aberration assay, and in vivo micronucleus test

    PubMed Central

    2014-01-01

    Background Guibi-Tang is a traditional herbal prescription made from 12 different herbs that is used in the treatment of amnesia and poor memory. Methods In the present study, we evaluated the acute oral toxicity and genotoxic potential of Guibi-Tang water extract (GBT) at doses up to 2000 μg/plate an using a bacterial reverse mutation test (Ames test) with Salmonella typhimurium strains TA100, TA1535, TA98, and TA1537, and Escherichia coli strain WP2uvrA. Acute toxicity and genotoxic potential were measured in the presence and absence of an exogenous source of metabolic activation, in an in vitro chromosome aberration assay with Chinese hamster lung (CHL) cells, and in an in vivo micronucleus test using ICR mice bone marrow as recommended by the Korean Food and Drug Administration. An acute oral toxicity test of GBT was performed in Sprague Dawley rats. The Ames test showed that GBT did not induce gene mutations in S. typhimurium or in E. coli in the presence or absence of S9 activation. Results GBT did not significantly increase the number of structural aberrations in CHL cells with or without S9 activation. The oral administration of GBT at a dose of up to 2000 mg/kg caused no significant increase in the number of micronucleated polychromatic erythrocytes or in the mean ratio of polychromatic to total erythrocytes. Conclusions However, as we did not identify the components of GBT responsible for these effects, other assays are needed to confirm its genotoxicity. PMID:24985139

  6. Chromosome aberrations induced by zebularine in triticale.

    PubMed

    Ma, Xuhui; Wang, Qing; Wang, Yanzhi; Ma, Jieyun; Wu, Nan; Ni, Shuang; Luo, Tengxiao; Zhuang, Lifang; Chu, Chenggen; Cho, Seong-Woo; Tsujimoto, Hisashi; Qi, Zengjun

    2016-07-01

    Chromosome engineering is an important approach for generating wheat germplasm. Efficient development of chromosome aberrations will facilitate the introgression and application of alien genes in wheat. In this study, zebularine, a DNA methylation transferase inhibitor, was successfully used to induce chromosome aberrations in the octoploid triticale cultivar Jinghui#1. Dry seeds were soaked in zebularine solutions (250, 500, and 750 μmol/L) for 24 h, and the 500 μmol/L treatment was tested in three additional treatment times, i.e., 12, 36, and 48 h. All treatments induced aberrations involving wheat and rye chromosomes. Of the 920 cells observed in 67 M1 plants, 340 (37.0%) carried 817 aberrations with an average of 0.89 aberrations per cell (range: 0-12). The aberrations included probable deletions, telosomes and acentric fragments (49.0%), large segmental translocations (28.9%), small segmental translocations (17.1%), intercalary translocations (2.6%), long chromosomes that could carry more than one centromere (2.0%), and ring chromosomes (0.5%). Of 510 M2 plants analyzed, 110 (21.6%) were found to carry stable aberrations. Such aberrations included 79 with varied rye chromosome numbers, 7 with wheat and rye chromosome translocations, 15 with possible rye telosomes/deletions, and 9 with complex aberrations involving variation in rye chromosome number and wheat-rye translocations. These indicated that aberrations induced by zebularine can be steadily transmitted, suggesting that zebularine is a new efficient agent for chromosome manipulation. PMID:27334255

  7. Psychometric Characteristics of the Aberrant Behavior Checklist.

    ERIC Educational Resources Information Center

    Aman, Michael G.; And Others

    1985-01-01

    Information is presented on the psychometric characteristics of the Aberrant Behavior Checklist, a measure of psychotropic drug effects. Internal consistency and test-retest reliability of the checklist appeared very good. Interrater reliability was generally in the moderate range. In general, validity was established for most Aberrant Behavior…

  8. Aberration averaging using point spread function for scanning projection systems

    NASA Astrophysics Data System (ADS)

    Ooki, Hiroshi; Noda, Tomoya; Matsumoto, Koichi

    2000-07-01

    Scanning projection system plays a leading part in current DUV optical lithography. It is frequently pointed out that the mechanically induced distortion and field curvature degrade image quality after scanning. On the other hand, the aberration of the projection lens is averaged along the scanning direction. This averaging effect reduces the residual aberration significantly. The aberration averaging based on the point spread function and phase retrieval technique in order to estimate the effective wavefront aberration after scanning is described in this paper. Our averaging method is tested using specified wavefront aberration, and its accuracy is discussed based on the measured wavefront aberration of recent Nikon projection lens.

  9. Aberrant DNA Methylation in Keratoacanthoma

    PubMed Central

    Nakagawa, Hidemi

    2016-01-01

    Background Keratoacanthoma (KA) is a self-limiting epidermal tumor for which histopathological examination sometimes suggests malignancy. Based on inconsistent clinical views, KA can be regarded as both a benign tumor and a variant of squamous cell carcinoma (SCC). Aberrant DNA methylation frequently occurs in malignant tumors but it scarcely occurs in benign tumors. Whether aberrant methylation occurs in KA has not been previously examined. Objective The aim is to elucidate whether aberrant methylation of CpG islands (CGI) containing a high density of cytosine-guanine dinucleotide (CpG) sites occurs in KA. Methods Five SCC cell lines, two cultured samples of normal human epidermal keratinocytes (NHEKs), 18 clinical SCC samples, and 21 clinical KA samples were analyzed with Infinium HumanMethylation450 BeadChips, quantitative real-time methylation-specific PCR (RT-MSP) and/or bisulfite sequencing. Results Genome-wide analyses of NHEK, KA, and SCC indicated that there was a greater number of aberrantly hypermethylated CGIs in SCC than in KA and there were aberrantly hypermethylated CGIs which are common in both. Among the common hypermethylated CGIs, RT-MSP and bisulfite sequencing targeting CGIs located on CCDC17, PVR, and MAP3K11 gene bodies also showed that methylation levels were significantly higher in KA than in normal epidermis. Statistical analyses suggested that the methylation level of CGI located on PVR in SCC might be correlated to lymph node metastasis (P = 0.013, Mann-Whitney U test) and that the methylation level of CGI in MAP3K11 in KA might be correlated to age (P = 0.031, linear regression analysis). Conclusion Aberrant DNA methylation occurs in KA. PMID:27788211

  10. How To Measure Gravitational Aberration?

    NASA Astrophysics Data System (ADS)

    Krizek, M.; Solcova, A.

    2007-08-01

    In 1905, Henri Poincaré predicted the existence of gravitational waves and assumed that their speed c[g] would be that of the speed of light c. If the gravitational aberration would also have the same magnitude as the aberration of light, we would observe several paradoxical phenomena. For instance, the orbit of two bodies of equal mass would be unstable, since two attractive forces arise that are not in line and hence form a couple. This tends to increase the angular momentum, period, and total energy of the system. This can be modelled by a system of ordinary differential equations with delay. A big advantage of computer simulation is that we can easily perform many test for various possible values of the speed of gravity [1]. In [2], Carlip showed that gravitational aberration in general relativity is almost cancelled out by velocity-dependent interactions. This means that rays of sunlight are not parallel to the attractive gravitational force of the Sun, i.e., we do not see the Sun in the direction of its attractive force, but slightly shifted about an angle less than 20``. We show how the actual value of the gravitational aberration can be obtained by measurement of a single angle at a suitable time instant T corresponding to the perihelion of an elliptic orbit. We also derive an a priori error estimate that expresses how acurately T has to be determined to attain the gravitational aberration to a prescribed tolerance. [1] M. Křížek: Numerical experience with the finite speed of gravitational interaction, Math. Comput. Simulation 50 (1999), 237-245. [2] S. Carlip: Aberration and the speed of gravity, Phys. Lett. A 267 (2000), 81-87.

  11. Interpreting Chromosome Aberration Spectra

    NASA Technical Reports Server (NTRS)

    Levy, Dan; Reeder, Christopher; Loucas, Bradford; Hlatky, Lynn; Chen, Allen; Cornforth, Michael; Sachs, Rainer

    2007-01-01

    Ionizing radiation can damage cells by breaking both strands of DNA in multiple locations, essentially cutting chromosomes into pieces. The cell has enzymatic mechanisms to repair such breaks; however, these mechanisms are imperfect and, in an exchange process, may produce a large-scale rearrangement of the genome, called a chromosome aberration. Chromosome aberrations are important in killing cells, during carcinogenesis, in characterizing repair/misrepair pathways, in retrospective radiation biodosimetry, and in a number of other ways. DNA staining techniques such as mFISH ( multicolor fluorescent in situ hybridization) provide a means for analyzing aberration spectra by examining observed final patterns. Unfortunately, an mFISH observed final pattern often does not uniquely determine the underlying exchange process. Further, resolution limitations in the painting protocol sometimes lead to apparently incomplete final patterns. We here describe an algorithm for systematically finding exchange processes consistent with any observed final pattern. This algorithm uses aberration multigraphs, a mathematical formalism that links the various aspects of aberration formation. By applying a measure to the space of consistent multigraphs, we will show how to generate model-specific distributions of aberration processes from mFISH experimental data. The approach is implemented by software freely available over the internet. As a sample application, we apply these algorithms to an aberration data set, obtaining a distribution of exchange cycle sizes, which serves to measure aberration complexity. Estimating complexity, in turn, helps indicate how damaging the aberrations are and may facilitate identification of radiation type in retrospective biodosimetry.

  12. Chromosomal aberrations in onion (Allium cepa) induced by water chlorination by-products

    SciTech Connect

    Al-Sabti, K.; Kurelec, B.

    1985-01-01

    It has recently come to light that water chlorination generates mutagens and carcinogens. The mutagenicity of nonvolatile mutagenic by-products of water chlorination has been demonstrated in short-term biological testings. The predictive value of short-term tests is considerably enhanced by the use of more than one test system. A scientifically stringent approach in formulating a testing program for the assessment of genotoxins is to rely on tests that directly measure gene mutations and chromosome alterations. Chromosome aberrations (CA) become such a relevant bioassay. The CA measurement in the allium test is suitable for measuring the cytogenotoxic potential of chemicals present in water; it is simple, cheap, sensitive, and it does not require a generally undefined step of concentrating chemicals present in polluted waters. In the present investigation CA in Allium were chosen for the detection of mutagenic potential of a polluted river waters before and after the under-breakpoint chlorination.

  13. Aberrant Radial Artery Causing Carpal Tunnel Syndrome

    PubMed Central

    Kokkalis, Zinon T.; Tolis, Konstantinos E.; Megaloikonomos, Panayiotis D.; Panagopoulos, Georgios N.; Igoumenou, Vasilios G.; Mavrogenis, Andreas F.

    2016-01-01

    Anatomical vascular variations are rare causes of carpal tunnel syndrome. An aberrant medial artery is the most common vascular variation, while an aberrant radial artery causing carpal tunnel syndrome is even more rare, with an incidence ranging less than 3%. This article reports a patient with compression of the median nerve at the carpal tunnel by an aberrant superficial branch of the radial artery. An 80- year- old man presented with a 5-year history of right hand carpal tunnel syndrome; Tinel sign, Phalen test and neurophysiological studies were positive. Open carpal tunnel release showed an aberrant superficial branch of the radial artery with its accompanying veins running from radially to medially, almost parallel to the median nerve, ending at the superficial palmar arterial arch. The median nerve was decompressed without ligating the aberrant artery. At the last follow-up, 2 years after diagnosis and treatment the patient is asymptomatic. PMID:27517078

  14. Aberrant Radial Artery Causing Carpal Tunnel Syndrome.

    PubMed

    Kokkalis, Zinon T; Tolis, Konstantinos E; Megaloikonomos, Panayiotis D; Panagopoulos, Georgios N; Igoumenou, Vasilios G; Mavrogenis, Andreas F

    2016-06-01

    Anatomical vascular variations are rare causes of carpal tunnel syndrome. An aberrant medial artery is the most common vascular variation, while an aberrant radial artery causing carpal tunnel syndrome is even more rare, with an incidence ranging less than 3%. This article reports a patient with compression of the median nerve at the carpal tunnel by an aberrant superficial branch of the radial artery. An 80- year- old man presented with a 5-year history of right hand carpal tunnel syndrome; Tinel sign, Phalen test and neurophysiological studies were positive. Open carpal tunnel release showed an aberrant superficial branch of the radial artery with its accompanying veins running from radially to medially, almost parallel to the median nerve, ending at the superficial palmar arterial arch. The median nerve was decompressed without ligating the aberrant artery. At the last follow-up, 2 years after diagnosis and treatment the patient is asymptomatic.

  15. Aberrant Radial Artery Causing Carpal Tunnel Syndrome.

    PubMed

    Kokkalis, Zinon T; Tolis, Konstantinos E; Megaloikonomos, Panayiotis D; Panagopoulos, Georgios N; Igoumenou, Vasilios G; Mavrogenis, Andreas F

    2016-06-01

    Anatomical vascular variations are rare causes of carpal tunnel syndrome. An aberrant medial artery is the most common vascular variation, while an aberrant radial artery causing carpal tunnel syndrome is even more rare, with an incidence ranging less than 3%. This article reports a patient with compression of the median nerve at the carpal tunnel by an aberrant superficial branch of the radial artery. An 80- year- old man presented with a 5-year history of right hand carpal tunnel syndrome; Tinel sign, Phalen test and neurophysiological studies were positive. Open carpal tunnel release showed an aberrant superficial branch of the radial artery with its accompanying veins running from radially to medially, almost parallel to the median nerve, ending at the superficial palmar arterial arch. The median nerve was decompressed without ligating the aberrant artery. At the last follow-up, 2 years after diagnosis and treatment the patient is asymptomatic. PMID:27517078

  16. Aberration corrected emittance exchange

    NASA Astrophysics Data System (ADS)

    Nanni, E. A.; Graves, W. S.

    2015-08-01

    Full exploitation of emittance exchange (EEX) requires aberration-free performance of a complex imaging system including active radio-frequency (rf) elements which can add temporal distortions. We investigate the performance of an EEX line where the exchange occurs between two dimensions with normalized emittances which differ by multiple orders of magnitude. The transverse emittance is exchanged into the longitudinal dimension using a double dogleg emittance exchange setup with a five cell rf deflector cavity. Aberration correction is performed on the four most dominant aberrations. These include temporal aberrations that are corrected with higher order magnetic optical elements located where longitudinal and transverse emittance are coupled. We demonstrate aberration-free performance of an EEX line with emittances differing by four orders of magnitude, i.e., an initial transverse emittance of 1 pm-rad is exchanged with a longitudinal emittance of 10 nm-rad.

  17. Operational test of micro-oven for {sup 48}Ca beam

    SciTech Connect

    Ozeki, K. Kageyama, T.; Kidera, M.; Higurashi, Y.; Nakagawa, T.

    2014-02-15

    In order to supply a high-intensity and stable {sup 48}Ca beam from the RIKEN 18-GHz electron cyclotron resonance ion source, we are conducting operational tests of a micro-oven. A mixture of CaO and Al powders is placed into the crucible of the micro-oven and heated to produce metallic calcium by a reductive reaction. The successful production of a calcium beam was confirmed. In addition, we reduced the material consumption rate by using a so-called “hot liner,” and we enhanced the beam intensity by applying a negative voltage bias to the micro-oven, the effect of which is similar to the effect of a “biased disk.”.

  18. Validation of US3D for Capsule Aerodynamics using 05-CA Wind Tunnel Test Data

    NASA Technical Reports Server (NTRS)

    Schwing, Alan

    2012-01-01

    Several comparisons of computational fluid dynamics to wind tunnel test data are shown for the purpose of code validation. The wind tunnel test, 05-CA, uses a 7.66% model of NASA's Multi-Purpose Crew Vehicle in the 11-foot test section of the Ames Unitary Plan Wind tunnel. A variety of freestream conditions over four Mach numbers and three angles of attack are considered. Test data comparisons include time-averaged integrated forces and moments, time-averaged static pressure ports on the surface, and Strouhal Number. The applicability of the US3D code to subsonic and transonic flow over a bluff body is assessed on a comprehensive data set. With close comparison, this work validates US3D for highly separated flows similar to those examined here.

  19. Image-based EUVL aberration metrology

    NASA Astrophysics Data System (ADS)

    Fenger, Germain Louis

    A significant factor in the degradation of nanolithographic image fidelity is optical wavefront aberration. As resolution of nanolithography systems increases, effects of wavefront aberrations on aerial image become more influential. The tolerance of such aberrations is governed by the requirements of features that are being imaged, often requiring lenses that can be corrected with a high degree of accuracy and precision. Resolution of lithographic systems is driven by scaling wavelength down and numerical aperture (NA) up. However, aberrations are also affected from the changes in wavelength and NA. Reduction in wavelength or increase in NA result in greater impact of aberrations, where the latter shows a quadratic dependence. Current demands in semiconductor manufacturing are constantly pushing lithographic systems to operate at the diffraction limit; hence, prompting a need to reduce all degrading effects on image properties to achieve maximum performance. Therefore, the need for highly accurate in-situ aberration measurement and correction is paramount. In this work, an approach has been developed in which several targets including phase wheel, phase disk, phase edges, and binary structures are used to generate optical images to detect and monitor aberrations in extreme ultraviolet (EUV) lithographic systems. The benefit of using printed patterns as opposed to other techniques is that the lithography system is tested under standard operating conditions. Mathematical models in conjunction with iterative lithographic simulations are used to determine pupil phase wavefront errors and describe them as combinations of Zernike polynomials.

  20. Accommodative lag and fluctuations when optical aberrations are manipulated.

    PubMed

    Gambra, Enrique; Sawides, Lucie; Dorronsoro, Carlos; Marcos, Susana

    2009-06-09

    We evaluated the accommodative response to a stimulus moving from 0 to 6 D following a staircase function under natural, corrected, and induced optical aberrations, using an adaptive-optics (AO) electromagnetic deformable mirror. The accommodative response of the eye (through the mirror) and the change of aberrations were measured on 5 subjects using a Hartmann-Shack wavefront sensor operating at 12.8 Hz. Five conditions were tested: (1) natural aberrations, (2) AO correction of the unaccommodated state and induction (over 6-mm pupils) of (3) +1 microm and (4) -1 microm of spherical aberration and (5) -2 microm of vertical coma. Four subjects showed a better accommodative response with AO correction than with their natural aberrations. The induction of negative spherical aberration also produced a better accommodative response in the same subjects. Accommodative lag increased in all subjects when positive spherical aberration and coma were induced. Fluctuations of the accommodative response (computed during each 1-D period of steady accommodation) increased with accommodative response when high-order aberrations were induced. The largest fluctuations occurred for induced negative spherical aberration and the smallest for natural and corrected aberrations. The study demonstrates that aberrations influence accommodative lag and fluctuations of accommodation and that correcting aberrations improves rather than compromises the accommodative response.

  1. Active mirrors warped using Zernike polynomials for correcting off-axis aberrations of fixed primary mirrors. II. Optical testing and performance evaluation.

    NASA Astrophysics Data System (ADS)

    Moretto, G.; Lemaitre, G. R.; Bactivelane, T.; Wang, M.; Ferrari, M.; Mazzanti, S.; di Biagio, B.; Borra, E. F.

    1995-12-01

    We investigate the aspherization of an active mirror for correcting third and fifth-order aberrations. We use a stainless steel AISI 420 mirror with a controlled pressure load, two series of 12-punctual radial positions of force application distributed symmetrically in two concentric rings around the mirror. We obtain the wavefronts for Cv1, Sph3, Coma3, Astm3, Comatri, Astm5 as well as those of the added wavefronts. Although this active prototype mirror has general uses, our goal is to compensate the aberrations of a liquid mirror observing at large angles from the zenith.

  2. Chromosome aberration, cancer mortality and hormetic phenomena among inhabitants in areas of high background radiation in China.

    PubMed

    Chen, D; Wei, L

    1991-12-01

    The respective average annual doses are about 330 and 110 mR/yr, in the high background radiation areas (HBRA) in Yangjiang County and the control areas (CA) in Enping and Taishan Counties. Both the HBRA and CA are in Guangdong Province which borders the South China Sea. The frequencies of chromosome aberration in circulating lymphocytes were examined for persons residing in the HBRA and CA. Those in the HBRA had increased frequencies of detectable abnormalities in stable aberrations (translocations and inversions) and unstable aberrations (dicentrics and rings). Previous reports have shown that when samples of circulating lymphocytes taken from inhabitants were tested in vitro for mitotic responses to phytohemagglutinin (PHA) and for the degree of unscheduled DNA synthesis (UDS) induced by UV-irradiation, there were higher responsiveness and UDS rates for those in the HBRA than in the CA. In contrast, mortality from all cancers and those from leukemia, breast and lung cancers that are inducible by radiation was not higher in the HBRA. Although the differences in the cancer mortality rates for the HBRA and CA are not significant, the findings are compatible with the assumption that the lower mortality from cancer in the HBRA is the result of the hormetic effects of the three-fold higher dose rate of background radiation in that areas. This assumption requires further study.

  3. Chromosome aberrations in Japanese fishermen exposed to fallout radiation 420-1200 km distant from the nuclear explosion test site at Bikini Atoll: report 60 years after the incident.

    PubMed

    Tanaka, Kimio; Ohtaki, Megu; Hoshi, Masaharu

    2016-08-01

    During the period from March to May, 1954, the USA conducted six nuclear weapon tests at the "Bravo" detonation sites at the Bikini and Enewetak Atolls, Marshall Islands. At that time, the crew of tuna fishing boats and cargo ships that were operating approximately 150-1200 km away from the test sites were exposed to radioactive fallout. The crew of the fishing boats and those on cargo ships except the "5th Fukuryu-maru" did not undergo any health examinations at the time of the incident. In the present study, chromosome aberrations in peripheral blood lymphocytes were examined in detail by the G-banding method in 17 crew members from 8 fishing boats and 2 from one cargo ship, 60 years after the tests. None of the subjects examined had suffered from cancer. The percentages of both stable-type aberrations such as translocation, inversion and deletion, and unstable-type aberrations such as dicentric and centric ring in the study group were significantly higher (1.4- and 2.3-fold, respectively) than those in nine age-matched controls. In the exposed and control groups, the percentages of stable-type aberrations were 3.35 % and 2.45 %, respectively, and the numbers of dicentric and centric ring chromosomes per 100 cells were 0.35 and 0.15, respectively. Small clones were observed in three members of the exposed group. These results suggest that the crews were exposed to slightly higher levels of fallout than had hitherto been assumed. PMID:27017218

  4. Chromosome aberrations in Japanese fishermen exposed to fallout radiation 420-1200 km distant from the nuclear explosion test site at Bikini Atoll: report 60 years after the incident.

    PubMed

    Tanaka, Kimio; Ohtaki, Megu; Hoshi, Masaharu

    2016-08-01

    During the period from March to May, 1954, the USA conducted six nuclear weapon tests at the "Bravo" detonation sites at the Bikini and Enewetak Atolls, Marshall Islands. At that time, the crew of tuna fishing boats and cargo ships that were operating approximately 150-1200 km away from the test sites were exposed to radioactive fallout. The crew of the fishing boats and those on cargo ships except the "5th Fukuryu-maru" did not undergo any health examinations at the time of the incident. In the present study, chromosome aberrations in peripheral blood lymphocytes were examined in detail by the G-banding method in 17 crew members from 8 fishing boats and 2 from one cargo ship, 60 years after the tests. None of the subjects examined had suffered from cancer. The percentages of both stable-type aberrations such as translocation, inversion and deletion, and unstable-type aberrations such as dicentric and centric ring in the study group were significantly higher (1.4- and 2.3-fold, respectively) than those in nine age-matched controls. In the exposed and control groups, the percentages of stable-type aberrations were 3.35 % and 2.45 %, respectively, and the numbers of dicentric and centric ring chromosomes per 100 cells were 0.35 and 0.15, respectively. Small clones were observed in three members of the exposed group. These results suggest that the crews were exposed to slightly higher levels of fallout than had hitherto been assumed.

  5. Mg/Ca-temperature and seawater-test chemistry relationships in the shallow-dwelling large benthic foraminifera Operculina ammonoides

    NASA Astrophysics Data System (ADS)

    Evans, David; Erez, Jonathan; Oron, Shai; Müller, Wolfgang

    2015-01-01

    The foraminifera Mg/Ca palaeothermometer contributes significantly to our understanding of palaeoceanic temperature variation. However, since seawater Mg/Ca has undergone large secular variation and the relationship between seawater and test Mg/Ca has not been calibrated in detail for any species with a substantial fossil record, it is only possible to assess relative temperature changes in pre-Pleistocene fossil samples. In order to establish the basis of accurate quantitative Mg/Ca-derived deep-time temperature reconstructions, we have calibrated the relationship between test Mg/Ca, seawater chemistry and temperature in laboratory cultures of the shallow-dwelling large benthic species Operculina ammonoides. Operculina has a fossil range extending back to the early Paleogene and is the nearest living relative of the abundant genus Nummulites. We find a temperature sensitivity of 1.7% °C-1 and a linear relationship between the Mg distribution coefficient and seawater Mg/Ca (Mg /Casw) with m = -1.9 × 10-3 , within error of the equivalent slope for inorganic calcite. The higher test Mg/Ca of O. ammonoides compared to inorganic calcite may be explained by an elevated pH of the calcifying fluid, implying that these foraminifera do not modify the Mg/Ca ratio of the seawater from which they calcify, differentiating them in this respect from most other perforate foraminifera. Applying these calibrations to previously published fossil data results in palaeo-Mg /Casw reconstruction consistent with independent proxy evidence. Furthermore, our data enable accurate absolute palaeotemperature reconstructions if Mg /Casw is constrained by another technique (e.g. ridge flank vein carbonate; fluid inclusions). Finally, we examine Li, Na, Sr and Ba incorporation into the test of O. ammonoides and discuss the control exerted by temperature, seawater chemistry, saturation state and growth rate on these emerging proxies.

  6. Optical aberrations of intraocular lenses measured in vivo and in vitro

    NASA Astrophysics Data System (ADS)

    Barbero, Sergio; Marcos, Susana; Jiménez-Alfaro, Ignacio

    2003-10-01

    Corneal and ocular aberrations were measured in a group of eyes before and after cataract surgery with spherical intraocular lens (IOL) implantation by use of well-tested techniques developed in our laboratory. By subtraction of corneal from total aberration maps, we also estimated the optical quality of the intraocular lens in vivo. We found that aberrations in pseudophakic eyes are not significantly different from aberrations in eyes before cataract surgery or from previously reported aberrations in healthy eyes of the same age. However, aberrations in pseudophakic eyes are significantly higher than in young eyes. We found a slight increase of corneal aberrations after surgery. The aberrations of the IOL and the lack of balance of the corneal spherical aberrations by the spherical aberrations of the intraocular lens also degraded the optical quality in pseudophakic eyes. We also measured the aberrations of the IOL in vitro, using an eye cell model, and simulated the aberrations of the IOL on the basis of the IOL's physical parameters. We found a good agreement among in vivo, in vitro, and simulated measures of spherical aberration: Unlike the spherical aberration of the young crystalline lens, which tends to be negative, the spherical aberration of the IOL is positive and increases with lens power. Computer simulations and in vitro measurements show that tilts and decentrations might be contributors to the increased third-order aberrations in vivo in comparison with in vitro measurements.

  7. Wavefront aberrations of x-ray dynamical diffraction beams.

    PubMed

    Liao, Keliang; Hong, Youli; Sheng, Weifan

    2014-10-01

    The effects of dynamical diffraction in x-ray diffractive optics with large numerical aperture render the wavefront aberrations difficult to describe using the aberration polynomials, yet knowledge of them plays an important role in a vast variety of scientific problems ranging from optical testing to adaptive optics. Although the diffraction theory of optical aberrations was established decades ago, its application in the area of x-ray dynamical diffraction theory (DDT) is still lacking. Here, we conduct a theoretical study on the aberration properties of x-ray dynamical diffraction beams. By treating the modulus of the complex envelope as the amplitude weight function in the orthogonalization procedure, we generalize the nonrecursive matrix method for the determination of orthonormal aberration polynomials, wherein Zernike DDT and Legendre DDT polynomials are proposed. As an example, we investigate the aberration evolution inside a tilted multilayer Laue lens. The corresponding Legendre DDT polynomials are obtained numerically, which represent balanced aberrations yielding minimum variance of the classical aberrations of an anamorphic optical system. The balancing of classical aberrations and their standard deviations are discussed. We also present the Strehl ratio of the primary and secondary balanced aberrations.

  8. Phase from chromatic aberrations.

    PubMed

    Waller, Laura; Kou, Shan Shan; Sheppard, Colin J R; Barbastathis, George

    2010-10-25

    We show that phase objects may be computed accurately from a single color image in a brightfield microscope, with no hardware modification. Our technique uses the chromatic aberration that is inherent to every lens-based imaging system as a phase contrast mechanism. This leads to a simple and inexpensive way of achieving single-shot quantitative phase recovery by a modified Transport of Intensity Equation (TIE) solution, allowing real-time phase imaging in a traditional microscope. PMID:21164620

  9. Psychometric characteristics of the aberrant behavior checklist.

    PubMed

    Aman, M G; Singh, N N; Stewart, A W; Field, C J

    1985-03-01

    Information was presented on the psychometric characteristics of the Aberrant Behavior Checklist. The internal consistency and test-retest reliability of the Checklist appeared to be very good. Interrater reliability tended to vary across raters and subscales and ranged from mediocre to good but was generally in the moderate range and acceptable for research purposes. Validity was assessed by comparing Checklist scores for residents presenting with attributes thought to reflect varying degrees of social adaptation. Validity was also evaluated by comparing Aberrant Behavior Checklist scores with ratings on adaptive behavior scales and with objective observations of behavior. In general, validity was established for most Aberrant Behavior Checklist subscales. Preliminary data from drug investigations suggested that the Checklist may provide a useful adjunct for the assessment of psychotropic drug effects.

  10. Testing for oncogenic molecular aberrations in cell-free DNA-based liquid biopsies in the clinic: are we there yet?

    PubMed

    Polivka, Jiri; Pesta, Martin; Janku, Filip

    2015-01-01

    The optimal choice of cancer therapy depends upon analysis of the tumor genome for druggable molecular alterations. The spatial and temporal intratumor heterogeneity of cancers creates substantial challenges, as molecular profile depends on time and site of tumor tissue collection. To capture the entire molecular profile, multiple biopsies from primary and metastatic sites at different time points would be required, which is not feasible for ethical or economic reasons. Molecular analysis of circulating cell-free DNA offers a novel, minimally invasive method that can be performed at multiple time-points and plausibly better represents the prevailing molecular profile of the cancer. Molecular analysis of this cell-free DNA offers multiple clinically useful applications, such as identification of molecular targets for cancer therapy, monitoring of tumor molecular profile in real time, detection of emerging molecular aberrations associated with resistance to particular therapy, determination of cancer prognosis and diagnosis of cancer recurrence or progression.

  11. Relationships between chromosome structure and chromosomal aberrations

    NASA Astrophysics Data System (ADS)

    Eidelman, Yuri; Andreev, Sergey

    An interphase nucleus of human lymphocyte was simulated by the novel Monte Carlo tech-nique. The main features of interphase chromosome structure and packaging were taken into account: different levels of chromatin organisation; nonrandom localisation of chromosomes within a nucleus; chromosome loci dynamics. All chromosomes in a nucleus were modelled as polymer globules. A dynamic pattern of intra/interchromosomal contacts was simulated. The detailed information about chromosomal contacts, such as distribution of intrachromoso-mal contacts over the length of each chromosome and dependence of contact probability on genomic separation between chromosome loci, were calculated and compared to the new exper-imental data obtained by the Hi-C technique. Types and frequencies of simple and complex radiation-induced chromosomal exchange aberrations (CA) induced by X-rays were predicted with taking formation and decay of chromosomal contacts into account. Distance dependence of exchange formation probability was calculated directly. mFISH data for human lymphocytes were analysed. The calculated frequencies of simple CA agreed with the experimental data. Complex CA were underestimated despite the dense packaging of chromosome territories within a nucleus. Possible influence of chromosome-nucleus structural organisation on the frequency and spectrum of radiation-induced chromosome aberrations is discussed.

  12. Ca2+-Transport through Plasma Membrane as a Test of Auxin Sensitivity

    PubMed Central

    Kirpichnikova, Anastasia A.; Rudashevskaya, Elena L.; Yemelyanov, Vladislav V.; Shishova, Maria F.

    2014-01-01

    Auxin is one of the crucial regulators of plant growth and development. The discovered auxin cytosolic receptor (TIR1) is not involved in the perception of the hormone signal at the plasma membrane. Instead, another receptor, related to the ABP1, auxin binding protein1, is supposed to be responsible for the perception at the plasma membrane. One of the fast and sensitive auxin-induced reactions is an increase of Ca2+ cytosolic concentration, which is suggested to be dependent on the activation of Ca2+ influx through the plasma membrane. This investigation was carried out with a plasmalemma enriched vesicle fraction, obtained from etiolated maize coleoptiles. The magnitude of Ca2+ efflux through the membrane vesicles was estimated according to the shift of potential dependent fluorescent dye diS-C3-(5). The obtained results showed that during coleoptiles ageing (3rd, 4th and 5th days of seedling etiolated growth) the magnitude of Ca2+ efflux from inside-out vesicles was decreased. Addition of ABP1 led to a recovery of Ca2+ efflux to the level of the youngest and most sensitive cells. Moreover, the efflux was more sensitive, responding from 10−8 to 10−6 M 1-NAA, in vesicles containing ABP1, whereas native vesicles showed the highest efflux at 10−6 M 1-NAA. We suggest that auxin increases plasma membrane permeability to Ca2+ and that ABP1 is involved in modulation of this reaction. PMID:27135501

  13. Testing the cation-hydration effect on the crystallization of Ca-Mg-CO3 systems.

    PubMed

    Xu, Jie; Yan, Chao; Zhang, Fangfu; Konishi, Hiromi; Xu, Huifang; Teng, H Henry

    2013-10-29

    Dolomite and magnesite are simple anhydrous calcium and/or magnesium carbonate minerals occurring mostly at Earth surfaces. However, laboratory synthesis of neither species at ambient temperature and pressure conditions has been proven practically possible, and the lack of success was assumed to be related to the strong solvation shells of magnesium ions in aqueous media. Here, we report the synthesis of MgCO3 and MgxCa(1-x)CO3 (0 < x < 1) solid phases at ambient conditions in the absence of water. Experiments were carried out in dry organic solvent, and the results showed that, although anhydrous phases were readily precipitated in the water-free environment, the precipitates' crystallinity was highly dependent on the Mg molar percentage content in the solution. In specific, magnesian calcite dominated in low [Mg(2+)]/[Ca(2+)] solutions but gave way to exclusive formation of amorphous MgxCa(1-x)CO3 and MgCO3 in high-[Mg(2+)]/[Ca(2+)] and pure-Mg solutions. At conditions of [Mg(2+)]/[Ca(2+)] = 1, both nanocrystals of Ca-rich protodolomite and amorphous phase of Mg-rich MgxCa(1-x)CO3 were formed. These findings exposed a previously unrecognized intrinsic barrier for Mg(2+) and CO3(2-) to develop long-range orders at ambient conditions and suggested that the long-held belief of cation-hydration inhibition on dolomite and magnesite mineralization needed to be reevaluated. Our study provides significant insight into the long-standing "dolomite problem" in geochemistry and mineralogy and may promote a better understanding of the fundamental chemistry in biomineralization and mineral-carbonation processes.

  14. Radiometric Calibration of Earth-Observing Sensors Using the Radiometric Calibration Test Site (RadCaTS)

    NASA Astrophysics Data System (ADS)

    Czapla-Myers, J.; Anderson, N. J.; Thome, K. J.; Biggar, S. F.

    2014-12-01

    The Remote Sensing Group (RSG) of the College of Optical Sciences at the University of Arizona uses the reflectance-based approach to perform the absolute radiometric calibration of such sensors as Landsat 5 TM, Landsat 7 ETM+, Landsat 8 OLI, Terra and Aqua MODIS, ASTER, RapidEye, and others. The reflectance-based approach requires that personnel be present at a test site during the sensor overpass, so the Radiometric Calibration Test Site (RadCaTS) was developed in order to capture data during every possible overpass, which assists in the temporal trending of the radiometric calibration of earth-observing sensors. The number of earth-observing sensors is rapidly increasing in recent years, and RadCaTS provides the ability to radiometrically calibrate them without the requirement of frequent field campaigns. The 2013 launch of Landsat 8 provides a unique opportunity for RadCaTS in that it is being used to supplement the in situ measurements by RSG ground personnel, and it will be used throughout the lifetime of the Landsat 8 mission. This allows more data to be collected throughout the year, and it also allows the accuracy and uncertainty of RadCaTS to be analyzed. The current top-of-atmosphere (TOA) spectral radiance uncertainty of the reflectance-based approach is ~2.6% in the mid-visible region of the spectrum, and current work indicates that the uncertainty of RadCaTS in TOA spectral radiance is ~3-4%. This work presents the radiometric calibration results of RadCaTS for a variety of sensors such as Landsat 7 ETM+, Landsat 8 OLI, Terra and Aqua MODIS, MISR, ASTER, and Suomi NPP VIIRS.

  15. Aberration correction of unstable resonators

    NASA Technical Reports Server (NTRS)

    Lang, Robert J. (Inventor)

    1994-01-01

    Construction of aspheric reflectors for unstable resonator lasers to provide an arbitrary laser mode inside the resonator to correct aberrations of an output beam by the construction of the shape of an end reflector opposite the output reflector of the resonator cavity, such as aberrations resulting from refraction of a beam exiting the solid of the resonator having an index of refraction greater than 1 or to produce an aberration in the output beam that will precisely compensate for the aberration of an optical train into which the resonator beam is coupled.

  16. Calculating carbon mass balance from unsaturated soil columns treated with CaSO₄₋minerals: test of soil carbon sequestration.

    PubMed

    Han, Young-Soo; Tokunaga, Tetsu K

    2014-12-01

    Renewed interest in managing C balance in soils is motivated by increasing atmospheric concentrations of CO2 and consequent climate change. Here, experiments were conducted in soil columns to determine C mass balances with and without addition of CaSO4-minerals (anhydrite and gypsum), which were hypothesized to promote soil organic carbon (SOC) retention and soil inorganic carbon (SIC) precipitation as calcite under slightly alkaline conditions. Changes in C contents in three phases (gas, liquid and solid) were measured in unsaturated soil columns tested for one year and comprehensive C mass balances were determined. The tested soil columns had no C inputs, and only C utilization by microbial activity and C transformations were assumed in the C chemistry. The measurements showed that changes in C inventories occurred through two processes, SOC loss and SIC gain. However, the measured SOC losses in the treated columns were lower than their corresponding control columns, indicating that the amendments promoted SOC retention. The SOC losses resulted mostly from microbial respiration and loss of CO2 to the atmosphere rather than from chemical leaching. Microbial oxidation of SOC appears to have been suppressed by increased Ca(2+) and SO4(2)(-) from dissolution of CaSO4 minerals. For the conditions tested, SIC accumulation per m(2) soil area under CaSO4-treatment ranged from 130 to 260 g C m(-1) infiltrated water (20-120 g C m(-1) infiltrated water as net C benefit). These results demonstrate the potential for increasing C sequestration in slightly alkaline soils via CaSO4-treatment.

  17. Antianxiety actions of Ca2+ channel antagonists with Vogel-type conflict test in rats.

    PubMed

    Matsumoto, Y; Kataoka, Y; Watanabe, Y; Miyazaki, A; Taniyama, K

    1994-10-13

    We examined the effects of various derivatives of Ca2+ channel antagonists in a modified rat Vogel-type conflict model. Flunarizine (10 and 20 mg/kg), nicardipine (20 mg/kg), and verapamil (20 mg/kg), given as single i.p. injections, significantly increased punished lickings by 50-110%. Chronic administration of diltiazem, at 20 mg/kg i.p. for 8 days, a dose ineffective with a single i.p. injection, produced a significant anticonflict action. The possibility that Ca2+ channel antagonists have anxiolytic action should be considered.

  18. Effects of heat treatment and testing temperature on fracture mechanics behavior of low-Si CA-15 stainless steel

    NASA Astrophysics Data System (ADS)

    Hsu, Cheng-Hsun; Lee, Shen-Chih; Teng, Hwei-Yuan

    2004-02-01

    This research studied the effects of heat treatment and testing temperature on fracture mechanics behavior of Si-modified CA-15 martensitic stainless steel (MSS), which is similar to AISI 403 grade stainless steel, which has been widely used in wall and blanket structures and in the pipe of nuclear power plant reactors, turbine blades, and nozzles. The results indicated that fracture toughness of low-Si CA-15 MSS is better than that of AISI 403. The specimens of the low-Si CA-15 MSS after austenitization at 1010 °C and then tempering at 300 °C have higher plane-strain fracture toughness (K IC ) values for both 25 °C and -150 °C testing temperatures. However, the specimens tested at 150 °C cannot satisfy the plane-strain fracture toughness criteria. The fatigue crack growth rate is the slowest after austenitization at 1010 °C for 2 hours and tempering at 400 °C. Observing the crack propagation paths using a metallographic test, it was found that the cracking paths preferred orientation and branched along ferrite phase, owing to martensite-phase strengthening and grain-boundary-carbide retarding after 300 °C to 400 °C tempering. Also, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction analysis were performed to correlate the properties attained to the microstructural observation.

  19. Influence of test size, water depth, and ecology on Mg/Ca, Sr/Ca, δ18O and δ13C in nine modern species of planktic foraminifers

    NASA Astrophysics Data System (ADS)

    Friedrich, Oliver; Schiebel, Ralf; Wilson, Paul A.; Weldeab, Syee; Beer, Christopher J.; Cooper, Matthew J.; Fiebig, Jens

    2012-02-01

    Mg/Ca palaeothermometry in foraminiferal calcite is a widely applied tool in palaeoceanography. However, our understanding of the effects of planktic foraminiferal ecology and early diagenesis on test calcite Mg/Ca is limited. Here we report results of a study designed to shed new light on ecological, size-related and very early (water column) diagenetic controls on Mg/Ca in planktic foraminiferal calcite. We analysed Mg/Ca and stable isotopes of nine modern planktic foraminiferal species across fourteen mostly 50 μm-window sieve fractions in a core-top sample from the North Atlantic Ocean. We also analysed Mg/Ca in four of these nine species from plankton-tow samples collected from 0 to 2500 m water depth in the North Atlantic Ocean and Arabian Sea. Our core-top study confirms that sensitivity of Mg/Ca to change in test size is species-specific but reveals an overall decrease in Mg/Ca with increasing test size in all but one species, Orbulina universa, for which Mg/Ca increases with size. These findings are broadly consistent with known ecological behaviour suggesting that the size-related signal is largely environmentally rather than calcification-rate controlled. Our results underscore the need to undertake Mg/Ca palaeothermometry on narrow size fractions of planktic foraminifers, particularly for shallow-dwelling species such as G. bulloides and G. ruber where Mg/Ca is most sensitive to test size across the size range of 200-350 μm. Our plankton-tow data from the Arabian Sea are in agreement with in-situ temperatures. In contrast, our data from the North Atlantic Ocean reveal large variability and marked offsets (to warmer values) from in-situ temperatures that are interpreted to reflect lateral advection from the south, storm-induced vertical mixing of the water column and/or the influence of surface-water salinity on the Mg/Ca signal. None of our plankton-tow Mg/Ca data shows any evidence of test dissolution in the water column. Our study provides important

  20. PIK3CA-Related Overgrowth Spectrum (PROS): Diagnostic and Testing Eligibility Criteria, Differential Diagnosis, and Evaluation

    PubMed Central

    Keppler-Noreuil, Kim M.; Rios, Jonathan J.; Parker, Victoria E.R.; Semple, Robert K.; Lindhurst, Marjorie J.; Sapp, Julie C.; Alomari, Ahmad; Ezaki, Marybeth; Dobyns, William; Biesecker, Leslie G.

    2015-01-01

    Somatic activating mutations in the phosphatidylinositol-3-kinase/AKT/mTOR pathway underlie heterogeneous segmental overgrowth phenotypes. Because of the extreme differences among patients, we sought to characterize the phenotypic spectrum associated with different genotypes and mutation burdens, including a better understanding of associated complications and natural history. Historically, the clinical diagnoses in patients with PIK3CA activating mutations have included Fibroadipose hyperplasia or Overgrowth (FAO), Hemihyperplasia Multiple Lipomatosis (HHML), Congenital Lipomatous Overgrowth, Vascular Malformations, Epidermal Nevi, Scoliosis/Skeletal and Spinal (CLOVES) syndrome, macrodactyly, Fibroadipose Infiltrating Lipomatosis, and the related megalencephaly syndromes, Megalencephaly-Capillary Malformation (MCAP or M-CM) and Dysplastic Megalencephaly (DMEG). A workshop was convened at the National Institutes of Health (NIH) to discuss and develop a consensus document regarding diagnosis and treatment of patients with PIK3CA-associated somatic overgrowth disorders. Participants in the workshop included a group of researchers from several institutions who have been studying these disorders and have published their findings, as well as representatives from patient-advocacy and support groups. The umbrella term of “PIK3CA-Related Overgrowth Spectrum (PROS)” was agreed upon to encompass both the known and emerging clinical entities associated with somatic PIK3CA mutations including, macrodactyly, FAO, HHML, CLOVES, and related megalencephaly conditions. Key clinical diagnostic features and criteria for testing were proposed, and testing approaches summarized. Preliminary recommendations for a uniform approach to assessment of overgrowth and molecular diagnostic testing were determined. Future areas to address include the surgical management of overgrowth tissue and vascular anomalies, the optimal approach to thrombosis risk, and the testing of potential

  1. Camera processing with chromatic aberration.

    PubMed

    Korneliussen, Jan Tore; Hirakawa, Keigo

    2014-10-01

    Since the refractive index of materials commonly used for lens depends on the wavelengths of light, practical camera optics fail to converge light to a single point on an image plane. Known as chromatic aberration, this phenomenon distorts image details by introducing magnification error, defocus blur, and color fringes. Though achromatic and apochromatic lens designs reduce chromatic aberration to a degree, they are complex and expensive and they do not offer a perfect correction. In this paper, we propose a new postcapture processing scheme designed to overcome these problems computationally. Specifically, the proposed solution is comprised of chromatic aberration-tolerant demosaicking algorithm and post-demosaicking chromatic aberration correction. Experiments with simulated and real sensor data verify that the chromatic aberration is effectively corrected. PMID:25163060

  2. Aerospace Testing Seminar, 13th, Manhattan Beach, CA, Oct. 8-10, 1991, Proceedings

    NASA Astrophysics Data System (ADS)

    The papers presented in this volume focus on the currently used aerospace test techniques, with attention given to the management of risk, cost, and problems encountered in attaining effective test methods. Topics discussed include a software environment for satellite environmental testing, modeling, and simulation; TQM as an operational process in testing; low-earth orbit global cellular communications network; and in place assembly and testing of satellites. Papers are also presented on lessons learned from modal testing of aerospace structures; the testability of software for the Space Station Freedom program; vibration testing of large structures; and solar probe shield development testing.

  3. Chromosome Aberrations in Astronauts

    NASA Technical Reports Server (NTRS)

    George, Kerry A.; Durante, M.; Cucinotta, Francis A.

    2007-01-01

    A review of currently available data on in vivo induced chromosome damage in the blood lymphocytes of astronauts proves that, after protracted exposure of a few months or more to space radiation, cytogenetic biodosimetry analyses of blood collected within a week or two of return from space provides a reliable estimate of equivalent radiation dose and risk. Recent studies indicate that biodosimetry estimates from single spaceflights lie within the range expected from physical dosimetry and biophysical models, but very large uncertainties are associated with single individual measurements and the total sample population remains low. Retrospective doses may be more difficult to estimate because of the fairly rapid time-dependent loss of "stable" aberrations in blood lymphocytes. Also, biodosimetry estimates from individuals who participate in multiple missions, or very long (interplanetary) missions, may be complicated by an adaptive response to space radiation and/or changes in lymphocyte survival and repopulation. A discussion of published data is presented and specific issues related to space radiation biodosimetry protocols are discussed.

  4. Correction of Distributed Optical Aberrations

    SciTech Connect

    Baker, K; Olivier, S; Carrano, C; Phillion, D

    2006-02-12

    The objective of this project was to demonstrate the use of multiple distributed deformable mirrors (DMs) to improve the performance of optical systems with distributed aberrations. This concept is expected to provide dramatic improvement in the optical performance of systems in applications where the aberrations are distributed along the optical path or within the instrument itself. Our approach used multiple actuated DMs distributed to match the aberration distribution. The project developed the algorithms necessary to determine the required corrections and simulate the performance of these multiple DM systems.

  5. Phase aberration effects in elastography.

    PubMed

    Varghese, T; Bilgen, M; Ophir, J

    2001-06-01

    In sonography, phase aberration plays a role in the corruption of sonograms. Phase aberration does not have a significant impact on elastography, if statistically similar phase errors are present in both the pre- and postcompression signals. However, if the phase errors are present in only one of the pre- or postcompression signal pairs, the precision of the strain estimation process will be reduced. In some cases, increased phase errors may occur only in the postcompression signal due to changes in the tissue structure with the applied compression. Phase-aberration effects increase with applied strain and may be viewed as an image quality derating factor, much like frequency-dependent attenuation or undesired lateral tissue motion. In this paper, we present a theoretical and simulation study of the effects of phase aberration on the elastographic strain-estimation process, using the strain filter approach.

  6. A challenging case due to uncommon aberrancies.

    PubMed

    Waleed, Mohammad; Raza, Ali; Minhaj, Tariq; Houghton, Timothy

    2015-09-24

    A 71-year-old man was referred to a rapid access chest pain clinic by his general practitioner. He presented with a 6-month history of twice weekly central chest pain lasting 2-3 min with walking and exertion, relieved with rest or co-codamol tablets. After initial investigations and a positive myoview scan, he was listed for an elective coronary angiogram. Unfortunately, the procedure was abandoned due to unclear course of the guide wire and a possible aberrant aortic course. Further non-invasive tests were arranged to clarify the anatomy of the vessels. After getting a clear idea of the aberrancies, coronary angiogram was replanned, and the patient underwent successful angiography with angioplasty to one of the coronary arteries, without any complications.

  7. Using Electromagnetic Techniques to Test Models for Shallow Permeability in the Surprise Valley, CA Geothermal System

    NASA Astrophysics Data System (ADS)

    Hawkes, S.; McClain, J. S.; Kahn, A.; Lewis, K.

    2013-12-01

    Surprise Valley in northeastern Modoc County, CA is the westernmost major extensional graben in the northwestern Basin and Range province. There are abundant faults coincident with moderate to boiling temperature hot springs that discharge along the western rim of the valley and in the central eastern part of the valley. Fluid recharge and discharge pathways are poorly understood despite sporadic geothermal exploration, drilling, and development since the 1950's and a wide variety of academic studies that have been focused in the region. It is hypothesized that thermal fluids discharged into the basin exploit fracture permeability related to active extensional faulting along the Surprise Valley Fault (SVF), Lake City Fault Zone (LCFZ), and faults in the Hays Canyon Range (HCR). We present several fault-perpendicular Magnetotelluric profiles conducted across the LCFZ and HCR faults with the goal of imaging the orientation and extent of the geothermal reservoir that supplies the hot springs. Initial results are consistent with the HCR faults tapping a deep conductive aquifer below shallow resistive extrusive igneous rocks, with narrow low resistivity regions beneath the faults. There is no conclusive evidence for or against the LCFZ acting as a preferred fluid pathway, due to relatively homogeneous distribution highly conductive materials and the difficulty in differentiating clay-rich lacustrine sediments from hydrothermal fluids or clays.

  8. Aberrant phenotypes in Kikuchi’s disease

    PubMed Central

    Wei, Xue-Jing; Zhou, Xiao-Ge; Xie, Jian-Lan; Zheng, Xiao-Dan; Zheng, Yuan-Yuan

    2014-01-01

    Initial reports emphasized the immunophenotypic similarities between benign and malignant T cell populations, while some previous studies indicating that aberrant T-cell antigen loss is a good marker for detecting malignant T-cell proliferation. Recently, we found a very interesting and thought-provoking phenomenon: In benign disease-28 of 38 (73.7%) cases of Kikuchi’s disease also showed aberrant phenotypes with loss of pan-T cell antigens, which makes the differential diagnosis between Kikuchi’s disease and T cell lymphoma more challenging. In our study, 38 cases of Kikuchi’s disease and 30 cases of reactive lymphoid hyperplasia (RLH) were studied by EliVision immunohistochemical staining. As well as TCR gene rearrangement using PCR was negative in 10 tested cases of the Kikuchi’s disease. Among these cases, the most common antigen deficiency was CD5 (22 cases), then CD7 (11 cases), CD2 (8 cases) and CD3 (2 cases). Compared with proliferative and xanthomatous types of Kikuchi’s disease, antigens tended to be lost in necrotizing type. Based on follow-up data, a correlation was not found between the occurrence of aberrant phenotypes and prognosis. In RLH, obvious pan-T cell antigen loss was also not found. In conclusion, this is the first study to demonstrate distinct patterns of antigen loss in Kikuchi’s disease, suggesting that T cell antigen loss is not reliable as an auxiliary diagnostic standard for T cell lymphoma. PMID:25337197

  9. Sexual aberration or instinctual vicissitude? Revisiting freud's "the sexual aberrations".

    PubMed

    Phillips, Sidney H

    2014-04-01

    The author reconsiders Freud's "The Sexual Aberrations," the first of his Three Essays on the Theory of Sexuality (1905), in light of contemporary psychoanalytic theory. Are the concepts of sexual aberration and norm still viable? The author argues that they are necessary but insufficient elements in current theory. He then presents a competing model in which sexuality can be reduced to a more elemental level of disturbance and wish, where it is an expression of a nonsexual wish--for example, to possess or control the object to eliminate separateness. The author presents clinical material to demonstrate this alternative model. PMID:24777366

  10. Surface characterization and testing II; Proceedings of the Meeting, San Diego, CA, Aug. 10, 11, 1989

    NASA Technical Reports Server (NTRS)

    Greivenkamp, John E. (Editor); Young, Matt (Editor)

    1989-01-01

    Various papers on surface characterization and testing are presented. Individual topics addressed include: simple Hartmann test data interpretation, optimum configuration of the Offner null corrector, system for phase-shifting interferometry in the presence of vibration, fringe variation and visibility in speckle-shearing interferometry, functional integral representation of rough surfaces, calibration of surface heights in an interferometric optical profiler, image formation in common path differential profilometers, SEM of optical surfaces, measuring surface profiles with scanning tunneling microscopes, surface profile measurements of curved parts, high-resolution optical profiler, scanning heterodyne interferometer with immunity from microphonics, real-time crystal axis measurements of semiconductor materials, radial metrology with a panoramic annular lens, surface analysis for the characterization of defects in thin-film processes, Spacelab Optical Viewport glass assembly optical test program for the Starlab mission, scanning differential intensity and phase system for optical metrology.

  11. Three traps in stellar aberration

    NASA Astrophysics Data System (ADS)

    Liebscher, Dierck-E.; Brosche, Peter

    The effect of aberration seems to be one of the simplest in astronomical observations. Nevertheless, it has a long and pertaining history of misunderstanding and wrong interpretation. In the time just before the advent of the theory of relativity, aberration and drag of the aether (as found in Michelson's experiment) are interpreted as contradiction. This contradiction vanishes with the theory of relativity. More obstinate is the misunderstanding that the aberration depends on the relative velocity of source and observer. In the twenties, some physicists and astronomers believed that the consequences of such a relativity, wrongly supposed but never found, would constitute a firm argument against Einstein's theory (Hayn, Tomaschek, Osten, v. Brunn, Courvoisier, Mohorovicic). History forgot their argument, but it is difficult to find a correct explanation of their error (Emden). Instead, the subject is forgotten, and one can conjecture it because of the political side of the argument. This attitude takes its revenge: Misunderstandings are still handed down from textbook to textbook.

  12. Overcoming Polarization Aberrations In Microscopy

    NASA Astrophysics Data System (ADS)

    Hansen, Eric W.

    1988-06-01

    A long-standing problem in polarized light microscopy has been the inability, due to polarization aberrations, to achieve simultaneously high spatial resolution and high contrast. The rotation of the plane of polarization at oblique interfaces between crossed polars causes the pupil function to resemble a dark cross rather than being uniformly dark. Likewise, the point spread function has the visual appearance of a four-leaf clover rather than the ideal Airy disk, and is also space-variant. Images formed with these systems are severely degraded. In this paper the theory of polarization aberrations is applied to the analysis of three solutions to this problem: Reducing the system aperture to block troublesome high-aperture rays; the AVEC-POL method, in which high bias compensation introduces counterbalancing aberrations; and the polarization rectifier, an optical element designed to introduce equal and opposite rotations of the electric vector.

  13. Chromosome Aberrations by Heavy Ions

    NASA Astrophysics Data System (ADS)

    Ballarini, Francesca; Ottolenghi, Andrea

    It is well known that mammalian cells exposed to ionizing radiation can show different types of chromosome aberrations (CAs) including dicentrics, translocations, rings, deletions and complex exchanges. Chromosome aberrations are a particularly relevant endpoint in radiobiology, because they play a fundamental role in the pathways leading either to cell death, or to cell conversion to malignancy. In particular, reciprocal translocations involving pairs of specific genes are strongly correlated (and probably also causally-related) with specific tumour types; a typical example is the BCR-ABL translocation for Chronic Myeloid Leukaemia. Furthermore, aberrations can be used for applications in biodosimetry and more generally as biomarkers of exposure and risk, that is the case for cancer patients monitored during Carbon-ion therapy and astronauts exposed to space radiation. Indeed hadron therapy and astronauts' exposure to space radiation represent two of the few scenarios where human beings can be exposed to heavy ions. After a brief introduction on the main general features of chromosome aberrations, in this work we will address key aspects of the current knowledge on chromosome aberration induction, both from an experimental and from a theoretical point of view. More specifically, in vitro data will be summarized and discussed, outlining important issues such as the role of interphase death/mitotic delay and that of complex-exchange scoring. Some available in vivo data on cancer patients and astronauts will be also reported, together with possible interpretation problems. Finally, two of the few available models of chromosome aberration induction by ionizing radiation (including heavy ions) will be described and compared, focusing on the different assumptions adopted by the authors and on how these models can deal with heavy ions.

  14. Germline MLH1 and MSH2 mutational spectrum including frequent large genomic aberrations in Hungarian hereditary non-polyposis colorectal cancer families: Implications for genetic testing

    PubMed Central

    Papp, Janos; Kovacs, Marietta E; Olah, Edith

    2007-01-01

    AIM: To analyze the prevalence of germline MLH1 and MSH2 gene mutations and evaluate the clinical characteristics of Hungarian hereditary non-polyposis colorectal cancer (HNPCC) families. METHODS: Thirty-six kindreds were tested for mutations using conformation sensitive gel electrophoreses, direct sequencing and also screening for genomic rearrangements applying multiplex ligation-dependent probe amplification (MLPA). RESULTS: Eighteen germline mutations (50%) were identified, 9 in MLH1 and 9 in MSH2. Sixteen of these sequence alterations were considered pathogenic, the remaining two were non-conservative missense alterations occurring at highly conserved functional motifs. The majority of the definite pathogenic mutations (81%, 13/16) were found in families fulfilling the stringent Amsterdam I/II criteria, including three rearrangements revealed by MLPA (two in MSH2 and one in MLH1). However, in three out of sixteen HNPCC-suspected families (19%), a disease-causing alteration could be revealed. Furthermore, nine mutations described here are novel, and none of the sequence changes were found in more than one family. CONCLUSION: Our study describes for the first time the prevalence and spectrum of germline mismatch repair gene mutations in Hungarian HNPCC and suspected-HNPCC families. The results presented here suggest that clinical selection criteria should be relaxed and detection of genomic rearrangements should be included in genetic screening in this population. PMID:17569143

  15. Lesion generation through ribs using histotripsy therapy without aberration correction.

    PubMed

    Kim, Yohan; Wang, Tzu-Yin; Xu, Zhen; Cain, Charles A

    2011-11-01

    This study investigates the feasibility of using high-intensity pulsed therapeutic ultrasound, or histotripsy, to non-invasively generate lesions through the ribs. Histotripsy therapy mechanically ablates tissue through the generation of a cavitation bubble cloud, which occurs when the focal pressure exceeds a certain threshold. We hypothesize that histotripsy can generate precise lesions through the ribs without aberration correction if the main lobe retains its shape and exceeds the cavitation initiation threshold and the secondary lobes remain below the threshold. To test this hypothesis, a 750-kHz focused transducer was used to generate lesions in tissue-mimicking phantoms with and without the presence of rib aberrators. In all cases, 8000 pulses with 16 to 18 MPa peak rarefactional pressure at a repetition frequency of 100 Hz were applied without aberration correction. Despite the high secondary lobes introduced by the aberrators, high-speed imaging showed that bubble clouds were generated exclusively at the focus, resulting in well-confined lesions with comparable dimensions. Collateral damage from secondary lobes was negligible, caused by single bubbles that failed to form a cloud. These results support our hypothesis, suggesting that histotripsy has a high tolerance for aberrated fields and can generate confined focal lesions through rib obstacles without aberration correction.

  16. Chromosome aberrations in workers exposed to arsenic.

    PubMed

    Beckman, G; Beckman, L; Nordenson, I

    1977-08-01

    The occurrence of chromosome aberrations was studied in short-term cultured lymphocytes from nine workers exposed to arsenic at the Rönnskär smeltery in northern Sweden. In the smelter workers, 87 aberrations were found in 819 mitoses. The number of aberrations varied individually from 0 to 25 aberrations per 100 cells. In a control material 13 aberrations were found in 1012 mitoses. The frequency of chromosome aberrations was significantly increased among the smelter workers, but due to the simultaneous exposure to other agents the effect of arsenic per se can not be assessed with certainty.

  17. [Influence of reagent storage in Sysmex CA7000 for different time on 4 test RESULTS: of the plasma coagulation].

    PubMed

    Chen, Tong-Qing; Li, Zhen-Xing

    2014-12-01

    The purpose of this study was to investigate the influence of blood coagulation reagents stored for different time on test results of the specimens prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (Fib). A total of 21 patient plasma specimens was taken and measured for homeostasis by Sysmex CA7000 automated blood coagulation analyzer and supporting reagent. The PT, APTT, TT and Fib of specimens were measured with the reagents stored in Sysmex CA7000 for different time. The differences of PT, APTT, TT and Fib were analyzed between values measured of the reagents stored for 0 hour and different time (TS:12, 24, 36,48, 60, 72 h; DA:24, 48, 72, 96, 120 h; TT:2, 4, 6, 8, 10, 12 h; TR:4, 8, 12, 16, 20, 24 h; OVB:1, 2, 3, 4, 5 ,6 h), respectively. The results showed that when coagulation reagent TS were stored for more than 48 h , DA 96 h, TT 10 h, TR 16 h and OVB 4 h, the values of PT, APTT, TT and Fib of samples were statistically different from the values measured with fresh coagulation reagent (P < 0.01), respectively. Compared 0 h with TS stored for 48-72, DA 96-120, TT 10-12, TR 16-24 and OVB 4-6 h, the percentage difference of PT, APTT, TT and Fib is in -2.6% ∼ 10.8%, -3.44% ∼ 4.8%, -3.9% ∼ 5.52%, -10.8% ∼ 3.3% and -17.2% ∼ 0.5%, the PT and Fib changes were more significant. Accordingly, the result of PT, APTT and TT had a uptrend as the reagent stored in Sysmex CA7000 analyzer for a long time, while Fib downtrend. It is concluded that the reagents showed be timely replaced when the plasma coagulation test is performed so as to obtain accurate results of examination.

  18. Acute Effect of Cigarette Smoking on Pupil Size and Ocular Aberrations: A Pre- and Postsmoking Study

    PubMed Central

    Erdem, Uzeyir; Gundogan, Fatih C.; Dinc, Umut Aslı; Yolcu, Umit; Ilhan, Abdullah; Altun, Salih

    2015-01-01

    Aim. To evaluate the acute effects of cigarette smoking on photopic and mesopic pupil sizes and wavefront aberrations. Methods. Cigarette smoker volunteers were recruited in the study. Photopic and mesopic pupil sizes and total ocular aberrations were measured before smoking and immediately after smoking. All volunteers were asked to smoke a single cigarette containing 1.0 mg nicotine. Pupil sizes and total ocular aberrations were assessed by optical path difference scanning system (OPD-Scan II ARK-10000, NIDEK). Only the right eyes were considered for statistical analysis. The changes of pupil size and total ocular aberrations after smoking were tested for significance by Wilcoxon signed ranks test. Results. Mean photopic pupil size decreased from 3.52 ± 0.73 mm to 3.29 ± 0.58 mm (P = 0.001) after smoking. Mean mesopic pupil size was also decreased from 6.42 ± 0.75 mm to 6.14 ± 0.75 mm after smoking (P = 0.001). There was a decrease in all the measured components of aberrations (total wavefront aberration, higher-order aberration, total coma, total trefoil, total tetrafoil, total spherical aberration and total higher-order aberration) after smoking; however the differences were insignificant for all (P > 0.05). Conclusion. Our results indicate that pupil constricts after smoking. On the other hand, smoking does not alter ocular aberrations. PMID:25699189

  19. Phase Aberrations in Diffraction Microscopy

    SciTech Connect

    Marchesini, S; Chapman, H N; Barty, A; Howells, M R; Spence, J H; Cui, C; Weierstall, U; Minor, A M

    2005-09-29

    In coherent X-ray diffraction microscopy the diffraction pattern generated by a sample illuminated with coherent x-rays is recorded, and a computer algorithm recovers the unmeasured phases to synthesize an image. By avoiding the use of a lens the resolution is limited, in principle, only by the largest scattering angles recorded. However, the imaging task is shifted from the experiment to the computer, and the algorithm's ability to recover meaningful images in the presence of noise and limited prior knowledge may produce aberrations in the reconstructed image. We analyze the low order aberrations produced by our phase retrieval algorithms. We present two methods to improve the accuracy and stability of reconstructions.

  20. In vitro degradation, cytocompatibility and hemolysis tests of CaF2 doped TiO2-SiO2 composite coating on AZ31 alloy

    NASA Astrophysics Data System (ADS)

    Li, Bing; Chen, Yun; Huang, Wei; Yang, Wenzhong; Yin, Xiaoshuang; Liu, Ying

    2016-09-01

    In this study, a CaF2 doped TiO2-SiO2 composite coating was successfully coated onto AZ31 alloy by sol-gel method. Electrochemical tests, in vitro degradation, direct cellular experiment and hemolysis tests were conducted and the results showed that the CaF2 doped TiO2-SiO2 composite coating can not only improve the corrosion resistance, but also enhance the biocompatibility of AZ31 alloy. XRD, SEM and EDX were also performed to characterize the crystalline structures, morphologies and chemical compositions of the coatings.

  1. New formulations between spherical aberration and spherical aberration coefficient using the Abbe sine condition

    NASA Astrophysics Data System (ADS)

    Kang, Songgao; Lu, Kaichang; Zhu, Yafei

    1991-12-01

    The relationship between aberration and the aberration coefficient is the basic formulation in the field of aberration theory. The Seidel's formulations can only be used in the case of low performance (small aperture and small field), so that a set of correct relations between spherical aberration (SA) and spherical aberration coefficient (SAC) must be derived for the application of large aperture and small viewing field.

  2. Perceived no reference image quality measurement for chromatic aberration

    NASA Astrophysics Data System (ADS)

    Lamb, Anupama B.; Khambete, Madhuri

    2016-03-01

    Today there is need for no reference (NR) objective perceived image quality measurement techniques as conducting subjective experiments and making reference image available is a very difficult task. Very few NR perceived image quality measurement algorithms are available for color distortions like chromatic aberration (CA), color quantization with dither, and color saturation. We proposed NR image quality assessment (NR-IQA) algorithms for images distorted with CA. CA is mostly observed in images taken with digital cameras, having higher sensor resolution with inexpensive lenses. We compared our metric performance with two state-of-the-art NR blur techniques, one full reference IQA technique and three general-purpose NR-IQA techniques, although they are not tailored for CA. We used a CA dataset in the TID-2013 color image database to evaluate performance. Proposed algorithms give comparable performance with state-of-the-art techniques in terms of performance parameters and outperform them in terms of monotonicity and computational complexity. We have also discovered that the proposed CA algorithm best predicts perceived image quality of images distorted with realistic CA.

  3. Micronucleus and chromosome aberrations induced in onion (Allium cepa) by a petroleum refinery effluent and by river water that receives this effluent.

    PubMed

    Hoshina, Márcia M; Marin-Morales, Maria A

    2009-11-01

    In this study, micronucleus (MN) and chromosome aberration (CA) tests in Allium cepa (onion) were carried out in order to make a preliminary characterization of the water quality of the Atibaia River in an area that is under the influence of petroleum refinery and also to evaluate the effectiveness of the treatments used by the refinery. For these evaluations, seeds of A. cepa were germinated in waters collected in five different sites related with the refinery in ultra-pure water (negative control) and in methyl methanesulfonate solution (positive control). According to our results, we can suggest that even after the treatments (physicochemical, biological and stabilization pond) the final refinery effluent could induce chromosome aberrations and micronucleus in meristematic cells of A. cepa and that the discharge of the petroleum refinery effluents in the Atibaia River can interfere in the quality of this river. PMID:19647317

  4. Testing the Deglacial Global Ocean Alkalization Hypothesis Using Foraminifer-based Mg/Ca, Shell Weight, and MFI

    NASA Astrophysics Data System (ADS)

    Ward, B. M.; Mekik, F.; Pourmand, A.

    2015-12-01

    In light of evidence for extensive modern ocean acidification, it has become imperative to better understand the global carbon cycle by reconstructing past ocean acidification/alkalization events. Our goal is to test the deglacial global alkalization hypothesis using a multi-proxy approach by reconstructing the pH, temperature, and [CO32-] of thermocline waters and the dissolution in deep sea sediments over the last 25,000 years in core ME-27 from the eastern equatorial Pacific. Our specific research questions are: Is there unequivocal evidence for a deglacial ocean alkalization event? If yes, what was the magnitude of the alkalization event? If no, how can we explain why evidence of this event is missing from our core? We inferred temperature from Mg/Ca, and habitat water [CO32-] from sized-normalized shell weight in Neogloboquadrina dutertrei. Dissolution in sediments was estimated using the Globorotalia menardii Fragmentation Index (MFI). We see no clear indication of a deglacial ocean alkalization event with our proxies. Neither our shell weight, nor MFI data show a more alkaline deglacial ocean compared to the Last Glacial Maximum and the modern Interglacial. Instead, we observe a steady decrease in thermocline [CO32-], and increase in deep sea calcite preservation since the LGM. Our results may indicate that the global alkalization event was obscured in ME-27 due to higher organic carbon fluxes during the deglacial, and/or due to yet undetermined effects of temperature on the foraminifer shell weight proxy.

  5. Increased chromosome aberration frequencies in the Bowen's patients compared to non-cancerous skin lesions individuals exposed to arsenic.

    PubMed

    Ghosh, Pritha; Banerjee, Mayukh; De Chaudhuri, Sujata; Das, Jayanta K; Sarma, Nilendu; Basu, Arindam; Giri, Ashok K

    2007-08-15

    Cytogenetic biomarkers are essential for assessing environmental exposure that can predict adverse human health effects such as cellular damage. Chromosomal aberrations are the most important cytogenetic end-points successfully used for the cancer risk assessment of populations occupationally or environmentally exposed to different toxic chemicals. Previous reports suggest that, increased frequency of chromosomal aberration (CA), in peripheral blood lymphocytes, is a predictor of cancer. Arsenic is a paradoxical human carcinogen, clastogen and aneugen. Despite of exposure at similar extent, only 15-20% of individuals show arsenic induced skin lesions including Bowen's disease (BD). Previously we have reported the significant increase in CA in the individuals with arsenic induced skin lesions when compared to individuals without any skin lesions, drinking arsenic contaminated water at similar extent. Presently, a matched case-control study was performed to examine whether biomarkers such as chromosomal aberrations can predict the development of arsenic induced Bowen's (in situ carcinoma) diseases. Chromosomal aberrations (both chromosome and chromatid types) and mitotic index were analyzed from the lymphocytes of 25 cases of Bowen's patient which was compared to matched control from the individuals with arsenic induced non-cancerous skin lesions such as raindrop pigmentation, keratosis of palm and sole, hypo and hyper pigmentation. Chromosomal aberrations/cell, chromosome type aberrations and total percentage of aberrant cells were significantly higher in cases compared to control (p<0.01). These results suggest that chromosomal aberrations can be used for cancer risk assessment of the population exposed to arsenic through drinking water.

  6. Fabrication and performance testing of CaO insulator coatings on V-5%Cr-5%Ti in liquid lithium

    SciTech Connect

    Park, J.H.; Dragel, G.

    1995-04-01

    Corrosion resistance of structural materials, and the magnetohydrodynamic (MHD) force and its influence on thermal hydraulics and corrosion, are major concerns in the design of liquid-metal blankets for magnetic fusion reactors (MFRs). The objective of this study is to develop in-situ stable coatings at the liquid-metal/structural-material interface, with emphasis on coatings that can be converted to an electrically insulating film to prevent adverse currents that are generated by the MHD force from passing through the structural walls. The electrical resistance of CaO coatings produced on V-5Cr-5Ti by exposure of the alloy to liquid Li that contained 0.5 - 8.5 wt.% dissolved Ca was measured as a function of time at temperatures between 250 and 600{degree}C. The solute element, Ca in liquid Li, reacted with the alloy substrate at 400-420{degree}C to produce a CaO coating.

  7. Automation of the in vitro micronucleus and chromosome aberration assay for the assessment of the genotoxicity of the particulate and gas-vapor phase of cigarette smoke.

    PubMed

    Roemer, Ewald; Zenzen, Volker; Conroy, Lynda L; Luedemann, Kathrin; Dempsey, Ruth; Schunck, Christian; Sticken, Edgar Trelles

    2015-01-01

    Total particulate matter (TPM) and the gas-vapor phase (GVP) of mainstream smoke from the Reference Cigarette 3R4F were assayed in the cytokinesis-block in vitro micronucleus (MN) assay and the in vitro chromosome aberration (CA) assay, both using V79-4 Chinese hamster lung fibroblasts exposed for up to 24 h. The Metafer image analysis platform was adapted resulting in a fully automated evaluation system of the MN assay for the detection, identification and reporting of cells with micronuclei together with the determination of the cytokinesis-block proliferation index (CBPI) to quantify the treatment-related cytotoxicity. In the CA assay, the same platform was used to identify, map and retrieve metaphases for a subsequent CA evaluation by a trained evaluator. In both the assays, TPM and GVP provoked a significant genotoxic effect: up to 6-fold more micronucleated target cells than in the negative control and up to 10-fold increases in aberrant metaphases. Data variability was lower in the automated version of the MN assay than in the non-automated. It can be estimated that two test substances that differ in their genotoxicity by approximately 30% can statistically be distinguished in the automated MN and CA assays. Time savings, based on man hours, due to the automation were approximately 70% in the MN and 25% in the CA assays. The turn-around time of the evaluation phase could be shortened by 35 and 50%, respectively. Although only cigarette smoke-derived test material has been applied, the technical improvements should be of value for other test substances. PMID:25986082

  8. Automation of the in vitro micronucleus and chromosome aberration assay for the assessment of the genotoxicity of the particulate and gas-vapor phase of cigarette smoke.

    PubMed

    Roemer, Ewald; Zenzen, Volker; Conroy, Lynda L; Luedemann, Kathrin; Dempsey, Ruth; Schunck, Christian; Sticken, Edgar Trelles

    2015-01-01

    Total particulate matter (TPM) and the gas-vapor phase (GVP) of mainstream smoke from the Reference Cigarette 3R4F were assayed in the cytokinesis-block in vitro micronucleus (MN) assay and the in vitro chromosome aberration (CA) assay, both using V79-4 Chinese hamster lung fibroblasts exposed for up to 24 h. The Metafer image analysis platform was adapted resulting in a fully automated evaluation system of the MN assay for the detection, identification and reporting of cells with micronuclei together with the determination of the cytokinesis-block proliferation index (CBPI) to quantify the treatment-related cytotoxicity. In the CA assay, the same platform was used to identify, map and retrieve metaphases for a subsequent CA evaluation by a trained evaluator. In both the assays, TPM and GVP provoked a significant genotoxic effect: up to 6-fold more micronucleated target cells than in the negative control and up to 10-fold increases in aberrant metaphases. Data variability was lower in the automated version of the MN assay than in the non-automated. It can be estimated that two test substances that differ in their genotoxicity by approximately 30% can statistically be distinguished in the automated MN and CA assays. Time savings, based on man hours, due to the automation were approximately 70% in the MN and 25% in the CA assays. The turn-around time of the evaluation phase could be shortened by 35 and 50%, respectively. Although only cigarette smoke-derived test material has been applied, the technical improvements should be of value for other test substances.

  9. The misalignment induced aberrations of TMA telescopes.

    PubMed

    Thompson, Kevin P; Schmid, Tobias; Rolland, Jannick P

    2008-12-01

    The next major space-borne observatory, the James Webb Space Telescope, will be a 6.6M field-biased, obscured, three-mirror anastigmat (TMA). Over the used field of view, the performance of TMA telescopes is dominated by 3(rd) order misalignment aberrations. Here it is shown that two dominant 3(rd) order misalignment aberrations arise for any TMA telescope. One aberration, field constant 3(rd) order coma is a well known misalignment aberration commonly seen in two-mirror Ritchey Chretien telescopes. The second aberration, field-asymmetric, field-linear, 3(rd) order astigmatism is a new and unique image orientation dependence with field derived here for the first time using nodal aberration theory.

  10. Phase and birefringence aberration correction

    DOEpatents

    Bowers, Mark; Hankla, Allen

    1996-01-01

    A Brillouin enhanced four wave mixing phase conjugate mirror corrects phase aberrations of a coherent electromagnetic beam and birefringence induced upon that beam. The stimulated Brillouin scattering (SBS) phase conjugation technique is augmented to include Brillouin enhanced four wave mixing (BEFWM). A seed beam is generated by a main oscillator which arrives at the phase conjugate cell before the signal beams in order to initiate the Brillouin effect. The signal beam which is being amplified through the amplifier chain is split into two perpendicularly polarized beams. One of the two beams is chosen to be the same polarization as some component of the seed beam, the other orthogonal to the first. The polarization of the orthogonal beam is then rotated 90.degree. such that it is parallel to the other signal beam. The three beams are then focused into cell containing a medium capable of Brillouin excitation. The two signal beams are focused such that they cross the seed beam path before their respective beam waists in order to achieve BEFWM or the two signal beams are focused to a point or points contained within the focused cone angle of the seed beam to achieve seeded SBS, and thus negate the effects of all birefringent and material aberrations in the system.

  11. Phase and birefringence aberration correction

    DOEpatents

    Bowers, M.; Hankla, A.

    1996-07-09

    A Brillouin enhanced four wave mixing phase conjugate mirror corrects phase aberrations of a coherent electromagnetic beam and birefringence induced upon that beam. The stimulated Brillouin scattering (SBS) phase conjugation technique is augmented to include Brillouin enhanced four wave mixing (BEFWM). A seed beam is generated by a main oscillator which arrives at the phase conjugate cell before the signal beams in order to initiate the Brillouin effect. The signal beam which is being amplified through the amplifier chain is split into two perpendicularly polarized beams. One of the two beams is chosen to be the same polarization as some component of the seed beam, the other orthogonal to the first. The polarization of the orthogonal beam is then rotated 90{degree} such that it is parallel to the other signal beam. The three beams are then focused into cell containing a medium capable of Brillouin excitation. The two signal beams are focused such that they cross the seed beam path before their respective beam waists in order to achieve BEFWM or the two signal beams are focused to a point or points contained within the focused cone angle of the seed beam to achieve seeded SBS, and thus negate the effects of all birefringent and material aberrations in the system. 5 figs.

  12. Aberrations of ellipsoidal reflectors for unit magnification.

    PubMed

    Mielenz, K D

    1974-12-01

    Ellipsoidal reflectors are useful for the 1:1 imaging of small objects without spherical and chromatic aberration. The magnitude of the off-axis aberrations of such reflectors is computed by application of Fermat's principle to the Hamiltonian point characteristic. The limiting form of the mirror aperture for which these aberrations do not exceed a set tolerance is an ellipse whose semiaxes depend on object size and angle of incidence. PMID:20134811

  13. Adaptive and aberrant reward prediction signals in the human brain.

    PubMed

    Roiser, Jonathan P; Stephan, Klaas E; den Ouden, Hanneke E M; Friston, Karl J; Joyce, Eileen M

    2010-04-01

    Theories of the positive symptoms of schizophrenia hypothesize a role for aberrant reinforcement signaling driven by dysregulated dopamine transmission. Recently, we provided evidence of aberrant reward learning in symptomatic, but not asymptomatic patients with schizophrenia, using a novel paradigm, the Salience Attribution Test (SAT). The SAT is a probabilistic reward learning game that employs cues that vary across task-relevant and task-irrelevant dimensions; it provides behavioral indices of adaptive and aberrant reward learning. As an initial step prior to future clinical studies, here we used functional magnetic resonance imaging to examine the neural basis of adaptive and aberrant reward learning during the SAT in healthy volunteers. As expected, cues associated with high relative to low reward probabilities elicited robust hemodynamic responses in a network of structures previously implicated in motivational salience; the midbrain, in the vicinity of the ventral tegmental area, and regions targeted by its dopaminergic projections, i.e. medial dorsal thalamus, ventral striatum and prefrontal cortex (PFC). Responses in the medial dorsal thalamus and polar PFC were strongly correlated with the degree of adaptive reward learning across participants. Finally, and most importantly, differential dorsolateral PFC and middle temporal gyrus (MTG) responses to cues with identical reward probabilities were very strongly correlated with the degree of aberrant reward learning. Participants who showed greater aberrant learning exhibited greater dorsolateral PFC responses, and reduced MTG responses, to cues erroneously inferred to be less strongly associated with reward. The results are discussed in terms of their implications for different theories of associative learning. PMID:19969090

  14. Influence of aberrations in microholographic recording

    NASA Astrophysics Data System (ADS)

    Katayama, Ryuichi

    2015-11-01

    The influence of various types of aberrations (spherical, coma, and astigmatic) of recording and readout beams on the readout signal in a microholographic recording was investigated through a numerical simulation. The simulation conditions were that the wavelength of the laser was 405 nm and the numerical aperture of the objective lenses was 0.85. The tolerance of the root-mean-square (RMS) wavefront aberrations was defined as the aberration when the normalized signal level decreased to 0.8. Among the three types of aberrations, the influence of the spherical aberration was the most significant. When both the recording and readout beams were aberrated and the signs of the aberrations were in the worst case, the tolerance of the RMS wavefront aberrations was less than half of the Maréchal's criterion. Moreover, when the RMS wavefront aberrations of the recording and readout beams were within the above tolerance, the bit intervals of 0.13 and 0.65 μm in the inplane and vertical directions, respectively, which correspond to the recording density of 91 bit/μm3 (recording capacity of 16 TB for a 120-mm-diameter optical disk having a 300-μm-thick recording layer), were shown to be feasible for confocal detection with an allowable signal-to-noise ratio.

  15. An adaptive optic for correcting low-order wavefront aberrations

    SciTech Connect

    Thompson, C A; Wilhelmsen, J

    1999-09-02

    Adaptive Optics used for correcting low-order wavefront aberrations were tested and compared using interferometry, beam propagation, and a far-field test. Results confirm that the design and manufacturing specifications were met. Experimental data also confirms theoretical performance expectations, indicating the usefulness of these optics (especially in a laser-beam processing system), and identifying the resulting differences between the two fabrication methods used to make the optics.

  16. Testing the CaR-FA-X Model: Investigating the Mechanisms Underlying Reduced Autobiographical Memory Specificity in Individuals With and Without a History of Depression

    PubMed Central

    Sumner, Jennifer A.; Mineka, Susan; Adam, Emma K.; Craske, Michelle G.; Vrshek-Schallhorn, Suzanne; Wolitzky-Taylor, Kate; Zinbarg, Richard E.

    2014-01-01

    Reduced autobiographical memory specificity (AMS) is an important cognitive phenomenon in major depressive disorder (MDD), but knowledge is lacking about its mechanisms. The CaR-FA-X model of Williams and colleagues proposed that three processes contribute to reduced AMS, alone or in interaction: capture and rumination (CaR), functional avoidance (FA), and impaired executive control (X). However, the entire CaR-FA-X model has not been tested. We addressed this gap in the literature by investigating contributions of the CaR-FA-X mechanisms to reduced AMS, alone or in interaction, in a subset of young adults (N=439) from the Northwestern-UCLA Youth Emotion Project. Participants were classified as those with (n=164) and without (n=275) a history of MDD at AMS assessment. They completed measures of: AMS; rumination (the brooding factor; CaR); childhood, adolescent, and early adulthood adversity (FA); avoidant coping (FA); and verbal fluency (X). Using structural equation modeling, we found greatest support for associations between reduced AMS and the capture and rumination, and impaired executive control mechanisms. In those with and without a history of MDD, brooding and verbal fluency interacted to contribute to reduced AMS. For participants without a history of MDD, lower verbal fluency (indicating impaired executive control) was associated with reduced AMS among those high on brooding. For participants with a history of MDD, lower verbal fluency was associated with reduced AMS among those low on brooding. The first finding was consistent with predictions from the CaR-FA-X model but the latter was not. Implications for conceptualizations of reduced AMS and its mechanisms are discussed. PMID:24978693

  17. Congenital Aberrant Tearing: A Re-Look

    PubMed Central

    Miller, Marilyn T.; Strömland, Kerstin; Ventura, Liana

    2008-01-01

    Purpose Congenital aberrant tearing is characterized by tearing when eating (“crocodile tears”), lack of emotional tearing, or both. Most reported cases are associated with Duane syndrome. In our previous studies we observed aberrant tearing in individuals with thalidomide embryopathy and Möbius sequence. This report summarizes the literature on the subject and adds 3 new studies that give information on this unusual condition. Methods Twenty-eight individuals with Möbius sequence were interviewed about tearing symptoms at a support group meeting in Italy. In Sweden 30 adults primarily from the original thalidomide series were reexamined. In this latter study, a Schirmer test was done at baseline and repeated 5 minutes after eating. Twenty families in Brazil who have children with Möbius sequence were questioned about tearing symptoms and exposure to misoprostol during pregnancy. Results In the 28 Italian individuals, either “crocodile tears” or lack of emotional tearing was noted in 7 cases. In the thalidomide study, 10 of 30 patients had tearing when eating and 7 had no emotional tearing. Low Schirmer scores or increased tearing after eating was noted in a few asymptomatic individuals. Among the 20 Brazilian children with Möbius sequence, 10 had some tearing abnormality. Conclusion Congenital anomalous lacrimation is rare but usually associated with Duane syndrome or abduction deficits, as in Möbius sequence and, less frequently, facial nerve palsy. Studies implicate an early insult in development at 4 to 6 weeks. At that time the facial nerve, sixth nerve, and lacrimal nucleus are in close proximity in the embryo. PMID:19277226

  18. [Fetal diagnosis from the mother's blood--noninvasive screening of chromosomal aberrations].

    PubMed

    Anttonen, Anna-Kaisa; Stefanovic, Vedran; Aittomäki, Kristiina

    2015-01-01

    In Finland, the screening of fetal chromosome aberrations is currently based on combined screening in the first trimester. Non-invasive prenatal testing (NIPT) is a new method enabling a more accurate screening than combined screening of fetal chromosome aberrations from the mother's blood sample by analyzing cell-free fetal DNA (cffDNA). In addition, it is possible to determine the gender of the fetus or assess the number of sex chromosomes. Although NIPT is an accurate screening method, an aberrant result should always be confirmed by an invasive fetal diagnostic test. PMID:26749901

  19. Harmonic oscillator states in aberration optics

    NASA Technical Reports Server (NTRS)

    Wolf, Kurt Bernardo

    1993-01-01

    The states of the three-dimensional quantum harmonic oscillator classify optical aberrations of axis-symmetric systems due to the isomorphism between the two mathematical structures. Cartesian quanta and angular momentum classifications have their corresponding aberration classifications. The operation of concatenation of optical elements introduces a new operation between harmonic oscillator states.

  20. Cadmium chloride strongly enhances cyclophosphamide-induced chromosome aberrations in mouse bone marrow cells

    SciTech Connect

    Pandurangarao, V.L.; Blazina, S.; Bherje, R.

    1997-10-01

    Earlier we reported that a single 5 mg cadmium chloride (CdCl{sub 2})/kg ip dose enhanced chromosome aberrations (ca) with 50 mg/kg cyclophosphamide (CP) in mouse bone marrow cells. In this report groups of 4 mice were injected ip with saline, 0.31, 0.62, 1.25, 2.5 or 5.0 mg/kg CdCl{sub 2}, followed by saline injections at 24 h. Other mice similarly uninjected at 0 h were injected with 50 mg/kg CP at 24 h. All the mice were injected ip with 4 mg colchicine/kg at 44 h. At 48 h the bone marrow cells were processed for chromosome spreads. After dissection, visual examination revealed obvious internal hemorrhaging of the testes at 1.25 CdCl{sub 2} mg/kg and higher doses. This effect was not further increased by CP treatment. The lowest ca enhancing dose of CdCl{sub 2} on CP was 0.625 mg/kg. Our hypothesis is that Cd replaces zinc presents in numerous DNA repair enzymes and proteins resulting in diminished repair. Subsequently, the excess of unrepaired DNA damage is seen as chromatid breaks, deletions, fragments and exchanges.

  1. Society of Flight Test Engineers, Annual Symposium, 21st, Garden Grove, CA, Aug. 6-10, 1990, Proceedings

    SciTech Connect

    Not Available

    1990-01-01

    The present conference on flight testing encompasses avionics, flight-testing programs, technologies for flight-test predictions and measurements, testing tools, analysis methods, targeting techniques, and flightline testing. Specific issues addressed include flight testing of a digital terrain-following system, a digital Doppler rate-of-descent indicator, a high-technology testbed, a low-altitude air-refueling flight-test program, techniques for in-flight frequency-response testing for helicopters, limit-cycle oscillation and flight-flutter testing, and the research flight test of a scaled unmanned air vehicle. Also addressed are AV-8B V/STOL performance analysis, incorporating pilot-response time in failure-case testing, the development of pitot static flightline testing, targeting techniques for ground-based hover testing, a low-profile microsensor for aerodynamic pressure measurement, and the use of a variable-capacitance accelerometer for flight-test measurements.

  2. Dai nippon printing co., ltd, Medi-Ca AC for enumeration of aerobic bacteria. Performance tested method 041302.

    PubMed

    Okochi, Norihiko; Yamazaki, Mamoru; Kiso, Shoichi; Kinoshita, Mai; Okita, Yurie; Kazama, Keisuke; Saito, Rui

    2014-01-01

    A ready-made dry medium method for aerobic count, the MediCa AC method, was compared to the AOAC Official Method 966.23, Microbiological Methods, for seven different heat-processed meat matrixes: cooked roast beef, Chinese barbecued pork (barbecued pork seasoned with honey-based sauce), bacon, cooked ham, frankfurter (made from beef and pork), and boiled and cooked pork sausage. The 95% confidence interval for the mean difference between the two methods at each contamination level for each matrix fell within the range of -0.50 to 0.50, and no statistical difference was observed at all three contamination levels for five matrixes. These results demonstrate that the Medi-Ca AC method is a reasonable alternative to the AOAC 966.23 method for cooked meat products.

  3. Quantitative analysis of radiation-induced chromosome aberrations.

    PubMed

    Sachs, R K; Levy, D; Hahnfeldt, P; Hlatky, L

    2004-01-01

    We review chromosome aberration modeling and its applications, especially to biodosimetry and to characterizing chromosome geometry. Standard results on aberration formation pathways, randomness, dose-response, proximity effects, transmissibility, kinetics, and relations to other radiobiological endpoints are summarized. We also outline recent work on graph-theoretical descriptions of aberrations, Monte-Carlo computer simulations of aberration spectra, software for quantifying aberration complexity, and systematic links of apparently incomplete with complete or truly incomplete aberrations. PMID:15162028

  4. Aberration correction past and present.

    PubMed

    Hawkes, P W

    2009-09-28

    Electron lenses are extremely poor: if glass lenses were as bad, we should see as well with the naked eye as with a microscope! The demonstration by Otto Scherzer in 1936 that skillful lens design could never eliminate the spherical and chromatic aberrations of rotationally symmetric electron lenses was therefore most unwelcome and the other great electron optician of those years, Walter Glaser, never ceased striving to find a loophole in Scherzer's proof. In the wartime and early post-war years, the first proposals for correcting C(s) were made and in 1947, in a second milestone paper, Scherzer listed these and other ways of correcting lenses; soon after, Dennis Gabor invented holography for the same purpose. These approaches will be briefly summarized and the work that led to the successful implementation of quadupole-octopole and sextupole correctors in the 1990 s will be analysed. In conclusion, the elegant role of image algebra in describing image formation and processing and, above all, in developing new methods will be mentioned. PMID:19687058

  5. Wavefront aberration statistics in normal eye populations: are they well described by the Kolmogorov model?

    PubMed

    Pailos, Eliseo; Bará, Salvador

    2014-06-01

    This Letter studies the statistics of wavefront aberrations in a sample of eyes with normal vision. Methods relying on the statistics of the measured wavefront slopes are used, not including the aberration estimation stage. Power-law aberration models, an extension of the Kolmogorov one, are rejected by χ2-tests performed on fits to the slope structure function data. This is due to the large weight of defocus and astigmatism variations in normal eyes. Models of only second-order changes are not ruled out. The results are compared with previous works in the area.

  6. Image Ellipticity from Atmospheric Aberrations

    SciTech Connect

    de Vries, W H; Olivier, S S; Asztalos, S J; Rosenberg, L J; Baker, K L

    2007-03-06

    We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand the errors in shape measurements of astronomical objects, such as those used to study weak gravitational lensing of field galaxies. The PSF modeling involves either a Fourier transform of the phase information in the pupil plane or a ray-tracing approach, which has the advantage of requiring fewer computations than the Fourier transform. Using a standard method, involving the Gaussian weighted second moments of intensity, we then calculate the ellipticity of the PSF patterns. We find significant ellipticity for the instantaneous patterns (up to more than 10%). Longer exposures, which we approximate by combining multiple (N) images from uncorrelated atmospheric realizations, yield progressively lower ellipticity (as 1/{radical}N). We also verify that the measured ellipticity does not depend on the sampling interval in the pupil plane using the Fourier method. However, we find that the results using the ray-tracing technique do depend on the pupil sampling interval, representing a gradual breakdown of the geometric approximation at high spatial frequencies. Therefore, ray tracing is generally not an accurate method of modeling PSF ellipticity induced by atmospheric turbulence unless some additional procedure is implemented to correctly account for the effects of high spatial frequency aberrations. The Fourier method, however, can be used directly to accurately model PSF ellipticity, which can give insights into errors in the statistics of field galaxy shapes used in studies of weak gravitational lensing.

  7. Transverse chromatic aberration after corneal refractive surgery

    NASA Astrophysics Data System (ADS)

    Anera, R. G.; Jiménez, J. R.; Jiménez del Barco, L.; Hita, E.

    2005-05-01

    An expression has been deduced theoretically from a schematic-eye model, for the transverse or lateral chromatic aberration (TCA) after refractive surgery. The aim was to investigate analytically how chromatic aberration varies after the emmetropization process. These changes in the TCA have been characterized from changes in corneal asphericity. The results indicate that TCA after refractive surgery diminishes as the degree of myopia increases, a trend contrary to that occurring with monochromatic aberrations, such as spherical or coma. These results can explain the fact that the real deterioration of the visual function under photopic conditions detected in those operated on for myopia is less than expected when only monochromatic aberrations are taken into account.

  8. Spherical aberration in electrically thin flat lenses.

    PubMed

    Ruphuy, Miguel; Ramahi, Omar M

    2016-08-01

    We analyze the spherical aberration of a new generation of lenses made of flat electrically thin inhomogeneous media. For such lenses, spherical aberration is analyzed quantitatively and qualitatively, and comparison is made to the classical gradient index rod. Both flat thin and thick lenses are made of gradient index materials, but the physical mechanisms and design equations are different. Using full-wave three-dimensional numerical simulation, we evaluate the spherical aberrations using the Maréchal criterion and show that the thin lens gives significantly better performance than the thick lens (rod). Additionally, based on ray tracing formulation, third-order analysis for longitudinal aberration and optical path difference are presented, showing strong overall performance of thin lenses in comparison to classical rod lenses. PMID:27505651

  9. Chromosome aberration and micronucleus frequencies in Allium cepa cells exposed to petroleum polluted water--a case study.

    PubMed

    Leme, Daniela Morais; Marin-Morales, Maria Aparecida

    2008-01-31

    In the present study, we applied Chromosome Aberration (CA) and Micronucleus (MN) tests to Allium cepa root cells, in order to evaluate the water quality of Guaecá river. This river, located in the city of São Sebastião, SP, Brazil, had been affected by an oil pipeline leak. Chemical analyses of Total Petroleum Hydrocarbons (TPHs) and Polycyclic Aromatic Hydrocarbons (PAHs) were also carried out in water samples, collected in July 2005 (dry season) and February 2006 (rainy season) in 4 different river sites. The largest CA and MN incidence in the meristematic cells of A. cepa was observed after exposure to water sample collected during the dry season, at the spring of the river, where the oil leak has arisen. The F(1) cells from roots exposed to such sample (non-merismatic region) were also analyzed for the incidence of MN, showing a larger frequency of irregularities, indicating a possible development of CA into MN. Lastly, our study reveals a direct correlation between water chemical analyses (contamination by TPHs and PAHs) and both genotoxic and mutagenic effects observed in exposed A. cepa cells. PMID:18068420

  10. Chromosome aberrations in decondensed sperm DNA

    SciTech Connect

    Preston, R.J.

    1982-01-01

    Factors that could influence the chromosomal aberration frequency observed at first cleavage following in vivo exposure of germ cells to chemical mutagens are discussed. The techniques of chromosome aberration analysis following sperm DNA condensation by in vitro fertilization or fusion seem to be viable research areas for providing information of human germ cell exposures. However, the potential sensitivity of the assay needs to be better understood, and factors that can influence this sensitivity require a great deal of further study using animal models.

  11. Proton and Fe Ion-Induced Early and Late Chromosome Aberrations in Different Cell Types

    NASA Technical Reports Server (NTRS)

    Lu, Tao; Zhang, Ye; Yeshitla, Samrawit; Bowler, Deborah; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2016-01-01

    Genomic instability, induced by various metabolic, genetic, and environmental factors, is the driving force of tumorigenesis. Radiation exposure from different types of radiation sources induces different types of DNA damages, increases mutation and chromosome aberration rates, and increases cellular transformation in vitro and in vivo experiments. The cell survival rates and frequency of chromosome aberrations depend on the genetic background and radiation sources. To further understand genomic instability induced by charged particles, we exposed human lymphocytes ex vivo, human fibroblast cells, human mammary epithelial cells, and bone marrow cells isolated from CBA/CaH and C57BL/6 mice to high energy protons and Fe ions, and collected chromosomes at different generations after exposure. Chromosome aberrations were analyzed with fluorescent in situ hybridization with whole chromosome specific probes.

  12. Dynamics of the eye's wave aberration.

    PubMed

    Hofer, H; Artal, P; Singer, B; Aragón, J L; Williams, D R

    2001-03-01

    It is well known that the eye's optics exhibit temporal instability in the form of microfluctuations in focus; however, almost nothing is known of the temporal properties of the eye's other aberrations. We constructed a real-time Hartmann-Shack (HS) wave-front sensor to measure these dynamics at frequencies as high as 60 Hz. To reduce spatial inhomogeneities in the short-exposure HS images, we used a low-coherence source and a scanning system. HS images were collected on three normal subjects with natural and paralyzed accommodation. Average temporal power spectra were computed for the wave-front rms, the Seidel aberrations, and each of 32 Zernike coefficients. The results indicate the presence of fluctuations in all of the eye's aberration, not just defocus. Fluctuations in higher-order aberrations share similar spectra and bandwidths both within and between subjects, dropping at a rate of approximately 4 dB per octave in temporal frequency. The spectrum shape for higher-order aberrations is generally different from that for microfluctuations of accommodation. The origin of these measured fluctuations is not known, and both corneal/lenticular and retinal causes are considered. Under the assumption that they are purely corneal or lenticular, calculations suggest that a perfect adaptive optics system with a closed-loop bandwidth of 1-2 Hz could correct these aberrations well enough to achieve diffraction-limited imaging over a dilated pupil. PMID:11265680

  13. Measurements of Pupillary Diameter and Wavefront Aberrations in Pregnant Women

    PubMed Central

    Altay, Mehmet Metin; Demirok, Gulizar; Balta, Ozgur; Bolu, Hulya

    2016-01-01

    Purpose. To show whether pregnancy affects the measurements of pupillary diameter and wavefront (WF) aberrations. Methods. This was a case-control study including 34 healthy pregnant women in the third trimester and age-matched 34 nonpregnant women. Only women who had no ocular abnormalities and no refractive error were included. We measured photopic and mesopic pupil diameter and WF aberrations at the third trimester and at the second postpartum month. Measurements of the right eyes were used in this study. The differences between groups were analysed by paired t-test and t-test. Results. Pregnant women's mean photopic pupil size in the third trimester was significantly higher than in postpartum period and in control group (3.74 ± 0.77, 3.45 ± 0.53, and 3.49 ± 0.15 mm, p < 0.05, resp.). Mesopic pupil size in the third trimester was also higher than in postpartum period and in control group (6.77 ± 0.52, 6.42 ± 0.55, and 6.38 ± 0.21 mm, p < 0.05, resp.). RMS-3 and RMS-5 values were higher in pregnancy but these differences were not statistically significant. Conclusion. Pregnancy increased photopic and mesopic pupil size significantly but did not increase wavefront aberrations notably. Increased pupil size may be due to increased sympathetic activity during pregnancy. And this activity can be noninvasively determined by measuring pupil size. PMID:26998383

  14. Effect of behavioral testing on spine density of basal dendrites in the CA1 region of the hippocampus modulated by (56)Fe irradiation.

    PubMed

    Raber, Jacob; Allen, Antiño R; Weber, Sydney; Chakraborti, Ayanabha; Sharma, Sourabh; Fike, John R

    2016-04-01

    A unique feature of the space radiation environment is the presence of high-energy charged particles, including (56)Fe ions, which can present a significant hazard to space flight crews during and following a mission. (56)Fe irradiation-induced cognitive changes often involve alterations in hippocampal function. These alterations might involve changes in spine morphology and density. In addition to irradiation, performing a cognitive task can also affect spine morphology. Therefore, it is often hard to determine whether changes in spine morphology and density are due to an environmental challenge or group differences in performance on cognitive tests. In this study, we tested the hypothesis that the ability of exploratory behavior to increase specific measures of hippocampal spine morphology and density is affected by (56)Fe irradiation. In sham-irradiated mice, exploratory behavior increased basal spine density in the CA1 region of the hippocampus and the enclosed blade of the dentate gyrus. These effects were not seen in irradiated mice. In addition, following exploratory behavior, there was a trend toward a decrease in the percent stubby spines on apical dendrites in the CA3 region of the hippocampus in (56)Fe-irradiated, but not sham-irradiated, mice. Other hippocampal regions and spine measures affected by (56)Fe irradiation showed comparable radiation effects in behaviorally naïve and cognitively tested mice. Thus, the ability of exploratory behavior to alter spine density and morphology in specific hippocampal regions is affected by (56)Fe irradiation. PMID:26801826

  15. Pulse compressor with aberration correction

    SciTech Connect

    Mankos, Marian

    2015-11-30

    In this SBIR project, Electron Optica, Inc. (EOI) is developing an electron mirror-based pulse compressor attachment to new and retrofitted dynamic transmission electron microscopes (DTEMs) and ultrafast electron diffraction (UED) cameras for improving the temporal resolution of these instruments from the characteristic range of a few picoseconds to a few nanoseconds and beyond, into the sub-100 femtosecond range. The improvement will enable electron microscopes and diffraction cameras to better resolve the dynamics of reactions in the areas of solid state physics, chemistry, and biology. EOI’s pulse compressor technology utilizes the combination of electron mirror optics and a magnetic beam separator to compress the electron pulse. The design exploits the symmetry inherent in reversing the electron trajectory in the mirror in order to compress the temporally broadened beam. This system also simultaneously corrects the chromatic and spherical aberration of the objective lens for improved spatial resolution. This correction will be found valuable as the source size is reduced with laser-triggered point source emitters. With such emitters, it might be possible to significantly reduce the illuminated area and carry out ultrafast diffraction experiments from small regions of the sample, e.g. from individual grains or nanoparticles. During phase I, EOI drafted a set of candidate pulse compressor architectures and evaluated the trade-offs between temporal resolution and electron bunch size to achieve the optimum design for two particular applications with market potential: increasing the temporal and spatial resolution of UEDs, and increasing the temporal and spatial resolution of DTEMs. Specialized software packages that have been developed by MEBS, Ltd. were used to calculate the electron optical properties of the key pulse compressor components: namely, the magnetic prism, the electron mirror, and the electron lenses. In the final step, these results were folded

  16. Frequency of Early and Late Chromosome Aberrations in Different Types of Cells After Proton and Fe Ion Irradiation

    NASA Astrophysics Data System (ADS)

    Lu, Tao; Wu, Honglu; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Bowler, Deborah

    2016-07-01

    DNA damages induced by space radiation, consisting of protons and high-LET charged particles, can be complex in nature, which are often left unrepaired and cause chromosomal aberrations. Increased level of genomic instability is attributed to tumorigenesis and increased cancer risks. To investigate genomic instability induced by charged particles, human lymphocytes ex vivo, human fibroblasts, and human mammary epithelial cells, as well as mouse bone marrow stem cells isolated from CBA/CaH and C57BL/6 strains were exposed to high energy protons and Fe ions. Metaphase chromosome spreads at different cell divisions after radiation exposure were collected and, chromosome aberrations were analyzed with fluorescence in situ hybridization with whole chromosome-specific probes for human cells. With proton irradiation, levels of chromosome aberrations decreased by about 50% in both lymphocytes and epithelial cells after multiple cell divisions, compared to initial chromosome aberrations at 48 hours post irradiation in both cell types. With Fe ion irradiation, however, the frequency of chromosome aberrations in lymphocytes after multiple cell divisions was significantly lower than that in epithelial cells at comparable cell divisions, while their initial chromosome aberrations were at similar levels. Similar to the human cells, after Fe ion irradiation, the frequency of late chromosome aberrations was similar to that of the early damages for radio-sensitive CBA cells, but different for radio-resistant C57 cells. Our results suggest that relative biological effectiveness (RBE) values are dependent not only on radiation sources, but also on cell types and cell divisions.

  17. Frequency of Early and Late Chromosome Aberrations in Different Types of Cells After Proton and Fe Ion Irradiation

    NASA Technical Reports Server (NTRS)

    Lu, Tao; Zhang, Ye; Yeshitla, Samrawit; Bowler, Deborah; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2016-01-01

    DNA damages induced by space radiation, consisting of protons and high-LET charged particles, can be complex in nature, which are often left unrepaired and cause chromosomal aberrations. Increased level of genomic instability is attributed to tumorigenesis and increased cancer risks. To investigate genomic instability induced by charged particles, human lymphocytes ex vivo, human fibroblasts, and human mammary epithelial cells, as well as mouse bone marrow stem cells isolated from CBA/CaH and C57BL/6 strains were exposed to high energy protons and Fe ions. Metaphase chromosome spreads at different cell divisions after radiation exposure were collected and, chromosome aberrations were analyzed with fluorescence in situ hybridization with whole chromosome-specific probes for human cells. With proton irradiation, levels of chromosome aberrations decreased by about 50% in both lymphocytes and epithelial cells after multiple cell divisions, compared to initial chromosome aberrations at 48 hours post irradiation in both cell types. With Fe ion irradiation, however, the frequency of chromosome aberrations in lymphocytes after multiple cell divisions was significantly lower than that in epithelial cells at comparable cell divisions, while their initial chromosome aberrations were at similar levels. Similar to the human cells, after Fe ion irradiation, the frequency of late chromosome aberrations was similar to that of the early damages for radio-sensitive CBA cells, but different for radio-resistant C57 cells. Our results suggest that relative biological effectiveness (RBE) values are dependent not only on radiation sources, but also on cell types and cell divisions.

  18. Aberrant regulation of Wnt signaling in hepatocellular carcinoma

    PubMed Central

    Liu, Li-Juan; Xie, Shui-Xiang; Chen, Ya-Tang; Xue, Jing-Ling; Zhang, Chuan-Jie; Zhu, Fan

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the most lethal malignancies in the world. Several signaling pathways, including the wingless/int-1 (Wnt) signaling pathway, have been shown to be commonly activated in HCC. The Wnt signaling pathway can be triggered via both catenin β1 (CTNNB1)-dependent (also known as “canonical”) and CTNNB1-independent (often referred to as “non-canonical”) pathways. Specifically, the canonical Wnt pathway is one of those most frequently reported in HCC. Aberrant regulation from three complexes (the cell-surface receptor complex, the cytoplasmic destruction complex and the nuclear CTNNB1/T-cell-specific transcription factor/lymphoid enhancer binding factor transcriptional complex) are all involved in HCC. Although the non-canonical Wnt pathway is rarely reported, two main non-canonical pathways, Wnt/planar cell polarity pathway and Wnt/Ca2+ pathway, participate in the regulation of hepatocarcinogenesis. Interestingly, the canonical Wnt pathway is antagonized by non-canonical Wnt signaling in HCC. Moreover, other signaling cascades have also been demonstrated to regulate the Wnt pathway through crosstalk in HCC pathogenesis. This review provides a perspective on the emerging evidence that the aberrant regulation of Wnt signaling is a critical mechanism for the development of HCC. Furthermore, crosstalk between different signaling pathways might be conducive to the development of novel molecular targets of HCC. PMID:27672271

  19. Aberrant regulation of Wnt signaling in hepatocellular carcinoma.

    PubMed

    Liu, Li-Juan; Xie, Shui-Xiang; Chen, Ya-Tang; Xue, Jing-Ling; Zhang, Chuan-Jie; Zhu, Fan

    2016-09-01

    Hepatocellular carcinoma (HCC) is one of the most lethal malignancies in the world. Several signaling pathways, including the wingless/int-1 (Wnt) signaling pathway, have been shown to be commonly activated in HCC. The Wnt signaling pathway can be triggered via both catenin β1 (CTNNB1)-dependent (also known as "canonical") and CTNNB1-independent (often referred to as "non-canonical") pathways. Specifically, the canonical Wnt pathway is one of those most frequently reported in HCC. Aberrant regulation from three complexes (the cell-surface receptor complex, the cytoplasmic destruction complex and the nuclear CTNNB1/T-cell-specific transcription factor/lymphoid enhancer binding factor transcriptional complex) are all involved in HCC. Although the non-canonical Wnt pathway is rarely reported, two main non-canonical pathways, Wnt/planar cell polarity pathway and Wnt/Ca(2+) pathway, participate in the regulation of hepatocarcinogenesis. Interestingly, the canonical Wnt pathway is antagonized by non-canonical Wnt signaling in HCC. Moreover, other signaling cascades have also been demonstrated to regulate the Wnt pathway through crosstalk in HCC pathogenesis. This review provides a perspective on the emerging evidence that the aberrant regulation of Wnt signaling is a critical mechanism for the development of HCC. Furthermore, crosstalk between different signaling pathways might be conducive to the development of novel molecular targets of HCC. PMID:27672271

  20. Aberrant regulation of Wnt signaling in hepatocellular carcinoma

    PubMed Central

    Liu, Li-Juan; Xie, Shui-Xiang; Chen, Ya-Tang; Xue, Jing-Ling; Zhang, Chuan-Jie; Zhu, Fan

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the most lethal malignancies in the world. Several signaling pathways, including the wingless/int-1 (Wnt) signaling pathway, have been shown to be commonly activated in HCC. The Wnt signaling pathway can be triggered via both catenin β1 (CTNNB1)-dependent (also known as “canonical”) and CTNNB1-independent (often referred to as “non-canonical”) pathways. Specifically, the canonical Wnt pathway is one of those most frequently reported in HCC. Aberrant regulation from three complexes (the cell-surface receptor complex, the cytoplasmic destruction complex and the nuclear CTNNB1/T-cell-specific transcription factor/lymphoid enhancer binding factor transcriptional complex) are all involved in HCC. Although the non-canonical Wnt pathway is rarely reported, two main non-canonical pathways, Wnt/planar cell polarity pathway and Wnt/Ca2+ pathway, participate in the regulation of hepatocarcinogenesis. Interestingly, the canonical Wnt pathway is antagonized by non-canonical Wnt signaling in HCC. Moreover, other signaling cascades have also been demonstrated to regulate the Wnt pathway through crosstalk in HCC pathogenesis. This review provides a perspective on the emerging evidence that the aberrant regulation of Wnt signaling is a critical mechanism for the development of HCC. Furthermore, crosstalk between different signaling pathways might be conducive to the development of novel molecular targets of HCC.

  1. Concurrent Sr/Ca Ratios and Bomb Test 14C Records from a Porites evermanni Colony on Kure Atoll: SST, Climate Change, Ocean Circulation and Management Applications

    NASA Astrophysics Data System (ADS)

    Covarrubias, S.; Potts, D.; Siciliano, D.; Andrews, A.; Franks, R.

    2013-12-01

    Coral reefs near their latitudinal and ecological limits may be affected disproportionately by global climate changes, especially by changing sea surface temperatures (SST's). One such reef is Kure Atoll, the northernmost reef in the Hawaiian chain. Kure Atoll experiences dramatic temperature and seasonal differences throughout the year. Tracking these fluctuations is important for understanding recent physical forces affecting coral growth in such marginal reefs, and for predicting likely responses to future climate and oceanic changes. We used Sr/Ca ratios of a 50cm Porites evermanni coral core collected in Kure (September 2002) as a SST proxy for reconstructing a temperature timescale spanning the length of the core (~62 years). After cutting a 5 mm thick slab through the center growth axis and X-raying it to identify annual density banding, we extracted 4 equally-spaced samples from each annual increment to quantify, seasonal, inter-annual, and decadal SST patterns. We measured Sr and Ca concentrations by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). We then converted Sr/Ca ratios (mmol/mol) to SST using published equations, and calibrated the more recent SST estimates against satellite-based SST imagery and instrumental records from Midway Atoll (ca. 90 km to SE). We coupled the ICP-OES data with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) scans along the core to provide higher temporal resolution for interpreting intra-seasonal and inter-seasonal trends. Higher resolution of temperature dating can help us interpret strong inter-seasonal changes not readily seen with low resolution measurements, giving us the ability to track temperature anomalies at interannual and decadal timescales, such as El Niño/Southern Oscillation or La Niña/North Pacific Decadal Oscillation. Further, the SST signature from the Sr/Ca analyses are being used in conjunction with bomb radiocarbon signals in order to establish a complete

  2. Comparative testing of various flow-cell detectors fabricated using CaF{sub 2} solid scintillator

    SciTech Connect

    Kawano, T.; Ohashi, H.; Hamada, Y.; Jamsranjav, E.

    2015-03-15

    A monitoring system based on a flow-cell detector was developed for measuring the tritium concentration in water. The flow-cell detector was fabricated using a granular CaF{sub 2} solid scintillator. This system does not use a liquid scintillation counting system and does not generate radioactive organic liquid waste. Moreover, continuous real-time measurements are possible, in contrast to a liquid scintillation counting system, which requires batch measurements. For further development of the system, four flow-cell detectors were fabricated. They included a single 3-mm-diameter cell, three 3-mm-diameter cells in series, a single 5-mm-diameter cell, and three 5-mm-diameter cells in series. Continuously flowing water containing tritium at various concentrations was passed through the flow cells, and tritium count were measured for 600 and 10000 s. Investigating the relation between the count rate and concentration, the three 5-mm-diameter cells were most sensitive, with a linear relation maintained down to approximately 2 Bq/ml and 10 Bq/ml for 10000- and 600-s measurements, respectively. (authors)

  3. Zonal spherical aberration correction utilizing axial electrodes

    NASA Astrophysics Data System (ADS)

    Chao, Liang C.

    2005-01-01

    Spherical aberration is important in focused ion beam applications where large aperture angles are needed to obtain high beam currents because it results in large tails on the current density distribution. Merwe has shown that for coaxial lenses, negative spherical aberration can be found for rays pass through zonal regions. Merwe"s calculation is valid only for periodic or quasi-periodic lenses and requires a constant axial potential distribution. We have calculated zonal focusing properties of lenses with axial electrodes using nine-point finite difference method and direct ray tracing. Our calculation results indicate that an axial electrode protruding partially into the lens can correct the spherical aberration. When a three-element electrostatic lens is operated at deceleration mode, the introduction of an axial electrode creates zonal regions where the spherical aberration is negative. At deceleration mode, the induced surface charges on the axial electrode have an opposite sign relative to the primary beam. This is in agreement with our previous findings on the study of the correction of spherical aberration utilizing space charges. Same phenomenon was found when an axial electrode is used in conjunction with a cathode lens.

  4. Aberration in proper motions for Galactic stars

    NASA Astrophysics Data System (ADS)

    Liu, J.-C.; Xie, Y.; Zhu, Z.

    2014-12-01

    Accelerations of both the solar system barycenter (SSB) and stars in the MilkyWay cause a systematic observational effect on the stellar proper motions, which was first studied by J. Kovalevsky (2003). This paper intends to extend that work and aims to estimate the magnitude and significance of the aberration in proper motions of stars, especially in the region near the Galactic center (GC). We adopt two models for the Galactic rotation curve to evaluate the aberrational effect on the Galactic plane. We show that the effect of aberration in proper motions depends on the galactocentric distance of stars; it is dominated by the acceleration of stars in the central region of the Galaxy. Then we investigate the applicability of the theoretical expressions: if the orbital period of stars is only a fraction of the light time from the star to the SSB, the expression with approximation proposed by Kovalevsky is not appropriate. With a more suitable formulation, we found that the aberration has no effect on the determination of the stellar orbits on the celestial sphere. In the future this aberrational effect under consideration should be considered with high-accurate astrometry, particularly in constructing the Gaia celestial reference system realized by Galactic stars.

  5. Evaluation of HFC-245ca for commercial use in low pressure chillers. Final report, Volume II: Chiller test data

    SciTech Connect

    Keuper, E.F.

    1996-03-01

    The data presented here were taken under Trane Laboratory Test Order 23127 between May and October 1995. The chiller was a 200 nominal ton three stage direct drive centrifugal chiller with two economizers. Three sets of impellers, three refrigerants and two oils were tested in the chiller according to the following matrix. Trane 22 is a mineral oil and Solest 68 is a polyolester oil. Runs 1 through 6 were to optimize the refrigerant charge using CFC-11. This was determined to be 360 lbm (163.3 Kg) and this value was used for all three refrigerants. The chiller takes a charge of six gallons of oil (22.7 liters). These data which follow are divided into Large Impeller, Medium Impeller and Small Impeller sets further subdivided by Imperial and Metric presentation. The data were taken in Imperial Units. These data are presented in four-page sets. Page 1 shows the reduced chiller test data. Page 2 shows some supporting calculations by curve fit, such as motor efficiency and motor speed. Pages 3 and 4 show the raw data as delivered by the laboratory. All following four-page sets are repetition of the form but for successive test runs.

  6. Pilot Tests of Satellite Snowcover/Runoff Forecasting Systems. [Arizona, Sierra Nevada Mountains (Ca), Colorado, Rocky Mountains (North America)

    NASA Technical Reports Server (NTRS)

    Rango, A.

    1978-01-01

    Major snow zones of the western U.S. were selected to test the capability of satellite systems for mapping snowcover in various snow, cloud, climatic, and vegetation regimes. Different satellite snowcover analysis methods used in each area are described along with results.

  7. Chromosome aberrations as bioindicators of environmental genotoxicity.

    PubMed

    Ibrulj, Slavica; Haverić, Sanin; Haverić, Anja

    2007-11-01

    Due to the exposure to various potentially genotoxic xenobiotics, derived from recent war activities such as NATO air strikes with antitank ammunition containing depleted uranium, we have evaluated chromosome aberrations in 84 peripheral blood samples from three local populations. One population sample included 30 individuals who lived in the Sarajevo area during and after the war (exposed to potential genotoxins), second population was presented with 26 employees of the tank repair facility in Hadzići (target of NATO air strikes), and 28 inhabitants of Posusje (not exposed to war-related activities) were treated as sample of control population. The mean of chromosome aberration frequencies for the population from Hadzići was significantly higher than the frequencies for the two other populations. Point bi-serial coefficient analysis did not reveal any relationship between the frequencies of chromosome aberrations and smoking habits or gender. Results suggest that depleted uranium could be a risk factor for human health.

  8. An aberrant precision account of autism

    PubMed Central

    Lawson, Rebecca P.; Rees, Geraint; Friston, Karl J.

    2014-01-01

    Autism is a neurodevelopmental disorder characterized by problems with social-communication, restricted interests and repetitive behavior. A recent and thought-provoking article presented a normative explanation for the perceptual symptoms of autism in terms of a failure of Bayesian inference (Pellicano and Burr, 2012). In response, we suggested that when Bayesian inference is grounded in its neural instantiation—namely, predictive coding—many features of autistic perception can be attributed to aberrant precision (or beliefs about precision) within the context of hierarchical message passing in the brain (Friston et al., 2013). Here, we unpack the aberrant precision account of autism. Specifically, we consider how empirical findings—that speak directly or indirectly to neurobiological mechanisms—are consistent with the aberrant encoding of precision in autism; in particular, an imbalance of the precision ascribed to sensory evidence relative to prior beliefs. PMID:24860482

  9. Designing Aberration-Corrected Solid Unstable Resonators

    NASA Technical Reports Server (NTRS)

    Lang, Robert J.

    1994-01-01

    In improved method of designing solid unstable resonator of laser diode, shapes of mirrors calculated to yield specified mode. Ray tracing used to compute shape of initially unspecified end mirror, given shape of initially specified end mirror and specified output mode. No need to accept aberrations or suboptimal circular shapes, to make iterative design computations in effort to converge on desired mode, or to assume paraxiality of rays: Angles between rays and optical axis large, cross sections of surfaces noncircular, and computed shape of end mirror exact. End mirror corrects for all aberrations.

  10. Seidel aberrations of an inflated membrane.

    PubMed

    Vaughan, H

    1980-09-15

    The Seidel aberrations of a shallow reflecting bowl are examined. In particular the bowl is formed by pressurizing a prestretched polymer membrane over the end of a cylindrical pressure vessel. Precise values for each of the five aberrations are given in terms of the bowl depth, radius, and amount of prestretch in the membrane for the case of an object at infinity and aperture stop in contact with the mirror. The analysis neglects terms of order (4)compared to unity where = bowl depth/bowl radius.

  11. Aberration corrected Lorentz scanning transmission electron microscopy.

    PubMed

    McVitie, S; McGrouther, D; McFadzean, S; MacLaren, D A; O'Shea, K J; Benitez, M J

    2015-05-01

    We present results from an aberration corrected scanning transmission electron microscope which has been customised for high resolution quantitative Lorentz microscopy with the sample located in a magnetic field free or low field environment. We discuss the innovations in microscope instrumentation and additional hardware that underpin the imaging improvements in resolution and detection with a focus on developments in differential phase contrast microscopy. Examples from materials possessing nanometre scale variations in magnetisation illustrate the potential for aberration corrected Lorentz imaging as a tool to further our understanding of magnetism on this lengthscale.

  12. [Corneal higher order aberrations and their changes with aging].

    PubMed

    Cermáková, S; Skorkovská, S

    2010-12-01

    Cornea is the most important refractive medium of the eye and affects its total aberration state. This paper deals with corneal higher order aberrations in healthy humans and evaluates their changes with aging and corneal curvature. The influence of the corneal anterior and posterior surfaces on aberrations of the whole cornea was also investigated. The examination was performed with a Scheimpflug camera which enables to examine the anterior and posterior corneal surface separately. The results show that higher order aberrations of the whole cornea are influenced mainly by the anterior surface aberrations. The main corneal higher order aberration is the Z (4,0) spherical aberration which has a positive value and increases with age. Also, 3rd order aberration values are of importance, especially coma which also increases with age. As a consequence, the root-mean-square of the 3rd and 4th order aberrations in elderly people has a higher value.

  13. [Estimation of bleomycin-induced chromosome aberrations in lymphocytes of laryngeal cancer subjects. Preliminary report].

    PubMed

    Kita, S; Jarmuz, M; Dabrowski, P; Biegalski, W; Jezewska, A; Kowalczyk, M; Szyfter, W; Szyfter, K

    1999-01-01

    Chromosome instability is associated with an increased risk of malignancy. However, the quantitative analysis of chromosome breaks provided by the bleomycin test requires additional analysis aimed for the localisation of chromosome aberrations. For this reason, the metaphasis slides prepared for bleomycin test were stained with fluorochrome DAPI to estimate chromosome breaks in particular chromosomes. The additional staining of chromosomes can be recognised as an extension of the classical bleomycin test addressed for identification of structural aberrations. Preliminary results indicate that the most frequent chromosome breaks were found in chromosomes 1, 2, 3, 7 and 13. PMID:10481493

  14. Multinodal fifth-order optical aberrations of optical systems without rotational symmetry: spherical aberration.

    PubMed

    Thompson, Kevin P

    2009-05-01

    Building off an earlier work on multinodal third-order aberrations [J. Opt. Soc. Am. A22, 1389 (2005)], this is the first in a series of papers that derives and illustrates the characteristic multinodal geometry for each of the fifth-order aberrations. Part I (as this paper will be referred to) will present the spherical aberration family: specifically, W(060), W(240M) and W(242), and W(080) (fifth-order spherical, oblique spherical, and seventh-order spherical). Nodal aberration theory is proving to be very effective as both an optical design tool for fully unobscured off-axis telescopes and as an analysis method, particularly in the context of the response of any imaging optical systems to misalignment. It is important to recognize that this multinodal approach to aberration theory is not restricted to small perturbations. The remaining papers in this series will result in a complete presentation of the intrinsic characteristic multinodal properties of each of the fifth-order aberrations. As such, this series provides a definitive theory of the optical aberrations of (nonanamorphic) imaging systems with a circular aperture stop. PMID:19412225

  15. Distributions of spontaneous chromosomal aberrations and of spontaneous and induced SCE and micronuclei in peripheral lymphocytes from a human population

    SciTech Connect

    Bender, M.A.; Setlow, R.B.

    1992-12-31

    Biomonitoring of human populations for exposure to genotoxic/clastogenic agents in the environment or the workplace must depend upon statistical tests for elevations in the frequencies of the biological endpoints being monitored, usually chromosomal aberrations (CA), micronuclei (MN), or sister chromatid exchanges (SCE) in peripheral blood lymphocytes. Statistical tests are based, in turn, upon certain assumptions regarding the distribution of the test statistic. When they are often not recognized as such, tests of significance can be in error, and any conclusion drawn that there is or is not a statistically significant difference between one population sample and another maybe erroneous. In population monitoring this means either false negatives or false positives can result and it is hard to know which is worse. Furthermore, even the intelligent design of studies whose object is to test for an elevated level in an exposed population must depend upon prior knowledge of the nature of both spontaneous and induced response; if variance is large enough, a given-sized study might be inconclusive, and an adequate study simply too large-to be practical.

  16. Distributions of spontaneous chromosomal aberrations and of spontaneous and induced SCE and micronuclei in peripheral lymphocytes from a human population

    SciTech Connect

    Bender, M.A.; Setlow, R.B.

    1992-01-01

    Biomonitoring of human populations for exposure to genotoxic/clastogenic agents in the environment or the workplace must depend upon statistical tests for elevations in the frequencies of the biological endpoints being monitored, usually chromosomal aberrations (CA), micronuclei (MN), or sister chromatid exchanges (SCE) in peripheral blood lymphocytes. Statistical tests are based, in turn, upon certain assumptions regarding the distribution of the test statistic. When they are often not recognized as such, tests of significance can be in error, and any conclusion drawn that there is or is not a statistically significant difference between one population sample and another maybe erroneous. In population monitoring this means either false negatives or false positives can result and it is hard to know which is worse. Furthermore, even the intelligent design of studies whose object is to test for an elevated level in an exposed population must depend upon prior knowledge of the nature of both spontaneous and induced response; if variance is large enough, a given-sized study might be inconclusive, and an adequate study simply too large-to be practical.

  17. HDR opportunities and challenges beyond the long-term flow test isco, CA, 24-26 Mar. 1992

    NASA Astrophysics Data System (ADS)

    Duchane, D. V.

    1992-06-01

    The long term flow test (LTFT) of the world's largest, deepest, and hottest hot dry rock (HDR) reservoir currently underway at Fenton Hill, NM is expected to demonstrate that thermal energy can be mined from hot rock within the earth on a sustainable basis with minimal water consumption. This test will simulate the operations of a commercial facility in some ways, but it will not show that energy from HDR can be produced at a variety of locations with different geological settings. Since the Fenton Hill system was designed as a research facility rather than strictly for production purposes, it will also not demonstrate economic viability, although it may well give indications of system modifications needed for economic HDR operations. A second production site must be constructed, ideally under the direction of the private geothermal community, to begin the process of proving that the vast HDR resources can be accessed on a worldwide scale. Finally, research and development work in areas such as reservoir interrogation and system modeling must be accelerated to increase the competitiveness and geographical applications of HDR and the geothermal industry in general. This paper addresses the above issues in detail and outlines possible paths to future prosperity for the commercial geothermal industry.

  18. Aberrations of diffracted wave fields. II. Diffraction gratings.

    PubMed

    Mahajan, V N

    2000-12-01

    The Rayleigh-Sommerfeld theory is applied to diffraction of a spherical wave by a grating. The grating equation is obtained from the aberration-free diffraction pattern, and its aberrations are shown to be the same as the conventional aberrations obtained by using Fermat's principle. These aberrations are shown to be not associated with the diffraction process. Moreover, it is shown that the irradiance distribution of a certain diffraction order is the Fraunhofer diffraction pattern of the grating aperture as a whole aberrated by the aberration of that order. PMID:11140481

  19. Measurement of CA1P and CA in leaves

    SciTech Connect

    Moore, B.d.; Kobza, J.; Seemann, J.R. )

    1990-05-01

    Carboxyarabinitol-1-phosphate (CA1P) and carboxyarabinitol (CA) were assayed in leaves by isotope dilution. {sup 14}C-labeled standards were synthesized from (2-{sup 14}C) CABP using acid (CA1P) or alkaline (CA) phosphatase. Either was added to boiling 80% EtOH along with liquid N{sub 2}-killed leaves. Each was largely purified by anion exchange chromatography. CA1P samples were subjected to 2D-TLE/TLC. The specific activity of the {sup 14}C-containing spot was measured using alkaline phosphatase. CA samples were run on an HPLC and the specific activity was determined using a UV monitor and a flow-through radioisotope detector. In 3 of the tested species, light/dark amount of CA1P (nmol/mg Chl) were kidney bean, 0.7/67; sugar beet, 0.8/33; and Alocasia, 0/3.4. Light/dark CA levels (nmol/mg Chl) in these respective species were 897/653, 3.2/3.5, and 5.7/4.6. These results support the hypothesis that CA is a product of CA1P metabolism in vivo under high light, but also indicate that CA is not the only intermediate involved in CA1P synthesis under low light/dark conditions.

  20. An observational test of the stress accumulation model based on seismicity preceding the 1992 Landers, CA earthquake

    NASA Astrophysics Data System (ADS)

    Levin, Shoshana Z.; Sammis, Charles G.; Bowman, David D.

    2006-02-01

    We test the Bowman and King [Bowman, D.D., King, G.C.P., 2001a, Accelerating seismicity and stress accumulation before large earthquakes. Geophys. Res. Lett., 28 (21), 4039-4042, Bowman, D.D., King, G.C.P., 2001b. Stress transfer and seismicity changes before large earthquakes. C. R. Acad. Sci. Paris, 333, 591-599] Stress Accumulation model by examining the evolution of seismicity rates prior to the 1992 Landers, California earthquake. The Stress Accumulation (SA) model was developed to explain observations of accelerating seismicity preceding large earthquakes. The model proposes that accelerating seismicity sequences result from the tectonic loading of large fault structures through aseismic slip in the elasto-plastic lower crust. This loading progressively increases the stress on smaller faults within a critical region around the main structure, thereby causing the observed acceleration of precursory activity. A secondary prediction of the SA model is that the precursory seismicity rates should increase first at the edges of the critical region, with the rates gradually rising over time at closer distances to the main fault. We test this prediction by examining year-long seismicity rates between 1960 and 2004, as a function of distance from the Landers rupture. To quantify the significance of trends in the seismicity rates, we auto-correlate the data, using a range of spatial and temporal lags. We find weak evidence for increased seismicity rates propagating towards the Landers rupture, but cannot conclusively distinguish these results from those obtained for a random earthquake catalog. However, we find a strong indication of periodicity in the rate fluctuations, as well as high correlation between activity 130-170 km from Landers and seismicity rates within 50 km of the Landers rupture temporally offset 1.5-2 years. The implications of this spatio-temporal correlation will be addressed in future studies.

  1. Cosmological parameter estimation: impact of CMB aberration

    SciTech Connect

    Catena, Riccardo; Notari, Alessio E-mail: notari@ffn.ub.es

    2013-04-01

    The peculiar motion of an observer with respect to the CMB rest frame induces an apparent deflection of the observed CMB photons, i.e. aberration, and a shift in their frequency, i.e. Doppler effect. Both effects distort the temperature multipoles a{sub lm}'s via a mixing matrix at any l. The common lore when performing a CMB based cosmological parameter estimation is to consider that Doppler affects only the l = 1 multipole, and neglect any other corrections. In this paper we reconsider the validity of this assumption, showing that it is actually not robust when sky cuts are included to model CMB foreground contaminations. Assuming a simple fiducial cosmological model with five parameters, we simulated CMB temperature maps of the sky in a WMAP-like and in a Planck-like experiment and added aberration and Doppler effects to the maps. We then analyzed with a MCMC in a Bayesian framework the maps with and without aberration and Doppler effects in order to assess the ability of reconstructing the parameters of the fiducial model. We find that, depending on the specific realization of the simulated data, the parameters can be biased up to one standard deviation for WMAP and almost two standard deviations for Planck. Therefore we conclude that in general it is not a solid assumption to neglect aberration in a CMB based cosmological parameter estimation.

  2. Aberration features in directional dark matter detection

    SciTech Connect

    Bozorgnia, Nassim; Gelmini, Graciela B.; Gondolo, Paolo E-mail: gelmini@physics.ucla.edu

    2012-08-01

    The motion of the Earth around the Sun causes an annual change in the magnitude and direction of the arrival velocity of dark matter particles on Earth, in a way analogous to aberration of stellar light. In directional detectors, aberration of weakly interacting massive particles (WIMPs) modulates the pattern of nuclear recoil directions in a way that depends on the orbital velocity of the Earth and the local galactic distribution of WIMP velocities. Knowing the former, WIMP aberration can give information on the latter, besides being a curious way of confirming the revolution of the Earth and the extraterrestrial provenance of WIMPs. While observing the full aberration pattern requires extremely large exposures, we claim that the annual variation of the mean recoil direction or of the event counts over specific solid angles may be detectable with moderately large exposures. For example, integrated counts over Galactic hemispheres separated by planes perpendicular to Earth's orbit would modulate annually, resulting in Galactic Hemisphere Annual Modulations (GHAM) with amplitudes larger than the usual non-directional annual modulation.

  3. Optical advantages of astigmatic aberration corrected heliostats

    NASA Astrophysics Data System (ADS)

    van Rooyen, De Wet; Schöttl, Peter; Bern, Gregor; Heimsath, Anna; Nitz, Peter

    2016-05-01

    Astigmatic aberration corrected heliostats adapt their shape in dependence of the incidence angle of the sun on the heliostat. Simulations show that this optical correction leads to a higher concentration ratio at the target and thus in a decrease in required receiver aperture in particular for smaller heliostat fields.

  4. Anti-forensics of chromatic aberration

    NASA Astrophysics Data System (ADS)

    Mayer, Owen; Stamm, Matthew C.

    2015-03-01

    Over the past decade, a number of information forensic techniques have been developed to identify digital image manipulation and falsification. Recent research has shown, however, that an intelligent forger can use anti-forensic countermeasures to disguise their forgeries. In this paper, an anti-forensic technique is proposed to falsify the lateral chromatic aberration present in a digital image. Lateral chromatic aberration corresponds to the relative contraction or expansion between an image's color channels that occurs due to a lens's inability to focus all wavelengths of light on the same point. Previous work has used localized inconsistencies in an image's chromatic aberration to expose cut-and-paste image forgeries. The anti-forensic technique presented in this paper operates by estimating the expected lateral chromatic aberration at an image location, then removing deviations from this estimate caused by tampering or falsification. Experimental results are presented that demonstrate that our anti-forensic technique can be used to effectively disguise evidence of an image forgery.

  5. Designing refractive beam shapers via aberration theory

    NASA Astrophysics Data System (ADS)

    Laskin, Alexander; Shealy, David

    2014-10-01

    In this paper, we use aberration theory to design a refractive laser beam shaper in the configuration of two-aspheric lenses, whose analytical equations are known, but rather complicated. Specifically, we use results from third order aberration theory to obtain the parameters of the refracting laser beam shaper from the transverse aberration, which are then used as a starting point for further optimization by using optical design software. This approach was developed during the beginning of the twentieth century, works well for systems with a low numerical aperture, and allows one to define the following parameters of an optical system: radii of curvature, indices of refraction, thicknesses or air gaps, and conic constants of second order aspheric surfaces. We shall consider surfaces of the second-order spherical and conic sections and shall consider the example of designing of a two-lens beam shaper of the Keplerian 1-to-1 telescopic design providing a theoretical flat phase front and a flat-top irradiance profile of the output beam, where the ray mapping function from the input aperture to the output aperture is known from the literature. Explicit expression for third order longitudinal aberration and the Seidel coefficients are expressed in terms beam waist and input beam geometrical parameter, indices, lens radii and conic constants.

  6. Hormone dependency of chromosome aberrations induced by 7,12-dimethylbenz(a)anthracene in rat bone marrow cells: site-specific increase by erythropoietin

    SciTech Connect

    Ueda, N.; Suglyama, T.; Chattopadhyay, S.C.; Goto-Mimura, K.; Maeda, S.

    1981-08-01

    The frequency of chromosome aberrations (CA) 6 hours after iv injection of 50 mg 7,12-dimethylbenz(a)anthracene (DMBA0/kg was studied in bone marrow cells of the noninbred Long-Evans rat under various hematopoietic conditions. The percentage of metaphase cells with CA was enhanced by anemia and suppressed by polycythemia. The low incidence of CA in polycythemic rats was reversed by 6 U of sheep erythropoietin (EP) injected at the time of DMBA treatment. The interchromosomal and intrachromosomal distribution of CA indicated that hematopoietic stimuli, more specifically EP, greatly enhanced DMBA-induced CA in specific chromosomal regions.

  7. Aberration measurement based on principal component analysis of aerial images of optimized marks

    NASA Astrophysics Data System (ADS)

    Yan, Guanyong; Wang, Xiangzhao; Li, Sikun; Yang, Jishuo; Xu, Dongbo

    2014-10-01

    We propose an aberration measurement technique based on principal component analysis of aerial images of optimized marks (AMAI-OM). Zernike aberrations are retrieved using a linear relationship between the aerial image and Zernike coefficients. The linear relationship is composed of the principal components (PCs) and regression matrix. A centering process is introduced to compensate position offsets of the measured aerial image. A new test mark is designed in order to improve the centering accuracy and theoretical accuracy of aberration measurement together. The new test marks are composed of three spaces with different widths, and their parameters are optimized by using an accuracy evaluation function. The offsets of the measured aerial image are compensated in the centering process and the adjusted PC coefficients are obtained. Then the Zernike coefficients are calculated according to these PC coefficients using a least square method. The simulations using the lithography simulators PROLITH and Dr.LiTHO validate the accuracy of our method. Compared with the previous aberration measurement technique based on principal component analysis of aerial image (AMAI-PCA), the measurement accuracy of Zernike aberrations under the real measurement condition of the aerial image is improved by about 50%.

  8. Risk of cancer in an occupationally exposed cohort with increased level of chromosomal aberrations.

    PubMed Central

    Smerhovsky, Z; Landa, K; Rössner, P; Brabec, M; Zudova, Z; Hola, N; Pokorna, Z; Mareckova, J; Hurychova, D

    2001-01-01

    We used cytogenetic analysis to carry out a cohort study in which the major objective was to test the association between frequency of chromosomal aberrations and subsequent risk of cancer. In spite of the extensive use of the cytogenetic analysis of human peripheral blood lymphocytes in biomonitoring of exposure to various mutagens and carcinogens on an ecologic level, the long-term effects of an increased frequency of chromosomal aberrations in individuals are still uncertain. Few epidemiologic studies have addressed this issue, and a moderate risk of cancer in individuals with an elevated frequency of chromosomal aberrations has been observed. In the present study, we analyzed data on 8,962 cytogenetic tests and 3,973 subjects. We found a significant and strong association between the frequency of chromosomal aberrations and cancer incidence in a group of miners exposed to radon, where a 1% increase in frequency of chromosomal aberrations was followed by a 64% increase in risk of cancer (p < 0.000). In contrast, the collected data are inadequate for a critical evaluation of the association with exposure to other chemicals. PMID:11171523

  9. Maternal age, reproduction and chromosomal aberrations in Wistar derived rats.

    PubMed

    Niggeschulze, A; Kast, A

    1994-01-01

    The fertility of rats ranges from one to 18 months. In standard teratogenicity testing young, mature females are used which may not reflect the situation in women above 35 years old. Reproduction among different age groups of Wistar ats (strain Chbb: THOM) was compared at 3, 6, 9, 12, 15 and 18 months. At least 20 virgin females were inseminated per age group. The copulation rate did not differ between the groups. From the maternal age of 12 months, the pregnancy rate was significantly decreased, from the age of 9 months, the litter values were significantly lowered and the resorption rates were increased. Maternal age did not influence the incidence of fetal variations and malformations. Additionally, the chromosomal aberration rate in the bone marrow was evaluated in male and female rats. Twelve animals of each sex were scheduled per group, and studied at the age of 1, 3, 6, 12, 15, 18, 21 or 24 months. In males, the aberration rate increased continuously from 0.18 through 3%, while in females the increase continued from 0.33 to 2.29% at 15 months old when a plateau was reached. When testing new compounds for embryotoxicity or genotoxicity in female rats, the animals should be of comparable age to man in order to avoid a misinterpretation of spontaneous abnormalities. From these studies, however, it was concluded that the use of higher age groups of female rats in teratogenicity studies would not improve the risk assessment.

  10. Wide-field aberration corrector for spherical gossamer primary mirrors

    NASA Astrophysics Data System (ADS)

    Beach, David A.

    2000-10-01

    If gossamer primary mirrors were to be constructed in a spherical form, it would be possible to arrange a simple null- test in situ. However, spherical mirrors would require correction of the large amount of spherical aberration created in pupils that generally will be greater than 2 m diameter. The design requirement is for diffraction-limited performance over a useful angular field. The otherwise excellent wide- field design solutions of the classical Schmidt and Maksutov are inapplicable in gossamer structures because of the mass and size penalty of large refractive components. However, it is possible for this mode of correction to be achieved near the prime focus by means of pupil transfer optics that minify the large entrance pupil down to more acceptable dimensions. A problem with these solutions is constraint of field coverage due to pupil aberrations created by the large spherical aberration of the primary mirror. This leads the designer towards slower primaries and the penalty of larger, heavier structures. A solution is presented here for spherical primaries with speeds up to f/4. This is based on the 'KiwiStar' principle presented here in 1997, in which a large spherical catoptric is combined by pupil-transfer with a smaller spherical catadioptric to give well corrected wide field images of high speed. This system is well suited to correction at the prime focus of large spherical mirrors, and has only one relatively small weak aspheric surface to provide zonal correction, all other surfaces being spherical. An example is presented of a 4 m diameter, f/2.5 system that is diffraction-limited over the whole of a 0.25 degree field (43 mm diameter), for a bandpass of 486 - 850 nm.

  11. Chromosome aberrations among the Yanomamma Indians.

    PubMed

    Bloom, A D; Neel, J V; Choi, K W; Iida, S; Chagnon, N

    1970-07-01

    The chromosomes of leucocytes cultured from the peripheral blood of 49 primitive Yanomama Indians of Venezuela were studied to determine the types and frequencies of aberrations in a human population not exposed to the same exogenous agents as civilized man. In all but one instance, 100 cells per individual were scored. In 13 cases, we found one or more cells with multiple complex breaks and rearrangements, represented by tetracentric, tricentric, and numerous dicentric chromosomes. From the standpoint of chromosomal damage, these cells are among the most abnormal cells yet described in vivo in man, and were not seen in the controls. There was also a higher than expected frequency of cells with an isolated structural aberration in both Indians and controls. This may be the result of a 24- to 48-hour delay in the initiation of culture. The cause of the more extensive damage to some cells remains to be determined.

  12. Involvement of aberrant cyclin-dependent kinase 5/p25 activity in experimental traumatic brain injury.

    PubMed

    Yousuf, Mohammad A; Tan, Chunfeng; Torres-Altoro, Melissa I; Lu, Fang-Min; Plautz, Erik; Zhang, Shanrong; Takahashi, Masaya; Hernandez, Adan; Kernie, Steven G; Plattner, Florian; Bibb, James A

    2016-07-01

    Traumatic brain injury (TBI) is associated with adverse effects on brain functions, including sensation, language, emotions and/or cognition. Therapies for improving outcomes following TBI are limited. A better understanding of the pathophysiological mechanisms of TBI may suggest novel treatment strategies to facilitate recovery and improve treatment outcome. Aberrant activation of cyclin-dependent kinase 5 (Cdk5) has been implicated in neuronal injury and neurodegeneration. Cdk5 is a neuronal protein kinase activated via interaction with its cofactor p35 that regulates numerous neuronal functions, including synaptic remodeling and cognition. However, conversion of p35 to p25 via Ca(2+) -dependent activation of calpain results in an aberrantly active Cdk5/p25 complex that is associated with neuronal damage and cell death. Here, we show that mice subjected to controlled cortical impact (CCI), a well-established experimental TBI model, exhibit increased p25 levels and consistently elevated Cdk5-dependent phosphorylation of microtubule-associated protein tau and retinoblastoma (Rb) protein in hippocampal lysates. Moreover, CCI-induced neuroinflammation as indicated by increased astrocytic activation and number of reactive microglia. Brain-wide conditional Cdk5 knockout mice (Cdk5 cKO) subjected to CCI exhibited significantly reduced edema, ventricular dilation, and injury area. Finally, neurophysiological recordings revealed that CCI attenuated excitatory post-synaptic potential field responses in the hippocampal CA3-CA1 pathway 24 h after injury. This neurophysiological deficit was attenuated in Cdk5 cKO mice. Thus, TBI induces increased levels of p25 generation and aberrant Cdk5 activity, which contributes to pathophysiological processes underlying TBI progression. Hence, selectively preventing aberrant Cdk5 activity may be an effective acute strategy to improve recovery from TBI. Traumatic brain injury (TBI) increases astrogliosis and microglial activation

  13. Involvement of aberrant cyclin-dependent kinase 5/p25 activity in experimental traumatic brain injury.

    PubMed

    Yousuf, Mohammad A; Tan, Chunfeng; Torres-Altoro, Melissa I; Lu, Fang-Min; Plautz, Erik; Zhang, Shanrong; Takahashi, Masaya; Hernandez, Adan; Kernie, Steven G; Plattner, Florian; Bibb, James A

    2016-07-01

    Traumatic brain injury (TBI) is associated with adverse effects on brain functions, including sensation, language, emotions and/or cognition. Therapies for improving outcomes following TBI are limited. A better understanding of the pathophysiological mechanisms of TBI may suggest novel treatment strategies to facilitate recovery and improve treatment outcome. Aberrant activation of cyclin-dependent kinase 5 (Cdk5) has been implicated in neuronal injury and neurodegeneration. Cdk5 is a neuronal protein kinase activated via interaction with its cofactor p35 that regulates numerous neuronal functions, including synaptic remodeling and cognition. However, conversion of p35 to p25 via Ca(2+) -dependent activation of calpain results in an aberrantly active Cdk5/p25 complex that is associated with neuronal damage and cell death. Here, we show that mice subjected to controlled cortical impact (CCI), a well-established experimental TBI model, exhibit increased p25 levels and consistently elevated Cdk5-dependent phosphorylation of microtubule-associated protein tau and retinoblastoma (Rb) protein in hippocampal lysates. Moreover, CCI-induced neuroinflammation as indicated by increased astrocytic activation and number of reactive microglia. Brain-wide conditional Cdk5 knockout mice (Cdk5 cKO) subjected to CCI exhibited significantly reduced edema, ventricular dilation, and injury area. Finally, neurophysiological recordings revealed that CCI attenuated excitatory post-synaptic potential field responses in the hippocampal CA3-CA1 pathway 24 h after injury. This neurophysiological deficit was attenuated in Cdk5 cKO mice. Thus, TBI induces increased levels of p25 generation and aberrant Cdk5 activity, which contributes to pathophysiological processes underlying TBI progression. Hence, selectively preventing aberrant Cdk5 activity may be an effective acute strategy to improve recovery from TBI. Traumatic brain injury (TBI) increases astrogliosis and microglial activation

  14. Chromosomal aberrations in oral solitary fibrous tumor.

    PubMed

    Manor, Esther; Bodner, Lipa

    2007-04-15

    The results of cytogenetic analysis of a solitary fibrous tumor (SFT) of the oral cavity in a 43-year-old man is reported. The abnormal cells carried a complex translocation with the karyotype 46,XY [15 cells]/46,XYt(1;17;18)(p13;q11.2;q21)[5 cells]. This is the first case reporting chromosomal aberrations in an oral SFT.

  15. Compact, holographic correction of aberrated telescopes.

    PubMed

    Andersen, G; Munch, J; Veitch, P

    1997-03-01

    We demonstrate a compact reflector telescope design that incorporates the holographic correction of a large, low-quality primary spherical mirror by using a laser beacon located at the center of curvature. The simple design makes use of conventional optics and is easily scalable to much larger apertures. Experimental results indicate diffraction-limited performance from a heavily aberrated 0.5-m-diameter spherical mirror.

  16. DNA Repair Defects and Chromosomal Aberrations

    NASA Technical Reports Server (NTRS)

    Hada, Megumi; George, K. A.; Huff, J. L.; Pluth, J. M.; Cucinotta, F. A.

    2009-01-01

    Yields of chromosome aberrations were assessed in cells deficient in DNA doublestrand break (DSB) repair, after exposure to acute or to low-dose-rate (0.018 Gy/hr) gamma rays or acute high LET iron nuclei. We studied several cell lines including fibroblasts deficient in ATM (ataxia telangiectasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. Chromosomes were analyzed using the fluorescence in situ hybridization (FISH) chromosome painting method in cells at the first division post irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). Gamma irradiation induced greater yields of both simple and complex exchanges in the DSB repair-defective cells than in the normal cells. The quadratic dose-response terms for both simple and complex chromosome exchanges were significantly higher for the ATM- and NBS-deficient lines than for normal fibroblasts. However, in the NBS cells the linear dose-response term was significantly higher only for simple exchanges. The large increases in the quadratic dose-response terms in these repair-defective cell lines points the importance of the functions of ATM and NBS in chromatin modifications to facilitate correct DSB repair and minimize the formation of aberrations. The differences found between ATM- and NBS-deficient cells at low doses suggest that important questions should with regard to applying observations of radiation sensitivity at high dose to low-dose exposures. For aberrations induced by iron nuclei, regression models preferred purely linear dose responses for simple exchanges and quadratic dose responses for complex exchanges. Relative biological effectiveness (RBE) factors of all of

  17. Chromatic variation of aberration: the role of induced aberrations and raytrace direction

    NASA Astrophysics Data System (ADS)

    Berner, A.; Nobis, T.; Shafer, D.; Gross, H.

    2015-09-01

    The design and optimization process of an optical system contains several first order steps. The definition of the appropriate lens type and the fixation of the raytrace direction are some of them. The latter can be understood as a hidden assumption rather than an aware design step. This is usually followed by the determination of the paraxial lens layout calculated for the primary wavelength. It is obvious, that for this primary wavelength the paraxial calculations are independent of raytrace direction. Today, most of the lens designs are specified not to work only for one wavelength, but in a certain wavelength range. Considering such rays of other wavelengths, one can observe that depending on the direction there will already occur differences in the first order chromatic aberrations and additionally in the chromatic variation of the third-order aberrations. The reason for this effect are induced aberrations emerging from one surface to the following surfaces by perturbed ray heights and ray angles. It can be shown, that the total amount of surface-resolved first order chromatic aberrations and the chromatic variation of the five primary aberrations can be split into an intrinsic part and an induced part. The intrinsic part is independent of the raytrace direction whereas the induced part is not.

  18. Effect of Mg(2+), Ca(2+), Sr(2+) and Ba(2+) metal ions on the antifungal activity of ZnO nanoparticles tested against Candida albicans.

    PubMed

    Haja Hameed, Abdulrahman Syedahamed; Karthikeyan, Chandrasekaran; Senthil Kumar, Venugopal; Kumaresan, Subramanian; Sasikumar, Seemaisamy

    2015-01-01

    The antifungal ability of pure and alkaline metal ion (Mg(2+), Ca(2+), Sr(2+) and Ba(2+)) doped ZnO nanoparticles (NPs) prepared by the co-precipitation method was tested against the pathogenic yeast, Candida albicans (C. albicans), and the results showed that the Mg-doped ZnO NPs possessed greater effect than the other alkaline metal ion doped ZnO NPs. The impact of the concentration of Mg doped ZnO sample on the growth of C. albicans was also studied. The Minimal Fungicidal Concentration (MFC) of the Mg doped ZnO NPs was found to be 2000 μg/ml for which the growth of C. albicans was completely inhibited. The ZnO:Mg sample (1.5mg/ml) with various concentrations of histidine reduced the fungicidal effect of the nanoparticles against C. albicans, which was deliberately explained by the role of ROS. The ZnO:Mg sample added with 5mM of histidine scavenged the ample amount of generated ROS effectively. The binding of the NPs with fungi was observed by their FESEM images and their electrostatic attraction is confirmed by the zeta potential measurement. PMID:25953555

  19. The absolute radiometric calibration of the Landsat 8 Operational Land Imager using the reflectance-based approach and the Radiometric Calibration Test Site (RadCaTS)

    NASA Astrophysics Data System (ADS)

    Czapla-Myers, Jeffrey; Anderson, Nikolaus; Thome, Kurtis; Biggar, Stuart

    2014-10-01

    Landsat 8 was launched on 11 February 2013 as the newest platform in the Landsat program. It contains two Earthobserving instruments, one of which is the Operational Land Imager (OLI). OLI includes an onboard radiometric calibration system that is used to monitor changes in its responsivity throughout the mission lifetime, and it consists of Spectralon solar diffuser panels as well as tungsten lamp assemblies. External techniques are used to monitor both OLI and its calibration system, and they include lunar views, side slither maneuvers of the satellite, and ground-based vicarious calibration. This work presents the absolute radiometric calibration results for Landsat 8 OLI that were obtained using two ground-based measurement techniques. The first is the reflectance-based approach, where measurements of atmospheric and surface properties are made during a Landsat 8 overpass, and it requires personnel to be on site during the time of measurement. The second uses the Radiometric Calibration Test Site (RadCaTS), which was developed by the Remote Sensing Group in the College of Optical Sciences at the University of Arizona so that radiometric calibration data can be collected without the requirement of on-site personnel. It allows more data to be collected annually, which increases the temporal sampling of trending results.

  20. [THE SOMATIC MUTATIONS AND ABERRANT METHYLATION AS POTENTIAL GENETIC MARKERS OF URINARY BLADDER CANCER].

    PubMed

    Mikhailenko, D S; Kushlinskii, N E

    2016-02-01

    All around the world, more than 330 thousands cases of bladder cancer are registered annually hence representing actual problem of modern oncology. Still in demand are search and characteristic of new molecular markers of bladder cancer detecting in tumor cells from urinary sediment and having high diagnostic accuracy. The studies of last decade, especially using methods of genome-wide sequencing, permitted to receive a large amount of experimental data concerning development and progression of bladder cancer The review presents systematic analysis of publications available in PubMed data base mainly of last five years. The original studies of molecular genetic disorders under bladder cancer and meta-analyzes were considered This approach permitted to detected the most common local alterations of DNA under bladder cancer which can be detected using routine genetic methods indifferent clinical material and present prospective interest for development of test-systems. The molecular genetic markers of disease can be activating missense mutations in 7 and 10 exons of gene of receptor of growth factor of fibroblasts 3 (FGFR3), 9 and 20 exons of gene of Phosphatidylinositol-4,5-bi-phosphate-3-kinase (PIK3CA) and mutation in -124 and -146 nucleotides in promoter of gene of catalytic subunit telomerase (TERT). The development of test-systems on the basis of aberrant methylation of CpG-islets of genes-suppressors still is seemed as a difficult task because of differences in pattern of methylation of different primary tumors at various stages of clonal evolution of bladder cancer though they can be considered as potential markers.

  1. [THE SOMATIC MUTATIONS AND ABERRANT METHYLATION AS POTENTIAL GENETIC MARKERS OF URINARY BLADDER CANCER].

    PubMed

    Mikhailenko, D S; Kushlinskii, N E

    2016-02-01

    All around the world, more than 330 thousands cases of bladder cancer are registered annually hence representing actual problem of modern oncology. Still in demand are search and characteristic of new molecular markers of bladder cancer detecting in tumor cells from urinary sediment and having high diagnostic accuracy. The studies of last decade, especially using methods of genome-wide sequencing, permitted to receive a large amount of experimental data concerning development and progression of bladder cancer The review presents systematic analysis of publications available in PubMed data base mainly of last five years. The original studies of molecular genetic disorders under bladder cancer and meta-analyzes were considered This approach permitted to detected the most common local alterations of DNA under bladder cancer which can be detected using routine genetic methods indifferent clinical material and present prospective interest for development of test-systems. The molecular genetic markers of disease can be activating missense mutations in 7 and 10 exons of gene of receptor of growth factor of fibroblasts 3 (FGFR3), 9 and 20 exons of gene of Phosphatidylinositol-4,5-bi-phosphate-3-kinase (PIK3CA) and mutation in -124 and -146 nucleotides in promoter of gene of catalytic subunit telomerase (TERT). The development of test-systems on the basis of aberrant methylation of CpG-islets of genes-suppressors still is seemed as a difficult task because of differences in pattern of methylation of different primary tumors at various stages of clonal evolution of bladder cancer though they can be considered as potential markers. PMID:27455559

  2. The prevalence of chromosomal aberrations associated with myelodysplastic syndromes in China.

    PubMed

    Hu, Qinyong; Chu, Yuxin; Song, Qibin; Yao, Yi; Yang, Weihong; Huang, Shiang

    2016-08-01

    This study aims to investigate the prevalence and distribution of diverse chromosomal aberrations associated with myelodysplastic syndromes (MDS) in China. Bone marrow samples were collected from multiple cities in China. Metaphase cytogenetic (MC) analysis and fluorescence in situ hybridization (FISH) were initially used to test chromosomal lesions. Affymetrix CytoScan 750 K genechip platform performed a genome-wide detection of chromosomal aberrations. Chromosomal gain was identified in 76 patients; the most prevalent was trisomy 8(17.9 %). New chromosomal gain was detected on chromosome 9, 19p, and X. Chromosomal loss was detected in 101 patients. The most frequent was loss 5q (21.0 %). Some loss and gain were not identified by MC or FISH but identified by genechip. UPD was solely identified by genechip in 51 patients; the most prevalent were UPD 7q (4.94 %) and UPD 17p (4.32 %). Furthermore, complex chromosomal aberrations were detected in 56 patients. In conclusion, Affymetrix CytoScan 750 K genechip was more precise than MC and FISH in detection of cryptic chromosomal aberrations relevant to MDS. Analysis of the prevalence and distribution of diverse chromosomal aberrations in China may improve strategies for MDS diagnosis and therapies. PMID:27225263

  3. Ocular aberrations up to the infrared range: from 632.8 to 1070 nm.

    PubMed

    Fernández, Enrique J; Artal, Pablo

    2008-12-22

    Ocular aberrations were measured by using a Hartmann-Shack wavefront sensor in the visible and infrared portions of the spectrum. In the latter, wavelengths 1030, 1050 and 1070 nm were used for the first time for the study of the optical quality of the eye. In this spectral range the retinal photoreceptors barely respond, so the radiation is virtually invisible for the subject. The results were confronted with those obtained by the same system at 780 and 632.8 nm. Monochromatic aberrations were found to be similar from the visible to the infrared. Longitudinal chromatic aberration was experimentally obtained, being approximately 1 D from 632.8 to 1070 nm. The feasibility of using the infrared for studying the eye was demonstrated. The employment of the infrared has an enormous potential for the better understanding of the impact and influence of the aberrations in vision with adaptive optics. It allows for measuring and controlling aberrations whilst the subject might eventually perform visual tests, with no interference from the beacon light.

  4. High-resolution adaptive optics scanning laser ophthalmoscope with dual deformable mirrors for large aberration correction

    SciTech Connect

    Chen, D; Jones, S M; Silva, D A; Olivier, S S

    2007-01-25

    Scanning laser ophthalmoscopes with adaptive optics (AOSLO) have been shown previously to provide a noninvasive, cellular-scale view of the living human retina. However, the clinical utility of these systems has been limited by the available deformable mirror technology. In this paper, we demonstrate that the use of dual deformable mirrors can effectively compensate large aberrations in the human retina, making the AOSLO system a viable, non-invasive, high-resolution imaging tool for clinical diagnostics. We used a bimorph deformable mirror to correct low-order aberrations with relatively large amplitudes. The bimorph mirror is manufactured by Aoptix, Inc. with 37 elements and 18 {micro}m stroke in a 10 mm aperture. We used a MEMS deformable mirror to correct high-order aberrations with lower amplitudes. The MEMS mirror is manufactured by Boston Micromachine, Inc with 144 elements and 1.5 {micro}m stroke in a 3 mm aperture. We have achieved near diffraction-limited retina images using the dual deformable mirrors to correct large aberrations up to {+-} 3D of defocus and {+-} 3D of cylindrical aberrations with test subjects. This increases the range of spectacle corrections by the AO systems by a factor of 10, which is crucial for use in the clinical environment. This ability for large phase compensation can eliminate accurate refractive error fitting for the patients, which greatly improves the system ease of use and efficiency in the clinical environment.

  5. RBE of Energetic Iron Ions for the Induction of Early and Late Chromosome Aberrations in Different Cell Types

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Yeshitla, Samrawit; Hada, Megumi; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2015-01-01

    Numerous published studies have reported the Relative Biological Effectiveness (RBE) values for chromosome aberrations induced by charged particles of different LET. The RBE for chromosome aberrations in human lymphocytes exposed ex vivo has been suggested to show a similar relationship as the quality factor for cancer induction. Therefore, increased chromosome aberrations in the astronauts' white blood cells post long-duration missions are used to determine the biological doses from exposures to space radiation. However, the RBE value is known to be very different for different types of cancer. Previously, we reported that, even though the RBE for initial chromosome damages was high in human lymphocytes exposed to Fe ions, the RBE was significantly reduced after multiple cell divisions post irradiation. To test the hypothesis that RBE values for chromosome aberrations are cell type dependent, and different between early and late damages, we exposed human lymphocytes ex vivo, and human mammary epithelial cells in vitro to various charged particles. Chromosome aberrations were quantified using the samples collected at first mitosis post irradiation for initial damages, and the samples collected after multiple generations for the remaining or late arising aberrations. Results of the study suggested that the effectiveness of high-LET charged particles for late chromosome aberrations may be cell type dependent, even though the RBE values are similar for early damages.

  6. Arrhythmia triggers in heart failure: the smoking gun of [Ca2+]i dysregulation.

    PubMed

    Aistrup, Gary L; Balke, C William; Wasserstrom, J Andrew

    2011-11-01

    Among the most serious problems associated with heart failure is the increased likelihood of life-threatening arrhythmias. Both triggered and reentrant arrhythmias in heart failure may arise as a result of aberrant intracellular Ca cycling. This article presents some new ideas, based on recent studies, about how altered Ca cycling in heart failure might serve as the cellular basis for arrhythmogenesis. PMID:21699870

  7. A non-stationary model for simulating the dynamics of ocular aberrations.

    PubMed

    Leahy, C; Dainty, C

    2010-09-27

    The time-evolution of ocular aberrations has been the subject of many studies, but so far there has been little discussion involving the modelling of the underlying temporal statistics. This paper presents a non-stationary modelling approach based on a coloured-noise generator, which can be applied to ocular aberration dynamics. The model parameters are computed from measured ocular aberration data. A custom-built aberrometer based on a Shack-Hartmann sensor was used for measurement. We present simulations based on our modelling approach, and validate them through comparison to real data. This work could be useful in areas such as the testing of ophthalmic devices and the development of improved algorithms for laser refractive surgery.

  8. Correcting the aero-optical aberration of the supersonic mixing layer with adaptive optics: concept validation.

    PubMed

    Gao, Qiong; Jiang, Zongfu; Yi, Shihe; Xie, Wenke; Liao, Tianhe

    2012-06-10

    We describe an adaptive optics (AO) system for correcting the aero-optical aberration of the supersonic mixing layer and test its performance with numerical simulations. The AO system is based on the measurement of distributed Strehl ratios and the stochastic parallel gradient descent (SPGD) algorithm. The aero-optical aberration is computed by the direct numerical simulation of a two-dimensional supersonic mixing layer. When the SPGD algorithm is applied directly, the AO cannot give effective corrections. This paper suggests two strategies to improve the performance of the SPGD algorithm for use in aero-optics. The first one is using an iteration process keeping finite memory, and the second is based on the frozen hypothesis. With these modifications, the performance of AO is improved and the aero-optical aberration can be corrected to some noticeable extent. The possibility of experimental implementation is also discussed. PMID:22695671

  9. Induction of chromosome aberrations in cultured human lymphocytes treated with ethoxyquin.

    PubMed

    Blaszczyk, A; Osiecka, R; Skolimowski, J

    2003-12-01

    The chromosomal aberration test was employed to investigate the effect in vitro of a known antioxidant and food preservative, ethoxyquin (EQ, 1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline) on human chromosomes. The studies were undertaken because there are no published in vitro data on genotoxicity of EQ in mammalian cells and there are many reports pointing out that it may be harmful to animals and human beings. Lymphocytes obtained from three healthy donors were incubated with EQ (0.01-0.5mM) both with and without metabolic activation. Stability studies performed by HPLC analysis showed that EQ was stable under the conditions of the lymphocyte cultures. The results of the chromosome aberration assay showed that EQ induces chromosome aberrations: gaps and breaks as well as dicentrics and atypical translocation chromosomes.

  10. Relations between Neurological Aberrations and Psychological Dysfunctions in Children with Serious Language Problems.

    ERIC Educational Resources Information Center

    Bo, Ola O.; And Others

    1992-01-01

    Relationships between neuropsychological aberrations and psychological dysfunction were studied for 20 Swedish children (average age around 10 years at first testing) with serious language problems through (1) electroencephalography; (2) brain stem response audiometry; (3) magnetic resonance imaging; and (4) brain electric activity mapping by…

  11. Chromosomal aberrations in ISS crew members

    NASA Astrophysics Data System (ADS)

    Johannes, Christian; Goedecke, Wolfgang; Antonopoulos, Alexandra

    2012-07-01

    High energy radiation is a major risk factor in manned space missions. Astronauts and cosmonauts are exposed to ionising radiations of cosmic and solar origin, while on the Earth's surface people are well protected by the atmosphere and a deflecting magnetic field. There are now data available describing the dose and the quality of ionising radiation on-board of the International Space Station (ISS). Nonetheless, the effect of increased radiation dose on mutation rates of ISS crew members are hard to predict. Therefore, direct measurements of mutation rates are required in order to better estimate the radiation risk for longer duration missions. The analysis of chromosomal aberrations in peripheral blood lymphocytes is a well established method to measure radiation-induced mutations. We present data of chromosome aberration analyses from lymphocyte metaphase spreads of ISS crew members participating in short term (10-14 days) or long term (around 6 months) missions. From each subject we received two blood samples. The first sample was drawn about 10 days before launch and a second one within 3 days after return from flight. From lymphocyte cultures metaphase plates were prepared on glass slides. Giemsa stained and in situ hybridised metaphases were scored for chromosome changes in pre-flight and post-flight blood samples and the mutation rates were compared. Results obtained in chromosomal studies on long-term flight crew members showed pronounced inter-individual differences in the response to elevated radiation levels. Overall slight but significant elevations of typical radiation induced aberrations, i.e., dicentric chromosomes and reciprocal translocations have been observed. Our data indicate no elevation of mutation rates due to short term stays on-board the ISS.

  12. Predicting aberrant CpG island methylation

    PubMed Central

    Feltus, F. A.; Lee, E. K.; Costello, J. F.; Plass, C.; Vertino, P. M.

    2003-01-01

    Epigenetic silencing associated with aberrant methylation of promoter region CpG islands is one mechanism leading to loss of tumor suppressor function in human cancer. Profiling of CpG island methylation indicates that some genes are more frequently methylated than others, and that each tumor type is associated with a unique set of methylated genes. However, little is known about why certain genes succumb to this aberrant event. To address this question, we used Restriction Landmark Genome Scanning to analyze the susceptibility of 1,749 unselected CpG islands to de novo methylation driven by overexpression of DNA cytosine-5-methyltransferase 1 (DNMT1). We found that although the overall incidence of CpG island methylation was increased in cells overexpressing DNMT1, not all loci were equally affected. The majority of CpG islands (69.9%) were resistant to de novo methylation, regardless of DNMT1 overexpression. In contrast, we identified a subset of methylation-prone CpG islands (3.8%) that were consistently hypermethylated in multiple DNMT1 overexpressing clones. Methylation-prone and methylation-resistant CpG islands were not significantly different with respect to size, C+G content, CpG frequency, chromosomal location, or promoter association. We used DNA pattern recognition and supervised learning techniques to derive a classification function based on the frequency of seven novel sequence patterns that was capable of discriminating methylation-prone from methylation-resistant CpG islands with 82% accuracy. The data indicate that CpG islands differ in their intrinsic susceptibility to de novo methylation, and suggest that the propensity for a CpG island to become aberrantly methylated can be predicted based on its sequence context. PMID:14519846

  13. Peripheral Aberrations and Image Quality for Contact Lens Correction

    PubMed Central

    Shen, Jie; Thibos, Larry N.

    2011-01-01

    Purpose Contact lenses reduced the degree of hyperopic field curvature present in myopic eyes and rigid contact lenses reduced sphero-cylindrical image blur on the peripheral retina, but their effect on higher order aberrations and overall optical quality of the eye in the peripheral visual field is still unknown. The purpose of our study was to evaluate peripheral wavefront aberrations and image quality across the visual field before and after contact lens correction. Methods A commercial Hartmann-Shack aberrometer was used to measure ocular wavefront errors in 5° steps out to 30° of eccentricity along the horizontal meridian in uncorrected eyes and when the same eyes are corrected with soft or rigid contact lenses. Wavefront aberrations and image quality were determined for the full elliptical pupil encountered in off-axis measurements. Results Ocular higher-order aberrations increase away from fovea in the uncorrected eye. Third-order aberrations are larger and increase faster with eccentricity compared to the other higher-order aberrations. Contact lenses increase all higher-order aberrations except 3rd-order Zernike terms. Nevertheless, a net increase in image quality across the horizontal visual field for objects located at the foveal far point is achieved with rigid lenses, whereas soft contact lenses reduce image quality. Conclusions Second order aberrations limit image quality more than higher-order aberrations in the periphery. Although second-order aberrations are reduced by contact lenses, the resulting gain in image quality is partially offset by increased amounts of higher-order aberrations. To fully realize the benefits of correcting higher-order aberrations in the peripheral field requires improved correction of second-order aberrations as well. PMID:21873925

  14. Aberrations in Fresnel Lenses and Mirrors

    NASA Technical Reports Server (NTRS)

    Gregory, Don

    1999-01-01

    The NASA/MSFC Shooting Star program revealed a number of technical problems that must be solved before solar thermal propulsion can become a reality. The fundamental problem of interest here is the collection of solar energy. This is the first step in the propulsion process and indeed the most important. Everything else depends on the efficiency and focusing ability of the collection lens or mirror. An initial model of Fresnel lens behavior using a wave optics approach has been completed and the results were encouraging enough to warrant an experimental investigation. This experimental investigation confirmed some of the effects predicted and produced invaluable photographic evidence of coherence based diffraction and aberration.

  15. Aberrant splicing and drug resistance in AML.

    PubMed

    de Necochea-Campion, Rosalia; Shouse, Geoffrey P; Zhou, Qi; Mirshahidi, Saied; Chen, Chien-Shing

    2016-01-01

    The advent of next-generation sequencing technologies has unveiled a new window into the heterogeneity of acute myeloid leukemia (AML). In particular, recurrent mutations in spliceosome machinery and genome-wide aberrant splicing events have been recognized as a prominent component of this disease. This review will focus on how these factors influence drug resistance through altered splicing of tumor suppressor and oncogenes and dysregulation of the apoptotic signaling network. A better understanding of these factors in disease progression is necessary to design appropriate therapeutic strategies recognizing specific alternatively spliced or mutated oncogenic targets. PMID:27613060

  16. Variable zoom system with aberration correction capability

    NASA Astrophysics Data System (ADS)

    Lu, Yang; Stockbridge, Christopher R.; Hoffman, Samuel M.; Bifano, Thomas G.

    2012-07-01

    We describe experiments conducted with two deformable mirrors (DMs) at fixed locations in an optical microscope imaging system. In this configuration, the DM shapes are controlled to provide 2.5× zoom capability, to allow dynamic focus control and to compensate for aberrations of the fixed optical components. Zoom is achieved by simultaneously adjusting focal lengths of the two DMs, which are inserted between an infinity-corrected microscope objective and a tube lens. Image quality is measured using contrast modulation, and performance of the system is quantified, demonstrating an improved point spread function in the adaptively compensated system.

  17. Temporary variations in chromosomal aberrations in a group of agricultural workers exposed to pesticides.

    PubMed

    Carbonell, E; Valbuena, A; Xamena, N; Creus, A; Marcos, R

    1995-10-01

    The induction of chromosomal aberrations (CA) was studied in the peripheral lymphocytes of 29 male agricultural workers occupationally exposed to several pesticides. To investigate possible exposure-related changes in the frequency of CA, a longitudinal study has been conducted. Two blood samples were taken from each individual: one in a period of high exposure (spring-summer) and the other in a period of lower exposure (autumn-winter). Simultaneously, two matched control groups constituted by 29 and 24 healthy men, without indication of exposure to pesticides, were analysed. During the period of major exposure, the group of agricultural workers showed a significant increase in the frequency of CA, mainly of chromatid-type, when compared to the unexposed control group; nevertheless, this increase in the expression of CA was not found in the period of minor exposure. This finding could indicate that the frequency of CA is related to the intensity of the pesticide exposure, and that CA have a relatively short-life, recovering the control value a few months later. In addition to the cytogenetic analysis, biochemical and haemotological blood parameters were also analysed and no significant variations were detected. PMID:7491130

  18. Controls on Sr/Ca and Mg/Ca in scleractinian corals: The effects of Ca-ATPase and transcellular Ca channels on skeletal chemistry

    NASA Astrophysics Data System (ADS)

    Emif Allison, Nicola; Cohen, Itay; Finch, Adrian A.; Erez, Jonathan

    2011-11-01

    The Sr/Ca of aragonitic coral skeletons is a commonly used palaeothermometer. However skeletal Sr/Ca is typically dominated by weekly-monthly oscillations which do not reflect temperature or seawater composition and the origins of which are currently unknown. To test the impact of transcellular Ca2+ transport processes on skeletal Sr/Ca, colonies of the branching coral, Pocillopora damicornis, were cultured in the presence of inhibitors of Ca-ATPase (ruthenium red) and Ca channels (verapamil hydrochloride). The photosynthesis, respiration and calcification rates of the colonies were monitored throughout the experiment. The skeleton deposited in the presence of the inhibitors was identified (by 42Ca spike) and analysed for Sr/Ca and Mg/Ca by secondary ion mass spectrometry. The Sr/Ca of the aragonite deposited in the presence of either of the inhibitors was not significantly different from that of the solvent (dimethyl sulfoxide) control, although the coral calcification rate was reduced by up to 66% and 73% in the ruthenium red and verapamil treatments, respectively. The typical precision (95% confidence limits) of mean Sr/Ca determinations within any treatment was <±1% and differences in skeletal Sr/Ca between treatments were correspondingly small. Either Ca-ATPase and Ca channels transport Sr2+ and Ca2+ in virtually the same ratio in which they are present in seawater or transcellular processes contribute little Ca2+ to the skeleton and most Ca is derived from seawater transported directly to the calcification site. Variations in the activities of Ca-ATPase and Ca-channels are not responsible for the weekly-monthly Sr/Ca oscillations observed in skeletal chronologies, assuming that the specificities of Ca transcellular transport processes are similar between coral genera.

  19. Controls on Sr/Ca and Mg/Ca in scleractinian corals: The effects of Ca-ATPase and transcellular Ca channels on skeletal chemistry

    NASA Astrophysics Data System (ADS)

    Allison, Nicola; Cohen, Itay; Finch, Adrian A.; Erez, Jonathan; EMIF

    2011-11-01

    The Sr/Ca of aragonitic coral skeletons is a commonly used palaeothermometer. However skeletal Sr/Ca is typically dominated by weekly-monthly oscillations which do not reflect temperature or seawater composition and the origins of which are currently unknown. To test the impact of transcellular Ca 2+ transport processes on skeletal Sr/Ca, colonies of the branching coral, Pocillopora damicornis, were cultured in the presence of inhibitors of Ca-ATPase (ruthenium red) and Ca channels (verapamil hydrochloride). The photosynthesis, respiration and calcification rates of the colonies were monitored throughout the experiment. The skeleton deposited in the presence of the inhibitors was identified (by 42Ca spike) and analysed for Sr/Ca and Mg/Ca by secondary ion mass spectrometry. The Sr/Ca of the aragonite deposited in the presence of either of the inhibitors was not significantly different from that of the solvent (dimethyl sulfoxide) control, although the coral calcification rate was reduced by up to 66% and 73% in the ruthenium red and verapamil treatments, respectively. The typical precision (95% confidence limits) of mean Sr/Ca determinations within any treatment was <±1% and differences in skeletal Sr/Ca between treatments were correspondingly small. Either Ca-ATPase and Ca channels transport Sr 2+ and Ca 2+ in virtually the same ratio in which they are present in seawater or transcellular processes contribute little Ca 2+ to the skeleton and most Ca is derived from seawater transported directly to the calcification site. Variations in the activities of Ca-ATPase and Ca-channels are not responsible for the weekly-monthly Sr/Ca oscillations observed in skeletal chronologies, assuming that the specificities of Ca transcellular transport processes are similar between coral genera.

  20. The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility.

    PubMed

    González-Vega, J Caroline; Walk, Carrie L; Liu, Yanhong; Stein, Hans H

    2014-01-01

    An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal tract Ca absorption takes place and if there are measurable quantities of basal endogenous Ca fluxes in the stomach, small intestine or large intestine. Diets contained calcium carbonate or L. calcareum Ca as the sole source of Ca, 0% or 1% phytic acid and 0.4% or 0.8% Ca. A Ca-free diet was also formulated and used to measure endogenous fluxes and losses of Ca. Nine growing pigs (initial body weight 23.8 ± 1.3 kg) were cannulated in the duodenum and in the distal ileum, and faecal, ileal and duodenal samples were collected. Duodenal endogenous fluxes of Ca were greater (p < 0.05) than ileal endogenous fluxes and total tract endogenous losses of Ca, but ileal endogenous fluxes were less (p < 0.05) than total tract endogenous losses. Standardised digestibility of Ca was not affected by the level of phytic acid, but decreased (p < 0.05) as Ca level increased in L. calcareum Ca diets, but that was not the case if calcium carbonate was the source of Ca (interaction, p < 0.05). The standardised duodenal digestibility (SDD), standardised ileal digestibility (SID) and standardised total tract digestibility (STTD) of Ca were not different if calcium carbonate was the source of dietary Ca. However, the STTD of Ca in L. calcareum Ca was greater (p < 0.05) than the SID and SDD of Ca. The SDD, SID and STTD of Ca in calcium carbonate were greater (p < 0.05) than those of L. calcareum Ca. In conclusion, under the conditions of this experiment, standardised digestibility of Ca is not affected by the level of phytic acid, but may be affected by dietary Ca level depending on the Ca source. Calcium from calcium carbonate is mostly

  1. Aberration measurement from specific photolithographic images: a different approach.

    PubMed

    Nomura, H; Tawarayama, K; Kohno, T

    2000-03-01

    Techniques for measurement of higher-order aberrations of a projection optical system in photolithographic exposure tools have been established. Even-type and odd-type aberrations are independently obtained from printed grating patterns on a wafer by three-beam interference under highly coherent illumination. Even-type aberrations, i.e., spherical aberration and astigmatism, are derived from the best focus positions of vertical, horizontal, and oblique grating patterns by an optical microscope. Odd-type aberrations, i.e., coma and three-foil, are obtained by detection of relative shifts of a fine grating pattern to a large pattern by an overlay inspection tool. Quantitative diagnosis of lens aberrations with a krypton fluoride (KrF) excimer laser scanner is demonstrated.

  2. Lymphocyte chromosomal aberration assay in radiation biodosimetry

    PubMed Central

    Agrawala, Paban K.; Adhikari, J. S.; Chaudhury, N. K.

    2010-01-01

    Exposure to ionizing radiations, whether medical, occupational or accidental, leads to deleterious biological consequences like mortality or carcinogenesis. It is considered that no dose of ionizing radiation exposure is safe. However, once the accurate absorbed dose is estimated, one can be given appropriate medical care and the severe consequences can be minimized. Though several accurate physical dose estimation modalities exist, it is essential to estimate the absorbed dose in biological system taking into account the individual variation in radiation response, so as to plan suitable medical care. Over the last several decades, lots of efforts have been taken to design a rapid and easy biological dosimeter requiring minimum invasive procedures. The metaphase chromosomal aberration assay in human lymphocytes, though is labor intensive and requires skilled individuals, still remains the gold standard for radiation biodosimetry. The current review aims at discussing the human lymphocyte metaphase chromosomal aberration assay and recent developments involving the application of molecular cytogenetic approaches and other technological advancements to make the assay more authentic and simple to use even in the events of mass radiation casualties. PMID:21829315

  3. Eye aberration analysis with Zernike polynomials

    NASA Astrophysics Data System (ADS)

    Molebny, Vasyl V.; Chyzh, Igor H.; Sokurenko, Vyacheslav M.; Pallikaris, Ioannis G.; Naoumidis, Leonidas P.

    1998-06-01

    New horizons for accurate photorefractive sight correction, afforded by novel flying spot technologies, require adequate measurements of photorefractive properties of an eye. Proposed techniques of eye refraction mapping present results of measurements for finite number of points of eye aperture, requiring to approximate these data by 3D surface. A technique of wave front approximation with Zernike polynomials is described, using optimization of the number of polynomial coefficients. Criterion of optimization is the nearest proximity of the resulted continuous surface to the values calculated for given discrete points. Methodology includes statistical evaluation of minimal root mean square deviation (RMSD) of transverse aberrations, in particular, varying consecutively the values of maximal coefficient indices of Zernike polynomials, recalculating the coefficients, and computing the value of RMSD. Optimization is finished at minimal value of RMSD. Formulas are given for computing ametropia, size of the spot of light on retina, caused by spherical aberration, coma, and astigmatism. Results are illustrated by experimental data, that could be of interest for other applications, where detailed evaluation of eye parameters is needed.

  4. Correcting Aberrations in Complex Magnet Systems for Muon Cooling Channels

    SciTech Connect

    J.A. Maloney, B. Erdelyi, A. Afanaciev, R.P. Johnson, Y.S. Derbenev, V.S. Morozov

    2011-03-01

    Designing and simulating complex magnet systems needed for cooling channels in both neutrino factories and muon colliders requires innovative techniques to correct for both chromatic and spherical aberrations. Optimizing complex systems, such as helical magnets for example, is also difficult but essential. By using COSY INFINITY, a differential algebra based code, the transfer and aberration maps can be examined to discover what critical terms have the greatest influence on these aberrations.

  5. Aberration influenced generation of rotating two-lobe light fields

    NASA Astrophysics Data System (ADS)

    Kotova, S. P.; Losevsky, N. N.; Prokopova, D. V.; Samagin, S. A.; Volostnikov, V. G.; Vorontsov, E. N.

    2016-08-01

    The influence of aberrations on light fields with a rotating intensity distribution is considered. Light fields were generated with the phase masks developed using the theory of spiral beam optics. The effects of basic aberrations, such as spherical aberration, astigmatism and coma are studied. The experimental implementation of the fields was achieved with the assistance of a liquid crystal spatial light modulator HOLOEYE HEO-1080P, operating in reflection mode. The results of mathematical modelling and experiments have been qualitatively compared.

  6. Comparison of Aberrations After Standard and Customized Refractive Surgery

    NASA Astrophysics Data System (ADS)

    Fang, L.; He, X.; Wang, Y.

    2013-09-01

    To detect possible differences in residual wavefront aberrations between standard and customized laser refractive surgery based onmathematical modeling, the residual optical aberrations after conventional and customized laser refractive surgery were compared accordingto the ablation profile with transition zone. The results indicated that ablation profile has a significant impact on the residual aberrations.The amount of residual aberrations for conventional correction is higher than that for customized correction. Additionally, the residualaberrations for high myopia eyes are markedly larger than those for moderate myopia eyes. For a 5 mm pupil, the main residual aberrationterm is coma and yet it is spherical aberration for a 7 mm pupil. When the pupil diameter is the same as optical zone or greater, themagnitudes of residual aberrations is obviously larger than that for a smaller pupil. In addition, the magnitudes of the residual fifth orsixth order aberrations are relatively large, especially secondary coma in a 6 mm pupil and secondary spherical aberration in a 7 mm pupil.Therefore, the customized ablation profile may be superior to the conventional correction even though the transition zone and treatmentdecentration are taken into account. However, the customized ablation profile will still induce significant amount of residual aberrations.

  7. Aberration design of zoom lens systems using thick lens modules.

    PubMed

    Zhang, Jinkai; Chen, Xiaobo; Xi, Juntong; Wu, Zhuoqi

    2014-12-20

    A systematic approach for the aberration design of a zoom lens system using a thick lens module is presented. Each component is treated as a thick lens module at the beginning of the design. A thick lens module refers to a thick lens component with a real lens structure, like lens materials, lens curvatures, lens thicknesses, and lens interval distances. All nine third-order aberrations of a thick lens component are considered during the design. The relationship of component aberrations in different zoom positions can be approximated from the aberration shift. After minimizing the aberrations of the zoom lens system, the nine third-order aberrations of every lens component can be determined. Then the thick lens structure of every lens component can be determined after optimization according to their first-order properties and third-order aberration targets. After a third optimization for minimum practical third-order aberrations of a zoom lens system, the aberration design using the thick lens module is complete, which provides a practical zoom lens system with thick lens structures. A double-sided telecentric zoom lens system is designed using the thick lens module in this paper, which shows that this method is practical for zoom lens design.

  8. Transverse ray aberrations of Wolter type 1 telescopes

    NASA Technical Reports Server (NTRS)

    Saha, Timo T.

    1986-01-01

    Transverse ray aberration expansions are derived for Wolter type 1 telescopes. The analysis gives third order aberration terms, most of the fifth order terms and two seventh order terms as functions of system parameters and entrance aperture coordinates. The third order distortion is negligible and, therefore, this term is omitted in the expansions. The spot diagrams derived from exact ray tracing and aberration expansions agree well. The importance of fifth and seventh order terms is discussed. The derived aberration expansions are also valid for Wolter type 2 telescopes.

  9. Aberrant glycosylation associated with enzymes as cancer biomarkers

    PubMed Central

    2011-01-01

    Background One of the new roles for enzymes in personalized medicine builds on a rational approach to cancer biomarker discovery using enzyme-associated aberrant glycosylation. A hallmark of cancer, aberrant glycosylation is associated with differential expressions of enzymes such as glycosyltransferase and glycosidases. The aberrant expressions of the enzymes in turn cause cancer cells to produce glycoproteins with specific cancer-associated aberrations in glycan structures. Content In this review we provide examples of cancer biomarker discovery using aberrant glycosylation in three areas. First, changes in glycosylation machinery such as glycosyltransferases/glycosidases could be used as cancer biomarkers. Second, most of the clinically useful cancer biomarkers are glycoproteins. Discovery of specific cancer-associated aberrations in glycan structures of these existing biomarkers could improve their cancer specificity, such as the discovery of AFP-L3, fucosylated glycoforms of AFP. Third, cancer-associated aberrations in glycan structures provide a compelling rationale for discovering new biomarkers using glycomic and glycoproteomic technologies. Summary As a hallmark of cancer, aberrant glycosylation allows for the rational design of biomarker discovery efforts. But more important, we need to translate these biomarkers from discovery to clinical diagnostics using good strategies, such as the lessons learned from translating the biomarkers discovered using proteomic technologies to OVA 1, the first FDA-cleared In Vitro Diagnostic Multivariate Index Assay (IVDMIA). These lessons, providing important guidance in current efforts in biomarker discovery and translation, are applicable to the discovery of aberrant glycosylation associated with enzymes as cancer biomarkers as well. PMID:21906357

  10. The influence of Ca²⁺ buffers on free [Ca²⁺] fluctuations and the effective volume of Ca²⁺ microdomains.

    PubMed

    Weinberg, Seth H; Smith, Gregory D

    2014-06-17

    Intracellular calcium (Ca(2+)) plays a significant role in many cell signaling pathways, some of which are localized to spatially restricted microdomains. Ca(2+) binding proteins (Ca(2+) buffers) play an important role in regulating Ca(2+) concentration ([Ca(2+)]). Buffers typically slow [Ca(2+)] temporal dynamics and increase the effective volume of Ca(2+) domains. Because fluctuations in [Ca(2+)] decrease in proportion to the square-root of a domain's physical volume, one might conjecture that buffers decrease [Ca(2+)] fluctuations and, consequently, mitigate the significance of small domain volume concerning Ca(2+) signaling. We test this hypothesis through mathematical and computational analysis of idealized buffer-containing domains and their stochastic dynamics during free Ca(2+) influx with passive exchange of both Ca(2+) and buffer with bulk concentrations. We derive Langevin equations for the fluctuating dynamics of Ca(2+) and buffer and use these stochastic differential equations to determine the magnitude of [Ca(2+)] fluctuations for different buffer parameters (e.g., dissociation constant and concentration). In marked contrast to expectations based on a naive application of the principle of effective volume as employed in deterministic models of Ca(2+) signaling, we find that mobile and rapid buffers typically increase the magnitude of domain [Ca(2+)] fluctuations during periods of Ca(2+) influx, whereas stationary (immobile) Ca(2+) buffers do not. Also contrary to expectations, we find that in the absence of Ca(2+) influx, buffers influence the temporal characteristics, but not the magnitude, of [Ca(2+)] fluctuations. We derive an analytical formula describing the influence of rapid Ca(2+) buffers on [Ca(2+)] fluctuations and, importantly, identify the stochastic analog of (deterministic) effective domain volume. Our results demonstrate that Ca(2+) buffers alter the dynamics of [Ca(2+)] fluctuations in a nonintuitive manner. The finding that Ca(2

  11. Energy-based adaptive focusing of waves: application to noninvasive aberration correction of ultrasonic wavefields

    PubMed Central

    Herbert, Eric; Pernot, Mathieu; Montaldo, Gabriel; Fink, Mathias; Tanter, Mickael

    2009-01-01

    An aberration correction method based on the maximization of the wave intensity at the focus of an emitting array is presented. The potential of this new adaptive focusing technique is investigated for ultrasonic focusing in biological tissues. The acoustic intensity is maximized non invasively through the direct measurement or indirect estimation of the beam energy at the focus for a series of spatially coded emissions. For ultrasonic waves, the acoustic energy at the desired focus can be indirectly estimated from the local displacements induced in tissues by the ultrasonic radiation force of the beam. Based on the measurement of these displacements, this method allows the precise estimation of the phase and amplitude aberrations and consequently the correction of aberrations along the beam travel path. The proof of concept is first performed experimentally using a large therapeutic array with strong electronic phase aberrations (up to 2π). Displacements induced by the ultrasonic radiation force at the desired focus are indirectly estimated using the time shift of backscattered echoes recorded on the array. The phase estimation is deduced accurately using a direct inversion algorithm which reduces the standard deviation of the phase distribution from σ = 1.89 before correction to σ = 0.53 following correction. The corrected beam focusing quality is verified using a needle hydrophone. The peak intensity obtained through the aberrator is found to be −7.69 dB below the reference intensity obtained without any aberration. Using the phase correction, a sharp focus is restored through the aberrator with a relative peak intensity of −0.89 dB. The technique is tested experimentally using a linear transmit/receive array through a real aberrating layer. The array is used to automatically correct its beam quality, as it both generates the radiation force with coded excitations and indirectly estimates the acoustic intensity at the focus with speckle tracking. This

  12. Aberration correction by maximizing generalized sharpness metrics.

    PubMed

    Fienup, J R; Miller, J J

    2003-04-01

    The technique of maximizing sharpness metrics has been used to estimate and compensate for aberrations with adaptive optics, to correct phase errors in synthetic-aperture radar, and to restore images. The largest class of sharpness metrics is the sum over a nonlinear point transformation of the image intensity. How the second derivative of the point nonlinearity varies with image intensity determines the effects of various metrics on the imagery. Some metrics emphasize making shadows darker, and other emphasize making bright points brighter. One can determine the image content needed to pick the best metric by computing the statistics of the image autocorrelation or of the Fourier magnitude, either of which is independent of the phase error. Computationally efficient, closed-form expressions for the gradient make possible efficient search algorithms to maximize sharpness.

  13. Overlapped Fourier coding for optical aberration removal

    PubMed Central

    Horstmeyer, Roarke; Ou, Xiaoze; Chung, Jaebum; Zheng, Guoan; Yang, Changhuei

    2014-01-01

    We present an imaging procedure that simultaneously optimizes a camera’s resolution and retrieves a sample’s phase over a sequence of snapshots. The technique, termed overlapped Fourier coding (OFC), first digitally pans a small aperture across a camera’s pupil plane with a spatial light modulator. At each aperture location, a unique image is acquired. The OFC algorithm then fuses these low-resolution images into a full-resolution estimate of the complex optical field incident upon the detector. Simultaneously, the algorithm utilizes redundancies within the acquired dataset to computationally estimate and remove unknown optical aberrations and system misalignments via simulated annealing. The result is an imaging system that can computationally overcome its optical imperfections to offer enhanced resolution, at the expense of taking multiple snapshots over time. PMID:25321982

  14. Patterns of Chromosomal Aberrations in Solid Tumors.

    PubMed

    Grade, Marian; Difilippantonio, Michael J; Camps, Jordi

    2015-01-01

    Chromosomal abnormalities are a defining feature of solid tumors. Such cytogenetic alterations are mainly classified into structural chromosomal aberrations and copy number alterations, giving rise to aneuploid karyotypes. The increasing detection of these genetic changes allowed the description of specific tumor entities and the associated patterns of gene expression. In fact, tumor-specific landscapes of gross genomic copy number changes, including aneuploidies of entire chromosome arms and chromosomes result in a global deregulation of the transcriptome of cancer cells. Furthermore, the molecular characterization of cytogenetic abnormalities has provided insights into the mechanisms of tumorigenesis and has, in a few instances, led to the clinical implementation of effective diagnostic and prognostic tools, as well as treatment strategies that target a specific genetic abnormality. PMID:26376875

  15. Aberrant pancreatic ductal organisation: a case report.

    PubMed

    Goel, Shivi; Rustagi, Shaifaly Madan; Saha, Susmita; Mehta, Vandana; Suri, Rajesh Kumar; Rath, Gayatri

    2015-07-01

    Anomalous pancreatic ductal system has always enthralled the anatomists, surgeons, gastroenterologists and radiologists alike. With the growing use of MRCP, ERCP and endoscopic and surgical procedures, the knowledge of anatomical aberrations of pancreaticobiliary tract becomes extremely important. Moreover, the anomalous pancreatic duct morphology may be responsible for atypical gastrointestinal complains. We report an exceptionally rare case of two accessory ventral pancreatic ducts opening separately into the common bile duct proximal to the hepato pancreatic ampulla. Concomitant occurrence of an ectopic major duodenal papilla, 3.8 cm distal to the pyloric end of stomach was also seen. Moreover, the accessory pancreatic duct and the minor duodenal papilla were absent. Clinical implications and embryological description of these rare anomalies are discussed. Awareness of such rare morphological variants can go a long way in assisting effective patient management.

  16. Patterns of Chromosomal Aberrations in Solid Tumors

    PubMed Central

    Grade, Marian; Difilippantonio, Michael J.

    2016-01-01

    Chromosomal abnormalities are a defining feature of solid tumors. Such cytogenetic alterations are mainly classified into structural chromosomal aberrations and copy number alterations, giving rise to aneuploid karyotypes. The increasing detection of these genetic changes allowed the description of specific tumor entities and the associated patterns of gene expression. In fact, tumor-specific landscapes of gross genomic copy number changes, including aneuploidies of entire chromosome arms and chromosomes result in a global deregulation of the transcriptome of cancer cells. Furthermore, the molecular characterization of cytogenetic abnormalities has provided insights into the mechanisms of tumorigenesis and has, in a few instances, led to the clinical implementation of effective diagnostic and prognostic tools, as well as treatment strategies that target a specific genetic abnormality. PMID:26376875

  17. Structural aberrations in group A Staphylococcus bacteriophages.

    PubMed Central

    Ackermann, H W; Berthiaume, L; Sonea, S; Kasatiya, S S

    1976-01-01

    Six related Staphylococcus phages spontaneously produced various abnormal head and tail structures: (i) giant capsids which were tailed and apparently contained nucleic acid; (ii) regular and irregular smooth polyheads; (iii) heads and polyheads with wavy outlines; (iv) mottled heads and polyheads; (v) abnormally long and short tails; and (vi) "double capsids" connected by a small bridge. Some of these structures are rare, or have not yet been reported. The frequency os specific aberrant particles varied from one phage to another. Length distribution of smooth irregular polyheads and of abnormal tails indicated that these structures assemble at random from protein synthesized in excess. These phages represent an interesting model for genetic and morphogentic studies. Images PMID:131865

  18. Aberrant diagnoses by individual surgical pathologists.

    PubMed

    Wakely, S L; Baxendine-Jones, J A; Gallagher, P J; Mullee, M; Pickering, R

    1998-01-01

    Methods of auditing the performance of histopathologists, such as external and internal quality assurance, clinicopathological conferences, and "double-reporting" of microscopic slides, show significant diagnostic errors in at least 1.2% of reports. Although some of these are in well-recognized areas of difficulty, such as melanoma or lymphoma, most errors are in common biopsy specimens. We have developed a method that compares diagnostic patterns of individual histopathologists. This aims to identify specific diagnoses that a pathologist makes more or less frequently than other colleagues and enables the individual to reflect on his or her own histologic expertise in reporting on specific biopsy results. The bottom line diagnoses of transurethral resection of prostate specimens; rectal, gastric, and bladder biopsy samples; and endometrial curettages were analyzed retrospectively. Analyses were performed on diagnoses made by at least 15 pathologists on each specimen type and expressed as a standardized ratio (SR) with 95% confidence intervals (CI). An SR of 1.0 indicated a pattern of diagnosis matching the combined pattern of other colleagues. An SR <1.0 indicated relative "underdiagnosis" and an SR >1.0 indicated relative "overdiagnosis." Diagnostic rates of individual pathologists whose CIs did not straddle the value of 1.0 were considered aberrant, although not necessarily incorrect. The 47 of 226 (20.8%) aberrant SRs included four pathologists' diagnoses of prostatic carcinoma, three each of endometrial, rectal, and bladder carcinoma, and one of gastric malignancy. This method, which could easily be automated and used regionally or nationally, should provide pathologists with a profile of their diagnostic patterns in comparison with their peers.

  19. Increased Asynchronous Release and Aberrant Calcium Channel Activation in Amyloid Precursor Protein Deficient Neuromuscular Synapses

    PubMed Central

    Yang, Li; Wang, Baiping; Long, Cheng; Wu, Gangyi; Zheng, Hui

    2007-01-01

    Despite the critical roles of the amyloid precursor protein (APP) in Alzheimer's disease pathogenesis, its physiological function remains poorly established. Our previous studies implicated a structural and functional activity of the APP family of proteins in the developing neuromuscular junction (NMJ). Here we performed comprehensive analyses of neurotransmission in mature neuromuscular synapse of APP deficient mice. We found that APP deletion led to reduced paired-pulse facilitation and increased depression of synaptic transmission with repetitive stimulation. Readily releasable pool size and total releasable vesicles were not affected, but probability of release was significantly increased. Strikingly, the amount of asynchronous release, a measure sensitive to presynaptic calcium concentration, was dramatically increased, and pharmacological studies revealed that it was attributed to aberrant activation of N- and L-type Ca2+ channels. We propose that APP modulates synaptic transmission at the NMJ by ensuring proper Ca2+ channel function. PMID:17919826

  20. 20 CFR 10.303 - Should the employer use a Form CA-16 to authorize medical testing when an employee is exposed to...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Related Benefits Emergency Medical Care § 10.303 Should the employer use a Form CA-16 to authorize medical... Occupational Safety and Health Administration at 29 CFR chapter XVII require employers to provide their... employees for exposure or feared exposure to such hazards, and provide health care screening and...

  1. Aberrant hippocampal Atp8a1 levels are associated with altered synaptic strength, electrical activity, and autistic-like behavior.

    PubMed

    Kerr, Daniel J; Marsillo, Alexandra; Guariglia, Sara R; Budylin, Tatyana; Sadek, Rodina; Menkes, Silvia; Chauhan, Abha; Wen, Guang Y; McCloskey, Daniel P; Wieraszko, Andrzej; Banerjee, Probal

    2016-09-01

    Type IV ATPases are putative aminophospholipid translocases (APLTs), more commonly known as flippases. A pronounced induction of the flippase Atp8a1 was observed in post-mortem tissue homogenates from the hippocampus and temporal lobe of juvenile autistic subjects compared to age-matched controls. In order to simulate the human data, C57BL/6 mice were allowed to develop after intra-hippocampal injection of recombinant lentivirus expressing Atp8a1 at the early developmental stage of postnatal day 6 (P6). Transmission electron microscopy (TEM) analysis of the lentivirus-Atp8a1 treated (Atp8a1+) mice in adulthood revealed fewer and weaker excitatory synapses in the hippocampal CA1 region compared to mice injected with empty virus. Significant inhibition of the Schaffer collateral pathway was observed in the Atp8a1+ mice in paired-pulse recording (PPR) at 20-ms inter-stimulus interval. In the three-chambered sociability test, the Atp8a1+ mice displayed no preference for an encaged stranger mouse over a novel object, which is a characteristic autistic-like behavior. In sharp contrast, Atp8a1 (-/-) mice displayed a preference for a stranger mouse over the novel object, which is characteristic of neurotypical mouse behavior. However, similar to the Atp8a1+ mice, the Atp8a1 (-/-) mice harbored fewer and weaker excitatory synapses in CA1 compared to wild-type controls, and displayed inhibition at 20-ms inter-stimulus interval in PPR. These findings suggest that both elevated and diminished levels of Atp8a1 during early development are detrimental to brain connectivity, but only elevated Atp8a1 is associated with aberrant social behavior. Mice with augmented levels of Atp8a1 may therefore serve as a potential model in autism research. PMID:27287255

  2. Optical aberrations measurement with a low cost optometric instrument

    NASA Astrophysics Data System (ADS)

    Furlan, Walter D.; Muñoz-Escrivá, L.; Pons, A.; Martínez-Corral, M.

    2002-08-01

    A simple experimental method for measuring optical aberrations of a single lens is proposed. The technique is based on the use of an optometric instrument employed for the assessment of the refractive state of the eye: the retinoscope. Experimental results for spherical aberration and astigmatism are obtained.

  3. Using Brief Assessments to Evaluate Aberrant Behavior Maintained by Attention.

    ERIC Educational Resources Information Center

    O'Reilly, Mark F.; Lancioni, Giulio E.; King, Lisa; Lally, Grainne; Dhomhnaill, Orla Nic

    2000-01-01

    Functional assessments were conducted for two Irish individuals with severe disabilities and aberrant behavior. A modified attention condition was introduced, which involved both parents interacting with a third person. Aberrant behavior occurred only in the modified attention condition. Successful treatment consisted of delivery of attention on a…

  4. Aberration analysis calculations for synchrotron radiation beamline design

    SciTech Connect

    McKinney, W.R.; Howells, M.; Padmore, H.A.

    1997-09-01

    The application of ray deviation calculations based on aberration coefficients for a single optical surface for the design of beamline optical systems is reviewed. A systematic development is presented which allows insight into which aberration may be causing the rays to deviate from perfect focus. A new development allowing analytical calculation of line shape is presented.

  5. Sextupole system for the correction of spherical aberration

    DOEpatents

    Crewe, A.V.; Kopf, D.A.

    In an electron beam device in which an electron beam is developed and then focused by a lens to a particular spot, there is provided a means for eliminating spherical aberration. A sextupole electromagnetic lens is positioned between two focusing lenses. The interaction of the sextupole with the beam compensates for spherical aberration. (GHT)

  6. Aberrations of the cathode objective lens up to fifth order.

    PubMed

    Tromp, R M; Wan, W; Schramm, S M

    2012-08-01

    In this paper we discuss a topic that was close to Prof. Gertrude Rempfer s interests for many years. On this occasion of her 100th birthday, we remember and honor Gertrude for her many outstanding contributions, and for the inspiring example that she set. We derive theoretical expressions for the aberration coefficients of the uniform electrostatic field up to 5th order and compare these with raytracing calculations for the cathode lens used in Low Energy Electron Microscopy and Photo Electron Emission Microscopy experiments. These higher order aberration coefficients are of interest for aberration corrected experiments in which chromatic (C(c)) and spherical (C₃) aberrations of the microscope are set to zero. The theoretical predictions are in good agreement with the results of raytracing. Calculations of image resolution using the Contrast Transfer Function method show that sub-nanometer resolution is achievable in an aberration corrected LEEM system. PMID:22188906

  7. Chaos in ocular aberration dynamics of the human eye

    PubMed Central

    Hampson, Karen M.; Mallen, Edward A. H.

    2012-01-01

    Since the characterization of the eye’s monochromatic aberration fluctuations in 2001, the power spectrum has remained the most widely used method for analyzing their dynamics. However, the power spectrum does not capture the complexities of the fluctuations. We measured the monochromatic aberration dynamics of six subjects using a Shack-Hartmann sensor sampling at 21 Hz. We characterized the dynamics using techniques from chaos theory. We found that the attractor embedding dimension for all aberrations, for all subjects, was equal to three. The embedding lag averaged across aberrations and subjects was 0.31 ± 0.07 s. The Lyapunov exponent of the rms wavefront error was positive for each subject, with an average value of 0.44 ± 0.15 µm/s. This indicates that the aberration dynamics are chaotic. Implications for future modeling are discussed. PMID:22567581

  8. Correction of spherochromatic aberration by system of thin layers

    NASA Astrophysics Data System (ADS)

    Miks, A.; Novak, J.

    2005-08-01

    It is well-known from the theory of optical imaging that optical systems generally show a presence of a chromatic aberration, which originates from a variation of the refraction index of glass on the wavelength of light. The chromatic aberration must be well corrected in order to obtain a good quality of optical image. In practice, it is used a proper combination of optical elements manufactured from different types of optical glass with a different dispersion in order to suppress the chromatic aberration. Our work shows a way how to correct spherochromatic aberration using a system of thin aspherical layers. The equations are derived for determination of parameters of thin layers with respect to a required spherochromatic aberration.

  9. Minimum change in spherical aberration that can be perceived

    PubMed Central

    Manzanera, Silvestre; Artal, Pablo

    2016-01-01

    It is important to know the visual sensitivity to optical blur from both a basic science perspective and a practical point of view. Of particular interest is the sensitivity to blur induced by spherical aberration because it is being used to increase depth of focus as a component of a presbyopic solution. Using a flicker detection-based procedure implemented on an adaptive optics visual simulator, we measured the spherical aberration thresholds that produce just-noticeable differences in perceived image quality. The thresholds were measured for positive and negative values of spherical aberration, for best focus and + 0.5 D and + 1.0 D of defocus. At best focus, the SA thresholds were 0.20 ± 0.01 µm and −0.17 ± 0.03 µm for positive and negative spherical aberration respectively (referred to a 6-mm pupil). These experimental values may be useful in setting spherical aberration permissible levels in different ophthalmic techniques.

  10. Aberrant NMDA-dependent LTD after perinatal ethanol exposure in young adult rat hippocampus.

    PubMed

    Kervern, Myriam; Silvestre de Ferron, Benoît; Alaux-Cantin, Stéphanie; Fedorenko, Olena; Antol, Johann; Naassila, Mickael; Pierrefiche, Olivier

    2015-08-01

    Irreversible cognitive deficits induced by ethanol exposure during fetal life have been ascribed to a lower NMDA-dependent synaptic long-term potentiation (LTP) in the hippocampus. Whether NMDA-dependent long-term depression (LTD) may also play a critical role in those deficits remains unknown. Here, we show that in vitro LTD induced with paired-pulse low frequency stimulation is enhanced in CA1 hippocampus field of young adult rats exposed to ethanol during brain development. Furthermore, single pulse low frequency stimulation, ineffective at this age (LFS600), induced LTD after ethanol exposure accompanied with a stronger response than controls during LFS600, thus revealing an aberrant form of activity-dependent plasticity at this age. Blocking NMDA receptor or GluN2B containing NMDA receptor prevented both the stronger response during LFS600 and LTD whereas Zinc, an antagonist of GluN2A containing NMDA receptor, was ineffective on both responses. In addition, LFS600-induced LTD was revealed in controls only with a reduced-Mg(2+) medium. In whole dissected hippocampus CA1 field, perinatal ethanol exposure increased GluN2B subunit expression in the synaptic compartment whereas GluN2A was unaltered. Using pharmacological tools, we suggest that LFS600 LTD was of synaptic origin. Altogether, we describe a new mechanism by which ethanol exposure during fetal life induces a long-term alteration of synaptic plasticity involving NMDA receptors, leading to an aberrant LTD. We suggest this effect of ethanol may reflect a delayed maturation of the synapse and that aberrant LTD may also participates to long-lasting cognitive deficits in fetal alcohol spectrum disorder.

  11. Multidetector computed tomographic angiography of aberrant subclavian arteries.

    PubMed

    Türkvatan, Aysel; Büyükbayraktar, Fatma Gül; Olçer, Tülay; Cumhur, Turhan

    2009-02-01

    The purpose of this study was to evaluate the utility of 16-slice multidetector computed tomographic (MDCT) angiography for identifying anatomic features of aberrant subclavian arteries. Seventeen patients with aberrant subclavian arteries were assessed by MDCT angiography. The aortic arch position, the presence of a Kommerell's diverticulum, aneurysm, vascular compression of trachea and oesophagus and associated cardiovascular abnormalities were evaluated. MDCT findings were confirmed by surgery in eight patients but in the other nine patients no further evaluation or management was warranted as the aberrant subclavian artery had no significant clinical consequence. Eleven patients had an aberrant right subclavian artery arising from the left aortic arch and six patients had an aberrant left subclavian artery arising from the right aortic arch. Kommerell's diverticulum was identified in three patients with an aberrant right subclavian artery and in five patients with an aberrant left subclavian artery. In two patients it was aneurysmal. Oesophageal compression was detected in eight patients, and tracheal compression was identified in only one paediatric patient. An aberrant subclavian artery was associated with complex congenital heart disease in one patient, intracardiac defects in two patients, aortic coarctation in two patients, patent ductus arteriosus in two patients and an aberrant vertebral artery in one patient. In conclusion, MDCT angiography is superior to digital subtraction angiography for the assessment of aberrant subclavian arteries since digital subtraction angiography has only a poor ability to visualize adjacent structures completely and is invasive in nature. MDCT angiography or magnetic resonance angiography are the current standard in the initial evaluation of thoracic vascular anomalies.

  12. Diagnostic Accuracy of PIK3CA Mutation Detection by Circulating Free DNA in Breast Cancer: A Meta-Analysis of Diagnostic Test Accuracy

    PubMed Central

    Zhu, Hanjiang; Lin, Yan; Pan, Bo; Zhang, Xiaohui; Huang, Xin; Xu, Qianqian; Xu, Yali; Sun, Qiang

    2016-01-01

    Mutation of p110 alpha-catalytic subunit of phosphatidylinositol 3-kinase (PIK3CA) has high predictive and prognostic values for breast cancer. Hence, there has been a marked interest in detecting and monitoring PIK3CA genotype with non-invasive technique, such as circulating free DNA (cfDNA). However, the diagnostic accuracy of PIK3CA genotyping by cfDNA is still a problem of controversy. Here, we conducted the first meta-analysis to evaluate overall diagnostic performance of cfDNA for PIK3CA mutation detection. Literature search was performed in Pubmed, Embase and Cochrane Central Register of Controlled Trials databases. Seven cohorts from five studies with 247 patients were included. The pooled sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio and area under summary receiver operating characteristic curve were calculated for accuracy evaluation. The pooled sensitivity and specificity were 0.86 (95% confidence interval [CI] 0.32–0.99) and 0.98 (95% CI 0.86–1.00), respectively; the pooled positive and negative likelihood ratio were 42.8 (95% CI 5.1–356.9) and 0.14 (95% CI 0.02–1.34), respectively; diagnostic odds ratio for evaluating the overall diagnostic performance was 300 (95% CI 8–11867); area under summary receiver operating characteristic curve reached 0.99 (95% CI 0.97–0.99). Subgroup analysis with metastatic breast cancer revealed remarkable improvement in diagnostic performance (sensitivity: 0.86–0.91; specificity: 0.98; diagnostic odds ratio: 300–428). This meta-analysis proved that detecting PIK3CA gene mutation by cfDNA has high diagnostic accuracy in breast cancer, especially for metastatic breast cancer. It may serve as a reliable non-invasive assay for detecting and monitoring PIK3CA mutation status in order to deliver personalized and precise treatment. PMID:27336598

  13. Model-based sensor-less wavefront aberration correction in optical coherence tomography.

    PubMed

    Verstraete, Hans R G W; Wahls, Sander; Kalkman, Jeroen; Verhaegen, Michel

    2015-12-15

    Several sensor-less wavefront aberration correction methods that correct nonlinear wavefront aberrations by maximizing the optical coherence tomography (OCT) signal are tested on an OCT setup. A conventional coordinate search method is compared to two model-based optimization methods. The first model-based method takes advantage of the well-known optimization algorithm (NEWUOA) and utilizes a quadratic model. The second model-based method (DONE) is new and utilizes a random multidimensional Fourier-basis expansion. The model-based algorithms achieve lower wavefront errors with up to ten times fewer measurements. Furthermore, the newly proposed DONE method outperforms the NEWUOA method significantly. The DONE algorithm is tested on OCT images and shows a significantly improved image quality. PMID:26670496

  14. Chromosomal aberrations induced by in vitro irradiation: comparisons between human sperm and lymphocytes

    SciTech Connect

    Brandriff, B.F.; Gordon, L.A.; Ashworth, L.K.; Carrano, A.V.

    1988-01-01

    Types and frequencies of structural aberrations in human sperm and lymphocyte chromosomes from one donor were compared after in vitro irradiation with 100, 200, and 400 rad in order to determine if cells with dramatically different chromatin configurations are similarly affected and to investigate the feasibility of using lymphocytes as surrogates for germ cells in risk estimation. Sperm chromosomes were analyzed after fusion with eggs from the golden hamster. Total frequencies of induced aberrations were similar in the two cell types. However, the relative frequencies of rejoined lesions (dicentrics), compared with unrejoined lesions (chromosome breaks and acentric fragments), were different. At the three doses tested, a constant ratio of 5 dicentrics in lymphocytes for every dicentric in sperm was induced. Conversely, for every chromosome break or acentric fragment induced in lymphocytes, 1.7 such events were induced in sperm at the three doses tested.

  15. Anodic reactions in the Ca/CaCrO/sub 4/ thermal battery

    SciTech Connect

    Guidotti, R.A.; Reinhardt, F.W.

    1985-09-01

    The reaction of Ca with a CaCrO/sub 4/-(LiCl-KCl eutectic) solution at temperatures of 400/sup 0/C to 500/sup 0/C was studied to better understand the nature of the chemical reactions and electrochemical processes that occur in the Ca/CaCrO/sub 4/ thermal battery at the anode during activation and discharge. Limited tests also were conducted with a CaCrO/sub 4/-(CaCl/sub 2/-NaCl-KCl eutectic) solution at 550/sup 0/C. Ca/CaCrO/sub 4/ and CaLi/sub 2//CaCrO/sub 4/ single cells were tested to observe the relative performance differences of Ca and CaLi/sub 2/ anodes. The discharged cells were analyzed by optical microscopy, electron microprobe, Auger electron spectroscopy, and secondary-ion mass spectroscopy. These analytical data were used in conjunction with the results of chemical-reaction experiments to propose a discharge mechanism for the Ca/CaCrO/sub 4/ thermal battery, consistent with experimental observations.

  16. Anodic reactions in the Ca/CaCrO4 thermal battery

    NASA Astrophysics Data System (ADS)

    Guidotti, R. A.; Reinhardt, F. W.

    1985-09-01

    The reaction of Ca with a CaCrO4-(LiCl-KCl eutectic) solution at temperatures of 400(0)C to 500(0)C was studied to better understand the nature of the chemical reactions and electrochemical processes that occur in the Ca/CaCrO4 thermal battery at the anode during activation and discharge. Limited tests also were conducted with a CaCrO4-(CaCl2-NaCl-KCl eutectic) solution at 550(0)C. Ca/CaCrO4 and CaLi2/CaCrO4 single cells were tested to observe the relative performance differences of Ca and CaLi2 anodes. The discharged cells were analyzed by optical microscopy, electron microprobe, Auger electron spectroscopy, and secondary-ion mass spectroscopy. These analytical data were used in conjunction with the results of chemical-reaction experiments to propose a discharge mechanism for the Ca/CaCrO4 thermal battery, consistent with experimental observations.

  17. Malignant hyperthermia susceptibility arising from altered resting coupling between the skeletal muscle L-type Ca2+ channel and the type 1 ryanodine receptor

    PubMed Central

    Eltit, Jose Miguel; Bannister, Roger A.; Moua, Ong; Altamirano, Francisco; Hopkins, Philip M.; Pessah, Isaac N.; Molinski, Tadeusz F.; López, Jose R.; Beam, Kurt G.; Allen, Paul D.

    2012-01-01

    Malignant hyperthermia (MH) susceptibility is a dominantly inherited disorder in which volatile anesthetics trigger aberrant Ca2+ release in skeletal muscle and a potentially fatal rise in perioperative body temperature. Mutations causing MH susceptibility have been identified in two proteins critical for excitation–contraction (EC) coupling, the type 1 ryanodine receptor (RyR1) and CaV1.1, the principal subunit of the L-type Ca2+ channel. All of the mutations that have been characterized previously augment EC coupling and/or increase the rate of L-type Ca2+ entry. The CaV1.1 mutation R174W associated with MH susceptibility occurs at the innermost basic residue of the IS4 voltage-sensing helix, a residue conserved among all CaV channels [Carpenter D, et al. (2009) BMC Med Genet 10:104–115.]. To define the functional consequences of this mutation, we expressed it in dysgenic (CaV1.1 null) myotubes. Unlike previously described MH-linked mutations in CaV1.1, R174W ablated the L-type current and had no effect on EC coupling. Nonetheless, R174W increased sensitivity of Ca2+ release to caffeine (used for MH diagnostic in vitro testing) and to volatile anesthetics. Moreover, in CaV1.1 R174W-expressing myotubes, resting myoplasmic Ca2+ levels were elevated, and sarcoplasmic reticulum (SR) stores were partially depleted, compared with myotubes expressing wild-type CaV1.1. Our results indicate that CaV1.1 functions not only to activate RyR1 during EC coupling, but also to suppress resting RyR1-mediated Ca2+ leak from the SR, and that perturbation of CaV1.1 negative regulation of RyR1 leak identifies a unique mechanism that can sensitize muscle cells to MH triggers. PMID:22547813

  18. Malignant hyperthermia susceptibility arising from altered resting coupling between the skeletal muscle L-type Ca2+ channel and the type 1 ryanodine receptor.

    PubMed

    Eltit, Jose Miguel; Bannister, Roger A; Moua, Ong; Altamirano, Francisco; Hopkins, Philip M; Pessah, Isaac N; Molinski, Tadeusz F; López, Jose R; Beam, Kurt G; Allen, Paul D

    2012-05-15

    Malignant hyperthermia (MH) susceptibility is a dominantly inherited disorder in which volatile anesthetics trigger aberrant Ca(2+) release in skeletal muscle and a potentially fatal rise in perioperative body temperature. Mutations causing MH susceptibility have been identified in two proteins critical for excitation-contraction (EC) coupling, the type 1 ryanodine receptor (RyR1) and Ca(V)1.1, the principal subunit of the L-type Ca(2+) channel. All of the mutations that have been characterized previously augment EC coupling and/or increase the rate of L-type Ca(2+) entry. The Ca(V)1.1 mutation R174W associated with MH susceptibility occurs at the innermost basic residue of the IS4 voltage-sensing helix, a residue conserved among all Ca(V) channels [Carpenter D, et al. (2009) BMC Med Genet 10:104-115.]. To define the functional consequences of this mutation, we expressed it in dysgenic (Ca(V)1.1 null) myotubes. Unlike previously described MH-linked mutations in Ca(V)1.1, R174W ablated the L-type current and had no effect on EC coupling. Nonetheless, R174W increased sensitivity of Ca(2+) release to caffeine (used for MH diagnostic in vitro testing) and to volatile anesthetics. Moreover, in Ca(V)1.1 R174W-expressing myotubes, resting myoplasmic Ca(2+) levels were elevated, and sarcoplasmic reticulum (SR) stores were partially depleted, compared with myotubes expressing wild-type Ca(V)1.1. Our results indicate that Ca(V)1.1 functions not only to activate RyR1 during EC coupling, but also to suppress resting RyR1-mediated Ca(2+) leak from the SR, and that perturbation of Ca(V)1.1 negative regulation of RyR1 leak identifies a unique mechanism that can sensitize muscle cells to MH triggers. PMID:22547813

  19. Using graph theory to describe and model chromosome aberrations.

    PubMed

    Sachs, Rainer K; Arsuaga, Javier; Vázquez, Mariel; Hlatky, Lynn; Hahnfeldt, Philip

    2002-11-01

    A comprehensive description of chromosome aberrations is introduced that is suitable for all cytogenetic protocols (e.g. solid staining, banding, FISH, mFISH, SKY, bar coding) and for mathematical analyses. "Aberration multigraphs" systematically characterize and interrelate three basic aberration elements: (1) the initial configuration of chromosome breaks; (2) the exchange process, whose cycle structure helps to describe aberration complexity; and (3) the final configuration of rearranged chromosomes, which determines the observed pattern but may contain cryptic misrejoinings in addition. New aberration classification methods and a far-reaching generalization of mPAINT descriptors, applicable to any protocol, emerge. The difficult problem of trying to infer actual exchange processes from cytogenetically observed final patterns is analyzed using computer algorithms, adaptations of known theorems on cubic graphs, and some new graph-theoretical constructs. Results include the following: (1) For a painting protocol, unambiguously inferring the occurrence of a high-order cycle requires a corresponding number of different colors; (2) cycle structure can be computed by a simple trick directly from mPAINT descriptors if the initial configuration has no more than one break per homologue pair; and (3) higher-order cycles are more frequent than the obligate cycle structure specifies. Aberration multigraphs are a powerful new way to describe, classify and quantitatively analyze radiation-induced chromosome aberrations. They pinpoint (but do not eliminate) the problem that, with present cytogenetic techniques, one observed pattern corresponds to many possible initial configurations and exchange processes. PMID:12385633

  20. PIK3CA genotype and a PIK3CA mutation-related gene signature and response to everolimus and letrozole in estrogen receptor positive breast cancer.

    PubMed

    Loi, Sherene; Michiels, Stefan; Baselga, Jose; Bartlett, John M S; Singhal, Sandeep K; Sabine, Vicky S; Sims, Andrew H; Sahmoud, Tarek; Dixon, J Michael; Piccart, Martine J; Sotiriou, Christos

    2013-01-01

    The phosphatidylinositol 3' kinase (PI3K) pathway is commonly activated in breast cancer and aberrations such as PI3K mutations are common. Recent exciting clinical trial results in advanced estrogen receptor-positive (ER) breast cancer support mTOR activation is a major means of estrogen-independent tumor growth. Hence the means to identify a responsive breast cancer population that would most benefit from these compounds in the adjuvant or earlier stage setting is of high interest. Here we study PIK3CA genotype as well as a previously reported PI3K/mTOR-pathway gene signature (PIK3CA-GS) and their ability to estimate the level of PI3K pathway activation in two clinical trials of newly diagnosed ER-positive breast cancer patients- a total of 81 patients- one of which was randomized between letrozole and placebo vs letrozole and everolimus. The main objectives were to correlate the baseline PIK3CA genotype and GS with the relative change from baseline to day 15 in Ki67 (which has been shown to be prognostic in breast cancer) and phosphorylated S6 (S240) immunohistochemistry (a substrate of mTOR). In the randomized dataset, the PIK3CA-GS could identify those patients with the largest relative decreases in Ki67 to letrozole/everolimus (R = -0.43, p = 0.008) compared with letrozole/placebo (R = 0.07, p = 0.58; interaction test p = 0.02). In a second dataset of pre-surgical everolimus alone, the PIK3CA-GS was not significantly correlated with relative change in Ki67 (R = -0.11, p = 0.37) but with relative change in phosphorlyated S6 (S240) (R = -0.46, p = 0.028). PIK3CA genotype was not significantly associated with any endpoint in either datasets. Our results suggest that the PIK3CA-GS has potential to identify those ER-positive BCs who may benefit from the addition of everolimus to letrozole. Further evaluation of the PIK3CA-GS as a predictive biomarker is warranted as it may facilitate better selection of responsive patient populations for mTOR inhibition in

  1. The Mechanisms of Aberrant Protein Aggregation

    NASA Astrophysics Data System (ADS)

    Cohen, Samuel; Vendruscolo, Michele; Dobson, Chris; Knowles, Tuomas

    2012-02-01

    We discuss the development of a kinetic theory for understanding the aberrant loss of solubility of proteins. The failure to maintain protein solubility results often in the assembly of organized linear structures, commonly known as amyloid fibrils, the formation of which is associated with over 50 clinical disorders including Alzheimer's and Parkinson's diseases. A true microscopic understanding of the mechanisms that drive these aggregation processes has proved difficult to achieve. To address this challenge, we apply the methodologies of chemical kinetics to the biomolecular self-assembly pathways related to protein aggregation. We discuss the relevant master equation and analytical approaches to studying it. In particular, we derive the underlying rate laws in closed-form using a self-consistent solution scheme; the solutions that we obtain reveal scaling behaviors that are very generally present in systems of growing linear aggregates, and, moreover, provide a general route through which to relate experimental measurements to mechanistic information. We conclude by outlining a study of the aggregation of the Alzheimer's amyloid-beta peptide. The study identifies the dominant microscopic mechanism of aggregation and reveals previously unidentified therapeutic strategies.

  2. Epigenetic aberrations and therapeutic implications in gliomas.

    PubMed

    Natsume, Atsushi; Kondo, Yutaka; Ito, Motokazu; Motomura, Kazuya; Wakabayashi, Toshihiko; Yoshida, Jun

    2010-06-01

    Almost all cancer cells have multiple epigenetic abnormalities, which combine with genetic changes to affect many cellular processes, including cell proliferation and invasion, by silencing tumor-suppressor genes. In this review, we focus on the epigenetic mechanisms of DNA hypomethylation and CpG island hypermethylation in gliomas. Aberrant hypermethylation in promoter CpG islands has been recognized as a key mechanism involved in the silencing of cancer-associated genes and occurs at genes with diverse functions related to tumorigenesis and tumor progression. Such promoter hypermethylation can modulate the sensitivity of glioblastomas to drugs and radiotherapy. As an example, the methylation of the O6-methylguanine DNA methyltransferase (MGMT) promoter is a specific predictive biomarker of tumor responsiveness to chemotherapy with alkylating agents. Further, we reviewed reports on pyrosequencing - a simple technique for the accurate and quantitative analysis of DNA methylation. We believe that the quantification of MGMT methylation by pyrosequencing might enable the selection of patients who are most likely to benefit from chemotherapy. Finally, we also evaluated the potential of de novo NY-ESO-1, the most immunogenic cancer/testis antigen (CTA) discovered thus far, as an immunotherapy target. The use of potent epigenetics-based therapy for cancer cells might restore the abnormally regulated epigenomes to a more normal state through epigenetic reprogramming. Thus, epigenetic therapy may be a promising and potent treatment for human neoplasia.

  3. Aneurysm of an Aberrant Right Subclavian Artery

    PubMed Central

    Gordini, Veliano; Collice, Massimo; Fedriga, Emanuele; Moreo, Antonella; Morello, Marco; Porrini, Annamaria; Donatelli, Francesco

    1991-01-01

    A 53-year-old man was admitted for treatment of an aberrant right subclavian artery aneurysm that had been diagnosed 5 years earlier and had recently begun to enlarge. The aneurysm, which involved the right subclavian artery from its origin, measured 47 mm in diameter and about 10 cm in length. Because of the lesion's size and friability, a 2-stage operation was performed. In the 1st stage, the right subclavian and right vertebral arteries were revascularized with double bypass grafts via a right cervical approach. In the 2nd stage, the patient was repositioned and a left thoracotomy incision was made. With the aid of left-heart bypass, the aorta was cross-clamped proximal and distal to the lesion, and the aneurysmal orifice was closed with a Dacron patch. The patient was discharged from the hospital on the 17th postoperative day and remains asymptomatic 24 months later. We recommend the 2-stage technique for similar cases because it prevents limb ischemia and reduces the risk of hemorrhagic and embolic complications. (Texas Heart Institute Journal 1991;18:76-9) Images PMID:15227513

  4. Axial tolerance in the position of aberration compensators placed in a converging beam.

    PubMed

    Morales, A; Servin, M; Malacara, D

    1996-04-01

    To perform a null test of aspherical surfaces we used a computer-generated hologram or a lens or a mirror compensator to compensate the aspherical aberration. When compensating in a convergent light beam the axial position of this hologram or compensator is critical. A holographic compensator to be used in the convergent beam of light was designed and constructed. We have established some relations to determine the tolerance in the axial positioning of these compensators.

  5. [Right aortic arch, Kommerell's diverticulum and aberrant left subclavian artery].

    PubMed

    Simón-Yarza, I; Viteri-Ramírez, G; Etxano, J; Roblero, P Slon; Ferreira, M; Alemañ, G Bastarrika

    2011-01-01

    The right aberrant subclavian artery or "arteria lusoria" is the most common anatomical variant of the embryonic development of the aorta and its branches, with a presence in 0.5-2% of the population. Less frequently, a right aortic arch with aberrant left subclavian artery may be present. These anatomical variations should be included in the differential diagnosis of superior mediastinal widening seen on chest radiographs. In this report, we present a right aortic arch with left aberrant subclavian artery dilated at its origin (Kommerell's diverticulum) as a cause of superior mediastinal widening detected incidentally on a chest radiograph.

  6. Electrostatic mirror objective with eliminated spherical and axial chromatic aberrations.

    PubMed

    Bimurzaev, Seitkerim B; Serikbaeva, Gulnur S; Yakushev, Evgeniy M

    2003-01-01

    Computational formulae for the coefficients of the third-order spherical aberration and the second-order axial chromatic aberration are presented for an axially symmetric electrostatic electron mirror. A technique for eliminating the high-order derivatives of the potential axial distribution in mirror systems from the integrands is described. Conditions for elimination of spherical and axial chromatic aberrations, either separately or simultaneously, are found for a three-electrode axially symmetric mirror composed of coaxial cylinders of the same diameter. A principal scheme of the transmission electron microscope, where an electrostatic electron mirror serves as its objective, is presented. PMID:14599097

  7. High order aberration and straylight evaluation after cataract surgery with implantation of an aspheric, aberration correcting monofocal intraocular lens

    PubMed Central

    Kretz, Florian T A; Tandogan, Tamer; Khoramnia, Ramin; Auffarth, Gerd U

    2015-01-01

    AIM To evaluate the quality of vision in respect to high order aberrations and straylight perception after implantation of an aspheric, aberration correcting, monofocal intraocular lens (IOL). METHODS Twenty-one patients (34 eyes) aged 50 to 83y underwent cataract surgery with implantation of an aspheric, aberration correcting IOL (Tecnis ZCB00, Abbott Medical Optics). Three months after surgery they were examined for uncorrected (UDVA) and corrected distance visual acuity (CDVA), contrast sensitivity (CS) under photopic and mesopic conditions with and without glare source, ocular high order aberrations (HOA, Zywave II) and retinal straylight (C-Quant). RESULTS Postoperatively, patients achieved a postoperative CDVA of 0.0 logMAR or better in 97.1% of eyes. Mean values of high order abberations were +0.02±0.27 (primary coma components) and -0.04±0.16 (spherical aberration term). Straylight values of the C-Quant were 1.35±0.44 log which is within normal range of age matched phakic patients. The CS measurements under mesopic and photopic conditions in combination with and without glare did not show any statistical significance in the patient group observed (P≥0.28). CONCLUSION The implantation of an aspherical aberration correcting monofocal IOL after cataract surgery resulted in very low residual higher order aberration (HOA) and normal straylight. PMID:26309872

  8. VLBI measurement of the secular aberration drift

    NASA Astrophysics Data System (ADS)

    Titov, O.; Lambert, S. B.; Gontier, A.-M.

    2011-05-01

    Aims: While analyzing decades of very long baseline interferometry (VLBI) data, we detected the secular aberration drift of the extragalatic radio source proper motions caused by the rotation of the Solar System barycenter around the Galactic center. Our results agree with the predicted estimate to be 4-6 micro arcseconds per year (μas/yr) towards α = 266° and δ = -29°. In addition, we tried to detect the quadrupole systematics of the velocity field. Methods: The analysis method consisted of three steps. First, we analyzed geodetic and astrometric VLBI data to produce radio source coordinate time series. Second, we fitted proper motions of 555 sources with long observational histories over the period 1990-2010 to their respective coordinate time series. Finally, we fitted vector spherical harmonic components of degrees 1 and 2 to the proper motion field. Results: Within the error bars, the magnitude and the direction of the dipole component agree with predictions. The dipole vector has an amplitude of 6.4 ± 1.5 μas/yr and is directed towards equatorial coordinates α = 263° and δ = -20°. The quadrupole component has not been detected. The primordial gravitational wave density, integrated over a range of frequencies less than 10-9 Hz, has a limit of 0.0042h-2 where h is the normalized Hubble constant is H0/(100 km s-1). We dedicate this work to the memory of Anne-Marie Gontier, our colleague and personal friend, and a widely recognized specialist of VLBI. She passed away shortly after this paper was submitted.Proper motion data is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/529/A91

  9. Focusing Diffraction Grating Element with Aberration Control

    NASA Technical Reports Server (NTRS)

    Iazikov, Dmitri; Mossberg, Thomas W.; Greiner, Christoph M.

    2010-01-01

    Diffraction gratings are optical components with regular patterns of grooves, which angularly disperse incoming light by wavelength in a single plane, called dispersion plane. Traditional gratings on flat substrates do not perform wavefront transformation in the plane perpendicular to the dispersion plane. The device proposed here exhibits regular diffraction grating behavior, dispersing light. In addition, it performs wavelength transformation (focusing or defocusing) of diffracted light in a direction perpendicular to the dispersion plane (called sagittal plane). The device is composed of a diffraction grating with the grooves in the form of equidistant arcs. It may be formed by defining a single arc or an arc approximation, then translating it along a certain direction by a distance equal to a multiple of a fixed distance ("grating period") to obtain other groove positions. Such groove layout is nearly impossible to obtain using traditional ruling methods, such as mechanical ruling or holographic scribing, but is trivial for lithographically scribed gratings. Lithographic scribing is the newly developed method first commercially introduced by LightSmyth Technologies, which produces gratings with the highest performance and arbitrary groove shape/spacing for advanced aberration control. Unlike other types of focusing gratings, the grating is formed on a flat substrate. In a plane perpendicular to the substrate and parallel to the translation direction, the period of the grating and, therefore, the projection of its k-vector onto the plane is the same for any location on the grating surface. In that plane, no waveform transformation by the grating k-vector occurs, except of simple redirection.

  10. Electron Optics for Biologists: Physical Origins of Spherical Aberrations

    ERIC Educational Resources Information Center

    Geissler, Peter; Zadunaisky, Jose

    1974-01-01

    Reports on the physical origins of spherical aberrations in axially symmetric electrostatic lenses to convey the essentials of electon optics to those who must think critically about the resolution of the electron microscope. (GS)

  11. Objective shearing digital holography for removing aberration from optical system.

    PubMed

    Pan, Weiqing; Tian, Kehan; Zhang, Chuhang

    2015-09-01

    We propose a new digital holography based on the lateral shearing interference concept to remove the total aberrations from the reference wave, illumination wave, and the optical elements. It uses three mutually shifted image holograms of the object that are divided from each other to obtain phase differences. The phase aberration can be removed and the original sample phase can be reconstructed by the phase differences. Then, the influence of the stage moving imprecision on the reconstruction quality is analyzed. Optical experiments verified that the proposed method can totally remove the phase aberrations. As a result, the proposed method could be used for ultra-precise optical measurement through eliminating optical phase aberration to increase the measurement accuracy. PMID:26368865

  12. Optical aberration coefficients: FORTRAN subroutines for symmetrical systems.

    PubMed

    Andersen, T B

    1981-09-15

    FORTRAN computer subroutines for the automatic computation of the optical aberration functions S, T, V, W, and K to the 15th order for rotationally symmetric systems are presented. The routines may be conveniently extended toward higher orders.

  13. Anisoplanatism in adaptive optics systems due to pupil aberrations

    SciTech Connect

    Bauman, B

    2005-08-01

    Adaptive optics systems typically include an optical relay that simultaneously images the science field to be corrected and also a set of pupil planes conjugate to the deformable mirror of the system. Often, in the optical spaces where DM's are placed, the pupils are aberrated, leading to a displacement and/or distortion of the pupil that varies according to field position--producing a type of anisoplanatism, i.e., a degradation of the AO correction with field angle. The pupil aberration phenomenon is described and expressed in terms of Seidel aberrations. An expression for anisoplanatism as a function of pupil distortion is derived, an example of an off-axis parabola is given, and a convenient method for controlling pupil-aberration-generated anisoplanatism is proposed.

  14. Using aberrant behaviors as reinforcers for autistic children.

    PubMed Central

    Charlop, M H; Kurtz, P F; Casey, F G

    1990-01-01

    In a series of experiments, we assessed the efficacy of using autistic children's aberrant behaviors as reinforcers to increase their correct task responding. In Experiment 1, reinforcer conditions of stereotypy, food, and varied (food or stereotypy) were compared. In Experiment 2, the conditions were delayed echolalia, food, and varied (food or delayed echolalia), and in Experiment 3, perseverative behavior was compared with stereotypy and food as potential reinforcers. A multielement design was used for all comparisons, and side-effect measures were recorded during and after teaching sessions as well as at home. Results indicated that, in general, task performance was highest when brief opportunities to engage in aberrant behaviors were provided as reinforcers. Edibles were associated with the lowest performance. Furthermore, no negative side effects (e.g., an increase in aberrant behaviors) occurred. The results are discussed in terms of suggesting a more pragmatic treatment approach by addressing the contingent use of autistic children's aberrant behaviors as reinforcers. PMID:2373653

  15. Using aberrant behaviors as reinforcers for autistic children.

    PubMed

    Charlop, M H; Kurtz, P F; Casey, F G

    1990-01-01

    In a series of experiments, we assessed the efficacy of using autistic children's aberrant behaviors as reinforcers to increase their correct task responding. In Experiment 1, reinforcer conditions of stereotypy, food, and varied (food or stereotypy) were compared. In Experiment 2, the conditions were delayed echolalia, food, and varied (food or delayed echolalia), and in Experiment 3, perseverative behavior was compared with stereotypy and food as potential reinforcers. A multielement design was used for all comparisons, and side-effect measures were recorded during and after teaching sessions as well as at home. Results indicated that, in general, task performance was highest when brief opportunities to engage in aberrant behaviors were provided as reinforcers. Edibles were associated with the lowest performance. Furthermore, no negative side effects (e.g., an increase in aberrant behaviors) occurred. The results are discussed in terms of suggesting a more pragmatic treatment approach by addressing the contingent use of autistic children's aberrant behaviors as reinforcers.

  16. Aberrant lacrimal gland and pleomorphic adenoma within the muscle cone.

    PubMed

    Mueller, E C; Borit, A

    1979-04-01

    Aberrant lacrimal gland tissue within the muscle cone formed a pleomorphic adenoma (benign mixed tumor). Histopathologically, the lesion was identical to similar neoplasms originating from lacrimal and other salivary glands as well as from other serous glands of the body.

  17. Pattern of Chromosomal Aberrations in Patients from North East Iran

    PubMed Central

    Ghazaey, Saeedeh; Mirzaei, Farzaneh; Ahadian, Mitra; Keifi, Fatemeh; Semiramis, Tootian; Abbaszadegan, Mohammad Reza

    2013-01-01

    Objective: Chromosomal aberrations are common causes of multiple anomaly syndromes. Recurrent chromosomal aberrations have been identified by conventional cytogenetic methods used widely as one of the most important clinical diagnostic techniques. Materials and Methods: In this retrospective study, the incidences of chromosomal aberrations were evaluated in a six year period from 2005 to 2011 in Pardis Clinical and Genetics Laboratory on patients referred to from Mashhad and other cities in Khorasan province. Karyotyping was performed on 3728 patients suspected of having chromosomal abnormalities. Results: The frequencies of the different types of chromosomal abnormalities were determined, and the relative frequencies were calculated in each group. Among these patients, 83.3% had normal karyotypes with no aberrations. The overall incidences of chromosomal abnormalities were 16.7% including sex and autosomal chromosomal anomalies. Of those, 75.1 % showed autosomal chromosomal aberrations. Down syndrome (DS) was the most prevalent autosomal aberration in the patients (77.1%). Pericentric inversion of chromosome 9 was seen in 5% of patients. This inversion was prevalent in patients with recurrent spontaneous abortion (RSA). Sex chromosomal aberrations were observed in 24.9% of abnormal patients of which 61% had Turner’s syndrome and 33.5% had Klinefelter’s syndrome. Conclusion: According to the current study, the pattern of chromosomal aberrations in North East of Iran demonstrates the importance of cytogenetic evaluation in patients who show clinical abnormalities. These findings provide a reason for preparing a local cytogenetic data bank to enhance genetic counseling of families who require this service. PMID:24027668

  18. Aberration in proper motions for stars in our Galaxy

    NASA Astrophysics Data System (ADS)

    Liu, J.-C.; Xie, Y.; Zhu, Z.

    2013-08-01

    Accelerations of both the Solar system barycentre (SSB) and stars in the Milky Way cause a systematic observational effect on the stellar proper motions, which was first studied in the early 1990s and developed by Kovalevsky (aberration in proper motions). This paper intends to extend that work and aims to estimate the magnitude and significance of the aberration in proper motions of stars, especially in the region near the Galactic Centre. We adopt two models for the Galactic rotation curve to evaluate the aberrational effect on the Galactic plane. Based on the theoretical developments, we show that the effect of aberration in proper motions depends on the Galactocentric distance of stars; it is dominated by the acceleration of stars in the central region of the Galaxy. Within 200 pc from the Galactic Centre, the systematic proper motion can reach an amplitude larger than 1000 μas yr- 1 by applying a flat rotation curve. With a more realistic rotation curve which is linearly rising in the core region of the Galaxy, the aberrational proper motions are limited up to about 150 μas yr- 1. Then we investigate the applicability of the theoretical expressions concerning the aberrational proper motions, especially for those stars with short period orbits. If the orbital period of stars is only a fraction of the light time from the star to the SSB, the expression proposed by Kovalevsky is not appropriate. With a more suitable formulation, we found that the aberration has no effect on the determination of the stellar orbits on the celestial sphere. The aberrational effect under consideration is small but not negligible with high-accurate astrometry in the future, particularly in constructing the Gaia celestial reference system realized by Galactic stars.

  19. Assessment of nicotine-induced DNA damage in a genotoxicological test battery.

    PubMed

    Ginzkey, Christian; Friehs, Gudrun; Koehler, Christian; Hackenberg, Stephan; Hagen, Rudolf; Kleinsasser, Norbert H

    2013-02-18

    The role of the tobacco-alkaloid nicotine in tumour biology is widely discussed in the literature. Due to a strong capacity to induce angiogenesis, a pro-mutagenic potential in non-tumour and cancer cells, and a pro- and anti-apoptotic influence, nicotine seems to promote the growth of established tumours. However, results indicating DNA damage and genetic instability associated with nicotine have been contradictory thus far. A variety of markers and endpoints of genotoxicity are required to characterize the genotoxic potential of nicotine. Induction of DNA single- and double-strand breaks, the formation of micronuclei, and the induction of sister chromatid exchange and chromosome aberrations represent possible genotoxicological endpoints at different cellular levels. Human lymphocytes were exposed to nicotine concentrations between 1μM and 1mM for 24h in vitro. The comet assay, the cytokinesis-block micronucleus test, the chromosome aberration (CA) test, and the sister chromatid exchange (SCE) test were then applied. Viability and apoptosis were measured by flow cytometry in combination with the annexin V-propidium iodide staining test. In this test setting, no enhanced DNA migration was measured by the comet assay. An increase in the micronucleus frequency was detected at a concentration of 100μM nicotine without affecting the frequency of apoptotic cells. A distinct genotoxic effect was determined by the CA test and the SCE test, with a significant increase in CA and SCE at a concentration of 1μM. In the annexin V test, nicotine did not influence the proportion of apoptotic or necrotic cells. The current data indicating the induction of CA by nicotine underscore the necessity of ongoing investigations on the potential of nicotine to initiate mutagenesis and tumour promotion. Taking into account the physiological nicotine plasma levels in smokers or in nicotine-replacement therapy, particularly the long-term use of nicotine should be critically discussed. PMID

  20. Dimensions of driving anger and their relationships with aberrant driving.

    PubMed

    Zhang, Tingru; Chan, Alan H S; Zhang, Wei

    2015-08-01

    The purpose of this study was to investigate the relationship between driving anger and aberrant driving behaviours. An internet-based questionnaire survey was administered to a sample of Chinese drivers, with driving anger measured by a 14-item short Driving Anger Scale (DAS) and the aberrant driving behaviours measured by a 23-item Driver Behaviour Questionnaire (DBQ). The results of Confirmatory Factor Analysis demonstrated that the three-factor model (hostile gesture, arrival-blocking and safety-blocking) of the DAS fitted the driving anger data well. The Exploratory Factor Analysis on DBQ data differentiated four types of aberrant driving, viz. emotional violation, error, deliberate violation and maintaining progress violation. For the anger-aberration relation, it was found that only "arrival-blocking" anger was a significant positive predictor for all four types of aberrant driving behaviours. The "safety-blocking" anger revealed a negative impact on deliberate violations, a finding different from previously established positive anger-aberration relation. These results suggest that drivers with different patterns of driving anger would show different behavioural tendencies and as a result intervention strategies may be differentially effective for drivers of different profiles.

  1. Induction of chromosome aberrations in human cells by charged particles

    NASA Technical Reports Server (NTRS)

    Wu, H.; Durante, M.; George, K.; Yang, T. C.

    1997-01-01

    Chromosome aberrations induced by high-energy charged particles in normal human lymphocytes and human fibroblasts have been investigated. The charged particles included 250 MeV/nucleon protons, 290 MeV/nucleon carbon ions and 1 GeV/nucleon iron ions. The energies of the charged particles were higher than in most of the studies reported in the literature. Lymphocytes were stimulated to grow immediately after irradiation, while fibroblasts were incubated at 37 degrees C for 24 h for repair. Chromosomes were collected at the first mitosis after irradiation and chromosome aberrations were scored using the fluorescence in situ hybridization (FISH) technique with a whole-chromosome 4 probe. Chromosome aberrations were classified as reciprocal exchanges, incomplete exchanges, deletions and complex exchanges. The relative biological effectiveness (RBE) for each type of aberration was calculated by dividing a dose of 4 Gy by the dose of the charged particles producing the same effect as 4 Gy of gamma rays. Results of this study showed that complex aberrations have the highest RBE for radiation of high linear energy transfer (LET) for human lymphocytes, but for fibroblasts, the greatest effect was for incomplete exchanges. For both lymphocytes and fibroblasts, iron ions induced a similar fraction of aberrant cells.

  2. RBE of Energetic Iron Ions for the Induction of Early and Late Chromosome Aberrations in Different Cell Types

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Yeshitla, Samrawit; Hada, Megumi; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2014-01-01

    Numerous published studies have reported the RBE values for chromosome chromosomes induced by charged particles of different LET. The RBE for chromosome aberrations in human lymphocytes exposed ex vivo showed a similar relationship as the quality factor for cancer induction. Consequently, increased chromosome aberrations in the astronauts' white blood cells post long-duration missions are used to determine the biological doses from exposures to space radiation. The RBE value is known to be very different for different types of cancer. Previously, we reported that the RBE for initial chromosome damages was high in human lymphocytes exposed to Fe ions. After multiple cell divisions post irradiation, the RBE was significantly smaller. To test the hypothesis that the RBE values for chromosome aberrations are different between early and late damages and also different between different cell types, we exposed human lymphocytes ex vivo, and human fibroblast cells and human mammary epithelial cells in vitro to 600 MeV/u Fe ions. Post irradiation, the cells were collected at first mitosis, or cultured for multiple generations for collections of remaining or late arising chromosome aberrations. The chromosome aberrations were quantified using fluorescent in situ hybridization (FISH) with whole chromosome specific probes. This study attempts to offer an explanation for the varying RBE values for different cancer types.

  3. Aberrant Salience Is Related to Reduced Reinforcement Learning Signals and Elevated Dopamine Synthesis Capacity in Healthy Adults.

    PubMed

    Boehme, Rebecca; Deserno, Lorenz; Gleich, Tobias; Katthagen, Teresa; Pankow, Anne; Behr, Joachim; Buchert, Ralph; Roiser, Jonathan P; Heinz, Andreas; Schlagenhauf, Florian

    2015-07-15

    The striatum is known to play a key role in reinforcement learning, specifically in the encoding of teaching signals such as reward prediction errors (RPEs). It has been proposed that aberrant salience attribution is associated with impaired coding of RPE and heightened dopamine turnover in the striatum, and might be linked to the development of psychotic symptoms. However, the relationship of aberrant salience attribution, RPE coding, and dopamine synthesis capacity has not been directly investigated. Here we assessed the association between a behavioral measure of aberrant salience attribution, the salience attribution test, to neural correlates of RPEs measured via functional magnetic resonance imaging while healthy participants (n = 58) performed an instrumental learning task. A subset of participants (n = 27) also underwent positron emission tomography with the radiotracer [(18)F]fluoro-l-DOPA to quantify striatal presynaptic dopamine synthesis capacity. Individual variability in aberrant salience measures related negatively to ventral striatal and prefrontal RPE signals and in an exploratory analysis was found to be positively associated with ventral striatal presynaptic dopamine levels. These data provide the first evidence for a specific link between the constructs of aberrant salience attribution, reduced RPE processing, and potentially increased presynaptic dopamine function. PMID:26180188

  4. Aberrant methylation patterns in cancer: a clinical view

    PubMed Central

    Paska, Alja Videtic; Hudler, Petra

    2015-01-01

    Epigenetic mechanisms, such as DNA methylation, DNA hydroxymethylation, post-translational modifications (PTMs) of histone proteins affecting nucleosome remodelling, and regulation by small and large non-coding RNAs (ncRNAs) work in concert with cis and trans acting elements to drive appropriate gene expression. Advances in detection methods and development of dedicated platforms and methylation arrays resulted in an explosion of information on aberrantly methylated sequences linking deviations in epigenetic landscape with the initiation and progression of complex diseases. Here, we consider how DNA methylation changes in malignancies, such as breast, pancreatic, colorectal, and gastric cancer could be exploited for the purpose of developing specific diagnostic tools. DNA methylation changes can be applicable as biomarkers for detection of malignant disease in easily accessible tissues. Methylation signatures are already proving to be an important marker for determination of drug sensitivity. Even more, promoter methylation patterns of some genes, such as MGMT, SHOX2, and SEPT9, have already been translated into commercial clinical assays aiding in patient assessment as adjunct diagnostic tools. In conclusion, the changes in DNA methylation patterns in tumour cells are slowly gaining entrance into routine diagnostic tests as promising biomarkers and as potential therapeutic targets. PMID:26110029

  5. Aberrant glycosylation of Igg heavy chain in multiple myeloma.

    PubMed

    Aurer, Igor; Lauc, Gordan; Dumić, Jerka; Rendić, Dubravko; Matisić, Danica; Milos, Marija; Heffer-Lauc, Marija; Flogel, Mirna; Labar, Boris

    2007-03-01

    Although the majority of eukaryotic proteins are glycosylated, there is a dearth of knowledge regarding protein sugar moieties and their changes in disease. Most multiple myeloma cases are characterized by production of monoclonal immunoglobulins (Ig). We studied galactosylation and sialylation of IgG heavy chains in 16 patients with IgG myeloma using lectin blotting and densitometry. In comparison to age and sex matched controls, galactosylation was reduced in multiple myeloma (median 317 vs. 362, range 153-410 vs. 309-447 relative units, p = 0.015, Student's t-test). Sialylation was stage dependent; samples from patients with stage IIA had lowest amounts of sialic acid, IIIA intermediate and IIIB highest (142.6 vs. 185.9 vs. 248.5 relative units, correlation coefficient r = 0.55). Both galactosylation and sialylation levels were independent of age, sex, treatment type, response to treatment, disease duration and IgG and b2 microglobulin concentration. These data indicate that multiple myeloma is characterized by aberrant immunoglobulin glycosylation. PMID:17598409

  6. Aberrant CpG Islands Hypermethylation Profiles in Malignant Gliomas

    PubMed Central

    Kim, Kwang Ryeol; Kim, Ealmaan

    2014-01-01

    Background The authors analyzed whether the promoter hypermethylation of cancer-related genes was involved in the tumorigenesis of malignant gliomas. Methods A total of 29 patients received surgery and histologically confirmed to have malignant gliomas from January 2000 to December 2006. The promoter methylation status of several genes, which were reported to be frequently methylated in malignant gliomas, was investigated using methylation-specific polymerase chain reaction. Results All cases of malignant gliomas represented the promoter hypermethylation in at least 2 or more genes tested. Of 29 tumors, 28 (96.55%) showed concurrent hypermethylation of 3 or more genes. Ras association domain family member 1, epithelial cadherin, O-6 methyl guanine DNA methyltransferase, thrombospondin 1, p14 and adenomatous polyposis coli were frequently methylated in high grade gliomas including glioblastomas, anaplastic astrocytomas, and anaplastic oligodendrogliomas. Conclusion Aberrant hypermethylation profile was closely related with malignant gliomas suggesting that epigenetic change may play a role in the development of malignant gliomas. Two or three target genes may provide useful clues to the development of the useful prognostic as well as diagnostic assays for malignant gliomas. PMID:24926469

  7. Aberrant glycosylation of Igg heavy chain in multiple myeloma.

    PubMed

    Aurer, Igor; Lauc, Gordan; Dumić, Jerka; Rendić, Dubravko; Matisić, Danica; Milos, Marija; Heffer-Lauc, Marija; Flogel, Mirna; Labar, Boris

    2007-03-01

    Although the majority of eukaryotic proteins are glycosylated, there is a dearth of knowledge regarding protein sugar moieties and their changes in disease. Most multiple myeloma cases are characterized by production of monoclonal immunoglobulins (Ig). We studied galactosylation and sialylation of IgG heavy chains in 16 patients with IgG myeloma using lectin blotting and densitometry. In comparison to age and sex matched controls, galactosylation was reduced in multiple myeloma (median 317 vs. 362, range 153-410 vs. 309-447 relative units, p = 0.015, Student's t-test). Sialylation was stage dependent; samples from patients with stage IIA had lowest amounts of sialic acid, IIIA intermediate and IIIB highest (142.6 vs. 185.9 vs. 248.5 relative units, correlation coefficient r = 0.55). Both galactosylation and sialylation levels were independent of age, sex, treatment type, response to treatment, disease duration and IgG and b2 microglobulin concentration. These data indicate that multiple myeloma is characterized by aberrant immunoglobulin glycosylation.

  8. Factor Validity and Reliability for the Aberrant Behavior Checklist-Community in a Japanese Population with Mental Retardation.

    ERIC Educational Resources Information Center

    Ono, Yoshiro

    1996-01-01

    Evaluation of the factor validity and reliability of the Aberrant Behavior Checklist (Japanese version) with 322 subjects (mean age 30) with moderate to profound mental retardation found most items loading on the same factors as in the original factor solution, high coefficient alphas across 5 subscales, high test-retest reliability, and…

  9. Genotoxicity assessment of cobalt chloride in Eisenia hortensis earthworms coelomocytes by comet assay and micronucleus test.

    PubMed

    Ciğerci, İbrahim Hakkı; Ali, Muhammad Muddassir; Kaygısız, Şöhret Yüksek; Liman, Recep

    2016-02-01

    Cobalt and its different compounds are extensively used worldwide and considered as possible environmental pollutant. Earthworms are useful model organism and its different species are used to monitor soil pollution. No study has been found to detect cobalt chloride (CoCl2) genotoxicity in earthworms. So, current study aimed to evaluate CoCl2 induced genotoxicity in Eisenia hortensis earthworms coelomocytes by alkaline comet assay (CA) and micronucleus (MN) test. The earthworms (n = 10 for each group) were exposed to different series of CoCl2 concentrations (100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, 600 ppm) to find LD50. The LD50 for CoCl2 was found at 226 ppm. Then, doses of LD50/2, LD50 and 2XLD50 for 48 h were used. CA and MN demonstrated the significant increase (P < 0.05) in DNA damage and chromosomal aberrations. Dose dependent relationship was found. Highest DNA damage and chromosomal aberrations were noticed at 2XLD50. The results concluded that CoCl2 induced DNA damage, cytokinesis failure and chromosomal aberrations in E. hortensis earthworms.

  10. Time course of changes in ocular wavefront aberration after administration of eye ointment

    PubMed Central

    Hiraoka, T; Yamamoto, T; Okamoto, F; Oshika, T

    2012-01-01

    Purpose To investigate the influence of an eye ointment on ocular aberration. Design Prospective, comparative study. Methods In 10 normal volunteers, ocular aberration was assessed before and 5, 30 min, 1, 2, 3, 6, and 12 h after administration of ofloxacin eye ointment. Ocular aberration was sequentially measured over a period of 10 s, and the root mean square (RMS) of the second-, third-, fourth-, and total higher-order aberrations (HOAs) were determined. From the sequential changes in total HOAs during 10 s, the fluctuation index (FI) and stability index (SI) were calculated. The obtained data were compared with those of another 17 normal volunteers who received timolol maleate gel-forming ophthalmic solution. Results No significant changes in second-order RMS were observed after administration of the ointment. HOAs such as third-, fourth-, and total higher-order RMS significantly changed during the study period (P<0.05, repeated-measures analysis of variance). The RMS of each HOA component significantly increased 5 min after administration compared with the baseline values (P<0.05, Dunnett test). FI also increased significantly 5 min after administration (P<0.05), but SI did not change significantly. When compared with the results of the gel-forming solution group, HOAs and FI showed significantly higher values at several time points during 6 h after application (P<0.05, Mann–Whitney U-test). Conclusions Administration of eye ointment significantly degrades optical quality of the eye by increasing and oscillating HOAs. These changes were more pronounced than those after instillation of gel-forming ophthalmic solution for at least several hours. PMID:22814810

  11. An improved system for exposure of cultured mammalian cells to gaseous compounds in the chromosomal aberration assay.

    PubMed

    Asakura, Masumi; Sasaki, Toshiaki; Sugiyama, Toshie; Arito, Heihachiro; Fukushima, Shoji; Matsushima, Taijiro

    2008-04-30

    A gas exposure system using rotating vessels was improved for exposure of cultured mammalian cells to gaseous compounds in the chromosomal aberration assay. This system was composed of 12 square culture vessels, a device for preparation of air containing test gas, and positive and negative control gases at target concentrations and for supplying these gases to the culture vessels, and a roller apparatus in an incubator. Chinese hamster lung cells (CHL/IU) were grown on one side of the inner surface of the square culture vessel in the MEM medium. Immediately prior to exposure, the medium was changed to the modified MEM. Air in the culture vessel was replaced with air containing test gas, positive or negative control gas. Then, the culture vessels were rotated at 1.0 rpm. The monolayered culture cells were exposed to test gas during about 3/4 rotation at upper positions and alternatively immersed into the culture medium during about 1/4 rotation at lower positions. This system allowed the chromosomal aberration assay simultaneously at least at three different concentrations of a test gas together with positive and negative control gases with and without metabolic activations, and duplicate culture at each exposure concentration. Seven gaseous compounds, 1,3-butadiene, chlorodifluoromethane, ethyl chloride, methyl bromide, methyl chloride, propyne, and vinyl chloride, none of which has been tested to date, were tested on CHL/IU for the chromosomal aberration assay using this gas exposure system. All the compounds except chlorodifluoromethane showed positive responses of the structural chromosomal aberrations, whereas polyploidy was not induced by any of these gases. This improved gas exposure system proved to be useful for detecting chromosomal aberrations of gaseous compounds.

  12. An improved system for exposure of cultured mammalian cells to gaseous compounds in the chromosomal aberration assay.

    PubMed

    Asakura, Masumi; Sasaki, Toshiaki; Sugiyama, Toshie; Arito, Heihachiro; Fukushima, Shoji; Matsushima, Taijiro

    2008-04-30

    A gas exposure system using rotating vessels was improved for exposure of cultured mammalian cells to gaseous compounds in the chromosomal aberration assay. This system was composed of 12 square culture vessels, a device for preparation of air containing test gas, and positive and negative control gases at target concentrations and for supplying these gases to the culture vessels, and a roller apparatus in an incubator. Chinese hamster lung cells (CHL/IU) were grown on one side of the inner surface of the square culture vessel in the MEM medium. Immediately prior to exposure, the medium was changed to the modified MEM. Air in the culture vessel was replaced with air containing test gas, positive or negative control gas. Then, the culture vessels were rotated at 1.0 rpm. The monolayered culture cells were exposed to test gas during about 3/4 rotation at upper positions and alternatively immersed into the culture medium during about 1/4 rotation at lower positions. This system allowed the chromosomal aberration assay simultaneously at least at three different concentrations of a test gas together with positive and negative control gases with and without metabolic activations, and duplicate culture at each exposure concentration. Seven gaseous compounds, 1,3-butadiene, chlorodifluoromethane, ethyl chloride, methyl bromide, methyl chloride, propyne, and vinyl chloride, none of which has been tested to date, were tested on CHL/IU for the chromosomal aberration assay using this gas exposure system. All the compounds except chlorodifluoromethane showed positive responses of the structural chromosomal aberrations, whereas polyploidy was not induced by any of these gases. This improved gas exposure system proved to be useful for detecting chromosomal aberrations of gaseous compounds. PMID:18342567

  13. 1990 report to the aerospace profession; Society of Experimental Test Pilots, Symposium, 34th, Beverly Hills, CA, Sept. 27-29, 1990, Proceedings

    SciTech Connect

    Not Available

    1990-01-01

    The present conference discusses the high-alpha X-29 aircraft, the F-15 STOL/Maneuvering Technology Demonstrator's thrust vectoring and reversing, F-14/F110 engine integration, V-22 flight testing, the USAF NASP program, the ARES light attack aircraft, F-117A flight testing, and YF-23A preliminary flight test results. Also discussed are development status reports for the JAS 39 Gripen fighter and the EH-101 helicopter, as well as development and flight test histories for the MiG 29 fighter prototype and the F5D Skylancer follow-on to the F4D Skyray.

  14. Transcranial phase aberration correction using beam simulations and MR-ARFI

    SciTech Connect

    Vyas, Urvi Kaye, Elena; Pauly, Kim Butts

    2014-03-15

    Purpose: Transcranial magnetic resonance-guided focused ultrasound surgery is a noninvasive technique for causing selective tissue necrosis. Variations in density, thickness, and shape of the skull cause aberrations in the location and shape of the focal zone. In this paper, the authors propose a hybrid simulation-MR-ARFI technique to achieve aberration correction for transcranial MR-guided focused ultrasound surgery. The technique uses ultrasound beam propagation simulations with MR Acoustic Radiation Force Imaging (MR-ARFI) to correct skull-caused phase aberrations. Methods: Skull-based numerical aberrations were obtained from a MR-guided focused ultrasound patient treatment and were added to all elements of the InSightec conformal bone focused ultrasound surgery transducer during transmission. In the first experiment, the 1024 aberrations derived from a human skull were condensed into 16 aberrations by averaging over the transducer area of 64 elements. In the second experiment, all 1024 aberrations were applied to the transducer. The aberrated MR-ARFI images were used in the hybrid simulation-MR-ARFI technique to find 16 estimated aberrations. These estimated aberrations were subtracted from the original aberrations to result in the corrected images. Each aberration experiment (16-aberration and 1024-aberration) was repeated three times. Results: The corrected MR-ARFI image was compared to the aberrated image and the ideal image (image with zero aberrations) for each experiment. The hybrid simulation-MR-ARFI technique resulted in an average increase in focal MR-ARFI phase of 44% for the 16-aberration case and 52% for the 1024-aberration case, and recovered 83% and 39% of the ideal MR-ARFI phase for the 16-aberrations and 1024-aberration case, respectively. Conclusions: Using one MR-ARFI image and noa priori information about the applied phase aberrations, the hybrid simulation-MR-ARFI technique improved the maximum MR-ARFI phase of the beam's focus.

  15. Persistence of Early Emerging Aberrant Behavior in Children with Developmental Disabilities

    ERIC Educational Resources Information Center

    Green, Vanessa A.; O'Reilly, Mark; Itchon, Jonathan; Sigafoos, Jeff

    2005-01-01

    This study examined the persistence of early emerging aberrant behavior in 13 preschool children with developmental disabilities. The severity of aberrant behavior was assessed every 6 months over a 3-year period. Teachers completed the assessments using the Aberrant Behavior Checklist [Aman, M. G., & Singh, N. N. (1986). "Aberrant Behavior…

  16. Tuning fifth-order aberrations in a Quadrupole-Octupole Corrector

    SciTech Connect

    Lupini, Andrew R; Pennycook, Stephen J

    2012-01-01

    The resolution of conventional electron microscopes is usually limited by spherical aberration. Microscopes equipped with aberration-correctors are then primarily limited by higher-order, chromatic, and misalignment aberrations. In particular the Nion third-order aberration correctors installed on machines with a low energy spread and possessing sophisticated alignment software were limited by the uncorrected fifth-order aberrations. Here we show how the Nion fifth-order aberration corrector can be used to adjust and reduce some of the fourth and fifth-order aberrations in a probe-corrected scanning transmission electron microscope.

  17. Aberrant Origin of Vertebral Artery and its Clinical Implications

    PubMed Central

    Yuan, Shi-Min

    2016-01-01

    Aberrant origin of vertebral artery is rare. The anatomical features and clinical significance of this lesion remain to be clarified. A comprehensive collection of the pertinent literature resulted in a cohort of 1286 cases involving 955 patients and 331 cadavers. There were more left than right and more unilateral than bilateral aberrant vertebral arteries. Patients with aberrant origin of vertebral artery were often asymptomatic and in only 5.5% of the patients their symptoms were probably related to the aberrant origin of vertebral artery. The acquired cardiovascular lesions were present in 9.5% of the patients, 20.9% of which were vertebral artery-associated lesions. Eight (0.8%) patients had a vertebral artery dissection. Logistic regression analysis showed significant regressions between bovine trunk and left vertebral artery (P=0.000), between the dual origins of vertebral artery and cerebral infarct/thrombus (P=0.041), between associated alternative congenital vascular variants and cervical/aortic dissection/atherosclerosis (P=0.008). Multiple logistic regression demonstrated that side of the aberrant origin of vertebral artery (left vertebral artery) (P=0.014), arch branch pattern (direct arch origin) (P=0.019), presence of the common trunk (P=0.019), associated acquired vascular disorder (P=0.034) and the patients who warranted management (P=0.000) were significant risk predictors for neurological sequelea. The patients with neurological symptoms and those for neck and chest operations/ interventions should be carefully screened for the possibility of an aberrant origin of vertebral artery. The results from the cadaver metrology study are very helpful in the design of the aortic stent. The arch branch pattern has to be taken into consideration before any maneuver in the local region so as to avoid unexpected events in relation to aberrant vertebral artery. PMID:27074275

  18. Chromosomal aberrations in peripheral lymphocytes of train engine drivers.

    PubMed

    Nordenson, I; Mild, K H; Järventaus, H; Hirvonen, A; Sandström, M; Wilén, J; Blix, N; Norppa, H

    2001-07-01

    Studies of Swedish railway employees have indicated that railroad engine drivers have an increased cancer morbidity and incidence of chronic lymphatic leukemia. The drivers are exposed to relatively high magnetic fields (MF), ranging from a few to over a hundred microT. Although the possible genotoxic potential of MF is unclear, some earlier studies have indicated that occupational exposure to MF may increase chromosome aberrations in blood lymphocytes. Since an increased level of chromosomal aberrations has been suggested to predict elevated cancer risk, we performed a cytogenetic analysis on cultured (48 h) peripheral lymphocytes of Swedish train engine drivers. A pilot study of 18 engine drivers indicated a significant difference in the frequency of cells with chromosomal aberrations (gaps included or excluded) in comparison with seven concurrent referents (train dispatchers) and a control group of 16 office workers. The engine drivers had about four times higher frequency of cells with chromosome-type aberrations (excluding gaps) than the office workers (P < 0.01) and the dispatchers (P < 0.05). Seventy-eight percent of the engine drivers showed at least one cell per 100 with chromosome-type aberrations compared with 29% among the dispatchers and 31% among the office workers. In a follow-up study, another 30 engine drivers showed an increase (P < 0.05) in the frequency of cells with chromosome-type aberrations (gaps excluded) as compared with 30 referent policemen. Sixty percent of the engine drivers had one or more cells (per 100 cells) with chromosome-type aberrations compared with 30% among the policemen. In conclusion, the results of the two studies support the hypothesis that exposure to MF at mean intensities of 2-15 microT can induce chromosomal damage.

  19. Experimentally observe the effect of spherical aberration on diffractive intraocular lens using adaptive optics

    NASA Astrophysics Data System (ADS)

    Guo, Huanqing; DeLestrange, Elie

    2015-03-01

    We first investigated the similarity in optical quality of a batch of diffractive intraocular lenses (DIOLs), providing experimental evidence for one DIOL as representative of a batch. Using adaptive optics, we then evaluated one DIOL under different levels of Zernike spherical aberration (SA) by applying both a point spread function test and a psychophysical visual acuity test. We found that for small aperture size SA has the effect of shifting the through-focus curve of DIOL. Also, for a relatively large aperture size, it has different effects on the distant and near foci.

  20. [Chromosome aberration frequency in workers in tire and industrial ruber manufacture].

    PubMed

    Aleksandrov, S E

    1982-01-01

    A cytogenetic study was carried out with the view to analyse blood and embryonic tissue cultures taken from female workers of various shops of tyre and rubber industry. In workers of preparation shops the level of chromosome aberrations in blood was equal to 2.63%, while in embryonic tissues the value was 6.33%. The number of aberrations on blood and embryonic tissue exhibited by workers of chemical shops was equal to 1.34 and 2.79%, respectively. No specific differences were observed in the sub-group of women having been in frequent contacts with gasoline or curing gases, as compared with the group on the whole. Curing accelerators which are ingredients of toxic dust in preparation shops of tyre and rubber industry cause a sharp increase in the number of chromosome aberrations both in blood and in the embryonic tissues of women. Data on induced abortions may be used for evaluation of the influence of chemicals on the developing fetus and can serve as a test models of mutagenic and embryotoxic effect. They also may be regarded as a part of the general system of the evaluation of mutagenic effects of chemicals in humans. PMID:7199008

  1. Protection of Chloroplast Membranes by VIPP1 Rescues Aberrant Seedling Development in Arabidopsis nyc1 Mutant

    PubMed Central

    Zhang, Lingang; Kusaba, Makoto; Tanaka, Ayumi; Sakamoto, Wataru

    2016-01-01

    Chlorophylls (Chl) in photosynthetic apparatuses, along with other macromolecules in chloroplasts, are known to undergo degradation during leaf senescence. Several enzymes involved in Chl degradation, by which detoxification of Chl is safely implemented, have been identified. Chl degradation also occurs during embryogenesis and seedling development. Some genes encoding Chl degradation enzymes such as Chl b reductase (CBR) function during these developmental stages. Arabidopsis mutants lacking CBR (NYC1 and NOL) have been reported to exhibit reduced seed storability, compromised germination, and cotyledon development. In this study, we examined aberrant cotyledon development and found that NYC1 is solely responsible for this phenotype. We inferred that oxidative damage of chloroplast membranes caused the aberrant cotyledon. To test the inference, we attempted to trans-complement nyc1 mutant with overexpressing VIPP1 protein that is unrelated to Chl degradation but which supports chloroplast membrane integrity. VIPP1 expression actually complemented the aberrant cotyledon of nyc1, whereas stay-green phenotype during leaf senescence remained. The swollen chloroplasts observed in unfixed cotyledons of nyc1, which are characteristics of chloroplasts receiving envelope membrane damage, were recovered by overexpressing VIPP1. These results suggest that chloroplast membranes are a target for oxidative damage caused by the impairment in Chl degradation. Trans-complementation of nyc1 with VIPP1 also suggests that VIPP1 is useful for protecting chloroplasts against oxidative stress. PMID:27200011

  2. Controls on Sr/Ca in Scleractinian Corals: The Effects of Ca-ATPase and Ca channels on Skeletal Chemistry

    NASA Astrophysics Data System (ADS)

    Allison, N.; Cohen, I.; Finch, A. A.; Erez, J.

    2010-12-01

    Coral skeletal Sr/Ca is a commonly used palaeothermometer and has been used to estimate past sea surface temperatures. However the processes controlling Sr incorporation in coral aragonite are poorly understood. The Sr/Ca chemistry of the massive Porites spp. corals typically used for palaeoenvironmental reconstruction is dominated by short-term (weekly-monthly) oscillations of ~10% which do not reflect seawater temperature. This heterogeneity may reflect variations in the composition of the fluid used for calcification. Coral skeletons precipitate from an extracellular calcifying fluid enclosed in a semi-isolated space between the skeleton and the calicoblastic epithelium (the tissue layer at the base of the coral organism). Seawater diffuses directly to the calcification site and the calcification fluid has a composition derived from that of seawater but modified by other transport processes. In zooxanthellate corals, Ca2+ is transported transcellularly to the calcification site by both calcium channels and by the carrier protein Ca-ATPase. Sr2+ has a similar ionic radius to Ca2+, but it is not clear if Sr2+ can substitute for Ca2+ in these transport mechanisms. Variations in the relative contributions of each of the transport mechanisms to the calcification fluid and the efficiencies with which each process transports Sr2+ and Ca2+ could explain the Sr/Ca heterogeneity observed in coral skeletons. To test the impact of transcellular Ca transport processes on skeletal Sr/Ca and Mg/Ca we cultured Pocillopora damicornis corals in the presence of inhibitors of Ca-ATPase (ruthenium red) and Ca channels (verapamil). The photosynthesis, respiration and calcification rates of the colonies were monitored throughout the experiment. The skeleton subsequently deposited was identified (by 42Ca spike) and analysed by secondary ion mass spectrometry. The Sr/Ca and Mg/Ca of the aragonite deposited in the presence of either of the inhibitors was not significantly different from

  3. The effect of dopamine agonists on adaptive and aberrant salience in Parkinson's disease.

    PubMed

    Nagy, Helga; Levy-Gigi, Einat; Somlai, Zsuzsanna; Takáts, Annamária; Bereczki, Dániel; Kéri, Szabolcs

    2012-03-01

    Clinical evidence suggests that after initiation of dopaminergic medications some patients with Parkinson's disease (PD) develop psychotic symptoms, such as hallucinations and delusions. Here, we tested the hypothesis that the neurocognitive basis of this phenomenon can be defined as the formation of arbitrary and illusory associations between conditioned stimuli and reward signals, called aberrant salience. Young, never-medicated PD patients and matched controls were assessed on a speeded reaction time task in which the probe stimulus was preceded by conditioned stimuli that could signal monetary reward by color or shape. The patients and controls were re-evaluated after 12 weeks during which the patients received a dopamine agonist (pramipexole or ropinirole). Results indicated that dopamine agonists increased both adaptive and aberrant salience in PD patients, that is, formation of real and illusory associations between conditioned stimuli and reward, respectively. This effect was present when associations were assessed by means of faster responding after conditioned stimuli signaling reward (implicit salience) and overt rating of stimulus-reward links (explicit salience). However, unusual feelings and experiences, which are subclinical manifestations of psychotic-like symptoms, were specifically related to irrelevant and illusory stimulus-reward associations (aberrant salience) in PD patients receiving dopamine agonists. The learning of relevant and real stimulus-reward associations (adaptive salience) was not related to unusual experiences. These results suggest that dopamine agonists may increase psychotic-like experiences in young patients with PD, possibly by facilitating dopaminergic transmission in the ventral striatum, which results in aberrant associations between conditioned stimuli and reward. PMID:22089321

  4. Fibroblast growth factor family aberrations in cancers: clinical and molecular characteristics.

    PubMed

    Parish, A; Schwaederle, M; Daniels, G; Piccioni, D; Fanta, P; Schwab, R; Shimabukuro, K; Parker, B A; Helsten, T; Kurzrock, R

    2015-01-01

    Fibroblast growth factor ligands and receptors (FGF and FGFR) play critical roles in tumorigenesis, and several drugs have been developed to target them. We report the biologic correlates of FGF/FGFR abnormalities in diverse malignancies. The medical records of patients with cancers that underwent targeted next generation sequencing (182 or 236 cancer-related genes) were reviewed. The following FGF/FGFR genes were tested: FGF3, 4, 6, 7, 10, 12, 14, 19, 23 and FGFR1, 2, 3, and 4. Of 391 patients, 56 (14.3%) had aberrant FGF (N = 38, all amplifications) and/or FGFR (N = 22 including 5 mutations and one FGFR3-TACC3 fusion). FGF/FGFR aberrations were most frequent in breast cancers (26/81, 32.1%, p = 0.0003). In multivariate analysis, FGF/FGFR abnormalities were independently associated with CCND1/2, RICTOR, ZNF703, RPTOR, AKT2, and CDK8 alterations (all P < 0.02), as well as with an increased median number of alterations (P < 0.0001). FGF3, FGF4, FGF19 and CCND1 were co-amplified in 22 of 391 patients (5.6%, P < 0.0001), most likely because they co-localize on the same chromosomal region (11q13). There was no significant difference in time to metastasis or overall survival when comparing patients harboring FGF/FGFR alterations versus those not. Overall, FGF/FGFR was one of the most frequently aberrant pathways in our population comprising patients with diverse malignancies. These aberrations frequently co-exist with anomalies in a variety of other genes, suggesting that tailored combination therapy may be necessary in these patients. PMID:25950492

  5. Fibroblast growth factor family aberrations in cancers: clinical and molecular characteristics

    PubMed Central

    Parish, A; Schwaederle, M; Daniels, G; Piccioni, D; Fanta, P; Schwab, R; Shimabukuro, K; Parker, BA; Helsten, T; Kurzrock, R

    2015-01-01

    Fibroblast growth factor ligands and receptors (FGF and FGFR) play critical roles in tumorigenesis, and several drugs have been developed to target them. We report the biologic correlates of FGF/FGFR abnormalities in diverse malignancies. The medical records of patients with cancers that underwent targeted next generation sequencing (182 or 236 cancer-related genes) were reviewed. The following FGF/FGFR genes were tested: FGF3, 4, 6, 7, 10, 12, 14, 19, 23 and FGFR1, 2, 3, and 4. Of 391 patients, 56 (14.3%) had aberrant FGF (N = 38, all amplifications) and/or FGFR (N = 22 including 5 mutations and one FGFR3-TACC3 fusion). FGF/FGFR aberrations were most frequent in breast cancers (26/81, 32.1%, p = 0.0003). In multivariate analysis, FGF/FGFR abnormalities were independently associated with CCND1/2, RICTOR, ZNF703, RPTOR, AKT2, and CDK8 alterations (all P < 0.02), as well as with an increased median number of alterations (P < 0.0001). FGF3, FGF4, FGF19 and CCND1 were co-amplified in 22 of 391 patients (5.6%, P < 0.0001), most likely because they co-localize on the same chromosomal region (11q13). There was no significant difference in time to metastasis or overall survival when comparing patients harboring FGF/FGFR alterations versus those not. Overall, FGF/FGFR was one of the most frequently aberrant pathways in our population comprising patients with diverse malignancies. These aberrations frequently co-exist with anomalies in a variety of other genes, suggesting that tailored combination therapy may be necessary in these patients. PMID:25950492

  6. Fibroblast growth factor family aberrations in cancers: clinical and molecular characteristics.

    PubMed

    Parish, A; Schwaederle, M; Daniels, G; Piccioni, D; Fanta, P; Schwab, R; Shimabukuro, K; Parker, B A; Helsten, T; Kurzrock, R

    2015-01-01

    Fibroblast growth factor ligands and receptors (FGF and FGFR) play critical roles in tumorigenesis, and several drugs have been developed to target them. We report the biologic correlates of FGF/FGFR abnormalities in diverse malignancies. The medical records of patients with cancers that underwent targeted next generation sequencing (182 or 236 cancer-related genes) were reviewed. The following FGF/FGFR genes were tested: FGF3, 4, 6, 7, 10, 12, 14, 19, 23 and FGFR1, 2, 3, and 4. Of 391 patients, 56 (14.3%) had aberrant FGF (N = 38, all amplifications) and/or FGFR (N = 22 including 5 mutations and one FGFR3-TACC3 fusion). FGF/FGFR aberrations were most frequent in breast cancers (26/81, 32.1%, p = 0.0003). In multivariate analysis, FGF/FGFR abnormalities were independently associated with CCND1/2, RICTOR, ZNF703, RPTOR, AKT2, and CDK8 alterations (all P < 0.02), as well as with an increased median number of alterations (P < 0.0001). FGF3, FGF4, FGF19 and CCND1 were co-amplified in 22 of 391 patients (5.6%, P < 0.0001), most likely because they co-localize on the same chromosomal region (11q13). There was no significant difference in time to metastasis or overall survival when comparing patients harboring FGF/FGFR alterations versus those not. Overall, FGF/FGFR was one of the most frequently aberrant pathways in our population comprising patients with diverse malignancies. These aberrations frequently co-exist with anomalies in a variety of other genes, suggesting that tailored combination therapy may be necessary in these patients.

  7. Measurement of non-common path static aberrations in an interferometric camera by phase diversity

    NASA Astrophysics Data System (ADS)

    Yan, Zhaojun; Herbst, Thomas M.; Yang, Pengqian; Bizenberger, Peter; Zhang, Xianyu; Conrad, Albert R.; Bertram, Thomas; Kuerster, Martin; Rix, Hans-Walter; Li, Xinyang; Rao, Changhui

    2012-10-01

    LINC-NIRVANA (LN) is a near-infrared image-plane beam combiner with advanced, multi-conjugated adaptive optics for the Large Binocular Telescope. Non-common path aberrations (NCPAs) between the near-infrared science camera and the wave-front sensor (WFS) are unseen by the WFS and therefore are not corrected in closed loop. This would prevent LN from achieving its ultimate performance. We use a modified phase diversity technique to measure the internal optical static aberrations and hence the NCPAs. Phase diversity is a methodology for estimating wave-front aberrations by solving an unconstrained optimization problem from multiple images whose pupil phases differ from one another by a known amount. We conduct computer simulations of the reconstruction of aberrations of an optical system with the phase diversity method. In the reconstruction, we fit the wave-front to Zernike polynomials to reduce the number of variables. The limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm is very well suited to phase diversity (PD) due to its good performance in solving large scale optimization problems. The main constraint for the implementation of PD for LN is that we cannot add extra components to the internal interferometric camera imaging system to obtain infocus and defocus images. In this paper, we introduce a new method, namely shifting the focal plane source, not the detector, to overcome this constraint. Some experiments were done to test and verify this method and the results are presented and discussed. The study shows that the method is very flexible and the paper gives practical guidelines for the application of phase diversity methods to characterize adaptive optics systems.

  8. Brahmarasayana protects against Ethyl methanesulfonate or Methyl methanesulfonate induced chromosomal aberrations in mouse bone marrow cells

    PubMed Central

    2012-01-01

    Background Ayurveda, the traditional Indian system of medicine has given great emphasis to the promotion of health. Rasayana is one of the eight branches of Ayurveda which refers to rejuvenant therapy. It has been reported that rasayanas have immuno-modulatory, antioxidant and antitumor functions, however, the genotoxic potential and modulation of DNA repair of many rasayanas have not been evaluated. Methods The present study assessed the role of Brahmarasayana (BR) on Ethyl methanesulfonate (EMS)-and Methyl methanesulfonate (MMS)-induced genotoxicity and DNA repair in in vivo mouse test system. The mice were orally fed with BR (5 g or 8 mg / day) for two months and 24 h later EMS or MMS was given intraperitoneally. The genotoxicity was analyzed by chromosomal aberrations, sperm count, and sperm abnormalities. Results The results have revealed that BR did not induce significant chromosomal aberrations when compared to that of the control animals (p >0.05). On the other hand, the frequencies of chromosomal aberrations induced by EMS (240 mg / kg body weight) or MMS (125 mg / kg body weight) were significantly higher (p<0.05) to that of the control group. The treatment of BR for 60 days and single dose of EMS or MMS on day 61, resulted in significant (p <0.05) reduction in the frequency of chromosomal aberrations in comparison to EMS or MMS treatment alone, indicating a protective effect of BR. Constitutive base excision repair capacity was also increased in BR treated animals. Conclusion The effect of BR, as it relates to antioxidant activity was not evident in liver tissue however rasayana treatment was observed to increase constitutive DNA base excision repair and reduce clastogenicity. Whilst, the molecular mechanisms of such repair need further exploration, this is the first report to demonstrate these effects and provides further evidence for the role of brahmarasayana in the possible improvement of quality of life. PMID:22853637

  9. Chromosome aberrations as biomarkers of radiation exposure: Modelling basic mechanisms

    NASA Astrophysics Data System (ADS)

    Ballarini, F.; Ottolenghi, A.

    The space radiation environment is a mixed field consisting of different particles having different energies, including high charge and energy (HZE) ions. Conventional measurements of absorbed doses may not be sufficient to completely characterise the radiation field and perform reliable estimates of health risks. Biological dosimetry, based on the observation of specific radiation-induced endpoints (typically chromosome aberrations), can be a helpful approach in case of monitored exposure to space radiation or other mixed fields, as well as in case of accidental exposure. Furthermore, various ratios of aberrations (e.g. dicentric chromosomes to centric rings and complex exchanges to simple exchanges) have been suggested as possible fingerprints of radiation quality, although all of them have been subjected to some criticisms. In this context a mechanistic model and a Monte Carlo code for the simulation of chromosome aberration induction were developed. The model, able to provide dose-responses for different aberrations (e.g. dicentrics, rings, fragments, translocations, insertions and other complex exchanges), was further developed to assess the dependence of various ratios of aberrations on radiation quality. The predictions of the model were compared with available data, whose experimental conditions were faithfully reproduced. Particular attention was devoted to the scoring criteria adopted in different laboratories and to possible biases introduced by interphase death and mitotic delay. This latter aspect was investigated by taking into account both metaphase data and data obtained with Premature Chromosome Condensation (PCC).

  10. Risk estimation based on chromosomal aberrations induced by radiation

    NASA Technical Reports Server (NTRS)

    Durante, M.; Bonassi, S.; George, K.; Cucinotta, F. A.

    2001-01-01

    The presence of a causal association between the frequency of chromosomal aberrations in peripheral blood lymphocytes and the risk of cancer has been substantiated recently by epidemiological studies. Cytogenetic analyses of crew members of the Mir Space Station have shown that a significant increase in the frequency of chromosomal aberrations can be detected after flight, and that such an increase is likely to be attributed to the radiation exposure. The risk of cancer can be estimated directly from the yields of chromosomal aberrations, taking into account some aspects of individual susceptibility and other factors unrelated to radiation. However, the use of an appropriate technique for the collection and analysis of chromosomes and the choice of the structural aberrations to be measured are crucial in providing sound results. Based on the fraction of aberrant lymphocytes detected before and after flight, the relative risk after a long-term Mir mission is estimated to be about 1.2-1.3. The new technique of mFISH can provide useful insights into the quantification of risk on an individual basis.

  11. Chromosome aberrations as biomarkers of radiation exposure: modelling basic mechanisms.

    PubMed

    Ballarini, F; Ottolenghi, A

    2003-01-01

    The space radiation environment is a mixed field consisting of different particles having different energies, including high charge and energy (HZE) ions. Conventional measurements of absorbed doses may not be sufficient to completely characterise the radiation field and perform reliable estimates of health risks. Biological dosimetry, based on the observation of specific radiation-induced endpoints (typically chromosome aberrations), can be a helpful approach in case of monitored exposure to space radiation or other mixed fields, as well as in case of accidental exposure. Furthermore, various ratios of aberrations (e.g. dicentric chromosomes to centric rings and complex exchanges to simple exchanges) have been suggested as possible fingerprints of radiation quality, although all of them have been subjected to some criticisms. In this context a mechanistic model and a Monte Carlo code for the simulation of chromosome aberration induction were developed. The model, able to provide dose-responses for different aberrations (e.g. dicentrics, rings, fragments, translocations, insertions and other complex exchanges), was further developed to assess the dependence of various ratios of aberrations on radiation quality. The predictions of the model were compared with available data, whose experimental conditions were faithfully reproduced. Particular attention was devoted to the scoring criteria adopted in different laboratories and to possible biases introduced by interphase death and mitotic delay. This latter aspect was investigated by taking into account both metaphase data and data obtained with Premature Chromosome Condensation (PCC). PMID:12971411

  12. Metaphase chromosome aberrations as markers of radiation exposure and dose

    SciTech Connect

    Brooks, A.L.; Khan, M.A.; Jostes, R.F.; Cross, F.T.

    1992-10-01

    Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes ``paints`` to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with {sup 144}Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to {sup 60}Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness.

  13. Metaphase chromosome aberrations as markers of radiation exposure and dose

    SciTech Connect

    Brooks, A.L.; Khan, M.A.; Jostes, R.F.; Cross, F.T.

    1992-10-01

    Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes paints'' to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with [sup 144]Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to [sup 60]Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness.

  14. Towards aberration correction of transcranial ultrasound using acoustic droplet vaporization.

    PubMed

    Haworth, Kevin J; Fowlkes, J Brian; Carson, Paul L; Kripfgans, Oliver D

    2008-03-01

    We report on the first experiments demonstrating the transcranial acoustic formation of stable gas bubbles that can be used for transcranial ultrasound aberration correction. It is demonstrated that the gas bubbles can be formed transcranially by phase-transitioning single, superheated, micron-size, liquid dodecafluoropentane droplets with ultrasound, a process known as acoustic droplet vaporization (ADV). ADV was performed at 550 kHz, where the skull is less attenuating and aberrating, allowing for higher-amplitudes to be reached at the focus. Additionally, it is demonstrated that time-reversal focusing at 1 MHz can be used to correct for transcranial aberrations with a single gas bubble acting as a point beacon. Aberration correction was performed using a synthetic aperture approach and verified by the realignment of the scattered waveforms. Under the conditions described below, time-reversal aberration correction using gas bubbles resulted in a gain of 1.9 +/- 0.3 in an introduced focusing factor. This is a small fraction of the gain anticipated from complete transmit-receive of a fully-populated two-dimensional array with sub-wavelength elements. (E-mail: khaworth@umich.edu).

  15. Minimum change in spherical aberration that can be perceived

    PubMed Central

    Manzanera, Silvestre; Artal, Pablo

    2016-01-01

    It is important to know the visual sensitivity to optical blur from both a basic science perspective and a practical point of view. Of particular interest is the sensitivity to blur induced by spherical aberration because it is being used to increase depth of focus as a component of a presbyopic solution. Using a flicker detection-based procedure implemented on an adaptive optics visual simulator, we measured the spherical aberration thresholds that produce just-noticeable differences in perceived image quality. The thresholds were measured for positive and negative values of spherical aberration, for best focus and + 0.5 D and + 1.0 D of defocus. At best focus, the SA thresholds were 0.20 ± 0.01 µm and −0.17 ± 0.03 µm for positive and negative spherical aberration respectively (referred to a 6-mm pupil). These experimental values may be useful in setting spherical aberration permissible levels in different ophthalmic techniques. PMID:27699113

  16. Chromosome aberrations and sister chromatid exchanges in cultured human lymphocytes treated with sodium metabisulfite, a food preservative.

    PubMed

    Rencüzogullari, E; Ila, H B; Kayraldiz, A; Topaktaş, M

    2001-02-20

    The aim of this study was to investigate the ability of sodium metabisulfite (SMB) which is used as an antimicrobial substance in food, to induce chromosome aberrations (CA) and sister chromatid exchanges (SCE) in human lymphocytes. SMB-induced CAs and SCEs at all concentrations (75, 150 and 300 microg/ml) and treatment periods (24 and 48h) dose-dependently. However, SMB decreased the replication index (RI) and the mitotic index (MI) at the concentrations of 150 and 300 microg/ml for 24 and 48h treatment periods. This decrease was dose-dependent as well.

  17. Influence of DNA repair gene polymorphisms of hOGG1, XRCC1, XRCC3, ERCC2 and the folate metabolism gene MTHFR on chromosomal aberration frequencies.

    PubMed

    Skjelbred, Camilla Furu; Svendsen, Marit; Haugan, Vera; Eek, Anette Kildal; Clausen, Kjell Oskar; Svendsen, Martin Veel; Hansteen, Inger-Lise

    2006-12-01

    We have studied the effect of genetic polymorphisms in the DNA repair genes hOGG1, XRCC1, XRCC3, ERCC2 and the MTHFR gene in the folate metabolism on the frequencies of cells with chromosomal aberrations (CA), chromosome-type aberrations (CSA), chromatid-type aberrations (CTA), chromatid breaks (CTB) and chromatid gaps (CTG) scored in peripheral blood lymphocytes from 651 Norwegian subjects of Caucasian descendant. DNA was extracted from fixed cell suspensions. The log-linear Poisson regression model was used for the combined data which included age, smoking, occupational exposure and genotype for 449 subjects. Our results suggest that individuals carrying the hOGG1 326Cys or the XRCC1 399Gln allele have an increased risk of chromosomal damage, while individuals carrying the XRCC1 194Trp or the ERCC2 751Gln allele have a reduced risk regardless of smoking habits and age. Individuals carrying the XRCC1 280His allele had an increased risk of CSA which was only apparent in non-smokers. This was independent of age. A protective effect of the XRCC3 241Met allele was only found in the older age group in non-smokers for CA, CSA and CTA, and in smokers for CSA. In the youngest age group, the opposite effect was found, with an increased risk for CA, CTA and CTG in smokers. Carrying the MTHFR 222Val allele gave an increased risk for chromosome and chromatid-type aberrations for both non-smokers and smokers, especially for individuals in the older age group, and with variable results in the youngest age group. The variables included in the different regression models accounted, however, for only 4-10% of the variation. The frequency ratio for CTG was significantly higher than for CTA and CTB for only 7 of the 43 comparisons performed. Some of the gap frequencies diverge from the trend in the CA, CSA, CTA and CTB results.

  18. Expressing freedom and taking liberties: the paradoxes of aberrant science.

    PubMed

    Little, M

    2006-06-01

    Complete freedom does not exist, despite people's preparedness to die for it. Scientific freedom is much defended and yet much misunderstood. Scientists have limits imposed on their freedom by the disciplines and discourse communities in which they place themselves. Freedom within these socially constructed constraints needs to be distinguished from taking liberties with the rules and practices that make up these constraints, and validate the activities of special groups within society. Scientists (and the public) perceive taking liberties with science's rules and practices as aberrant science, and they often react punitively. Aberrant science can be broadly examined under four headings: wicked science, naughty science, dysfunctional science, and ideologically unacceptable science. When we examine examples of perceived aberrant science, we find that these categories of "misconduct" are connected and often confused. Scientific freedom needs to be redefined with due regard to current understandings of scientists as human beings facing powerful social pressures to deliver results of a particular kind.

  19. Spherical aberration of aspheric contact lenses on eye.

    PubMed

    Hammer, R M; Holden, B A

    1994-08-01

    It is important to assess aspheric rigid contact lenses not only for fit, but also for optical performance. Using ray tracing techniques, on-eye total longitudinal aberration induced by aspheric contact lenses and the variation of the tangential focus with ray height were determined. Both the contact lens and tear lens were taken into account. The front and back surface profiles of the contact lens and the corneal profile were modeled as conic sections. On-eye aberration was found to become strongly more positive as the p-value of the contact lens front surface increased. It became more negative as the back surface p-value increased, but the tendency was weaker. These calculations indicate that selection of a contact lens back surface p-value according to fitting considerations without choosing a front surface p-value to minimize aberrations could, in some circumstances, lead to a reduction in visual performance.

  20. Conformal dome aberration correction by designing the inner surface

    NASA Astrophysics Data System (ADS)

    Zhang, Wang; Chen, Shouqian; Fan, Zhigang

    2016-12-01

    The ray transmission models of optical domes were established, and the characteristics of the rays while passing through a hemispherical dome and a conformal dome were comparatively analysed. Acquiring the minimum deviated angles from the inner surface of the conformal dome was then determined to be the designing goal for reducing the dynamic aberrations. Based on this, the inner surface of the conformal dome was optimized and thus, the dynamic aberrations were reduced. Finally, a completely cooled conformal optical system was designed. The results show that the optical system have produced good imaging quality within all the fields of regard, which further illustrates that designing the inner surface of a conformal dome is an effective method for aberration correction.

  1. Ischemic stroke injury is mediated by aberrant Cdk5.

    PubMed

    Meyer, Douglas A; Torres-Altoro, Melissa I; Tan, Zhenjun; Tozzi, Alessandro; Di Filippo, Massimiliano; DiNapoli, Vincent; Plattner, Florian; Kansy, Janice W; Benkovic, Stanley A; Huber, Jason D; Miller, Diane B; Greengard, Paul; Calabresi, Paolo; Rosen, Charles L; Bibb, James A

    2014-06-11

    Ischemic stroke is one of the leading causes of morbidity and mortality. Treatment options are limited and only a minority of patients receive acute interventions. Understanding the mechanisms that mediate neuronal injury and death may identify targets for neuroprotective treatments. Here we show that the aberrant activity of the protein kinase Cdk5 is a principal cause of neuronal death in rodents during stroke. Ischemia induced either by embolic middle cerebral artery occlusion (MCAO) in vivo or by oxygen and glucose deprivation in brain slices caused calpain-dependent conversion of the Cdk5-activating cofactor p35 to p25. Inhibition of aberrant Cdk5 during ischemia protected dopamine neurotransmission, maintained field potentials, and blocked excitotoxicity. Furthermore, pharmacological inhibition or conditional knock-out (CKO) of Cdk5 prevented neuronal death in response to ischemia. Moreover, Cdk5 CKO dramatically reduced infarctions following MCAO. Thus, targeting aberrant Cdk5 activity may serve as an effective treatment for stroke.

  2. Increased frequency of chromosomal aberrations in railroad car painters.

    PubMed

    Piña-Calva, A; Madrigal-Bujaidar, E; Fuentes, M V; Neria, P; Pérez-Lucio, C; Vélez-Zamora, N M

    1991-01-01

    The purpose of this study was to determine if exposure to paints and solvents contributes to chromosomal alterations in occupationally exposed individuals. A total of 25 male railroad and underground railroad car painters were studied. This group had a mean age of 32.7 y and a mean exposure time of 5.2 y. The results were compared with those obtained for 25 healthy (unexposed) males. The scoring of structural chromosome aberrations clearly revealed an increase in the number of all types of aberrations considered in the population of painters. This suggests that exposure to a combination of chemicals may increase genotoxicity in industrial workers. PMID:1772257

  3. Aberration-Free Imaging for Light and Electrons

    SciTech Connect

    Fluegel, B.; Mascarenhas, A.

    2008-01-01

    The equations for refraction of either the extraordinary wave of light or the wavefunction of an electron at a planar boundary between two misoriented uniaxially anisotropic materials are shown via raytracing to yield a transverse displacement of the object point. The displacement is independent of ray incidence angle and is thus free from spherical aberration, yielding a perfect virtual image which can have applications in birefringent optics. The general conditions for this aberration-free imaging are found to be identical to those required for amphoteric total refraction.

  4. Measurement of eye aberrations in a speckle field

    SciTech Connect

    Larichev, A V; Ivanov, P V; Iroshnikov, N G; Shmalgauzen, V I

    2001-12-31

    The influence of speckles on the performance of a Shark-Hartmann wavefront sensor is investigated in the eye aberration studies. The dependence of the phase distortion measurement error on the characteristic speckle size is determined experimentally. Scanning of the reference source was used to suppress the speckle structure of the laser beam scattered by the retina. The technique developed by us made it possible to study the time dependence of the human eye aberrations with a resolution of 30 ms. (laser applications and other topics in quantum electronics)

  5. Dysphagia Lusoria Caused by an Aberrant Right Subclavian Artery

    PubMed Central

    Carrizo, Gonzalo J.; Marjani, Massoud A.

    2004-01-01

    A 36-year-old, otherwise-healthy woman with a 6-year history of progressive dysphagia underwent an esophagogram that revealed an oblique extrinsic defect with an inferior-to-superior (left-to-right) course consistent with an aberrant right subclavian artery. An aortogram confirmed the diagnosis of aberrant right subclavian artery. She underwent surgical repair, tolerated the procedure well, and was discharged home, symptom free, on postoperative day 3. We found that the right supraclavicular approach provides good exposure and avoids the morbidity of the classically described approach via a median sternotomy or thoracotomy. PMID:15212130

  6. Measurement of wavefront aberrations of diffractive imaging elements

    NASA Astrophysics Data System (ADS)

    Zajac, Marek; Dubik, Boguslawa

    1998-01-01

    Diffractive optics is more and more widely used nowadays. One of its most important applications is diffractive imaging element (DIE). The DIE can be a lens (Holo-lens, diffractive lens, hybrid lens) or a part of complex imaging system (e.g. an aberration corrector). Apart of such problems occurring when dealing with DIE as its design, manufacture or copying the problem of its control is important. By this we mean the measurement of wavefront generated by DIE, i.e. the evaluation of wavefront aberrations. To this aim we propose two different experimental methods: one of them employs diffraction interferometer, the other one holographic shearing interferometer.

  7. Aberration Theory - A Spectrum Of Design Techniques For The Perplexed

    NASA Astrophysics Data System (ADS)

    Shafer, David

    1986-10-01

    The early medieval scholar Maimonides wrote a famous book called "Guide for the Perplexed", which explained various thorny philosophical and religious questions for the benefit of the puzzled novice. I wish I had had such a person to guide me when I first started a career in lens design. There the novice is often struck by how much of an "art" this endeavor is. The best bet, for a beginner with no experience, should be to turn to optical aberration theory - which, in principle, should explain much of what goes into designing an optical system. Unfortunately, this subject is usually presented in the form of proofs and derivations, with little time spent on the practical implications of aberration theory. Furthermore, a new generation of lens designers, who grew up with the computer, often consider aberration theory as an unnecessary relic from the past. My career, by contrast, is based on the conviction that using the results of aberration theory is the only intelligent way to design optical systems. Computers are an invaluable aide, but we must, ultimately, bite the bullet and think. Along these lines, I have given several papers over the last few years which deal directly with the philosophy of lens design; the kind of guides for the perplexed that I wished I had had from the start. These papers include: "Lens design on a desert island - A simple method of optical design", "A modular method of optical design", "Optical design with air lenses", "Optical design with 'phantom' aspherics", "Optical design methods: your head as a personal computer", "Aberration theory and the meaning of life", and a paper at Innsbruck - "Some interesting correspondences in aberration theory". In all cases, the emphasis is on using your head to think, and the computer to help you out with the numerical work and the "fine-tuning" of a design. To hope that the computer will do the thinking for you is folly. Solutions gained by this route rarely equal the results of an experienced and

  8. Suppression of aberrant transient receptor potential cation channel, subfamily V, member 6 expression in hyperproliferative colonic crypts by dietary calcium.

    PubMed

    Peleg, Sara; Sellin, Joseph H; Wang, Yu; Freeman, Michael R; Umar, Shahid

    2010-09-01

    Dietary calcium is believed to reduce colon cancer risk, but the mechanism by which this occurs is poorly understood. Employing the Citrobacter rodentium-induced transmissible murine colonic hyperplasia (TMCH) model, we previously showed that a high-calcium diet (hCa) significantly abrogated hyperplasia in the distal colons of NIH-Swiss mice. Here, we explored the mechanism of dietary protection by hCa by analyzing the expression of genes involved in the regulation of Ca uptake/flux in the intestinal epithelium, including the Ca-sensing receptor, vitamin D receptor, Ca binding protein, and transient receptor potential cation channels, subfamily V, members 5 and 6 (TRPV5/6). Interestingly, while TRPV6 expression increased significantly during TMCH, the expression of the other gene products was unchanged. This elevated TRPV6 expression was significantly abrogated by a hCa diet. Immunofluorescence revealed apical membrane localization of TRPV6 in the normal colon, whereas during TMCH we observed intense apical pole and cytoplasmic staining along the entire longitudinal crypt axis, including the expanded proliferating zone. The hCa diet reversed this effect. In humans, overexpression of TRPV6 was associated with early-stage colon cancer, and in colon carcinoma cells, inhibition of TRPV6 expression by small interfering RNA inhibited their proliferation and induced apoptosis. TRPV6 small interfering RNA also diminished the transcriptional activity of the calcium-dependent nuclear factors in activated T cells. Thus the aberrant overexpression of TRPV6 contributes to colonic crypt hyperplasia in mice and to colon cancer cell proliferation in humans. Therefore, it is likely that suppression of TRPV6 by a hCa diet is required for its protective effects in the colon.

  9. Cytogenetic investigation of chromosomal aberrations in cells treated with plantamajoside from Plantago asiatica.

    PubMed

    Koo, Yun-Chang; Jung, Sung-Hoon; Yang, Ji-Hee; Ryu, Yung-Sun; Kim, Eun-Jin; Lee, Kwang-Won

    2009-10-01

    Plantago asiatica is a member of the Plantaginaceae family, and is widely distributed in East Asia. In our previous work, a single active compound, plantamajoside was isolated and confirmed to have glycation inhibitory activity, and did not possess toxicity during a 90 day repeated oral toxicity test in rats. In the present study, a chromosomal aberration test was performed to investigate the genotoxicity of plantamajoside. From the results of the cytotoxicity test, plantamajoside proved to be less toxic when it was treated combined with S9 cell fractions. However, there was a significant increase in structural aberrations during the short-term treatment of plantamajoside at its highest dose (5000 microg/mL) even when combined with S9. This seems to have been a natural phenomenon due to the very high dose of plantamajoside that was used. However, to confirm the safety of plantamajoside for its potential use as a phytochemical agent in health products, additional mutagenicity tests are necessary. PMID:19288521

  10. Aberration of a negative ion beam caused by space charge effect.

    PubMed

    Miyamoto, K; Wada, S; Hatayama, A

    2010-02-01

    Aberrations are inevitable when the charged particle beams are extracted, accelerated, transmitted, and focused with electrostatic and magnetic fields. In this study, we investigate the aberration of a negative ion accelerator for a neutral beam injector theoretically, especially the spherical aberration caused by the negative ion beam expansion due to the space charge effect. The negative ion current density profiles with the spherical aberration are compared with those without the spherical aberration. It is found that the negative ion current density profiles in a log scale are tailed due to the spherical aberration.

  11. Measurement of true calcium absorption in premature infants using intravenous 46Ca and oral 44Ca.

    PubMed

    Hillman, L S; Tack, E; Covell, D G; Vieira, N E; Yergey, A L

    1988-06-01

    We have developed a method for measuring true fractional calcium absorption (alpha) in premature infants using two stable isotopes of calcium and tested it in seven studies in seven infants (birth weight 1543 +/- 65 g, gestation 32.8 +/- 7 wk). A total of 7.5 micrograms/kg 46Ca was given as a single intravenous bolus. Immediately thereafter 1.25 mg/kg of 44Ca was given in a single gavage feeding of standard infant formula (Enfamil). A metabolic isolette was used to obtain 4-h collections of urine for 24 h total. 46Ca and 44Ca were measured in urine by thermal ionization mass spectroscopy and expressed as the ratio to naturally occurring 48Ca. The differences in the 46Ca/48Ca and 44Ca/48Ca ratios from natural levels (delta % excess 46Ca and delta % excess 44Ca) were calculated. Percent absorption (alpha) equals a constant times cumulative delta % excess 44Ca/delta % excess 46Ca. The calculation of alpha is independent of urine volume or concentration. The delta % excess 46Ca, showed the expected multiexponential decline as a function of time, and delta % excess 44Ca usually peaked during a 4- to 8-h urine collection. Calculations of alpha using increasingly long sampling times showed that a plateau had been reached by 12 h. alpha values calculated after 16-24 h in the seven infants at 2 wk of age were 41, 48, 45, 46, 25, 55, and 51%. Repeat studies at 3 wk of age were 46, 60, and 54%. These values are somewhat higher than net percent calcium absorption values reported for standard formula and thus appear very appropriate.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Diesel exhaust particulate matter dispersed in a phospholipid surfactant induces chromosomal aberrations and micronuclei but not 6-thioguanine-resistant gene mutation in V79 cells.

    PubMed

    Gu, Zu-Wei; Keane, Michael J; Ong, Tong-man; Wallace, William E

    2005-03-26

    Diesel exhaust particulate material (DPM) was assayed for induction of chromosomal aberrations (CA), micronucleus (MN) formation, and 6-thioguanine-resistant (TG9 gene mutation in V79 cells as a dispersion in dipalmitoyl phosphatidylcholine (DPPC) in physiological saline, a simulated pulmonary surfactant. Filter-collected automobile DPM provided for the study was not organic solvent extracted, but was directly mixed into DPPC in saline dispersion as a model of pulmonary surfactant conditioning of a soot particle depositing in a lung alveolus. A statistically significant difference was found between treated and control groups at all concentrations tested in a CA assay. Assay for MN induction also gave a positive response: Above 50 microg/ml, the frequencies of micronucleated cells (MNC) were about 2 times higher than those in the control group. The forward gene mutation assay did not show a positive response when cells were treated with up to 136 microg DPM/ml for 24 h, as dispersion in DPPC in saline. Some comparison assays were run on direct dispersions of the DPM into dimethyl sulfoxide, with results equivalent to those seen with a DPPC-saline preparation: DPM in dimethyl sulfoxide (DMSO) was positive for MN induction but was negative for forward gene mutation in V79 cells. The positive clastogenicity results are consistent with other studies of DPM dispersed into DPPC-saline surfactant that have shown activity in mammalian cells for sister chromatid exchange, unscheduled DNA synthesis, and MN induction. The forward gene mutation negative results are consistent with studies of that assay applied to V79 cells challenged with DPM solvent extract.

  13. Mitochondrial Ca2+ Remodeling is a Prime Factor in Oncogenic Behavior

    PubMed Central

    Rimessi, Alessandro; Patergnani, Simone; Bonora, Massimo; Wieckowski, Mariusz R.; Pinton, Paolo

    2015-01-01

    Cancer is sustained by defects in the mechanisms underlying cell proliferation, mitochondrial metabolism, and cell death. Mitochondrial Ca2+ ions are central to all these processes, serving as signaling molecules with specific spatial localization, magnitude, and temporal characteristics. Mutations in mtDNA, aberrant expression and/or regulation of Ca2+-handling/transport proteins and abnormal Ca2+-dependent relationships among the cytosol, endoplasmic reticulum, and mitochondria can cause the deregulation of mitochondrial Ca2+-dependent pathways that are related to these processes, thus determining oncogenic behavior. In this review, we propose that mitochondrial Ca2+ remodeling plays a pivotal role in shaping the oncogenic signaling cascade, which is a required step for cancer formation and maintenance. We will describe recent studies that highlight the importance of mitochondria in inducing pivotal “cancer hallmarks” and discuss possible tools to manipulate mitochondrial Ca2+ to modulate cancer survival. PMID:26161362

  14. Aberrant Pattern of Scanning in Prosopagnosia Reflects Impaired Face Processing

    ERIC Educational Resources Information Center

    Stephan, Blossom Christa Maree; Caine, Diana

    2009-01-01

    Visual scanpath recording was used to investigate the information processing strategies used by a prosopagnosic patient, SC, when viewing faces. Compared to controls, SC showed an aberrant pattern of scanning, directing attention away from the internal configuration of facial features (eyes, nose) towards peripheral regions (hair, forehead) of the…

  15. Chromosome aberrations in plants as a monitoring system.

    PubMed Central

    Grant, W F

    1978-01-01

    The potential of higher plants as a first-tier assay system for detecting chemical mutagens is evaluated. The use of plant tissue (primarily root tips and pollen mother cells) for studying the induction of chromosomal aberrations is one of the oldest, simplest, most reliable, and inexpensive methods available. Specific types of abnormalities have been induced by different classes of pesticides. Chromosome clumping, contraction, stickiness, paling, fragmentation, dissolution, chromosome and chromatid bridges, C-mitosis, and endoploidy have been reported in the literature. Examples of cytogenetic studies with pesticides demonstrating the usefulness of higher plants as a monitoring system are reviewed. Pesticides which cause chromosome aberrations in plant cells also produce chromosome aberrations in cultured animal cells. Frequently, the aberrations are identical. For example, studies have shown that compounds which have a C-mitotic effect on plant cells have the same effect on animal cells. It is recommended that plant systems be accepted as a first-tier assay system for the detection of possible genetic damage by environmental chemicals. PMID:367773

  16. Corneal primary aberrations compensation by oblique light incidence

    NASA Astrophysics Data System (ADS)

    Espinosa, Julian; Mas, David; Kasprzak, Henryk T.

    2009-07-01

    The eye is not a centered system. The line of sight connects the fovea with the center of the pupil and is usually tilted in the temporal direction. Thus, off-axis optical aberrations, mainly coma and oblique astigmatism, are introduced at the fovea. Tabernero et al. [J. Opt. Soc. Am. A 24(10), 3274-3283 (2007)] showed that a horizontal tilt of the crystalline lens generates a horizontal coma aberration that is compensated by the oblique light incidence on the eye. Here we suggest that corneal astigmatism may also play a role in compensation of oblique aberrations, and we propose a simple model to analyze such a possibility. A theoretical Kooijman eye model with a slight (~0.6 D) with-the-rule astigmatism is analyzed. Light rays at different incidence angles to the optical axis are considered, and the corresponding point spread functions (PSFs) at the retina are calculated. A quality criterion is used to determine the incidence angle that provides the narrowest and highest PSF energy peak. We show that the best image is obtained for a tilted incidence angle compatible with mean values of the angle kappa. This suggests that angle kappa, lens tilt, and corneal astigmatism may combine to provide a passive compensation mechanism to minimize aberrations on the fovea.

  17. Mapping magnetism with atomic resolution using aberrated electron probes

    NASA Astrophysics Data System (ADS)

    Idrobo, Juan; Rusz, Ján; McGuire, Michael A.; Symons, Christopher T.; Vatsavai, Ranga Raju; Lupini, Andrew R.

    2015-03-01

    In this talk, we report a direct experimental real-space mapping of magnetic circular dichroism with atomic resolution in aberration-corrected scanning transmission electron microscopy (STEM). Using an aberrated electron probe with customized phase distribution, we reveal with electron energy-loss (EEL) spectroscopy the checkerboard antiferromagnetic ordering of Mn moments in LaMnAsO by observing a dichroic signal in the Mn L-edge. The aberrated probes allow the collection of EEL spectra using the transmitted beam, which results in a magnetic circular dichroic signal with intrinsically larger signal-to-noise ratios than those obtained via nanodiffraction techniques (where most of the transmitted electrons are discarded). The novel experimental setup presented here, which can easily be implemented in aberration-corrected STEM, opens new paths for probing dichroic signals in materials with unprecedented spatial resolution. This research was supported by DOE SUFD MSED, by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the US DOE, and by the Swedish Research Council and Swedish National Infrastructure for Computing (NSC center)

  18. Nanowire growth kinetics in aberration corrected environmental transmission electron microscopy

    DOE PAGES

    Chou, Yi -Chia; Panciera, Federico; Reuter, Mark C.; Stach, Eric A.; Ross, Frances M.

    2016-03-15

    Here, we visualize atomic level dynamics during Si nanowire growth using aberration corrected environmental transmission electron microscopy, and compare with lower pressure results from ultra-high vacuum microscopy. We discuss the importance of higher pressure observations for understanding growth mechanisms and describe protocols to minimize effects of the higher pressure background gas.

  19. High-Resolution Transmission Electron Microscopy Using Negative Spherical Aberration

    NASA Astrophysics Data System (ADS)

    Jia, Chun-Lin; Lentzen, Markus

    2004-04-01

    A novel imaging mode for high-resolution transmission electron microscopy is described. It is based on the adjustment of a negative value of the spherical aberration CS of the objective lens of a transmission electron microscope equipped with a multipole aberration corrector system. Negative spherical aberration applied together with an overfocus yields high-resolution images with bright-atom contrast. Compared to all kinds of images taken in conventional transmission electron microscopes, where the then unavoidable positive spherical aberration is combined with an underfocus, the contrast is dramatically increased. This effect can only be understood on the basis of a full nonlinear imaging theory. Calculations show that the nonlinear contrast contributions diminish the image contrast relative to the linear image for a positive-CS setting whereas they reinforce the image contrast relative to the linear image for a negative-CS setting. The application of the new mode to the imaging of oxygen in SrTiO3 and YBa2Cu3O7 demonstrates the benefit to materials science investigations. It allows us to image directly, without further image processing, strongly scattering heavy-atom columns together with weakly scattering light-atom columns.

  20. Chromosomal aberrations analysis in a Brazilian population exposed to pesticides.

    PubMed

    Antonucci, G A; de Syllos Cólus, I M

    2000-01-01

    In spite of being harmful, pesticides are widely used in Brazil. Their genotoxic effects might be studied through population monitoring by means of the analysis of chromosomal aberrations in occupationally exposed individuals. The aim of this study was to evaluate the chromosomal aberration frequencies in temporary cultures of lymphocytes from periferic blood of 23 workers professionally exposed to a mixture of pesticides. The workers were employed by the Agronomic Institute of Parana (Brazil) and used all of the prevention measures provided. A detailed history of pesticide use, as well as personal data, smoking habits, and history of recent illnesses and medical treatment were collected through a standardized questionnaire administered to each subject. Nonexposed subjects, matched for age, sex, and smoking habits, served as the negative control. A total of 100 cells were analyzed from each individual. A significant increase in chromosomal aberration frequencies was observed in exposed individuals when compared to the control group. Some individual characteristics such as age, sex, time of exposure to the pesticides, and smoking habits showed no correlation with chromosomal aberrations. Therefore, the positive results may be considered true effects of pesticides on human somatic cells. PMID:10992273

  1. The Aberrant Salience Inventory: A New Measure of Psychosis Proneness

    ERIC Educational Resources Information Center

    Cicero, David C.; Kerns, John G.; McCarthy, Denis M.

    2010-01-01

    Aberrant salience is the unusual or incorrect assignment of salience, significance, or importance to otherwise innocuous stimuli and has been hypothesized to be important for psychosis and psychotic disorders such as schizophrenia. Despite the importance of this concept in psychosis research, no questionnaire measures are available to assess…

  2. The Geometrical Optics PSF with Third Order Aberrations

    NASA Astrophysics Data System (ADS)

    Díaz-Uribe, Rufino; Campos-García, Manuel

    2008-04-01

    In this paper the calculation of the GPSF from the Geometrical Optics Irradiance Law (GOIL) is recalled, including some details not found in other references. Also it is explored an alternative solution based on the Irradiance Transport Equation (ITE). Some simulations of images of an extended object produced by an image forming instrument affected by spherical aberration are shown.

  3. Membrane-based deformable mirror: intrinsic aberrations and alignment issues

    NASA Astrophysics Data System (ADS)

    Raja Bayanna, A.; Louis, Rohan E.; Chatterjee, S.; Mathew, Shibu K.; Venkatakrishnan, P.

    2015-03-01

    A Deformable Mirror (DM) is an important component of an Adaptive Optics system. It is known that an on-axis spherical/parabolic optical component, placed at an angle to the incident beam introduces defocus as well as astigmatism in the image plane. Although the former can be compensated by changing the focal plane position, the latter cannot be removed by mere optical re-alignment. Since the DM is to be used to compensate a turbulence-induced curvature term in addition to other aberrations, it is necessary to determine the aberrations induced by such (curved DM surface) an optical element when placed at an angle (other than 0 degree) of incidence in the optical path. To this effect, we estimate to a first order, the aberrations introduced by a DM as a function of the incidence angle and deformation of the DM surface. We record images using a simple setup in which the incident beam is reflected by a 37 channel Micro-machined Membrane Deformable Mirror for various angles of incidence. It is observed that astigmatism is a dominant aberration which was determined by measuring the difference between the tangential and sagital focal planes. We justify our results on the basis of theoretical simulations and discuss the feasibility of using such a system for adaptive optics considering a trade-off between wavefront correction and astigmatism due to deformation.

  4. ISTFA 1987 - International Symposium for Testing and Failure Analysis: Advanced materials; Proceedings of the Symposium, Los Angeles, CA, Nov. 9-13, 1987

    SciTech Connect

    Not Available

    1987-01-01

    The present conference discusses topics in the failure analysis of metallic materials, metal-matrix composites (MMCs), environmental effects on metallics materials, the failure analysis of polymers and ceramics and of resin-based composites, case histories in metal-failure analysis, failure-mechanisms in resin-based composites, innovations in test methodologies, and failures in weldments. Attention is given to fatigue cracking in Al-Li alloys, flow and fracture in discontinuous MMCs with high ductility, the service failure of a 7049 T73 Al alloy aircraft forging, the fracture behavior of electronic ceramics, microscopy of composite delamination, a helicopter crew-seat failure analysis, cracking in marine composites, quantitative fractography, and the significance of repair welds in service failures.

  5. Space and Ground observations of Pre-earthquake Anomalies.Prospective/Retrospective Testing for M6.0 August 24, 2014 South Napa, CA

    NASA Astrophysics Data System (ADS)

    Ouzounov, D.; Kafatos, M.; Petrov, L.; Pulinets, S. A.; Liu, J. Y.; Su, Y. C.; Chen, S.

    2014-12-01

    We integrate multiple geo-space and ground sensors for monitoring pre-earthquake geophysical anomalies that can provide significant early notification for earthquakes higher than M5.5 in California. The latest M6.0 event of August 24 in South Napa, generated a pre-earthquake signature during our prospective tests for California, and an experimental warning was documented about 17 days in advance. We process in controlled environment different satellite and ground data for California and several other test areas by using: A.) TIR (thermal infrared) data from the NPOES recording long-wavelength radiation (OLR) and; B.) 2/GNSS, FORMOSAT (GPS/TEC); 3) Earth Observing System assimilation models from NASA and 4) ground-based gas observations and meteorological data. On Aug 4th, we detected (prospectively) a large anomaly of OLR transient field in the atmosphere over Northern California. The location was shifted in the northeast direction about 150 km from the Aug 23rd epicentral area. Compared to the reference field of August 2004 to 2014, a rapid change in the thermals anomalous flux rate, of >1.6 W/m2 at 7:00AM LT been observed on Aug 4. The hotspot anomaly was the largest energy flux anomaly over the entire continental United States at this time. Based on the temporal and spatial estimates of the anomaly, on August 4th we issued an internal warning for a M5.5+ earthquake in Northern California within the next 1-4 weeks. Our approach needs additional continuous validation. The results could be explained within the framework of a model of Lithosphere-Atmosphere-Ionosphere Coupling between the crust and the atmosphere/ionosphere.

  6. Identification of Chromosomal Aberrations by Using Trypsin G-banding in Hepatocellular Carcinoma Patients (HCC) in Tamil Nadu, India.

    PubMed

    Mohana Devi, Subramaniam; Balachandar, Vellingiri; Murugan, Palanivel Vel; Sasikala, Keshavarao; Manikantan, Pappusamy; Venkatakrishnan, Leela Krishnan

    2010-08-01

    Hepatocellular carcinoma (HCC) (or liver cancer) is one of the most common human malignancies worldwide. Aetiologically, HCC is closely associated with chronic hepatitis B and C virus infection, cirrhosis and alcohol intake. The objective of the present study was to elucidate the chromosomal abberations (CA) in HCC patients using the trypsin G-banding technique. This study may help in understanding the pattern of the disease and to assess whether these aberrations are associated with HCC susceptibility. The study examined 51 HCC cases and an equal number (n = 51) of age and gender matched cancer-free controls recruited from the hospitals in Tamil Nadu. The HCC cases were grouped depending upon their age into group I (≤ 45 years) and group II (≥ 46 years). The development of effective markers for the detection of HCC could have an impact on cancer mortality and may have significant public health implications worldwide. Subjects were recruited based on their alpha-fetoprotein (AFP) serum level, which is an effective marker for HCC. In the HCC cases, a higher number of chromatid aberrations [group I 13(25.5%) and group II 43(84.3%)] and CA [group I 10(19.6%) and group II 28(54.9%)] were observed. In contrast, controls showed a lower number of chromatid [group I 5(9.8%) and group II 12(23.5%)] and CA [group I 4(7.8%) and group II 9(17.6%)]. In conclusion, the results of this study contribute to the validation of CA as an intermediate end point in carcinogenesis. Because many people are unaware of this lethal disease, this study will raise awareness of this cancer.

  7. Identification of Chromosomal Aberrations by Using Trypsin G-banding in Hepatocellular Carcinoma Patients (HCC) in Tamil Nadu, India

    PubMed Central

    Mohana Devi, Subramaniam; Balachandar, Vellingiri; Murugan, Palanivel Vel; Sasikala, Keshavarao; Manikantan, Pappusamy; Venkatakrishnan, Leela Krishnan

    2010-01-01

    Hepatocellular carcinoma (HCC) (or liver cancer) is one of the most common human malignancies worldwide. Aetiologically, HCC is closely associated with chronic hepatitis B and C virus infection, cirrhosis and alcohol intake. The objective of the present study was to elucidate the chromosomal abberations (CA) in HCC patients using the trypsin G-banding technique. This study may help in understanding the pattern of the disease and to assess whether these aberrations are associated with HCC susceptibility. The study examined 51 HCC cases and an equal number (n = 51) of age and gender matched cancer-free controls recruited from the hospitals in Tamil Nadu. The HCC cases were grouped depending upon their age into group I (≤ 45 years) and group II (≥ 46 years). The development of effective markers for the detection of HCC could have an impact on cancer mortality and may have significant public health implications worldwide. Subjects were recruited based on their alpha-fetoprotein (AFP) serum level, which is an effective marker for HCC. In the HCC cases, a higher number of chromatid aberrations [group I 13(25.5%) and group II 43(84.3%)] and CA [group I 10(19.6%) and group II 28(54.9%)] were observed. In contrast, controls showed a lower number of chromatid [group I 5(9.8%) and group II 12(23.5%)] and CA [group I 4(7.8%) and group II 9(17.6%)]. In conclusion, the results of this study contribute to the validation of CA as an intermediate end point in carcinogenesis. Because many people are unaware of this lethal disease, this study will raise awareness of this cancer. PMID:24575188

  8. Induction of colonic aberrant crypts in mice by feeding apparent N-nitroso compounds derived from hot dogs

    PubMed Central

    Davis, Michael E; Lisowyj, Michal P; Zhou, Lin; Wisecarver, James L; Gulizia, James M; Shostrom, Valerie K; Naud, Nathalie; Corpet, Denis E; Mirvish, Sidney S

    2012-01-01

    Nitrite-preserved meats (e.g., hot dogs) may help cause colon cancer because they contain N-nitroso compounds. We tested whether purified hot-dog-derived total apparent N-nitroso compounds (ANC) could induce colonic aberrant crypts, which are putative precursors of colon cancer. We purified ANC precursors in hot dogs and nitrosated them to produce ANC. In preliminary tests, CF1 mice received 1 or 3 i.p. injections of 5mg azoxymethane (AOM)/kg. In Experiments 1 and 2, female A/J mice received ANC in diet. In Experiment 1, ANC dose initially dropped sharply because the ANC precursors had mostly decomposed but, later in Experiment 1 and throughout Experiment 2, ANC remained at 85 nmol/g diet. Mice were killed after 8 (AOM tests) or 17–34 (ANC tests) wk. Median numbers of aberrant crypts in the distal 2 cm of the colon for 1 and 3 AOM injections, CF1 controls, ANC (Experiment 1), ANC (Experiment 2),and untreated A/J mice were 31, 74, 12, 20, 12, and 5–6, with P < 0.01 for both ANC tests. Experiment 2 showed somewhat increased numbers of colonic mucin-depleted foci in the ANC-treated group. We conclude that hot-dog-derived ANC induced significant numbers of aberrant crypts in the mouse colon. PMID:22293095

  9. Canine urothelial carcinoma: genomically aberrant and comparatively relevant

    PubMed Central

    Shapiro, S. G.; Raghunath, S.; Williams, C.; Motsinger-Reif, A. A.; Cullen, J. M.; Liu, T.; Albertson, D.; Ruvolo, M.; Lucas, A. Bergstrom; Jin, J.; Knapp, D. W.; Schiffman, J. D.

    2015-01-01

    Urothelial carcinoma (UC), also referred to as transitional cell carcinoma (TCC), is the most common bladder malignancy in both human and canine populations. In human UC, numerous studies have demonstrated the prevalence of chromosomal imbalances. Although the histopathology of the disease is similar in both species, studies evaluating the genomic profile of canine UC are lacking, limiting the discovery of key comparative molecular markers associated with driving UC pathogenesis. In the present study, we evaluated 31 primary canine UC biopsies by oligonucleotide array comparative genomic hybridization (oaCGH). Results highlighted the presence of three highly recurrent numerical aberrations: gain of dog chromosome (CFA) 13 and 36 and loss of CFA 19. Regional gains of CFA 13 and 36 were present in 97% and 84% of cases, respectively, and losses on CFA 19 were present in 77% of cases. Fluorescence in situ hybridization (FISH), using targeted bacterial artificial chromosome (BAC) clones and custom Agilent SureFISH probes, was performed to detect and quantify these regions in paraffin-embedded biopsy sections and urine-derived urothelial cells. The data indicate that these three aberrations are potentially diagnostic of UC. Comparison of our canine oaCGH data with that of 285 human cases identified a series of shared copy number aberrations. Using an informatics approach to interrogate the frequency of copy number aberrations across both species, we identified those that had the highest joint probability of association with UC. The most significant joint region contained the gene PABPC1, which should be considered further for its role in UC progression. In addition, cross-species filtering of genome-wide copy number data highlighted several genes as high-profile candidates for further analysis, including CDKN2A, S100A8/9, and LRP1B. We propose that these common aberrations are indicative of an evolutionarily conserved mechanism of pathogenesis and harbor genes key to

  10. Non-Gaussianity and CMB aberration and Doppler

    SciTech Connect

    Catena, Riccardo; Liguori, Michele; Renzi, Alessandro; Notari, Alessio E-mail: michele.liguori@pd.infn.it E-mail: arenzi@pd.infn.it

    2013-09-01

    The peculiar motion of an observer with respect to the CMB rest frame induces a deflection in the arrival direction of the observed photons (also known as CMB aberration) and a Doppler shift in the measured photon frequencies. As a consequence, aberration and Doppler effects induce non trivial correlations between the harmonic coefficients of the observed CMB temperature maps. In this paper we investigate whether these correlations generate a bias on non-Gaussianity estimators f{sub NL}. We perform this analysis simulating a large number of temperature maps with Planck-like resolution (lmax = 2000) as different realizations of the same cosmological fiducial model (WMAP7yr). We then add to these maps aberration and Doppler effects employing a modified version of the HEALPix code. We finally evaluate a generalization of the Komatsu, Spergel and Wandelt non-Gaussianity estimator for all the simulated maps, both when peculiar velocity effects have been considered and when these phenomena have been neglected. Using the value v/c = 1.23 × 10{sup −3} for our peculiar velocity, we found that the aberration/Doppler induced non-Gaussian signal is at most of about half of the cosmic variance σ for f{sub NL} both in a full-sky and in a cut-sky experimental configuration, for local, equilateral and orthogonal estimators. We conclude therefore that when estimating f{sub NL} it is safe to ignore aberration and Doppler effects if the primordial map is already Gaussian. More work is necessary however to assess whether a map which contains non-Gaussianity can be significantly distorted by a peculiar velocity.

  11. Chromatin structure and ionizing-radiation-induced chromosome aberrations

    SciTech Connect

    Muehlmann-Diaz, M.C.

    1993-01-01

    The possible influence of chromatic structure or activity on chromosomal radiosensitivity was studied. A cell line was isolated which contained some 10[sup 5] copies of an amplified plasmid in a single large mosquito artificial chromosome (MAC). This chromosome was hypersensitive to DNase I. Its radiosensitivity was some three fold greater than normal mosquito chromosomes in the same cell. In cultured human cells irradiated during G[sub 0], the initial breakage frequency in chromosome 4, 19 and the euchromatic and heterochromatic portions of the Y chromosome were measured over a wide range of doses by inducing Premature Chromosome Condensation (PCC) immediately after irradiation with Cs-137 gamma rays. No evidence was seen that Y heterochromatin or large fragments of it remained unbroken. The only significant deviation from the expected initial breakage frequency per Gy per unit length of chromosome was that observed for the euchromatic portion of the Y chromosome, with breakage nearly twice that expected. The development of aberrations involving X and Y chromosomes at the first mitosis after irradation was also studied. Normal female cells sustained about twice the frequency of aberrations involving X chromosomes for a dose of 7.3 Gy than the corresponding male cells. Fibroblasts from individuals with supernumerary X chromosomes did not show any further increase in X aberrations for this dos. The frequency of aberrations involving the heterochromatic portion of the long arm of the Y chromosome was about what would be expected for a similar length of autosome, but the euchromatic portion of the Y was about 3 times more radiosensitive per unit length. 5-Azacytidine treatment of cultured human female fibroblasts or fibroblasts from a 49,XXXXY individual, reduced the methylation of cytosine residues in DNA, and resulted in an increased chromosomal radiosensitivity in general, but it did not increase the frequency of aberrations involving the X chromosomes.

  12. Proton and Fe Ion-Induced Early and Late Chromosome Aberrations in Different Cell Types

    NASA Technical Reports Server (NTRS)

    Wu, Honglu; Lu, Tao; Yeshitla, Samrawit; Zhang, Ye; Kadhim, Munira

    2016-01-01

    An early stage of cancer development is believed to be genomic instability (GI) which accelerates the mutation rate in the descendants of the cells surviving radiation exposure. To investigate GI induced by charged particles, we exposed human lymphocytes, human fibroblast cells, and human mammary epithelial cells to high energy protons and Fe ions. In addition, we also investigated GI in bone marrow cells isolated from CBA/CaH (CBA) and C57BL/6 (C57) mice, by analyzing cell survival and chromosome aberrations in the cells after multiple cell divisions. Results analyzed so far from the experiments indicated different sensitivities to charged particles between CBA/CaH (CBA) and C57BL/6 (C57) mouse strains, suggesting that there are two main types of response to irradiation: 1) responses associated with survival of damaged cells and 2) responses associated with the induction of non-clonal chromosomal instability in the surviving progeny of stem cells. Previously, we reported that the RBE for initial chromosome damages was high in human lymphocytes exposed to Fe ions. Our results with different cell types demonstrated different RBE values between different cell types and between early and late chromosomal damages. This study also attempts to offer an explanation for the varying RBE values for different cancer types.

  13. Aberrations measurement of freeform spectacle lenses based on Hartmann wavefront technology.

    PubMed

    Yu, Jing; Fang, Fengzhou; Qiu, Zhongjun

    2015-02-10

    Freeform spectacle lenses have been popularized in the past few years. Traditional evaluation methods only focused on the refractive power parameters. The inspection technology of wavefront aberration has been introduced to optometry. In this paper, the wavefront aberration is used to evaluate the freeform spectacle lenses. The Shack-Hartmann wavefront technology is used to measure the same zones on the lenses with different designed forms. It shows that the aberration distributions are different from each other. The design with the freeform surface on the back can obtain the smallest aberrations in the entire surface. The aberrations on different zones for the same lens are analyzed. The blending zones show the greatest aberrations. The aberration on the progressive corridor is greater than the other zones. The Hartmann wavefront technology can be used to measure the wavefront aberration of freeform spectacle lenses. PMID:25968012

  14. Image transfer with spatial coherence for aberration corrected transmission electron microscopes.

    PubMed

    Hosokawa, Fumio; Sawada, Hidetaka; Shinkawa, Takao; Sannomiya, Takumi

    2016-08-01

    The formula of spatial coherence involving an aberration up to six-fold astigmatism is derived for aberration-corrected transmission electron microscopy. Transfer functions for linear imaging are calculated using the newly derived formula with several residual aberrations. Depending on the symmetry and origin of an aberration, the calculated transfer function shows characteristic symmetries. The aberrations that originate from the field's components, having uniformity along the z direction, namely, the n-fold astigmatism, show rotational symmetric damping of the coherence. The aberrations that originate from the field's derivatives with respect to z, such as coma, star, and three lobe, show non-rotational symmetric damping. It is confirmed that the odd-symmetric wave aberrations have influences on the attenuation of an image via spatial coherence. Examples of image simulations of haemoglobin and Si [211] are shown by using the spatial coherence for an aberration-corrected electron microscope.

  15. [Aberrations of the alarm call of the steppe marmot, Marmota bobak (Rodentia, Sciuridae)].

    PubMed

    Nikol'skiĭ, A A

    2008-01-01

    Aberrations, or deviations from the normal type of alarm call have been studied in the steppe marmot. One regular and several rare aberrations have been identified. The regular aberration manifests itself in all six populations studied, from the Kharkov Region in the west to the eastern border of the Orenburg Region in the east, with its frequency in the populations varying in different years from 10 to 66%. Rare aberrations occur sporadically and not in all populations.

  16. Aberrant left subclavian artery associated with a Kommerell's diverticulum and a left-sided aortic arch.

    PubMed

    Yu, Pey-Jen; Balsam, Leora B; Mussa, Firas F; DeAnda, Abe

    2012-09-01

    Kommerell's diverticulum is most commonly associated with either an aberrant left subclavian artery from a right-sided aortic arch or an aberrant right subclavian artery from a left-sided aortic arch. We describe an exceedingly rare case of an aberrant left subclavian artery arising from a Kommerell's diverticulum in a patient with a left-sided aortic arch, the "nonaberrant aberrant left subclavian artery."

  17. The BHVI-EyeMapper: Peripheral Refraction and Aberration Profiles

    PubMed Central

    Fedtke, Cathleen; Ehrmann, Klaus; Falk, Darrin; Bakaraju, Ravi C.; Holden, Brien A.

    2014-01-01

    ABSTRACT Purpose The aim of this article was to present the optical design of a new instrument (BHVI-EyeMapper, EM), which is dedicated to rapid peripheral wavefront measurements across the visual field for distance and near, and to compare the peripheral refraction and higher-order aberration profiles obtained in myopic eyes with and without accommodation. Methods Central and peripheral refractive errors (M, J180, and J45) and higher-order aberrations (C[3, 1], C[3, 3], and C[4, 0]) were measured in 26 myopic participants (mean [±SD] age, 20.9 [±2.0] years; mean [±SD] spherical equivalent, −3.00 [±0.90] diopters [D]) corrected for distance. Measurements were performed along the horizontal visual field with (−2.00 to −5.00 D) and without (+1.00 D fogging) accommodation. Changes as a function of accommodation were compared using tilt and curvature coefficients of peripheral refraction and aberration profiles. Results As accommodation increased, the relative peripheral refraction profiles of M and J180 became significantly (p < 0.05) more negative and the profile of M became significantly (p < 0.05) more asymmetric. No significant differences were found for the J45 profiles (p > 0.05). The peripheral aberration profiles of C[3, 1], C[3, 3], and C[4, 0] became significantly (p < 0.05) less asymmetric as accommodation increased, but no differences were found in the curvature. Conclusions The current study showed that significant changes in peripheral refraction and higher-order aberration profiles occurred during accommodation in myopic eyes. With its extended measurement capabilities, that is, permitting rapid peripheral refraction and higher-order aberration measurements up to visual field angles of ±50 degrees for distance and near (up to −5.00 D), the EM is a new advanced instrument that may provide additional insights in the ongoing quest to understand and monitor myopia development. PMID:25105690

  18. Influence of radiofrequency radiation on chromosome aberrations in CHO cells and its interaction with DNA-damaging agents.

    PubMed

    Kerbacher, J J; Meltz, M L; Erwin, D N

    1990-09-01

    A limited number of contradictory reports have appeared in the literature about the ability of radiofrequency (rf) radiation to induce chromosome aberrations in different biological systems. The technical documentation associated with such reports is often absent or deficient. In addition, no information is available as to whether any additional genotoxic hazard would result from a simultaneous exposure of mammalian cells to rf radiation and a chemical which (by itself) induces chromosome aberrations. In the work described, we have therefore tested two hypotheses. The first is that rf radiation by itself, at power densities and exposure conditions which are higher than is consistent with accepted safety guidelines, can induce chromosome aberrations in mammalian cells. The second is that, during a simultaneous exposure to a chemical known to be genotoxic, rf radiation can affect molecules, biochemical processes, or cellular organelles, and thus result in an increase or decrease in chromosome aberrations. Mitomycin C (MMC) and Adriamycin (ADR) were selected because they act by different mechanisms, and because they might put normal cells at risk during combined-modality rf radiation (hyperthermia)-chemotherapy treatment of cancer. The studies were performed with suitable 37 degrees C and equivalent convection heating-temperature controls in a manner designed to discriminate between any thermal and possible nonthermal action. Radiofrequency exposures were conducted for 2 h under conditions resulting in measurable heating (a maximum increase of 3.2 degrees C), with pulsed-wave rf radiation at a frequency of 2450 MHz and an average net forward power of 600 W, resulting in an SAR of 33.8 W/kg. Treatments with MMC or ADR were for a total of 2.5 h and encompassed the 2-h rf radiation exposure period. The CHO cells from each of the conditions were subsequently analyzed for chromosome aberrations. In cells exposed to rf radiation alone, and where a maximum temperature of

  19. Astrocyte Reactivity Following Blast Exposure Involves Aberrant Histone Acetylation

    PubMed Central

    Bailey, Zachary S.; Grinter, Michael B.; VandeVord, Pamela J.

    2016-01-01

    Blast induced neurotrauma (BINT) is a prevalent injury within military and civilian populations. The injury is characterized by persistent inflammation at the cellular level which manifests as a multitude of cognitive and functional impairments. Epigenetic regulation of transcription offers an important control mechanism for gene expression and cellular function which may underlie chronic inflammation and result in neurodegeneration. We hypothesize that altered histone acetylation patterns may be involved in blast induced inflammation and the chronic activation of glial cells. This study aimed to elucidate changes to histone acetylation occurring following injury and the roles these changes may have within the pathology. Sprague Dawley rats were subjected to either a 10 or 17 psi blast overpressure within an Advanced Blast Simulator (ABS). Sham animals underwent the same procedures without blast exposure. Memory impairments were measured using the Novel Object Recognition (NOR) test at 2 and 7 days post-injury. Tissues were collected at 7 days for Western blot and immunohistochemistry (IHC) analysis. Sham animals showed intact memory at each time point. The novel object discrimination decreased significantly between two and 7 days for each injury group (p < 0.05). This is indicative of the onset of memory impairment. Western blot analysis showed glial fibrillary acidic protein (GFAP), a known marker of activated astrocytes, was elevated in the prefrontal cortex (PFC) following blast exposure for both injury groups. Analysis of histone protein extract showed no changes in the level of any total histone proteins within the PFC. However, acetylation levels of histone H2b, H3, and H4 were decreased in both groups (p < 0.05). Co-localization immunofluorescence was used to further investigate any potential correlation between decreased histone acetylation and astrocyte activation. These experiments showed a similar decrease in H3 acetylation in astrocytes exposed to a 17

  20. Astrocyte Reactivity Following Blast Exposure Involves Aberrant Histone Acetylation.

    PubMed

    Bailey, Zachary S; Grinter, Michael B; VandeVord, Pamela J

    2016-01-01

    Blast induced neurotrauma (BINT) is a prevalent injury within military and civilian populations. The injury is characterized by persistent inflammation at the cellular level which manifests as a multitude of cognitive and functional impairments. Epigenetic regulation of transcription offers an important control mechanism for gene expression and cellular function which may underlie chronic inflammation and result in neurodegeneration. We hypothesize that altered histone acetylation patterns may be involved in blast induced inflammation and the chronic activation of glial cells. This study aimed to elucidate changes to histone acetylation occurring following injury and the roles these changes may have within the pathology. Sprague Dawley rats were subjected to either a 10 or 17 psi blast overpressure within an Advanced Blast Simulator (ABS). Sham animals underwent the same procedures without blast exposure. Memory impairments were measured using the Novel Object Recognition (NOR) test at 2 and 7 days post-injury. Tissues were collected at 7 days for Western blot and immunohistochemistry (IHC) analysis. Sham animals showed intact memory at each time point. The novel object discrimination decreased significantly between two and 7 days for each injury group (p < 0.05). This is indicative of the onset of memory impairment. Western blot analysis showed glial fibrillary acidic protein (GFAP), a known marker of activated astrocytes, was elevated in the prefrontal cortex (PFC) following blast exposure for both injury groups. Analysis of histone protein extract showed no changes in the level of any total histone proteins within the PFC. However, acetylation levels of histone H2b, H3, and H4 were decreased in both groups (p < 0.05). Co-localization immunofluorescence was used to further investigate any potential correlation between decreased histone acetylation and astrocyte activation. These experiments showed a similar decrease in H3 acetylation in astrocytes exposed to a 17

  1. A Case Study of the Reduction of Aberrant, Repetitive Responses of an Adolescent with Autism.

    ERIC Educational Resources Information Center

    Gunter, Philip L.; And Others

    1993-01-01

    In this case study, music was applied noncontingently and contingently across four settings with an adolescent male with autism, to reduce aberrant, repetitive vocalizations. The intervention was associated with dramatic reductions in the primary aberrant behavior and reductions in two other aberrant behaviors. Task performance was differentially…

  2. Detection of aberrant responding on a personality scale in a military sample: an application of evaluating person fit with two-level logistic regression.

    PubMed

    Woods, Carol M; Oltmanns, Thomas F; Turkheimer, Eric

    2008-06-01

    Person-fit assessment is used to identify persons who respond aberrantly to a test or questionnaire. In this study, S. P. Reise's (2000) method for evaluating person fit using 2-level logistic regression was applied to 13 personality scales of the Schedule for Nonadaptive and Adaptive Personality (SNAP; L. Clark, 1996) that had been administered to military recruits (N = 2,026). Results revealed significant person-fit heterogeneity and indicated that for 5 SNAP scales (Disinhibition, Entitlement, Exhibitionism, Negative Temperament, and Workaholism), the scale was more discriminating for some people than for others. Possible causes of aberrant responding were explored with several covariates. On all 5 scales, severe pathology emerged as a key influence on responses, and there was evidence of differential test functioning with respect to gender, ethnicity, or both. Other potential sources of aberrancy were carelessness, haphazard responding, or uncooperativeness. Social desirability was not as influential as expected.

  3. A Model-Independent Algorithm to Derive Ca2+ Fluxes Underlying Local Cytosolic Ca2+ Transients

    PubMed Central

    Ventura, Alejandra C.; Bruno, Luciana; Demuro, Angelo; Parker, Ian; Ponce Dawson, Silvina

    2005-01-01

    Local intracellular Ca2+ signals result from Ca2+ flux into the cytosol through individual channels or clusters of channels. To gain a mechanistic understanding of these events we need to know the magnitude and spatial distribution of the underlying Ca2+ flux. However, this is difficult to infer from fluorescence Ca2+ images because the distribution of Ca2+-bound dye is affected by poorly characterized processes including diffusion of Ca2+ ions, their binding to mobile and immobile buffers, and sequestration by Ca2+ pumps. Several methods have previously been proposed to derive Ca2+ flux from fluorescence images, but all require explicit knowledge or assumptions regarding these processes. We now present a novel algorithm that requires few assumptions and is largely model-independent. By testing the algorithm with both numerically generated image data and experimental images of sparklets resulting from Ca2+ flux through individual voltage-gated channels, we show that it satisfactorily reconstructs the magnitude and time course of the underlying Ca2+ currents. PMID:15681645

  4. The Ca(2+)/Calmodulin/CaMKK2 Axis: Nature's Metabolic CaMshaft.

    PubMed

    Marcelo, Kathrina L; Means, Anthony R; York, Brian

    2016-10-01

    Calcium (Ca(2+)) is an essential ligand that binds its primary intracellular receptor calmodulin (CaM) to trigger a variety of downstream processes and pathways. Central to the actions of Ca(2+)/CaM is the activation of a highly conserved Ca(2+)/CaM kinase (CaMK) cascade that amplifies Ca(2+) signals through a series of subsequent phosphorylation events. Proper regulation of Ca(2+) flux is necessary for whole-body metabolism and disruption of Ca(2+) homeostasis has been linked to various metabolic diseases. Here we provide a synthesis of recent advances that highlight the roles of the Ca(2+)/CaMK axis in key metabolic tissues. An appreciation of this information is critical to understanding the mechanisms by which Ca(2+)/CaM-dependent signaling contributes to metabolic homeostasis and disease.

  5. Comparison of two types of visual quality analyzer for the measurement of high order aberrations

    PubMed Central

    Hao, Jing; Li, Lin; Tian, Fang; Zhang, Hong

    2016-01-01

    AIM To compare the difference and agreement of KR-1W and iTrace for measurement of high order aberrations. METHODS KR-1W and iTrace were respectively used in a group of healthy people (40 volunteers, 32 eyes) to measure the high order aberration (HOA) of corneal, internal and total ocular. The clinical difference and agreement of two instruments were respectively evaluated by paired-samples t-test and Bland-Altman analysis. RESULTS The paired-samples t-test showed that the corneal HOA measured by the two instruments had no statistical differences (P>0.05); but the internal and total ocular HOA had significant statistical differences (P<0.05), and the mean results measured by iTrace were higher than that of KR-1W. However, Bland-Altman analysis revealed that the HOA of corneal and internal were all in 95% limits of agreement; and just one point of total ocular HOA was beyond the 95% limits of agreement. CONCLUSION KR-1W and iTrace were consistent well in the measurement of corneal, internal and total ocular HOA, especially for the cornea. PMID:26949654

  6. Correlation among auto-refractor, wavefront aberration, and subjective manual refraction

    NASA Astrophysics Data System (ADS)

    Li, Qi; Ren, Qiushi

    2005-01-01

    Three optometry methods which include auto-refractor, wavefront aberrometer and subjective manual refraction were studied and compared in measuring low order aberrations of 60 people"s 117 normal eyes. Paired t-test and linear regression were used to study these three methods" relationship when measuring myopia with astigmatism. In order to make the analysis more clear, we divided the 117 normal eyes into different groups according to their subjective manual refraction and redid the statistical analysis. Correlations among three methods show significant in sphere, cylinder and axis in all groups, with sphere"s correlation coefficients largest(R>0.98, P<0.01) and cylinder"s smallest (0.90test before grouping showed the difference of three optometry methods in measuring sphere was significant (P<0.01) while axis"s difference was not significant (P>0.01). Auto-refractor had significant change from the other two methods when measuring cylinder (P<0.01). The results after grouping differed a little from the analysis among total people. Although three methods showed significant change from each other in certain parameters, the amplitude of these differences were not large, which indicated that the coherence of auto-refractor, wavefront aberrometer and subjective refraction is good. However, we suggested that wavefront aberration measurement could be a good starting point of optometry, subjective refraction is still necessary for refinement.

  7. Reliability of the Aberrant Behavior Checklist and the effect of variations in instructions.

    PubMed

    Aman, M G; Singh, N N; Turbott, S H

    1987-09-01

    Interrater and test-retest reliabilities of the Aberrant Behavior Checklist were compared on the basis of type of instructions to raters. Three nurses in each of three residential units twice rated 28 mentally retarded residents, using one type of rating system, and the ratings were repeated 4 weeks later. The frequency-based instructions resulted in both higher interrater and test-retest reliability coefficients than did the other instructional types. Frequency-based ratings were performed again in another residential unit, but the higher reliabilities were not replicated. Interrater and test-retest reliability correlations varied markedly both across subscales and raters but were comparable to levels derived with other symptom checklists. We concluded that rater characteristics (e.g., motivation) are more powerful variables than are scoring systems.

  8. Nuclear anomalies, chromosomal aberrations and proliferation rates in cultured lymphocytes of head and neck cancer patients.

    PubMed

    George, Alex; Dey, Rupraj; Bhuria, Vikas; Banerjee, Shouvik; Ethirajan, Sivakumar; Siluvaimuthu, Ashok; Saraswathy, Radha

    2014-01-01

    Head and neck cancers (HNC) are extremely complex disease types and it is likely that chromosomal instability is involved in the genetic mechanisms of its genesis. However, there is little information regarding the background levels of chromosome instability in these patients. In this pilot study, we examined spontaneous chromosome instability in short-term lymphocyte cultures (72 hours) from 72 study subjects - 36 newly diagnosed HNC squamous cell carcinoma patients and 36 healthy ethnic controls. We estimated chromosome instability (CIN) using chromosomal aberration (CA) analysis and nuclear level anomalies using the Cytokinesis Block Micronucleus Cytome Assay (CBMN Cyt Assay). The proliferation rates in cultures of peripheral blood lymphocytes (PBL) were assessed by calculating the Cytokinesis Block Proliferation Index (CBPI). Our results showed a significantly higher mean level of spontaneous chromosome type aberrations (CSAs), chromatid type aberration (CTAs) dicentric chromosomes (DIC) and chromosome aneuploidy (CANEUP) in patients (CSAs, 0.0294±0.0038; CTAs, 0.0925±0.0060; DICs, 0.0213±0.0028; and CANEUPs, 0.0308±0.0035) compared to controls (CSAs, 0.0005±0.0003; CTAs, 0.0058±0.0015; DICs, 0.0005±0.0003; and CANEUPs, 0.0052±0.0013) where p<0.001. Similarly, spontaneous nuclear anomalies showed significantly higher mean level of micronuclei (MNi), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) among cases (MNi, 0.01867±0.00108; NPBs, 0.01561±0.00234; NBUDs, 0.00658±0.00068) compared with controls (MNi, 0.00027±0.00009; NPBs, 0.00002±0.00002; NBUDs, 0.00011±0.00007).The evaluation of CBPI supported genomic instability in the peripheral blood lymphocytes showing a significantly lower proliferation rate in HNC patients (1.525±0.005552) compared to healthy subjects (1.686±0.009520 ) (p<0.0001). In conclusion, our preliminary results showed that visible spontaneous genomic instability and low rate proliferation in the cultured peripheral

  9. Assessment of chromosomal aberrations and micronuclei in peripheral lymphocytes from tunisian hospital workers exposed to ionizing radiation.

    PubMed

    Sakly, Amina; Ayed, Yosra; Chaari, Neila; Akrout, Mohamed; Bacha, Hassen; Cheikh, Hassen Ben

    2013-09-01

    Epidemiological studies suggest that cytogenetic biomarkers, such as micronuclei (MN) in peripheral blood lymphocytes may predict cancer risk because they indicate genomic instability. The objective of the present study was to evaluate the frequencies of MN and chromosome aberrations (CA) in peripheral blood lymphocytes of hospital workers exposed to ionizing radiation and healthy subjects. The study was conducted using peripheral blood lymphocytes from 30 workers from the radiology department and 30 from the cardiology department. This study included 27 healthy age- and sex-matched individuals as the control group. The assessment of chromosomal damage was carried out by the use of CA and micronucleus assays in peripheral lymphocytes. Our results show that CA and micronucleus frequencies were significantly higher among the exposed groups when compared to controls. Our finding of significant increase of CA and MN frequencies in peripheral lymphocytes in exposed workers indicates a potential cytogenetic hazard due to this exposure. The enhanced chromosomal damage of subjects exposed to genotoxic agents emphasizes the need to develop safety programs. PMID:23216272

  10. Generation and Behavior Characterization of CaMKIIβ Knockout Mice

    PubMed Central

    Tu, Tao; Goulding, Danielle S.; Haiech, Jacques; Watterson, D. Martin; Van Eldik, Linda J.

    2014-01-01

    The calcium/calmodulin-dependent protein kinase II (CaMKII) is abundant in the brain, where it makes important contributions to synaptic organization and homeostasis, including playing an essential role in synaptic plasticity and memory. Four genes encode isoforms of CaMKII (α, β, δ, γ), with CaMKIIα and CaMKIIβ highly expressed in the brain. Decades of molecular and cellular research, as well as the use of a large number of CaMKIIα mutant mouse lines, have provided insight into the pivotal roles of CaMKIIα in brain plasticity and cognition. However, less is known about the CaMKIIβ isoform. We report the development and extensive behavioral and phenotypic characterization of a CaMKIIβ knockout (KO) mouse. The CaMKIIβ KO mouse was found to be smaller at weaning, with an altered body mass composition. The CaMKIIβ KO mouse showed ataxia, impaired forelimb grip strength, and deficits in the rotorod, balance beam and running wheel tasks. Interestingly, the CaMKIIβ KO mouse exhibited reduced anxiety in the elevated plus maze and open field tests. The CaMKIIβ KO mouse also showed cognitive impairment in the novel object recognition task. Our results provide a comprehensive behavioral characterization of mice deficient in the β isoform of CaMKII. The neurologic phenotypes and the construction of the genotype suggest the utility of this KO mouse strain for future studies of CaMKIIβ in brain structure, function and development. PMID:25127391

  11. Aberrantly methylated genes in human papillary thyroid cancer and their association with BRAF/RAS mutation

    PubMed Central

    Kikuchi, Yasuko; Tsuji, Eiichi; Yagi, Koichi; Matsusaka, Keisuke; Tsuji, Shingo; Kurebayashi, Junichi; Ogawa, Toshihisa; Aburatani, Hiroyuki; Kaneda, Atsushi

    2013-01-01

    Cancer arises through accumulation of epigenetic and genetic alteration. Aberrant promoter methylation is a common epigenetic mechanism of gene silencing in cancer cells. We here performed genome-wide analysis of DNA methylation of promoter regions by Infinium HumanMethylation27 BeadChip, using 14 clinical papillary thyroid cancer samples and 10 normal thyroid samples. Among the 14 papillary cancer cases, 11 showed frequent aberrant methylation, but the other three cases showed no aberrant methylation at all. Distribution of the hypermethylation among cancer samples was non-random, which implied existence of a subset of preferentially methylated papillary thyroid cancer. Among 25 frequently methylated genes, methylation status of six genes (HIST1H3J, POU4F2, SHOX2, PHKG2, TLX3, HOXA7) was validated quantitatively by pyrosequencing. Epigenetic silencing of these genes in methylated papillary thyroid cancer cell lines was confirmed by gene re-expression following treatment with 5-aza-2′-deoxycytidine and trichostatin A, and detected by real-time RT-PCR. Methylation of these six genes was validated by analysis of additional 20 papillary thyroid cancer and 10 normal samples. Among the 34 cancer samples in total, 26 cancer samples with preferential methylation were significantly associated with mutation of BRAF/RAS oncogene (P = 0.04, Fisher's exact test). Thus, we identified new genes with frequent epigenetic hypermethylation in papillary thyroid cancer, two subsets of either preferentially methylated or hardly methylated papillary thyroid cancer, with a concomitant occurrence of oncogene mutation and gene methylation. These hypermethylated genes may constitute potential biomarkers for papillary thyroid cancer. PMID:24367375

  12. Chromosomal aberration analysis among underground water well workers in Saudi Arabia.

    PubMed

    AlSuhaibani, Entissar S

    2011-03-01

    In the absence of permanent rivers or bodies of water, half of the Saudi Arabia domestic water consumption is provided through desalination. The other half is derived from groundwater. Groundwater from the Disi aquifer is already used for drinking water in parts of Jordan and, more extensively, in Saudi Arabia, where it is known as the Saq aquifer. Some of the geological analyses of the host sandstone aquifer rocks show (228)Ra and (226)Ra. The usefulness of chromosomal aberrations analysis as a bioindicator for ionising radiation effect was tested in underground water well workers of Saudi Arabia in this industry producing technologically enhanced naturally occurring radioactive material. The incidence of chromosomal aberrations was evaluated using the metaphase analysis method in the lymphocytes of peripheral blood of 10 persons working in underground water well. The age range of the workers was 25-40 y and their duration of service ranged from 3-7 y. For comparison, blood samples were also collected from 10 subjects (controls) who belonged to same age and socioeconomic status. Subjects in the both groups were non-smokers and non-alcoholics. Results showed that the mean frequencies of dicentrics and acentrics in underground water well workers are significantly higher than those in controls. The higher frequency of chromosomal aberration in lymphocytes of underground water well workers compared with controls could be due to the accumulative effect of radiation. The results of this study demonstrated that occupational exposure to radiation leads to a significant induction of cytogenetic damage in peripheral lymphocytes of workers engaged in underground water well.

  13. Aberrations and adaptive optics in super-resolution microscopy.

    PubMed

    Booth, Martin; Andrade, Débora; Burke, Daniel; Patton, Brian; Zurauskas, Mantas

    2015-08-01

    As one of the most powerful tools in the biological investigation of cellular structures and dynamic processes, fluorescence microscopy has undergone extraordinary developments in the past decades. The advent of super-resolution techniques has enabled fluorescence microscopy - or rather nanoscopy - to achieve nanoscale resolution in living specimens and unravelled the interior of cells with unprecedented detail. The methods employed in this expanding field of microscopy, however, are especially prone to the detrimental effects of optical aberrations. In this review, we discuss how super-resolution microscopy techniques based upon single-molecule switching, stimulated emission depletion and structured illumination each suffer from aberrations in different ways that are dependent upon intrinsic technical aspects. We discuss the use of adaptive optics as an effective means to overcome this problem.

  14. Aberrant expression and function of gap junctions during carcinogenesis.

    PubMed Central

    Yamasaki, H

    1991-01-01

    Gap junctional intercellular communication plays a key role in the maintenance of homeostasis in multicellular organisms. Reflecting deranged homeostasis in cancer cells, most transformed or cancerous cells show aberrant gap junctional intercellular communication; they have decreased junctional communication between each other and/or with surrounding normal cells. Studies with in vitro cell transformation and animal carcinogenesis models suggest an involvement of blocked intercellular communication in later stages of carcinogenesis. Analysis of expression of gap junction proteins (connexins) and corresponding mRNA indicates that a number of regulation sites are involved in aberrant function of gap junctions during carcinogenesis. Suppression of transformed phenotypes is often seen when transformed cells are physically in contact with their normal counterparts. Some studies suggest that gap junctional intercellular communication is involved in such tumor suppression. PMID:1663449

  15. Electromagnetic Induction Aberration: The Possible Mechanism of Tic Douloureux.

    PubMed

    Rish, Berkley

    2015-03-01

    A theory based on the principles of electromagnetic induction aberration is presented as the possible mechanism of classic trigeminal neuralgia, tic douloureux. The anatomy of the dorsal root entry zone of the trigeminal nerve at the pons in the proximity of the superior cerebellar artery presents a scenario conducive to the phenomenon of electromagnetic induction. When the action potentials traversing the axons in this zone of the compromised myelin come into juxtaposition with the vascular structure, the criteria for electromagnetic induction are satisfied. The laws of physics governing the phenomenon indicate that a new current, an aberration, would be produced. This could be responsible for the clinical symptoms of tic douloureux. Other clinical situations with similar features could share this mechanism. This proposed theory, a merger of anatomy, neurophysiology, and the physics of electromagnetic induction, extends the established concept of vascular compression as the etiology of tic douloureux.

  16. Evaluation of an automated karyotyping system for chromosome aberration analysis

    NASA Technical Reports Server (NTRS)

    Prichard, Howard M.

    1987-01-01

    Chromosome aberration analysis is a promising complement to conventional radiation dosimetry, particularly in the complex radiation fields encountered in the space environment. The capabilities of a recently developed automated karyotyping system were evaluated both to determine current capabilities and limitations and to suggest areas where future development should be emphasized. Cells exposed to radiometric chemicals and to photon and particulate radiation were evaluated by manual inspection and by automated karyotyping. It was demonstrated that the evaluated programs were appropriate for image digitization, storage, and transmission. However, automated and semi-automated scoring techniques must be advanced significantly if in-flight chromosome aberration analysis is to be practical. A degree of artificial intelligence may be necessary to realize this goal.

  17. Aberrant hippocampal neurogenesis contributes to epilepsy and associated cognitive decline.

    PubMed

    Cho, Kyung-Ok; Lybrand, Zane R; Ito, Naoki; Brulet, Rebecca; Tafacory, Farrah; Zhang, Ling; Good, Levi; Ure, Kerstin; Kernie, Steven G; Birnbaum, Shari G; Scharfman, Helen E; Eisch, Amelia J; Hsieh, Jenny

    2015-03-26

    Acute seizures after a severe brain insult can often lead to epilepsy and cognitive impairment. Aberrant hippocampal neurogenesis follows the insult but the role of adult-generated neurons in the development of chronic seizures or associated cognitive deficits remains to be determined. Here we show that the ablation of adult neurogenesis before pilocarpine-induced acute seizures in mice leads to a reduction in chronic seizure frequency. We also show that ablation of neurogenesis normalizes epilepsy-associated cognitive deficits. Remarkably, the effect of ablating adult neurogenesis before acute seizures is long lasting as it suppresses chronic seizure frequency for nearly 1 year. These findings establish a key role of neurogenesis in chronic seizure development and associated memory impairment and suggest that targeting aberrant hippocampal neurogenesis may reduce recurrent seizures and restore cognitive function following a pro-epileptic brain insult.

  18. Detection of epigenetic aberrations in the development of hepatocellular carcinoma.

    PubMed

    Zhang, Yujing

    2015-01-01

    Hepatocellular carcinoma (HCC) is the third most common cause of cancer death worldwide. Hepatocarcinogenesis is a complex, multistep process. It is now recognized that HCC is a both genetic and epigenetic disease; genetic and epigenetic components cooperate at all stages of hepatocarcinogenesis. Epigenetic changes involve aberrant DNA methylation, posttranslational histone modifications and aberrant expression of microRNAs all of which can affect the expression of oncogenes, tumor suppressor genes and other tumor-related genes and alter the pathways in cancer development. Several risk factors for HCC, including hepatitis B and C virus infections and exposure to the chemical carcinogen aflatoxin B1 have been found to influence epigenetic changes. Their interactions could play an important role in the initiation and progression of HCC. Discovery and detection of biomarkers for epigenetic changes is a promising area for early diagnosis and risk prediction of HCC.

  19. Functional annotation of rare gene aberration drivers of pancreatic cancer.

    PubMed

    Tsang, Yiu Huen; Dogruluk, Turgut; Tedeschi, Philip M; Wardwell-Ozgo, Joanna; Lu, Hengyu; Espitia, Maribel; Nair, Nikitha; Minelli, Rosalba; Chong, Zechen; Chen, Fengju; Chang, Qing Edward; Dennison, Jennifer B; Dogruluk, Armel; Li, Min; Ying, Haoqiang; Bertino, Joseph R; Gingras, Marie-Claude; Ittmann, Michael; Kerrigan, John; Chen, Ken; Creighton, Chad J; Eterovic, Karina; Mills, Gordon B; Scott, Kenneth L

    2016-01-01

    As we enter the era of precision medicine, characterization of cancer genomes will directly influence therapeutic decisions in the clinic. Here we describe a platform enabling functionalization of rare gene mutations through their high-throughput construction, molecular barcoding and delivery to cancer models for in vivo tumour driver screens. We apply these technologies to identify oncogenic drivers of pancreatic ductal adenocarcinoma (PDAC). This approach reveals oncogenic activity for rare gene aberrations in genes including NAD Kinase (NADK), which regulates NADP(H) homeostasis and cellular redox state. We further validate mutant NADK, whose expression provides gain-of-function enzymatic activity leading to a reduction in cellular reactive oxygen species and tumorigenesis, and show that depletion of wild-type NADK in PDAC cell lines attenuates cancer cell growth in vitro and in vivo. These data indicate that annotating rare aberrations can reveal important cancer signalling pathways representing additional therapeutic targets. PMID:26806015

  20. The effect of wavefront aberrations in atom interferometry

    NASA Astrophysics Data System (ADS)

    Schkolnik, V.; Leykauf, B.; Hauth, M.; Freier, C.; Peters, A.

    2015-08-01

    Wavefront aberrations are one of the largest uncertainty factors in present atom interferometers. We present a detailed numerical and experimental analysis of this effect based on measured aberrations from optical windows. By placing windows into the Raman beam path of our atomic gravimeter, we verify for the first time the induced bias in very good agreement with theory. Our method can be used to reduce the uncertainty in atomic gravimeters by one order of magnitude, resulting in an error of <3 × 10-10g, and it is suitable in a wide variety of atom interferometers with thermal or ultracold atoms. We discuss the limitations of our method, potential improvements, and its role in future generation experiments.

  1. EUV phase-shifting masks and aberration monitors

    NASA Astrophysics Data System (ADS)

    Deng, Yunfei; Neureuther, Andrew R.

    2002-07-01

    Rigorous electromagnetic simulation with TEMPEST is used to examine the use of phase-shifting masks in EUV lithography. The effects of oblique incident illumination and mask patterning by ion-mixing of multilayers are analyzed. Oblique incident illumination causes streamers at absorber edges and causes position shifting in aerial images. The diffraction waves between ion-mixed and pristine multilayers are observed. The phase-shifting caused by stepped substrates is simulated and images show that it succeeds in creation of phase-shifting effects. The diffraction process at the phase boundary is also analyzed. As an example of EUV phase-shifting masks, a coma pattern and probe based aberration monitor is simulated and aerial images are formed under different levels of coma aberration. The probe signal rises quickly as coma increases as designed.

  2. Application of pupil spherical aberration in tuning zoom lens design

    NASA Astrophysics Data System (ADS)

    Lin, Chen-Hung; Chang, Horng; Lin, Hoang Yan

    2012-06-01

    Fine tuning the performance of a zoom lens, at the final design stage, is still a challenging problem for lens designers. This is mainly due to the difficulties in setting up a reliable criterion as the discriminator. In this paper, following some previous studies on pupil spherical aberration (PSA, denoted as SVI) (Wynne 1952 Proc. Phys. Soc. 65 429-37, Kidger 1996 Proc. SPIE 2774 722-7) where the conditions for invariance of Seidel aberration during conjugate changes were given, a simple method was derived to analyze the steady zone of a zoom lens variator. A previously designed zoom system (Laikin 2006 Lens Design 3rd edn (Boca Raton, FL: CRC Press) pp 393-5) was selected as an example and it was shown how its image quality can be balanced and improved computationally. The potential application of our method was also addressed in the conclusion.

  3. Spherical Aberration Corrections for the Electrostatic Gridded Lens

    SciTech Connect

    Pikin,A.

    2008-05-01

    Two methods of spherical aberration corrections of an electrostatic gridded lens have been studied with ray tracing simulations. Both methods are based on modifying electrostatic field on the periphery of the lens. In a simplest case such modification is done by extending the part of the grid support on its radial periphery in axial direction. In alternative method the electric field on the radial periphery of the lens is modified by applying an optimum voltage on an electrically isolated correcting electrode. It was demonstrated, that for a given focal length the voltage on this lens can be optimized for minimum aberration The performance of lenses is presented as a lens contribution to the beam RMS normalized emittance.

  4. Aberrant hippocampal neurogenesis contributes to epilepsy and associated cognitive decline.

    PubMed

    Cho, Kyung-Ok; Lybrand, Zane R; Ito, Naoki; Brulet, Rebecca; Tafacory, Farrah; Zhang, Ling; Good, Levi; Ure, Kerstin; Kernie, Steven G; Birnbaum, Shari G; Scharfman, Helen E; Eisch, Amelia J; Hsieh, Jenny

    2015-01-01

    Acute seizures after a severe brain insult can often lead to epilepsy and cognitive impairment. Aberrant hippocampal neurogenesis follows the insult but the role of adult-generated neurons in the development of chronic seizures or associated cognitive deficits remains to be determined. Here we show that the ablation of adult neurogenesis before pilocarpine-induced acute seizures in mice leads to a reduction in chronic seizure frequency. We also show that ablation of neurogenesis normalizes epilepsy-associated cognitive deficits. Remarkably, the effect of ablating adult neurogenesis before acute seizures is long lasting as it suppresses chronic seizure frequency for nearly 1 year. These findings establish a key role of neurogenesis in chronic seizure development and associated memory impairment and suggest that targeting aberrant hippocampal neurogenesis may reduce recurrent seizures and restore cognitive function following a pro-epileptic brain insult. PMID:25808087

  5. Functional annotation of rare gene aberration drivers of pancreatic cancer

    PubMed Central

    Tsang, Yiu Huen; Dogruluk, Turgut; Tedeschi, Philip M.; Wardwell-Ozgo, Joanna; Lu, Hengyu; Espitia, Maribel; Nair, Nikitha; Minelli, Rosalba; Chong, Zechen; Chen, Fengju; Chang, Qing Edward; Dennison, Jennifer B.; Dogruluk, Armel; Li, Min; Ying, Haoqiang; Bertino, Joseph R.; Gingras, Marie-Claude; Ittmann, Michael; Kerrigan, John; Chen, Ken; Creighton, Chad J.; Eterovic, Karina; Mills, Gordon B.; Scott, Kenneth L.

    2016-01-01

    As we enter the era of precision medicine, characterization of cancer genomes will directly influence therapeutic decisions in the clinic. Here we describe a platform enabling functionalization of rare gene mutations through their high-throughput construction, molecular barcoding and delivery to cancer models for in vivo tumour driver screens. We apply these technologies to identify oncogenic drivers of pancreatic ductal adenocarcinoma (PDAC). This approach reveals oncogenic activity for rare gene aberrations in genes including NAD Kinase (NADK), which regulates NADP(H) homeostasis and cellular redox state. We further validate mutant NADK, whose expression provides gain-of-function enzymatic activity leading to a reduction in cellular reactive oxygen species and tumorigenesis, and show that depletion of wild-type NADK in PDAC cell lines attenuates cancer cell growth in vitro and in vivo. These data indicate that annotating rare aberrations can reveal important cancer signalling pathways representing additional therapeutic targets. PMID:26806015

  6. Method for identifying and quantifying nucleic acid sequence aberrations

    DOEpatents

    Lucas, J.N.; Straume, T.; Bogen, K.T.

    1998-07-21

    A method is disclosed for detecting nucleic acid sequence aberrations by detecting nucleic acid sequences having both a first and a second nucleic acid sequence type, the presence of the first and second sequence type on the same nucleic acid sequence indicating the presence of a nucleic acid sequence aberration. The method uses a first hybridization probe which includes a nucleic acid sequence that is complementary to a first sequence type and a first complexing agent capable of attaching to a second complexing agent and a second hybridization probe which includes a nucleic acid sequence that selectively hybridizes to the second nucleic acid sequence type over the first sequence type and includes a detectable marker for detecting the second hybridization probe. 11 figs.

  7. Method for identifying and quantifying nucleic acid sequence aberrations

    DOEpatents

    Lucas, Joe N.; Straume, Tore; Bogen, Kenneth T.

    1998-01-01

    A method for detecting nucleic acid sequence aberrations by detecting nucleic acid sequences having both a first and a second nucleic acid sequence type, the presence of the first and second sequence type on the same nucleic acid sequence indicating the presence of a nucleic acid sequence aberration. The method uses a first hybridization probe which includes a nucleic acid sequence that is complementary to a first sequence type and a first complexing agent capable of attaching to a second complexing agent and a second hybridization probe which includes a nucleic acid sequence that selectively hybridizes to the second nucleic acid sequence type over the first sequence type and includes a detectable marker for detecting the second hybridization probe.

  8. Holographic optical system for aberration corrections in laser Doppler velocimetry

    NASA Technical Reports Server (NTRS)

    Kim, R. C.; Case, S. K.; Schock, H. J.

    1985-01-01

    An optical system containing multifaceted holographic optical elements (HOEs) has been developed to correct for aberrations introduced by nonflat windows in laser Doppler velocimetry. The multifacet aberration correction approach makes it possible to record on one plate many sets of adjacent HOEs that address different measurement volume locations. By using 5-mm-diameter facets, it is practical to place 10-20 sets of holograms on one 10 x 12.5-cm plate, so that the procedure of moving the entire optical system to examine different locations may not be necessary. The holograms are recorded in dichromated gelatin and therefore are nonabsorptive and suitable for use with high-power argon laser beams. Low f-number optics coupled with a 90-percent efficient distortion-correcting hologram in the collection side of the system yield high optical efficiency.

  9. Automated spherical aberration correction in scanning confocal microscopy

    NASA Astrophysics Data System (ADS)

    Yoo, H. W.; van Royen, M. E.; van Cappellen, W. A.; Houtsmuller, A. B.; Verhaegen, M.; Schitter, G.

    2014-12-01

    Mismatch between the refractive indexes of immersion media and glass coverslips introduces spherical aberrations in microscopes especially for high numerical aperture objectives. This contribution demonstrates an automated adjustment of the coverslip correction collar in scanning confocal microscopy to compensate for spherical aberrations due to coverslip thickness mismatch. With a motorized coverslip correction collar, the adjustment procedure consists of xz image scans, image processing, correction quality evaluation, the mismatch estimation, and eventually the optimal adjustment of the correction collar. For fast correction with less photodamage, coarse-fine Gaussian fitting algorithms are proposed and evaluated with various specimen for their estimation accuracy. The benefits of the proposed automated correction are demonstrated for various coverslips with biological specimens, showing the optimized resolution of the confocal microscope.

  10. Pericellular Ca2+ recycling potentiates thrombin-evoked Ca2+ signals in human platelets

    PubMed Central

    Sage, Stewart O; Pugh, Nicholas; Farndale, Richard W; Harper, Alan G S

    2013-01-01

    We have previously demonstrated that Na+/Ca2+ exchangers (NCXs) potentiate Ca2+ signaling evoked by thapsigargin in human platelets, via their ability to modulate the secretion of autocoids from dense granules. This link was confirmed in platelets stimulated with the physiological agonist, thrombin, and experiments were performed to examine how Ca2+ removal by the NCX modulates platelet dense granule secretion. In cells loaded with the near-membrane indicator FFP-18, thrombin stimulation was observed to elicit an NCX-dependent accumulation of Ca2+ in a pericellular region around the platelets. To test whether this pericellular Ca2+ accumulation might be responsible for the influence of NCXs over platelet function, platelets were exposed to fast Ca2+ chelators or had their glycocalyx removed. Both manipulations of the pericellular Ca2+ rise reduced thrombin-evoked Ca2+ signals and dense granule secretion. Blocking Ca2+-permeable ion channels had a similar effect, suggesting that Ca2+ exported into the pericellular region is able to recycle back into the platelet cytosol. Single cell imaging with extracellular Fluo-4 indicated that thrombin-evoked rises in extracellular [Ca2+] occurred within the boundary described by the cell surface, suggesting their presence within the open canalicular system (OCS). FFP-18 fluorescence was similarly distributed. These data suggest that upon thrombin stimulation, NCX activity creates a rise in [Ca2+] within the pericellular region of the platelet from where it recycles back into the platelet cytosol, acting to both accelerate dense granule secretion and maintain the initial rise in cytosolic [Ca2+]. PMID:24303163

  11. Thoracic Kidney: Extremely Rare State of Aberrant Kidney

    PubMed Central

    Khoshchehreh, Mahdi; Paknejad, Omalbanin; Bakhshayesh-Karam, Mehrdad; Pazoki, Marzieh

    2015-01-01

    The thorax is the rarest place among all forms of renal ectopia. We report a rare case of an unacquired thoracic kidney. Only about 200 cases of the thoracic kidney have ever been reported in medical literature worldwide. In this paper we present the rarest form of nontraumatic nonhernia associated, truly ectopic thoracic kidney. The differential diagnosis and management options and classification of this rare form of aberrant kidney are discussed. PMID:26301113

  12. Aberrations and spherocylindrical powers within subapertures of freeform surfaces.

    PubMed

    Raasch, Thomas

    2011-12-01

    A method is described for the derivation of refractive properties and aberration structure of subapertures of freeform surfaces. Surface shapes are described in terms of Zernike polynomials. The method utilizes matrices to transform between Zernike and Taylor coefficients. Expression as a Taylor series facilitates the translation and size rescaling of subapertures of the surface. An example operation using a progressive addition lens surface illustrates the method. PMID:22193277

  13. Influence of chromatic aberrations on space charge ion optics.

    PubMed

    Whealton, J H; Tsai, C C

    1978-04-01

    By solution to the Poisson-Vlasov equation the influence of fluctuations (chromatic aberrations) on ion optics is shown for various accelerator designs : (1) cylindrical bore triode with various aspect ratios, (2) pseudo-Pierce shaped electrode triode at various aspect ratios, (3) insulated coating emission electrode triode for various preacceleration potentials, and (4) cylindrical bore tetrodes for various field distributions. Fluctuation levels of 20% can be very important in limiting the ion optics in certain cases.

  14. Aberrant Phenotype in Iranian Patients with Acute Myeloid Leukemia

    PubMed Central

    Jahedi, Mehdi; Shamsasenjan, Karim; Sanaat, Zohreh; Aliparasti, MohammadReza; Almasi, Shohreh; Mohamadian, Mozhdeh; Nejati, Babak; Kamalifar, Amir; Movassaghpour, Ali Akbar

    2014-01-01

    Purpose: The aim of this study was to evaluate the incidence of aberrant phenotypes and possible prognostic value in peripheral and bone marrow blood mononuclear cells of Iranian patients with AML. Methods: 56 cases of de novo AML (2010-2012) diagnosed by using an acute panel of monoclonal antibodies by multiparametric flowcytometry. Immunophenotyping was done on fresh bone marrow aspirate and/or peripheral blood samples using the acute panel of MoAbs is stained with Phycoerythrin (PE) /fluorescein isothiocyanate (FITC), Allophycocyanin (APC) and Peridinin-chlorophyll protein complex (perCP). We investigated Co-expression of lymphoid-associated markers CD2, CD3, CD7, CD 10, CD19, CD20 and CD22 in myeloblasts. Results: Out of the 56 cases, 32 (57.1%) showed AP. CD7 was positive in 72.7% of cases in M1 and 28.5% in M2 but M3 and M4 cases lacked this marker. We detected CD2 in 58.35 of M1cases, 21.40% of M2 cases, 33.3 of M3 and 20% of M5; but M4 patients lacked this marker. The CBC analysis demonstrated a wide range of haemoglobin concentration, Platelet and WBC count which varied from normal to anaemia, thrombocytopenia to thrombocytosis and leukopenia to hyper leukocytosis. Conclusions: Our findings showed that CD7 and CD2 were the most common aberrant marker in Iranian patients with AML. However, we are not find any significant correlation between aberrant phenotype changing and MRD in our population. Taken together, this findings help to provide new insights in to the investigation of other aberrant phenotypes that may play roles in diagnosis and therapeutic of AML. PMID:24409408

  15. Chromosome aberrations in ataxia telangiectasia cells exposed to heavy ions

    NASA Astrophysics Data System (ADS)

    Kawata, T.; Cucinotta, F.; George, K.; Wu, H.; Shigematsu, N.; Furusawa, Y.; Uno, T.; Isobe, K.; Ito, H.

    Understanding of biological effects of heavy ions is important to assess healt h risk in space. One of the most important issues may be to take into account individual susceptibility. Ataxia telangiectasia (A-T) cells are known to exhibit abnormal responses to radiations but the mechanism of hyper radiosensitivity of A-T still remains unknown. We report chromosome aberrations in normal human fibroblasts and AT fibroblasts exposed to low- and high-LET radiations. A chemical-induced premature chromosome condensation (PCC) technique combined with chromosome- painting technique was applied to score chromosome aberrations in G2/M-phase cells. Following gamma irradiation, GM02052 cells were approximately 5 times more sensitive to g-rays than AG1522 cells. GM02052 cells had a much higher frequency of deletions and misrejoining than AG1522 cells. When the frequency of complex type aberrations was compared, GM02052 cells showed more than 10 times higher frequency than AG1522 cells. The results will be compared with those obtained from high-LET irradiations.

  16. Polarization Aberrations in Astronomical Telescopes: The Point Spread Function

    NASA Astrophysics Data System (ADS)

    Breckinridge, James B.; Lam, Wai Sze T.; Chipman, Russell A.

    2015-05-01

    Detailed knowledge of the image of the point spread function (PSF) is necessary to optimize astronomical coronagraph masks and to understand potential sources of errors in astrometric measurements. The PSF for astronomical telescopes and instruments depends not only on geometric aberrations and scalar wave diffraction but also on those wavefront errors introduced by the physical optics and the polarization properties of reflecting and transmitting surfaces within the optical system. These vector wave aberrations, called polarization aberrations, result from two sources: (1) the mirror coatings necessary to make the highly reflecting mirror surfaces, and (2) the optical prescription with its inevitable non-normal incidence of rays on reflecting surfaces. The purpose of this article is to characterize the importance of polarization aberrations, to describe the analytical tools to calculate the PSF image, and to provide the background to understand how astronomical image data may be affected. To show the order of magnitude of the effects of polarization aberrations on astronomical images, a generic astronomical telescope configuration is analyzed here by modeling a fast Cassegrain telescope followed by a single 90° deviation fold mirror. All mirrors in this example use bare aluminum reflective coatings and the illumination wavelength is 800 nm. Our findings for this example telescope are: (1) The image plane irradiance distribution is the linear superposition of four PSF images: one for each of the two orthogonal polarizations and one for each of two cross-coupled polarization terms. (2) The PSF image is brighter by 9% for one polarization component compared to its orthogonal state. (3) The PSF images for two orthogonal linearly polarization components are shifted with respect to each other, causing the PSF image for unpolarized point sources to become slightly elongated (elliptical) with a centroid separation of about 0.6 mas. This is important for both astrometry

  17. Pancreatic cancer genomes reveal aberrations in axon guidance pathway genes.

    PubMed

    Biankin, Andrew V; Waddell, Nicola; Kassahn, Karin S; Gingras, Marie-Claude; Muthuswamy, Lakshmi B; Johns, Amber L; Miller, David K; Wilson, Peter J; Patch, Ann-Marie; Wu, Jianmin; Chang, David K; Cowley, Mark J; Gardiner, Brooke B; Song, Sarah; Harliwong, Ivon; Idrisoglu, Senel; Nourse, Craig; Nourbakhsh, Ehsan; Manning, Suzanne; Wani, Shivangi; Gongora, Milena; Pajic, Marina; Scarlett, Christopher J; Gill, Anthony J; Pinho, Andreia V; Rooman, Ilse; Anderson, Matthew; Holmes, Oliver; Leonard, Conrad; Taylor, Darrin; Wood, Scott; Xu, Qinying; Nones, Katia; Fink, J Lynn; Christ, Angelika; Bruxner, Tim; Cloonan, Nicole; Kolle, Gabriel; Newell, Felicity; Pinese, Mark; Mead, R Scott; Humphris, Jeremy L; Kaplan, Warren; Jones, Marc D; Colvin, Emily K; Nagrial, Adnan M; Humphrey, Emily S; Chou, Angela; Chin, Venessa T; Chantrill, Lorraine A; Mawson, Amanda; Samra, Jaswinder S; Kench, James G; Lovell, Jessica A; Daly, Roger J; Merrett, Neil D; Toon, Christopher; Epari, Krishna; Nguyen, Nam Q; Barbour, Andrew; Zeps, Nikolajs; Kakkar, Nipun; Zhao, Fengmei; Wu, Yuan Qing; Wang, Min; Muzny, Donna M; Fisher, William E; Brunicardi, F Charles; Hodges, Sally E; Reid, Jeffrey G; Drummond, Jennifer; Chang, Kyle; Han, Yi; Lewis, Lora R; Dinh, Huyen; Buhay, Christian J; Beck, Timothy; Timms, Lee; Sam, Michelle; Begley, Kimberly; Brown, Andrew; Pai, Deepa; Panchal, Ami; Buchner, Nicholas; De Borja, Richard; Denroche, Robert E; Yung, Christina K; Serra, Stefano; Onetto, Nicole; Mukhopadhyay, Debabrata; Tsao, Ming-Sound; Shaw, Patricia A; Petersen, Gloria M; Gallinger, Steven; Hruban, Ralph H; Maitra, Anirban; Iacobuzio-Donahue, Christine A; Schulick, Richard D; Wolfgang, Christopher L; Morgan, Richard A; Lawlor, Rita T; Capelli, Paola; Corbo, Vincenzo; Scardoni, Maria; Tortora, Giampaolo; Tempero, Margaret A; Mann, Karen M; Jenkins, Nancy A; Perez-Mancera, Pedro A; Adams, David J; Largaespada, David A; Wessels, Lodewyk F A; Rust, Alistair G; Stein, Lincoln D; Tuveson, David A; Copeland, Neal G; Musgrove, Elizabeth A; Scarpa, Aldo; Eshleman, James R; Hudson, Thomas J; Sutherland, Robert L; Wheeler, David A; Pearson, John V; McPherson, John D; Gibbs, Richard A; Grimmond, Sean M

    2012-11-15

    Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis.

  18. Pancreatic cancer genomes reveal aberrations in axon guidance pathway genes

    PubMed Central

    Biankin, Andrew V.; Waddell, Nicola; Kassahn, Karin S.; Gingras, Marie-Claude; Muthuswamy, Lakshmi B.; Johns, Amber L.; Miller, David K.; Wilson, Peter J.; Patch, Ann-Marie; Wu, Jianmin; Chang, David K.; Cowley, Mark J.; Gardiner, Brooke B.; Song, Sarah; Harliwong, Ivon; Idrisoglu, Senel; Nourse, Craig; Nourbakhsh, Ehsan; Manning, Suzanne; Wani, Shivangi; Gongora, Milena; Pajic, Marina; Scarlett, Christopher J.; Gill, Anthony J.; Pinho, Andreia V.; Rooman, Ilse; Anderson, Matthew; Holmes, Oliver; Leonard, Conrad; Taylor, Darrin; Wood, Scott; Xu, Qinying; Nones, Katia; Fink, J. Lynn; Christ, Angelika; Bruxner, Tim; Cloonan, Nicole; Kolle, Gabriel; Newell, Felicity; Pinese, Mark; Mead, R. Scott; Humphris, Jeremy L.; Kaplan, Warren; Jones, Marc D.; Colvin, Emily K.; Nagrial, Adnan M.; Humphrey, Emily S.; Chou, Angela; Chin, Venessa T.; Chantrill, Lorraine A.; Mawson, Amanda; Samra, Jaswinder S.; Kench, James G.; Lovell, Jessica A.; Daly, Roger J.; Merrett, Neil D.; Toon, Christopher; Epari, Krishna; Nguyen, Nam Q.; Barbour, Andrew; Zeps, Nikolajs; Kakkar, Nipun; Zhao, Fengmei; Wu, Yuan Qing; Wang, Min; Muzny, Donna M.; Fisher, William E.; Brunicardi, F. Charles; Hodges, Sally E.; Reid, Jeffrey G.; Drummond, Jennifer; Chang, Kyle; Han, Yi; Lewis, Lora R.; Dinh, Huyen; Buhay, Christian J.; Beck, Timothy; Timms, Lee; Sam, Michelle; Begley, Kimberly; Brown, Andrew; Pai, Deepa; Panchal, Ami; Buchner, Nicholas; De Borja, Richard; Denroche, Robert E.; Yung, Christina K.; Serra, Stefano; Onetto, Nicole; Mukhopadhyay, Debabrata; Tsao, Ming-Sound; Shaw, Patricia A.; Petersen, Gloria M.; Gallinger, Steven; Hruban, Ralph H.; Maitra, Anirban; Iacobuzio-Donahue, Christine A.; Schulick, Richard D.; Wolfgang, Christopher L.; Morgan, Richard A.; Lawlor, Rita T.; Capelli, Paola; Corbo, Vincenzo; Scardoni, Maria; Tortora, Giampaolo; Tempero, Margaret A.; Mann, Karen M.; Jenkins, Nancy A.; Perez-Mancera, Pedro A.; Adams, David J.; Largaespada, David A.; Wessels, Lodewyk F. A.; Rust, Alistair G.; Stein, Lincoln D.; Tuveson, David A.; Copeland, Neal G.; Musgrove, Elizabeth A.; Scarpa, Aldo; Eshleman, James R.; Hudson, Thomas J.; Sutherland, Robert L.; Wheeler, David A.; Pearson, John V.; McPherson, John D.; Gibbs, Richard A.; Grimmond, Sean M.

    2012-01-01

    Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis. PMID:23103869

  19. Phase aberration correction by correlation in digital holographic adaptive optics

    PubMed Central

    Liu, Changgeng; Yu, Xiao; Kim, Myung K.

    2013-01-01

    We present a phase aberration correction method based on the correlation between the complex full-field and guide-star holograms in the context of digital holographic adaptive optics (DHAO). Removal of a global quadratic phase term before the correlation operation plays an important role in the correction. Correlation operation can remove the phase aberration at the entrance pupil plane and automatically refocus the corrected optical field. Except for the assumption that most aberrations lie at or close to the entrance pupil, the presented method does not impose any other constraints on the optical systems. Thus, it greatly enhances the flexibility of the optical design for DHAO systems in vision science and microscopy. Theoretical studies show that the previously proposed Fourier transform DHAO (FTDHAO) is just a special case of this general correction method, where the global quadratic phase term and a defocus term disappear. Hence, this correction method realizes the generalization of FTDHAO into arbitrary DHAO systems. The effectiveness and robustness of this method are demonstrated by simulations and experiments. PMID:23669707

  20. The association of wavefront aberration and accommodative lag in myopes.

    PubMed

    He, Ji C; Gwiazda, Jane; Thorn, Frank; Held, Richard; Vera-Diaz, Fuensanta A

    2005-02-01

    Accommodative lags, induced by a target at 33 cm (distance-induced condition) and by a -3.0 D lens (lens-induced condition), and wavefront aberrations were measured in 27 young myopic eyes. The accommodative lags and Strehl ratios derived from the wavefront aberrations in myopes were compared with those from 57 emmetropes. Accommodation was measured using a Canon R-1 autorefractor, while aberrations were measured using a psychophysical ray-tracing technique. In accord with previous results, larger accommodative lags were found for the myopes than the emmetropes in both the lens-induced and distance-induced conditions. The mean Strehl ratio was smaller in the myopes (0.079) than the emmetropes (0.091); this difference approached significance (p = 0.055). In addition, for myopes the accommodative lag was significantly correlated with the Strehl ratio in the lens-induced condition (r = -0.45, p < 0.02) and approached significance in the distance-induced condition (r = -0.35, p = 0.07). No significant correlations were found for emmetropes. Possible reasons to account for these results are discussed.

  1. Estimation of phase wave-front aberration distribution function using wavelet transform profilometry.

    PubMed

    Rahbar, Kambiz; Faez, Karim; Attaran-Kakhki, Ebrahim

    2012-06-01

    Reduction of image quality under the effects of wavefront aberration of the optical system has a direct impact on the vision system's performance. This paper tries to estimate the amount of aberration with the use of wavelet transform profilometry. The basic idea is based on the principle that under aberration effects, the position of the fringes' image on the image plane will change, and this change correlates with the amount of aberration. So the distribution of aberration function can directly be extracted through measuring the amount of changes in the fringes' image on the image plane. Experimental results and the empirical validity of this idea are evaluated.

  2. Origin of 48Ca

    NASA Astrophysics Data System (ADS)

    Clayton, Donald D.; Krishnan, Tracy D.; Meyer, Bradley S.

    1997-02-01

    We stress conceptual understanding of why 48Ca survives low-entropy expansions but not high-entropy expansions. Type Ia supernovae are thereby demonstrated to be its source. The interdependence of the quasiequilibrium cluster (QSE) and the number of heavy nuclei is the key. By varying reaction rates, we show that nuclear cross sections are not a sensitive need for the problem of 48Ca nucleosynthesis.

  3. Persistence of early emerging aberrant behavior in children with developmental disabilities.

    PubMed

    Green, Vanessa A; O'Reilly, Mark; Itchon, Jonathan; Sigafoos, Jeff

    2005-01-01

    This study examined the persistence of early emerging aberrant behavior in 13 preschool children with developmental disabilities. The severity of aberrant behavior was assessed every 6 months over a 3-year period. Teachers completed the assessments using the Aberrant Behavior Checklist [Aman, M. G., & Singh, N. N. (1986). Aberrant Behavior Checklist: Manual. East Aurora, NY: Slosson Educational Publications; (1994). Aberrant Behavior Checklist--Community. East Aurora, NY: Slosson Educational Publications]. Problem behaviors were present in all children at the beginning of the study. Nine of the 13 children entered the study with relatively high levels of aberrant behaviors that showed little change over the 3 years. These data suggest that aberrant behaviors often emerge early and can be highly persistent during the preschool years. Prevention would, therefore, seem to require home-based interventions that begin before 4 years of age.

  4. p53 loss promotes acute myeloid leukemia by enabling aberrant self-renewal

    PubMed Central

    Zhao, Zhen; Zuber, Johannes; Diaz-Flores, Ernesto; Lintault, Laura; Kogan, Scott C.; Shannon, Kevin; Lowe, Scott W.

    2010-01-01

    The p53 tumor suppressor limits proliferation in response to cellular stress through several mechanisms. Here, we test whether the recently described ability of p53 to limit stem cell self-renewal suppresses tumorigenesis in acute myeloid leukemia (AML), an aggressive cancer in which p53 mutations are associated with drug resistance and adverse outcome. Our approach combined mosaic mouse models, Cre-lox technology, and in vivo RNAi to disable p53 and simultaneously activate endogenous KrasG12D—a common AML lesion that promotes proliferation but not self-renewal. We show that p53 inactivation strongly cooperates with oncogenic KrasG12D to induce aggressive AML, while both lesions on their own induce T-cell malignancies with long latency. This synergy is based on a pivotal role of p53 in limiting aberrant self-renewal of myeloid progenitor cells, such that loss of p53 counters the deleterious effects of oncogenic Kras on these cells and enables them to self-renew indefinitely. Consequently, myeloid progenitor cells expressing oncogenic Kras and lacking p53 become leukemia-initiating cells, resembling cancer stem cells capable of maintaining AML in vivo. Our results establish an efficient new strategy for interrogating oncogene cooperation, and provide strong evidence that the ability of p53 to limit aberrant self-renewal contributes to its tumor suppressor activity. PMID:20595231

  5. Electroacupuncture Treatment Alleviates Central Poststroke Pain by Inhibiting Brain Neuronal Apoptosis and Aberrant Astrocyte Activation

    PubMed Central

    Tian, Gui-Hua; Tao, Shan-Shan; Chen, Man-Tang; Li, Yu-Sang; Shang, Hong-Cai; Tang, Xiao-Yi; Chen, Jian-Xin

    2016-01-01

    Electroacupuncture (EA) is reported to effectively relieve the central poststroke pain (CPSP). However, the underlying mechanism remains unclear. The present study investigated the detailed mechanisms of action of EA treatment at different frequencies for CPSP. A CPSP model was established with a single collagenase injection to the left ventral posterolateral nucleus of the thalamus. The EA-treated groups then received EA treatment at frequency of 2, 2/15, or 15 Hz for 30 min daily for five days. The pain-related behavioral responses, neuronal apoptosis, glial activation, and the expression of pain signal transmission-related factors (β-catenin, COX-2, and NK-1R) were assessed using behavioral tests, Nissl staining, TUNEL staining, and immunohistochemical staining, respectively. The low-frequency EA treatment significantly (1) reduced brain tissue damage and hematoma sizes and (2) inhibited neuronal apoptosis, thereby exerting abirritative effects. Meanwhile, the high-frequency EA treatment induced a greater inhibition of the aberrant astrocyte activation, accompanied by the downregulation of the expressions of COX-2, β-catenin, and subsequently NK-1R, thereby alleviating inflammation and producing strong analgesic effects. Together, these findings suggest that CPSP is closely related to pathological changes of the neocortex and hippocampus. EA treatments at different frequencies may exert abirritative effects by inhibiting brain neuronal apoptosis and aberrant astrocyte activation in the brain. PMID:27774321

  6. Chromosome aberrations, micronucleus and sperm head abnormalities in mice treated with natamycin, [corrected] a food preservative.

    PubMed

    Rasgele, Pinar Goc; Kaymak, Fisun

    2010-03-01

    Natamycin [corrected] is used as preservative in foods. The genotoxic effects of the food preservative natamycin [corrected] were evaluated using chromosome aberrations and micronucleus test in bone marrow cells and sperm head abnormality assays in mice. Blood samples were taken from mice and levels of total testosterone in serum were also determined. Natamycin [corrected] was intraperitoneally (ip) injected at 200, 400 and 800 mg/kg. Natamycin [corrected] did not induce chromosome aberrations but significantly increased the number of micronucleated polychromatic erythrocytes in bone marrow and sperm head abnormalities at all concentrations and treatment periods. It also decreased MI at all concentrations for 6, 12 and 24h treatment periods. Natamycin [corrected] decreased PCE/NCE ratio at all concentrations for 48h in female mice, for 24 and 48h treatment periods in male mice. At the 800 mg/kg concentration, natamycin [corrected] decreased PCE/NCE ratio for 24 and 72h in female mice. A dose dependent increase was observed in the percentage of sperm head abnormalities. The levels of serum testosterone decreased dose-dependently. The obtained results indicate that natamycin [corrected] is not clastogenic, but it is aneugenic in mice bone marrow and it is a potential germ cell mutagen in sperm cells.

  7. Diffractive-refractive optics: low-aberration Bragg-case focusing by precise parabolic surfaces.

    PubMed

    Oberta, P; Mikulík, P; Kittler, M; Hrdý, J; Peverini, L

    2010-01-01

    Based on analytical formulae calculations and ray-tracing simulations a low-aberration focal spot with a high demagnification ratio was predicted for a diffractive-refractive crystal optics device with parabolic surfaces. Two Si(111) crystals with two precise parabolic-shaped grooves have been prepared and arranged in a dispersive position (+,-,-,+) with high asymmetry. Experimental testing of the device at beamline BM05 at the ESRF provided a focal spot size of 38.25 microm at a focal distance of 1.4 m for 7.31 keV. This is the first experiment with a parabolic-shaped groove; all previous experiments were performed with circular grooves which introduced extreme aberration broadening of the focal spot. The calculated and simulated focal size was 10.8 microm at a distance of 1.1 m at 7.31 keV. It is assumed that the difference between the measured and calculated/simulated focal spot size and focal distance is due to insufficient surface quality and to alignment imperfection.

  8. The oncogenic BRD4-NUT chromatin regulator drives aberrant transcription within large topological domains

    PubMed Central

    Alekseyenko, Artyom A.; Walsh, Erica M.; Wang, Xin; Grayson, Adlai R.; Hsi, Peter T.; Kharchenko, Peter V.; Kuroda, Mitzi I.; French, Christopher A.

    2015-01-01

    NUT midline carcinoma (NMC), a subtype of squamous cell cancer, is one of the most aggressive human solid malignancies known. NMC is driven by the creation of a translocation oncoprotein, BRD4-NUT, which blocks differentiation and drives growth of NMC cells. BRD4-NUT forms distinctive nuclear foci in patient tumors, which we found correlate with ∼100 unprecedented, hyperacetylated expanses of chromatin that reach up to 2 Mb in size. These “megadomains” appear to be the result of aberrant, feed-forward loops of acetylation and binding of acetylated histones that drive transcription of underlying DNA in NMC patient cells and naïve cells induced to express BRD4-NUT. Megadomain locations are typically cell lineage-specific; however, the cMYC and TP63 regions are targeted in all NMCs tested and play functional roles in tumor growth. Megadomains appear to originate from select pre-existing enhancers that progressively broaden but are ultimately delimited by topologically associating domain (TAD) boundaries. Therefore, our findings establish a basis for understanding the powerful role played by large-scale chromatin organization in normal and aberrant lineage-specific gene transcription. PMID:26220994

  9. Effect of aspirin on chromosome aberration and DNA damage induced by X-rays in mice

    NASA Astrophysics Data System (ADS)

    Niikawa, M.; Chuuriki, K.; Shibuya, K.; Seo, M.; Nagase, H.

    In order to reveal the anticlastogenic potency of aspirin, we evaluated the suppressive ability of aspirin on chromosome aberrations induced by X-ray. Aspirin at doses of 0.5, 5 and 50 mg/kg was administrated intraperitoneally or orally at 0.5 h after or before the X-ray irradiation. The anticlastogenic activity of aspirin on chromosome aberrations induced by X-ray was determined in the mouse micronucleus test and alkaline single cell gel electrophoresis (SCG) assay in vivo. The frequency by polychromatic erythrocytes with micronuclei (MNPCEs) was decreased by about 19-61% at 0.5 h after and about 23-62% at 0.5 h before the X-ray irradiation. DNA damage by X-ray was significantly decreased by oral administration of aspirin at 0.5 h after or before the X-ray irradiation for the SCG assay. We consider aspirin can be used as preventive agents against exposure of X-ray.

  10. [Partial cross-cultural adaptation of the Aberrant Behavior Checklist (ABC) scale for analysis of patients with mental retardation].

    PubMed

    Losapio, Mirella Fiuza; Silva, Lis Gomes; Pondé, Milena Pereira; Novaes, Camila Marinho; Santos, Darci Neves dos; Argollo, Nayara; Oliveira, Ivete Maria Santos; Brasil, Heloisa Helena Alves

    2011-05-01

    The aim of the ABC (Aberrant Behavior Checklist) is to evaluate the treatment response for aberrant behavior in patients with mental retardation. The aim of this study was to describe the partial cross-cultural adaptation of the ABC scale to Brazilian Portuguese. The process included conceptual and item equivalence, two translations (T1, T2) and their back-translations (R1, R2), evaluation of referential and general equivalence, expert evaluations, a pre-test, and elaboration of the final version. Conceptual and item equivalences of the ABC were considered pertinent to Brazilian culture. Semantic equivalence showed good correspondence between R1 items and ABC. Reasonable correspondence was obtained between ABC items and R2. All of the professors understood 94.8% of the items in the scale, while relatives understood 87.9%. The Brazilian Portuguese version of the ABC scale thus is available for use, with the appropriate conceptual, item, and semantic equivalence.

  11. Detection of Aberrant Responding on a Personality Scale in a Military Sample: An Application of Evaluating Person Fit with Two-Level Logistic Regression

    ERIC Educational Resources Information Center

    Woods, Carol M.; Oltmanns, Thomas F.; Turkheimer, Eric

    2008-01-01

    Person-fit assessment is used to identify persons who respond aberrantly to a test or questionnaire. In this study, S. P. Reise's (2000) method for evaluating person fit using 2-level logistic regression was applied to 13 personality scales of the Schedule for Nonadaptive and Adaptive Personality (SNAP; L. Clark, 1996) that had been administered…

  12. Open-loop wavefront sensing scheme for specimen aberrations correction in two-photon excited fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Aviles-Espinosa, Rodrigo; Andilla, Jordi; Porcar-Guezenec, Rafael; Levecq, Xavier; Artigas, David; Loza-Alvarez, Pablo

    2011-07-01

    The recent linkage between adaptive optics, a technique borrowed from astronomy and various imaging devices, has enabled to push forward their imaging capabilities by improving its contrast and resolution. A specific case is nonlinear microscopy (NLM) that, although it brings several inherent advantages (compared to linear fluorescence techniques) due to its nonlinear dependence on the excitation beam, its enhanced capabilities can be limited by the sample inhomogeneous structure. In this work, we demonstrate how these imaging capabilities can be enhanced by, employing adaptive optics in a two step correction process. Firstly, a closed-loop methodology aided by Shack-Hartman Wavefront sensing scheme is implemented for compensating the aberrations produced by the laser and the optical elements before the high numerical aperture microscope objective, resulting in a one-time calibration process. Then the residual aberrations are produced by the microscope objective and the sample. These are measured in a similar way as it is done in astronomy (employing a laser guide-star), using the two-photon excited fluorescence. The properties of this incoherent emission produced inside a test sample are compared to a genetically modified Caenorhabditis. elegans nematode expressing GFP showing that the emission of this protein (at 810nm) can be sensed efficiently with our WFS by modifying the exposure time. Therefore the recorded wavefront will capture the sample aberrations which are used to shape a deformable mirror in an open-loop configuration. This correction principle is demonstrated in a test sample by correcting aberrations in a "single-shot" resulting in a reduced sample exposure.

  13. Analysis of Chromosomal Aberrations after Low and High Dose Rate Gamma Irradiation in ATM or NBS Suppressed Human Fibroblast Cells

    NASA Technical Reports Server (NTRS)

    Hada, M.; Huff, J. L.; Patel, Z.; Pluth, J. M.; George, K. A.; Cucinotta, F. A.

    2009-01-01

    A detailed understanding of the biological effects of heavy nuclei is needed for space radiation protection and for cancer therapy. High-LET radiation produces more complex DNA lesions that may be non-repairable or that may require additional processing steps compared to endogenous DSBs, increasing the possibility of misrepair. Interplay between radiation sensitivity, dose, and radiation quality has not been studied extensively. Previously we studied chromosome aberrations induced by low- and high- LET radiation in several cell lines deficient in ATM (ataxia telangactasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. We found that the yields of both simple and complex chromosomal aberrations were significantly increased in the DSB repair defective cells compared to normal cells. The increased aberrations observed for the ATM and NBS defective lines was due to a significantly larger quadratic dose-response term compared to normal fibroblasts for both simple and complex aberrations, while the linear dose-response term was significantly higher in NBS cells only for simple exchanges. These results point to the importance of the functions of ATM and NBS in chromatin modifications that function to facilitate correct DSB repair and minimize aberration formation. To further understand the sensitivity differences that were observed in ATM and NBS deficient cells, in this study, chromosomal aberration analysis was performed in normal lung fibroblast cells treated with KU-55933, a specific ATM kinase inhibitor, or Mirin, an MRN complex inhibitor involved in activation of ATM. We are also testing siRNA knockdown of these proteins. Normal and ATM or NBS suppressed cells were irradiated with gamma-rays and chromosomes were collected with a premature chromosome

  14. Aberration-Coreected Electron Microscopy at Brookhaven National Laboratory

    SciTech Connect

    Zhu,Y.; Wall, J.

    2008-04-01

    The last decade witnessed the rapid development and implementation of aberration correction in electron optics, realizing a more-than-70-year-old dream of aberration-free electron microscopy with a spatial resolution below one angstrom [1-9]. With sophisticated aberration correctors, modern electron microscopes now can reveal local structural information unavailable with neutrons and x-rays, such as the local arrangement of atoms, order/disorder, electronic inhomogeneity, bonding states, spin configuration, quantum confinement, and symmetry breaking [10-17]. Aberration correction through multipole-based correctors, as well as the associated improved stability in accelerating voltage, lens supplies, and goniometers in electron microscopes now enables medium-voltage (200-300kV) microscopes to achieve image resolution at or below 0.1nm. Aberration correction not only improves the instrument's spatial resolution but, equally importantly, allows larger objective lens pole-piece gaps to be employed thus realizing the potential of the instrument as a nanoscale property-measurement tool. That is, while retaining high spatial resolution, we can use various sample stages to observe the materials response under various temperature, electric- and magnetic- fields, and atmospheric environments. Such capabilities afford tremendous opportunities to tackle challenging science and technology issues in physics, chemistry, materials science, and biology. The research goal of the electron microscopy group at the Dept. of Condensed Matter Physics and Materials Science and the Center for Functional Nanomaterials, as well as the Institute for Advanced Electron Microscopy, Brookhaven National Laboratory (BNL), is to elucidate the microscopic origin of the physical- and chemical-behavior of materials, and the role of individual, or groups of atoms, especially in their native functional environments. We plan to accomplish this by developing and implementing various quantitative electron

  15. Mental status testing

    MedlinePlus

    Mental status exam; Neurocognitive testing; Dementia-mental status testing ... A health care provider will ask a number of questions. The test can be ... cognitive assessment (MoCA). The following may be tested: ...

  16. MicroRNA-145 suppresses ROS-induced Ca{sup 2+} overload of cardiomyocytes by targeting CaMKIIδ

    SciTech Connect

    Cha, Min-Ji; Jang, Jin-Kyung; Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon; Lee, Chang Yeon; Park, Jun-Hee; Lee, Jiyun; Seo, Hyang-Hee; Choi, Eunhyun; Jeon, Woo-min; Hwang, Hye Jin; Shin, Hyun-Taek; and others

    2013-06-14

    Highlights: •CaMKIIδ mediates H{sub 2}O{sub 2}-induced Ca{sup 2+} overload in cardiomyocytes. •miR-145 can inhibit Ca{sup 2+} overload. •A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. •Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca{sup 2+}) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca{sup 2+} signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca{sup 2+}-mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H{sub 2}O{sub 2}-mediated Ca{sup 2+} overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca{sup 2+} overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca{sup 2+}-related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca{sup 2+} overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses.

  17. Aberration-free short focal length x-ray lenses.

    PubMed

    Alianelli, Lucia; del Rio, Manuel Sánchez; Fox, Oliver J L; Korwin-Mikke, Katarzyna

    2015-12-01

    We treat the problem of defining the ideal x-ray refractive lens design for point focusing of low emittance x-ray beams at third- and fourth-generation synchrotron sources. The task is accomplished by using Fermat's principle to define a lens shape that is completely free from geometrical aberrations. Current microfabrication resolution limits are identified, and a design that tolerates the inherent fabrication imperfections is proposed. The refractive lens design delivers nanometer-sized focused x-ray beams and is compatible with current microfabrication techniques. PMID:26625057

  18. [The aberrant parasitism of horse botflies (Diptera: Gasterophilidae)].

    PubMed

    Rastegaev, Iu M

    1990-01-01

    Alongside with a high intensity of infection of horses with botfly larvae there was observed mass aberrant parasitism of horse botflies in farms of Astrakhan, Guryev and Uralsk Provinces, and in the Kalmyk ASSR in 1980-1981 and 1987. As a result of extremely high aggregation of horse botfly larvae in their usual localization places, Gasterophilus pecorum larvae remained, due to interspecific competition, in nonspecific places (oral cavity, pharynx), adapted to new habitats and normally developed. Their number varied from 260 to 750 specimens. Localization of G. pecorum larvae in the mentioned departments of the alimentary canal results in serious morbidity of horses.

  19. 3-D stimulated emission depletion microscopy with programmable aberration correction.

    PubMed

    Lenz, Martin O; Sinclair, Hugo G; Savell, Alexander; Clegg, James H; Brown, Alice C N; Davis, Daniel M; Dunsby, Chris; Neil, Mark A A; French, Paul M W

    2014-01-01

    We present a stimulated emission depletion (STED) microscope that provides 3-D super resolution by simultaneous depletion using beams with both a helical phase profile for enhanced lateral resolution and an annular phase profile to enhance axial resolution. The 3-D depletion point spread function is realised using a single spatial light modulator that can also be programmed to compensate for aberrations in the microscope and the sample. We apply it to demonstrate the first 3-D super-resolved imaging of an immunological synapse between a Natural Killer cell and its target cell.

  20. Intrinsic instability of aberration-corrected electron microscopes.

    PubMed

    Schramm, S M; van der Molen, S J; Tromp, R M

    2012-10-19

    Aberration-corrected microscopes with subatomic resolution will impact broad areas of science and technology. However, the experimentally observed lifetime of the corrected state is just a few minutes. Here we show that the corrected state is intrinsically unstable; the higher its quality, the more unstable it is. Analyzing the contrast transfer function near optimum correction, we define an "instability budget" which allows a rational trade-off between resolution and stability. Unless control systems are developed to overcome these challenges, intrinsic instability poses a fundamental limit to the resolution practically achievable in the electron microscope.

  1. Propagation of aberrated wavefronts using a ray transfer matrix.

    PubMed

    Raasch, Thomas W

    2014-05-01

    A ray transfer matrix is used to calculate the propagation of aberrated wavefronts across a homogeneous refractive index. The wavefront is represented by local surface normals, i.e., by a ray bundle, and the propagation is accomplished by transferring those rays across the space. Wavefront shape is generated from the slopes and positions of the collection of rays. Calculation methods are developed for the paraxial case, for higher-order expansions, and for the exact tangent case. A numerical example is used to compare results between an analytical method and the methods developed here.

  2. Chaetophractus villosus as a sentinel organism: Baseline values of mitotic index, chromosome aberrations and sister chromatid exchanges.

    PubMed

    Rossi, Luis Francisco; Luaces, Juan Pablo; Browne, Melanie; Chirino, Mónica Gabriela; Merani, María Susana; Mudry, Marta Dolores

    2016-01-15

    Sentinel species are useful tools for studying the deleterious effects of xenobiotics on wildlife. The large hairy armadillo (Chaetophractus villosus) is the most abundant and widely distributed mammal in Argentina. It is a long-lived, omnivorous, burrowing species, with fairly restricted home ranges. To evaluate the level of spontaneous genetic damage in this mammal, we determined the baseline values of several genotoxicity biomarkers. The study included 20 C. villosus adults of both sexes from eight pristine localities within its geographic distribution range. Genotoxicity analysis was performed on 72-h lymphocyte cultures, using mitomycin C as positive control. We obtained the baseline values of mitotic index (MI=10.52±0.30 metaphases/total cells, n=20), chromosome aberrations (CA=0.13±0.22, n=20), sister chromatid exchanges (SCE)=6.55±0.26, n=6) and replication index (RI=1.66, n=6). MI and CA did not show significant differences (P>0.05) among localities or between sexes. No significant differences in MI, CA, SCE, and RI (P>0.05) were found between values from the pristine localities and historical data. There were significant differences in CA, SCE, and RI (P<0.05) between lymphocyte cultures from pristine localities and those exposed to mitomycin C. We propose the large hairy armadillo as a sentinel organism for environmental biomonitoring of genotoxic chemicals due to its abundance, easy manipulation, well-known biology, the fact that it is usually exposed to different mixtures and concentrations of environmental contaminants, and the baseline values of genetic damage characterized by MI, CA, SCE and RI as biomarkers. PMID:26778508

  3. Analysis of Terminal Deletions using a Generalized Time-Dependent Model of Radiation-Induced Formation of Chromosomal Aberrations

    NASA Technical Reports Server (NTRS)

    Ponomarev, Artem L.; George, K.; Cucinotta, Francis A.

    2011-01-01

    We have developed a model that can simulate different types of radiation induced chromosomal aberrations (CA's) and can provide predictions on the frequency and size of chromosomes with terminal deletions. Chromosomes with terminal deletions lack telomeres and this can elicit sister chromatid unions and the prolonged breakage/fusion/bridge (B/F/B) cycles that have been observed in mammalian tumors. The loss of a single telomere has been shown to cause extensive genomic instability through the B/F/B cycle process. Our model uses a stochastic process of DNA broken end joining, in which a realistic spectrum of CA's is created from improperly joined DNA free ends formed by DNA double strand breaks (DSBs). The distribution of the DNA free ends is given by a mechanistic model that takes into account the chromatin structure and track structure for high-LET radiation. The model allows for DSB clustering from high-LET radiation and simulates the formation of CA's in stages that correspond to the actual time after radiation exposure. The time scale for CA formation is derived from experimental data on DSB repair kinetics. At any given time a nucleus may have intact chromosomes, CA's, and/or unrepaired fragments, some of which are defined as terminal deletions, if they are capped by one telomere. The model produces a spectrum of terminal deletions with their corresponding probabilities and size distributions for different heavy ions exposures for the first division after exposure. This data provides valuable information because there is limited experimental data available in the literature on the on the actual size of terminal deletions. We compare our model output to the available experimental data and make a reasonable extrapolation on the number of chromosomes lacking telomeres in human lymphocytes exposed to heavy ions. This model generates data which may lead to predictions on the rate of genomic instability in cells after exposure to high charge and energy nuclei

  4. Chaetophractus villosus as a sentinel organism: Baseline values of mitotic index, chromosome aberrations and sister chromatid exchanges.

    PubMed

    Rossi, Luis Francisco; Luaces, Juan Pablo; Browne, Melanie; Chirino, Mónica Gabriela; Merani, María Susana; Mudry, Marta Dolores

    2016-01-15

    Sentinel species are useful tools for studying the deleterious effects of xenobiotics on wildlife. The large hairy armadillo (Chaetophractus villosus) is the most abundant and widely distributed mammal in Argentina. It is a long-lived, omnivorous, burrowing species, with fairly restricted home ranges. To evaluate the level of spontaneous genetic damage in this mammal, we determined the baseline values of several genotoxicity biomarkers. The study included 20 C. villosus adults of both sexes from eight pristine localities within its geographic distribution range. Genotoxicity analysis was performed on 72-h lymphocyte cultures, using mitomycin C as positive control. We obtained the baseline values of mitotic index (MI=10.52±0.30 metaphases/total cells, n=20), chromosome aberrations (CA=0.13±0.22, n=20), sister chromatid exchanges (SCE)=6.55±0.26, n=6) and replication index (RI=1.66, n=6). MI and CA did not show significant differences (P>0.05) among localities or between sexes. No significant differences in MI, CA, SCE, and RI (P>0.05) were found between values from the pristine localities and historical data. There were significant differences in CA, SCE, and RI (P<0.05) between lymphocyte cultures from pristine localities and those exposed to mitomycin C. We propose the large hairy armadillo as a sentinel organism for environmental biomonitoring of genotoxic chemicals due to its abundance, easy manipulation, well-known biology, the fact that it is usually exposed to different mixtures and concentrations of environmental contaminants, and the baseline values of genetic damage characterized by MI, CA, SCE and RI as biomarkers.

  5. Assessment of genotoxicity of inorganic mercury in rats in vivo using both chromosomal aberration and comet assays.

    PubMed

    Bhowmik, Niladri; Patra, Manomita

    2015-07-01

    The major objective of the present investigation was to assess the genotoxic effects of mercuric chloride (HgCl2), an inorganic mercury (Hg), in rats (Rattus norvegicus) using two different genetic endpoints, namely, chromosomal aberration (CA) and comet assays following both short-term (acute) and long-term (chronic) exposures. The study showed that the acute exposures to HgCl2 at 2 and 5 mg/kg body weight (b.w.) induced nonsignificant effects. HgCl2 at 10 and 12 mg/kg b.w. was significantly toxic and is exhibited by the induction of different types of CAs like chromatid breaks, chromosomal breaks, clumps and damaged cells and types of comets. HgCl2 at 15 mg/kg b.w. was found to be highly toxic, as mitostatic condition of cells were observed in CA assay. Chronic exposure to the lowest dose (2 mg/kg b.w.) of HgCl2 for 15 consecutive days produced a significant genotoxicity. Although Hg was found to induce both DNA strand breakage and chromosomal breaks in a dose-dependent manner, the results of the present investigation showed that the combination of comet and CA assays provided a better choice for assessing the genotoxicity of inorganicHg. PMID:23448859

  6. Influence of retinol on carcinogen-induced sister chromatid exchangers and chromosome aberrations in V79 cells

    SciTech Connect

    Qin, S.; Batt, T.; Huang, C.C.

    1985-01-01

    The influence of retinol (Rol) on sister chromatid exchangers (SCE) in V79 cells induced by six indirect and two direct carcinogens, and on chromosome aberration (CA) in V79 cells induced by four indirect carcinogens were studied. The indirect carcinogens used were aflatoxin B/sub 1/ (AFB), cyclophosphamide (CPP), benzo(a)anthracene (BA), benzo(a)pyrene (BP), 9,10-dimethyl-1,2-benz(a)anthracene (DMBA), and 3-methylcholanthrene (MCA). The two direct carcinogens were ethyl methane sulfonate (EMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Rol effectively inhibited SCE and CA induced by AFB and CPP in a dose-dependent manner, but it had no effect on SCE induced by BA, BP, DMBA, MCA, EMS, and MNNG. To the contrary, Rol had an enhancing effect on CA induced by BP and DMBA. The possibility that Rol exerts its anticarcinogenic effects by inhibiting certain forms of the cytochrome P-450 isoenzymes required for activation of precarcinogens, such as AFB and CPP but not those enzymes required by BA, BP, DMBA, and MCA, is discussed.

  7. Memory retrieval along the proximodistal axis of CA1.

    PubMed

    Nakazawa, Yuki; Pevzner, Aleksandr; Tanaka, Kazumasa Z; Wiltgen, Brian J

    2016-09-01

    The proximal and distal segments of CA1 are thought to perform distinct computations. Neurons in proximal CA1 are reciprocally connected with the medial entorhinal cortex (MEC) and exhibit precise spatial firing. In contrast, cells in distal CA1 communicate with the lateral entorhinal cortex (LEC), exhibit more diffuse spatial firing and are affected by the presence of objects in the environment. To determine if these segments make unique contributions to memory retrieval, we examined cellular activity along the proximodistal axis of CA1 using transgenic reporter mice. Neurons tagged during context learning in proximal CA1 were more likely to be reactivated during testing than those in distal CA1. This was true following context fear conditioning and after exposure to a novel environment. Reactivation was also higher in brain regions connected to proximal CA1 (MEC, distal CA3) than those connected to the distal segment (LEC, proximal CA3). To examine contributions to memory retrieval, we performed neurotoxic lesions of proximal or distal CA1 after training. Lesions of the proximal segment significantly impaired memory retrieval while damage to distal CA1 had no effect. These data suggest that context memories are retrieved by a hippocampal microcircuit that involves the proximal but not distal segment of CA1. © 2016 Wiley Periodicals, Inc. PMID:27068122

  8. Hartmann test of aspherical mirrors.

    PubMed

    Malacara, D

    1972-01-01

    Astronomical aspherical mirrors may be tested in the optical shop with a Hartmann null test. A null test is obtained by placing small wedges over each hole of the Hartmann screen. The wedges have an angle between the two faces such that the spherical aberration with the object and the image at the center of curvature is just compensated.

  9. Mate pair sequencing for the detection of chromosomal aberrations in patients with intellectual disability and congenital malformations

    PubMed Central

    Vergult, Sarah; Van Binsbergen, Ellen; Sante, Tom; Nowak, Silke; Vanakker, Olivier; Claes, Kathleen; Poppe, Bruce; Van der Aa, Nathalie; van Roosmalen, Markus J; Duran, Karen; Tavakoli-Yaraki, Masoumeh; Swinkels, Marielle; van den Boogaard, Marie-José; van Haelst, Mieke; Roelens, Filip; Speleman, Frank; Cuppen, Edwin; Mortier, Geert; Kloosterman, Wigard P; Menten, Björn

    2014-01-01

    Recently, microarrays have replaced karyotyping as a first tier test in patients with idiopathic intellectual disability and/or multiple congenital abnormalities (ID/MCA) in many laboratories. Although in about 14–18% of such patients, DNA copy-number variants (CNVs) with clinical significance can be detected, microarrays have the disadvantage of missing balanced rearrangements, as well as providing no information about the genomic architecture of structural variants (SVs) like duplications and complex rearrangements. Such information could possibly lead to a better interpretation of the clinical significance of the SV. In this study, the clinical use of mate pair next-generation sequencing was evaluated for the detection and further characterization of structural variants within the genomes of 50 ID/MCA patients. Thirty of these patients carried a chromosomal aberration that was previously detected by array CGH or karyotyping and suspected to be pathogenic. In the remaining 20 patients no causal SVs were found and only benign aberrations were detected by conventional techniques. Combined cluster and coverage analysis of the mate pair data allowed precise breakpoint detection and further refinement of previously identified balanced and (complex) unbalanced aberrations, pinpointing the causal gene for some patients. We conclude that mate pair sequencing is a powerful technology that can provide rapid and unequivocal characterization of unbalanced and balanced SVs in patient genomes and can be essential for the clinical interpretation of some SVs. PMID:24105367

  10. Mate pair sequencing for the detection of chromosomal aberrations in patients with intellectual disability and congenital malformations.

    PubMed

    Vergult, Sarah; Van Binsbergen, Ellen; Sante, Tom; Nowak, Silke; Vanakker, Olivier; Claes, Kathleen; Poppe, Bruce; Van der Aa, Nathalie; van Roosmalen, Markus J; Duran, Karen; Tavakoli-Yaraki, Masoumeh; Swinkels, Marielle; van den Boogaard, Marie-José; van Haelst, Mieke; Roelens, Filip; Speleman, Frank; Cuppen, Edwin; Mortier, Geert; Kloosterman, Wigard P; Menten, Björn

    2014-05-01

    Recently, microarrays have replaced karyotyping as a first tier test in patients with idiopathic intellectual disability and/or multiple congenital abnormalities (ID/MCA) in many laboratories. Although in about 14-18% of such patients, DNA copy-number variants (CNVs) with clinical significance can be detected, microarrays have the disadvantage of missing balanced rearrangements, as well as providing no information about the genomic architecture of structural variants (SVs) like duplications and complex rearrangements. Such information could possibly lead to a better interpretation of the clinical significance of the SV. In this study, the clinical use of mate pair next-generation sequencing was evaluated for the detection and further characterization of structural variants within the genomes of 50 ID/MCA patients. Thirty of these patients carried a chromosomal aberration that was previously detected by array CGH or karyotyping and suspected to be pathogenic. In the remaining 20 patients no causal SVs were found and only benign aberrations were detected by conventional techniques. Combined cluster and coverage analysis of the mate pair data allowed precise breakpoint detection and further refinement of previously identified balanced and (complex) unbalanced aberrations, pinpointing the causal gene for some patients. We conclude that mate pair sequencing is a powerful technology that can provide rapid and unequivocal characterization of unbalanced and balanced SVs in patient genomes and can be essential for the clinical interpretation of some SVs.

  11. Assessment of contrast sensitivity and aberrations after photorefractive keratectomy in patients with myopia greater than 5 diopters.

    PubMed

    Fahim, Alireza; Rezvan, Bijan; Hashemi, Hassan

    2013-01-01

    This study aimed to assess changes in contrast sensitivity and aberrations in cases of myopia greater than 5.0 diopter (D) who had photorefractive keratectomy (PRK). In this semi-experimental study, 20 eyes of ten patients were studied. Inclusion criteria were at least 5.0 D of myopia, stable refraction in the past year, no history of refractive surgery, a minimum corneal thickness of 480 μm, and having surgery in both eyes. Exclusion criteria were the presence of any corneal condition. In addition to the routine tests, aberrometry and assessment of contrast sensitivity was done using the WaveLight Allegro Analyzer and the VectorVision CSV-1000. After PRK using the Concerto Excimer Laser (WaveLight, Alcon), patients were scheduled to have follow-up visits at 1 month, 3 months, and 1 year after surgery. Contrast sensitivity with glare showed an increasing trend only at the spatial frequency of 3 cycles per degree (cpd) (P=0.013). Contrast sensitivity without glared increased postoperatively at special frequencies of 3, 6, and 18 cpd (P<0.05). The preoperative level of higher order aberrations root mean square (HOA RMS) of 0.24±0.08 reached 0.71±0.25 at 12 months after surgery. Assessment of comma and trefoil showed no significant difference between preoperative and postoperative values, but the amount of spherical aberration changed from a mean preoperative value of 0.0±0.09 to 0.27±0.15 at 12 months after surgery. In the treatment of myopia greater than 5.0 D, PRK with the Concerto Excimer Laser can improve contrast sensitivity in certain spatial frequencies. This is while HOA RMS and spherical aberration increase.

  12. An experimental study of aero-optical aberration and dithering of supersonic mixing layer via BOS

    NASA Astrophysics Data System (ADS)

    Zhao, Yuxin; Yi, Shihe; Tian, Lifeng; He, Lin; Cheng, Zhongyu

    2010-01-01

    The optical performance of supersonic mixing layer is heavily deteriorated by the aero-optical aberration and dithering of coherent structures, but current measuring methods limit the spatiotemporal resolution in relevant studies. A high resolution whole-field aero-optical aberration and dithering measuring method based on the Background Orient Schlieren (BOS) technique was studied. The systematic structure, sensitivity and resolution of BOS are analyzed in this paper. The aero-optical aberration and dithering of streamwise structures in supersonic mixing layers were quantificationally studied with BOS. The aberration field of spanwise structures revealed the ribbon-like aberration structures, which heavily restrict the optical performance of a mixing layer. The quantifications of aero-optical aberration and dithering are very important in studying aero-optical performance of supersonic mixing layer.

  13. Ray and wave aberrations revisited: a Huygens-like construction yields exact relations.

    PubMed

    Restrepo, John; Stoerck, Pawel J; Ihrke, Ivo

    2016-02-01

    The aberrations of an optical system can be described in terms of the wave aberrations, defined as the departure from the ideal spherical wavefront; or the ray aberrations, which are in turn the deviations from the paraxial ray intersections measured in the image plane. The classical connection between the two descriptions is an approximation, the error of which has, to our knowledge, so far not been quantified analytically. We derive exact analytical equations for computing the wavefront surface, the aberrated ray directions, and the transverse ray aberrations in terms of the wave aberrations (OPD) and the reference sphere. We introduce precise conditions for a function to be an OPD function, show that every such function has an associated wavefront, and study the error arising from the classical approximation. We establish strict conditions for the error to be small. We illustrate our results with numerical simulations. Our results show that large numerical apertures and OPD functions with strong gradients yield larger approximation errors.

  14. Tunable liquid crystal cylindrical micro-optical array for aberration compensation.

    PubMed

    Algorri, J F; Urruchi, V; Bennis, N; Sánchez-Pena, J M; Otón, J M

    2015-06-01

    A tunable aberration compensation device for rectangular micro-optical systems is proposed and demonstrated. This device, which is based in nematic liquid crystal and a micro-electrode structure, forms gradients in the index of refraction as a function of voltage. We have developed a fringe skeletonizing application in order to extract the 3D wavefront from an interference pattern. This software tool obtains the optical aberrations using Chebyshev polynomials. By using phase shifted electrical signals the aberrations can be controlled independently. A complete independent control over the spherical and coma aberration has been demonstrated. Also, an independent control over the astigmatism aberration has been demonstrated in a broad range. This device has promising applications where aberration compensation is required. The independent compensation achieved for some coefficients, such as astigmatism for example, is more than 2.4 waves. PMID:26072760

  15. Wavefront aberrations in eyes of emmetropic and moderately myopic school children and young adults.

    PubMed

    He, Ji C; Sun, Pei; Held, Richard; Thorn, Frank; Sun, Xiuru; Gwiazda, Jane E

    2002-04-01

    Wavefront aberrations were measured using a psychophysical ray-tracing technique in both eyes of 316 emmetropic and moderately myopic school children and young adults. Myopic subjects were found to have greater mean root mean square (RMS) value of wavefront aberrations than emmetropic subjects. Emmetropic adults had the smallest mean RMS, which remained smaller than the values for myopic adults and children and for emmetropic children both when second order Zernike aberrations (astigmatism) and third order Zernike aberrations were removed. Twenty percent of myopic adults had RMS values greater than values for all of the emmetropic adults, with significantly greater values for Zernike aberrations from second to seventh orders. High amounts of wavefront aberrations, which degrade the retinal image, may play a role in the development of myopia.

  16. Aberrant functional brain connectome in people with antisocial personality disorder.

    PubMed

    Tang, Yan; Long, Jun; Wang, Wei; Liao, Jian; Xie, Hua; Zhao, Guihu; Zhang, Hao

    2016-01-01

    Antisocial personality disorder (ASPD) is characterised by a disregard for social obligations and callous unconcern for the feelings of others. Studies have demonstrated that ASPD is associated with abnormalities in brain regions and aberrant functional connectivity. In this paper, topological organisation was examined in resting-state fMRI data obtained from 32 ASPD patients and 32 non-ASPD controls. The frequency-dependent functional networks were constructed using wavelet-based correlations over 90 brain regions. The topology of the functional networks of ASPD subjects was analysed via graph theoretical analysis. Furthermore, the abnormal functional connectivity was determined with a network-based statistic (NBS) approach. Our results revealed that, compared with the controls, the ASPD patients exhibited altered topological configuration of the functional connectome in the frequency interval of 0.016-0.031 Hz, as indicated by the increased clustering coefficient and decreased betweenness centrality in the medial superior frontal gyrus, precentral gyrus, Rolandic operculum, superior parietal gyrus, angular gyrus, and middle temporal pole. In addition, the ASPD patients showed increased functional connectivity mainly located in the default-mode network. The present study reveals an aberrant topological organisation of the functional brain network in individuals with ASPD. Our findings provide novel insight into the neuropathological mechanisms of ASPD.

  17. Mechanistic modeling of aberrant energy metabolism in human disease

    PubMed Central

    Sangar, Vineet; Eddy, James A.; Simeonidis, Evangelos; Price, Nathan D.

    2012-01-01

    Dysfunction in energy metabolism—including in pathways localized to the mitochondria—has been implicated in the pathogenesis of a wide array of disorders, ranging from cancer to neurodegenerative diseases to type II diabetes. The inherent complexities of energy and mitochondrial metabolism present a significant obstacle in the effort to understand the role that these molecular processes play in the development of disease. To help unravel these complexities, systems biology methods have been applied to develop an array of computational metabolic models, ranging from mitochondria-specific processes to genome-scale cellular networks. These constraint-based (CB) models can efficiently simulate aspects of normal and aberrant metabolism in various genetic and environmental conditions. Development of these models leverages—and also provides a powerful means to integrate and interpret—information from a wide range of sources including genomics, proteomics, metabolomics, and enzyme kinetics. Here, we review a variety of mechanistic modeling studies that explore metabolic functions, deficiency disorders, and aberrant biochemical pathways in mitochondria and related regions in the cell. PMID:23112774

  18. Enhanced Deletion Formation by Aberrant DNA Replication in Escherichia Coli

    PubMed Central

    Saveson, C. J.; Lovett, S. T.

    1997-01-01

    Repeated genes and sequences are prone to genetic rearrangements including deletions. We have investigated deletion formation in Escherichia coli strains mutant for various replication functions. Deletion was selected between 787 base pair tandem repeats carried either on a ColE1-derived plasmid or on the E. coli chromosome. Only mutations in functions associated with DNA Polymerase III elevated deletion rates in our assays. Especially large increases were observed in strains mutant in dnaQ, the ε editing subunit of Pol III, and dnaB, the replication fork helicase. Mutations in several other functions also altered deletion formation: the α polymerase (dnaE), the γ clamp loader complex (holC, dnaX), and the β clamp (dnaN) subunits of Pol III and the primosomal proteins, dnaC and priA. Aberrant replication stimulated deletions through several pathways. Whereas the elevation in dnaB strains was mostly recA- and lexA-dependent, that in dnaQ strains was mostly recA- and lexA-independent. Deletion product analysis suggested that slipped mispairing, producing monomeric replicon products, may be preferentially increased in a dnaQ mutant and sister-strand exchange, producing dimeric replicon products, may be elevated in dnaE mutants. We conclude that aberrant Polymerase III replication can stimulate deletion events through several mechanisms of deletion and via both recA-dependent and independent pathways. PMID:9177997

  19. Consistent numerical chromosome aberrations in thecofibromas of the ovary.

    PubMed

    Micci, Francesca; Haugom, Lisbeth; Abeler, Vera M; Tropé, Claes G; Danielsen, Håvard E; Heim, Sverre

    2008-03-01

    Sex cord-stromal tumors of the ovary comprise 8% of all ovarian neoplasms. Because they consist of cells that resemble embryonic sex cord and/or specialized ovarian stroma cells, their cytologic and histologic features can be viewed as reflecting a continuum from fibromas to thecomas with thecofibromas in between. Existing cytogenetic knowledge about ovarian thecomas-thecofibromas-fibromas is restricted to 44 cases with chromosomal abnormalities. The most common aberration has been trisomy 12, identified either by karyotyping or using fluorescence in situ hybridization (FISH). We wanted to obtain more information about the genomic composition of these tumors, and, therefore, examined 29 new thecoma-thecofibroma-fibroma tumors of the ovary using karyotyping, comparative genomic hybridization, interphase FISH, and DNA ploidy analysis. We detected aneuploidy in 21 tumors. Trisomy and/or tetrasomy 12 was the most common chromosomal aberration, found in 15 tumors (71.5% of the aneuploid tumors or 51.5% of all analyzed tumors), followed by trisomy for chromosomes 10, 18, 4, and 9. Some monosomies (for chromosomes 4, 9, 10, and 18) were also identified, either as the sole change or in combination with trisomies. The nonrandom occurrence of these aneuploidies in these benign tumors strongly indicates that they play a major pathogenetic role, but how trisomies and other aneuploidies contribute to tumorigenesis remains unknown. PMID:18188592

  20. Aberrant functional brain connectome in people with antisocial personality disorder

    PubMed Central

    Tang, Yan; Long, Jun; Wang, Wei; Liao, Jian; Xie, Hua; Zhao, Guihu; Zhang, Hao

    2016-01-01

    Antisocial personality disorder (ASPD) is characterised by a disregard for social obligations and callous unconcern for the feelings of others. Studies have demonstrated that ASPD is associated with abnormalities in brain regions and aberrant functional connectivity. In this paper, topological organisation was examined in resting-state fMRI data obtained from 32 ASPD patients and 32 non-ASPD controls. The frequency-dependent functional networks were constructed using wavelet-based correlations over 90 brain regions. The topology of the functional networks of ASPD subjects was analysed via graph theoretical analysis. Furthermore, the abnormal functional connectivity was determined with a network-based statistic (NBS) approach. Our results revealed that, compared with the controls, the ASPD patients exhibited altered topological configuration of the functional connectome in the frequency interval of 0.016–0.031 Hz, as indicated by the increased clustering coefficient and decreased betweenness centrality in the medial superior frontal gyrus, precentral gyrus, Rolandic operculum, superior parietal gyrus, angular gyrus, and middle temporal pole. In addition, the ASPD patients showed increased functional connectivity mainly located in the default-mode network. The present study reveals an aberrant topological organisation of the functional brain network in individuals with ASPD. Our findings provide novel insight into the neuropathological mechanisms of ASPD. PMID:27257047

  1. Aberration-Corrected TEM Imaging of Oxygen Occupancy in YSZ.

    PubMed

    An, Jihwan; Koh, Ai Leen; Park, Joong Sun; Sinclair, Robert; Gür, Turgut M; Prinz, Fritz B

    2013-04-01

    We present atomic-scale imaging of oxygen columns and show quantitative analysis on the occupancy of the columns in yttria-stabilized zirconia (YSZ) using aberration-corrected TEM operated under the negative Cs condition. Also, individual contributions both from oxygen column occupancy and the static displacement of oxygen atoms due to occupancy change to the observed column intensities of TEM images were systematically investigated using HRTEM simulation. We found that oxygen column intensity is governed primarily by column occupancy rather than by static displacement of oxygen atoms. Utilizing the aberration-corrected TEM capability and HRTEM simulation results, we experimentally verified that oxygen vacancies segregate near the single grain boundary of a YSZ bicrystal. The methodology and the high spatial resolution characterization tool employed in the present study provide insights into the distribution of oxygen vacancies in the bulk as well as near grain boundaries and pave the way for further investigation and atomic-scale analysis in other important oxide materials.

  2. Seeing Inside Materials by Aberration-Corrected Electron Microscopy

    SciTech Connect

    Pennycook, Stephen J

    2011-01-01

    The recent successful correction of lens aberrations in the electron microscope has improved resolution by more than a factor of two in just a few years, bringing many benefits for the study of materials. These benefits extend significantly beyond enhanced resolution alone. Aberration correction gives higher resolution by allowing the objective lens to have a wider aperture, which also results in a reduced depth of field. This effect can be used to only focus specific sections inside materials for the first time. In this contribution we describe recent results exploiting this capability. Additionally, we show how combining the microscopy data with first-principles theory gives new insights into materials properties. We cover two applications, both involving heavy atoms in a lighter host. The first shows how single Hf atoms can be mapped in three dimensions inside the 1 nm-wide SiO2 region of a high dielectric constant device structure, and how a link to macroscopic device properties results through theoretical calculations. The second example is from the field of nanoscience, where individual Au atoms are imaged inside Si nanowires grown by a vapor-liquid-solid mechanism. The majority of Au atoms are probably injected by the highly energetic electron beam. However, their observed sites and atomic configurations represent at least meta-stable configurations and match well to results from density functional calculations.

  3. Diverticula of Kommerell and Aberrant Subclavian Arteries Complicated by Aneurysms

    SciTech Connect

    Fisher, R. G. Whigham, C. J.; Trinh, C.

    2005-06-15

    This is a retrospective evaluation of the incidence of aberrant subclavian arteries (ASAs) and diverticula of Kommerell, as well as the occurrence and significance of associated aneurysms. Thoracic aortograms obtained during a 12.5-year period were reviewed, seeking the presence of aberrant right and left subclavian arteries (ARSAs/ALSAs), diverticula of Kommerell, and the incidence of associated aortic aneurysms. Several cases were evaluated with computed tomography concomitantly. Results were correlated with a literature review. Twenty-two ASAs were identified. Nineteen were on the right (ARSAs) and three were on the left (ALSAs). A diverticulum of Kommerell (DOK) was also present on the right in seven and on the left in three. Five of these patients had complicating aneurysms. Four of these were associated with ARSAs and their diverticula. Two were atherosclerotic; one was a limited dissection and one of uncertain etiology was ruptured. One additional aneurysm (atherosclerotic) involved an ALSA/DOK. The patient with the ruptured aneurysm died in surgery; three were managed conservatively because of concomitant disease; and one is being followed because of the small size (2.5 cm) of the aneurysm. ARSAs are relatively uncommon and ALSAs are rare. Both ARSA and ALSA are frequently associated with a DOK. Aneurysms rarely involve ASAs (with or without a DOK), but they are associated with a high mortality rate if they are not discovered before rupture. Early diagnosis plus surgical and/or endovascular management can be lifesaving.

  4. Stable chromosome aberration frequencies in men occupationally exposed to radiation.

    PubMed

    Tawn, E Janet; Whitehouse, Caroline A

    2003-09-01

    The introduction of fluorescence in situ hybridisation techniques to cytogenetic biodosimetry has enabled the detection of stable aberrations, e.g. translocations, which can provide an integrated measure of radiation exposure. The opportunity to study stable aberration frequencies in lymphocyte cultures from occupationally exposed workers with well-documented dosimetry records enables the establishment of dose-response relationships which can be compared with those obtained from studies of populations with high acute exposures. Since there is good mechanistic evidence for the role of translocations in oncogenesis, this provides an insight into the risks associated with low-dose exposure for which no direct epidemiological evidence is available. This paper provides preliminary data on a group of 98 individuals with cumulative occupational doses > 500 mSv and 96 controls with doses < 50 mSv. An increased frequency of translocations was found for the high-dose group (20.50 +/- 0.78 x 10(-3) per genome equivalent) in comparison with the control group (11.71 +/- 0.59 x 10(-3) per genome equivalent). Further analysis of the control group revealed increasing frequencies of translocations with increasing age. An increase associated with ever-smoking status was found for the control group which appeared to be driven by the lower age groups but no overall effect of smoking was seen in the > 500 mSv group.

  5. Aberrant functional brain connectome in people with antisocial personality disorder.

    PubMed

    Tang, Yan; Long, Jun; Wang, Wei; Liao, Jian; Xie, Hua; Zhao, Guihu; Zhang, Hao

    2016-01-01

    Antisocial personality disorder (ASPD) is characterised by a disregard for social obligations and callous unconcern for the feelings of others. Studies have demonstrated that ASPD is associated with abnormalities in brain regions and aberrant functional connectivity. In this paper, topological organisation was examined in resting-state fMRI data obtained from 32 ASPD patients and 32 non-ASPD controls. The frequency-dependent functional networks were constructed using wavelet-based correlations over 90 brain regions. The topology of the functional networks of ASPD subjects was analysed via graph theoretical analysis. Furthermore, the abnormal functional connectivity was determined with a network-based statistic (NBS) approach. Our results revealed that, compared with the controls, the ASPD patients exhibited altered topological configuration of the functional connectome in the frequency interval of 0.016-0.031 Hz, as indicated by the increased clustering coefficient and decreased betweenness centrality in the medial superior frontal gyrus, precentral gyrus, Rolandic operculum, superior parietal gyrus, angular gyrus, and middle temporal pole. In addition, the ASPD patients showed increased functional connectivity mainly located in the default-mode network. The present study reveals an aberrant topological organisation of the functional brain network in individuals with ASPD. Our findings provide novel insight into the neuropathological mechanisms of ASPD. PMID:27257047

  6. Exercise protects against methamphetamine-induced aberrant neurogenesis

    PubMed Central

    Park, Minseon; Levine, Harry; Toborek, Michal

    2016-01-01

    While no effective therapy is available for the treatment of methamphetamine (METH)-induced neurotoxicity, aerobic exercise is being proposed to improve depressive symptoms and substance abuse outcomes. The present study focuses on the effect of exercise on METH-induced aberrant neurogenesis in the hippocampal dentate gyrus in the context of the blood-brain barrier (BBB) pathology. Mice were administered with METH or saline by i.p. injections for 5 days with an escalating dose regimen. One set of mice was sacrificed 24 h post last injection of METH, and the remaining animals were either subjected to voluntary wheel running (exercised mice) or remained in sedentary housing (sedentary mice). METH administration decreased expression of tight junction (TJ) proteins and increased BBB permeability in the hippocampus. These changes were preserved post METH administration in sedentary mice and were associated with the development of significant aberrations of neural differentiation. Exercise protected against these effects by enhancing the protein expression of TJ proteins, stabilizing the BBB integrity, and enhancing the neural differentiation. In addition, exercise protected against METH-induced systemic increase in inflammatory cytokine levels. These results suggest that exercise can attenuate METH-induced neurotoxicity by protecting against the BBB disruption and related microenvironmental changes in the hippocampus. PMID:27677455

  7. Encoding, consolidation, and retrieval of contextual memory: differential involvement of dorsal CA3 and CA1 hippocampal subregions.

    PubMed

    Daumas, Stéphanie; Halley, Hélène; Francés, Bernard; Lassalle, Jean-Michel

    2005-01-01

    Studies on human and animals shed light on the unique hippocampus contributions to relational memory. However, the particular role of each hippocampal subregion in memory processing is still not clear. Hippocampal computational models and theories have emphasized a unique function in memory for each hippocampal subregion, with the CA3 area acting as an autoassociative memory network and the CA1 area as a critical output structure. In order to understand the respective roles of the CA3- and CA1-hippocampal areas in the formation of contextual memory, we studied the effects of the reversible inactivation by lidocaine of the CA3 or CA1 areas of the dorsal hippocampus on acquisition, consolidation, and retrieval of a contextual fear conditioning. Whereas infusions of lidocaine never impaired elementary tone conditioning, their effects on contextual conditioning provided interesting clues about the role of these two hippocampal regions. They demonstrated first that the CA3 area is necessary for the rapid elaboration of a unified representation of the context. Secondly, they suggested that the CA1 area is rather involved in the consolidation process of contextual memory. Third, they showed that CA1 or CA3 inactivation during retention test has no effect on contextual fear retrieval when a recognition memory procedure is used. In conclusion, our findings point as evidence that CA1 and CA3 subregions of the dorsal hippocampus play important and different roles in the acquisition and consolidation of contextual fear memory, whereas they are not required for context recognition.

  8. Childhood poverty and stress reactivity are associated with aberrant functional connectivity in default mode network.

    PubMed

    Sripada, Rebecca K; Swain, James E; Evans, Gary W; Welsh, Robert C; Liberzon, Israel

    2014-08-01

    Convergent research suggests that childhood poverty is associated with perturbation in the stress response system. This might extend to aberrations in the connectivity of large-scale brain networks, which subserve key cognitive and emotional functions. Resting-state brain activity was measured in adults with a documented history of childhood poverty (n=26) and matched controls from middle-income families (n=26). Participants also underwent a standard laboratory social stress test and provided saliva samples for cortisol assay. Childhood poverty was associated with reduced default mode network (DMN) connectivity. This, in turn, was associated with higher cortisol levels in anticipation of social stress. These results suggest a possible brain basis for exaggerated stress sensitivity in low-income individuals. Alterations in DMN may be associated with less efficient cognitive processing or greater risk for development of stress-related psychopathology among individuals who experienced the adversity of chronic childhood poverty.

  9. Induction of chromosome aberrations by cis-platinum(II)diamminodichloride in Drosophila melanogaster

    SciTech Connect

    Brodberg, R.K.; Lyman, R.F.; Woodruff, R.C.

    1983-01-01

    The authors have determined the in vivo effects of cis-platinum(II)diamminodichloride (cis-PDD) treatment on the induction of chromosome aberrations in Drosophila melanogaster germ cells. cis-PDD treatment induces significant increases in chromosome breakage in all stages of spermatogenesis in a battery of test systems using ring or rod-X males and repair-proficient or deficient females. Since no increase in nondisjunction was induced by cis-PDD in either male or female germ cells, any aneuploidy inducing effects of this compound should result from its clastogenic action. They also find that mei-9 excision repair function is involved in the repair of cis-PDD-induced DNA lesions in a manner that provides additional evidence that partital and ring chromosome losses are not completely homologous.

  10. The Distribution of Chromosomal Aberrations in Human Cells Predicted by a Generalized Time-Dependent Model of Radiation-Induced Formation of Aberrations

    NASA Technical Reports Server (NTRS)

    Ponomarev, Artem L.; George, K.; Cucinotta, F. A.

    2011-01-01

    New experimental data show how chromosomal aberrations for low- and high-LET radiation are dependent on DSB repair deficiencies in wild-type, AT and NBS cells. We simulated the development of chromosomal aberrations in these cells lines in a stochastic track-structure-dependent model, in which different cells have different kinetics of DSB repair. We updated a previously formulated model of chromosomal aberrations, which was based on a stochastic Monte Carlo approach, to consider the time-dependence of DSB rejoining. The previous version of the model had an assumption that all DSBs would rejoin, and therefore we called it a time-independent model. The chromosomal-aberrations model takes into account the DNA and track structure for low- and high-LET radiations, and provides an explanation and prediction of the statistics of rare and more complex aberrations. We compared the program-simulated kinetics of DSB rejoining to the experimentally-derived bimodal exponential curves of the DSB kinetics. We scored the formation of translocations, dicentrics, acentric and centric rings, deletions, and inversions. The fraction of DSBs participating in aberrations was studied in relation to the rejoining time. Comparisons of simulated dose dependence for simple aberrations to the experimental dose-dependence for HF19, AT and NBS cells will be made.

  11. Polarization aberrations in the solar activity measurements experiments (SAMEX) solar vector magnetograph

    NASA Technical Reports Server (NTRS)

    Mcguire, James P., Jr.; Chipman, Russell A.

    1989-01-01

    An optical design and polarization analysis of the Air Force/NASA Solar Activity Measurements Experiments solar vector magnetograph optical system is performed. Polarization aberration theory demonstrates that conventional telescope coating designs introduce unacceptably high levels of polarization aberrations into the optical system. Several ultralow polarization mirror and lens coatings designs for this instrument are discussed. Balancing of polarization aberrations at different surfaces is demonstrated.

  12. Method for measuring ocular aberrations induced by thermal lensing in vivo

    NASA Astrophysics Data System (ADS)

    Vincelette, Rebecca; Oliver, Jeff; Noojin, Gary; Schuster, Kurt; Shingledecker, Aurora; Welch, Ashley J.

    2010-02-01

    An adaptive optics imaging system was used to qualitatively observe the types of aberrations induced by an infrared laser in a rhesus eye. Thermal lensing was induced with an infrared laser radiation wavelength of 1150-nm. The adaptive optics system tracked the temporal response of the aberrations at a frequency of 30 Hz for continuous-wave exposures. Results are compared against thermal lensing aberrations induced in an artificial eye.

  13. Optimization of holographic data storage system based on Seidel aberrations reduction

    NASA Astrophysics Data System (ADS)

    Liu, Ren-Chung; Lin, Shiuan-Huei; Hsu, Ken-Yuh

    2015-08-01

    In this research, we investigate the influence of Seidel aberrations on the point spread function and the probability density function of holographic data storage systems, and thus the storage capacity and bit error rate of storage system can be obtained. The aberrations tolerances of storage systems with different numerical aperture are obtained. Optimization on BER and SC of holographic data storage systems by reducing Seidel aberrations will be demonstrated numerically.

  14. Utilization of the excimer laser and a moving piezoelectric mirror to accomplish the customized contact lens ablation to correct high-order aberrations

    NASA Astrophysics Data System (ADS)

    de Matos, Luciana; Yasuoka, Fátima M. M.; Schor, Paulo; de Oliveira, Enos; Bagnato, Vanderlei S.; Carvalho, Luis A. V.

    2014-02-01

    The use of the Hartman-Shack sensor in ophthalmology allowed the identification of higher-order aberrations, which make possible the search for methods to correct them. Customized refractive surgery is one of the most successful methods, although there are patients which cannot be submitted to this surgery due to a variety of abnormal limiting factors such as cornea thickness and quantity of higher-order aberrations. Being this an irreversible process, the alternative is to develop a non-surgical method. This work proposes a method to obtain personalized contact lenses to correct high-order aberrations via the development of a customized ablation system using an excimer laser and a moving piezoelectric mirror. The process to produce such lenses consists of four steps. 1) The map of total aberrations of the patient's eye is measured by using an aberrometer with a Hartman-Shack sensor. 2) The measured aberration map is used to determine the maps for correction and related distribution of laser pulses for the ablation process with the excimer laser. 3) The lens production is performed following the same principle as customized refractive surgery. 4) The quality control of the lens is evaluated by two tests. 4.1) The lens is measured by a non-commercial lensometer, which is assembled specially for this measurement, as the ones commercially available are not capable of measuring asymmetric and irregular surfaces. 4.2) The evaluation of the lens-eye system is made using the aberrometer of the first step in order to verify the residual aberrations. Here, the lenses are ablated with a customized refractive surgery system.

  15. Influences of reference plane and direction of measurement on eye aberration measurement

    NASA Astrophysics Data System (ADS)

    Atchison, David A.; Charman, W. Neil

    2005-12-01

    We explored effects of measurement conditions on wave aberration estimates for uncorrected, axially myopic model eyes. Wave aberrations were initially referenced to either the anterior corneal pole or the natural entrance pupil of symmetrical eye models, with rays traced into the eye from infinity (into the eye) to simulate normal vision, into the eye from infinity and then back out of the eye from the retinal intercepts (into/out of the eye), or out of the eye from the retinal fovea (out of the eye). The into-the-eye and out-of-the-eye ray traces gave increases in spherical aberration as myopia increased, but the into/out-of-the-eye ray trace showed little variation in spherical aberration. Reference plane choice also affected spherical aberration. Corresponding residual aberrations were calculated after the models had been optically corrected, either by placing the object or image plane at the paraxial far point or by modifying corneas to simulate laser ablation corrections. Correcting aberrations by ablation was more complete if the original aberrations were referenced to the cornea rather than to the entrance pupil. For eyes corrected by spectacle lenses, failure to allow for effects of pupil magnification on apparent entrance pupil diameter produced larger changes in measured aberrations. The general findings regarding choice of reference plane and direction of measurement were found to be equally applicable to eyes that lacked rotational symmetry.

  16. Development of optical design algorithms on the base of the exact (all orders) geometrical aberration theory

    NASA Astrophysics Data System (ADS)

    Hristov, Boian A.

    2011-10-01

    The process of optical design today is both an art and a science mainly due to the lack of exact and suitable aberration theory. In this paper we propose an exact (without any approximations) analytical aberration theory. It describes exactly the relations between the on-axis image aberrations and on-axis object aberrations via so called relative parameters, real aperture incidence angles, real aperture slope angles, refraction indexes and object distance. The image field aberrations (distortion, astigmatism, tangential curvature, sagittal curvature and field curvature) are described in a mathematically exact way by means of relative parameters, real incidence angles and slope angles of the chief rays, refraction indexes, object distance and corresponding object aberrations. For the image tangential coma and image sagittal coma we propose differential formulae. To verify the correction of every single aberration we use the commercial program OSLO. The differences between our and OSLO results for each aberration (except for the tangential and sagittal coma) are less than 1x10-8 mm. In addition we propose some exact aberration's correction algorithms for a very distant object and variety of constructive design solutions which confirm the truth of the proposed theory.

  17. Effects of aberrations in vortex-beams generated with amplitude diffraction gratings

    NASA Astrophysics Data System (ADS)

    Cuartas-Vélez, Carlos; Echeverri-Chacón, Santiago; Restrepo, René

    2016-03-01

    We present a mathematical model for the generation of vortex-beams by using a square profile amplitude fork diffraction grating with arbitrary topological charge. The mathematical framework of aberrations in the forked-shape diffraction grating is analysed, and the resulting diffracted pattern is simulated. Three cases of desired distortions (aberrations) in the diffraction grating are considered, obtaining phase modulation from the amplitude grating. Experimental optical vortices are generated by using a transmission spatial light modulator, which is used as a dynamic diffraction grating, allowing us to aberrate it. We show the effect of aberrations in the experimental diffracted vortex-beams and compare it with the numerical simulation.

  18. Aberration correction for direct laser written waveguides in a transverse geometry.

    PubMed

    Huang, L; Salter, P S; Payne, F; Booth, M J

    2016-05-16

    The depth dependent spherical aberration is investigated for ultrafast laser written waveguides fabricated in a transverse writing geometry using the slit beam shaping technique in the low pulse repetition rate regime. The axial elongation of the focus caused by the aberration leads to a distortion of the refractive index change, and waveguides designed as single mode become multimode. We theoretically estimate a depth range over which the aberration effects can be compensated simply by adjusting the incident laser power. If deeper fabrication is required, it is demonstrated experimentally that the aberration can be successfully removed using adaptive optics to fabricate single mode optical waveguides over a depth range > 1 mm. PMID:27409879

  19. The Gaussian formula and spherical aberrations of static and relativistic curved mirrors from Fermat's principle

    NASA Astrophysics Data System (ADS)

    Sutanto, Sylvia H.; Tjiang, Paulus C.

    2011-10-01

    The Gaussian formula and spherical aberrations of static and relativistic curved mirrors are analyzed using the optical path length (OPL) and Fermat's principle. The geometrical figures generated by the rotation of conic sections about their symmetry axes are considered for the shapes of the mirrors. By comparing the results in static and relativistic cases, it is shown that the focal lengths and the spherical aberration relations of the relativistic mirrors obey the Lorentz contraction. Further analysis of the spherical aberrations for both static and relativistic cases have resulted in information about the limits for the paraxial approximation, as well as for the minimum speed of the systems to reduce the spherical aberrations.

  20. Efficient estimation and large-scale evaluation of lateral chromatic aberration for digital image forensics

    NASA Astrophysics Data System (ADS)

    Gloe, Thomas; Borowka, Karsten; Winkler, Antje

    2010-01-01

    The analysis of lateral chromatic aberration forms another ingredient for a well equipped toolbox of an image forensic investigator. Previous work proposed its application to forgery detection1 and image source identification.2 This paper takes a closer look on the current state-of-the-art method to analyse lateral chromatic aberration and presents a new approach to estimate lateral chromatic aberration in a runtime-efficient way. Employing a set of 11 different camera models including 43 devices, the characteristic of lateral chromatic aberration is investigated in a large-scale. The reported results point to general difficulties that have to be considered in real world investigations.

  1. A right-sided aortic arch and aberrant left subclavian artery with proximal segment hypoplasia.

    PubMed

    Margolis, Justin; Bilfinger, Thomas; Labropoulos, Nicos

    2012-03-01

    The right-sided thoracic aortic arch is a rare congenital malformation occurring during embryologic development. A majority of the cases present with two anatomic variations, one of which is an aberrant left subclavian artery (LSA) originating off the distal descending aortic arch. This aberrant LSA courses across and compresses thoracic structures on its way to the left thoracic outlet. While this aberrant vessel causes mostly benign symptoms, patients may first present with rupture of a thoracic aneurysm. This thoracic aneurysm is commonly known as Kommerell's diverticulum. This paper presents a case of an aberrant LSA originating off Kommerell's diverticulum with a proximal long-segment hypoplasia, a very rare anatomic variation.

  2. Examples of the topographies of the wavefront-variance merit function at different aberration orders

    NASA Astrophysics Data System (ADS)

    Johnston, Steve C.

    1991-01-01

    The wavefront variance merit function is constructed with aberration orders identified and partitioned. The partitioned merit function topographies of three optical systems are examined. 1. INTRODUCFION The study of the behavior of individual wavefront aberration coefficients with respect to optical system parameters has long been successfully employed to gain insight into the properties of optical systems. However for many optical systems it is more appropriate to examine the wavefront aberrations collectively rather than individually. New insight into the imaging characteristics of optical systems may be obtained by using the individual wavefront aberration coefficients to construct the average wavefront variance function. This can be done in such a way that the merit function may be separated into partitions which are associated with a single aberration order. The partitions are a small number of image quality indicators that may be examined individually. Each indicator ifiustrates the behavior of the optical system at a particular aberration order. 2. FORMULATION OF THE MERIT FUNCTION The wavefront variance merit function is defined by K w2 )ftuld '' (1) where the angle brackets denote averaging over the pupil or field as indicated in the equation and W is the wavefront aberration function as a function of pupil position p. and field position H. For axially symmetric optical systems the aberration coefficients are introduced by writing the wavefront aberration function as a Taylor series expansion in p and

  3. An integrative genomic and proteomic analysis of PIK3CA, PTEN and AKT mutations in breast cancer

    SciTech Connect

    Stemke-Hale, Katherine; Gonzalez-Angulo, Ana Maria; Lluch, Ana; Neve, Richard M.; Kuo, Wen-Lin; Davies, Michael; Carey, Mark; Hu, Zhi; Guan, Yinghui; Sahin, Aysegul; Symmans, W. Fraser; Pusztai, Lajos; Nolden, Laura K.; Horlings, Hugo; Berns, Katrien; Hung, Mien-Chie; van de Vijver, Marc J.; Valero, Vicente; Gray, Joe W.; Bernards, Rene; Mills, Gordon B.; Hennessy, Bryan T.

    2008-05-06

    Phosphatidylinositol-3-kinase (PI3K)/AKT pathway aberrations are common in cancer. By applying mass spectroscopy-based sequencing and reverse phase protein arrays to 547 human breast cancers and 41 cell lines, we determined the subtype specificity and signaling effects of PIK3CA, AKT and PTEN mutations, and the effects of PIK3CA mutations on responsiveness to PI3K inhibition in-vitro and on outcome after adjuvant tamoxifen. PIK3CA mutations were more common in hormone receptor positive (33.8%) and HER2-positive (24.6%) than in basal-like tumors (8.3%). AKT1 (1.4%) and PTEN (2.3%) mutations were restricted to hormone receptor-positive cancers with PTEN protein levels also being significantly lower in hormone receptor-positive cancers. Unlike AKT1 mutations, PIK3CA (39%) and PTEN (20%) mutations were more common in cell lines than tumors, suggesting a selection for these but not AKT1 mutations during adaptation to culture. PIK3CA mutations did not have a significant impact on outcome in 166 hormone receptor-positive breast cancer patients after adjuvant tamoxifen. PIK3CA mutations, in comparison with PTEN loss and AKT1 mutations, were associated with significantly less and indeed inconsistent activation of AKT and of downstream PI3K/AKT signaling in tumors and cell lines, and PTEN loss and PIK3CA mutation were frequently concordant, suggesting different contributions to pathophysiology. PTEN loss but not PIK3CA mutations rendered cells sensitive to growth inhibition by the PI3K inhibitor LY294002. Thus, PI3K pathway aberrations likely play a distinct role in the pathogenesis of different breast cancer subtypes. The specific aberration may have implications for the selection of PI3K-targeted therapies in hormone receptor-positive breast cancer.

  4. Growth rate effects on Mg/Ca and Sr/Ca ratios constrained by belemnite calcite

    NASA Astrophysics Data System (ADS)

    Vinzenz Ullmann, Clemens

    2016-04-01

    Multiple temperature proxies from single species are important to achieve robust palaeotemperature estimates. Besides the commonly employed oxygen isotope thermometer, also Mg/Ca and Sr/Ca ratios perform well as proxies for calcification temperature in the shells of some species. While salinity changes affect the ratios of earth alkaline elements much less than the δ18O thermometer, metabolic effects may exert a strong control on the expression of element ratios. Such effects are hard to study because biomineralization experiments have to overcome large intraspecific variability and can hardly ever isolate the controls of a single parameter on shell geochemistry. The unique geometry of the belemnite rostrum constitutes an exception to this rule. Its shape, large size, and the visibility of growth increments as bands enable the analysis of multiple, correlatable, high resolution geochemical profiles in a single fossil. The effects of the growth rate variability amongst these profiles on Mg/Ca and Sr/Ca ratios has been tested here. Within a specimen of Passaloteuthis bisulcata (Early Toarcian, Cleveland Basin, UK), Mg/Ca and Sr/Ca data were obtained from four profiles. With respect to growth rate in the first profile, which was taken as a reference, the relative growth rates in the remaining three profiles varied by a factor of 0.9 to 2.7. Results suggest that relative growth rate is linearly correlated with Mg/Ca and Sr/Ca, with a decrease of Mg/Ca by 8 % and increase of Sr/Ca by 6 % per 100 % increase in relative growth rate. The observed trends are consistent with abiogenic precipitation experiments and suggest that crystal precipitation rate exerts a significant, predictable control on the element distribution in biogenic calcite.

  5. The Allium Test--A Simple, Eukaryote Genotoxicity Assay.

    ERIC Educational Resources Information Center

    Babich, H.; Segall, M. A.; Fox, K. D.

    1997-01-01

    Explains the allium test in which roots are excised from onion bulblets grown in aqueous solutions of a test agent. Root tips are then isolated and stained with aceto-orcein, and chromosomal aberrations are microscopically observed. (Author/AIM)

  6. Los Angeles, CA, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This rare cloud and smog free view of Los Angeles, CA (34.0N, 118.5W) is a result of strong Santa Ana winds blowing from the east. Both cultural and natural features are well displayed and all of the major streets, highways and freeways can be traced in their entirety throughout the city as well as the major business and commercial sections. On the eastern edge of the scene, the San Andreas fault cuts across from southeast to northwest.

  7. Identification of Copy Number Aberrations in Breast Cancer Subtypes Using Persistence Topology

    PubMed Central

    Arsuaga, Javier; Borrman, Tyler; Cavalcante, Raymond; Gonzalez, Georgina; Park, Catherine

    2015-01-01

    DNA copy number aberrations (CNAs) are of biological and medical interest because they help identify regulatory mechanisms underlying tumor initiation and evolution. Identification of tumor-driving CNAs (driver CNAs) however remains a challenging task, because they are frequently hidden by CNAs that are the product of random events that take place during tumor evolution. Experimental detection of CNAs is commonly accomplished through array comparative genomic hybridization (aCGH) assays followed by supervised and/or unsupervised statistical methods that combine the segmented profiles of all patients to identify driver CNAs. Here, we extend a previously-presented supervised algorithm for the identification of CNAs that is based on a topological representation of the data. Our method associates a two-dimensional (2D) point cloud with each aCGH profile and generates a sequence of simplicial complexes, mathematical objects that generalize the concept of a graph. This representation of the data permits segmenting the data at different resolutions and identifying CNAs by interrogating the topological properties of these simplicial complexes. We tested our approach on a published dataset with the goal of identifying specific breast cancer CNAs associated with specific molecular subtypes. Identification of CNAs associated with each subtype was performed by analyzing each subtype separately from the others and by taking the rest of the subtypes as the control. Our results found a new amplification in 11q at the location of the progesterone receptor in the Luminal A subtype. Aberrations in the Luminal B subtype were found only upon removal of the basal-like subtype from the control set. Under those conditions, all regions found in the original publication, except for 17q, were confirmed; all aberrations, except those in chromosome arms 8q and 12q were confirmed in the basal-like subtype. These two chromosome arms, however, were detected only upon removal of three patients

  8. Identification of Copy Number Aberrations in Breast Cancer Subtypes Using Persistence Topology

    PubMed Central

    Arsuaga, Javier; Borrman, Tyler; Cavalcante, Raymond; Gonzalez, Georgina; Park, Catherine

    2015-01-01

    DNA copy number aberrations (CNAs) are of biological and medical interest because they help identify regulatory mechanisms underlying tumor initiation and evolution. Identification of tumor-driving CNAs (driver CNAs) however remains a challenging task, because they are frequently hidden by CNAs that are the product of random events that take place during tumor evolution. Experimental detection of CNAs is commonly accomplished through array comparative genomic hybridization (aCGH) assays followed by supervised and/or unsupervised statistical methods that combine the segmented profiles of all patients to identify driver CNAs. Here, we extend a previously-presented supervised algorithm for the identification of CNAs that is based on a topological representation of the data. Our method associates a two-dimensional (2D) point cloud with each aCGH profile and generates a sequence of simplicial complexes, mathematical objects that generalize the concept of a graph. This representation of the data permits segmenting the data at different resolutions and identifying CNAs by interrogating the topological properties of these simplicial complexes. We tested our approach on a published dataset with the goal of identifying specific breast cancer CNAs associated with specific molecular subtypes. Identification of CNAs associated with each subtype was performed by analyzing each subtype separately from the others and by taking the rest of the subtypes as the control. Our results found a new amplification in 11q at the location of the progesterone receptor in the Luminal A subtype. Aberrations in the Luminal B subtype were found only upon removal of the basal-like subtype from the control set. Under those conditions, all regions found in the original publication, except for 17q, were confirmed; all aberrations, except those in chromosome arms 8q and 12q were confirmed in the basal-like subtype. These two chromosome arms, however, were detected only upon removal of three patients

  9. Epigenetic upregulation of large-conductance Ca2+-activated K+ channel expression in uterine vascular adaptation to pregnancy.

    PubMed

    Chen, Man; Dasgupta, Chiranjib; Xiong, Fuxia; Zhang, Lubo

    2014-09-01

    Our previous study demonstrated that pregnancy increased large-conductance Ca(2+)-activated potassium channel β1 subunit (BKβ1) expression and large-conductance Ca(2+)-activated potassium channel activity in uterine arteries, which were abrogated by chronic hypoxia. The present study tested the hypothesis that promoter methylation/demethylation is a key mechanism in epigenetic reprogramming of BKβ1 expression patterns in uterine arteries. Ovine BKβ1 promoter of 2315 bp spanning from -2211 to +104 of the transcription start site was cloned, and an Sp1-380 binding site that contains CpG dinucleotide in its core binding sequences was identified. Site-directed deletion of the Sp1 site significantly decreased the BKβ1 promoter activity. Estrogen receptor-α bound to the Sp1 site through tethering to Sp1 and upregulated the expression of BKβ1. The Sp1 binding site at BKβ1 promoter was highly methylated in uterine arteries of nonpregnant sheep, and methylation inhibited transcription factor binding and BKβ1 promoter activity. Pregnancy caused a significant decrease in CpG methylation at the Sp1 binding site and increased Sp1 binding to the BKβ1 promoter and BKβ1 mRNA abundance. Chronic hypoxia during gestation abrogated this pregnancy-induced demethylation and upregulation of BKβ1 expression. The results provide evidence of a novel mechanism of promoter demethylation in pregnancy-induced reprogramming of large-conductance Ca(2+)-activated potassium channel expression and function in uterine arteries and suggest new insights of epigenetic mechanisms linking gestational hypoxia to aberrant uteroplacental circulation and increased risk of preeclampsia.

  10. Sulfide capacities of CaO-CaF2-CaCl2 melts

    NASA Astrophysics Data System (ADS)

    Simeonov, Simeon; Sakai, Toshihiko; Maeda, Masafumi

    1992-06-01

    The sulfide capacityC_{s^{2 - } } = ({text{pct S}}^{{text{2 - }}} )(p_{{text{O}}_{text{2}} } /p_{{text{S}}_{text{2}} } )^{1/2} ) of CaO-CaF2-CaCl2 slag was determined at temperatures from 1000 °C to 1300 °C by equilibrating molten slag, molten silver, and CO-CO2-Ar gas mixture. The sulfide capacity increases with replacing CaCl2 by CaF2 in slags of constant CaO contents. The sulfide capacity also increases with increasing temperature as well as with increasing CaO content at a constant ratio of CaF2/CaCl2 of unity. A linear relationship between the sulfide capacity and carbonate capacity in literature was observed on a logarithmic scale.

  11. Differences and correlation of serum CEA, CA19-9 and CA72-4 in gastric cancer

    PubMed Central

    YU, JUNXIU; ZHANG, SHUGUANG; ZHAO, BINGBO

    2016-01-01

    The sensitivity of three biomarkers, carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9 and CA72-4, in combination has been identified to be greater than that of any of the biomarkers considered in isolation in cases of gastric cancer (GC). However, the fundamental cause underlying this phenomenon remains to be fully elucidated. In the present study, the differences and correlation of these three biomarkers were investigated in patients with GC in order to determine how the three biomarkers in combination work more effectively compared with any of the biomarkers considered alone. The serum levels of CEA, CA19-9 and CA72-4 of 216 patients with gastric adenocarcinoma were analyzed on admission to hospital. The differences in positive rates and the serum levels of CEA, CA19-9 and CA72-4 were analyzed using the χ2 test and the non-parametric Wilcoxon two-sample test. Phi (f) correlation analysis was used to study the correlation among the expression (positive or not) levels of CEA, CA19-9 and CA72-4. The correlation among the serum levels of biomarkers was analyzed using Spearman's test. The results demonstrated that the combined positive rate of CEA, CA19-9 and CA72-4 was significantly higher compared with the individual CEA, CA19-9 and CA72-4 positive rates (44.91% vs. 22.69, 18.98 and 22.69%, respectively; all P<0.05). The positive rate of CA19-9 and CA72-4 in the extent of the primary tumor/involvement of regional lymph node/distant metastases (TNM)-III/IV stage subgroup was higher compared with that in the TNM-I/II subgroup (χ2=5.902, P=0.015; χ2=8.009, P=0.005), although not the positive rate of CEA (χ2=0.302, P=0.583). A significant correlation was identified between the expression level of CEA and CA72-4 (f correlation coefficient=0.182; P=0.008) and between that of CA19-9 and CA72-4 (f correlation coefficient=0.189; P=0.006), although not between that of CEA and CA19-9 (f correlation coefficient=0.048; P=0.482) in the total number of patients

  12. Evaluation of chromosome aberration and micronucleus frequencies in blood lymphocytes of workers exposed to low concentrations of benzene.

    PubMed

    Lovreglio, Piero; Maffei, Francesca; Carrieri, Mariella; D'Errico, Maria N; Drago, Ignazio; Hrelia, Patrizia; Bartolucci, Giovanni B; Soleo, Leonardo

    2014-08-01

    The frequency of chromosome aberrations (CA) and micronuclei (MN) was investigated in the peripheral lymphocytes of workers occupationally exposed to low or very low concentrations of benzene. The study included 43 exposed workers (all males), namely 19 fuel-tanker drivers and 24 filling-station attendants, and 31 male subjects with no occupational exposure to the toxicant (controls). Benzene exposure was verified by means of environmental monitoring with passive personal samplers (Radiello(®)), and through biological monitoring, i.e. by measurement of urinary trans,trans-muconic acid, S-phenylmercapturic acid and benzene. The frequency of CA and MN in peripheral lymphocytes was determined according to standard procedures. Exposure to benzene was found to be significantly higher for fuel-tanker drivers (median 246.6 μg/m(3)) than for filling-station attendants (median 19.9 μg/m(3)). Both groups had significantly higher exposure than controls (median 4.3 μg/m(3)). No increased frequency of CA and MN was observed in either fuel-tanker drivers or filling-station attendants compared with controls. In all subjects examined as a single group, the frequency of MN was significantly dependent on age. Only in the fuel-tanker drivers was the frequency of MN found to depend not only on age, but also on exposure to benzene. In conclusion, the frequency of MN, but not of CA, could be influenced by exposure to benzene concentrations of up to one order of magnitude lower than the threshold limit value (time-weighted average).

  13. Total ocular, anterior corneal and lenticular higher order aberrations in hyperopic, myopic and emmetropic eyes.

    PubMed

    Philip, Krupa; Martinez, Aldo; Ho, Arthur; Conrad, Fabian; Ale, Jit; Mitchell, Paul; Sankaridurg, Padmaja

    2012-01-01

    Total ocular higher order aberrations and corneal topography of myopic, emmetropic and hyperopic eyes of 675 adolescents (16.9 ± 0.7 years) were measured after cycloplegia using COAS aberrometer and Medmont videokeratoscope. Corneal higher order aberrations were computed from the corneal topography maps and lenticular (internal) higher order aberrations derived by subtraction of corneal aberrations from total ocular aberrations. Aberrations were measured for a pupil diameter of 5mm. Multivariate analysis of variance followed by multiple regression analysis found significant difference in the fourth order aberrations (SA RMS, primary spherical aberration coefficient) between the refractive error groups. Hyperopic eyes (+0.083 ± 0.05 μm) had more positive total ocular primary spherical aberration compared to emmetropic (+0.036 ± 0.04 μm) and myopic eyes (low myopia=+0.038 ± 0.05 μm, moderate myopia=+0.026 ± 0.06 μm) (p<0.05). No difference was observed for the anterior corneal spherical aberration. Significantly less negative lenticular spherical aberration was observed for the hyperopic eyes (-0.038 ± 0.05 μm) than myopic (low myopia=-0.088 ± 0.04 μm, moderate myopia=-0.095 ± 0.05 μm) and emmetropic eyes (-0.081 ± 0.04 μm) (p<0.05). These findings suggest the existence of differences in the characteristics of the crystalline lens (asphericity, curvature and gradient refractive index) of hyperopic eyes versus other eyes.

  14. The nature of chromosomal aberrations detected in humans exposed to benzene.

    PubMed

    Zhang, Luoping; Eastmond, David A; Smith, Martyn T

    2002-01-01

    Benzene is an established cause of human leukemia that is thought to act by producing chromosomal aberrations and altered in cell differentiation. In several recent studies increased levels of chromosomal aberrations in peripheral blood lymphocytes were correlated with a heightened risk of cancer, especially hematological malignancies. Thus, chromosomal aberrations may be a predictor of future leukemia risk. Previous studies exploring whether benzene exposure induces chromosomal aberrations have yielded mostly positive results. However, it remains unclear whether the chromosomal aberrations induced by benzene occur in a distinct pattern. Here, we thoroughly review the major chromosome studies published to date in benzene-exposed workers, benzene-poisoned and preleukemia patients, and leukemia cases associated with benzene expose. Although three cytogenetic markers (chromosomal aberrations, sister chromatid exchanges, and micronuclei) are commonly examined, our primary focus is on studies of chromosomal aberrations, because only this marker has so far been correlated with increased cancer risk. This review surveys the published literature, analyzes the study results, and discusses the characteristics of effects reported. In most studies of currently exposed workers, increases in chromosomal aberrations were observed. However, due to the relatively small number of affected individuals and variability in the reported aberrations, firm conclusions cannot be made about the involvement of specific chromosomes or chromosome regions. Further, in leukemia cases associated with benzene exposure, there is no evidence of a unique pattern of benzene-induced chromosomal aberrations in humans. Leukemia cases associated with benzene exposure are, however, more likely to contain clonal chromosome aberrations then those arising de novo in the general population.

  15. The Effect of Optical Aberrations on Laser-Induced Gas Breakdown.

    NASA Astrophysics Data System (ADS)

    Ryan, Daniel Joseph

    Over the past twenty years, much work has gone into developing a theoretical model for laser-induced gas breakdown. Out of all this work evolved the theories of multiphoton absorption and inverse Bremsstrahlung absorption. These two theories together provide a reasonable explanation of the processes of laser-induced gas breakdown. There are, however, many experimental results which are not in agreement with the theoretical results. One of the reasons for this is that aberrations in the focusing optics have, for the most part, been ignored in the studies of gas breakdown. The work presented in this dissertation examines the effects of aberrations on the imaging quality of lenses and on the energy distribution at the focal plane. Experimental results are shown comparing gas breakdown threshold for near diffraction limited lenses and for lenses having many wavelengths of aberrations. The results of the calculations on imaging performance and breakdown thresholds are then used to generate the aberration calibration curve. The calibration curve is a plot of the relationship between the number of wavelengths of aberrations and the percent of the total energy entering the aperture of the lens which is actually within the diffraction limited spot. Knowing the aberration characteristics of a lens, a corrected breakdown threshold intensity can be determined. A breakdown model which includes the effects of aberrations employs the aberration calibration curve to determine the intensity, assumes a diffraction limited spot size, and models the focal volume as an oblate spheroid. Presently accepted solutions to the continuity equation are then adaptable to include the effects of aberrations using these definitions of intensity, spot size and focal volume. The experimental results indicate the effectiveness of the aberration calibration curve in accounting for the contribution of aberrations in gas breakdown. The curve was successfully applied to previously published results

  16. The Oncoprotein BRD4-NUT Generates Aberrant Histone Modification Patterns

    PubMed Central

    Zee, Barry M.; Dibona, Amy B.; Alekseyenko, Artyom A.; French, Christopher A.; Kuroda, Mitzi I.

    2016-01-01

    Defects in chromatin proteins frequently manifest in diseases. A striking case of a chromatin-centric disease is NUT-midline carcinoma (NMC), which is characterized by expression of NUT as a fusion partner most frequently with BRD4. ChIP-sequencing studies from NMC patients revealed that BRD4-NUT (B4N) covers large genomic regions and elevates transcription within these domains. To investigate how B4N modulates chromatin, we performed affinity purification of B4N when ectopically expressed in 293-TREx cells and quantified the associated histone posttranslational modifications (PTM) using proteomics. We observed significant enrichment of acetylation particularly on H3 K18 and of combinatorial patterns such as H3 K27 acetylation paired with K36 methylation. We postulate that B4N complexes override the preexisting histone code with new PTM patterns that reflect aberrant transcription and that epigenetically modulate the nucleosome environment toward the NMC state. PMID:27698495

  17. Studying Atomic Structures by Aberration-Corrected Transmission Electron Microscopy

    NASA Astrophysics Data System (ADS)

    Urban, Knut W.

    2008-07-01

    Seventy-five years after its invention, transmission electron microscopy has taken a great step forward with the introduction of aberration-corrected electron optics. An entirely new generation of instruments enables studies in condensed-matter physics and materials science to be performed at atomic-scale resolution. These new possibilities are meeting the growing demand of nanosciences and nanotechnology for the atomic-scale characterization of materials, nanosynthesized products and devices, and the validation of expected functions. Equipped with electron-energy filters and electron-energy loss spectrometers, the new instruments allow studies not only of structure but also of elemental composition and chemical bonding. The energy resolution is about 100 milli electron volts, and the accuracy of spatial measurements has reached a few picometers. However, understanding the results is generally not straightforward and only possible with extensive quantum-mechanical computer calculations.

  18. Studying atomic structures by aberration-corrected transmission electron microscopy.

    PubMed

    Urban, Knut W

    2008-07-25

    Seventy-five years after its invention, transmission electron microscopy has taken a great step forward with the introduction of aberration-corrected electron optics. An entirely new generation of instruments enables studies in condensed-matter physics and materials science to be performed at atomic-scale resolution. These new possibilities are meeting the growing demand of nanosciences and nanotechnology for the atomic-scale characterization of materials, nanosynthesized products and devices, and the validation of expected functions. Equipped with electron-energy filters and electron-energy-loss spectrometers, the new instruments allow studies not only of structure but also of elemental composition and chemical bonding. The energy resolution is about 100 milli-electron volts, and the accuracy of spatial measurements has reached a few picometers. However, understanding the results is generally not straightforward and only possible with extensive quantum-mechanical computer calculations. PMID:18653874

  19. Catadioptric lens with aberrations balanced by aspherizing one surface

    NASA Astrophysics Data System (ADS)

    Bystricky, K. M.; Yoder, P. R., Jr.

    1985-04-01

    In this paper a description is provided of an optical system with one surface aspherized to give a specific level of performance and to equalize the intensity profiles of star images over the field. The system was a 25.4-cm EFL, 5.8 deg field, f/1.53 catadioptric Cassegrain. It was designed to determine the attitude of a space platform by detecting and mapping the geometric pattern of stars observed to ninth visual magnitude. Aberrations were controlled over a 0.5-1.1-micron spectral region. A comparison is conducted of the polychromatic performance of the design to one conventionally optimized. How the spherical substrate base radius was chosen to minimize glass removal is also described.

  20. Dissecting the role of aberrant DNA methylation in human leukemia

    PubMed Central

    Amabile, Giovanni; Di Ruscio, Annalisa; Müller, Fabian; Welner, Robert S; Yang, Henry; Ebralidze, Alexander K; Zhang, Hong; Levantini, Elena; Qi, Lihua; Martinelli, Giovanni; Brummelkamp, Thijn; Le Beau, Michelle M; Figueroa, Maria E; Bock, Christoph; Tenen, Daniel G

    2015-01-01

    Chronic Myeloid Leukemia (CML) is a myeloproliferative disorder characterized by the genetic translocation t(9;22)(q34;q11.2) encoding for the BCR-ABL fusion oncogene. However, many molecular mechanisms of the disease progression still remain poorly understood. A growing body of evidence suggests that epigenetic abnormalities are involved in tyrosine kinase resistance in CML, leading to leukemic clone escape and disease propagation. Here we show that, by applying cellular reprogramming to primary CML cells, aberrant DNA methylation contributes to the disease evolution. Importantly, using a BCR-ABL inducible murine model, we demonstrate that a single oncogenic lesion triggers DNA methylation changes which in turn act as a precipitating event in leukemia progression. PMID:25997600

  1. Aberrant expression of a chemokinetic glycoprotein in psoriatic skin.

    PubMed

    Rajaraman, S; Schmalsteig, F C; Brysk, M M; Hendrick, S J; Solomon, A R

    1987-05-01

    Clinically involved and uninvolved skin samples of 6 psoriatic patients, 4 samples each of normal skin specimens, basal cell carcinoma and keratoacanthoma were studied by an indirect immunofluorescence technique. The monospecific antibody used in this study was directed against a 30 kD glycoprotein, normally expressed by the terminally differentiated corneocytes. Functional characterization of this glycoprotein was evaluated by neutrophil cell movement assays. The involved and uninvolved skin of psoriatic patients expressed the 30 kD glycoprotein not only in the stratum corneum but in all the viable epidermal layers as well. Functional studies revealed this glycoprotein to be a potent chemokinetic molecule. These results suggest that the 30 kD glycoprotein is an intrinsic chemokinetic molecule of the terminally differentiated corneocytes, and its precocious and aberrant expression in psoriatic epidermis is potentially responsible for some of the pathophysiologic aspects of psoriasis. PMID:3302266

  2. Sphere-cone-polynomial special window with good aberration characteristic

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Zhang, Xin; Qu, He-Meng; Wang, Ling-Jie; Wang, Yu

    2013-07-01

    Optical windows with external surfaces shaped to satisfy operational environment needs are known as special windows. A novel special window, a sphere-cone-polynomial (SCP) window, is proposed. The formulas of this window shape are given. An SCP MgF2 window with a fineness ratio of 1.33 is designed as an example. The field-of-regard (FOR) angle is ±75°. From the window system simulation results obtained with the calculated fluid dynamics (CFD) and optical design software, we find that compared to the conventional window forms, the SCP shape can not only introduce relatively less drag in the airflow, but also have the minimal effect on imaging. So the SCP window optical system can achieve a high image quality across a super wide FOR without adding extra aberration correctors. The tolerance analysis results show that the optical performance can be maintained with a reasonable fabricating tolerance to manufacturing errors.

  3. Aberration-free, all-reflective laser pulse stretcher

    DOEpatents

    Perry, Michael D.; Banks, Paul S.; Stuart, Brent C.; Fochs, Scott N.

    1999-09-28

    An all-reflective pulse stretcher for laser systems employing chirped-pulse amplification enables on-axis use of the focusing mirror which results in ease of use, significantly decreased sensitivity to alignment and near aberration-free performance. By using a new type of diffraction grating which contains a mirror incorporated into the grating, the stretcher contains only three elements: 1) the grating, 2) a spherical or parabolic focusing mirror, and 3) a flat mirror. Addition of a fourth component, a retro-reflector, enables multiple passes of the same stretcher resulting in stretching ratios beyond the current state of the art in a simple and compact design. The pulse stretcher has been used to stretch pulses from 20 fsec to over 600 psec (a stretching ratio in excess of 30,000).

  4. The prevalence of chromosomal aberrations in Argentine air crew members.

    PubMed

    De Luca, Julio César; Picco, Sebastián Julio; Macintyre, Carlos; Dulout, Fernando Noel; Lopez-Larraza, Daniel Mario

    2009-01-01

    The authors analyzed the effects of chronic exposure of Argentine air crew members to low doses of ionizing radiations. Genetic damage induced by either low doses or low rates of ionizing radiation was higher than expected. Seventy-one heparinized blood samples were obtained from technical ground workers (group A; n = 10), pilots of domestic flights (group B; n = 14), pilots of transequatorial flights (group C; n = 17;), pilots of transpolar flights (group D; n = 17) and retired pilots (group E; n = 10) The frequency of dicentric chromosomes was higher in groups B and C compared with groups D and E. These observations suggest that the exposure of the aircraft to ionizing radiations may induce chromosomal aberrations. However, dicentric chromosomes in both domestic and retired pilots are still high compared with dicentric control participants. PMID:19395340

  5. [B0 aberrant genotype of AB0 blood group system].

    PubMed

    Zachová, M; Pexa, T; Zelený, M; Mazura, I; Hirt, M

    2004-07-01

    The AB0 blood group system typing remains one of the basic laboratory tasks in a forensic practice. However, problems arise when the analysed samples are seriously degraded. The DNA analysis promised to solve this but an unexpected complication was encountered. For the AB0 blood group system typing a Polymerase Chain Reaction method was used to amplify glycosyltransferase gene, when DNA had been isolated from artificially created blood stains, followed by their subsequent artificial thermal degradation. In the B0 genotype an aberrant genotype was suprisingly found and its structure was confirmed by sequencing. This meant that a newly formed B00 (not the original BO) genotype was present. Such a finding, to our best knowledge, had not been observed yet and we were unable to find any references in the professional literature. The explanation of this result thus remains unclear. PMID:15493712

  6. Gene expression analysis of aberrant signaling pathways in meningiomas

    PubMed Central

    TORRES-MARTÍN, MIGUEL; MARTINEZ-GLEZ, VICTOR; PEÑA-GRANERO, CAROLINA; ISLA, ALBERTO; LASSALETTA, LUIS; DE CAMPOS, JOSE M.; PINTO, GIOVANNY R.; BURBANO, ROMMEL R.; MELÉNDEZ, BÁRBARA; CASTRESANA, JAVIER S.; REY, JUAN A.

    2013-01-01

    Examining aberrant pathway alterations is one method for understanding the abnormal signals that are involved in tumorigenesis and tumor progression. In the present study, expression arrays were performed on tumor-related genes in meningiomas. The GE Array Q Series HS-006 was used to determine the expression levels of 96 genes that corresponded to six primary biological regulatory pathways in a series of 42 meningiomas, including 32 grade I, four recurrent grade I and six grade II tumors, in addition to three normal tissue controls. Results showed that 25 genes that were primarily associated with apoptosis and angiogenesis functions were downregulated and 13 genes frequently involving DNA damage repair functions were upregulated. In addition to the inactivation of the neurofibromin gene, NF2, which is considered to be an early step in tumorigenesis, variations of other biological regulatory pathways may play a significant role in the development of meningioma. PMID:23946817

  7. Gene expression analysis of aberrant signaling pathways in meningiomas.

    PubMed

    Torres-Martín, Miguel; Martinez-Glez, Victor; Peña-Granero, Carolina; Isla, Alberto; Lassaletta, Luis; DE Campos, Jose M; Pinto, Giovanny R; Burbano, Rommel R; Meléndez, Bárbara; Castresana, Javier S; Rey, Juan A

    2013-07-01

    Examining aberrant pathway alterations is one method for understanding the abnormal signals that are involved in tumorigenesis and tumor progression. In the present study, expression arrays were performed on tumor-related genes in meningiomas. The GE Array Q Series HS-006 was used to determine the expression levels of 96 genes that corresponded to six primary biological regulatory pathways in a series of 42 meningiomas, including 32 grade I, four recurrent grade I and six grade II tumors, in addition to three normal tissue controls. Results showed that 25 genes that were primarily associated with apoptosis and angiogenesis functions were downregulated and 13 genes frequently involving DNA damage repair functions were upregulated. In addition to the inactivation of the neurofibromin gene, NF2, which is considered to be an early step in tumorigenesis, variations of other biological regulatory pathways may play a significant role in the development of meningioma. PMID:23946817

  8. Longitudinal chromatic aberration of the human infant eye

    PubMed Central

    Wang, Jingyun; Candy, T. Rowan; Teel, Danielle F. W.; Jacobs, Robert J.

    2008-01-01

    Although the longitudinal chromatic aberration (LCA) of the adult eye has been studied, there are no data collected from the human infant eye. A chromatic retinoscope was used to measure cyclopleged infant and adult refractions with four pseudomonochromatic sources (centered at 472, 538, 589, and 652 nm) and with polychromatic light. The LCA of the infant eyes between 472 and 652 nm was a factor of 1.7 greater than the LCA found in the adult group: infant mean=1.62 D, SD±0.14 D; adult mean=0.96 D, SD±0.17 D. The elevated level of LCA in infant eyes is consistent with the greater optical power of the immature eye and indicates similar chromatic dispersion in infant and adult eyes. The implications for visual performance, defocus detection, and measurement of refraction are discussed. PMID:18758552

  9. Spherical aberration standards and measurement system stability over time

    NASA Astrophysics Data System (ADS)

    Compertore, David; Ignatovich, Filipp; Marcus, Michael

    2015-10-01

    A Shack-Hartmann wave-front sensor system has been used to measure a set of plano-convex lenses at two different times, separated by almost 2 years. The plano-convex lenses were selected to cover a range of powers and apertures relevant to intraocular lenses, and were measured at two different orientations. The results demonstrate the high temporal stability of the measurement system, as well as of the glass standard. In addition, both times the effective focal lengths of the standards were measured using a NIST traceable nodal slide bench, and the center thicknesses were measured using low-coherence interferometer. The spherical aberration and the effective focal length results are analyzed for statistically significant changes. The results are also compared to the Zemax models of the standards.

  10. Genomic aberrations frequently alter chromatin regulatory genes in chordoma.

    PubMed

    Wang, Lu; Zehir, Ahmet; Nafa, Khedoudja; Zhou, Nengyi; Berger, Michael F; Casanova, Jacklyn; Sadowska, Justyna; Lu, Chao; Allis, C David; Gounder, Mrinal; Chandhanayingyong, Chandhanarat; Ladanyi, Marc; Boland, Patrick J; Hameed, Meera

    2016-07-01

    Chordoma is a rare primary bone neoplasm that is resistant to standard chemotherapies. Despite aggressive surgical management, local recurrence and metastasis is not uncommon. To identify the specific genetic aberrations that play key roles in chordoma pathogenesis, we utilized a genome-wide high-resolution SNP-array and next generation sequencing (NGS)-based molecular profiling platform to study 24 patient samples with typical histopathologic features of chordoma. Matching normal tissues were available for 16 samples. SNP-array analysis revealed nonrandom copy number losses across the genome, frequently involving 3, 9p, 1p, 14, 10, and 13. In contrast, copy number gain is uncommon in chordomas. Two minimum deleted regions were observed on 3p within a ∼8 Mb segment at 3p21.1-p21.31, which overlaps SETD2, BAP1 and PBRM1. The minimum deleted region on 9p was mapped to CDKN2A locus at 9p21.3, and homozygous deletion of CDKN2A was detected in 5/22 chordomas (∼23%). NGS-based molecular profiling demonstrated an extremely low level of mutation rate in chordomas, with an average of 0.5 mutations per sample for the 16 cases with matched normal. When the mutated genes were grouped based on molecular functions, many of the mutation events (∼40%) were found in chromatin regulatory genes. The combined copy number and mutation profiling revealed that SETD2 is the single gene affected most frequently in chordomas, either by deletion or by mutations. Our study demonstrated that chordoma belongs to the C-class (copy number changes) tumors whose oncogenic signature is non-random multiple copy number losses across the genome and genomic aberrations frequently alter chromatin regulatory genes. © 2016 Wiley Periodicals, Inc.

  11. Genomic Aberrations Frequently Alter Chromatin Regulatory Genes in Chordoma

    PubMed Central

    Wang, Lu; Zehir, Ahmet; Nafa, Khedoudja; Zhou, Nengyi; Berger, Michael F.; Casanova, Jacklyn; Sadowska, Justyna; Lu, Chao; Allis, C. David; Gounder, Mrinal; Chandhanayingyong, Chandhanarat; Ladanyi, Marc; Boland, Patrick J; Hameed, Meera

    2016-01-01

    Chordoma is a rare primary bone neoplasm that is resistant to standard chemotherapies. Despite aggressive surgical management, local recurrence and metastasis is not uncommon. To identify the specific genetic aberrations that play key roles in chordoma pathogenesis, we utilized a genome-wide high-resolution SNP-array and next generation sequencing (NGS)-based molecular profiling platform to study 24 patient samples with typical histopathologic features of chordoma. Matching normal tissues were available for 16 samples. SNP-array analysis revealed nonrandom copy number losses across the genome, frequently involving 3, 9p, 1p, 14, 10, and 13. In contrast, copy number gain is uncommon in chordomas. Two minimum deleted regions were observed on 3p within a ~8 Mb segment at 3p21.1–p21.31, which overlaps SETD2, BAP1 and PBRM1. The minimum deleted region on 9p was mapped to CDKN2A locus at 9p21.3, and homozygous deletion of CDKN2A was detected in 5/22 chordomas (~23%). NGS-based molecular profiling demonstrated an extremely low level of mutation rate in chordomas, with an average of 0.5 mutations per sample for the 16 cases with matched normal. When the mutated genes were grouped based on molecular functions, many of the mutation events (~40%) were found in chromatin regulatory genes. The combined copy number and mutation profiling revealed that SETD2 is the single gene affected most frequently in chordomas, either by deletion or by mutations. Our study demonstrated that chordoma belongs to the C-class (copy number changes) tumors whose oncogenic signature is non-random multiple copy number losses across the genome and genomic aberrations frequently alter chromatin regulatory genes. PMID:27072194

  12. Longitudinal trajectories of aberrant behavior in fragile X syndrome.

    PubMed

    Hustyi, Kristin M; Hall, Scott S; Jo, Booil; Lightbody, Amy A; Reiss, Allan L

    2014-11-01

    The Aberrant Behavior Checklist-Community (ABC-C; Aman et al., 1995) has been increasingly adopted as a primary tool for measuring behavioral change in clinical trials for individuals with fragile X syndrome (FXS). To our knowledge, however, no study has documented the longitudinal trajectory of aberrant behaviors in individuals with FXS using the ABC-C. As part of a larger longitudinal study, we examined scores obtained on the ABC-C subscales for 124 children and adolescents (64 males, 60 females) with FXS who had two or more assessments (average interval between assessments was approximately 4 years). Concomitant changes in age-equivalent scores on the Vineland Adaptive Behavior Scales (VABS) were also examined. As expected for an X-linked genetic disorder, males with FXS obtained significantly higher scores on all subscales of the ABC-C and significantly lower age-equivalent scores on the VABS than females with FXS. In both males and females with FXS, scores on the Irritability/Agitation and Hyperactivity/Noncompliance subscales of the ABC-C decreased significantly with age, with little to no change occurring over time on the Lethargy/Social Withdrawal, Stereotypic Behavior, and Inappropriate Speech subscales. The decrease in scores on the Hyperactivity/Noncompliance domain was significantly greater for males than for females. In both males and females, age-equivalent scores on the VABS increased significantly over this developmental period. These results establish a basis upon which to evaluate long-term outcomes from intervention-based research. However, longitudinal direct observational studies are needed to establish whether the severity of problem behavior actually decreases over time in this population.

  13. Measuring Low-Order Aberrations in a Segmented Telescope

    NASA Technical Reports Server (NTRS)

    Ohara, Catherine; Redding, David; Shi, Fang; Green, Joseph; Dumont, Philip; Basinger, Scott; Lowman, Andrew; Burns, Laura; Petrone, Peter

    2005-01-01

    The in-focus PSF optimizer (IPO) is an algorithm for use in monitoring and controlling the alignment of the segments of a segmented-mirror astronomical telescope. IPO is so named because it computes wave-front aberrations of the telescope from digitized pointspread functions (PSFs) measured in infocus images. Inasmuch as distant astronomical objects that behave optically as point sources can typically be seen in almost any astronomical image, the main benefit afforded by IPO may be to enable maintenance of mirror-segment alignments without detracting from valuable scientific-observation time. IPO evolved from prescription-retrieval type algorithms. Prescription retrieval uses in-focus and out-of-focus PSFs to infer the state of an imaging optical system. The state, in this context, refers to the positions, orientations, and low-order figure errors of the optical elements in the system. Both prescription- retrieval and IPO use an iterative, nonlinear, least-squares optimizer to compute the optimal state parameters such that a digital computer-generated model image matches the digitized image acquired from the real system. The difference between IPO and prescription- retrieval algorithms is that IPO is specifically designed to utilize infocus images only. Although the restriction to in-focus images limits IPO to calculating only the lowest-order wave front aberrations, it also causes the resulting computation to take much less time because fewer degrees of freedom are included in the optimization process. In the prescription retrieval software developed at JPL, the model images are generated using the ray-trace/physical optics program, MACOS. IPO, on the other hand, uses a linear sensitivity matrix to compute the exit-pupil wave front from the system parameters; the wave front is then converted into a complex pupil field, which is then propagated to the image plane via a fast Fourier transform. This approach is computationally faster and requires less computer memory

  14. Aberrant meiotic behavior in Agave tequilana Weber var. azul

    PubMed Central

    Ruvalcaba-Ruiz, Domingo; Rodríguez-Garay, Benjamin

    2002-01-01

    Background Agave tequilana Weber var. azul, is the only one variety permitted by federal law in México to be used for tequila production which is the most popular contemporary alcoholic beverage made from agave and recognized worldwide. Despite the economic, genetic, and ornamental value of the plant, it has not been subjected to detailed cytogenetic research, which could lead to a better understanding of its reproduction for future genetic improvement. The objective of this work was to study the meiotic behavior in pollen mother cells and its implications on the pollen viability in Agave tequilana Weber var. azul. Results The analysis of Pollen Mother Cells in anaphase I (A-I) showed 82.56% of cells with a normal anaphase and, 17.44% with an irregular anaphase. In which 5.28% corresponded to cells with side arm bridges (SAB); 3.68% cells with one bridge and one fragment; 2.58% of irregular anaphase showed cells with one or two lagging chromosomes and 2.95% showed one acentric fragment; cells with two bridges and cells with two bridges and one acentric fragment were observed in frequencies of 1.60% and 1.35% respectively. In anaphase II some cells showed bridges and fragments too. Aberrant A-I cells had many shrunken or empty pollen grains (42.00%) and 58.00 % viable pollen. Conclusion The observed meiotic irregularities suggest that structural chromosome aberrations have occurred, such as heterozygous inversions, sister chromatid exchanges, deletions and duplications which in turn are reflected in a low pollen viability. PMID:12396234

  15. Materials compatibility during the chlorination of molten CaCl/sub 2/. CaO salts. [CaCl/sub 2/. CaO salt

    SciTech Connect

    Rense, C.E.C.; Fife, K.W.; Bowersox, D.F.; Ferran, M.D.

    1987-01-01

    As part of our effort to develop a semicontinuous PuO/sub 2/ reduction process, we are investigating promising materials for containing a 900/sup 0/C molten CaCl/sub 2/ . CaO chlorination reaction. We want the material to contain this reaction and to be reusable. We tested candidate materials in a simulated salt (no plutonium) using anhydrous HCl as the chlorinating agent. Data are presented on the performance of 36 metals and alloys, 9 ceramics, and 3 coatings.

  16. Aberrant RSPO3-LGR4 signaling in Keap1-deficient lung adenocarcinomas promotes tumor aggressiveness.

    PubMed

    Gong, X; Yi, J; Carmon, K S; Crumbley, C A; Xiong, W; Thomas, A; Fan, X; Guo, S; An, Z; Chang, J T; Liu, Q J

    2015-09-01

    The four R-spondins (RSPO1-4) and their three related receptors LGR4, 5 and 6 (LGR4-6) have emerged as a major ligand-receptor system with critical roles in development and stem cell survival through modulation of Wnt signaling. Recurrent, gain-of-expression gene fusions of RSPO2 (to EIF3E) and RSPO3 (to PTPRK) occur in a subset of human colorectal cancer. However, the exact roles and mechanisms of the RSPO-LGR system in oncogenesis remain largely unknown. We found that RSPO3 is aberrantly expressed at high levels in approximately half of Keap1-mutated lung adenocarcinomas (ADs). This high RSPO3 expression is driven by a combination of demethylation of its own promoter region and deficiency in Keap1 instead of gene fusion as in colon cancer. Patients with RSPO3-high tumors (~9%, 36/412) displayed much poorer survival than the rest of the cohort (median survival of 28 vs 163 months, log-rank test P<0.0001). Knockdown (KD) of RSPO3, LGR4 or their signaling mediator IQGAP1 in lung cancer cell lines with Keap1 deficiency and high RSPO3-LGR4 expression led to reduction in cell proliferation and migration in vitro, and KD of LGR4 or IQGAP1 resulted in decrease in tumor growth and metastasis in vivo. These findings suggest that aberrant RSPO3-LGR4 signaling potentially acts as a driving mechanism in the aggressiveness of Keap1-deficient lung ADs.

  17. Aberrant RSPO3-LGR4 signaling in Keap1-deficient lung adenocarcinomas promotes tumor aggressiveness

    PubMed Central

    Gong, Xing; Yi, Jing; Carmon, Kendra S.; Crumbley, Christine A.; Xiong, Wei; Thomas, Anthony; Fan, Xuejun; Guo, Shan; An, Zhiqiang; Chang, Jeffrey T.; Liu, Qingyun J.

    2015-01-01

    The four R-spondins (RSPO1-4) and their three related receptors LGR4, 5 and 6 (LGR4-6) have emerged as a major ligand-receptor system with critical roles in development and stem cell survival through modulation of Wnt signaling. Recurrent, gain-of-expression gene fusions of RSPO2 (to EIF3E) and RSPO3 (to PTPRK) occur in a subset of human colorectal cancer. However, the exact roles and mechanisms of the RSPO-LGR system in oncogenesis remain largely unknown. We found that RSPO3 is aberrantly expressed at high levels in approximately half of the Keap1-mutated lung adenocarcinomas. This high RSPO3 expression is driven by a combination of demethylation of its own promoter region and deficiency in Keap1 instead of gene fusion as in colon cancer. Patients with RSPO3-high tumors (~9%, 36/412) displayed much poorer survival than the rest of the cohorts (median survival of 28 vs. 163 months, logrank test p < 0.0001). Knockdown of RSPO3, LGR4, or their signaling mediator IQGAP1 in lung cancer cell lines with Keap1 deficiency and high RSPO3-LGR4 expression led to reduction in cell proliferation and migration in vitro, and knockdown of LGR4 or IQGAP1 resulted in decrease in tumor growth and metastasis in vivo. These findings suggest that aberrant RSPO3-LGR4 signaling potentially acts as a driving mechanism in the aggressiveness of Keap1-deficient lung adenocarcinomas. PMID:25531322

  18. DNA repair and chromosome aberrations: the effect of cytosine arabinoside on the frequency of chromosome aberrations induced by radiation and chemicals

    SciTech Connect

    Preston, R.J.

    1980-01-01

    The frequency of x-ray-induced chromosome aberrations in G0 human lymphocytes was greatly increased when cells were incubated with cytosine arabinoside (ara-C) after irradiation. The frequency of dicentrics increased with increasing ara-C incubation times (one, two, and three hours). Lymphocytes from Down syndrome individuals were more sensitive to aberration induction by x-rays in G0, and the increase in dicentric frequency with ara-C incubation was much more rapid than with normal cells. When G2 normal lymphocytes were x-irradiated and incubated for two or three hours with ara-C until fixation, there was a large increase in deletion frequency compared to cells x-irradiated and incubated in the absence of ara-C. However, no exchanges were observed in the presence of ara-C, compared to 0.29 per cell as when x-rays alone were given. These results form the basis for a discussion of the mechanism of aberration induction by x-rays. Experiments with two chemicals, 4-nitroquinoline-N-oxide and methyl methanesulfonate, show that chromosome-type aberrations can be induced in G1 treated lymphocytes incubated with ara-C. However, these chemicals, in the absence of ara-C incubation, induced no aberrations in G1 at the concentrations used. The mechanism of aberration induction is discussed, particularly in terms of whether or not chemicals can be defined as S-phase dependent.

  19. Study on the modification of measured wavefront aberration data for customized visual correction

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Zhang, Yong; Zhang, Zhidong; Quan, Wei; An, Li

    2008-12-01

    Wavefront aberration of human eye is an important foundation for customized vision correction. In most current aberrometers, near infrared light is used to measure ocular wavefront aberration, whereas for customized visual correction, wavefront aberration data in visible range are required. With the measured wavefront aberration, corneal topography and eye's axial lengths data, individual eye models for twenty normal human eyes are constructed with the optical design software ZEMAX. Changing the incidence light wavelength and the refractive indexes of eye models, the values of defocus, astigmatism, higher-order aberrations in the measuring wavelength (833nm) and at the most sensitive wavelength of human eye (555nm) are obtained. Average focus shift between 833nm and 555nm is found to be about 0.94D, and different slightly for different individuals; the differences of astigmatism and higher-order aberrations between 833nm and 555nm are quite slight. For customized visual correction, the measured defocus value should be modified, whereas the measured astigmatism and higher-order aberrations could be used directly for the current correction precision. Individual eye model is a useful tool for accurate transformation of the measured wavefront aberration data into the data for visible spectrum.

  20. Accuracy of Person-Fit Statistics: A Monte Carlo Study of the Influence of Aberrance Rates

    ERIC Educational Resources Information Center

    St-Onge, Christina; Valois, Pierre; Abdous, Belkacem; Germain, Stephane

    2011-01-01

    Using a Monte Carlo experimental design, this research examined the relationship between answer patterns' aberrance rates and person-fit statistics (PFS) accuracy. It was observed that as the aberrance rate increased, the detection rates of PFS also increased until, in some situations, a peak was reached and then the detection rates of PFS…

  1. A case of valvular pulmonic stenosis and an aberrant coronary artery in a Brittany spaniel.

    PubMed

    Estey, Chelsie

    2011-05-01

    Valvular pulmonic stenosis and aberrancy of the right coronary artery with subsequent subvalvular stenosis was found on echocardiographic evaluation of a 9-month-old Brittany spaniel. Previous echocardiography at 4 mo of age revealed the pulmonic stenosis; however, the aberrant coronary artery only became apparent during the second evaluation.

  2. Patterns of Aberrant Eating among Pre-Adolescent Children in Foster Care

    ERIC Educational Resources Information Center

    Tarren-Sweeney, Michael

    2006-01-01

    The paper reports epidemiological and phenomenological investigations of aberrant eating among 347 pre-adolescent children in court-ordered foster and kinship care, in New South Wales, Australia. A quarter of children displayed clinically significant aberrant eating problems, with no evidence of gender or age effects. Two distinct patterns were…

  3. Criteria for admissible values of smooth aberrations for nondiffractive laser beams

    SciTech Connect

    Malashko, Ya I; Khabibulin, V M

    2014-04-28

    We have derived analytical expressions, verified by the methods of numerical simulation, to evaluate the angular divergence of nondiffractive laser beams containing smooth aberrations, i.e., spherical defocusing, astigmatism and toroid. Using these expressions we have formulated the criteria for admissible values of smooth aberrations. (laser applications and other topics in quantum electronics)

  4. Aberrance Detection Powers of the BW and Person-Fit Indices

    ERIC Educational Resources Information Center

    Huang, Tsai-Wei

    2012-01-01

    The study compared the aberrance detection powers of the BW person-fit indices with other group-based indices (SCI, MCI, NCI, and Wc&Bs) and item response theory based (IRT-based) indices (OUTFITz, INFITz, ECI2z, ECI4z, and lz). Four kinds of comparative conditions, including content category (CC), types of aberrance (AT), severity of aberrance…

  5. Simultaneous visualization of spatial and chromatic aberrations by two-dimensional Fourier transform spectral interferometry

    NASA Astrophysics Data System (ADS)

    Amir, W.; Planchon, T. A.; Durfee, C. G.; Squier, J. A.; Gabolde, P.; Trebino, R.; Müller, M.

    2006-10-01

    We demonstrate the use of a simple tool to simultaneously visualize and characterize chromatic and spherical aberrations that are present in multiphoton microscopy. Using two-dimensional Fourier transform spectral interferometry, we measured these aberrations, deducing in a single shot spatiotemporal effects in high-numerical-aperture objectives.

  6. Simple Demonstration of the Impact of Spherical Aberration on Optical Imaging

    ERIC Educational Resources Information Center

    Escobar, Isabel; Saavedra, Genaro; Pons, Amparo; Martinez-Corral, Manuel

    2008-01-01

    We present an experiment, well adapted for students of introductory optics courses, for the visualization of the impact of spherical aberration in the point spread function of imaging systems. The demonstrations are based on the analogy between the point-spread function of spherically aberrated systems, and the defocused patterns of 1D slit-like…

  7. Combining Noncontingent Reinforcement and Differential Reinforcement Schedules as Treatment for Aberrant Behavior.

    ERIC Educational Resources Information Center

    Marcus, Bethany A.; Vollmer, Timothy R.

    1996-01-01

    In this study with three children (ages four and five) with severe developmental disabilities and aberrant behavior maintained by tangible positive reinforcement, noncontingent reinforcement, and differential reinforcement of alternative behavior were found to decrease the frequency of aberrant behavior while strengthening mands. (Author/DB)

  8. The role of aberrant salience and self-concept clarity in psychotic-like experiences.

    PubMed

    Cicero, David C; Becker, Theresa M; Martin, Elizabeth A; Docherty, Anna R; Kerns, John G

    2013-01-01

    Most theories of psychotic-like experiences posit the involvement of cognitive mechanisms. The current research examined the relations between psychotic-like experiences and two cognitive mechanisms, high aberrant salience and low self-concept clarity. In particular, we examined whether aberrant salience, or the incorrect assignment of importance to neutral stimuli, and low self-concept clarity interacted to predict psychotic-like experiences. The current research included three large samples (n = 667, 724, 744) of participants and oversampled for increased schizotypal personality traits. In all three studies, an interaction between aberrant salience and self-concept clarity was found such that participants with high aberrant salience and low self-concept clarity had the highest levels of psychotic-like experiences. In addition, aberrant salience and self-concept clarity interacted to predict a supplemental measure of delusions in Study 2. In Study 3, in contrast to low self-concept clarity, neuroticism did not interact with aberrant salience to predict psychotic-like experiences, suggesting that the relation between low self-concept clarity and psychosis may not be a result of neuroticism. Additionally, aberrant salience and self-concept clarity did not interact to predict two other SPD criteria, social anhedonia or trait paranoia, which suggests the interaction is specific to psychotic-like experiences. Overall, our results are consistent with several cognitive models of psychosis suggesting that aberrant salience and self-concept clarity might be important mechanisms in the occurrence of psychotic-like symptoms.

  9. CA Condensates as a Retrospective Search Tool. A Commentary

    ERIC Educational Resources Information Center

    Hansen, Inge Berg

    1973-01-01

    A retrospective test search on one year of CA Condensates was carried out in order to calculate the costs per profile and to get an impression of how CA Condensates would suffice as a database for retrospective use. (11 references) (Author)

  10. Ca2+/calmodulin-dependent protein kinase IIγ enhances stem-like traits and tumorigenicity of lung cancer cells

    PubMed Central

    Wang, Yongfang; Zhou, You; Zhang, Chenchen; Yang, Yiming; Yang, Ying; Xu, Haiyan; Xu, Rongzhen; Wang, Kai

    2015-01-01

    Highly tumorigenic stem-like cells, considered tumor-initiating cells (TICs), are the main cause of lung cancer initiation, relapse, and drug resistance. In this study, we identified that Ca2+/calmodulin-dependent protein kinase IIγ (CaMKIIγ) was aberrantly expressed in highly tumorigenic stem-like lung cancer cells, and was also correlated with poor prognosis in human lung cancer. Functionally, CaMKIIγ enhanced stem-like traits and the tumorigenicity of lung cancer cells in an Akt- and β-catenin-dependent manner. In addition, we found that CaMKIIγ upregulated Oct4 expression via Akt-mediated histone acetylation. Taken together, our findings reveal a critical role of CaMKIIγ in regulating the stemness and tumorigenicity of lung cancer cells and offer a promising therapeutic target for TICs. PMID:25965829

  11. Altered Intrinsic Pyramidal Neuron Properties and Pathway-Specific Synaptic Dysfunction Underlie Aberrant Hippocampal Network Function in a Mouse Model of Tauopathy

    PubMed Central

    Booth, Clair A.; Witton, Jonathan; Nowacki, Jakub; Tsaneva-Atanasova, Krasimira; Jones, Matthew W.; Randall, Andrew D.

    2016-01-01

    The formation and deposition of tau protein aggregates is proposed to contribute to cognitive impairments in dementia by disrupting neuronal function in brain regions, including the hippocampus. We used a battery of in vivo and in vitro electrophysiological recordings in the rTg4510 transgenic mouse model, which overexpresses a mutant form of human tau protein, to investigate the effects of tau pathology on hippocampal neuronal function in area CA1 of 7- to 8-month-old mice, an age point at which rTg4510 animals exhibit advanced tau pathology and progressive neurodegeneration. In vitro recordings revealed shifted theta-frequency resonance properties of CA1 pyramidal neurons, deficits in synaptic transmission at Schaffer collateral synapses, and blunted plasticity and imbalanced inhibition at temporoammonic synapses. These changes were associated with aberrant CA1 network oscillations, pyramidal neuron bursting, and spatial information coding in vivo. Our findings relate tauopathy-associated changes in cellular neurophysiology to altered behavior-dependent network function. SIGNIFICANCE STATEMENT Dementia is characterized by the loss of learning and memory ability. The deposition of tau protein aggregates in the brain is a pathological hallmark of dementia; and the hippocampus, a brain structure known to be critical in processing learning and memory, is one of the first and most heavily affected regions. Our results show that, in area CA1 of hippocampus, a region involved in spatial learning and memory, tau pathology is associated with specific disturbances in synaptic, cellular, and network-level function, culminating in the aberrant encoding of spatial information and spatial memory impairment. These studies identify several novel ways in which hippocampal information processing may be disrupted in dementia, which may provide targets for future therapeutic intervention. PMID:26758828

  12. Ca(2+) Binding and Transport Studied with Ca(2+)/EGTA Buffers and (45)Ca(2+).

    PubMed

    Sehgal, Pankaj; Olesen, Claus; Møller, Jesper V

    2016-01-01

    The chapter describes procedures useful for determination of Ca(2+) binding by membranous Ca(2+)-ATPase based on the correction for the removal of Ca(2+) present in a non-bound state in the suspension medium. This is done by a filtration procedure that retains the membranous material on the Millipore filters. With suitable sucking devices it is possible to gently remove without dehydration nearly all medium from the Ca(2+) containing membranes, except that required for wetting of the filters on which they are deposited. Correction for this effect can be done with a double-filter where the radioactive content of the lower (protein-free) filter is subtracted from that present in the upper filter for calculation of Ca(2+) binding. This methodology can be used to study the effect of inhibitors on Ca(2+) binding and -transport, and with Ca(2+)/EGTA buffers to explore the Ca(2+) binding affinities and cooperative aspects of the two transport sites.

  13. Measuring ocular aberrations in the peripheral visual field using Hartmann-Shack aberrometry.

    PubMed

    Atchison, David A; Scott, Dion H; Charman, W Neil

    2007-09-01

    We have used the Hartmann-Shack technique previously to measure ocular aberrations along the horizontal meridian of the visual field. This requires considerable modifications from the technique for measuring the aberrations corresponding to the fovea. We now further develop the technique so that it can be used for any meridian of the visual field. Allowance is made for any auxiliary optics placed in front of the eye to compensate for the limited range of the Hartmann-Shack technique and for the case where aberrations are estimated at a wavelength other than the measuring wavelength. Zernike wave aberrations are converted to peripheral refractions. Examples are presented showing the developments, and we discuss change in wave aberrations when converting from a circular to an elliptical pupil. PMID:17767268

  14. Four-zone varifocus mirrors with adaptive control of primary and higher-order spherical aberration.

    PubMed

    Lukes, Sarah J; Downey, Ryan D; Kreitinger, Seth T; Dickensheets, David L

    2016-07-01

    Electrostatically actuated deformable mirrors with four concentric annular electrodes can exert independent control over defocus as well as primary, secondary, and tertiary spherical aberration. In this paper we use both numerical modeling and physical measurements to characterize recently developed deformable mirrors with respect to the amount of spherical aberration each can impart, and the dependence of that aberration control on the amount of defocus the mirror is providing. We find that a four-zone, 4 mm diameter mirror can generate surface shapes with arbitrary primary, secondary, and tertiary spherical aberration over ranges of ±0.4, ±0.2, and ±0.15  μm, respectively, referred to a non-normalized Zernike polynomial basis. We demonstrate the utility of this mirror for aberration-compensated focusing of a high NA optical system. PMID:27409212

  15. Four-zone varifocus mirrors with adaptive control of primary and higher-order spherical aberration.

    PubMed

    Lukes, Sarah J; Downey, Ryan D; Kreitinger, Seth T; Dickensheets, David L

    2016-07-01

    Electrostatically actuated deformable mirrors with four concentric annular electrodes can exert independent control over defocus as well as primary, secondary, and tertiary spherical aberration. In this paper we use both numerical modeling and physical measurements to characterize recently developed deformable mirrors with respect to the amount of spherical aberration each can impart, and the dependence of that aberration control on the amount of defocus the mirror is providing. We find that a four-zone, 4 mm diameter mirror can generate surface shapes with arbitrary primary, secondary, and tertiary spherical aberration over ranges of ±0.4, ±0.2, and ±0.15  μm, respectively, referred to a non-normalized Zernike polynomial basis. We demonstrate the utility of this mirror for aberration-compensated focusing of a high NA optical system.

  16. Vision improvement by correcting higher-order aberrations with customized soft contact lenses in keratoconic eyes

    NASA Astrophysics Data System (ADS)

    Sabesan, Ramkumar; Jeong, Tae Moon; Carvalho, Luis; Cox, Ian G.; Williams, David R.; Yoon, Geunyoung

    2007-04-01

    Higher-order aberration correction in abnormal eyes can result in significant vision improvement, especially in eyes with abnormal corneas. Customized optics such as phase plates and customized contact lenses are one of the most practical, nonsurgical ways to correct these ocular higher-order aberrations. We demonstrate the feasibility of correcting higher-order aberrations and improving visual performance with customized soft contact lenses in keratoconic eyes while compensating for the static decentration and rotation of the lens. A reduction of higher-order aberrations by a factor of 3 on average was obtained in these eyes. The higher-order aberration correction resulted in an average improvement of 2.1 lines in visual acuity over the conventional correction of defocus and astigmatism alone.

  17. Transitionality in addiction: A "temporal continuum" hypotheses involving the aberrant motivation, the hedonic dysregulation, and the aberrant learning.

    PubMed

    Patrono, Enrico; Gasbarri, Antonella; Tomaz, Carlos; Nishijo, Hisao

    2016-08-01

    Addiction is a chronic compulsion and relapsing disorder. It involves several brain areas and circuits, which encode vary functions such as reward, motivation, and memory. Drug addiction is defined as a "pathological pattern of use of a substance", characterized by the loss of control on drug-taking-related behaviors, the pursuance of those behaviors even in the presence of negative consequences, and a strong motivated activity to assume substances. Three different theories guide experimental research on drug addiction. Each of these theories consider singles features, such as an aberrant motivation, a hedonic dysregulation, and an aberrant habit learning as the main actor to explain the entire process of the addictive behaviors. The major goal of this study is to present a new hypotheses of transitionality from a controlled use to abuse of addictive substances trough the overview of the three different theories, considering all the single features of each single theory together on the same "temporal continuum" from use to abuse of addictive substances. Recently, it has been suggested that common neural systems may be activated by natural and pharmacological stimuli, raising the hypotheses that binge-eating disorders could be considered as addictive behaviors. The second goal of this study is to present evidences in order to highlight a possible psycho-bio-physiological superimposition between drug and "food addiction". Finally, interesting questions are brought up starting from last findings about a theoretical/psycho-bio-physiological superimposition between drug and "food addiction" and their possibly same transitionality along the same "temporal continuum" from use to abuse of addictive substances in order to investigate new therapeutic strategies based on new therapeutic strategies based on the individual moments characterizing the transition from the voluntary intake of substances to the maladaptive addictive behavior.

  18. Transitionality in addiction: A "temporal continuum" hypotheses involving the aberrant motivation, the hedonic dysregulation, and the aberrant learning.

    PubMed

    Patrono, Enrico; Gasbarri, Antonella; Tomaz, Carlos; Nishijo, Hisao

    2016-08-01

    Addiction is a chronic compulsion and relapsing disorder. It involves several brain areas and circuits, which encode vary functions such as reward, motivation, and memory. Drug addiction is defined as a "pathological pattern of use of a substance", characterized by the loss of control on drug-taking-related behaviors, the pursuance of those behaviors even in the presence of negative consequences, and a strong motivated activity to assume substances. Three different theories guide experimental research on drug addiction. Each of these theories consider singles features, such as an aberrant motivation, a hedonic dysregulation, and an aberrant habit learning as the main actor to explain the entire process of the addictive behaviors. The major goal of this study is to present a new hypotheses of transitionality from a controlled use to abuse of addictive substances trough the overview of the three different theories, considering all the single features of each single theory together on the same "temporal continuum" from use to abuse of addictive substances. Recently, it has been suggested that common neural systems may be activated by natural and pharmacological stimuli, raising the hypotheses that binge-eating disorders could be considered as addictive behaviors. The second goal of this study is to present evidences in order to highlight a possible psycho-bio-physiological superimposition between drug and "food addiction". Finally, interesting questions are brought up starting from last findings about a theoretical/psycho-bio-physiological superimposition between drug and "food addiction" and their possibly same transitionality along the same "temporal continuum" from use to abuse of addictive substances in order to investigate new therapeutic strategies based on new therapeutic strategies based on the individual moments characterizing the transition from the voluntary intake of substances to the maladaptive addictive behavior. PMID:27372858

  19. Aberrant changes of somatostatin and neuropeptide Y in brain of a genetic rat model for epilepsy: tremor rat.

    PubMed

    Xu, Xiaoxue; Guo, Feng; Cai, Xinze; Yang, Jun; Zhao, Jiuhan; Min, Dongyu; Wang, Qianhui; Hao, Liying; Cai, Jiqun

    2016-01-01

    Excessive excitation or loss of inhibitory neurotransmission has been closely related to epileptic activity. Somatostatin (SST) and Neuropeptide Y (NPY) are members of endogenous neuropeptides which are recognized as important modulator of classical neurotransmitter, distributed abundantly in mammalian central nervous system. Abnormal expression of these two neuropeptides evidenced in some epileptic models highlights the relevance of SST or NPY in the pathogenesis of epilepsy. The tremor rat (TRM) is a genetic epileptic animal model which can manifest tonic convulsions without any external stimuli. The present study aimed to investigate the distribution and expression of SST and NPY in TRM brains, including hippocampus, temporal lobe cortex and cerebellum. Our RT‑PCR data showed that up-regulated mRNA expression of SST and NPY was discovered in TRM hippocampus and temporal lobe cortex compared with control (Wistar) rats. The peptide levels of these neuropeptides in brain areas mentioned above were both apparently higher than that in normal Wistar rats as well. However, in cerebellums, neither SST nor NPY was significantly changed compared with control group. The immunohistochemical data showed that SST and NPY were widely present throughout CA1, CA3 and the hilus of hippocampus, the entorhinal cortex of temporal lobe cortex, as well as cerebellar Purkinje layer. In conclusion, our results discovered the aberrant changes of SST and NPY in several TRM brain regions, suggesting that the peptidergic system might be involved in TRM epileptiform activity. PMID:27685769

  20. Assessment of chromosomal aberration in the bone marrow cells of Swiss Albino mice treated by 4-methylimidazole.

    PubMed

    Norizadeh Tazehkand, Mostafa; Topaktas, Mehmet; Yilmaz, Mehmet Bertan

    2016-01-01

    4-Methylimidazole (4-MEI) is formed during the production of certain caramel coloring agents used in many food and drink products. It may also be formed during the cooking, roasting, or other processing of some foods and beverages. So it was unintentionally consumed in worldwide. This study was aimed to investigate the genotoxic and cytotoxic effects of 4-MEI using chromosome aberration (CA) and mitotic index (MI) in Swiss Albino mice. In this research, CA and MI of the mouse bone marrow cells were analyzed after treating the animals with 4-MEI (100, 130 and 160 mg/kg) for 12 h and 24 h treatment times. All data were analyzed using statistical methods. 4-MEI significantly increased the percentage of CAs at all concentrations for 12 h and at highest concentration for 24 h treatment periods. 4-MEI at highest concentration for 12 h and at all concentrations for 24 h decreased the MI in comparison with control. Genotoxic and cytotoxic effects of 4-MEI at 24 h treatment periods were concentration dependent. Consequently, it can be said that 4-MEI have genotoxic and cytotoxic effect in mouse. PMID:26634952