Chromosome segregation depends on the spindle checkpoint, which delays anaphase until all chromosomes have bound microtubules and have been placed under tension. The Mad1-Mad2 complex is an essential component of the checkpoint. We studied the consequences of removing one copy of MAD2 in diploid cells of the budding yeast, Saccharomyces cerevisiae. Compared to MAD2/MAD2 cells, ...

High-level expression of mitotic arrest defective protein 2 (MAD2), a central component of the spindle assembly checkpoint, has been observed in a variety of human malignancies. Aim of the present study was to observe the expression of MAD2 in human non-small-cell lung cancer (NSCLC) and explore its clinicopathologic significance and ...

Background:Testicular germ cell tumors (TGCTs) are characterized by an aneuploid DNA content. Aberrant expression of spindle proteins such as the Aurora kinases and the spindle checkpoint proteins MAD2 and BUB1B, are thought to contribute to the development of chromosomal instability and DNA aneuploidy in cancer. The importance of ...

Mitotic arrest deficient protein MAD2B, an enzyme involved in translesion DNA synthesis, has been implicated in several cancers. However, its role in human glioma has not been defined. In the present study, we investigated the expression levels of MAD2B in human gliomas and normal brain tissues, and determined whether depletion of ...

Cyclin A, cyclin E, BUBR1, MAD2 and Aurora A are all cell-cycle regulatory proteins and have been proven to play crucial roles in carcinogenesis. However, their expression patterns in invasive ductal breast carcinoma (IDBC) are controversial and unclear. In this study, we examined the expression status of these candidate proteins in a set of 117 invasive ...

., 2004). Given that the time constant for the O-Mad2 C-Mad2 transition is >9 h, newly expressed Mad2 in this paper: APC, anaphase-promoting complex/cyclo- some; C-Mad2, closed Mad2; ...

Recent findings showed that BRCA1, in addition to its role in DNA damage response, acts as an upstream regulator of genes involved in the mitotic checkpoint regulation, thus protecting against promotion of aberrant divisions and aneuploidy. Moreover, there is also an indication that the BRCA1 protein is downregulated in chronic myeloid leukemia (CML) patients. We have ...

During early development of the human embryo, chromosomal imbalance and instability may cause spontaneous miscarriages. In this study, we observe aberrant chromosome numbers in nearly half of spontaneous miscarriage embryo samples, most of which show abnormalities in karotype. We also detect significantly reduced expression of two important mitotic checkpoint proteins, ...

In response to misaligned sister chromatids during mitosis, the spindle checkpoint protein Mad2 inhibits the anaphase-promoting complex or cyclosome (APC/C) through binding to its mitotic activator Cdc20, thus delaying anaphase onset. Mad1, an upstream regulator of Mad2, forms a tight core complex with Mad2 and facilitates ...

In many eukaryotes, disruption of the spindle checkpoint protein Mad2 results in an increase in meiosis I nondisjunction, suggesting that Mad2 has a conserved role in ensuring faithful chromosome segregation in meiosis. To characterize the meiotic function of Mad2, we analyzed individual budding yeast cells undergoing meiosis. We find that Mad2 sets the ...

One of the hallmarks of lung cancer is chromosome instability (CIN), particularly a tetraploid phenotype, which is normally prevented by the spindle assembly checkpoint. Hexavalent chromium Cr(VI) is an established human lung carcinogen, and Cr(VI) induces tumors at lung bifurcation sites where Cr(VI) particles impact and persist. However, the effects of Cr(VI) on the spindle assembly checkpoint ...

BackgroundLamin A (LMNA) is a component of the nuclear lamina and is mutated in several human diseases, including Emery-Dreifuss muscular dystrophy (EDMD; OMIM ID# 181350) and the premature aging syndrome Hutchinson-Gilford progeria syndrome (HGPS; OMIM ID# 176670). Cells from progeria patients exhibit cell cycle defects in both interphase and mitosis. Mouse models with loss of LMNA function have ...

the resultant image Usually has severe chromatic aberrations. reduced to the level of fifth order aberration. This setup may ...

SummaryPremature anaphase onset is prevented by the mitotic checkpoint through production of a �wait anaphase� inhibitor(s) that blocks recognition of cyclin B and securin by Cdc20-activated APC/C, an E3 ubiquitin ligase which targets them for destruction. Using physiologically-relevant levels of Mad2, Bub3, BubR1, and Cdc20, we demonstrate that unattached kinetochores on ...

Error-free mitosis depends on fidelity-monitoring checkpoint systems that ensure correct temporal and spatial coordination of chromosome segregation by the microtubule spindle apparatus. Defects in these checkpoint systems can lead to genomic instability, an important aspect of tumorigenesis. Here we show that the von Hippel-Lindau (VHL) tumour suppressor protein, pVHL, which is inactivated in ...

We have examined the mechanism of normal DNA methyltransferase 1 (DNMT1) degradation as well as its mechanism of dysregulation in cancer. We have previously reported that DNMT1 protein levels were elevated and abnormally stabilized because of defective degradation through its N-terminal destruction domain. Here, we report that DNMT1 was abnormally stabilized in several cancer ...

Kinetochores use the spindle checkpoint to delay anaphase onset until all chromosomes have formed bipolar attachments to spindle microtubules. Here, we use controlled monopolar spindle formation to systematically define the requirements for spindle checkpoint signaling in the Caenorhabditis elegans embryo. The results, when interpreted in light of kinetochore assembly epistasis analysis, indicate ...

Anterior corneal and internal component contributions to overall peripheral aberrations of five human eyes were determined, based on corneal topography and overall aberration measurements. Anterior corneal position and orientation (tilt) were referenced to the line of sight. Ray tracing was performed through the anterior cornea for 6-mm-diameter pupils at ...

... We explored the possibility that different testosterone levels may influence prostate tumor growth. We have completed the ...

Regulated conformational changes of proteins are critical for cellular signal transduction. The spindle checkpoint protein Mad2 is an unusual protein with two native folds: the latent open conformer (O-Mad2) and the activated closed conformer (C-Mad2). During mitosis, ...

The relationship between activity of chromosomal nucleolus-organizer regions and levels of chromosome aberrations was studied in 215 residents of the Kursk region by visual semiquantitative method (silver staining of the nucleolus-organizer regions, NOR) in chromosomes of peripheral blood lymphocytes. The levels of chromosome ...

Although the retinal image is typically polychromatic, few studies have examined polychromatic image quality in the human eye. We begin with a conceptual framework including the formulation of a psychophysical linking hypothesis that underlies the utility of image quality metrics based on the polychromatic point-spread function. We then outline strategies for computing polychromatic point-spread ...

Multiple mechanisms have been proposed to explain how Rb and p53 tumor suppressor loss lead to chromosome instability (CIN). It was recently shown that Rb pathway inhibition causes overexpression of the mitotic checkpoint gene Mad2, but whether Mad2 overexpression is required to generate CIN in this context is ...

We show, for the first time, that hydrophobic bile acids cause aberrations of the mitotic machinery of colon cells that can give rise to aneuploidy, the chromosomal perturbations common in colon tumors. First, we show that DOC induces a statistically significant fourfold increase in the number of micronuclei in NCM-460 cells (a noncancerous colon cell line) and a threefold ...

Correlation between the level of somatic pathology and cytogenetic characteristics of blood was analyzed in a group of liquidators of the accident at the Chernobyl Nuclear Power Plant (ChNPP). A statistically significant correlation was found between the occurrence of cardiovascular diseases and the level of chromosome aberrations ...

The present paper will report on the existence of chromosomal aberrations in natural populations of C. tentans, and the difference in aberrations observed between populations receiving higher than background levels of radiation due to radioactive nuclides in the environment and other populations exposed to background radiation only. In ...

We have developed and tested a method for minimizing static aberrations in adaptive optics systems. In order to correct the static phase aberrations, we need to measure the aberrations through the entire system. We have employed various phase retrieval algorithms to detect these aberrations. We have performed ...

The application of aberration compensation devices can support the trend to higher information densities in optical data storage. The information content of a disc may be increased while maintaining acceptable tolerance levels. For example, disc tilt depe...

Traditional bioassays are unsuitable for assessing sublethal effects from ocean disposal of low-level radioactive waste because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration and sister chromat...

Traditional bioassays are unsuitable for assessing sublethal effects of low levels of radioactivity because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration (CA) and sister chromatid exchange (SC...

The relationship between the penetration depth and the level and distribution of chromosomal aberration of the root tip cells were investigated by exposure of the superposed tomato seeds to 80 MeV/u carbon ions. The results showed that on the entrance of the beam the chromosomal aberration level was low. Damage ...

Six MaMADS-box genes have been cloned from the banana fruit cultivar Grand Nain. The similarity of these genes to tomato LeRIN is low and neither MaMADS2 nor MaMADS1 complement the tomato rin mutation. Nevertheless, the expression patterns, specifically in fruit and the induction during ripening and in response to ethylene and 1-MCP, suggest that some of ...

Six MaMADS-box genes have been cloned from the banana fruit cultivar Grand Nain. The similarity of these genes to tomato LeRIN is low and neither MaMADS2 nor MaMADS1 complement the tomato rin mutation. Nevertheless, the expression patterns, specifically in fruit and the induction during ripening and in response to ethylene and 1-MCP, suggest that some of ...

Several methodologies are available for screening human populations for exposure to ionizing radiation. Of these, aberration frequency determined in peripheral blood lymphocytes is the best developed. Individual exposures to large doses can easily be quantitated, and population exposures to occupational levels can be detected. However, determination of ...

To answer whether the age-related accumulation of chromosomal damage differs in men and women, and whether the aberration level in centenarians is proportional to their age, cytogenetic aberrations in dividing cells were analyzed. G-band karyotyping of mitotic spreads from lymphocytes was performed in 52 Polish centenarians and 71 ...

Future aberration corrected transmission electron microscopes (TEM) will have a strong impact in materials science, since such microscopes yield information on chemical bonding and structure of interfaces, grain boundaries and lattice defects at an atomic level. Beyond this aberration correction offers new possibilities for in situ ...

We examine the effects of aberrations induced by a refractive index mismatch on the signal level and resolution of single-photon (1-p) and two-photon (2-p), conventional and confocal scanning microscopes. In particular, we consider the aberrations introduced by an interface between oil/glass and water. Resolution is defined in terms of ...

We examine the effects of aberrations induced by a refractive index mismatch on the signal level and resolution of single-photon (1-p) and two-photon (2-p), conventional and confocal scanning microscopes. In particular, we consider the aberrations introduced by an interface between oil/glass and water. Resolution is defined in terms of ...

Structural changes in the mitotic arrest deficient protein 2 (Mad2) have been proposed to be essential for spindle checkpoint function. Current models for checkpoint activation propose that a C-Mad2-Mad1 core complex at unattached kinetochores is required for the structural activation through a process involving the interaction of two ...

Chromosome aberrations in donor peripheral blood lymphocyte culture were evaluated before, 14 and 30 days after treatment with a vitamin/mineral complex. Treatment with the complex had no effect on spontaneous level of aberrant cells. The number of chromosome aberrations induced by dioxidine or cadmium chloride in ...

Shogaols have been previously reported to induce cancer cell death via multiple mechanisms, among which one analog 6-shogaol has been reported to cause microtubule damage through specific reaction with sulfhydryl groups in tubulin. In this study, a series of shogaols with different side chain lengths (4-, 6-, 8- and 10-shogaol) was synthesized and evaluated for antiproliferative activity in HCT ...

Aneuploidy is defined as numerical abnormalities of chromosomes and is frequently (>90%) present in solid tumors. In general, tumor cells become increasingly aneuploid with tumor progression. It has been proposed that enhanced genomic instability at least contributes significantly to, if not requires, tumor progression. Two major modes for genomic instability are microsatellite instability ...

Aneuploidy is defined as numerical abnormalities of chromosomes and is frequently (>90%) present in solid tumors. In general, tumor cells become increasingly aneuploid with tumor progression. It has been proposed that enhanced genomic instability at least contributes significantly to, if not requires, tumor progression. Two major modes for genomic instability are microsatellite instability ...

Spherical aberration limits the ability of a human eye to form a clear image. The amount of Spherical Aberration found in a given eye is different across a population and is actively changing as a function of accommodation, light level, and age. Any attempt made to correct spherical aberration will need to have an ...

... as a Biosafety Level 1 (BSL1) microorganism by the American Type Culture ... chromosomal aberration assay with either human lymphocytes or Chinese hamster ovary ...

The data on the variability of an elevated level of the frequencies of chromosome aberrations for a group of liquidators of the Chernobyl Nuclear Station accident depending on genotypes by candidate loci are presented. The genotyping was carried out by sites, which previously showed the associations with the cytogenetic variability in control experiments. ...

Mar 3, 2011 ... Solid granite bedrock : occurs at depths of three to nine meters. .... On-Site, Point of Contact Agency Information Agency : Jet Propulsion ...

Nov 19, 1999 ... Solid granite bedrock : occurs at depths of three to nine meters. .... On-Site, Point of Contact Agency Information Agency : JPL Preferred ...

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). ...

Chromosomal aberration frequency in peripheral lymphocytes of healthy individuals has been found to be predictive of future cancer risk. The variability of chromosomal aberrations over time, which is largely unknown, should be clarified to interpret the strength of this association and to determine its use in cancer prediction. Intra- and interindividual ...

The mitotic checkpoint has evolved to prevent chromosome mis-segregations by delaying mitosis when unattached chromosomes are present. Inducing severe chromosome segregation errors by ablating the mitotic checkpoint causes cell death. Here we have analyzed the consequences of gradual increases in chromosome segregation errors on the viability of tumor cells and normal human fibroblasts. Partial ...

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 decreased with ...

Visual semiquantitative method of silver staining of nucleolus organizer regions in peripheral blood leukocytes was applied for evaluation of the correlation between activity of nucleolus organizer regions and the level of chromosome aberrations in 241 residents of Kursk region. Significant differences in the percent of chromosome ...

The common marmoset, Callithrix jacchus, is a primate model for emmetropization studies. The refractive development of the marmoset eye depends on visual experience, so knowledge of the optical quality of the eye is valuable. We report on the wavefront aberrations of the marmoset eye, measured with a clinical Hartmann-Shack aberrometer (COAS, AMO Wavefront Sciences). ...

As the industry drives to lower k1 imaging we commonly accept the use of higher NA imaging and advanced illumination conditions. The advent of this technology shift has given rise to very exotic pupil spread functions that have some areas of high thermal energy density creating new modeling and control challenges. Modern scanners are equipped with advanced lens manipulators that introduce ...

This retrospective bibliography contains citations concerning low level radiation and the incidence of chromosome aberration. Many types of chromosome abnormalities are covered and include aneuploidy and nondisjunction. Hematopoietic pathology and the increased risk of cancer are noted. The cytological methods available to study chromosomes are mentioned. ...

SUMMARYThe status of spindle checkpoint signaling depends on the balance of two opposing dynamic processes that regulate the highly unusual two-state behavior of Mad2. In mitosis, a Mad1-Mad2 core complex recruits cytosolic Mad2 to kinetochores through Mad2 dimerization and converts ...

AimTo evaluate chromosome aberration and fluorescent in situ hybridization (FISH) assays as a method to estimate of health risk, we monitored 9 male subjects occupationally exposed to low doses of both ionizing radiation and ultrasound during a period of over 3 years.MethodsSampling was performed at 6-month intervals during a three-year period. First we used conventional ...

In this study on the mutagenic effects of different concentrations of chromium trioxide (CrO(3)) on Vicia faba root tip, micronucleus assay and chromosome aberration assay were used to determine the mitotic indexes, micronucleus aberration rate and chromosome aberration rate of Vicia faba root tip cells. The results showed that the ...

Specimen-induced aberrations cause a reduction in signal levels and resolution in fluorescence microscopy. Aberrations also affect the image contrast achieved by these microscopes. We model the effects of aberrations on the fluorescence signals acquired from different specimen structures, such as point-like, ...

Onion seeds were exposed to l000 r x irradiation and stored in an oven at 42 deg C to hasten the aging process. Artificial aging did not increase the aberration frequency during the first three weeks, but with subsequent aging the aberration frequency increased rapidly and at an accelerated rate in the control seeds. The ...

The spindle checkpoint arrests the cell cycle at metaphase in the presence of defects in the mitotic spindle or in the attachment of chromosomes to the spindle. When spindle assembly is disrupted, the budding yeast mad and bub mutants fail to arrest and rapidly lose viability. We have cloned the MAD2 gene, which encodes a protein of 196 amino acids that remains at a constant ...

As part of a broader geological study of loess/palaesol sequences in Alaska, the paleomagnetism of a section at Gold Hill near Fairbanks has been investigated. Samples were collected at 5 cm intervals through a 5 m loess-paleosol-loess sequence. Detailed alternating field demagnetization of the natural remanent magnetization yields excellent results (average MAD = ...

Bone marrow specimens from 185 patients with plasma cell disorders (PCD) were investigated by fluorescence in situ hybridization (FISH) in order to determine the temporal sequence of cytogenetic aberrations. In 25 cases combined FISH analysis has also been performed at single cell level. Clonal evolution was observed in 16% of cases. The ?13 was preceded ...

The spindle checkpoint senses unattached or improperly attached kinetochores during mitosis, inhibits the anaphase-promoting complex or cyclosome (APC/C), and delays anaphase onset to prevent aneuploidy. The mitotic checkpoint complex (MCC) consisting of BubR1, Bub3, Mad2, and Cdc20 is a critical APC/C-inhibitory checkpoint complex in human cells. At the ...

The execution of the mitotic program with high fidelity is dependent upon precise spatiotemporal regulation of posttranslational protein modifications. For example, the timely polyubiquitination of critical mitotic regulators by Anaphase Promoting Complex/Cyclosome (APC/C) is essential for the metaphase to anaphase transition and mitotic exit. The spindle assembly checkpoint prevents unscheduled ...

Cohesin maintains sister chromatid cohesion until its Rad21/Scc1/Mcd1 is cleaved by separase during anaphase. DNA topoisomerase II (topo II) maintains the proper topology of chromatid DNAs and is essential for chromosome segregation. Here we report direct observations of mitotic progression in individual HeLa cells after functional disruptions of hRad21, NIPBL, a loading factor for hRad21, and ...

Mitotic centromere-associated kinesin (MCAK) is an ATP-dependent microtubule (MT) depolymerase regulated by Aurora kinase (AURK) phosphorylation and implicated in resolution of improper MT attachments in mitosis. Distribution of MCAK was studied in oocyte maturation by anti-MCAK antibody, anti-tubulin antibody, anti-AURKB antibody and anti-centromere antibody (ACA) and by the expression of ...

We investigated the impact in spatial visual performance of the combined presence of different amounts of spherical aberration and intraocular scattering in the eye. In a group of subjects, contrast sensitivity at 6 cycles per degree was measured when viewing through holographic diffusers to produce different levels of scattering and with their spherical ...

Dynamic correction of monochromatic aberrations of the eye is known to affect the accommodation response to a step change in stimulus vergence. We used an adaptive optics system to determine how the temporal location of the correction affects the response. The system consists of a Shack-Hartmann sensor sampling at 20 Hz and a 37-actuator piezoelectric deformable mirror. An ...

Dynamic correction of monochromatic aberrations of the eye is known to affect the accommodation response to a step change in stimulus vergence. We used an adaptive optics system to determine how the temporal location of the correction affects the response. The system consists of a Shack-Hartmann sensor sampling at 20 Hz and a 37-actuator piezoelectric deformable mirror. An ...

The author represents results of studying genotoxic effects caused in workers by beryllium compounds. Increasing age and length of service apperared to correlate with higher level of chromosomal aberration in peripheral WBC. Findings are that obtaining beryllium and its compounds is associated with changed level of chromosomal damages. ...

A study was made of the effect of kinetin when administered separately or in combination with actinomycin D on the chromosomal aberrations in Crepis capillaris L. irradiated by X-rays. Dry seeds were treated after irradiation or seeds soaked, prior to irradiation. Significant decrease in the frequency of chromosomal aberrations was shown when actinomycin D ...

The incidence of chromosome aberrations in peripheral blood lymphocytes of 197 dockyard workers has been followed over a 10-yr period. These workers were exposed to mixed neutron-gamma radiation during the refuelling of nuclear reactors, but most exposures were below the internationally accepted maximum permissible level of 5 rem per yr. There was a ...

Retinal image quality is important for normal eye growth. Optical aberrations are of interest for two reasons: first, they degrade retinal images; second, they might provide some cues to defocus. Higher than normal ocular aberrations have been previously associated with human myopia. However, these studies were cross-sectional in design, and only reported ...

An infrared-optical zoom system using binary element is proposed in this paper. The two main advantages of the zoom system introducing here are: bigger F-number and lower cost. The primary optical properties are: F/#=1,zoom ratio =1:4,and dual field are 26.6�and 5.6�respectively. Wider field of view is used for search and the smaller one is used for imaging details. This system uses un-cooled ...

High-contrast imaging systems with a stellar halo suppression level of 10(-10) are required for direct detection of Earth-like extra-solar planets. We investigated a novel high-contrast imaging system with an unbalanced nulling interferometer (UNI) followed by phase and amplitude correction (PAC), which not only can reduce starlight but also can suppress the speckle ...

... dynamic aberrations. For the dynamic aberration case, elimination of ... dynamic aberrations. For the dynamic aberration case, elimination of ...

PURPOSE: To examine the effect of trabeculectomy on ocular and corneal higher order wavefront aberrations. METHODS: Trabeculectomy with a limbal-based conjunctival flap was performed in 13 patients (13 eyes). Ocular and corneal higher order aberrations were measured using a wavefront analyzer before and after surgery. The higher order ...

The purpose of this study was to elucidate whether an enhanced skin radiation reaction correlated with an enhanced chromosome radiation response. Twelve patients with late radiation skin ulcers formed after courses of radiation therapy were chosen as a group of individuals with elevated skin radiosensitivity. Half of the venous blood samples from each donor were irradiated with 2 Gy gamma-rays; ...

The pretreatment of Tradescantia inflorescences with one atmosphere of CO/sub 2/ plus one of air is effective in increasing the number of chromosome aberrations induced by x rays by about 1.6 times. Separating the CO/sub 2/ pretreatment and radiation by increasing periods in air has shown that the CO/sub 2/ effect persists for about 20 min. After this period the ...

Exposure to steady magnetic field (SMF) for different periods of time did not elicit statistically reliable increase in chromosome aberrations in human peripheral blood lymphocytes. Metaphase analysis of Crepis capilaris cells revealed that SMF (9 k0e, 200 0e/cm) for 2 days did not induce chromosome aberrations. Nor were any changes demonstrated in roots ...

A pinhole diagnostics system has been used to measure beam aberrations as a function of steering angle for an expanded beam at the ANL Neutral Particulate Beam Test Stand. The experiment began with a low-abberation unsteered beam. The horizontal steering angle was varied through the range {plus minus}3.5 mrad, and the vertical steering angle varied though the range {plus ...

The yields of dicentric and ring chromosomes were recorded during telecobalt therapy for mammary carcinoma. The data were fitted to a power or a quadratic function and were compared with those obtained in patients treated for ankylosing spondylitis and nuclear dockyard workers as well as with the results of an in vitro blood irradiation. As expected, the aberration yield for ...

BackgroundPreviously, we identified the mitotic arrest deficient protein MAD2B (MAD2L2) as a bona fide interactor of the renal cell carcinoma (RCC)-associated protein PRCC. In addition, we found that fusion of PRCC with the transcription factor TFE3 in t(X;1)(p11;q21)-positive RCCs results in an impairment of this ...

BackgroundAlthough the mitotic arrest deficient protein MAD2B (MAD2L2) is thought to inhibit the anaphase promoting complex (APC) by binding to CDC20 and/or CDH1 (FZR1), its exact role in cell cycle control still remains to be established.Methodology/Principal FindingsUsing a yeast two-hybrid interaction trap we ...

The spindle assembly checkpoint (SAC) monitors chromosome attachment to spindle microtubules. SAC proteins operate at kinetochores, scaffolds mediating chromosome-microtubule attachment. The ubiquitous SAC constituents Mad1 and Mad2 are recruited to kinetochores in prometaphase. Mad2 sequesters Cdc20 to prevent its ability to mediate anaphase onset. Its ...

Chromatic aberrations arise as a consequence of the disper- ..... Chromatic aberrations are divided into chromatic aberration ...

... superior to electrostatic systems with respect to total aberration, but their ... The two limiting aberrations, spherical and chromatic, are analyzed in this ...

... KNOWN EXPRESSIONS FOR THE ABERRATIONS OF PLANE ... CAN CONSIDERABLY REDUCE THE SPHERICAL ABERRATION AND COMA ...

Human diploid lung fibroblast cells were exposed to various dose levels of ethylene oxide (EtO) to determine the relationship between dose, dose-rate or concentration-time effects and the formation of chromosome aberrations (CA), aneuploidy, and DNA single strand breaks (SSB) 1 d...

The goal of this study was to assess the persistence of chromosomal aberrations and micronuclei of three victims 2 y after accidental radiation exposure to Co gamma rays. Traditional chromosome aberration analysis was performed by scoring the dicentric chromosomes (dic) and rings (r) in peripheral blood lymphocytes. Micronuclei were detected using the ...

Studies after the Chernobyl Disaster revealed an increased level of chromosome aberrations in cultured lymphocytes of the inhabitants of the radiation-polluted regions. This work estimates the resolution capacity of a method of accounting for chromosomal aberrations in human lymphocyte culture. The results reveal population effects of ...

Various enviromental pollutants are suspected of being capable of causing cancers or genetic defects even at low levels of exposure. In order to estimate risk from exposure to these pollutants, it would be useful to have some indicator of exposure. It is suggested that chromosomes are ideally suited for this purpose. Through the phenonema of chromosome ...

The text article, Sodium dimethyldithiocarbamate, was tested in the chromosome aberration assay using Chinese hamster ovary cells. The assay was conducted both in the absence and presence of an Aroclor-induced S-9 activation system at dose levels of 3, 1,...

. The question of finite-sized pinhole is addressed and it is found, in general, that it is sufficient to correct to restore the signal level � and the noise � by merely increasing the size of the detector pinhole in pinhole radius, np1/2, for various focal depths and degrees of aberration correction. (b) The point resolu

Purpose: To measure ocular aberrations before and at several time periods after LASIK surgery to determine the change to the aberration structure of the eye. Methods: A Shack-Hartmann wavefront sensor was used to measure 88 LASIK patients pre-operatively and at 1 week and 12 months following surgery. Reconstructed wavefront errors are compared to look at ...

The objectives of this study were to determine if cadmium would induce chromosomal aberration, to determine if simultaneous aberration events occurred in somatic and germinal tissue, and to determine an estimated minimum exposure time required for significant chromosomal change. Bone marrow chromosome aberrations, specifically breaks ...

The dynamics of karyotypical instability of Allium fistulosum L. (Welsh onion) during aging of genetically homogenous seeds from plants grown in three different areas was studied. We analyzed the frequency of anaphase cells with chromosomal aberrations "damage", as a number of chromosomal aberrations per cell with aberrations, and ...

The eukaryotic nucleolus is multifunctional and involved in the metabolism and assembly of many different RNAs and ribonucleoprotein particles as well as in cellular functions, such as cell division and transcriptional silencing in plants. We previously showed that Arabidopsis thaliana exon junction complex proteins associate with the nucleolus, suggesting a role for the nucleolus in mRNA ...

Cultured peripheral blood lymphocytes of controls and uranium miners were analyzed for the prevalence of structural chromosomal aberrations. The frequency data are compared between controls and five groups of miners with exposures expressed in working level months (WLM). The results demonstrate: (i) the prevalence of dicentrics + rings is not a good ...

The metamorphic Mad2 protein acts as a molecular switch in the checkpoint mechanism that monitors proper chromosome attachment to spindle microtubules during cell division. The remarkably slow spontaneous rate of Mad2 switching between its checkpoint inactive and active forms is catalyzed onto a physiologically relevant time scale by a self-self ...

The dose dependencies of growth and cytogenetical values have been built to determine the critical level of root apical meristem damage induced by cute irradiation in the range from 2 to 20 Gr. We have analyzed the frequencies of aberrant anaphases and the aberration distribution per cell, on the one hand, and the growth of biomass, ...

PurposeTo examine the impact on visual acuity of different aberrations modes (e.g. coma, astigmatism, spherical aberration (SA)) and different aberration basis functions (Zernike or Seidel).MethodsComputational optics was used to generate retinal images degraded by either the Zernike or Seidel forms of 2^nd ...

The frequency of chromosomal aberrations in bone marrow cells under the effect of long-term stress and cyclophosphamide was studied in rat lines selected for different levels of nervous system excitability. After both kinds of treatment, differences between lines in frequencies of chromosomal aberrations were observed. Stress had a ...

The modulation by dietary fat levels of intestine carcinogenesis is well documented. New developments suggest that calcium ions may also play a role. A rapid bioassay, the induction of foci of aberrant crypts in the colon, was used to explore the interaction between dietary fat and calcium. Male F344 rats 6 weeks of age were placed on diets containing 5 or ...

For a total radiated power of 23 W (sim~~lt,a.rleously at, S and X bands) the resulting acceleration is a0 = 2.2 x cm/s", a . level of two orders of magnitude smaller ...

We have measured the levels of amplification of oncogenes and tumor marker genes or other genes of interest in nine human lung tumor cell lines in comparison to normal human bronchial epithelial cells or normal blood lymphocytes to test the hypothesis that aberrant amplification ...

... study, we examined changes in the aneuploidy of chromosomes 1, 10, 11 and 17 in human PBLs after in vitro exposure in a waveguide ... n = 5 TABLE 1 Incidence of Aneuploidy for Chromosomes 1, 10, 11 or...

... incisor wear and age. Dental anomalies (e.g., fluoride toxicosis and aberrant tooth wear) plague ungulates inhabiting ... National Park (YNP) due to high levels of fluoride and silica in the water, soils,...

Structural chromosome aberrations are hallmarks of many human genetic diseases. The precise mapping of translocation breakpoints in tumors is important for identification of genes with altered levels of expression, prediction of tumor progression, therapy...

... weeks in rats (21) and 30 years in humans (20), and can induce chromosome aberrations in nonirradiated cells when added to in vitro cultures (18�22). It should be noted, however, that the results ... ...

The natural host for avian influenza virus (AIV) is in wild birds, including ducks, gulls, and shorebirds, where the virus causes primarily an enteric infection with little disease. However, AIV can infect a wide variety of host species, and with a certain level of adaptation for the aberrant host ...

A method for producing a phase hologram using e-beam lithography provides n-ary levels of phase and amplitude by first producing an amplitude hologram on a transparent substrate by e-beam exposure of a resist over a film of metal by exposing n is less tha...

Contents: Establishment of a mercury body burden based on neurological toxic symptoms; Toxic effects at low levels of mercury exposure(Human chromosomal aberrations, Further effects of mercury on humans); Determination of 'safe' maximum daily intake of me...

... This study was conducted to examine expression of centromere protein B (CENPB), spindle checkpoint protein MAD2 (mitotic ... the first type comprises constitutive proteins, such as centromere protein (CEN...

... normal spindle formation, MAD2 can check the chromosome misalignment before ProM-I and its activity disappeared only ... ...

The mitotic checkpoint maintains genomic stability by ensuring that chromosomes are accurately segregated during mitosis. When the checkpoint is activated, the mitotic checkpoint complex (MCC), assembled from BUBR1, BUB3, CDC20, and MAD2, directly binds and inhibits the anaphase-promoting complex/cyclosome (APC/C) until all chromosomes are properly attached and aligned. The mechanisms underlying ...

Seeds of Vicia faba were planted in soil which strontium-90 had been previously applied. The soil was contaminated with strontium-90 in the following experimental variants: (1) 1.2 mCi/m/sup 2/, (2) 6.0, (3) 12, (4) 60, (5) 250, and (6) 1250 mCi/m/sup 2/. Observations at the seedling stage revealed a lethal effect from using 1250 mCi/m/sup 2/ strontium 90. Data for the other experimental variants ...

The salivary gland chromosomes of Chironomus tentans larvae collected from White Oak Creek, an area contaminated by radioactive waste from the Oak Ridge National Laboratory, and from six uncontaminated areas were examined for chromosomal aberrations. White Oak Creek populations were exposed to absorbed doses as high as 230 rads per year or about 1000 times background. ...

The Coxsackie virus B1 has been studied for its effect on the chromosome apparatus in cells of mouse feti and newborn mice in case of intraperitoneal infection of females on the 3d week of pregnancy. It is stated that the virus readily moves across the placental barrier and induces chromosome aberrations in the cells of feti, their number being 2.5 times higher than the ...

The seeds of Crepis capillaris were used to examine the mutagenic und antimutagenic properties of human whole blood, plasma, serum albumin and gamma-globulin by recording chromosomal and chromatid aberrations. The antimutagenic activity was determined by preliminary, simultaneous, and subsequent biosubstrate treatments of the seeds. The whole and twice-diluted blood, as well ...

Several enzymes of the metabolic pathways responsible for metabolism of cytosolic ribonucleotides and deoxyribonucleotides are located in mitochondria. Studies described in this paper suggest dysfunction of the mitochondria to affect these metabolic pathways and limit the available levels of cytosolic ribonucleotides and deoxyribonucleotides, which in turn can result in ...

either injected with fluorescently labeled Alexa 488-XMad2 or trans- fected with GFP-hMAD2. Real-time) Graphs of integrated fluorescence intensity minus background versus time were plotted in Excel. Mad2 half of the time-lapse fluorescent and phase Mad2 images accompanying Figs. 2 (Videos 1 and 2), 5 A (Video 3), 8

either injected with fluorescently labeled Alexa 488-XMad2 or trans- fected with GFP-hMAD2. Real-time time were plotted in Excel. Mad2 half-life (turnover rate) was calculated essen- tially as described Quicktime movies of the time-lapse fluorescent and phase Mad2 images accompanying Figs. 2 (Videos 1 and 2

The spindle checkpoint prevents errors in chromosome segregation by inhibiting anaphase onset until all chromosomes have aligned at the spindle equator through attachment of their sister kinetochores to microtubules from opposite spindle poles. A key checkpoint component is the mitotic arrest�deficient protein 2 (Mad2), which localizes to unattached ...

-neutral tobacco), and Raphanus sativus also function as transcriptional activators. #12;421 Materials and methods deletion clones were constructed. RsMADS1, NsMADS2, and Nt- MADS5 were isolated from Raphanus sativus from Raphanus sativus (radish). NsMADS2 and NtMADS5 were isolated from Nicotiana sylvestris (long

Pediatric solid tumors of different histologic types are often treated with drugs (such as vincristine) that directly or indirectly target the mitotic spindle and the spindle checkpoint, leading to mitotic arrest, mitotic catastrophe and apoptosis. hMad2 (mitosis arrest deficient 2) expression in neuroblastoma has suggested utility in predicting prognosis. ...

The spindle checkpoint prevents anaphase from occurring until all chromosomes have attached properly to the mitotic spindle. The checkpoint components Mad1 and Mad2 associate with unattached kinetochores and are probably involved in triggering the checkpoint. We now demonstrate that in Xenopus egg extracts Mad1 and Mad2 form a stable complex, whereas a fraction of Mad2 molecules is not bound to ...

Mammalian centromeric cohesin is protected from phosphorylation-dependent displacement in mitotic prophase by shugoshin-1 (Sgo1), while shugoshin-2 (Sgo2) protects cohesin from separase-dependent cleavage in meiosis I. In higher eukaryotes, progression and faithful execution of both mitosis and meiosis are controlled by the spindle assembly checkpoint, which delays anaphase onset until chromosomes ...

BackgroundAberrations of allelic replication timing are epigenetic markers observed in peripheral blood cells of cancer patients. The aberrant markers are non-cancer-type-specific and are accompanied by increased levels of sporadic aneuploidy. The study aimed at following the epigenetic markers and aneuploidy ...

The laser wavefront of the NIF Beamlet demonstration system is corrected for static aberrations with a wavefront control system. The system operates closed loop with a probe beam prior to a shot and has a loop bandwidth of about 3 Hz. However, until recently the wavefront control system was disabled several minutes prior to the shot to allow time to manually reconfigure its ...

The purpose of this study is to determine if cues within the blurred retinal image due to the Stiles�Crawford (SC) effect and the eye�s monochromatic aberrations can drive accommodation with a small pupil (3 mm) that is typical of bright photopic conditions.The foveal, psychophysical SC function (17 min arc) and ocular monochromatic aberrations were ...

In accordance with the present international standard for intraocular lenses (IOLs), their imaging performance should be measured in a model eye having an aberration-free cornea. This was an acceptable setup when IOLs had all surfaces spherical and hence the measured result reflected the spherical aberration of the IOL. With newer IOLs designed to ...

Following the pioneering development of atomic resolution in-situ environmental TEM (ETEM) for direct probing of gas-solid reactions, recent developments are presented of dynamic real time in-situ studies at the Angstrom level in an aberration corrected electron microscope. The in-situ data from Pt-Pd nanoparticles on carbon with the corresponding ...

Chromosome aberrations induced by daunomycin, a widely used positive control compound for in vitro cytogenetics assays, were identified by multi-colour fluorescence in situ hybridization with probes for chromosomes 1, 2 and 3. The frequency and distribution of aberration types were compared to conventional metaphase analysis of Giemsastained chromosomes ...

Chromosome aberration frequencies in peripheral blood lymphocytes from a selected sample of a population in Badgastein, Austria, subjected to an increased natural background of ..cap alpha.. irradiation, and persons occupationally exposed to additional levels of radiation have been investigated. The accumulated ..gamma.. and ..cap alpha.. blood doses were ...

Chromosome fragility in 96 h, low-folate cultures was found to be associated with smoking status, coffee consumption, and blood folate level. The higher proportion of cells with chromosome aberrations in cigarette smokers was attributable to lower red cell folate levels in smokers compared with nonsmokers. There was a positive linear ...

BackgroundThe spindle checkpoint delays the onset of anaphase until all sister chromatids are aligned properly at the metaphase plate. To investigate the role san-1, the MAD3 homologue, has in Caenorhabditis elegans embryos we used RNA interference (RNAi) to identify genes synthetic lethal with the viable san-1(ok1580) deletion mutant.ResultsThe san-1(ok1580) animal has low penetrating phenotypes ...

Genotoxic stress such as ionizing radiation halts entry into mitosis by activation of the G(2) DNA damage checkpoint. The CHK1 inhibitor 7-hydroxystaurosporine (UCN-01) can bypass the checkpoint and induce unscheduled mitosis in irradiated cells. Precisely, how cells behave following checkpoint abrogation remains to be defined. In this study, we tracked the fates of individual cells after ...

PURPOSE:To determine whether the spatial demodulation processing of Shack-Hartmann images is suitable for extracting wavefront gradients for ocular wavefront sensors.METHODS:We developed a custom software program to implement the spatial demodulation technique. To test the algorithm�s performance, we generated simulated spot images and obtained an eye examination image. We generated a collection ...

Since the invention of transmission electron microscopy (TEM) in 1932 (Z. Physik 78 (1932) 318) engineering improvements have advanced system resolutions to levels that are now limited only by the two fundamental aberrations of electron lenses; spherical and chromatic aberration (Z. Phys. 101 (1936) 593). Since both ...

CONTEXT: The treatment of pain in patients with substance use disorders creates tensions for clinicians between undertreating pain and enabling opioid analgesic misuse. OBJECTIVES: To characterize prevalence and factors associated with aberrant opioid analgesic behaviors in a cohort of HIV-infected individuals who are at high risk for opioid analgesic misuse. METHODS: We ...

Practitioners, familiar with the design of two-level fractional factorials, are often frustrated when confronted with factors that have more than two levels. This article provides a guide for the inclusion of four-level factors into standard two-level factorial designs. Tables are presented to allow for the design ...

Caffeine is known to induce chromosomal aberrations in proliferating cells when they are incubated during G2 and mitotic prophase. In the present paper, this caffeine effect has been analyzed in Allium cepa root meristems growing at different culture temperatures under steady-state kinetics. Caffeine (1-10 mM) induces chromosomal aberrations in a ...

This resource explains that water levels are part of the ebb and flow of nature and the difference between the amount of water coming into a lake and the amount going out is the determining factor in whether the water level will rise, fall or remain stable. Students will learn that there are three types of water level fluctuations: ...

It has been suggested that high levels of axial aberration or specific patterns of peripheral refraction could play a role in myopia development. Possible mechanisms involving high levels of retinal image blur caused by axial aberrations include form deprivation through poor retinal image quality in distance ...

A multiphoton microscope incorporating a Hartmann-Shack (HS) wavefront sensor to control the ultrafast laser beam's wavefront aberrations has been developed. This instrument allowed us to investigate the impact of the laser beam aberrations on two-photon autofluorescence imaging of human retinal tissues. We demonstrated that nonlinear microscopy images are ...

A multiphoton microscope incorporating a Hartmann-Shack (HS) wavefront sensor to control the ultrafast laser beam's wavefront aberrations has been developed. This instrument allowed us to investigate the impact of the laser beam aberrations on two-photon autofluorescence imaging of human retinal tissues. We demonstrated that nonlinear microscopy images are ...

It is stated that although much information has been collected on chromosome mutations in Drosophila melanogaster, as analyzed by genetic methods, there has so far been no cytological analysis of the chromosome mutations induced in somatic cells. In the studies described cells were irradiated, in which it was known that somatic pairing was present, to verify earlier studies on the ...

Human and marsupial whole blood and blood-medium mixtures were irradiated with various doses of 2.25 MHz ultrasound and gamma rays. Doses of ultrasonic irradiation orders of magnitude higher than those used for diagnostic studies produced very few chromosome aberrations. A large proportion of the chromosome aberrations observed were gaps, rather ...

In this paper we present a new method to achieve quantitative phase contrast imaging in Digital Holographic Microscopy (DHM) that allows to compensate for phase aberrations and image distortion by recording of a single reference hologram.We demonstrate that in particular cases in which the studied specimen does not have abrupt edges, the specimen�s hologram itself can be ...

It seems that the determination of peripheral lymphocyte chriomosome aberration levels is now firmly established as a means of biological dosimetry of great value in many phases of the nuclear industry. In the case of large external exposure it can provide valuable quantitative estimates, as well as information on dose distribution and radiation quality. ...

Five different wavelengths (730, 760, 780, 810, and 820 m mu ) and two levels of irradiance ( 1500 and 200 mu wcm/sup 2/) were employed to determine the action spectrum of the potentiating effect of far-red radiant energy on x-ray- induced chromatid aberrations in Vicia root tips. It was found that radiant energy in the region from 760 to 780 m mu ...

Experimental results were reported to the determination of protective action of cysteamine on the yield of genetic mutations, chromosome aberrations and cell kill during reproduction, evidently due to damage of genetic structures. The experiments were performed on transplanted fibroblast cells of Chinese hamsters, clone 431 in which 80% of the cells had pseudodiloidy. A ...

A comparison of chromosomal abnormalities in bone marrow leukaemic cells and of stable and unstable aberrations in lymphocytes of patients with hematological malignancies who live in areas with or without contamination by the Chernobyl nuclear accident has been made using FISH and G-banding. Healthy residents of these areas comprised the control group. No systematic ...

CAP and ZOIN were tested in vivo for their ability to induce sister-chromatid exchanges (SCE) and chromosome aberrations in mouse bone marrow cells. Single intraperitoneal injections of ZOIN to a maximum of 3000 mg/kg body weight failed to increase the number of SCEs in metaphases recovered 24 h post-treatment, and doses of 1500 mg/kg did not induce measurable increases in ...

One can control the aberrations of an optical readout system by varying the width of a strip of antireflection coatings deposited upon plastic objective lenses. It is found that one can control the magnitude of the third-order astigmatism of the system by changing the coating width. This process has the advantage that it does not significantly cause other kinds of ...

As for master-oscillator-power-amplifier (MOPA) laser systems, Aberrations generated by thermal effects, the mirrors surface and optical elements play important roles to deteriorate laser beam quality. To obtain good beam performance, a compact adaptive optics (AO) system for a Nd:YAG zigzag slab amplifier is built. A rectangular tilt mirror (DM) and a 39-element rectangular ...

Saccharomyces cerevisiae BUB1 encodes a protein kinase required for spindle assembly checkpoint function. In the presence of spindle damage, BUB1 is required to prevent cell cycle progression into anaphase. We have identified a dominantly acting BUB1 allele that appears to activate the spindle assembly checkpoint pathway in cells with undamaged spindles. High-level expression ...

Saccharomyces cerevisiae BUB1 encodes a protein kinase required for spindle assembly checkpoint function. In the presence of spindle damage, BUB1 is required to prevent cell cycle progression into anaphase. We have identified a dominantly acting BUB1 allele that appears to activate the spindle assembly checkpoint pathway in cells with undamaged spindles. High-level expression ...

The effect of low-dose irradiation and of age on the radiosensitivity of human lymphocytes was studies in two groups: control (67 people) and exposed to uncontrolled low-dose irradiation in past (165 people). Radiosensitivity of lymphocytes was estimated by the level of chromosome aberrations induced in vitro by gamma-radiation Cs137 at the dose 1.5 Gy. In ...

We investigate the potential for the third-order aberrations coma and trefoil to provide a signed cue to accommodation. It is first demonstrated theoretically (with some assumptions) that the point spread function is insensitive to the sign of spherical defocus in the presence of odd-order aberrations. In an experimental investigation, the accommodation ...

Tissue velocity and attenuation inhomogeneities reduce ultrasound image quality in many patients. Over the years a number of methods have been developed to estimate the corrective delays necessary for phase aberration correction. Past methods were based on assumptions of the target or required a separate transducer acting as a transponder point source. A method is proposed ...

Mice of both sexes with a weight of 18 to 20 grams were given x-ray doses of 200, 400, 700, and 1000 r. The mice were killed 1/4, 1, 2, 3, 5, and 8 days after the irradiation. Samples of the thigh marrow were fixed and stained in order to count the chromosomal aberrations which were determined at the late anaphase or early telophase stage. Six hours after the ...

... surface membrane to correct for aberrations. ... less curvature results in less aberration. ... a negative conic constant helps reduce spherical aberration. ...

... for the case when piston error, tilt, defocus, spherical aberration, astigmatism or ... The effects of the aberrations on the optical wavefront, the point ...

... for chromatic aberration, astigmatism, thermal effects, and spherical aberration. An important reason for controlling aberrations through combination ...

Feb 1, 1999 ... The remaining three aberrations, spherical aberration, coma, and astigmatism, ... (Note: If there is significant spherical aberration, ...

... Right: Ratio of the RMS wavefront aberration to the original comatic RMS wavefront aberration as a function of the decenter E (full line), and the ...

... Longitudinal-chromatic and -spherical aberration, and lateral ... reducing both aberrations are discussed. ... volume hologram aberration is discussed ...

Mutagenic and antimutagenic properties of humans, bull, rabbit, chick, rat, and mouse were studied using seeds of Crepis capillaries (the chromosome aberration test). Antimutagenic activity was found in pre-processing, combined, and post-processing conditions of the seeds with a blood relative to the mutation inductors. Whole human and animal blood was found to be capable of ...

When the corneal epithelium of the Chinese hamster is irradiated with ionizing radiation in vivo, a rectilinear relationship is observed between the yield of chromosome aberrations and the dose of x rays within a dose range of 10 to 150 r. There is no threshold effect for chromosome breakage down to the 10-r level. The mean breakage rate of ...

Morphological aberrations in Typha populations inhabiting a once thermally stressed aquatic system on the Savannah River Plant in South Carolina were investigated by using both morphological and enzymatic procedures. No evidence of hybridization or introgression between T. latifolia and T. domingensis was found. Exposures of these populations to post-thermal conditions and low ...

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) ...

Doses of 62.5, 125 and 250 mg/kg of theophylline were administered to male B6C3F1 mice by intraperitoneal injection. Chromosome aberrations were scored in first-division metaphases of marrow cells 18 and 36 h post-treatment and sister-chromatid exchanges were quantified in second-division metaphases at 24 h. A modest but statistically significant increase in the number of SCEs ...

The purpose of this study was to investigate the genotoxic effects of Hg released from dental amalgams. The chromosome aberration test was conducted using original extracts and their diluted solutions of conventional type amalgam and high copper amalgam. The concentrations of Hg, Cu and Ag in the original extract of high copper amalgam were 17.64, 7.97 and 43.90 microM, ...