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  1. Transchromosomic cell model of Down syndrome shows aberrant migration, adhesion and proteome response to extracellular matrix

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    Cotter Finbarr E

    2009-08-01

    Full Text Available Abstract Background Down syndrome (DS, caused by trisomy of human chromosome 21 (HSA21, is the most common genetic birth defect. Congenital heart defects (CHD are seen in 40% of DS children, and >50% of all atrioventricular canal defects in infancy are caused by trisomy 21, but the causative genes remain unknown. Results Here we show that aberrant adhesion and proliferation of DS cells can be reproduced using a transchromosomic model of DS (mouse fibroblasts bearing supernumerary HSA21. We also demonstrate a deacrease of cell migration in transchromosomic cells independently of their adhesion properties. We show that cell-autonomous proteome response to the presence of Collagen VI in extracellular matrix is strongly affected by trisomy 21. Conclusion This set of experiments establishes a new model system for genetic dissection of the specific HSA21 gene-overdose contributions to aberrant cell migration, adhesion, proliferation and specific proteome response to collagen VI, cellular phenotypes linked to the pathogenesis of CHD.

  2. Abundant Focal Adhesion Kinase Causes Aberrant Neuronal Migration Via Its Phosphorylation at Tyr925.

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    An, Lei; Li, Weiwei; Hu, Xinde; Zhang, Wei; Zhao, Shanting

    2018-01-01

    The process of neuronal migration is precisely regulated by different molecules during corticogenesis. The FAK (focal adhesion kinase) plays a critical role in embryogenesis and is involved in cell motility through focal adhesions, but the underlying mechanisms on inordinate expression are unclear. To investigate the effect of FAK overexpression on neuronal migration spatiotemporally, mice FAK was transfected into the neurons in vivo by electroporation. Results showed that exogenous FAK distributed in the cytoplasm (in vivo) and co-localized with vinculin (in vitro) and induced aberrant neuronal migration via phosphorylation of FAK at Tyr925 during cerebral cortex development. Meanwhile, FAK Y925F mutant also induced aberrant neuronal migration like inordinate FAK/GFP phenotype. All these results implied that FAK-induced abnormal phenotype depended on phosphorylation of FAK at Tyr925, and this demonstrated that the overexpression of FAK impaired neuronal migration through its phosphorylation and activity of FAK during corticogenesis.

  3. Atomic-scale observation of migration and coalescence of Au nanoclusters on YSZ surface by aberration-corrected STEM.

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    Li, Junjie; Wang, Zhongchang; Chen, Chunlin; Huang, Sumei

    2014-07-01

    Unraveling structural dynamics of noble metal nanoclusters on oxide supports is critical to understanding reaction process and origin of catalytic activity in heterogeneous catalysts. Here, we show that aberration-corrected scanning transmission electron microscopy can provide direct atomic-resolution imaging of surface migration, coalescence, and atomic rearrangement of Au clusters on an Y:ZrO₂ (YSZ) support. The high resolution enables us to reveal migration and coalescence process of Au clusters at the atomic scale, and to demonstrate that the coalesced clusters undergo a cooperative atomic rearrangement, which transforms the coherent into incoherent Au/YSZ interface. This approach can help to elucidate atomistic mechanism of catalytic activities and to develop novel catalysts with enhanced functionality.

  4. Aberrant migration of Ancylostoma caninum to the os penis of a dog.

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    Bolton, L A; Camby, D; Boomker, J

    1996-09-01

    A male pitbull terrier was presented with a history of stranguria and depression. On clinical and radiological examination a suspected necrogranuloma of the caudal os penis, which obstructed the urethra, was found. The necrogranuloma was removed surgically and contained blood and necrotic tissue as well as several adult male and female Ancylostoma caninum worms. The urethral obstruction resulted in post-renal azotaemia, hydronephrosis and eventually bladder rupture. A rare case of aberrant migration of A. caninum to the os penis of a dog is described.

  5. Traumatic Brain Injury Causes Aberrant Migration of Adult-Born Neurons in the Hippocampus.

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    Ibrahim, Sara; Hu, Weipeng; Wang, Xiaoting; Gao, Xiang; He, Chunyan; Chen, Jinhui

    2016-02-22

    Traumatic brain injury (TBI) promotes neural stem/progenitor cell (NSC) proliferation in an attempt to initiate innate repair mechanisms. However, all immature neurons in the CNS are required to migrate from their birthplace to their final destination to develop into functional neurons. Here we assessed the destination of adult-born neurons following TBI. We found that a large percentage of immature neurons migrated past their normal stopping site at the inner granular cell layer (GCL), and became misplaced in the outer GCL of the hippocampal dentate gyrus. The aberrant migration of adult-born neurons in the hippocampus occurred 48 hours after TBI, and lasted for 8 weeks, resulting in a great number of newly generated neurons misplaced in the outer GCL in the hippocampus. Those misplaced neurons were able to become mature and differentiate into granular neurons, but located ectopically in the outer GCL with reduced dendritic complexity after TBI. The adult-born neurons at the misplaced position may make wrong connections with inappropriate nearby targets in the pre-existing neural network. These results suggest that although stimulation of endogenous NSCs following TBI might offer new avenues for cell-based therapy, additional intervention is required to further enhance successful neurogenesis for repairing the damaged brain.

  6. Korean patients with chronic lymphocytic leukemia show the similar types of chromosomal aberrations as those in Europe and North America.

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    Chang, Yoon Hwan; Park, Junwan; Kim, Hee Chan; Chun, Hong Ku; Kim, Young Ree; Kim, Myungshin; Han, Kyungja; Lee, Je-Hwan; Lee, Kyoo-Hyung; Cho, Han Ik; Lee, Yun Song; Lee, Dong Soon

    2006-06-01

    Chronic lymphocytic leukemia (CLL) is frequent in the West, but rare in Korea. In this study, the frequency of chromosome aberration in Korean CLL patients was examined by applying interphase fluorescence in situ hybridization (FISH). Conventional cytogenetic test and FISH were performed on bone marrow aspirates obtained from 16 CLL patients. By applying DNA probes (Vysis, Downers Grove, IL, USA), the deletion in 11q22-23, 13q14, 13q34, and 17p13, and trisomy 12 were examined. With FISH, molecular cytogenetic aberration was detected in 10 of 16 patients [63%, 95% confidence interval (CI) 39-86], whereas with conventional cytogenetic test, chromosomal aberration was detected only in 2 out of 13 cases (15%, 95% CI 0-35). In total, the cases with one or more chromosomal aberrations were 11 out of 16 cases (69%, 95% CI 46-92). The most frequently detected aberration was the 13q14 deletion (69%, 95% CI 44-94), followed by trisomy 12 (19%, 95% CI 0-38) and 11q22 deletion (14%, 95% CI 0-33). No deletion in 17p13 was observed. In conclusion, CLL in Korean is a heterogeneous genetic disorder, showing similar genetic changes in Europe and North America.

  7. Patients with schizophrenia show aberrant patterns of basal ganglia activation: Evidence from ALE meta-analysis.

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    Bernard, Jessica A; Russell, Courtney E; Newberry, Raeana E; Goen, James R M; Mittal, Vijay A

    2017-01-01

    The diverse circuits and functional contributions of the basal ganglia, coupled with known differences in dopaminergic function in patients with schizophrenia, suggest they may be an important contributor to the etiology of the hallmark symptoms and cognitive dysfunction experienced by these patients. Using activation-likelihood-estimation meta-analysis of functional imaging research, we investigated differences in activation patterns in the basal ganglia in patients with schizophrenia, relative to healthy controls across task domains. This analysis included 42 functional neuroimaging studies, representing a variety of behavioral domains that have been linked to basal ganglia function in prior work. We provide important new information about the functional activation patterns and functional topography of the basal ganglia for different task domains in healthy controls. Crucially however, we demonstrate that across task domains, patients with schizophrenia show markedly decreased activation in the basal ganglia relative to healthy controls. Our results provide further support for basal ganglia dysfunction in patients with schizophrenia, and the broad dysfunction across task domains may contribute to the symptoms and cognitive deficits associated with schizophrenia.

  8. Migration of Single Iridium Atoms and Tri-iridium Clusters on MgO Surfaces. Aberration-Corrected STEM Imaging and ab-initio Calculations

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    Han, Chang W. [Purdue Univ., West Lafayette, IN (United States); Iddir, Hakim [Argonne National Lab. (ANL), Argonne, IL (United States); Uzun, Alper [Koc Univ., Instanbul (Turkey); Curtiss, Larry A. [Argonne National Lab. (ANL), Argonne, IL (United States); Browning, Nigel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gates, Bruce C. [Univ. of California, Davis, CA (United States); Ortalan, Volkan [Purdue Univ., West Lafayette, IN (United States)

    2015-11-06

    To address the challenge of fast, direct atomic-scale visualization of the diffusion of atoms and clusters on surfaces, we used aberration-corrected scanning transmission electron microscopy (STEM) with high scan speeds (as little as ~0.1 s per frame) to visualize the diffusion of (1) a heavy atom (Ir) on the surface of a support consisting of light atoms, MgO(100), and (2) an Ir3 cluster on MgO(110). Sequential Z-contrast images elucidate the diffusion mechanisms, including the hopping of Ir1 and the rotational migration of Ir3 as two Ir atoms remain anchored to the surface. Density functional theory (DFT) calculations provided estimates of the diffusion energy barriers and binding energies of the iridium species to the surfaces. The results show how the combination of fast-scan STEM and DFT calculations allow real-time visualization and fundamental understanding of surface diffusion phenomena pertaining to supported catalysts and other materials.

  9. Whole blood DNA aberrant methylation in pancreatic adenocarcinoma shows association with the course of the disease: a pilot study.

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    Albertas Dauksa

    Full Text Available Pancreatic tumors are usually diagnosed at an advanced stage in the progression of the disease, thus reducing the survival chances of the patients. Non-invasive early detection would greatly enhance therapy and survival rates. Toward this aim, we investigated in a pilot study the power of methylation changes in whole blood as predictive markers for the detection of pancreatic tumors. We investigated methylation levels at selected CpG sites in the CpG rich regions at the promoter regions of p16, RARbeta, TNFRSF10C, APC, ACIN1, DAPK1, 3OST2, BCL2 and CD44 in the blood of 30 pancreatic tumor patients and in the blood of 49 matching controls. In addition, we studied LINE-1 and Alu repeats using degenerate amplification approach as a surrogate marker for genome-wide methylation. The site-specific methylation measurements at selected CpG sites were done by the SIRPH method. Our results show that in the patient's blood, tumor suppressor genes were slightly but significantly higher methylated at several CpG sites, while repeats were slightly less methylated compared to control blood. This was found to be significantly associated with higher risk for pancreatic ductal adenocarcinoma. Additionally, high methylation levels at TNFRSCF10C were associated with positive perineural spread of tumor cells, while higher methylation levels of TNFRSF10C and ACIN1 were significantly associated with shorter survival. This pilot study shows that methylation changes in blood could provide a promising method for early detection of pancreatic tumors. However, larger studies must be carried out to explore the clinical usefulness of a whole blood methylation based test for non-invasive early detection of pancreatic tumors.

  10. Disruption of genital ridge development causes aberrant primordial germ cell proliferation but does not affect their directional migration.

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    Chen, Su-Ren; Zheng, Qiao-Song; Zhang, Yang; Gao, Fei; Liu, Yi-Xun

    2013-03-05

    The directional migration and the following development of primordial germ cells (PGCs) during gonad formation are key steps for germline development. It has been proposed that the interaction between germ cells and genital ridge (GR) somatic cells plays essential roles in this process. However, the in vivo functional requirements of GR somatic cells in germ cell development are largely unknown. Wt1 mutation (Wt1(R394W/R394W)) results in GR agenesis through mitotic arrest of coelomic epitheliums. In this study, we employed the GR-deficient mouse model, Wt1(R394W/R394W), to investigate the roles of GR somatic cells in PGC migration and proliferation. We found that the number of PGCs was dramatically reduced in GR-deficient embryos at embryonic day (E) 11.5 and E12.5 due to decreased proliferation of PGCs, involving low levels of BMP signaling. In contrast, the germ cells in Wt1(R394W/R394W) embryos were still mitotically active at E13.5, while all the germ cells in control embryos underwent mitotic arrest at this stage. Strikingly, the directional migration of PGCs was not affected by the absence of GR somatic cells. Most of the PGCs reached the mesenchyme under the coelomic epithelium at E10.5 and no ectopic PGCs were noted in GR-deficient embryos. However, the precise positioning of PGCs was disrupted. Our work provides in vivo evidence that the proliferation of germ cells is precisely regulated by GR somatic cells during different stages of gonad development. GR somatic cells are probably dispensable for the directional migration of PGCs, but they are required for precise positioning of PGCs at the final step of migration.

  11. Disruption of genital ridge development causes aberrant primordial germ cell proliferation but does not affect their directional migration

    OpenAIRE

    Chen, Su-Ren; Zheng, Qiao-Song; Zhang, Yang; Gao, Fei; Liu, Yi-Xun

    2013-01-01

    Background The directional migration and the following development of primordial germ cells (PGCs) during gonad formation are key steps for germline development. It has been proposed that the interaction between germ cells and genital ridge (GR) somatic cells plays essential roles in this process. However, the in vivo functional requirements of GR somatic cells in germ cell development are largely unknown. Results Wt1 mutation (Wt1 R394W/R394W) results in GR agenesis through mitotic arrest of...

  12. Testing an emerging paradigm in migration ecology shows surprising differences in efficiency between flight modes.

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    Adam E Duerr

    Full Text Available To maximize fitness, flying animals should maximize flight speed while minimizing energetic expenditure. Soaring speeds of large-bodied birds are determined by flight routes and tradeoffs between minimizing time and energetic costs. Large raptors migrating in eastern North America predominantly glide between thermals that provide lift or soar along slopes or ridgelines using orographic lift (slope soaring. It is usually assumed that slope soaring is faster than thermal gliding because forward progress is constant compared to interrupted progress when birds pause to regain altitude in thermals. We tested this slope-soaring hypothesis using high-frequency GPS-GSM telemetry devices to track golden eagles during northbound migration. In contrast to expectations, flight speed was slower when slope soaring and eagles also were diverted from their migratory path, incurring possible energetic costs and reducing speed of progress towards a migratory endpoint. When gliding between thermals, eagles stayed on track and fast gliding speeds compensated for lack of progress during thermal soaring. When thermals were not available, eagles minimized migration time, not energy, by choosing energetically expensive slope soaring instead of waiting for thermals to develop. Sites suited to slope soaring include ridges preferred for wind-energy generation, thus avian risk of collision with wind turbines is associated with evolutionary trade-offs required to maximize fitness of time-minimizing migratory raptors.

  13. Aberrant activation of ERK/FOXM1 signaling cascade triggers the cell migration/invasion in ovarian cancer cells.

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    Gabriel T M Lok

    Full Text Available Forkhead box M1 (FOXM1 is a proliferation-associated transcription factor essential for cell cycle progression. Numerous studies have documented that FOXM1 has multiple functions in tumorigenesis and its elevated levels are frequently associated with cancer progression. Here, we characterized the role of ERK/FOXM1 signaling in mediating the metastatic potential of ovarian cancer cells. Immunohistochemical (IHC, immunoblotting and semi-quantitative RT-PCR analyses found that both phospho-ERK and FOXM1 were frequently upregulated in ovarian cancers. Intriguingly, the overexpressed phospho-ERK (p<0.001 and FOXM1 (p<0.001 were significantly correlated to high-grade ovarian tumors with aggressive behavior such as metastasized lymph node (5 out of 6. Moreover, the expressions of phospho-ERK and FOXM1 had significantly positive correlation (p<0.001. Functionally, ectopic expression of FOXM1B remarkably enhanced cell migration/invasion, while FOXM1C not only increased cell proliferation but also promoted cell migration/invasion. Conversely, inhibition of FOXM1 expression by either thiostrepton or U0126 could significantly impair FOXM1 mediated oncogenic capacities. However, the down-regulation of FOXM1 by either thiostrepton or U0126 required the presence of p53 in ovarian cancer cells. Collectively, our data suggest that over-expression of FOXM1 might stem from the constitutively active ERK which confers the metastatic capabilities to ovarian cancer cells. The impairment of metastatic potential of cancer cells by FOXM1 inhibitors underscores its therapeutic value in advanced ovarian tumors.

  14. Contrasting life history responses to fish released infochemicals of two co-occurring Daphnia species that show different migration behaviour

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    Vijverberg, J.; Doksaeter, A.; Van Donk, E.

    2006-01-01

    In a previous field study (Flik & Vijverberg 2003) we showed that in an oligotrophic-mesotrophic lake in the Netherlands (L. Maarsseveen) two co-occurring Daphnia species, Daphnia pulicaria and Daphnia galeata × hyalina performed distinct vertical migration behaviour during summer which is induced

  15. ISO-66, a novel inhibitor of macrophage migration, shows efficacy in melanoma and colon cancer models.

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    Ioannou, Kyriaki; Cheng, Kai Fan; Crichlow, Gregg V; Birmpilis, Anastasios I; Lolis, Elias J; Tsitsilonis, Ourania E; Al-Abed, Yousef

    2014-10-01

    Macrophage migration inhibitory factor (MIF) is a pleiotropic pro-inflammatory cytokine, which possesses a contributing role in cancer progression and metastasis and, thus, is now considered a promising anticancer drug target. Many MIF-inactivating strategies have proven successful in delaying cancer growth. Here, we report on the synthesis of ISO-66, a novel, highly stable, small-molecule MIF inhibitor, an analog of ISO-1 with improved characteristics. The MIF:ISO-66 co-crystal structure demonstrated that ISO-66 ligates the tautomerase active site of MIF, which has previously been shown to play an important role in its biological functions. In vitro, ISO-66 enhanced specific and non-specific anticancer immune responses, whereas prolonged administration of ISO-66 in mice with established syngeneic melanoma or colon cancer was non-toxic and resulted in a significant decrease in tumor burden. Subsequent ex vivo analysis of mouse splenocytes revealed that the observed decrease in tumor growth rates was likely mediated by the selective in vivo expansion of antitumor-reactive effector cells induced by ISO-66. Compared to other MIF-inactivating strategies employed in vivo, the anticancer activity of ISO-66 is demonstrated to be of equal or better efficacy. Our findings suggest that targeting MIF, via highly specific and stable compounds, such as ISO-66, may be effective for cancer treatment and stimulation of anticancer immune responses.

  16. Sr - an element shows the way - Applications of Sr isotopes for provenance, tracing and migration (Invited)

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    Prohaska, T.; Irrgeher, J.; Zitek, A.; Teschler Nicola, M.

    2010-12-01

    presented for Sr isotope ratios simply supported by the fact that a higher statistical number of samples could be analyzed. Further supported by direct introductions systems such as laser ablation, the popularity of Sr in science has increased steadily. A number of fields of applications make nowadays use of the system so far: anthropology and archaeology as well as food science, chemical technology, forensic science, medicine or biology. The Sr isotope system will be presented along with analytical techniques applied. Selected examples making use of the natural Sr isotopic variation will be reported: Proof of provenance of food, forensic applications and migration studies on prehistoric cultures or modern biological systems. In addition, the application of enriched Sr isotope spikes will be presented. The spikes are administered in order to investigate Sr turnovers (e.g. as proxy for Ca in biomedical studies), marking tissues for tracing and migration experiments and investigating environmental processes.

  17. Chemically primed bone-marrow derived mesenchymal stem cells show enhanced expression of chemokine receptors contributed to their migration capability

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    Hamid Reza Bidkhori

    2016-01-01

    Full Text Available Objective(s:The limited homing potential of bone-marrow-derived mesenchymal stem cells (BM-MSC is the key obstacle in MSC-based therapy. It is believed that chemokines and chemokine receptor interactions play key roles in cellular processes associated with migration. Meanwhile, MSCs express a low level of distinct chemokine receptors and they even lose these receptors on their surface after a few passages which influence their therapeutic applications negatively. This study investigated whether treatment of BM-MSCs with hypoxia-mimicking agents would increase expression of some chemokine receptors and cell migration. Materials and Methods: BM-MSCs were treated at passage 2 for our gene expression profiling. All qPCR experiments were performed by SYBR Green method in CFX-96 Bio-Rad Real-Time PCR. The Boyden chamber assay was utilized to investigate BM-MSC homing. Results:Possible approaches to increasing the expression level of chemokine receptors by different hypoxia-mimicking agents such as valproic acid (VPA, CoCl2, and desferrioxamine (DFX are described. Results show DFX efficiently up-regulate the CXCR7 and CXCR4 gene expression while VPA increase only the CXCR7 gene expression and no significant change in expression level of CXCR4 and the CXCR7 gene was detectable by CoCl2 treatment. Chemotaxis assay results show that pre-treatment with DFX, VPA, and Cocl2 enhances significantly the migration ability of BM-MSCs compared with the untreated control group and DFX treatment accelerates MSCs homing significantly with a higher rate than VPA and Cocl2 treatments. Conclusion: Our data supports the notion that pretreatment of MSC with VPA and DFX improves the efficiency of MSC therapy by triggering homing regulatory signaling pathways.

  18. Endometrial Cancer Side-Population Cells Show Prominent Migration and Have a Potential to Differentiate into the Mesenchymal Cell Lineage

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    Kato, Kiyoko; Takao, Tomoka; Kuboyama, Ayumi; Tanaka, Yoshihiro; Ohgami, Tatsuhiro; Yamaguchi, Shinichiro; Adachi, Sawako; Yoneda, Tomoko; Ueoka, Yousuke; Kato, Keiji; Hayashi, Shinichi; Asanoma, Kazuo; Wake, Norio

    2010-01-01

    Cancer stem-like cell subpopulations, referred to as “side-population” (SP) cells, have been identified in several tumors based on their ability to efflux the fluorescent dye Hoechst 33342. Although SP cells have been identified in the normal human endometrium and endometrial cancer, little is known about their characteristics. In this study, we isolated and characterized the SP cells in human endometrial cancer cells and in rat endometrial cells expressing oncogenic human K-Ras protein. These SP cells showed i) reduction in the expression levels of differentiation markers; ii) long-term proliferative capacity of the cell cultures; iii) self-renewal capacity in vitro; iv) enhancement of migration, lamellipodia, and, uropodia formation; and v) enhanced tumorigenicity. In nude mice, SP cells formed large, invasive tumors, which were composed of both tumor cells and stromal-like cells with enriched extracellular matrix. The expression levels of vimentin, α-smooth muscle actin, and collagen III were enhanced in SP tumors compared with the levels in non-SP tumors. In addition, analysis of microdissected samples and fluorescence in situ hybridization of Hec1-SP-tumors showed that the stromal-like cells with enriched extracellular matrix contained human DNA, confirming that the stromal-like cells were derived from the inoculated cells. Moreober, in a Matrigel assay, SP cells differentiated into α-smooth muscle actin-expressing cells. These findings demonstrate that SP cells have cancer stem-like cell features, including the potential to differentiate into the mesenchymal cell lineage. PMID:20008133

  19. MUTZ-3 derived Langerhans cells in human skin equivalents show differential migration and phenotypic plasticity after allergen or irritant exposure

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    Kosten, Ilona J.; Spiekstra, Sander W. [Department of Dermatology, VU University Medical Center, Amsterdam (Netherlands); Gruijl, Tanja D. de [Department of Dermatology Medical Oncology, VU University Medical Center, Amsterdam (Netherlands); Gibbs, Susan, E-mail: s.gibbs@acta.nl [Department of Dermatology, VU University Medical Center, Amsterdam (Netherlands); Department of Oral Cell Biology, Academic Center for Dentistry (ACTA), Amsterdam (Netherlands)

    2015-08-15

    After allergen or irritant exposure, Langerhans cells (LC) undergo phenotypic changes and exit the epidermis. In this study we describe the unique ability of MUTZ-3 derived Langerhans cells (MUTZ-LC) to display similar phenotypic plasticity as their primary counterparts when incorporated into a physiologically relevant full-thickness skin equivalent model (SE-LC). We describe differences and similarities in the mechanisms regulating LC migration and plasticity upon allergen or irritant exposure. The skin equivalent consisted of a reconstructed epidermis containing primary differentiated keratinocytes and CD1a{sup +} MUTZ-LC on a primary fibroblast-populated dermis. Skin equivalents were exposed to a panel of allergens and irritants. Topical exposure to sub-toxic concentrations of allergens (nickel sulfate, resorcinol, cinnamaldehyde) and irritants (Triton X-100, SDS, Tween 80) resulted in LC migration out of the epidermis and into the dermis. Neutralizing antibody to CXCL12 blocked allergen-induced migration, whereas anti-CCL5 blocked irritant-induced migration. In contrast to allergen exposure, irritant exposure resulted in cells within the dermis becoming CD1a{sup −}/CD14{sup +}/CD68{sup +} which is characteristic of a phenotypic switch of MUTZ-LC to a macrophage-like cell in the dermis. This phenotypic switch was blocked with anti-IL-10. Mechanisms previously identified as being involved in LC activation and migration in native human skin could thus be reproduced in the in vitro constructed skin equivalent model containing functional LC. This model therefore provides a unique and relevant research tool to study human LC biology in situ under controlled in vitro conditions, and will provide a powerful tool for hazard identification, testing novel therapeutics and identifying new drug targets. - Highlights: • MUTZ-3 derived Langerhans cells integrated into skin equivalents are fully functional. • Anti-CXCL12 blocks allergen-induced MUTZ-LC migration.

  20. Spherical aberration in contact lens wear.

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    Lindskoog Pettersson, A; Jarkö, C; Alvin, A; Unsbo, P; Brautaset, R

    2008-08-01

    The aim of the present studies was to investigate the effect on spherical aberration of different non custom-made contact lenses, both with and without aberration control. A wavefront analyser (Zywave, Bausch & Lomb) was used to measure the aberrations in each subject's right eye uncorrected and with the different contact lenses. The first study evaluated residual spherical aberration with a standard lens (Focus Dailies Disposable, Ciba Vision) and with an aberration controlled contact lens (ACCL) (Definition AC, Optical Connection Inc.). The second study evaluated the residual spherical aberrations with a monthly disposable silicone hydrogel lens with aberration reduction (PureVision, Bausch & Lomb). Uncorrected spherical aberration was positive for all pupil sizes in both studies. In the first study, residual spherical aberration was close to zero with the standard lens for all pupil sizes whereas the ACCL over-corrected spherical aberration. The results of the second study showed that the monthly disposable lens also over-corrected the aberration making it negative. The changes in aberration were statistically significant (plenses. Since the amount of aberration varies individually we suggest that aberrations should be measured with lenses on the eye if the aim is to change spherical aberration in a certain direction.

  1. Optical Aberrations and Wavefront

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    Nihat Polat

    2014-08-01

    Full Text Available The deviation of light to create normal retinal image in the optical system is called aberration. Aberrations are divided two subgroup: low-order aberrations (defocus: spherical and cylindrical refractive errors and high-order aberrations (coma, spherical, trefoil, tetrafoil, quadrifoil, pentafoil, secondary astigmatism. Aberrations increase with aging. Spherical aberrations are compensated by positive corneal and negative lenticular spherical aberrations in youth. Total aberrations are elevated by positive corneal and positive lenticular spherical aberrations in elderly. In this study, we aimed to analyze the basic terms regarding optic aberrations which have gained significance recently. (Turk J Ophthalmol 2014; 44: 306-11

  2. Forage plants of an Arctic-nesting herbivore show larger warming response in breeding than wintering grounds, potentially disrupting migration phenology

    NARCIS (Netherlands)

    Lameris, Thomas K.; Jochems, Femke; Graaf, van der Alexandra J.; Andersson, Mattias; Limpens, Juul; Nolet, Bart A.

    2017-01-01

    During spring migration, herbivorous waterfowl breeding in the Arctic depend on peaks in the supply of nitrogen-rich forage plants, following a "green wave" of grass growth along their flyway to fuel migration and reproduction. The effects of climate warming on forage plant growth are expected to

  3. Forage plants of an Arctic-nesting herbivore show larger warming response in breeding than wintering grounds, potentially disrupting migration phenology

    NARCIS (Netherlands)

    Lameris, T.K.; Jochems, Femke; van der Graaf, A.J.; Andersson, M.; Limpens, J.; Nolet, B.A.

    2017-01-01

    During spring migration, herbivorous waterfowl breeding in the Arctic depend on peaks in the supply of nitrogen-rich forage plants, following a “green wave” of grass growth along their flyway to fuel migration and reproduction. The effects of climate warming on forage plant growth are expected to be

  4. A preference for migration

    OpenAIRE

    Stark, Oded

    2007-01-01

    At least to some extent migration behavior is the outcome of a preference for migration. The pattern of migration as an outcome of a preference for migration depends on two key factors: imitation technology and migration feasibility. We show that these factors jointly determine the outcome of a preference for migration and we provide examples that illustrate how the prevalence and transmission of a migration-forming preference yield distinct migration patterns. In particular, the imitation of...

  5. A new loess distribution map for the Carpathian Basin facilitates surface sediment transects and showing migration pathways for modern human dispersal

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    Lehmkuhl, Frank; Lindner, Heiko; Bösken, Janina; Zeeden, Christian

    2017-04-01

    Quaternary studies in the Carpathian Basin require a detailed knowledge of the distribution of surface sediments. Existing and often cited maps, such as Haase et al. (2007), are not detailed enough for various purposes and difficult in detail as a result of the basic input data and due to the used scale. In addition, many of the maps presenting the distribution of loess and other geological features in Europe display inconsistencies such as displacements, shifts or even abrupt delimitations of different geological units such as loess across national borders. In fact, if geoscientific data from different regions or countries are combined, national borders in many medium- and large-scale thematic datasets appear as artificial breaks. To create a higher resolution map showing the more detailed distribution of Quaternary surface sediments in the Carpathian Basin the spatial data from several countries were used and combined. Particularly some issues occurred because of the thematically content of the underlying international geodata, but also due to geodetical basics such as projections and linguistic barriers, respectively. In addition to maps, transects of surface sediments from the lowlands to the uplands are provided. Together these visualizations are used for discussing the loess distribution and possible origins. This map provides a valuable contribution to the potential migration route for the dispersal of the modern humans. We can show that the distribution of Aurignacian open air sites is connect to elevations between 200 and 500 m at the foothills of the mountains and often situated in loess environments.

  6. Chromosome Aberrations by Heavy Ions

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    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.

  7. Aberrant Radial Artery Causing Carpal Tunnel Syndrome

    Directory of Open Access Journals (Sweden)

    Zinon T. Kokkalis

    2016-07-01

    Full Text Available 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.

  8. Aberrant Radial Artery Causing Carpal Tunnel Syndrome.

    Science.gov (United States)

    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.

  9. Generalized beam quality factor of aberrated truncated Gaussian laser beams

    CSIR Research Space (South Africa)

    Mafusire, C

    2011-07-01

    Full Text Available The authors outline a theory for the calculation of the beam quality factor of an aberrated laser beam. They provide closed form equations that show that the beam quality factor of an aberrated Gaussian beam depends on all primary aberrations except...

  10. [Monochromatic aberration in accommodation. Dynamic wavefront analysis].

    Science.gov (United States)

    Fritzsch, M; Dawczynski, J; Jurkutat, S; Vollandt, R; Strobel, J

    2011-06-01

    Monochromatic aberrations may influence the visual acuity of the eye. They are not stable and can be affected by different factors. The subject of the following paper is the dynamic investigation of the changes in wavefront aberration with accommodation. Dynamic measurement of higher and lower order aberrations was performed with a WASCA Wavefront Analyzer (Carl-Zeiss-Meditec) and a specially constructed target device for aligning objects in far and near distances on 25 subjects aged from 15 to 27 years old. Wavefront aberrations showed some significant changes in accommodation. In addition to the characteristic sphere reaction accompanying miosis and changes in horizontal prism (Z(1) (1)) in the sense of a convergence movement of the eyeball also occurred. Furthermore defocus rose (Z(2) (0)) and astigmatism (Z(2) (-2)) changed. In higher-order aberrations a decrease in coma-like Zernike polynomials (Z(3) (-1), Z(3) (1)) was found. The most obvious change appeared in spherical aberration (Z(4) (0)) which increased and changed from positive to negative. In addition the secondary astigmatism (Z(4) (-2)) and quadrafoil (Z(4) (4)) rise also increased. The total root mean square (RMS), as well as the higher-order aberrations (RMS-HO) significantly increased in accommodation which is associated with a theoretical reduction of visual acuity. An analysis of the influence of pupil size on aberrations showed significant increases in defocus, spherical aberration, quadrafoil, RMS and RMS HO by increasing pupil diameter. By accommodation-associated miosis, the growing aberrations are partially compensated by focusing on near objects. Temporal analysis of the accommodation process with dynamic wavefront analysis revealed significant delays in pupil response and changing of prism in relation to the sphere reaction. In accommodation to near objects a discrete time ahead of third order aberrations in relation to the sphere response was found. Using dynamic wavefront measurement

  11. Pathophysiology of MDS: genomic aberrations.

    Science.gov (United States)

    Ichikawa, Motoshi

    2016-01-01

    Myelodysplastic syndromes (MDS) are characterized by clonal proliferation of hematopoietic stem/progenitor cells and their apoptosis, and show a propensity to progress to acute myelogenous leukemia (AML). Although MDS are recognized as neoplastic diseases caused by genomic aberrations of hematopoietic cells, the details of the genetic abnormalities underlying disease development have not as yet been fully elucidated due to difficulties in analyzing chromosomal abnormalities. Recent advances in comprehensive analyses of disease genomes including whole-genome sequencing technologies have revealed the genomic abnormalities in MDS. Surprisingly, gene mutations were found in approximately 80-90% of cases with MDS, and the novel mutations discovered with these technologies included previously unknown, MDS-specific, mutations such as those of the genes in the RNA-splicing machinery. It is anticipated that these recent studies will shed new light on the pathophysiology of MDS due to genomic aberrations.

  12. Forage plants of an Arctic-nesting herbivore show larger warming response in breeding than wintering grounds, potentially disrupting migration phenology.

    Science.gov (United States)

    Lameris, Thomas K; Jochems, Femke; van der Graaf, Alexandra J; Andersson, Mattias; Limpens, Juul; Nolet, Bart A

    2017-04-01

    During spring migration, herbivorous waterfowl breeding in the Arctic depend on peaks in the supply of nitrogen-rich forage plants, following a "green wave" of grass growth along their flyway to fuel migration and reproduction. The effects of climate warming on forage plant growth are expected to be larger at the Arctic breeding grounds than in temperate wintering grounds, potentially disrupting this green wave and causing waterfowl to mistime their arrival on the breeding grounds. We studied the potential effect of climate warming on timing of food peaks along the migratory flyway of the Russian population of barnacle geese using a warming experiment with open-top chambers. We measured the effect of 1.0-1.7°C experimental warming on forage plant biomass and nitrogen concentration at three sites along the migratory flyway (temperate wintering site, temperate spring stopover site, and Arctic breeding site) during 2 months for two consecutive years. We found that experimental warming increased biomass accumulation and sped up the decline in nitrogen concentration of forage plants at the Arctic breeding site but not at temperate wintering and stop-over sites. Increasing spring temperatures in the Arctic will thus shorten the food peak of nitrogen-rich forage at the breeding grounds. Our results further suggest an advance of the local food peak in the Arctic under 1-2°C climate warming, which will likely cause migrating geese to mistime their arrival at the breeding grounds, particularly considering the Arctic warms faster than the temperate regions. The combination of a shorter food peak and mistimed arrival is likely to decrease goose reproductive success under climate warming by reducing growth and survival of goslings after hatching.

  13. Study of ocular aberrations with age.

    Science.gov (United States)

    Athaide, Helaine Vinche Zampar; Campos, Mauro; Costa, Charles

    2009-01-01

    Aging has various effects on visual system. Vision deteriorate, contrast sensitivity decreases and ocular aberrations apparently make the optical quality worse across the years. To prospective evaluate ocular aberrations along the ages. Three hundred and fifteen patients were examined, 155 were male (39.36%) and 160 were female (60.63%). Ages ranged from 5 to 64 year-old, the study was performed from February to November, 2004. Patients were divided into 4 age-groups according to IBGE (Instituto Brasileiro de Geografia e Estatística) classification: 68 patients from 5 to 14 year-old, 55 patients from 15 to 24 year-old, 116 from 25 to 44 year-old and 76 from 45 to 67 year-old. All patients had the following characteristics: best corrected visual acuity > 20/25, emmetropia or spherical equivalent < 3.50 SD, refractive astigmatism < 1.75 CD on cycloplegic refraction, normal ophthalmologic exam and no previous ocular surgeries. This protocol was approved by Federal University of São Paulo Institutional Review Board. Total optical aberrations were measured by H-S sensor LadarWave Custom Cornea Wavefront System (Alcon Laboratories Inc, Orlando, FLA, USA) and were statistically analysed. Corneal aberrations were calculated using CT-View software Version 6.89 (Sarver and Associates, Celebration, FL, USA). Lens aberrations were calculated by subtraction. High-order (0.32 e 0.48 microm) and ocular spherical aberrations (0.02 e 0.26 microm) increased respectively in child and middle age groups. High order (0.27 microm) and corneal spherical aberrations (0.05 microm) did not show changes with age. Lens showed a statistically significant spherical aberration increase (from -0.02 to 0.22 microm). Vertical (from 0.10 to -0.07 microm) and horizontal coma (from 0.01 to -0.12 microm) presented progressively negative values with aging. High-order and spherical aberrations increased with age due to lens contribution. The cornea did not affect significantly changes observed on ocular

  14. Effect of Quartic Phase Optical Aberration on Laser Beam Quality

    Science.gov (United States)

    Bencheikh, A.; Bouafia, M.; Boubetra, Dj.

    2009-09-01

    Laser beam quality is related to the aberration effect. Quartic phase aberration, more commonly known as spherical aberration, can result from aberrated optical components such as beam expanding telescopes, focusing or collimating lenses, or other conventional optical elements; from thermal focusing or thermal blooming in high power laser windows, lenses, amplifier rods, optical isolators, and other absorbing media. In general any kind of quartic aberration will lead to increased far field beam spread, degraded laser beam focusability and increased values of the beam quality. Currently, a well established quality parameter for laser beams is the M2 factor. This paper presents a new mathematical set for the spherical aberration coefficient C4 of Gaussian beams. The main idea comes from the estimation of the laser beam quality factor M2 given by Siegman. We show that this coefficient concerns only the case of geometrical optics.

  15. Human axial chromatic aberration found not to decline with age.

    Science.gov (United States)

    Ware, C

    1982-01-01

    Millodot (1976) reported a dramatic decline in the amount of axial chromatic aberration of the human eye with age. The present study represents a failure to replicate that finding using a more standard procedure. No difference in chromatic aberration was found between a young and an older group of observers. Also, the chromatic aberrations of two observers which had been measured 25 years previously showed no decline when these measurements were repeated, even though their ages at first and second testing straddled the period over which Millodot reported the most change in chromatic aberration.

  16. Calculation of aberration coefficients by ray tracing.

    Science.gov (United States)

    Oral, M; Lencová, B

    2009-10-01

    In this paper we present an approach for the calculation of aberration coefficients using accurate ray tracing. For a given optical system, intersections of a large number of trajectories with a given plane are computed. In the Gaussian image plane the imaging with the selected optical system can be described by paraxial and aberration coefficients (geometric and chromatic) that can be calculated by least-squares fitting of the analytical model on the computed trajectory positions. An advantage of such a way of computing the aberration coefficients is that, in comparison with the aberration integrals and the differential algebra method, it is relatively easy to use and its complexity stays almost constant with the growing complexity of the optical system. This paper shows a tested procedure for choosing proper initial conditions and computing the coefficients of the fifth-order geometrical and third-order, first-degree chromatic aberrations by ray tracing on an example of a weak electrostatic lens. The results are compared with the values for the same lens from a paper Liu [Ultramicroscopy 106 (2006) 220-232].

  17. Effects of chalazion excision on ocular aberrations.

    Science.gov (United States)

    Sabermoghaddam, Ali A; Zarei-Ghanavati, Siamak; Abrishami, Mojtaba

    2013-06-01

    The goal of this study was to compare higher-order aberrations before and after upper lid chalazion excision. Fourteen eyes from 12 patients (8 females, mean age: 28.7 ± 2.7 years) with upper lid chalazion were enrolled in this prospective interventional case series. Chalazia were excised by standard transconjunctival vertical incision. Ocular aberrations were evaluated by aberrometry (ZyWave) before and 2 months after chalazion excision. Root mean square of total higher-order aberrations decreased from 0.67 ± 0.12 to 0.43 ± 0.15 μm (P = 0.012) after excision. The root mean square of Zernike orders in the vertical and horizontal trefoil and horizontal coma were decreased after excision. Orbscan IIz tomography showed a statistically significant decrease in 5 mm zone irregularity (P = 0.027) and an increase in minimum simulated keratometry after surgery (P = 0.046). Chalazion increases higher-order aberrations, as measured by the Hartmann-Shack aberrometer, which could affect the preoperative evaluation and results of refractive surgery, especially wavefront-guided approaches. Chalazion excision could reduce ocular aberrations and is recommended before refractive surgeries.

  18. [Internal migration].

    Science.gov (United States)

    Borisovna, L

    1991-06-01

    Very few studies have been conducted that truly permit explanation of internal migration and it repercussions on social and economic structure. It is clear however that a profound knowledge of the determinants and consequences of internal migration will be required as a basis for economic policy decisions that advance the goal of improving the level of living of the population. the basic supposition of most studies of the relationship of population and development is that socioeconomic development conditions demographic dynamics. The process of development in Mexico, which can be characterized by great heterogeneity, consequently produces great regional disparities. At the national level various studies have estimated the volume of internal migration in Mexico, but they have usually been limited to interstate migration because the main source of data, the census, is classified by states. But given the great heterogeneity within states in all the elements related to internal migration, it is clear that studies of internal migration within states are also needed. Such studies are almost nonexistent because of their technical difficulty. National level studies show that interstate migration increased significantly between 1940-80. The proportion of Mexicans living outside their states of birth increased by 558% in those years, compared to the 342% increase in the total Mexican population. Although Puebla has a high rate of increase, migration has kept it below Mexico's national growth rate. Migration between Puebla and other states and within Puebla has led to an increasing unevenness of spatial distribution. Between 1970-80, 57 of Puebla's municipios had growth rates above the state average of 2.8%/year, 6 had growth rates equal to the average, and 129 had growth rates that were below the average but not negative. 25 states with negative growth rates that were considered strongly expulsive. In 1980, 51.7% of the population was concentrated in the 57 municipios

  19. An Analysis of Trafficking Receptors Shows that CD44 and P-Selectin Glycoprotein Ligand-1 Collectively Control the Migration of Activated Human T-Cells

    Directory of Open Access Journals (Sweden)

    Amal J. Ali

    2017-05-01

    Full Text Available Selectins guide the traffic of activated T-cells through the blood stream by mediating their tethering and rolling onto inflamed endothelium, in this way acting as beacons to help navigate them to sites of inflammation. Here, we present a comprehensive analysis of E-selectin ligands expressed on activated human T-cells. We identified several novel glycoproteins that function as E-selectin ligands. Specifically, we compared the role of P-selectin glycoprotein ligand-1 (PSGL-1 and CD43, known E-selectin ligands, to CD44, a ligand that has not previously been characterized as an E-selectin ligand on activated human T-cells. We showed that CD44 acts as a functional E-selectin ligand when expressed on both CD4+ and CD8+ T-cells. Moreover, the CD44 protein carries a binding epitope identifying it as hematopoietic cell E- and/or L-selectin ligand (HCELL. Furthermore, by knocking down these ligands individually or together in primary activated human T-cells, we demonstrated that CD44/HCELL, and not CD43, cooperates with PSGL-1 as a major E-selectin ligand. Additionally, we demonstrated the relevance of our findings to chronic autoimmune disease, by showing that CD44/HCELL and PSGL-1, but not CD43, from T-cells isolated from psoriasis patients, bind E-selectin.

  20. An Analysis of Trafficking Receptors Shows that CD44 and P-Selectin Glycoprotein Ligand-1 Collectively Control the Migration of Activated Human T-Cells

    KAUST Repository

    Ali, Amal J.

    2017-05-03

    Selectins guide the traffic of activated T-cells through the blood stream by mediating their tethering and rolling onto inflamed endothelium, in this way acting as beacons to help navigate them to sites of inflammation. Here, we present a comprehensive analysis of E-selectin ligands expressed on activated human T-cells. We identified several novel glycoproteins that function as E-selectin ligands. Specifically, we compared the role of P-selectin glycoprotein ligand-1 (PSGL-1) and CD43, known E-selectin ligands, to CD44, a ligand that has not previously been characterized as an E-selectin ligand on activated human T-cells. We showed that CD44 acts as a functional E-selectin ligand when expressed on both CD4+ and CD8+ T-cells. Moreover, the CD44 protein carries a binding epitope identifying it as hematopoietic cell E- and/or L-selectin ligand (HCELL). Furthermore, by knocking down these ligands individually or together in primary activated human T-cells, we demonstrated that CD44/HCELL, and not CD43, cooperates with PSGL-1 as a major E-selectin ligand. Additionally, we demonstrated the relevance of our findings to chronic autoimmune disease, by showing that CD44/HCELL and PSGL-1, but not CD43, from T-cells isolated from psoriasis patients, bind E-selectin.

  1. GDF11/BMP11 activates both smad1/5/8 and smad2/3 signals but shows no significant effect on proliferation and migration of human umbilical vein endothelial cells.

    Science.gov (United States)

    Zhang, Yong-Hui; Cheng, Feng; Du, Xue-Ting; Gao, Jin-Lai; Xiao, Xiao-Lin; Li, Na; Li, Shan-Liang; Dong, De Li

    2016-03-15

    GDF11/BMP11, a member of TGF-β superfamily, was reported to rejuvenate heart, skeletal muscle and blood vessel architecture in aged mice. However, the rejuvenative effects of GDF11 were questioned recently. Here, we investigated the effects of GDF11 on smad and non-smad signals in human umbilical vein endothelial cells (HUVECs) and the effects of GDF11 on proliferation and migration of HUVECs and primary rat aortic endothelial cells (RAECs). GDF11 factor purchased from two different companies (PeproTech and R&D Systems) was comparatively studied. Western blot was used to detect the protein expressions. The cell viability and migration were examined by using MTT and wound healing assays. Results showed that GDF11 activated both smad1/5/8 and smad2/3 signals in HUVECs. GDF11 increased protein expression of NADPH oxidase 4(NOX4) in HUVECs. GDF11 showed no significant effect on the protein level of p38, p-p38, ERK, p-ERK, Akt, p-Akt (Ser473) and p-Akt(Thr308), but increased the protein level of p-JNK and p-AMPK in HUVECs, and these increases were inhibited by antioxidant mitoTEMPO treatment. GDF11 slightly increased cell viability after short-term treatment and slightly decreased cell viability after long-term treatment. GDF11 showed no significant effect on cell proliferation and migration. These data indicated that the notion of GDF11 as a rejuvenation-related factor for endothelial cells needs to be cautious.

  2. Dcx reexpression reduces subcortical band heterotopia and seizure threshold in an animal model of neuronal migration disorder.

    Science.gov (United States)

    Manent, Jean-Bernard; Wang, Yu; Chang, Yoonjeung; Paramasivam, Murugan; LoTurco, Joseph J

    2009-01-01

    Disorders of neuronal migration can lead to malformations of the cerebral neocortex that greatly increase the risk of seizures. It remains untested whether malformations caused by disorders in neuronal migration can be reduced by reactivating cellular migration and whether such repair can decrease seizure risk. Here we show, in a rat model of subcortical band heterotopia (SBH) generated by in utero RNA interference of the Dcx gene, that aberrantly positioned neurons can be stimulated to migrate by reexpressing Dcx after birth. Restarting migration in this way both reduces neocortical malformations and restores neuronal patterning. We further find that the capacity to reduce SBH continues into early postnatal development. Moreover, intervention after birth reduces the convulsant-induced seizure threshold to a level similar to that in malformation-free controls. These results suggest that disorders of neuronal migration may be eventually treatable by reengaging developmental programs both to reduce the size of cortical malformations and to reduce seizure risk.

  3. Aberrant laryngeal location of Onchocerca lupi in a dog.

    Science.gov (United States)

    Alho, Ana Margarida; Cruz, Luís; Coelho, Ana; Martinho, Filipe; Mansinho, Mário; Annoscia, Giada; Lia, Riccardo P; Giannelli, Alessio; Otranto, Domenico; de Carvalho, Luís Madeira

    2016-06-01

    Onchocerca lupi (Spirurida, Onchocercidae) is an emerging vector-borne helminth that causes nodular lesions associated with acute or chronic ocular disease in dogs and cats. Since its first description in dogs in 1991, this zoonotic filarioid has been increasingly reported in Europe and the United States. An 8-year-old outdoor mixed-breed female dog from the Algarve (southern Portugal) was presented with a history of severe dyspnoea. Cervical and thoracic radiographs revealed a slight reduction in the diameter of the cervical trachea and a moderate increase in radiopacity of the laryngeal soft tissue. An exploratory laryngoscopy was performed, revealing filiform worms associated with stenosis of the thyroid cartilage and a purulent necrotic tissue in the larynx lumen. A single sessile nodule, protruding from the dorsal wall of the laryngeal lumen caused a severe reduction of the glottis and tracheal diameter. Fragments of the worms were morphologically and molecularly identified as O. lupi. Histological examination of the nodule showed a granulomatous reaction with sections of coiled gravid female nematodes. Following laryngoscopy, a tracheostomy tube was inserted to relieve dyspnoea and ivermectin (300 μg/kg, once a week, for 8 weeks) combined with prednisolone was prescribed. The dog showed a complete recovery. Although O. lupi has been isolated in human patients from the spinal cord, this is the first report of an aberrant migration of O. lupi in a dog. The veterinary medical community should pay attention to aberrant location of O. lupi and consider onchocercosis as a differential diagnosis for airway obstruction in dogs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Prospects for electron beam aberration correction using sculpted phase masks

    Energy Technology Data Exchange (ETDEWEB)

    Shiloh, Roy, E-mail: royshilo@post.tau.ac.il; Remez, Roei; Arie, Ady

    2016-04-15

    Technological advances in fabrication methods allowed the microscopy community to take incremental steps towards perfecting the electron microscope, and magnetic lens design in particular. Still, state of the art aberration-corrected microscopes are yet 20–30 times shy of the theoretical electron diffraction limit. Moreover, these microscopes consume significant physical space and are very expensive. Here, we show how a thin, sculpted membrane is used as a phase-mask to induce specific aberrations into an electron beam probe in a standard high resolution TEM. In particular, we experimentally demonstrate beam splitting, two-fold astigmatism, three-fold astigmatism, and spherical aberration. - Highlights: • Thin membranes can be used as aberration correctors in electron columns. • We demonstrate tilt, twofold-, threefold-astigmatism, and spherical aberrations. • Experimental and physical-optics simulation results are in good agreement. • Advantages in cost, size, nonmagnetism, and nearly-arbitrary correction.

  5. Higher-order aberrations and anisometropia.

    Science.gov (United States)

    Hartwig, Andreas; Atchison, David A; Radhakrishnan, Hema

    2013-01-01

    Myopia incidence is increasing around the world. Myopization is considered to be caused by a variety of factors. One consideration is whether higher-order aberrations (HOA) influence myopization. More knowledge of optics in anisometropic eyes might give further insight into the development of refractive error. To analyze the possible influence of HOA on refractive error development, we compared HOA between anisometropes and isometropes. We analyzed HOA up to the 4th order for both eyes of 20 anisometropes (mean age: 43 ± 17 years) and 20 isometropes (mean age: 33 ± 17 years). HOA were measured with the Shack-Hartman i.Profiler (Carl Zeiss, Germany) and were recalculated for a 4 mm pupil. Mean spherical equivalent (MSE) was based on the subjective refraction. Anisometropia was defined as ≥1 D interocular difference in MSE. The mean absolute differences between right and left eyes in spherical equivalent were 0.28 ± 0.21 D in the isometropic group and 2.81 ± 2.04 D in the anisometropic group. Interocular differences in HOA were compared with the interocular difference in MSE using correlations. For isometropes oblique trefoil, vertical coma, horizontal coma and spherical aberration showed significant correlations between the two eyes. In anisometropes, all analyzed higher-order aberrations correlated significantly between the two eyes except oblique secondary astigmatism and secondary astigmatism. When analyzing anisometropes and isometropes separately, no significant correlations were found between interocular differences of higher-order aberrations and MSE. For isometropes and anisometropes combined, tetrafoil correlated significantly with MSE in left eyes. The present study could not show that interocular differences of higher-order aberrations increase with increasing interocular difference in MSE.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, Fumio, E-mail: hosokawa@bio-net.co.jp [BioNet Ltd., 2-3-28 Nishikityo, Tachikwa, Tokyo (Japan); Tokyo Institute of Technology, 4259 Nagatsuta, Midoriku, Yokohama 226-8503 (Japan); Sawada, Hidetaka [JEOL (UK) Ltd., JEOL House, Silver Court, Watchmead, Welwyn Garden City, Herts AL7 1LT (United Kingdom); Shinkawa, Takao [BioNet Ltd., 2-3-28 Nishikityo, Tachikwa, Tokyo (Japan); Sannomiya, Takumi [Tokyo Institute of Technology, 4259 Nagatsuta, Midoriku, Yokohama 226-8503 (Japan)

    2016-08-15

    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. - Highlights: • The formula of partial coherence for aberration corrected TEM is derived. • Transfer functions are calculated with several residual aberrations. • The calculated transfer function shows the characteristic damping. • The odd-symmetric wave aberrations can cause the attenuation of image via coherence. • The examples of aberration corrected TEM image simulations are shown.

  7. Aberrant attachment of orbicularis oculi: Case report

    Directory of Open Access Journals (Sweden)

    Sehgal Ritu

    2005-01-01

    Full Text Available A morphological peculiarity was observed in the form of an aberrant lateral bony attachment of the orbital part of the Orbicularis oculi muscle on the zygomatic bone, during routine dissection of a cadaver of an adult male of Indian origin. Fibers of this part of the muscle are not known to show any lateral attachment on bone. This paper discusses the presentation, probable embryological cause and clinical implications of this unusual finding.

  8. Chromosome aberrations in solid tumors have a stochastic nature

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Mauro A.A. [Departamento de Bioquimica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600-anexo, Porto Alegre 90035-003 (Brazil) and Departamento de Medicina Interna, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2350, Porto Alegre 90035-903 (Brazil) and Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, Porto Alegre 91501-970 (Brazil) and Universidade Luterana do Brasil, Rua Miguel Tostes 101, Canoas 92420-280 (Brazil)]. E-mail: mauro@ufrgs.br; Onsten, Tor G.H. [Departamento de Medicina Interna, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2350, Porto Alegre 90035-903 (Brazil); Universidade Luterana do Brasil, Rua Miguel Tostes 101, Canoas 92420-280 (Brazil); Moreira, Jose C.F. [Departamento de Bioquimica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600-anexo, Porto Alegre 90035-003 (Brazil); Almeida, Rita M.C. de [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, Porto Alegre 91501-970 (Brazil)

    2006-08-30

    An important question nowadays is whether chromosome aberrations are random events or arise from an internal deterministic mechanism, which leads to the delicate task of quantifying the degree of randomness. For this purpose, we have defined several Shannon information functions to evaluate disorder inside a tumor and between tumors of the same kind. We have considered 79 different kinds of solid tumors with 30 or more karyotypes retrieved from the Mitelman Database of Chromosome Aberrations in Cancer. The Kaplan-Meier cumulative survival was also obtained for each solid tumor type in order to correlate data with tumor malignance. The results here show that aberration spread is specific for each tumor type, with high degree of diversity for those tumor types with worst survival indices. Those tumor types with preferential variants (e.g. high proportion of a given karyotype) have shown better survival statistics, indicating that aberration recurrence is a good prognosis. Indeed, global spread of both numerical and structural abnormalities demonstrates the stochastic nature of chromosome aberrations by setting a signature of randomness associated to the production of disorder. These results also indicate that tumor malignancy correlates not only with karyotypic diversity taken from different tumor types but also taken from single tumors. Therefore, by quantifying aberration spread, we could confront diverse models and verify which of them points to the most likely outcome. Our results suggest that the generating process of chromosome aberrations is neither deterministic nor totally random, but produces variations that are distributed between these two boundaries.

  9. Impact of primary aberrations on coherent lidar performance

    DEFF Research Database (Denmark)

    Hu, Qi; Rodrigo, Peter John; Iversen, Theis Faber Quist

    2014-01-01

    In this work we investigate the performance of a monostatic coherent lidar system in which the transmit beam is under the influence of primary phase aberrations: spherical aberration (SA) and astigmatism. The experimental investigation is realized by probing the spatial weighting function...... of the lidar system using different optical transceiver configurations. A rotating belt is used as a hard target. Our study shows that the lidar weighting function suffers from both spatial broadening and shift in peak position in the presence of aberration. It is to our knowledge the first experimental...... demonstration of these tendencies. Furthermore, our numerical and experimental results show good agreement. We also demonstrate how the truncation of the transmit beam affects the system performance. It is both experimentally and numerically proven that aberration effects have profound impact on the antenna...

  10. Astrocyte Hypertrophy Contributes to Aberrant Neurogenesis after Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Clark Robinson

    2016-01-01

    Full Text Available Traumatic brain injury (TBI is a widespread epidemic with severe cognitive, affective, and behavioral consequences. TBIs typically result in a relatively rapid inflammatory and neuroinflammatory response. A major component of the neuroinflammatory response is astrocytes, a type of glial cell in the brain. Astrocytes are important in maintaining the integrity of neuronal functioning, and it is possible that astrocyte hypertrophy after TBIs might contribute to pathogenesis. The hippocampus is a unique brain region, because neurogenesis persists in adults. Accumulating evidence supports the functional importance of these newborn neurons and their associated astrocytes. Alterations to either of these cell types can influence neuronal functioning. To determine if hypertrophied astrocytes might negatively influence immature neurons in the dentate gyrus, astrocyte and newborn neurons were analyzed at 30 days following a TBI in mice. The results demonstrate a loss of radial glial-like processes extending through the granule cell layer after TBI, as well as ectopic growth and migration of immature dentate neurons. The results further show newborn neurons in close association with hypertrophied astrocytes, suggesting a role for the astrocytes in aberrant neurogenesis. Future studies are needed to determine the functional significance of these alterations to the astrocyte/immature neurons after TBI.

  11. Rab23 Regulates Radial Migration of Projection Neurons via N-cadherin.

    Science.gov (United States)

    Hor, Catherine H H; Goh, Eyleen L K

    2018-02-06

    Radial migration of cortical projection neurons is a prerequisite for shaping a distinct multilayered cerebral cortex during mammalian corticogenesis. Members of Rab GTPases family were reported to regulate radial migration. Here, in vivo conditional knockout or in utero knockdown (KD) of Rab23 in mice neocortex causes aberrant polarity and halted migration of cortical projection neurons. Further investigation of the underlying mechanism reveals down-regulation of N-cadherin in the Rab23-deficient neurons, which is a cell adhesion protein previously known to modulate radial migration. (Shikanai M, Nakajima K, Kawauchi T. 2011. N-cadherin regulates radial glial fiber-dependent migration of cortical locomoting neurons. Commun Integr Biol. 4:326-330.) Interestingly, pharmacological inhibition of extracellular signal-regulated kinases (ERK1/2) also decreases the expression of N-cadherin, implicating an upstream effect of ERK1/2 on N-cadherin and also suggesting a link between Rab23 and ERK1/2. Further biochemical studies show that silencing of Rab23 impedes activation of ERK1/2 via perturbed platelet-derived growth factor-alpha (PDGFRα) signaling. Restoration of the expression of Rab23 or N-cadherin in Rab23-KD neurons could reverse neuron migration defects, indicating that Rab23 modulates migration through N-cadherin. These studies suggest that cortical neuron migration is mediated by a molecular hierarchy downstream of Rab23 via N-cadherin. © The Author(s) 2018. Published by Oxford University Press.

  12. Pten deletion causes mTorc1-dependent ectopic neuroblast differentiation without causing uniform migration defects.

    Science.gov (United States)

    Zhu, Guo; Chow, Lionel M L; Bayazitov, Ildar T; Tong, Yiai; Gilbertson, Richard J; Zakharenko, Stanislav S; Solecki, David J; Baker, Suzanne J

    2012-09-01

    Neuronal precursors, generated throughout life in the subventricular zone, migrate through the rostral migratory stream to the olfactory bulb where they differentiate into interneurons. We found that the PI3K-Akt-mTorc1 pathway is selectively inactivated in migrating neuroblasts in the subventricular zone and rostral migratory stream, and activated when these cells reach the olfactory bulb. Postnatal deletion of Pten caused aberrant activation of the PI3K-Akt-mTorc1 pathway and an enlarged subventricular zone and rostral migratory stream. This expansion was caused by premature termination of migration and differentiation of neuroblasts and was rescued by inhibition of mTorc1. This phenotype is reminiscent of lamination defects caused by Pten deletion in developing brain that were previously described as defective migration. However, live imaging in acute slices showed that Pten deletion did not cause a uniform defect in the mechanics of directional neuroblast migration. Instead, a subpopulation of Pten-null neuroblasts showed minimal movement and altered morphology associated with differentiation, whereas the remainder showed unimpeded directional migration towards the olfactory bulb. Therefore, migration defects of Pten-null neurons might be secondary to ectopic differentiation.

  13. The Art of Optical Aberrations

    Science.gov (United States)

    Wylde, Clarissa Eileen Kenney

    Art and optics are inseparable. Though seemingly opposite disciplines, the combination of art and optics has significantly impacted both culture and science as they are now known. As history has run its course, in the sciences, arts, and their fruitful combinations, optical aberrations have proved to be a problematic hindrance to progress. In an effort to eradicate aberrations the simple beauty of these aberrational forms has been labeled as undesirable and discarded. Here, rather than approach aberrations as erroneous, these beautiful forms are elevated to be the photographic subject in a new body of work, On the Bright Side. Though many recording methods could be utilized, this work was composed on classic, medium-format, photographic film using white-light, Michelson interferometry. The resulting images are both a representation of the true light rays that interacted on the distorted mirror surfaces (data) and the artist's compositional eye for what parts of the interferogram are chosen and displayed. A detailed description of the captivating interdisciplinary procedure is documented and presented alongside the final artwork, CCD digital reference images, and deformable mirror contour maps. This alluring marriage between the arts and sciences opens up a heretofore minimally explored aspect of the inextricable art-optics connection. It additionally provides a fascinating new conversation on the importance of light and optics in photographic composition.

  14. Corneal aberrations before and after small-incision cataract surgery.

    Science.gov (United States)

    Guirao, Antonio; Tejedor, Jaime; Artal, Pablo

    2004-12-01

    To study the effect of small-incision cataract surgery on the optical aberrations of the cornea. Corneal topography was measured before and after cataract surgery on 70 eyes of 70 patients. Monofocal foldable IOLs were implanted after phacoemulsification through a clear-cornea, 3.5-mm incision without suture. Corneal aberrations, up to the fifth order and 6-mm pupil, were calculated by ray-tracing from the corneal topography. Pre- and postoperative aberrations were compared in each patient and the optical changes induced by surgery investigated. The root mean square of the wave aberration slightly increased on average after surgery (pre, 0.65 +/- 0.46 microm; post, 0.85 +/- 0.63 microm). Most aberration terms were similar, averaged across the 70 patients, before and after surgery (spherical aberration: pre, 0.32 +/- 0.12 microm, and post, 0.34 +/- 0.19 microm; astigmatism: pre, 0.9 +/- 0.8 D, and post, 1.1 +/- 1.0 D; coma: pre, 0.27 +/- 0.18 microm, and post, 0.32 +/- 0.33 microm). However, in each patient, there were changes after surgery in the magnitude (either increasing or decreasing) and/or orientation of aberrations. The mean induced astigmatism was -1.0 +/- 0.9 D at the orientation of the surgical meridian. Induced trefoil also showed a predominant pattern at this direction. Patients with nasal incisions experienced larger changes. Small-incision surgery does not systematically degrade the optical quality of the anterior corneal surface. However, it introduces changes in some aberrations, especially in nonrotationally symmetric terms such as astigmatism, coma, and trefoil. The incision site plays a main role in the corneal changes after surgery.

  15. In-situ heating studies of gold nanoparticles in an aberration corrected transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, M J; Gai, P L; Boyes, E D [Department of Physics, University of York, Nanocentre, York, YO10 5DD (United Kingdom); Yoshida, K, E-mail: mw527@york.ac.u [Department of Chemistry, University of York, Nanocentre, York, YO10 5DD (United Kingdom)

    2010-07-01

    Gold nanoparticles have a high catalytic activity for CO oxidation at low temperatures providing they remain less than 5nm in diameter. Their structure and stability and the growth processes that occur during heating have been investigated using Angstrom resolution in-situ double aberration corrected transmission electron microscopy with a JEOL JEM-2200FS. Colloidal Au nanoparticles suspended in water, with mean diameters of 2nm and 5.6nm, have been deposited onto 3.5nm thin carbon supported on holey carbon grids and onto Si{sub 3}N{sub 4} membranes. Dynamic in-situ high resolution AC-TEM images show competitive sintering processes on the different supports. Whilst the 5.6nm particles were observed to be very stable on the carbon, the 2nm particles showed sintering predominantly through particle migration and coalescence, with particle migration occurring as early as {approx}200{sup 0}C, peaking at {approx}500{sup 0}C. In contrast Au nanoparticles on Si{sub 3}N{sub 4} membranes were observed to coalesce at {approx}180{sup 0}C, before Ostwald Ripening became the dominant growth process at higher temperatures. It is believed that atoms and small clusters migrate away from their original particle before becoming trapped on the Si{sub 3}N{sub 4} substrate. These trapped clusters then build up to form the small particles observed, before having sufficient energy to continue to migrate and join another larger particle at {approx}500{sup 0}C.

  16. Phase Aberrations in Diffraction Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Genomic aberrations in borderline ovarian tumors

    Directory of Open Access Journals (Sweden)

    Davidson Ben

    2010-02-01

    Full Text Available Abstract Background According to the scientific literature, less than 30 borderline ovarian tumors have been karyotyped and less than 100 analyzed for genomic imbalances by CGH. Methods We report a series of borderline ovarian tumors (n = 23 analyzed by G-banding and karyotyping as well as high resolution CGH; in addition, the tumors were analyzed for microsatellite stability status and by FISH for possible 6q deletion. Results All informative tumors were microsatellite stable and none had a deletion in 6q27. All cases with an abnormal karyotype had simple chromosomal aberrations with +7 and +12 as the most common. In three tumors with single structural rearrangements, a common breakpoint in 3q13 was detected. The major copy number changes detected in the borderline tumors were gains from chromosome arms 2q, 6q, 8q, 9p, and 13q and losses from 1p, 12q, 14q, 15q, 16p, 17p, 17q, 19p, 19q, and 22q. The series included five pairs of bilateral tumors and, in two of these pairs, informative data were obtained as to their clonal relationship. In both pairs, similarities were found between the tumors from the right and left side, strongly indicating that bilaterality had occurred via a metastatic process. The bilateral tumors as a group showed more aberrations than did the unilateral ones, consistent with the view that bilaterality is a sign of more advanced disease. Conclusion Because some of the imbalances found in borderline ovarian tumors seem to be similar to imbalances already known from the more extensively studied overt ovarian carcinomas, we speculate that the subset of borderline tumors with detectable imbalances or karyotypic aberrations may contain a smaller subset of tumors with a tendency to develop a more malignant phenotype. The group of borderline tumors with no imbalances would, in this line of thinking, have less or no propensity for clonal evolution and development to full-blown carcinomas.

  18. 'Migration & Integration'

    OpenAIRE

    Lisa Pilgram

    2011-01-01

    Migration, Integration : [kommunalpolitische Herausforderungen]. - Augsburg : Geo-Anwenderzentrum, [ca. 2004]. - XVIII, 281 S. - (Angewandte Sozialgeographie ; 49) (GEO-Taschenbuch). - Zugl.: Augsburg, Univ., Diss., 2003

  19. [Migration processes in small towns].

    Science.gov (United States)

    Makowska, K

    1988-10-01

    Changing migration patterns in Poland and their impact on small towns are analysed with a focus on the period since the 1950s. The analysis shows that although migration previously benefited major urban areas at the expense of small towns, the migration situation of small towns has recently improved.

  20. Ocular aberrations and wavefront aberrometry: A review

    Directory of Open Access Journals (Sweden)

    Holly A. Unterhorst

    2015-03-01

    Full Text Available Wavefront aberrations can be described as deviations of the wavefront exiting the eye froma reference wavefront that is aberration free and diffraction limited. Ocular aberrations canbe sub-categorised as lower and higher order aberrations. Ocular aberrations have promptedinterest amongst the ocular healthcare community owing to their influences on the visualfunctioning of patients as well as differences observed in ocular aberrations through the useof refractive surgery both pre- and post-operatively. Uncompensated refractive error remainsone of the most common reasons for which patients consult optometrists. Compensationof refractive error, or lower order aberrations, has become a routine procedure during anoptometric examination. However, there are some patients who experience visual symptomseven after their refractive errors have been compensated via spectacles or contact lenses.Higher-order aberrations may be the source of these visual disturbances. Refractive surgeryhas been found to influence and even induce various changes in higher-order aberrationspost-operatively, which in turn has led to increased interest in wavefront aberrations and howthe measurement of these aberrations can improve diagnosis and treatment within optometryand ophthalmology.

  1. Geography of European Migration

    Directory of Open Access Journals (Sweden)

    Zhitin Dmitry V.

    2016-08-01

    Full Text Available In recent decades, the role of international migration has increased dramatically in most European countries. The growth in migration has made some authors proclaim the beginning of a second Migration Period that could transform the social and cultural identity of Europe. The article presents an analysis of international migration geography in Europe in the last twenty-five years. The authors identify the main trends in migration, provide migration profiles of European countries, and propose a classification based on the recent changes in the migrant stock. Changes in the migrant stock (total emigration and immigration reflect the level of involvement in international and global processes. They can serve as an indicator of a country’s attractiveness for both foreigners and the country’s citizens. The study shows that European countries are increasingly split into ‘immigrant’ and ‘emigrant’ states. The authors describe spatial patterns of migration. The volume and localisation of migration flows in Europe are affected not only by cultural and historical circumstance, such as a colonial past or a common language. The scale of immigrant influx often does not depend on a donor country’s demographic potential or the level of its socio-economic development. The links between the place of origin and destination are often more complex than it might initially seem. The authors stress the importance of a differentiated immigration policy taking into account ethnic and cultural features of host societies.

  2. Gendering Migration

    Directory of Open Access Journals (Sweden)

    Mirjana Morokvašić

    2014-12-01

    Full Text Available Migration patterns, migration discourse and underlying representations, migrants’ experiences, obligations and duties as well as the expectations relative to their migration are gendered. Since the pioneering feminist migration scholars’ questioning of men as a universal reference and the invisibility of women or their stereotypical representations as dependents in the mainstream production of knowledge on migration, the scholarship has evolved considerably. It is argued in the paper that the ongoing process of cross-fertilization of developments in two separate epistemologies, each initially questioning monolithic and essentialist visions of a “migrant” on one hand and a “woman” on the other, produced a fecund subfield of research “migration and gender”. The paper provides an insight into this, reviewing work on the issues related to gendering different phases of migration. Bridging migration and gender brought to the top of research agendas issues that used to be on the margins, creating new visibilities but leaving out other gendered dimensions of complex realities of migrant experience.

  3. Temporal dynamics of ocular aberrations: monocular vs binocular vision.

    Science.gov (United States)

    Mira-Agudelo, A; Lundström, L; Artal, P

    2009-05-01

    The temporal dynamics of ocular aberrations are important for the evaluation of, e.g. the accuracy of aberration estimates, the correlation to visual performance, and the requirements for real-time correction with adaptive optics. Traditionally, studies on the eye's dynamic behavior have been performed monocularly, which might have affected the results. In this study we measured aberrations and their temporal dynamics both monocularly and binocularly in the relaxed and accommodated state for six healthy subjects. Temporal frequencies up to 100 Hz were measured with a fast-acquisition Hartmann-Shack wavefront sensor having an open field-of-view configuration which allowed fixation to real targets. Wavefront aberrations were collected in temporal series of 5 s duration during binocular and monocular vision with fixation targets at 5 m and 25 cm distance. As expected, a larger temporal variability was found in the root-mean-square wavefront error when the eye accommodated, mainly for frequencies lower than 30 Hz. A statistically-significant difference in temporal behavior between monocular and binocular viewing conditions was found. However, on average it was too small to be of practical importance, although some subjects showed a notably higher variability for the monocular case during near vision. We did find differences in pupil size with mono- and binocular vision but the pupil size temporal dynamics did not behave in the same way as the aberrations' dynamics.

  4. Prospects for electron beam aberration correction using sculpted phase masks.

    Science.gov (United States)

    Shiloh, Roy; Remez, Roei; Arie, Ady

    2016-04-01

    Technological advances in fabrication methods allowed the microscopy community to take incremental steps towards perfecting the electron microscope, and magnetic lens design in particular. Still, state of the art aberration-corrected microscopes are yet 20-30 times shy of the theoretical electron diffraction limit. Moreover, these microscopes consume significant physical space and are very expensive. Here, we show how a thin, sculpted membrane is used as a phase-mask to induce specific aberrations into an electron beam probe in a standard high resolution TEM. In particular, we experimentally demonstrate beam splitting, two-fold astigmatism, three-fold astigmatism, and spherical aberration. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Conformal dome aberration correction by designing the inner surface

    Science.gov (United States)

    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.

  6. Experimental demonstration of a light beam with superior aberration resilience.

    Science.gov (United States)

    Gaffar, Md; Kalita, Ranjan; Boruah, Bosanta R

    2016-10-01

    In this Letter, we present the experimental results of a focused light beam that exhibits superior resilience to various common monochromatic aberrations. The light beam, obtained by applying a helical phase mask on an azimuthally polarized beam, has an Airy pattern that is like a circularly symmetric focal spot. Our results show that the beam in the presence of aberrations has better performance in terms of the Strehl ratio and the effect on the radius of the encircled energy relative to a normal linearly polarized or circularly polarized beam. Our experimental results agree well with the corresponding theoretical results.

  7. Phase and birefringence aberration correction

    Science.gov (United States)

    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.

  8. Modelling the effects of secondary spherical aberration on refractive error, image quality and depth of focus.

    Science.gov (United States)

    Xu, Renfeng; Bradley, Arthur; López Gil, Norberto; Thibos, Larry N

    2015-01-01

    To examine the role of Zernike secondary spherical aberration and its component terms on refraction, image quality and depth of focus. Computational methods were used to define wavefronts with controlled levels of r(6) , r(4) and r(2) terms, and image quality associated with these terms for a range of target vergences. Target vergences that generated maximum image quality were used as an objective measures of refractive error. Unlike primary Zernike spherical aberration, which generates peak image quality with a near paraxial focus, in the absence of other higher order aberrations, peak image quality with secondary spherical aberration is achieved with a near marginal focus. When alone, positive primary and secondary spherical aberration induce small hyperopic shifts in refraction, but in the presence of other higher order aberrations, secondary spherical aberration can induce significant myopic shifts in refractive error, as predicted by the combined lower order r(4) & r(2) component of Z60. The predicted expansion in depth of focus associated with increased primary or secondary spherical aberration is mostly absent if a strict image quality criterion is applied. The expansion of depth of focus observed with a low image quality criterion when opposite sign Z40 and Z60 are combined is primarily due to the elevated r(4) term. Secondary Zernike spherical aberration can have a significant impact on refractive error, image quality and depth of focus, but mostly due to the lower order components within this polynomial. Our analysis shows that the r(6) term that defines secondary spherical aberration actually narrows rather than expands depth of focus, when in the presence of the r(4) term within Z60. Therefore, a multifocal lens generated with exclusively primary spherical aberration is likely to be more effective than one that includes opposite sign of primary and secondary spherical aberration. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College

  9. Aberrations of magnetooptical system of SALO recirculator

    Science.gov (United States)

    Guk, I. S.; Dovbnya, A. N.; Kononenko, S. G.; Peev, F. A.; Tarasenko, A. S.

    2010-12-01

    The influence of spatial and chromatic aberrations on the parameters of the 730 MeV beam extracted from a SALO recirculator is studied using numerical simulation. The influence of fringing fields and the heterogeneity of the guide field of dipole magnets on the beam parameters at the extraction point is studied for different orders and types of aberrations. Estimates of the contributions of the different types of aberrations to the extracted beam emittance are presented.

  10. Aberrant expression of STYK1 and E-cadherin confer a poor prognosis for pancreatic cancer patients.

    Science.gov (United States)

    Chen, Luguang; Ma, Chao; Bian, Yun; Shao, Chengwei; Wang, Tiegong; Li, Jing; Chong, Xiaodan; Su, Li; Lu, Jianping

    2017-12-19

    Previous studies showed that aberrant Serine/threonine/tyrosine kinase 1 (STYK1, also known as NOK) or/and E-cadherin were involved in the progression of some types of human cancers. However, whether they contributed to the development of pancreatic cancer was unknown. Here, we investigated the prognostic significance of aberrant STYK1 and E-cadherin in pancreatic cancer. Our results showed that STYK1 expression increased while E-cadherin decreased in pancreatic cancer tissues compared with normal pancreas tissues. STYK1 level was positively correlated with lymph node metastasis and clinical stage in pancreatic cancer patients. E-cadherin expression was inversely correlated with STYK1 expression in pancreatic cancer tissue samples. Patients with high STYK1 and low E-cadherin expression had the worst prognosis. In addition, STYK1 knockdown in pancreatic cancer cell lines inhibited cell proliferation, enhanced cell apoptosis, induced cell cycle arrest, and prohibited cell migration, while STYK1 over-expression showed the opposite effects. Silencing STYK1 also increased E-cadherin expression and inhibited epithelial-to-mesenchymal transition (EMT) and p-p38 expression in vitro. Over-expression had showed the opposite trends, and treatment with p38 inhibitor, SB203580, could reverse the trends. Thus, STYK1 repressed E-cadherin expression and promoted EMT, mediated by p38 MAPK signaling pathway, which was the possible mechanism for STYK1-mediated pancreatic cancer cell proliferation and migration. In summary, our results showed that STYK1 might be a prognostic marker for pancreatic cancer patients and might be a novel strategy for the treatment of pancreatic cancer.

  11. Cohort migration.

    Science.gov (United States)

    Taeuber, K E

    1966-06-01

    Most migration analyses focus on net migration and are concerned with areal redistributions of population. Migration may also be studied as an event in the life-cycle of an individual, and migration rates may be defined as properties of cohorts. A number of efforts to examine migration as a cohort process has been hampered by the character of available data [or the United States. Rather than await the development of a registration system-either directly or via social security and tax records-the collection of residence histories is suggested as the most feasible approach to obtaining suitable data. A schematic representation of residence histories clarifies their relation to other types of migration data and illustrates the need to design such surveys with specific research purposes in mind. Exploratory work with the 1958 Residence History Supplement to the Current Population Survey (by Beale, Shryock, myself, and various colleagues) demonstrates the utility of this approach.Local studies have made fruitful use of residence histories but typically are unable to delineate birth cohorts or other appropriate base populations exposed to risk. Development of cohort migration techniques analogous to the life table approach to mortality or cohort Jertility analysis requires national data. But migration, unlike Jertility and mortality, involves events that are reversible and repeatable. Hence the demographer's stock of analytic tools requires expansion. To the sociologist-demographer, experimentation with cohort migration models seems to be getting at one of the crucial methodological problems of sociology, the analysis of social mobility. A mutually profitable interchange with students of social mobility is envisaged.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    Shafer, David

    1986-10-01

    /or intelligent human thinker. Other writers who have emphasized this same theme before me, and whom I highly recommend, are Bob Hopkins, Jan Hoogland, and Erhard Glatzel. This paper will not attempt to review the many different design methods set forth in the papers just listed. It will, however, "walk through" the thinking behind just one optical design in a way which will show the enormous power and versatility of aberration theory as a design tool. It is my strong conviction that just about everything worth saying about the results and implications of aberration theory (which is highly mathematical) can be stated in ordinary English, so there will be no mathematics in this paper.

  14. Aberrant behavior of preschool children: Evaluation of questionnaire

    Directory of Open Access Journals (Sweden)

    Fajgelj Stanislav

    2007-01-01

    Full Text Available In the study metric characteristics of children aberrant behavior questionnaire were analyzed. The analysis was performed on the sample of 1.165 children, aged 4-7, in preschool institutions in several towns of Vojvodina. The questionnaire contained 36 items of the Likert-type scale and was filled in by one parent of each child. The authors examined main metric characteristics of the complete questionnaire, as well as individual items under the Rasche’s measurement model. Generally, parents seldom notice aberrant behavior in their children. Most frequently they notice stubbornness, while very rarely torturing of animals. The item discrimination, on the whole, was found satisfying. The reliability of the questionnaire is 0.84., and all indicators of misfit are within satisfactory ranges. According to differential functioning of the items, the authors found gender and age specificities of parents’ evaluation of aberrant behavior of their children. Parents often notice stubbornness and moldiness in girls, and aggression in boys. According to the parent’s observations, younger children are characterized by nail nibbling, ticklishness, and fearfulness, whereas older children show a tendency to force their way by crying, waywardness and bed-wetting. By means of factor analysis of the items, three principal facets of aberrant behavior were determined: overindulgence, shyness and quarrelsomeness. Cross validation (hold out showed that these three facets were robust in relation to the selection of the sample.

  15. WASP family proteins and formins compete in pseudopod- and bleb-based migration.

    Science.gov (United States)

    Davidson, Andrew J; Amato, Clelia; Thomason, Peter A; Insall, Robert H

    2017-11-30

    Actin pseudopods induced by SCAR/WAVE drive normal migration and chemotaxis in eukaryotic cells. Cells can also migrate using blebs, in which the edge is driven forward by hydrostatic pressure instead of actin. In Dictyostelium discoideum, loss of SCAR is compensated by WASP moving to the leading edge to generate morphologically normal pseudopods. Here we use an inducible double knockout to show that cells lacking both SCAR and WASP are unable to grow, make pseudopods or, unexpectedly, migrate using blebs. Remarkably, amounts and dynamics of actin polymerization are normal. Pseudopods are replaced in double SCAR/WASP mutants by aberrant filopods, induced by the formin dDia2. Further disruption of the gene for dDia2 restores cells' ability to initiate blebs and thus migrate, though pseudopods are still lost. Triple knockout cells still contain near-normal F-actin levels. This work shows that SCAR, WASP, and dDia2 compete for actin. Loss of SCAR and WASP causes excessive dDia2 activity, maintaining F-actin levels but blocking pseudopod and bleb formation and migration. © 2018 Davidson et al.

  16. The Distribution of Chromosomal Aberrations in Human Cells Predicted by a Generalized Time-Dependent Model of Radiation-Induced Formation of Aberrations

    Science.gov (United States)

    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.

  17. Contrast sensitivity with soft contact lenses compensated for spherical aberration in high ametropia.

    Science.gov (United States)

    De Brabander, J; Chateau, N; Bouchard, F; Guidollet, S

    1998-01-01

    In optical systems, it is usual to compensate for longitudinal spherical aberration. In order to increase image quality, lens surfaces can be made aspheric to bring all object light rays into focus at the image plane. Theoretically, soft contact lenses with high power and spherical surfaces show significant amounts of spherical aberration. The use of spherical aberration-free soft contact lenses could therefore improve retinal image quality in the case of high ametropia. However, because of ocular aberration, accommodation effects, pupil dynamics, contact lens flexure, and positioning, the computation of the spherical aberration induced when a contact lens is placed on the eye is complicated. In this study, the spatial contrast sensitivity (CS) of 61 high ametropes wearing soft contact lenses with, and without, in-air spherical aberration compensation is measured. A slightly better overall performance was found with the standard lenses. There was no significant influence by the type of ametropia, age, and gender. If individual results are considered, clinically significant differences between the two lens groups are observed in approximately 30% of the cases. It seems that correcting in-air soft contact lens spherical aberration systematically is of no clinical interest. However, selective manipulation of spherical aberration could, in high power soft contact lenses, significantly improve CS in individuals.

  18. Mechanisms for the induction of gastric cancer by Helicobacter pylori infection: aberrant DNA methylation pathway.

    Science.gov (United States)

    Maeda, Masahiro; Moro, Hiroshi; Ushijima, Toshikazu

    2017-03-01

    Multiple pathogenic mechanisms by which Helicobacter pylori infection induces gastric cancer have been established in the last two decades. In particular, aberrant DNA methylation is induced in multiple driver genes, which inactivates them. Methylation profiles in gastric cancer are associated with specific subtypes, such as microsatellite instability. Recent comprehensive and integrated analyses showed that many cancer-related pathways are more frequently altered by aberrant DNA methylation than by mutations. Aberrant DNA methylation can even be present in noncancerous gastric mucosae, producing an "epigenetic field for cancerization." Mechanistically, H. pylori-induced chronic inflammation, but not H. pylori itself, plays a direct role in the induction of aberrant DNA methylation. The expression of three inflammation-related genes, Il1b, Nos2, and Tnf, is highly associated with the induction of aberrant DNA methylation. Importantly, the degree of accumulated aberrant DNA methylation is strongly correlated with gastric cancer risk. A recent multicenter prospective cohort study demonstrated the utility of epigenetic cancer risk diagnosis for metachronous gastric cancer. Suppression of aberrant DNA methylation by a demethylating agent was shown to inhibit gastric cancer development in an animal model. Induction of aberrant DNA methylation is the major pathway by which H. pylori infection induces gastric cancer, and this can be utilized for translational opportunities.

  19. Chromosome aberration assays in Allium

    Energy Technology Data Exchange (ETDEWEB)

    Grant, W.F.

    1982-01-01

    The common onion (Allium cepa) is an excellent plant for the assay of chromosome aberrations after chemical treatment. Other species of Allium (A. cepa var. proliferum, A. carinatum, A. fistulosum and A. sativum) have also been used but to a much lesser extent. Protocols have been given for using root tips from either bulbs or seeds of Allium cepa to study the cytological end-points, such as chromosome breaks and exchanges, which follow the testing of chemicals in somatic cells. It is considered that both mitotic and meiotic end-points should be used to a greater extent in assaying the cytogenetic effects of a chemical. From a literature survey, 148 chemicals are tabulated that have been assayed in 164 Allium tests for their clastogenic effect. Of the 164 assays which have been carried out, 75 are reported as giving a positive reaction, 49 positive and with a dose response, 1 positive and temperature-related, 9 borderline positive, and 30 negative; 76% of the chemicals gave a definite positive response. It is proposed that the Allium test be included among those tests routinely used for assessing chromosomal damage induced by chemicals.

  20. Role of the nuclear migration protein Lis1 in cell morphogenesis in Ustilago maydis

    Science.gov (United States)

    Valinluck, Michael; Ahlgren, Sara; Sawada, Mizuho; Locken, Kristopher; Banuett, Flora

    2010-01-01

    Ustilago maydis is a basidiomycete fungus that exhibits a yeast-like and a filamentous form. Growth of the fungus in the host leads to additional morphological transitions. The different morphologies are characterized by distinct nuclear movements. Dynein and α-tubulin are required for nuclear movements and for cell morphogenesis of the yeast-like form. Lis1 is a microtubule plus-end tracking protein (+TIPs) conserved in eukaryotes and required for nuclear migration and spindle positioning. Defects in nuclear migration result in altered cell fate and aberrant development in metazoans, slow growth in fungi and disease in humans (e.g. lissencephaly). Here we investigate the role of the human LIS1 homolog in U. maydis and demonstrate that it is essential for cell viability, not previously seen in other fungi. With a conditional null mutation we show that lis1 is necessary for nuclear migration in the yeast-like cell and during the dimorphic transition. Studies of asynchronous exponentially growing cells and time-lapse microscopy uncovered novel functions of lis1: It is necessary for cell morphogenesis, positioning of the septum and cell wall integrity. lis1-depleted cells exhibit altered axes of growth and loss of cell polarity leading to grossly aberrant cells with clusters of nuclei and morphologically altered buds devoid of nuclei. Altered septum positioning and cell wall deposition contribute to the aberrant morphology. lis1-depleted cells lyse, indicative of altered cell wall properties or composition. We also demonstrate, with indirect immunofluorescence to visualize tubulin, that lis1 is necessary for the normal organization of the microtubule cytoskeleton: lis1-depleted cells contain more and longer microtubules that can form coils perpendicular to the long axis of the cell. We propose that lis1 controls microtubule dynamics and thus the regulated delivery of vesicles to growth sites and other cell domains that govern nuclear movements. PMID:20524583

  1. Migrating Worker

    DEFF Research Database (Denmark)

    Hansen, Hans

    This is the preliminary report on the results obtained in the Migrating Worker-project. This project was initiated by the Danish Ministry of Finance with the aim of illustrating the effects of the 1408/71 agreement and the bilateral double taxation agreements Denmark has with the countries included...

  2. Dateline Migration.

    Science.gov (United States)

    Tomasi, Lydio E., Ed.

    1995-01-01

    Presents data on international migration and its effects in and between various countries in North America, Europe, and Africa. Discussions include refugee, immigrant, and migrant worker flows; the legal, political, and social problems surrounding immigrants; alien terrorism and law enforcement problems; and migrant effects on education, social…

  3. Genetic and Molecular Approaches to Study Neuronal Migration in the Developing Cerebral Cortex.

    Science.gov (United States)

    Dudok, Jacobus J; Leonards, Pim E G; Wijnholds, Jan

    2017-05-05

    The migration of neuronal cells in the developing cerebral cortex is essential for proper development of the brain and brain networks. Disturbances in this process, due to genetic abnormalities or exogenous factors, leads to aberrant brain formation, brain network formation, and brain function. In the last decade, there has been extensive research in the field of neuronal migration. In this review, we describe different methods and approaches to assess and study neuronal migration in the developing cerebral cortex. First, we discuss several genetic methods, techniques and genetic models that have been used to study neuronal migration in the developing cortex. Second, we describe several molecular approaches to study aberrant neuronal migration in the cortex which can be used to elucidate the underlying mechanisms of neuronal migration. Finally, we describe model systems to investigate and assess the potential toxicity effect of prenatal exposure to environmental chemicals on proper brain formation and neuronal migration.

  4. Chromosomal aberrations in uranium and coal miners

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, G.; Arndt, D.; Kotschy-Lang, N.; Obe, G. [Robert Koch Inst., Berlin (Germany)

    2004-02-01

    Peripheral lymphocytes from 66 Wismut uranium miners (WUM) and 29 Ruhr coal miners (RGM) were cultured and analysed for structural chromosomal aberrations in Giemsa-stained M1 metaphases. Cytogenetic data from 23 male white-collar workers from public services were used as a historical control group. The frequencies of chromosomal aberrations and sister chromatid exchanges in WUM and RCM were quite similar. Compared with public services workers, WUM and RCM had significantly higher frequencies of chromosomal aberrations. It is concluded that chromosomal aberrations in WUM are not induced by radioactive particles inhaled during underground mining but as in RCM rather result from factors such as age, lifestyle, illnesses, medications and diagnostic irradiations.

  5. An aberrant precision account of autism

    National Research Council Canada - National Science Library

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

    2014-01-01

    ... (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...

  6. Aberration corrected Lorentz scanning transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    McVitie, S., E-mail: stephen.mcvitie@glasgow.ac.uk; McGrouther, D.; McFadzean, S.; MacLaren, D.A.; O’Shea, K.J.; Benitez, M.J.

    2015-05-15

    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. - Highlights: • Demonstration of nanometre scale resolution in magnetic field free environment using aberration correction in the scanning transmission electron microscope (STEM). • Implementation of differential phase contrast mode of Lorentz microscopy in aberration corrected STEM with improved sensitivity. • Quantitative imaging of magnetic induction of nanostructures in amorphous and cross-section samples.

  7. Epigenetic aberrations in myeloid malignancies (Review).

    Science.gov (United States)

    Takahashi, Shinichiro

    2013-09-01

    The development of novel technologies, such as massively parallel DNA sequencing, has led to the identification of several novel recurrent gene mutations, such as DNA methyltransferase (Dnmt)3a, ten-eleven-translocation oncogene family member 2 (TET2), isocitrate dehydrogenase (IDH)1/2, additional sex comb-like 1 (ASXL1), enhancer of zeste homolog 2 (EZH2) and ubiquitously transcribed tetratricopeptide repeat X chromosome (UTX) mutations in acute myeloid leukemia (AML) and other myeloid malignancies. These findings strongly suggest a link between recurrent genetic alterations and aberrant epigenetic regulations, resulting from an abnormal DNA methylation and histone modification status. This review focuses on the current findings of aberrant epigenetic signatures by these newly described genetic alterations. Moreover, epigenetic aberrations resulting from transcription factor aberrations, such as mixed lineage leukemia (MLL) rearrangement, ecotropic viral integration site 1 (Evi1) overexpression, chromosomal translocations and the downregulation of PU.1 are also described.

  8. Clinical importance of spherical and chromatic aberration on the accommodative response in contact lens wear

    Science.gov (United States)

    Wahlberg, M.; Lindskoog Pettersson, A.; Rosén, R.; Nilsson, M.; Unsbo, P.; Brautaset, R.

    2011-11-01

    The aim of this study was to evaluate the accommodation response under both mono- and polychromatic light while varying the amount of spherical aberration. It is thought that chromatic and spherical aberrations are directional cues for the accommodative system and could affect response time, velocity or lag. Spherical aberration is often eliminated in modern contact lenses in order to enhance image quality in the unaccommodated eye. This study was divided into two parts. The first part was done to evaluate the amount of spherical and other Zernike aberrations in the unaccommodated eye when uncorrected and with two types of correction (trial lens and spherical-aberration controlled contact lens) and the second part evaluated the dynamic accommodation responses obtained when wearing each of the corrections under polychromatic and monochromatic conditions. Measurements of accommodation showed no significant differences in time, velocity and lag of accommodation after decreasing the spherical aberration with a contact lens, neither in monochromatic nor polychromatic light. It is unlikely that small to normal changes of spherical aberration in white light or monochromatic mid-spectral light affect directional cues for the accommodative system, not in white light or mid-spectral monochromatic light, since the accommodative response did not show any change.

  9. Self-Selection Patterns in Mexico-U.S. Migration: The Role of Migration Networks

    OpenAIRE

    David McKenzie; Hillel Rapoport

    2010-01-01

    The authors examine the role of migration networks in determining self-selection patterns of Mexico-U.S. migration. They first present a simple theoretical framework showing how such networks impact on migration incentives at different education levels and, consequently, how they are likely to affect the expected skill composition of migration. Using survey data from Mexico, the authors th...

  10. Pulse compressor with aberration correction

    Energy Technology Data Exchange (ETDEWEB)

    Mankos, Marian [Electron Optica, Inc., Palo Alto, CA (United States)

    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

  11. MMP13 mediates cell cycle progression in melanocytes and melanoma cells: in vitro studies of migration and proliferation.

    NARCIS (Netherlands)

    Meierjohann, S.; Hufnagel, A.; Wende, E.; Kleinschmidt, M.A.; Wolf, K. van der; Friedl, P.H.A.; Gaubatz, S.; Schartl, M.

    2010-01-01

    BACKGROUND: Melanoma cells are usually characterized by a strong proliferative potential and efficient invasive migration. Among the multiple molecular changes that are recorded during progression of this disease, aberrant activation of receptor tyrosine kinases (RTK) is often observed. Activation

  12. Magnetic fluid based deformable mirror for aberration correction of liquid telescope

    Science.gov (United States)

    Wu, Jun-qiu; Wu, Zhi-zheng; Kong, Xiang-hui; Zhang, Zhu; Liu, Mei

    2017-03-01

    A magnetic fluid based deformable mirror (MFDM) that could produce a large stroke more than 100 μm is designed and demonstrated experimentally with respect to the characteristics of the aberration of the liquid telescope. Its aberration correction performance is verified by the co-simulation using COMSOL and MATLAB. Furthermore, the stroke performance of the MFDM and the decentralized linear quadratic Gaussian (LQG) mirror surface control approach are experimentally evaluated with a prototype of MFDM in an adaptive optics system to show its potential application for the large aberration correction of liquid telescopes.

  13. Transventricular Migration of Neurocysticercosis.

    Science.gov (United States)

    Shah, Abhidha; Vutha, Ravikiran; Sankhe, Shilpa; Goel, Atul

    2017-09-01

    The movements of a neurocysticercosis cyst within the ventricular cavity have been identified rarely. A 22-year old male patient presented with the main symptom of diplopia for about a week. Findings of the neurologic examination revealed bilateral sixth cranial nerve weakness. Investigations during the period showed an intraventricular tumor that migrated from lateral ventricle to the third ventricle and subsequently to the fourth ventricle. The lesion was resected from the fourth ventricle and was identified to be a neurocysticercosis cyst. Such an intraventricular migration of any kind of tumor has not been recorded in the literature. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Migration = cloning; aliasiing

    DEFF Research Database (Denmark)

    Hüttel, Hans; Kleist, Josva; Nestmann, Uwe

    1999-01-01

    In Obliq, a lexically scoped, distributed, object-oriented programming language, object migration was suggested as the creation of a copy of an object’s state at the target site, followed by turning the object itself into an alias, also called surrogate, for the remote copy. We consider the creat......In Obliq, a lexically scoped, distributed, object-oriented programming language, object migration was suggested as the creation of a copy of an object’s state at the target site, followed by turning the object itself into an alias, also called surrogate, for the remote copy. We consider...... the creation of object surrogates as an abstraction of the abovementioned style of migration. We introduce Øjeblik, a distribution-free subset of Obliq, and provide three different configuration-style semantics, which only differ in the respective aliasing model. We show that two of the semantics, one of which...... matches Obliq’s implementation, render migration unsafe, while our new proposal for a third semantics is provably safe. Our work suggests a straightforward repair of Obliq’s aliasing model such that it allows programs to safely migrate objects....

  15. Influence of cosmetically tinted soft contact lenses on higher-order wavefront aberrations and visual performance.

    Science.gov (United States)

    Hiraoka, Takahiro; Ishii, Yuko; Okamoto, Fumiki; Oshika, Tetsuro

    2009-02-01

    To investigate the influence of cosmetically tinted soft contact lenses on ocular higher-order aberrations and visual performance, and to analyze the relationship between these parameters after the lens wear. In 44 eyes of 22 subjects, visual acuity, contrast sensitivity under photopic and mesopic conditions, and ocular higher-order aberrations were evaluated before and after wearing the tinted soft contact lenses (1-day Acuvue Colours; Vistakon, Jacksonville, FL). Contrast sensitivity under a photopic condition was determined at 3, 6, 12, and 18 cycles per degree, and the area under the log contrast sensitivity function (AULCSF) was calculated. Mesopic contrast sensitivity with and without glare was assessed. Ocular higher-order aberrations for a 4-mm pupil were measured, and coma-like, spherical-like, and total higher-order aberrations were determined. The tinted contact lens wearing resulted in significant decreases in log contrast sensitivity at all spatial frequencies (P 0.05), the changes in total higher-order aberrations showed a significant correlation with those in AULCSF (P 0.05). Cosmetically tinted contact lenses increase ocular higher-order aberrations and worsen contrast sensitivity under both photopic and mesopic conditions. Increases in higher-order aberrations are responsible for decreased contrast sensitivity under the photopic condition. Tinted contact lens wearers should be sufficiently informed about the possible reduction in optical quality of the eye and quality of vision.

  16. Analysis of nodal aberration properties in off-axis freeform system design.

    Science.gov (United States)

    Shi, Haodong; Jiang, Huilin; Zhang, Xin; Wang, Chao; Liu, Tao

    2016-08-20

    Freeform surfaces have the advantage of balancing off-axis aberration. In this paper, based on the framework of nodal aberration theory (NAT) applied to the coaxial system, the third-order astigmatism and coma wave aberration expressions of an off-axis system with Zernike polynomial surfaces are derived. The relationship between the off-axis and surface shape acting on the nodal distributions is revealed. The nodal aberration properties of the off-axis freeform system are analyzed and validated by using full-field displays (FFDs). It has been demonstrated that adding Zernike terms, up to nine, to the off-axis system modifies the nodal locations, but the field dependence of the third-order aberration does not change. On this basis, an off-axis two-mirror freeform system with 500 mm effective focal length (EFL) and 300 mm entrance pupil diameter (EPD) working in long-wave infrared is designed. The field constant aberrations induced by surface tilting are corrected by selecting specific Zernike terms. The design results show that the nodes of third-order astigmatism and coma move back into the field of view (FOV). The modulation transfer function (MTF) curves are above 0.4 at 20 line pairs per millimeter (lp/mm) which meets the infrared reconnaissance requirement. This work provides essential insight and guidance for aberration correction in off-axis freeform system design.

  17. Migration and health.

    Science.gov (United States)

    Evans, J; Baldwin, W

    1987-01-01

    processes will consider all of the types of movement and characterize them as dynamic processes rather than as discrete events. The articles in this issue all touch on the ways in which migration can affect the health of migrants, and show the circle range of ways migration and health are interrelated. A special introductory note also suggests Acquired Immunodeficiency Syndrome (AIDS) should receive special attention in the study of this interrelationship. The uneven distribution of AIDS is heightening concern about the health implications for receiving countries.

  18. Substrate curvature regulates cell migration.

    Science.gov (United States)

    He, Xiuxiu; Jiang, Yi

    2017-05-23

    Cell migration is essential in many aspects of biology. Many basic migration processes, including adhesion, membrane protrusion and tension, cytoskeletal polymerization, and contraction, have to act in concert to regulate cell migration. At the same time, substrate topography modulates these processes. In this work, we study how substrate curvature at micrometer scale regulates cell motility. We have developed a 3D mechanical model of single cell migration and simulated migration on curved substrates with different curvatures. The simulation results show that cell migration is more persistent on concave surfaces than on convex surfaces. We have further calculated analytically the cell shape and protrusion force for cells on curved substrates. We have shown that while cells spread out more on convex surfaces than on concave ones, the protrusion force magnitude in the direction of migration is larger on concave surfaces than on convex ones. These results offer a novel biomechanical explanation to substrate curvature regulation of cell migration: geometric constrains bias the direction of the protrusion force and facilitates persistent migration on concave surfaces.

  19. Aberrant Phenotype in Iranian Patients with Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Mehdi Jahedi

    2014-03-01

    Full Text Available 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.

  20. Describing ocular aberrations with wavefront vergence maps.

    Science.gov (United States)

    Nam, Jayoung; Thibos, Larry N; Iskander, D Robert

    2009-05-01

    A common optometric problem is to specify the eye's ocular aberrations in terms of Zernike coefficients and to reduce that specification to a prescription for the optimum sphero-cylindrical correcting lens. The typical approach is first to reconstruct wavefront phase errors from measurements of wavefront slopes obtained by a wavefront aberrometer. This paper applies a new method to this clinical problem that does not require wavefront reconstruction. Instead, we base our analysis of axial wavefront vergence as inferred directly from wavefront slopes. The result is a wavefront vergence map that is similar to the axial power maps in corneal topography and hence has a potential to be favoured by clinicians. We use our new set of orthogonal Zernike slope polynomials to systematically analyse details of the vergence map analogous to Zernike analysis of wavefront maps. The result is a vector of slope coefficients that describe fundamental aberration components. Three different methods for reducing slope coefficients to a spherocylindrical prescription in power vector forms are compared and contrasted. When the original wavefront contains only second order aberrations, the vergence map is a function of meridian only and the power vectors from all three methods are identical. The differences in the methods begin to appear as we include higher order aberrations, in which case the wavefront vergence map is more complicated. Finally, we discuss the advantages and limitations of vergence map representation of ocular aberrations.

  1. Apoptosis-Like Cell Death Induction and Aberrant Fibroblast Properties in Human Incisional Hernia Fascia

    Science.gov (United States)

    Diaz, Ramon; Quiles, Maria T.; Guillem-Marti, Jordi; Lopez-Cano, Manuel; Huguet, Pere; Ramon-y-Cajal, Santiago; Reventos, Jaume; Armengol, Manel; Arbos, Maria A.

    2011-01-01

    Incisional hernia often occurs following laparotomy and can be a source of serious problems. Although there is evidence that a biological cause may underlie its development, the mechanistic link between the local tissue microenvironment and tissue rupture is lacking. In this study, we used matched tissue-based and in vitro primary cell culture systems to examine the possible involvement of fascia fibroblasts in incisional hernia pathogenesis. Fascia biopsies were collected at surgery from incisional hernia patients and non-incisional hernia controls. Tissue samples were analyzed by histology and immunoblotting methods. Fascia primary fibroblast cultures were assessed at morphological, ultrastructural, and functional levels. We document tissue and fibroblast loss coupled to caspase-3 activation and induction of apoptosis-like cell-death mechanisms in incisional hernia fascia. Alterations in cytoskeleton organization and solubility were also observed. Incisional hernia fibroblasts showed a consistent phenotype throughout early passages in vitro, which was characterized by significantly enhanced cell proliferation and migration, reduced adhesion, and altered cytoskeleton properties, as compared to non-incisional hernia fibroblasts. Moreover, incisional hernia fibroblasts displayed morphological and ultrastructural alterations compatible with autophagic processes or lysosomal dysfunction, together with enhanced sensitivity to proapoptotic challenges. Overall, these data suggest an ongoing complex interplay of cell death induction, aberrant fibroblast function, and tissue loss in incisional hernia fascia, which may significantly contribute to altered matrix maintenance and tissue rupture in vivo. PMID:21641387

  2. Refractive surgery, optical aberrations, and visual performance.

    Science.gov (United States)

    Applegate, R A; Howland, H C

    1997-01-01

    Visual optics is taking on new clinical significance. Given that current refractive procedures can and do induce large amounts of higher order ocular aberration that often affects the patient's daily visual function and quality of life, we can no longer relegate the considerations of ocular aberrations to academic discussions. Instead, we need to move toward minimizing (not increasing) the eye's aberrations at the same time we are correcting the eye's spherical and cylindrical refractive error. These are exciting times in refractive surgery, which need to be tempered by the fact that after all the research, clinical, and marketing dust settles, the level to which we improve the quality of the retinal image will be guided by the trade-off between cost and the improvement in the quality of life that refractive surgery offers.

  3. An aberrant precision account of autism.

    Directory of Open Access Journals (Sweden)

    Rebecca P Lawson

    2014-05-01

    Full Text Available Autism is a neurodevelopmental disorder characterised by problems with social-communication, restricted interests and repetitive behaviour. A recent and controversial article presented a compelling 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 interference 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.

  4. Optical aberrations in professional baseball players.

    Science.gov (United States)

    Kirschen, David G; Laby, Daniel M; Kirschen, Matthew P; Applegate, Raymond; Thibos, Larry N

    2010-03-01

    To determine the presence, type, and size of optical higher-order aberrations (HOAs) in professional athletes with superior visual acuity and to compare them with those in an age-matched population of nonathletes. Vero Beach and Fort Myers, Florida, USA. Players from 2 professional baseball teams were studied. Each player's optical aberrations were measured with a naturally dilated 4.0 mm pupil using a Z-Wave aberrometer and a LADARWave aberrometer. One hundred sixty-two players (316 eyes) were evaluated. The HOAs were less than 0.026 mum in all cases. Spherical aberration C(4,0) was the largest aberration with both aberrometers. There were small but statistically significant differences between the aberrometers in mean values for trefoil C(3,3) and C(3,-3) and secondary astigmatism C(4,2). Although statistically significant, the differences were clinically insignificant, being similar at approximately 0.031 diopter (D) of spherical power. A statistically significant difference was found between the professional baseball players and the control population in trefoil C(3,-3). These differences were clinically insignificant, similar to 0.071 D of spherical power. Professional baseball players have small higher-order optical aberrations when tested with naturally dilated pupils. No clinically significant differences were found between the 2 aberrometers. Statistically significant differences in trefoil were found between the players and the control population; however, the difference was clinically insignificant. It seems as though the visual system of professional baseball players is limited by lower-order aberrations and that the smaller HOAs do not enhance visual function over that in a control population. Copyright 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  5. Influences of environmental cues, migration history and habitat familiarity on partial migration

    DEFF Research Database (Denmark)

    Skov, Christian; Aarestrup, Kim; Baktoft, Henrik

    2010-01-01

    The factors that drive partial migration in organisms are not fully understood. Roach (Rutilus rutilus), a freshwater fish, engage in partial migration where parts of populations switch between summer habitats in lakes and winter habitats in connected streams. To test if the partial migration trait...... is phenotypically plastic or has genetic components, we translocated roach from 2 populations with different opportunities for migration to a lake with migration opportunity, containing a local roach population. This enabled monitoring of partial migration of fish in 3 different situations: 1) previous opportunity...... in the lake with migration opportunity where from group 2 fish were translocated. Directional migration in and out of the lakes was monitored using Passive Integrated Transponder technology. Translocated fish with previous migration opportunity showed migration patterns more similar to local fish than...

  6. Ocular Chromatic Aberrations and Their Effects on Polychromatic Retinal Image Quality

    Science.gov (United States)

    Zhang, Xiaoxiao

    Previous studies of ocular chromatic aberrations have concentrated on chromatic difference of focus (CDF). Less is known about the chromatic difference of image position (CDP) in the peripheral retina and no experimental attempt has been made to measure the ocular chromatic difference of magnification (CDM). Consequently, theoretical modelling of human eyes is incomplete. The insufficient knowledge of ocular chromatic aberrations is partially responsible for two unsolved applied vision problems: (1) how to improve vision by correcting ocular chromatic aberration? (2) what is the impact of ocular chromatic aberration on the use of isoluminance gratings as a tool in spatial-color vision?. Using optical ray tracing methods, MTF analysis methods of image quality, and psychophysical methods, I have developed a more complete model of ocular chromatic aberrations and their effects on vision. The ocular CDM was determined psychophysically by measuring the tilt in the apparent frontal parallel plane (AFPP) induced by interocular difference in image wavelength. This experimental result was then used to verify a theoretical relationship between the ocular CDM, the ocular CDF and the entrance pupil of the eye. In the retinal image after correcting the ocular CDF with existing achromatizing methods, two forms of chromatic aberration (CDM and chromatic parallax) were examined. The CDM was predicted by theoretical ray tracing and measured with the same method used to determine ocular CDM. The chromatic parallax was predicted with a nodal ray model and measured with the two-color vernier alignment method. The influence of these two aberrations on polychromatic MTF were calculated. Using this improved model of ocular chromatic aberration, luminance artifacts in the images of isoluminance gratings were calculated. The predicted luminance artifacts were then compared with experimental data from previous investigators. The results show that: (1) A simple relationship exists between

  7. Chromosome aberrations in ataxia telangiectasia cells exposed to heavy ions

    Science.gov (United States)

    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.

  8. Nutritional rehabilitation of mitochondrial aberrations in aplastic anaemia.

    Science.gov (United States)

    He, Ling; Miao, Xiaoyan; Lv, Guangyan; Yang, Peiman; Wu, Wenguo; Jia, Li

    2011-04-01

    Aplastic anaemia (AA) is a disease characterised by bone marrow hypocellularity and peripheral blood pancytopenia. AA is also associated with mitochondrial aberrations. The present study was undertaken primarily to test the hypothesis that a nutrient mixture could affect the nutritional rehabilitation of mitochondrial aberrations in AA mice. BALB/c AA mice were induced by a combination of hypodermic injections of acetylphenylhydrazine (100 mg/kg), X-rays (2·0 Gy) and intraperitoneal injections of cyclophosphamide (80 mg/kg). We treated these mice with nutrient mixture-supplemented diets in a dose-dependent manner (1445·55, 963·7, 674·59 mg/kg per d), and the effects of the nutrient mixture for mitochondrial rehabilitation were analysed in AA mice. Transmission electron microscopy showed that mitochondrial ultrastructural abnormalities in bone marrow cells, splenocytes and hepatocytes of the nutrient mixture groups were restored markedly, compared with the AA group. Mitochondrial membrane potentials of the nutrient mixture groups were increased remarkably. Western blot analysis also revealed that the nutrient mixture significantly inhibited cytochrome c release of mitochondria in the AA group. Furthermore, the mitochondrial DNA content of the nutrient mixture groups was also increased. Our data suggest that the nutrient mixture may promote the rehabilitation of mitochondrial aberrations, and consequently protects against mitochondrial dysfunction in AA mice.

  9. Aberrant behavior and cognitive ability in preschool children

    Directory of Open Access Journals (Sweden)

    Bala Gustav

    2007-01-01

    Full Text Available The sample included 712 preschool boys and girls at the age of 4 to 7 years (mean 5.96 decimal years and standard deviation .96 from preschool institutions in Novi Sad, Sombor, Sremska Mitrovica and Bačka Palanka. Information concerning 36 indicators of aberrant behavior of the children were supplied by their parents, whereas their cognitive ability was tested by Raven’s progressive colored matrices. Based on factor analysis (promax method, four factors i.e. generators of aberrant behavior in children were singled out: aggression, anxiousness, dissociation, and hysteria, whose relations with cognitive functioning and age were also analyzed by factor analysis. Aberrant behavior and cognitive abilities show significant interrelatedness. Owing to orderly developed cognitive abilities, a child understands essence and reality of problems, realizes possibilities and manners of solving them, and succeeds in realizing successful psycho-social functioning. Developed cognitive abilities enable a child to recognize and understand her/his own reactions in different situations and develop manners of reacting, which leads to strengthening psycho-social safety and adapting behavior in accordance with her/his age and abilities.

  10. Aberration production using a high-resolution liquid-crystal spatial light modulator.

    Science.gov (United States)

    Schmidt, Jason D; Goda, Matthew E; Duncan, Bradley D

    2007-05-01

    Phase-only liquid-crystal spatial light modulators provide a powerful means of wavefront control. With high resolution and diffractive (modulo 2pi) operation, they can accurately represent large-dynamic-range phase maps. As a result, they provide an excellent means of producing electrically controllable, dynamic, and repeatable aberrations. However, proper calibration is critical to achieving accurate phase maps. Several calibration methods from previous literature were considered. With simplicity and accuracy in mind, we selected one method for each type of necessary calibration. We augmented one of the selected methods with a new step that improves its accuracy. After calibrating our spatial light modulator with our preferred methods, we evaluated its ability to produce aberrations in the laboratory. We studied Zernike polynomial aberrations using interferometry and Fourier-transform-plane images, and atmospheric aberrations using a Shack-Hartmann wavefront sensor. These measurements show the closest agreement with theoretical expectations that we have seen to date.

  11. Optimizing coronagraph designs to minimize their contrast sensitivity to low-order optical aberrations

    Science.gov (United States)

    Green, Joseph J.; Shaklan, Stuart B.

    2003-11-01

    The presence of optical aberrations in the entrance pupil of a coronagraph causes the stellar light to scatter about the occulting spot, reducing the effective contrast achievable. Even if these aberrations are sufficiently corrected with a deformable mirror to enable planet detection, small drifts in the optical alignment of the telescope introduce additional low-order aberrations. The design parameters of the coronagraph itself (e.g. occulting spot size, Lyot stop diameter, etc.) affect how these aberrations impact the contrast in the focal plane. In this study, we examine the sensitivity of contrast to low-order optical errors for several coronagraph concepts over their respective design parameters. By combining these sensitivities with the telescope throughput, we show that for each coronagraph concept there is an optimum selection of the design parameters that provides efficient, high-contrast imaging at the inner working distance in the presence of alignment errors.

  12. Digital aberration correction of fluorescent images with coherent holographic image reconstruction by phase transfer (CHIRPT)

    Science.gov (United States)

    Field, Jeffrey J.; Bartels, Randy A.

    2016-03-01

    Coherent holographic image reconstruction by phase transfer (CHIRPT) is an imaging method that permits digital holographic propagation of fluorescent light. The image formation process in CHIRPT is based on illuminating the specimen with a precisely controlled spatio-temporally varying intensity pattern. This pattern is formed by focusing a spatially coherent illumination beam to a line focus on a spinning modulation mask, and image relaying the mask plane to the focal plane of an objective lens. Deviations from the designed spatio-temporal illumination pattern due to imperfect mounting of the circular modulation mask onto the rotation motor induce aberrations in the recovered image. Here we show that these aberrations can be measured and removed non-iteratively by measuring the disk aberration phase externally. We also demonstrate measurement and correction of systematic optical aberrations in the CHIRPT microscope.

  13. Measuring International Migration in Azerbaijan

    Directory of Open Access Journals (Sweden)

    Serhat Yüksel

    2018-01-01

    Full Text Available International migration significantly affects economic, social, cultural, and political factors of the country. Owing to this situation, it can be said that the reasons of international migration should be analyzed in order to control this problem. The purpose of this study is to determine the influencing factors of international migration in Azerbaijan. In this scope, annual data of 11 explanatory variables for the period of 1995–2015 was analyzed via Multivariate Adaptive Regression Splines (MARS method. According to the results of this analysis, it was identified that people prefer to move other countries in case of high unemployment rates. In addition, the results of the study show that population growth and high mortality rate increases the migration level. While considering these results, it was recommended that Azerbaijan should focus on these aspects to control international migration problem.

  14. A Foreign Body Aspiration Showing Migration and Penetration: Hordeum Murinum

    Directory of Open Access Journals (Sweden)

    Duygu Mergan

    2012-10-01

    Full Text Available Aspiration of foreign bodies is an important cause of mortality and morbidity in the childhood period. Very rarely seen among the tracheobronchial foreign body aspirations is the Hordeum Murinum, which has an atypical clinical presentation. It may cause unavoidable sequelae in the bronchial system requiring surgery, like bronchiectasis and destruction of the lung parenchyma in patients with delayed diagnosis. Hordeum Murinum, which is hard to pull out due to its progressive nature, may cause interesting clinical pictures. In this study, a case of Hordeum Murinum aspiration is reported which has been diagnosed early due to hemopty-sis could be pulled out by thoracotomy after negative bronchoscopy.

  15. [Rural migration in Poland].

    Science.gov (United States)

    Rakowski, W

    1985-01-01

    Migration of the rural population in Poland from 1946 to 1983 is analyzed, with a focus on rural-urban migration. Consideration is given to regional variations in migration patterns, the causes of migration, and the impact of migration on areas of origin.

  16. Temporal Dependence of Chromosomal Aberration on Radiation Quality and Cellular Genetic Background

    Science.gov (United States)

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

    2017-01-01

    Radiation induced cancer risks are driven by genetic instability. It is not well understood how different radiation sources induce genetic instability in cells with different genetic background. Here we report our studies on genetic instability, particularly chromosome instability using fluorescence in situ hybridization (FISH), in human primary lymphocytes, normal human fibroblasts, and transformed human mammary epithelial cells in a temporal manner after exposure to high energy protons and Fe ions. The chromosome spread was prepared 48 hours, 1 week, 2 week, and 1 month after radiation exposure. Chromosome aberrations were analyzed with whole chromosome specific probes (chr. 3 and chr. 6). After exposure to protons and Fe ions of similar cumulative energy (??), Fe ions induced more chromosomal aberrations at early time point (48 hours) in all three types of cells. Over time (after 1 month), more chromosome aberrations were observed in cells exposed to Fe ions than in the same type of cells exposed to protons. While the mammary epithelial cells have higher intrinsic genetic instability and higher rate of initial chromosome aberrations than the fibroblasts, the fibroblasts retained more chromosomal aberration after long term cell culture (1 month) in comparison to their initial frequency of chromosome aberration. In lymphocytes, the chromosome aberration frequency at 1 month after exposure to Fe ions was close to unexposed background, and the chromosome aberration frequency at 1 month after exposure to proton was much higher. In addition to human cells, mouse bone marrow cells isolated from strains CBA/CaH and C57BL/6 were irradiated with proton or Fe ions and were analyzed for chromosome aberration at different time points. Cells from CBA mice showed similar frequency of chromosome aberration at early and late time points, while cells from C57 mice showed very different chromosome aberration rate at early and late time points. Our results suggest that relative

  17. Orthonormal aberration polynomials for anamorphic optical imaging systems with circular pupils.

    Science.gov (United States)

    Mahajan, Virendra N

    2012-06-20

    In a recent paper, we considered the classical aberrations of an anamorphic optical imaging system with a rectangular pupil, representing the terms of a power series expansion of its aberration function. These aberrations are inherently separable in the Cartesian coordinates (x,y) of a point on the pupil. Accordingly, there is x-defocus and x-coma, y-defocus and y-coma, and so on. We showed that the aberration polynomials orthonormal over the pupil and representing balanced aberrations for such a system are represented by the products of two Legendre polynomials, one for each of the two Cartesian coordinates of the pupil point; for example, L(l)(x)L(m)(y), where l and m are positive integers (including zero) and L(l)(x), for example, represents an orthonormal Legendre polynomial of degree l in x. The compound two-dimensional (2D) Legendre polynomials, like the classical aberrations, are thus also inherently separable in the Cartesian coordinates of the pupil point. Moreover, for every orthonormal polynomial L(l)(x)L(m)(y), there is a corresponding orthonormal polynomial L(l)(y)L(m)(x) obtained by interchanging x and y. These polynomials are different from the corresponding orthogonal polynomials for a system with rotational symmetry but a rectangular pupil. In this paper, we show that the orthonormal aberration polynomials for an anamorphic system with a circular pupil, obtained by the Gram-Schmidt orthogonalization of the 2D Legendre polynomials, are not separable in the two coordinates. Moreover, for a given polynomial in x and y, there is no corresponding polynomial obtained by interchanging x and y. For example, there are polynomials representing x-defocus, balanced x-coma, and balanced x-spherical aberration, but no corresponding y-aberration polynomials. The missing y-aberration terms are contained in other polynomials. We emphasize that the Zernike circle polynomials, although orthogonal over a circular pupil, are not suitable for an anamorphic system as

  18. The correction of electron lens aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Hawkes, P.W., E-mail: peter.hawkes@cemes.fr

    2015-09-15

    The progress of electron lens aberration correction from about 1990 onwards is chronicled. Reasonably complete lists of publications on this and related topics are appended. A present for Max Haider and Ondrej Krivanek in the year of their 65th birthdays. By a happy coincidence, this review was completed in the year that both Max Haider and Ondrej Krivanek reached the age of 65. It is a pleasure to dedicate it to the two leading actors in the saga of aberration corrector design and construction. They would both wish to associate their colleagues with such a tribute but it is the names of Haider and Krivanek (not forgetting Joachim Zach) that will remain in the annals of electron optics, next to that of Harald Rose. I am proud to know that both regard me as a friend as well as a colleague. - Highlights: • Geometrical aberration correction. • Chromatic aberration correction. • 50 pm resolution. • High-resolution electron energy-loss spectroscopy. • Extensive bibliographies.

  19. Chromosomal aberrations induced by Markhamia tomentosa (Benth ...

    African Journals Online (AJOL)

    Markhamia tomentosa (Benth.) K. Schum. Ex Engl. (Bignoniaceae) is used traditionally in the treatment of pain, oedema, pulmonary troubles and cancer. The genotoxic and cytotoxic effects of the ethanolic extract of the leaves of M. tomentosa was investigated using the Allium cepa root chromosomal aberration assay.

  20. Anti-forensics of chromatic aberration

    Science.gov (United States)

    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.

  1. Migration of birds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the migration of birds. Topics covered include why birds migrate, when birds migrate, speed, altitude, courses, distance, major flyways and...

  2. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    overlay maps of effort to try and remove any induced artefacts in the data. Differences in timing or the route of migration has often been studies separately. Lokki and Saurola (Lokki & Saurola, 2004 develop an omnibus procedure to test if the migration timing and/or route differ among two populations of birds (e.g. males vs females. It uses a randomization test to calibrate the test statistic. However, it makes the key assumptions about equal recovery effort in time and space so that the method may be most applicable to comparison among species with similar migration timing and movement to keep differential sighting/recovery rates from affecting the result. Of course, it is in these cases where it is most difficulty to separate the groups which will require substantial samples to have good performance. Thorup and Rahbek (Thorup & Rahbek, 2004 provide a framework for accounting for unequal spatial recovery probability investigating the geometric influence of ocean and sea on observed migratory patterns. Taking the data set of Pied Flycatchers (Ficedula hypoleuca ringed as nestlings in Scandinavia and recovered en route on their initial migration and using a model based on the clock–and–compass innate navigation hypothesis they are showing that geometric constraints explain quite a bit of the variation in ring–recoveries. The model also shows that ring recovery patterns do reflect the migratory patterns, and that they are suitable for an analysis of the concentration of the migratory route which is important for the general use of ringing data in studies of migration. This is important for the general use of ringing data in studies of migration and dispersal. The new approach has also implications for understanding the migratory orientation program. The compiled papers highlight some novel ideas of how to analyse band recoveries to investigate migration routes and migration behaviour as well as dispersal patterns among birds and dolphins. Multistate modeling appears

  3. Syrian Crisis and Migration

    OpenAIRE

    Pinar Yazgan; Deniz Eroglu Utku; Ibrahim Sirkeci

    2015-01-01

    With the growing insurrections in Syria in 2011, an exodus in large numbers have emerged. The turmoil and violence have caused mass migration to destinations both within the region and beyond. The current "refugee crisis" has escalated sharply and its impact is widening from neighbouring countries toward Europe. Today, the Syrian crisis is the major cause for an increase in displacement and the resultant dire humanitarian situation in the region. Since the conflict shows no signs of abating i...

  4. Corneal aberration changes after rigid gas permeable contact lens wear in keratokonic patients.

    Science.gov (United States)

    Shokrollahzadeh, Fereshteh; Hashemi, Hassan; Jafarzadehpur, Ebrahim; Mirzajani, Ali; Khabazkhoob, Mehdi; Yekta, Abbasali; Asgari, Soheila

    2016-12-01

    To determine the short-term effect of rigid gas permeable (RGP) contact lenses on corneal aberrations in keratoconic patients. Sixteen keratoconic eyes with no history of RGP lens wear were included. They all had corneal aberrometry using Pentacam, and different aberration indices of the anterior and posterior surfaces of the cornea were measured before and 3 months after fitting RGP lenses. The effect of baseline parameters on these changes was tested in univariate and multiple models. Total aberrations and individual Zernike coefficients did not show statistically significant changes after using RGP lenses. Although not statistically significant, vertical coma decreased in the anterior (p = 0.073) and posterior surface (p = 0.095). Relationships that remained statistically significant in the multiple model were between baseline central corneal thickness and changes in total higher order aberrations and anterior 4th order astigmatism 0°, and between baseline 2nd order astigmatism 45° and its changes. In this study, corneal aberrations remained unchanged 3 months after wearing RGP contact lens. Further studies with sufficient samples in different groups of keratoconus severity or baseline aberrations are needed to obtain more accurate results.

  5. Evolution with Stochastic Fitness and Stochastic Migration

    Science.gov (United States)

    Rice, Sean H.; Papadopoulos, Anthony

    2009-01-01

    Background Migration between local populations plays an important role in evolution - influencing local adaptation, speciation, extinction, and the maintenance of genetic variation. Like other evolutionary mechanisms, migration is a stochastic process, involving both random and deterministic elements. Many models of evolution have incorporated migration, but these have all been based on simplifying assumptions, such as low migration rate, weak selection, or large population size. We thus have no truly general and exact mathematical description of evolution that incorporates migration. Methodology/Principal Findings We derive an exact equation for directional evolution, essentially a stochastic Price equation with migration, that encompasses all processes, both deterministic and stochastic, contributing to directional change in an open population. Using this result, we show that increasing the variance in migration rates reduces the impact of migration relative to selection. This means that models that treat migration as a single parameter tend to be biassed - overestimating the relative impact of immigration. We further show that selection and migration interact in complex ways, one result being that a strategy for which fitness is negatively correlated with migration rates (high fitness when migration is low) will tend to increase in frequency, even if it has lower mean fitness than do other strategies. Finally, we derive an equation for the effective migration rate, which allows some of the complex stochastic processes that we identify to be incorporated into models with a single migration parameter. Conclusions/Significance As has previously been shown with selection, the role of migration in evolution is determined by the entire distributions of immigration and emigration rates, not just by the mean values. The interactions of stochastic migration with stochastic selection produce evolutionary processes that are invisible to deterministic evolutionary theory

  6. Clinical results after implantation of a spherical aberration-free intraocular lens: effect of contrast sensitivity and wavefront aberration--a clinical comparative study.

    Science.gov (United States)

    Choi, Jin-A; Kim, Chan-Young; Na, Kyung-Sun; Park, Shin-Hae; Joo, Choun-Ki

    2009-01-01

    To compare the clinical results of the spherical aberration-free Akreos AO (Bausch & Lomb) with the Akreos Adapt (Bausch & Lomb), the parent model of spherical optic design. Fifty patients (100 eyes) were randomly assigned to bilaterally receive Akreos AO or Akreos Adapt intraocular lenses (IOLs) after phacoemulsification. At 6 months postoperatively, best-corrected contrast sensitivities were determined at 3, 4.8, 7.5, 12 and 19 cycles per degree using a Visual Capacity Analyzer (L2 Informatique) under mesopic (5 cd/m(2)) and photopic (100 cd/m(2)) conditions with undilated pupils. Wavefront analysis of total aberration was performed with the WaveScan WaveFront System (Advanced Medical Optics VISX). Postoperative contrast sensitivities were not statistically different under mesopic and photopic conditions. On the other hand, fourth-order spherical aberration was lower in the AO group than the Adapt group with only a marginal difference (p = 0.048). Other higher-order aberrations such as coma and trefoil were not significantly different between the two groups (p = 0.657, 0.614). The questionnaire on subjective visual quality in terms of glare disability, distant vision and night driving did not reveal an improved visual function in the AO group. The spherical aberration-free Akreos AO IOL did not show improved visual quality compared with its spherical counterpart. (c) 2009 S. Karger AG, Basel.

  7. Optimization of high-numerical-aperture objectives by splitting a singlet with control of higher-order aberration

    Science.gov (United States)

    Cheng, Xuemin; Wang, Yongtian; Hao, Qun

    2006-01-01

    A scheme is proposed for the automatic control of higher-order aberrations during the course of lens optimization, as well as third-order aberrations. First, the singlet with the larger paraxial marginal ray slope difference is modified into a doublet. The doublet is combined with two elements, for which their refractive index difference is selected to be small, instead of the traditional combination with the crown and flint glasses. And the middle surface in the doublet will give a variably controllable higher-order aberration contribution to the image quality, whereas the third-order aberration is comparably fixed, so that the "system aberration balance" would be achieved in the optimization run. The optimization of a photographic objective is investigated using this method. The design result can provide good image quality. Results of manufacturing simulations are also given for the systems, which show that the optical system optimized with our scheme can be successfully fabricated.

  8. Theoretical investigation of aberrations upon ametropic human eyes

    Science.gov (United States)

    Tan, Bo; Chen, Ying-Ling; Lewis, J. W. L.; Baker, Kevin

    2003-11-01

    The human eye aberrations are important for visual acuity and ophthalmic diagnostics and surgical procedures. Reported monochromatic aberration data of the normal 20/20 human eyes are scarce. There exist even fewer reports of the relation between ametropic conditions and aberrations. We theoretically investigate the monochromatic and chromatic aberrations of human eyes for refractive errors of -10 to +10 diopters. Schematic human eye models are employed using optical design software for axial, index, and refractive types of ametropia.

  9. Spherical aberration from trajectories in real and hard-edge ...

    Indian Academy of Sciences (India)

    (3)–(4) by comparing with spherical aberration obtained from the ensemble of particle trajectories. The scaled field gives the same focal length. 3. Particle trajectory. 3.1 Ray equation with aberration. The particle trajectory in a solenoid magnet with aberrations is governed by the third-order paraxial ray equation given in eq.

  10. Dendritic cells from Crohn's disease patients show aberrant STAT1 and STAT3 signaling.

    Directory of Open Access Journals (Sweden)

    Janne K Nieminen

    Full Text Available Abnormalities of dendritic cells (DCs and STAT proteins have been reported in Crohn's disease (CD. Studies on JAK/STAT signaling in DCs are, however, lacking in CD. We applied a flowcytometric single-cell-based phosphoepitope assay to evaluate STAT1 and STAT3 pathways in DC subsets from CD patients. In addition, circulating DC counts were determined, together with the activation-related immunophenotype. We found that IL-6- and IFN-α-induced STAT3 phosphorylation and IFN-α-induced STAT1 phosphorylation were impaired in plasmacytoid DCs (pDCs from CD patients (P = 0.005, P = 0.013, and P = 0.006, respectively. In myeloid DCs (mDCs, IFN-α-induced STAT1 and STAT3 phosphorylation were attenuated (P<0.001 and P = 0.048, respectively, but IL-10-induced STAT3 phosphorylation was enhanced (P = 0.026. IFN-γ-induced STAT1 signaling was intact in both DC subtypes. Elevated plasma IL-6 levels were detected in CD (P = 0.004, which strongly correlated with disease activity (ρ = 0.690, P<0.001 but not with IL-6-induced STAT3 phosphorylation. The numbers of pDCs and BDCA3+ mDCs were decreased, and CD40 expression on CD1c+ mDCs was increased in CD. When elucidating the effect of IL-6 signaling on pDC function, we observed that IL-6 treatment of healthy donor pDCs affected the maturation of and modified the T-cell priming by pDCs, favoring Th2 over Th1 type of response and the expression of IL-10 in T cells. Our results implicate DC signaling in human CD. Reduced IL-6 responsiveness in pDCs, together with the attenuated IFN-α-induced signaling in both DC subtypes, may contribute to the immunological dysregulation in CD patients.

  11. Developmental trends of communicative skills in children with chromosome 14 aberrations.

    Science.gov (United States)

    Zampini, Laura; Zanchi, Paola; Rinaldi, Berardo; Novara, Francesca; Zuffardi, Orsetta

    2017-04-01

    Children with chromosome 14 aberrations usually show developmental delays, intellectual disability, neurological disorders and behaviour problems. The aim of the present study is to describe the developmental trajectories of the communicative skills of children with chromosome 14 aberrations, considering the possible relationships between the patterns of language development and the children's clinical characteristics (e.g., intellectual disability or autistic traits). Longitudinal data on five children (four with linear deletions and one with ring 14 syndrome) followed for 3 years are presented. Four out of five children showed profound intellectual disability, and three out of five showed autistic traits. A high individual variability was found in both vocal and gestural productions. However, only a modest increase in the children's communicative and symbolic skills was detected over time (e.g., in the quality of preverbal productions). The increase of communicative skills in children with chromosome 14 aberration is very slow. We need to consider the children's characteristics, in terms of type of chromosome aberration, level of intellectual disability and presence/absence of autistic traits, to predict their possible linguistic outcomes and to give a more realistic expectation to their parents. What is known: • The communicative skills of children with chromosome 14 aberrations are usually impaired. • The presence of autistic traits is frequent in these children. What is new: • The increase of communicative skills in children with chromosome 14 aberrations is very slow. • The level of intellectual disability and the presence/absence of autistic traits appeared to have a role in predicting the possible linguistic outcomes in children with chromosome 14 aberrations.

  12. Why Migrate: For Study or for Work?

    Directory of Open Access Journals (Sweden)

    Elise S. Brezis

    2016-08-01

    Full Text Available Over the past decades, globalization has led to a huge increase in the migration of workers, as well as students. This paper develops a simple two-step model that describes the decisions of an individual vis-à-vis education and migration, and presents a unified model, wherein the two migration decisions are combined into a single, unique model. This paper shows that under the plausible assumption that costs of migration differ over the human life cycle, the usual brain drain strategy is sub-optimal. With an increase in globalization, the brain drain strategy will be replaced by the strategy of migration of students.

  13. Family migration and relative earnings potentials

    DEFF Research Database (Denmark)

    Foged, Mette

    2016-01-01

    A unitarian model of family migration in which families may discount wives’ private gains is used to derive testable predictions regarding the type of couples that select into migrating. The empirical tests show that gender neutral family migration cannot be rejected against the alternative...... of husband centered migration. Couples are more likely to migrate if household earnings potential is disproportionally due to one partner, and families react equally strongly to a male and a female relative advantage in educational earnings potential. These results are driven by households with a strong...

  14. Metallicity, planetary formation and migration

    OpenAIRE

    Livio, M.; Pringle, J. E.

    2003-01-01

    Recent observations show a clear correlation between the probability of hosting a planet and the metallicity of the parent star. Since radial velocity surveys are biased, however, towards detecting planets with short orbital periods, the probability-metallicity correlation could merely reflect a dependence of migration rates on metallicity. We investigated the possibility, but find no basis to suggest that the migration process is sensitive to the metallicity. The indication is, therefore, th...

  15. Effective object planes for aberration-corrected transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, R., E-mail: ryu@tsinghua.edu.cn [Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Lentzen, M. [Institute of Solid State Research and Ernst Ruska Centre, Research Centre Juelich, 52425 Juelich (Germany); Zhu, J. [Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2012-01-15

    In aberration-corrected transmission electron microscopy, the image contrast depends sensitively on the focus value. With the point resolution extended to an information limit of below 0.1 nm, even a focus change of as small as one nanometer could give a significant change in image contrast. Therefore, it is necessary to consider in detail the optimum focus condition in order to take full advantage of aberration-correction. In this study, the thickness dependence of the minimum contrast focus has been investigated by dynamical image simulations for amorphous model structures of carbon, germanium, and tungsten, which were constructed by molecular dynamics simulations. The calculation results show that the minimum contrast focus varies with the object thickness, supporting the use of an effective object plane close to the midplane instead of the exit plane of a sample, as suggested by Bonhomme and Beorchia [J. Phys. D: Appl. Phys. 16, 705 (1983)] and Lentzen [Microscopy and Microanalysis 12, 191 (2006)]. Thus supported particles and wedge-shaped crystals with symmetrical top and bottom surfaces could be imaged at a focus condition independent of the uneven bottom face. Image simulations of crystalline samples as a function of focus and thickness show: for an object thickness of less than 10 nm, the optimum focus condition is matched better if the midplane of the object, instead of the exit plane, is chosen as reference plane. -- Highlights: Black-Right-Pointing-Pointer Stringent focus condition is required for aberration-corrected TEM. Black-Right-Pointing-Pointer Optimum focus should be set with respect to the midplane of a sample. Black-Right-Pointing-Pointer The focus condition could be independent of the lateral position on a wedged sample.

  16. The effects of chalazion excision on corneal surface aberrations.

    Science.gov (United States)

    Park, Young Min; Lee, Jong Soo

    2014-10-01

    This study is the first to consider the effects of chalazion on corneal surface aberrations taking into account of corneal zones, and to establish the size standard for the excision of chalazion. Twenty three eyes from 23 patients with central upper eyelid chalazion larger than 3mm were recruited in this prospective study. The participants were classified into two groups, depending on size of the lesion: Group 1 with lesion size 3-5mm and Group 2 with lesion size >5mm Chalazion was excised by standard transconjunctival vertical incision. Corneal surface aberrations were measured using a Galilei™ analyzer and an auto-refractometer before and 2 months after the excision. Corneal astigmatism in all patients decreased significantly in both auto refractometer (P=0.012) and Galilei™ (P=0.020) measurements after chalazion excision. RMS of total HOAs decreased significantly in 6mm (P=0.043) and 3mm zone (P=0.051). The RMS of Zernike orders in the vertical and horizontal trefoil decreased significantly in 6mm (P=0.035) and 3mm (P=0.041) zone. Group 2 showed a significant decrease in corneal astigmatism in both auto refractometer (P=0.040) and Galilei™ (P=0.017) parameters after chalazion excision. Group 1 showed an insignificant decrease in corneal astigmatism. Unlike Group 1, the RMS of total HOAs and vertical and horizontal trefoil in 6mm zone decreased significantly in Group 2 (Pchalazion increases astigmatism and HOAs, especially at the peripheral cornea. Significantly induced astigmatism and HOAs are caused by chalazion >5mm in size. Thus, we recommend the surgical excision of chalazion >5mm in size to reduce corneal surface aberrations. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  17. The correction of electron lens aberrations.

    Science.gov (United States)

    Hawkes, P W

    2015-09-01

    The progress of electron lens aberration correction from about 1990 onwards is chronicled. Reasonably complete lists of publications on this and related topics are appended. A present for Max Haider and Ondrej Krivanek in the year of their 65th birthdays. By a happy coincidence, this review was completed in the year that both Max Haider and Ondrej Krivanek reached the age of 65. It is a pleasure to dedicate it to the two leading actors in the saga of aberration corrector design and construction. They would both wish to associate their colleagues with such a tribute but it is the names of Haider and Krivanek (not forgetting Joachim Zach) that will remain in the annals of electron optics, next to that of Harald Rose. I am proud to know that both regard me as a friend as well as a colleague. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. The aberrant retroesophageal right subclavian artery.

    Science.gov (United States)

    Seres-Sturm, M; Maros, T N; Seres-Sturm, L

    1985-01-01

    Two cases with arteria lusoria were found at 278 routine dissections. These arteria arise as the last branches of the aortic arch and have a retroesophageal position. At the crossing point, the esophagus narrows due to the groove caused by the artery. The appearance of this malposition is the consequence of the perturbation in the organo-genesis of the right dorsal aorta and fourth branchial artery. The aberration can lead to disphagia lusoria.

  19. Retrotracheal aberrant left brachiocephalic vein: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, Adalet E.; Haliloglu, Mithat; Karcaaltincaba, Musturay; Ariyurek, Macit O. [Hacettepe University Faculty of Medicine, Department of Radiology, Ankara (Turkey)

    2008-03-15

    We present a child with double aberrant left brachiocephalic vein (ALBCV) that was an incidental finding on CT. The anterior and thin branch was above the aortic arch and behind the truncus brachiocephalicus and drained into the superior vena cava (SVC). The posterior and thick branch of the ALBCV coursed posterior to the trachea and oesophagus and joined with the azygos vein before draining into the SVC. To our knowledge, retrotracheal ALBCV has not been previously described. (orig.)

  20. DNA Repair Defects and Chromosomal Aberrations

    Science.gov (United States)

    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

  1. Aberrant expression of long noncoding RNAs in autistic brain.

    Science.gov (United States)

    Ziats, Mark N; Rennert, Owen M

    2013-03-01

    The autism spectrum disorders (ASD) have a significant hereditary component, but the implicated genetic loci are heterogeneous and complex. Consequently, there is a gap in understanding how diverse genomic aberrations all result in one clinical ASD phenotype. Gene expression studies from autism brain tissue have demonstrated that aberrantly expressed protein-coding genes may converge onto common molecular pathways, potentially reconciling the strong heritability and shared clinical phenotypes with the genomic heterogeneity of the disorder. However, the regulation of gene expression is extremely complex and governed by many mechanisms, including noncoding RNAs. Yet no study in ASD brain tissue has assessed for changes in regulatory long noncoding RNAs (lncRNAs), which represent a large proportion of the human transcriptome, and actively modulate mRNA expression. To assess if aberrant expression of lncRNAs may play a role in the molecular pathogenesis of ASD, we profiled over 33,000 annotated lncRNAs and 30,000 mRNA transcripts from postmortem brain tissue of autistic and control prefrontal cortex and cerebellum by microarray. We detected over 200 differentially expressed lncRNAs in ASD, which were enriched for genomic regions containing genes related to neurodevelopment and psychiatric disease. Additionally, comparison of differences in expression of mRNAs between prefrontal cortex and cerebellum within individual donors showed ASD brains had more transcriptional homogeneity. Moreover, this was also true of the lncRNA transcriptome. Our results suggest that further investigation of lncRNA expression in autistic brain may further elucidate the molecular pathogenesis of this disorder.

  2. An economic analysis of migration in Mexico.

    Science.gov (United States)

    Greenwood, M J; Ladman, J R

    1978-07-01

    This paper analyzes internal migration in Mexico over the 1960-70 period. A model of the determinants of migration is specified and estimated for aggregated interstate migration flows. Results show that distance serves as a significant deterrent to migration, that higher destination earning levels are attractive to migrants, and that regions with high unemployment rates experience lower rates of inmigration. An unanticipated finding is that regions with higher earning levels have greater rates of outmigration. The data are disaggregated to examine separate migration relationships for each state. The results are that distance is a lesser deterrent for those migrants with more accessible alternatives, that higher earning levels reduce the deterring effects of distance, and that regions with higher earning levels have lower associated elasticities of migration. It is concluded that economic factors have played a crucial role in internal migration and thus in the changing occupational and geographic structure of the Mexican labor force.

  3. Migration from New EU Member Countries

    DEFF Research Database (Denmark)

    Pytlikova, Mariola

    2007-01-01

    The main purpose of the paper is to give predictions of the migration potential from the 7 new EU member countries to the EEA/EU-13 countries. Being able to analyze 'real' migration behavior from these particular countries over the period 1990-2000 helps me to avoid problems related to (double) out......-of sample forecasts and to the assumption of invariance of migration behavior across a space that previous studies had to hold. Results of the econometric analyses reveal the importance of controlling for pairs of countries unobserved heterogeneity. Preliminary results regarding the predictions of future...... gross and net migration flows show that the magnitude of the estimated gross and net migration flows is relatively high and lower, respectively, compared to forecasts from previous studies. Such a development in gross and net migration flows indicates that migration from the new EU member countries...

  4. Biclonal chromosomal aberrations in a child with myelodysplastic syndrome.

    Science.gov (United States)

    Jakab, Z; Balogh, E; Kiss, C; Pajor, L; Oláh, E

    1999-01-01

    Hematological malignancies and premalignant diseases are generally of monoclonal origin. The prognostic and therapeutic significance of finding two genetically independent clones remains to be determined. We followed a case of childhood myelodysplastic syndrome showing biclonal chromosomal abnormalities (+8, -7) by conventional cytogenetic examination and double target fluorescence in situ hybridization (FISH). A 7-year-old girl presented with Plaut-Vincent angina and leukopenia. The cytogenetic aberration of +8 was the first sign to suggest MDS. Serial bone marrow controls, prompted by a progressive clinical course detected myelodysplastic changes and a new clonal aberration (-7). The presence of -7 and +8 in two independent clones was verified by double-target FISH. While at diagnosis and during cytokine treatment more cells showed +8, after successful all-trans retinoic acid (ATRA) therapy, the clone with -7 predominated. Following allogeneic bone marrow transplantation the patient displayed donor-derived hematopoesis. Our data stress the significance of cytogenetic and FISH examinations in detecting specific genetic abnormalities and progressive clonal changes as an indicator and guideline for therapy. Different cell clones characterized by different genetic changes might be associated with different biologic features reflected in their response to treatment.

  5. Genome-wide identification of significant aberrations in cancer genome

    Directory of Open Access Journals (Sweden)

    Yuan Xiguo

    2012-07-01

    Full Text Available Abstract Background Somatic Copy Number Alterations (CNAs in human genomes are present in almost all human cancers. Systematic efforts to characterize such structural variants must effectively distinguish significant consensus events from random background aberrations. Here we introduce Significant Aberration in Cancer (SAIC, a new method for characterizing and assessing the statistical significance of recurrent CNA units. Three main features of SAIC include: (1 exploiting the intrinsic correlation among consecutive probes to assign a score to each CNA unit instead of single probes; (2 performing permutations on CNA units that preserve correlations inherent in the copy number data; and (3 iteratively detecting Significant Copy Number Aberrations (SCAs and estimating an unbiased null distribution by applying an SCA-exclusive permutation scheme. Results We test and compare the performance of SAIC against four peer methods (GISTIC, STAC, KC-SMART, CMDS on a large number of simulation datasets. Experimental results show that SAIC outperforms peer methods in terms of larger area under the Receiver Operating Characteristics curve and increased detection power. We then apply SAIC to analyze structural genomic aberrations acquired in four real cancer genome-wide copy number data sets (ovarian cancer, metastatic prostate cancer, lung adenocarcinoma, glioblastoma. When compared with previously reported results, SAIC successfully identifies most SCAs known to be of biological significance and associated with oncogenes (e.g., KRAS, CCNE1, and MYC or tumor suppressor genes (e.g., CDKN2A/B. Furthermore, SAIC identifies a number of novel SCAs in these copy number data that encompass tumor related genes and may warrant further studies. Conclusions Supported by a well-grounded theoretical framework, SAIC has been developed and used to identify SCAs in various cancer copy number data sets, providing useful information to study the landscape of cancer genomes

  6. Aberrant “Barbed-Wire” Nuclear Projections of Neutrophils in Trisomy 18 (Edwards Syndrome

    Directory of Open Access Journals (Sweden)

    Basil M. Kahwash

    2015-01-01

    Full Text Available We discuss the significance of neutrophils with increased, aberrant nuclear projections mimicking “barbed-wire” in a newborn child with trisomy 18 (T18. Increased, aberrant nuclear projections have been previously reported in trisomy of the D group of chromosomes (chromosomes 13, 14, and 15, and we report similar findings in a patient with T18. The peripheral blood smear showed relative neutrophilia with the majority (37% of neutrophils showing two or more thin, rod-shaped or spike-shaped, and often pedunculated aberrant nuclear projections. The number of projections ranged from 2 to 6 per cell, averaged 2 per affected neutrophil, and ranged in length from 0.22 μm to 0.83 μm. This case confirms that the morphologic finding described is not restricted to trisomy of one of the chromosomes in group D, as implied in the literature.

  7. A Cilia Independent Role of Ift88/Polaris during Cell Migration.

    Directory of Open Access Journals (Sweden)

    Christopher Boehlke

    Full Text Available Ift88 is a central component of the intraflagellar transport (Ift complex B, essential for the building of cilia and flagella from single cell organisms to mammals. Loss of Ift88 results in the absence of cilia and causes left-right asymmetry defects, disordered Hedgehog signaling, and polycystic kidney disease, all of which are explained by aberrant ciliary function. In addition, a number of extraciliary functions of Ift88 have been described that affect the cell-cycle, mitosis, and targeting of the T-cell receptor to the immunological synapse. Similarly, another essential ciliary molecule, the kinesin-2 subunit Kif3a, which transports Ift-B in the cilium, affects microtubule (MT dynamics at the leading edge of migrating cells independently of cilia. We now show that loss of Ift88 impairs cell migration irrespective of cilia. Ift88 is required for the polarization of migrating MDCK cells, and Ift88 depleted cells have fewer MTs at the leading edge. Neither MT dynamics nor MT nucleation are dependent on Ift88. Our findings dissociate the function of Ift88 from Kif3a outside the cilium and suggest a novel extraciliary function for Ift88. Future studies need to address what unifying mechanism underlies the different extraciliary functions of Ift88.

  8. A Cilia Independent Role of Ift88/Polaris during Cell Migration.

    Science.gov (United States)

    Boehlke, Christopher; Janusch, Heike; Hamann, Christoph; Powelske, Christian; Mergen, Miriam; Herbst, Henriette; Kotsis, Fruzsina; Nitschke, Roland; Kuehn, E Wolfgang

    2015-01-01

    Ift88 is a central component of the intraflagellar transport (Ift) complex B, essential for the building of cilia and flagella from single cell organisms to mammals. Loss of Ift88 results in the absence of cilia and causes left-right asymmetry defects, disordered Hedgehog signaling, and polycystic kidney disease, all of which are explained by aberrant ciliary function. In addition, a number of extraciliary functions of Ift88 have been described that affect the cell-cycle, mitosis, and targeting of the T-cell receptor to the immunological synapse. Similarly, another essential ciliary molecule, the kinesin-2 subunit Kif3a, which transports Ift-B in the cilium, affects microtubule (MT) dynamics at the leading edge of migrating cells independently of cilia. We now show that loss of Ift88 impairs cell migration irrespective of cilia. Ift88 is required for the polarization of migrating MDCK cells, and Ift88 depleted cells have fewer MTs at the leading edge. Neither MT dynamics nor MT nucleation are dependent on Ift88. Our findings dissociate the function of Ift88 from Kif3a outside the cilium and suggest a novel extraciliary function for Ift88. Future studies need to address what unifying mechanism underlies the different extraciliary functions of Ift88.

  9. Aberrant sialylation of granulocyte membranes in chronic myelogenous leukemia.

    Science.gov (United States)

    Baker, M A; Taub, R N; Whelton, C H; Hindenburg, A

    1984-05-01

    Peripheral blood granulocytes from patients with chronic myelogenous leukemia (CML) were studied for accessibility of membrane sialic acid and galactose residues to sodium borohydride-3H radiolabeling after oxidation with sodium metaperiodate (PI/B3H4) or with galactose oxidase (GO/B3H4). Granulocytes from untreated patients with chronic myelogenous leukemia showed increased radiolabeling with PI/B3H4, and decreased labeling with GO/B3H4 when compared to normal granulocytes. Granulocytes from leukemic patients receiving chemotherapy showed normal labeling patterns. Gel electrophoresis of membrane extracts showed that the changes in PI/B3H4 and GO/B3H4 reactivity of CML cells were distributed over all membrane protein bands. Our data suggest that CML granulocyte membrane proteins are aberrantly sialylated, with decreased accessibility of galactose residues, and that these changes may be reversed by clinical drug treatment.

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

    Science.gov (United States)

    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.

  11. Ocular aberrations in barn owl eyes.

    Science.gov (United States)

    Harmening, Wolf M; Vobig, Michael A; Walter, Peter; Wagner, Hermann

    2007-10-01

    Optical quality in barn owl eyes is presented in terms of measuring the ocular wavefront aberrations with a standard Tscherning-type wavefront aberrometer under natural viewing conditions. While accommodative state was uncontrolled, all eyes were focused within 0.4D with respect to the plane of the aberrometer. Total RMS wavefront error was between 0.06 and 0.15 microm (mean: 0.10 microm, STD: 0.03 microm, defocus cancelled) for a 6 mm pupil. The results suggest that image quality in barn owl eyes is excellent.

  12. Aberrant activity in degenerated retinas revealed by electrical imaging

    Directory of Open Access Journals (Sweden)

    Günther eZeck

    2016-02-01

    Full Text Available In this review I present and discuss the current understanding of aberrant electrical activity found in the ganglion cell layer (GCL of rod-degenerated (rd mouse retinas. The reported electrophysiological properties revealed by electrical imaging using high-density microelectrode arrays can be subdivided between spiking activity originating from retinal ganglion cells (RGCs and local field potentials reflecting strong trans-membrane currents within the GCL. RGCs in rod-degenerated retinas show increased and rhythmic spiking compared to age-matched wild-type retinas. Fundamental spiking frequencies range from 5 to 15 Hz in various mouse models. The rhythmic RGC spiking is driven by a presynaptic network comprising AII amacrine and bipolar cells. In the healthy retina this rhythm-generating circuit is inhibited by photoreceptor input. A unique physiological feature of rd retinas is rhythmic local field potentials (LFP manifested as spatially-restricted low-frequency (5–15 Hz voltage changes. Their spatiotemporal characterization revealed propagation and correlation with RGC spiking. LFPs rely on gap-junctional coupling and are shaped by glycinergic and by GABAergic transmission. The aberrant RGC spiking and LFPs provide a simple readout of the functionality of the remaining retinal circuitry which can be used in the development of improved vision restoration strategies.

  13. Harmonic source wavefront aberration correction for ultrasound imaging

    Science.gov (United States)

    Dianis, Scott W.; von Ramm, Olaf T.

    2011-01-01

    A method is proposed which uses a lower-frequency transmit to create a known harmonic acoustical source in tissue suitable for wavefront correction without a priori assumptions of the target or requiring a transponder. The measurement and imaging steps of this method were implemented on the Duke phased array system with a two-dimensional (2-D) array. The method was tested with multiple electronic aberrators [0.39π to 1.16π radians root-mean-square (rms) at 4.17 MHz] and with a physical aberrator 0.17π radians rms at 4.17 MHz) in a variety of imaging situations. Corrections were quantified in terms of peak beam amplitude compared to the unaberrated case, with restoration between 0.6 and 36.6 dB of peak amplitude with a single correction. Standard phantom images before and after correction were obtained and showed both visible improvement and 14 dB contrast improvement after correction. This method, when combined with previous phase correction methods, may be an important step that leads to improved clinical images. PMID:21303031

  14. Prompt cytomolecular identification of chromosome aberration in irradiated blood cells

    Directory of Open Access Journals (Sweden)

    Seyed Akbar Moosavi

    2017-02-01

    Full Text Available Background: understanding the genomic alteration induced by ionizing radiation still remains to be a methodological challenge in genetic field. The energy released from this type of radiation can potentially causes structural and numerical alterations in lymphocytes, which in turn converts them into abnormal tumor cells. Chromosomal abnormalities associated with specific type of hematological malignancies are determinant factors in evaluation of radiation dose and its potential in harming the body. None the less early detection of chromosomal aberration (CA is crucial in prognosis and selection of therapy for the people exposed to irradiations. The aim of this study was to explore a swift and accurate genetic test that identifies CAs in radiologist exposed to X-rays. In addition synergistic effect of other clastogens in irradiated workers was also evaluated. Material and methods: thirty four heparinized blood samples were obtained from radiology workers exposed to X-rays. Blood samples were cultured in RPMI 1640 and F-10 Medias with and without PHA stimulation. Lymphocytes were harvested, separated and arrested at metaphase and their chromosomes were analyzed by solid and G-Banding techniques. Lymphocytic CA was also analyzed through whole chromosome painting FISH. Results: of the 37 blood sample from workers, 60% had various structural aberrations in which both the frequency and type of CAs were intensified among tobacco smokers. Conclusion: the results did not show any significant differences between the genders but other carcinogen like smoking can significantly increases the rate of CAs

  15. Exaggerated translation causes synaptic and behavioural aberrations associated with autism.

    Science.gov (United States)

    Santini, Emanuela; Huynh, Thu N; MacAskill, Andrew F; Carter, Adam G; Pierre, Philippe; Ruggero, Davide; Kaphzan, Hanoch; Klann, Eric

    2013-01-17

    Autism spectrum disorders (ASDs) are an early onset, heterogeneous group of heritable neuropsychiatric disorders with symptoms that include deficits in social interaction skills, impaired communication abilities, and ritualistic-like repetitive behaviours. One of the hypotheses for a common molecular mechanism underlying ASDs is altered translational control resulting in exaggerated protein synthesis. Genetic variants in chromosome 4q, which contains the EIF4E locus, have been described in patients with autism. Importantly, a rare single nucleotide polymorphism has been identified in autism that is associated with increased promoter activity in the EIF4E gene. Here we show that genetically increasing the levels of eukaryotic translation initiation factor 4E (eIF4E) in mice results in exaggerated cap-dependent translation and aberrant behaviours reminiscent of autism, including repetitive and perseverative behaviours and social interaction deficits. Moreover, these autistic-like behaviours are accompanied by synaptic pathophysiology in the medial prefrontal cortex, striatum and hippocampus. The autistic-like behaviours displayed by the eIF4E-transgenic mice are corrected by intracerebroventricular infusions of the cap-dependent translation inhibitor 4EGI-1. Our findings demonstrate a causal relationship between exaggerated cap-dependent translation, synaptic dysfunction and aberrant behaviours associated with autism.

  16. Dose-Response Curve of Chromosome Aberrations in Human Lymphocytes Induced by Gamma-Rays

    Directory of Open Access Journals (Sweden)

    Y. Lusiyanti

    2013-12-01

    Full Text Available Chromosome aberration is a biomarker to predict the level of cell damage caused by exposure to ionizing radiation on human body. Dicentric chromosome is a specific chromosome aberration caused by ionizing radiation and is used as a gold standard biodosimetry of individuals over exposed to ionizing radiation. In radiation accident the dicentric assays has been applied as biological dosimetry to estimate radiation absorbed dose and also to confirm the radiation dose received to radiation workers.The purpose of this study was to generate a dose response curve of chromosome aberration (dicentric in human lymphocyte induced by gamma radiation. Peripheral blood samples from three non smoking healthy volunteers aged between 25-48 years old with informed consent were irradiated with dose between 0.1-4.0 Gy and a control using gamma teletherapy source. The culture procedure was conducted following the IAEA standard procedures with slight modifications. Analysis of dose-response curves used was LQ model Y = a + αD + βD2. The result showed that α and β values of the curve obtained were 0.018 ± 0.006 and 0.013 ± 0.002, respectively. Dose response calibration curve for dicentric chromosome aberrations in human lymphocytes induced by gamma-radiation fitted to linear quadratic model. In order to apply the dose response curve of chromosome aberration disentric for biodosimetry, this standar curve still need to be validated.

  17. Diurnal fluctuation of higher order ocular aberrations: correlation with intraocular pressure and corneal thickness.

    Science.gov (United States)

    Mierdel, Peter; Krinke, Hans-Eberhard; Pollack, Katharina; Spoerl, Eberhard

    2004-01-01

    Optimal wavefront-guided refractive corneal laser surgery requires sufficiently exact data of optical higher order aberrations. We investigated whether these aberrations had a systematic during-the-day variation, studied the range of variation, and changes in intraocular pressure and central corneal thickness. In 22 eyes of 22 young volunteers the optical aberrations of higher order were measured by means of a Tscherning-type ocular aberrometer three times during one day (7 AM, 12 noon, 4 PM). In addition, in 12 of these eyes the intraocular pressure and central corneal thickness were measured. The intraocular wavefront aberration was computed using Zernike polynomials up to the sixth order, and Zernike coefficients of third and fourth order were analyzed. Only the coefficient Z 2/4 (C13) showed a significant increase during the day by a mean 0.016 microm. A significant regression could be detected between changes of coefficients Z3/3, Z-2/4, Z0/4, Z4/4, and changes of intraocular pressure or central corneal thickness during the day. Due to the small values, the measured during-the-day changes of higher order aberrations had no direct practical consequences for the aberrometry-guided corneal laser surgery. Alterations of some Zernike coefficients during the day may be explained by the biomechanical behavior of the cornea.

  18. Spinning pipe gas lens aberrations along the axis and in the boundary layer

    Directory of Open Access Journals (Sweden)

    Cosmas Mafusire

    2013-11-01

    Full Text Available When the walls of an open-ended horizontal steel pipe are heated before the pipe is rotated along its axis, the exchange of the expelled heated air with the incoming cooler air, sucked in along the axis, results in a medium capable of focusing a laser beam propagating along the pipes axis a spinning pipe gas lens. However, the interaction of the heated and cooler air generates local density fluctuations which generate aberrations on the laser beam wavefront. We present results for the characterisation of these aberrations using a Shack- Hartmann wavefront sensor. The measurements show that along the axis, rotating the pipe decreasesy-tilt as a result of the removal of distortions caused by gravity, although there is an increase in higher-order aberrations. However, in the boundary layer, the dominant aberration isx-astigmatism which increases with rotation speed. The results are confirmed by the measurement of the beam quality factor which increases as a result of the increase in the size of the higher-order aberrations. The spinning pipe gas lens is a device which can be used to focus laser beams using air only, but, in the process, the air introduces distortions which reduce the quality of the beam.

  19. Targeted Lesion Generation Through the Skull Without Aberration Correction Using Histotripsy.

    Science.gov (United States)

    Sukovich, Jonathan; Xu, Zhen; Kim, Yohan; Cao, Hui; Nguyen, Thai-Son; Pandey, Aditya; Hall, Timothy; Cain, Charles

    2016-02-18

    This study demonstrates the ability of histotripsy to generate targeted lesions through the skullcap without using aberration correction. Histotripsy therapy was delivered using a 500 kHz, 256-element hemispherical transducer with an aperture diameter of 30 cm and a focal distance of 15 cm fabricated in our lab. This transducer is theoretically capable of producing peak rarefactional pressures, based on linear estimation, (p-)LE, in the free field in excess of 200MPa with pulse durations 2 acoustic cycles. Three excised human skullcaps were used displaying attenuations of 73-81% of the acoustic pressure without aberration correction. Through all three skullcaps, compact lesions with radii less than 1mm were generated in red blood cell (RBC) agarose tissue phantoms without aberration correction, using estimated (p-)LE of 28-39MPa, a pulse repetition frequency of 1Hz, and a total number of 300 pulses. Lesion generation was consistently observed at the geometric focus of the transducer as the position of the skullcap with respect to the transducer was varied, and multiple patterned lesions were generated transcranially by mechanically adjusting the position of the skullcap with respect to the transducer to target different regions within. These results show that compact, targeted lesions with sharp boundaries can be generated through intact skullcaps using histotripsy with very short pulses without using aberration correction. Such capability has the potential to greatly simplify transcranial ultrasound therapy for non-invasive transcranial applications, as current ultrasound transcranial therapy techniques all require sophisticated aberration correction.

  20. The effects of cordycepin on the cell proliferation, migration and apoptosis in human lung cancer cell lines A549 and NCI-H460.

    Science.gov (United States)

    Tao, Xiandong; Ning, Ye; Zhao, Xuewei; Pan, Tiewen

    2016-07-01

    Our study aimed to evaluate the effect of cordycepin on human lung cancer cell lines A549 and NCI-H460. Human lung cancer A549 cells and NCI-H460 cells were treated with different concentrations of cordycepin for different times. Cells incubated without cordycepin were defined as a control. The cell proliferation, migration and apoptosis were, respectively, determined by MTT assay, transwell migration assay and flow cytometry. Additionally, the expression levels of related proteins associated with cell cycle, epithelial-mesenchymal transition (EMT) and apoptosis were examined. The survival rate of A549 cells and NCI-H460 cells treated with cordycepin significantly decreased compared with untreated cells in a concentration-dependent manner, while the apoptosis rate increased. The migration number of cells treated with cordycepin significantly decreased as the increase in concentration. qRT-PCR and Western blot analysis showed that the aberrant expression of related molecules associated with cell cycle, migration and apoptosis was observed in the lung cancer cells, such as cyclin B, cyclin E, MMP-9, caspase-3 and Bcl-2. Cordycepin may exert inhibitory effects on the development of human lung cancer via inhibiting cell proliferation, suppressing migration and inducing apoptosis, suggesting that cordycepin may have therapeutic potential for the treatment of this disease. © 2016 Royal Pharmaceutical Society.

  1. [Big-city migration in historical perspective].

    Science.gov (United States)

    Croes, M M; Van Huis, L T

    1997-01-01

    "The migration flows to and from the four largest Dutch municipalities (Amsterdam, Rotterdam, The Hague and Utrecht) show a number of similarities. During the past few decades internal migration has been characterized by a move away from the large cities, while the much smaller international migration flow had an opposite direction. This has resulted in a net decrease of the total population in the largest cities." (SUMMARY IN ENG) excerpt

  2. Wavefront aberration function in terms of R. V. Shack's vector product and Zernike polynomial vectors.

    Science.gov (United States)

    Gray, Robert W; Rolland, Jannick P

    2015-10-01

    Previous papers have shown how, for rotationally symmetric optical imaging systems, nodes in the field dependence of the wavefront aberration function develop when a rotationally symmetric optical surface within an imaging optical system is decentered and/or tilted. In this paper, we show how Shack's vector product (SVP) can be used to express the wavefront aberration function and to define vectors in terms of the Zernike polynomials. The wavefront aberration function is then expressed in terms of the Zernike vectors. It is further shown that SVP fits within the framework of two-dimensional geometric algebra (GA). Within the GA framework, an equation for the third-order node locations for the binodal astigmatism term that emerge in the presence of tilts and decenters is then demonstrated. A computer model of a three-mirror telescope system is used to demonstrate the validity of the mathematical development.

  3. Aberration-corrected STEM for atomic-resolution imaging and analysis.

    Science.gov (United States)

    Krivanek, O L; Lovejoy, T C; Dellby, N

    2015-09-01

    Aberration-corrected scanning transmission electron microscopes are able to form electron beams smaller than 100 pm, which is about half the size of an average atom. Probing materials with such beams leads to atomic-resolution images, electron energy loss and energy-dispersive X-ray spectra obtained from single atomic columns and even single atoms, and atomic-resolution elemental maps. We review briefly how such electron beams came about, and show examples of applications. We also summarize recent developments that are propelling aberration-corrected scanning transmission electron microscopes in new directions, such as complete control of geometric aberration up to fifth order, and ultra-high-energy resolution EELS that is allowing vibrational spectroscopy to be carried out in the electron microscope. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  4. Image system analysis of human eye wave-front aberration on the basis of HSS

    Science.gov (United States)

    Xu, Ancheng

    2017-07-01

    Hartmann-Shack sensor (HSS) has been used in objective measurement of human eye wave-front aberration, but the research on the effects of sampling point size on the accuracy of the result has not been reported. In this paper, point spread function (PSF) of the whole system mathematical model was obtained via measuring the optical imaging system structure of human eye wave-front aberration measurement. The impact of Airy spot size on the accuracy of system was analyzed. Statistics study show that the geometry of Airy spot size of the ideal light source sent from eye retina formed on the surface of HSS is far smaller than the size of the HSS sample point image used in the experiment. Therefore, the effect of Airy spot on the precision of the system can be ignored. This study theoretically and experimentally justifies the reliability and accuracy of human eye wave-front aberration measurement based on HSS.

  5. Aberration-free ultrathin flat lenses and axicons at telecom wavelengths based on plasmonic metasurfaces.

    Science.gov (United States)

    Aieta, Francesco; Genevet, Patrice; Kats, Mikhail A; Yu, Nanfang; Blanchard, Romain; Gaburro, Zeno; Capasso, Federico

    2012-09-12

    The concept of optical phase discontinuities is applied to the design and demonstration of aberration-free planar lenses and axicons, comprising a phased array of ultrathin subwavelength-spaced optical antennas. The lenses and axicons consist of V-shaped nanoantennas that introduce a radial distribution of phase discontinuities, thereby generating respectively spherical wavefronts and nondiffracting Bessel beams at telecom wavelengths. Simulations are also presented to show that our aberration-free designs are applicable to high-numerical aperture lenses such as flat microscope objectives.

  6. Aberrant Myokine Signaling in Congenital Myotonic Dystrophy

    Directory of Open Access Journals (Sweden)

    Masayuki Nakamori

    2017-10-01

    Full Text Available Summary: Myotonic dystrophy types 1 (DM1 and 2 (DM2 are dominantly inherited neuromuscular disorders caused by a toxic gain of function of expanded CUG and CCUG repeats, respectively. Although both disorders are clinically similar, congenital myotonic dystrophy (CDM, a severe DM form, is found only in DM1. CDM is also characterized by muscle fiber immaturity not observed in adult DM, suggesting specific pathological mechanisms. Here, we revealed upregulation of the interleukin-6 (IL-6 myokine signaling pathway in CDM muscles. We also found a correlation between muscle immaturity and not only IL-6 expression but also expanded CTG repeat length and CpG methylation status upstream of the repeats. Aberrant CpG methylation was associated with transcriptional dysregulation at the repeat locus, increasing the toxic RNA burden that upregulates IL-6. Because the IL-6 pathway is involved in myocyte maturation and muscle atrophy, our results indicate that enhanced RNA toxicity contributes to severe CDM phenotypes through aberrant IL-6 signaling. : Congenital myotonic dystrophy (CDM manifests characteristic genetic (very large CTG repeat expansions, epigenetic (CpG hypermethylation upstream of the repeat, and phenotypic (muscle immaturity features not seen in adult DM. Nakamori et al. find phenotype-genotype and epigenotype correlation in CDM muscle and reveal involvement of the IL-6 myokine signaling pathway in the disease process. Keywords: CTCF, ER stress, IL-6, muscular dystrophy, NF-κB, trinucleotide, cytokine, splicing

  7. Primary aberration coefficients for axial gradient-index lenses

    Science.gov (United States)

    Bociort, Florian

    1999-08-01

    As for homogeneous lenses, for axial gradients the analysis of the Seidel and chromatic aberration coefficients can be very useful in lens design. However, at present few commercial optical design programs list the Seidel aberrations of GRIN lenses and none of them lists the chromatic aberrations. In order to facilitate the computer implementation of the chromatic aberrations of axial GRIN lenses a new mathematical derivation for the axial and lateral color coefficients is presented. Also, new qualitative insight into the properties of axial GRIN lenses is obtained by introducing the thin-lens approximation in the aberration expressions. Within the domain of validity of this approximation, the primary aberrations of an axial GRIN lens are equivalent to those of a pair of homogeneous aspherical lens in contact, having a common plane surface and having refractive indices and Abbe numbers equal to the corresponding axial GRIN values at the two end surfaces.

  8. How neurons migrate: a dynamic in-silico model of neuronal migration in the developing cortex

    LENUS (Irish Health Repository)

    Setty, Yaki

    2011-09-30

    Abstract Background Neuronal migration, the process by which neurons migrate from their place of origin to their final position in the brain, is a central process for normal brain development and function. Advances in experimental techniques have revealed much about many of the molecular components involved in this process. Notwithstanding these advances, how the molecular machinery works together to govern the migration process has yet to be fully understood. Here we present a computational model of neuronal migration, in which four key molecular entities, Lis1, DCX, Reelin and GABA, form a molecular program that mediates the migration process. Results The model simulated the dynamic migration process, consistent with in-vivo observations of morphological, cellular and population-level phenomena. Specifically, the model reproduced migration phases, cellular dynamics and population distributions that concur with experimental observations in normal neuronal development. We tested the model under reduced activity of Lis1 and DCX and found an aberrant development similar to observations in Lis1 and DCX silencing expression experiments. Analysis of the model gave rise to unforeseen insights that could guide future experimental study. Specifically: (1) the model revealed the possibility that under conditions of Lis1 reduced expression, neurons experience an oscillatory neuron-glial association prior to the multipolar stage; and (2) we hypothesized that observed morphology variations in rats and mice may be explained by a single difference in the way that Lis1 and DCX stimulate bipolar motility. From this we make the following predictions: (1) under reduced Lis1 and enhanced DCX expression, we predict a reduced bipolar migration in rats, and (2) under enhanced DCX expression in mice we predict a normal or a higher bipolar migration. Conclusions We present here a system-wide computational model of neuronal migration that integrates theory and data within a precise

  9. Father's Labour Migration and Children's School Discontinuation in Rural Mozambique.

    Science.gov (United States)

    Yabiku, Scott T; Agadjanian, Victor

    2017-08-01

    We examine how the discontinuation of schooling among left-behind children is related to multiple dimensions of male labor migration: the accumulation of migration experience, the timing of these migration experiences in the child's life course, and the economic success of the migration. Our setting is rural southern Mozambique, an impoverished area with massive male labor out-migration. Results show that fathers' economically successful labor migration is more beneficial for children's schooling than unsuccessful migration or non-migration. There are large differences, however, by gender: compared to sons of non-migrants, sons of migrant fathers (regardless of migration success) have lower rates of school discontinuation, while daughters of migrant fathers have rates of school discontinuation no different than daughters of non-migrants. Furthermore, accumulated labor migration across the child's life course is beneficial for boys' schooling, but not girls'. Remittances sent in the past year reduce the rate of discontinuation for sons, but not daughters.

  10. Pseudo-voluntary migration: the case of internal migration system in former Yugoslavia

    Directory of Open Access Journals (Sweden)

    Damir Josipovič

    2013-12-01

    Full Text Available Migration theory has been dichotomised from several different analytical perspectives. The aim of this article is to view migration movements in a holistic scheme taking into account the geographical factors shaping migration patterns at both the point of origin and destination, rather than on the conceptualizations involving the built-in dualisms. The former Yugoslavia with its myriad of cases shows that migration has to be viewed without biased international or internal lenses. Furthermore, the author argues that the migration movements were instead part of a more or less organized system which tended to create circumstances, possibilities and/or impossibilities to migrate. In this way, instead of classifying migrations as either forced or voluntary, the concept of pseudo-voluntary migration movements was proposed. In changing the perspective in which migrations are view in this, the article draws extensively on the moorings theory developed by Bruce Moon. The author gives an updated framework for individual or small group migration analysis. The latter is supplemented by a set of variables and factors in order to make a further use possible at the level of international or internal migration. The author argues that the internal Yugoslav migration system between 1945 and 1991 should be viewed within a framework of potentially coerced, semi-coerced or ‘pseudo-voluntary migration’.

  11. Malaysia and forced migration

    National Research Council Canada - National Science Library

    Arzura Idris

    2012-01-01

    This paper analyzes the phenomenon of "forced migration" in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants...

  12. Migration and revolution

    Directory of Open Access Journals (Sweden)

    Nando Sigona

    2012-06-01

    Full Text Available The Arab Spring has not radically transformed migration patterns in the Mediterranean, and the label ‘migration crisis’ does not do justice to the composite and stratified reality.

  13. Hydronephrosis by an Aberrant Renal Artery: A Case Report

    OpenAIRE

    Park, Byoung Seok; Jeong, Taek Kyun; Ma, Seong Kwon; Kim, Soo Wan; Kim, Nam Ho; Choi, Ki Chul; Jeong, Yong Yeon

    2003-01-01

    Ureteropelvic junction obstruction is usually intrinsic and is most common in children. Aberrant renal arteries are present in about 30% of individuals. Aberrant renal arteries to the inferior pole cross anteriorly to the ureter and may cause hydronephrosis. To the best of our knowledge, although there are some papers about aberrant renal arteries producing ureteropelvic junction obstruction, there is no report of a case which is diagnosed by the new modalities, such as computed tomography an...

  14. Higher order aberrations of the eye: Part one

    Directory of Open Access Journals (Sweden)

    Marsha Oberholzer

    2016-03-01

    Full Text Available This article is the first in a series of two articles that provide a comprehensive literature review of higher order aberrations (HOAs of the eye. The present article mainly explains the general principles of such HOAs as well as HOAs of importance, and the measuring apparatus used to measure HOAs of the eye. The second article in the series discusses factors contributing to variable results in measurements of HOAs of the eye.Keywords: Higher order aberrations; wavefront aberrations; aberrometer

  15. Wnt/β-catenin signalling pathway mediated aberrant hippocampal neurogenesis in kainic acid-induced epilepsy.

    Science.gov (United States)

    Qu, Zhengyi; Su, Fang; Qi, Xueting; Sun, Jianbo; Wang, Hongcai; Qiao, Zhenkui; Zhao, Hong; Zhu, Yulan

    2017-10-01

    Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis with massive neuronal loss and severe gliosis. Aberrant neurogenesis has been shown in the epileptogenesis process of temporal lobe epilepsy. However, the molecular mechanisms underlying aberrant neurogenesis remain unclear. The roles of Wnt signalling cascade have been well established in neurogenesis during multiple aspects. Here, we used kainic acid-induced rat epilepsy model to investigate whether Wnt/β-catenin signalling pathway is involved in the aberrant neurogenesis in temporal lobe epilepsy. Immunostaining and western blotting results showed that the expression levels of β-catenin, Wnt3a, and cyclin D1, the key regulators in Wnt signalling pathway, were up-regulated during acute epilepsy induced by the injection of kainic acids, indicating that Wnt signalling pathway was activated in kainic acid-induced temporal lobe epilepsy. Moreover, BrdU labelling results showed that blockade of the Wnt signalling by knocking down β-catenin attenuated aberrant neurogenesis induced by kainic acids injection. Altogether, Wnt/β-catenin signalling pathway mediated hippocampal neurogenesis during epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis. Aberrant neurogenesis has been shown to involve in the epileptogenesis process of temporal lobe epilepsy. In the present study, we discovered that Wnt3a/β-catenin signalling pathway serves as a link between aberrant neurogenesis and underlying remodelling in the hippocampus, leading to temporal lobe epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Aberrant meiotic behavior in Agave tequilana Weber var. azul

    Directory of Open Access Journals (Sweden)

    Rodríguez-Garay Benjamin

    2002-10-01

    Full Text Available Abstract 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.

  17. Essays on temporary migration

    OpenAIRE

    Mestres Domenech, J.

    2012-01-01

    My thesis dissertation focuses on the temporariness of migration, its diverse effects as well as on migration selection. The first paper, A Dynamic Model of Return Migration analyzes the decision process underlying return migration using a dynamic model. We explain how migrants decide whether to stay or to go back to their home country together with their savings and consumption decisions. We simulate our model with return intentions and perform policy simulations. The se...

  18. Irregular Migration of Egyptians

    OpenAIRE

    ROMAN, Howaida

    2008-01-01

    Euro-Mediterranean Consortium for Applied Research on International Migration (CARIM) After defining irregular migration and tackling its different dimensions, the analytical note proposes to analyse the causes and dynamics of irregular migration in Egypt. It highlights furthermore the determinants of EU Policies in the realm of irregular migration, and Egypt’s policy-making approach towards irregular migrants. The conclusion emphasizes the necessity of forging coherent and effective polic...

  19. Frizzled3a and Celsr2 function in the neuroepithelium to regulate migration of facial motor neurons in the developing zebrafish hindbrain.

    Science.gov (United States)

    Wada, Hironori; Tanaka, Hideomi; Nakayama, Satomi; Iwasaki, Miki; Okamoto, Hitoshi

    2006-12-01

    Migration of neurons from their birthplace to their final target area is a crucial step in brain development. Here, we show that expression of the off-limits/frizzled3a (olt/fz3a) and off-road/celsr2 (ord/celsr2) genes in neuroepithelial cells maintains the facial (nVII) motor neurons near the pial surface during their caudal migration in the zebrafish hindbrain. In the absence of olt/fz3a expression in the neuroepithelium, nVII motor neurons extended aberrant radial processes towards the ventricular surface and mismigrated radially to the dorsomedial part of the hindbrain. Our findings reveal a novel role for these genes, distinctive from their already known functions, in the regulation of the planar cell polarity (i.e. preventing integration of differentiated neurons into the neuroepithelial layer). This contrasts markedly with their reported role in reintegration of neuroepithelial daughter cells into the neuroepithelial layer after cell division.

  20. More Myths of Migration.

    Science.gov (United States)

    Basch, Linda; Lerner, Gail

    1986-01-01

    Challenges "myths" about women and migration, including (1) the causes of migration are economic, not racism; (2) migrant women receive support from feminist groups and trade unions; (3) transnational corporations are positive forces in developing nations; (4) migration today has little impact on family life; and (5) most migrants cluster in…

  1. Adaptive long-range migration promotes cooperation under tempting conditions.

    Science.gov (United States)

    Ichinose, Genki; Saito, Masaya; Sayama, Hiroki; Wilson, David Sloan

    2013-01-01

    Migration is a fundamental trait in humans and animals. Recent studies investigated the effect of migration on the evolution of cooperation, showing that contingent migration favors cooperation in spatial structures. In those studies, only local migration to immediate neighbors was considered, while long-range migration has not been considered yet, partly because the long-range migration has been generally regarded as harmful for cooperation as it would bring the population to a well-mixed state that favors defection. Here, we studied the effects of adaptive long-range migration on the evolution of cooperation through agent-based simulations of a spatial Prisoner's Dilemma game where individuals can jump to a farther site if they are surrounded by more defectors. Our results show that adaptive long-range migration strongly promotes cooperation, especially under conditions where the temptation to defect is considerably high. These findings demonstrate the significance of adaptive long-range migration for the evolution of cooperation.

  2. Effect of Spherical Aberration on the Optical Quality after Implantation of Two Different Aspherical Intraocular Lenses

    Directory of Open Access Journals (Sweden)

    Michael Lasta

    2017-01-01

    Full Text Available Purpose. To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses. Methods. 120 eyes of 60 patients underwent phacoemulsification. In patients’ eyes, an aberration-free IOL (Aspira-aA; Human Optics or an aberration-correcting aspherical IOL (Tecnis ZCB00; Abott Medical Optics was randomly implanted. After surgery, contrast sensitivity and wavefront measurements as well as tilt and decentration measurements were performed. Results. Contrast sensitivity was significantly higher in eyes with Aspira lens under mesopic conditions with 12 cycles per degree (CPD and under photopic conditions with 18 CPD (p=0.02. Wavefront measurements showed a higher total spherical aberration with a minimal pupil size of 4 mm in the Aspira group (0.05 ± 0.03 than in the Tecnis group (0.03 ± 0.02 (p=0.001. Strehl ratio was higher in eyes with Tecnis (0.28 ± 0.17 with a minimal pupil size larger than 5 mm than that with Aspira (0.16 ± 0.14 (p=0.04. In pupils with a minimum diameter of 4 mm spherical aberration had a significant effect on Strehl ratio, but not in pupils with a diameter less than 4 mm. Conclusions. Optical quality was better in eyes with the aberration-correcting Tecnis IOL when pupils were large. In contrast, this could not be shown in eyes with pupils under 4 mm or larger. This trial is registered with Clinicaltrials.gov NCT03224728.

  3. Aberrant intestinal microbiota in individuals with prediabetes

    DEFF Research Database (Denmark)

    Allin, Kristine H; Tremaroli, Valentina; Caesar, Robert

    2018-01-01

    AIMS/HYPOTHESIS: Individuals with type 2 diabetes have aberrant intestinal microbiota. However, recent studies suggest that metformin alters the composition and functional potential of gut microbiota, thereby interfering with the diabetes-related microbial signatures. We tested whether specific gut...... among individuals with prediabetes (mean log2 fold change -1.74 (SEM 0.41), p adj  = 2 × 10-3 and -1.65 (SEM 0.34), p adj  = 4 × 10-4, respectively). Faecal transfer from donors with prediabetes or screen-detected, drug-naive type 2 diabetes to germfree Swiss Webster or conventional C57BL/6 J mice did...... with prediabetes, overweight, insulin resistance, dyslipidaemia and low-grade inflammation and 134 age- and sex-matched individuals with normal glucose regulation. RESULTS: We found that five bacterial genera and 36 operational taxonomic units (OTUs) were differentially abundant between individuals...

  4. Overlapped Fourier coding for optical aberration removal

    Science.gov (United States)

    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

  5. Diet, aberrant crypt foci and colorectal cancer.

    Science.gov (United States)

    Bruce, W R; Archer, M C; Corpet, D E; Medline, A; Minkin, S; Stamp, D; Yin, Y; Zhang, X M

    1993-11-01

    We have used the aberrant crypt focus (ACF) assay to test and develop hypotheses linking diet and colon cancer. The hypotheses were suggested by epidemiological studies that identified possible dietary factors associated with colorectal cancer risk. The ACF assay was used to quantitate the effect of the dietary factors on the initiation and growth of these putative precursors of colon cancers in experimental animals. Using this approach we have developed 3 new hypotheses for the role of diet in colorectal cancer. These are (1) a risk associated with 5-hydroxymethyl-2-furaldehyde in caramelized sugar, (2) a risk associated with some factor in thermolyzed casein, and (3) a risk associated with single nutrient boluses of sucrose and fructose. The importance of these hypotheses has still to be tested in long term carcinogenesis experiments, in analytic epidemiology studies and then, perhaps, in intervention trials.

  6. Aberrant crypt foci and microadenoma as markers for colon cancer.

    Science.gov (United States)

    Archer, M C; Bruce, W R; Chan, C C; Corpet, D E; Medline, A; Roncucci, L; Stamp, D; Zhang, X M

    1992-11-01

    Foci of aberrant crypts similar to those seen in experimental animals exposed to colon carcinogens have been identified and quantified on the mucosal surface of fixed resections of human colon after methylene blue staining. Many of the foci in humans showed dysplasia on histologic examination and were considered to be microadenoma (MA). These lesions may be precursors for adenomatous polyps and colorectal cancer. Rats and mice initiated with azoxymethane, then fed diets containing sucrose or casein heated at 180 degrees C to stimulate normal cooking conditions, had three to five times more large MA after 100 days than controls. Thus, cooked sugar and protein contain promoters of the growth of colonic MA. 5-Hydroxymethylfuraldehyde was identified as a promoter in cooked sugar.

  7. Planning the future's forests with assisted migration

    Science.gov (United States)

    Mary I. Williams; R. Kasten Dumroese

    2014-01-01

    Studies show that changes in climate may exceed plant adaptation and migration. The mismatch in rates between climate change and plant adaptation and migration will pose significant challenges for practitioners that select, grow, and outplant native tree species. Native tree species and populations that are planted today must meet the climatic challenges that they will...

  8. Migration and rural development in the Caribbean.

    Science.gov (United States)

    Momsen, J D

    1986-01-01

    The relationship between migration and agricultural development in the Caribbean is examined. The data, collected by survey, concern the islands of Nevis, Montserrat, and Saint Lucia. The results show that migration is not associated with agricultural innovation or the use of specific technical inputs and that it frequently has a negative impact on agricultural productivity and attitudes toward farming.

  9. Aberrant Reduction of MiR-141 Increased CD47/CUL3 in Hirschsprung's Disease

    Directory of Open Access Journals (Sweden)

    Weibing Tang

    2013-12-01

    Full Text Available Background: MiR-141 has been confirmed to be associated with various human diseases. However, whether miR-141 is involved in the pathogenesis of Hirschsprung's disease (HSCR remains unknown. Here, we design the experiment to reveal the relationship between miR-141 and HSCR. Methods: Quantitative real-time PCR and Western blot were used to detect the expression levels of miR-141 and its potential genes in 70 tissues of HSCR compared with 60 controls. Bisulfite sequencing PCR (BSP assay was applied to explain the possible mechanism of the aberrant expression level of miR-141. We employed a dual-luciferase reporter assay to validate the regulation relation between miR-141 and CD47/CUL3. Cell migration, proliferation, apoptosis, and cell cycle progression were examined by transwell assay, MTT assay, and flow cytometry, respectively. Results: MiR-141 was down-regulated whereas CD47 and CUL3 expression was increased in colon tissues from patients with HSCR compared with control group, The increased level of CD47 and CUL3 induced by miR-141 reduced proliferation and migration of 293T and SH-SY5Y cells. Furthermore, this suppression was reversed by reducing of CD47 and CUL3. Hypermethylation of a CpG Island in the promoter region of miR-141 gene was confirmed in HSCR tissues. Conclusion: Aberrant reduction of miR-141 may play an important role in the pathogenesis of HSCR with the inhibiting affection on cell migration and proliferation abilities. The present study demonstrates for the first time the role of miR-141 and its target genes in the occurrence of HSCR, and provides us a new direction for the study of the pathogenesis of Hirschsprung's disease.

  10. Bird Migration Across the Himalayas

    NARCIS (Netherlands)

    Prins, Herbert H.T.; Namgail, Tsewang

    2017-01-01

    Birds migrating across the Himalayan region fly over the highest peaks in the world, facing immense physiological and climatic challenges. The authors show the different strategies used by birds to cope with these challenges. Many wetland avian species are seen in the high-altitude lakes of the

  11. The International-Migration Network

    CERN Document Server

    Fagiolo, Giorgio

    2012-01-01

    This paper studies international migration from a complex-network perspective. We define the international-migration network (IMN) as the weighted-directed graph where nodes are world countries and links account for the stock of migrants originated in a given country and living in another country at a given point in time. We characterize the binary and weighted architecture of the network and its evolution over time in the period 1960-2000. We find that the IMN is organized around a modular structure characterized by a small-world pattern displaying disassortativity and high clustering, with power-law distributed weighted-network statistics. We also show that a parsimonious gravity model of migration can account for most of observed IMN topological structure. Overall, our results suggest that socio-economic, geographical and political factors are more important than local-network properties in shaping the structure of the IMN.

  12. Surgical treatment of aberrant aortic origin of coronary arteries.

    Science.gov (United States)

    Kooij, Marlotte; Vliegen, Hubert W; de Graaf, Michiel A; Hazekamp, Mark G

    2015-11-01

    Aberrant origin of the coronary arteries is rare but can be life threatening. It is an important cause of sudden death in athletes and other young adults, and may be treated surgically. Consensus exists that interarterial left coronary artery (LCA) should be surgically repaired. For interarterial right coronary artery (RCA), the discussion remains open. The purpose of this study was to analyse our surgical experience. From 2001 until 2014, 31 patients were operated for interarterial RCA, interarterial LCA or intraseptal course of the LCA. Twenty-six patients had interarterial RCA, 4 patients interarterial LCA and 1 patient an intraseptal course of the LCA. Median age at operation was 38 years (range 9-66 years). Twenty-eight patients had previous or current symptoms. The most important were a life-threatening event with resuscitation in 3 and myocardial infarction in 3 others. Surgical repair of interarterial RCA consisted of unroofing of the ostium with or without reimplantation in 25 patients and CABG on the RCA with a venous graft in 1 patient. Reconstruction of interarterial LCA consisted of ostium reconstruction of the LCA with a venous patch in 4 patients. The patient with an intraseptal course had a complete release of the LCA out of the septum and reimplantation in the correct coronary sinus. Follow-up was done by analysis of outpatient records, direct patient contact, echocardiography, electrocardiography, CT-angiography and an exercise test. Median follow-up was 6 years (range 0-11 years). One patient was lost to follow-up. No early or late mortality occurred. Three patients had ischaemia with ventricular fibrillation or ventricular tachycardia shortly after surgery. Two were immediately reoperated, 1 had a stent implantation 1.5 months after release of intraseptal LCA. Two of these patients show a slight dysfunction of the left ventricle at follow-up. All other patients are asymptomatic. Surgery for aberrant origin of coronary arteries is safe. There is

  13. Étude cytogenetique des aberrations chromosomiques chez des ...

    African Journals Online (AJOL)

    After 48 hours of culture in the presence of BrdU, the samples underwent the whole procedure of the metaphase cytogenetic analysis technique. Results: The 22 technicians totaled 4856 metaphases containing 421 chromosomal aberrations and 28 sister chromatid exchanges. It was noted the complex aberrations ...

  14. Numerical correction of aberrations via phase retrieval with speckle illumination

    DEFF Research Database (Denmark)

    Almoro, Percival; Gundu, Phanindra Narayan; Hanson, Steen Grüner

    2009-01-01

    What we believe to be a novel technique for wavefront aberration measurement using speckle patterns is presented. The aberration correction is done numerically. A tilted lens is illuminated with a partially developed speckle field, and the transmitted light intensity is sampled at axially displaced...

  15. An aberrant uterus: Case report | Ondieki | East African Medical ...

    African Journals Online (AJOL)

    A case of an aberrant uterus is presented and literature reviewed. The patient presented with abnormal uterine bleeding, left iliac fossa pain and was managed by excising the aberrant uterus. This case was an enigma as it didn't present in the classical way one with anomalies of the uterus would present. Despite ...

  16. Aberrant Breast in a Rare Site: A Case Report

    Directory of Open Access Journals (Sweden)

    Levent Yeniay

    2012-01-01

    Full Text Available Aberrant breast tissue is an anomaly in the embryogenesis of the breast that is found along the mammary ridge or out of that line. We report a case of a 71-year-old female patient with an abdominal aberrant breast tissue found incidentally in a piece of mesenteric biopsy. The histological features were consistent with breast tissue.

  17. Morphological constraints on changing avian migration phenology.

    Science.gov (United States)

    Møller, A P; Rubolini, D; Saino, N

    2017-06-01

    Many organisms at northern latitudes have responded to climate warming by advancing their spring phenology. Birds are known to show earlier timing of spring migration and reproduction in response to warmer springs. However, species show heterogeneous phenological responses to climate warming, with those that have not advanced or have delayed migration phenology experiencing population declines. Although some traits (such as migration distance) partly explain heterogeneity in phenological responses, the factors affecting interspecies differences in the responsiveness to climate warming have yet to be fully explored. In this comparative study, we investigate whether variation in wing aspect ratio (reflecting relative wing narrowness), an ecomorphological trait that is strongly associated with flight efficiency and migratory behaviour, affects the ability to advance timing of spring migration during 1960-2006 in a set of 80 European migratory bird species. Species with larger aspect ratio (longer and narrower wings) showed smaller advancement of timing of spring migration compared to species with smaller aspect ratio (shorter and wider wings) while controlling for phylogeny, migration distance and other life-history traits. In turn, migration distance positively predicted aspect ratio across species. Hence, species that are better adapted to migration appear to be more constrained in responding phenologically to rapid climate warming by advancing timing of spring migration. Our findings corroborate the idea that aspect ratio is a major evolutionary correlate of migration, and suggest that selection for energetically efficient flights, as reflected by high aspect ratio, may hinder phenotypically plastic/microevolutionary adjustments of migration phenology to ongoing climatic changes. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  18. Migration processes in SCO member states

    Directory of Open Access Journals (Sweden)

    Valentina Sergeevna Antonyuk

    2012-12-01

    Full Text Available The article concerns modern state and development of migration processes in SCO member states. As a main method of research statistical analysis was applied. The article shows that migration streams between SCO member states are rather intensive, and the problem of labor migration becomes more and more urgent. The countries of consuming and supplying of labour force are clearly differentiated in the region. For some countries, labor export is the key sector of economy. At the same time, interstate relations between SCO member states sometimes are rather disputed. The most urgent factors causing the development of migration processes in the region were determined. Among them, thefactor of growing outflows from China isespecially noted. It is noted that migration processes are discussed by SCO member states nowadays in terms of illegal migration and international criminality connected with it. It means that the question of labor migration is a real problem. It is indicated that the creation of a specific joint commission on migration policy affiliated with the Council of Foreign Ministers of SCO member states is the necessary condition of effective interaction in migration questions within the framework of Shanghai Cooperation Organization.

  19. Criteria for correction of quadratic field-dependent aberrations.

    Science.gov (United States)

    Zhao, Chunyu; Burge, James H

    2002-11-01

    Aberrations of imaging systems can be described by using a polynomial expansion of the dependence on field position, or the off-axis distance of a point object. On-axis, or zero-order, aberrations can be calculated directly. It is well-known that aberrations with linear field dependence can be calculated and controlled by using the Abbe sine condition, which evaluates only on-axis behavior. We present a new set of relationships that fully describe the aberrations that depend on the second power of the field. A simple set of equations is derived by using Hamilton's characteristic functions and simplified by evaluating astigmatism in the pupil. The equations, which we call the pupil astigmatism criteria, use on-axis behavior to evaluate and control all aberrations with quadratic dependence on the field and arbitrary dependence on the pupil. These relations are explained and are validated by using several specific optical designs.

  20. Binocular visual performance and summation after correcting higher order aberrations.

    Science.gov (United States)

    Sabesan, Ramkumar; Zheleznyak, Len; Yoon, Geunyoung

    2012-12-01

    Although the ocular higher order aberrations degrade the retinal image substantially, most studies have investigated their effect on vision only under monocular conditions. Here, we have investigated the impact of binocular higher order aberration correction on visual performance and binocular summation by constructing a binocular adaptive optics (AO) vision simulator. Binocular monochromatic aberration correction using AO improved visual acuity and contrast sensitivity significantly. The improvement however, differed from that achieved under monocular viewing. At high spatial frequency (24 c/deg), the monocular benefit in contrast sensitivity was significantly larger than the benefit achieved binocularly. In addition, binocular summation for higher spatial frequencies was the largest in the presence of subject's native higher order aberrations and was reduced when these aberrations were corrected. This study thus demonstrates the vast potential of binocular AO vision testing in understanding the impact of ocular optics on habitual binocular vision.

  1. Hydronephrosis by an Aberrant Renal Artery: A Case Report

    Science.gov (United States)

    Park, Byoung Seok; Jeong, Taek Kyun; Ma, Seong Kwon; Kim, Soo Wan; Kim, Nam Ho; Choi, Ki Chul; Jeong, Yong Yeon

    2003-01-01

    Ureteropelvic junction obstruction is usually intrinsic and is most common in children. Aberrant renal arteries are present in about 30% of individuals. Aberrant renal arteries to the inferior pole cross anteriorly to the ureter and may cause hydronephrosis. To the best of our knowledge, although there are some papers about aberrant renal arteries producing ureteropelvic junction obstruction, there is no report of a case which is diagnosed by the new modalities, such as computed tomography angiogram (CTA) or magnetic resonance angiogram (MRA). We describe a 36-year-old woman with right hydronephrosis. Kidney ultrasonogram and excretory urogram revealed right hydronephrosis. CTA and MRA clearly displayed an aberrant renal artery and hydronephrosis. The patient underwent surgical exploration. For the evaluation of hydronephrosis by an aberrant renal artery, use of CTA and MRA is advocated. PMID:12760271

  2. Aberration-corrected STEM: current performance and future directions

    Energy Technology Data Exchange (ETDEWEB)

    Nellist, P D [Department of Physics, University of Dublin, Trinity College, Dublin 2 (Ireland); Chisholm, M F [Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6030 (United States); Lupini, A R [Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6030 (United States); Borisevich, A [Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6030 (United States); Jr, W H Sides [Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6030 (United States); Pennycook, S J [Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6030 (United States); Dellby, N [Nion Co., 1102 8th St., Kirkland, WA 98033 (United States); Keyse, R [Nion Co., 1102 8th St., Kirkland, WA 98033 (United States); Krivanek, O L [Nion Co., 1102 8th St., Kirkland, WA 98033 (United States); Murfitt, M F [Nion Co., 1102 8th St., Kirkland, WA 98033 (United States); Szilagyi, Z S [Nion Co., 1102 8th St., Kirkland, WA 98033 (United States)

    2006-02-22

    Through the correction of spherical aberration in the scanning transmission electron microscope (STEM), the resolving of a 78 pm atomic column spacing has been demonstrated along with information transfer to 61 pm. The achievement of this resolution required careful control of microscope instabilities, parasitic aberrations and the compensation of uncorrected, higher order aberrations. Many of these issues are improved in a next generation STEM fitted with a new design of aberration corrector, and an initial result demonstrating aberration correction to a convergence semi-angle of 40 mrad is shown. The improved spatial resolution and beam convergence allowed for by such correction has implications for the way in which experiments are performed and how STEM data should be interpreted.

  3. Image based method for aberration measurement of lithographic tools

    Science.gov (United States)

    Xu, Shuang; Tao, Bo; Guo, Yongxing; Li, Gongfa

    2018-01-01

    Information of lens aberration of lithographic tools is important as it directly affects the intensity distribution in the image plane. Zernike polynomials are commonly used for a mathematical description of lens aberrations. Due to the advantage of lower cost and easier implementation of tools, image based measurement techniques have been widely used. Lithographic tools are typically partially coherent systems that can be described by a bilinear model, which entails time consuming calculations and does not lend a simple and intuitive relationship between lens aberrations and the resulted images. Previous methods for retrieving lens aberrations in such partially coherent systems involve through-focus image measurements and time-consuming iterative algorithms. In this work, we propose a method for aberration measurement in lithographic tools, which only requires measuring two images of intensity distribution. Two linear formulations are derived in matrix forms that directly relate the measured images to the unknown Zernike coefficients. Consequently, an efficient non-iterative solution is obtained.

  4. Wafer-based aberration metrology for lithographic systems using overlay measurements on targets imaged from phase-shift gratings.

    Science.gov (United States)

    van Haver, Sven; Coene, Wim M J; D'havé, Koen; Geypen, Niels; van Adrichem, Paul; de Winter, Laurens; Janssen, Augustus J E M; Cheng, Shaunee

    2014-04-20

    In this paper, a new methodology is presented to derive the aberration state of a lithographic projection system from wafer metrology data. For this purpose, new types of phase-shift gratings (PSGs) are introduced, with special features that give rise to a simple linear relation between the PSG image displacement and the phase aberration function of the imaging system. By using the PSGs as the top grating in a diffraction-based overlay stack, their displacement can be measured as an overlay error using a standard wafer metrology tool. In this way, the overlay error can be used as a measurand based on which the phase aberration function in the exit pupil of the lithographic system can be reconstructed. In practice, the overlay error is measured for a set of different PSG targets, after which this information serves as input to a least-squares optimization problem that, upon solving, provides estimates for the Zernike coefficients describing the aberration state of the lithographic system. In addition to a detailed method description, this paper also deals with the additional complications that arise when the method is implemented experimentally and this leads to a number of model refinements and a required calibration step. Finally, the overall performance of the method is assessed through a number of experiments in which the aberration state of the lithographic system is intentionally detuned and subsequently estimated by the new method. These experiments show a remarkably good agreement, with an error smaller than 5  mλ, among the requested aberrations, the aberrations measured by the on-tool aberration sensor, and the results of the new wafer-based method.

  5. Pancreatic mitochondrial complex I exhibits aberrant hyperactivity in diabetes

    Directory of Open Access Journals (Sweden)

    Jinzi Wu

    2017-09-01

    Full Text Available It is well established that NADH/NAD+ redox balance is heavily perturbed in diabetes, and the NADH/NAD+ redox imbalance is a major source of oxidative stress in diabetic tissues. In mitochondria, complex I is the only site for NADH oxidation and NAD+ regeneration and is also a major site for production of mitochondrial reactive oxygen species (ROS. Yet how complex I responds to the NADH/NAD+ redox imbalance and any potential consequences of such response in diabetic pancreas have not been investigated. We report here that pancreatic mitochondrial complex I showed aberrant hyperactivity in either type 1 or type 2 diabetes. Further studies focusing on streptozotocin (STZ-induced diabetes indicate that complex I hyperactivity could be attenuated by metformin. Moreover, complex I hyperactivity was accompanied by increased activities of complexes II to IV, but not complex V, suggesting that overflow of NADH via complex I in diabetes could be diverted to ROS production. Indeed in diabetic pancreas, ROS production and oxidative stress increased and mitochondrial ATP production decreased, which can be attributed to impaired pancreatic mitochondrial membrane potential that is responsible for increased cell death. Additionally, cellular defense systems such as glucose 6-phosphate dehydrogenase, sirtuin 3, and NQO1 were found to be compromised in diabetic pancreas. Our findings point to the direction that complex I aberrant hyperactivity in pancreas could be a major source of oxidative stress and β cell failure in diabetes. Therefore, inhibiting pancreatic complex I hyperactivity and attenuating its ROS production by various means in diabetes might serve as a promising approach for anti-diabetic therapies.

  6. FREQUENCY OF CHROMOSOMAL ABERRATIONS AND MICRONUCLEI IN HORSE LYMPHOCYTES FOLLOWING IN VITRO EXPOSURE TO LOW DOSE IONISING RADIATION

    Directory of Open Access Journals (Sweden)

    Dunja Rukavina

    2012-07-01

    Full Text Available Ionising radiation is known to cause chromosomal instability, which is observed as increased frequency of chromosomal aberration and micronuclei. These are listed as reliable criteria in biological dosimetry. Numerous experiments conducted on both animal and plant models demonstrated that increase in radiation dosage is followed by increased mutation frequency, and that mutations occur even at the lowest exposure. We used horse blood in vitro irradiated by low doses of ionizing radiation. Cultivation of peripheral blood lymphocytes and micronucleus test were used as biomarkers of genetic damage. The observed aberrations were recorded and classified in accordance with the International System of Cytogenetic Nomenclature. Micronuclei were identified on the basis of criteria proposed by Fenech et al. (8. Analysis of chromosomal aberration showed increased frequency of aberrations in blood cultures exposed to 0,1 Gy and 0,2 Gy compared to the controls. Microscopic analysis of chromosomal damage in in vitro micronucleus test revealed that the applied radiation dose induced micronuclei while no binucleated cells with micronuclei were found in lymphocytes that were not irradiated. In this paper we analysed the influence of low dose ionising radiation on frequency of chromosomal aberration and micronuclei in horse lymphocytes following in vitro exposure to X-rays (0,1 Gy and 0,2 Gy. Key words: chromosomal aberrations, micronuclei, ionising radiation, horse lymphocytes

  7. TNF-α-induced LRG1 promotes angiogenesis and mesenchymal stem cell migration in the subchondral bone during osteoarthritis.

    Science.gov (United States)

    Wang, Yiyun; Xu, Jiajia; Zhang, Xudong; Wang, Chuandong; Huang, Yan; Dai, Kerong; Zhang, Xiaoling

    2017-03-30

    The incomplete understanding of aberrant neovascularization, which contributes to osteoarthritis suggests that additional modulators have yet to be identified. Our objective was to identify the role of Leucine-rich-alpha-2-glycoprotein1 (LRG1), a new regulator of pathogenic angiogenesis, in osteoarthritis progression and to develop effective treatment strategies. In this study, immunohistochemistry showed that LRG1 was increased in the subchondral bone and articular cartilage in anterior cruciate ligament transection (ACLT) mice. Further studies were focused on the role of LRG1 in osteoarthritis. Results showed that LRG1 promoted angiogenesis and mesenchymal stem cells (MSC) migration, which contribute to aberrant bone formation in the subchondral bone. Moreover, tumor necrosis factor-α (TNF-α), not interleukin-1β (IL-1β), IL-6 or IL-17, induced the LRG1 expression in human umbilical vein endothelial cells and this effect was inhibited by p38 mitogen-activated protein kinase or NF-κB inhibitor. Notably, inhibition of TNF-α and LRG1 activity by Lenalidomide, an inhibitor of TNF-α production, in ACLT mice attenuated degeneration of osteoarthritis articular cartilage. This study shows that TNF-α is the predominant proinflammatory cytokine that induces the secretion of LRG1. LRG1 contributes to angiogenesis-coupled de novo bone formation by increasing angiogenesis and recruiting MSCs in the subchondral bone of osteoarthritis joints. Inhibition of TNF-α and LRG1 by Lenalidomide could be a potential therapeutic approach.

  8. [Influence of age on optical aberrations of the human eye].

    Science.gov (United States)

    Jahnke, M; Wirbelauer, C; Pham, D T

    2006-07-01

    Currently the influence of age on corneal and ocular aberrations is still insufficiently known. The aim of this clinical study was to compare age-related aberrations of human eyes. In a prospective study 98 eyes of 49 healthy patients ranging from 17 to 65 years of age (38.6+/-10.0 years) were consecutively examined. The best corrected visual acuity ranged from 0.8 to 1.6; 48 eyes were emmetropic (SE+/-0.5 D), 42 eyes myopic (SE +0.5 to +3.88 D). The corneal aberrations were derived from corneal topography (Keratron Scout, Optikon). The measurement of ocular aberrations was performed with a Tscherning wavefront aberrometer (ORK, Schwind). The aberrations of the Zernike coefficients and RMS values (1st to 4th order) were determined. The mean corneal and ocular Zernike coefficients of higher order were smaller than 0.2 microm. There was an evident decrease of wavefront aberrations with increasing order. Higher order corneal aberrations were larger than the corresponding ocular aberrations. With increasing age higher optical errors increased in complexity, and the correlation of corneal and ocular aberrations decreased with significant differences. Although the corneal ocular RMS value of the 3rd and 4th order correlated in the younger group (r=0.51, p=0.0001), there was no correlation in the older group (r=-0.48, p=0.832). The influence of age caused a significant increase of ocular aberrations of the 3rd and 4th order, in particular a tenfold extension of coma (C07) (p=0.002), a twofold extension of spherical aberration (C12) (p=0.0001), and an increase of the 3rd and 4th order RMS values (p=0.001). Increased age induced an increase in optical aberrations of the eye, which demonstrates the influence of the lens on ocular aberrations. The combination of corneal and ocular diagnostic methods is recommendable for a better understanding of visual performance.

  9. Dialogues on migration policy

    OpenAIRE

    Giugni, Marco; Passy, Florence

    2006-01-01

    Dialogues on Migration Policy brings together leading American and European scholars of immigration politics to address migration policy. Editors Marco Giugni and Florence Passy's aim to present a number of informed "dialogues" addressing three main theoretical concerns in this field: the role of the national state in a globalizing world, the determinants of policy change, and the role of collective interests in migration policy. Adopting an unconventional format, the novelty of Dialogues on ...

  10. Many Faces of Migrations

    OpenAIRE

    Milica Antić Gaber; Marko Krevs

    2013-01-01

    Temporary or permanent, local or international, voluntary or forced, legal or illegal, registered or unregistered migrations of individuals, whole communities or individual groups are an important factor in constructing and modifying (modern) societies. The extent of international migrations is truly immense. At the time of the preparation of this publication more than 200 million people have been involved in migrations in a single year according to the United Nations. Furthermore, three time...

  11. Socio-Economic Determinants of International Migration

    Directory of Open Access Journals (Sweden)

    Yaroslav PRYTULA

    2012-05-01

    Full Text Available Since economic factors cannot fully explain the determinants of bilateral migration, this study explores the social and cultural determinants that influence an individual’s decision to migrate. Values, norms and interests in a given culture, may determine whether an individual’s intention to move translates into actual migration. Work values inherent in different cultures could explain why people move or do not move under the condition of perceived economic advantages of migration. A gravity type migration model is used to incorporate variables related both to economic indicators and work values. It is perhaps the first migration study to use the World Value Survey (WVS and the European Value Survey (EVS. We use 2000 stock bilateral migration dataset collected by the World Bank. Our findings indicate that if more aspects of work are valued in a country, this country sends more migrants. Also we show that countries with higher extrinsic work value orientation tend to send more migrants, while countries with higher intrinsic work value orientation tend to send fewer migrants. Our finding shows that the value of work and the level of job security in a country may significantly change migration decision.

  12. Higher-Order Wavefront Aberrations for Populations of Young Emmetropes and Myopes

    Directory of Open Access Journals (Sweden)

    Jinhua Bao

    2009-01-01

    Conclusions: Human eyes have systematical higher order aberrations in population, and factors that cause bilateral symmetry of wavefront aberrations between the right and left eyes made important contribution to the systematical aberrations.

  13. Depth migration and de-migration for 3-D migration velocity analysis; Migration profondeur et demigration pour l'analyse de vitesse de migration 3D

    Energy Technology Data Exchange (ETDEWEB)

    Assouline, F.

    2001-07-01

    for the application of migration velocity analysis. We are interested in particular in an important problem: the influence of irregularities in seismic acquisition on the quality of the depth migrated images. Indeed, 3-D seismic acquisitions show irregularities which are characterized by offset variations as well as a non uniform spatial sampling of the data. To overcome the first kind of irregularities, we propose to introduce the concept of migration by offset class in which are migrated all seismic traces that belong to a given offset class, and we show that such a migration relies on a sound theoretical basis whenever the offset varies smoothly with the midpoint coordinate. These theoretical considerations are validated experimentally: offset classes constructed so that the offset varies slowly with the midpoint coordinate allow to obtain the required imaging quality for migration velocity analysis. The influence, on the quality of the migrated images, of a non uniform spatial sampling of the data is, as for it, much more important than the one linked to offset variations: the computation of the superposition of migrated images associated with each midpoint requires the use of a genuine numerical integration formula. We study quadrature formulas based on polynomial interpolation procedures of the function to be integrated. We recommend to use the Hermite interpolation based numerical integration formula if we are primarily interested in amplitude variations in the case of gently dipping layers, and the Lagrange interpolation based numerical integration formula for the imaging of structures involving some complexity. Moreover, the implementation of these schemes of interpolation consists of a preprocessing of the data and does not really increase the CPU time required for running the migration itself. Of course, these approaches require that the distribution of midpoints is dense enough so as to take correctly into account the variations of the function to be

  14. Regional Redistribution and Migration

    DEFF Research Database (Denmark)

    Manasse, Paolo; Schultz, Christian

    We study a model with free migration between a rich and a poor region. Since there is congestion, the rich region has an incentive to give the poor region a transfer in order to reduce immigration. Faced with free migration, the rich region voluntarily chooses a transfer, which turns out...... to be equal to that a social planner would choose. Provided migration occurs in equilibrium, this conclusion holds even in the presence of moderate mobility costs. However, large migration costs will lead to suboptimal transfers in the market solution...

  15. Migration and Its Consequences

    OpenAIRE

    Ivan Vasile Ivanoff

    2017-01-01

    ABSTRACT: Migration, as a social phenomenon, has an especially complex character and can be analyzed from the point of view of the state which is the source of the migration as well as from the point of view of the state which is the destination of the migration. Its causes are especially complex but the economic ones are determinant and are fundamentally different of the causes which determine the population to seek refuge in case of armed conflict. The effects of the migration are equally c...

  16. Migration into art

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    This book addresses a topic of increasing importance to artists, art historians and scholars of cultural studies, migration studies and international relations: migration as a profoundly transforming force that has remodelled artistic and art institutional practices across the world. It explores...... contemporary art's critical engagement with migration and globalisation as a key source for improving our understanding of how these processes transform identities, cultures, institutions and geopolitics. The author explores three interwoven issues of enduring interest: identity and belonging, institutional...... visibility and recognition of migrant artists, and the interrelations between aesthetics and politics, including the balancing of aesthetics, politics and ethics in representations of forced migration....

  17. Heterogeneous Workers, Trade, and Migration

    OpenAIRE

    Heiland, Inga; Kohler, Wilhelm

    2013-01-01

    We argue that the narrative of variety-induced gains from trade in differentiated goods needs revision. If producing differentiated varieties of a good requires differentiated skills and if the work force is heterogeneous in these skills, then firms are likely to have monopsony power. We show that trade then has adverse labor market effects: It increases the monopsony power of firms and worsens the average quality of matches between firms and workers. We also show that international migration...

  18. Automated computational aberration correction method for OCT and OCM (Conference Presentation)

    Science.gov (United States)

    Liu, Yuan-Zhi; Pande, Paritosh; South, Fredrick A.; Boppart, Stephen A.

    2017-02-01

    Aberrations in an optical system cause a reduction in imaging resolution and poor image contrast, and limit the imaging depth when imaging biological samples. Computational adaptive optics (CAO) provides an inexpensive and simpler alternative to the traditionally used hardware-based adaptive optics (HAO) techniques. In this paper, we present an automated computational aberration correction method for broadband interferometric imaging techniques, e.g. optical coherence tomography (OCT) and optical coherence microscopy (OCM). In the proposed method, the process of aberration correction is modeled as a filtering operation on the aberrant image using a phase filter in the Fourier domain. The phase filter is expressed as a linear combination of Zernike polynomials with unknown coefficients, which are estimated through an iterative optimization scheme based on maximizing an image sharpness metric. The Resilient backpropagation (Rprop) algorithm, which was originally proposed as an alternative to the gradient-descent-based backpropagation algorithm for training the weights in a multilayer feedforward neural network, is employed to optimize the Zernike polynomial coefficients because of its simplicity and the robust performance to the choice of various parameters. Stochastic selection of the number and type of Zernike modes is introduced at each optimization step to explore different trajectories to enable search for multiple optima in the multivariate search space. The method was validated on various tissue samples and shows robust performance for samples with different scattering properties, e.g. a phantom with subresolution particles, an ex vivo rabbit adipose tissue, and an in vivo photoreceptor layer of the human retina.

  19. Chromatin Folding, Fragile Sites, and Chromosome Aberrations Induced by Low- and High- LET Radiation

    Science.gov (United States)

    Zhang, Ye; Cox, Bradley; Asaithamby, Aroumougame; Chen, David J.; Wu, Honglu

    2013-01-01

    We previously demonstrated non-random distributions of breaks involved in chromosome aberrations induced by low- and high-LET radiation. To investigate the factors contributing to the break point distribution in radiation-induced chromosome aberrations, human epithelial cells were fixed in G1 phase. Interphase chromosomes were hybridized with a multicolor banding in situ hybridization (mBAND) probe for chromosome 3 which distinguishes six regions of the chromosome in separate colors. After the images were captured with a laser scanning confocal microscope, the 3-dimensional structure of interphase chromosome 3 was reconstructed at multimega base pair scale. Specific locations of the chromosome, in interphase, were also analyzed with bacterial artificial chromosome (BAC) probes. Both mBAND and BAC studies revealed non-random folding of chromatin in interphase, and suggested association of interphase chromatin folding to the radiation-induced chromosome aberration hotspots. We further investigated the distribution of genes, as well as the distribution of breaks found in tumor cells. Comparisons of these distributions to the radiation hotspots showed that some of the radiation hotspots coincide with the frequent breaks found in solid tumors and with the fragile sites for other environmental toxins. Our results suggest that multiple factors, including the chromatin structure and the gene distribution, can contribute to radiation-induced chromosome aberrations.

  20. Annual spatiotemporal migration schedules in three larger insectivorous birds

    DEFF Research Database (Denmark)

    Jacobsen, Lars Bo; Jensen, Niels Odder; Willemoes, Mikkel

    2017-01-01

    Background: Knowledge of spatiotemporal migration patterns is important for our understanding of migration ecology and ultimately conservation of migratory species. We studied the annual migration schedules of European nightjar, a large nocturnal insectivore and compared it with two other larger...... the annual migrations of nightjars and swifts and compared these with satellite tracking of cuckoo migration. Results: Individuals of the three species migrated to wintering grounds centered in Central Africa, except some common swifts that remained in West Africa, crossing or circumventing the Sahara along...... different routes in spring and fall. Overall, all species showed similar regional and seasonal use of several stopover areas during migration. Among the three species, European nightjars and common cuckoos showed the most similar spatiotemporal migration patterns. The nightjars wintered in SW Central Africa...

  1. The cell surface glycoprotein CUB domain-containing protein 1 (CDCP1) contributes to epidermal growth factor receptor-mediated cell migration.

    Science.gov (United States)

    Dong, Ying; He, Yaowu; de Boer, Leonore; Stack, M Sharon; Lumley, John W; Clements, Judith A; Hooper, John D

    2012-03-23

    Epidermal growth factor (EGF) activation of the EGF receptor (EGFR) is an important mediator of cell migration, and aberrant signaling via this system promotes a number of malignancies including ovarian cancer. We have identified the cell surface glycoprotein CDCP1 as a key regulator of EGF/EGFR-induced cell migration. We show that signaling via EGF/EGFR induces migration of ovarian cancer Caov3 and OVCA420 cells with concomitant up-regulation of CDCP1 mRNA and protein. Consistent with a role in cell migration CDCP1 relocates from cell-cell junctions to punctate structures on filopodia after activation of EGFR. Significantly, disruption of CDCP1 either by silencing or the use of a function blocking antibody efficiently reduces EGF/EGFR-induced cell migration of Caov3 and OVCA420 cells. We also show that up-regulation of CDCP1 is inhibited by pharmacological agents blocking ERK but not Src signaling, indicating that the RAS/RAF/MEK/ERK pathway is required downstream of EGF/EGFR to induce increased expression of CDCP1. Our immunohistochemical analysis of benign, primary, and metastatic serous epithelial ovarian tumors demonstrates that CDCP1 is expressed during progression of this cancer. These data highlight a novel role for CDCP1 in EGF/EGFR-induced cell migration and indicate that targeting of CDCP1 may be a rational approach to inhibit progression of cancers driven by EGFR signaling including those resistant to anti-EGFR drugs because of activating mutations in the RAS/RAF/MEK/ERK pathway.

  2. The Mechanisms of Aberrant Protein Aggregation

    Science.gov (United States)

    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.

  3. Evolution of Mammalian Migrations for Refuge, Breeding, and Food

    OpenAIRE

    Gnanadesikan, Gitanjali E.; Pearse, William; Shaw, Allison K

    2017-01-01

    Abstract Many organisms migrate between distinct habitats, exploiting variable resources while profoundly affecting ecosystem services, disease spread, and human welfare. However, the very characteristics that make migration captivating and significant also make it difficult to study, and we lack a comprehensive understanding of which species migrate and why. Here we show that, among mammals, migration is concentrated within Cetacea and Artiodactyla but also diffusely spread throughout the cl...

  4. Prestack exploding reflector modeling and migration in TI media

    KAUST Repository

    Wang, H.

    2014-01-01

    Prestack depth migration in anisotropic media, especially those that exhibit tilt, can be costly using reverse time migration (RTM). We present two-way spectral extrapolation of prestack exploding reflector modeling and migration (PERM) in acoustic transversely isotropic (TI) media. We construct systematic ways to evaluate phase angles and phase velocities in dip oriented TI (DTI), vertical TI (VTI) and tilted TI (TTI) media. Migration results from the Marmousi VTI model and the BP2007 TTI model show the feasibility of our approach.

  5. Broadband aberration-free focusing reflector for acoustic waves

    Science.gov (United States)

    Wang, Aixia; Qu, Shaobo; Ma, Hua; Wang, Jiafu; Jiang, Wei; Feng, Mingde

    2017-11-01

    An aberration-free focusing reflector (AFR) for acoustic waves is proposed with the aim to eliminate spherical aberration and coma simultaneously. Meanwhile, the AFR can focus acoustic waves with low dispersion in a wide frequency range of 14-50 kHz. The broadband aberration-free focusing effect is originated from an elliptical reflection phase gradient profile, which is achieved by milling different depths of axisymmetric grooves on a planoconcave-like brass plate using the ray theory. Theoretical and numerical results are in good agreement. The designed AFR can find broad engineering, industrial and medical applications.

  6. Simple numerical chromosome aberrations in two pituitary adenomas

    DEFF Research Database (Denmark)

    Dietrich, C U; Pandis, N; Bjerre, P

    1993-01-01

    -secreting adenoma, three aberrant clones were detected, giving the karyotype 45,X, -Y[20]/47,XY, +Y[6]/45,XY, -21[3]/46,XY[21]. One cell had the chromosome complement 46,X, -Y, +9; no other nonclonal aberrations were detected. The only hitherto published case of pituitary adenoma analyzed by banding techniques (Rey...... et al. [1986]: Cancer Genet Cytogenet 23:171-174) also had only numerical clonal changes that included extra copies of chromosome 9. We conclude that pituitary adenomas may be karyotypically characterized by numerical aberrations and that trisomy 9 seems to be the best candidate for a primary...

  7. Cellular origin of prognostic chromosomal aberrations in AML patients

    DEFF Research Database (Denmark)

    Mora-Jensen, H.; Jendholm, J.; Rapin, N.

    2015-01-01

    chromosomal structural rearrangements and single nucleotide variants (SNVs). Conventional AML diagnostics and recent seminal next-generation sequencing (NGS) studies have identified more than 200 recurrent genetic aberrations presenting in various combinations in individual patients. Significantly, many...... of these aberrations occur in normal hematopoietic stem and progenitor cells (HSCs/HPCs) before definitive leukemic transformation through additional acquisition of a few (that is, mostly 1 or 2) leukemia-promoting driver aberrations. NGS studies on sorted bone marrow (BM) populations of AML patients with a normal...

  8. State Taxes, Tax Exemptions, and Elderly Migration

    National Research Council Canada - National Science Library

    Ali Sina Önder; Herwig Schlunk

    2015-01-01

    .... We show that the elderly prefer to migrate to states with low inheritance taxes, high property taxes, low amounts of federal revenue transfers, low cost of living, and higher average temperatures...

  9. Aberrations of Genetic Material as Biomarkers of Ionizing Radiation Effects

    Energy Technology Data Exchange (ETDEWEB)

    Milacic, S.

    2004-07-01

    Ionizing radiation is the most powerful mutagen in environmental and working conditions. The result of genotoxic effect of radiation is the development of chromosome aberrations. The structural chromosome aberrations in peripheral blood lymphocytes are dicentric, ring, acentric fragment. The observation of chromosome aberration frequency in lymphocyte karyotype is the conclusive method to assess the absorbed dose of ionizing radiation. Our study compared the incidence of chromosome aberrations in occupationally exposed healthy medical workers and in non-exposed healthy population. We analyzed the effect of working place, dose by thermo luminescence personal dosimeter (TLD), duration of occupational exposure (DOE) and age to the sum of aberrant cells and aberrations. four-year study included 462 subjects, mean-aged 42.3 years, who were occupational exposed to ionizing radiation and 95 subjects, mean-aged 35,2 years, who were not exposed to ionizing radiation, during the same time period and from the same territory. All of them possess thermo luminescence personal dosimeter (TLD) which is read by scanner for thermo luminescence dosimeters. Modified Moorheard's micro method for peripheral blood lymphocytes and conventional cytogenetic technique of chromosome aberration analysis were used for analysis of chromosome aberrations. Stained preparations (Giemsa) are observed in immersion by light microscope. The karyotype of 200 lymphocytes in metaphase is analyzed the most characteristic aberration: dicentric, then the ring and acentric fragments. The increased incidence of chromosome aberrations was found to tbe 21.6% in the exposed group and 2.1% in the controls, while the findings within the limits (non-specific chromosome lesions-gaps breaks, elongations, and exchanges) were equal in both groups (22%). Among occupationally exposed medical workers, the highest incidence was found in nuclear medicine workers (42.6%), then in orthopedists (27.08%). There is highly

  10. Migrating Art History

    DEFF Research Database (Denmark)

    Ørum, Tania

    2012-01-01

    Review of Hiroko Ikegami, The Great Migrator. Robert Rauschenberg and the Global Rise of American Art. Cambridge Mass., The MIT Press, 2010. 277 pages. ISBN 978-0-262-01425-0.......Review of Hiroko Ikegami, The Great Migrator. Robert Rauschenberg and the Global Rise of American Art. Cambridge Mass., The MIT Press, 2010. 277 pages. ISBN 978-0-262-01425-0....

  11. Migration in Burkina Faso

    NARCIS (Netherlands)

    Wouterse, F.S.

    2007-01-01

    Migration plays an important role in development and as a strategy for poverty reduction. A recent World Bank investigation finds a significant positive relationship between international migration and poverty reduction at the country level (Adams and Page 2003). Burkina Faso, whose conditions for

  12. Migration, Narration, Identity

    DEFF Research Database (Denmark)

    Leese, Peter

    (co-editor with Carly McLaughlin and Wladyslaw Witalisz) This book presents articles resulting from joint research on the representations of migration conducted in connection with the Erasmus Intensive Programme entitled «Migration and Narration» taught to groups of international students over...

  13. The Globalisation of migration

    Directory of Open Access Journals (Sweden)

    Milan Mesić

    2002-04-01

    Full Text Available The paper demonstrates that contemporary international migration is a constitutive part of the globalisation process. After defining the concepts of globalisation and the globalisation of migration, the author discusses six key themes, linking globalisation and international migration (“global cities”, the scale of migration; diversification of migration flows; globalisation of science and education; international migration and citizenship; emigrant communities and new identities. First, in accordance with Saskia Sassen’s analysis, the author rejects the wide-spread notion that unqualified migrants have lost an (important role in »global cities«, i.e. in the centres of the new (global economy. Namely, the post-modern service sector cannot function without the support of a wide range of auxiliary unqualified workers. Second, a critical comparison with traditional overseas mass migration to the USA at the turn of the 19th and 20th centuries indicates that present international migration is, perhaps, less extensive – however it is important to take into consideration various limitations that previously did not exist, and thus the present migration potential is in really greater. Third, globalisation is more evident in a diversification of the forms of migration: the source area of migrants to the New World and Europe has expanded to include new regions in the world; new immigration areas have arisen (the Middle East, new industrial countries of the Far East, South Europe; intra-regional migration has intensified. Forth, globalisation is linked to an increased migration of experts and the pessimistic notion of a brain drain has been replaced by the optimistic idea of a brain gain. Fifth, contemporary international migration has been associated with a crisis of the national model of citizenship. Sixth, the interlinking of (migrant cultural communities regardless of distance and the physical proximity of cultural centres (the

  14. Retinoblastoma protein controls growth, survival and neuronal migration in human cerebral organoids.

    Science.gov (United States)

    Matsui, Takeshi; Nieto-Estévez, Vanesa; Kyrychenko, Sergii; Schneider, Jay W; Hsieh, Jenny

    2017-03-15

    The tumor suppressor retinoblastoma protein (RB) regulates S-phase cell cycle entry via E2F transcription factors. Knockout (KO) mice have shown that RB plays roles in cell migration, differentiation and apoptosis, in developing and adult brain. In addition, the RB family is required for self-renewal and survival of human embryonic stem cells (hESCs). Since little is known about the role of RB in human brain development, we investigated its function in cerebral organoids differentiated from gene-edited hESCs lacking RB. We show that RB is abundantly expressed in neural stem and progenitor cells in organoids at 15 and 28 days of culture. RB loss promoted S-phase entry in DCX + cells and increased apoptosis in Sox2 + neural stem and progenitor cells, and in DCX + and Tuj1 + neurons. Associated with these cell cycle and pro-apoptotic effects, we observed increased CCNA2 and BAX gene expression, respectively. Moreover, we observed aberrant Tuj1 + neuronal migration in RB-KO organoids and upregulation of the gene encoding VLDLR, a receptor important in reelin signaling. Corroborating the results in RB-KO organoids in vitro , we observed ectopically localized Tuj1 + cells in RB-KO teratomas grown in vivo Taken together, these results identify crucial functions for RB in the cerebral organoid model of human brain development. © 2017. Published by The Company of Biologists Ltd.

  15. Migration and Environmental Hazards

    Science.gov (United States)

    Hunter, Lori M.

    2011-01-01

    Losses due to natural hazards (e.g., earthquakes, hurricanes) and technological hazards (e.g., nuclear waste facilities, chemical spills) are both on the rise. One response to hazard-related losses is migration, with this paper offering a review of research examining the association between migration and environmental hazards. Using examples from both developed and developing regional contexts, the overview demonstrates that the association between migration and environmental hazards varies by setting, hazard types, and household characteristics. In many cases, however, results demonstrate that environmental factors play a role in shaping migration decisions, particularly among those most vulnerable. Research also suggests that risk perception acts as a mediating factor. Classic migration theory is reviewed to offer a foundation for examination of these associations. PMID:21886366

  16. Migration of health workers.

    Science.gov (United States)

    Buchan, James

    2008-01-01

    The discussion and debate stimulated by these papers focused across a range of issues but there were four main areas of questioning: "measuring" and monitoring migration (issues related to comparability, completeness and accuracy of data sets on human resources); the impact of migration of health workers on health systems; the motivations of individual health workers to migrate (the "push" and "pull" factors) and the effect of policies designed either to reduce migration (e.g "self ufficiency") or to stimulate it (e.g active international recruitment). It was recognised that there was a critical need to examine migratory flows within the broader context of all health care labour market dynamics within a country, that increasing migration of health workers was an inevitable consequence of globalisation, and that there was a critical need to improve monitoring so as to better inform policy formulation and policy testing in this area.

  17. Music models aberrant rule decoding and reward valuation in dementia.

    Science.gov (United States)

    Clark, Camilla N; Golden, Hannah L; McCallion, Oliver; Nicholas, Jennifer M; Cohen, Miriam H; Slattery, Catherine F; Paterson, Ross W; Fletcher, Phillip D; Mummery, Catherine J; Rohrer, Jonathan D; Crutch, Sebastian J; Warren, Jason D

    2017-11-24

    Aberrant rule- and reward-based processes underpin abnormalities of socio-emotional behaviour in major dementias. However, these processes remain poorly characterised. Here we used music to probe rule decoding and reward valuation in patients with frontotemporal dementia syndromes and Alzheimer's disease relative to healthy age-matched individuals. We created short melodies that were either harmonically resolved ('finished') or unresolved ('unfinished'); the task was to classify each melody as finished or unfinished (rule processing) and rate its subjective pleasantness (reward valuation). Results were adjusted for elementary pitch and executive processing; neuroanatomical correlates were assessed using voxel-based morphometry. Relative to healthy older controls, patients with behavioural variant frontotemporal dementia showed impairments of both musical rule decoding and reward valuation, while patients with semantic dementia showed impaired reward valuation but intact rule decoding, patients with Alzheimer's disease showed impaired rule decoding but intact reward valuation and patients with progressive nonfluent aphasia performed comparably to healthy controls. Grey matter associations with task performance were identified in anterior temporal, medial and lateral orbitofrontal cortices, previously implicated in computing diverse biological and non-biological rules and rewards. The processing of musical rules and reward distils cognitive and neuroanatomical mechanisms relevant to complex socio-emotional dysfunction in major dementias. © The Author (2017). Published by Oxford University Press.

  18. Migration highways and migration barriers created by host-parasite interactions.

    Science.gov (United States)

    Zhang, Quan-Guo; Buckling, Angus

    2016-12-01

    Co-evolving parasites may play a key role in host migration and population structure. Using co-evolving bacteria and viruses, we test general hypotheses as to how co-evolving parasites affect the success of passive host migration between habitats that can support different intensities of host-parasite interactions. First, we show that parasites aid migration from areas of intense to weak co-evolutionary interactions and impede migration in the opposite direction, as a result of intraspecific apparent competition mediated via parasites. Second, when habitats show qualitative difference such that some environments support parasite persistence while others do not, different population regulation forces (either parasitism or competitive exclusion) will reduce the success of migration in both directions. Our study shows that co-evolution with parasites can predictably homogenises or isolates host populations, depending on heterogeneity of abiotic conditions, with the second scenario constituting a novel type of 'isolation by adaptation'. © 2016 John Wiley & Sons Ltd/CNRS.

  19. Early Development of Children with Sex Chromosome Aberrations.

    Science.gov (United States)

    Haka-Ilse, Katerina; And Others

    1978-01-01

    Arthur Retlaw and Associates, Inc., Suite 2080, 1603 Orrington Avenue, Evanston, Illinois 60201. A prospective study was made of the early development of 42 children with sex chromosome aberrations. (Author)

  20. Chromosome aberrations in pesticide-exposed greenhouse workers

    DEFF Research Database (Denmark)

    Lander, B F; Knudsen, Lisbeth E.; Gamborg, M O

    2000-01-01

    OBJECTIVES: The aim of this study was to investigate the possibility of subtoxic exposure to pesticides causing chromosome aberrations in greenhouse workers. METHODS: In a cross-sectional and prospective study design chromosome aberration frequencies in cultured lymphocytes were examined for 116...... greenhouse workers exposed to a complex mixture of almost 50 insecticides, fungicides, and growth regulators and also for 29 nonsmoking, nonpesticide-exposed referents. RESULTS: The preseason frequencies of chromosome aberrations were slightly but not statistically significantly elevated for the greenhouse...... workers when they were compared with the referents. After a summer season of pesticide spraying in the greenhouses, the total frequencies of cells with chromosome aberrations were significantly higher than in the preseason samples (P=0.02) and also higher than for the referents (P=0.05). This finding...

  1. Aberrant internal carotid artery in the middle ear

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Keun Tak; Kang, Hyun Koo [Dept. of Radiology, Seoul Veterans Hospital, Seoul (Korea, Republic of)

    2014-10-15

    The knowledge about the aberrant internal carotid artery (ICA) in the middle ear is essential for clinicians, because a misdiagnosis of the aberrant ICA could have serious consequences such as excessive aural bleeding during a middle ear surgery. A 38-year-old woman presented with tinnitus and hearing difficulties of the left ear that had started 5 years ago. During otoscopy, an anteroinferior bluish mass was seen in the tympanic space. Computed tomography and magnetic resonance imaging demonstrated a left-side aberrant ICA with bony dehiscence of the carotid canal in the middle ear and a reduced diameter of the tympanic ICA. Herein we report a case of an aberrant ICA in the middle ear. We also review the literature regarding this important vascular anomaly of the temporal bone which may lead to disastrous surgical complications.

  2. Not Always Black and White: Colour Aberrations in the Dovekie

    National Research Council Canada - National Science Library

    DARIUSZ JAKUBAS; KATARZYNA WOJCZULANIS-JAKUBAS

    2012-01-01

    We describe four records of colour aberrations in the dovekie (Alle alle). During six years of studies of breeding ecology in two large dovekie colonies in West Spitsbergen, we recorded one albino chick...

  3. Are persistent delusions in schizophrenia associated with aberrant salience?

    Directory of Open Access Journals (Sweden)

    Rafeef Abboud

    2016-06-01

    Conclusion: These findings do not support the hypothesis that persistent delusions are related to aberrant motivational salience processing in TRS patients. However, they do support the view that patients with schizophrenia have impaired reward learning.

  4. [Cystic dystrophy on aberrant pancreas. Contribution of ultrasound-endoscopy].

    Science.gov (United States)

    Andrieu, J; Palazzo, L; Chikli, F; Doll, J; Chome, J

    1989-06-01

    Cystic dystrophy of aberrant pancreatic tissue without chronic pancreatitis is a rare disease described by Potet and Duclert in 1970. Clinical diagnosis is possible by endoscopy and intraluminalsonography; we report the first case diagnosed by intraluminalsonography.

  5. Domestic and International Climate Migration from Rural Mexico.

    Science.gov (United States)

    Nawrotzki, Raphael J; Runfola, Daniel M; Hunter, Lori M; Riosmena, Fernando

    2016-12-01

    Evidence is increasing that climate change and variability may influence human migration patterns. However, there is less agreement regarding the type of migration streams most strongly impacted. This study tests whether climate change more strongly impacted international compared to domestic migration from rural Mexico during 1986-99. We employ eight temperature and precipitation-based climate change indices linked to detailed migration histories obtained from the Mexican Migration Project. Results from multilevel discrete-time event-history models challenge the assumption that climate-related migration will be predominantly short distance and domestic, but instead show that climate change more strongly impacted international moves from rural Mexico. The stronger climate impact on international migration may be explained by the self-insurance function of international migration, the presence of strong migrant networks, and climate-related changes in wage difference. While a warming in temperature increased international outmigration, higher levels of precipitation declined the odds of an international move.

  6. Migration within China and from China to the USA: the effects of migration networks, selectivity, and the rural political economy in Fujian Province.

    Science.gov (United States)

    Liang, Zai; Chunyu, Miao David

    2013-07-01

    This paper tests a new strategy for simultaneously studying internal migration within, and international migration from, China. Our theoretical discussion draws on ideas from migration-networks theory and studies of the transition to a market-oriented economy. Data collection is modelled on the Mexican Migration Project. We find that education is more important in initiating internal migration than international migration. Second, although the role of migration networks at a community level seems similar to that for Mexico-USA migration, the networks at a family level show a different pattern. Third, there is evidence that internal and international migration are competing options. Finally, we find that individuals with cadres (public officials) in the family are less likely to undertake internal migration, but more likely to participate in international migration, a finding that highlights the continuing significance of the cadres in coastal rural China.

  7. Modified matching Ronchi test to visualize lens aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Hassani, Kh; Ziafi, H Hooshmand, E-mail: hassanikh@ut.ac.ir [Optics Research Lab 3, Department of Physics, University of Tehran, PO Box 14395/547, Tehran (Iran, Islamic Republic of)

    2011-09-15

    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.

  8. Gendered Patterns of Migration in Rural South Africa

    Science.gov (United States)

    Camlin, Carol S.; Snow, Rachel C.; Hosegood, Victoria

    2013-01-01

    Gender is increasingly recognized as fundamental to understanding migration processes, causes and consequences. In South Africa, it is intrinsic to the social transformations fueling high levels of internal migration and complex forms of mobility. While female migration in Africa has often been characterized as less prevalent than male migration, and primarily related to marriage, in South Africa a feminization of internal migration is underway, fueled by women’s increasing labor market participation. In this paper, we report sex differences in patterns, trends and determinants of internal migration based on data collected in a demographic surveillance system between 2001 and 2006 in rural KwaZulu-Natal. We show that women were somewhat more likely than men to undertake any migration, but sex differences in migration trends differed by migration flow, with women more likely to migrate into the area than men, and men more likely to out-migrate. Out-migration was suppressed by marriage particularly for women, but most women were not married; both men’s and women’s out-migrations were undertaken mainly for purposes of employment. Over half of female out-migrations (versus 35% of male out-migrations) were to nearby rural areas. The findings highlight the high mobility of this population and the extent to which gender is intimately related to the processes determining migration. We consider the implications of these findings for the measurement of migration and mobility, in particular for health and social policy and research among highly mobile populations in southern Africa. PMID:25332690

  9. European migration: Push and pull

    National Research Council Canada - National Science Library

    Zimmermann, Klaus F

    1994-01-01

      In recent decades, Europe has experienced periods of push and pull migration. Whereas pull migration has been seen as economically beneficial, there is concern that push migration will accelerate the employment crisis...

  10. Mediterranean Migrations: Regionalisms Versus Globalisation

    Directory of Open Access Journals (Sweden)

    Martin Baldwin-Eduards

    2004-06-01

    Full Text Available This paper challenges the claim of globalisation as a cause ofimmigration into Southern Europe and, on an empirical basis, identifies regionalisation as being the primary issue, along with networked migratory patterns. However, the changing patterns of immigration do present challenges to both state and society. It is argued here that recent policy responses in Portugal, Italy and Spain have been inconsistent and irrational – reflecting more the ‘securitisation’ of migration than European reality. Earlier policy innovations are identified, by country and date: most of these have now been abandoned. It is suggested that all of Southern Europe has converged onto a statist, restrictionist model of immigration control that was formerly held only by Greece. The principal characteristics of this model are outlined, along with a migration flowchart and indicative data for migrant flows and sub-flows in Italy and Spain. In the final section, I try to show that the needs of the economy cannot be predicted, immigration cannot becontrolled in the manner currently being enforced across Southern Europe, and attempts to do so will damage rather than improve economic productivity and growth. The concept of an accomodating immigration policy is advanced, whereby the state tries to manage the needs of both employers and potential migrants. Six guidelines for policy development are suggested – most of which have alreadybeen successfully carried out in the European Union. These are the following: migration in order to find a job; circular cross-border migration; EU level negotiation of readmission agreements; the need for a variety of migration-for-employment schemes; legal residence should not depend upon continuity of employment; and discreet legalisation will still be needed in Southern Europe.

  11. Migration in far west Nepal: intergenerational linkages between internal and international migration of rural-to-urban migrants.

    Science.gov (United States)

    Poertner, Ephraim; Junginger, Mathias; Müller-Böker, Ulrike

    2011-01-01

    In Nepal, international labor migration to India and overseas, as well as internal migration to the rural Nepalese lowlands, is of high socioeconomic significance. Scholarly debates about migration in Nepal have gradually shifted from an economic to a more holistic perspective, also incorporating social dimensions. However, little evidence has been generated about internal migration to urban destinations and the potential linkages between international and internal migration. This article draws on Bourdieu's “Theory of Practice” and sees migration as a social practice. Accordingly, migration practice is regarded as a strategy social agents apply to increase or transfer capitals and ultimately secure or improve their social position. Evidence for this argument is based on a qualitative case study of rural to urban migrants in Far West Nepal conducted in July and August 2009. The study at hand addresses linkages between internal and international migration practices and provides insight about a social stratum that is often neglected in migration research: the middle class and, more precisely, government employees. The authors show that social relations are crucial for channeling internal migration to a specific destination. Furthermore, they unveil how internal migration is connected to the international labor migration of former generations. Finally, the authors examine how migration strategies adopted over generations create multi-local social networks rooted in the family's place of origin.

  12. Generalized Alvarez lens for correction of laser aberrations

    Energy Technology Data Exchange (ETDEWEB)

    LaFortune, K N

    2004-12-02

    The Alvarez lens (US Patent No. 3,305,294 [1]) is a compact aberration corrector. The original design emphasized in the patent consists of a pair of adjacent optical elements that provide a variable focus. A lens system with a variable effective focal length is nothing new. Such systems are widely used in cameras, for example. It is the compactness and simplicity of operation that is the key advantage of the Alvarez lens. All of the complexity is folded into the design and fabrication of the optical elements. As mentioned in the Alvarez patent [1] and elaborated upon in Palusinski et al. [2], if one is willing to fold even more complexity into the optical elements, it is possible to correct higher-order aberrations as well. There is no theoretical limit to the number or degree of wavefront distortions that can be corrected. The only limitation is that there must be a fixed relative magnitude of the aberrations. Independent correction of each component of the higher-order aberrations can not be performed without additional elements and degrees of freedom [3]. Under some circumstances, coupling may be observed between different aberrations. This can be mitigated with the appropriate choice of design parameters. New methods are available today that increase the practicality of making higher-order aberration correctors [4,5,6].

  13. Aberrant Wnt/β-Catenin Signaling in Pancreatic Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Gang Zeng

    2006-04-01

    Full Text Available Wnt/β-catenin signaling plays an important role in normal development. However, its aberrant activation is associated with several cancers. The aim of this study is to examine the Wnt/β-catenin pathway in patients with advanced pancreatic adenocarcinoma (n = 31. Paraffin sections from tumors (n = 16 and normal pancreata (n = 3 were used to determine the localization of β-catenin. An additional 15 frozen tumors, adjacent normal pancreata (n = 5, or normal pancreata (n = 4 were utilized for protein isolation. Tumors were also examined for mutations in exon 3 of the CTNNB1 gene. More than 65% of the tumors showed an increase in total β-catenin, consistent with its enhanced membranous, cytoplasmic, and nuclear localization, but only two showed mutations in CTNNB1. The majority of the remaining tumors demonstrated concurrent increases in Wnt-1 and frizzled-2 (positive regulators and a decrease in Ser45/Thr41-phospho-β-catenin. Electrophoretic mobility shift assay demonstrated β-cateninT-cell factor binding in tumors only. Adenomatous polyposis coli and axin, which are both negative regulators, remained unchanged. Unexpectedly, total glycogen synthase kinase-3β protein was elevated in these tumors. Elevated levels of E-cadherin were also observed, although E-cadherin-β-catenin association in tumors remained unaffected. Thus, Wnt/β-catenin activation was observed in 65% of pancreatic adenocarcinomas, independently of β-catenin gene mutations in most tumors.

  14. Aberrant ocular architecture and function in patients with Klinefelter syndrome.

    Science.gov (United States)

    Brand, Cristin; Zitzmann, Michael; Eter, Nicole; Kliesch, Sabine; Wistuba, Joachim; Alnawaiseh, Maged; Heiduschka, Peter

    2017-10-13

    Klinefelter Syndrome (KS), the most common chromosomal disorder in men (47,XXY), is associated with numerous comorbidities. Based on a number of isolated case reports, we performed the first systematic and comprehensive evaluation of eye health in KS patients with a focus on ocular structure and vascularization. Twenty-one KS patients and 26 male and 38 female controls underwent a variety of non-invasive examinations investigating ocular morphology (examination of retinal thickness, optic nerve head, and cornea) and function (visual field testing and quantification of ocular vessel density by optical coherence tomography angiography). In comparison to healthy controls, KS patients exhibited a smaller foveal avascular zone and a decreased retinal thickness due to a drastically thinner outer nuclear layer. The cornea of KS patients showed a decreased peripheral thickness and volume. In perimetry evaluation, KS patients required brighter stimuli and gave more irregular values. KS patients show an ocular phenotype including morphological and functional features, which is very likely caused by the supernumerary X chromosome. Thus, KS should not be limited to infertility, endocrine dysfunction, neurocognitive and psychosocial comorbidities. Defining an aberrant ocular morphology and function, awareness for possible eye problems should be raised.

  15. A genome-wide map of aberrantly expressed chromosomal islands in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Castanos-Velez Esmeralda

    2006-09-01

    Full Text Available Abstract Background Cancer development is accompanied by genetic phenomena like deletion and amplification of chromosome parts or alterations of chromatin structure. It is expected that these mechanisms have a strong effect on regional gene expression. Results We investigated genome-wide gene expression in colorectal carcinoma (CRC and normal epithelial tissues from 25 patients using oligonucleotide arrays. This allowed us to identify 81 distinct chromosomal islands with aberrant gene expression. Of these, 38 islands show a gain in expression and 43 a loss of expression. In total, 7.892 genes (25.3% of all human genes are located in aberrantly expressed islands. Many chromosomal regions that are linked to hereditary colorectal cancer show deregulated expression. Also, many known tumor genes localize to chromosomal islands of misregulated expression in CRC. Conclusion An extensive comparison with published CGH data suggests that chromosomal regions known for frequent deletions in colon cancer tend to show reduced expression. In contrast, regions that are often amplified in colorectal tumors exhibit heterogeneous expression patterns: even show a decrease of mRNA expression. Because for several islands of deregulated expression chromosomal aberrations have never been observed, we speculate that additional mechanisms (like abnormal states of regional chromatin also have a substantial impact on the formation of co-expression islands in colorectal carcinoma.

  16. Migration and AIDS.

    Science.gov (United States)

    1998-01-01

    This article presents the perspectives of UNAIDS and the International Organization for Migration (IOM) on migration and HIV/AIDS. It identifies research and action priorities and policy issues, and describes the current situation in major regions of the world. Migration is a process. Movement is enhanced by air transport, rising international trade, deregulation of trade practices, and opening of borders. Movements are restricted by laws and statutes. Denial to freely circulate and obtain asylum is associated with vulnerability to HIV infections. A UNAIDS policy paper in 1997 and IOM policy guidelines in 1988 affirm that refugees and asylum seekers should not be targeted for special measures due to HIV/AIDS. There is an urgent need to provide primary health services for migrants, voluntary counseling and testing, and more favorable conditions. Research is needed on the role of migration in the spread of HIV, the extent of migration, availability of health services, and options for HIV prevention. Research must be action-oriented and focused on vulnerability to HIV and risk taking behavior. There is substantial mobility in West and Central Africa, economic migration in South Africa, and nonvoluntary migration in Angola. Sex workers in southeast Asia contribute to the spread. The breakup of the USSR led to population shifts. Migrants in Central America and Mexico move north to the US where HIV prevalence is higher.

  17. Migration of the population.

    Science.gov (United States)

    Krasinets, E

    1998-03-01

    Two factors influence foreign migration balance of the Russian Federation. The first factor involves the migration process between Russia and former union republics. The influx of population to the Russian Federation from other republics of the former Soviet Union is considered as one of the largest in the world. The average annual migratory growth of Russia during the years 1991-94 as a result of this migration exchange has tripled as compared with 1986-90, with a total of 2.7 million Russians who migrated into Russia. However, from 1996 up to the present time, the number of persons arriving in Russia declined dramatically. Meanwhile, the second factor that determines the country's migration balance is emigration to the far abroad. The most significant trend in determining the development of internal migration in Russia is the outflow of population from northern and eastern regions. The directions of internal and external migratory flows have a large influence on the migration balance in Russia's rural areas. The reduction of migratory flows in rural areas is the direct result of processes in the economic sphere. It confirms the reconstruction of rural-urban migratory exchange.

  18. Aberrant cervical vasculature anastomosis as cause of neck pain and successful treatment with embolization technique.

    Science.gov (United States)

    He, Lucy; Ladner, Travis R; Cobb, Mark; Mocco, J

    2016-01-27

    We report a patient with non-dermatomal radiating neck pain without focal neurologic deficit. Traditional workup could not identify an anatomic or biomechanical cause. Imaging showed a deep cervical vessel centered in the region of pain. Angiography later identified an aberrant anastomosis of this vessel with the occipital artery. Subsequent endovascular embolization of this arterial trunk resulted in complete pain relief. 2016 BMJ Publishing Group Ltd.

  19. Chromatic aberration compensation in numerical reconstruction of digital holograms by Fresnel-Bluestein propagation.

    Science.gov (United States)

    Hincapie, Diego; Velasquez, Daniel; Garcia-Sucerquia, Jorge

    2017-12-15

    In this Letter, we present a method for chromatic compensation in numerical reconstruction of digitally recorded holograms based on Fresnel-Bluestein propagation. The proposed technique is applied to correct the chromatic aberration that arises in the reconstruction of RGB holograms of both millimeter- and micrometer-sized objects. The results show the feasibility of this strategy to remove the wavelength dependence of the size of the numerically propagated wavefields.

  20. Show-Bix &

    DEFF Research Database (Denmark)

    2014-01-01

    The anti-reenactment 'Show-Bix &' consists of 5 dias projectors, a dial phone, quintophonic sound, and interactive elements. A responsive interface will enable the Dias projectors to show copies of original dias slides from the Show-Bix piece ”March på Stedet”, 265 images in total. The copies...... are made from digital scans of the original dias slides located in the collection of the Museum of Contemporary Art in Roskilde. In front of the audience entering the space and placed on it’s own stand, is an original 60s style telephone with turning dial. Action begins when the audience lift the phone...... and dial a number. Any number will make the Dias change. All numbers are also assigned to specific sound documents: clips form rare interviews and the complete sound-re-enactment of the Show-Bix piece ‘Omringning’ (‘Surrounding’) in five channels (a quintophonie). This was originally produced...

  1. Show and Tell

    DEFF Research Database (Denmark)

    2013-01-01

    Fredag d. 1 november blev Kunsthal Charlottenborg indtaget af performanceprogrammet Show & Tell med et bredspektret program af danske og internationale kunstnere indenfor performance-, lyd- og installationskunst. Programmet præsenterer værker, der undersøger kroppens stadig mere symbiotiske forhold...... og studienævnet på Performance-design. Show & Tell - Performance program: kl. 16.30-19 Adresse: Kunsthal Charlottenborg, Nyhavn 2, 1051 København K...

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

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, Urvi, E-mail: urvi.vyas@gmail.com; Kaye, Elena; Pauly, Kim Butts [Department of Radiology, Stanford University, Stanford, California 94305 (United States)

    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.

  3. The Transverse Chromatic Aberration of the Human Eye.

    Science.gov (United States)

    Simonet, Pierre

    1990-01-01

    In this study, the horizontal components of optical and perceived transverse chromatic aberration (T.C.A.) at the fovea are measured between 486 and 656 nm using a vernier task at 30 and 1000 lux. The relationship between chromostereopsis and T.C.A. is analysed at these two levels of illuminance. During these experiments, a new video frame grabbing technique with a computer generated overlay is used to monitor the pupil size and pupil centration or to visualize the position of the image of a point source, producing a Maxwellian view, in the natural entrance pupil. Optical T.C.A. can be measured either directly in a semi-Maxwellian view when longitudinal chromatic aberration is compensated for, or indirectly in dual Maxwellian view by a chromatic parallax method. Optical T.C.A. measured in dual Maxwellian view and perceived T.C.A. assessed in normal view with a natural pupil were evaluated in a sample of 13 eyes at 30 lux and of 11 eyes at 1000 lux. The sample mean of each type of T.C.A. is in the same direction but substantially less than the predictions of schematic eye models. Perceived T.C.A. shows a greater variability among eyes than optical T.C.A. For some subjects, it appears that optical and perceived T.C.A. differ substantially at both levels of illuminance. This indicates that the effective centre of the pupil differs from the geometric centre as a consequence of the involvement of the Stiles -Crawford effect or coma in the perception of T.C.A. with natural pupils. For some subjects, perceived T.C.A. may adversely affect the optical quality of the eye. In a sample of 30 emmetropic subjects at 10 and 1000 lux, in most cases, there is an absence of perceived T.C.A. although chromostereopsis is reported. In a subset of 9 emmetropic subjects, measured chromostereopsis does not differ significantly at 1000 lux from predicted chromostereopsis, computed as the average of the monocular perceived T.C.A.s. At 30 lux, the expected relationship between

  4. Partial Dislocations in Graphene and Their Atomic Level Migration Dynamics.

    Science.gov (United States)

    Robertson, Alex W; Lee, Gun-Do; He, Kuang; Fan, Ye; Allen, Christopher S; Lee, Sungwoo; Kim, Heeyeon; Yoon, Euijoon; Zheng, Haimei; Kirkland, Angus I; Warner, Jamie H

    2015-09-09

    We demonstrate the formation of partial dislocations in graphene at elevated temperatures of ≥500 °C with single atom resolution aberration corrected transmission electron microscopy. The partial dislocations spatially redistribute strain in the lattice, providing an energetically more favorable configuration to the perfect dislocation. Low-energy migration paths mediated by partial dislocation formation have been observed, providing insights into the atomistic dynamics of graphene during annealing. These results are important for understanding the high temperature plasticity of graphene and partial dislocation behavior in related crystal systems, such as diamond cubic materials.

  5. Migration og etnicitet

    DEFF Research Database (Denmark)

    Christiansen, Connie Carøe

    2004-01-01

    Migration og etnicitet er aktuelle og forbundne fænomener, idet migration øger berøringsfladerne mellem befolkningsgrupper. Etniciteter formes i takt med at grænser drages imellem disse grupper. Imod moderniserings-teoriernes forventning forsvandt etnicitet ikke som en traditionel eller oprindelig...... måde at skabe tilhørsforhold på; globalt set fremstår vor tid istedet som en "migrationens tidsalder", der tilsyneladende også er en tidsalder, hvor kulturelle særtræk, i form af etnicitet, udgør vigtige linjer, hvorefter grupper skilller sig ud fra hinanden. Både migration og etnicitet bringer fokus...... den finder sted i modtagerlandet, men nyere perspektiver på migration, som begreber om medborgerskab, transnationalisme og diaspora er eksponenter for, søger udover den nationalstatslige ramme og inddrager konsekvenserne af migrationen for afsenderlande....

  6. Multi-source least-squares migration of marine data

    KAUST Repository

    Wang, Xin

    2012-11-04

    Kirchhoff based multi-source least-squares migration (MSLSM) is applied to marine streamer data. To suppress the crosstalk noise from the excitation of multiple sources, a dynamic encoding function (including both time-shifts and polarity changes) is applied to the receiver side traces. Results show that the MSLSM images are of better quality than the standard Kirchhoff migration and reverse time migration images; moreover, the migration artifacts are reduced and image resolution is significantly improved. The computational cost of MSLSM is about the same as conventional least-squares migration, but its IO cost is significantly decreased.

  7. Migrations and nutritional status in the sahel.

    Science.gov (United States)

    Autier, P; D'Altilia, J P; Callewaert, B; Tamboura, B; Delamalle, J P; Vercruysse, V

    1989-09-01

    In the Sahel, migration is of considerable importance. It permits the peasants to adjust to variable food conditions. In areas affected by food shortages, cluster sample studies of villages showed that, as the number of recently abandoned houses in a cluster increased, the prevalence of malnutrition decreased, and this linear trend was significant (p nutritional surveillance. The article provides also a brief description of the current migration patterns in the Sahel and underlines the effects droughts have had on them.

  8. [Migration to and from sections of Rotterdam].

    Science.gov (United States)

    Croes, M M; Van Huis, L T

    1997-01-01

    "The number of people that move to, from or within large cities is, in a relative sense, far greater than the corresponding figure for the other parts of the Netherlands. Big city mobility concerns mostly internal migration. The 1995 migration statistics on sections of Rotterdam show dissimilarities between the different sections of the city with respect to composition and intensity of population flows. This article focuses on the differences between two sections of Rotterdam." (SUMMARY IN ENG) excerpt

  9. Volumetric optical coherence microscopy enabled by aberrated optics (Conference Presentation)

    Science.gov (United States)

    Mulligan, Jeffrey A.; Liu, Siyang; Adie, Steven G.

    2017-02-01

    Optical coherence microscopy (OCM) is an interferometric imaging technique that enables high resolution, non-invasive imaging of 3D cell cultures and biological tissues. Volumetric imaging with OCM suffers a trade-off between high transverse resolution and poor depth-of-field resulting from defocus, optical aberrations, and reduced signal collection away from the focal plane. While defocus and aberrations can be compensated with computational methods such as interferometric synthetic aperture microscopy (ISAM) or computational adaptive optics (CAO), reduced signal collection must be physically addressed through optical hardware. Axial scanning of the focus is one approach, but comes at the cost of longer acquisition times, larger datasets, and greater image reconstruction times. Given the capabilities of CAO to compensate for general phase aberrations, we present an alternative method to address the signal collection problem without axial scanning by using intentionally aberrated optical hardware. We demonstrate the use of an astigmatic spectral domain (SD-)OCM imaging system to enable single-acquisition volumetric OCM in 3D cell culture over an extended depth range, compared to a non-aberrated SD-OCM system. The transverse resolution of the non-aberrated and astigmatic imaging systems after application of CAO were 2 um and 2.2 um, respectively. The depth-range of effective signal collection about the nominal focal plane was increased from 100 um in the non-aberrated system to over 300 um in the astigmatic system, extending the range over which useful data may be acquired in a single OCM dataset. We anticipate that this method will enable high-throughput cellular-resolution imaging of dynamic biological systems over extended volumes.

  10. Aberrant repair and fibrosis development in skeletal muscle

    Directory of Open Access Journals (Sweden)

    Mann Christopher J

    2011-05-01

    Full Text Available Abstract The repair process of damaged tissue involves the coordinated activities of several cell types in response to local and systemic signals. Following acute tissue injury, infiltrating inflammatory cells and resident stem cells orchestrate their activities to restore tissue homeostasis. However, during chronic tissue damage, such as in muscular dystrophies, the inflammatory-cell infiltration and fibroblast activation persists, while the reparative capacity of stem cells (satellite cells is attenuated. Abnormal dystrophic muscle repair and its end stage, fibrosis, represent the final common pathway of virtually all chronic neurodegenerative muscular diseases. As our understanding of the pathogenesis of muscle fibrosis has progressed, it has become evident that the muscle provides a useful model for the regulation of tissue repair by the local microenvironment, showing interplay among muscle-specific stem cells, inflammatory cells, fibroblasts and extracellular matrix components of the mammalian wound-healing response. This article reviews the emerging findings of the mechanisms that underlie normal versus aberrant muscle-tissue repair.

  11. Petit point a candid portrait on the aberrations of science

    CERN Document Server

    De Gennes, Pierre-Gilles

    2004-01-01

    In this fascinating book, Nobel Prize winner Pierre-Gilles de Gennes wittily captures the lives of personalities from both the academic and the industrial world in delightful bite-size stories. Most of the characters in this collection are like those in Aesop's fables, but in modern-day research settings. The book provides a critical account of aberrations (fortunately rare) of the scientific community. Many lessons can be drawn from the stories. For the young researcher, this book is like a telescope: for seeing other human beings beyond his or her laboratory. For the administrator, this book is like a microscope: for seeing inside the human beings huge and complex structures. However, like Aesop's fables, you would not offer the book as a gift to anyone other than a close and wise friend. Petit Point is not a book to be devoured in a single sitting. It is one to be savored and reflected upon — it shows what the world may be like and what we ourselves may become. It is like a mirror — to be visited from ...

  12. Detecting and Explaining Aberrant Responding to the Outcome Questionnaire-45.

    Science.gov (United States)

    Conijn, Judith M; Emons, Wilco H M; De Jong, Kim; Sijtsma, Klaas

    2015-08-01

    We applied item response theory based person-fit analysis (PFA) to data of the Outcome Questionnaire-45 (OQ-45) to investigate the prevalence and causes of aberrant responding in a sample of Dutch clinical outpatients. The [Formula: see text] person-fit statistic was used to detect misfitting item-score patterns and the standardized residual statistic for identifying the source of the misfit in the item-score patterns identified as misfitting. Logistic regression analysis was used to predict person misfit from clinical diagnosis, OQ-45 total score, and Global Assessment of Functioning code. The [Formula: see text] statistic classified 12.6% of the item-score patterns as misfitting. Person misfit was positively related to the severity of psychological distress. Furthermore, patients with psychotic disorders, somatoform disorders, or substance-related disorders more likely showed misfit than the baseline group of patients with mood and anxiety disorders. The results suggest that general outcome measures such as the OQ-45 are not equally appropriate for patients with different disorders. Our study emphasizes the importance of person-misfit detection in clinical practice. © The Author(s) 2014.

  13. Phenotypic aberrations during micropropagation of Soymida febrifuga (Roxb. Adr. Juss

    Directory of Open Access Journals (Sweden)

    Kishore Kumar CHIRUVELLA

    2014-03-01

    Full Text Available Like most of the medicinal plants Soymida febrifuga (Meliaceae possess significance for its valuable secondary metabolites. Multiplication of this endemic plant is limited by difficulty in rooting of stem cuttings, high seedling mortality rates and low seed viability period. Hence efficient protocols for in vitro mass propagation has been established from field grown and aseptic seedlings explants. Strikingly, we observed aberrant structures such as vitrified shoots, faciated shoots, albino shoots as well shoot necrosis during its micropropagation. These phenotypic maladies were observed during organogenesis and rooting. Compared to other abnormalities, shoot necrosis nonetheless was frequent and pronounced leading to plant death. Shoots when subjected to rooting also displayed necrosis which was controlled by transferring to MS medium containing various concentrations and combinations of calcium levels, activated charcoal, glucose, fructose and auxins. Microshoots initiated roots on half strength MS medium with IBA and IAA individually or in combination within two weeks. MS half strength solid medium supplemented with CAN (556 mg l–1, CAP (1.0 mg l–1, IAA (2.0 mg l–1 and IBA (2.0 mg l–1 in combination was found to be more efficient in showing high frequency (95% of root regeneration. Rooted plantlets were successfully hardened and 70-85% of regenerated plants were successfully acclimatized to natural environment. In vitro derived plantlets were morphologically similar to in vivo plants.

  14. Aberrant and alternative splicing in skeletal system disease.

    Science.gov (United States)

    Fan, Xin; Tang, Liling

    2013-10-01

    The main function of skeletal system is to support the body and help movement. A variety of factors can lead to skeletal system disease, including age, exercise, and of course genetic makeup and expression. Pre-mRNA splicing plays a crucial role in gene expression, by creating multiple protein variants with different biological functions. The recent studies show that several skeletal system diseases are related to pre-mRNA splicing. This review focuses on the relationship between pre-mRNA splicing and skeletal system disease. On the one hand, splice site mutation that leads to aberrant splicing often causes genetic skeletal system disease, like COL1A1, SEDL and LRP5. On the other hand, alternative splicing without genomic mutation may generate some marker protein isoforms, for example, FN, VEGF and CD44. Therefore, understanding the relationship between pre-mRNA splicing and skeletal system disease will aid in uncovering the mechanism of disease and contribute to the future development of gene therapy. © 2013 Elsevier B.V. All rights reserved.

  15. Sixth-order wave aberration theory of ultrawide-angle optical systems.

    Science.gov (United States)

    Lu, Lijun; Cao, Yiqing

    2017-10-20

    In this paper, we develop sixth-order wave aberration theory of ultrawide-angle optical systems like fisheye lenses. Based on the concept and approach to develop wave aberration theory of plane-symmetric optical systems, we first derive the sixth-order intrinsic wave aberrations and the fifth-order ray aberrations; second, we present a method to calculate the pupil aberration of such kind of optical systems to develop the extrinsic aberrations; third, the relation of aperture-ray coordinates between adjacent optical surfaces is fitted with the second-order polynomial to improve the calculation accuracy of the wave aberrations of a fisheye lens with a large acceptance aperture. Finally, the resultant aberration expressions are applied to calculate the aberrations of two design examples of fisheye lenses; the calculation results are compared with the ray-tracing ones with Zemax software to validate the aberration expressions.

  16. Higher-order aberration corrector for an image-forming system in a transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, H., E-mail: hsawada@jeol.co.jp [CREST, Japan Science and Technology Agency, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo (Japan); Sasaki, T. [CREST, Japan Science and Technology Agency, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo (Japan); Hosokawa, F.; Yuasa, S.; Terao, M.; Kawazoe, M.; Nakamichi, T. [JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo (Japan); Kaneyama, T. [CREST, Japan Science and Technology Agency, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo (Japan); Kondo, Y. [CREST, Japan Science and Technology Agency, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Kimoto, K. [CREST, Japan Science and Technology Agency, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Suenaga, K. [CREST, Japan Science and Technology Agency, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Research Center for Advanced Carbon Materials, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565 (Japan)

    2010-07-15

    We developed a new electron optical system with three dodecapoles to compensate for spherical aberration and six-fold astigmatism, which generally remains in a two-hexapole type corrector. In this study, we applied the corrector for image-forming system in transmission electron microscope. Compensation for higher-order aberration was demonstrated through a diffractogram tableau using a triple three-fold astigmatism field system, which was then compared with a double hexapole field system. Using this electron optical system, six-fold astigmatism was measured to be less than 0.1 mm at an acceleration voltage of 60 kV, showing that the system successfully compensated for six-fold astigmatism.

  17. Aberration-free volumetric high-speed imaging of in vivo retina

    CERN Document Server

    Hillmann, Dierck; Hain, Carola; Sudkamp, Helge; Franke, Gesa; Pfäffle, Clara; Winter, Christian; Hüttmann, Gereon

    2016-01-01

    Research and medicine rely on non-invasive optical techniques to image living tissue with high resolution in space and time. But so far a single data acquisition could not provide entirely diffraction-limited tomographic volumes of rapidly moving or changing targets, which additionally becomes increasingly difficult in the presence of aberrations, e.g., when imaging retina in vivo. We show, that a simple interferometric setup based on parallelized optical coherence tomography acquires volumetric data with 10 billion voxels per second, exceeding previous imaging speeds by an order of magnitude. This allows us to computationally obtain and correct defocus and aberrations resulting in entirely diffraction-limited volumes. As demonstration, we imaged living human retina with clearly visible nerve fiber layer, small capillary networks, and photoreceptor cells, but the technique is also applicable to obtain phase-sensitive volumes of other scattering structures at unprecedented acquisition speeds.

  18. Talking with TV shows

    DEFF Research Database (Denmark)

    Sandvik, Kjetil; Laursen, Ditte

    2014-01-01

    User interaction with radio and television programmes is not a new thing. However, with new cross-media production concepts such as X Factor and Voice, this is changing dramatically. The second-screen logic of these productions encourages viewers, along with TV’s traditional one-way communication...... mode, to communicate on interactive (dialogue-enabling) devices such as laptops, smartphones and tablets. Using the TV show Voice as our example, this article shows how the technological and situational set-up of the production invites viewers to engage in new ways of interaction and communication....... More specifically, the article demonstrates how online comments posted on the day of Voice’s 2012 season finale can be grouped into four basic action types: (1) Invitation to consume content, (2) Request for participation, (3) Request for collaboration and (4) Online commenting. These action types...

  19. Um show de cacau

    OpenAIRE

    Rezende, José Francisco; UNIGRANRIO / PPGA; Mello, Simone; UNIGRANRIO

    2016-01-01

    O caso de ensino apresenta a trajetória de Alexandre Tadeu da Costa e da chocolateria Cacau Show. Seu objetivo é levar os estudantes a identificar alternativas e tomar decisões sobre posicionamento para continuidade do desenvolvimento de vantagens competitivas, sustentação de competência logística e possíveis abordagens ao mercado externo. 

  20. Demodex-associated Bacillus proteins induce an aberrant wound healing response in a corneal epithelial cell line: possible implications for corneal ulcer formation in ocular rosacea.

    Science.gov (United States)

    O'Reilly, Niamh; Gallagher, Clair; Reddy Katikireddy, Kishore; Clynes, Martin; O'Sullivan, Finbarr; Kavanagh, Kevin

    2012-05-31

    The aim of the work presented here was to establish the response of a corneal epithelial cell line (hTCEpi) to protein extracted from a bacterium (Bacillus oleronius) previously isolated from a Demodex mite from a rosacea patient. The response of the corneal epithelial cell line to Bacillus proteins was measured in terms of alterations in cell migration and invasiveness. Changes in the expression of metalloproteinase genes and proteins were also assessed. The results indicated increased cell migration (14.5-fold, P = 0.001) as measured using 8-μm PET inserts (BD Falcon) in a transwell assay and invasiveness (1.7-fold, P = 0.003) as measured using 8-μm Matrigel (BD Biocoat) invasion inserts in a 24-well plate assay format, following exposure to the Bacillus proteins. Cells exposed to the Bacillus protein showed a dose-dependent increase in expression of genes coding for matrix metalloprotease (MMP)-3 (61-fold) and MPP-9 (301-fold). This dose-dependent increase in gene expression was also reflected in elevated levels of MMP-9 protein (1.34-fold, P = 0.033) and increased matrix metalloprotease activity (1.96-fold, P = 0.043) being present in the culture supernatant. Cells also displayed reduced levels of β-integrin (1.25-fold, P = 0.01), indicative of increased motility and elevated levels of vinculin (2.7-fold, P = 0.0009), suggesting altered motility. The results indicate that exposure of corneal epithelial cells to Bacillus proteins results in an aberrant wound healing response as visualized using a scratch wound assay. These results suggest a possible link between the high density of Demodex mites on the eyelashes of ocular rosacea patients and the development of corneal ulcers.

  1. Fabrication of polarization-independent waveguides deeply buried in lithium niobate crystal using aberration-corrected femtosecond laser direct writing

    Science.gov (United States)

    Wang, Peng; Qi, Jia; Liu, Zhengming; Liao, Yang; Chu, Wei; Cheng, Ya

    2017-01-01

    Writing optical waveguides with femtosecond laser pulses provides the capability of forming three-dimensional photonic circuits for manipulating light fields in both linear and nonlinear manners. To fully explore this potential, large depths of the buried waveguides in transparent substrates are often desirable to facilitate achieving vertical integration of waveguides in a multi-layer configuration, which, however, is hampered by rapidly degraded axial resolution caused by optical aberration. Here, we show that with the correction of the spherical aberration, polarization-independent waveguides can be inscribed in a nonlinear optical crystal lithium niobate (LN) at depths up to 1400 μm, which is more than one order of magnitude deeper than the waveguides written with aberration uncorrected femtosecond laser pulses. Our technique is beneficial for applications ranging from miniaturized nonlinear light sources to quantum information processing.

  2. Impact of consolidation pressure on contaminant migration in clay liner

    Directory of Open Access Journals (Sweden)

    Zhi-hong Zhang

    2013-07-01

    Full Text Available Consolidation deformation occurs in clay liners under the self-weight of wastes at a simple garbage dump or dredged sediment dump, which leads to a decrease in the porosity. However, the migration of contaminants in clay liners is influenced by the porosity. Thus, the impact of consolidation deformation of clay liners on the migration of contaminants cannot be ignored. Based on Biot's consolidation theory, the contaminant migration theory, and consideration of the three kinds of migration mechanisms of convection, diffusion, and adsorption, a one-dimensional migration model of contaminants in deforming porous media was established, and the finite difference method was adopted to obtain the numerical solutions for an established initial-boundary value problem. The impact of consolidation pressure on the migration law of a contaminant was studied. The results show that, regardless of adsorption modes, different consolidation pressures have similar impacts on the migration law of the contaminant. Namely, over a certain migration time, the greater the consolidation pressure is, the smaller the migration depth of the contaminant. The results also show that, while the migration time increases, the impact of a certain increment of consolidation pressure on the variation of contaminant concentration with the depth increases gradually and, while the migration depth increases, the impact of a certain increment of consolidation pressure on the variation of the contaminant concentration with time increases gradually.

  3. MODERN MIGRATION POLICY OF RUSSIA

    OpenAIRE

    Kobylinsky S. V.; Usenko A. S.

    2014-01-01

    Several peculiarities of the implementation of migration policy in the Russian Federation were considered in this article. We have shown main provisions on refugees and forced migrants from the Ukraine and labor migration. On the basis of the study we have suggested an improvement of migration legislation, in particular, creation of a single codex and migration police

  4. Assessing influence of stimulation on mood and aberrant behavior of persons with multiple disabilities during brief treadmill sessions.

    Science.gov (United States)

    Lancioni, G E; O'Reilly, M F; Singh, N N; Oliva, D; Piazzolla, G; Groeneweg, J

    2004-12-01

    This study assessed the influence of favorite stimuli on indices of happiness, e.g., smiling or excited vocalizations, and aberrant behavior, e.g., cantilena-like vocalizations or hand waving, of two young adults with multiple disabilities during 5-min. treadmill sessions. Several favorite stimuli, e.g., music and vibratory events, were available for the participants. The stimuli were presented in a rotation fashion during the sessions. To control for the effects of the stimuli, treadmill sessions without stimuli were also conducted. Analysis showed that the treadmill sessions with stimuli led to higher indices of happiness and lower aberrant behavior for both participants, compared to the treadmill sessions without stimuli.

  5. Aberrant light directly impairs mood and learning through melanopsin-expressing neurons.

    Science.gov (United States)

    LeGates, Tara A; Altimus, Cara M; Wang, Hui; Lee, Hey-Kyoung; Yang, Sunggu; Zhao, Haiqing; Kirkwood, Alfredo; Weber, E Todd; Hattar, Samer

    2012-11-22

    The daily solar cycle allows organisms to synchronize their circadian rhythms and sleep-wake cycles to the correct temporal niche. Changes in day-length, shift-work, and transmeridian travel lead to mood alterations and cognitive function deficits. Sleep deprivation and circadian disruption underlie mood and cognitive disorders associated with irregular light schedules. Whether irregular light schedules directly affect mood and cognitive functions in the context of normal sleep and circadian rhythms remains unclear. Here we show, using an aberrant light cycle that neither changes the amount and architecture of sleep nor causes changes in the circadian timing system, that light directly regulates mood-related behaviours and cognitive functions in mice. Animals exposed to the aberrant light cycle maintain daily corticosterone rhythms, but the overall levels of corticosterone are increased. Despite normal circadian and sleep structures, these animals show increased depression-like behaviours and impaired hippocampal long-term potentiation and learning. Administration of the antidepressant drugs fluoxetine or desipramine restores learning in mice exposed to the aberrant light cycle, suggesting that the mood deficit precedes the learning impairments. To determine the retinal circuits underlying this impairment of mood and learning, we examined the behavioural consequences of this light cycle in animals that lack intrinsically photosensitive retinal ganglion cells. In these animals, the aberrant light cycle does not impair mood and learning, despite the presence of the conventional retinal ganglion cells and the ability of these animals to detect light for image formation. These findings demonstrate the ability of light to influence cognitive and mood functions directly through intrinsically photosensitive retinal ganglion cells.

  6. Interaction between Corneal and Internal Ocular Aberrations Induced by Orthokeratology and Its Influential Factors

    Science.gov (United States)

    Chen, Qingzhong; Me, Rao; Yu, Yunjie; Shi, Guangsen

    2017-01-01

    Purpose To investigate the interaction between corneal, internal, and total wavefront aberrations (WAs) and their influential factors during orthokeratology (OK) treatment in Chinese adolescents. Methods Thirty teenagers (n = 30 eyes) were enrolled in the study; spherical equivalent refraction (SE), corneal curvature radius (CCR), central corneal thickness (CCT), WAs, and the difference in limbal transverse diameter and OK lens diameter (ΔLLD) were detected before and after one-month OK treatment. Every component of WAs was measured simultaneously by iTrace aberrometer. The influential factors of OK-induced WAs were analyzed. Results SE and CCT decreased while CCR increased significantly (P < 0.01). Higher-order aberrations (HOAs), Spherical aberrations (SAs), and coma increased significantly (P < 0.01). Corneal horizontal coma (Z31-C) and corneal spherical aberrations (Z40-C) increased (P < 0.01). The HOAs, coma, SAs, Z31-C, Z31-T, Z40-C, and Z40-T were positively correlated with SE and CCR (P < 0.01). Z3−1-C showed negative correlations with (ΔLLD) and positive correlations with SE (P < 0.05). Conclusions The increase in OK-induced HOAs is mainly attributed to Z31 and Z40 of cornea. Z3−1 in the internal component showed a compensative effect on the corneal vertical coma. The degree of myopic correction and increase in CCR may be the essential influential factors of the increase in Z31 and Z40. The appropriate size of the OK lens may be helpful to decrease OK-induced vertical coma. PMID:28845432

  7. Revisiting Cross-Channel Information Transfer for Chromatic Aberration Correction

    KAUST Repository

    Sun, Tiancheng

    2017-12-25

    Image aberrations can cause severe degradation in image quality for consumer-level cameras, especially under the current tendency to reduce the complexity of lens designs in order to shrink the overall size of modules. In simplified optical designs, chromatic aberration can be one of the most significant causes for degraded image quality, and it can be quite difficult to remove in post-processing, since it results in strong blurs in at least some of the color channels. In this work, we revisit the pixel-wise similarity between different color channels of the image and accordingly propose a novel algorithm for correcting chromatic aberration based on this cross-channel correlation. In contrast to recent weak prior-based models, ours uses strong pixel-wise fitting and transfer, which lead to significant quality improvements for large chromatic aberrations. Experimental results on both synthetic and real world images captured by different optical systems demonstrate that the chromatic aberration can be significantly reduced using our approach.

  8. Optical aberrations induced by subclinical decentrations of the ablation pattern

    Science.gov (United States)

    Mrochen, Michael; Kaemmerer, Maik; Riedel, Peter; Mierdel, Peter; Krinke, Hans-Eberhard; Seiler, Theo

    2000-06-01

    Purpose: The aim of this work was to study the effect of currently used ablation profiles along with eccentric ablations on the increase of higher order aberrations observed after PRK. Material and Methods: The optical aberrations of 10 eyes were tested before and after PRK. Refractive surgery was performed using a ArF-excimer laser system. In all cases, the ablation zone was 6 mm or larger. The spherical equivalent of the correction was ranging from -2.5 D to -6.0 D. The measured wavefront error was compared to numerical simulations done with the reduced eye model and currently used ablation profiles as well as compared with experimental results obtained from ablation on PMMA balls. Results: The aberration measurements result in a considerable change of the spherical- and coma-like wavefront errors. This result was in good correlation with the numerical simulations and the experimental results. Furthermore, it has been derived that the major contribution on the induced higher order aberrations are a result of the small decentration (less than 1.0 mm) of the ablation zone. Conclusions: Higher order spherical- and coma-like aberrations after PRK are mainly determined by the decentration of the ablation zone during laser refractive surgery. However, future laser systems should use efficient eye-tracking systems and aspherical ablation profiles to overcome this problem.

  9. Semen quality in men with Y chromosome aberrations.

    Science.gov (United States)

    Antonelli, A; Marcucci, L; Elli, R; Tanzi, N; Paoli, D; Radicioni, A; Lombardo, F; Lenzi, A; Gandini, L

    2011-10-01

    Infertile males sometimes bear structurally balanced chromosome aberrations, such as translocations and inversions, which involve both autosomes and sex chromosomes. The aim of this study was to evaluate genotype-phenotype correlations in a sample of infertile men with various types of Y chromosome abnormalities. In particular, we examined the effect of (i) balanced structural aberrations such as translocations between sex chromosomes and autosomes; (ii) unbalanced structural aberrations such as deletions or isodicentrics, both [idic(Yp)] and [idic(Yq)]. We studied 13 subjects bearing Y chromosome aberrations. Each patient underwent seminal fluid examination, andrological inspection, hormone study, testicular ultrasound, conventional and molecular cytogenetic analysis and study of Y chromosome microdeletions. Comparison of genotype and sperm phenotype in infertile patients with various Y chromosome aberrations revealed the key role of meiotic pairing defects in arresting spermatogenesis, both in the presence and in the absence of azoospermic factor microdeletions and cell mosaicism. The failure of meiosis and, in consequence, spermatogenesis may be a result of the failure to inactivate the X chromosome in the meiotic prophase, which is necessary for normal male spermatogenesis to take place. © 2010 The Authors. International Journal of Andrology © 2011 European Academy of Andrology.

  10. Anisotropic Complementary Acoustic Metamaterial for Canceling out Aberrating Layers

    Directory of Open Access Journals (Sweden)

    Chen Shen

    2014-11-01

    Full Text Available In this paper, we investigate a type of anisotropic, acoustic complementary metamaterial (CMM and its application in restoring acoustic fields distorted by aberrating layers. The proposed quasi two-dimensional (2D, nonresonant CMM consists of unit cells formed by membranes and side branches with open ends. Simultaneously, anisotropic and negative density is achieved by assigning membranes facing each direction (x and y directions different thicknesses, while the compressibility is tuned by the side branches. Numerical examples demonstrate that the CMM, when placed adjacent to a strongly aberrating layer, could acoustically cancel out that aberrating layer. This leads to dramatically reduced acoustic field distortion and enhanced sound transmission, therefore virtually removing the layer in a noninvasive manner. In the example where a focused beam is studied, using the CMM, the acoustic intensity at the focus is increased from 28% to 88% of the intensity in the control case (in the absence of the aberrating layer and the CMM. The proposed acoustic CMM has a wide realm of potential applications, such as cloaking, all-angle antireflection layers, ultrasound imaging, detection, and treatment through aberrating layers.

  11. Sub-ångstrom resolution using aberration corrected electron optics.

    Science.gov (United States)

    Batson, P E; Dellby, N; Krivanek, O L

    2002-08-08

    Following the invention of electron optics during the 1930s, lens aberrations have limited the achievable spatial resolution to about 50 times the wavelength of the imaging electrons. This situation is similar to that faced by Leeuwenhoek in the seventeenth century, whose work to improve the quality of glass lenses led directly to his discovery of the ubiquitous "animalcules" in canal water, the first hints of the cellular basis of life. The electron optical aberration problem was well understood from the start, but more than 60 years elapsed before a practical correction scheme for electron microscopy was demonstrated, and even then the remaining chromatic aberrations still limited the resolution. We report here the implementation of a computer-controlled aberration correction system in a scanning transmission electron microscope, which is less sensitive to chromatic aberration. Using this approach, we achieve an electron probe smaller than 1 A. This performance, about 20 times the electron wavelength at 120 keV energy, allows dynamic imaging of single atoms, clusters of a few atoms, and single atomic layer 'rafts' of atoms coexisting with Au islands on a carbon substrate. This technique should also allow atomic column imaging of semiconductors, for detection of single dopant atoms, using an electron beam with energy below the damage threshold for silicon.

  12. Primary chromatic aberration elimination via optimization work with genetic algorithm

    Science.gov (United States)

    Wu, Bo-Wen; Liu, Tung-Kuan; Fang, Yi-Chin; Chou, Jyh-Horng; Tsai, Hsien-Lin; Chang, En-Hao

    2008-09-01

    Chromatic Aberration plays a part in modern optical systems, especially in digitalized and smart optical systems. Much effort has been devoted to eliminating specific chromatic aberration in order to match the demand for advanced digitalized optical products. Basically, the elimination of axial chromatic and lateral color aberration of an optical lens and system depends on the selection of optical glass. According to reports from glass companies all over the world, the number of various newly developed optical glasses in the market exceeds three hundred. However, due to the complexity of a practical optical system, optical designers have so far had difficulty in finding the right solution to eliminate small axial and lateral chromatic aberration except by the Damped Least Squares (DLS) method, which is limited in so far as the DLS method has not yet managed to find a better optical system configuration. In the present research, genetic algorithms are used to replace traditional DLS so as to eliminate axial and lateral chromatic, by combining the theories of geometric optics in Tessar type lenses and a technique involving Binary/Real Encoding, Multiple Dynamic Crossover and Random Gene Mutation to find a much better configuration for optical glasses. By implementing the algorithms outlined in this paper, satisfactory results can be achieved in eliminating axial and lateral color aberration.

  13. Taking in a Show.

    Science.gov (United States)

    Boden, Timothy W

    2016-01-01

    Many medical practices have cut back on education and staff development expenses, especially those costs associated with conventions and conferences. But there are hard-to-value returns on your investment in these live events--beyond the obvious benefits of acquired knowledge and skills. Major vendors still exhibit their services and wares at many events, and the exhibit hall is a treasure-house of information and resources for the savvy physician or administrator. Make and stick to a purposeful plan to exploit the trade show. You can compare products, gain new insights and ideas, and even negotiate better deals with representatives anxious to realize returns on their exhibition investments.

  14. Alkaline phosphatase retained in HepG2 hepatocarcinoma cells vs. alkaline phosphatase released to culture medium: difference of aberrant glycosylation.

    Science.gov (United States)

    Nowrouzi, Azin; Yazdanparast, Razieh

    2005-05-06

    Liver tissue is the source of 90% of serum alkaline phosphatase (AP). The serum levels and structures of tumor marker proteins change under many disease conditions as well as cancer. The study was aimed at determining the type of alkaline phosphatase (AP) present in HepG2 hepatocellular carcinoma cell line. Alkaline phosphatase rich extracts of healthy human liver, HepG2 hepatocarcinoma cells, as well as the condition medium of HepG2 cells were prepared by extraction with 40% n-butanol and 30-50% acetone precipitation, and subjected to various chromatographic procedures. Lectin affinity chromatography of the samples with concanavalin A-Sepharose 4B showed considerable differences in the elution patterns. Non-denaturing polyacrylamide gel electrophoresis of the culture medium yielded a relatively slow migrating band of activity that coincided with none of the three bands of activity produced by the normal liver extract, nor with the bands of the cell pellet extract. Inhibition patterns were established by measuring the enzyme activities in the presence of varying concentrations of L-phenylalanine, L-leucine, L-homoarginine, and levamisole. The APs from the cell line were neuraminidase sensitive. According to the results the main AP produced and released to the medium by HepG2 cell line is an aberrantly glycosylated tissue non-specific AP. In addition, the differences between the cell-pellet AP and the culture medium AP seemed to stem from different sugar moieties in their structures.

  15. Postnatal Migration of Cerebellar Interneurons

    Directory of Open Access Journals (Sweden)

    Ludovic Galas

    2017-06-01

    Full Text Available Due to its continuing development after birth, the cerebellum represents a unique model for studying the postnatal orchestration of interneuron migration. The combination of fluorescent labeling and ex/in vivo imaging revealed a cellular highway network within cerebellar cortical layers (the external granular layer, the molecular layer, the Purkinje cell layer, and the internal granular layer. During the first two postnatal weeks, saltatory movements, transient stop phases, cell-cell interaction/contact, and degradation of the extracellular matrix mark out the route of cerebellar interneurons, notably granule cells and basket/stellate cells, to their final location. In addition, cortical-layer specific regulatory factors such as neuropeptides (pituitary adenylate cyclase-activating polypeptide (PACAP, somatostatin or proteins (tissue-type plasminogen activator (tPA, insulin growth factor-1 (IGF-1 have been shown to inhibit or stimulate the migratory process of interneurons. These factors show further complexity because somatostatin, PACAP, or tPA have opposite or no effect on interneuron migration depending on which layer or cell type they act upon. External factors originating from environmental conditions (light stimuli, pollutants, nutrients or drug of abuse (alcohol also alter normal cell migration, leading to cerebellar disorders.

  16. There and back again: migration in freshwater fishes

    DEFF Research Database (Denmark)

    Brönmark, C.; Hulthén, K.; Nilsson, P.A.

    2013-01-01

    that migration occurs in a range of freshwater fish taxa from many different habitats. In this review we focus on the causes and consequences of migration in freshwater fishes. We start with an introduction of concepts and categories of migration, and then address the evolutionary causes that drive individuals...... to make these migratory journeys. The basis for the decision of an individual fish to migrate or stay resident is an evaluation of the costs and benefits of different strategies to maximize its lifetime reproductive effort. We provide examples by discussing our own work on the causes behind seasonal......Animal migration is an amazing phenomenon that has fascinated humans for long. Many freshwater fishes also show remarkable migrations, whereof the spectacular mass migrations of salmonids from the spawning streams are the most well known and well studied. However, recent studies have shown...

  17. Evolution of mammalian migrations for refuge, breeding, and food.

    Science.gov (United States)

    Gnanadesikan, Gitanjali E; Pearse, William D; Shaw, Allison K

    2017-08-01

    Many organisms migrate between distinct habitats, exploiting variable resources while profoundly affecting ecosystem services, disease spread, and human welfare. However, the very characteristics that make migration captivating and significant also make it difficult to study, and we lack a comprehensive understanding of which species migrate and why. Here we show that, among mammals, migration is concentrated within Cetacea and Artiodactyla but also diffusely spread throughout the class (found in 12 of 27 orders). We synthesize the many ecological drivers of round-trip migration into three types of movement-between breeding and foraging sites, between breeding and refuge sites, and continuous tracking of forage/prey-each associated with different traits (body mass, diet, locomotion, and conservation status). Our results provide only partial support for the hypothesis that migration occurs without phylogenetic constraint. Furthermore, our findings suggest that categorizing migration into these three types may aid predictions of migrants' responses to environmental changes.

  18. Aberrations in preliminary design of ITER divertor impurity influx monitor

    Energy Technology Data Exchange (ETDEWEB)

    Kitazawa, Sin-iti, E-mail: kitazawa.siniti@jaea.go.jp [Naka Fusion Institute, Japan Atomic Energy Agency, JAEA, Naka 311-0193 (Japan); Ogawa, Hiroaki [Naka Fusion Institute, Japan Atomic Energy Agency, JAEA, Naka 311-0193 (Japan); Katsunuma, Atsushi; Kitazawa, Daisuke [Core Technology Center, Nikon Corporation, Yokohama 244-8533 (Japan); Ohmori, Keisuke [Customized Products Business Unit, Nikon Corporation, Mito 310-0843 (Japan)

    2015-12-15

    Highlights: • Divertor impurity influx monitor for ITER (DIM) is procured by JADA. • DIM is designed to observe light from nuclear fusion plasma directly. • DIM is under preliminary design phase. • The spot diagrams were suppressed within the core of receiving fiber. • The aberration of DIM is suppressed in the preliminary design. - Abstract: Divertor impurity influx monitor for ITER (DIM) is a diagnostic system that observes light from nuclear fusion plasma directly. This system is affected by various aberrations because it observes light from the fan-array chord near the divertor in the ultraviolet–near infrared wavelength range. The aberrations should be suppressed to the extent possible to observe the light with very high spatial resolution. In the preliminary design of DIM, spot diagrams were suppressed within the core of the receiving fiber's cross section, and the resulting spatial resolutions satisfied the design requirements.

  19. Correcting the Chromatic Aberration in Barrel Distortion of Endoscopic Images

    Directory of Open Access Journals (Sweden)

    Y. M. Harry Ng

    2003-04-01

    Full Text Available Modern endoscopes offer physicians a wide-angle field of view (FOV for minimally invasive therapies. However, the high level of barrel distortion may prevent accurate perception of image. Fortunately, this kind of distortion may be corrected by digital image processing. In this paper we investigate the chromatic aberrations in the barrel distortion of endoscopic images. In the past, chromatic aberration in endoscopes is corrected by achromatic lenses or active lens control. In contrast, we take a computational approach by modifying the concept of image warping and the existing barrel distortion correction algorithm to tackle the chromatic aberration problem. In addition, an error function for the determination of the level of centroid coincidence is proposed. Simulation and experimental results confirm the effectiveness of our method.

  20. An electron microscope for the aberration-corrected era.

    Science.gov (United States)

    Krivanek, O L; Corbin, G J; Dellby, N; Elston, B F; Keyse, R J; Murfitt, M F; Own, C S; Szilagyi, Z S; Woodruff, J W

    2008-02-01

    Improved resolution made possible by aberration correction has greatly increased the demands on the performance of all parts of high-end electron microscopes. In order to meet these demands, we have designed and built an entirely new scanning transmission electron microscope (STEM). The microscope includes a flexible illumination system that allows the properties of its probe to be changed on-the-fly, a third-generation aberration corrector which corrects all geometric aberrations up to fifth order, an ultra-responsive yet stable five-axis sample stage, and a flexible configuration of optimized detectors. The microscope features many innovations, such as a modular column assembled from building blocks that can be stacked in almost any order, in situ storage and cleaning facilities for up to five samples, computer-controlled loading of samples into the column, and self-diagnosing electronics. The microscope construction is described, and examples of its capabilities are shown.

  1. An electron microscope for the aberration-corrected era

    Energy Technology Data Exchange (ETDEWEB)

    Krivanek, O.L. [Nion Co., 1102 8th Street, Kirkland, WA 98033 (United States)], E-mail: krivanek.ondrej@gmail.com; Corbin, G.J.; Dellby, N.; Elston, B.F.; Keyse, R.J.; Murfitt, M.F.; Own, C.S.; Szilagyi, Z.S.; Woodruff, J.W. [Nion Co., 1102 8th Street, Kirkland, WA 98033 (United States)

    2008-02-15

    Improved resolution made possible by aberration correction has greatly increased the demands on the performance of all parts of high-end electron microscopes. In order to meet these demands, we have designed and built an entirely new scanning transmission electron microscope (STEM). The microscope includes a flexible illumination system that allows the properties of its probe to be changed on-the-fly, a third-generation aberration corrector which corrects all geometric aberrations up to fifth order, an ultra-responsive yet stable five-axis sample stage, and a flexible configuration of optimized detectors. The microscope features many innovations, such as a modular column assembled from building blocks that can be stacked in almost any order, in situ storage and cleaning facilities for up to five samples, computer-controlled loading of samples into the column, and self-diagnosing electronics. The microscope construction is described, and examples of its capabilities are shown.

  2. Split-plot fractional designs: Is minimum aberration enough?

    DEFF Research Database (Denmark)

    Kulahci, Murat; Ramirez, Jose; Tobias, Randy

    2006-01-01

    Split-plot experiments are commonly used in industry for product and process improvement. Recent articles on designing split-plot experiments concentrate on minimum aberration as the design criterion. Minimum aberration has been criticized as a design criterion for completely randomized fractional...... factorial design and alternative criteria, such as the maximum number of clear two-factor interactions, are suggested (Wu and Hamada (2000)). The need for alternatives to minimum aberration is even more acute for split-plot designs. In a standard split-plot design, there are several types of two...... for completely randomized designs. Consequently, we provide a modified version of the maximum number of clear two-factor interactions design criterion to be used for split-plot designs....

  3. Showing Value (Editorial

    Directory of Open Access Journals (Sweden)

    Denise Koufogiannakis

    2009-06-01

    Full Text Available When Su Cleyle and I first decided to start Evidence Based Library and Information Practice, one of the things we agreed upon immediately was that the journal be open access. We knew that a major obstacle to librarians using the research literature was that they did not have access to the research literature. Although Su and I are both academic librarians who can access a wide variety of library and information literature from our institutions, we belong to a profession where not everyone has equal access to the research in our field. Without such access to our own body of literature, how can we ever hope for practitioners to use research evidence in their decision making? It would have been contradictory to the principles of evidence based library and information practice to do otherwise.One of the specific groups we thought could use such an open access venue for discovering research literature was school librarians. School librarians are often isolated and lacking access to the research literature that may help them prove to stakeholders the importance of their libraries and their role within schools. Certainly, school libraries have been in decline and the use of evidence to show value is needed. As Ken Haycock noted in his 2003 report, The Crisis in Canada’s School Libraries: The Case for Reform and Reinvestment, “Across the country, teacher-librarians are losing their jobs or being reassigned. Collections are becoming depleted owing to budget cuts. Some principals believe that in the age of the Internet and the classroom workstation, the school library is an artifact” (9. Within this context, school librarians are looking to our research literature for evidence of the impact that school library programs have on learning outcomes and student success. They are integrating that evidence into their practice, and reflecting upon what can be improved locally. They are focusing on students and showing the impact of school libraries and

  4. The BHVI-EyeMapper: peripheral refraction and aberration profiles.

    Science.gov (United States)

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

    2014-10-01

    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. 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. As accommodation increased, the relative peripheral refraction profiles of M and J180 became significantly (p 0.05). The peripheral aberration profiles of C[3, 1], C[3, 3], and C[4, 0] became significantly (p 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.

  5. Reducing starbursts in highly aberrated eyes with pupil miosis.

    Science.gov (United States)

    Xu, Renfeng; Kollbaum, Pete; Thibos, Larry; Lopez-Gil, Norberto; Bradley, Arthur

    2018-01-01

    To test the hypothesis that marginal ray deviations determine perceived starburst sizes, and to explore different strategies for decreasing starburst size in highly aberrated eyes. Perceived size of starburst images and visual acuities were measured psychophysically for eyes with varying levels of spherical aberration, pupil sizes, and defocus. Computationally, we use a polychromatic eye model including the typical levels of higher order aberrations (HOAs) for keratoconic and post-LASIK eyes to quantify the image quality (the visually weighted Strehl ratio derived from the optical transfer function, VSOTF) with different pupil sizes at both photopic and mesopic light levels. For distance corrected post-LASIK and keratoconic eyes with a night-time pupil (e.g., 7 mm), the starburst diameter is about 1.5 degrees (1 degree for normal presbyopic eyes), which can be reduced to ≤0.25 degrees with pupil sizes ≤3 mm. Starburst size is predicted from the magnitude of the longitudinal spherical aberration. Refracting the eye to focus the pupil margin also removed starbursts, but, unlike small pupils, significantly degraded visual acuity. Reducing pupil diameter to 3 mm improved image quality for these highly aberrated eyes by about 2.7 ×  to 1.7 ×  relative to the natural pupils when light levels were varied from 0.1 to 1000 cd m-2 , respectively. Subjects with highly aberrated eyes observed larger starbursts around bright lights at night predictable by the deviated marginal rays. These were effectively attenuated by reducing pupil diameters to ≤3 mm, which did not cause a drop in visual acuity or modelled image quality even at mesopic light levels. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

  6. The effects of dietary selenomethionine on polyamines and azoxymethane-induced aberrant crypts.

    Science.gov (United States)

    Baines, A T; Holubec, H; Basye, J L; Thorne, P; Bhattacharyya, A K; Spallholz, J; Shriver, B; Cui, H; Roe, D; Clark, L C; Earnest, D L; Nelson, M A

    2000-11-28

    We evaluated the effects of dietary selenomethionine supplementation on colonic polyamine levels and the ability of L-selenomethionine supplementation to modulate the carcinogenic activity of azoxymethane (AOM) in the rat colon. Four-week-old male F344 rats were treated with 15 mg/kg body weight of AOM once a week for 2 weeks. Dietary selenomethionine at a concentration of either 1 or 2 ppm was administered in AIN-76A rodent diet to AOM-treated animals for 16 weeks. Aberrant crypt foci (ACF), precursor lesions of colon cancer, were investigated after the 16 week treatment course. Selenomethionine given in the diet at 2 ppm markedly reduced the number of aberrant crypt foci. The multiplicity of ACFs (i.e. the number of aberrant crypts/focus) and the percentage of microadenomas were also affected by selenomethionine in a dose dependent manner. However, evaluation of the colonic tissue polyamine levels between control and treated groups showed no significant difference. These results demonstrate that selenomethionine can modulate the development of AOM-induced premalignant lesions through a polyamine-independent mechanism.

  7. On the benefit of the negative-spherical-aberration imaging technique for quantitative HRTEM

    Energy Technology Data Exchange (ETDEWEB)

    Jia, C.L., E-mail: c.jia@fz-juelich.de [Institute of Solid State Research and Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons, Research Centre Juelich, D-52425 Juelich (Germany); Houben, L.; Thust, A.; Barthel, J. [Institute of Solid State Research and Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons, Research Centre Juelich, D-52425 Juelich (Germany)

    2010-04-15

    Employing an aberration corrector in a high-resolution transmission electron microscope, the spherical aberration C{sub S} can be tuned to negative values, resulting in a novel imaging technique, which is called the negative C{sub S} imaging (NCSI) technique. The image contrast obtained with the NCSI technique is compared quantitatively with the image contrast formed with the traditional positive C{sub S} imaging (PCSI) technique. For the case of thin objects negative C{sub S} images are superior to positive C{sub S} images concerning the magnitude of the obtained contrast, which is due to constructive rather than destructive superposition of fundamental contrast contributions. As a consequence, the image signal obtained with a negative spherical aberration is significantly more robust against noise caused by amorphous surface layers, resulting in a measurement precision of atomic positions which is by a factor of 2-3 better at an identical noise level. The quantitative comparison of the two alternative C{sub S}-corrected imaging modes shows that the NCSI mode yields significantly more precise results in quantitative high-resolution transmission electron microscopy of thin objects than the traditional PCSI mode.

  8. Determination of chromatic aberration in the human eye by means of Fresnel propagation theory

    Science.gov (United States)

    Mas, David; Perez, Jorge; Illueca, Carlos; Espinosa, Julian; Hernandez, Consuelo; Vazquez, Carmen; Miret, Juan J.

    2005-09-01

    In this communication, the authors have determined the longitudinal chromatic aberrations in real eyes. The method that has been used combines real data of corneal morphology, central thickness of crystalline lens and biometric measures of axial length together with numerical calculation of the propagation process. The curvature of the crystalline lens has been adjusted to different curvature models and refractive index distributions. The wavelength dependence of all ocular media has been modelled through the Cauchy formula. Propagation through anterior and posterior chambers has been accomplished through numerical calculation of diffraction integral instead of classical ray-tracing approach. This imposes serous restrictions on the number of samples that are needed for a full propagation process. If we are only interested in amplitude calculations the method consists of evaluating propagation from cornea to crystalline lens with a spectrum propagation method. Propagation from the lens to the best image plane is accomplished by a direct calculation of Fresnel integral. With this model, we have obtained the refraction chromatic difference in diopters for several eyes. Results are compared with real measures of the chromatic aberration, showing a good agreement with numerical calculations. The capabilities of the technique have been demonstrated by applying the method to the study of the chromatic aberration of a keratoconus.

  9. SURF imaging beams in an aberrative medium: Generation and postprocessing enhancement.

    Science.gov (United States)

    Näsholm, Sven Peter; Angelsen, Bjørn A J

    2012-11-01

    This paper presents numerical simulations of dual-frequency second-order ultrasound field (SURF) reverberation suppression transmit-pulse complexes. Such propagation was previously studied in a homogeneous medium. In this work, the propagation path includes a strongly aberrating body wall modeled by a sequence of delay screens. Each of the applied SURF transmit pulse complexes consists of a high-frequency 3.5-MHz imaging pulse combined with a low-frequency 0.5-MHz sound speed manipulation pulse. Furthermore, the feasibility of two signal postprocessing methods are investigated using the aberrated transmit SURF beams. These methods have previously been shown to adjust the depth of maximum SURF reverberation suppression within a homogeneous medium. The need for this study arises because imaging situations in which reverberation suppression is useful are also likely to produce pulse wave front distortion (aberration). Such distortions could potentially produce time delays that cancel the accumulated propagation time delay needed for the SURF reverberation suppression technique. Results show that both the generation of synthetic SURF reverberation suppression imaging transmit beams and the following postprocessing adjustments are attainable even when a body wall introduces time delays which are larger than previously reported delays measured on human body wall specimens.

  10. Monitoring Count Time Series in R: Aberration Detection in Public Health Surveillance

    Directory of Open Access Journals (Sweden)

    Maëlle Salmon

    2016-05-01

    Full Text Available Public health surveillance aims at lessening disease burden by, e.g., timely recognizing emerging outbreaks in case of infectious diseases. Seen from a statistical perspective, this implies the use of appropriate methods for monitoring time series of aggregated case reports. This paper presents the tools for such automatic aberration detection offered by the R package surveillance. We introduce the functionalities for the visualization, modeling and monitoring of surveillance time series. With respect to modeling we focus on univariate time series modeling based on generalized linear models (GLMs, multivariate GLMs, generalized additive models and generalized additive models for location, shape and scale. Applications of such modeling include illustrating implementational improvements and extensions of the well-known Farrington algorithm, e.g., by spline-modeling or by treating it in a Bayesian context. Furthermore, we look at categorical time series and address overdispersion using beta-binomial or Dirichlet-multinomial modeling. With respect to monitoring we consider detectors based on either a Shewhart-like single timepoint comparison between the observed count and the predictive distribution or by likelihoodratio based cumulative sum methods. Finally, we illustrate how surveillance can support aberration detection in practice by integrating it into the monitoring workflow of a public health institution. Altogether, the present article shows how well surveillance can support automatic aberration detection in a public health surveillance context.

  11. A resolution insensitive to geometrical aberrations by using incoherent illumination and interference imaging

    Science.gov (United States)

    Xiao, Peng; Fink, Mathias; Gandjbakhche, Amir H.; Claude Boccara, A.

    2017-05-01

    This contribution is another opportunity to acknowledge the influence of Roger Maynard on our research work when he pushed one of us (ACB) to explore the field of waves propagating in complex media rather than limiting ourselves to the wavelength scale of thermal waves or near field phenomena. Optical tomography is used for imaging in-depth scattering media such as biological tissues. Optical coherence tomography (OCT) plays an important role in imaging biological samples. Coupling OCT with adaptive optics (AO) in order to correct eye aberrations has led to cellular imaging of the retina. By using our approach called Full-Field OCT (FFOCT) we show that, with spatially incoherent illumination, the width of the point-spread function (PSF) that governs the resolution is not affected by aberrations that induce only a reduction of the signal level. We will describe our approach by starting with the PSF experimental data followed by a simple theoretical analysis, and numerical calculations. Finally full images obtained through or inside scattering and aberrating media will be shown.

  12. STRADalpha deficiency results in aberrant mTORC1 signaling during corticogenesis in humans and mice.

    Science.gov (United States)

    Orlova, Ksenia A; Parker, Whitney E; Heuer, Gregory G; Tsai, Victoria; Yoon, Jason; Baybis, Marianna; Fenning, Robert S; Strauss, Kevin; Crino, Peter B

    2010-05-01

    Polyhydramnios, megalencephaly, and symptomatic epilepsy syndrome (PMSE) is a rare human autosomal-recessive disorder characterized by abnormal brain development, cognitive disability, and intractable epilepsy. It is caused by homozygous deletions of STE20-related kinase adaptor alpha (STRADA). The underlying pathogenic mechanisms of PMSE and the role of STRADA in cortical development remain unknown. Here, we found that a human PMSE brain exhibits cytomegaly, neuronal heterotopia, and aberrant activation of mammalian target of rapamycin complex 1 (mTORC1) signaling. STRADalpha normally binds and exports the protein kinase LKB1 out of the nucleus, leading to suppression of the mTORC1 pathway. We found that neurons in human PMSE cortex exhibited abnormal nuclear localization of LKB1. To investigate this further, we modeled PMSE in mouse neural progenitor cells (mNPCs) in vitro and in developing mouse cortex in vivo by knocking down STRADalpha expression. STRADalpha-deficient mNPCs were cytomegalic and showed aberrant rapamycin-dependent activation of mTORC1 in association with abnormal nuclear localization of LKB1. Consistent with the observations in human PMSE brain, knockdown of STRADalpha in vivo resulted in cortical malformation, enhanced mTORC1 activation, and abnormal nuclear localization of LKB1. Thus, we suggest that the aberrant nuclear accumulation of LKB1 caused by STRADalpha deficiency contributes to hyperactivation of mTORC1 signaling and disruption of neuronal lamination during corticogenesis, and thereby the neurological features associated with PMSE.

  13. STRADα deficiency results in aberrant mTORC1 signaling during corticogenesis in humans and mice

    Science.gov (United States)

    Orlova, Ksenia A.; Parker, Whitney E.; Heuer, Gregory G.; Tsai, Victoria; Yoon, Jason; Baybis, Marianna; Fenning, Robert S.; Strauss, Kevin; Crino, Peter B.

    2010-01-01

    Polyhydramnios, megalencephaly, and symptomatic epilepsy syndrome (PMSE) is a rare human autosomal-recessive disorder characterized by abnormal brain development, cognitive disability, and intractable epilepsy. It is caused by homozygous deletions of STE20-related kinase adaptor α (STRADA). The underlying pathogenic mechanisms of PMSE and the role of STRADA in cortical development remain unknown. Here, we found that a human PMSE brain exhibits cytomegaly, neuronal heterotopia, and aberrant activation of mammalian target of rapamycin complex 1 (mTORC1) signaling. STRADα normally binds and exports the protein kinase LKB1 out of the nucleus, leading to suppression of the mTORC1 pathway. We found that neurons in human PMSE cortex exhibited abnormal nuclear localization of LKB1. To investigate this further, we modeled PMSE in mouse neural progenitor cells (mNPCs) in vitro and in developing mouse cortex in vivo by knocking down STRADα expression. STRADα-deficient mNPCs were cytomegalic and showed aberrant rapamycin-dependent activation of mTORC1 in association with abnormal nuclear localization of LKB1. Consistent with the observations in human PMSE brain, knockdown of STRADα in vivo resulted in cortical malformation, enhanced mTORC1 activation, and abnormal nuclear localization of LKB1. Thus, we suggest that the aberrant nuclear accumulation of LKB1 caused by STRADα deficiency contributes to hyperactivation of mTORC1 signaling and disruption of neuronal lamination during corticogenesis, and thereby the neurological features associated with PMSE. PMID:20424326

  14. Identification of candidate driver genes in common focal chromosomal aberrations of microsatellite stable colorectal cancer.

    Directory of Open Access Journals (Sweden)

    George J Burghel

    Full Text Available Colorectal cancer (CRC is a leading cause of cancer deaths worldwide. Chromosomal instability (CIN is a major driving force of microsatellite stable (MSS sporadic CRC. CIN tumours are characterised by a large number of somatic chromosomal copy number aberrations (SCNA that frequently affect oncogenes and tumour suppressor genes. The main aim of this work was to identify novel candidate CRC driver genes affected by recurrent and focal SCNA. High resolution genome-wide comparative genome hybridisation (CGH arrays were used to compare tumour and normal DNA for 53 sporadic CRC cases. Context corrected common aberration (COCA analysis and custom algorithms identified 64 deletions and 32 gains of focal minimal common regions (FMCR at high frequency (>10%. Comparison of these FMCR with published genomic profiles from CRC revealed common overlap (42.2% of deletions and 34.4% of copy gains. Pathway analysis showed that apoptosis and p53 signalling pathways were commonly affected by deleted FMCR, and MAPK and potassium channel pathways by gains of FMCR. Candidate tumour suppressor genes in deleted FMCR included RASSF3, IFNAR1, IFNAR2 and NFKBIA and candidate oncogenes in gained FMCR included PRDM16, TNS1, RPA3 and KCNMA1. In conclusion, this study confirms some previously identified aberrations in MSS CRC and provides in silico evidence for some novel candidate driver genes.

  15. [The influence of phenylephrine and tropicamide on higher order monochromatic aberrations].

    Science.gov (United States)

    Jurkutat, S; Loosberg, B; Hemmelmann, C; Dawszynski, J; Strobel, J

    2007-03-01

    For wave-front guided corneal surgery, measuring higher order monochromatic aberrations in mydriasis is needed. However, a potential influence of mydriatic drugs on such aberrations could distort the ablation profile. Wave-front analysis was carried out on 20 (tropicamide) and 19 (phenylephrine) eyes after dark adaptation, followed by measurement after the instillation of the mydriatics one after another. Phenylephrine had no significant influence on the wave-front; neither sphere nor RMS data differed from those taken after dark adaptation. After instilling tropicamide, significant changes in Z(2) (0) and, in parallel, also of the sphere were found. The RMS showed no significant difference, only the spherical aberration Z(4) (0) was reduced by an average of 0.035 microm. The wave-front changes individually through the mydriasis due to phenylephrine and tropicamide. In the case of tropicamide, the deviation is statistically significant. Therefore, abandonment of these mydriatics before refractive surgery can be recommended, as can the use physiological pupil dilatation. Because of its lower influence, phenylephrine should be the first choice if dimout effects no adequate mydriasis.

  16. Identification of candidate driver genes in common focal chromosomal aberrations of microsatellite stable colorectal cancer.

    Science.gov (United States)

    Burghel, George J; Lin, Wei-Yu; Whitehouse, Helen; Brock, Ian; Hammond, David; Bury, Jonathan; Stephenson, Yvonne; George, Rina; Cox, Angela

    2013-01-01

    Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. Chromosomal instability (CIN) is a major driving force of microsatellite stable (MSS) sporadic CRC. CIN tumours are characterised by a large number of somatic chromosomal copy number aberrations (SCNA) that frequently affect oncogenes and tumour suppressor genes. The main aim of this work was to identify novel candidate CRC driver genes affected by recurrent and focal SCNA. High resolution genome-wide comparative genome hybridisation (CGH) arrays were used to compare tumour and normal DNA for 53 sporadic CRC cases. Context corrected common aberration (COCA) analysis and custom algorithms identified 64 deletions and 32 gains of focal minimal common regions (FMCR) at high frequency (>10%). Comparison of these FMCR with published genomic profiles from CRC revealed common overlap (42.2% of deletions and 34.4% of copy gains). Pathway analysis showed that apoptosis and p53 signalling pathways were commonly affected by deleted FMCR, and MAPK and potassium channel pathways by gains of FMCR. Candidate tumour suppressor genes in deleted FMCR included RASSF3, IFNAR1, IFNAR2 and NFKBIA and candidate oncogenes in gained FMCR included PRDM16, TNS1, RPA3 and KCNMA1. In conclusion, this study confirms some previously identified aberrations in MSS CRC and provides in silico evidence for some novel candidate driver genes.

  17. Internal migration, international migration, and physical growth of left-behind children: A study of two settings.

    Science.gov (United States)

    Lu, Yao

    2015-11-01

    Parental out-migration has become a common experience of childhood worldwide and tends to have important ramifications for child development. There has been much debate on whether overall children benefit or suffer from parental out-migration. The present study examines how the relationship between parental out-migration and children's growth differs by the type of migration (internal vs. international). This comparison is conducted in two diverse settings, Mexico and Indonesia. Data are from two national longitudinal surveys: the Mexican Family Life Survey and the Indonesian Family Life Survey. Results from fixed-effect regressions show that international migration tends to have a less beneficial, sometimes even more detrimental, impact on the growth of children left behind than internal migration. Results also reveal contextual differences in the role of parental out-migration. Possible explanations are discussed. Copyright © 2015. Published by Elsevier Ltd.

  18. Generalized Doppler and aberration kernel for frequency-dependent cosmological observables

    Science.gov (United States)

    Yasini, Siavash; Pierpaoli, Elena

    2017-11-01

    We introduce a frequency-dependent Doppler and aberration transformation kernel for the harmonic multipoles of a general cosmological observable with spin weight s , Doppler weight d and arbitrary frequency spectrum. In the context of cosmic microwave background (CMB) studies, the frequency-dependent formalism allows to correct for the motion-induced aberration and Doppler effects on individual frequency maps with different masks. It also permits to deboost background radiations with non-blackbody frequency spectra, like extragalactic foregrounds and CMB spectra with primordial spectral distortions. The formalism can also be used to correct individual E and B polarization modes and account for motion-induced E/B mixing of polarized observables with d ≠1 at different frequencies. We apply the generalized aberration kernel on polarized and unpolarized specific intensity at 100 and 217 GHz and show that the motion-induced effects typically increase with the frequency of observation. In all-sky CMB experiments, the frequency-dependence of the motion-induced effects for a blackbody spectrum are overall negligible. However in a cut-sky analysis, ignoring the frequency dependence can lead to percent level error in the polarized and unpolarized power spectra over all angular scales. In the specific cut-sky used in our analysis (b >4 5 ° ,fsky≃14 % ), and for the dipole-inferred velocity β =0.00123 typically attributed to our peculiar motion, the Doppler and aberration effects can change polarized and unpolarized power spectra of specific intensity in the CMB rest frame by 1 - 2 % , but we find the polarization cross-leakage between E and B modes to be negligible.

  19. Mirror Symmetry of Peripheral Monochromatic Aberrations in Fellow Eyes of Isomyopes and Anisomyopes.

    Science.gov (United States)

    Osuagwu, Uchechukwu L; Suheimat, Marwan; Atchison, David A

    2016-06-01

    To investigate mirror symmetry of peripheral ocular aberrations in fellow eyes of iso- and anisomyopes. Peripheral aberration was measured over the central 42° × 32° visual field for a 5-mm pupil in both eyes of 19 isomyopic (spherical equivalent refraction M [right/left]: -2.5 ± 2.1 diopters [D]/-2.7 ± 2.3 D) and 10 anisomyopic (M: -4.0 ± 1.8 D/-4.3 ± 2.8 D) young adults. Isomyopes had less than 1.0 D fellow eye refraction difference and anisomyopes had between 1.0 D and 2.6 D fellow eye differences (mean difference: 1.3 ± 0.6 D). Orthogonal regression of Zernike coefficients determined right-left eye correlations in isomyopes. For anisomyopes, higher and lower myopic eye coefficients were compared. For isomyopes, the percentages of visual field locations with significant coefficient correlations between fellow eyes varied from 100% for astigmatism ( ) to 18% for tetrafoil ( ). Positive correlations were found for , , , , , and , and negative correlations were found for , , , , and coefficients, indicating that the signs are different for corresponding locations of fellow eyes for the last five of these coefficients. Slopes of correlations were not different from ± 1, except for , , and (+0.95, -0.97, and +0.52, respectively). In anisomyopes, significant but small fellow eye differences were found for only and coefficients, with significant interactions between anisometropia and field position for only two coefficients. Peripheral aberration coefficients across the visual field show mirror symmetry in isomyopes, and in a pooled data set the coefficients with negative correlations require sign changes for left eye data. Anisometropia contributes no more to peripheral aberration differences between fellow eyes than could be expected on the basis of refraction differences between people.

  20. [Prenatal diagnostics of chromosomal aberrations Czech Republic: 1994-2007].

    Science.gov (United States)

    Gregor, V; Sípek, A; Sípek, A; Horácek, J '; Langhammer, P; Petrzílková, L; Calda, P

    2009-02-01

    An analysis of prenatal diagnostics efficiency of selected types of chromosomal aberrations in the Czech Republic in 2007. Update of 1994-2007 data according to particular selected diagnoses. Retrospective epidemiological analysis of pre- and postnatal chromosomal aberrations diagnostics and its efficiency. Data on pre- and postnatally diagnosed birth defects in the Czech Republic during 1994-2007 were used. Data on prenatally diagnosed birth defects (and for terminated pregnancies) were collected from particular departments of prenatal diagnostics, medical genetics and ultrasound diagnostics in the Czech Republic, data on birth defects in births from the National Birth Defects Register (Institute for Health Information and Statistics). Total numbers over the period under the study, mean incidences of selected types of chromosomal aberrations and mean prenatal diagnostics efficiencies were analyzed. Following chromosomal aberrations were studied: Down, Edwards, Patau, Turner and Klinefelter syndromes and syndromes 47,XXX and 47,XYY. A relative proportion of Down, Edwards and Patau syndromes as well as other autosomal and gonosomal aberration is presented in figures. Recently, trisomies 13, 18 and 21 present around 70% of all chromosomal aberrations in selectively aborted fetuses, in other pregnancies, "other chromosomal aberrations" category (mostly balanced reciprocal translocations and inversions) present more than 2/3 of all diagnoses. During the period under the study, following total numbers, mean relative incidences (per 10,000 live births, in brackets) and mean prenatal diagnostics efficiency (in %) were found in following chromosomal syndromes: Down syndrome 2,244 (16.58) and 63.37%, Edwards syndrome 521 (3.85) and 79.93%, Patau syndrome 201 (1.49) and 68.87%, Turner syndrome 380 (2.81) and 79.89%, 47,XXX syndrome 61 (0.45) and 59.74%, Klinefelter syndrome 163 (1.20) and 73.65% and 47,XYY syndrome 22 (0.16) and 54.76%. The study gives updated results of

  1. Climate change may affect human migration in Mongolia

    Science.gov (United States)

    Kakinuma, K.; Puma, M. J.; Kanae, S.

    2016-12-01

    Assessments of risks to climate changes are one of the most important issues in the world. It has become apparent that migration has a central role in adaptation measures for climate changes. Migration creates risk as well as benefits for migrants and sending and receiving regions. However, multiple drivers affect migration and it is difficult to estimate patterns of human migration under climate changes. Here we examined effects of climatic factors (such as temperature and precipitation in summer and winter season) on peoples' migration in Mongolia. Mongolia, where is located in central Asia, has a long history of pastoralism. There are concerned the increase of temperature and the decrease of precipitation in the future. We used migration data and climate data for all of prefectures during 1983-2015. We demonstrated generalized linear model and used migration data as a response variable, climate data as explanatory variables. As a result, some climatic conditions (few summer precipitation and hot temperature) affected people's migration at western and southern part of Mongolia. These areas were reported that heat waves have been increased since 1990. Such climatic conditions may become trigger to human migration. We showed empirical evidences that climatic factors may affect migration in some regions. These results suggested that future climate changes may cause people's migration in Mongolia.

  2. En fornemmelse for migration

    DEFF Research Database (Denmark)

    Schütze, Laura Maria

    Afhandlingen undersøger, hvordan sted, museets rolle som aktør og religion er relevante for produktionen af migration på Immigrantmuseet (2012) og i Københavns Museums udstilling At blive københavner (2010). Afhandlingen er baseret på udstillingsanalyse samt interview med relevant museumsfagligt......, anvendes som virkemidler til at nuancere migration og distancere udstillingen fra den offentlige debat om indvandring. Afhandlingen peger på, at produktionen af den nyere danske historie på museum er præget af et fravær af religion. Det skyldes, at de museumsfaglige praksisser og traditioner afspejler en...... identiteter, som vi tager for givet: nationer, byer, kvinder - såvel som migration og religion. Afhandlingen argumenterer følgelig for, at museernes produktion af (materiel) religion er et særdeles relevant, men kun ringe udforsket, genstandsfelt for religionssociologien....

  3. More myths of migration.

    Science.gov (United States)

    Basch, L; Lerner, G

    1986-01-01

    This paper discusses some of the myths of migration. The 5 myths presented are: 1) racism has little to do with the causes of migration and does not necessarily impede the adjustment or success of migrants; 2) in areas where there is a strong feminist movement and trade unions, migrant women receive their support and can count on the solidarity of these organizations; 3) transnational corporations are positive forces in the developing countries where they operate--not only do they provide these states with new sources of capital, but they also impart new industrial skills to the labor force; 4) migration today is essentially short-term in nature--it therefore does not have a strong impact on family life; and 5) most migrants cluster together in ethnic enclaves which provide a strong source of support and diminish dislocation inherent in the migrant process.

  4. The aberrant asynchronous replication — characterizing lymphocytes of cancer patients — is erased following stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Korenstein-Ilan Avital

    2010-05-01

    Full Text Available Abstract Background Aberrations 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 levels in cells of patients with haematological malignancies from diagnosis to full remission, as achieved by allogeneic stem cell transplantation (alloSCT. Methods TP53 (a tumor suppressor gene assigned to chromosome 17, AML1 (a gene assigned to chromosome 21 and involved in the leukaemia-abundant 8;21 translocation and the pericentomeric satellite sequence of chromosome 17 (CEN17 were used for replication timing assessments. Aneuploidy was monitored by enumerating the copy numbers of chromosomes 17 and 21. Replication timing and aneuploidy were detected cytogenetically using fluorescence in situ hybridization (FISH technology applied to phytohemagglutinin (PHA-stimulated lymphocytes. Results We show that aberrant epigenetic markers are detected in patients with hematological malignancies from the time of diagnosis through to when they are scheduled to undergo alloSCT. These aberrations are unaffected by the clinical status of the disease and are displayed both during accelerated stages as well as in remission. Yet, these markers are eradicated completely following stem cell transplantation. In contrast, the increased levels of aneuploidy (irreversible genetic alterations displayed in blood lymphocytes at various stages of disease are not eliminated following transplantation. However, they do not elevate and remain unchanged (stable state. A demethylating anti-cancer drug, 5-azacytidine, applied in vitro to lymphocytes of patients prior to transplantation mimics the effect of transplantation: the epigenetic aberrations disappear while aneuploidy stays unchanged. Conclusions The reversible nature of the replication aberrations may

  5. Migration, Narration, Identity

    DEFF Research Database (Denmark)

    Leese, Peter

    three consecutive summers from 2010 to 2012. The articles focus on various aspects of the migrant experience and try to answer questions about migrant identity and its representations in literature and the media. The book closes with an original play by Carlos Morton, the Chicano playwright working......(co-editor with Carly McLaughlin and Wladyslaw Witalisz) This book presents articles resulting from joint research on the representations of migration conducted in connection with the Erasmus Intensive Programme entitled «Migration and Narration» taught to groups of international students over...

  6. International Migration of Couples

    DEFF Research Database (Denmark)

    Junge, Martin; Munk, Martin D.; Nikolka, Till

    2018-01-01

    Migrant self-selection is important to labor markets and public finances in both origin and destination countries. We develop a theoretical model regarding the migration of dual-earner couples and test it using population-wide administrative data from Denmark. Our model predicts that the probabil......Migrant self-selection is important to labor markets and public finances in both origin and destination countries. We develop a theoretical model regarding the migration of dual-earner couples and test it using population-wide administrative data from Denmark. Our model predicts...

  7. Samtidskunst og migration

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2010-01-01

    "Samtidskunst og migration. En oversigt over faglitteraturen" er en forskningsoversigt der gør status over hvad der hidtil er skrevet inden for det kunsthistoriske område om vor tids billedkunst og migration som politisk, socialt og kulturelt fænomen, primært i forbindelse med immigration til...... Europa og i bredere forstand Vesten. Rapporten er en intern rapport som er lavet i tilknytning til det kollektive forskningsprojekt "Islam i europæisk litteratur" på Afdelingen for Litteraturvidenskab og Moderne Kultur og indleveret til dette projekts leder, Peter Madsen....

  8. Making Migration Meaningful

    DEFF Research Database (Denmark)

    Benwell, Ann Fenger

    2013-01-01

    . The article focuses on changing patterns of mobility in the Mongolian ‘age of the market’ and its effects on population groups. Internal and international migration has continually risen as individuals and families have moved to places of opportunity. Connections are believed to be maintained during periods...... of absence by migrant family members, as both men and women are culturally permitted to be separate from their families. Migration is understood to contribute to prosperity, and separations contribute to generate growth and hishig (good fortune) for the good of the family. However, such mobility is also...

  9. Unix Application Migration Guide

    CERN Document Server

    Microsoft. Redmond

    2003-01-01

    Drawing on the experience of Microsoft consultants working in the field, as well as external organizations that have migrated from UNIX to Microsoft® Windows®, this guide offers practical, prescriptive guidance on the issues you are likely to face when porting existing UNIX applications to the Windows operating system environment. Senior IT decision makers, network managers, and operations managers will get real-world guidance and best practices on planning and implementation issues to understand the different methods through which migration or co-existence can be accomplished. Also detailing

  10. [Migration and diabetes].

    Science.gov (United States)

    Aydinkoc-Tuzcu, Kadriye; Schindler, Karin; Kautzky-Willer, Alexandra; Ludvik, Bernhard; Fasching, Peter

    2016-04-01

    The article deals with the demographic data of migration in Austria and with therapeutic advice concerning drug therapy and diabetes education for patients with migration background. In this context socio-cultural specifics are discussed. These suggestions are seen complementary to the general treatment guidelines of the Austrian Diabetes Association.Especially for the fast months Ramadan there are a lot of informations. The most important point is that the patient care must be highly individualized and the management plan may differ for each patient.

  11. What's driving migration?

    Science.gov (United States)

    Kane, H

    1995-01-01

    During the 1990s investment in prevention of international or internal migration declined, and crisis intervention increased. The budgets of the UN High Commissioner for Refugees and the UN Development Program remained about the same. The operating assumption is that war, persecution, famine, and environmental and social disintegration are inevitable. Future efforts should be directed to stabilizing populations through investment in sanitation, public health, preventive medicine, land tenure, environmental protection, and literacy. Forces pushing migration are likely to increase in the future. Forces include depletion of natural resources, income disparities, population pressure, and political disruption. The causes of migration are not constant. In the past, migration occurred during conquests, settlement, intermarriage, or religious conversion and was a collective movement. Current migration involves mass movement of individuals and the struggle to survive. There is new pressure to leave poor squatter settlements and the scarcities in land, water, and food. The slave trade between the 1500s and the 1800s linked continents, and only 2-3 million voluntarily crossed national borders. Involuntary migration began in the early 1800s when European feudal systems were in a decline, and people sought freedom. Official refugees, who satisfy the strict 1951 UN definition, increased from 15 million in 1980 to 23 million in 1990 but remained a small proportion of international migrants. Much of the mass movement occurs between developing countries. Migration to developed countries is accompanied by growing intolerance, which is misinformed. China practices a form of "population transfer" in Tibet in order to dilute Tibetan nationalism. Colonization of countries is a new less expensive form of control over territory. Eviction of minorities is another popular strategy in Iraq. Public works projects supported by foreign aid displace millions annually. War and civil conflicts

  12. Caveat mTOR: aberrant signaling disrupts corticogenesis.

    Science.gov (United States)

    Osborne, Lucy R

    2010-05-01

    The mammalian target of rapamycin (mTOR) signaling pathway is activated in several disorders associated with benign tumors and malformations of the cerebral cortex. In this issue of the JCI, Orlova et al. have now definitively added another disorder to this group by demonstrating that activation of mTOR signaling is associated with polyhydramnios, megalencephaly, and symptomatic epilepsy syndrome (PMSE), which is characterized by severe intractable epilepsy and megalencephaly. PMSE is caused by lack of the pseudokinase STE20-related kinase adaptor alpha (STRADalpha), and Orlova et al. show that reduction of STRADalpha levels during corticogenesis in the mouse results in a cellular phenotype and neuronal migration defects similar to those observed in patients with PMSE, clearly demonstrating a pivotal role for STRADalpha in cell polarity and growth. This study helps pave the way for possible therapeutic intervention with rapamycin to control the epilepsy and learning disabilities associated with this disorder.

  13. Association analysis of schizophrenia on 18 genes involved in neuronal migration

    DEFF Research Database (Denmark)

    Kähler, Anna K; Djurovic, Srdjan; Kulle, Bettina

    2008-01-01

    Several lines of evidence support the theory of schizophrenia (SZ) being a neurodevelopmental disorder. The structural, cytoarchitectural and functional brain abnormalities reported in patients with SZ, might be due to aberrant neuronal migration, since the final position of neurons affects...... neuronal function, morphology, and formation of synaptic connections. We have investigated the putative association between SZ and gene variants engaged in the neuronal migration process, by performing an association study on 839 cases and 1,473 controls of Scandinavian origin. Using a gene-wide approach...

  14. Integrating meteorology into research on migration.

    Science.gov (United States)

    Shamoun-Baranes, Judy; Bouten, Willem; van Loon, E Emiel

    2010-09-01

    Atmospheric dynamics strongly influence the migration of flying organisms. They affect, among others, the onset, duration and cost of migration, migratory routes, stop-over decisions, and flight speeds en-route. Animals move through a heterogeneous environment and have to react to atmospheric dynamics at different spatial and temporal scales. Integrating meteorology into research on migration is not only challenging but it is also important, especially when trying to understand the variability of the various aspects of migratory behavior observed in nature. In this article, we give an overview of some different modeling approaches and we show how these have been incorporated into migration research. We provide a more detailed description of the development and application of two dynamic, individual-based models, one for waders and one for soaring migrants, as examples of how and why to integrate meteorology into research on migration. We use these models to help understand underlying mechanisms of individual response to atmospheric conditions en-route and to explain emergent patterns. This type of models can be used to study the impact of variability in atmospheric dynamics on migration along a migratory trajectory, between seasons and between years. We conclude by providing some basic guidelines to help researchers towards finding the right modeling approach and the meteorological data needed to integrate meteorology into their own research. © The Author 2010. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved.

  15. Polystyrene cups and containers: styrene migration.

    Science.gov (United States)

    Tawfik, M S; Huyghebaert, A

    1998-07-01

    The level of styrene migration from polystyrene cups was monitored in different food systems including: water, milk (0.5, 1.55 and 3.6% fat), cold beverages (apple juice, orange juice, carbonated water, cola, beer and chocolate drink), hot beverages (tea, coffee, chocolate and soup (0.0, 0.5, 1, 2, and 3.6% fat), take away foods (yogurt, jelly, pudding and ice-cream), as well as aqueous food simulants (3% acetic acid, 15, 50, and 100% ethanol) and olive oil. Styrene migration was found to be strongly dependent upon the fat content and storage temperature. Drinking water gave migration values considerably lower than all of the fatty foods. Ethanol at 15% showed a migration level equivalent to milk or soup containing 3.6% fat. Maximum observed migration for cold or hot beverages and take-away foods was 0.025% of the total styrene in the cup. Food simulants were responsible for higher migration (0.37% in 100% ethanol). A total of 60 food samples (yogurt, rice with milk, fromage, biogardes, and cheese) packed in polystyrene containers were collected from retail markets in Belgium, Germany, and the Netherlands. The level of styrene detected in the foods was always fat dependent.

  16. Spring Bird Migration Phenology in Eilat, Israel

    Directory of Open Access Journals (Sweden)

    Reuven Yosef

    2009-12-01

    Full Text Available Analysis of the mean date of first captures and median arrival dates of spring migration for 34 species of birds at Eilat, Israel, revealed that the earlier a species migrates through Eilat, the greater is the inter-annual variation in the total time of its passage. Birds arrive during spring migration in Eilat in four structured and independent waves. The annual fluctuation in the initial arrival dates (initial capture dates and median dates (median date of all captures, not including recaptures, did not depend on the length of the migratory route. This implies that migrants crossing the Sahara desert depart from their winter quarters on different Julian days in different years. We suggest that negative correlations between the median date of the spring migration of early and late migrants depends upon the easterly (Hamsin wind period. Moreover, we believe that the phenology of all birds during spring migration in Eilat is possibly also determined by external factors such as weather conditions on the African continent or global climatic processes in the Northern hemisphere. Orphean Warblers (Sylvia hortensis show a strong positive correlation (rs=-0.502 of initial capture date with calendar years, whereas other species such as Barred Warbler (S. nisoria; rs = -0.391 and Spotted Flycatcher (Muscicapa striata; rs = -0.398 display an insignificant trend. The Dead Sea Sparrow (Passer moabiticus and Red-Backed Shrike (Lanius collurio are positively correlated regarding initial arrival date and medians of spring migration.

  17. A behavioral evaluation of sex differences in a mouse model of severe neuronal migration disorder.

    Directory of Open Access Journals (Sweden)

    Dongnhu T Truong

    Full Text Available Disruption of neuronal migration in humans is associated with a wide range of behavioral and cognitive outcomes including severe intellectual disability, language impairment, and social dysfunction. Furthermore, malformations of cortical development have been observed in a number of neurodevelopmental disorders (e.g. autism and dyslexia, where boys are much more commonly diagnosed than girls (estimates around 4 to 1. The use of rodent models provides an excellent means to examine how sex may modulate behavioral outcomes in the presence of comparable abnormal neuroanatomical presentations. Initially characterized by Rosen et al. 2012, the BXD29- Tlr4(lps-2J /J mouse mutant exhibits a highly penetrant neuroanatomical phenotype that consists of bilateral midline subcortical nodular heterotopia with partial callosal agenesis. In the current study, we confirm our initial findings of a severe impairment in rapid auditory processing in affected male mice. We also report that BXD29- Tlr4(lps-2J /J (mutant female mice show no sparing of rapid auditory processing, and in fact show deficits similar to mutant males. Interestingly, female BXD29- Tlr4(lps-2J /J mice do display superiority in Morris water maze performance as compared to wild type females, an affect not seen in mutant males. Finally, we report new evidence that BXD29- Tlr4(lps-2J /J mice, in general, show evidence of hyper-social behaviors. In closing, the use of the BXD29- Tlr4(lps-2J /J strain of mice - with its strong behavioral and neuroanatomical phenotype - may be highly useful in characterizing sex independent versus dependent mechanisms that interact with neural reorganization, as well as clinically relevant abnormal behavior resulting from aberrant neuronal migration.

  18. Analysis of four aberrometers for evaluating lower and higher order aberrations.

    Directory of Open Access Journals (Sweden)

    Fabiano Cade

    Full Text Available PURPOSE: To compare the measurements of lower and higher order aberrations (HOA of 4 commonly used aberrometers. SETTING: Massachusetts Eye & Ear Infirmary, Boston, USA. DESIGN: Prospective, cross-sectional study, in a controlled, single-blinded fashion. METHODS: Multiple readings were obtained in 42 eyes of 21 healthy volunteers, at a single visit, with each of the following aberrometers: Alcon LADARWave®, Visx WaveScan®, B & L Zywave®, and Wavelight Allegro Analyzer®. Results were compared and analyzed in regards to the lower and HOA, to the different wavefront sensing devices and software, Tscherning and Hartmann-Shack and between the Fourier and Zernike algorithms. Statistical analysis included Bland-Altman plots, Intraclass Correlation Coefficient (ICC, multiple comparison tests with Analysis of Variance and Kruskal-Wallis. Significant level was set to p<0.05 and alpha level correction was adjusted under the Bonferroni criteria. RESULTS: Most measurements of all 4 aberrometers were comparable. However, statistically significant differences were found between the aberrometers in total HOA (tHOA, spherical aberration (SA, horizontal coma and astigmatism (2,2. LADARwave and Wavescan showed significant differences in tHOA (P<0.001, ICC = 0.549, LoA = 0.19±0.5 and in SA (P<0.001, ICC = 0.733, LoA = 0.16±0.37. Wavescan showed a significant difference compared to Zywave (p<0.001, ICC = 0.920, LoA = 0.09±0.13 in SA. Comparisons between Allegro Analyzer and Zywave demonstrated significant differences in both Horizontal Coma (3,1 (p<0.001, ICC = -0.207, LoA = -0.15±0.48 and Astigmatism (2,2 (P = 0.003, ICC = -0.965, LoA = 0.2±2.5. Allegro Analyzer also differed from Wavescan in Horizontal Coma (3,1 (P<0.001, ICC = 0.725, LoA = -0.07±0.25. CONCLUSIONS: Although some measurements were comparable predominately in the lower order aberrations, significant differences were found in the tHOA, SA, horizontal coma and astigmatism. Our analysis

  19. Internal migration: why do Filipinos move?

    Science.gov (United States)

    Jolipa, N

    1980-01-01

    The rapid movement of Filipinos from 1 part of the Philippines to another is not a new phenomenon, but mobility has been increasing. A study conducted by Peter C. Smith revealed that interprovincial lifetime mobility of the national population increased from 15.8% in 1960 to 17.6% in 1970, while interregional mobility increased from 12.7% to 13.4%. People still disagree as to whether the size and rate of growth of the population are excessive, but there seems to be total consensus as regards its spatial imbalance. Because internal migration appears to be an important factor in national development, a need exists to examine different aspects of internal migration, such as the directions taken by migration flows, the migrants' reasons for moving, the migrants' characteristics, the migrants' success or lack of success at their places of destination, the social problems accompanying internal migration, effforts to deal with the problems caused by internal migration, and the implications of migration trends for policy and for the country's development programs. The most dominant migration trend in the Philippines in recent years has been toward the urban, or more accurately the suburban, areas adjacent to Metropolitan Manila. The city of Manila itself suffered a net outflow, further pointing to the trend toward suburbanization. Migration flows are primarily caused by economic reasons. About one half the sample of a Filipinas Foundation Study moved to provinces other than the province of birth in the pursuit of employment and other economic opportunities. A study of the country's migrant population age 15 and older showed that 53% of migrants were female. For male migrants, age ranges from 20-40; it ranges from 15-35 for females. Where cash income is concerned, migrants in Pernia's study of rural urban migration were better off than nonmigrants. Migrants were, on the average, as well off as native urbanites or metropolitanites. Among the more significant points raised by

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

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, K. [Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502 (Japan); Wada, S.; Hatayama, A. [Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2010-02-15

    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.

  1. Migration scenarii in extrasolar systems

    Directory of Open Access Journals (Sweden)

    Crida A.

    2011-02-01

    Full Text Available In this review talk, I present the theory of type I migration of small mass planets, and its latest developments that open the possibility of outward migration in the inner part of a protoplanetary disk. I also review the type II migration of giant planets, and mention the runaway, type III. Then, we focus on the migration of pairs of planets in resonance. The eccentricity of the planets raise, and possibly their mutual inclination as well. Also, the migration rate can be changed, and directed outward if the outer planet is the lighter. Last, we present a synthetic scenario of migration for the giant planets of our Solar System.

  2. Gambogenic acid kills lung cancer cells through aberrant autophagy.

    Directory of Open Access Journals (Sweden)

    Wang Mei

    Full Text Available Lung cancer is one of the most common types of cancer and causes 1.38 million deaths annually, as of 2008 worldwide. Identifying natural anti-lung cancer agents has become very important. Gambogenic acid (GNA is one of the active compounds of Gamboge, a traditional medicine that was used as a drastic purgative, emetic, or vermifuge for treating tapeworm. Recently, increasing evidence has indicated that GNA exerts promising anti-tumor effects; however, the underlying mechanism remains unclear. In the present paper, we found that GNA could induce the formation of vacuoles, which was linked with autophagy in A549 and HeLa cells. Further studies revealed that GNA triggers the initiation of autophagy based on the results of MDC staining, AO staining, accumulation of LC3 II, activation of Beclin 1 and phosphorylation of P70S6K. However, degradation of p62 was disrupted and free GFP could not be released in GNA treated cells, which indicated a block in the autophagy flux. Further studies demonstrated that GNA blocks the fusion between autophagosomes and lysosomes by inhibiting acidification in lysosomes. This dysfunctional autophagy plays a pro-death role in GNA-treated cells by activating p53, Bax and cleaved caspase-3 while decreasing Bcl-2. Beclin 1 knockdown greatly decreased GNA-induced cell death and the effects on p53, Bax, cleaved caspase-3 and Bcl-2. Similar results were obtained using a xenograft model. Our findings show, for the first time, that GNA can cause aberrant autophagy to induce cell death and may suggest the potential application of GNA as a tool or viable drug in anticancer therapies.

  3. Effects of ocular transverse chromatic aberration on peripheral word identification.

    Science.gov (United States)

    Yang, Shun-Nan; Tai, Yu-chi; Laukkanen, Hannu; Sheedy, James E

    2011-11-01

    Transverse chromatic aberration (TCA) smears the retinal image of peripheral stimuli. We previously found that TCA significantly reduces the ability to recognize letters presented in the near fovea by degrading image quality and exacerbating crowding effect from adjacent letters. The present study examined whether TCA has a significant effect on near foveal and peripheral word identification, and whether within-word orthographic facilitation interacts with TCA effect to affect word identification. Subjects were briefly presented a 6- to 7-letter word of high or low frequency in each trial. Target words were generated with weak or strong horizontal color fringe to attenuate the TCA in the right periphery and exacerbate it in the left. The center of the target word was 1°, 2°, 4°, and 6° to the left or right of a fixation point. Subject's eye position was monitored with an eye-tracker to ensure proper fixation before target presentation. They were required to report the identity of the target word as soon and accurately as possible. Results show significant effect of color fringe on the latency and accuracy of word recognition, indicating existing TCA effect. Observed TCA effect was more salient in the right periphery, and was affected by word frequency more there. Individuals' subjective preference of color-fringed text was correlated to the TCA effect in the near periphery. Our results suggest that TCA significantly affects peripheral word identification, especially when it is located in the right periphery. Contextual facilitation such as word frequency interacts with TCA to influence the accuracy and latency of word recognition. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Asperger's syndrome and aberrant neurofunctional organization--a case report.

    Science.gov (United States)

    Huang, Huei-Lin; Shieh, Yu-Lien; Wu, Hsiu-Jung; Chuang, Sheng-Fa; Yang, Pinchen; Jong, Yuh-Jyh

    2002-04-01

    Asperger's Syndrome(AS) is a severe developmental disorder characterized primarily by marked and sustained difficulties in social interaction and unusual patterns of circumscribed interests and behavioral peculiarities. AS differs from autism primarily in that there is no general delay or retardation in language. A 3. 5 year-old boy with AS was referred for psychological assessment and treatment. When the boy was 23 months old, he was assessed with Bayley Scales of Infant Development (2nd ed.). Both MDI and PDI were within normal limits. After the referral, this boy was assessed with WPPSI-R and then prescribed 5 weekly intervention sessions consisting of communication skills training. At a one week's follow-up the boy was reassessed with Leiter-R. The results of WPPSI-R and Leiter-R showed the boy was in the normal intelligence range. From the second session to the fifth session, the boy's mother recorded 526 of his utterances. According to the analysis of these speech data, the language development for this boy was at Stage V, which indicated that his language development was in the superior range for his age. After 5 intervention sessions, the improvements in the child's communication skills were such that no further sessions were warranted. This boy might represent a case of aberrant neurofunctional organization. He has defects in perceptual organization but has good pattern recognition, which is based on features. It is theorized that his excellent verbal ability competed with the perceptual organization, so that he compensated for perceptual organization with verbal ability. An intervention designed to inhibit verbal compensation and facilitate configural processing is recommended.

  5. Substrate Curvature Regulates Cell Migration -A Computational Study

    Science.gov (United States)

    He, Xiuxiu; Jiang, Yi

    Cell migration in host microenvironment is essential to cancer etiology, progression and metastasis. Cellular processes of adhesion, cytoskeletal polymerization, contraction, and matrix remodeling act in concert to regulate cell migration, while local extracellular matrix architecture modulate these processes. In this work we study how stromal microenvironment with native and cell-derived curvature at micron-meter scale regulate cell motility pattern. We developed a 3D model of single cell migration on a curved substrate. Mathematical analysis of cell morphological adaption to the cell-substrate interface shows that cell migration on convex surfaces deforms more than on concave surfaces. Both analytical and simulation results show that curved surfaces regulate the cell motile force for cell's protruding front through force balance with focal adhesion and cell contraction. We also found that cell migration on concave substrates is more persistent. These results offer a novel biomechanical explanation to substrate curvature regulation of cell migration. NIH 1U01CA143069.

  6. Preventing and managing aberrant drug-related behavior in primary care: systematic review of outcomes evidence.

    Science.gov (United States)

    Argoff, Charles E; Kahan, Meldon; Sellers, Edward M

    2014-01-01

    Several strategies for preventing, identifying, and responding to aberrant opioid-related behaviors are recommended in pain management guidelines. This systematic review evaluated data supporting basic strategies for addressing aberrant opioid-related behaviors. Risk reduction strategies were identified via a review of available guidelines. Systematic literature searches of PubMed (May 1, 2007-January 18, 2013) identified articles with evidence relevant to nine basic strategies. Reference lists from relevant articles were reviewed for additional references of interest. Levels of evidence for articles identified were graded on a four-point scale (strongest evidence = level 1; weakest evidence = level 4) using Oxford Centre for Evidence-Based Medicine Levels of Evidence criteria. Weak to moderate evidence supports the value of thorough patient assessment, risk-screening tools, controlled-substance agreements, careful dose titration, opioid dose ceilings, compliance monitoring, and adherence to practice guidelines. Moderate to strong evidence suggests that prescribing tamper-resistant opioids may help prevent misuse but may also have the unintended consequence of prompting a migration of users to other marketed opioids, heroin, or other substances. Similarly, preliminary evidence suggests that although recent regulatory and legal efforts may reduce misuse, they also impose barriers to the legitimate treatment of pain. Despite an absence of consistent, strong supporting evidence, clinicians are advised to use each of the available risk-mitigation strategies in combination in an attempt to minimize the risk of abuse in opioid treatment patients. Physicians must critically evaluate their opioid prescribing and not only increase their efforts to prevent substance abuse but also not compromise pain management in patients who benefit from it.

  7. Migration and regional inequality

    DEFF Research Database (Denmark)

    Peng, Lianqing; Swider, Sarah

    2017-01-01

    rising, regional inequality has actually decreased, and most recently, remained stable. Our study suggests that China’s unique migratory regime is crucial to understanding these findings. We conduct a counterfactual simulation to demonstrate how migration and remittances have mitigated income inequality...

  8. Migration as Adventure

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2018-01-01

    Narratives of adventure constitute a well-established convention of describing travel experiences, yet the significance of this narrative genre in individuals’ accounts of their migration and life abroad has been little investigated. Drawing on Simmel and Bakhtin, among others, this article...

  9. Digitizing migration heritage

    DEFF Research Database (Denmark)

    Marselis, Randi

    2011-01-01

    Museums are increasingly digitizing their collections and making them available to the public on-line. Creating such digital resources may become means for social inclusion. For museums that acknowledge migration history and cultures of ethnic minority groups as important subjects in multiethnic...

  10. Diel vertical migrat..

    African Journals Online (AJOL)

    2002-01-24

    Jan 24, 2002 ... crustacean zooplankton but also in a Wide array of different marine zooplankton groups. (Russell 1927, McLaren 1963). Thus there is no doubt that ..... cooperation during field work and for their fruitful discussion on the draft manuscript. REFERENCES. Bayly lAE 1986 Aspects of diel vertical migration in ...

  11. Migration and Africa

    DEFF Research Database (Denmark)

    Zoppi, Marco

    2014-01-01

    European powers imposed the nation-state on Africa through colonialism. But even after African independencies, mainstream discourses and government policies have amplified the idea that sedentariness and the state are the only acceptable mode of modernity. Migration is portrayed as a menace...

  12. Describing migration spatial structure

    NARCIS (Netherlands)

    Rogers, A; Willekens, F; Little, J; Raymer, J

    The age structure of a population is a fundamental concept in demography and is generally depicted in the form of an age pyramid. The spatial structure of an interregional system of origin-destination-specific migration streams is, however, a notion lacking a widely accepted definition. We offer a

  13. Migrating the Light

    DEFF Research Database (Denmark)

    Sørensen, Bent

    The migration of Blaga’s universalist, even centralist poems from Romanian of the first third of the 20th C. into American of the first fifth of the 21st C. illustrates the uses of Pierre Joris’s nomadic methods. My translations of Blaga read well for a teenage audience whose only exposure to lit...

  14. Practical Data Migration

    CERN Document Server

    Morris, Johny

    2012-01-01

    This book is for executives and practitioners tasked with the movement of data from old systems to a new repository. It uses a series of steps guaranteed to get the reader from an empty new system to one that is working and backed by the user population. Using this proven methodology will vastly increase the chances of a successful migration.

  15. Two Theobroma cacao genotypes with contrasting pathogen tolerance show aberrant transcriptional and ROS responses after salicylic acid treatment.

    Science.gov (United States)

    Fister, Andrew S; O'Neil, Shawn T; Shi, Zi; Zhang, Yufan; Tyler, Brett M; Guiltinan, Mark J; Maximova, Siela N

    2015-10-01

    Understanding the genetic basis of pathogen susceptibility in various crop plants is crucial to increasing the stability of food, feed, and fuel production. Varietal differences in defence responses provide insights into the mechanisms of resistance and are a key resource for plant breeders. To explore the role of salicylic acid in the regulation of defence in cacao, we demonstrated that SA treatment decreased susceptibility to a pod rot pathogen, Phytophthora tropicalis in two genotypes, Scavina 6 and Imperial College Selection 1, which differ in their resistance to several agriculturally important pathogens. Transient overexpression of TcNPR1, a major transcriptional regulator of the SA-dependent plant immune system, also increased pathogen tolerance in cacao leaves. To explore further the genetic basis of resistance in cacao, we used microarrays to measure gene expression profiles after salicylic acid (SA) treatment in these two cacao genotypes. The two genotypes displayed distinct transcriptional responses to SA. Unexpectedly, the expression profile of the susceptible genotype ICS1 included a larger number of pathogenesis-related genes that were induced by SA at 24h after treatment, whereas genes encoding many chloroplast and mitochondrial proteins implicated in reactive oxygen species production were up-regulated in the resistant genotype, Sca6. Sca6 accumulated significantly more superoxide at 24h after treatment of leaves with SA. These experiments revealed critical insights regarding the molecular differences between cacao varieties, which will allow a better understanding of defence mechanisms to help guide breeding programmes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  16. A Mouse Model of Hyperproliferative Human Epithelium Validated by Keratin Profiling Shows an Aberrant Cytoskeletal Response to Injury.

    Science.gov (United States)

    Zhussupbekova, Samal; Sinha, Rohit; Kuo, Paula; Lambert, Paul F; Frazer, Ian H; Tuong, Zewen K

    2016-07-01

    A validated animal model would assist with research on the immunological consequences of the chronic expression of stress keratins KRT6, KRT16, and KRT17, as observed in human pre-malignant hyperproliferative epithelium. Here we examine keratin gene expression profile in skin from mice expressing the E7 oncoprotein of HPV16 (K14E7) demonstrating persistently hyperproliferative epithelium, in nontransgenic mouse skin, and in hyperproliferative actinic keratosis lesions from human skin. We demonstrate that K14E7 mouse skin overexpresses stress keratins in a similar manner to human actinic keratoses, that overexpression is a consequence of epithelial hyperproliferation induced by E7, and that overexpression further increases in response to injury. As stress keratins modify local immunity and epithelial cell function and differentiation, the K14E7 mouse model should permit study of how continued overexpression of stress keratins impacts on epithelial tumor development and on local innate and adaptive immunity. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  17. A Mouse Model of Hyperproliferative Human Epithelium Validated by Keratin Profiling Shows an Aberrant Cytoskeletal Response to Injury

    Directory of Open Access Journals (Sweden)

    Samal Zhussupbekova

    2016-07-01

    Full Text Available A validated animal model would assist with research on the immunological consequences of the chronic expression of stress keratins KRT6, KRT16, and KRT17, as observed in human pre-malignant hyperproliferative epithelium. Here we examine keratin gene expression profile in skin from mice expressing the E7 oncoprotein of HPV16 (K14E7 demonstrating persistently hyperproliferative epithelium, in nontransgenic mouse skin, and in hyperproliferative actinic keratosis lesions from human skin. We demonstrate that K14E7 mouse skin overexpresses stress keratins in a similar manner to human actinic keratoses, that overexpression is a consequence of epithelial hyperproliferation induced by E7, and that overexpression further increases in response to injury. As stress keratins modify local immunity and epithelial cell function and differentiation, the K14E7 mouse model should permit study of how continued overexpression of stress keratins impacts on epithelial tumor development and on local innate and adaptive immunity.

  18. Thermal lensing measurement from the coefficient of defocus aberration

    CSIR Research Space (South Africa)

    Bell, Teboho

    2016-03-01

    Full Text Available We measured the thermally induced lens from the coefficient of defocus aberration using a Shack-Hartmann wavefront sensor (SHWFS). As a calibration technique, we infer the focal length of standard lenses probed by a collimated Gaussian beam...

  19. Expressions for third-order aberration theory for holographic images

    Indian Academy of Sciences (India)

    Expressions for third-order aberration theory for holographic images. S K Tripathy S Ananda Rao. Brief Reports Volume 60 Issue 1 January 2003 pp 151-157 ... Author Affiliations. S K Tripathy1 S Ananda Rao1. Department of Physics, Jagannath Institute for Technology and Management, Parlakhemundi 761 200, India ...

  20. Intrachanges as part of complex chromosome-type exchange aberrations

    NARCIS (Netherlands)

    Boei, JJWA; Vermeulen, S; Moser, J; Mullenders, LHF; Natarajan, AT

    2002-01-01

    The chromosome-type exchange aberrations induced by ionizing radiation during the G(0)/G(1) phase of the cell cycle are believed to be the result of illegitimate rejoining of chromosome breaks. From numerous studies using chromosome painting, it has emerged that even after a moderate dose of

  1. Aberrant Right Subclavian Artery: A Life‑threatening Anomaly that ...

    African Journals Online (AJOL)

    Lusoria artery or aberrant right subclavian artery (ARSA) is a rare anatomical variation of the origin of the right subclavian artery. Essentially, right subclavian artery originates from the brachiocephalic artery, but in 0.4-1.8% of the general population it may arise directly from the aortic arch distal to the left subclavian artery.

  2. Chromosomal aberration frequency in lymphocytes predicts the risk of cancer

    DEFF Research Database (Denmark)

    Bonassi, Stefano; Norppa, Hannu; Ceppi, Marcello

    2008-01-01

    Mechanistic evidence linking chromosomal aberration (CA) to early stages of cancer has been recently supported by the results of epidemiological studies that associated CA frequency in peripheral lymphocytes of healthy individuals to future cancer incidence. To overcome the limitations of single...

  3. Thermally induced lensing determination from the coefficient of defocus aberration

    CSIR Research Space (South Africa)

    Bell, Teboho

    2014-07-01

    Full Text Available The effects of a temperature gradient in a laser crystal in an end-pumped configuration in a solid-state laser resonator results in thermally induced aberrations. Of particular interest we measure the thermally induced lens from the coefficient...

  4. Axial chromatic aberration of the human eye: frequency or wavelength?

    Science.gov (United States)

    Pease, P L; Barbeito, R

    1989-04-01

    The axial chromatic aberration of the human eye is nearly perfectly described by a linear function when expressed in terms of frequency rather than wavelength. Since linear functions are simple to work with and more readily understood, there are advantages for the expression of these data in terms of frequency.

  5. Joint denoising, demosaicing, and chromatic aberration correction for UHD video

    Science.gov (United States)

    Jovanov, Ljubomir; Philips, Wilfried; Damstra, Klaas Jan; Ellenbroek, Frank

    2017-09-01

    High-resolution video capture is crucial for numerous applications such as surveillance, security, industrial inspection, medical imaging and digital entertainment. In the last two decades, we are witnessing a dramatic increase of the spatial resolution and the maximal frame rate of video capturing devices. In order to achieve further resolution increase, numerous challenges will be facing us. Due to the reduced size of the pixel, the amount of light also reduces, leading to the increased noise level. Moreover, the reduced pixel size makes the lens imprecisions more pronounced, which especially applies to chromatic aberrations. Even in the case when high quality lenses are used some chromatic aberration artefacts will remain. Next, noise level additionally increases due to the higher frame rates. To reduce the complexity and the price of the camera, one sensor captures all three colors, by relying on Color Filter Arrays. In order to obtain full resolution color image, missing color components have to be interpolated, i.e. demosaicked, which is more challenging than in the case of lower resolution, due to the increased noise and aberrations. In this paper, we propose a new method, which jointly performs chromatic aberration correction, denoising and demosaicking. By jointly performing the reduction of all artefacts, we are reducing the overall complexity of the system and the introduction of new artefacts. In order to reduce possible flicker we also perform temporal video enhancement. We evaluate the proposed method on a number of publicly available UHD sequences and on sequences recorded in our studio.

  6. Measurement of low-order aberrations with an autostigmatic microscope

    Science.gov (United States)

    Kuhn, William P.

    2017-08-01

    The addition of a piezo-electric focusing stage and phase retrieval algorithms to a compact, adaptable autostigmatic microscope provides for both improved focus sensitivity during optical system alignment as well as the ability to measure low-order aberrations for system qualification. A description of the instrument and initial results are reported.

  7. Municipal landfill leachates induced chromosome aberrations in rat ...

    African Journals Online (AJOL)

    This study examined the potential mutagenic effects of raw and simulated leachates from Olushosun municipal solid waste (MSW) landfill using rat bone marrow chromosome aberration assay. Raw leachate obtained directly from the landfill and simulated leachate obtained via the American Society for Testing and Materials ...

  8. Municipal landfill leachates induced chromosome aberrations in rat ...

    African Journals Online (AJOL)

    user

    2006-11-16

    Nov 16, 2006 ... leachate induced chromosome aberration in rat. Other reports on leachate induced genotoxicity in Allium cepa. (Cabrera and Rodriguez, 1999; Bakare and Wale-. Adeyemo, 2004; Chandra et al., 2005.), Vicia faba. (Radetski et al., 2004; Sang and Li, 2004), Drosophila melanogaster (Siddique et al., 2005) ...

  9. Prediction and Migration of Surface-related Resonant Multiples

    KAUST Repository

    Guo, Bowen

    2015-08-19

    Surface-related resonant multiples can be migrated to achieve better resolution than migrating primary reflections. We now derive the formula for migrating surface-related resonant multiples, and show its super-resolution characteristics. Moreover, a method is proposed to predict surface-related resonant multiples with zero-offset primary reflections. The prediction can be used to indentify and extract the true resonant multiple from other events. Both synthetic and field data are used to validate this prediction.

  10. GABAergic anxiolytic drug in water increases migration behaviour in salmon

    OpenAIRE

    Hellström, Gustav; Klaminder, Jonatan; Finn, Fia; Persson, Lo; Alanärä, Anders; Jonsson, Micael; Fick, Jerker; Brodin, Tomas

    2016-01-01

    Migration is an important life-history event in a wide range of taxa, yet many migrations are influenced by anthropogenic change. Although migration dynamics are extensively studied, the potential effects of environmental contaminants on migratory physiology are poorly understood. In this study we show that an anxiolytic drug in water can promote downward migratory behaviour of Atlantic salmon (Salmo salar) in both laboratory setting and in a natural river tributary. Exposing salmon smolt to ...

  11. Canada’s International Migration System: 1986-1996

    Directory of Open Access Journals (Sweden)

    Ann H. Kim

    2007-12-01

    The findings reveal that for a given year, social networks and export trade were the two key factors that determined the variation of in-migration flows across source countries. The examination of change in the migration system showed that changes in migration flows were more likely to be explained by changes in the level of development in origin countries and in the size of immigrant communities in the host country than by changes in the value of economic trade.

  12. From Migration Regime to Regional Citizenry: Migration and Identity ...

    African Journals Online (AJOL)

    I examine the East African common market, taken as a regional migration regime, and draw its implications for intra-regional migration and identity formation. Using desk research, I analyse the common market Protocol's provisions and envisage the implications of its implementation for intraregional migration and identity ...

  13. The International Organization for Migration in Global Migration Governance

    OpenAIRE

    Poulsen, Sofie Havn; Andersen, Lise

    2011-01-01

    This project focuses on the IOM, the notion of global governance of migration and the interaction between these two. The point of departure has been an attempt to grasp the current global approach to migration and comprehend whether, or to what degree, there is governance of migration issues taking place at a global level.

  14. Globalization, Migration and Development

    Directory of Open Access Journals (Sweden)

    George, Susan

    2002-01-01

    Full Text Available EnglishMigration may become the most important branch of demography in the earlydecades of the new millennium in a rapidly globalizing world. This paper discusses the causes, costsand benefits of international migration to countries of the South and North, and key issues of commonconcern. International migration is as old as national boundaries, though its nature, volume,direction, causes and consequences have changed. The causes of migration are rooted in the rate ofpopulation growth and the proportion of youth in the population, their education and training,employment opportunities, income differentials in society, communication and transportationfacilities, political freedom and human rights and level of urbanization. Migration benefits the Souththrough remittances of migrants, improves the economic welfare of the population (particularly womenof South countries generally, increases investment, and leads to structural changes in the economy.However, emigration from the South has costs too, be they social or caused by factors such as braindrain. The North also benefits by migration through enhancement of economic growth, development ofnatural resources, improved employment prospects, social development and through exposure toimmigrants' new cultures and lifestyles. Migration also has costs to the North such as of immigrantintegration, a certain amount of destabilization of the economy, illegal immigration, and socialproblems of discrimination and exploitation. Issues common to both North and South include impact onprivate investment, trade, international cooperation, and sustainable development. Both North andSouth face a dilemma in seeking an appropriate balance between importing South's labour or itsproducts and exporting capital and technology from the North.FrenchLa migration est sans doute devenue la partie la plus importante de la démographie des premières décennies du nouveau millénaire dans un monde qui change rapidement. Ce

  15. Zimbabwe's Exodus Crisis, Migration, Survival

    International Development Research Centre (IDRC) Digital Library (Canada)

    Remittances, Informalisation and Dispossession in Urban Zimbabwe Sarah Bracking and Lloyd Sachikonye. 324. Chapter Fifteen Transnationalism and Undocumented Migration Between Rural Zimbabwe and South Africa France Maphosa. 346. Chapter Sixteen Metaphors of Migration: Zimbabwean Migrants in the South ...

  16. Subjective face recognition difficulties, aberrant sensibility, sleeping disturbances and aberrant eating habits in families with Asperger syndrome

    Directory of Open Access Journals (Sweden)

    Källman Tiia

    2005-04-01

    Full Text Available Abstract Background The present study was undertaken in order to determine whether a set of clinical features, which are not included in the DSM-IV or ICD-10 for Asperger Syndrome (AS, are associated with AS in particular or whether they are merely a familial trait that is not related to the diagnosis. Methods Ten large families, a total of 138 persons, of whom 58 individuals fulfilled the diagnostic criteria for AS and another 56 did not to fulfill these criteria, were studied using a structured interview focusing on the possible presence of face recognition difficulties, aberrant sensibility and eating habits and sleeping disturbances. Results The prevalence for face recognition difficulties was 46.6% in individuals with AS compared with 10.7% in the control group. The corresponding figures for subjectively reported presence of aberrant sensibilities were 91.4% and 46.6%, for sleeping disturbances 48.3% and 23.2% and for aberrant eating habits 60.3% and 14.3%, respectively. Conclusion An aberrant processing of sensory information appears to be a common feature in AS. The impact of these and other clinical features that are not incorporated in the ICD-10 and DSM-IV on our understanding of AS may hitherto have been underestimated. These associated clinical traits may well be reflected by the behavioural characteristics of these individuals.

  17. Subjective face recognition difficulties, aberrant sensibility, sleeping disturbances and aberrant eating habits in families with Asperger syndrome

    Science.gov (United States)

    Nieminen-von Wendt, Taina; Paavonen, Juulia E; Ylisaukko-Oja, Tero; Sarenius, Susan; Källman, Tiia; Järvelä, Irma; von Wendt, Lennart

    2005-01-01

    Background The present study was undertaken in order to determine whether a set of clinical features, which are not included in the DSM-IV or ICD-10 for Asperger Syndrome (AS), are associated with AS in particular or whether they are merely a familial trait that is not related to the diagnosis. Methods Ten large families, a total of 138 persons, of whom 58 individuals fulfilled the diagnostic criteria for AS and another 56 did not to fulfill these criteria, were studied using a structured interview focusing on the possible presence of face recognition difficulties, aberrant sensibility and eating habits and sleeping disturbances. Results The prevalence for face recognition difficulties was 46.6% in individuals with AS compared with 10.7% in the control group. The corresponding figures for subjectively reported presence of aberrant sensibilities were 91.4% and 46.6%, for sleeping disturbances 48.3% and 23.2% and for aberrant eating habits 60.3% and 14.3%, respectively. Conclusion An aberrant processing of sensory information appears to be a common feature in AS. The impact of these and other clinical features that are not incorporated in the ICD-10 and DSM-IV on our understanding of AS may hitherto have been underestimated. These associated clinical traits may well be reflected by the behavioural characteristics of these individuals. PMID:15826308

  18. Direct observations of the kinetics of migrating T cells suggest active retention by endothelial cells with continual bidirectional migration.

    Science.gov (United States)

    McGettrick, Helen M; Hunter, Kirsty; Moss, Paul A; Buckley, Christopher D; Rainger, G Ed; Nash, Gerard B

    2009-01-01

    The kinetics and regulatory mechanisms of T cell migration through the endothelium have not been fully defined. In experimental, filter-based assays in vitro, transmigration of lymphocytes takes hours, compared with minutes, in vivo. We cultured endothelial cell (EC) monolayers on filters, solid substrates, or collagen gels and treated them with TNF-alpha, IFN-gamma, or both prior to analysis of lymphocyte migration in the presence or absence of flow. PBL, CD4+ cells, or CD8+ cells took many hours to migrate through EC-filter constructs for all cytokine treatments. However, direct microscopic observations of EC filters, which had been mounted in a flow chamber, showed that PBL crossed the endothelial monolayer in minutes and were highly motile in the subendothelial space. Migration through EC was also observed on clear plastic, with or without flow. After a brief settling without flow, PBL and isolated CD3+ or CD4+ cells crossed EC in minutes, but the numbers of migrated cells varied little with time. Close observation revealed that lymphocytes migrated back and forth continuously across endothelium. Under flow, migration kinetics and the proportions migrating back and forth were altered little. On collagen gels, PBL again crossed EC in minutes and migrated back and forth but showed little penetration of the gel over hours. In contrast, neutrophils migrated efficiently through EC and into gels. These observations suggest a novel model for lymphoid migration in which EC support migration but retain lymphocytes (as opposed to neutrophils), and additional signal(s) are required for onward migration.

  19. Nuclear mRNA quality control in yeast is mediated by Nrd1 co-transcriptional recruitment, as revealed by the targeting of Rho-induced aberrant transcripts.

    Science.gov (United States)

    Honorine, Romy; Mosrin-Huaman, Christine; Hervouet-Coste, Nadège; Libri, Domenico; Rahmouni, A Rachid

    2011-04-01

    The production of mature export-competent transcripts is under the surveillance of quality control steps where aberrant mRNP molecules resulting from inappropriate or inefficient processing and packaging reactions are subject to exosome-mediated degradation. Previously, we have shown that the heterologous expression of bacterial Rho factor in yeast interferes in normal mRNP biogenesis leading to the production of full-length yet aberrant transcripts that are degraded by the nuclear exosome with ensuing growth defect. Here, we took advantage of this new tool to investigate the molecular mechanisms by which an integrated system recognizes aberrancies at each step of mRNP biogenesis and targets the defective molecules for destruction. We show that the targeting and degradation of Rho-induced aberrant transcripts is associated with a large increase of Nrd1 recruitment to the transcription complex via its CID and RRM domains and a concomitant enrichment of exosome component Rrp6 association. The targeting and degradation of the aberrant transcripts is suppressed by the overproduction of Pcf11 or its isolated CID domain, through a competition with Nrd1 for recruitment by the transcription complex. Altogether, our results support a model in which a stimulation of Nrd1 co-transcriptional recruitment coordinates the recognition and removal of aberrant transcripts by promoting the attachment of the nuclear mRNA degradation machinery.

  20. Generalized diffraction-stack migration and filtering of coherent noise

    KAUST Repository

    Zhan, Ge

    2014-01-27

    We reformulate the equation of reverse-time migration so that it can be interpreted as summing data along a series of hyperbola-like curves, each one representing a different type of event such as a reflection or multiple. This is a generalization of the familiar diffraction-stack migration algorithm where the migration image at a point is computed by the sum of trace amplitudes along an appropriate hyperbola-like curve. Instead of summing along the curve associated with the primary reflection, the sum is over all scattering events and so this method is named generalized diffraction-stack migration. This formulation leads to filters that can be applied to the generalized diffraction-stack migration operator to mitigate coherent migration artefacts due to, e.g., crosstalk and aliasing. Results with both synthetic and field data show that generalized diffraction-stack migration images have fewer artefacts than those computed by the standard reverse-time migration algorithm. The main drawback is that generalized diffraction-stack migration is much more memory intensive and I/O limited than the standard reverse-time migration method. © 2014 European Association of Geoscientists & Engineers.

  1. Movement ecology of migration in turkey vultures

    Science.gov (United States)

    Mandel, J. T.; Bildstein, K. L.; Bohrer, G.; Winkler, D. W.

    2008-01-01

    We develop individual-based movement ecology models (MEM) to explore turkey vulture (Cathartes aura) migration decisions at both hourly and daily scales. Vulture movements in 10 migration events were recorded with satellite-reporting GPS sensors, and flight behavior was observed visually, aided by on-the-ground VHF radio-tracking. We used the North American Regional Reanalysis dataset to obtain values for wind speed, turbulent kinetic energy (TKE), and cloud height and used a digital elevation model for a measure of terrain ruggedness. A turkey vulture fitted with a heart-rate logger during 124 h of flight during 38 contiguous days showed only a small increase in mean heart rate as distance traveled per day increased, which suggests that, unlike flapping, soaring flight does not lead to greatly increased metabolic costs. Data from 10 migrations for 724 hourly segments and 152 daily segments showed that vultures depended heavily upon high levels of TKE in the atmospheric boundary layer to increase flight distances and maintain preferred bearings at both hourly and daily scales. We suggest how the MEM can be extended to other spatial and temporal scales of avian migration. Our success in relating model-derived atmospheric variables to migration indicates the potential of using regional reanalysis data, as here, and potentially other regional, higher-resolution, atmospheric models in predicting changing movement patterns of soaring birds under various scenarios of climate and land use change. PMID:19060195

  2. Movement ecology of migration in turkey vultures.

    Science.gov (United States)

    Mandel, J T; Bildstein, K L; Bohrer, G; Winkler, D W

    2008-12-09

    We develop individual-based movement ecology models (MEM) to explore turkey vulture (Cathartes aura) migration decisions at both hourly and daily scales. Vulture movements in 10 migration events were recorded with satellite-reporting GPS sensors, and flight behavior was observed visually, aided by on-the-ground VHF radio-tracking. We used the North American Regional Reanalysis dataset to obtain values for wind speed, turbulent kinetic energy (TKE), and cloud height and used a digital elevation model for a measure of terrain ruggedness. A turkey vulture fitted with a heart-rate logger during 124 h of flight during 38 contiguous days showed only a small increase in mean heart rate as distance traveled per day increased, which suggests that, unlike flapping, soaring flight does not lead to greatly increased metabolic costs. Data from 10 migrations for 724 hourly segments and 152 daily segments showed that vultures depended heavily upon high levels of TKE in the atmospheric boundary layer to increase flight distances and maintain preferred bearings at both hourly and daily scales. We suggest how the MEM can be extended to other spatial and temporal scales of avian migration. Our success in relating model-derived atmospheric variables to migration indicates the potential of using regional reanalysis data, as here, and potentially other regional, higher-resolution, atmospheric models in predicting changing movement patterns of soaring birds under various scenarios of climate and land use change.

  3. Corneal aberration changes after rigid gas permeable contact lens wear in keratokonic patients

    Directory of Open Access Journals (Sweden)

    Fereshteh Shokrollahzadeh

    2016-12-01

    Conclusion: In this study, corneal aberrations remained unchanged 3 months after wearing RGP contact lens. Further studies with sufficient samples in different groups of keratoconus severity or baseline aberrations are needed to obtain more accurate results.

  4. Effects of intraocular lenses with different diopters on chromatic aberrations in human eye models

    National Research Council Canada - National Science Library

    Song, Hui; Yuan, Xiaoyong; Tang, Xin

    2016-01-01

    In this study, the effects of intraocular lenses (IOLs) with different diopters (D) on chromatic aberration were investigated in human eye models, and the influences of the central thickness of IOLs on chromatic aberration were compared...

  5. Numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana

    NARCIS (Netherlands)

    Ji, X.

    2014-01-01

    Numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana. I studied numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana. The large genomic changes are important for

  6. An update on ECARUCA, the European Cytogeneticists Association Register of Unbalanced Chromosome Aberrations

    NARCIS (Netherlands)

    Vulto-van Silfhout, Anneke T.; van Ravenswaaij, Conny M. A.; Hehir-Kwa, Jayne Y.; Verwiel, Eugene T. P.; Dirks, Rita; van Vooren, Steven; Schinzel, Albert; de Vries, Bert B. A.; de Leeuw, Nicole

    The European Cytogeneticists Association Register of Unbalanced Chromosome Aberrations (ECARUCA, www.ecaruca.net) is an online database initiated in 2003 that collects and provides detailed, curated clinical and molecular information on rare unbalanced chromosome aberrations. ECARUCA now contains

  7. Chromosomal Aberrations in Monozygotic and Dizygotic Twins Versus Singletons in Denmark During 1968-2009

    DEFF Research Database (Denmark)

    Kristensen, Lone Krøldrup; Larsen, Lisbeth A; Fagerberg, Christina

    2017-01-01

    BACKGROUND: Hall (Embryologic development and monozygotic twinning. Acta Geneticae Medicae et Gemellologiae, Vol. 45, 1996, pp. 53-57) hypothesized that chromosomal aberrations can lead to monozygotic (MZ) twinning. However, twinning and chromosomal aberrations increase prenatal mortality and could...

  8. Musei del migration heritage / Migration heritage museums

    Directory of Open Access Journals (Sweden)

    Patrizia Dragoni

    2015-01-01

    Since the second half of the 1960s of the 20th century, a profound cultural innovation was accompanied to the radical change in the social, political and economic climate. The anthropological notion of culture as opposed to idealistic vision, the unusual and strong interest in material culture, the enunciation of the concept of cultural property by the Franceschini Commission, the luck of the Public History bring a change of the disciplinary statutes of historical sciences, which begin to attend to social history, focusing on the spontaneous sources of information and initiating experiences of oral history. To all this a remarkable transformation of the themes and of the social function of museums is added. This paper illustrates, in relation to this more general context, the foundation and the dissemination of museums dedicated to the history of migration in Italy and in the world, enunciates their possible social utility for the integration of present migrants in Italy and illustrates, by way of example, the museum recently opened in Recanati.

  9. Implication of IRF4 aberrant gene expression in the acute leukemias of childhood.

    Directory of Open Access Journals (Sweden)

    Maria Adamaki

    Full Text Available The most frequent targets of genetic alterations in human leukemias are transcription factor genes with essential functions in normal blood cell development. The Interferon Regulatory Factor 4 (IRF4 gene encodes a transcription factor important for key developmental stages of hematopoiesis, with known oncogenic implications in multiple myeloma, adult leukemias and lymphomas. Very few studies have reported an association of IRF4 with childhood malignancy, whereas high transcript levels have been observed in the more mature immunophenotype of ALL. Our aim was to investigate the expression levels of IRF4 in the diagnostic samples of pediatric leukemias and compare them to those of healthy controls, in order to determine aberrant gene expression and whether it extends to leukemic subtypes other than the relatively mature ALL subpopulation. Quantitative real-time RT-PCR methodology was used to investigate IRF4 expression in 58 children with acute leukemias, 4 leukemic cell lines and 20 healthy children. We show that aberrant IRF4 gene expression is implicated in a variety of leukemic subtypes; higher transcript levels appear in the more immature B-common ALL subtype and in T-cell than in B-cell leukemias, with the highest expression levels appearing in the AML group. Interestingly, we show that childhood leukemia, irrespective of subtype or cell maturation stage, is characterised by a minimum of approximately twice the amount of IRF4 gene expression encountered in healthy children. A statistically significant correlation also appeared to exist between high IRF4 expression and relapse. Our results show that ectopic expression of IRF4 follows the reverse expression pattern of what is encountered in normal B-cell development and that there might be a dose-dependency of childhood leukemia for aberrantly expressed IRF4, a characteristic that could be explored therapeutically. It is also suggested that high IRF4 expression might be used as an additional

  10. Refractive Changes Induced by Spherical Aberration in Laser Correction Procedures: An Adaptive Optics Study.

    Science.gov (United States)

    Amigó, Alfredo; Martinez-Sorribes, Paula; Recuerda, Margarita

    2017-07-01

    To study the effect on vision of induced negative and positive spherical aberration within the range of laser vision correction procedures. In 10 eyes (mean age: 35.8 years) under cyclopegic conditions, spherical aberration values from -0.75 to +0.75 µm in 0.25-µm steps were induced by an adaptive optics system. Astigmatism and spherical refraction were corrected, whereas the other natural aberrations remained untouched. Visual acuity, depth of focus defined as the interval of vision for which the target was still perceived acceptable, contrast sensitivity, and change in spherical refraction associated with the variation in pupil diameter from 6 to 2.5 mm were measured. A refractive change of 1.60 D/µm of induced spherical aberration was obtained. Emmetropic eyes became myopic when positive spherical aberration was induced and hyperopic when negative spherical aberration was induced (R2 = 81%). There were weak correlations between spherical aberration and visual acuity or depth of focus (R2 = 2% and 3%, respectively). Contrast sensitivity worsened with the increment of spherical aberration (R2 = 59%). When pupil size decreased, emmetropic eyes became hyperopic when preexisting spherical aberration was positive and myopic when spherical aberration was negative, with an average refractive change of 0.60 D/µm of spherical aberration (R2 = 54%). An inverse linear correlation exists between the refractive state of the eye and spherical aberration induced within the range of laser vision correction. Small values of spherical aberration do not worsen visual acuity or depth of focus, but positive spherical aberration may induce night myopia. In addition, the changes in spherical refraction when the pupil constricts may worsen near vision when positive spherical aberration is induced or improve it when spherical aberration is negative. [J Refract Surg. 2017;33(7):470-474.]. Copyright 2017, SLACK Incorporated.

  11. Upregulation of long noncoding RNA SPRY4-IT1 modulates proliferation, migration, apoptosis, and network formation in trophoblast cells HTR-8SV/neo.

    Directory of Open Access Journals (Sweden)

    Yanfen Zou

    Full Text Available SPRY4-IT1 has been reported to have extremely high expression in normal placenta tissues. It is a Long noncoding RNA (lncRNA, which is associated with cell growth, migration, invasion, and apoptosis in melanoma. A 2.8-fold increase of SPRY4-IT1 expression was validated by Real-time reverse transcription-polymerase chain reaction (qRT-PCR in severe preeclamptic placenta as compared with that of the normal ones (n=25 in this study. Furthermore, the role of SPRY4-IT1 in proliferation, migration, apoptosis, and network formation ability of trophoblast cells HTR-8/SVneo was assessed. Suppression of SPRY4-IT1 using siRNA treatment and its overexpression using plasmid targeting SPRY4-IT1 were performed in order to explore the biological function of SPRY4-IT1 in the development and progression of trophoblast cells HTR-8/SVneo, in vitro. The results showed that SPRY4-IT1 knockdown enhanced the cell migration and proliferation, and reduced the response of cells to apoptosis. However, exogenous SPRY4-IT1 overexpression significantly decreased the cell migration and proliferation, while increased cell apoptosis. Our study showed for the first time that aberrant expression of lncRNA SPRY4-IT1 might contribute to the abnormal condition of trophoblast cells HTR-8/SVneo. Therefore, we proposed SPRY4-IT1 as a novel lncRNA molecule, which might be associated with the pathogenesis of preeclampsia and might provide a new target for its early diagnosis and treatment.

  12. Focus on environmental risks and migration: causes and consequences

    Science.gov (United States)

    Adger, W. Neil; Arnell, Nigel W.; Black, Richard; Dercon, Stefan; Geddes, Andrew; Thomas, David S. G.

    2015-06-01

    Environmental change poses risks to societies, including disrupting social and economic systems such as migration. At the same time, migration is an effective adaptation to environmental and other risks. We review novel science on interactions between migration, environmental risks and climate change. We highlight emergent findings, including how dominant flows of rural to urban migration mean that populations are exposed to new risks within destination areas and the requirement for urban sustainability. We highlight the issue of lack of mobility as a major issue limiting the effectiveness of migration as an adaptation strategy and leading to potentially trapped populations. The paper presents scenarios of future migration that show both displacement and trapped populations over the incoming decades. Papers in the special issue bring new insights from demography, human geography, political science and environmental science to this emerging field.

  13. Father's Migration and Leaving the Parental Home in Rural Mozambique

    Science.gov (United States)

    Chae, Sophia; Hayford, Sarah R.; Agadjanian, Victor

    2016-01-01

    Migration is an increasingly common demographic phenomenon and has important implications for the well-being of family members left behind. Although extensive research has examined the impact of parental labor migration on school-age children, less is known about its effect on adolescents. In this study, the authors used longitudinal survey data collected in rural Mozambique (N = 515) to assess the association between father's migration and adolescent children's leaving the parental home, an important component of the transition to adulthood. The results showed that father's migration delays home-leaving for adolescent girls and that these effects are not mediated by school enrollment. The results for boys were inconclusive. The authors also found that remittances and longer durations of paternal migration were negatively associated with the transition out of the home. On the basis of the findings, they argue that father's migration delays girls’ marriage. PMID:27499554

  14. Determinants of spring migration departure decision in a bat.

    Science.gov (United States)

    Dechmann, Dina K N; Wikelski, M; Ellis-Soto, D; Safi, K; O'Mara, M Teague

    2017-09-01

    Migratory decisions in birds are closely tied to environmental cues and fat stores, but it remains unknown if the same variables trigger bat migration. To learn more about the rare phenomenon of bat migration, we studied departure decisions of female common noctules ( Nyctalus noctula ) in southern Germany. We did not find the fattening period that modulates departure decisions in birds. Female noctules departed after a regular evening foraging session, uniformly heading northeast. As the day of year increased, migratory decisions were based on the interactions among wind speed, wind direction and air pressure. As the migration season progressed, bats were likely to migrate on nights with higher air pressure and faster tail winds in the direction of travel, and also show high probability of migration on low-pressure nights with slow head winds. Common noctules thus monitor complex environmental conditions to find the optimal migration night. © 2017 The Authors.

  15. [Medical genetics and migration].

    Science.gov (United States)

    Feingold, J

    1988-01-01

    Any migration results in the transfer of normal and pathological genes from one population to another. The frequency of pathological genes may vary according to the population, sickle cell anaemia, for instance, being frequent in Africa and cystic fibrosis in Europe. It follows that the hereditary pathology of migrants is not the same as that of the host population, at least during the immediate post-migration years; subsequently, all depends on the degree of cross-breeding. In epidemiological genetics the study of the frequency of some diseases in the original population, among migrants and in the host population enables the effects of genes and environment on the aetiology of these diseases to be investigated.

  16. Tracking migrating birds

    DEFF Research Database (Denmark)

    Willemoes, Mikkel

    Migratory movements of birds has always fascinated man and led to many questions concerning the ecological drivers behind, the necessary adaptations and the navigational abilities required. However, especially for the long-distance migrants, basic descriptions of their movements are still lacking...... and many experiments are only becoming possible with the current development of tracking technologies. During this thesis work I have been tracking the poorly known movements of several species of long-distance migrants and document highly complex migration patterns. In three manuscripts these movements...... were related to the yearly progression of an environmental surrogate for food availability along the course of migration. In one species, with multiple, different non-breeding staging sites, environmental conditions explain movements well and also how yearly differences explain differences in timing...

  17. Religion, migration og integration

    DEFF Research Database (Denmark)

    Borup, Jørn

    2010-01-01

    Sammenhængen mellem religion og integration har de sidste år været genstand for debat. Artiklen kommer ind på begreber og sammenhænge relateret til området (migration, diaspora, assimilation, etnicitet, kultur) og ser på religionens mulige rolle som negativ eller positiv ressource i integrationss......Sammenhængen mellem religion og integration har de sidste år været genstand for debat. Artiklen kommer ind på begreber og sammenhænge relateret til området (migration, diaspora, assimilation, etnicitet, kultur) og ser på religionens mulige rolle som negativ eller positiv ressource i...

  18. Forced Migration: Refugee Populations

    Science.gov (United States)

    Boyle, Joyceen S.

    2015-01-01

    Undocumented migration is a global phenomenon that manifests in various contexts. This article describes the impact of the movement of large numbers of people in several African countries, producing a unique type of migrant—the refugee. We describe issues that refugee movements create on fragile health care systems, situations that precipitate refugee movements, certain human rights violations that are of particular concern such as gender based violence (GBV) and child soldiers, and lastly, implications for nursing practice and policy. We use examples from several countries in Sub-Saharan Africa, including the Democratic Republic of the Congo, Rwanda, Liberia, Sierra Leone, and Mozambique. Drawing on key documents from the United Nations High Commissioner for Refugees, current literature, as well as the international experience of the authors, this article presents an overview of forced migration and discusses opportunities for nurses to impact research, practice and policy related to refugee health. PMID:25645484

  19. Random migration processes between two stochastic epidemic centers.

    Science.gov (United States)

    Sazonov, Igor; Kelbert, Mark; Gravenor, Michael B

    2016-04-01

    We consider the epidemic dynamics in stochastic interacting population centers coupled by random migration. Both the epidemic and the migration processes are modeled by Markov chains. We derive explicit formulae for the probability distribution of the migration process, and explore the dependence of outbreak patterns on initial parameters, population sizes and coupling parameters, using analytical and numerical methods. We show the importance of considering the movement of resident and visitor individuals separately. The mean field approximation for a general migration process is derived and an approximate method that allows the computation of statistical moments for networks with highly populated centers is proposed and tested numerically. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Effect of Single Administration of Coffee on Pupil Size and Ocular Wavefront Aberration Measurements in Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Handan Bardak

    2016-01-01

    Full Text Available No study has so far evaluated the impact of coffee drinking on ocular wavefront aberration (OWA measurements. This study presents novel findings regarding the OWA of the eye following coffee intake. We aimed to evaluate the acute changes in pupil size and OWA of the eye after single administration of coffee. A total of 30 otherwise healthy participants were included in this prospective study. All subjects drank a cup of coffee containing 57 mg caffeine. Measurements of pupil size, total coma (TC, total trefoil (TF, total spherical aberration (TSA, and total higher order aberration (HOA were performed before and at 5 minutes, at 30 minutes, and at 4 hours after coffee drinking using a wavefront aberrometer device (Irx3, Imagine Eyes, Orsay, France. The mean age of the study population was 20.30 ± 2.74 years. Pupil size did not show a significant change during the measurements (p>0.05. A significant increase was observed in TF and HOA measurements following coffee intake (p=0.029 and p=0.009, resp.. Single administration of coffee results in significant increase in TF and total HOAs in healthy subjects without any effect on pupil diameter. Ultrastructural changes in the cornea following coffee intake might be of relevance to the alterations in ocular aberrations in healthy subjects.

  1. No significant level of inheritable interchromosomal aberrations in the progeny of bystander primary human fibroblasts after alpha particle irradiation

    Science.gov (United States)

    Hu, Burong; Zhu, Jiayun; Zhou, Hongning; Hei, Tom K.

    2013-02-01

    A major concern for bystander effects is the probability that normal healthy cells adjacent to the irradiated cells become genomically unstable and undergo further carcinogenesis after therapeutic irradiation or space mission where astronauts are exposed to low dose of heavy ions. Genomic instability is a hallmark of cancer cells. In the present study, two irradiation protocols were performed in order to ensure pure populations of bystander cells and the genomic instability in their progeny were investigated. After irradiation, chromosomal aberrations of cells were analyzed at designated time points using G2 phase premature chromosome condensation (G2-PCC) coupled with Giemsa staining and with multiplex fluorescent in situ hybridization (mFISH). Our Giemsa staining assay demonstrated that elevated yields of chromatid breaks were induced in the progeny of pure bystander primary fibroblasts up to 20 days after irradiation. mFISH assay showed no significant level of inheritable interchromosomal aberrations were induced in the progeny of the bystander cell groups, while the fractions of gross aberrations (chromatid breaks or chromosomal breaks) significantly increased in some bystander cell groups. These results suggest that genomic instability occurred in the progeny of the irradiation associated bystander normal fibroblasts exclude the inheritable interchromosomal aberration.

  2. Association of Cigarette Smoking with Aberrant Methylation of the Tumor Suppressor Gene RARβ2 in Papillary Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Katja eKiseljak-Vassiliades

    2011-12-01

    Full Text Available Aberrant gene methylation is often seen in thyroid cancer, a common endocrine malignancy. Tobacco smoking has been shown to be associated with aberrant gene methylation in several cancers, but its relationship with gene methylation in thyroid cancer has not been examined. In the present study, we investigated the relationship between smoking of patients and aberrant methylation of tumor suppressor genes for TIMP3, SLC5A8, death-associated protein kinase, and retinoic acid receptor β2 (RARβ2 in papillary thyroid cancer (PTC, the most common type of thyroid cancer. The promoter methylation status of these genes was analyzed using quantitative real-time methylation-specific PCR on bisulfite-treated genomic DNA isolated from tumor tissues and correlated with smoking history of the patients. Among the four genes, methylation of the RARβ2 gene was significantly associated with smoking and other three genes showed a trend of association. Specifically, among the 138 patients investigated, 13/42 (31.0% ever smokers vs. 10/96 (10.4% never smokers harbored methylation of the RARβ2 gene (P = 0.003. This association was highly significant also in the subset of conventional variant PTC (P = 0.005 and marginally significant in follicular variant PTC (p = 0.06. The results demonstrate that smoking-associated aberrant methylation of the RARβ2 gene is a specific molecular event that may represent an important mechanism in thyroid tumorigenesis in smokers.

  3. Retrograde Gastrojejunostomy Tube Migration

    Directory of Open Access Journals (Sweden)

    Adeleke Adesina

    2014-01-01

    Full Text Available Percutaneous enteral feeding tubes are placed about 250,000 times each year in the United States. Although they are relatively safe, their placement may be complicated by perforation, infection, bleeding, vomiting, dislodgment, and obstruction. There have been numerous reports of antegrade migration of gastrojejunostomy (G-J tubes. We report a case of G-J tube regurgitation following protracted vomiting and discuss the management of this very rare entity.

  4. American Migration Controversies

    OpenAIRE

    Milan Mesić

    1998-01-01

    The USA has been and has remained the world's most important immigration country. The last quarter of the 20th century has been marked by a new mass immigration wave that in absolute size of the immigration flow can be compared to the highest flows in the previous century. This recent migration, however, differs from traditional immigration to America in that it includes a greater ethnic, religious and cultural diversity. The vast majority of today's immigrants, both legal and clandestine, co...

  5. Enforcement and illegal migration

    OpenAIRE

    Pia Orrenius

    2014-01-01

    Border enforcement of immigration laws attempts to raise the costs of illegal immigration, while interior enforcement also lowers the benefits. Border and interior enforcement therefore reduce the net benefits of illegal immigration and should lower the probability that an individual will decide to migrate. While some empirical studies find that border and interior enforcement serve as significant deterrents to illegal immigration, immigration enforcement is costly and carries significant uni...

  6. Partial diel vertical migrations in pelagic fish.

    Science.gov (United States)

    Mehner, Thomas; Kasprzak, Peter

    2011-07-01

    1. Field studies on diel vertical migration (DVM) usually report uniform behaviour with population-wide ascents and descents during crepuscular periods. This contrasts partial seasonal migrations of many animal populations, where individuals choose either the resident or the migrant strategy depending on population density, feeding opportunity and predation risk in the resident and migrant habitats. 2. We tested whether DVM of freshwater zooplanktivorous fish (Coregonus spp.) resembles partial migrations. Twenty-eight hydroacoustic surveys were performed in the deep Lake Stechlin (Germany) between 2000 and 2010, with samplings encompassing all months between March and December. Zooplankton samples were simultaneously taken in epilimnetic and hypolimnetic layers. Fish obtained from depth-stratified samplings by a midwater trawl were used to test for individual differences between residents and migrants. 3. We show for the first time that DVMs of freshwater fish resemble patterns of partial migrations often found in seasonal environments. Across all samplings, 7-33% of fish did not ascend at dusk, but exhibited the resident strategy. The proportion or residents increased at low zooplankton feeding rates in the daytime habitat and during months when the temperature difference between daytime and night-time habitats was minor. 4. Slightly larger size and higher caloric density of migrants over residents in one of the coexisting Coregonus species suggested that individual differences contributed to the migration strategy performed. However, these results were based on one sample only, and extrapolation to the entire data set is not possible. 5. Our results are indirect evidence that the balance between migrants and residents may primarily depend on the trade-off between feeding gains and metabolic and predation costs of migration. However, the results also suggest that the global fitness consequences for the resident and migrant strategies may not be identical

  7. Conservation physiology of animal migration

    Science.gov (United States)

    Lennox, Robert J.; Chapman, Jacqueline M.; Souliere, Christopher M.; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D.; Cooke, Steven J.

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  8. Dose Response for Chromosome Aberrations in Human Lymphocytes and Fibroblasts After Exposure to Very Low Dose of High Let Radiation

    Science.gov (United States)

    Hada, M.; George, K.; Chappell, L.; Cucinotta, F. A.

    2011-01-01

    The relationship between biological effects and low doses of absorbed radiation is still uncertain, especially for high LET radiation exposure. Estimates of risks from low-dose and low-dose-rates are often extrapolated using data from Japanese atomic bomb survivor with either linear or linear quadratic models of fit. In this study, chromosome aberrations were measured in human peripheral blood lymphocytes and normal skin fibroblasts cells after exposure to very low dose (0.01 - 0.20 Gy) of 170 MeV/u Si-28 ions or 600 MeV/u Fe-56 ions, including doses where on average less than one direct ion traversal per cell nucleus occurs. Chromosomes were analyzed using the whole-chromosome fluorescence in situ hybridization (FISH) technique during the first cell division after irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). The responses for doses above 0.1 Gy (more than one ion traverses a cell) showed linear dose responses. However, for doses less than 0.1 Gy, both Si-28 ions and Fe-56 ions showed a dose independent response above background chromosome aberrations frequencies. Possible explanations for our results are non-targeted effects due to aberrant cell signaling [1], or delta-ray dose fluctuations [2] where a fraction of cells receive significant delta-ray doses due to the contributions of multiple ion tracks that do not directly traverse cell nuclei where chromosome aberrations are scored.

  9. Migration Profile NIGERIA 1. Structural Migration Profile 2. Flash Migration Profile (January - March 2017)

    OpenAIRE

    BRYTON DIAS MARQUES FERNANDO; URSO GIULIANA

    2017-01-01

    The new generation of Migration Profiles aims at collecting knowledge on migration and development at regular, short intervals (3/6 months) and with a sub-national coverage, providing tailored monitoring and ensuring comparability across countries. It links migration, developmental and humanitarian aspects as well as analyses on the EU strategic role vis-à-vis the third country, including its political, financial and humanitarian support. This publication reproduces the Migration Profile of N...

  10. Many Faces of Migrations

    Directory of Open Access Journals (Sweden)

    Milica Antić Gaber

    2013-12-01

    We believe that in the present thematic issue we have succeeded in capturing an important part of the modern European research dynamic in the field of migration. In addition to well-known scholars in this field several young authors at the beginning their research careers have been shortlisted for the publication. We are glad of their success as it bodes a vibrancy of this research area in the future. At the same time, we were pleased to receive responses to the invitation from representatives of so many disciplines, and that the number of papers received significantly exceeded the maximum volume of the journal. Recognising and understanding of the many faces of migration are important steps towards the comprehensive knowledge needed to successfully meet the challenges of migration issues today and even more so in the future. It is therefore of utmost importance that researchers find ways of transferring their academic knowledge into practice – to all levels of education, the media, the wider public and, of course, the decision makers in local, national and international institutions. The call also applies to all authors in this issue of the journal.

  11. Are changes in ocular aberrations with age a significant problem for refractive surgery?

    Science.gov (United States)

    Marcos, Susana

    2002-01-01

    We discuss current knowledge about the change of aberrations with aging, cataract surgery, and laser in situ keratomileusis (LASIK) for myopia. Based on this evidence, we speculate about the long-term expectations for postoperative LASIK eyes in terms of aberrations. Standard myopic LASIK surgery produces a significant increase in aberrations, particularly corneal spherical aberration, which changes to positive values. Aberrations increase with age, and in particular, the spherical aberration of the crystalline lens shifts toward positive values. Therefore, no compensatory effect is expected to occur with age after standard myopic LASIK, but rather the unusually high amount of aberrations in postoperative LASIK patients is expected to worsen with age. The amount of aberrations in patients after cataract surgery with implantation of standard intraocular lenses (IOLs) is higher than in normal young subjects. If an ideal customized ablation (not inducing aberrations and reducing naturally existing aberrations) is ever possible, the perfect correction will not last (due to the change of aberrations with age), and aberrations of the crystalline lens corrected on the cornea are likely to reappear after conventional cataract surgery. Potential benefits of customized IOLs for cataract surgery and improved optics in older patients are discussed.

  12. Photon Sieve Bandwidth Broadening by Reduction of Chromatic Aberration Effects Using Second-Stage Diffractive Optics

    Science.gov (United States)

    2015-03-26

    thesis. 25 Still another manner in which to view chromatic aberration is in terms of Lateral Chromatic Aberration ( LCA ). Eq. 18 illustrates a...wavelength in addition to the in-focus location. This difference in height of images at two different colors is LCA (21:268). Aberration Correction

  13. Migrations in Slovenian geography textbooks

    Directory of Open Access Journals (Sweden)

    Jurij Senegačnik

    2013-12-01

    Full Text Available In Slovenia, the migrations are treated in almost all geographical textbooks for different levels of education. In the textbooks for the elementary school from the sixth to ninth grade, students acquire knowledge of the migrations by the inductive approach. Difficulty level of treatment and quantity of information are increasing by the age level. In the grammar school program a trail of gaining knowledge on migration is deductive. Most attention is dedicated to migrations in general geography textbooks. The textbooks for vocational and technical school programs deal with migrations to a lesser extent and with different approaches.

  14. Physical Guidance of Cell Migration

    Science.gov (United States)

    Losert, Wolfgang

    Cells migrate as individuals or groups, to perform critical functions in life from organ development to wound healing and the immune response. While directed migration of cells is often mediated by chemical or physical gradients, our recent work has demonstrated that the physical properties of the microenvironment can also control and guide migration. I will describe how an underlying wave-like process of the actin scaffolding drives persistent migration, and how such actin waves are nucleated and guided by the texture of the microenvironment. Based on this observation we design textures capable of guiding cells in a single preferred direction using local asymmetries in nano/microtopography on subcellular scales, or altering migration in other ways. This phenomenon is observed both for the pseudopod-dominated migration of Dictyostelium cells and for the lamellipod-driven migration of human neutrophils. The conservation of this mechanism across cell types suggests that actin-wave-based guidance is important in biology and physiology.

  15. Frequent and distinct aberrations of DNA methylation patterns in fibrolamellar carcinoma of the liver.

    Directory of Open Access Journals (Sweden)

    Wolfgang Tränkenschuh

    Full Text Available BACKGROUND: Gene silencing due to aberrant DNA methylation is a frequent event in hepatocellular carcinoma (HCC and also in hepatocellular adenoma (HCA. However, very little is known about epigenetic defects in fibrolamellar carcinoma (FLC, a rare variant of hepatocellular carcinoma that displays distinct clinical and morphological features. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the methylation status of the APC, CDH1, cyclinD2, GSTπ1, hsa-mir-9-1, hsa-mir-9-2, and RASSF1A gene in a series of 15 FLC and paired normal liver tissue specimens by quantitative high-resolution pyrosequencing. Results were compared with common HCC arising in non-cirrhotic liver (n = 10. Frequent aberrant hypermethylation was found for the cyclinD2 (19% and the RASSF1A (38% gene as well as for the microRNA genes mir-9-1 (13% and mir-9-2 (33%. In contrast to common HCC the APC and CDH1 (E-cadherin genes were found devoid of any DNA methylation in FLC, whereas the GSTπ1 gene showed comparable DNA methylation in tumor and surrounding tissue at a moderate level. Changes in global DNA methylation level were measured by analyzing methylation status of the highly repetitive LINE-1 sequences. No evidence of global hypomethylation could be found in FLCs, whereas HCCs without cirrhosis showed a significant reduction in global methylation level as described previously. CONCLUSIONS: FLCs display frequent and distinct gene-specific hypermethylation in the absence of significant global hypomethylation indicating that these two epigenetic aberrations are induced by different pathways and that full-blown malignancy can develop in the absence of global loss of DNA methylation. Only quantitative DNA methylation detection methodology was able to identify these differences.

  16. Chromosomal aberration analysis among underground water well workers in Saudi Arabia.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Yasuko eKikuchi

    2013-12-01

    Full Text Available 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.

  18. Aberrant distributions of nuclear pore complex proteins in ALS mice and ALS patients.

    Science.gov (United States)

    Shang, Jingwei; Yamashita, Toru; Nakano, Yumiko; Morihara, Ryuta; Li, Xianghong; Feng, Tian; Liu, Xia; Huang, Yong; Fukui, Yusuke; Hishikawa, Nozomi; Ohta, Yasuyuki; Abe, Koji

    2017-05-14

    Nuclear pore complexes (NPCs) play important roles in traffic of molecules between the nucleus and cytoplasm, aberrant distributions of components of NPCs were demonstrated in C9orf72 amyotrophic lateral sclerosis (C9-ALS) patients, but it is elusive whether such abnormities are also the case with other cause of ALS disease. In the present study, we investigated the spatiotemporal distributions of RanGAP1 and 4 representative nucleoporins (GP210, NUP205, NUP107 and NUP50) of NPCs in human Cu/Zn superoxide dismutase-1 mutation transgenic (SOD1-Tg) mice and sporadic ALS patients. Compared with wild type (WT), these proteins displayed age-dependent and progressive nuclear precipitations, and cytoplasmic aberrant expressions in motor neurons of lumbar cord in SOD1-Tg mice from 10 to 18weeks (W). Double immunofluorescent analysis showed abnormal nuclear retention and apparent co-localizations of RanGAPl with NUP205 and NUP205 with NUPl07, meanwhile, GP210 with NUP205 mainly co-localized in the nuclear envelope (NE) of motor neurons. Furthermore, RanGAP1, GP210 and NUP50 showed similarly abnormal nuclear precipitations and cytoplasmic upregulations in SOD1-Tg mice and ALS patients, moreover, aberrant co-localizations of RanGAP1 with TDP-43 and NUP205 with TDP-43 were also observed in motor neurons. The present study indicated that the mislocalization of these proteins of NPCs may underlie the pathogenesis of ALS both in SOD1-Tg mice and human sporadic ALS patients, and these dysfunctions may be a fundamental pathway for ALS that is not specific only in C9-ALS but also in SOD1-ALS, which may be amenable to pharmacotherapeutic intervention. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. Diel vertical migration of zooplankton in the Tanzanian waters of ...

    African Journals Online (AJOL)

    The diel vertical migration of zooplankton was studied in the Southern part of Lake Victoria in January and July 2002. A van dorn water sampler was used to collect zooplankton. In January 2002, zooplankton showed a pronounced diel vertical migration whereby zooplankton were moving upward at around sunset and ...

  20. Hypoxia stimulates invasion and migration of human cervical cancer ...

    Indian Academy of Sciences (India)

    Here we show that hypoxiaincreases tumour cell invasion and migration by the modulation of Rab11, an important molecule for vesicular trafficking.In our study, we found that Rab11, together with the activation of Rac1, could stimulate invasion and migration of cervicalcancer cell lines HeLa/SiHa in hypoxia. Activation of ...

  1. Analysis of primary cilia in directional cell migration in fibroblasts

    DEFF Research Database (Denmark)

    Christensen, Søren Tvorup; Veland, Iben; Schwab, Albrecht

    2013-01-01

    Early studies of migrating fibroblasts showed that primary cilia orient in front of the nucleus and point toward the leading edge. Recent work has shown that primary cilia coordinate a series of signaling pathways critical to fibroblast cell migration during development and in wound healing. In p...

  2. Migration et hivernage de quelques passereaux au Maroc: Mise au ...

    African Journals Online (AJOL)

    The analysis of the autumn migration across Morocco confirms that many birds pass near the Atlantic coast. Winter recoveries in Morocco are mainly concentrated in the northern and central regions. The analysis of the spring migration shows that most birds use approximately the same routes in both autumn and spring, but ...

  3. Luanda-Holanda; irregular migration from Angola to the Netherlands

    NARCIS (Netherlands)

    van Wijk, J.

    2008-01-01

    Against the backdrop of push-pull and social network theories on migration and criminological theory on human smuggling, this article tries to answer the questions of why and how Angolan asylum-seekers migrated to the Netherlands since the end of the 1990s. The study shows that the migrants can be

  4. Migration to and from the terai: shifting movements and motives

    NARCIS (Netherlands)

    Gartaula, H.N.; Niehof, Anke

    2013-01-01

    In Nepal, the historical evidence shows that migration to the terai increased after the eradication of malaria in the late 1950s and has been increasing ever since. More recently, however, out-migration from the terai is rapidly increasing. By applying both qualitative and quantitative research

  5. Chromosomal Aberrations in Humans Induced by Urban Air Pollution

    DEFF Research Database (Denmark)

    Knudsen, Lisbeth E.; Norppa, Hannu; Gamborg, Michael O.

    1999-01-01

    that long-term exposure to urban air pollution (with traffic as the main contributor) induces chromosome damage in human somatic cells. Low DNA repair capacity and GSTM1 and NAT2 variants associated with reduced detoxification ability increase susceptibility to such damage. The effect of the GSTM1 genotype......We have studied the influence of individual susceptibility factors on the genotoxic effects of urban air pollution in 106 nonsmoking bus drivers and 101 postal workers in the Copenhagen metropolitan area. We used the frequency of chromosomal aberrations in peripheral blood lymphocytes......, which was observed only in the bus drivers, appears to be associated with air pollution, whereas the NAT2 genotype effect, which affected all subjects, may influence the individual response to some other common exposure or the baseline level of chromosomal aberrations....

  6. Deep Tissue Wavefront Estimation for Sensorless Aberration Correction

    Directory of Open Access Journals (Sweden)

    Ibrahimovic Emina

    2015-01-01

    Full Text Available The multiple light scattering in biological tissues limits the measurement depth for traditional wavefront sensor. The attenuated ballistic light and the background noise caused by the diffuse light give low signal to noise ratio for wavefront measurement. To overcome this issue, we introduced a wavefront estimation method based on a ray tracing algorithm to overcome this issue. With the knowledge of the refractive index of the medium, the wavefront is estimated by calculating optical path length of rays from the target inside of the samples. This method can provide not only the information of spherical aberration from the refractive-index mismatch between the medium and biological sample but also other aberrations caused by the irregular interface between them. Simulations based on different configurations are demonstrated in this paper.

  7. Membrane-based aberration-corrected tunable micro-lenses

    Science.gov (United States)

    Waibel, Philipp; Ermantraut, Eugen; Mader, Daniel; Zappe, Hans; Seifert, Andreas

    2010-05-01

    We present measurements and simulations of membrane-based micro-lens stacks, tunable in focal length in the range of 10mm to 50mm without chromatic aberration. The pressure-actuated, liquid-filled, membrane-based micro-lenses are fabricated by an all-silicone molding approach and consist of three chambers separated by two highly flexible silicone-membranes. Based on the idea of the classical achromatic Fraunhofer doublet, two different liquids with suitable optical properties are used. Pressure-dependent surface topologies are measured by profilometry for determining the correlation between refraction and applied pressure. The profiles are fit to polynomials; the coefficients of the polynomials are pressure-dependent and fit to empirically determined functions which are then used as an input for optical ray-tracing. Using this approach, the focal length is tunable while compensating for chromatic aberration by suitably applied pressures.

  8. Aberrations and adaptive optics in super-resolution microscopy

    Science.gov (United States)

    Booth, Martin; Andrade, Débora; Burke, Daniel; Patton, Brian; Zurauskas, Mantas

    2015-01-01

    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. PMID:26124194

  9. Aberration characteristics of plane-parallel compensator plate

    Science.gov (United States)

    Komarova, I. E.

    1984-02-01

    A specially constructed plane parallel compensator plate in a ring telescope catodioptric objective does not affect the size of the dead zone in the pupil and will not only eliminate parasitic flare or bright spots but also allow the relative aperture of each mirror and of the entire objective to be substantially enlarged. Such a plate consists of two elements, the smaller one with a diameter equal to that of the secondary mirror placed at the center of the larger one so as to face that mirror. Here the aberration characteristics of this compensator are analyzed according to the laws of geometric optics for wide beams of light rays. Five different compensator configurations are conceived on this basis for complete correction of spherical aberration, with the appropriate formulas given for calculating the necessary plate thickness.

  10. Stretch due to Penile Prosthesis Reservoir Migration

    Directory of Open Access Journals (Sweden)

    E. Baten

    2016-03-01

    Full Text Available A 43-year old patient presented to the emergency department with stretch, due to impossible deflation of the penile prosthesis, 4 years after successful implant. A CT-scan showed migration of the reservoir to the left rectus abdominis muscle. Refilling of the reservoir was inhibited by muscular compression, causing stretch. Removal and replacement of the reservoir was performed, after which the prosthesis was well-functioning again. Migration of the penile prosthesis reservoir is extremely rare but can cause several complications, such as stretch.

  11. Human neutrophils facilitate tumor cell transendothelial migration.

    LENUS (Irish Health Repository)

    Wu, Q D

    2012-02-03

    Tumor cell extravasation plays a key role in tumor metastasis. However, the precise mechanisms by which tumor cells migrate through normal vascular endothelium remain unclear. In this study, using an in vitro transendothelial migration model, we show that human polymorphonuclear neutrophils (PMN) assist the human breast tumor cell line MDA-MB-231 to cross the endothelial barrier. We found that tumor-conditioned medium (TCM) downregulated PMN cytocidal function, delayed PMN apoptosis, and concomitantly upregulated PMN adhesion molecule expression. These PMN treated with TCM attached to tumor cells and facilitated tumor cell migration through different endothelial monolayers. In contrast, MDA-MB-231 cells alone did not transmigrate. FACScan analysis revealed that these tumor cells expressed high levels of intercellular adhesion molecule-1 (ICAM-1) but did not express CD11a, CD11b, or CD18. Blockage of CD11b and CD18 on PMN and of ICAM-1 on MDA-MB-231 cells significantly attenuated TCM-treated, PMN-mediated tumor cell migration. These tumor cells still possessed the ability to proliferate after PMN-assisted transmigration. These results indicate that TCM-treated PMN may serve as a carrier to assist tumor cell transendothelial migration and suggest that tumor cells can exploit PMN and alter their function to facilitate their extravasation.

  12. Managing migration: scaling sovereignty on islands

    Directory of Open Access Journals (Sweden)

    Jenna M. Loyd

    2014-05-01

    Full Text Available Island and maritime spaces between regions have become central places of recurrent crises over human migration and re-articulations of state sovereignty. Islands, the very sites where land meets water, are among the contested sites of struggle over entry and exclusion. In this paper, the Mediterranean is our main area of geographical inquiry. We explore the connections between crises of sovereignty, migration and islands, seeking to enhance connections between scholarship on migration and sovereignty. We argue that migration management and its geographical articulation on islands involve persistent reconfigurations of sovereignty, particularly evident during times of crisis over human migration. Such crises and re-articulations of sovereignty are creative uses of geography that repeatedly lead to a failure to protect human rights. To develop this argument, we bring feminist theorists of state sovereignty into conversation with political geographers. We move across scales of governance and political mobilization to show how a reconfiguration of sovereignty through regional and national management regimes leads to complex legal geographies and sovereign entanglements that migrants and advocates must navigate to claim rights.

  13. Human neutrophils facilitate tumor cell transendothelial migration.

    Science.gov (United States)

    Wu, Q D; Wang, J H; Condron, C; Bouchier-Hayes, D; Redmond, H P

    2001-04-01

    Tumor cell extravasation plays a key role in tumor metastasis. However, the precise mechanisms by which tumor cells migrate through normal vascular endothelium remain unclear. In this study, using an in vitro transendothelial migration model, we show that human polymorphonuclear neutrophils (PMN) assist the human breast tumor cell line MDA-MB-231 to cross the endothelial barrier. We found that tumor-conditioned medium (TCM) downregulated PMN cytocidal function, delayed PMN apoptosis, and concomitantly upregulated PMN adhesion molecule expression. These PMN treated with TCM attached to tumor cells and facilitated tumor cell migration through different endothelial monolayers. In contrast, MDA-MB-231 cells alone did not transmigrate. FACScan analysis revealed that these tumor cells expressed high levels of intercellular adhesion molecule-1 (ICAM-1) but did not express CD11a, CD11b, or CD18. Blockage of CD11b and CD18 on PMN and of ICAM-1 on MDA-MB-231 cells significantly attenuated TCM-treated, PMN-mediated tumor cell migration. These tumor cells still possessed the ability to proliferate after PMN-assisted transmigration. These results indicate that TCM-treated PMN may serve as a carrier to assist tumor cell transendothelial migration and suggest that tumor cells can exploit PMN and alter their function to facilitate their extravasation.

  14. THALASSAEMIA AND ABERRATIONS OF GROWTH AND PUBERTY

    Directory of Open Access Journals (Sweden)

    Andreas Kyriakou

    2009-07-01

    Full Text Available Endocrine dysfunction in Thalassaemia major (TM is a common and disturbing complication, which requires prompt recognition and treatment. The contribution of the underlying molecular defect in TM to the development of endocrinopathies is significant because the patients with the more severe genetic defects have a greater rate of iron loading through higher red cell consumption. TM patients frequently present delay of growth and puberty with reduction of final height. The pathogenesis of growth failure is multifactorial and is mainly due to chronic anemia and hypoxia, chronic liver disease, zinc and folic acid deficiency, iron overload, intensive use of chelating agents, emotional factors, and endocrinopathies (hypogonadism, delayed puberty, hypothyroidism and GH-IGF-1 axis dysregulation. Although appropriate iron chelation therapy can improve growth and development, TM children and adolescents treated intensively with desferrioxamine remain short as well, showing body disproportion between the upper and lower body segment. Body disproportion is independent of prepubertal or pubertal period of greater height gain. Treatment with recombinant GH (rhGH is recommended when GH deficiency is established, and even so, the therapeutic response is often non satisfactory. Growth acceleration is mostly promoted with sex steroids in children with associated pubertal delay. Sexual complications in TM, which include Delayed Puberty, Arrested Puberty and Hypogonadism, present the commonest endocrine complication. Iron deposition on gonadotroph cells of the pituitary leads to disruption of gonadotrophin production which is proven by the poor response of FSH and LH to GnRH stimulation. In the majority of patients gonadal function is normal as most women with Amenorrhea are capable of achieving pregnancy with hormonal treatment and similarly men with azoospermia become fathers. Secondary Hypogonadism appears later in life,    and is manifested in women as

  15. Brainstem respiratory oscillators develop independently of neuronal migration defects in the Wnt/PCP mouse mutant looptail.

    Directory of Open Access Journals (Sweden)

    Muriel Thoby-Brisson

    Full Text Available The proper development and maturation of neuronal circuits require precise migration of component neurons from their birthplace (germinal zone to their final positions. Little is known about the effects of aberrant neuronal position on the functioning of organized neuronal groups, especially in mammals. Here, we investigated the formation and properties of brainstem respiratory neurons in looptail (Lp mutant mice in which facial motor neurons closely apposed to some respiratory neurons fail to migrate due to loss of function of the Wnt/Planar Cell Polarity (PCP protein Vangl2. Using calcium imaging and immunostaining on embryonic hindbrain preparations, we found that respiratory neurons constituting the embryonic parafacial oscillator (e-pF settled at the ventral surface of the medulla in Vangl2(Lp/+ and Vangl2(Lp/Lp embryos despite the failure of tangential migration of its normally adjacent facial motor nucleus. Anatomically, the e-pF neurons were displaced medially in Lp/+ embryos and rostro-medially Lp/Lp embryos. Pharmacological treatments showed that the e-pF oscillator exhibited characteristic network properties in both Lp/+ and Lp/Lp embryos. Furthermore, using hindbrain slices, we found that the other respiratory oscillator, the preBötzinger complex, was also anatomically and functionally established in Lp mutants. Importantly, the displaced e-pF oscillator established functional connections with the preBötC oscillator in Lp/+ mutants. Our data highlight the robustness of the developmental processes that assemble the neuronal networks mediating an essential physiological function.

  16. MiR-132 prohibits proliferation, invasion, migration, and metastasis in breast cancer by targeting HN1

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhan-Guo, E-mail: zhang_zhanguo@hotmail.com; Chen, Wei-Xun, E-mail: chenweixunclark@163.com; Wu, Yan-Hui, E-mail: wuyanhui84@126.com; Liang, Hui-Fang, E-mail: lianghuifang1997@126.com; Zhang, Bi-Xiang, E-mail: bixiangzhang@163.com

    2014-11-07

    Highlights: • MiR-132 is down-regulated in breast cancer tissues and cell lines. • MiR-132 directly regulates HN1 by binding its 3′ UTR. • MiR-132 shows regulatory role in proliferation, invasion, migration and metastasis. • HN1 is involved in miR-132-mediated cell behavior. • Aberrant HN1 is associated with worse overall survival of breast cancer patients. - Abstract: Accumulating evidence indicates that miRNAs play critical roles in tumorigenesis and cancer progression. This study aims to investigate the role and the underlying mechanism of miR-132 in breast cancer. Here, we report that miR-132 is significantly down-regulated in breast cancer tissues and cancer cell lines. Additional study identifies HN1 as a novel direct target of miR-132. MiR-132 down-regulates HN1 expression by binding to the 3′ UTR of HN1 transcript, thereby, suppressing multiple oncogenic traits such as cancer cell proliferation, invasion, migration and metastasis in vivo and in vitro. Overexpression of HN1 restores miR-132-suppressed malignancy. Importantly, higher HN1 expression is significantly associated with worse overall survival of breast cancer patients. Taken together, our data demonstrate a critical role of miR-132 in prohibiting cell proliferation, invasion, migration and metastasis in breast cancer through direct suppression of HN1, supporting the potential utility of miR-132 as a novel therapeutic strategy against breast cancer.

  17. Migrated Archives Revisited | Mnjama | ESARBICA Journal: Journal ...

    African Journals Online (AJOL)

    The article begins by identifying the broad categories that constitute migrated archives and shows how agencies such as the International Council on Archives, the United Nations Educational, Scientific and Cultural Organization the United Nations have sought solutions to this issue. The article explores various options for ...

  18. Migration from atolls as climate change adaptation

    DEFF Research Database (Denmark)

    Birk, Thomas Ladegaard Kümmel; Rasmussen, Kjeld

    2014-01-01

    that migration currently improves access to financial and social capital, reduces pressure on natural resources and makes island communities less vulnerable to extreme weather events and other shocks — all factors that contribute positively to adaptive capacity. It also shows that there are major barriers...

  19. [Aberration of somatic karyotype in normozoospermic males from infertile couples].

    Science.gov (United States)

    Mordalska, A; Barczyk, A; Hübner, H; Malinowski, A; Szpakowski, M

    1998-06-01

    During the complex investigation of couple infertility, a group of 40 normozoospermic males having low density of semen was selected. Cytogenetic analysis revealed 2 cases of somatic karyotype aberrations: 47,XYY and 46,XY,t(14;19), and 2 cases of chromosomal polymorphisms: 46,XYq+ i 46,XY,14p+. In the article the mechanism of fertility disturbances evoked by these findings is discussed in aspects of the function of spermatozoa and its genetic material content.

  20. Hybridoma fusion cell lines contain an aberrant kappa transcript.

    Science.gov (United States)

    Carroll, W L; Mendel, E; Levy, S

    1988-10-01

    The V region sequence of a non-productive kappa transcript from two myeloma fusion partners has been determined. This transcript has an aberrant VJ recombination site resulting in a translation stop site at position 105. It is variably expressed in hybridomas made from all fusion partners derived from the original MOPC-21 tumor. The amount of this transcript may greatly exceed levels of the productive light chain mRNA.

  1. Aberrant Lymphatic Endothelial Progenitors in Lymphatic Malformation Development

    OpenAIRE

    Wu, June K.; Christopher Kitajewski; Maia Reiley; Keung, Connie H.; Julie Monteagudo; Andrews, John P.; Peter Liou; Arul Thirumoorthi; Alvin Wong; Kandel, Jessica J; Shawber, Carrie J.

    2015-01-01

    Lymphatic malformations (LMs) are vascular anomalies thought to arise from dysregulated lymphangiogenesis. These lesions impose a significant burden of disease on affected individuals. LM pathobiology is poorly understood, hindering the development of effective treatments. In the present studies, immunostaining of LM tissues revealed that endothelial cells lining aberrant lymphatic vessels and cells in the surrounding stroma expressed the stem cell marker, CD133, and the lymphatic endothelial...

  2. Carbon export by vertically migrating zooplankton

    DEFF Research Database (Denmark)

    Hansen, Agnethe Nøhr; Visser, André W.

    2016-01-01

    of the active transport of carbon by different size fractions of the migrating zooplankton population as function of time and space. The approach is motivated by the difficulty in incorporating behavioral aspects of carbon transport into large scale carbon budgets of the world's oceans. The results show......Through diel vertical migration (DVM), zooplankton add an active transport to the otherwise passive sinking of detrital material that constitutes the biological pump. This active transport has proven difficult to quantify. We present a model that estimates both the temporal and depth characteristic...... that despite their lower abundance, large zooplankton (length circa 1–2 mm) migrate deeper and transport approximately twice as much carbon as do the smaller zooplankton (length circa 0.2–0.3 mm). In mid- latitudes (∼30°N to ∼45°N), where pronounced spring blooms are observed, up to 20% more carbon...

  3. Multiples least-squares reverse time migration

    KAUST Repository

    Zhang, Dongliang

    2013-01-01

    To enhance the image quality, we propose multiples least-squares reverse time migration (MLSRTM) that transforms each hydrophone into a virtual point source with a time history equal to that of the recorded data. Since each recorded trace is treated as a virtual source, knowledge of the source wavelet is not required. Numerical tests on synthetic data for the Sigsbee2B model and field data from Gulf of Mexico show that MLSRTM can improve the image quality by removing artifacts, balancing amplitudes, and suppressing crosstalk compared to standard migration of the free-surface multiples. The potential liability of this method is that multiples require several roundtrips between the reflector and the free surface, so that high frequencies in the multiples are attenuated compared to the primary reflections. This can lead to lower resolution in the migration image compared to that computed from primaries.

  4. Aberrant gene promoter methylation associated with sporadic multiple colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Victoria Gonzalo

    Full Text Available BACKGROUND: Colorectal cancer (CRC multiplicity has been mainly related to polyposis and non-polyposis hereditary syndromes. In sporadic CRC, aberrant gene promoter methylation has been shown to play a key role in carcinogenesis, although little is known about its involvement in multiplicity. To assess the effect of methylation in tumor multiplicity in sporadic CRC, hypermethylation of key tumor suppressor genes was evaluated in patients with both multiple and solitary tumors, as a proof-of-concept of an underlying epigenetic defect. METHODOLOGY/PRINCIPAL FINDINGS: We examined a total of 47 synchronous/metachronous primary CRC from 41 patients, and 41 gender, age (5-year intervals and tumor location-paired patients with solitary tumors. Exclusion criteria were polyposis syndromes, Lynch syndrome and inflammatory bowel disease. DNA methylation at the promoter region of the MGMT, CDKN2A, SFRP1, TMEFF2, HS3ST2 (3OST2, RASSF1A and GATA4 genes was evaluated by quantitative methylation specific PCR in both tumor and corresponding normal appearing colorectal mucosa samples. Overall, patients with multiple lesions exhibited a higher degree of methylation in tumor samples than those with solitary tumors regarding all evaluated genes. After adjusting for age and gender, binomial logistic regression analysis identified methylation of MGMT2 (OR, 1.48; 95% CI, 1.10 to 1.97; p = 0.008 and RASSF1A (OR, 2.04; 95% CI, 1.01 to 4.13; p = 0.047 as variables independently associated with tumor multiplicity, being the risk related to methylation of any of these two genes 4.57 (95% CI, 1.53 to 13.61; p = 0.006. Moreover, in six patients in whom both tumors were available, we found a correlation in the methylation levels of MGMT2 (r = 0.64, p = 0.17, SFRP1 (r = 0.83, 0.06, HPP1 (r = 0.64, p = 0.17, 3OST2 (r = 0.83, p = 0.06 and GATA4 (r = 0.6, p = 0.24. Methylation in normal appearing colorectal mucosa from patients with multiple and solitary CRC showed no relevant

  5. Distribution, abundance and vertical migration pattern of krill - Euphausia superba Dana at fishing area 58 of the Indian Ocean sector of Southern Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Rathod, V.

    good feeding conditions the amplitude is maximal, and the migration cycle approaches 24 h. Adult individuals exhibit 24 h migration, whereas juveniles show lower migration, and their submergence is shallower. Water stratification may also affect krill...

  6. Aberration correction for time-domain ultrasound diffraction tomography

    Science.gov (United States)

    Mast, T. Douglas

    2002-07-01

    Extensions of a time-domain diffraction tomography method, which reconstructs spatially dependent sound speed variations from far-field time-domain acoustic scattering measurements, are presented and analyzed. The resulting reconstructions are quantitative images with applications including ultrasonic mammography, and can also be considered candidate solutions to the time-domain inverse scattering problem. Here, the linearized time-domain inverse scattering problem is shown to have no general solution for finite signal bandwidth. However, an approximate solution to the linearized problem is constructed using a simple delay-and-sum method analogous to "gold standard" ultrasonic beamforming. The form of this solution suggests that the full nonlinear inverse scattering problem can be approximated by applying appropriate angle- and space-dependent time shifts to the time-domain scattering data; this analogy leads to a general approach to aberration correction. Two related methods for aberration correction are presented: one in which delays are computed from estimates of the medium using an efficient straight-ray approximation, and one in which delays are applied directly to a time-dependent linearized reconstruction. Numerical results indicate that these correction methods achieve substantial quality improvements for imaging of large scatterers. The parametric range of applicability for the time-domain diffraction tomography method is increased by about a factor of 2 by aberration correction. copyright 2002 Acoustical Society of America.

  7. Pancreatic cancer genomes reveal aberrations in axon guidance pathway genes.

    Science.gov (United States)

    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.

  8. The vector behavior of aberrations in high numerical aperture (0.9 < NA < 3.1) laser focusing systems

    Science.gov (United States)

    Jo, Sseunhyeun

    This dissertation investigates vector behavior of aberrations for high numerical aperture optical systems using a solid immersion lens (SIL). In order to analyze the system, this dissertation introduces the illumination system transfer function (ISTF), which is a map in the space of the exit pupil that shows reflection and transmission properties of individual plane waves that are emitted from corresponding points in the exit pupil. A vector analysis using ISTF presents the role of propagating and evanescent energy in the SIL systems, where the boundary between the them is defined by total internal reflection. The behavior of third-order aberrations such as coma and astigmatism, are dramatically affected by polarization in high NA systems. The irradiance distribution exhibits significantly different characteristics, depending on how coma or astigmatism is aligned with the incident linear polarized light. Vector effects including diffraction, polarization, and aberration, are used to analyze tolerances along with a comparison to geometrical optics. Apodization in amplitude and phase of the angular spectrum is generated in high NA focusing systems due to the difference in vector transmission and reflection for each plane wave. The size of the incident gaussian beam is effectively reduced at the exit pupil by the amplitude apodization and causes a spot size increase in image space. The apodization in phase is called gap-induced aberration due to its dependence on the air gap. The gap- induced aberration does not come from lens surface imperfection, and it exhibits multiple orders of spherical aberration and astigmatism. The apodization in amplitude and phase is well characterized by separable supergaussian functions, where each function depends on the refractive index of the SIL n SIL and the air gap height h. The best defocus, based on characteristics of gap-induced aberration, is suggested to be a good compensator only for low nSIL and h. The system performance, as

  9. Aberrant Long-Range Temporal Correlations in Depression Are Attenuated after Psychological Treatment

    Directory of Open Access Journals (Sweden)

    Matti Gärtner

    2017-06-01

    Full Text Available The spontaneous oscillatory activity in the human brain shows long-range temporal correlations (LRTC that extend over time scales of seconds to minutes. Previous research has demonstrated aberrant LRTC in depressed patients; however, it is unknown whether the neuronal dynamics normalize after psychological treatment. In this study, we recorded EEG during eyes-closed rest in depressed patients (N = 71 and healthy controls (N = 25, and investigated the temporal dynamics in depressed patients at baseline, and after attending either a brief mindfulness training or a stress reduction training. Compared to the healthy controls, depressed patients showed stronger LRTC in theta oscillations (4–7 Hz at baseline. Following the psychological interventions both groups of patients demonstrated reduced LRTC in the theta band. The reduction of theta LRTC differed marginally between the groups, and explorative analyses of separate groups revealed noteworthy topographic differences. A positive relationship between the changes in LRTC, and changes in depressive symptoms was observed in the mindfulness group. In summary, our data show that aberrant temporal dynamics of ongoing oscillations in depressive patients are attenuated after treatment, and thus may help uncover the mechanisms with which psychotherapeutic interventions affect the brain.

  10. Chromosomal aberrations in the bone marrow cells of mice induced by accelerated {sup 12}C{sup 6+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Ma Xiaofei [Department of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang Hong, E-mail: zhangh@impac.ac.cn [Department of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Wang Zhenhua; Min Xianhua; Liu Yang; Wu Zhenhua [Department of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Sun Chao [Department of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Hu Bitao [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China)

    2011-11-01

    Highlights: {yields} 220 MeV/u {sup 12}C{sup 6+} ions is 1.5 times more effective than X-rays in inducing chromosomal aberration in bone marrow cell. {yields} The ratio of dose averaged liner energy transfer is approach the RBE. {yields} {sup 12}C{sup 6+} ions could induce severe mitosis delay. {yields} The cell cycle is not recovered 72 h following irradiation. - Abstract: The whole bodies of 6-week-old male Kun-Ming mice were exposed to different doses of {sup 12}C{sup 6+} ions or X-rays. Chromosomal aberrations of the bone marrow (gaps, terminal deletions and breaks, fragments, inter-chromosomal fusions and sister-chromatid union) were scored in metaphase 9 h after exposure, corresponding to cells exposed in the G{sub 2}-phase of the first mitosis cycle. Dose-response relationships for the frequency of chromosomal aberrations were plotted both by linear and linear-quadratic equations. The data showed that there was a dose-related increase in the frequency of chromosomal aberrations in all treated groups compared to controls. Linear-quadratic equations were a good fit for both radiation types. The compound theory of dual radiation action was applied to decipher the bigger curvature (D{sup 2}) of the dose-response curves of X-rays compared to those of {sup 12}C{sup 6+} ions. Different distributions of the five types of aberrations and different degrees of homogeneity were found between {sup 12}C{sup 6+} ion and X-ray irradiation and the possible underlying mechanism for these phenomena were analyzed according to the differences in the spatial energy deposition of both types of radiation.

  11. Correction method of wavefront aberration on signal quality in holographic memory

    Science.gov (United States)

    Kimura, Eri; Nakajima, Akihito; Akieda, Kensuke; Ohori, Tomohiro; Katakura, Kiyoto; Kondo, Yo; Yamamoto, Manabu

    2011-02-01

    One of the problems that affects the practical use of holographic memory is deterioration of the reproduced images due to aberration in the optical system. The medium must be interchangeable, and hence it is necessary to clarify the influence of aberration in the optical system on the signal quality and perform aberration correction for drive compatibility. In this study, aberration is introduced in the reference light beam during image reproduction, and the deterioration of the reproduced image signal is examined. In addition, for a basic study of aberration correction, the correction technique using a two-dimensional signal processing is studied.

  12. Multi-source least-squares reverse time migration

    KAUST Repository

    Dai, Wei

    2012-06-15

    Least-squares migration has been shown to improve image quality compared to the conventional migration method, but its computational cost is often too high to be practical. In this paper, we develop two numerical schemes to implement least-squares migration with the reverse time migration method and the blended source processing technique to increase computation efficiency. By iterative migration of supergathers, which consist in a sum of many phase-encoded shots, the image quality is enhanced and the crosstalk noise associated with the encoded shots is reduced. Numerical tests on 2D HESS VTI data show that the multisource least-squares reverse time migration (LSRTM) algorithm suppresses migration artefacts, balances the amplitudes, improves image resolution and reduces crosstalk noise associated with the blended shot gathers. For this example, the multisource LSRTM is about three times faster than the conventional RTM method. For the 3D example of the SEG/EAGE salt model, with a comparable computational cost, multisource LSRTM produces images with more accurate amplitudes, better spatial resolution and fewer migration artefacts compared to conventional RTM. The empirical results suggest that multisource LSRTM can produce more accurate reflectivity images than conventional RTM does with a similar or less computational cost. The caveat is that the LSRTM image is sensitive to large errors in the migration velocity model. © 2012 European Association of Geoscientists & Engineers.

  13. Quantitative assessment of effects of phase aberration and noise on high-frame-rate imaging.

    Science.gov (United States)

    Chen, Hong; Lu, Jian-yu

    2013-01-01

    The goal of this paper is to quantitatively study effects of phase aberration and noise on high-frame-rate (HFR) imaging using a set of traditional and new parameters. These parameters include the traditional -6-dB lateral resolution, and new parameters called the energy ratio (ER) and the sidelobe ratio (SR). ER is the ratio between the total energy of sidelobe and the total energy of mainlobe of a point spread function (PSF) of an imaging system. SR is the ratio between the peak value of the sidelobe and the peak value of the mainlobe of the PSF. In the paper, both simulation and experiment are conducted for a quantitative assessment and comparison of the effects of phase aberration and noise on the HFR and the conventional delay-and-sum (D&S) imaging methods with the set of parameters. In the HFR imaging method, steered plane waves (SPWs) and limited-diffraction beams (LDBs) are used in transmission, and received signals are processed with the Fast Fourier Transform to reconstruct images. In the D&S imaging method, beams focused at a fixed depth are used in transmission and dynamically focused beams are used in reception for image reconstruction. The simulation results show that the average differences between the -6-dB lateral beam widths of the HFR imaging and the D&S imaging methods are -0.1337mm for SPW and -0.1481mm for LDB, which means that the HFR imaging method has a higher lateral image resolution than the D&S imaging method since the values are negative. In experiments, the average differences are also negative, i.e., -0.2804mm for SPW and -0.3365mm for LDB. The results for the changes of ER and SR between the HFR and the D&S imaging methods have negative values, too. After introducing phase aberration and noise, both simulations and experiments show that the HFR imaging method has also less change in the -6-dB lateral resolution, ER, and SR as compared to the conventional D&S imaging method. This means that the HFR imaging method is less sensitive to

  14. Chromosomal Aberrations in Normal and AT Cells Exposed to High Dose of Low Dose Rate Irradiation

    Science.gov (United States)

    Kawata, T.; Shigematsu, N.; Kawaguchi, O.; Liu, C.; Furusawa, Y.; Hirayama, R.; George, K.; Cucinotta, F.

    2011-01-01

    Ataxia telangiectasia (A-T) is a human autosomally recessive syndrome characterized by cerebellar ataxia, telangiectases, immune dysfunction, and genomic instability, and high rate of cancer incidence. A-T cell lines are abnormally sensitive to agents that induce DNA double strand breaks, including ionizing radiation. The diverse clinical features in individuals affected by A-T and the complex cellular phenotypes are all linked to the functional inactivation of a single gene (AT mutated). It is well known that cells deficient in ATM show increased yields of both simple and complex chromosomal aberrations after high-dose-rate irradiation, but, less is known on how cells respond to low-dose-rate irradiation. It has been shown that AT cells contain a large number of unrejoined breaks after both low-dose-rate irradiation and high-dose-rate irradiation, however sensitivity for chromosomal aberrations at low-dose-rate are less often studied. To study how AT cells respond to low-dose-rate irradiation, we exposed confluent normal and AT fibroblast cells to up to 3 Gy of gamma-irradiation at a dose rate of 0.5 Gy/day and analyzed chromosomal aberrations in G0 using fusion PCC (Premature Chromosomal Condensation) technique. Giemsa staining showed that 1 Gy induces around 0.36 unrejoined fragments per cell in normal cells and around 1.35 fragments in AT cells, whereas 3Gy induces around 0.65 fragments in normal cells and around 3.3 fragments in AT cells. This result indicates that AT cells can rejoin breaks less effectively in G0 phase of the cell cycle? compared to normal cells. We also analyzed chromosomal exchanges in normal and AT cells after exposure to 3 Gy of low-dose-rate rays using a combination of G0 PCC and FISH techniques. Misrejoining was detected in the AT cells only? When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, the yield of unrejoined breaks decreased in both normal and AT

  15. ILO - International Migration Programme.

    Science.gov (United States)

    Boudraa, Miriam

    2011-01-01

    In a wide International Context characterised not only by the economical development but also by the social, cultural, political and individual development, we witness more and more to a exchange between the developed and the developing countries, which can be translated especially in the migration of the work force. In theory, all countries are either countries of origin either countries of transit or destination, and they are all responsible for the rights of migrant workers by promoting the rights, by monitoring and by preventing the abusive conditions. The process of migration of the workforce can be divided into three stages: the first coincides with the period prior to departure, the second is represented by the aftermath of the departure and the period of stay in the country of destination, the third stage corresponds to the return in the country of origin. The workers must be protected throughout this process by the international organizations that perform the catalytic role of communication and exchange between countries, for the only purpose of protecting the rights of immigrant and/or immigrants workers. The responsibility for the protection of workers is divided among the various players in the International Labour Organisation. Every country has to apply measures according to the international standards regarding workers' rights, standards that guide the various countries in the formulation and implementation of their policies and legislation. These standards are suggested by International Conventions, the ILO Conventions and other international instruments such as the human rights instrument. There has been a big step forward once the ILO Fundamental Conventions and Conventions on Migrant Workers where implemented and this implementation represented the use of the Guidelines "ILO Multilateral Framework on Labour Migration".

  16. Transnational Solidarity—Not Aid: The Perspective of Migration on the Hype about Migration&Development

    Directory of Open Access Journals (Sweden)

    Maria Schwertl

    2017-09-01

    Full Text Available Migrants have organized transnational support for non-migrants, stay-at-homes, citizens and noncitizens, as well as for developmental or integrationist nation state projects for decades. These solidarities have been framed as “cultural programs,” “autochthone support of hometowns,” “development aid” or “diaspora politics.” Since the turn of the century especially those projects that could be framed as “development aid” have gained a lot of interest from official development aid and its agencies. More and more programs have been launched to coordinate and professionalize the transnational support labor of migrants under the aegis of development. This is what I call the hype about migration&development. In this article, I want to show why the notion of “migrant development aid” used in the hype falls short of what is at stake when it comes to transnational migrant solidarities. Thereby, I want to argue that looking at migration through its governance and through migration or development politics is short-sighted and insensitive towards the desires, ethics and politics of migration. This is the reason that a perspective of migration—such as that propagated by the autonomy of migration approach—needs to be brought into debates on migration&development.

  17. Facilitators and constraints at each stage of the migration decision process.

    Science.gov (United States)

    Kley, Stefanie

    2017-10-01

    Behavioural models of migration emphasize the importance of migration decision-making for the explanation of subsequent behaviour. But empirical migration research regularly finds considerable gaps between those who intend to migrate and those who actually realize their intention. This paper applies the Theory of Planned Behaviour, enriched by the Rubicon model, to test specific hypotheses about distinct effects of facilitators and constraints on specific stages of migration decision-making and behaviour. The data come from a tailor-made panel survey based on random samples of people drawn from two German cities in 2006-07. The results show that in conventional models the effects of facilitators and constraints on migration decision-making are likely to be underestimated. Splitting the process of migration decision-making into a pre-decisional and a pre-actional phase helps to avoid bias in the estimated effects of facilitators and constraints on both migration decision-making and migration behaviour.

  18. MIGRATE: A FOSS WEB MAPPING APPLICATION FOR EDUCATING AND RAISING AWARENESS ABOUT MIGRATION FLOWS IN EUROPE

    Directory of Open Access Journals (Sweden)

    M. A. Brovelli

    2017-07-01

    Full Text Available Recent years have seen a noticeable growth in migration flows from Africa and Middle East to Southern Europe, thus generating a remarkable increase of attention on media and public opinion, sometimes resulting in stereotypes and prejudices. Funded by the European Commission – Joint Research Centre through the MYGEOSS program, MIGRation pATtterns in Europe (MIGRATE aims at educating the citizens about migration fluxes in Europe using a gamification approach based on a trivia game. MIGRATE is completely developed with Free and Open Source Software. On the server-side Django is used to define the models that handle all the required data and tables are created in a PostgreSQL database. Questions and answers are sent in JSON format to the client, while the geospatial layers in GeoJSON format are rendered on the map interface using OpenLayers 3. Bootstrap, HTML5 and CSS3 are used for responsive design, while the jQuery library is used to ease the JavaScript programming. All the data sources used within MIGRATE are available as full and open access with no restrictions for reuse, except for the obligation to mention the source of the input data. Exploited data sources include OpenStreetMap for geospatial information, and UNHCR, IOM, Eurostat and The Migrant’s Files project for non-geospatial information. Overall, data shows how the users’ perceptions change while playing and that players’ awareness of migration-related problems increases with the number of games played. The source code of MIGRATE and the collected data are available respectively under the EU Public License (EUPL and the CC BY 4.0 license.

  19. International Migration of Couples

    OpenAIRE

    Junge, Martin; Munk, Martin D.; Nikolka, Till; Poutvaara, Panu

    2017-01-01

    We analyze emigration and return decisions of Danish couples. Our main questions are how emigration and return migration decisions depend on education, earnings, and the number and age of children. We use register data on full population from 1982 to 2006, focusing on opposite-gender couples in which the female is aged 23 to 37, and the male 25 to 39. We find that power couples in which both are highly educated are most likely to emigrate, but also most likely to return. Couples in which only...

  20. Globalization, migration and health.

    Science.gov (United States)

    Burnett, Angela

    2002-01-01

    The term 'globalization' describes the integration of economic systems through improved communication, but it also represents increased insecurity for those with few resources--particularly refugees. This article examines why people migrate, their numbers, constraints on their movement and their particular health care needs. Immigrants have much to contribute to their recipient countries, but at some loss to their homelands. Both economically and morally, more liberal immigration policies would be beneficial. Policies towards asylum seekers should not be more restrictive in the aftermath of 11 September 2001 and detention should be the exception rather than the rule. Globalization should be managed so as to improve people's lives throughout the world.

  1. [Obesity, migration and adolescence].

    Science.gov (United States)

    Chamay-Weber, Catherine; Shehu-Brovina, Shqipe; Narring, Françoise

    2012-06-13

    Weight management interventions during adolescence are challenging. Migration adds complexity to this problem, making migrant families more vulnerable. Teenagers confront families to new values transmitted by the host society: opulence, junk food, video games. Obesity should not be seen as a single issue of calories-excess, but must be considered as being part of a larger problem, which takes into account the context of the familial and societal life of the migrants. The caregivers must have an overall view of the situation to provide appropriate approaches to weight management.

  2. Urbanization, Migration, Information

    Directory of Open Access Journals (Sweden)

    Konstantin Lidin

    2016-05-01

    Full Text Available In the contemporary world urbanization becomes a large-scale process. Huge flows of people migrate from poorer districts to the cities with a higher level of consumption. It takes migrants about 15-25 years to give up their traditional ascetic way of life. In this period the ‘new citizens’ try to arrange compact settlements with an archaic way of life, insanitary conditions, high criminogenity and an authoritative local self-government. The processes of formation and decay of the ascetic enclave are viewed through the example of the ‘Shanghai’ trading neighborhood in Irkutsk.

  3. Migration and loving

    OpenAIRE

    Gevrek, Deniz

    2010-01-01

    This paper explores the relationship between anti-miscegenation laws, interracial marriage and black males' geographical distribution in the U.S. during and after the Great Migration. The U.S. Supreme Court decision in the case of Loving v. Virginia in 1967, which forced the last 16 Southern states to strike down their anti-miscegenation laws, creates a unique opportunity to explore the impact of an exogenous change in a state's laws regulating interracial marriages. Analyzing the U.S. Census...

  4. Glucocorticoid Administration Improves Aberrant Fear-Processing Networks in Spider Phobia.

    Science.gov (United States)

    Nakataki, Masahito; Soravia, Leila M; Schwab, Simon; Horn, Helge; Dierks, Thomas; Strik, Werner; Wiest, Roland; Heinrichs, Markus; de Quervain, Dominique J-F; Federspiel, Andrea; Morishima, Yosuke

    2017-01-01

    Glucocorticoids reduce phobic fear in patients with anxiety disorders. Previous studies have shown that fear-related activation of the amygdala can be mediated through the visual cortical pathway, which includes the fusiform gyrus, or through other pathways. However, it is not clear which of the pathways that activate the amygdala is responsible for the pathophysiology of a specific phobia and how glucocorticoid treatment alleviates fear processing in these neural networks. We recorded the brain activity with functional magnetic resonance imaging in patients with spider phobia, who received either 20 mg of cortisol or a placebo while viewing pictures of spiders. We also tested healthy participants who did not receive any medication during the same task. We performed dynamic causal modelling (DCM), a connectivity analysis, to examine the effects of cortisol on the networks involved in processing fear and to examine if there was an association between these networks and the symptoms of the phobia. Cortisol administration suppressed the phobic stimuli-related amygdala activity to levels comparable to the healthy participants and reduced subjective phobic fear. The DCM analysis revealed that cortisol administration suppressed the aberrant inputs into the amygdala that did not originate from the visual cortical pathway, but rather from a fast subcortical pathway mediated by the pulvinar nucleus, and suppressed the interactions between the amygdala and fusiform gyrus. This network changes were distinguishable from healthy participants and considered the residual changes under cortisol administration. We also found that the strengths of the aberrant inputs into the amygdala were positively correlated with the severity of spider phobia. This study demonstrates that patients with spider phobia show an aberrant functional connectivity of the amygdala when they are exposed to phobia-related stimuli and that cortisol administration can alleviate this fear-specific neural

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

    Science.gov (United States)

    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. © 2015 Wiley Periodicals, Inc.

  6. Aberrant DNA methylation of cancer-related genes in giant breast fibroadenoma: a case report

    Directory of Open Access Journals (Sweden)

    Orozco Javier I

    2011-10-01

    Full Text Available Abstract Introduction Giant fibroadenoma is an uncommon variant of benign breast lesions. Aberrant methylation of CpG islands in promoter regions is known to be involved in the silencing of genes (for example, tumor-suppressor genes and appears to be an early event in the etiology of breast carcinogenesis. Only hypermethylation of p16INK4a has been reported in non-giant breast fibroadenoma. In this particular case, there are no previously published data on epigenetic alterations in giant fibroadenomas. Our previous results, based on the analysis of 49 cancer-related CpG islands have confirmed that the aberrant methylation is specific to malignant breast tumors and that it is completely absent in normal breast tissue and breast fibroadenomas. Case presentation A 13-year-old Hispanic girl was referred after she had noted a progressive development of a mass in her left breast. On physical examination, a 10 × 10 cm lump was detected and axillary lymph nodes were not enlarged. After surgical removal the lump was diagnosed as a giant fibroadenoma. Because of the high growth rate of this benign tumor, we decided to analyze the methylation status of 49 CpG islands related to cell growth control. We have identified the methylation of five cancer-related CpG islands in the giant fibroadenoma tissue: ESR1, MGMT, WT-1, BRCA2 and CD44. Conclusion In this case report we show for the first time the methylation analysis of a giant fibroadenoma. The detection of methylation of these five cancer-related regions indicates substantial epigenomic differences with non-giant fibroadenomas. Epigenetic alterations could explain the higher growth rate of this tumor. Our data contribute to the growing knowledge of aberrant methylation in breast diseases. In this particular case, there exist no previous data regarding the role of methylation in giant fibroadenomas, considered by definition as a benign breast lesion.

  7. Controlling plasma distributions as driving forces for ion migration during fs laser writing

    CERN Document Server

    Fernandez, Toney Teddy; Hoyo, Jesus; Sotillo, Belen; Fernandez, Paloma; Solis, Javier

    2014-01-01

    The properties of structures written inside dielectrics with high repetition rate femtosecond lasers are known to depend strongly on the complex interplay of a large number of writing parameters. Recently, ion migration within the laser-excited volume has been identified as a powerful mechanism for changing the local element distribution and producing efficient optical waveguides. In this work it is shown that the transient plasma distribution induced during laser irradiation is a reliable monitor for predicting the final refractive index distribution of the waveguide caused by ion migration. By performing in-situ plasma emission microscopy during the writing process inside a La-phosphate glass it is found that the long axis of the plasma distribution determines the axis of ion migration, being responsible for the local refractive index increase. This observation is also valid when strong positive or negative spherical aberration is induced, greatly deforming the focal volume and inverting the index profile. ...

  8. Stolt's f-k migration for plane wave ultrasound imaging.

    Science.gov (United States)

    Garcia, Damien; Le Tarnec, Louis; Muth, Stéphan; Montagnon, Emmanuel; Porée, Jonathan; Cloutier, Guy

    2013-09-01

    Ultrafast ultrasound is an emerging modality that offers new perspectives and opportunities in medical imaging. Plane wave imaging (PWI) allows one to attain very high frame rates by transmission of planar ultrasound wave-fronts. As a plane wave reaches a given scatterer, the latter becomes a secondary source emitting upward spherical waves and creating a diffraction hyperbola in the received RF signals. To produce an image of the scatterers, all the hyperbolas must be migrated back to their apexes. To perform beamforming of plane wave echo RFs and return high-quality images at high frame rates, we propose a new migration method carried out in the frequency-wavenumber (f-k) domain. The f-k migration for PWI has been adapted from the Stolt migration for seismic imaging. This migration technique is based on the exploding reflector model (ERM), which consists in assuming that all the scatterers explode in concert and become acoustic sources. The classical ERM model, however, is not appropriate for PWI. We showed that the ERM can be made suitable for PWI by a spatial transformation of the hyperbolic traces present in the RF data. In vitro experiments were performed to outline the advantages of PWI with Stolt's f-k migration over the conventional delay-and-sum (DAS) approach. The Stolt's f-k migration was also compared with the Fourier-based method developed by J.-Y. Lu. Our findings show that multi-angle compounded f-k migrated images are of quality similar to those obtained with a stateof- the-art dynamic focusing mode. This remained true even with a very small number of steering angles, thus ensuring a highly competitive frame rate. In addition, the new FFT-based f-k migration provides comparable or better contrast-to-noise ratio and lateral resolution than the Lu's and DAS migration schemes. Matlab codes for the Stolt's f-k migration for PWI are provided.

  9. Spontaneous intraluminal migration of gossypiboma

    Directory of Open Access Journals (Sweden)

    Sebastian Saji

    2011-01-01

    Full Text Available Retained surgical mops following surgery is an avoidable but serious complication. They are seldom reported because of medicolegal implications but clinicians need to be aware about varied presentations of this entity to avoid unnecessary morbidity. We report a case of a 28-year-old woman who presented with chronic diarrhea and lower abdominal pain due to intraluminal migration of the surgical mop into the sigmoid colon 6 months after myomectomy of the uterus. The possibility of gossypiboma was suggested by the contrast-enhanced CT scan of the abdomen. Flexible sigmoidosocpy showed the remnants of the mop inside the lumen of the sigmoid colon. She underwent laparotomy and removal of the surgical mop and became completely asymptomatic. Though gossypiboma is rare clinicians should keep it in mind in patients who had undergone laparotomy previously.

  10. Primary cutaneous adenoid cystic carcinoma with MYB aberrations: report of three cases and comprehensive review of the literature.

    Science.gov (United States)

    Prieto-Granada, Carlos N; Zhang, Lei; Antonescu, Cristina R; Henneberry, Jean M; Messina, Jane L

    2017-02-01

    Adenoid cystic carcinoma (ACC) is a relatively rare slow-growing and often-aggressive epithelial-myoepithelial neoplasm that arises in multiple organs including the skin. The t(6;9) (q22-23;p23-24) translocation, resulting in a MYB-NFIB gene fusion has been found in ACCs from the salivary glands and other organs. Recently, MYB aberrations occurring in a subset (40%) of primary cutaneous ACC (PCACC) examples was described. Herein, we report three additional cases of PCACC harboring MYB aberrations. The tumors presented in three males aged 43, 81 and 55 years old and affected the extremities in the first two patients and the scalp in the third one. None of the patients had history of prior or concurrent ACC elsewhere. Lesions exhibited the classic ACC morphology of nests of basaloid cells arranged in cribriform and adenoid patterns. Sentinel lymph node biopsy was performed in two cases with one case showing lymph node positivity. Fluorescence in situ hybridization with break-apart probes for MYB and NFIB loci revealed that two cases showed MYB rearrangements while one case showed loss of one MYB signal. None of the cases showed NFIB rearrangements. We contribute with three additional cases of PCACC exhibiting MYB aberrations, the apparent driving genetic abnormality in these tumors. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans......-Saharan migrants than autumn migration. Information about the behavior and interactions of migrants during the nonbreeding season in sub-Saharan Africa is also scarce for many species. Furthermore, very little is known about intra-African migration. This thesis summarizes my research on the autumn migration...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...

  12. Runaway gas accretion and gap opening versus type I migration

    Science.gov (United States)

    Crida, A.; Bitsch, B.

    2017-03-01

    Growing planets interact with their natal protoplanetary disc, which exerts a torque onto them allowing them to migrate in the disc. Small mass planets do not affect the gas profile and migrate in the fast type-I migration. Although type-I migration can be directed outwards for planets smaller than 20 - 30M⊕ in some regions of the disc, planets above this mass should be lost into the central star long before the disc disperses. Massive planets push away material from their orbit and open a gap. They subsequently migrate in the slower, type II migration, which could save them from migrating all the way to the star. Hence, growing giant planets can be saved if and only if they can reach the gap opening mass, because this extends their migration timescale, allowing them to eventually survive at large orbits until the disc itself disperses. However, most of the previous studies only measured the torques on planets with fixed masses and orbits to determine the migration rate. Additionally, the transition between type-I and type-II migration itself is not well studied, especially when taking the growth mechanism of rapid gas accretion from the surrounding disc into account. Here we use isothermal 2D disc simulations with FARGO-2D1D to study the migration behaviour of gas accreting protoplanets in discs. We find that migrating giant planets always open gaps in the disc. We further show analytically and numerically that in the runaway gas accretion regime, the growth time-scale is comparable to the type-I migration time-scale, indicating that growing planets will reach gap opening masses before migrating all the way to the central star in type-I migration if the disc is not extremely viscous and/or thick. An accretion rate limited to the radial gas flow in the disc, in contrast, is not fast enough. When gas accretion by the planet is taken into account, the gap opening process is accelerated because the planet accretes material originating from its horseshoe region. This

  13. Network migration for printers

    CERN Multimedia

    2016-01-01

    Further to the recent General Purpose (office) Network reorganisation (as announced in the Bulletin - see here), please note that the majority of print devices will be automatically migrated to the new network IP address range on Tuesday 27 September.   This change should be transparent for these devices and therefore end-users, provided you have installed the printers from the Print Service website. A small number of devices will require manual intervention from the Printer Support team in order to migrate correctly. These devices will not change their IP address until the manual intervention, which will be carried out before Monday 3rd October. However, if you have mistakenly connected directly to the printer’s IP address, then your printing will be affected – please uninstall the printer (for help, see: KB3785), and re-install it from the Print Service website (or follow instructions for visitor machines). Please do this as soon as possible in order to avoid printing issues, t...

  14. Engendering climate change-induced migration

    Science.gov (United States)

    Caretta, Martina Angela; Miletto, Michela

    2017-04-01

    Climate change leads to increased climate variability, which is manifest in extreme weather events such as floods and droughts. These put at stake agricultural productivity, forestry, inland fisheries, aquaculture, water supply and sanitation which in turn hamper poorest householdś self-sufficiency and capability to cope with risks. Due to the risk of losing or the actual loss of livelihood, farmers in the Global South must look for alternative strategies to diversify risk. Migration is one of those strategies, which that can be seen either as an adaptive measure or an indicator of limits to adaptation to environmental stress. 60% of young migrants live in the Global South (UN, 2013). Many internally displaced people in the world are under the age of 18, some move with their families, other, mostly in South Asia and West Africa, migrate alone. Youth, as all migrants, are seeking better economic opportunities to support themselves and their families. Migration is a gendered process which plays out differently in diverse societies depending on local cultural norms that do not only affect and are affected by gender roles, but also by age, class and ethnicity. Threats to water availability, access and water hazards have diverse impacts on men and women. The link gender and climate-induced migration is still under investigation and few studies provide concrete country specific examples of this phenomenon. Our paper will present a state of the art literature review around climate-induced migration in the Global South from a gender perspective showing how meńs and womeńs migratory decisions, patterns and outcomes differ at the stage pre-during post migration.

  15. Circular Migration and Human Development

    OpenAIRE

    Newland, Kathleen

    2009-01-01

    This paper explores the human development implications of circular migration — both where it occurs naturally and where governments work to create it. The paper discusses various conceptions and definitions of circular migration, and concludes that circular migration is not intrinsically positive or negative in relation to human development; its impact depends upon the circumstances in which it occurs, the constraints that surround it and—above all—the degree of choice that individuals can ex...

  16. The challenges of managing migration

    Energy Technology Data Exchange (ETDEWEB)

    Tacoli, Cecilia

    2005-10-15

    Migration and urbanisation are driven by economic growth and social change, but also by deepening inequalities. Managing migration should not be equated with curbing it, as this inevitably reduces migrants' rights. But managing population movement whilst respecting the rights of migrants and nonmigrants, supporting the contribution of migration to poverty reduction and economic growth in sending and receiving areas and reducing the human and material costs of movement means that fundamental challenges need to be addressed.

  17. Climate Vulnerability and Human Migration in Global Perspective

    Directory of Open Access Journals (Sweden)

    Martina Grecequet

    2017-04-01

    Full Text Available The relationship between climate change and human migration is not homogenous and depends critically on the differential vulnerability of population and places. If places and populations are not vulnerable, or susceptible, to climate change, then the climate–migration relationship may not materialize. The key to understanding and, from a policy perspective, planning for whether and how climate change will impact future migration patterns is therefore knowledge of the link between climate vulnerability and migration. However, beyond specific case studies, little is known about this association in global perspective. We therefore provide a descriptive, country-level portrait of this relationship. We show that the negative association between climate vulnerability and international migration holds only for countries least vulnerable to climate change, which suggests the potential for trapped populations in more vulnerable countries. However, when analyzed separately by life supporting sector (food, water, health, ecosystem services, human habitat, and infrastructure and vulnerability dimension (exposure, sensitivity, and adaptive capacity, we detect evidence of a relationship among more, but not the most, vulnerable countries. The bilateral (i.e., country-to-country migration show that, on average, people move from countries of higher vulnerability to lower vulnerability, reducing global risk by 15%. This finding is consistent with the idea that migration is a climate adaptation strategy. Still, ~6% of bilateral migration is maladaptive with respect to climate change, with some movement toward countries with greater climate change vulnerability.

  18. Simulation of Complex Tremor Migration Patterns

    Science.gov (United States)

    Luo, Y.; Ampuero, J. P.

    2012-12-01

    The discovery of slow-slip events (SSE) and non-volcanic tremors has greatly enriched the spectrum of earthquake behavior and offers a unique window into the mechanics of the deeper portion of the seismogenic zone of active faults, an uncharted region of great importance in the nucleation of large earthquakes. In Northern Cascadia, tremors show an intriguing hierarchy of migration patterns: large-scale tremor migrating along-strike at about 10 km/day, sparsely distributed swarms that propagate 10 times faster in the opposite direction ('rapid tremor reversals' or RTRs) and even 10 times faster swarms that propagate along-dip. Moreover, during the initial phase of ETS (Episodic Tremor and Slip) the tremor source amplitude shows a linear growth and up-dip propagation. We have proposed a model to reproduce these observations based on interaction of brittle asperities (frictionally unstable, velocity-weakening patches) embedded in a relatively stable fault, mediated by creep transients. We continue quantitative studies of this model through numerical simulations of heterogeneous rate-and-state faults under the Quasi-DYNamic approximation (open-source software project QDYN, hosted online at http://code.google.com/p/qdyn/). We performed both 2D and 3D simulations and successfully reproduced all the major phenomena of complex tremor migration patterns (forward migration, RTRs and along-dip swarms). We will show a complete analysis of friction properties and geometrical settings (i.e. asperity size, distance, etc.) that affects spatial-temporal distribution and migration velocity of tremors. Our study shows that by decreasing the distance between asperities or by increasing the value of (a-b)*sigma inside them, both RTR migration velocity and distance increase positively correlated, and the proportion of moment released seismically during the ETS increases, while the ratio of RTR versus forward tremor migration speed remains mostly the same. While the density of these deep

  19. On the Consistent Migration of Unsplittable Flows

    DEFF Research Database (Denmark)

    Förster, Klaus-Tycho

    2017-01-01

    In consistent flow migration, the task is to change the paths the flows take in the network, but without inducing congestion during the  update process. Even though the rise of Software Defined Networks allows for centralized control of path changes, the execution is still performed in an inheren......In consistent flow migration, the task is to change the paths the flows take in the network, but without inducing congestion during the  update process. Even though the rise of Software Defined Networks allows for centralized control of path changes, the execution is still performed...... of consistently migrating splittable flows is well understood, for the practically more relevant unsplittable flows, few non-heuristic results are known – and upper complexity bounds are missing. We give a dynamic programming algorithm for unsplittable flows, showing the containment in EXPTIME, for both...... computation time and schedule length. In particular, there are cases where flows must switch between paths back and forth repeatedly: as thus, flow migration is not just an ordering problem. We also study lower bounds and show NP-hardness already for two flows, via reduction from edge-disjoint path problems...

  20. Meiotic interstrand DNA damage escapes paternal repair and causes chromosomal aberrations in the zygote by maternal misrepair

    OpenAIRE

    Marchetti, Francesco; Bishop, Jack; Gingerich, John; Wyrobek, Andrew J.

    2015-01-01

    De novo point mutations and chromosomal structural aberrations (CSA) detected in offspring of unaffected parents show a preferential paternal origin with higher risk for older fathers. Studies in rodents suggest that heritable mutations transmitted from the father can arise from either paternal or maternal misrepair of damaged paternal DNA, and that the entire spermatogenic cycle can be at risk after mutagenic exposure. Understanding the susceptibility and mechanisms of transmission of patern...

  1. Macrostabilization of the Migration Phenomenon

    Directory of Open Access Journals (Sweden)

    Cristina Burghelea

    2014-03-01

    Full Text Available MacLabour migration is a present phenomenon in the European Union. This phenomenon takes over the entire European continent, but especially in the EU countries. The labor market in Europe is increasingly affected by population aging. Economic differences between European countries make workforce in developing countries to move to developed countries where they find it easier to work and receive higher remuneration than in their home countries. This article tracks labor migration from/to EU, employment in Romania and Romanian migration towards the countries of Western Europe. It also presents statistics on labor migration in the EU and its impact on the labor market

  2. On the interrelations between migration and commuting

    Directory of Open Access Journals (Sweden)

    Lukić Vesna

    2013-01-01

    conducted in Serbia during the 1980s showed that around 30 per cent of commuters expressed desire to move to their place of work, the degree of realization of these intentions remained unknown. While in some countries traffic studies and data from the management of the enterprises are used as sources of data on commuting, the studies on the commuter population in Serbia are based solely onto two types of data sources. These are census and poll surveys. Although they have more potential than the official statistics for the analysis of the links between migration and commuting and other characteristics of commuters, poll surveys on this topic in Serbia are relatively rare due to financial and organizational obstacles. Indeed, the last major survey was conducted in the 1980s. Therefore, even though the interrelations between migration and commuting have been confirmed, there is still a lot of space for their research indicating the need for further methodology developments in researching these types of population mobility.

  3. Les questions de migrations internationales (Questions of International Migrations).

    Science.gov (United States)

    Samman, Mouna Liliane

    1993-01-01

    Education about international migration should (1) utilize a framework of historical evolution; (2) stress the growing interdependence of nations; (3) emphasize universal moral values and the role of the individual in human rights; and (4) consider the complementary or competing portraits of international migration presented by the media. (DMM)

  4. Countering inbreeding with migration 1. Migration from unrelated ...

    African Journals Online (AJOL)

    The eff'ect of migration on inbreeding is moclelled fbr small populations with immigrants from a large unrelated population. Different migration rates and numbers fbr the two sexes are assumed, and a general recursion equation for inbreeding progress derived, which can be shown to lead to an equilibrium inbreeding ...

  5. Aberration-Coreected Electron Microscopy at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    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

  6. The Last Adventure: Retirement Migration, Climate and "Amenities"

    Directory of Open Access Journals (Sweden)

    Saša Božić

    2001-12-01

    Full Text Available The rising number of European retirement migrants on the Mediterranean coasts, especially in the EU countries shows that the practical and scientific relevance of the new forms of migration in Europe is on the rise. "Retirement migration" evolved from a descriptive term to a candidate for a scientific or a research concept, at least if the use of the term IRM (international retirement migration is considered. However, it is necessary to solve several problems before this term can really become a coherent concept, useful for the research and explanation of the "new" migration phenomena. The author claims that the studies usually do not distinguish clearly between the migration of the elderly and retirement migration. The naming of the concept in this case mixes the characteristics of the migrants with the reasons for migration. The author shows that the usually mentioned reasons for retirement migration cannot be clearly formulated as factors which explain retirement migration. Further on, retirement as such is not a pull, push or staying put factor. Migration rates of retired, although rising, are still lower than the migration rates of the working age population and the Mediterranean coasts are also a destination for professionals who have the means to detach the job from the working place. Only a combination of conditions that enable migration and migration decisions, as well as a combination of motives and perceptions of reasons for migration, can partially "explain" retirement migration. One of the problems that has to be solved before retirement migration is affirmed as a concept is the treatment of the temporal and spatial dimension of the mobility of the retirement migrants. The author shows that a clear positioning of retirement migration on the temporal scale of mobility is hardly possible. Retirement migration is too wide and too complex a phenomenon to be easily localised in the temporal continuum. A similar problem emerges when the

  7. Patterns of East to West migration in the context of European migration systems possibilities and limits of migration control

    OpenAIRE

    Irina Molodikova

    2008-01-01

    This paper gives an overview of the main migration trends of the CIS (Commonwealth of Independent States) migration system in the context of the development of EU migration and migration control and seeks to explain the peculiarities of the CIS migration system’s development.

  8. Impaired Reelin-Dab1 Signaling Contributes to Neuronal Migration Deficits of Tuberous Sclerosis Complex

    Directory of Open Access Journals (Sweden)

    Uk Yeol Moon

    2015-08-01

    Full Text Available Tuberous sclerosis complex (TSC is associated with neurodevelopmental abnormalities, including defects in neuronal migration. However, the alterations in cell signaling mechanisms critical for migration and final positioning of neurons in TSC remain unclear. Our detailed cellular analyses reveal that reduced Tsc2 in newborn neurons causes abnormalities in leading processes of migrating neurons, accompanied by significantly delayed migration. Importantly, we demonstrate that Reelin-Dab1 signaling is aberrantly regulated in TSC mouse models and in cortical tubers from TSC patients owing to enhanced expression of the E3 ubiquitin ligase Cul5, a known mediator of pDab1 ubiquitination. Likewise, mTORC1 activation by Rheb overexpression generates similar neuronal and Reelin-Dab1 signaling defects, and directly upregulates Cul5 expression. Inhibition of mTORC1 by rapamycin treatment or by reducing Cul5 largely restores normal leading processes and positioning of migrating neurons. Thus, disrupted Reelin-Dab1 signaling is critically involved in the neuronal migration defects of TSC.

  9. DMPD: Macrophage migration inhibitory factor and host innate immune responses tomicrobes. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14620137 Macrophage migration inhibitory factor and host innate immune responses to...microbes. Calandra T. Scand J Infect Dis. 2003;35(9):573-6. (.png) (.svg) (.html) (.csml) Show Macrophage migration... inhibitory factor and host innate immune responses tomicrobes. PubmedID 14620137 Title Macrophage migration

  10. Migration of nanosized layered double hydroxide platelets from polylactide nanocomposite films

    DEFF Research Database (Denmark)

    Schmidt, Bjørn; Katiyar, Vimal; Plackett, David

    2011-01-01

    standard method. All three films showed migration of nanosized LDH, which was quantified using acid digestion followed by inductively coupled plasma mass spectrometric (ICP–MS) detection of 26Mg. Migration of LDH from the films was also confirmed by examining migrates using transmission electron microscopy...... detected arises from the use of organotin catalysts in the manufacture of PLA....

  11. Theory of aberration fields for general optical systems with freeform surfaces.

    Science.gov (United States)

    Fuerschbach, Kyle; Rolland, Jannick P; Thompson, Kevin P

    2014-11-03

    This paper utilizes the framework of nodal aberration theory to describe the aberration field behavior that emerges in optical systems with freeform optical surfaces, particularly φ-polynomial surfaces, including Zernike polynomial surfaces, that lie anywhere in the optical system. If the freeform surface is located at the stop or pupil, the net aberration contribution of the freeform surface is field constant. As the freeform optical surface is displaced longitudinally away from the stop or pupil of the optical system, the net aberration contribution becomes field dependent. It is demonstrated that there are no new aberration types when describing the aberration fields that arise with the introduction of freeform optical surfaces. Significantly it is shown that the aberration fields that emerge with the inclusion of freeform surfaces in an optical system are exactly those that have been described by nodal aberration theory for tilted and decentered optical systems. The key contribution here lies in establishing the field dependence and nodal behavior of each freeform term that is essential knowledge for effective application to optical system design. With this development, the nodes that are distributed throughout the field of view for each aberration type can be anticipated and targeted during optimization for the correction or control of the aberrations in an optical system with freeform surfaces. This work does not place any symmetry constraints on the optical system, which could be packaged in a fully three dimensional geometry, without fold mirrors.

  12. Aberrant microRNA expression in multiple myeloma

    DEFF Research Database (Denmark)

    Dimopoulos, Konstantinos; Gimsing, Peter; Grønbæk, Kirsten

    2013-01-01

    Multiple myeloma (MM) is a devastating disease with a complex biology, and in spite of improved survivability by novel treatment strategies over the last decade, MM is still incurable by current therapy. MicroRNAs (miRNAs) are small, non-coding RNA molecules that regulate gene expression at a post......-transcriptional level. More than half of all protein coding genes are estimated to be controlled by miRNAs, and their expression is frequently deregulated in many diseases, including cancer. Recent studies have reported aberrant miRNA expression patterns in MM, and the function of individual miRNAs in MM has been...

  13. Variational image segmentation for endoscopic human colonic aberrant crypt foci.

    Science.gov (United States)

    Figueiredo, Isabel N; Figueiredo, Pedro N; Stadler, Georg; Ghattas, Omar; Araujo, Adérito

    2010-04-01

    The aim of this paper is to introduce a variational image segmentation method for assessing the aberrant crypt foci (ACF) in the human colon captured in vivo by endoscopy. ACF are thought to be precursors for colorectal cancer, and therefore their early detection may play an important clinical role. We enhance the active contours without edges model of Chan and Vese to account for the ACF's particular structure. We employ level sets to represent the segmentation boundaries and discretize in space by finite elements and in (artificial) time by finite differences. The approach is able to identify the ACF, their boundaries, and some of the internal crypts' orifices.

  14. Chromosomal aberrations and SCEs as biomarkers of cancer risk

    DEFF Research Database (Denmark)

    Norppa, H; Bonassi, S; Hansteen, I-L

    2006-01-01

    Previous studies have suggested that the frequency of chromosomal aberrations (CAs), but not of sister chromatid exchanges (SCEs), predicts cancer risk. We have further examined this relationship in European cohorts comprising altogether almost 22,000 subjects, in the framework of a European...... collaborative project (CancerRiskBiomarkers). The present paper gives an overview of some of the results of the project, especially as regards CAs and SCEs. The results confirm that a high level of CAs is associated with an increased risk of cancer and indicate that this association does not depend on the time...

  15. Migration - utopia or myopia?

    Directory of Open Access Journals (Sweden)

    Peter Osborne

    1998-03-01

    Full Text Available Peter Osborne spent a sabbatical in northern America and was surprised that so many scientists and students stated that caribou migration was largely the result of mosquito pressure. He failed however to find any documented evidence of this claim although he was constantly confronted by the well known «facts» that mosquitoes had been observed to drive caribou crazy and even kill juveniles. The issue Osborne wishes to focus is that an experimentally unsubstantiated anthropomorphism appears to have become critical evidence in support of a theory. A recent article in Nature (393, 511-513, 1998 devoted to the uses of 'science in fiction' to stimulate thought and discussion about aspects of academia encouraged him to write the following comment in the form of a parody of ancient Greek dialogues.

  16. Nightly Test system migration

    CERN Document Server

    Win-Lime, Kevin

    2013-01-01

    The summer student program allows students to participate to the Cern adventure. They can follow several interesting lectures about particle science and participate to the experiment work. As a summer student, I had worked for LHCb experiment. LHCb uses a lot of software to analyze its data. All this software is organized in packages and projects. They are built and tested during the night using an automated system and the results are displayed on a web interface. Actually, LHCb is changing this system. It is looking for a replacement candidate. So I was charged to unify some internal interfaces to permit a swift migration. In this document, I will describe shortly the system used by LHCb, then I will explain what I have done in detail.

  17. Migration issues important -- Mongolia.

    Science.gov (United States)

    1999-01-01

    Migration and urbanization are issues that require increasing attention in Mongolia. Mr. Sodov Sonin, Minister of Health and Social Welfare, stated at the Forum that fertility has declined, but mortality, in particular the mortality of children and mothers, is still too high. In addition, there is a significant gap between the knowledge of and behaviors concerning reproductive health, which is one of the causes of the country's high abortion rates. However, on the positive side, literacy is high among women--70% of the students in Mongolia's higher educational institutions are female and the State recognizes equal rights for women. Moreover, programs that promote health and education, including the National Program on Reproductive Health, are being implemented; but despite all these, Mongolia still lacks the human and financial resources to implement the ICPD Program of Action satisfactorily. The country also needs dramatic changes in mind-set and in terms of capacity building, given its ongoing socioeconomic transition.

  18. Spatial-temporal-covariance-based modeling, analysis, and simulation of aero-optics wavefront aberrations.

    Science.gov (United States)

    Vogel, Curtis R; Tyler, Glenn A; Wittich, Donald J

    2014-07-01

    We introduce a framework for modeling, analysis, and simulation of aero-optics wavefront aberrations that is based on spatial-temporal covariance matrices extracted from wavefront sensor measurements. Within this framework, we present a quasi-homogeneous structure function to analyze nonhomogeneous, mildly anisotropic spatial random processes, and we use this structure function to show that phase aberrations arising in aero-optics are, for an important range of operating parameters, locally Kolmogorov. This strongly suggests that the d5/3 power law for adaptive optics (AO) deformable mirror fitting error, where d denotes actuator separation, holds for certain important aero-optics scenarios. This framework also allows us to compute bounds on AO servo lag error and predictive control error. In addition, it provides us with the means to accurately simulate AO systems for the mitigation of aero-effects, and it may provide insight into underlying physical processes associated with turbulent flow. The techniques introduced here are demonstrated using data obtained from the Airborne Aero-Optics Laboratory.

  19. Reduced cul-5 activity causes aberrant follicular morphogenesis and germ cell loss in Drosophila oogenesis.

    Directory of Open Access Journals (Sweden)

    Jan-Michael Kugler

    2010-02-01

    Full Text Available Drosophila oogenesis is especially well suited for studying stem cell biology, cellular differentiation, and morphogenesis. The small modifier protein ubiquitin regulates many cellular pathways. Ubiquitin is conjugated to target proteins by a diverse class of enzymes called ubiquitin E3 ligases. Here we characterize the requirement of Cul-5, a key component of a subgroup of Cullin-RING-type ubiquitin E3 ligases, in Drosophila oogenesis. We find that reduced cul-5 activity causes the formation of aberrant follicles that are characterized by excess germ cells. We show that germ line cells overproliferate in cul-5 mutant females, causing the formation of abnormally large germ line cysts. Also, the follicular epithelium that normally encapsulates single germ line cysts develops aberrantly in cul-5 mutant, leading to defects in cyst formation. We additionally found that Cul-5 is required for germ cell maintenance, as germ cells are depleted in a substantial fraction of cul-5 mutant ovaries. All of these cul-5 phenotypes are strongly enhanced by reduced activity of gustavus (gus, which encodes a substrate receptor of Cul-5-based ubiquitin E3 ligases. Taken together, our results implicate Cul-5/Gus ubiquitin E3 ligases in ovarian tissue morphogenesis, germ cell proliferation and maintenance of the ovarian germ cell population.

  20. Aberrant epigenetic changes and gene expression in cloned cattle dying around birth

    Directory of Open Access Journals (Sweden)

    Zhao Dingsheng

    2008-02-01

    Full Text Available Abstract Background Aberrant reprogramming of donor somatic cell nuclei may result in many severe problems in animal cloning. To assess the extent of abnormal epigenetic modifications and gene expression in clones, we simultaneously examined DNA methylation, histone H4 acetylation and expression of six genes (β-actin, VEGF, oct4, TERT, H19 and Igf2 and a repetitive sequence (art2 in five organs (heart, liver, spleen, lung and kidney from two cloned cattle groups that had died at different stages. In the ED group (early death, n = 3, the cloned cattle died in the perinatal period. The cattle in the LD group (late death, n = 3 died after the perinatal period. Normally reproduced cattle served as a control group (n = 3. Results Aberrant DNA methylation, histone H4 acetylation and gene expression were observed in both cloned groups. The ED group showed relatively fewer severe DNA methylation abnormalities (p Conclusion Deaths of clones may be ascribed to abnormal expression of a very limited number of genes.