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Sample records for core-binding factor cbf

  1. Deletion of Core-binding factor β (Cbfβ) in mesenchymal progenitor cells provides new insights into Cbfβ/Runxs complex function in cartilage and bone development

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    Wu, Mengrui; Li, Chenguan; Zhu, Guochun; Wang, Yiping; Jules, Joel; Lu, Yun; McConnell, Matthew; Wang, Yong-Jun; Shao, Jian-Zhong; Li, Yi-Ping; Chen, Wei

    2015-01-01

    Core-binding factor β (Cbfβ) is a subunit of the Cbf family of heterodimeric transcription factors which plays a critical role in skeletal development through its interaction with the Cbfα subunits, also known as Runt-related transcription factors (Runxs). However, the mechanism by which Cbfβ regulates cartilage and bone development remains unclear. Existing Cbfβ-deficient mouse models cannot specify the role of Cbfβ in skeletal cell lineage. Herein, we sought to specifically address the role of Cbfβ in cartilage and bone development by using a conditional knockout (CKO) approach. A mesenchymal-specific Cbfβ CKO mouse model was generated by using the Dermo1-Cre mouse line to specifically delete Cbfβ in mesenchymal stem cells, which give rise to osteoblasts and chondrocytes. Surprisingly, the mutant mice had under-developed larynx and tracheal cartilage causing alveolus defects which led to death shortly after birth from suffocation. Also, the mutant mice exhibited severe skeletal deformities from defective intramembranous and endochondral ossification, owing to delayed chondrocyte maturation and impaired osteoblast differentiation. Almost all bones of the mutant mice, including the calvariae, vertebrae, tibiae, femurs, ribs, limbs and sternums were defective. Importantly, we showed that Cbfβ was expressed throughout the skeleton during both embryonic and postnatal development, which explains the multiple-skeletal defects observed in the mutant mice. Consistently, Cbfβ deficiency impaired both chondrocyte proliferation and hypertrophy zone hypertrophy during growth-plate development in the long bones of mutant mice. Notably, Cbfβ, Runx1 and Runx2 displayed different expression patterns in the growth plates of the wildtype mice indicating that Cbfβ/Runx1 complex and Cbfβ/Runx2 complex may regulate chondrocyte proliferation and hypertrophy, respectively, in a spatial and temporal manner. Cbfβ deletion in the mesenchymal progenitors impacted bone

  2. Core binding factor beta (Cbfβ) controls the balance of chondrocyte proliferation and differentiation by upregulating Indian hedgehog (Ihh) expression and inhibiting parathyroid hormone-related protein receptor (PPR) expression in postnatal cartilage and bone formation.

    Science.gov (United States)

    Tian, Fei; Wu, Mengrui; Deng, Lianfu; Zhu, Guochun; Ma, Junqing; Gao, Bo; Wang, Lin; Li, Yi-Ping; Chen, Wei

    2014-07-01

    Core binding factor beta (Cbfβ) is essential for embryonic bone morphogenesis. Yet the mechanisms by which Cbfβ regulates chondrocyte proliferation and differentiation as well as postnatal cartilage and bone formation remain unclear. Hence, using paired-related homeobox transcription factor 1-Cre (Prx1-Cre) mice, mesenchymal stem cell-specific Cbfβ-deficient (Cbfβ(f/f) Prx1-Cre) mice were generated to study the role of Cbfβ in postnatal cartilage and bone development. These mutant mice survived to adulthood but exhibited severe sternum and limb malformations. Sternum ossification was largely delayed in the Cbfβ(f/f) Prx1-Cre mice and the xiphoid process was noncalcified and enlarged. In newborn and 7-day-old Cbfβ(f/f) Prx1-Cre mice, the resting zone was dramatically elongated, the proliferation zone and hypertrophic zone of the growth plates were drastically shortened and disorganized, and trabecular bone formation was reduced. Moreover, in 1-month-old Cbfβ(f/f) Prx1-Cre mice, the growth plates were severely deformed and trabecular bone was almost absent. In addition, Cbfβ deficiency impaired intramembranous bone formation both in vivo and in vitro. Interestingly, although the expression of Indian hedgehog (Ihh) was largely reduced, the expression of parathyroid hormone-related protein (PTHrP) receptor (PPR) was dramatically increased in the Cbfβ(f/f) Prx1-Cre growth plate, indicating that that Cbfβ deficiency disrupted the Ihh-PTHrP negative regulatory loop. Chromatin immunoprecipitation (ChIP) analysis and promoter luciferase assay demonstrated that the Runx/Cbfβ complex binds putative Runx-binding sites of the Ihh promoter regions, and also the Runx/Cbfβ complex directly upregulates Ihh expression at the transcriptional level. Consistently, the expressions of Ihh target genes, including CyclinD1, Ptc, and Pthlh, were downregulated in Cbfβ-deficient chondrocytes. Taken together, our study reveals not only that Cbfβ is essential for chondrocyte

  3. Comprehensive mutational profiling of core binding factor acute myeloid leukemia.

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    Duployez, Nicolas; Marceau-Renaut, Alice; Boissel, Nicolas; Petit, Arnaud; Bucci, Maxime; Geffroy, Sandrine; Lapillonne, Hélène; Renneville, Aline; Ragu, Christine; Figeac, Martin; Celli-Lebras, Karine; Lacombe, Catherine; Micol, Jean-Baptiste; Abdel-Wahab, Omar; Cornillet, Pascale; Ifrah, Norbert; Dombret, Hervé; Leverger, Guy; Jourdan, Eric; Preudhomme, Claude

    2016-05-19

    Acute myeloid leukemia (AML) with t(8;21) or inv(16) have been recognized as unique entities within AML and are usually reported together as core binding factor AML (CBF-AML). However, there is considerable clinical and biological heterogeneity within this group of diseases, and relapse incidence reaches up to 40%. Moreover, translocations involving CBFs are not sufficient to induce AML on its own and the full spectrum of mutations coexisting with CBF translocations has not been elucidated. To address these issues, we performed extensive mutational analysis by high-throughput sequencing in 215 patients with CBF-AML enrolled in the Phase 3 Trial of Systematic Versus Response-adapted Timed-Sequential Induction in Patients With Core Binding Factor Acute Myeloid Leukemia and Treating Patients with Childhood Acute Myeloid Leukemia with Interleukin-2 trials (age, 1-60 years). Mutations in genes activating tyrosine kinase signaling (including KIT, N/KRAS, and FLT3) were frequent in both subtypes of CBF-AML. In contrast, mutations in genes that regulate chromatin conformation or encode members of the cohesin complex were observed with high frequencies in t(8;21) AML (42% and 18%, respectively), whereas they were nearly absent in inv(16) AML. High KIT mutant allele ratios defined a group of t(8;21) AML patients with poor prognosis, whereas high N/KRAS mutant allele ratios were associated with the lack of KIT or FLT3 mutations and a favorable outcome. In addition, mutations in epigenetic modifying or cohesin genes were associated with a poor prognosis in patients with tyrosine kinase pathway mutations, suggesting synergic cooperation between these events. These data suggest that diverse cooperating mutations may influence CBF-AML pathophysiology as well as clinical behavior and point to potential unique pathogenesis of t(8;21) vs inv(16) AML. © 2016 by The American Society of Hematology.

  4. Transcriptome Profiling of Pediatric Core Binding Factor AML.

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    Chih-Hao Hsu

    Full Text Available The t(8;21 and Inv(16 translocations disrupt the normal function of core binding factors alpha (CBFA and beta (CBFB, respectively. These translocations represent two of the most common genomic abnormalities in acute myeloid leukemia (AML patients, occurring in approximately 25% pediatric and 15% of adult with this malignancy. Both translocations are associated with favorable clinical outcomes after intensive chemotherapy, and given the perceived mechanistic similarities, patients with these translocations are frequently referred to as having CBF-AML. It remains uncertain as to whether, collectively, these translocations are mechanistically the same or impact different pathways in subtle ways that have both biological and clinical significance. Therefore, we used transcriptome sequencing (RNA-seq to investigate the similarities and differences in genes and pathways between these subtypes of pediatric AMLs. Diagnostic RNA from patients with t(8;21 (N = 17, Inv(16 (N = 14, and normal karyotype (NK, N = 33 were subjected to RNA-seq. Analyses compared the transcriptomes across these three cytogenetic subtypes, using the NK cohort as the control. A total of 1291 genes in t(8;21 and 474 genes in Inv(16 were differentially expressed relative to the NK controls, with 198 genes differentially expressed in both subtypes. The majority of these genes (175/198; binomial test p-value < 10(-30 are consistent in expression changes among the two subtypes suggesting the expression profiles are more similar between the CBF cohorts than in the NK cohort. Our analysis also revealed alternative splicing events (ASEs differentially expressed across subtypes, with 337 t(8;21-specific and 407 Inv(16-specific ASEs detected, the majority of which were acetylated proteins (p = 1.5 x 10(-51 and p = 1.8 x 10(-54 for the two subsets. In addition to known fusions, we identified and verified 16 de novo fusions in 43 patients, including three fusions involving NUP98 in six

  5. Genetics Home Reference: core binding factor acute myeloid leukemia

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    ... binding factor acute myeloid leukemia Core binding factor acute myeloid leukemia Printable PDF Open All Close All Enable Javascript ... on PubMed (1 link) PubMed OMIM (1 link) LEUKEMIA, ACUTE MYELOID Sources for This Page Goyama S, Mulloy JC. Molecular ...

  6. Systemic mastocytosis uncommon in KIT D816V mutation positive core-binding factor acute myeloid leukemia

    DEFF Research Database (Denmark)

    Kristensen, Thomas; Preiss, Birgitte; Broesby-Olsen, Sigurd

    2012-01-01

    Abstract The KIT D816V mutation is detected in the vast majority of adult cases of systemic mastocytosis (SM). The mutation is also frequently detected in core-binding factor acute myeloid leukemia (CBF-AML) defined by the presence of t(8;21)(q22;q22); RUNX1-RUNX1T1 or inv(16)(p13.1;q22)/t(16;16)(p...

  7. Central Role of Core Binding Factor β2 in Mucosa-Associated Lymphoid Tissue Organogenesis in Mouse.

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    Nagatake, Takahiro; Fukuyama, Satoshi; Sato, Shintaro; Okura, Hideaki; Tachibana, Masashi; Taniuchi, Ichiro; Ito, Kosei; Shimojou, Michiko; Matsumoto, Naomi; Suzuki, Hidehiko; Kunisawa, Jun; Kiyono, Hiroshi

    2015-01-01

    Mucosa-associated lymphoid tissue (MALT) is a group of secondary and organized lymphoid tissue that develops at different mucosal surfaces. Peyer's patches (PPs), nasopharynx-associated lymphoid tissue (NALT), and tear duct-associated lymphoid tissue (TALT) are representative MALT in the small intestine, nasal cavity, and lacrimal sac, respectively. A recent study has shown that transcriptional regulators of core binding factor (Cbf) β2 and promotor-1-transcribed Runt-related transcription factor 1 (P1-Runx1) are required for the differentiation of CD3-CD4+CD45+ lymphoid tissue inducer (LTi) cells, which initiate and trigger the developmental program of PPs, but the involvement of this pathway in NALT and TALT development remains to be elucidated. Here we report that Cbfβ2 plays an essential role in NALT and TALT development by regulating LTi cell trafficking to the NALT and TALT anlagens. Cbfβ2 was expressed in LTi cells in all three types of MALT examined. Indeed, similar to the previous finding for PPs, we found that Cbfβ2-/- mice lacked NALT and TALT lymphoid structures. However, in contrast to PPs, NALT and TALT developed normally in the absence of P1-Runx1 or other Runx family members such as Runx2 and Runx3. LTi cells for NALT and TALT differentiated normally but did not accumulate in the respective lymphoid tissue anlagens in Cbfβ2-/- mice. These findings demonstrate that Cbfβ2 is a central regulator of the MALT developmental program, but the dependency of Runx proteins on the lymphoid tissue development would differ among PPs, NALT, and TALT.

  8. Down-regulation of MicroRNAs 222/221 in Acute Myelogenous Leukemia with Deranged Core-Binding Factor Subunits

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    Matteo Brioschi

    2010-11-01

    Full Text Available Core-binding factor leukemia (CBFL is a subgroup of acutemyeloid leukemia (AML characterized by genetic mutations involving the subunits of the core-binding factor (CBF. The leukemogenesis model for CBFL posits that one, or more, gene mutations inducing increased cell proliferation and/or inhibition of apoptosis cooperate with CBF mutations for leukemia development. One of the most commonmutations associated with CBF mutations involves the KIT receptor. A high expression of KIT is a hallmark of a high proportion of CBFL. Previous studies indicate that microRNA (MIR 222/221 targets the 3′ untranslated region of the KIT messenger RNA and our observation that AML1 can bind the MIR-222/221 promoter, we hypothesized that MIR-222/221 represents the link between CBF and KIT. Here, we show that MIR-222/221 expression is upregulated after myeloid differentiation of normal bone marrow AC133+ stem progenitor cells. CBFL blasts with either t(8;21 or inv(16 CBF rearrangements with high expression levels of KIT (CD117 display a significantly lower level of MIR-222/221 expression than non-CBFL blasts. Consistently, we found that the t(8;21 AML1-MTG8 fusion protein binds the MIR-222/221 promoter and induces transcriptional repression of a MIR-222/221-LUC reporter. Because of the highly conserved sequence homology, we demonstrated concomitant MIR-222/221 down-regulation and KIT up-regulation in the 32D/WT1 mouse cell model carrying the AML1-MTG16 fusion protein. This study provides the first hint that CBFL-associated fusion proteins may lead to up-regulation of the KIT receptor by down-regulating MIR-222/221, thus explaining the concomitant occurrence of CBF genetic rearrangements and overexpression of wild type or mutant KIT in AML.

  9. Prognostic Markers in Core-Binding Factor AML and Improved Survival with Multiple Consolidation Cycles of Intermediate/High-dose Cytarabine.

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    Prabahran, Ashvind; Tacey, Mark; Fleming, Shaun; Wei, Andrew; Tate, Courtney; Marlton, Paula; Wight, Joel; Grigg, Andrew; Tuckfield, Annabel; Szer, Jeff; Ritchie, David; Chee, Lynette

    2018-05-02

    Core-binding factor acute myeloid leukaemia (CBF AML) defined by t(8;21)(q22;q22) or inv(16)(p13q22)/t(16;16)(p13;q22) has a favourable prognosis, however 30-40% of patients still relapse after chemotherapy. We sought to evaluate risk factors for relapse in a de novo CBF AML cohort. A retrospective review of patients from 4 Australian tertiary centres from 2001-2012, comprising 40 t(8;21) and 30 inv(16) AMLs. Multivariate analysis identified age (p=0.032) and WCC>40 (p=0.025) as significant predictors for inferior OS and relapse respectively. Relapse risk was higher in the inv(16) group vs the t(8;21) group (57% vs 18%, HR 4.31, 95% CI: 1.78-10.42, p=0.001). Induction therapy had no bearing on OS or relapse free survival (RFS) however, consolidation treatment with >3 cycles of intermediate/high dose cytarabine improved OS (p=0.035) and relapse-free survival (RFS) (p=0.063). 5 patients demonstrated post-treatment stable q PCR positivity without relapse. (1)>3 consolidation cycles of intermediate/ high-dose cytarabine improves patient outcomes. (2)Age and inv(16) CBF AML subtype are predictors of inferior OS and RFS respectively. (3)Stable low-level MRD by qPCR does not predict relapse. (4)Similar OS in the inv(16) cohort compared to the t(8;21) cohort, despite a higher relapse rate, confirms salvageability of relapsed disease. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  10. Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses

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    Su Zhen

    2011-07-01

    Full Text Available Abstract Background Salt stress hinders the growth of plants and reduces crop production worldwide. However, different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene, MtCBF4, for experimental validation. Results A microarray experiment was conducted using root samples collected 6, 24, and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned, and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4, which belongs to the AP2-EREBP transcription factor family, is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses, including salt, drought, cold, and abscisic acid, suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis over-expressing MtCBF4 enhanced tolerance to drought and salt stress, and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream genes. Conclusion Comprehensive transcriptomic analysis revealed complex mechanisms exist in plants in response to salt stress. The novel transcription factor gene MtCBF4 identified here played an important role in response to abiotic stresses, indicating that it might be a good candidate gene for genetic improvement to produce stress-tolerant plants.

  11. Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses

    Science.gov (United States)

    2011-01-01

    Background Salt stress hinders the growth of plants and reduces crop production worldwide. However, different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene, MtCBF4, for experimental validation. Results A microarray experiment was conducted using root samples collected 6, 24, and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned, and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4, which belongs to the AP2-EREBP transcription factor family, is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses, including salt, drought, cold, and abscisic acid, suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis over-expressing MtCBF4 enhanced tolerance to drought and salt stress, and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream genes. Conclusion Comprehensive transcriptomic analysis revealed complex mechanisms exist in plants in response to salt stress. The novel transcription factor gene MtCBF4 identified here played an important role in response to abiotic stresses, indicating that it might be a good candidate gene for genetic improvement to produce stress-tolerant plants. PMID:21718548

  12. The precise regulation of different COR genes by individual CBF transcription factors in Arabidopsis thaliana.

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    Shi, Yihao; Huang, Jiaying; Sun, Tianshu; Wang, Xuefei; Zhu, Chenqi; Ai, Yuxi; Gu, Hongya

    2017-02-01

    The transcription factors CBF1/2/3 are reported to play a dominant role in the cold responsive network of Arabidopsis by directly regulating the expression levels of cold responsive (COR) genes. In this study, we obtained CRISPR/Cas9-mediated loss-of-function mutants of cbf1∼3. Over 3,000 COR genes identified by RNA-seq analysis showed a slight but significant change in their expression levels in the mutants compared to the wild-type plants after being treated at 4 °C for 12 h. The C-repeat (CRT) motif (5'-CCGAC-3') was enriched in promoters of genes that were up-regulated by CBF2 and CBF3 but not in promoters of genes up-regulated by CBF1. These data suggest that CBF2 and CBF3 play a more important role in directing the cold response by regulating different sets of downstream COR genes. More than 2/3 of COR genes were co-regulated by two or three CBFs and were involved mainly in cellular signal transduction and metabolic processes; less than 1/3 of the genes were regulated by one CBF, and those genes up-regulated were enriched in cold-related abiotic stress responses. Our results indicate that CBFs play an important role in the trade-off between cold tolerance and plant growth through the precise regulation of COR genes in the complicated transcriptional network. © 2016 The Authors. Journal of Integrative Plant Biology Published by John Wiley & Sons Australia, Ltd on behalf of Institute of Botany, Chinese Academy of Sciences.

  13. Potential language and attentional networks revealed through factor analysis of rCBF data measured with SPECT

    DEFF Research Database (Denmark)

    McLaughlin, T; Steinberg, B; Christensen, B

    1992-01-01

    's area (left hemisphere), when subjects listened to narrative speech, compared to white noise (baseline). No significant rCBF differences were detected with this test during dichotic stimulation vs. white noise. A more sophisticated statistical method (factor analysis) disclosed patterns of functionally...... brain networks involved in (I) auditory/linguistic, (II) attentional, and (III) visual imaging activity....

  14. Three grape CBF/DREB1 genes respond to low temperature, drought and abscisic acid.

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    Xiao, Huogen; Siddiqua, Mahbuba; Braybrook, Siobhan; Nassuth, Annette

    2006-07-01

    The C-repeat (CRT)-binding factor/dehydration-responsive element (DRE) binding protein 1 (CBF/ DREB1) transcription factors control an important pathway for increased freezing and drought tolerance in plants. Three CBF/DREB1-like genes, CBF 1-3, were isolated from both freezing-tolerant wild grape (Vitis riparia) and freezing-sensitive cultivated grape (Vitis vinifera). The deduced proteins in V. riparia are 63-70% identical to each other and 96-98% identical to the corresponding proteins in V. vinifera. All Vitis CBF proteins are 42-51% identical to AtCBF1 and contain CBF-specific amino acid motifs, supporting their identification as CBF proteins. Grape CBF sequences are unique in that they contain 20-29 additional amino acids and three serine stretches. Agro-infiltration experiments revealed that VrCBF1b localizes to the nucleus. VrCBF1a, VrCBF1b and VvCBF1 activated a green fluorescent protein (GFP) or glucuronidase (GUS) reporter gene behind CRT-containing promoters. Expression of the endogenous CBF genes was low at ambient temperature and enhanced upon low temperature (4 degrees C) treatment, first for CBF1, followed by CBF2, and about 2 d later by CBF3. No obvious significant difference was observed between V. riparia and V. vinifera genes. The expression levels of all three CBF genes were higher in young tissues than in older tissues. CBF1, 2 and 3 transcripts also accumulated in response to drought and exogenous abscisic acid (ABA) treatment, indicating that grape contains unique CBF genes.

  15. Molecular cloning and characterization of a novel freezing-inducible DREB1/CBF transcription factor gene in boreal plant Iceland poppy (Papaver nudicaule

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    Zhuo Huang

    Full Text Available Abstract DREB1 of the AP2/ERF superfamily plays a key role in the regulation of plant response to low temperatures. In this study, a novel DREB1/CBF transcription factor, PnDREB1, was isolated from Iceland poppy (Papaver nudicaule, a plant adaptive to low temperature environments. It is homologous to the known DREB1s of Arabidopsis and other plant species. It also shares similar 3D structure, and conserved and functionally important motifs with DREB1s of Arabidopsis. The phylogenetic analysis indicated that the AP2 domain of PnDREB1 is similar to those of Glycine max, Medicago truncatula, and M. sativa. PnDREB1 is constitutively expressed in diverse tissues and is increased in roots. qPCR analyses indicated that PnDREB1 is significantly induced by freezing treatment as well as by abscissic acid. The expression levels induced by freezing treatment were higher in the variety with higher degree of freezing tolerance. These results suggested that PnDREB1 is a novel and functional DREB1 transcription factor involved in freezing response and possibly in other abiotic stresses. Furthermore, the freezing-induction could be suppressed by exogenous gibberellins acid, indicating that PnDREB1 might play some role in the GA signaling transduction pathway. This study provides a basis for better understanding the roles of DREB1 in adaption of Iceland poppy to low temperatures.

  16. Soybean DREB1/CBF-type transcription factors function in heat and drought as well as cold stress-responsive gene expression.

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    Kidokoro, Satoshi; Watanabe, Keitaro; Ohori, Teppei; Moriwaki, Takashi; Maruyama, Kyonoshin; Mizoi, Junya; Myint Phyu Sin Htwe, Nang; Fujita, Yasunari; Sekita, Sachiko; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2015-02-01

    Soybean (Glycine max) is a globally important crop, and its growth and yield are severely reduced by abiotic stresses, such as drought, heat, and cold. The cis-acting element DRE (dehydration-responsive element)/CRT plays an important role in activating gene expression in response to these stresses. The Arabidopsis DREB1/CBF genes that encode DRE-binding proteins function as transcriptional activators in the cold stress responsive gene expression. In this study, we identified 14 DREB1-type transcription factors (GmDREB1s) from a soybean genome database. The expression of most GmDREB1 genes in soybean was strongly induced by a variety of abiotic stresses, such as cold, drought, high salt, and heat. The GmDREB1 proteins activated transcription via DREs (dehydration-responsive element) in Arabidopsis and soybean protoplasts. Transcriptome analyses using transgenic Arabidopsis plants overexpressing GmDREB1s indicated that many of the downstream genes are cold-inducible and overlap with those of Arabidopsis DREB1A. We then comprehensively analyzed the downstream genes of GmDREB1B;1, which is closely related to DREB1A, using a transient expression system in soybean protoplasts. The expression of numerous genes induced by various abiotic stresses were increased by overexpressing GmDREB1B;1 in soybean, and DREs were the most conserved element in the promoters of these genes. The downstream genes of GmDREB1B;1 included numerous soybean-specific stress-inducible genes that encode an ABA receptor family protein, GmPYL21, and translation-related genes, such as ribosomal proteins. We confirmed that GmDREB1B;1 directly activates GmPYL21 expression and enhances ABRE-mediated gene expression in an ABA-independent manner. These results suggest that GmDREB1 proteins activate the expression of numerous soybean-specific stress-responsive genes under diverse abiotic stress conditions. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  17. Constitutive expression of DaCBF7, an Antarctic vascular plant Deschampsia antarctica CBF homolog, resulted in improved cold tolerance in transgenic rice plants.

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    Byun, Mi Young; Lee, Jungeun; Cui, Li Hua; Kang, Yoonjee; Oh, Tae Kyung; Park, Hyun; Lee, Hyoungseok; Kim, Woo Taek

    2015-07-01

    Deschampsia antarctica is an Antarctic hairgrass that grows on the west coast of the Antarctic peninsula. In this report, we have identified and characterized a transcription factor, D. antarctica C-repeat binding factor 7 (DaCBF7), that is a member of the monocot group V CBF homologs. The protein contains a single AP2 domain, a putative nuclear localization signal, and the typical CBF signature. DaCBF7, like other monocot group V homologs, contains a distinct polypeptide stretch composed of 43 amino acids in front of the AP2 motif. DaCBF7 was predominantly localized to nuclei and interacted with the C-repeat/dehydration responsive element (CRT/DRE) core sequence (ACCGAC) in vitro. DaCBF7 was induced by abiotic stresses, including drought, cold, and salinity. To investigate its possible cellular role in cold tolerance, a transgenic rice system was employed. DaCBF7-overexpressing transgenic rice plants (Ubi:DaCBF7) exhibited markedly increased tolerance to cold stress compared to wild-type plants without growth defects; however, overexpression of DaCBF7 exerted little effect on tolerance to drought or salt stress. Transcriptome analysis of a Ubi:DaCBF7 transgenic line revealed 13 genes that were up-regulated in DaCBF7-overexpressing plants compared to wild-type plants in the absence of cold stress and in short- or long-term cold stress. Five of these genes, dehydrin, remorin, Os03g63870, Os11g34790, and Os10g22630, contained putative CRT/DRE or low-temperature responsive elements in their promoter regions. These results suggest that overexpression of DaCBF7 directly and indirectly induces diverse genes in transgenic rice plants and confers enhanced tolerance to cold stress. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Divergent regulation of CBF regulon on cold tolerance and plant phenotype in cassava overexpressing Arabidopsis CBF3 gene

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    Dong An

    2016-12-01

    Full Text Available Cassava is a tropical origin plant that is sensitive to chilling stress. In order to understand the CBF cold response pathway, a well-recognized regulatory mechanism in temperate plants, in cassava, overexpression of an Arabidopsis CBF3 gene is studied. This gene renders cassava increasingly tolerant to cold and drought stresses but is associated with retarded plant growth, leaf curling, reduced storage root yield, and reduced anthocyanin accumulation in a transcript abundance-dependent manner. Physiological analysis revealed that the transgenic cassava increased proline accumulation, reduced malondialdehyde production, and electrolyte leakage under cold stress. These transgenic lines also showed high relative water content when faced with drought. The expression of partial CBF-targeted genes in response to cold displayed temporal and spatial variations in the wild-type and transgenic plants: highly inducible in leaves and less altered in apical buds. In addition, anthocyanin accumulation was inhibited by downregulating the expression of genes involved in its biosynthesis and by interplaying between the CBF3 and the endogenous transcription factors. Thus, the heterologous CBF3 modulates the expression of stress-related genes and carries out a series of physiological adjustments under stressful conditions, showing a varied regulation pattern of CBF regulon from that of cassava CBFs.

  19. Alteration of CBF and CMRO2 and TRH effects on CBF in spinocerebellar degeneration

    International Nuclear Information System (INIS)

    Harada, Kiyoshi; Fukuyama, Hidenao; Miyoshi, Toshihiko; Namura, Yasuhiro; Kameyama, Masakuni

    1988-01-01

    The purpose of this study is to elucidate the effects of thyrotropin-releasing hormone (TRH) on cerebral blood flow (CBF) in patients with spinocerebellar degeneration (SCD) and to evaluate the cerebral circulation and metabolism in patients with SCD. We performed a positron emission tomography study on each of six SCD patients (mean age 47.7 ± 3.6 : 5 cases; OPCA of Dejerene-Thomas type, 1 case; OPCA of Menzel type) and twelve normal volunteers. In SCD patients there were marked reductions in CBF (p < 0.01) and CMRO2 (p < 0.01) in the cerebellum compared with normal volunteers, while in the cerebral cortices and the thalamus, SCD patients showed normal values. There were no significant changes in regional and global CBF after 2 mg TRH intravenous injection in the SCD patients. But comparing CBF before TRH administration with corrected CBF (CBF after TRH · mean global CBF before TRH/mean global CBF after TRH), it is only the CBF of the cerebellum that increased after TRH administration (paired t test, p < 0.02). This elevation of CBF in the cerebellum would be related to some clinical effects of TRH in SCD patients. (author)

  20. Meta-analysis of the effect of overexpression of CBF/DREB family genes on drought stress response

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    Transcription factors C-repeat/dehydration-responsive element binding proteins (CBF/DREB) play an important role in plant response to abiotic stresses. Over-expression of various CBF/DREB genes in diverse plants have been reported, but inconsistency of gene donor, recipient genus, parameters used i...

  1. Cerebral blood flow (CBF) with 133Xe inhalation method

    International Nuclear Information System (INIS)

    Kusunoki, Tadaki; Masumura, Michio; Tamaki, Norihiko; Matsumoto, Satoshi; Yamashita, Hideyuki.

    1982-01-01

    The effects of CO 2 inhalation on the cerebral blood flow (CBF) were examined with 133 Xe inhalation method (Novo Inhalation Cerebrograph) on 9 normal peoples and 20 patients. Nine normal peoples were divided into 3 groups consisting of each 3 peoples, namely young age group, middle age group, and old age group. Each increased CBF (%) by CO 2 inhalation was 40 -- 44 in young age group, 36 -- 37 in middle age group, and 35 -- 36 in old age group in the blood flow of the first compartment (F 1 ), and 27 -- 28 in young age group, 30 -- 31 in middle age group and 23 -- 24 in old age group in the initial slope index (ISI). Each CO 2 reactivity factor (RF) was 5.5 -- 5.8 in young age group, 3.8 -- 4.0 in middle age group and 3.3 in old age group in F 1 , and 3.1 -- 3.2 in young age group, 2.0 -- 3.3 in middle age group, and 1.2 -- 1.3 in old age group in ISI. Twenty patients consisted of 15 patients of occlusive cerebrovascular disease, 2 patients of head injury, 2 patients of normal pressure hydrocephalus and one patient of subarachnoid hemorrhage. RF was abnormally lower than normal value in 5 patients in F 1 , but in 7 in ISI. Clinical benefits of CBF study during CO 2 inhalation with 133 Xe inhalation method were discussed. (author)

  2. Ethylene and cold participate in the regulation of LeCBF1 gene expression in postharvest tomato fruits.

    Science.gov (United States)

    Zhao, Danying; Shen, Lin; Fan, Bei; Yu, Mengmeng; Zheng, Yang; Lv, Shengnan; Sheng, Jiping

    2009-10-20

    C-repeat/dehydration-responsive element binding factor (CBF) is a transcription factor regulating cold response in plants, of which little is known in fruits. We showed a double-peak expression pattern of Lycopersicon esculentum putative transcriptional activator CBF1 (LeCBF1) in mature green fruit. The peaks appeared at 2 and 16 h after subjection to cold storage (2 degrees C). The second peak was coincident with, and thus caused by a peak in endogenous ethylene production. We showed that LeCBF1 expression was regulated by exogenous ethylene and 1-methylcyclopropene, and was not expressed without cold induction. LeCBF1 expression was different in the five maturation stages of fruits, but expression peaked at 2 h at all stages.

  3. Tomographic analysis of CBF in cerebral infarction

    International Nuclear Information System (INIS)

    Segawa, Hiromu; Kimura, Kazumoto; Ueda, Yuichi; Nagai, Masakatsu; Yoshimasu, Norio.

    1983-01-01

    Cerebral perfusion was examined in various types of occlusive disease by computed tomographic CBF method. The method utilized has several advantages over conventional studies using isotope, providing high resolution images in a direct relation to CT anatomy. Ten representative cases were presented from 25 consective cases of occlusive disease studied by this method. The method included inhalation of 40 to 60% xenon with serial CT scanning for 25 min. K (build-up rate), lambda (partition coefficient) and CBF values were calculated from ΔHU for each pixel and ΔXe in expired air, based on Fick's principle, and displayed on CRT as K-, lambda- and CBF-map separately. CBF for gray matter of normal control was 82 +- 11 ml/100 gm/min and that for white matter was 24 +- 5 ml/100 gm/min. The ischemic threshold for gray matter appeared to be approximately 20 ml/100 gm/min, as blood flow in focus of complete infarction was below this level. Blood flow between 20 - 30 ml/ 100 gm/min caused some change on CT, such as localized atrophy, cortical thinning, loss of distinction between gray and white matter and decreased or increased density, which were considered to be compatible with pathological changes of laminar necrosis or gliosis with neuronal loss. In a case with occlusion of middle cerebral artery with subsequent recanalization, causing hemorrhagic infarct, hyperemia was observed in the infarcted cortex that was enhanced by iodine. Periventricular lucency observed in two cases, where blood flow was decreased below threshold, could be classified as ''watershed infarction'' mainly involving white matter. In moyamoya disease, blood flow in the anterior circulation was decreased near ischemic level, whereas that in basal ganglia and territory of posterior cerebral artery was fairly preserved, which was compatible with general angiographic finding of this disease. (author)

  4. A comparison of the low temperature transcriptomes and CBF regulons of three plant species that differ in freezing tolerance: Solanum commersonii, Solanum tuberosum, and Arabidopsis thaliana

    OpenAIRE

    Carvallo, Marcela A.; Pino, María-Teresa; Jeknić, Zoran; Zou, Cheng; Doherty, Colleen J.; Shiu, Shin-Han; Chen, Tony H. H.; Thomashow, Michael F.

    2011-01-01

    Solanum commersonii and Solanum tuberosum are closely related plant species that differ in their abilities to cold acclimate; whereas S. commersonii increases in freezing tolerance in response to low temperature, S. tuberosum does not. In Arabidopsis thaliana, cold-regulated genes have been shown to contribute to freezing tolerance, including those that comprise the CBF regulon, genes that are controlled by the CBF transcription factors. The low temperature transcriptomes and CBF regulons of ...

  5. CBF tomographic measurement with the scintillation camera

    International Nuclear Information System (INIS)

    Kayayan, R.; Philippon, B.; Pehlivanian, E.

    1989-01-01

    Single photon emission tomography (SPECT) allows calculation of regional cerebral blood flow (CBF) in multiple cross-sections of the human brain. The methods of Kanno and Lassen is utilized and a study of reproductibility in terms of integration numbers and period of integrations is performed by computer simulation and experimental study with a Gamma-camera. Finally, the possibility of calculating the regional cerabral blood flow with a double headed rotating Gamma-camera by inert gas inhalation, like the Xenon-133 is discussed [fr

  6. Statistic rCBF study of extrapyramidal disorders

    Energy Technology Data Exchange (ETDEWEB)

    Kamei, Hiroshi; Nakajima, Takashi; Fukuhara, Nobuyoshi [National Saigata Hospital, Ogata, Niigata (Japan)

    2002-08-01

    We studied regional cerebral blood flow (rCBF) in 16 patients with Parkinson's disease (PD), 2 patients with dementia with Lewy bodies (DLB), 2 patients with progressive supranuclear palsy (PSP), 2 patients with striatonigral degeneration, and 16 normal volunteers, using Three-dimensional stereotactic surface projections (3D-SSP). Decreased rCBF in PD patients was shown in the posterior parietal and occipital cortex. Decreased rCBF in DLB was shown in the frontal, parietal and occipital cortex with relative sparing of the sensorimotor cortex.. Decreased rCBF in PSP was shown in the frontal cortex. Decreased rCBF in SND was shown in the frontal cortex and cerebellum. Statistic rCBF analysis using 3D-SSP was a useful measure for the early differential diagnosis of extrapyramidal disorders. (author)

  7. Effects of normal aging on regional CBF and CMRO2 in humans

    International Nuclear Information System (INIS)

    Pantano, P.; Baron, J.C.; Lebrun-Grandie, P.; Duquesnoy, N.; Bousser, M.G.; Comar, D.

    1983-07-01

    The oxygen-15 continuous inhalation technique and positron emission tomography were used in order to investigate age-related changes of cerebral blood flow (CBF) and oxygen consumption (CMRO 2 ). 27 patients aged 19 to 76 years without evidence of dementia, brain disease or vascular risk factors, were studied. Regional CBF and CMRO 2 were calculated in seven different brain structures. In gray matter CBF and CMRO 2 decreased with aging (respectively 18% and 17%, p 2 was found to be diffuse but to affect principally the frontal and temporo-sylvian cortex. Neuronal loss and/or a diminished metabolic activity of residual neurons are the most likely hypotheses to explain these findings

  8. Lambda-guided calculation method (LGC method) for xenon/CT CBF

    Energy Technology Data Exchange (ETDEWEB)

    Sase, Shigeru [Anzai Medical Co., Ltd., Tokyo (Japan); Honda, Mitsuru; Kushida, Tsuyoshi; Seiki, Yoshikatsu; Machida, Keiichi; Shibata, Iekado [Toho Univ., Tokyo (Japan). School of Medicine

    2001-12-01

    A quantitative CBF calculation method for xenon/CT was developed by logically estimating time-course change rate (rate constant) of arterial xenon concentration from that of end-tidal xenon concentration. A single factor ({gamma}) was introduced to correlate the end-tidal rate constant (Ke) with the arterial rate constant (Ka) in a simplified equation. This factor ({gamma}) is thought to reflect the diffusing capacity of the lung for xenon. When an appropriate value is given to {gamma}, it is possible to calculate the arterial rate constant (Calculated Ka) from Ke. To determine {gamma} for each xenon/CT CBF examination, a procedure was established which utilizes the characteristics of white matter lambda; lambda refers to xenon brain-blood partition coefficient. Xenon/CT studies were performed on four healthy volunteers. Hemispheric CBF values (47.0{+-}9.0 ml/100 g/min) with use of Calculated Ka were close to the reported normative values. For a 27-year-old healthy man, the rate constant for the common carotid artery was successfully measured and nearly equal to Calculated Ka. The authors conclude the method proposed in this work, lambda-guided calculation method, could make xenon/CT CBF substantially reliable and quantitative by effective use of end-tidal xenon. (author)

  9. Lambda-guided calculation method (LGC method) for xenon/CT CBF

    International Nuclear Information System (INIS)

    Sase, Shigeru; Honda, Mitsuru; Kushida, Tsuyoshi; Seiki, Yoshikatsu; Machida, Keiichi; Shibata, Iekado

    2001-01-01

    A quantitative CBF calculation method for xenon/CT was developed by logically estimating time-course change rate (rate constant) of arterial xenon concentration from that of end-tidal xenon concentration. A single factor (γ) was introduced to correlate the end-tidal rate constant (Ke) with the arterial rate constant (Ka) in a simplified equation. This factor (γ) is thought to reflect the diffusing capacity of the lung for xenon. When an appropriate value is given to γ, it is possible to calculate the arterial rate constant (Calculated Ka) from Ke. To determine γ for each xenon/CT CBF examination, a procedure was established which utilizes the characteristics of white matter lambda; lambda refers to xenon brain-blood partition coefficient. Xenon/CT studies were performed on four healthy volunteers. Hemispheric CBF values (47.0±9.0 ml/100 g/min) with use of Calculated Ka were close to the reported normative values. For a 27-year-old healthy man, the rate constant for the common carotid artery was successfully measured and nearly equal to Calculated Ka. The authors conclude the method proposed in this work, lambda-guided calculation method, could make xenon/CT CBF substantially reliable and quantitative by effective use of end-tidal xenon. (author)

  10. A study comparing the use of dynamic CT and Xe-CT CBF for ischemic cerebro-vascular disease

    International Nuclear Information System (INIS)

    Terada, Tomoaki; Kikuchi, Haruhiko; Kuriyama, Yoshihiro; Nagata, Izumi; Yamagata, Sen; Naruo, Yoshito; Minamikawa, Jun; Kaneko, Takaji; Sakashita, Yoshiharu

    1987-01-01

    The simultaneous measurement of dynamic computerized tomography scanning (DCT) with an iodine-contrast enhancement material bolus injection and a simultaneous xenon CT-CBF-study was done on 15 patients (8 cases of unilateral internal carotid occlusion; 3, of unilateral middle cerebral arterial occlusion, and 4, without any major cerebral arterial occlusion or significant arterial stenosis) with ischemic cerebro-vascular diseases at the subacute and/or chronic stage. The value of the width and corrected first moment (cMT1) as well as their functional images, as acquired from DCT data, were compared to the 1-CBF value and the 1-CBF map of the xenon CT-CBF-study. A comparison of the functional images of DCT and 1-CBF showed that there was a good correlation between them in the cases without leptomeningeal anastomosis as a collateral circulation. However, a poor correlation between them was found in the cases with leptomeningeal anastomosis as a collateral circulation. The correlation of 1-CBF and 1/width with 1/cMT1 was significant (r = 0.78, p < 0.01) in the former cases, but it was not significant in the latter cases. The results of our data were thought to be due to the difference in the tracer inflow pattern between the cases without leptomeningeal anastomosis and those with it as a collateral circulation. The factor of cerebral blood volume should be considered in a more detailed study, although our cases did not include any patients with acute cerebral infarction or recanalized cases, which are thought to show various changes in the cerebral blood volume. The 1/width and 1/cMT1 values acquired from DCT well reflected the CBF in the cases without leptomeningeal anastomosis as a collateral circulation. (author)

  11. Oil palm EgCBF3 conferred stress tolerance in transgenic tomato plants through modulation of the ethylene signaling pathway.

    Science.gov (United States)

    Ebrahimi, Mortaza; Abdullah, Siti Nor Akmar; Abdul Aziz, Maheran; Namasivayam, Parameswari

    2016-09-01

    CBF/DREB1 is a group of transcription factors that are mainly involved in abiotic stress tolerance in plants. They belong to the AP2/ERF superfamily of plant-specific transcription factors. A gene encoding a new member of this group was isolated from ripening oil palm fruit and designated as EgCBF3. The oil palm fruit demonstrates the characteristics of a climacteric fruit like tomato, in which ethylene has a major impact on the ripening process. A transgenic approach was used for functional characterization of the EgCBF3, using tomato as the model plant. The effects of ectopic expression of EgCBF3 were analyzed based on expression profiling of the ethylene biosynthesis-related genes, anti-freeze proteins (AFPs), abiotic stress tolerance and plant growth and development. The EgCBF3 tomatoes demonstrated altered phenotypes compared to the wild type tomatoes. Delayed leaf senescence and flowering, increased chlorophyll content and abnormal flowering were the consequences of overexpression of EgCBF3 in the transgenic tomatoes. The EgCBF3 tomatoes demonstrated enhanced abiotic stress tolerance under in vitro conditions. Further, transcript levels of ethylene biosynthesis-related genes, including three SlACSs and two SlACOs, were altered in the transgenic plants' leaves and roots compared to that in the wild type tomato plant. Among the eight AFPs studied in the wounded leaves of the EgCBF3 tomato plants, transcript levels of SlOSM-L, SlNP24, SlPR5L and SlTSRF1 decreased, while expression of the other four, SlCHI3, SlPR1, SlPR-P2 and SlLAP2, were up-regulated. These findings indicate the possible functions of EgCBF3 in plant growth and development as a regulator of ethylene biosynthesis-related and AFP genes, and as a stimulator of abiotic stress tolerance. Copyright © 2016 Elsevier GmbH. All rights reserved.

  12. Altered cerebral blood flow in chronic neck pain patients but not in whiplash patients: a 99mTc-HMPAO rCBF study.

    Science.gov (United States)

    Sundström, Torbjörn; Guez, Michel; Hildingsson, Christer; Toolanen, Göran; Nyberg, Lars; Riklund, Katrine

    2006-08-01

    A cross-sectional study to investigate regional cerebral blood flow (rCBF) in patients with chronic whiplash syndrome and chronic neck pain patients without previous history of trauma along with a healthy control group. Chronic neck pain is a common disorder and a history of cervical spine injury including whiplash trauma constitute a risk factor for persistent neck pain. The aetiology of the late whiplash syndrome is unknown with no specific diagnostic criteria based on imaging, physiological, or psychological examination. Earlier studies indicate a parieto-occipital hypoperfusion but it is unclear if the hypoperfusion represents a response to chronic pain. The rCBF was monitored in 45 patients with chronic neck pain: 27 cases with chronic whiplash syndrome and 18 age and gender matched cases with non-traumatic chronic neck pain. The rCBF was estimated with single-photon emission computed tomography (SPECT) using technetium-99m hexamethylpropylene amine oxime (HMPAO). The non-traumatic patients displayed rCBF changes in comparison with the whiplash group and the healthy control group. These changes included rCBF decreases in a right temporal region close to hippocampus, and increased rCBF in left insula. The whiplash group displayed no significant differences in rCBF in comparison with the healthy controls. The present study suggests different pain mechanisms in patients with chronic neck pain of non-traumatic origin compared to those with chronic neck pain due to a whiplash trauma.

  13. Simultaneous Imaging of CBF Change and BOLD with Saturation-Recovery-T1 Method.

    Directory of Open Access Journals (Sweden)

    Xiao Wang

    Full Text Available A neuroimaging technique based on the saturation-recovery (SR-T1 MRI method was applied for simultaneously imaging blood oxygenation level dependence (BOLD contrast and cerebral blood flow change (ΔCBF, which is determined by CBF-sensitive T1 relaxation rate change (ΔR1CBF. This technique was validated by quantitatively examining the relationships among ΔR1CBF, ΔCBF, BOLD and relative CBF change (rCBF, which was simultaneously measured by laser Doppler flowmetry under global ischemia and hypercapnia conditions, respectively, in the rat brain. It was found that during ischemia, BOLD decreased 23.1±2.8% in the cortical area; ΔR1CBF decreased 0.020±0.004s-1 corresponding to a ΔCBF decrease of 1.07±0.24 ml/g/min and 89.5±1.8% CBF reduction (n=5, resulting in a baseline CBF value (=1.18 ml/g/min consistent with the literature reports. The CBF change quantification based on temperature corrected ΔR1CBF had a better accuracy than apparent R1 change (ΔR1app; nevertheless, ΔR1app without temperature correction still provides a good approximation for quantifying CBF change since perfusion dominates the evolution of the longitudinal relaxation rate (R1app. In contrast to the excellent consistency between ΔCBF and rCBF measured during and after ischemia, the BOLD change during the post-ischemia period was temporally disassociated with ΔCBF, indicating distinct CBF and BOLD responses. Similar results were also observed for the hypercapnia study. The overall results demonstrate that the SR-T1 MRI method is effective for noninvasive and quantitative imaging of both ΔCBF and BOLD associated with physiological and/or pathological changes.

  14. Apparent CBF decrease with normal aging due to partial volume effects: MR-based partial volume correction on CBF SPECT.

    Science.gov (United States)

    Inoue, Kentaro; Ito, Hiroshi; Goto, Ryoi; Nakagawa, Manabu; Kinomura, Shigeo; Sato, Tachio; Sato, Kazunori; Fukuda, Hiroshi

    2005-06-01

    Several studies using single photon emission tomography (SPECT) have shown changes in cerebral blood flow (CBF) with age, which were associated with partial volume effects by some authors. Some studies have also demonstrated gender-related differences in CBF. The present study aimed to examine age and gender effects on CBF SPECT images obtained using the 99mTc-ethyl cysteinate dimer and a SPECT scanner, before and after partial volume correction (PVC) using magnetic resonance (MR) imaging. Forty-four healthy subjects (29 males and 15 females; age range, 27-64 y; mean age, 50.0 +/- 9.8 y) participated. Each MR image was segmented to yield grey and white matter images and coregistered to a corresponding SPECT image, followed by convolution to approximate the SPECT spatial resolution. PVC-SPECT images were produced using the convoluted grey matter MR (GM-MR) and white matter MR images. The age and gender effects were assessed using SPM99. Decreases with age were detected in the anterolateral prefrontal cortex and in areas along the lateral sulcus and the lateral ventricle, bilaterally, in the GM-MR images and the SPECT images. In the PVC-SPECT images, decreases in CBF in the lateral prefrontal cortex lost their statistical significance. Decreases in CBF with age found along the lateral sulcus and the lateral ventricle, on the other hand, remained statistically significant, but observation of the spatially normalized MR images suggests that these findings are associated with the dilatation of the lateral sulcus and lateral ventricle, which was not completely compensated for by the spatial normalization procedure. Our present study demonstrated that age effects on CBF in healthy subjects could reflect morphological differences with age in grey matter.

  15. The effect of selective intraarterial infusion of the anticancer agents on cerebral hemodynamics: Concerned with the change of CBF in the non-tumoral tissue. Quantitative evaluation using 123-IMP-SPECT

    International Nuclear Information System (INIS)

    Hirano, Hiroko; Tomura, Noriaki; Kobayashi, Mitsuru; Ohyama, Yoichi; Watarai, Jiro

    1996-01-01

    The effect of intraarterial chemotherapy on cerebral blood flow (CBF) of patients with brain tumor was quantitatively studied by means of single photon emission computed tomography (SPECT). The subjects consisted of twenty patients with brain tumor (2 fibrillary astrocytoma grade II, 9 malignant astrocytoma grade III, 7 glioblastoma grade IV, 1 pineoblastoma grade IV and 1 malignant glioma). In twenty patients, twenty-four intraarterial infusions (IAs) were performed. IA chemotherapy was selectively performed through the Tracker-18 catheter, using nimustine (ACNU) in 22 infusions and tumor necrotizing factor-α (TNF) in 2 infusions. CBF was quantitatively measured by Kuhl's method, using N-isopropyl-p= 123 I=-iodoamphetamine (IMP). All patients underwent a baseline SPECT scan 1-10 days prior to IA chemotherapy, and a scan 1-22 days after IA. The change of CBF before and after IA, particularly in the non-tumoral tissue, was highlighted. CBF in the infused region as well as in the non-infused region variously changed after IA. The mean CBF of the whole brain before IA was 47.8±11.9 (mean±SD, n=24) ml/100 ml/min and than after IA was 49.3±12.4. CBF in the infused region changed (-17-+52%) after IA chemotherapy. In 12 patients whose CBF measurement was performed within 5 days after IA, CBF increased in 6 patients compared with that measured before IA. In 3 patients whose CBF measurement was performed more than 10 days after IA, CBF decreased in all of patients. This result suggested that the increase of CBF may possibly be an early change after IA chemotherapy, and that an augmented cellular metabolism and/or acute inflammatory reaction may explain this early change after IA chemotherapy. (author)

  16. What does rCBF-SPECT offer in schizophrenia?

    International Nuclear Information System (INIS)

    Syed, G.M.S.; Barrett, J.J.; Toone, B.K.

    1992-01-01

    Schizophrenia is a major psychiatric problem common in the younger population. Structural imaging and findings on autopsy have not yet revealed a specific deficit in these patients. Uncertainty in clinical diagnosis based on a set of signs and symptoms is another drawback in the management of this patient population. Regional cerebral blood flow studies (rCBF) using single photon emission computed tomography (SPECT) offers the opportunity to study the underlying phenomenon and to detect the specific functional deficits in schizophrenia. (Author)

  17. Regional CBF in chronic stable TBI treated with hyperbaric oxygen.

    Science.gov (United States)

    Barrett, K F; Masel, B; Patterson, J; Scheibel, R S; Corson, K P; Mader, J T

    2004-01-01

    To investigate whether Hyperbaric Oxygen Therapy (HBO2) could improve neurologic deficits and regional cerebral blood flow (rCBF) in chronic traumatic brain injuries (TBI), the authors employed a nonrandomized control pilot trial. Five subjects, at least three years post head injury, received HBO2. Five head injured controls (HIC) were matched for age, sex, and type of injury. Five healthy subjects served as normal controls. Sixty-eight normal volunteers comprised a reference data bank against which to compare SPECT brain scans. HBO2 subjects received 120 HBO2 in blocks of 80 and 40 treatments with an interval five-month break. Normal controls underwent a single SPECT brain scan, HBO2, and repeat SPECT battery. TBI subjects were evaluated by neurologic, neuropsychometric, exercise testing, and pre and post study MRIs, or CT scans if MRI was contraindicated. Statistical Parametric Mapping was applied to SPECT scans for rCBF analysis. There were no significant objective changes in neurologic, neuropsychometric, exercise testing, MRIs, or rCBF. In this small pilot study, HBO2 did not effect clinical or regional cerebral blood flow improvement in TBI subjects.

  18. Reliability and error analysis on xenon/CT CBF

    International Nuclear Information System (INIS)

    Zhang, Z.

    2000-01-01

    This article provides a quantitative error analysis of a simulation model of xenon/CT CBF in order to investigate the behavior and effect of different types of errors such as CT noise, motion artifacts, lower percentage of xenon supply, lower tissue enhancements, etc. A mathematical model is built to simulate these errors. By adjusting the initial parameters of the simulation model, we can scale the Gaussian noise, control the percentage of xenon supply, and change the tissue enhancement with different kVp settings. The motion artifact will be treated separately by geometrically shifting the sequential CT images. The input function is chosen from an end-tidal xenon curve of a practical study. Four kinds of cerebral blood flow, 10, 20, 50, and 80 cc/100 g/min, are examined under different error environments and the corresponding CT images are generated following the currently popular timing protocol. The simulated studies will be fed to a regular xenon/CT CBF system for calculation and evaluation. A quantitative comparison is given to reveal the behavior and effect of individual error resources. Mixed error testing is also provided to inspect the combination effect of errors. The experiment shows that CT noise is still a major error resource. The motion artifact affects the CBF results more geometrically than quantitatively. Lower xenon supply has a lesser effect on the results, but will reduce the signal/noise ratio. The lower xenon enhancement will lower the flow values in all areas of brain. (author)

  19. The correlative analysis between CBF measured by SPECT and Chinese reading test in childhood reading disorder

    International Nuclear Information System (INIS)

    Wu Yonggang; Su Jianzhi; He Jianjun; Yang Zhiwei; Liu Guofeng

    2002-01-01

    Objective: To investigate changes of cerebral blood flow (CBF) and its association with Chinese reading skill diagnostic test (CRSDT) in childhood reading disorder (RD). Methods: In 25 RD children and 20 age-matched control subjects, the authors quantitatively determined CBF and regional cerebral blood flow (rCBF) with SPECT using the non-blood-withdrew method. The authors studied the correlation between the CBF and the total raw scores by CRSDT. Results: CBF in case group was (38.87 +- 3.77) ml·100 g -1 ·min -1 and was significantly lower than that in control group [43.65 +- 2.64) mL·100 g -1 ·min -1 (P < 0.01)]. These reduction in CBF correlated with the total raw scores by CRSDT. Conclusion: These results suggest the children with reading disorder have CBF reduction and SPECT is useful for evaluation of cerebral functioning in reading disorder children

  20. Head holder using negative pressure bag packed with plastic beads in xenon CT CBF study

    International Nuclear Information System (INIS)

    Araki, Yuzo; Sakai, Noboru

    2003-01-01

    Employing analysis of cerebral blood flow (CBF) confidence maps, we investigated the usefulness of a head holder using a negative pressure bag packed with plastic beads in a xenon CT CBF study. A total of 272 consecutive patients for the CBF study were enrolled and classified into 3 groups: 88 patients with a negative pressure bag (M group), 87 patients with an air pillow (A group), and 97 patients with a sponge pillow (S group). The degree of effect of head movements on the CBF measurement in each patient was expressed as a confidence value (mean of the confidence values at one CT slice). The mean of confidence value in the M group (0.461) was statistically lower than that in the A group (0.866) and that in the S group (1.043). These findings showed that the head holder described here was useful for obtaining CBF maps of high quality in a xenon CT CBF study. (author)

  1. Low Residual CBF Variability in Alzheimer's Disease after Correction for CO(2) Effect

    DEFF Research Database (Denmark)

    Rodell, Anders Bertil; Aanerud, Joel; Braendgaard, Hans

    2012-01-01

    We tested the claim that inter-individual CBF variability in Alzheimer's disease (AD) is substantially reduced after correction for arterial carbon dioxide tension (PaCO(2)). Specifically, we tested whether the variability of CBF in brain of patients with AD differed significantly from brain of age...... for the differences of CO(2) tension, the patients with AD lost the inter-individual CBF variability that continued to characterize the HC subjects. The difference (¿K(1)) between the blood-brain clearances (K(1)) of water (the current measure of CBF) and oxygen (the current measure of oxygen clearance) was reduced......-matched healthy control subjects (HC). To eliminate the CO(2)-induced variability, we developed a novel and generally applicable approach to the correction of CBF for changes of PaCO(2) and applied the method to positron emission tomographic (PET) measures of CBF in AD and HC groups of subjects. After correction...

  2. Regional cerebral blood flow (rCBF) changes in major depression

    International Nuclear Information System (INIS)

    Ohtaki, Junichi

    1992-01-01

    Regional cerebral blood flow (rCBF) in patients with major depression and in normal controls was measured by single photon emission computed tomography (SPECT) using N-isopropyl-p [ 123 I]-iodoamphetamine (IMP). The subjects were 22 patients with major depression and 14 normal controls. The rCBF was calculated by the ratio of activity per pixel in the cortical regions to activity per pixel in the cerebellum. IMP-SPECT was conducted in patients with major depression under the depressive and remitted states. rCBF values in the frontal, parietal, temporal, basal ganglia and the occipital regions, and the mean rCBF values were significantly lower in depressive patients than in the controls. Increased rCBF values were observed, and the mean rCBF became normal in the state of remittence. There was no significant difference in mean rCBF between depressive patients and the controls. Therefore, because the lower rCBF was normalized following improvement in expressive symptoms, the rCBF values could be useful as 'state dependent markers' in patients with major depression. (author)

  3. An ancient neurotrophin receptor code; a single Runx/Cbfβ complex determines somatosensory neuron fate specification in zebrafish.

    Science.gov (United States)

    Gau, Philia; Curtright, Andrew; Condon, Logan; Raible, David W; Dhaka, Ajay

    2017-07-01

    In terrestrial vertebrates such as birds and mammals, neurotrophin receptor expression is considered fundamental for the specification of distinct somatosensory neuron types where TrkA, TrkB and TrkC specify nociceptors, mechanoceptors and proprioceptors/mechanoceptors, respectively. In turn, Runx transcription factors promote neuronal fate specification by regulating neurotrophin receptor and sensory receptor expression where Runx1 mediates TrkA+ nociceptor diversification while Runx3 promotes a TrkC+ proprioceptive/mechanoceptive fate. Here, we report in zebrafish larvae that orthologs of the neurotrophin receptors in contrast to terrestrial vertebrates mark overlapping and distinct subsets of nociceptors suggesting that TrkA, TrkB and TrkC do not intrinsically promote nociceptor, mechanoceptor and proprioceptor/mechanoceptor neuronal fates, respectively. While we find that zebrafish Runx3 regulates nociceptors in contrast to terrestrial vertebrates, it shares a conserved regulatory mechanism found in terrestrial vertebrate proprioceptors/mechanoceptors in which it promotes TrkC expression and suppresses TrkB expression. We find that Cbfβ, which enhances Runx protein stability and affinity for DNA, serves as an obligate cofactor for Runx in neuronal fate determination. High levels of Runx can compensate for the loss of Cbfβ, indicating that in this context Cbfβ serves solely as a signal amplifier of Runx activity. Our data suggests an alteration/expansion of the neurotrophin receptor code of sensory neurons between larval teleost fish and terrestrial vertebrates, while the essential roles of Runx/Cbfβ in sensory neuron cell fate determination while also expanded are conserved.

  4. Exogenous application of molybdenum affects the expression of CBF14 and the development of frost tolerance in wheat.

    Science.gov (United States)

    Al-Issawi, Mohammed; Rihan, Hail Z; Woldie, Wondwossen Abate; Burchett, Stephen; Fuller, Michael P

    2013-02-01

    Wheat is able to cold acclimate in response to low temperatures and thereby increase its frost tolerance and the extent of this acclimation is greater in winter genotypes compared to spring genotypes. Such up-regulation of frost tolerance is controlled by Cbf transcription factors. Molybdenum (Mo) application has been shown to enhance frost tolerance of wheat and this study aimed to investigate the effect of Mo on the development of frost tolerance in winter and spring wheat. Results showed that Mo treatment increased the expression of Cbf14 in wheat under non-acclimating condition but did not alter frost tolerance. However, when Mo was applied in conjunction with exposure of plants to low temperature, Mo increased the expression of Cbf14 and enhanced frost tolerance in both spring and winter genotypes but the effect was more pronounced in the winter genotype. It was concluded that the application of Mo could be useful in situations where enhanced frost resistance is required. Further studies are proposed to elucidate the effect of exogenous of applications of Mo on frost resistance in spring and winter wheat at different growth stages. Crown Copyright © 2012. Published by Elsevier Masson SAS. All rights reserved.

  5. rCBF in radiation necrosis as measured by xenon-enhanced CT

    International Nuclear Information System (INIS)

    Nakamura, Osamu; Nomura, Kazuhiro; Segawa, Hiromu; Nakagomi, Tadayoshi; Tanaka, Hideki; Yoshimasu, Norio; Takakura, Kintomo.

    1986-01-01

    We experienced a case of radiation necrosis in which the necrosis occurred two and a half years after radiation therapy against craniopharyngioma. In this case, we evaluated the regional cerebral blood flow (rCBF) by means of the Xe-enhanced CT method and studied the change in rCBF in comparison with the rCBF pattern of brain tumors or cerebral infarctions. In general, rCBF decreased in accordance with the low-density area in a conventional CT scan. The decrease in rCBF was most significant in the white matter, but the rCBF in the thinned cortex was also lowered. On the contrary, that of the basal ganglia was almost completely preserved. The rCBF pattern was different from those of brain tumors or diffuse cerebral infarction caused by the occlusion of the main arteries and was thought to be characteristic of radiation necrosis. Differential diagnosis between radiation necrosis and the recurrence of brain tumor has been thought to be difficult, but with this rCBF analysis the possibility of differential diagnosis between the two lesions was clearly indicated. (author)

  6. Alpha-contingent EEG feedback reduces SPECT rCBF variability

    DEFF Research Database (Denmark)

    McLaughlin, Thomas; Steinberg, Bruce; Mulholland, Thomas

    2005-01-01

    EEG feedback methods, which link the occurrence of alpha to the presentation of repeated visual stimuli, reduce the relative variability of subsequent, alpha-blocking event durations. The temporal association between electro-cortical field activation and regional cerebral blood flow (rCBF) led us...... to investigate whether the reduced variability of alpha-blocking durations with feedback is associated with a reduction in rCBF variability. Reduced variability in the rCBF response domain under EEG feedback control might have methodological implications for future brain-imaging studies. Visual stimuli were...... to quantify the variance-reducing effects of ACS across multiple, distributed areas of the brain. Both EEG and rCBF measures demonstrated decreased variability under ACS. This improved control was seen for localized as well as anatomically distributed rCBF measures....

  7. Changes of rCBF on major depressed patients following TMS treatment: and SPM analysis

    International Nuclear Information System (INIS)

    Zheng, X.M.

    2000-01-01

    Full text: Changes of regional Cerebral Blood Flow (rCBF) on five drug-resistant depressed patients were examined by Single Photon Emission Computed Tomography (SPECT) with 99 Tc m - Hexamethylpropyleneamine Oxime ( 99 Tc m HMPAO) before and after Transcranial Magnetic Stimulation (TMS). The SPECT images were analysed by Statistical Parametric Mapping (SPM) package. TMS at the left Dorsolateral Prefrontal Cortex (DLPFC) of the depressed patients resulted in an increase of rCBF at a focal region in the vicinity of the stimulation site. No change was observed at any remote region. A 34.8% global CBF reduction for the depressed patients was found in their raw data. SPM analysis of the globally scaled images shows that there are increases of rCBF in the parietal region for the depressed patients. Global CBF scaling might contribute to these increases. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  8. The significance of CBF measurements for precise management of carotid stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawara, Jyoji; Kamiyama, Kenji; Usui, Reiko; Takeda, Rihei; Nakamura, Hirohiko [Nakamura Memorial Hospital, Sapporo (Japan)

    2002-12-01

    Severe hemodynamic cerebral ischemia associated with carotid stenosis could be one of the difining characteristics of the high-risk group for carotid endarterectomy (CEA). Measurements of cerebral blood flow (CBF) and vascular reactivity in patients treated with CEA were analyzed to clarify the significance of preoperative evaluation of hemodynamic cerebral ischemia using CBF-SPECT. Both the resting and acetazolamide-activated rCBF, and the severity of the hemodynamic cerebral ischemia (Stage 0-II) were quantified using the {sup 123}I-IMP autoradiography (ARG) method and preoperative cerebral hemodynamics were compared in both symptomatic patients (n=30) and asymptomatic patients (n=24). Postoperative improvement of resting rCBF was estimated in both groups. Stage II ischemia was quantitatively defined as both a resting rCBF of less than 80% of normal mean CBF and a vascular reserve (VR: (acetazolamide-activated rCBF/Resting rCBF-1) x 100%) of less than 10%. In the other 31 patients treated with CEA, postoperative hyperperfusion was investigated using CBF-SPECT within 24 hours after CEA. Preoperatively, Stage II ischemia (hemodynamically compromised state) was observed in 20% of symptomatic patients and 8% of asymptomatic patients. A significant difference in resting rCBF was indicated between symptomatic patients (31.8{+-}6.1 ml/100 g/min) and asymptomatic patients (37.6{+-}6.6 ml/100 g/min)(p<0.002, t-test). Severity of hemodynamic cerebral ischemia was generally moderate in symptomatic patients. Postoperatively, a significant increase of resting CBF was observed in symptomatic patients but not in asymptomatic patients. In the other 31 patients treated by CEA, symptomatic hyperperfusion was observed in 3 of 4 patients with Stage II ischemia and asymptomatic hyperperfusion was indicated in 3 of 4 patients with Stage I ischemia with a VR of less than 10%. Preoperative CBF measurements in patients treated with CEA were significant to define severe hemodynamic

  9. Resting state rCBF mapping with single-photon emission tomography and positron emission tomography: magnitude and origin of differences

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, C.; Kimiaei, S.; Larsson, S.A. [Section of Nuclear Medicine, Department of Hospital Physics, Karolinska Hospital and Department of Medical Radiation Physics, Stockholm University, Stockholm (Sweden); Pagani, M. [Institute of Experimental Medicine, CNR, Rome (Italy); Ingvar, M. [Section of Cognitive Neurophysiology, Karolinska Hospital, Stockholm (Sweden); Thurfjell, L. [Center of Image Analysis, Uppsala University, Uppsala (Sweden); Jacobsson, H. [Department of Diagnostic Radiology, Karolinska Hospital, Stockholm (Sweden)

    1998-02-01

    Single-photon emission tomography (SPET), using technetium-99m hexamethylpropylene amine oxime, and positron emission tomography (PET), using oxygen-15 butanol were compared in six healthy male volunteers with regard to the mapping of resting state regional cerebral blood flow (rCBF). A computerized brain atlas was utilized for 3D regional analyses and comparison of 64 selected and normalized volumes of interest (VOIs). The normalized mean rCBF values in SPET, as compared to PET, were higher in most of the Brodmann areas in the frontal and parietal lobes (4.8% and 8.7% respectively). The average differences were small in the temporal (2.3%) and occipital (1.1%) lobes. PET values were clearly higher in small VOIs like the thalamus (12.3%), hippocampus (12.3%) and basal ganglia (9.9%). A resolution phantom study showed that the in-plane SPET/PET system resolution was 11.0/7.5 mm. In conclusion, SPET and PET data demonstrated a fairly good agreement despite the superior spatial resolution of PET. The differences between SPET and PET rCBF are mainly due to physiological and physical factors, the data processing, normalization and co-registration methods. In order to further improve mapping of rCBF with SPET it is imperative not only to improve the spatial resolution but also to apply accurate correction techniques for scatter, attenuation and non-linear extraction. (orig.) With 6 figs., 3 tabs., 23 refs.

  10. Resting state rCBF mapping with single-photon emission tomography and positron emission tomography: magnitude and origin of differences

    International Nuclear Information System (INIS)

    Jonsson, C.; Kimiaei, S.; Larsson, S.A.; Pagani, M.; Ingvar, M.; Thurfjell, L.; Jacobsson, H.

    1998-01-01

    Single-photon emission tomography (SPET), using technetium-99m hexamethylpropylene amine oxime, and positron emission tomography (PET), using oxygen-15 butanol were compared in six healthy male volunteers with regard to the mapping of resting state regional cerebral blood flow (rCBF). A computerized brain atlas was utilized for 3D regional analyses and comparison of 64 selected and normalized volumes of interest (VOIs). The normalized mean rCBF values in SPET, as compared to PET, were higher in most of the Brodmann areas in the frontal and parietal lobes (4.8% and 8.7% respectively). The average differences were small in the temporal (2.3%) and occipital (1.1%) lobes. PET values were clearly higher in small VOIs like the thalamus (12.3%), hippocampus (12.3%) and basal ganglia (9.9%). A resolution phantom study showed that the in-plane SPET/PET system resolution was 11.0/7.5 mm. In conclusion, SPET and PET data demonstrated a fairly good agreement despite the superior spatial resolution of PET. The differences between SPET and PET rCBF are mainly due to physiological and physical factors, the data processing, normalization and co-registration methods. In order to further improve mapping of rCBF with SPET it is imperative not only to improve the spatial resolution but also to apply accurate correction techniques for scatter, attenuation and non-linear extraction. (orig.)

  11. Genome-Wide Analysis of the AP2/ERF Family in Eucalyptus grandis: An Intriguing Over-Representation of Stress-Responsive DREB1/CBF Genes

    Science.gov (United States)

    SanClemente, H.; Mounet, F.; Dunand, C.; Marque, G.; Marque, C.; Teulières, C.

    2015-01-01

    Background The AP2/ERF family includes a large number of developmentally and physiologically important transcription factors sharing an AP2 DNA-binding domain. Among them DREB1/CBF and DREB2 factors are known as master regulators respectively of cold and heat/osmotic stress responses. Experimental Approaches The manual annotation of AP2/ERF family from Eucalyptus grandis, Malus, Populus and Vitis genomes allowed a complete phylogenetic study for comparing the structure of this family in woody species and the model Arabidopsis thaliana. Expression profiles of the whole groups of EgrDREB1 and EgrDREB2 were investigated through RNAseq database survey and RT-qPCR analyses. Results The structure and the size of the AP2/ERF family show a global conservation for the plant species under comparison. In addition to an expansion of the ERF subfamily, the tree genomes mainly differ with respect to the group representation within the subfamilies. With regard to the E. grandis DREB subfamily, an obvious feature is the presence of 17 DREB1/CBF genes, the maximum reported to date for dicotyledons. In contrast, only six DREB2 have been identified, which is similar to the other plants species under study, except for Malus. All the DREB1/CBF and DREB2 genes from E. grandis are expressed in at least one condition and all are heat-responsive. Regulation by cold and drought depends on the genes but is not specific of one group; DREB1/CBF group is more cold-inducible than DREB2 which is mainly drought responsive. Conclusion These features suggest that the dramatic expansion of the DREB1/CBF group might be related to the adaptation of this evergreen tree to climate changes when it expanded in Australia. PMID:25849589

  12. Genome-wide analysis of the AP2/ERF family in Eucalyptus grandis: an intriguing over-representation of stress-responsive DREB1/CBF genes.

    Directory of Open Access Journals (Sweden)

    P B Cao

    Full Text Available The AP2/ERF family includes a large number of developmentally and physiologically important transcription factors sharing an AP2 DNA-binding domain. Among them DREB1/CBF and DREB2 factors are known as master regulators respectively of cold and heat/osmotic stress responses.The manual annotation of AP2/ERF family from Eucalyptus grandis, Malus, Populus and Vitis genomes allowed a complete phylogenetic study for comparing the structure of this family in woody species and the model Arabidopsis thaliana. Expression profiles of the whole groups of EgrDREB1 and EgrDREB2 were investigated through RNAseq database survey and RT-qPCR analyses.The structure and the size of the AP2/ERF family show a global conservation for the plant species under comparison. In addition to an expansion of the ERF subfamily, the tree genomes mainly differ with respect to the group representation within the subfamilies. With regard to the E. grandis DREB subfamily, an obvious feature is the presence of 17 DREB1/CBF genes, the maximum reported to date for dicotyledons. In contrast, only six DREB2 have been identified, which is similar to the other plants species under study, except for Malus. All the DREB1/CBF and DREB2 genes from E. grandis are expressed in at least one condition and all are heat-responsive. Regulation by cold and drought depends on the genes but is not specific of one group; DREB1/CBF group is more cold-inducible than DREB2 which is mainly drought responsive.These features suggest that the dramatic expansion of the DREB1/CBF group might be related to the adaptation of this evergreen tree to climate changes when it expanded in Australia.

  13. The carboxy-terminal domain of Dictyostelium C-module-binding factor is an independent gene regulatory entity.

    Directory of Open Access Journals (Sweden)

    Jörg Lucas

    Full Text Available The C-module-binding factor (CbfA is a multidomain protein that belongs to the family of jumonji-type (JmjC transcription regulators. In the social amoeba Dictyostelium discoideum, CbfA regulates gene expression during the unicellular growth phase and multicellular development. CbfA and a related D. discoideum CbfA-like protein, CbfB, share a paralogous domain arrangement that includes the JmjC domain, presumably a chromatin-remodeling activity, and two zinc finger-like (ZF motifs. On the other hand, the CbfA and CbfB proteins have completely different carboxy-terminal domains, suggesting that the plasticity of such domains may have contributed to the adaptation of the CbfA-like transcription factors to the rapid genome evolution in the dictyostelid clade. To support this hypothesis we performed DNA microarray and real-time RT-PCR measurements and found that CbfA regulates at least 160 genes during the vegetative growth of D. discoideum cells. Functional annotation of these genes revealed that CbfA predominantly controls the expression of gene products involved in housekeeping functions, such as carbohydrate, purine nucleoside/nucleotide, and amino acid metabolism. The CbfA protein displays two different mechanisms of gene regulation. The expression of one set of CbfA-dependent genes requires at least the JmjC/ZF domain of the CbfA protein and thus may depend on chromatin modulation. Regulation of the larger group of genes, however, does not depend on the entire CbfA protein and requires only the carboxy-terminal domain of CbfA (CbfA-CTD. An AT-hook motif located in CbfA-CTD, which is known to mediate DNA binding to A+T-rich sequences in vitro, contributed to CbfA-CTD-dependent gene regulatory functions in vivo.

  14. Stable xenon CT CBF measurements in prevalent cerebrovascular disorders (stroke)

    International Nuclear Information System (INIS)

    Meyer, J.S.; Okayasu, H.; Tachibana, H.; Okabe, T.

    1984-01-01

    Local cerebral blood flow (LCBF) and local tissue: blood partition coefficient (L lambda) values were measured for small volumes of gray or white matter by CT CBF. Single compartment analysis was used but fitted to infinity in normal volunteers aged between 20 to 100 years (N . 20). Hemispheric LCBF and L lambda values were compared to those of 61 age matched patients with transient ischemic attacks (TIAs, N . 10), reversible ischemic neurologic deficits (RINDS, N . 10), acute and chronic cerebral infarctions associated with emboli from atherosclerotic plaques or complete occlusion of internal carotid or middle cerebral arteries (n . 9) or of cardiac origin (N . 3), cerebral hemorrhage (N . 1), multi-infarct dementia (MID) (N . 11) and arteriovenous malformations (AVM) (N . 17). In normal aging, L lambda s were normal, but LCBF showed diffuse age-related declines. Symptomatic cerebrovascular disease was characterized by accentuation of age-related LCBF declines. TIAs with unilateral ICA occlusion showed bilateral reductions of LCBF more evident in ischemic hemispheres. TIAs due to fibrino-platelet emboli from ulcerated, non-occlusive ICA plaques were characterized by transient unilateral, localized LCBF reductions. All TIAs showed normal L lambda values. RINDS showed both LCBF and L lambda reductions. Larger embolic infarctions of ICA origin, whether acute or chronic, showed zones of zero flow with surrounding reductions of LCBF and L lambda values. Recent cerebral embolism of cardiac origin likewise exhibited zones of zero flow surrounded by reduced LCBF and L lambda values; but in chronic stages LCBF and L lambda values adjacent to zero flow zones were normal. MID was characterized by patchy reductions of LCBF and L lambda values throughout both hemispheres. Brain tissues surrounding AVM showed normal L lambda values but LCBF values were reduced due to steal

  15. Correlative study between a serial changes of rCBF and aphasia in hypertensive intracerebral hemorrhage

    International Nuclear Information System (INIS)

    Shi Yizhen; He Guangren

    1998-01-01

    Purpose: To explore the dynamic changes of rCBF of aphasic patients and its correlation with clinical findings. Methods: 32 dominant lateral hypertensive intracerebral hemorrhagic patients underwent the language function evaluation, rCBF tomographic imaging and CT scans. Semiquantitative analysis was used. Results: 1) 19 of 32 cases were aphasia while 13 were not. 2) There was a close correlation between aphasia and the size and location of hematoma. 3) There was only hemonrrhagic foci demonstrated with CT while multiple and extensive cortical hypo-perfused area were found in SPECT, especially in aphasic cases. Frontal and temporal lobes of each aphasia were involved 100%. 4) The rCBF ratio in both Broca's and Wernicke's areas of aphasias were lower than those of non-aphasias (t = 4.31, 5.52, P < 0.001). The degree of rCBF decrement in Wernicke's area varied with different aphasic types, among which the rCBF of sensory aphasia was the lowest (t 2.53, P<0.05). 5) 10 aphasias were followed with SPECT, CT and clinic evaluation 1 week, 1 month and 3 months after hemorrhage respectively. The rCBF ratios in cerebral cortex of 5 recovery cases increased gradually, but not in 5 not recovered cases. Conclusions: SPECT was superior to CT, it can provide useful information for diagnosing and staging aphasias, especially in early stage, and can also assess the prognosis of the disease

  16. The effect of education on rCBF changes in Alzheimer's disease: a longitudinal SPECT study

    International Nuclear Information System (INIS)

    Hanyu, Haruo; Sato, Tomohiko; Shimizu, Soichiro; Kanetaka, Hidekazu; Iwamoto, Toshihiko; Koizumi, Kiyoshi

    2008-01-01

    To determine the relationship of differing levels of education on regional cerebral blood flow (rCBF) in patients with Alzheimer's disease (AD). Fifty-three patients with AD followed-up for an average of 36 months were divided into the high-educated group (HE, ≥12 years of schooling) and low-educated group (LE, 123 I]-iodoamphetamine and the SPECT data were analyzed by 3D-stereotactic surface projections. At initial evaluation, the HE group had greater rCBF deficits in the parietotemporal regions than did the LE group, even though both groups had comparable MMSE and FAST scores. When compared with initial SPECT, follow-up SPECT showed a significant rCBF reduction in widespread regions, including the frontal, parietal, temporal, and limbic lobes of the HE group, while it a significant rCBF reduction in scattered and small regions of the parietotemporal, cingulate, and occipital areas of the LE group, as the HE group had faster cognitive and functional decline than the LE group. The HE group showed lower rCBF at initial SPECT than the LE group, suggesting more advanced AD pathology. As a result, the HE group demonstrated a more extensive and severe reduction of rCBF on follow-up SPECT in association with faster cognitive and functional decline than the LE group. Our SPECT study provides stronger support for the cognitive reserve effects of education in AD. (orig.)

  17. Regional cerebral blood flow (rCBF) measurement by 133Xe inhalation (Inhamatic 33rCBF measuring instrument)

    International Nuclear Information System (INIS)

    Kuroda, Kiyoshi; Onodera, Hideki; Endo, Hideo.

    1982-01-01

    The rCBF and its patterns obtained by 133 Xe inhalation on 20 healthy subjects were studied. In a group of subjects aged 25 years or less, the fast flow (F1) representing the mean cerebral blood flow (MCBF) was 97.1 +- 15.7 m1/100 g/min (abbreviated as m1) in the left hemisphere and 96.6 +- 16.8 m1 in the right; and the initial slope index (ISI), 65.8 +- 10.4 m1 for the left and 65.1 +- 10.7 m1 for the right. In a group of subjects aged 25 or more, F1 was 83.5 +- 10.1 m1 for the left and 84.8 +- 9.6 m1 for the right; and ISI, 55.7 +- 6.9 m1 for the left and 55.8 +- 6.7 m1 for the right. In both groups, F1 showed a hyperfrontal pattern in which F1 was higher than MCBF in the frontal region by about 10%, and ISI showed high values primarily in the sylvian fissure. With respect to the variation of F1 values from the 1st to 2nd measurements, MCBF was 7.6 +- 5.1% in the left hemisphere and 9.0 +- 4.7% in the right; and ISI, 14.6 +- 5.1% in the left and 14.4 +- 10.6% in the right. Thus, F1 values showed higher reproducibility. Depending on the difference in start fit time (SFT), both F1 and ISI values showed great changes, particularly so when SFT was close to the peak of the head curve. (Chiba, N.)

  18. Discrepant 99mTc-ECD images of CBF in patients with subacute cerebral infarction. A comparison of CBF, CMRO2 and 99mTc-HMPAO imaging

    International Nuclear Information System (INIS)

    Shishido, Fumio; Uemura, Kazuo; Inugami, Atsushi; Ogawa, Toshihide; Fujita, Hideaki; Shimosegawa, Eku; Nagata, Ken.

    1995-01-01

    Three patients with subacute ischemic cerebral infarction examined by SPECT with 99m Tc-ECD and PET within the same day showed signs of luxury perfusion in the subacute phase, which is between 9 to 20 days after the onset. A 99m Tc-HMPAO SPECT study was also performed within 2 days of the ECD-SPECT study. ECD-SPECT images of three patients displayed a focal decreased uptake in the infarcted lesions, while in infarcted foci, there was almost equivalent or increased CBF compared to normal and unaffected areas, decreased CMRO 2 , and high HMPAO uptake. The ECD-SPECT results were similar to those of CMRO 2 rather than CBF, though the HMPAO-SPECT image was similar to that of CBF. In one patient, HMPAO images revealed hyperfixation of the tracer. In the chronic phase and in the acute phase before 5 days after the onset, there were no discrepancies among the ECD-SPECT, CBF, HMPAO-SPECT, and CMRO 2 images. These observations indicated that 99m Tc-ECD is a good indicator of damaged brain tissues in subacute ischemic infarction. They also suggested that 99m Tc-ECD is a potential agent with which to evaluate cerebral tissue viability in some pathological states of cerebrovascular disease. The characteristics may be suitable for confirming the effects of thrombolytic therapy in acute ischemia, because these conditions often show signs of luxury perfusion when the therapy is successful. (author)

  19. Altered cerebral blood flow in chronic neck pain patients but not in whiplash patients: a 99mTc-HMPAO rCBF study

    OpenAIRE

    Sundström, Torbjörn; Guez, Michel; Hildingsson, Christer; Toolanen, Göran; Nyberg, Lars; Riklund, Katrine

    2006-01-01

    A cross-sectional study to investigate regional cerebral blood flow (rCBF) in patients with chronic whiplash syndrome and chronic neck pain patients without previous history of trauma along with a healthy control group. Chronic neck pain is a common disorder and a history of cervical spine injury including whiplash trauma constitute a risk factor for persistent neck pain. The aetiology of the late whiplash syndrome is unknown with no specific diagnostic criteria based on imaging, physiologica...

  20. Memory-provoked rCBF-SPECT as a diagnostic tool in Alzheimer's disease?

    International Nuclear Information System (INIS)

    Sundstroem, Torbjoern; Riklund, Katrine Aa.; Elgh, Eva; Naesman, Birgitta; Larsson, Anne; Nyberg, Lars

    2006-01-01

    Alzheimer's disease (AD) is a primary degenerative disease that progressively affects all brain functions, with devastating consequences for the patient, the patient's family and society. Rest regional cerebral blood flow (rCBF) could have a strategic role in differentiating between AD patients and normal controls, but its use for this purpose has a low discriminatory capacity. The purpose of this study was to evaluate whether the diagnostic sensitivity of rCBF single-photon emission computed tomography (SPECT) could be increased by using an episodic memory task provocation, i.e. memory-provoked rCBF-SPECT (MP-SPECT). Eighteen persons (73.2±4.8 years) with mild AD and 18 healthy elderly (69.4±3.9 years) were included in the study. The subjects were injected with 99m Tc-hexamethylpropylene amine oxime (HMPAO) during memory provocation with faces and names, followed by an rCBF-SPECT study. The rCBF 99m Tc-HMPAO SPECT images were analysed using statistical parametric mapping (SPM2). Peaks with a false discovery rate corrected value of 0.05 were considered significant. On MP-SPECT, the AD group showed a significant rCBF reduction in the left parietal cortex in comparison with healthy elderly. At rest, no significant group differences were seen. Memory provocation increased the sensitivity of rCBF-SPECT for the detection of AD-related blood flow changes in the brain at the group level. Further studies are needed to evaluate MP-SPECT as a diagnostic tool at the individual level. If a higher sensitivity for AD at the individual level is verified in future studies, a single MP-SPECT study might be sufficient in the clinical setting. (orig.)

  1. Priming within and across modalities: exploring the nature of rCBF increases and decreases.

    Science.gov (United States)

    Badgaiyan, R D; Schacter, D L; Alpert, N M

    2001-02-01

    Neuroimaging studies suggest that within-modality priming is associated with reduced regional cerebral blood flow (rCBF) in the extrastriate area, whereas cross-modality priming is associated with increased rCBF in prefrontal cortex. To characterize the nature of rCBF changes in within- and cross-modality priming, we conducted two neuroimaging experiments using positron emission tomography (PET). In experiment 1, rCBF changes in within-modality auditory priming on a word stem completion task were observed under same- and different-voice conditions. Both conditions were associated with decreased rCBF in extrastriate cortex. In the different-voice condition there were additional rCBF changes in the middle temporal gyrus and prefrontal cortex. Results suggest that the extrastriate involvement in within-modality priming is sensitive to a change in sensory modality of target stimuli between study and test, but not to a change in the feature of a stimulus within the same modality. In experiment 2, we studied cross-modality priming on a visual stem completion test after encoding under full- and divided-attention conditions. Increased rCBF in the anterior prefrontal cortex was observed in the full- but not in the divided-attention condition. Because explicit retrieval is compromised after encoding under the divided-attention condition, prefrontal involvement in cross-modality priming indicates recruitment of an aspect of explicit retrieval mechanism. The aspect of explicit retrieval that is most likely to be involved in cross-modality priming is the familiarity effect. Copyright 2001 Academic Press.

  2. Regional cerebral blood flow (rCBF) in psychiatry: Methodological issues

    International Nuclear Information System (INIS)

    Prohovnik, I.

    1984-01-01

    Traditionally, measurements of regional cerebral blood flow (rCBF) have been confined to neurology and nuclear medicine. Only one laboratory had concentrated on using this technique in psychiatric studies. Recently, however, rCBF has been increasingly used in psychiatry, and it seems appropriate at this time to examine the value and limitations of this method. The present article reviews selected methodological issues that may complicate the performance and interpretation of rCBF studies, with the aim of providing some means to evaluate published work and to plan further psychiatric research. In this paper, the term rCBF refers only to the two-dimensional, noninvasive methods that rely on inhalation or intravenous injection of xenon-133. The growing interest of rCBF to psychiatry stems mostly from the fact that this technique can indirectly map cerebral metabolism and, by interface, neural activity or information processing. Regional metabolism and blood flow are closely coupled to the human brain in the absence of gross pathology, and since psychiatric patients rarely present acute neurological abnormalities that might disrupt this coupling, one may infer regional metabolism from flow

  3. rCBF measurement by one-point venous sampling with the ARG method

    International Nuclear Information System (INIS)

    Yoshida, Nobuhiro; Okamoto, Toshiaki; Takahashi, Hidekado; Hattori, Teruo

    1997-01-01

    We investigated the possibility of using venous blood sampling instead of arterial blood sampling for the current method of ARG (autoradiography) used to determine regional cerebral blood flow (rCBF) on the basis of one session of arterial blood sampling and SPECT. For this purpose, the ratio of the arterial blood radioactivity count to the venous blood radioactivity count, the coefficient of variation, and the correlation and differences between arterial blood-based rCBF and venous blood-based rCBF were analyzed. The coefficient of variation was lowest (4.1%) 20 minutes after injection into the dorsum manus. When the relationship between venous and arterial blood counts was analyzed, arterial blood counts correlated well with venous blood counts collected at the dorsum manus 20 or 30 minutes after intravenous injection and with venous blood counts collected at the wrist 20 minutes after intravenous injection (r=0.97 or higher). The difference from rCBF determined on the basis of arterial blood was smallest (0.7) for rCBF determined on the basis of venous blood collected at the dorsum manus 20 minutes after intravenous injection. (author)

  4. A new collimator for measurement of rCBF by means of gamma camera

    International Nuclear Information System (INIS)

    Zechmann, W.; Oberladstaetter, M.; Raccabona, G.; Vogl, G.; Gerstenbrand, F.

    1982-01-01

    Atraumatic measurement of rCBF by means of gamma camera and conventional collimators requires high doses of 133 Xenon to obtain high count rates over the cerebral ROI's. The input of time-activity curve of breathing air by means of a probe measurement is not possible on line without difficulties. A new collimator, developed by ours, which is comparable with standard rCBF-Multiprobe systems, which allows high countrates and low dose of 133 Xenon is presented. A special air bypass enables to get the breathing curve with simple ROI technique. The collimator can easily be adapted to the camera by means of an insert adapter ring. With this collimator the rCBF measurement with conventional equipment of a nuclear medicine department is possible. (Author)

  5. Cerebral arteriovenous malformations. the relationship between clinical related events and rCBF SPECT imaging

    International Nuclear Information System (INIS)

    Sun Bo; Shi Xiangen

    1996-01-01

    To evaluate the relationship between clinical related events and rCBF SPECT imaging in patients with arteriovenous malformations (AVMs), the radioactive counting difference between normal and lesion site was divided by regional pixel considered as ischemic index (II). II was measured in 20 AVM cases and compared with patients' age, sex,neurological history and the size of lesions. The degree of rCBF reduction correlated with clinical neurological manifestation and showed no significant relationship with the age, sex and size of malformed vessels. II in patients with seizures was higher than that in patients with hemorrhage. The rCBF SPECT imaging may be useful for evaluation of the hemodynamics in AVMs

  6. Altered relationships between rCBF in different brain regions of never-treated schizophrenics

    International Nuclear Information System (INIS)

    Sabri, O.; Schreckenberger, M.; Cremerius, U.; Dickmann, C.; Schulz, G.; Zimny, M.; Buell, U.; Erkwoh, R.; Owega, A.; Sass, H.

    1997-01-01

    Aim of this study was to investigate the relations between regional cerebral blood flow (rCBF) of different brain regions in acute schizophrenia and following neuroleptic treatment. Methods: Twenty-two never-treated, acute schizophrenic patients were examined with HMPAO brain SPECT and assessed psychopathologically, and reexamined following neuroleptic treatment (over 96.8 days) and psychopathological remission. rCBF was determined by region/cerebellar count quotients obtained from 98 irregular regions of interest (ROIs), summed up to 11 ROIs on each hemisphere. In acute schizophrenics, interregional rCBF correlations of each ROI to every other ROI were compared to the interregional correlations following neuroleptic treatment and to those of controls. Results: All significant correlations of rCBF ratios of different brain regions were exclusively positive in controls and patients. In controls, all ROIs of one hemisphere except the mesial temporal ROI correlated significantly to its contralateral ROI. Each hemisphere showed significant frontal-temporal correlations, as well as cortical-subcortical and some cortico-limbic. In contrast, in acute schizophrenics nearly every ROI correlated significantly with every other ROI, without a grouping or relation of the rCBF of certain ROIs as in controls. After neuroleptic treatment and clinical improvement, this diffuse pattern of correlations remained. Conclusions: These results indicate differences in the neuronal interplay between regions in schizophrenic and healthy subjects. In nevertreated schizophrenics, diffuse interregional rCBF correlations can be seen as a sign of change and dysfunction of the systems regulating specificity and diversity of the neuronal functions. Neuroleptic therapy and psychopathologic remission showed no normalizing effect on interregional correlations. (orig.) [de

  7. The sensitivity of CT and rCBF-studies for the pathology of strokes

    International Nuclear Information System (INIS)

    Kohlmeyer, K.

    1980-01-01

    A localized pathology of the cerebral circulation or cerebral metabolism and the morphology of the brain tissue can be visualized by the use of new techniques in radiology and nuclear medicine: measurements of rCBF by radioactive diffusible isotopes, of the densitiy of the brain tissue, by CT, and of the cerebral metabolism regionally by positron-emission tomography. Having studied 475 stroke patients par rCBF measurements and 335 by CT we think it useful to compare the value of these two methods in revealing information on the pathology underlying focal disorders of brain functions due to stroke. (orig./VJ) [de

  8. Clinical advances of SPECT rCBF and interventional imaging applied in the diagnosis of dementias

    International Nuclear Information System (INIS)

    Zhang Kaijun

    2002-01-01

    Brain perfusion SPECT is a functional and noninvasive neuroimaging technique that allow the investigation of physiological and physiopathologic events in the human brain, including cerebral perfusion and function. Interventional rCBF imaging can also evaluate cerebrovascular reserve. In clinically, rCBF imaging play an important role in the diagnosis and differential diagnosis of dementias, especially vascular and Alzheimer's dementia. If etiology of some types of dementias is determined so that it can be early diagnosed, treated and taken prevention; the partial patients with dementia can get recovery or remission

  9. Positron tomography investigation in humans of the local coupling among CBF, oxygen consumption and glucose utilization

    Energy Technology Data Exchange (ETDEWEB)

    Baron, J C; Rougemont, D; Soussaline, F; Crouzel, C; Bousser, M G; Comar, D

    1983-06-01

    Positron tomography investigation of the local coupling among cerebral blood flow (CBF), oxygen consumption (CMRO/sub 2/) and glucose utilization (CMRGlc) was performed in 5 controls and 6 ischemic stroke patients, using oxygen 15 inhalation technique immediately followed by I.V. injection of /sup 18/F-Fluoro-Desoxyglucose (/sup 18/FDG). The normal couple among all 3 variables was demonstrated; but on the other hand significant disruption of either or both the CBF-CMRGlc and the CMRO/sub 2/-CMRGlc couples was found in all 6 stroke patients. Comments on these new findings were made.

  10. Redox Signaling and CBF-Responsive Pathway Are Involved in Salicylic Acid-Improved Photosynthesis and Growth under Chilling Stress in Watermelon

    Science.gov (United States)

    Cheng, Fei; Lu, Junyang; Gao, Min; Shi, Kai; Kong, Qiusheng; Huang, Yuan; Bie, Zhilong

    2016-01-01

    Salicylic acid (SA) plays an important role in plant response to abiotic stresses. This study investigated the potential role of SA in alleviating the adverse effects of chilling stress on photosynthesis and growth in watermelon (Citrullus lanatus). Chilling stress induced the simultaneous accumulation of free and conjugated SA in watermelon plants, and the chilling-induced SA production was attributed to the phenylalanine ammonia-lyase pathway. Applying SA at moderate concentrations induced chilling tolerance, whereas inhibition of SA biosynthesis by L-α-aminooxy-β-phenylpropionic acid (AOPP) increased the photooxidation of PS II under chilling stress in watermelon, resulting in reduced photosynthesis and growth. Chilling induced a transient increase in the ratios of reduced to oxidized glutathione and reduced ascorbate to dehydroascorbate. Then, the expression of antioxidant genes was upregulated, and the activities of antioxidant enzymes were enhanced. Furthermore, SA-induced chilling tolerance was associated with cellular glutathione and ascorbate homeostasis, which served as redox signals to regulate antioxidant metabolism under chilling stress. AOPP treatment stimulated the chilling-induced expression of cold-responsive genes, particularly via C-repeat binding factors CBF3 and CBF4. These results confirm the synergistic role of SA signaling and the CBF-dependent responsive pathway during chilling stress in watermelon. PMID:27777580

  11. Redox Signaling and CBF-Responsive Pathway are Involved in Salicylic Acid-Improved Photosynthesis and Growth under Chilling Stress in Watermelon

    Directory of Open Access Journals (Sweden)

    Fei Cheng

    2016-10-01

    Full Text Available Salicylic acid (SA plays an important role in plant response to abiotic stresses. This study investigated the potential role of SA in alleviating the adverse effects of chilling stress on photosynthesis and growth in watermelon (Citrullus lanatus. Chilling stress induced the simultaneous accumulation of free and conjugated SA in watermelon plants, and the chilling-induced SA production was attributed to the phenylalanine ammonia-lyase pathway. Applying SA at moderate concentrations induced chilling tolerance, whereas inhibition of SA biosynthesis by L-ɑ-aminooxy-β-phenylpropionic acid (AOPP increased the photooxidation of PS II under chilling stress in watermelon, resulting in reduced photosynthesis and growth. Chilling induced a transient increase in the ratios of reduced to oxidized glutathione and reduced ascorbate to dehydroascorbate. Then, the expression of antioxidant genes was upregulated, and the activities of antioxidant enzymes were enhanced. Furthermore, SA-induced chilling tolerance was associated with cellular glutathione and ascorbate homeostasis, which served as redox signals to regulate antioxidant metabolism under chilling stress. AOPP treatment stimulated the chilling-induced expression of cold-responsive genes, particularly via C-repeat binding factors CBF3 and CBF4. These results confirm the synergistic role of SA signaling and the CBF-dependent responsive pathway during chilling stress in watermelon.

  12. CBF and CMRo2 during craniotomy for small supratentorial cerebral tumours in enflurane anaesthesia. A dose-response study

    International Nuclear Information System (INIS)

    Madsen, J.B.; Cold, G.E.; Eriksen, H.O.; Eskesen, V.; Blatt-Lyon, B.

    1986-01-01

    In 14 patients with supratentorial cerebral tumours with midline shift ≤ 10 mm, cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRo 2 ) were measured twice on the contralateral side of the craniotomy, using a modification of the Kety and Schmidt method. For induction of anaesthesia, thiopental, fentanyl and pancuronium were used. The anaesthesia was maintained with enflurane 1% in nitrous oxide 67%. Moderate hypocapnia to a level averaging 4.3 kPa was achieved. The patients were divided into two groups. In group 1 (n=7), 1% enflurane was used throughout the anaesthesia, and CBF and CMRo 2 measured about 70 min after induction averaged 30.1 ml 100 g -1 min -1 and 1.98 ml O 2 100 g -1 min -1 , respectively. During the second CBF study 1 h later, CBF and CMRo 2 were unchanged (P>0.05). In group 2 (n=7), the inspiratory enflurane concentration was increased from 1 to 2% after the first CBF measurement. In this group a significant decrease in CMRo 2 was observed, while CBF was unchanged. In six patients EEG was recorded simultaneously with the CBF measurements. In patients subjected to increasing enflurane concentration (Group 2), a suppression in the EEG activity was observed without spike waves. It is concluded that enflurane induces a dose-related decrease in CMRo 2 and suppression in the EEG activity, whereas CBF was unchanged (author)

  13. rCBF activation studies and neuronal circuitry related to vision

    NARCIS (Netherlands)

    deJong, BM

    Three principles of neuronal interaction within cortically distributed networks are discussed PET-rCBF activation methods provide an opportunity to acquire insight in the distribution of functionally related areas of the human brain in vivo. The distinction of visual areas, activated by either

  14. Focal hyperemia followed by spreading oligemia and impaired activation of rCBF in classic migraine

    DEFF Research Database (Denmark)

    Olesen, J; Larsen, B; Lauritzen, M

    1981-01-01

    anteriorly in the course of 15 to 45 minutes. In 4 patients a global oligemia was observed. In 4 patients severe headache was present concomitantly with oligemia and with no sign of hyperemia or nonhomogeneous brain perfusion. The normal rCBF increase during cortical activity (hand movement, speech...

  15. CIR, a corepressor of CBF1, binds to PAP-1 and effects alternative splicing

    International Nuclear Information System (INIS)

    Maita, Hiroshi; Kitaura, Hirotake; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M.M.

    2005-01-01

    We have reported that PAP-1, a product of a causative gene for autosomal retinitis pigmentosa, plays a role in splicing. In this study, CIR, a protein originally identified as a CBF1-interacting protein and reported to act as a transcriptional corepressor, was identified as a PAP-1 binding protein and its function as a splicing factor was investigated. In addition to a basic lysine and acidic serine-rich (BA) domain and a zinc knuckle-like motif, CIR has an arginine/serine dipeptide repeat (RS) domain in its C terminal region. The RS domain has been reported to be present in the superfamily of SR proteins, which are involved in splicing reactions. We generated CIR mutants with deletions of each BA and RS domain and studied their subcellular localizations and interactions with PAP-1 and other SR proteins, including SC35, SF2/ASF, and U2AF 35 . CIR was found to interact with U2AF 35 through the BA domain, with SC35 and SF2/ASF through the RS domain, and with PAP-1 outside the BA domain in vivo and in vitro. CIR was found to be colocalized with SC35 and PAP-1 in nuclear speckles. Then the effect of CIR on splicing was investigated using the E1a minigene as a reporter in HeLa cells. Ectopic expression of CIR with the E1a minigene changed the ratio of spliced isoforms of E1a that were produced by alternative selection of 5'-splice sites. These results indicate that CIR is a member of the family of SR-related proteins and that CIR plays a role in splicing regulation

  16. The usefulness of CBF brain SPECT in forensic medicine: the civil law codes cases. A description of four cases

    International Nuclear Information System (INIS)

    Piskunowicz, M.; Lass, P.; Bandurski, T.; Krzyzanowski, M.

    2003-01-01

    The aim of this report was to assess the usefulness of cerebral blood flow (CBF) scanning utilising the SPECT technique in forensic medicine cases in the area of civil law cases. CBF SPECT scanning was performed in four patients utilising 99m Tc-ECD and a triple-head gammacamera. In the analysis both the asymmetry index and cerebellar normalisation were applied. Reference values were obtained by studying 30 healthy volunteers. In those cases CBF SPECT scanning played an important role in forensic argument. It influenced the sentence and the amount of financial compensation. CBF SPECT scanning may provide valuable information in forensic medicine argument in civil law cases, but only when taken together with psychometric tests and other neuroimaging methods (CT, MRI). The value of CBF SPECT scanning alone may be limited in judicial proceedings. (author)

  17. Acute effects of electroconvulsive therapy on regional cerebral blood flow (rCBF) in psychiatric disorders

    International Nuclear Information System (INIS)

    Prohovnik, I.; Alderson, P.O.; Sackheim, H.A.; Decina, P.; Kahn, D.

    1984-01-01

    Electroconvulsive therapy (ECT) is frequently used in the treatment of major depression and other psychiatric disorders; its mechanism of action is not established, but previous evidence suggests that it is associated with postictal metabolic suppression. The authors have used measurements of rCBF as an index of cortical metabolic activity to study the acute effects of ECT. Measurements of rCBF were made in 32 cortical regions in 10 patients (pts) following one minute breathing of Xe-133 (5mCi/L); the measurements were performed 30min before and 50min after ECT. Bilateral ECT was administered to six pts (five diagnosed as major depressives and one schizophrenic) and unilateral ECT to four (all diagnosed as unipolar or bipolar affective disorder). The total rCBF material consists of 52 measurements in these pts, made before and after 16 bilateral and 10 unilateral treatments. ECT was found to cause significant reduction of rCBF. Mean hemispheric flows (using the Initial Slope Index to measure grey-matter flow) were reduced by about 5% in both hemispheres following bilateral treatment. Unilateral treatment caused a 9% reduction of flow in the treated hemisphere, but only 2% contralaterally. Regional patterns of flow decreases also differed between the two treatment modes: bilateral frontal reductions were found after bilateral treatment, whereas unilateral ECT caused a widespread flow reduction in the treated hemisphere, and almost no effect contralaterally. These results suggest that rCBF studies are useful for assessing ECT, and indicate that the acute cerebral effects of ECT vary with the mode of treatment

  18. Memory functions and rCBF 99mTc-HMPAO SPET: developing diagnostics in Alzheimer's disease

    International Nuclear Information System (INIS)

    Elgh, Eva; Naesman, Birgitta; Sundstroem, Torbjoern; Aahlstroem, Katrine Riklund; Nyberg, Lars

    2002-01-01

    Alzheimer's disease (AD) is a primary degenerative disease of the brain. The prevalence increases with age, with devastating consequences for the individual and society. The aim of this study was to evaluate whether patients with early AD show an altered regional cerebral blood flow (rCBF) compared with control persons. Furthermore, we aimed to investigate the correlation between rCBF in sublobar volumes of the brain and performance on memory tests. Memory tests were chosen to evaluate episodic and semantic memory. Fourteen patients (aged 75.2±8.8 years) with early AD and 15 control persons (aged 71.4±3.2 years) were included. rCBF measurements with single-photon emission tomography (SPET) using technetium-99m hexamethylpropylene amine oxime (HMPAO) were performed. The rCBF 99m Tc-HMPAO SPET images were spatially transformed to fit a brain atlas and normalised for differences in rCBF (Computerised Brain Atlas software). Cortical and subcortical volumes of interest (VOIs) were analysed and compared. Compared with the controls, AD patients showed a significantly lower rCBF ratio in temporoparietal regions, including the left hippocampus. The diagnostic sensitivity and specificity for AD were high in temporoparietal regions. AD patients had significantly reduced performance on semantic and, in particular, episodic memory tests compared with age-matched normative data, and their performance on several episodic tests correlated with rCBF ratios in parietal and temporal regions, including the left hippocampus. The correlation between rCBF ratio and level of episodic memory performance suggests that abnormalities in rCBF pattern underlie impaired episodic memory functioning in AD. (orig.)

  19. Memory functions and rCBF-99mTc-HMPAO-SPECT: Developing diagnostics in Alzheimer's Disease

    International Nuclear Information System (INIS)

    Sundstroem, T.; Riklund Ahlstroem, K.; Elgh, E.; Naesman, B.; Nyberg, L.

    2002-01-01

    Alzheimer's disease (AD) is a primary degenerative disease of the brain. The prevalence increases with age with devastating consequences for the individual and for the society. The aim of this study was to evaluate if patients with early AD show an altered regional cerebral blood flow (rCBF) compared to control persons. The aim was furthermore to investigate the correlation between rCBF in sub-lobar volumes of the brain and performance on memory tests. Memory tests were chosen to evaluate episodic and semantic memory. Fourteen patients (75.2±8.8 yrs) with early AD, and 15 control persons (71.4±3.2 yrs) were included. rCBF measurements with single photon emission computerized tomography (SPECT) using 99m Tc-hexamethyl propylenamine oxime (HMPAO) were performed. The rCBF- 99m Tc-HMPAO-SPECT images were spatially transformed to fit a brain atlas and normalized for differences in rCBF (Computerized Brain Atlas software). Cortical and sub-cortical volumes of interests (VOI) were analyzed and compared. Compared to the controls, AD-patients showed a significantly lower rCBF ratio in temporoparietal regions including left hippocampus. The diagnostic sensitivity and specificity for AD were high in temporoparietal regions. AD-patients had significantly reduced performance on semantic and, in particular, episodic memory tests compared to age matched normative data, and their performance on several episodic tests correlated with rCBF ratios in parietal and temporal regions including left hippocampus. The correlation between rCBF ratio and level of episodic memory performance suggests that abnormalities in rCBF pattern underlie impaired episodic memory functioning in AD

  20. Determination of relative CMRO2 from CBF and BOLD changes: significant increase of oxygen consumption rate during visual stimulation

    DEFF Research Database (Denmark)

    Kim, S.G.; Rostrup, Egill; Larsson, H.B.

    1999-01-01

    signal changes were measured simultaneously using the flow-sensitive alternating inversion recovery (FAIR) technique. During hypercapnia established by an end-tidal CO2 increase of 1.46 kPa, CBF in the visual cortex increased by 47.3 +/- 17.3% (mean +/- SD; n = 9), and deltaR2* was -0.478 +/- 0.147 sec......The blood oxygenation level-dependent (BOLD) effect in functional magnetic resonance imaging depends on at least partial uncoupling between cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) changes. By measuring CBF and BOLD simultaneously, the relative change in CMRO2 can...

  1. Local CBF, oxygen extraction fraction (OEF) and CMRO/sub 2/: prognostic value in recent supratentorial infarction in humans

    Energy Technology Data Exchange (ETDEWEB)

    Baron, J C; Rougemont, D; Bousser, M G; Lebrun-Grandie, P; Iba-Zizen, M T; Chiras, J

    1983-06-01

    Cerebral blood flow (CBF) and oxygen consumption (CMRO/sub 2/) have been measured locally using positron emission tomography (PET) in 25 patients (34 studies) with recent cerebral infarction. The data analysis yielded threshold values for CBF and CMRO/sub 2/ that reliably separated the brain areas spontaneously evolving to necrosis from those maintaining integrity (as determined by C.T. Scanning) but still showing significant changes in CBF and/or CMRO/sub 2/. These results suggest the potential use of PET for estimation of tissue prognosis in recent cerebral infarction.

  2. Effect of memantine on CBF and CMRO2 in patients with early Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, P; Vafaee, M; Ostergaard, K

    2008-01-01

    Objectives –  Parkinson’s disease (PD) may be associated with increased energy metabolism in overactive regions of the basal ganglia. Therefore, we hypothesized that treatment with the N-methyl-d-aspartate receptor (NMDAR) antagonist memantine would decrease regional cerebral blood flow (rCBF) an...... ganglia oxygen consumption, our data suggest that treatment with memantine actively modulates neuronal activity and/or hemodynamic response in basal ganglia of PD patients. This finding may be relevant to the putative neuroprotective properties of NMDAR antagonists.......CBF) and oxygen metabolism in the basal ganglia of patients with early-stage PD. Methods –  Quantitative positron emission tomography (PET) recordings were obtained with [15O]water and [15O]oxygen in 10 patients, scanned first in a baseline condition, and again 6 weeks after treatment with a daily dose of 20 mg...

  3. Combination of dynamic and integral methods for generating reproducible functional CBF images

    International Nuclear Information System (INIS)

    Lammertsma, A.A.; Cunningham, V.J.; Deiber, M.P.; Heather, J.D.; Bloomfield, P.M.; Nutt, J.; Frackowiak, R.S.; Jones, T.

    1990-01-01

    A new method to measure regional CBF is presented, applying both dynamic and integral analyses to a dynamic sequence of positron emission tomographic scans collected during and following the administration of H2(15)O (inhalation of C15O2). The dynamic analysis is used to correct continuously monitored arterial whole-blood activity for delay and dispersion relative to tissue scans. An integral analysis including corrections for this delay and dispersion is then used to calculate CBF on a pixel-by-pixel basis. Normal values and reproducibility over a 2-h period are presented, together with the results of validation and simulation studies. The results indicate that the single-tissue compartment model adequately describes the distribution of H2(15)O in the brain, without recourse to postulating a nonexchanging water pool

  4. Cassava C-repeat binding factor 1 gene responds to low temperature and enhances cold tolerance when overexpressed in Arabidopsis and cassava.

    Science.gov (United States)

    An, Dong; Ma, Qiuxiang; Wang, Hongxia; Yang, Jun; Zhou, Wenzhi; Zhang, Peng

    2017-05-01

    Cassava MeCBF1 is a typical CBF transcription factor mediating cold responses but its low expression in apical buds along with a retarded response cause inefficient upregulation of downstream cold-related genes, rendering cassava chilling-sensitive. Low temperature is a major abiotic stress factor affecting survival, productivity and geographic distribution of important crops worldwide. The C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB) are important regulators of abiotic stress response in plants. In this study, MeCBF1, a CBF-like gene, was identified in the tropical root crop cassava (Manihot esculenta Crantz). The MeCBF1 encodes a protein that shares strong homology with DREB1As/CBFs from Arabidopsis as well as other species. The MeCBF1 was localized to the nucleus and is mainly expressed in stem and mature leaves, but not in apical buds or stem cambium. MeCBF1 expression was not only highly responsive to cold, but also significantly induced by salt, PEG and ABA treatment. Several stress-associated cis-elements were found in its promoter region, e.g., ABRE-related, MYC recognition sites, and MYB responsive element. Compared with AtCBF1, the MeCBF1 expression induced by cold in cassava was retarded and upregulated only after 4 h, which was also confirmed by its promoter activity. Overexpression of MeCBF1 in transgenic Arabidopsis and cassava plants conferred enhanced crytolerance. The CBF regulon was smaller and not entirely co-regulated with MeCBF1 expression in overexpressed cassava. The retarded MeCBF1 expression in response to cold and attenuated CBF-regulon might lead cassava to chilling sensitivity.

  5. Changes of rCBF 99mTc-HMPAO SPECT in a selected disorders

    International Nuclear Information System (INIS)

    Junik, R.

    2003-01-01

    With single photon emission computer tomography (SPECT) and HMPAO a noninvasive examination of regional cerebral blood flow can be performed (rCBF). The purpose of the SPECT examinations was to define the location and magnitude of blood flow disorder in selected diseases and the assessment of the results as complementary to morphological tests CT and MRI or functional tests, such as EEG. The examinations were carried out in 455 patients: 91 - patients with depression, 29 - congenital hypothyroidism, 66 - migraine, 34 - epilepsy, 6 - Landau-Kleffner syndrome, 20 - Alzheimer disease, 55 - with suspected Alzheimer disease, 105 - cerebral stroke, and 48 - transient cerebral ischemia. The control group comprised of 26 subjects. The SPECT method was used to perform examinations. The images were evaluated based on semiquantitative method. The asymmetry of activity and activity referred to the referential region were measured using symmetrical ROIs localized in hypoperfusion foci. The differences in perfusion in symmetric locations exceeding 10% were considered abnormal. During the depression stage, in patients with depression, a decrease of rCBF occurred. Regression of depression results in an increase of rCBF almost in the entire cerebrum. In patients with depression, SPECT examination is a useful method to monitor course of a disease and to objectively verify the results of treatment. 2. Disorders of rCBF, a decrease and/or asymmetry, occurred in patients with congenital hypothyroidism, migraine, and epilepsy. 3. There is a relation between patterns of cerebral perfusion in stroke, visible in SPECT image, and an extent and intensity of cerebral ischemia. (author)

  6. rCBF change in the brain of patients with major depressive disorder

    International Nuclear Information System (INIS)

    Sun Da; Xu Wei; Zhan Hongwei; Liu Hongbiao

    2010-01-01

    Purpose Major depressive disorder is a frequent emotional mood disorder. To evaluate the changes of brain blood flow in patients with depressive disorder and the correlation between rCBF and clinical feature is very important to diagnosis and treatment of this decease. Methods: Regional cerebral perfusion was investigated using SPECT in 75 patients with depressive disorders. The mean ages of the patients were 41.9 (17-74) Years old. The course of disease was different from several days to over 20 years. Results: 97.3 per cent of patients (73/75) had relative hypoperfusions in some cerebral regions. The patients had a significant decrease of rCBF in the frontal lobesbilaterally, and temporal lobes, basal ganglia, thalamus and parietal lobe. The course of disease and age of the patients had a negative correlation with the changes of rCBF. Conclusion: According to the results of our study, patients with depressive disorders had profound dysfunction of the frontal lobes bilaterally. The temporal cortices and basal ganglia were involved in most patients too. It is coincident with the results of other studies. The function of frontal lobes and temporal lobes is close relation close with affective action, attention, memory, thinking, abstraction, and other brain cognitive function. The clinical symptom of depressive disorder may be relevant with hypoperfusions of frontal lobes and temporal lobes. (authors)

  7. Focal hyperemia followed by spreading oligemia and impaired activation of rCBF in classic migraine

    International Nuclear Information System (INIS)

    Olesen, J.; Larsen, B.; Lauritzen, M.

    1981-01-01

    Regional cerebral blood flow (rCBF) was measured in 254 areas of a hemisphere with the xenon 133 intraarterial injection method. Six cases of classic migraine were followed from the normal state into the prodromal phase, and in 3 cases further into the headache phase. One patient with common migraine was similarly followed during his only classic attack. The attacks were initiated by focal hyperemia in 3 patients. During prodromes all patients displayed occipitoparietal rCBF reduction (oligemia), but in only 1 case did the reduction approach critical values. Oligemia gradually spread anteriorly in the course of 15 to 45 minutes. In 4 patients a global oligemia was observed. In 4 patients severe headache was present concomitantly with oligemia and with no sign of hyperemia or nonhomogeneous brain perfusion. The normal rCBF increase during cortical activity (hand movement, speech, and similar activities) was impaired in 6 patients. The results indicate that the vasospastic model of the migraine attack is too simplistic

  8. Usefulness of rCBF analysis in diagnosing Parkinson's disease. Supplemental role with MIBG myocardial scintigraphy

    International Nuclear Information System (INIS)

    Nagamachi, Shigeki; Wakamatsu, Hideyuki; Kiyohara, Shogo

    2008-01-01

    123 I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is a useful tool for differentiating idiopathic Parkinson's disease (PD) from parkinsonism (PS) caused by other disorders. However, cardiac MIBG uptake is affected by various causes. Alternatively, hypoperfusion in the occipital lobe of PD is reported recently. The objective is to clarify the correlation between regional cerebral blood flow (rCBF) alteration and cardiac MIBG uptake in PD. In addition, we examined whether additional brain perfusion analysis improved the differential diagnostic ability for PD from PS when compared with MIBG scintigraphy alone. Forty-nine patients with PD (27 mild groups: Hoehn and Yahr stages I, II; 22 severe groups: Hoehn and Yahr stages III, IV) and 28 patients with PS participated. We compared absolute rCBF values between PD and PS. In addition, we determined correlation between MIBG parameters and each rCBF value. Finally, we compared the diagnostic ability for the differentiation of PD from PS between two diagnostic criteria, each MIBG index abnormality alone [heart-to-mediastinum ratio, H/M (E) 40%] and each MIBG index abnormality or occipital lobe hypoperfusion ( 123 I-MIBG myocardial imaging can be recommended. (author)

  9. Cyclosporine A, FK506, and NIM811 ameliorate prolonged CBF reduction and impaired neurovascular coupling after cortical spreading depression

    DEFF Research Database (Denmark)

    Hansen, Henning Piilgaard; Witgen, Brent Marvin; Rasmussen, Peter

    2011-01-01

    Cortical spreading depression (CSD) is associated with mitochondrial depolarization, increasing intracellular Ca(2+), and the release of free fatty acids, which favor opening of the mitochondrial permeability transition pore (mPTP) and activation of calcineurin (CaN). Here, we test the hypothesis...... and the specific CaN blocker FK506. Cortical spreading depression was induced in rat frontal cortex. Electrocortical activity was recorded by glass microelectrodes, CBF by laser Doppler flowmetry, and tissue oxygen tension with polarographic microelectrodes. Electrocortical activity, basal CBF, CMRO(2......), and neurovascular and neurometabolic coupling were unaffected by all three drugs under control conditions. NIM811 augmented the rise in CBF observed during CSD. Cyclosporine A and FK506 ameliorated the persistent decrease in CBF after CSD. All three drugs prevented disruption of neurovascular coupling after CSD...

  10. Comparison of rCBF between patients with medial temporal lobe epilepsy and normal controls using H215O PET

    International Nuclear Information System (INIS)

    Kang, Eun Joo; Lee, Jae Sung; Nam, Hyun Woo; Lee, Sang Kun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul

    2002-01-01

    The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H 2 15 O-PET. 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Duirng the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Epilepsy induced changes were found not only in relative increase/ decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period

  11. The study of correlation between neurological function rehabilitation and dynamic change of rCBF in patients with aphasia

    International Nuclear Information System (INIS)

    Liu Haibo; Song Debiao; Kong Jun; Lv Junfeng; Tian Jing

    2004-01-01

    Objective: To evaluate the result of SPECT and CT in the patients with acute cerebral infarction and further more, to study the correlation between aphasia and dynamic change of regional cerebral blood flow (rCBF) in patients. Methods: Thirty cases with cerebral infarction of left basal ganglia were divided into two groups according to the presence or absence of aphasia; the vision and semi-ration analysis were used in photograph reading and region of interest (ROI) technology, respectively. Results: 1) Group A: there was a low rCBF in left basal ganglia, the dimension was larger than that in CT. There was also a low rCBF in frontal lobe and temporal lobe. Group B: there was only a low rCBF in left basal ganglia. 2) There were 6 cases with crossed cerebellar diaschisis (CCD) in the patients with aphasia. 3) The comparison about aphasia: the rCBF was higher in language center in the patients with improved language function than that in the patients without language function improvement and the difference between them was significant. Conclusions: The neurological function can be indirectly reflected through the study of the rCBF. At the same time, it may conduce to the locating of the damage in the central nervous system and to the differentiation diagnosis. It may also conduce to the programming of the therapeutic course and prognostication. (authors)

  12. The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes.

    Science.gov (United States)

    Hemsley, Piers A; Hurst, Charlotte H; Kaliyadasa, Ewon; Lamb, Rebecca; Knight, Marc R; De Cothi, Elizabeth A; Steele, John F; Knight, Heather

    2014-01-01

    The Mediator16 (MED16; formerly termed SENSITIVE TO FREEZING6 [SFR6]) subunit of the plant Mediator transcriptional coactivator complex regulates cold-responsive gene expression in Arabidopsis thaliana, acting downstream of the C-repeat binding factor (CBF) transcription factors to recruit the core Mediator complex to cold-regulated genes. Here, we use loss-of-function mutants to show that RNA polymerase II recruitment to CBF-responsive cold-regulated genes requires MED16, MED2, and MED14 subunits. Transcription of genes known to be regulated via CBFs binding to the C-repeat motif/drought-responsive element promoter motif requires all three Mediator subunits, as does cold acclimation-induced freezing tolerance. In addition, these three subunits are required for low temperature-induced expression of some other, but not all, cold-responsive genes, including genes that are not known targets of CBFs. Genes inducible by darkness also required MED16 but required a different combination of Mediator subunits for their expression than the genes induced by cold. Together, our data illustrate that plants control transcription of specific genes through the action of subsets of Mediator subunits; the specific combination defined by the nature of the stimulus but also by the identity of the gene induced.

  13. Memory-provoked rCBF-SPECT as a diagnostic tool in Alzheimer's disease?

    Energy Technology Data Exchange (ETDEWEB)

    Sundstroem, Torbjoern; Riklund, Katrine Aa. [Umeaa University, Umeaa University Hospital, Department of Radiation Sciences, Diagnostic Radiology, Umeaa (Sweden); Elgh, Eva; Naesman, Birgitta [Umeaa University, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeaa (Sweden); Larsson, Anne [Umeaa University, Department of Radiation Sciences, Radiation Physics, Umeaa (Sweden); Nyberg, Lars [Umeaa University, Department of Psychology, Umeaa (Sweden)

    2006-01-01

    Alzheimer's disease (AD) is a primary degenerative disease that progressively affects all brain functions, with devastating consequences for the patient, the patient's family and society. Rest regional cerebral blood flow (rCBF) could have a strategic role in differentiating between AD patients and normal controls, but its use for this purpose has a low discriminatory capacity. The purpose of this study was to evaluate whether the diagnostic sensitivity of rCBF single-photon emission computed tomography (SPECT) could be increased by using an episodic memory task provocation, i.e. memory-provoked rCBF-SPECT (MP-SPECT). Eighteen persons (73.2{+-}4.8 years) with mild AD and 18 healthy elderly (69.4{+-}3.9 years) were included in the study. The subjects were injected with{sup 99m}Tc-hexamethylpropylene amine oxime (HMPAO) during memory provocation with faces and names, followed by an rCBF-SPECT study. The rCBF{sup 99m}Tc-HMPAO SPECT images were analysed using statistical parametric mapping (SPM2). Peaks with a false discovery rate corrected value of 0.05 were considered significant. On MP-SPECT, the AD group showed a significant rCBF reduction in the left parietal cortex in comparison with healthy elderly. At rest, no significant group differences were seen. Memory provocation increased the sensitivity of rCBF-SPECT for the detection of AD-related blood flow changes in the brain at the group level. Further studies are needed to evaluate MP-SPECT as a diagnostic tool at the individual level. If a higher sensitivity for AD at the individual level is verified in future studies, a single MP-SPECT study might be sufficient in the clinical setting. (orig.)

  14. Corticotropin-releasing factor: effect on cerebral blood flow in physiologic and ischaemic conditions.

    Science.gov (United States)

    De Michele, Manuela; Touzani, Omar; Foster, Alan C; Fieschi, Cesare; Sette, Giuliano; McCulloch, James

    2005-09-01

    The expression of corticotrophin-releasing factor (CRF) receptors in cerebral arteries and arterioles suggests that CRF may modulate cerebral blood flow (CBF). In the present study, the effects of CRF, CRF-like peptides and the CRF broad spectrum antagonist DPhe-CRF on CBF have been investigated under normal physiologic conditions and in the margins of focal ischaemic insult. The experiments were carried out in anaesthetised and ventilated rats. Changes in CBF after subarachnoid microapplication of CRF and related peptides were assessed with a laser-Doppler flowmetry (LDF) probe. In the ischaemic animals, agents were injected approximately 60 minutes after permanent middle cerebral artery occlusion (MCAo). Microapplication of CRF and related peptides in normal rats into the subarachnoid space produced sustained concentration-dependent increases in CBF. This effect was attenuated by co-application with DPhe-CRF, which did not alter CBF itself. A second microapplication of CRF 30 min after the first failed to produce increases in CBF in normal animals. Microapplication of CRF in the subarachnoid space overlying the ischaemic cortex effected minor increases in CBF whereas D-Phe-CRF had no significant effect on CBF. Activation of the CRF peptidergic system increases CBF in the rat. Repeated activation of CRF receptors results in tachyphylaxis of the vasodilator response. CRF vasodilator response is still present after MCAo in the ischaemic penumbra, suggesting that the CRF peptidergic system may modulate CBF in ischaemic stroke.

  15. Clinical application of stable xenon CT-CBF studies without denitrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Touho, Hajime; Karasawa, Jun; Shishido, Hisashi; Yamada, Keisuke [Osaka Neurological Institute, Toyonaka (Japan)

    1990-08-01

    Noninvasive and simplified methods for estimating regional cerebral blood flow (CBF) and regional partition coefficient ({lambda}) using the inhalation of stable xenon (Xe{sup s}) and computed tomographic (CT) scanning are described. Thirty percent Xe{sup s} in 70% oxygen was inhaled for 240 seconds and exhaled for 160 seconds during serial CT scanning without denitrogenation in 26 patients with cerebrovascular diseases and four volunteer controls. During the investigation, the end-tidal Xe{sup s} concentration was continuously monitored with a thermoconductivity analyzer to determine the build-up range (A value) and build-up rate constant (K value) of the artery by the curve fitting method. Calculated A and K values were corrected by the following formulae reported previously: for patients aged 0-20 years, A{sub e} = 0.75A{sub a} + 2.15, K{sub e} = 0.67K{sub a} + 0.69; 21-40 years, A{sub e} = 0.56A{sub a} + 3.24, K{sub e} = 0.38K{sub a} + 1.12; 41-60 years, A{sub e} = 0.91A{sub a} + 1.95, K{sub e} = 0.38K{sub a} + 1.32; over 61 years, A{sub e} = 0.52A{sub a} + 3.81, K{sub e} = 0.31K{sub a} + 1.55 (A{sub e} and K{sub e} were calculated with end-tidal Xe{sup s} concentration, A{sub a} and K{sub a} were calculated by direct sampling of arterial blood). A CBF map (f map) and {lambda} map made with corrected A and K values demonstrated reliable distribution. The CBF was high in the gray matter, low in the white matter, and much lower in the infarcted area. {lambda} was high in the white matter, low in the gray matter, and much lower in the infarcted area. Eight patients were examined with and without denitrogenation. Both the f map and {lambda} map with denitrogenation were compatible with those without denitrogenation. Xe{sup s} CT-CBF studies without denitrogenation are useful in clinical neurosurgery and outpatients for estimating regional cerebral circulation. (author).

  16. Age-related changes in the rCBF in neonates

    International Nuclear Information System (INIS)

    Song Wenzhong; Chen Changhui; Chen Mingxi; Xie Hongjun; Zhou Aiqun

    2001-01-01

    Objective: To study the age-related changes of neonatal regional cerebral blood flow (rCBF) [gestation weeks (GW) and days after birth (DAB)]. Methods: Sixteen neonates who had the normal rCBF determined by 99 Tc m -ethylcysteinate dimer (ECD) SPECT imaging and the normal results in the neurological workup after long term clinical follow-up were divided into preterm neonate group (G1: male 3, female 2, GW 34.8 +- 1.2, DAB 7.2 +- 1.3), full-term younger neonate group (G2: male 3, female 2, GW 39.4 +- 1.4, DAB 4.0 +- 1.7) and full-term older neonate (G3: male 5, female 1, GW 40.0 +- 0.8, DAB 14.2 +- 1.9). The radioactivity uptake ratio of different gray matter regions to thalamic region were calculated by ROI. Results: The primary sensomotoric and occipital radioactivity uptake ratio of G1 (0.66 +- 0.08, 0.56 +- 0.10) were significantly lower compared with that of G2 (0.83 +- 0.10, 0.71 +- 0.08, P < 0.05) and G3 (0.94 +- 0.06, 0.79 +- 0.07, P < 0.01). The middle frontal and parietal radioactivity uptake ratio of G1 (0.50 +- 0.07, 0.56 +- 0.10) were significantly lower compared with G3 (0.60 +- 0.05, P < 0.05, 0.69 +- 0.05, P < 0.05). The rCBF of other gray matter regions tended to increase with GW and DAB. The most obvious difference of images between G1 and G2 was at the primary sensomotoric area. Conclusion: These results show that the difference of rCBF between different groups is clearly related to the neonatal age and sequence of neuro-development of the neonates

  17. Plasma Membrane CRPK1-Mediated Phosphorylation of 14-3-3 Proteins Induces Their Nuclear Import to Fine-Tune CBF Signaling during Cold Response.

    Science.gov (United States)

    Liu, Ziyan; Jia, Yuxin; Ding, Yanglin; Shi, Yiting; Li, Zhen; Guo, Yan; Gong, Zhizhong; Yang, Shuhua

    2017-04-06

    In plant cells, changes in fluidity of the plasma membrane may serve as the primary sensor of cold stress; however, the precise mechanism and how the cell transduces and fine-tunes cold signals remain elusive. Here we show that the cold-activated plasma membrane protein cold-responsive protein kinase 1 (CRPK1) phosphorylates 14-3-3 proteins. The phosphorylated 14-3-3 proteins shuttle from the cytosol to the nucleus, where they interact with and destabilize the key cold-responsive C-repeat-binding factor (CBF) proteins. Consistent with this, the crpk1 and 14-3-3κλ mutants show enhanced freezing tolerance, and transgenic plants overexpressing 14-3-3λ show reduced freezing tolerance. Further study shows that CRPK1 is essential for the nuclear translocation of 14-3-3 proteins and for 14-3-3 function in freezing tolerance. Thus, our study reveals that the CRPK1-14-3-3 module transduces the cold signal from the plasma membrane to the nucleus to modulate CBF stability, which ensures a faithfully adjusted response to cold stress of plants. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. A nonparametric mean-variance smoothing method to assess Arabidopsis cold stress transcriptional regulator CBF2 overexpression microarray data.

    Science.gov (United States)

    Hu, Pingsha; Maiti, Tapabrata

    2011-01-01

    Microarray is a powerful tool for genome-wide gene expression analysis. In microarray expression data, often mean and variance have certain relationships. We present a non-parametric mean-variance smoothing method (NPMVS) to analyze differentially expressed genes. In this method, a nonlinear smoothing curve is fitted to estimate the relationship between mean and variance. Inference is then made upon shrinkage estimation of posterior means assuming variances are known. Different methods have been applied to simulated datasets, in which a variety of mean and variance relationships were imposed. The simulation study showed that NPMVS outperformed the other two popular shrinkage estimation methods in some mean-variance relationships; and NPMVS was competitive with the two methods in other relationships. A real biological dataset, in which a cold stress transcription factor gene, CBF2, was overexpressed, has also been analyzed with the three methods. Gene ontology and cis-element analysis showed that NPMVS identified more cold and stress responsive genes than the other two methods did. The good performance of NPMVS is mainly due to its shrinkage estimation for both means and variances. In addition, NPMVS exploits a non-parametric regression between mean and variance, instead of assuming a specific parametric relationship between mean and variance. The source code written in R is available from the authors on request.

  19. Transcriptome Profiling Reveals the Negative Regulation of Multiple Plant Hormone Signaling Pathways Elicited by Overexpression of C-Repeat Binding Factors

    Directory of Open Access Journals (Sweden)

    Aixin Li

    2017-09-01

    Full Text Available C-repeat binding factors (CBF are a subfamily of AP2 transcription factors that play critical roles in the regulation of plant cold tolerance and growth in low temperature. In the present work, we sought to perform a detailed investigation into global transcriptional regulation of plant hormone signaling associated genes in transgenic plants engineered with CBF genes. RNA samples from Arabidopsis thaliana plants overexpressing two CBF genes, CBF2 and CBF3, were subjected to Illumina HiSeq 2000 RNA sequencing (RNA-Seq. Our results showed that more than half of the hormone associated genes that were differentially expressed in CBF2 or CBF3 transgenic plants were related to auxin signal transduction and metabolism. Most of these alterations in gene expression could lead to repression of auxin signaling. Accordingly, the IAA content was significantly decreased in young tissues of plants overexpressing CBF2 and CBF3 compared with wild type. In addition, genes associated with the biosynthesis of Jasmonate (JA and Salicylic acid (SA, as well as the signal sensing of Brassinolide (BR and SA, were down-regulated, while genes associated with Gibberellin (GA deactivation were up-regulated. In general, overexpression of CBF2 and CBF3 negatively affects multiple plant hormone signaling pathways in Arabidopsis. The transcriptome analysis using CBF2 and CBF3 transgenic plants provides novel and integrated insights into the interaction between CBFs and plant hormones, particularly the modulation of auxin signaling, which may contribute to the improvement of crop yields under abiotic stress via molecular engineering using CBF genes.

  20. An atypical R2R3 MYB transcription factor increases cold hardiness by CBF-dependent and CBF-independent pathways in apple

    NARCIS (Netherlands)

    Xie, Yinpeng; Chen, Pengxiang; Yan, Yan; Bao, Chana; Li, Xuewei; Wang, Liping; Shen, Xiaoxia; Li, Haiyan; Liu, Xiaofang; Niu, Chundong; Zhu, Chen; Fang, Nan; Shao, Yun; Zhao, Tao; Yu, Jiantao; Zhu, Jianhua; Xu, Lingfei; Nocker, van Steven; Ma, Fengwang; Guan, Qingmei

    2018-01-01

    Apple (Malus × domestica) trees are vulnerable to freezing temperatures. However, there has been only limited success in developing cold-hardy cultivars. This lack of progress is due at least partly to lack of understanding of the molecular mechanisms of freezing tolerance in apple. In this study,

  1. Statistical parametric mapping in the detection of rCBF changes in mild Alzheimer's disease

    International Nuclear Information System (INIS)

    Rowe, C.; Barnden, L.; Boundy, K.; McKinnon, J.; Liptak, M.

    1998-01-01

    Full text: Reduction in temporoparietal regional cerebral blood flow (rCBF) is proportional to the degree of cognitive deficit in patients with Alzheimer's Disease (AD). The characteristic pattern is readily apparent in advanced disease but is often subtle in early stage AD, reducing the clinical value of SPECT in the management of this condition. We have previously reported that Statistical Parametric Mapping (SPM95) revealed significant temporoparietal hypoperfusion when 10 patients with mild AD (classified by the Clinical Dementia Rating Scale) were compared to 10 age matched normals. We have now begun to evaluate the sensitivity and specificity of SPM95 in individuals with mild AD by comparison to our bank of 39 normals (30 female, 9 male, age range 26 to 74, mean age 52). Preliminary results reveal low sensitivity (<40%) when the standard reference region for normalization (i.e. global brain counts) is used. Better results are expected from normalizing to the cerebellum or basal ganglia and this is under investigation. An objective method to improve the accuracy of rCBF imaging for the diagnosis of early AD would be very useful in clinical practice. This study will demonstrate whether SPM can fulfill this role

  2. SPECT image analysis using SPM in patients with parkinson's disease and essential tremor : rCBF correlates of immediate surgical outcome following unilateral thalamo-pallidotomy in PD

    International Nuclear Information System (INIS)

    Kim, Jong Ho; Kim, Nam Bum; Lee, Uhn

    2002-01-01

    This study investigated alterations in regional cerebral blood flow (rCBF) in patients with PD and essential tremor (ET) using statistical parametric mapping (SPM) and rCBF correlates of immediate surgical outcome following unilateral thalamo-pallidotomy in patients with PD. Noninvasive rCBF measurements using 99m Tc-ethyl cysteinate dimer (ECD) SPECT were performed on 10 PD (60.5±8.7), 10 ET (55.5±17.7) patients and 10 healthy controls (56.2±12.0). Eight patients with PD following unilateral right thalamo-pallidotomy and five following unilateral left thalamo-pallidotomy underwent pre- and post-operative rCBF SPECT both one week before and after surgery. Acquisition were acquired within 30 min, 360 rotations with 90 projections were collected in a 128 x 128 matrix using a dual head gamma camera (Siemens, Multispect II). Data were analyzed using SPM 99. We found definite bilateral decreased rCBF in perfrontal cortex, bilateral increased rCBF in dentate nucleus of superomedial cerebellum in patients with PD and bilateral increased rCBF in lateral aspect of cerebellum in ET, respectively, compared with healthy controls. In addition, rCBF suspiciousely increased bilaterally in left dorsolateral frontal cortex in ET with equivocal clinical significance. Following 8 right and 5 left unilateral thalamo-pallidotomy in PD patients, immediate postop declines in ipsilateral fronto-temporal and temporal cortical perfusion, respectively, as well as pallidothalamic hypoperfusion were significant. SPM analysis showed that significantly decreased rCBF in bilateral perfrontal cortex and increased rCBF in dentate uncleus of superomedial cerebellum in PD and increased bilateral rCBF in lateral aspect of cerebellum in ET. Unilateral thalamo-pallidotomy in PD patients reduced the immediate post-operative rCBF declines in ipsilateral temporal (frontal) cortex as well as pallidothalamic hypoperfusion which is suggestive of thalamo-cortical diaschisis

  3. Imaging of the appearance time of cerebral blood using [15O]H2O PET for the computation of correct CBF.

    Science.gov (United States)

    Kudomi, Nobuyuki; Maeda, Yukito; Sasakawa, Yasuhiro; Monden, Toshihide; Yamamoto, Yuka; Kawai, Nobuyuki; Iida, Hidehiro; Nishiyama, Yoshihiro

    2013-05-23

    Quantification of cerebral blood flow (CBF) is important for the understanding of normal and pathologic brain physiology. Positron emission tomography (PET) with H215O (or C15O2) can quantify CBF and apply kinetic analyses, including autoradiography (ARG) and the basis function methods (BFM). These approaches, however, are sensitive to input function errors such as the appearance time of cerebral blood (ATB), known as the delay time. We estimated brain ATB in an image-based fashion to correct CBF by accounting for differences in computed CBF values using three different analyses: ARG and BFM with and without fixing the partition coefficient. Subject groups included those with no significant disorders, those with elevated cerebral blood volume, and those with reduced CBF. All subjects underwent PET examination, and CBF was estimated using the three analyses. The ATB was then computed from the differences of the obtained CBF values, and ATB-corrected CBF values were computed. ATB was also estimated for regions of interest (ROIs) of multiple cortical regions. The feasibility of the present method was tested in a simulation study. There were no significant differences in the obtained ATB between the image- and ROI-based methods. Significantly later appearance was found in the cerebellum compared to other brain regions for all groups. In cortical regions where CBF was reduced due to occlusive lesions, the ATB was 0.2 ± 1.2 s, which was significantly delayed relative to the contralateral regions. A simulation study showed that the ATB-corrected CBF was less sensitive to errors in input function, and noise on the tissue curve did not enhance the degree of noise on ATB-corrected CBF image. This study demonstrates the potential utility of visualizing the ATB in the brain, enabling the determination of CBF with less sensitivity to error in input function.

  4. A study of cerebral hemodynamics in various cerebrovascular disorders by means of rCBF measurement with single photon emission computed tomography

    International Nuclear Information System (INIS)

    Harano, Hideyuki

    1987-01-01

    Using single photon emission computed tomography (SPECT) with Xe-133 inhalation method, regional cerebral blood flow (rCBF) was measured for the purpose of analyzing the pathophysiology of various cerebrovascular disorders. Included in this series were 38 normal volunteers (N), 72 patients with ischemic cerebrovascular disease (ICD), 16 with subarachnoid hemorrhage (SAH), 9 with arteriovenous malformation (AVM), 6 with Moyamoya disease (MD), and 4 with hypertensive intracerebral hematoma (HIH). In the N group, rCBF was independent of sex and laterality. Increased rCBF was observed in the frontal region, as compared with other regions. A significantly increased rCBF was observed in the thirties decade of life; the difference in rCBF was, however, not statistically significant above the age of 30 years. In the ICD group, rCBF decreased in association with severer disorder. In cases of severe disorder, a significantly decreased rCBF was observed in the whole area, as compared with the control group. SPECT allowed early detection of decreased rCBF due to vaso-spasm in the SAH group. The groups of AVM, MD, and HIH showed decreased rCBF in the surrounding areas of the lesions. (Namekawa, K.)

  5. DREB1/CBF transcription factors: their structure, function and role in ...

    Indian Academy of Sciences (India)

    2012-12-10

    Dec 10, 2012 ... across the globe and reduce potential crop yields by as much .... conserved positions; dashes indicate gaps in the amino acid sequences introduced to optimize ..... maize, was reported to be involved in cold-responsive gene.

  6. In vivo detection of prion amyloid plaques using [{sup 11}C]BF-227 PET

    Energy Technology Data Exchange (ETDEWEB)

    Okamura, Nobuyuki; Yanai, Kazuhiko [Tohoku University School of Medicine, Department of Pharmacology, Sendai (Japan); Shiga, Yusei; Itoyama, Yasuhito [Tohoku University School of Medicine, Department of Neurology, Sendai (Japan); Furumoto, Shozo [Tohoku University School of Medicine, Department of Pharmacology, Sendai (Japan); Tohoku University, Division of Radiopharmaceutical Chemistry, Cyclotron and Radioisotope Center, Sendai (Japan); Tashiro, Manabu [Tohoku University, Division of Cyclotron Nuclear Medicine, Cyclotron and Radioisotope Center, Sendai (Japan); Tsuboi, Yoshio [Fukuoka University School of Medicine, Department of Neurology, Fukuoka (Japan); Furukawa, Katsutoshi; Arai, Hiroyuki [Institute of Development, Aging, and Cancer, Tohoku University, Department of Geriatrics and Gerontology, Division of Brain Sciences, Sendai (Japan); Iwata, Ren [Tohoku University, Division of Radiopharmaceutical Chemistry, Cyclotron and Radioisotope Center, Sendai (Japan); Kudo, Yukitsuka [Tohoku University, Innovation of New Biomedical Engineering Center, Sendai (Japan); Doh-ura, Katsumi [Tohoku University School of Medicine, Department of Prion Research, 2-1 Seiryo-machi, Aoba-ku, Sendai (Japan)

    2010-05-15

    In vivo detection of pathological prion protein (PrP) in the brain is potentially useful for the diagnosis of transmissible spongiform encephalopathies (TSEs). However, there are no non-invasive ante-mortem means for detection of pathological PrP deposition in the brain. The purpose of this study is to evaluate the amyloid imaging tracer BF-227 with positron emission tomography (PET) for the non-invasive detection of PrP amyloid in the brain. The binding ability of BF-227 to PrP amyloid was investigated using autoradiography and fluorescence microscopy. Five patients with TSEs, including three patients with Gerstmann-Straeussler-Scheinker disease (GSS) and two patients with sporadic Creutzfeldt-Jakob disease (CJD), underwent [{sup 11}C]BF-227 PET scans. Results were compared with data from 10 normal controls and 17 patients with Alzheimer's disease (AD). The regional to pons standardized uptake value ratio was calculated as an index of BF-227 retention. Binding of BF-227 to PrP plaques was confirmed using brain samples from autopsy-confirmed GSS cases. In clinical PET study, significantly higher retention of BF-227 was detected in the cerebellum, thalamus and lateral temporal cortex of GSS patients compared to that in the corresponding tissues of normal controls. GSS patients also showed higher retention of BF-227 in the cerebellum, thalamus and medial temporal cortex compared to AD patients. In contrast, the two CJD patients showed no obvious retention of BF-227 in the brain. Although [{sup 11}C]BF-227 is a non-specific imaging marker of cerebral amyloidosis, it is useful for in vivo detection of PrP plaques in the human brain in GSS, based on the regional distribution of the tracer. PET amyloid imaging might provide a means for both early diagnosis and non-invasive disease monitoring of certain forms of TSEs. (orig.)

  7. In vivo detection of prion amyloid plaques using [11C]BF-227 PET

    International Nuclear Information System (INIS)

    Okamura, Nobuyuki; Yanai, Kazuhiko; Shiga, Yusei; Itoyama, Yasuhito; Furumoto, Shozo; Tashiro, Manabu; Tsuboi, Yoshio; Furukawa, Katsutoshi; Arai, Hiroyuki; Iwata, Ren; Kudo, Yukitsuka; Doh-ura, Katsumi

    2010-01-01

    In vivo detection of pathological prion protein (PrP) in the brain is potentially useful for the diagnosis of transmissible spongiform encephalopathies (TSEs). However, there are no non-invasive ante-mortem means for detection of pathological PrP deposition in the brain. The purpose of this study is to evaluate the amyloid imaging tracer BF-227 with positron emission tomography (PET) for the non-invasive detection of PrP amyloid in the brain. The binding ability of BF-227 to PrP amyloid was investigated using autoradiography and fluorescence microscopy. Five patients with TSEs, including three patients with Gerstmann-Straeussler-Scheinker disease (GSS) and two patients with sporadic Creutzfeldt-Jakob disease (CJD), underwent [ 11 C]BF-227 PET scans. Results were compared with data from 10 normal controls and 17 patients with Alzheimer's disease (AD). The regional to pons standardized uptake value ratio was calculated as an index of BF-227 retention. Binding of BF-227 to PrP plaques was confirmed using brain samples from autopsy-confirmed GSS cases. In clinical PET study, significantly higher retention of BF-227 was detected in the cerebellum, thalamus and lateral temporal cortex of GSS patients compared to that in the corresponding tissues of normal controls. GSS patients also showed higher retention of BF-227 in the cerebellum, thalamus and medial temporal cortex compared to AD patients. In contrast, the two CJD patients showed no obvious retention of BF-227 in the brain. Although [ 11 C]BF-227 is a non-specific imaging marker of cerebral amyloidosis, it is useful for in vivo detection of PrP plaques in the human brain in GSS, based on the regional distribution of the tracer. PET amyloid imaging might provide a means for both early diagnosis and non-invasive disease monitoring of certain forms of TSEs. (orig.)

  8. Delayed reflow of an ischemic infarct after spontaneous thrombolysis studied by CBF tomography using SPECT and Tc-99m HMPAO

    DEFF Research Database (Denmark)

    Companioni, J M; Lassen, N A; Tfelt-Hansen, P

    1991-01-01

    A patient with a large ischemic infarct in the left middle cerebral artery territory was studied six times in the acute/subacute phase by cerebral blood flow (CBF) tomography using Tc-99m-HMPAO. The SPECT instrument used was a brain dedicated highly sensitive four-camera system (TOMOMATIC 232...

  9. Study on localization diagnosis with SPECT rCBF image in childhood epilepsy: in comparison with EEG and MRI findings

    International Nuclear Information System (INIS)

    Wu Meiqian; Tang Jihong; Wu Jinchang; Shi Yizhen

    1999-01-01

    Objective: To evaluate the diagnostic value of SPECT rCBF imaging in localization of childhood epileptic foci. Methods: rCBF imaging was performed in 74 epileptic patients not in seizure and 10 epileptic patients right in seizure. EEG was performed in 84, MRI in 67 of the subjects mentioned above. All the results of three modalities were compared with each other. Results: The highest positive rate (82.14%) was found in SPECT rCBF imaging, the positive rate in EEG or MRI was 71.43 or 47.76%. The epileptic foci localized by EEG (60 abnormalities) and by MRI (32 abnormalities) were 70.59% or 58.82% in concordance with those by SPECT, respectively. Conclusions: SPECT rCBF imaging is a sensitive and effective method for epileptic foci localization. It may have some advantages over EEG and MRI in detecting and localizing epileptic foci. However, abnormal SPECT areas may cover some abnormalities which do not belong to epileptic category. A combination of these three methods (SPECT, EEG and MRI) will improve the positive rate and accuracy for localizing

  10. Dose response from pharmacological interventions for CBF changes in a baboon model using 99Tcm-HMPAO and SPECT

    International Nuclear Information System (INIS)

    Dormehl, I.C.; Hugo, N.; Oliver, D.W.

    1993-01-01

    This study assesses the sensitivity of the baboon model under anaesthesia to determine by single photon emission computed tomography (SPECT) and 99 Tc m -hexamethylpropyleneamine oxime (HMPAO) dose responses from drugs (acetazolamide) with known regional cerebral blood flow (rCBF) effects on humans. Three dosages of acetazolamide were chosen: 250, 500 and 750 mg. The effects of these were studied by conventional SPECT 5 min after intravenous (i.v.) administration and compared to previous studies of rCBF with the baboons under anaesthesia only. An additional study concerned the effect of 500 mg acetazolamide at 15 min after administration. Haemodynamic parameters and blood gases were also monitored. No statistically significant regional effects were noted. The largest increase in CBF (39%) was observed from 500 mg acetazolamide after 5 min. This was statistically significantly different from control values only at a 10% level of confidence; then following a 27% increase above control values after 750 mg (5 min). At 15 min 500 mg yielded values lower by 10% than the high dose. No effects were observed from 250 mg acetazolamide; only pO 2 showed changes which largely confirm the CBF findings. The model did not give significant results at a 5% level of confidence but large fluctuations were observed, also in the haemodynamic and blood gas values. At a 10% level a significant dose response was confirmed for acetazolamide. (author)

  11. Cerebrovascular ETB, 5-HT1B, and AT1 receptor upregulation correlates with reduction in regional CBF after subarachnoid hemorrhage

    DEFF Research Database (Denmark)

    Ansar, Saema; Vikman, Petter; Nielsen, Marianne

    2007-01-01

    with the reduction in regional and global cerebral blood flow (CBF) after subarachnoid hemorrhage (SAH). SAH was induced by injecting 250 microl blood into the prechiasmatic cistern in rats. The cerebral arteries were removed 0, 1, 3, 6, 12, 24, and 48 h after the SAH for functional and molecular studies...

  12. Interictal rCBF SPECT, MRI and Surgical Outcome of Intractable Temporal Lobe Epilepsy

    International Nuclear Information System (INIS)

    Zeon, Seok Kil; Joo, Yang Goo; Lee, Sang Doe; Son, Eun Ik; Lee, Young Hwan

    1994-01-01

    Interictal single photon emission computed tomography of regional cerebral blood flow (rCBF SPECT) in 18 intractable temporal lobe epilepsy patients (8 male and 10 female patients: average 23.5 years old) were compared with 2.0 T magnetic resonance imaging (MRI). And surgical outcome was analysed with the findings, symptom duration and lateralization of temporal lobe. Preoperatively rCRF SPECT was done in all 18 patients with intravenous injection of 740 MRq 99 m T c-HMPAO. MRI was also done preoperatively in 13 patients. Surgical outcome was classified by Engel's outcome classification (four part classification recommended at the first Palm Desert conference). rCRF SPECT detected correctly lateralising abnormality of temporal lobe hypoperfusion in 13/ 18 (72.2%), contralateral temporal lobe hypoperfusion in 2/18 (11.1%) and showed no definite abnormality in 3/18 (16.7%). The positive predictive value of unilateral temporal lobe hypoperfusion was 87%. MRI detected correct localising abnormality in 8/13 (61.5%), such as hippocampal atrophy (7/13), asymmetric temporal horn (6/13), anterior temporal lobe atrophy (1/13), increased signal intensity from hippocampus (1/13) and calcific density (1/13), and no abnormal finding was noted in 5/13 (38.5%), There was no false positive findings and the positive predictive value of MRI was 100%, Only 2 cases showed same lateralization findings in rCBF SPECT and MRI. There was no significant correlation between symptom duration and no abnormal findings on SPECT or MRI. Surgical outcome showed class I in 15/18 (83.3%), and class II in 2/18 (11.1%). One case of no abnormal finding in both SPECT and MRI showed class III surgical outcome. No class IV surgical out.come was noted. Surgical outcome, lateralization of epileptic focus in temporal lobe and abnormal findings in rCBR SPECT or MRI were not significantly correlated.

  13. Hypersensitivity to thromboxane receptor mediated cerebral vasomotion and CBF oscillations during acute NO-deficiency in rats.

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    Béla Horváth

    Full Text Available BACKGROUND: Low frequency (4-12 cpm spontaneous fluctuations of the cerebrovascular tone (vasomotion and oscillations of the cerebral blood flow (CBF have been reported in diseases associated with endothelial dysfunction. Since endothelium-derived nitric oxide (NO suppresses constitutively the release and vascular effects of thromboxane A(2 (TXA(2, NO-deficiency is often associated with activation of thromboxane receptors (TP. In the present study we hypothesized that in the absence of NO, overactivation of the TP-receptor mediated cerebrovascular signaling pathway contributes to the development of vasomotion and CBF oscillations. METHODOLOGY/PRINCIPAL FINDINGS: Effects of pharmacological modulation of TP-receptor activation and its downstream signaling pathway have been investigated on CBF oscillations (measured by laser-Doppler flowmetry in anesthetized rats and vasomotion (measured by isometric tension recording in isolated rat middle cerebral arteries, MCAs both under physiological conditions and after acute inhibition of NO synthesis. Administration of the TP-receptor agonist U-46619 (1 µg/kg i.v. to control animals failed to induce any changes of the systemic or cerebral circulatory parameters. Inhibition of the NO synthesis by nitro-L-arginine methyl ester (L-NAME, 100 mg/kg i.v. resulted in increased mean arterial blood pressure and a decreased CBF accompanied by appearance of CBF-oscillations with a dominant frequency of 148±2 mHz. U-46619 significantly augmented the CBF-oscillations induced by L-NAME while inhibition of endogenous TXA(2 synthesis by ozagrel (10 mg/kg i.v. attenuated it. In isolated MCAs U-46619 in a concentration of 100 nM, which induced weak and stable contraction under physiological conditions, evoked sustained vasomotion in the absence of NO, which effect could be completely reversed by inhibition of Rho-kinase by 10 µM Y-27632. CONCLUSION/SIGNIFICANCE: These results suggest that hypersensitivity of the TP

  14. Memory functions and rCBF {sup 99m}Tc-HMPAO SPET: developing diagnostics in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Elgh, Eva; Naesman, Birgitta [Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeaa University, 901 85 Umeaa (Sweden); Sundstroem, Torbjoern; Aahlstroem, Katrine Riklund [Department of Radiation Sciences, Diagnostic Radiology, Umeaa University, Umeaa (Sweden); Nyberg, Lars [Department of Psychology, Umeaa University, Umeaa (Sweden)

    2002-09-01

    Alzheimer's disease (AD) is a primary degenerative disease of the brain. The prevalence increases with age, with devastating consequences for the individual and society. The aim of this study was to evaluate whether patients with early AD show an altered regional cerebral blood flow (rCBF) compared with control persons. Furthermore, we aimed to investigate the correlation between rCBF in sublobar volumes of the brain and performance on memory tests. Memory tests were chosen to evaluate episodic and semantic memory. Fourteen patients (aged 75.2{+-}8.8 years) with early AD and 15 control persons (aged 71.4{+-}3.2 years) were included. rCBF measurements with single-photon emission tomography (SPET) using technetium-99m hexamethylpropylene amine oxime (HMPAO) were performed. The rCBF {sup 99m}Tc-HMPAO SPET images were spatially transformed to fit a brain atlas and normalised for differences in rCBF (Computerised Brain Atlas software). Cortical and subcortical volumes of interest (VOIs) were analysed and compared. Compared with the controls, AD patients showed a significantly lower rCBF ratio in temporoparietal regions, including the left hippocampus. The diagnostic sensitivity and specificity for AD were high in temporoparietal regions. AD patients had significantly reduced performance on semantic and, in particular, episodic memory tests compared with age-matched normative data, and their performance on several episodic tests correlated with rCBF ratios in parietal and temporal regions, including the left hippocampus. The correlation between rCBF ratio and level of episodic memory performance suggests that abnormalities in rCBF pattern underlie impaired episodic memory functioning in AD. (orig.)

  15. Xenon contrast CT-CBF measurements in patients with pre- and post-correction of platelet hyper-aggregability, and in the white matter lesions

    International Nuclear Information System (INIS)

    Fujita, Shigekiyo

    2004-01-01

    About 10 years ago, the author found that, patients with headache, vertigo, dizziness and dementia, had a high prevalence (about 70%) of platelet hyper-aggregability which was especially prevalent (up to 100%) in Binswanger's dementia. Correction of the platelet hyper-aggregability in those patients led to remarkable improvement of symptoms. Based on this effective result with treatment of platelet hyper-aggregability, the author hypothesized that patients may show improvement or recovery of cerebral blood flow from the decreased blood flow by the correction of the platelet hyper-aggregability. The present report consist of two parts: 1) comparison of regional cerebral blood flow (CBF) before and after correction of platelet hyper-aggregability, 2) measurements of CBF in patients with severe white matter lesions, and the CBF within white matter lesions. The results of 1) showed CBF was decreased by about 20 to 30% before treatment and marked increase to normal CBF after correction of platelet hyper-aggregability, particularly in the thalamus and cortex. The increase was statistically significant except in bilateral frontal cortex and bilateral anterior white matter and left posterior white matter. From these results, it is confirmed that platelet hyper-aggregability is associated with decreased CBF, and after correction of platelet hyper-aggregability, CBF increases markedly. The results of 2) showed moderate to severe decreases of blood flow in all areas of the brain, and marked decreases of CBF in white matter lesions, 12.8±2.7 m1/100 g/min on average, which corresponded approximately to 60% of normal white matter CBF. (author)

  16. Effect of recirculation and regional counting rate on reliability of noninvasive bicompartmental CBF measurements

    International Nuclear Information System (INIS)

    Herholz, K.

    1985-01-01

    Based on data from routine intravenous Xe133-rCBF studies in 50 patients, using Obrist's algorithm the effect of counting rate statistics and amount of recirculating activity on reproducibility of results was investigated at five simulated counting rate levels. Dependence of the standard deviation of compartmental and noncompartmental flow parameters on recirculation and counting rate was determined by multiple linear regression analysis. Those regression equations permit determination of the optimum accuracy that may be expected from individual flow measurements. Mainly due to a delay of the start-of-fit time an exponential increase in standard deviation of flow measurements was observed as recirculation increased. At constant start-of-fit, however, a linear increase in standard deviation of compartmental flow parameters only was found, while noncompartmental results remained constant. Therefore, and in regard to other studies of potential sources of error, an upper limit of 2.5 min for the start-of-fit time and usage of noncompartmental flow parameters for measurements affected by high recirculation are suggested

  17. Brain regions involved in voluntary movements as revealed by radioisotopic mapping of CBF or CMR-glucose changes

    DEFF Research Database (Denmark)

    Lassen, N A; Ingvar, D H

    1990-01-01

    Mapping of cortical and subcortical grey matter active during voluntary movements by means of measurements of local increases of CBF or CMR-Glucose is reviewed. Most of the studies concern observations in man during hand movements using the intracarotid Xenon-133 injection technique, an approach...... that only allows to image the cortex of the hemisphere on one side (the injected side) of the brain. The results show that simple static or repetitive movements mainly activate the contralateral primary hand area (MI and SI); complex preprogrammed or spontaneous purposeful movements the supplementary motor...... area SMA on both sides increase in CBF/CMR-glucose and even internally ("mentally") going through the trained movements, causes such changes; complex purposeful movements also activate the premotor cortex, a response that is bilateral with greatest response contralaterally. Studies in patients...

  18. Interictal SPECT of rCBF is of clinical utility in the preoperative evaluation of patients with partial epilepsy

    DEFF Research Database (Denmark)

    Andersen, A R; Hansen, B A; Høgenhaven, H

    1996-01-01

    Fifty-eight patients with drug-resistant partial epilepsy were studied preoperatively by interictal rCBF measurements using 99mTc-HMPAO and a dedicated brain SPECT camera (Tomomatic 64). Follow-up of seizure outcome, using the "Engel score", was at least 3 years. The data were analyzed in a blinded...... set-up, first visually and subsequently quantitatively by an automatic regional analysis. By visual analysis 95% of the patients were considered abnormal in one part of the brain, of whom 27% were abnormal on CT, 45% on MRI and 98% on scalp EEG. Using a quantitative regional analysis subdividing each...... patients ictal SPECT of rCBF was additionally performed. In 2 cases it added further information to the patient evaluation....

  19. Interictal SPECT of rCBF is of clinical utility in the preoperative evaluation of patients with partial epilepsy

    DEFF Research Database (Denmark)

    Andersen, A.R.; Hansen, B.A.; Hogenhaven, H

    1996-01-01

    Fifty-eight patients with drug-resistant partial epilepsy were studied preoperatively by interictal rCBF measurements using 99mTc-HMPAO and a dedicated brain SPECT camera (Tomomatic 64). Follow-up of seizure outcome, using the 'Engel score', was at least 3 years. The data were analyzed in a blinded...... set-up, first visually and subsequently quantitatively by an automatic regional analysis. By visual analysis 95% of the patients were considered abnormal in one part of the brain, of whom 27% were abnormal on CT, 45% on MRI and 98% on scalp EEG. Using a quantitative regional analysis subdividing each...... patients ictal SPECT of rCBF was additionally performed. In 2 cases it added further information to the patient evaluation...

  20. Reduced CBF recovery detected by longitudinal 3D-SSP SPECT analyses predicts outcome of postoperative patients after subarachnoid haemorrhage.

    Science.gov (United States)

    Mutoh, Tatsushi; Totsune, Tomoko; Takenaka, Shunsuke; Tatewaki, Yasuko; Nakagawa, Manabu; Suarez, Jose I; Taki, Yasuyuki; Ishikawa, Tatsuya

    2018-02-01

    The aim of this study was to evaluate the impact of cerebral blood flow (CBF) recovery obtained from brain single-photon emission computed tomography (SPECT) images on postoperative outcome after aneurysmal subarachnoid haemorrhage (SAH). Twenty-nine patients who had undergone surgical clipping for ruptured anterior communicating artery aneurysms were analyzed prospectively. Routine measurements of CBF were performed using technetium-99 m hexamethyl propyleneamine oxine SPECT on days 4 and 14 after SAH. Regional voxel data analyzed by three dimensional stereotactic surface projection (3D-SSP) were compared between patients and age-matched normal database (NDB). In 3D-SSP analysis of all patients, cortical hypoperfusion around the surgical site in bilateral frontal lobes was evident on day 4 (P SSP SPECT image analyses can be a potential predictor of poor prognosis in postoperative patients after SAH. © 2017 John Wiley & Sons Australia, Ltd.

  1. Improvement in regional CBF by L-serine contributes to its neuroprotective effect in rats after focal cerebral ischemia.

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    Tao-Jie Ren

    Full Text Available To investigate the mechanisms underlying the neuroprotective effect of L-serine, permanent focal cerebral ischemia was induced by occlusion of the middle cerebral artery while monitoring cerebral blood flow (CBF. Rats were divided into control and L-serine-treated groups after middle cerebral artery occlusion. The neurological deficit score and brain infarct volume were assessed. Nissl staining was used to quantify the cortical injury. L-serine and D-serine levels in the ischemic cortex were analyzed with high performance liquid chromatography. We found that L-serine treatment: 1 reduced the neurological deficit score, infarct volume and cortical neuron loss in a dose-dependent manner; 2 improved CBF in the cortex, and this effect was inhibited in the presence of apamin plus charybdotoxin while the alleviation of both neurological deficit score and infarct volume was blocked; and 3 increased the amount of L-serine and D-serine in the cortex, and inhibition of the conversion of L-serine into D-serine by aminooxyacetic acid did not affect the reduction of neurological deficit score and infarct volume by L-serine. In conclusion, improvement in regional CBF by L-serine may contribute to its neuroprotective effect on the ischemic brain, potentially through vasodilation which is mediated by the small- and intermediate-conductance Ca(2+-activated K(+ channels on the cerebral blood vessel endothelium.

  2. Effects of exogenous salicylic acid on physiological traits and CBF gene expression in peach floral organs under freezing stress

    Directory of Open Access Journals (Sweden)

    Zhang Binbin

    2017-01-01

    Full Text Available To elucidate the effects of exogenous salicylic acid (SA treatment on the cold resistance of peach flower, the floral organs of two peach cultivars were treated with 20 mg/L SA and stored at 0°C for observation and sample collection. Water application was the control. After a treatment period, the anther relative water content of the control and SA-treated flowers decreased. The extent of the reduction was greater in the control, suggesting that the SA treatment significantly helped to maintain the anther water content of peach. Analysis of the stigma relative electric conductivity revealed that the SA treatment prevented membrane injury during the low temperature treatment. Additionally, we measured CBF gene expression at low temperature in the petal, stigma and ovary. The expression was markedly upregulated in the cold-treated floral organs. CBF gene expression after SA treatment was higher than in the control when cold conditions continued. These results suggest that the effects of SA on ameliorating the freezing injury to peach floral organs and on enhancing cold tolerance may be associated with the induction of CBF gene.

  3. Somatotype and body composition of referees and assistant referees from the CBF

    Directory of Open Access Journals (Sweden)

    Cassiano Ricardo Rech

    2008-04-01

    Full Text Available The aim of this study was to determine and compare the somatotype and body composition of principal soccer referees and assistant soccer referees from the state of Paraná in Brazil, all working for the Brazilian Soccer Confederation – (CBF Confederaçao Brasileira de Futebol. Twenty-five referees participated in this study: 12 principal referees (PR and 13 assistant referees (AR, all male. The variables body mass, height, skinfolds, body girth and bone diameters were collected with the aim of estimating the referees’ body composition and determining their somatotypes. Data are presented in the form of descriptive statistics. Comparisons between the PR and AR groups were made using Student’s t test for independent samples. The PR referees had a mean age of 38.5 + 5.1 years of age, body mass of 80.9 + 7.61 Kg, mean height of 179 + 3.3 cm and an average percentage of fat of 20.81 + 3.29%. The AR group were significantly younger on average (37.3 + 3.1 years old, p Resumo O objetivo do presente estudo foi determinar e comparar o somatotipo e a composição corporal de árbitros e árbitros assistentes de futebol do Estado do Paraná, Brasil, que atuam junto à Confederação Brasileira de Futebol (CBF. Participaram do estudo 25 árbitros, sendo 12 árbitros principais (AP e 13 árbitros assistentes (AA ambos do sexo masculino. As variáveis de massa corporal, estatura, espessura de dobras cutâneas, perímetros corporais e diâmetros ósseos foram coletados com a finalidade de estimar a composição corporal e determinar o somatotipo dos árbitros. Os dados são apresentados mediante estatística descritiva, a comparação entre os grupos de AP e AA foi realizada por meio do teste “t” de student para amostras independentes. Os AP apresentaram uma idade média de 38,5±5,1 anos, massa corporal de 80,9±7,61 kg, estatura 179±3,3 cm e um percentual de gordura médio de 20,81±3,29 %. O grupo de AA apresentou uma idade média menor (37,3±3

  4. Three-dimensional stereotactic surface projections of rCBF analysis on the forgetfulness of patients using Mini-Mental State Examination results

    International Nuclear Information System (INIS)

    Nakatsuka, Hiroki; Matsubara, Ichirou; Ohtani, Haruhiko

    2003-01-01

    The aim of this single photon emission computed tomography (SPECT) study was to determine the abnormality of the regional cerebral blood flow (rCBF), using a three-dimensional stereotactic surface projection (3D-SSP), in 18 patients referred to the hospital due to forgetfulness. An intergroup comparison, by 3D-SSP analysis, was conducted based on Mini-Mental State Examination (MMSE) results of the total score, time orientation, place orientation, recall, serial sevens and figure copy. In each abnormal group, rCBF was partially decreased in the temporo-parietal cortex, medial temporal structure and posterior cingulate gyrus; these areas with decreased rCBF are similar to the pattern found in Alzheimer's disease. In the abnormal group, at the time of orientation and figure copy, rCBF was decreased in the right parieto-occipital area. (author)

  5. Regional cerebral blood flow (rCBF) measurement using D.S.P.E.C.T. and xenon inhalation: first results in distal encephalic juvenile ischemia

    International Nuclear Information System (INIS)

    Steinling, M.; Guerouaou, D.; Dubois, P.; Bouchez, P.; Arnott, G.; Vergnes, R.

    1984-01-01

    Xenon inhalation and D.S.P.E.C.T. were used for rCBF measurement in 16 patients with distal encephalic juvenile ischemia. 8 patients immediately had a second study, 15 minutes after IV injection of 500 mg acetazolamide. Results show that rCBF was abnormal in 13 patients, including some who had only minor clinical symptoms. rCBF measurement complemented neuroradiological data in 12 of 16 cases and proved more informative in 7 cases. Our most striking finding is perhaps that no patient responded normally to acetazolamide injection: three failed to respond and five showed complex (heterogeneous responses). Follow up of these patients will perhaps provide information as to the prognostic value of rCBF and acetazolamide reactivity measurements [fr

  6. Acute rCBF changes in depressed patients receiving repetitive transcranial magnetic stimulation (rTMS)

    International Nuclear Information System (INIS)

    Haindl, W.; Loo, C.; Mitchell, P.; Sachdev, P.; Zheng, X.; Som, S.; Walker, B.

    1999-01-01

    Full text: Electroconvulsant therapy (ECT) is very effective in treatment resistant severe depression with response rates of 70-90%. However, ECT has major limitations including the need for anaesthesia, memory difficulties and public apprehension about its use. Transcranial magnetic stimulation (rTMS) has been used as a diagnostic technique in neurology with recent reports of potential benefit in depressed patients. In this study, 5 patients (3 females, 2 males aged 36-66 years, mean 48.6 years) with major depression underwent SPET brain scanning using a Picker 3000 triple-headed camera. Each patient had a baseline rCBF scan with 500 MBq of 99 Tc m HMPAO injected intravenously during sham rTMS. On the following day, each patient received another 500 MBq of 99 Tc m HMPAo during rTMS to the left dorsolateral prefrontal cortex using a Magstim Super Rapid magnetic stimulator with a 70-mm figure eight coil. The stimulator parameters were 15 Hz, 90% of resting motor threshold, 1 s on 3 s off for 30 trains prior to injection and 15-30 trains following injection. Each patient continued to receive their usual medication during this period. The reconstructed SPET data sets were normalized to the global mean, registered to the Talairach template and analysed using statistical parametric mapping (SPM). Compared with the baseline group, the rTMS group showed a significant perfusion increase in the pre-frontal cortices, especially on the left, and also in the anterior left temporal lobe (P < 0.05). Frontal lobe perfusion reduction is a common finding in depression. This study demonstrates the ability of rTMS to acutely increase frontal lobe perfusion, and therefore a possible mechanism for its therapeutic use as an adjunct to pharmacological therapy or as an alternative to ECT in depression

  7. Metabolism of choline in brain of the aged CBF-1 mouse

    International Nuclear Information System (INIS)

    Saito, M.; Kindel, G.; Karczmar, A.G.; Rosenberg, A.

    1986-01-01

    In order to quantify the changes that occur in the cholinergic central nervous system with aging, we have compared acetylcholine (Ach) formation in brain cortex slice preparations from 2-year-old aged CBF-1 mouse brains and compared the findings with those in 2-4-month-old young adult mouse brain slices. Incorporation of exogenous radioactively labelled choline (31 nM [ 3 H] choline) into acetyl choline in incubated brain slices was linear with time for 90 min. Percentage of total choline label distributed into Ach remained constant from 5 min after starting the incubation to 90 min. In contrast, distribution of label into intracellular free choline (Ch) and phosphorylcholine (Pch) changed continuously over this period suggesting that the Ch pool for Ach synthesis in brain cortex is different from that for Pch synthesis. Incorporation of radioactivity into Ach was not influenced by administration of 10 microM eserine, showing that the increment of radioactivity in Ach reflects rate of Ach formation, independently from degradation by acetylcholine esterases. Under our experimental conditions, slices from cortices of aged 24-month-old mouse brain showed a significantly greater (27%) incorporation of radioactivity into intracellular Ach than those from young, 2-4-month-old, brain cortices. Inhibitors of Ach release, 1 mM ATP or GABA, had no effect. Since concentration of radioactive precursor in the incubation medium was very low (31 nM), the Ch pool for Ach synthesis in slices was labelled without measurably changing the size of the endogenous pool. These data suggest a compensatory acceleration of Ach synthesis or else a smaller precursor pool specific for Ach synthesis into which labelled Ch migrated in aged brain

  8. Vascular risk factors, atherosclerosis, cerebral white matter lesions and cerebral perfusion in a population-based study

    International Nuclear Information System (INIS)

    Claus, J.J.; Breteler, M.M.B.; Hasan, D.; Krenning, E.P.; Bots, M.L.; Grobbee, D.E.; Swieten, J.C. van; Harskamp, F. van; Hofman, A.

    1996-01-01

    We studied risk factors for cerebral vascular disease (blood pressure and hypertension, factor VIIc, factor VIIIc, fibrinogen), indicators of atherosclerosis (intima-media thickness and plaques in the carotid artery) and cerebral white matter lesions in relation to regional cerebral blood flow (rCBF) in 60 persons (aged 65-85 years) recruited from a population-based study. rCBF was assessed with single-photon emission tomography using technetium-99m d,l-hexamethylpropylene amine oxime ( 99m Tc-HMPAO). Statistical analysis was performed with multiple linear regression with adjustment for age, sex and ventricle-to-brain ratio. A significant positive association was found between systolic and diastolic blood pressure and temporo-parietal rCBF. In analysis with quartiles of the distribution, we found a threshold effect for the relation of low diastolic blood pressure (≤60 mmHg) and low temporo-parietal rCBF. Levels of plasma fibrinogen were inversely related to parietal rCBF, with a threshold effect of high fibrinogen levels (>3.2 g/l) and low rCBF. Increased atherosclerosis was related to low rCBF in all cortical regions, but these associations were not significant. No consistent relation was observed between severity of cerebral white matter lesions and rCBF. Our results may have implications for blood pressure control in the elderly population. (orig.)

  9. CBF and CMRo/sub 2/ during craniotomy for small supratentorial cerebral tumours in enflurane anaesthesia. A dose-response study

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, J.B.; Cold, G.E.; Eriksen, H.O.; Eskesen, V.; Blatt-Lyon, B.

    1986-01-01

    In 14 patients with supratentorial cerebral tumors with midline shift less than or equal to 10 mm, cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRo/sub 2/) were measured twice on the contralateral side of the craniotomy, using a modification of the Kety and Schmidt method. For induction of anaesthesia, thiopental, fentanyl and pancuronium were used. The anaesthesia was maintained with enflurane 1% in nitrous oxide 67%. Moderate hypocapnia to a level averaging 4.3 kPa was achieved. The patients were divided into two groups. In group 1 (n=7), 1% enflurane was used throughout the anaesthesia, and CBF and CMRo/sub 2/ measured about 70 min after induction averaged 30.1 ml 100 g/sup -1/ min/sub -1/ and 1.98 ml O/sub 2/ 100 g/sup -1/ min/sup -1/, respectively. During the second CBF study 1 h later, CBF and CMRo/sub 2/ were unchanged (P>0.05). In group 2 (n=7), the inspiratory enflurane concentration was increased from 1 to 2% after the first CBF measurement. In this group a significant decrease in CMRo/sub 2/ was observed, while CBF was unchanged. In six patients EEG was recorded simultaneously with the CBF measurements. In patients subjected to increasing enflurane concentration (Group 2), a suppression in the EEG activity was observed without spike waves. It is concluded that enflurane induces a dose-related decrease in CMRo/sub 2/ and suppression in the EEG activity, whereas CBF was unchanged.

  10. Comparison of rCBF between patients with medial temporal lobe epilepsy and normal controls using H{sub 2}{sup 15}O PET

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Eun Joo; Lee, Jae Sung; Nam, Hyun Woo; Lee, Sang Kun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2002-06-01

    The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H{sub 2}{sup 15}O-PET. 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Duirng the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Epilepsy induced changes were found not only in relative increase/ decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period.

  11. Cell- and stage-specific chromatin structure across the Complement receptor 2 (CR2/CD21) promoter coincide with CBF1 and C/EBP-beta binding in B cells.

    Science.gov (United States)

    Cruickshank, Mark N; Fenwick, Emily; Karimi, Mahdad; Abraham, Lawrence J; Ulgiati, Daniela

    2009-08-01

    Stringent developmental transcription requires multiple transcription factor (TF) binding sites, cell-specific expression of signaling molecules, TFs and co-regulators and appropriate chromatin structure. During B-lymphopoiesis, human Complement receptor 2 (CR2/CD21) is detected on immature and mature B cells but not on B cell precursors and plasma cells. We examined cell- and stage-specific human CR2 gene regulation using cell lines modeling B-lymphopoiesis. Chromatin accessibility assays revealed a region between -409 and -262 with enhanced accessibility in mature B cells and pre-B cells, compared to either non-lymphoid or plasma cell-types, however, accessibility near the transcription start site (TSS) was elevated only in CR2-expressing B cells. A correlation between histone acetylation and CR2 expression was observed, while histone H3K4 dimethylation was enriched near the TSS in both CR2-expressing B cells and non-expressing pre-B cells. Candidate sites within the CR2 promoter were identified which could regulate chromatin, including a matrix attachment region associated with CDP, SATB1/BRIGHT and CEBP-beta sites as well as two CBF1 sites. ChIP assays verified that both CBF1 and C/EBP-beta bind the CR2 promoter in B cells raising the possibility that these factors facilitate or respond to alterations in chromatin structure to control the timing and/or level of CR2 transcription.

  12. The Arabidopsis Mediator Complex Subunits MED16, MED14, and MED2 Regulate Mediator and RNA Polymerase II Recruitment to CBF-Responsive Cold-Regulated Genes[C][W][OPEN

    Science.gov (United States)

    Hemsley, Piers A.; Hurst, Charlotte H.; Kaliyadasa, Ewon; Lamb, Rebecca; Knight, Marc R.; De Cothi, Elizabeth A.; Steele, John F.; Knight, Heather

    2014-01-01

    The Mediator16 (MED16; formerly termed SENSITIVE TO FREEZING6 [SFR6]) subunit of the plant Mediator transcriptional coactivator complex regulates cold-responsive gene expression in Arabidopsis thaliana, acting downstream of the C-repeat binding factor (CBF) transcription factors to recruit the core Mediator complex to cold-regulated genes. Here, we use loss-of-function mutants to show that RNA polymerase II recruitment to CBF-responsive cold-regulated genes requires MED16, MED2, and MED14 subunits. Transcription of genes known to be regulated via CBFs binding to the C-repeat motif/drought-responsive element promoter motif requires all three Mediator subunits, as does cold acclimation–induced freezing tolerance. In addition, these three subunits are required for low temperature–induced expression of some other, but not all, cold-responsive genes, including genes that are not known targets of CBFs. Genes inducible by darkness also required MED16 but required a different combination of Mediator subunits for their expression than the genes induced by cold. Together, our data illustrate that plants control transcription of specific genes through the action of subsets of Mediator subunits; the specific combination defined by the nature of the stimulus but also by the identity of the gene induced. PMID:24415770

  13. Study of a simple method and software for quantitative measurement of rCBF with 99Tcm-ECD SPECT brain imaging

    International Nuclear Information System (INIS)

    Shu Boxue; Lai Huaan; Li Zhigang; Shi An

    2000-01-01

    Objective: To create a simple, practical, stable and easy to popularize rCBF quantitative measurement method. Methods: 1) Creating attenuation correction factor (δ) of brain; 2) Proving a factor (ρ) between planar image and tomographic image; 3) Creating SPECT system to determine the dead time and to correct linear regression equation; 4) Measuring lung retardation rate (R 1 ); 5) Improving Nickel model and editing the software; 6) Clinical application; The modified method was performed in 24 subjects, including 15 healthy controls, 8 patients with epilepsy in intermission and 1 patient with brain infarction. Results: δ = 1.7, ρ = 2.23, R 1 -1 ·100 g -1 . The rCBFs of foci in 8 cases of epilepsy were obviously decreased, (22.5∼34.2) mL·min -1 ·100 g -1 , and in the case of brain infarction was only 7.2 mL·min -1 ·100 g -1 . Conclusions: The method is reliable, practical and easy to perform with good quality control. Overall, it is of high clinical value

  14. Melatonin-induced CBF/DREB1s are essential for diurnal change of disease resistance and CCA1 expression in Arabidopsis.

    Science.gov (United States)

    Shi, Haitao; Wei, Yunxie; He, Chaozu

    2016-03-01

    Melatonin (N-acetyl-5-methoxytryptamine) is an important regulator of circadian rhythms and immunity in animals. However, the diurnal changes of endogenous melatonin and melatonin-mediated diurnal change of downstream responses remain unclear in Arabidopsis. Using the publicly available microarray data, we found that the transcript levels of two melatonin synthesis genes (serotonin N-acetyltransferase (SNAT) and caffeate O-methyltransferase (COMT)) and endogenous melatonin level were regulated by diurnal cycles, with different magnitudes of change. Moreover, the transcripts of C-repeat-binding factors (CBFs)/Drought response element Binding 1 factors (DREB1s) were co-regulated by exogenous melatonin and diurnal changes, indicating the possible correlation among clock, endogenous melatonin level and AtCBFs expressions. Interestingly, diurnal change of plant immunity against Pst DC3000 and CIRCADIANCLOCK ASSOCIATED 1 (CCA1) expression were largely lost in AtCBFs knockdown line-amiR-1. Taken together, this study identifies the molecular pathway underlying the diurnal changes of immunity in Arabidopsis. Notably, the diurnal changes of endogenous melatonin may regulate corresponding changes of AtCBF/DREB1s expression and their underlying diurnal cycle of plant immunity and AtCCA1. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. Effect of simulated weightlessness on the expression of Cbfα1 induced by fluid shear stress in MG-63 osteosarcoma cells.

    Science.gov (United States)

    Yang, Z.; Zhang, S.; Wang, B.; Sun, X. Q.

    Objective The role of mechanical load in the functional regulation of osteoblasts becomes an emphasis in osseous biomechanical researches recently This study was aim to explore the effect of flow shear stress on the expression of Cbf alpha 1 in human osteosarcoma cells and to survey its functional alteration in simulated weightlessness Method After cultured for 72 h in two different gravitational environments i e 1G terrestrial gravitational condition and simulated weightlessness condition human osteosarcoma cells MG-63 were treated with 0 5 Pa or 1 5 Pa fluid shear stress FSS in a flow chamber for 15 30 60 min respectively The total RNA in cells was isolated Transcription PCR analysis was made to examine the gene expression of Cbf alpha 1 And the total protein of cells was extracted and the expression of Cbf alpha 1 protein was detected by means of Western Blotting Results MG-63 cultured in 1G condition reacted to FSS treatment with an enhanced expression of Cbf alpha 1 Compared with no FSS control group Cbf alpha 1 mRNA and protein expression increased significantly at 30 and 60 min with the treatment of FSS P 0 01 And there was remarkable difference on the Cbf alpha 1 mRNA and protein expression between the treatments of 0 5 Pa and 1 5 Pa FSS at 30 min or 60 min P 0 01 As to the osteoblasts cultured in simulated weightlessness by using clinostat the expression of Cbf alpha 1 was significantly different between 1G and simulated weightlessness conditions at each test time P 0 05 Compared with no FSS

  16. An intravenous isotope method for measuring regional cerebral blood flow (rCBF) and volume (rCBV)

    International Nuclear Information System (INIS)

    Kuikka, J.; Ahonen, A.; Koivula, A.; Kallanranta, T.; Laitinen, J.

    1977-01-01

    The regional cerebal blood flow (rCBF), initial slope index (ISI), transfer time (t - sub(h)) and volume (rCBV) were measured simultaneously in 43 hospital patients using a 133 Xe intravenous injection method and quantitative dynamic 99 Tcsup(m) brain scintigraphy. The measurements were made with a gamma camera and the data processing interfaced with a small digital computer. The mean values and standard deviations were obtained from 50 control hemispheres standardized to the age of 40 years. Good agreement was found between the blood flow values determined from the intra-arterial and intravenous injection techniques. (author)

  17. Cloning of Ammopiptanthus mongolicus C-repeat-binding factor gene and its cold-induced tolerance in transgenic tobacco

    Directory of Open Access Journals (Sweden)

    Lijiang Gu

    2013-12-01

    Full Text Available C-repeat-binding factors (CBFs are a type of important regulon in stress-related signal transduction pathways that control plant tolerance of abiotic stress. Ammopiptanthus mongolicus is the only evergreen broadleaf shrub in the northwest desert of China. The species shows strong resistance to environmental stress, especially to cold stress. An A. mongolicus CBF1 gene (AmCBF1 was cloned and transformed into tobacco. Expression of AmCBF1 could be detected in A. mongolicus shortly after exposure to low temperature of 4°C. Analysis on ratio of electrolytic leakage, soluble sugar content, free proline content, malondialdehyde (MDA content and peroxidase (POD activity before and after cold treatment (4°C for 24 h indicated AmCBF1 conferred higher cold tolerance to AmCBF1 transgenic tobacco compared with the wild type and empty vector transformed tobacco.

  18. Cbf11 and Cbf12, the fission yeast CSL proteins, play opposing roles in cell adhesion and coordination of cell and nuclear division

    Czech Academy of Sciences Publication Activity Database

    Převorovský, M.; Groušl, Tomáš; Staňurová, J.; Ryneš, J.; Nellen, W.; Půta, F.; Folk, P.

    2009-01-01

    Roč. 315, č. 8 (2009), s. 1533-1547 ISSN 0014-4827 R&D Projects: GA ČR(CZ) GD204/03/H066 Grant - others:UK(CZ) 157/2005/B-BIO/PrF Institutional research plan: CEZ:AV0Z50200510 Keywords : csl family * fission yeast * adhesion Subject RIV: EE - Microbiology, Virology Impact factor: 3.589, year: 2009

  19. One-year follow-up of neuropsychology, MRI, rCBF and glucose metabolism (rMRGlu) in cerebral microangiopathy

    International Nuclear Information System (INIS)

    Sabri, O.; Hellwig, D.; Schreckenberger, M.; Kaiser, H.-J.; Wagenknecht, G.; Setani, K.; Reinartz, P.; Zimny, M.; Buell, U.; Schneider, R.; Mull, M.; Ringelstein, E.-B.

    2000-01-01

    Background: MRI shows lacunar infarctions (LI), deep white matter lesions (DWML) and atrophy in cerebral microangiopathy, which is said to lead to vascular dementia. In a first trial series on 57 patients with confirmed pure cerebral microangiopathy (without concomitant macroangiopathy), neuropsychological impairment and (where present) brain atrophy correlated with decreased rCBF and rMRGlu. LI and DWML did not correlate with either neuropsychological impairment or decreased rCBF/rMRGlu. This study was done one year later to detect changes in any of the study parameters. Methods: 26 patients were re-examined for rCBF, rMRGlu, LI, DWML, atrophy and neuropsychological performance (7 cognitive, 3 mnestic, 4 attentiveness tests). Using a special head holder for exact repositioning, rCBF (SPECT) and rMRGlu (PET) were measured and imaged slice by slice. White matter/cortex were quantified using MRI-defined ROIs. Results: After one year the patients did not show significant decreases in rCBF or rMRGlu either in cortex or in white matter (p>0.05), nor did any patient show LI, DWML or atrophy changes on MRI. There were no significant neuropsychological decreases (p>0.05). (orig.) [de

  20. Correlation of experimental rCBF determinations in goats with flow measurements from a Doppler-modified carotid artery shunt

    International Nuclear Information System (INIS)

    Loftus, C.M.; Silvidi, J.A.; Becker, J.A.; Miller, B.V.; Bernstein, D.D.

    1989-01-01

    A carotid artery shunt system has been developed that continuously monitors blood flow rates by embedding a Doppler crystal in the shunt wall. The crystal ranges through a liquid lens that enables it to be placed without violation of the shunt lumen. Because the crystal is at a fixed angle (45 degrees) to the axis of blood flow and the diameter of the lumen remains constant, a linear relationship exists between flow rates and the Doppler velocity signal. This shunt system was previously tested in vitro using a pulsatile pump and was found to be accurate to within 4.7% of the actual flow rate. In the present study, animal (goat) experiments were performed consisting of simultaneous carotid shunt flow and bilateral rCBF measurements by the radiolabeled microsphere technique to determine in vivo the accuracy of this Doppler modified shunt and to ascertain the ability of shunt flow to increase in the face of acute contralateral carotid occlusion. Data from five animals show that in vivo shunt flow can be recorded to within 13% of control rCBF and that shunt flow increases nearly 50% under conditions of distal demand (contralateral carotid occlusion). This device may prove useful in laboratory studies of carotid shunt dynamics and in clinical practice to quickly detect correctable shunt flow abnormalities

  1. A technique for a rapid imaging of regional CBF and partition coefficient using dynamic SPECT and N-isopropyl-p-[123I]iodoamphetamine (123I-IMP)

    International Nuclear Information System (INIS)

    Itoh, Hiroshi; Iida, Hidehiro; Murakami, Matsutaro

    1993-01-01

    IMP (iodoamphetamine) is a flow tracer due to a large first pass extraction fraction and high affinity in the brain, but significant clearance from the brain causes change of distribution when the beginning time of scan is delayed. The purpose of the present study was to develop a new method to rapidly calculate a quantitative cerebral blood flow (CBF) image by taking clearance effects into account. A dynamic SPECT scan was performed on 5 subjects (4 patients with cerebral infarction and one normal volunteer) following slow intravenous infusion of 123 I-IMP. The arterial input function was obtained by frequent blood sampling and by measuring an octanol extraction ratio for each sample. Firstly, non-linear least square fitting (NLS) was performed to investigate the tracer kinetics of 123 I-IMP. The 3 compartment model analysis yielded negligibly small k 3 (retaining rate constant) (0.0056±0.0128 (ml/ml/min)), and consistent k 1 (transport rate constant) with those determined by 2 compartment model (2CM) analysis (r=0.96, p 1 was consistent with CBF measured by 15 O water PET technique. These observations suggested the validity of using 2CM for describing the IMP tracer kinetics. Secondly, a weighted integration (WI) technique has been implemented to calculate rapidly images of CBF and partition coefficient (V d ). The WI technique yielded values of CBF (k 1 ) and V d (k 1 /k 2 ). They were confirmed to be consistent with those determined by NLS technique (CBF; r=0.99, p d ; r=0.99, p 1 agreed well with PET CBF (r=0.91, p d in infarcted patients. This supports an importance for calculating V d image. V d image will provide additional clinical information because 123 I-IMP binding mechanism may be related to cell viability. (author)

  2. One-year follow-up of neuropsychology, MRI, rCBF and glucose metabolism (rMRGlu) in cerebral microangiopathy

    Energy Technology Data Exchange (ETDEWEB)

    Sabri, O.; Hellwig, D.; Schreckenberger, M.; Kaiser, H.-J.; Wagenknecht, G.; Setani, K.; Reinartz, P.; Zimny, M.; Buell, U. [Department of Nuclear Medicine, Technische Univ. Aachen (Germany); Schneider, R. [Department of Neurology, Technische Univ. Aachen (Germany); Mull, M. [Department of Neuroradiology, Technische Univ. Aachen (Germany); Ringelstein, E.-B. [Department of Neurology, Muenster Univ. (Germany)

    2000-07-01

    Background: MRI shows lacunar infarctions (LI), deep white matter lesions (DWML) and atrophy in cerebral microangiopathy, which is said to lead to vascular dementia. In a first trial series on 57 patients with confirmed pure cerebral microangiopathy (without concomitant macroangiopathy), neuropsychological impairment and (where present) brain atrophy correlated with decreased rCBF and rMRGlu. LI and DWML did not correlate with either neuropsychological impairment or decreased rCBF/rMRGlu. This study was done one year later to detect changes in any of the study parameters. Methods: 26 patients were re-examined for rCBF, rMRGlu, LI, DWML, atrophy and neuropsychological performance (7 cognitive, 3 mnestic, 4 attentiveness tests). Using a special head holder for exact repositioning, rCBF (SPECT) and rMRGlu (PET) were measured and imaged slice by slice. White matter/cortex were quantified using MRI-defined ROIs. Results: After one year the patients did not show significant decreases in rCBF or rMRGlu either in cortex or in white matter (p>0.05), nor did any patient show LI, DWML or atrophy changes on MRI. There were no significant neuropsychological decreases (p>0.05). (orig.) [German] Ziel: In der MRT zeigen sich bei zerebraler Mikroangiopathie (ZMA) lakunaere Infarkte (LI), Deep White Matter Lesions (DWML) und Atrophie (Atr). Die sogenannte vaskulaere Demenz wurde dabei hauptsaechlich auf die Laesionen der weissen Substanz zurueckgefuehrt. In einer ersten Untersuchungsreihe waren bei 57 Patienten mit gesicherter ZMA nur neuropsychologische Defizite (Nps) und, falls vorhanden, Atr als Grundlage fuer erniedrigte rCBF/rMRGlu-Werte zu eruieren, jedoch nicht LI/DWML. Es sollte geklaert werden, ob sich im Verlauf der Erkrankung nach einem Jahr Veraenderungen dieser Parameter ergeben. Methode: 26 Patienten wurden nach einem Jahr erneut neuropsychologisch untersucht (7 kognitive, 3 mnestrische, 4 Aufmerksamkeitstests). Mittels eines speziellen Kopfhalterungssystems wurden in

  3. Neuropsychological functions and rCBF SPECT in Parkinson's disease patients considered candidates for deep brain stimulation

    International Nuclear Information System (INIS)

    Paschali, Anna; Lakiotis, Velissarios; Vassilakos, Paulos; Messinis, Lambros; Lyros, Epameinondas; Papathanasopoulos, Panagiotis; Constantoyannis, Costas; Kefalopoulou, Zinovia

    2009-01-01

    In the present study, we examined relationships between neuropsychological functions and brain single photon emission computed tomography (SPECT) regional cerebral blood flow (rCBF) observed at presurgical evaluation for deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD) patients. Twenty advanced non-demented PD patients, candidates for DBS surgery, underwent perfusion brain SPECT study and neuropsychological assessment prior to surgery (range: 30-50 days). Patients were further assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr (H and Y) scale. During all assessments patients were ''on'' standard medication. NeuroGam software, which permits voxel by voxel analysis, was used to compare the brain perfusion of PD patients with a normal database adjusted for sex and age. Neuropsychological scores were compared to age, education and sex-adjusted normative databases. Our results indicated that the distribution of rCBF showed significant differences when compared to an age- and sex-adjusted normative database. We found impaired blood flow in 17 (85%) of our patients in the left prefrontal lobe, in 14 (70%) in the right prefrontal lobe and in 11 (55%) in the left frontal and right parietal lobes. Neuropsychological testing revealed that 18 (90%) of our patients had significant impairments in measures of executive functions (set-shifting) and 15 (75%) in response inhibition. Furthermore, we found significant correlations between measures of visual attention, executive functions and the right frontal lobe region. The presence of widespread blood flow reduction was observed mainly in the frontal lobes of dementia-free patients with advanced PD. Furthermore, performance on specific cognitive measures was highly related to perfusion brain SPECT findings. (orig.)

  4. Neuropsychological functions and rCBF SPECT in Parkinson's disease patients considered candidates for deep brain stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Paschali, Anna; Lakiotis, Velissarios; Vassilakos, Paulos [University of Patras Medical School, Department of Nuclear Medicine, Patras (Greece); Messinis, Lambros; Lyros, Epameinondas; Papathanasopoulos, Panagiotis [University of Patras Medical School, Department of Neurology, Neuropsychology Section, Patras (Greece); Constantoyannis, Costas; Kefalopoulou, Zinovia [University of Patras Medical School, Department of Neurosurgery, Patras (Greece)

    2009-11-15

    In the present study, we examined relationships between neuropsychological functions and brain single photon emission computed tomography (SPECT) regional cerebral blood flow (rCBF) observed at presurgical evaluation for deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD) patients. Twenty advanced non-demented PD patients, candidates for DBS surgery, underwent perfusion brain SPECT study and neuropsychological assessment prior to surgery (range: 30-50 days). Patients were further assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr (H and Y) scale. During all assessments patients were ''on'' standard medication. NeuroGam software, which permits voxel by voxel analysis, was used to compare the brain perfusion of PD patients with a normal database adjusted for sex and age. Neuropsychological scores were compared to age, education and sex-adjusted normative databases. Our results indicated that the distribution of rCBF showed significant differences when compared to an age- and sex-adjusted normative database. We found impaired blood flow in 17 (85%) of our patients in the left prefrontal lobe, in 14 (70%) in the right prefrontal lobe and in 11 (55%) in the left frontal and right parietal lobes. Neuropsychological testing revealed that 18 (90%) of our patients had significant impairments in measures of executive functions (set-shifting) and 15 (75%) in response inhibition. Furthermore, we found significant correlations between measures of visual attention, executive functions and the right frontal lobe region. The presence of widespread blood flow reduction was observed mainly in the frontal lobes of dementia-free patients with advanced PD. Furthermore, performance on specific cognitive measures was highly related to perfusion brain SPECT findings. (orig.)

  5. Overexpression of a peach cbf-transcription factor gene in apple regulates both dormancy and freezing tolerance in apple

    Science.gov (United States)

    Economic production of fruit trees in a temperate climate is dependent upon seasonal changes in cold acclimation and dormancy. Evidence indicates that these processes will be greatly affected by climate change (higher atmospheric carbon dioxide and temperatures). This problem may also be exacerbat...

  6. Hemodynamic evaluation in patients with superficial temporal artery-middle cerebral artery anastomosis; Stable xenon CT-CBF study and acetazolamide

    Energy Technology Data Exchange (ETDEWEB)

    Touho, Hajime; Karasawa, Jun; Shishido, Hisashi; Morisako, Toshitaka; Yamada, Keisuke; Shibamoto, Keiji [Osaka Neurological Inst., Toyonaka (Japan)

    1990-12-01

    Sixteen patients with minor completed stroke in the chronic stage underwent superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. The acetazolamide-activated regional cerebral blood flow (rCBF) was measured 20 minutes after the injection using inhalation of stable xenon and computed tomographic scanning (Xe{sup s} CT-CBF study) pre- and postoperatively. Eleven patients (Group 1) showed immediate improvement in neurological state within a few days of the operation, while five (Group 2) showed no improvements. Preoperative rCBF in the ischemic areas without infarction was 30.8+-3.0 ml/100 gm/min in Group 1 and 53.0+-5.2 ml/100 gm/min in Group 2. Preoperative vasodilatory capacity with acetazolamide in Group 1 was 5.7+-8.6 and significantly increased to 19.8+-4.9 after surgery. In Group 2, pre- and postoperative vasodilatory capacity was 12.7+-3.1 and 14.9+-2.9, respectively, and there was no significant change. These results suggested that minor stroke patients with moderate decrease of affected side rCBF (less than 40 ml/100 gm/min) and with hemodynamic impairment may have the surgical indication for STA-MCA anastomosis. (author).

  7. Preserved benzodiazepine receptors in Alzheimer's disease measured with C-11 flumazenil PET and I-123 iomazenil SPECT in comparison with CBF

    International Nuclear Information System (INIS)

    Ohyama, Masashi; Kitamura, Shin; Mishina, Masahiro; Katayama, Yasuo; Senda, Michio; Ishiwata, Kiichi; Ishii, Kenji; Toyama, Hinako; Oda, Keiichi

    1999-01-01

    This study evaluates the regional cerebral blood flow (CBF) with H 2 15 O-PET and the distribution of central benzodiazepine receptor (BZR) with C-11 flumazenil (FMZ) by PET and I-123 iomazenil (IMZ) by SPECT in Alzheimer's disease (AD). In AD, whereas the CBF was diminished in the frontal, temporal, parietal, and occipital cortex, the distribution volume of FMZ and delayed activity of IMZ were relatively preserved in these cortices, suggesting that the BZR reduction, reflecting neuronal loss, is less prominent than the CBF suppression. The mini-mental state examination score (MMS) was weakly correlated with the CBF in the parietal cortex but not with BZR. It is speculated that the neuronal density reflected by BZR is less impaired than the neuronal function assessed with blood flow in the association cortex of AD. High correlation was found between the uptake of FMZ and the delayed activity of IMZ. The delayed image of IMZ-SPECT is clinically useful to evaluate the preservation of neuronal density in the affected temoporoparietal association cortex in AD. (author)

  8. Separation of input function for rapid measurement of quantitative CMRO2 and CBF in a single PET scan with a dual tracer administration method

    International Nuclear Information System (INIS)

    Kudomi, Nobuyuki; Watabe, Hiroshi; Hayashi, Takuya; Iida, Hidehiro

    2007-01-01

    Cerebral metabolic rate of oxygen (CMRO 2 ), oxygen extraction fraction (OEF) and cerebral blood flow (CBF) images can be quantified using positron emission tomography (PET) by administrating 15 O-labelled water (H 15 2 O) and oxygen ( 15 O 2 ). Conventionally, those images are measured with separate scans for three tracers C 15 O for CBV, H 15 2 O for CBF and 15 O 2 for CMRO 2 , and there are additional waiting times between the scans in order to minimize the influence of the radioactivity from the previous tracers, which results in a relatively long study period. We have proposed a dual tracer autoradiographic (DARG) approach (Kudomi et al 2005), which enabled us to measure CBF, OEF and CMRO 2 rapidly by sequentially administrating H 15 2 O and 15 O 2 within a short time. Because quantitative CBF and CMRO 2 values are sensitive to arterial input function, it is necessary to obtain accurate input function and a drawback of this approach is to require separation of the measured arterial blood time-activity curve (TAC) into pure water and oxygen input functions under the existence of residual radioactivity from the first injected tracer. For this separation, frequent manual sampling was required. The present paper describes two calculation methods: namely a linear and a model-based method, to separate the measured arterial TAC into its water and oxygen components. In order to validate these methods, we first generated a blood TAC for the DARG approach by combining the water and oxygen input functions obtained in a series of PET studies on normal human subjects. The combined data were then separated into water and oxygen components by the present methods. CBF and CMRO 2 were calculated using those separated input functions and tissue TAC. The quantitative accuracy in the CBF and CMRO 2 values by the DARG approach did not exceed the acceptable range, i.e., errors in those values were within 5%, when the area under the curve in the input function of the second tracer

  9. Local application of 133Xenon for measurement of regional cerebral blood flow (rCBF) during halothane, enflurane, and isoflurane anesthesia in humans

    International Nuclear Information System (INIS)

    Eintrei, C.; Leszniewski, W.; Carlsson, C.

    1985-01-01

    It is well known that halothane causes an increase in cerebral blood flow (CBF). In this study the effects of halothane, enflurane, and isoflurane on regional cerebral blood flow (rCBF) in humans were determined in the presence of 70% N 2 O at a combined MAC concentration of 1.5. CBF was determined in 24 patients from the washout of locally applied 133 Xenon with the use of an external scintillation. All 24 patients (control n = 6, halothane n = 6, enflurane n = 6, and isoflurane n = 6) were undergoing neurosurgical procedures. All patients were anesthetized with thiopental, fentanyl, droperidol, and 70% N 2 O in oxygen and paralyzed with pancuronium. The measurements were performed after the dura had been opened and before definitive surgery. The first measurement was done in the absence of any volatile agent, and the wash-out curve was registered for 6 min. The second measurement was done after one of the volatile agents had been added for at least 20 min and had reached a concentration of 0.58% for halothane, 1.14% for enflurane, or 1.0% for isoflurane in the expiratory gases in order to obtain about 1.5 MAC with each volatile anesthetic. The anesthetic concentrations were measured with the Engstroem multigas analyzer EMMA. The physiologic variables changed very little throughout the period of observation. Body temperature, heart rate, blood pressure, PaCO 2 , and PaO 2 were stable. Ephedrine was used to maintain a stable arterial pressure. At approximately 1.5 MAC, halothane (plus N 2 O) increased rCBF to nearly three times (166%) the control value, while enflurane induced only a slight increase (35%) in rCBF

  10. [Immigration and factors associated with breastfeeding. CALINA study].

    Science.gov (United States)

    Oves Suárez, B; Escartín Madurga, L; Samper Villagrasa, M P; Cuadrón Andrés, L; Alvarez Sauras, M L; Lasarte Velillas, J J; Moreno Aznar, L A; Rodríguez Martínez, G

    2014-07-01

    To identify socio-cultural, obstetric and perinatal characteristics associated with complete breastfeeding (CBF) during the first 4 months of age, depending on maternal origin. Socio-cultural, obstetric and perinatal aspects associated with breastfeeding depending on maternal origin were evaluated in a longitudinal study in a representative infant population from Aragon (n = 1452). The prevalence of CBF was higher in immigrant mothers than in those from Spain. CBF was maintained in 37.2% of mothers from Spain at 4 months, compared with 43% of immigrants (P=.039) (RR Spanish/immigrants=0.76; 95% CI: 0.58-0.99); at 6 months this occurred in 13.9% vs. 23.8%, respectively (P<.001) (RR Spanish/immigrants=0.52; 95% CI: 0.37-0.72). The factors associated with CBF at 4 months are different between both groups. Mothers born in Spain are older (P=.002), have higher academic level (P=.001), greater parity (P=.003), and a higher probability of vaginal delivery (P=.005); and their children have the highest anthropometric values at birth. However, in immigrant mothers, the maintenance of CBF was associated with a higher maternal body mass index and with working at home. In both groups, CBF remains more frequently in those mothers who do not smoke (P=.001). The prevalence of CBF during the first months of life is higher in immigrant mothers than in those from Spain, and socio-cultural, obstetric and perinatal factors are different, depending on maternal origin. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  11. The early diagnostic value of oral acetazolamide load combined with SPECT rCBF imaging in patients with transient ischemia attack in brain

    International Nuclear Information System (INIS)

    Liu Xintong; Zheng Zhiping; Qiao Suixian; Tang Anwu

    2001-01-01

    Objective: In order to assess the diagnostic value of acetazolamide (ACZ) combined with rCBF-SPECT imaging in patients with transient ischemia attack (TIA). Methods: SPECT imaging was performed before and after oral ACZ with visual and semiquantitative analysis of the images. Blood gas analysis was done before and after ACZ administration either. Results: After ACZ loading, in normal group, 99 Tc m -ECD was distributed symmetrically on correspondent parts of the brain and rCBF was generally increased. The blood pH was decreased and blood PCO 2 was increased, respectively in TIA group, the positive rate of hypoperfusion foci on SPECT images were increased from 5/6 to 6/6 in symptomatic patients and from 60% to 92% in asymptomatic patients. The total positive rate was 93%. Conclusion: Oral ACZ before SPECT imaging is a simple, reliable way for early diagnosis in patients with TIA

  12. The Possible Role of CO2 in Producing A Post-Stimulus CBF and BOLD Undershoot

    Science.gov (United States)

    Yücel, Meryem A.; Devor, Anna; Akin, Ata; Boas, David A.

    2009-01-01

    Comprehending the underlying mechanisms of neurovascular coupling is important for understanding the pathogenesis of neurodegenerative diseases related to uncoupling. Moreover, it elucidates the casual relation between the neural signaling and the hemodynamic responses measured with various imaging modalities such as functional magnetic resonance imaging (fMRI). There are mainly two hypotheses concerning this mechanism: a metabolic hypothesis and a neurogenic hypothesis. We have modified recent models of neurovascular coupling adding the effects of both NO (nitric oxide) kinetics, which is a well-known neurogenic vasodilator, and CO2 kinetics as a metabolic vasodilator. We have also added the Hodgkin–Huxley equations relating the membrane potentials to sodium influx through the membrane. Our results show that the dominant factor in the hemodynamic response is NO, however CO2 is important in producing a brief post-stimulus undershoot in the blood flow response that in turn modifies the fMRI blood oxygenation level-dependent post-stimulus undershoot. Our results suggest that increased cerebral blood flow during stimulation causes CO2 washout which then results in a post-stimulus hypocapnia induced vasoconstrictive effect. PMID:20027233

  13. Noninvasive quantitative assessment of cerebral blood flow (CBF) using Tc-99m ECD SPECT with adjunctive radionuclide angiography in ischemic stroke

    International Nuclear Information System (INIS)

    Yim, Jun Sung; Choi, Yun Young; Kim, Seung Hyun; Kim, Myung Ho; Cho, Suk Shin

    1999-01-01

    Quantitative CBF measurements are essential for diagnosing ischemic lesion, evaluating the therapeutic effects and predicting the prognosis of cerebral ischemia. Even though several methods have been introduced, these techniques are too cumbersome and invasive to be applied to routine studies. In this study, a non-invasive simple method for the quantitative angiography. Fifteen normal controls and 27 patients with unilateral carotid ischemic stoke were selected. Brain perfusion index (BPI) of each hemisphere was measured in each subject by acquisition of serial radionuclide angiography after injection of 20mCi of Tc-99m ECD. With Lassen's correction algorithm of curve-linear relationship between the brain activity and blood flow, rCBF on transaxial SPECT slice corresponding with MRI lesion sites (ischemic core, border zone and contralateral mirror locus) were calculated. BPI values for normal controls showed a significant negative correlation with advantage age (r=-0.64, p=0.021) and hemisphric BPI were 11.02±1.6 and 7.8±1.4 for normal controls and patient, respectively. Significant differences were observed between two groups (p=0.0012). rCBF obtained from core zone (12±2.5 ml/100/min), boneder zone (29.2±8.1) and contralateral mirror locus (52.1±15.1) were clearly defined in each subject of patient group. Measurement of BPI and rCBF using Tc-99m ECD SPECT with adjunctive radionuclide angiography could be an useful, simple and non-invasive method in evaluation of the cerebral flood in the ischemic stroke

  14. Amelioration of rCBF and PbtO2 following TBI at high altitude by hyperbaric oxygen pre-conditioning.

    Science.gov (United States)

    Hu, Shengli; Li, Fei; Luo, Haishui; Xia, Yongzhi; Zhang, Jiuquan; Hu, Rong; Cui, Gaoyu; Meng, Hui; Feng, Hua

    2010-03-01

    Hypobaric hypoxia at high altitude can lead to brain damage and pre-conditioning with hyperbaric oxygen (HBO) can reduce ischemic/hypoxic brain injury. This study investigates the effects of high altitude on traumatic brain injury (TBI) and examines the neuroprotection provided by HBO preconditioning against TBI. Rats were randomly divided into four groups: HBO pre-conditioning group (HBOP, n=10), high altitude group (HA, n=10), plain control group (PC, n=10) and plain sham operation group (sham, n=10). All groups were subjected to head trauma by weight drop device except for the sham group. Rats from each group were examined for neurological function, regional cerebral blood flow (rCBF) and brain tissue oxygen pressure (PbtO(2)) and were killed for analysis by transmission electron microscope. The score of neurological deficits in the HA group was highest, followed by the HBOP group and the PC group, respectively. Both rCBF and PbtO(2) were the lowest in the HA group. Brain morphology and structure seen via the transmission electron microscope was diminished in the HA group, while fewer pathological injuries occurred in the HBOP and PC groups. High altitude aggravates TBI significantly and HBO pre-conditioning can attenuate TBI in rats at high altitude by improvement of rCBF and PbtO(2). Pre-treatment with HBO might be beneficial for people traveling to high altitude locations.

  15. Comparison of D2 receptor binding (123I-IBZM) and rCBF (99mTc-HMPAO) in extrapyramidal disorders

    International Nuclear Information System (INIS)

    Saur, H.B.; Bartenstein, P.; Schober, O.; Oberwittler, C.; Lerch, H.; Masur, H.

    1994-01-01

    The aim of this SPECT study was to determine whether there is a correlation between rCBF ( 99m Tc-HMPAO) and D2 receptor binding ( 123 I-IBZM) in disorders of the extrapyramidal system and in which situation the 99 MTc-HMPAO scan could predict the outcome of the 123 I-IBZM study. 13 patients with Parkinson's syndrome and 13 patients with hyperkinetic extrapyramidal disorders were studied. In all patients the two SPECT studies were performed within 2-7 days. ROIs were placed over the basal ganglia (BG), the frontal cortex (FC) and the cerebellum (CE). The ratios BG/FC and BG/CE were calculated. In both groups the scatter was lower when the frontal cortex was used as reference region. Among the patients with hyperkinetic extrapyramidal hyperkinetic extrapyramidal disorders the two patients with Huntington's chorea had lower rCBF and D2 receptor binding compared to other hyperkinetic extrapyramidal disorders. There was no correlation between D2 receptor binding and rCBF in the basal ganglia. The 99 MTc-HMPAO studies did not provide clinically useful information, except in Huntington's chorea. (orig.) [de

  16. Imaging of dopamine transporters with 99Tcm-TRODAT-1, rCBF and MRI in animal model of parkinson disease

    International Nuclear Information System (INIS)

    Deng Haoyu; Wang Wei; Li Xinhui; Yu Xiaoping

    2001-01-01

    Objective: To study the relationship between radioactivity distribution and changes of regional cerebral blood flow (rCBF) and tissue structure in the striatum of Parkinson disease (PD) model monkeys with 99 Tc m - TRODAT-1 and to estimate the value of imaging with 99 Tc m -TRODAT-1 in early diagnosis of PD. Methods: 99 Tc m -TRODAT-1 and rCBF imaging were performed on five monkeys before and after being made into a single side PD model. Two of the 5 PD model monkeys also received MRI. Results: In 99 Tc m -TRODAT-1 imaging the radioactivity ratio of striatum to cerebellum (S/C) in the normal monkeys was 1.48 at 180 min after injection of the imaging agent, the ratio of radioactivity in PD model monkeys in their destroyed striatum to that in cerebellum and in normal side striatum were 0.96 and 1.43, respectively. There was no difference in rCBF perfusion between normal and destroyed striatum of the PD model monkeys and between striatum tissue in two hemispheres of the normal monkeys either. The destruction of the tissue structure was not detected in PD model monkeys with MRI. Conclusions: 90 Tc m -TRODAT-1 can specifically bind dopamine transporters (DAT), sensitively display DAT uptake decrease ahead of the structural damage and cerebral blood flow perfusion decrease in PD model monkeys. It could become a useful imaging modality for the early diagnosis of PD

  17. Quantification of regional cerebral blood flow (rCBF) measurement with one point sampling by sup 123 I-IMP SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Munaka, Masahiro [University of Occupational and Enviromental Health, Kitakyushu (Japan); Iida, Hidehiro; Murakami, Matsutaro

    1992-02-01

    A handy method of quantifying regional cerebral blood flow (rCBF) measurement by {sup 123}I-IMP SPECT was designed. A standard input function was made and the sampling time to calibrate this standard input function by one point sampling was optimized. An average standard input function was obtained from continuous arterial samplings of 12 healthy adults. The best sampling time was the minimum differential value between the integral calculus value of the standard input function calibrated by one point sampling and the input funciton by continuous arterial samplings. This time was 8 minutes after an intravenous injection of {sup 123}I-IMP and an error was estimated to be {+-}4.1%. The rCBF values by this method were evaluated by comparing them with the rCBF values of the input function with continuous arterial samplings in 2 healthy adults and a patient with cerebral infarction. A significant correlation (r=0.764, p<0.001) was obtained between both. (author).

  18. Analysis of voxel-based rCBF in patients with olivopontocerebellar atrophy of multiple system atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Kim, Sang Ho; Kim, Jae Woo [School of Medicine, Dong-A University, Busan (Korea, Republic of)

    2004-07-01

    Olivopontocerebellar Atrophy (OPCA) is one phenotype of multiple system atrophy (MSA) and is characterized neuropathologically by neuronal degeneration in the inferior olives, pons and cerebellar cortex. The diagnosis of OPCA requires clinical evaluation to exclude other diseases. And it's usually supported by atrophy of the cerebellum and brainstem visualized on CT or MRI. But there are some reports that the disease can occur without demonstrable atrophy in these anatomic studies. There are only a few reports about perfusion SPECT imaging in patients with OPCA. The aim of this study was to describe voxel-based rCBF of OPCA in comparison of healthy volunteers. We studied 5 patients with OPCA (1 men, 4 women: age 50.4{+-}9.6y) and age matched 13 healthy volunteers (4 men, 9 women: age 54.9{+-}6.6y). All subjects injected 20mCi of Tc-99m HMPAO and scanning was initiated 20 min after injection. Images were analyzed using SPM (SPM99) with Matlab 5.3. On visual analysis, in 3 patients with OPCA, SPECT image showed significant hypoperfusion in the cerebellum. In another 2 patients, diffuse hypoperfusion was found in the both cerebro-cerebellar hemispheres, untypical perfusion pattern in OPCA. So there is existed limitation to diagnosis by only visual analysis. On SPM analysis, in OPCA patients significantly decreased perfusion was present in culmen, tonsil, tuber in Lt. cerebellum and declive, tonsil, pyramid and inf. Semi-lunar lobule in Rt. cerebellum, Rt. inf. frontal gyrus and Rt. temporal lobe (p<0.001, uncorrected). We also performed individual analysis with SPM. Two of 5 patients have additional hypoperfusion brain lesions. In one patient, decreased perfusion found in Lt. temporal, both occipital lobe, Lt. parahippocampal gyrus. In another patient, decreased perfusion found in both frontal and parietal lobe. This study is one of a few trials analysis with SPM for OPCA. We defined the specific location of decreased perfusion in patients with OPCA.

  19. Analysis of voxel-based rCBF in patients with olivopontocerebellar atrophy of multiple system atrophy

    International Nuclear Information System (INIS)

    Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Kim, Sang Ho; Kim, Jae Woo

    2004-01-01

    Olivopontocerebellar Atrophy (OPCA) is one phenotype of multiple system atrophy (MSA) and is characterized neuropathologically by neuronal degeneration in the inferior olives, pons and cerebellar cortex. The diagnosis of OPCA requires clinical evaluation to exclude other diseases. And it's usually supported by atrophy of the cerebellum and brainstem visualized on CT or MRI. But there are some reports that the disease can occur without demonstrable atrophy in these anatomic studies. There are only a few reports about perfusion SPECT imaging in patients with OPCA. The aim of this study was to describe voxel-based rCBF of OPCA in comparison of healthy volunteers. We studied 5 patients with OPCA (1 men, 4 women: age 50.4±9.6y) and age matched 13 healthy volunteers (4 men, 9 women: age 54.9±6.6y). All subjects injected 20mCi of Tc-99m HMPAO and scanning was initiated 20 min after injection. Images were analyzed using SPM (SPM99) with Matlab 5.3. On visual analysis, in 3 patients with OPCA, SPECT image showed significant hypoperfusion in the cerebellum. In another 2 patients, diffuse hypoperfusion was found in the both cerebro-cerebellar hemispheres, untypical perfusion pattern in OPCA. So there is existed limitation to diagnosis by only visual analysis. On SPM analysis, in OPCA patients significantly decreased perfusion was present in culmen, tonsil, tuber in Lt. cerebellum and declive, tonsil, pyramid and inf. Semi-lunar lobule in Rt. cerebellum, Rt. inf. frontal gyrus and Rt. temporal lobe (p<0.001, uncorrected). We also performed individual analysis with SPM. Two of 5 patients have additional hypoperfusion brain lesions. In one patient, decreased perfusion found in Lt. temporal, both occipital lobe, Lt. parahippocampal gyrus. In another patient, decreased perfusion found in both frontal and parietal lobe. This study is one of a few trials analysis with SPM for OPCA. We defined the specific location of decreased perfusion in patients with OPCA

  20. Seismic Response and Performance Evaluation of Self-Centering LRB Isolators Installed on the CBF Building under NF Ground Motions

    Directory of Open Access Journals (Sweden)

    Junwon Seo

    2016-01-01

    Full Text Available This paper mainly treats the seismic behavior of lead-rubber bearing (LRB isolation systems with superealstic shape memory alloy (SMA bending bars functioning as damper and self-centering devices. The conventional LRB isolators that are usually installed at the column bases supply extra flexibility to the centrically braced frame (CBF building with a view to elongate its vibration period, and thus make a contribution to mitigating seismic acceleration transferred from ground to structure. However, these base isolation systems are somehow susceptible to shear failure due to the lack of lateral resistance. In the construction site, they have been used to be integrated with displacement control dampers additionally withstanding lateral seismic forces. For this motivation, LRB isolation systems equipped with superelastic SMA bending bars, which possess not only excellent energy dissipation but also outstanding recentering capability, are proposed in this study. These reinforced and recentering LRB base isolators are modeled as nonlinear component springs, and then assigned into the bases of 2D frame models used for numerical simulation. Their seismic performance and capacity in the base-isolated frame building can be evaluated through nonlinear dynamic analyses conducted with historic ground motion data. After comparative study with analyses results, it is clearly shown that 2D frame models with proposed LRB isolators generally have smaller maximum displacements than those with conventional LRB isolators. Furthermore, the LRB isolation systems with superelastic SMA bending bars effectively reduce residual displacement as compared to those with steel bending bars because they provide more flexibility and recentering force to the entire building structure.

  1. Quantitative kinetic analysis of PET amyloid imaging agents [11C]BF227 and [18F]FACT in human brain

    International Nuclear Information System (INIS)

    Shidahara, Miho; Watabe, Hiroshi; Tashiro, Manabu; Okamura, Nobuyuki; Furumoto, Shozo; Watanuki, Shoichi; Furukawa, Katsutoshi; Arakawa, Yuma; Funaki, Yoshihito; Iwata, Ren; Gonda, Kohsuke; Kudo, Yukitsuka; Arai, Hiroyuki; Ishiwata, Kiichi; Yanai, Kazuhiko

    2015-01-01

    Introduction: The purpose of this study was to compare two amyloid imaging agents, [ 11 C]BF227 and [ 18 F]FACT (derivative from [ 11 C]BF227) through quantitative pharmacokinetics analysis in human brain. Methods: Positron emission tomography studies were performed on six elderly healthy control (HC) subjects and seven probable Alzheimer’s disease (AD) patients with [ 11 C]BF227 and 10 HC subjects and 10 probable AD patients with [ 18 F]FACT. Data from nine regions of interest were analyzed by several approaches, namely non-linear least-squared fitting methods with arterial input functions (one-tissue compartment model(1TCM), two-tissue compartment model (2TCM)), Logan plot, and linearized methods with reference region (Reference Logan plot (RefLogan), MRTM0, MRTM2). We also evaluated SUV and SUVR for both tracers. The parameters estimated by several approaches were compared between two tracers for detectability of differences between HC and AD patients. Results: For [ 11 C]BF227, there were no significant difference of V T (2TCM, 1TCM) and SUV in all regions (Student t-test; p < 0.05) and significant differences in the DVRs (Logan, RefLogan, and MRTM2) and SUVRs in six neocortical regions (p < 0.05) between the HC and AD groups. For [ 18 F]FACT, significant differences in DVRs (RefLogan, MRTM0, and MRTM2) were observed in more than four neocortical regions between the HC and AD groups (p < 0.05), and the significant differences were found in SUVRs for two neocortical regions (inferior frontal coretex and lateral temporal coretex). Our results showed that both tracers can clearly distinguish between HC and AD groups although the pharmacokinetics and distribution patterns in brain for two tracers were substantially different. Conclusion: This study revealed that although the PET amyloid imaging agents [ 11 C]BF227 and [ 18 F]FACT have similar chemical and biological properties, they have different pharmacokinetics, and caution must be paid for usage of the

  2. Compromised Cerebral Blood Flow(CBF) in Congestive Heart Failure (CHB): non-invasive quantification with {sup 99m}Tc-ECD radionuclide angiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Seung; Kim, Jae Joong; Lim, Ki Chun; Lee, Hee Kyung; Moon, Dae Hyuk [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    2002-07-01

    Recent reports revealed that cerebral metabolism in CHF was abnormally deranged and proposed as a potential marker of disease severity. Since deranged cerebral metabolism in CHF may result from compromised cerebral perfusion, quantification of CHF may be useful for accurate risk stratification of CHF. Therefore, we investigated whether CHF in patients with CHF is compromised and correlated with clinical parameters. Fifteen patients (M/F:11/5, 45{+-}9yr) with CHF (LVEF<40%) and 7 healthy controls (M/F:5/2, 41{+-}8yr) were prospectively studied. All patients underwent radionuclide angiography including cerebral hemispheres and aortic arch using {sup 99m}Tc-ECD. Global CBF was measured non-invasively by the application of Patlak graphical plot analysis. All patients were also evaluated using a standardized protocol that included echocardiography and clinical evaluation. Global CBF (40.3{+-}5.2 ml/min/100g) of the patients with CHF were significantly lower than those (49.7{+-}2.4 ml/min/100g) of controls (p<0.01). Global CBF were correlated with NYHA functional class (r=-0.617, p=0.43), but not correlated with other clinical parameters such as age (r=-0.463, p=0.082), duration (r=0.237, p>0.1), systolic BP (r=-0.063, p>0.5), LVEF (r=-0.13, p>0.1), LV dimension(r=0.139, p>0.5), and PV pressure gradients (r=0.072, p>0.5). Cerebral perfusion of the patients with CHF was compromised and not correlated with cardiopulmonary hemodynamic parameters.

  3. CBF before and after extracranial-intracranial bypass surgery in patients with ischemic cerebrovascular disease studied with 133Xe-inhalation tomography

    DEFF Research Database (Denmark)

    Vorstrup, S; Lassen, N A; Henriksen, L

    1985-01-01

    Cerebral blood flow (CBF) was studied by 133Xenon inhalation tomography in 22 patients with symptoms of ischemic cerebrovascular disease before and after establishment of an extracranial-intracranial bypass shunt. Selection of patients for shunting was based on angiographically demonstrated...... arterial occlusions and on the finding of focal low flow areas corresponding to the clinical symptoms, that consisted mainly of minor stroke with good remission and with or without subsequent TIAs. It was required that the area of low flow should clearly exceed the CT lesion present in practically all...

  4. r-CBF brain SPET before surgery and during subthalamic nuclei (STN) high frequency stimulation (DBS) in Parkinson's Disease

    International Nuclear Information System (INIS)

    Gerundini, P.; Benti, R.; De Notaris, A.; Ferrari, M.; Raimondi, A.; Mariani, C.; Antonini, A.; Pezzoli, G.; Gaini, S.M.

    2002-01-01

    Deep brain stimulation (DBS) of the subthalamic nuclei (STN) can improve motor symptoms and reduces the need for medical therapy in severe Parkinson's Disease (PD). Moreover, DBS can affect, as the medical treatment, cerebral perfusion/metabolism even in cortical/subcortical areas not primarily involved in PD motor symptoms. Aim of the study was the assessment of r-CBF changes by mean of brain SPECT in severe PD .before surgery and during DBS of the STN. Methods. 14 PD patients (duration 15.2±5.1 ys; H and Y off-score 3.6±0.7) underwent STN electrode implantation. Residual motor dysfunction was assessed by UPDRS score up to one year after surgery. SPECT was performed after i.v. injection of Tc-99m ECD (740 MBq) in PD group before and 6-9 months after surgery and in 13 age matched normals. Standardized ROIs templates were applied in brain sections to generate perfusion ratios in the cerebral cortex and basal ganglia. Statistical Parametric Mapping (SPM) analysis of SPET studies was also obtained. Results: 6 months after surgery the mean UPDRS score improvement was 48.8±26.1% (DBS on) vs pre surgery. 8 patients (R+) had UPDRS improvement >50% (mean 67.7±8.8%); 6 patients (R-) had score improvement <50% (mean 22.9±18.9%). Before surgery, motor dysfunction during therapy was similar in R+ and R- groups (mean UPDRS 19.8±8.2 vs. 21.3±9.6). During BDS, UPDRS mean score without medical therapy was lower in R+ (15.6±5.6) vs. R- (35.0±12.4; p<0.001). ROIs and SPM analysis of pre-surgery SPET studies showed significant hypoperfusion (p<0.01) in the occipital gyri of PD vs control groups. No significant differences were found by comparing pre/post surgery SPECT patterns in whole PD group. However, in R- group SPECT showed significant hypoperfusion in pre-frontal areas, parietal and occipital gyri vs R+ patients (p<0.02) and controls (p<0.01). Before surgery, R+ group had borderline occipital hypoperfusion (p=0.04) and mild increase of putaminal perfusion (p=0.03) vs

  5. Regional cerebral blood flow (rCBF) in schizophrenia during verbal memory activation: a 99mTc-HMPAO single photon emission tomography (SPET) study.

    Science.gov (United States)

    Busatto, G F; Costa, D C; Ell, P J; Pilowsky, L S; David, A S; Kerwin, R W

    1994-05-01

    Regional cerebral blood flow (rCBF) was investigated in a group of medicated DSM-III-R schizophrenic patients and age, sex and handedness matched normal volunteers using a split-dose 99mTc-HMPAO Single Photon Emission Tomography (SPET) protocol. Measures were taken during the performance of a verbal memory task aimed at activating the left medial temporal lobe, a region repeatedly suggested to be structurally abnormal in schizophrenia. In normal subjects, the performance of the task was associated with significant rCBF increases in the left medial temporal, left inferior frontal and anterior cingulate cortices, and right cerebellum. Despite their significantly poorer performance on the memory task, the degree of medial temporal activation measured in the schizophrenic patients was not significantly different from that found in the control group. This finding suggests that memory deficits in schizophrenia do not necessarily imply failure to activate the left medial temporal lobe as assessed by 99mTc-HMPAO SPET.

  6. Serodiagnosis of sporotrichosis infection in cats by enzyme-linked immunosorbent assay using a specific antigen, SsCBF, and crude exoantigens.

    Science.gov (United States)

    Fernandes, Geisa Ferreira; Lopes-Bezerra, Leila Maria; Bernardes-Engemann, Andréa Reis; Schubach, Tânia Maria Pacheco; Dias, Maria Adelaide Galvão; Pereira, Sandro Antonio; de Camargo, Zoilo Pires

    2011-01-27

    The main objective of this study is to standardize an ELISA for the diagnosis of feline sporotrichosis. Sporothrix schenckii is the etiological agent of human and animal sporotrichosis. Cats may act as reservoirs for S. schenckii and can transmit the infection to humans by a bite or scratch. There are few methods for the serological diagnosis of fungal diseases in animals. In this paper, an ELISA test for the diagnosis of cat sporotrichosis is proposed, which detects S. schenckii-specific antibodies in feline sera. Two different kinds of antigens were used: "SsCBF", a specific molecule from S. schenckii that consists of a Con A-binding fraction derived from a peptido-rhamnomannan component of the cell wall, and a S. schenckii crude exoantigen preparation. The ELISA was developed, optimized, and evaluated using sera from 30 cats with proven sporotrichosis (by culture isolation); 22 sera from healthy feral cats from a zoonosis center were used as negative controls. SsCBF showed 90% sensitivity and 96% specificity in ELISA; while crude exoantigens demonstrated 96% sensitivity and 98% specificity. The ELISA assay described here would be a valuable screening tool for the detection of specific S. schenckii antibodies in cats with sporotrichosis. The assay is inexpensive, quick to perform, easy to interpret, and permits the diagnosis of feline sporotrichosis. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Local cerebral blood flow (1CBF) and oxygen consumption (1CMRO2) in evolving irreversible ischemic infarction: a study with positron tomography and oxygen-15

    International Nuclear Information System (INIS)

    Baron, J.C.; Rougemont, D.; Lebrun-Grandie, P.; Comar, D.; Bousser, M.G.; Bories, J.; Castaigne, P.; Cabanis, E.

    1982-09-01

    In 25 patients suffering from cerebral ischemia set up in the area of the internal carotid artery the local cerebral blood flow (lCBF) and local cerebral oxygen consumption (lCMRO 2 ) were measured by the method of continuous inhalation of oxygen 15-labelled gas combined with positron emission tomography. These two local parameters and their ratio, the local oxygen extraction rate (lO 2 E), were studied inside the brain region tending spontaneously towards ischemic necrosis, a zone defined by means of repeated tomodensitometric examinations. The essential facts observed are the variability of the lCBF and the lO 2 E values, from extremely low to extremely high, whereas the collapse of the lCMRO 2 is constant. Consequently this last parameter alone would be a good prognostic index, an lCMRO 2 decrease to a level below about 70% of the controlateral value indicating that the necrosis is spontaneously irreparable. These results are discussed in the light of published data

  8. Numerical study of the influence of applied voltage on the current balance factor of single layer organic light-emitting diodes

    International Nuclear Information System (INIS)

    Lu, Fei-ping; Liu, Xiao-bin; Xing, Yong-zhong

    2014-01-01

    Current balance factor (CBF) value, the ratio of the recombination current density and the total current density of a device, has an important function in fluorescence-based organic light-emitting diodes (OLEDs), as well as in the performance of the organic electrophosphorescent devices. This paper investigates the influence of the applied voltage of a device on the CBF value of single layer OLED based on the numerical model of a bipolar single layer OLED with organic layer trap free and without doping. Results show that the largest CBF value can be achieved when the electron injection barrier (ϕ n ) is equal to the hole injection barrier (ϕ p ) in the lower voltage region at any instance. The largest CBF in the higher voltage region can be achieved in the case of ϕ n  > ϕ p under the condition of electron mobility (μ 0n ) > hole mobility (μ 0p ), whereas the result for the case of μ 0n   0p , is opposite. The largest CBF when μ 0n  = μ 0p can be achieved in the case of ϕ n  = ϕ p in the entire region of the applied voltage. In addition, the CBF value of the device increases with increasing applied voltage. The results obtained in this paper can present an in-depth understanding of the OLED working mechanism and help in the future fabrication of high efficiency OLEDs

  9. Dynamic susceptibility contrast (DSC) perfusion MRI in differential diagnosis between radionecrosis and neoangiogenesis in cerebral metastases using rCBV, rCBF and K2.

    Science.gov (United States)

    Muto, Mario; Frauenfelder, Giulia; Senese, Rossana; Zeccolini, Fabio; Schena, Emiliano; Giurazza, Francesco; Jäger, Hans Rolf

    2018-07-01

    Distinction between treatment-related changes and tumour recurrence in patients who have received radiation treatment for brain metastases can be difficult on conventional MRI. In this study, we investigated the ability of dynamic susceptibility contrast (DSC) perfusion in differentiating necrotic changes from pathological angiogenesis and compared measurements of relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF) and K2, using a dedicated software. Twenty-nine patients with secondary brain tumors were included in this retrospective study and underwent DSC perfusion MRI with a 3-month follow-up imaging after chemo- or radiation-therapy. Region-of-interests were drawn around the contrast enhancing lesions and measurements of rCBV, rCBF and K2 were performed in all patients. Based on subsequent histological examination or clinico-radiological follow-up, the cohort was divided in two groups: recurrent disease and stable disease. Differences between the two groups were analyzed using the Student's t test. Sensitivity, specificity and diagnostic accuracy of rCBV measurements were analyzed considering three different cut-off values. Between patients with and without disease, only rCBV and rCBF values were significant (p < 0.05). The only cut-off value giving the best diagnostic accuracy of 100% was rCBV = 2.1 (sensitivity = 100%; specificity = 100%). Patients with tumor recurrence showed a higher mean value of rCBV (mean = 4.28, standard deviation = 2.09) than patients with necrotic-related changes (mean = 0.77, standard deviation = 0.44). DSC-MRI appears a clinically useful method to differentiate between tumor recurrence, tumor necrosis and pseudoprogression in patients treated for cerebral metastases. Relative CBV using a cut-off value of 2.1 proved to be the most accurate and reliable parameter.

  10. 99mTc-bicisate reliably images CBF in chronic brain diseases but fails to show reflow hyperemia in subacute stroke

    DEFF Research Database (Denmark)

    Lassen, N A; Sperling, B

    1994-01-01

    of 115 cases were collected, and of these 105 were considered technically adequate, comprising 18 normal subjects, 18 senile dementia, eight epilepsy, one brain tumor, eight chronic head trauma, and 52 stroke cases. As expected, bicisate gave better spatial resolution than Xe. Agreement between...... the results of the two methods was noted in 98 cases, but not in the remaining 7, all belonging to the stroke group. These seven all suffered from a subacute stroke (11-23 days after onset), and the disagreement in all cases consisted of bicisate showing low count rate in the area of the infarct and Xe...... a normal or elevated flow (luxury perfusion) as sign of spontaneous thrombolysis with reperfusion; in fact, these seven cases comprised all the reperfusion cases in the series. The results validate bicisate as a tracer of CBF in normal humans and in chronic brain diseases. Only in a subgroup of subacute...

  11. A limitation of the split-dose method for evaluating rCBF changes using {sup 99m}Tc-ECD and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Odano, Ikuo; Takahashi, Makoto; Noguchi, Eikichi; Ohtaki, Hiro; Shibaki, Mitsurou; Kasahara, Tosifumi; Hatano, Masayoshi [Niigata Univ. (Japan). School of Medicine; Ohkubo, Masaki

    1997-05-01

    The purpose of the study is to validate the split-dose method corrected with dose ratio of {sup 99m}Tc-ECD for brain perfusion scan. A dose of 600 MBq of {sup 99m}Tc-ECD was divided into two with various dose ratios from 1 : 1 to 1 : 4, and injected to eleven patients with various cerebral diseases. A lesser dose of {sup 99m}Tc-ECD was injected under a control state for the first SPECT scan, and 15 min SPECT scan was performed 10 min after injection with a triple-head high resolution gamma camera. After the scan, the other dose of {sup 99m}Tc-ECD was injected under the same control state and the second SPECT scan was performed as same as above. A ratio of the activity of the first scan to the net activity of the second scan corrected by dose ratio, defined as K, was measured in brain regions of each subject. Expected value of K was 1, but the value was distributed with large variations in each subject. The mean % error of the K value was 10.4{+-}4.9%. Hence it is considered that activity changes by more than 20% from the control values should be required to detect a significant rCBF change in an activation SPECT study. Then, we proposed a new method in which the activity of both two SPECT scans was normalized by cerebellar or occipital activity and compared. The ratio obtained by the proposed method came closer to 1 with less variations and with less mean % error in comparison with those of K value obtained by the dose-correction method. Although the proposed method has a limitation in the use of an activation study loaded with Diamox, it may be useful to evaluate an alteration of rCBF in the study such as postural testing or finger-moving test. (author)

  12. A limitation of the split-dose method for evaluating rCBF changes using 99mTc-ECD and SPECT

    International Nuclear Information System (INIS)

    Odano, Ikuo; Takahashi, Makoto; Noguchi, Eikichi; Ohtaki, Hiro; Shibaki, Mitsurou; Kasahara, Tosifumi; Hatano, Masayoshi; Ohkubo, Masaki.

    1997-01-01

    The purpose of the study is to validate the split-dose method corrected with dose ratio of 99m Tc-ECD for brain perfusion scan. A dose of 600 MBq of 99m Tc-ECD was divided into two with various dose ratios from 1 : 1 to 1 : 4, and injected to eleven patients with various cerebral diseases. A lesser dose of 99m Tc-ECD was injected under a control state for the first SPECT scan, and 15 min SPECT scan was performed 10 min after injection with a triple-head high resolution gamma camera. After the scan, the other dose of 99m Tc-ECD was injected under the same control state and the second SPECT scan was performed as same as above. A ratio of the activity of the first scan to the net activity of the second scan corrected by dose ratio, defined as K, was measured in brain regions of each subject. Expected value of K was 1, but the value was distributed with large variations in each subject. The mean % error of the K value was 10.4±4.9%. Hence it is considered that activity changes by more than 20% from the control values should be required to detect a significant rCBF change in an activation SPECT study. Then, we proposed a new method in which the activity of both two SPECT scans was normalized by cerebellar or occipital activity and compared. The ratio obtained by the proposed method came closer to 1 with less variations and with less mean % error in comparison with those of K value obtained by the dose-correction method. Although the proposed method has a limitation in the use of an activation study loaded with Diamox, it may be useful to evaluate an alteration of rCBF in the study such as postural testing or finger-moving test. (author)

  13. A comprehensive protein-protein interactome for yeast PAS kinase 1 reveals direct inhibition of respiration through the phosphorylation of Cbf1.

    Science.gov (United States)

    DeMille, Desiree; Bikman, Benjamin T; Mathis, Andrew D; Prince, John T; Mackay, Jordan T; Sowa, Steven W; Hall, Tacie D; Grose, Julianne H

    2014-07-15

    Per-Arnt-Sim (PAS) kinase is a sensory protein kinase required for glucose homeostasis in yeast, mice, and humans, yet little is known about the molecular mechanisms of its function. Using both yeast two-hybrid and copurification approaches, we identified the protein-protein interactome for yeast PAS kinase 1 (Psk1), revealing 93 novel putative protein binding partners. Several of the Psk1 binding partners expand the role of PAS kinase in glucose homeostasis, including new pathways involved in mitochondrial metabolism. In addition, the interactome suggests novel roles for PAS kinase in cell growth (gene/protein expression, replication/cell division, and protein modification and degradation), vacuole function, and stress tolerance. In vitro kinase studies using a subset of 25 of these binding partners identified Mot3, Zds1, Utr1, and Cbf1 as substrates. Further evidence is provided for the in vivo phosphorylation of Cbf1 at T211/T212 and for the subsequent inhibition of respiration. This respiratory role of PAS kinase is consistent with the reported hypermetabolism of PAS kinase-deficient mice, identifying a possible molecular mechanism and solidifying the evolutionary importance of PAS kinase in the regulation of glucose homeostasis. © 2014 DeMille et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  14. The relationship between the endothelium-derived vasoactive factor and regional cerebral blood flow in acute stroke

    International Nuclear Information System (INIS)

    Li Jiaqiang; Li Wei

    1999-01-01

    Objective: To explore the plasma concentration of the endothelium-derived vasoactive factors such as endothelin (ET), thromboxane B 2 (TXB 2 ), 6-keto-prostaglandin F 1α (6-K-PGF 1α ) and their effects on regional cerebral blood flow (rCBF). Methods: Plasma ET, TXB 2 , 6-K-PGF 1α were measured with radioimmunoassay in 64 patients with acute stroke and 30 control subjects. Meanwhile, the rCBF was determined using 133 Xe inhalation method in all patients and the control group. The data of stroke group were studied by t test. The linear correlation between alterations of vasoactive factors and rCBF was analysed. Results: The mean ET, TXB 2 plasma level [respectively (103.8 +- 42.6) and (152.2 +- 59.1) ng/L] was significantly higher in 64 stroke patients than in normal subjects [respectively (47.8 +- 7.8) and (84.4 +- 11.5) ng/L], P 1α [(93.7 +- 28.8) ng/L] as compared with the healthy controls [(104.7 +- 17.4) ng/L, P -1 ·min -1 ; mean: (46.9 +- 7.9) mL·100 g -1 ·min -1 vs (63.3 +- 6.5) mL·100 g -1 ·min -1 , P 2 in patients with large infarct or hemorrhage volume were markedly higher than those of patients with small foci; to the opposite, rCBF was decreased remarkably. The same situation was seen while compared the date of patients with basilar nuclei stroke with those of patients with lobar stroke. Both ET and TXB 2 had a significant negative correlation with rCBF ( r = -0.751, -0.454, P 2 and rCBF might be useful in assessment of brain damage caused by acute stroke

  15. Support vector machine-based classification of neuroimages in Alzheimer’s disease: direct comparison of FDG-PET, rCBF-SPECT and MRI data acquired from the same individuals

    Directory of Open Access Journals (Sweden)

    Luiz K. Ferreira

    2017-10-01

    Full Text Available Objective: To conduct the first support vector machine (SVM-based study comparing the diagnostic accuracy of T1-weighted magnetic resonance imaging (T1-MRI, F-fluorodeoxyglucose-positron emission tomography (FDG-PET and regional cerebral blood flow single-photon emission computed tomography (rCBF-SPECT in Alzheimer’s disease (AD. Method: Brain T1-MRI, FDG-PET and rCBF-SPECT scans were acquired from a sample of mild AD patients (n=20 and healthy elderly controls (n=18. SVM-based diagnostic accuracy indices were calculated using whole-brain information and leave-one-out cross-validation. Results: The accuracy obtained using PET and SPECT data were similar. PET accuracy was 68∼71% and area under curve (AUC 0.77∼0.81; SPECT accuracy was 68∼74% and AUC 0.75∼0.79, and both had better performance than analysis with T1-MRI data (accuracy of 58%, AUC 0.67. The addition of PET or SPECT to MRI produced higher accuracy indices (68∼74%; AUC: 0.74∼0.82 than T1-MRI alone, but these were not clearly superior to the isolated neurofunctional modalities. Conclusion: In line with previous evidence, FDG-PET and rCBF-SPECT more accurately identified patients with AD than T1-MRI, and the addition of either PET or SPECT to T1-MRI data yielded increased accuracy. The comparable SPECT and PET performances, directly demonstrated for the first time in the present study, support the view that rCBF-SPECT still has a role to play in AD diagnosis.

  16. An evaluation of the regional cerebral blood flow (rCBF) measurement by xenon-enhanced dynamic CT with helical scanning technique and the functional imaging by multiplanar reconstruction (MPR). Fundamental study and clinical application

    International Nuclear Information System (INIS)

    Watanabe, Kenichi

    1997-01-01

    We evaluated the quantitative rCBF by xenon-enhanced dynamic CT with helical scanning technique on all brain regions, and also examined clinical usefulness of coronal and sagittal section images which are similar to SPECT images obtained by the functional multiplanar reconstitution (MPR) imaging of many successive flow maps. We used 14 clinical cases. The conventional xenon-enhanced CT was simple and ideal method to measure rCBF, however, it had disadvantages; it gives a few laminagraphical images or only the axial directional images, compared to SPECT or PET. There is a risk to overlook lesions out of the image or not to obtain the whole images of the lesion. Although the helical scanning technique has a methodological characteristics to use adjacent data for the image reconstitution, it is by no means inferior to the conventional method in the contrast resolution or the image resolution when the co-helical function and an appropriate reconstituted function were used. It has an advantage to scan all brain regions by only one cycle of scanning. Furthermore on making good use of the property that the helical scanning technique can give the successive data, we can observe rCBF by coronal and sagittal images when many flow maps were made up by reconstituted images of the narrow steps. This shows the clinical usefulness of this technique. One of the future problem to be solved is to decrease the exposure dose. (K.H.)

  17. Brain-derived neurotrophic factor mediates cognitive improvements following acute exercise.

    Science.gov (United States)

    Borror, Andrew

    2017-09-01

    The mechanisms causing improved cognition following acute exercise are poorly understood. This article proposes that brain-derived neurotrophic factor (BDNF) is the main factor contributing to improved cognition following exercise. Additionally, it argues that cerebral blood flow (CBF) and oxidative stress explain the release of BDNF from cerebral endothelial cells. One way to test these hypotheses is to block endothelial function and measure the effect on BDNF levels and cognitive performance. The CBF and oxidative stress can also be examined in relationship to BDNF using a multiple linear regression. If these hypotheses are true, there would be a linear relationship between CBF+oxidative stress and BDNF levels as well as between BDNF levels and cognitive performance. The novelty of these hypotheses comes from the emphasis on the cerebral endothelium and the interplay between BDNF, CBF, and oxidative stress. If found to be valid, these hypotheses would draw attention to the cerebral endothelium and provide direction for future research regarding methods to optimize BDNF release and enhance cognition. Elucidating these mechanisms would provide direction for expediting recovery in clinical populations, such as stroke, and maintaining quality of life in the elderly. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A single-repeat R3-MYB transcription factor MYBC1 negatively regulates freezing tolerance in Arabidopsis

    International Nuclear Information System (INIS)

    Zhai, Hong; Bai, Xi; Zhu, Yanming; Li, Yong; Cai, Hua; Ji, Wei; Ji, Zuojun; Liu, Xiaofei; Liu, Xin; Li, Jing

    2010-01-01

    We had previously identified the MYBC1 gene, which encodes a single-repeat R3-MYB protein, as a putative osmotic responding gene; however, no R3-MYB transcription factor has been reported to regulate osmotic stress tolerance. Thus, we sought to elucidate the function of MYBC1 in response to osmotic stresses. Real-time RT-PCR analysis indicated that MYBC1 expression responded to cold, dehydration, salinity and exogenous ABA at the transcript level. mybc1 mutants exhibited an increased tolerance to freezing stress, whereas 35S::MYBC1 transgenic plants exhibited decreased cold tolerance. Transcript levels of some cold-responsive genes, including CBF/DREB genes, KIN1, ADC1, ADC2 and ZAT12, though, were not altered in the mybc1 mutants or the 35S::MYBC1 transgenic plants in response to cold stress, as compared to the wild type. Microarray analysis results that are publically available were investigated and found transcript level of MYBC1 was not altered by overexpression of CBF1, CBF2, and CBF3, suggesting that MYBC1 is not down regulated by these CBF family members. Together, these results suggested that MYBC1is capable of negatively regulating the freezing tolerance of Arabidopsis in the CBF-independent pathway. In transgenic Arabidopsis carrying an MYBC1 promoter driven β-glucuronidase (GUS) construct, GUS activity was observed in all tissues and was relatively stronger in the vascular tissues. Fused MYBC1 and GFP protein revealed that MYBC1 was localized exclusively in the nuclear compartment.

  19. CBF tomograms with [/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

    International Nuclear Information System (INIS)

    Costa, D.C.; Ell, P.J.; Burns, A.; Philpot, M.; Levy, R.

    1988-01-01

    We present preliminary data on the utility of functional brain imaging with [99mTc]-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of [99mTc]-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. [99mTc]-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions

  20. CBF tomograms with (/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

    Energy Technology Data Exchange (ETDEWEB)

    Costa, D.C.; Ell, P.J.; Burns, A.; Philpot, M.; Levy, R.

    1988-12-01

    We present preliminary data on the utility of functional brain imaging with (99mTc)-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of (99mTc)-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. (99mTc)-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions.

  1. N-termini of fungal CSL transcription factors are disordered, enriched in regulatory motifs and inhibit DNA binding in fission yeast.

    Directory of Open Access Journals (Sweden)

    Martin Převorovský

    Full Text Available CSL (CBF1/RBP-Jκ/Suppressor of Hairless/LAG-1 transcription factors are the effector components of the Notch receptor signalling pathway, which is critical for metazoan development. The metazoan CSL proteins (class M can also function in a Notch-independent manner. Recently, two novel classes of CSL proteins, designated F1 and F2, have been identified in fungi. The role of the fungal CSL proteins is unclear, because the Notch pathway is not present in fungi. In fission yeast, the Cbf11 and Cbf12 CSL paralogs play antagonistic roles in cell adhesion and the coordination of cell and nuclear division. Unusually long N-terminal extensions are typical for fungal and invertebrate CSL family members. In this study, we investigate the functional significance of these extended N-termini of CSL proteins.We identify 15 novel CSL family members from 7 fungal species and conduct bioinformatic analyses of a combined dataset containing 34 fungal and 11 metazoan CSL protein sequences. We show that the long, non-conserved N-terminal tails of fungal CSL proteins are likely disordered and enriched in phosphorylation sites and PEST motifs. In a case study of Cbf12 (class F2, we provide experimental evidence that the protein is proteolytically processed and that the N-terminus inhibits the Cbf12-dependent DNA binding activity in an electrophoretic mobility shift assay.This study provides insight into the characteristics of the long N-terminal tails of fungal CSL proteins that may be crucial for controlling DNA-binding and CSL function. We propose that the regulation of DNA binding by Cbf12 via its N-terminal region represents an important means by which fission yeast strikes a balance between the class F1 and class F2 paralog activities. This mode of regulation might be shared with other CSL-positive fungi, some of which are relevant to human disease and biotechnology.

  2. Numerical study of the influence of applied voltage on the current balance factor of single layer organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Fei-ping, E-mail: lufp-sysu@163.com; Liu, Xiao-bin; Xing, Yong-zhong [College of Physics and Information Science, Tianshui Normal University, Tianshui 741001 (China)

    2014-04-28

    Current balance factor (CBF) value, the ratio of the recombination current density and the total current density of a device, has an important function in fluorescence-based organic light-emitting diodes (OLEDs), as well as in the performance of the organic electrophosphorescent devices. This paper investigates the influence of the applied voltage of a device on the CBF value of single layer OLED based on the numerical model of a bipolar single layer OLED with organic layer trap free and without doping. Results show that the largest CBF value can be achieved when the electron injection barrier (ϕ{sub n}) is equal to the hole injection barrier (ϕ{sub p}) in the lower voltage region at any instance. The largest CBF in the higher voltage region can be achieved in the case of ϕ{sub n} > ϕ{sub p} under the condition of electron mobility (μ{sub 0n}) > hole mobility (μ{sub 0p}), whereas the result for the case of μ{sub 0n} < μ{sub 0p}, is opposite. The largest CBF when μ{sub 0n} = μ{sub 0p} can be achieved in the case of ϕ{sub n} = ϕ{sub p} in the entire region of the applied voltage. In addition, the CBF value of the device increases with increasing applied voltage. The results obtained in this paper can present an in-depth understanding of the OLED working mechanism and help in the future fabrication of high efficiency OLEDs.

  3. Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development

    KAUST Repository

    Park, Myoungryoul; Yun, Kilyoung; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Wijaya, Edward; Bajic, Vladimir B.; Yun, Songjoong; De Los Reyes, Benildo G.

    2010-01-01

    acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co

  4. CBFB-MYH11/RUNX1 together with a compendium of hematopoietic regulators, chromatin modifiers and basal transcription factors occupies self-renewal genes in inv(16) acute myeloid leukemia

    NARCIS (Netherlands)

    Mandoli, A; Singh, A A; Jansen, P W T C; Wierenga, A T J; Riahi, H; Franci, G; Prange, K; Saeed, S; Vellenga, E; Vermeulen, M; Stunnenberg, H G; Martens, J H A

    Different mechanisms for CBF beta-MYH11 function in acute myeloid leukemia with inv(16) have been proposed such as tethering of RUNX1 outside the nucleus, interference with transcription factor complex assembly and recruitment of histone deacetylases, all resulting in transcriptional repression of

  5. Cerebral blood flow and related factors in hyperthyroidism patients by SPECT imaging and statistical parametric mapping analysis

    International Nuclear Information System (INIS)

    Xiu Yan; Shi Hongcheng; Liu Wenguan; Chen Xuefen; Gu Yushen; Chen Shuguang; Yu Haojun; Yu Yiping

    2010-01-01

    Objective: To investigate the cerebral blood flow (CBF) perfusion patterns and related factors in hyperthyroidism patients. Methods: Twenty-five patients with hyperthyroidism and twenty-two healthy controls matched for age, sex, education were enrolled. 99 Tc m -ethylene cysteinate dimer (ECD) SPECT CBF perfusion imaging was performed at rest. Statistical parametric mapping 5.0 software (SPM5) was used and a statistical threshold of P 3 , FT 4 ), thyroid autoimmune antibodies: sensitive thyroid stimulating hormone (sTSH), thyroid peroxidase antibody (TPOAb) and TSH receptor antibody (TRAb) by Pearson analysis, with disease duration by Spearman analysis. Results: rCBF was decreased significantly in limbic system and frontal lobe, including parahippocampal gyrus, uncus (posterior entorhinal cortex, posterior parolfactory cortex, parahippocampal cortex, anterior cingulate, right inferior temporal gyrus), left hypothalamus and caudate nucleus (P 3 (r=-0.468, -0.417, both P 4 (r=-0.4M, -0.418, -0.415, -0.459, all P 4 (r=0.419, 0.412, both P<0.05). rCBF in left insula was negatively correlated with concentration of sTSH, and right auditory associated cortex was positively correlated with concentration of sTSH (r=-0.504, 0.429, both P<0.05). rCBF in left middle temporal gyrus, left angular gyrus was positively correlated with concentration of TRAb while that in right thalamus, right hypothalamus, left anterior nucleus,left ventralis nucleus was negatively correlated with concentration of TRAb (r=0.750, 0.862, -0.691, -0.835, -0.713, -0.759, all P<0.05). rCBF in right anterior cingulate, right cuneus, right rectus gyrus, right superior marginal gyrus was positively correlated with concentration of TPOAb (r=0.696, 0.581, 0.779, 0.683, all P<0.05). rCBF in postcentral gyrus, temporal gyrus, left superior marginal gyrus and auditory associated cortex was positively correlated with disease duration (r=0.502, 0.457, 0.524, 0.440, all P<0.05). Conclusion: Hypoperfusions in

  6. Quantitative cerebral blood flow calculation method using xenon CT. Introduction of a factor reflecting diffusing capacity of the lung for xenon

    International Nuclear Information System (INIS)

    Sase, Shigeru; Honda, Mitsuru; Noguchi, Yoshitaka

    2007-01-01

    In calculating cerebral blood flow (CBF) using the Fick principle, time-course information on arterial tracer concentration is indispensable and exerts considerable influence on the accuracy of CBF. In xenon-enhanced CT (Xe-CT), the time-course change rate for end-tidal xenon concentration (Ke), which can be measured, and that for arterial xenon concentration (Ka) have been assumed to be equal. However, it has been pointed out that there are large differences between Ke and Ka in many cases. We have introduced a single factor (γ) which correlates Ke with Ka in the equation Ka=γ x (1-e -Ke/γ ). This factor, γ, reflects the diffusing capacity of the lung for xenon; larger γ values correspond to larger diffusing capacities and Ka is equal to Ke when γ is infinity. Kety's equation contains two parameters: CBF and xenon solubility coefficient We added a third parameter, γ, to Kety's equation, and developed an efficient method to obtain the γ value for each Xe-CT study. Applying this method to ten normal subjects (35.4±16.3 years, mean±standard deviation (SD)), we obtained γ value of 1.01±0.17 and the average CBF value of 38.8±7.5 mL/100 g/min in basal ganglia. The wash-in period could be shortened to two minutes using this method. Xe-CT with this factor (γ) as a parameter enhances its clinical availability as well as the accuracy of CBF. (author)

  7. Evaluation of factor for one-point venous blood sampling method based on the causality model

    International Nuclear Information System (INIS)

    Matsutomo, Norikazu; Onishi, Hideo; Kobara, Kouichi; Sasaki, Fumie; Watanabe, Haruo; Nagaki, Akio; Mimura, Hiroaki

    2009-01-01

    One-point venous blood sampling method (Mimura, et al.) can evaluate the regional cerebral blood flow (rCBF) value with a high degree of accuracy. However, the method is accompanied by complexity of technique because it requires a venous blood Octanol value, and its accuracy is affected by factors of input function. Therefore, we evaluated the factors that are used for input function to determine the accuracy input function and simplify the technique. The input function which uses the time-dependent brain count of 5 minutes, 15 minutes, and 25 minutes from administration, and the input function in which an objective variable is used as the artery octanol value to exclude the venous blood octanol value are created. Therefore, a correlation between these functions and rCBF value by the microsphere (MS) method is evaluated. Creation of a high-accuracy input function and simplification of technique are possible. The rCBF value obtained by the input function, the factor of which is a time-dependent brain count of 5 minutes from administration, and the objective variable is artery octanol value, had a high correlation with the MS method (y=0.899x+4.653, r=0.842). (author)

  8. rCBF and cognitive impairment changes assessed by SPECT and ADAS-cog in late-onset Alzheimer's disease after 18 months of treatment with the cholinesterase inhibitors donepezil or galantamine.

    Science.gov (United States)

    Shirayama, Yukihiko; Takahashi, Michio; Oda, Yasunori; Yoshino, Kouhei; Sato, Koichi; Okubo, Toshiyuki; Iyo, Masaomi

    2017-12-15

    Late-onset Alzheimer's disease (AD) differs substantially from early-onset AD. In this cross sectional study we investigated brain perfusion changes after 18 months of treatment with cholinesterase inhibitors (ChEIs) donepezil or galantamine. Twenty-five drug-naïve late-onset AD patients were recruited from outpatient clinics. We examined brain perfusion using single photon emission computed tomography (SPECT) and used three-dimensional stereotactic surface projection (3D-SSP) and the stereotactic extraction estimation method (SEE) level 3 to analyze classified gyrus level segments. We assessed cognitive function using the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) grouped into three subgroup domains, language, memory, and praxis. In the follow-up data, some regions were further hypoperfused, reflecting worsening of the disease, while other regions showed alleviated hypoperfusion, potentially related to the ChEIs treatment. Regional cerebral blood flow (rCBF) decreased in the parietal cortex and increased in the frontal and the limbic cortices. Increased hypoperfusion significantly correlated with ADAS-cog scores changes were seen in the superior parietal lobule, inferior parietal lobule, angular gyrus, and supramarginal gyrus of the parietal cortex. Alleviated hypoperfusion significantly related to recovery of ADAS-cog scores were seen in the rectal and paracentral lobule of the frontal cortex, and the anterior cingulate of the limbic cortex. These regions showed significant relationships with total ADAS-cog and language, memory and praxis subscales scores. The current longitudinal study indicates prominent rCBF changes and their relationships with changes in ADAS-cog scores in late-onset AD patients.

  9. EBNA3C Directs Recruitment of RBPJ (CBF1) to Chromatin during the Process of Gene Repression in EBV Infected B Cells.

    Science.gov (United States)

    Kalchschmidt, Jens S; Gillman, Adam C T; Paschos, Kostas; Bazot, Quentin; Kempkes, Bettina; Allday, Martin J

    2016-01-01

    It is well established that Epstein-Barr virus nuclear antigen 3C (EBNA3C) can act as a potent repressor of gene expression, but little is known about the sequence of events occurring during the repression process. To explore further the role of EBNA3C in gene repression-particularly in relation to histone modifications and cell factors involved-the three host genes previously reported as most robustly repressed by EBNA3C were investigated. COBLL1, a gene of unknown function, is regulated by EBNA3C alone and the two co-regulated disintegrin/metalloproteases, ADAM28 and ADAMDEC1 have been described previously as targets of both EBNA3A and EBNA3C. For the first time, EBNA3C was here shown to be the main regulator of all three genes early after infection of primary B cells. Using various EBV-recombinants, repression over orders of magnitude was seen only when EBNA3C was expressed. Unexpectedly, full repression was not achieved until 30 days after infection. This was accurately reproduced in established LCLs carrying EBV-recombinants conditional for EBNA3C function, demonstrating the utility of the conditional system to replicate events early after infection. Using this system, detailed chromatin immunoprecipitation analysis revealed that the initial repression was associated with loss of activation-associated histone modifications (H3K9ac, H3K27ac and H3K4me3) and was independent of recruitment of polycomb proteins and deposition of the repressive H3K27me3 modification, which were only observed later in repression. Most remarkable, and in contrast to current models of RBPJ in repression, was the observation that this DNA-binding factor accumulated at the EBNA3C-binding sites only when EBNA3C was functional. Transient reporter assays indicated that repression of these genes was dependent on the interaction between EBNA3C and RBPJ. This was confirmed with a novel EBV-recombinant encoding a mutant of EBNA3C unable to bind RBPJ, by showing this virus was incapable of

  10. Brain-Derived Neurotrophic Factor Val66Met Polymorphism Affects the Relationship Between an Anxiety-Related Personality Trait and Resting Regional Cerebral Blood Flow.

    Science.gov (United States)

    Wei, Shau-Ming; Eisenberg, Daniel P; Nabel, Katherine G; Kohn, Philip D; Kippenhan, J Shane; Dickinson, Dwight; Kolachana, Bhaskar; Berman, Karen F

    2017-03-01

    Brain-derived neurotrophic factor (BDNF) is an important modulator of constitutive stress responses mediated by limbic frontotemporal circuits, and its gene contains a functional polymorphism (Val66Met) that may influence trait stress sensitivity. Reports of an association of this polymorphism with anxiety-related personality traits have been controversial and without clear neurophysiological support. We, therefore, determined the relationship between resting regional cerebral blood flow (rCBF) and a well-validated measure of anxiety-related personality, the TPQ Harm Avoidance (HA) scale, as a function of BDNF Val66Met genotype. Sixty-four healthy participants of European ancestry underwent resting H215O positron emission tomography scans. For each genotype group separately, we first determined the relationship between participants' HA scores and their resting rCBF values in each voxel across the entire brain, and then directly compared these HA-rCBF relationships between Val66Met genotype groups. HA-rCBF relationships differed between Val homozygotes and Met carriers in several regions relevant to stress regulation: subgenual cingulate, orbital frontal cortex, and the hippocampal/parahippocampal region. In each of these areas, the relationship was positive in Val homozygotes and negative in Met carriers. These data demonstrate a coupling between trait anxiety and basal resting blood flow in frontolimbic neurocircuitry that may be determined in part by genetically mediated BDNF signaling. Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  11. A novel Zea mays ssp. mexicana L. MYC-type ICE-like transcription factor gene ZmmICE1, enhances freezing tolerance in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Lu, Xiang; Yang, Lei; Yu, Mengyuan; Lai, Jianbin; Wang, Chao; McNeil, David; Zhou, Meixue; Yang, Chengwei

    2017-04-01

    The annual Zea mays ssp. mexicana L., a member of the teosinte group, is a close wild relative of maize and thus can be effectively used in maize improvement. In this study, an ICE-like gene, ZmmICE1, was isolated from a cDNA library of RNA-Seq from cold-treated seedling tissues of Zea mays ssp. mexicana L. The deduced protein of ZmmICE1 contains a highly conserved basic helix-loop-helix (bHLH) domain and C-terminal region of ICE-like proteins. The ZmmICE1 protein localizes to the nucleus and shows sumoylation when expressed in an Escherichia coli reconstitution system. In addition, yeast one hybrid assays indicated that ZmmICE1 has transactivation activities. Moreover, ectopic expression of ZmmICE1 in the Arabidopsis ice1-2 mutant increased freezing tolerance. The ZmmICE1 overexpressed plants showed lower electrolyte leakage (EL), reduced contents of malondialdehyde (MDA). The expression of downstream cold related genes of Arabidopsis C-repeat-binding factors (AtCBF1, AtCBF2 and AtCBF3), cold-responsive genes (AtCOR15A and AtCOR47), kinesin-1 member gene (AtKIN1) and responsive to desiccation gene (AtRD29A) was significantly induced when compared with wild type under low temperature treatment. Taken together, these results indicated that ZmmICE1 is the homolog of Arabidopsis inducer of CBF expression genes (AtICE1/2) and plays an important role in the regulation of freezing stress response. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Evaluating response modification factor (R for some types of steel structure

    Directory of Open Access Journals (Sweden)

    Doralba Valencia Restrepo

    2008-01-01

    Full Text Available Response modification factor (R, tabulated in the Colombian Design Code as NSR-98, is used in this paper for eva-luating internal member forces produced by design earthquake action on steel structures and the inconsistencies pre-sent when designing structures when 1% drift limits must be complied with. The article presents the design of 45 frames corresponding to the seismic resistance system of 5 buildings: 15 special moment frames (SMF, 15 special concentrically-braced frames (CBF and 15 eccentrically-braced frames (EBF. External loads and their combination were used in estimating internal loads and rigidity demands (1% drift were evaluated in line with NSR-98 requi-rements. Member strength requirements were evaluated by using the AISC-2005 seismic provisions for steel structu-red buildings. Modal pushover analysis was used for evaluating the response modification factor for the 45 given frames at different structural performance levels. It was found that this factor was not constant for any of the three structural systems (SMF, CBF and EBF suggested by NSR-98 and that the values of the response modification factor found in the present investigation were smaller than those tabulated in this design code governing everyday structural design. This would lead to significant errors being made in evaluating design forces, not only in the structures but in the support elements (base-plates, foundations, shear walls and any structures attached to buildings constructed in line with the seismic resistance system.

  13. Salicylic-Acid-Induced Chilling- and Oxidative-Stress Tolerance in Relation to Gibberellin Homeostasis, C-Repeat/Dehydration-Responsive Element Binding Factor Pathway, and Antioxidant Enzyme Systems in Cold-Stored Tomato Fruit.

    Science.gov (United States)

    Ding, Yang; Zhao, Jinhong; Nie, Ying; Fan, Bei; Wu, Shujuan; Zhang, Yu; Sheng, Jiping; Shen, Lin; Zhao, Ruirui; Tang, Xuanming

    2016-11-02

    Effects of salicylic acid (SA) on gibberellin (GA) homeostasis, C-repeat/dehydration-responsive element binding factor (CBF) pathway, and antioxidant enzyme systems linked to chilling- and oxidative-stress tolerance in tomato fruit were investigated. Mature green tomatoes (Solanum lycopersicum L. cv. Moneymaker) were treated with 0, 0.5, and 1 mM SA solution for 15 min before storage at 4 °C for 28 days. In comparison to 0 or 0.5 mM SA, 1 mM SA significantly decreased the chilling injury (CI) index in tomato fruit. In the SA-treated fruit, the upregulation of GA biosynthetic gene (GA3ox1) expression was followed by gibberellic acid (GA 3 ) surge and DELLA protein degradation. CBF1 participated in the SA-modulated tolerance and stimulated the expression of GA catabolic gene (GA2ox1). Furthermore, 1 mM SA enhanced activities of antioxidant enzymes and, thus, reduced reactive oxygen species accumulation. Our findings suggest that SA might protect tomato fruit from CI and oxidative damage through regulating GA metabolism, CBF1 gene expression, and antioxidant enzyme activities.

  14. Platelet activating factor induces transient blood-brain barrier opening to facilitate edaravone penetration into the brain.

    Science.gov (United States)

    Fang, Weirong; Zhang, Rui; Sha, Lan; Lv, Peng; Shang, Erxin; Han, Dan; Wei, Jie; Geng, Xiaohan; Yang, Qichuan; Li, Yunman

    2014-03-01

    The blood-brain barrier (BBB) greatly limits the efficacy of many neuroprotective drugs' delivery to the brain, so improving drug penetration through the BBB has been an important focus of research. Here we report that platelet activating factor (PAF) transiently opened BBB and facilitated neuroprotectant edaravone penetration into the brain. Intravenous infusion with PAF induced a transient BBB opening in rats, reflected by increased Evans blue leakage and mild edema formation, which ceased within 6 h. Furthermore, rat regional cerebral blood flow (rCBF) declined acutely during PAF infusion, but recovered slowly. More importantly, this transient BBB opening significantly increased the penetration of edaravone into the brain, evidenced by increased edaravone concentrations in tissue interstitial fluid collected by microdialysis and analyzed by Ultra-performance liquid chromatograph combined with a hybrid quadrupole time-of-flight mass spectrometer (UPLC-MS/MS). Similarly, incubation of rat brain microvessel endothelial cells monolayer with 1 μM PAF for 1 h significantly increased monolayer permeability to (125)I-albumin, which recovered 1 h after PAF elimination. However, PAF incubation with rat brain microvessel endothelial cells for 1 h did not cause detectable cytotoxicity, and did not regulate intercellular adhesion molecule-1, matrix-metalloproteinase-9 and P-glycoprotein expression. In conclusion, PAF could induce transient and reversible BBB opening through abrupt rCBF decline, which significantly improved edaravone penetration into the brain. Platelet activating factor (PAF) transiently induces BBB dysfunction and increases BBB permeability, which may be due to vessel contraction and a temporary decline of regional cerebral blood flow (rCBF) triggered by PAF. More importantly, the PAF induced transient BBB opening facilitates neuroprotectant edaravone penetration into brain. The results of this study may provide a new approach to improve drug delivery into

  15. Distinct genetic alteration profiles of acute myeloid leukemia between Caucasian and Eastern Asian population.

    Science.gov (United States)

    Wei, Hui; Wang, Ying; Zhou, Chunlin; Lin, Dong; Liu, Bingcheng; Liu, Kaiqi; Qiu, Shaowei; Gong, Benfa; Li, Yan; Zhang, Guangji; Wei, Shuning; Gong, Xiaoyuan; Liu, Yuntao; Zhao, Xingli; Gu, Runxia; Mi, Yingchang; Wang, Jianxiang

    2018-02-10

    Racial and ethnic disparities in malignancies attract extensive attention. To investigate whether there are racial and ethnic disparities in genetic alteration between Caucasian and Eastern Asian population, data from several prospective AML trials were retrospectively analyzed in this study. We found that there were more patients with core binding factor (CBF) leukemia in Eastern Asian cohorts and there were different CBF leukemia constitutions between them. The ratios of CBF leukemia are 27.7, 22.1, 21.1, and 23.4%, respectively, in our (ChiCTR-TRC-10001202), another Chinese, Korean, and Japanese Eastern Asian cohorts, which are significantly higher than those in ECOG1900, MRC AML15, UK NCRI AML17, HOVON/SAKK AML-42, and German AML2003 (15.5, 12.5, 9.3, 10.2, and 12%, respectively). And CBFbeta-MYH11 occurred more prevalently in HOVON/SAKK AML- 42 and ECOG1900 trials (50.0 and 54.3% of CBF leukemia, respectively) than in Chinese and Japanese trials (20.1 and 20.8%, respectively). The proportion of FLT3-ITD mutation is 11.2% in our cohort, which is lower than that in MRC AML15 and UK NCRI AML17 (24.6 and 17.9%, respectively). Even after excluding the age bias, there are still different incidence rates of mutation between Caucasian and Eastern Asian population. These data suggest that there are racial and ethnic disparities in genetic alteration between Caucasian and Eastern Asian population.

  16. Dissociation between vascular endothelial growth factor receptor-2 and blood vessel density in the caudate nucleus after chronic hydrocephalus.

    Science.gov (United States)

    Deshpande, Abhishek; Dombrowski, Stephen M; Leichliter, Anna; Krajcir, Natalie; Zingales, Nicholas; Inoue, Masahiro; Schenk, Soren; Fukamachi, Kiyotaka; Luciano, Mark G

    2009-11-01

    Chronic hydrocephalus (CH) is characterized by the presence of ventricular enlargement, decreased cerebral blood flow (CBF), and brain tissue oxygen delivery. Although the underlying pathophysiological role of vascular endothelial growth factor (VEGF) is not clear, ischemic-hypoxic events in CH are known to trigger its release. Previously, we have shown increased VEGF receptor-2 (VEGFR-2) and blood vessel density (BVd) in the hippocampus after CH. We investigated changes in neuronal and glial VEGFR-2 density and BVd in the caudate nucleus in an experimental model of CH. Animals with CH were divided into short term (ST, 2 to 4 weeks) and long term (LT, 12 to 16 weeks) and were compared with surgical controls (SCs, 12 to 16 weeks). The cellular and BVds were estimated using immunohistochemical and stereological counting methods. Overall, percentage (%)VEGFR-2 neurons were approximately two times greater in CH (ST, LT) than in SC. By comparison, glial cell %VEGFR-2 was greater by 10% to 17% in ST and 4% to 11% lower in LT compared with that in SC. Blood vessel density was significantly lower in CH than in SC in the superficial caudate. Changes in cerebrospinal fluid ventricular volume and pressure, as well as in CBF did not correlate with either VEGFR-2 or BVd. These observed findings suggest that destructive forces may outweigh angiogenic forces and possibly show a disassociation between VEGFR-2 and BV expressions.

  17. Over-Expression of CYP2E1 mRNA and Protein: Implications of Xenobiotic Induced Damage in Patients with De Novo Acute Myeloid Leukemia with inv(16(p13.1q22; CBFβ-MYH11

    Directory of Open Access Journals (Sweden)

    Carlos E. Bueso-Ramos

    2012-08-01

    Full Text Available Environmental exposure to benzene occurs through cigarette smoke, unleaded gasoline and certain types of plastic. Benzene is converted to hematotoxic metabolites by the hepatic phase-I enzyme CYP2E1, and these metabolites are detoxified by the phase-II enzyme NQO1. The genes encoding these enzymes are highly polymorphic and studies of these polymorphisms have shown different pathogenic and prognostic features in various hematological malignancies. The potential role of different cytochrome p450 metabolizing enzymes in the pathogenesis of acute myeloid leukemia (AML in an area of active interest. In this study, we demonstrate aberrant CYP2E1 mRNA over-expression by quantitative real-time polymerase chain reaction in 11 cases of de novo AML with inv(16; CBFβ-MYH11. CYP2E1 mRNA levels correlated with CBFβ-MYH11 transcript levels and with bone marrow blast counts in all cases. CYP2E1 over-expression correlated positively with NQO1 mRNA levels (R2 = 0.934, n = 7. By immunohistochemistry, CYP2E1 protein was more frequently expressed in AML with inv(16 compared with other types of AML (p < 0.001. We obtained serial bone marrow samples from two patients with AML with inv(16 before and after treatment. CYP2E1 mRNA expression levels decreased in parallel with CBFβ-MYH11 transcript levels and blast counts following chemotherapy. In contrast, CYP1A2 transcript levels did not change in either patient. This is the first study to demonstrate concurrent over-expression of CYP2E1 and NQO1 mRNA in AML with inv(16. These findings also suggest that a balance between CYP2E1 and NQO1 may be important in the pathogenesis of AML with inv(16.

  18. Spatial distribution of osteoblast-specific transcription factor Cbfa1 and bone formation in atherosclerotic arteries.

    Science.gov (United States)

    Bobryshev, Yuri V; Killingsworth, Murray C; Lord, Reginald S A

    2008-08-01

    The mechanisms of ectopic bone formation in arteries are poorly understood. Osteoblasts might originate either from stem cells that penetrate atherosclerotic plaques from the blood stream or from pluripotent mesenchymal cells that have remained in the arterial wall from embryonic stages of the development. We have examined the frequency of the expression and spatial distribution of osteoblast-specific factor-2/core binding factor-1 (Osf2/Cbfa1) in carotid and coronary arteries. Cbfa1-expressing cells were rarely observed but were found in all tissue specimens in the deep portions of atherosclerotic plaques under the necrotic cores. The deep portions of atherosclerotic plaques under the necrotic cores were characterized by the lack of capillaries of neovascularization. In contrast, plaque shoulders, which were enriched by plexuses of neovascularization, lacked Cbfa1-expressing cells. No bone formation was found in any of the 21 carotid plaques examined and ectopic bone was observed in only two of 12 coronary plaques. We speculate that the sparse invasion of sprouts of neovascularization into areas underlying the necrotic cores, where Cbfa1-expressing cells reside, might explain the rarity of events of ectopic bone formation in the arterial wall. This study has also revealed that Cbfa1-expressing cells contain alpha-smooth muscle actin and myofilaments, indicating their relationship with arterial smooth muscle cells.

  19. responsive transcription factor from Hevea brasiliensis Muell. Arg.

    African Journals Online (AJOL)

    Jane

    2011-08-29

    Aug 29, 2011 ... members of CBF/DREB subfamily from different plant species. Quantitative ..... mechanisms of hormonal (ethylene) stimulation. In: D'Auzac J, .... wide interacting effects of sucrose and herbicide-mediated stress in. Arabidopsis ...

  20. Low-temperature-induced expression of rice ureidoglycolate amidohydrolase is mediated by a C-repeat/dehydration-responsive element that specifically interacts with rice C-repeat-binding factor 3

    Directory of Open Access Journals (Sweden)

    Juan eLi

    2015-11-01

    Full Text Available Nitrogen recycling and redistribution are important for the environmental stress response of plants. In non nitrogen-fixing plants, ureide metabolism is crucial to nitrogen recycling from organic sources. Various studies have suggested that the rate-limiting components of ureide metabolism respond to environmental stresses. However, the underlying regulation mechanism is not well understood. In this report, rice ureidoglycolate amidohydrolase (OsUAH, which is a recently identified enzyme catalyzing the final step of ureide degradation, was identified as low-temperature- (LT but not abscisic acid- (ABA regulated. To elucidate the LT regulatory mechanism at the transcriptional level, we isolated and characterized the promoter region of OsUAH (POsUAH. Series deletions revealed that a minimal region between -522 and -420 relative to the transcriptional start site was sufficient for the cold induction of POsUAH. Detailed analyses of this 103-bp fragment indicated that a C-repeat/dehydration-responsive (CRT/DRE element localized at position -434 was essential for LT-responsive expression. A rice C-repeat-binding factors/DRE-binding proteins 1 (CBFs/DREB1s subfamily member, OsCBF3, was screened to specifically bind to the CRT/DRE element in the minimal region both in yeast one-hybrid assays and in in vitro gel-shift analysis. Moreover, the promoter could be exclusively trans-activated by the interaction between the CRT/DRE element and OsCBF3 in vivo. These findings may help to elucidate the regulation mechanism of stress-responsive ureide metabolism genes and provide an example of the member-specific manipulation of the CBF/DREB1 subfamily.

  1. Sensitivity of rCBF to focal lesions

    International Nuclear Information System (INIS)

    Halsey, J.H. Jr.; Nakai, K.; Wariyar, B.

    1981-01-01

    The ability of the 133Xenon inhalation method to lateralize cerebral infarctions visible on CT scan was tested in 39 patients. At each of 7 hemispheric regions the flow rate in the lesioned hemisphere was divided by that in the unaffected hemisphere and this ratio was compared with the corresponding ratio for normal subjects. The fast compartment relative flow f1 correctly lateralized the lesion in only 6 patients with no false lateralizations. If the fast compartment relative weight w1 was also considered, the correct lateralizations were increased to about 50%. With the less well-known ISI and the Fractional Flow considered together, the laterality of the lesion was identified correctly in 85% of cases, with no false lateralizations

  2. Bilateral CBF measurements in patients with global and flow disturbances

    International Nuclear Information System (INIS)

    Fenske, A.; Meinig, G.; Kreysch, G.; Schuermann, K.

    1979-01-01

    The diagnostic value of the Xe-inhalation method, related to the clinical picture and to other noninvasive methods which had shown to a limited extent cerebral vascular lesions, is considered. In patients with angiomas, NPH and local cerebral vascular lesions, the inhalation technique seems to be a clinically useful and reliable examination method which is able to detect even small hemispheric and regional flow defects which were not sufficiently traceable by other methods. (Auth./C.F.)

  3. Risk Factors

    Science.gov (United States)

    ... cells do not invade nearby tissues or spread. Risk Factors Key Points Factors That are Known to ... chemicals . Factors That are Known to Increase the Risk of Cancer Cigarette Smoking and Tobacco Use Tobacco ...

  4. Principal component analysis for predicting transcription-factor binding motifs from array-derived data

    Directory of Open Access Journals (Sweden)

    Vincenti Matthew P

    2005-11-01

    Full Text Available Abstract Background The responses to interleukin 1 (IL-1 in human chondrocytes constitute a complex regulatory mechanism, where multiple transcription factors interact combinatorially to transcription-factor binding motifs (TFBMs. In order to select a critical set of TFBMs from genomic DNA information and an array-derived data, an efficient algorithm to solve a combinatorial optimization problem is required. Although computational approaches based on evolutionary algorithms are commonly employed, an analytical algorithm would be useful to predict TFBMs at nearly no computational cost and evaluate varying modelling conditions. Singular value decomposition (SVD is a powerful method to derive primary components of a given matrix. Applying SVD to a promoter matrix defined from regulatory DNA sequences, we derived a novel method to predict the critical set of TFBMs. Results The promoter matrix was defined to establish a quantitative relationship between the IL-1-driven mRNA alteration and genomic DNA sequences of the IL-1 responsive genes. The matrix was decomposed with SVD, and the effects of 8 potential TFBMs (5'-CAGGC-3', 5'-CGCCC-3', 5'-CCGCC-3', 5'-ATGGG-3', 5'-GGGAA-3', 5'-CGTCC-3', 5'-AAAGG-3', and 5'-ACCCA-3' were predicted from a pool of 512 random DNA sequences. The prediction included matches to the core binding motifs of biologically known TFBMs such as AP2, SP1, EGR1, KROX, GC-BOX, ABI4, ETF, E2F, SRF, STAT, IK-1, PPARγ, STAF, ROAZ, and NFκB, and their significance was evaluated numerically using Monte Carlo simulation and genetic algorithm. Conclusion The described SVD-based prediction is an analytical method to provide a set of potential TFBMs involved in transcriptional regulation. The results would be useful to evaluate analytically a contribution of individual DNA sequences.

  5. Factor XII (Hageman factor) deficiency

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000545.htm Factor XII (Hageman factor) deficiency To use the sharing features on this ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  6. Robust factorization

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Fisker, Rune; Åström, Kalle

    2002-01-01

    Factorization algorithms for recovering structure and motion from an image stream have many advantages, but they usually require a set of well-tracked features. Such a set is in generally not available in practical applications. There is thus a need for making factorization algorithms deal effect...

  7. Organizational factors

    International Nuclear Information System (INIS)

    Holy, J.

    1999-12-01

    The following organizational factors are considered with respect to the human factor and operating safety of nuclear power plants: external influences; objectives and strategy; positions and ways of management; allocation of resources; working with human resources; operators' training; coordination of work; knowledge of organization and management; proceduralization of the topic; labour organizing culture; self-improvement system; and communication. (P.A.)

  8. El factoring

    Directory of Open Access Journals (Sweden)

    Alberto Rosenthal

    1988-04-01

    Full Text Available RESUMEN El artículo  presenta, una conceptualización general de lo que es el factoring, el origen del mismo, su evolución y hace una clasificación de los distintos tipos de factoring.

  9. Cerebral Blood Flow Measurements in Adults: A Review on the Effects of Dietary Factors and Exercise

    Directory of Open Access Journals (Sweden)

    Peter J. Joris

    2018-04-01

    Full Text Available Improving cerebrovascular function may be a key mechanism whereby a healthy lifestyle, of which a healthy diet combined with increased physical activity levels is a cornerstone, protects against cognitive impairments. In this respect, effects on cerebral blood flow (CBF—a sensitive physiological marker of cerebrovascular function—are of major interest. This review summarizes the impact of specific dietary determinants and physical exercise on CBF in adults and discusses the relation between these effects with potential changes in cognitive function. A limited number of randomized controlled trials have already demonstrated the beneficial effects of an acute intake of nitrate and polyphenols on CBF, but evidence for a relationship between these effects as well as improvements in cognitive functioning is limited. Moreover, long-term trans-resveratrol supplementation has been shown to increase CBF in populations at increased risk of accelerated cognitive decline. Long-term supplementation of n-3 long-chain polyunsaturated fatty acids may also increase CBF, but related effects on cognitive performance have not yet been found. Significant decreases in cerebral perfusion were observed by commonly consumed amounts of caffeine, while alcohol intake was shown to increase CBF in a dose-dependent way. However, the long-term effects are not clear. Finally, long-term exercise training may be a promising approach to improve CBF, as increases in perfusion may contribute to the beneficial effects on cognitive functioning observed following increased physical activity levels.

  10. El factoring

    Directory of Open Access Journals (Sweden)

    Alberto Rosenthal

    2015-04-01

    Full Text Available RESUMEN Se presenta la segunda parte del artículo aparecido en  el número 6 de la revista EAN. Su contenido es complementario a lo expuesto en dicho número, en está aparecen las ventajas del factoring, conveniencias, limitaciones así como la forma  de efectuar un factor en Colombia,  su necesidad, incidencia económica, etc.

  11. Quality factors

    International Nuclear Information System (INIS)

    Kerr, G.D.

    1986-01-01

    The quality factor, Q, is a dimensionless modifier used in converting absorbed dose, expressed in rads (or grays), to dose equivalent, expressed in rems (or seiverts). The dose equivalent is used in radiation protection to account for the biological effectiveness of different kinds of radiation. The quality factor is related to both the linear energy transfer (LET) and relative biological effectiveness (RBE). The RBE's obtained from biological experiments depend in a complex way on the observed biological effect, the specific test organism, and the experimental conditions. Judgement is involved, therefore, in the choice of the quality factor. Questions regarding the adequacy of current Q values for neutrons were raised first in a 1980 statement by the National Council on Radiation Protection (NCRP) and later in a 1985 statement by the International Commission on Radiological Protection (ICRP). In 1980, the NCRP alerted the technical community to possible future increases between a factor of three and ten in the Q for neutrons, and in 1985, the ICRP suggested an increase by a factor of two in Q for neutrons. Both the ICRP and NRCP are now recommending essentially the same guidance with regard to Q for neutrons: an increase by a factor of two. The Q for neutrons is based on a large, albeit unfocused, body of experimental data. In spite of the lack of focus, the data supporting a change in the neutron quality factor are substantial. However, the proposed doubling of Q for neutrons is clouded by other issues regarding its application. 33 refs., 4 figs., 6 tabs

  12. Neonatal Cerebral Ischemia: A Risk Factor for ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-03-01

    Full Text Available The effect of low neonatal cerebral blood flow (CBF on dopaminergic neurotransmission was studied in 6 genetically susceptible high-risk, preterm neonates followed with attention deficit hyperactivity disorder (ADHD at Aarhus University Hospital, Denmark, and tested at 12-14 years of age.

  13. Risk factors

    International Nuclear Information System (INIS)

    Dennery, M.; Dupont, M.A.

    2007-01-01

    This article deals with the development of risk management in the gas sector business: why a risk factor legal mention must precede any published financial information? Do gas companies have to face new risks? Is there specific risks bound to gas activities? Why companies want to master their risks? Is it mandatory or just a new habit? Do they expect a real benefit in return? These are the risk management questions that are analyzed in this article which is based on the public communication of 15 gas companies randomly selected over the world. The information comes from their annual reports or from documents available on their web sites. The intention of this document is not to be exhaustive or to make statistics but only to shade light on the risk factors of the gas sector. (J.S.)

  14. Organizational factors

    International Nuclear Information System (INIS)

    Wahlstroem, B.; Kettunen, J.

    2005-01-01

    The goal of this lecture is to give an overview of important concepts connected to organisational factors and to provide an understanding of mechanisms by which they can contribute to safe or unsafe behaviour of people. The lecture gives examples of ways to organise work, organisational deficiencies and good practices applied in safety oriented organisations. The lecture also gives an introduction to international work and Finnish national regulation connected to organisation and management. (orig.)

  15. Factor analysis

    CERN Document Server

    Gorsuch, Richard L

    2013-01-01

    Comprehensive and comprehensible, this classic covers the basic and advanced topics essential for using factor analysis as a scientific tool in psychology, education, sociology, and related areas. Emphasizing the usefulness of the techniques, it presents sufficient mathematical background for understanding and sufficient discussion of applications for effective use. This includes not only theory but also the empirical evaluations of the importance of mathematical distinctions for applied scientific analysis.

  16. Naringin promotes osteogenic differentiation of bone marrow stromal cells by up-regulating Foxc2 expression via the IHH signaling pathway.

    Science.gov (United States)

    Lin, Fei-Xiang; Du, Shi-Xin; Liu, De-Zhong; Hu, Qin-Xiao; Yu, Guo-Yong; Wu, Chu-Cheng; Zheng, Gui-Zhou; Xie, Da; Li, Xue-Dong; Chang, Bo

    2016-01-01

    Naringin is an active compound extracted from Rhizoma Drynariae, and studies have revealed that naringin can promote proliferation and osteogenic differentiation of bone marrow stromal cells (BMSCs). In this study, we explored whether naringin could promote osteogenic differentiation of BMSCs by upregulating Foxc2 expression via the Indian hedgehog (IHH) signaling pathway. BMSCs were cultured in basal medium, basal medium with naringin, osteogenic induction medium, osteogenic induction medium with naringin and osteogenic induction medium with naringin in the presence of the IHH inhibitor cyclopamine (CPE). We examined cell proliferation by using a WST-8 assay, and differentiation by Alizarin Red S staining (for mineralization) and alkaline phosphatase (ALP) activity. In addition, we detected core-binding factor α1 (Cbfα1), osteocalcin (OCN), bone sialoprotein (BSP), peroxisome proliferation-activated receptor gamma 2 (PPARγ2) and Foxc2 expression by using RT-PCR. We also determined Foxc2 and IHH protein levels by western blotting. Naringin increased the mineralization of BMSCs, as shown by Alizarin red S assays, and induced ALP activity. In addition, naringin significantly increased the mRNA levels of Foxc2, Cbfα1, OCN, and BSP, while decreasing PPARγ2 mRNA levels. Furthermore, the IHH inhibitor CPE inhibited the osteogenesis-potentiating effects of naringin. Naringin increased Foxc2 and stimulated the activation of IHH, as evidenced by increased expression of proteins that were inhibited by CPE. Our findings indicate that naringin promotes osteogenic differentiation of BMSCs by up-regulating Foxc2 expression via the IHH signaling pathway.

  17. The experimental study of CT-guided hepatocyte growth factor gene therapy for cerebral ischemic diseases

    International Nuclear Information System (INIS)

    Zhang Xiaobo; Jin Zhengyu; Li Mingli; Wang Renzhi; Li Guilin; Kong Yanguo; Wang Jianming; Gao Shan; Guan Hongzhi; Wang Detian; Luo Yufeng

    2006-01-01

    Objectives: To investigate the feasibility of CT guided hepatocyte growth factor (HGF) gene therapy for cerebral ischemic diseases. Methods: Human HGF cDNA was ligated to pIRES 2 -EGFP vector. The recombinant plasmid was transfected into the penumbra tissue with liposome, guided by CT perfusion images. After seven days of transfer with recombinant plasmid, the cut sections of rat brain tissues of the treated and control groups were analyzed including immunohistochemistry, vessel count, cerebral blood flow and infarct volume etc. in order to investigate HGF gene expression and biological effect. Results: Enzymatic digestion and electrophoresis confirmed that HGF fragments had been correctly cloned into the space between the BamH I and Sal I sites of pIRES 2 -EGFP. After 7 days of HGF gene transfection, expression of HGF in transfected neurocytes of treated group was observed with immunohistochemistry. The number of vessels in penumbra tissues transfected with HGF vectors and the CBF measured by perfusion CT all were significantly increased than those of the controls (P 2 -EGFP-HGF complexes can transfect the penumbra tissues and definitely express HGF protein. The HGF gene products can stimulate angiogenesis, promote collateral circulation formation and reduce infarct volume in vivo and therefore is beneficial to the treatment of cerebral ischemia. (authors)

  18. Human factors

    International Nuclear Information System (INIS)

    Brown, G.J.

    1991-01-01

    Recent reactor accidents have spurred the major review, described here, of the contribution of operator personnel to safety in Scottish Nuclear Power Stations. The review aims to identify factors leading to the Chernobyl accident and take preventative measures to avoid possible recurrence. Scottish Nuclear power stations aim to remove the operator from a position where failure to take correct action could lead to a safety hazard. Instead operators concentrate on routine and breakdown maintenance and measures are taken to minimize the probability of operator error. The review concluded that most safety procedures were satisfactory but safety analysis supported by good design practices may offer a significant reduction in the risk of operator error. (UK)

  19. [The role of Smads and related transcription factors in the signal transduction of bone morphogenetic protein inducing bone formation].

    Science.gov (United States)

    Xu, Xiao-liang; Dai, Ke-rong; Tang, Ting-ting

    2003-09-01

    To clarify the mechanisms of the signal transduction of bone morphogenetic proteins (BMPs) inducing bone formation and to provide theoretical basis for basic and applying research of BMPs. We looked up the literature of the role of Smads and related transcription factors in the signal transduction of BMPs inducing bone formation. The signal transduction processes of BMPs included: 1. BMPs combined with type II and type I receptors; 2. the type I receptor phosphorylated Smads; and 3. Smads entered the cell nucleus, interacted with transcription factors and influenced the transcription of related proteins. Smads could be divided into receptor-regulated Smads (R-Smads: Smad1, Smad2, Smad3, Smad5, Smad8 and Smad9), common-mediator Smad (co-Smad: Smad4), and inhibitory Smads (I-Smads: Smad6 and Smad7). Smad1, Smad5, Smad8, and probable Smad9 were involved in the signal transduction of BMPs. Multiple kinases, such as focal adhesion kinase (FAK), Ras-extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K), and Akt serine/threonine kinase were related to Smads signal transduction. Smad1 and Smad5 related with transcription factors included core binding factor A1 (CBFA1), smad-interacting protein 1 (SIP1), ornithine decarboxylase antizyme (OAZ), activating protein-1 (AP-1), xenopus ventralizing homeobox protein-2 (Xvent-2), sandostatin (Ski), antiproliferative proteins (Tob), and homeodomain-containing transcriptian factor-8 (Hoxc-8), et al. CBFA1 could interact with Smad1, Smad2, Smad3, and Smad5, so it was involved in TGF-beta and BMP-2 signal transduction, and played an important role in the bone formation. Cleidocranial dysplasia (CCD) was thought to be caused by heterozygous mutations in CBFA1. The CBFA1 knockout mice showed no osteogenesis and had maturational disturbance of chondrocytes. Smads and related transcription factors, especially Smad1, Smad5, Smad8 and CBFA1, play an important role in the signal transduction of BMPs inducing bone

  20. The effects of low dose X-irradiation on osteoblastic MC3T3-E1 cells in vitro

    Directory of Open Access Journals (Sweden)

    Xu Wei

    2012-06-01

    Full Text Available Abstract Background It has been indicated that moderate or high dose of X-irradiation could delay fracture union and cause osteoradionecrosis, in part, mediated by its effect on proliferation and differentiation of osteoblasts. However, whether low dose irradiation (LDI has similar roles on osteoblasts is still unknown. In this study, we investigated whether and to what extent LDI could affect the proliferation, differentiation and mineralization of osteoblasts in vitro. Methods The MC3T3-E1 cells were exposed to single dose of X-irradiation with 0, 0.1, 0.5, 1.0 Gy respectively. Cell proliferation, apoptosis, alkaline phosphatase (ALP activity, and mineralization was evaluated by methylthiazoletetrazolium (MTT and bromodeoxyuridine (BrdU assay, flow cytometry, ALP viability kit and von Kossa staining, respectively. Osteocalcin (OCN and core-binding factor α1 (Cbfα1 expressions were measured by real time-PCR and western blot, respectively. Results The proliferation of the cells exposed to 2.0 Gy was significantly lower than those exposed to ≤1.0 Gy (p  Conclusions LDI have different effects on proliferation and differentiation of osteoblasts from those of high dose of X-irradiation, which might suggest that LDI could lead to promotion of frature healing through enhancing the differentiation and mineralization of osteoblasts.

  1. Overexpression of a wheat (Triticum aestivum L.) bZIP transcription factor gene, TabZIP6, decreased the freezing tolerance of transgenic Arabidopsis seedlings by down-regulating the expression of CBFs.

    Science.gov (United States)

    Cai, Wangting; Yang, Yaling; Wang, Weiwei; Guo, Guangyan; Liu, Wei; Bi, Caili

    2018-03-01

    The basic leucine zipper (bZIP) proteins play important roles against abiotic stress in plants, including cold stress. However, most bZIPs involved in plant freezing tolerance are positive regulators. Only a few bZIPs function negatively in cold stress response. In this study, TabZIP6, a Group C bZIP transcription factor gene from common wheat (Triticum aestivum L.), was cloned and characterized. The transcript of TabZIP6 was strongly induced by cold treatment (4 °C). TabZIP6 is a nuclear-localized protein with transcriptional activation activity. Arabidopsis plants overexpressing TabZIP6 showed decreased tolerance to freezing stress. Microarray as well as quantitative real-time PCR (qRT-PCR) analysis showed that CBFs and some key COR genes, including COR47 and COR15B, were down-regulated by cold treatment in TabZIP6-overexpressing Arabidopsis lines. TabZIP6 was capable of binding to the G-box motif and the CBF1 and CBF3 promoters in yeast cells. A yeast two-hybrid assay revealed that TabZIP6, as well as the other two Group S bZIP proteins involved in cold stress tolerance in wheat, Wlip19 and TaOBF1, can form homodimers by themselves and heterodimers with each other. These results suggest that TabZIP6 may function negatively in the cold stress response by binding to the promoters of CBFs, and thereby decreasing the expression of downstream COR genes in TabZIP6-overexpressing Arabidopsis seedlings. Copyright © 2018. Published by Elsevier Masson SAS.

  2. Combined Effects of Vascular Endothelial Growth Factor and Bone Morphogenetic Protein 2 on Odonto/Osteogenic Differentiation of Human Dental Pulp Stem Cells In Vitro.

    Science.gov (United States)

    Aksel, Hacer; Huang, George T-J

    2017-06-01

    The purpose of this study was to investigate whether combined and concerted delivery of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) enhances odonto/osteogenic differentiation of human dental pulp stem cells (DPSCs) in vitro. Various concentrations of VEGF and/or BMP-2 with or without the presence of odonto/osteogenic medium (OM) were added into DPSC cultures for 21 days. The mineral formation in cultures was evaluated using alizarin red stain (ARS). Optimal concentrations of VEGF and BMP-2 were codelivered to DPSCs for total of 21 days with the following experimental groups: (1) group 1: OM only, (2) group 2: OM + VEGF, (3) group 3: OM + BMP-2, and (4) group 4: OM + VEGF + BMP-2 (subgroup 4a: VEGF present the first 7 days, 4b: BMP-2 present the last 14 days, and 4c, both present for 21 days). Cultures were then subjected to quantitative ARS analysis or harvested for quantitative polymerase chain reaction analysis for the expression of core-binding factor alpha 1 (CBFA1), alkaline phosphatase (ALP), and dentin matrix protein 1 (DMP-1). No mineral formation was detected by ARS when VEGF and/or BMP-2 were used without OM. OM + VEGF, but not OM + BMP-2, formed more mineralization than OM (P  .05) in the expression of the 3 genes. VEGF addition in the early phase rather than a continuous presence of both VEGF and BMP-2 enhances odonto/osteogenic differentiation of DPSCs. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. Banana NAC transcription factor MusaNAC042 is positively associated with drought and salinity tolerance.

    Science.gov (United States)

    Tak, Himanshu; Negi, Sanjana; Ganapathi, T R

    2017-03-01

    Banana is an important fruit crop and its yield is hampered by multiple abiotic stress conditions encountered during its growth. The NAC (NAM, ATAF, and CUC) transcription factors are involved in plant response to biotic and abiotic stresses. In the present study, we studied the induction of banana NAC042 transcription factor in drought and high salinity conditions and its overexpression in transgenic banana to improve drought and salinity tolerance. MusaNAC042 expression was positively associated with stress conditions like salinity and drought and it encoded a nuclear localized protein. Transgenic lines of banana cultivar Rasthali overexpressing MusaNAC042 were generated by Agrobacterium-mediated transformation of banana embryogenic cells and T-DNA insertion was confirmed by PCR and Southern blot analysis. Our results using leaf disc assay indicated that transgenic banana lines were able to tolerate drought and high salinity stress better than the control plants and retained higher level of total chlorophyll and lower level of MDA content (malondialdehyde). Transgenic lines analyzed for salinity (250 mM NaCl) and drought (Soil gravimetric water content 0.15) tolerance showed higher proline content, better Fv/Fm ratio, and lower levels of MDA content than control suggesting that MusaNAC042 may be involved in responses to higher salinity and drought stresses in banana. Expression of several abiotic stress-related genes like those coding for CBF/DREB, LEA, and WRKY factors was altered in transgenic lines indicating that MusaNAC042 is an efficient modulator of abiotic stress response in banana.

  4. Cerebral Blood Flow during Rest Associates with General Intelligence and Creativity

    Science.gov (United States)

    Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Nagase, Tomomi; Nouchi, Rui; Kawashima, Ryuta

    2011-01-01

    Recently, much scientific attention has been focused on resting brain activity and its investigation through such methods as the analysis of functional connectivity during rest (the temporal correlation of brain activities in different regions). However, investigation of the magnitude of brain activity during rest has focused on the relative decrease of brain activity during a task, rather than on the absolute resting brain activity. It is thus necessary to investigate the association between cognitive factors and measures of absolute resting brain activity, such as cerebral blood flow (CBF), during rest (rest-CBF). In this study, we examined this association using multiple regression analyses. Rest-CBF was the dependent variable and the independent variables included two essential components of cognitive functions, psychometric general intelligence and creativity. CBF was measured using arterial spin labeling and there were three analyses for rest-CBF; namely mean gray matter rest-CBF, mean white matter rest-CBF, and regional rest-CBF. The results showed that mean gray and white matter rest-CBF were significantly and positively correlated with individual psychometric intelligence. Furthermore, mean white matter rest-CBF was significantly and positively correlated with creativity. After correcting the effect of mean gray matter rest-CBF the significant and positive correlation between regional rest-CBF in the perisylvian anatomical cluster that includes the left superior temporal gyrus and insula and individual psychometric intelligence was found. Also, regional rest-CBF in the precuneus was significantly and negatively correlated with individual creativity. Significance of these results of regional rest-CBF did not change when the effect of regional gray matter density was corrected. The findings showed mean and regional rest-CBF in healthy young subjects to be correlated with cognitive functions. The findings also suggest that, even in young cognitively intact

  5. Heart disease - risk factors

    Science.gov (United States)

    Heart disease - prevention; CVD - risk factors; Cardiovascular disease - risk factors; Coronary artery disease - risk factors; CAD - risk ... a certain health condition. Some risk factors for heart disease you cannot change, but some you can. ...

  6. Statistical parametric mapping analysis of the relationship between regional cerebral blood flow and symptom clusters of the depressive mood in patients with pre-dialytic chronic kidney disease

    International Nuclear Information System (INIS)

    Kim, Seong-Jang; Song, Sang Heon; Kim, Ji Hoon; Kwak, Ihm Soo

    2008-01-01

    The aim of this study is to investigate the relationship between regional cerebral blood flow (rCBF) and symptom clusters of depressive mood in pre-dialytic chronic kidney disease (CKD). Twenty-seven patients with stage 4-5 CKD were subjected to statistical parametric mapping analysis of brain single-photon emission computed tomography. Correlation analyses between separate symptom clusters of depressive mood and rCBF were done. The first factor (depressive mood) was negatively correlated with rCBF in the right insula, posterior cingulate gyrus, and left superior temporal gyrus, and positively correlated with rCBF in the left fusiform gyrus. The second factor (insomnia) was negatively correlated with rCBF in the right middle frontal gyrus, bilateral cingulate gyri, right insula, right putamen, and right inferior parietal lobule, and positively correlated with rCBF in left fusiform gyrus and bilateral cerebellar tonsils. The third factor (anxiety and psychomotor aspects) was negatively correlated with rCBF in the left inferior frontal gyms, right superior frontal gyms, right middle temporal gyrus, right superior temporal gyrus, and left superior frontal gyrus, and positively correlated with rCBF in the right ligual gyrus and right parahippocampal gyrus. In this study, the separate symptom clusters were correlated with specific rCBF patterns similar to those in major depressive disorder patients without CKD. However, some areas with discordant rCBF patterns were also noted when compared with major depressive disorder patients. Further larger scale investigations are needed. (author)

  7. Risk factor analysis of cerebral white matter hyperintensities in children with sickle cell disease

    NARCIS (Netherlands)

    van der Land, Veronica; Mutsaerts, Henri J. M. M.; Engelen, Marc; Heijboer, Harriët; Roest, Mark; Hollestelle, Martine J.; Kuijpers, Taco W.; Nederkoorn, Paul J.; Cnossen, Marjon H.; Majoie, Charles B. L. M.; Nederveen, Aart J.; Fijnvandraat, Karin

    2016-01-01

    Sickle cell disease (SCD) is complicated by silent cerebral infarcts, visible as white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI). Both local vaso-occlusion, elicited by endothelial dysfunction, and insufficiency of cerebral blood flow (CBF) have been proposed to be involved

  8. Cutaneous and subcutaneous blood flow measurements in psoriasis

    International Nuclear Information System (INIS)

    Klemp, P.

    1987-01-01

    The experiments - published in 7 papers in The Journal of Investigative Dermatology 1983-86 - have demonstrated: 1. The accuracy of the local 133 Xe washout method is about 15% for estimation of the cutaneous blood flow (CBF), and about 10% for subcutaneous blood flow measurements (SBF). In measurements of absolute CBF values a graphic curve resolution of the washout curve should alwaus be performed. Otherwise the CBF might be considerably underestimated. 2. CdTe(Cl) mini-detectors can be attached directly to the skin, and might yield measurements of both CBF and SBF that can substitute for those made with conventional detectors. 3. The laser Doppler measurements could not be correlated to quantitative measurements of the CBF. 4. The tissue-to-blood partition coefficient for 133 Xe of lesional psoriatic skin (LS) is increased. 5. In untreated, LS of patients with active psoriasis the CBF is about a factor of 10 times higher than the CBF of normal individuals. In non-lesional skin (NLS) of patients with active psoriasis the CBF is about a factor of 2 higher than the CBF of normal individuals. However, the CBF did not differ in NLS of patients with minimal skin manifestations. The high CBF decreases gradualy during antipsoriatic treatment. 6. A paradoxical autoregulation of the CBF was observed in LS. 7. The high CBF is not due to a maximally dilated vascular bed. 8. The SBF in LS areas was a factor of higher than the SBF in normal individuals. 9. A normal, local regulation of the SBF was found. (author)

  9. Electroweak form factors

    International Nuclear Information System (INIS)

    Singh, S.K.

    2002-01-01

    The present status of electroweak nucleon form factors and the N - Δ transition form factors is reviewed. Particularly the determination of dipole mass M A in the axial vector form factor is discussed

  10. Risk Factors for Scleroderma

    Science.gov (United States)

    ... You are here: Home For Patients Risk Factors Risk Factors for Scleroderma The cause of scleroderma is ... what biological factors contribute to scleroderma pathogenesis. Genetic Risk Scleroderma does not tend to run in families ...

  11. Risk Factors and Prevention

    Science.gov (United States)

    ... Resources Risk Factors & Prevention Back to Patient Resources Risk Factors & Prevention Even people who look healthy and ... Blood Pressure , high cholesterol, diabetes, and thyroid disease. Risk Factors For Arrhythmias and Heart Disease The following ...

  12. Factors and factorizations of graphs proof techniques in factor theory

    CERN Document Server

    Akiyama, Jin

    2011-01-01

    This book chronicles the development of graph factors and factorizations. It pursues a comprehensive approach, addressing most of the important results from hundreds of findings over the last century. One of the main themes is the observation that many theorems can be proved using only a few standard proof techniques. This stands in marked contrast to the seemingly countless, complex proof techniques offered by the extant body of papers and books. In addition to covering the history and development of this area, the book offers conjectures and discusses open problems. It also includes numerous explanatory figures that enable readers to progressively and intuitively understand the most important notions and proofs in the area of factors and factorization.

  13. Sources of variability of resting cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Kruuse, Christina Rostrup; Olesen, Jes

    2013-01-01

    Measurements of cerebral blood flow (CBF) show large variability among healthy subjects. The aim of the present study was to investigate the relative effect of established factors influencing CBF on the variability of resting CBF. We retrospectively analyzed spontaneous variability in 430 CBF...... measurements acquired in 152 healthy, young subjects using (133)Xe single-photon emission computed tomography. Cerebral blood flow was correlated positively with both end-tidal expiratory PCO2 (PETCO2) and female gender and inversely with hematocrit (Hct). Between- and within-subject CO2 reactivity...... when Hct was also accounted for. The present study confirms large between-subject variability in CBF measurements and that gender, Hct, and PETCO2 explain only a small part of this variability. This implies that a large fraction of CBF variability may be due to unknown factors such as differences...

  14. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  15. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  16. Foundations of factor analysis

    CERN Document Server

    Mulaik, Stanley A

    2009-01-01

    Introduction Factor Analysis and Structural Theories Brief History of Factor Analysis as a Linear Model Example of Factor AnalysisMathematical Foundations for Factor Analysis Introduction Scalar AlgebraVectorsMatrix AlgebraDeterminants Treatment of Variables as Vectors Maxima and Minima of FunctionsComposite Variables and Linear Transformations Introduction Composite Variables Unweighted Composite VariablesDifferentially Weighted Composites Matrix EquationsMulti

  17. Blood coagulation factor VIII

    Indian Academy of Sciences (India)

    Factor VIII (FVIII) functions as a co-factor in the blood coagulation cascade for the proteolytic activation of factor X by factor IXa. Deficiency of FVIII causes hemophilia A, the most commonly inherited bleeding disorder. This review highlights current knowledge on selected aspects of FVIII in which both the scientist and the ...

  18. Constructivism, Factoring, and Beliefs.

    Science.gov (United States)

    Rauff, James V.

    1994-01-01

    Discusses errors made by remedial intermediate algebra students in factoring polynomials in light of student definitions of factoring. Found certain beliefs about factoring to logically imply many of the errors made. Suggests that belief-based teaching can be successful in teaching factoring. (16 references) (Author/MKR)

  19. Factors affecting construction performance: exploratory factor analysis

    Science.gov (United States)

    Soewin, E.; Chinda, T.

    2018-04-01

    The present work attempts to develop a multidimensional performance evaluation framework for a construction company by considering all relevant measures of performance. Based on the previous studies, this study hypothesizes nine key factors, with a total of 57 associated items. The hypothesized factors, with their associated items, are then used to develop questionnaire survey to gather data. The exploratory factor analysis (EFA) was applied to the collected data which gave rise 10 factors with 57 items affecting construction performance. The findings further reveal that the items constituting ten key performance factors (KPIs) namely; 1) Time, 2) Cost, 3) Quality, 4) Safety & Health, 5) Internal Stakeholder, 6) External Stakeholder, 7) Client Satisfaction, 8) Financial Performance, 9) Environment, and 10) Information, Technology & Innovation. The analysis helps to develop multi-dimensional performance evaluation framework for an effective measurement of the construction performance. The 10 key performance factors can be broadly categorized into economic aspect, social aspect, environmental aspect, and technology aspects. It is important to understand a multi-dimension performance evaluation framework by including all key factors affecting the construction performance of a company, so that the management level can effectively plan to implement an effective performance development plan to match with the mission and vision of the company.

  20. The joy of factoring

    CERN Document Server

    Wagstaff, Samuel S

    2013-01-01

    This book is about the theory and practice of integer factorization presented in a historic perspective. It describes about twenty algorithms for factoring and a dozen other number theory algorithms that support the factoring algorithms. Most algorithms are described both in words and in pseudocode to satisfy both number theorists and computer scientists. Each of the ten chapters begins with a concise summary of its contents. The book starts with a general explanation of why factoring integers is important. The next two chapters present number theory results that are relevant to factoring. Further on there is a chapter discussing, in particular, mechanical and electronic devices for factoring, as well as factoring using quantum physics and DNA molecules. Another chapter applies factoring to breaking certain cryptographic algorithms. Yet another chapter is devoted to practical vs. theoretical aspects of factoring. The book contains more than 100 examples illustrating various algorithms and theorems. It also co...

  1. Natural variation in monoterpene synthesis in kiwifruit: transcriptional regulation of terpene synthases by NAC and ETHYLENE-INSENSITIVE3-like transcription factors.

    Science.gov (United States)

    Nieuwenhuizen, Niels J; Chen, Xiuyin; Wang, Mindy Y; Matich, Adam J; Perez, Ramon Lopez; Allan, Andrew C; Green, Sol A; Atkinson, Ross G

    2015-04-01

    Two kiwifruit (Actinidia) species with contrasting terpene profiles were compared to understand the regulation of fruit monoterpene production. High rates of terpinolene production in ripe Actinidia arguta fruit were correlated with increasing gene and protein expression of A. arguta terpene synthase1 (AaTPS1) and correlated with an increase in transcript levels of the 2-C-methyl-D-erythritol 4-phosphate pathway enzyme 1-deoxy-D-xylulose-5-phosphate synthase (DXS). Actinidia chinensis terpene synthase1 (AcTPS1) was identified as part of an array of eight tandemly duplicated genes, and AcTPS1 expression and terpene production were observed only at low levels in developing fruit. Transient overexpression of DXS in Nicotiana benthamiana leaves elevated monoterpene synthesis by AaTPS1 more than 100-fold, indicating that DXS is likely to be the key step in regulating 2-C-methyl-D-erythritol 4-phosphate substrate flux in kiwifruit. Comparative promoter analysis identified potential NAC (for no apical meristem [NAM], Arabidopsis transcription activation factor [ATAF], and cup-shaped cotyledon [CUC])-domain transcription factor) and ETHYLENE-INSENSITIVE3-like transcription factor (TF) binding sites in the AaTPS1 promoter, and cloned members of both TF classes were able to activate the AaTPS1 promoter in transient assays. Electrophoretic mobility shift assays showed that AaNAC2, AaNAC3, and AaNAC4 bind a 28-bp fragment of the proximal NAC binding site in the AaTPS1 promoter but not the A. chinensis AcTPS1 promoter, where the NAC binding site was mutated. Activation could be restored by reintroducing multiple repeats of the 12-bp NAC core-binding motif. The absence of NAC transcriptional activation in ripe A. chinensis fruit can account for the low accumulation of AcTPS1 transcript, protein, and monoterpene volatiles in this species. These results indicate the importance of NAC TFs in controlling monoterpene production and other traits in ripening fruits. © 2015 American

  2. Natural Variation in Monoterpene Synthesis in Kiwifruit: Transcriptional Regulation of Terpene Synthases by NAC and ETHYLENE-INSENSITIVE3-Like Transcription Factors1

    Science.gov (United States)

    Nieuwenhuizen, Niels J.; Chen, Xiuyin; Wang, Mindy Y.; Matich, Adam J.; Perez, Ramon Lopez; Allan, Andrew C.; Green, Sol A.; Atkinson, Ross G.

    2015-01-01

    Two kiwifruit (Actinidia) species with contrasting terpene profiles were compared to understand the regulation of fruit monoterpene production. High rates of terpinolene production in ripe Actinidia arguta fruit were correlated with increasing gene and protein expression of A. arguta terpene synthase1 (AaTPS1) and correlated with an increase in transcript levels of the 2-C-methyl-d-erythritol 4-phosphate pathway enzyme 1-deoxy-d-xylulose-5-phosphate synthase (DXS). Actinidia chinensis terpene synthase1 (AcTPS1) was identified as part of an array of eight tandemly duplicated genes, and AcTPS1 expression and terpene production were observed only at low levels in developing fruit. Transient overexpression of DXS in Nicotiana benthamiana leaves elevated monoterpene synthesis by AaTPS1 more than 100-fold, indicating that DXS is likely to be the key step in regulating 2-C-methyl-d-erythritol 4-phosphate substrate flux in kiwifruit. Comparative promoter analysis identified potential NAC (for no apical meristem [NAM], Arabidopsis transcription activation factor [ATAF], and cup-shaped cotyledon [CUC])-domain transcription factor) and ETHYLENE-INSENSITIVE3-like transcription factor (TF) binding sites in the AaTPS1 promoter, and cloned members of both TF classes were able to activate the AaTPS1 promoter in transient assays. Electrophoretic mobility shift assays showed that AaNAC2, AaNAC3, and AaNAC4 bind a 28-bp fragment of the proximal NAC binding site in the AaTPS1 promoter but not the A. chinensis AcTPS1 promoter, where the NAC binding site was mutated. Activation could be restored by reintroducing multiple repeats of the 12-bp NAC core-binding motif. The absence of NAC transcriptional activation in ripe A. chinensis fruit can account for the low accumulation of AcTPS1 transcript, protein, and monoterpene volatiles in this species. These results indicate the importance of NAC TFs in controlling monoterpene production and other traits in ripening fruits. PMID:25649633

  3. Molecular basis of Acute Myelogenous Leukemia As bases moleculares da leucemia mielóide aguda

    Directory of Open Access Journals (Sweden)

    Eduardo M. Rego

    2002-01-01

    Full Text Available Acute Myelogenous Leukemia (AML is frequently associated with recurring chromosomal translocations, which lead to the fusion of two genes encoding transcription factors. As the moieties of these fusion proteins retain part of the functional domains of the wild-type proteins, they may interfere directly or indirectly with the transcriptional regulation of the leukemic cell, conferring survival advantage. The majority of the transcription factors commonly involved in recurring chromosomal translocations may be grouped in one of the following families: core binding factor (CBF, retinoic acid receptor alpha (RARalpha, homeobox (HOX family, and mixed lineage leukemia (MLL. In vivo analysis of the molecular basis of leukemogenesis through the generation of transgenic mouse models revealed that a common theme is the recruitment of transcriptional co-activators and co-repressors by these fusion proteins. However, the expression of the fusion protein is not sufficient to induce full blown leukemia, as evidenced in part by the long latencies required for disease development in the transgenic models of leukemia, and therefore, second mutagenic events may contribute to AML pathogenesis.A leucemia mielóide aguda (LMA está freqüentemente associada a translocações cromossômicas recorrentes. Em muitos casos, os genes presentes nos pontos de quebra cromossômica são conhecidos e, quase todos codificam para fatores de transcrição. O gene híbrido, resultante da justaposição de exons de genes distintos, codifica para proteínas de fusão. Como estas retêm a maior parte dos domínios funcionais das proteínas selvagens, elas interferem direta ou indiretamente com regulação da transcrição gênica, conferindo vantagem à sobrevivência das células leucêmicas. A maioria dos fatores de transcrição afetados pelas translocações cromossômicas associadas a LMA pode ser agrupada numa das seguintes famílias: dos core binding factors (CBF, do receptor

  4. Factor VII deficiency

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000548.htm Factor VII deficiency To use the sharing features on this page, please enable JavaScript. Factor VII (seven) deficiency is a disorder caused by a ...

  5. Annual Adjustment Factors

    Data.gov (United States)

    Department of Housing and Urban Development — The Department of Housing and Urban Development establishes the rent adjustment factors - called Annual Adjustment Factors (AAFs) - on the basis of Consumer Price...

  6. Stroke - risk factors

    Science.gov (United States)

    ... oxygen. Brain cells can die, causing lasting damage. Risk factors are things that increase your chance of ... a disease or condition. This article discusses the risk factors for stroke and things you can do ...

  7. rCBF SPECT in Parkinson's disease patients with mental dysfunction

    International Nuclear Information System (INIS)

    Bissessur, S.; Tissingh, G.; Wolters, E.C.; Scheltens, P.

    1997-01-01

    Functional imaging of the brain using SPECT provides information correlative to the alterations of regional blood flow. In this paper we review the literature pertaining to SPECT in Parkinson's disease with and without dementia and depression. Parkinson's disease itself is not associated with a consistent pattern of cerebral blood flow alterations in the basal ganglia, but reduced parietal blood flow is more often reported. The heterogeneity of blood flow changes possibly reflects the multifactorial pathophysiology of the disease. In demented Parkinson's disease patients frontal hypoperfusion is often found or bilateral temporoparietal deficits, probably indicative of concomitant Alzheimer's disease. The SPECT studies undertaken in depressed patients with and without Parkinson's disease show highly conflicting and inconsistent results, probably due to methodological and diagnostic flaws (especially the inclusion of demented Parkinson patients). Several lines of reasoning point to a prefrontal dysfunction and future SPECT studies are planned to study this region in non-demented Parkinson's disease patients with and without major depression. (author)

  8. Cortical and subcortical hyperfusion during migraine and cluster headache measured by Xe CT-CBF

    International Nuclear Information System (INIS)

    Kobari, M.; Meyer, J.S.; Ichijo, M.; Kawamura, J.; Baylor Univ., Houston, TX

    1990-01-01

    High-resolution, color-coded images of local cerebral blood flow (LCBF) were made utilizing stable xenon-enhanced computed tomography among patients with common migraine (n=18), classic migraine (n=12) and cluster headache (n=5). During spontaneously occurring headache in common and classic migraine patients, LCBF values for cerebral cortex and subcortical gray and white matter were diffusely increased by 20-40% with the exception of the occipital lobes. LCBF increases involved both hemispheres whether the head pain was unilateral or bilateral. No significant differences were noted in the degree or pattern of LCBF increases during headaches of common and classic migraineurs. Similar cerebral hyperperfusion of greater magnitude was observed during cluster headaches but was more prominent on the side of the head pain. Present observations do not support the hypothesis of spreading cortical depression as a cause of classic migraine. From a hemodynamic viewpoint, LCBF increases during headaches of common or classic migraine or cluster appear similar. Evidence is adduced that sympathetic hypofunction with denervation hypersensitivity of cerebral vessels plays a role in the cerebral hyperperfusion of migraine headaches. More pronounced unilateral autonomic derangements appear to account for the symptoms and cerebral hyperperfusion associated with cluster headaches. (orig.)

  9. CBF-measurement of Xe-133 inhalation. Validity and clinical applications in psychiatry

    International Nuclear Information System (INIS)

    Risberg, J.

    1980-01-01

    Some methodological questions are dealt with, especially elimination of influence from non-cerebral sources of radiation. Experience from clinical applications of the method in psychiatry are briefly reviewed. (Auth.)

  10. rCBF differences between panic disorder patients and control subjects during anticipatory anxiety and rest

    NARCIS (Netherlands)

    Boshuisen, ML; Ter Horst, GJ; Paans, AMJ; Reinders, AATS; den Boer, JA

    2002-01-01

    Background: Our goal was to identify brain structures involved in anticipatory anxiety in panic disorder (PD) patients compared to control subjects. Methods: Seventeen PD patients and 21 healthy control subjects were studied with H, 150 positron emission oil tomography scan, before and after a

  11. Human factors in training

    International Nuclear Information System (INIS)

    Dutton, J.W.; Brown, W.R.

    1981-01-01

    The Human Factors concept is a focused effort directed at those activities which require human involvement. Training is, by its nature, an activity totally dependent on the Human Factor. This paper identifies several concerns significant to training situations and discusses how Human Factor awareness can increase the quality of learning. Psychology in the training arena is applied Human Factors. Training is a method of communication represented by sender, medium, and receiver. Two-thirds of this communications model involves the human element directly

  12. Neutron electromagnetic form factors

    International Nuclear Information System (INIS)

    Finn, J.M.; Madey, R.; Eden, T.; Markowitz, P.; Rutt, P.M.; Beard, K.; Anderson, B.D.; Baldwin, A.R.; Keane, D.; Manley, D.M.; Watson, J.W.; Zhang, W.M.; Kowalski, S.; Bertozzi, W.; Dodson, G.; Farkhondeh, M.; Dow, K.; Korsch, W.; Tieger, D.; Turchinetz, W.; Weinstein, L.; Gross, F.; Mougey, J.; Ulmer, P.; Whitney, R.; Reichelt, T.; Chang, C.C.; Kelly, J.J.; Payerle, T.; Cameron, J.; Ni, B.; Spraker, M.; Barkhuff, D.; Lourie, R.; Verst, S.V.; Hyde-Wright, C.; Jiang, W.-D.; Flanders, B.; Pella, P.; Arenhoevel, H.

    1992-01-01

    Nucleon form factors provide fundamental input for nuclear structure and quark models. Current knowledge of neutron form factors, particularly the electric form factor of the neutron, is insufficient to meet these needs. Developments of high-duty-factor accelerators and polarization-transfer techniques permit new experiments that promise results with small sensitivities to nuclear models. We review the current status of the field, our own work at the MIT/Bates linear accelerator, and future experimental efforts

  13. Disconnected electromagnetic form factors

    International Nuclear Information System (INIS)

    Wilcox, Walter

    2001-01-01

    Preliminary results of a calculation of disconnected nucleon electromagnetic factors factors on the lattice are presented. The implementation of the numerical subtraction scheme is outlined. A comparison of results for electric and magnetic disconnected form factors on two lattice sizes with those of the Kentucky group is presented. Unlike previous results, the results found in this calculation are consistent with zero in these sectors

  14. Mesonic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Frederic D. R. Bonnet; Robert G. Edwards; George T. Fleming; Randal Lewis; David Richards

    2003-07-22

    We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors.

  15. Cerebral blood flow in patients with thalamic hemorrhage, 2

    International Nuclear Information System (INIS)

    Ueda, Mikiya; Matsumoto, Yukihiro; Omiya, Nobuyuki; Mikami, Junichi; Sato, Hiroyuki; Inoue, Yoshitoshi; Okawara, Shuji; Matsuoka, Takahiro; Takeda, Satoshi.

    1989-01-01

    In twenty-nine patients with thalamic hemorrhage, single photon emission CT (SPECT) and CT were performed in the acute stage. Measurement of cerebral blood flow (CBF) was performed by the 133-Xe inhalation method using SPECT (Tomomatic 64). CT findings such as hematoma volume, involvement of internal capsule, ventricular hematoma and topographical localization of hematoma were investigated. We studied etiological analysis of decreased CBF in the acute stage. CBF values in the group of large-volume hematoma (≥10 ml) decreased moderately on the hematoma side and mildly on the nonhematoma side. CBF values in the group of small-volume hematoma (<10 ml) decreased mildly on the hematoma side but didn't decrease on the nonhematoma side. CBF values of the former on the hematoma side decreased significantly compared with the latter. Linear correlation between hematoma volume and CBF was significant. As to topographical localization, CBF values of the group which involved medial thalamus decreased significantly compared with the other group. Factors of involvement of internal capsule and ventricular hematoma didn't affect CBF values. In conclusion, major factors which affected decreased CBF in the acute stage were hematoma volume and tomographical localization. (author)

  16. demographic factors associated factors associated with malaria

    African Journals Online (AJOL)

    userpc

    .8%) than those in other nce of 35.4% which was actors can predispose alence of malaria in a study were significantly eveloping guidelines and more effective disease endemic areas (Bashar et therefore attempts to rmation on possible demographic factors d out in four selected geria; Major Ibrahim B. Hospital Zaria, Hajiya.

  17. Aspects of QCD factorization

    International Nuclear Information System (INIS)

    Neubert, Matthias

    2001-01-01

    The QCD factorization approach provides the theoretical basis for a systematic analysis of nonleptonic decay amplitudes of B mesons in the heavy-quark limit. After recalling the basic ideas underlying this formalism, several tests of QCD factorization in the decays B→D (*) L, B→K * γ, and B→πK, ππ are discussed. It is then illustrated how factorization can be used to obtain new constraints on the parameters of the unitarity triangle

  18. Oversimplifying quantum factoring.

    Science.gov (United States)

    Smolin, John A; Smith, Graeme; Vargo, Alexander

    2013-07-11

    Shor's quantum factoring algorithm exponentially outperforms known classical methods. Previous experimental implementations have used simplifications dependent on knowing the factors in advance. However, as we show here, all composite numbers admit simplification of the algorithm to a circuit equivalent to flipping coins. The difficulty of a particular experiment therefore depends on the level of simplification chosen, not the size of the number factored. Valid implementations should not make use of the answer sought.

  19. Radioimmunoassay of human Hageman factor (factor XII)

    International Nuclear Information System (INIS)

    Saito, H.; Ratnoff, O.D.; Pensky, J.

    1976-01-01

    A specific, sensitive, and reproducible radioimmunoassay for human Hageman factor (HF, factor XII) has been developed with purified human HF and monospecific rabbit antibody. Precise measurements of HF antigen were possible for concentrations as low as 0.1 percent of that in normal pooled plasma. A good correlation (correlation coefficient = 0.82) existed between the titers of HF measured by clot-promoting assays and radioimmunoassays among 42 normal adults. Confirming earlier studies, HF antigen was absent in Hageman trait plasma, but other congenital deficient plasmas, including those of individuals with Fletcher trait and Fitzgerald trait, contained normal amounts of HF antigen. HF antigen was reduced in the plasmas of patients with disseminated intravascular coagulation or advanced liver cirrhosis, but it was normal in those of patients with chronic renal failure or patients under treatment with warfarin. HF antigen was detected by this assay in plasmas of primates, but not detectable in plasmas of 11 nonprimate mammalian and one avian species

  20. What Are Rare Clotting Factor Deficiencies?

    Science.gov (United States)

    ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ... Deficiency Factor V Deficiency Combined FV & FVIII Deficiencies Factor VII Deficiency Factor X Deficiency Factor XI Deficiency Factor ...

  1. PAYMENT CAPACITY SENSITIVITY FACTORS

    Directory of Open Access Journals (Sweden)

    Daniel BRÎNDESCU – OLARIU

    2014-11-01

    The results of the study facilitate the determination and classification of the main sensitivity factors for the payment capacity at sample level, the establishment of general benchmarks for the payment capacity (as no such benchmarks currently exist in the Romanian literature and the identification of the mechanisms through which the variation of different factors impacts the payment capacity.

  2. Respirator field performance factors

    International Nuclear Information System (INIS)

    Skaggs, B.J.; DeField, J.D.; Strandberg, S.W.; Sutcliffe, C.R.

    1985-01-01

    The Industrial Hygiene Group assisted OSHA and the NRC in measurements of respirator performance under field conditions. They reviewed problems associated with sampling aerosols within the respirator in order to determine fit factors (FFs) or field performance factor (FPF). In addition, they designed an environmental chamber study to determine the effects of temperature and humidity on a respirator wearer

  3. Factors affecting nuclear development

    International Nuclear Information System (INIS)

    Stevens, G.H.; Girouard, P.

    1995-01-01

    Among the factors affecting nuclear development, some depend more or less on public authorities, but many are out of public authorities control (foreign policies, market and deregulation, socials and environmental impacts, public opinion). As far as possible, the following study tries to identify those factors. (D.L.). 2 photos

  4. Soil Forming Factors

    Science.gov (United States)

    It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils Soil Forming Factors 2 A Top to Bottom Guide 3 Making a Soil Monolith 4 Soil Orders 5 State Soil Monoliths 6 Where in the Soil World Are You? >> A Top to

  5. Hemoglobin, hematocrit, and changes in cerebral blood flow: the Second Manifestations of ARTerial disease-Magnetic Resonance study.

    Science.gov (United States)

    van der Veen, Pieternella H; Muller, Majon; Vincken, Koen L; Westerink, Jan; Mali, Willem P T M; van der Graaf, Yolanda; Geerlings, Mirjam I

    2015-03-01

    Hemoglobin and hematocrit are important determinants of blood viscosity and arterial oxygen content and may therefore influence cerebral blood flow (CBF). We examined cross-sectional and prospective associations of hemoglobin and hematocrit with CBF in 569 patients with manifest arterial disease (mean age 57 ± 10 years) with available data on magnetic resonance angiography to measure parenchymal CBF. Mean (SD) parenchymal CBF at baseline was 52.3 (9.8) mL/min/100 mL and decreased with 1.5 (11.0) mL/min/100 mL after on average 3.9 years of follow-up. Linear regression analyses showed that greater hemoglobin and hematocrit values were associated with lower baseline parenchymal CBF and more decline in parenchymal CBF over time, independent of cardiovascular risk factors, use of antiplatelet drugs, anticoagulants, or diuretics, and brain measures: adjusted mean differences (95% confidence interval [CI]) in decline in parenchymal CBF between patients in the lower and upper quartiles of hemoglobin and hematocrit were -2.48 (95% CI -3.70 to -1.25) and -3.69 (95% CI -5.45 to -1.94) mL/min/100 mL. Higher hemoglobin and hematocrit were associated with lower baseline parenchymal CBF and a greater decline in parenchymal CBF over time, possibly as a result of physiological compensating mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Two-factor authentication

    CERN Document Server

    Stanislav, Mark

    2015-01-01

    During the book, readers will learn about the various technical methods by which two-factor authentication is implemented, security concerns with each type of implementation, and contextual details to frame why and when these technologies should be used. Readers will also be provided with insight about the reasons that two-factor authentication is a critical security control, events in history that have been important to prove why organization and individual would want to use two factor, and core milestones in the progress of growing the market.

  7. Business Intelligence Success Factors

    DEFF Research Database (Denmark)

    Gaardboe, Rikke; Jonasen, Tanja Svarre

    2018-01-01

    Business intelligence (BI) is a strategically important practice in many organizations. Several studies have investigated the factors that contribute to BI success; however, an overview of the critical success factors (CSFs) involved is lacking in the extant literature. We have integrated...... 34 CSFs related to BI success. The distinct CSFs identified in the extant literature relate to project management skills (13 papers), management support (20 papers), and user involvement (11 papers). In the articles with operationalized BI success, we found several distinct factors: system quality...

  8. Human factor reliability program

    International Nuclear Information System (INIS)

    Knoblochova, L.

    2017-01-01

    The human factor's reliability program was at Slovenske elektrarne, a.s. (SE) nuclear power plants. introduced as one of the components Initiatives of Excellent Performance in 2011. The initiative's goal was to increase the reliability of both people and facilities, in response to 3 major areas of improvement - Need for improvement of the results, Troubleshooting support, Supporting the achievement of the company's goals. The human agent's reliability program is in practice included: - Tools to prevent human error; - Managerial observation and coaching; - Human factor analysis; -Quick information about the event with a human agent; -Human reliability timeline and performance indicators; - Basic, periodic and extraordinary training in human factor reliability(authors)

  9. [Human factors in medicine].

    Science.gov (United States)

    Lazarovici, M; Trentzsch, H; Prückner, S

    2017-01-01

    The concept of human factors is commonly used in the context of patient safety and medical errors, all too often ambiguously. In actual fact, the term comprises a wide range of meanings from human-machine interfaces through human performance and limitations up to the point of working process design; however, human factors prevail as a substantial cause of error in complex systems. This article presents the full range of the term human factors from the (emergency) medical perspective. Based on the so-called Swiss cheese model by Reason, we explain the different types of error, what promotes their emergence and on which level of the model error prevention can be initiated.

  10. Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

    Background: Positron emission tomography (PET) imaging of anaesthetised pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the kinetics of several radiotracers. However, the impact of physiological factors regulating CBF...

  11. Shell Buckling Knockdown Factors

    Data.gov (United States)

    National Aeronautics and Space Administration — The Shell Buckling Knockdown Factor (SBKF) Project, NASA Engineering and Safety Center (NESC) Assessment #: 07-010-E, was established in March of 2007 by the NESC in...

  12. Risk factors for neoplasms

    International Nuclear Information System (INIS)

    Brachner, A.; Grosche, B.

    1991-06-01

    A broad survey is given of risk factors for neoplasms. The main carcinogenic substances (including also ionizing radiation and air pollution) are listed, and are correlated with the risk factors for various cancers most frequently explained and discussed in the literature. The study is intended to serve as a basis for a general assessment of the incidence of neoplasms in children, and of cancer mortality in the entire population of Bavaria in the years 1983-1989, or 1979-1988, respectively, with the principal idea of drawing up an environment-related health survey. The study therefore takes into account not only ionizing radiation as a main risk factor, but also other risk factors detectable within the ecologic context, as e.g. industrial installations and their effects, refuse incineration plants or waste dumps, or the social status. (orig./MG) [de

  13. Factor IX assay

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003679.htm Factor IX assay To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  14. Factor VIII assay

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003678.htm Factor VIII assay To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  15. Factor II assay

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003674.htm Factor II assay To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  16. Factor V deficiency

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000550.htm Factor V deficiency To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  17. Rheumatoid factor (RF)

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003548.htm Rheumatoid factor (RF) To use the sharing features on this ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  18. Factor II deficiency

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000549.htm Factor II deficiency To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  19. Factor VII assay

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003676.htm Factor VII assay To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  20. Factor X deficiency

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000553.htm Factor X deficiency To use the sharing features on ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  1. New microbial growth factor

    Science.gov (United States)

    Bok, S. H.; Casida, L. E., Jr.

    1977-01-01

    A screening procedure was used to isolate from soil a Penicillium sp., two bacterial isolates, and a Streptomyces sp. that produced a previously unknown microbial growth factor. This factor was an absolute growth requirement for three soil bacteria. The Penicillium sp. and one of the bacteria requiring the factor, an Arthrobacter sp., were selected for more extensive study concerning the production and characteristics of the growth factor. It did not seem to be related to the siderochromes. It was not present in soil extract, rumen fluid, or any other medium component tested. It appears to be a glycoprotein of high molecular weight and has high specific activity. When added to the diets for a meadow-vole mammalian test system, it caused an increased consumption of diet without a concurrent increase in rate of weight gain.

  2. Human factors in aviation

    National Research Council Canada - National Science Library

    Salas, Eduardo; Maurino, Daniel E

    2010-01-01

    .... HFA offers a comprehensive overview of the topic, taking readers from the general to the specific, first covering broad issues, then the more specific topics of pilot performance, human factors...

  3. [Risk factors of schizophrenia].

    Science.gov (United States)

    Suvisaari, Jaana

    2010-01-01

    Schizophrenia is a multifactorial, neurodevelopmental disorder caused by a combination of genetic and environmental risk factors. Disturbances of brain development begin prenatally, while different environmental insults further affect postnatal brain maturation during childhood and adolescence. Genome-wide association studies (GWAS) have succeeded in identifying hundreds of new risk variants for common, multifactorial diseases. In schizophrenia research, GWAS have found several rare copy number variants that considerably increase the risk of schizophrenia, and have shown an association between schizophrenia and the major histocompatibility complex. Research on environmental risk factors in recent years has provided new information particularly on risk factors related to pregnancy and childhood rearing environment. Gene-environment interactions have become a central research topic. There is evidence that genetically susceptible children are more vulnerable to the effects of unstable childhood rearing environment and other environmental risk factors.

  4. Human Factors Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The purpose of the Human Factors Laboratory is to further the understanding of highway user needs so that those needs can be incorporated in roadway design,...

  5. Factors Affecting Wound Healing

    Science.gov (United States)

    Guo, S.; DiPietro, L.A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds. PMID:20139336

  6. The stem factor challenge

    International Nuclear Information System (INIS)

    Russell, M.J.; Steele, R. Jr.; DeWall, K.G.; Watkins, J.C.; Bramwell, D.

    1994-01-01

    One of the most important challenges that still needs to be met in the effort to understand the operation of motor-operated, rising-stem valves is the ability to determine stem factor throughout the valve's load range. The stem factor represents the conversion of operator torque to stem thrust. Determining the stem factor is important because some motor-operated valves (MOVs) cannot be tested in the plant at design basis conditions. The ability of these valves to perform their design basis function (typically, to operate against specified flow and pressure loads) must be ensured by analytical methods or by extrapolating from the results of tests conducted at lower loads. Because the stem factor tends to vary in response to friction and lubrication phenomena that occur during loading and wedging, analytical methods and extrapolation methods have been difficult to develop and implement. Early investigations into variability in the stem factor tended to look only at the tip of the iceberg; they focused on what was happening at torque switch trip, which usually occurs at full wedging. In most stems, the stem factor is better (lower) in the wedging transient than before wedging, so working with torque switch trip data alone led many early researchers to false conclusions about the relationship between stem factor and load. However, research at the Idaho National Engineering Laboratory (INEL) has taken a closer look at what happens during the running portion of the closing stroke along with the wedging portion. This shift in focus is important, because functional failure of a valve typically consists of a failure to isolate flow, not a failure to achieve full wedging. Thus, the stem factor that must be determined for a valve's design basis closing requirements is the one that corresponds with the running load before wedging

  7. Factors Affecting Wound Healing

    OpenAIRE

    Guo, S.; DiPietro, L.A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutane...

  8. Los factores de riesgo

    Directory of Open Access Journals (Sweden)

    Justo Senado Dumoy

    1999-01-01

    Full Text Available Sobre el fundamento filosófico de los conceptos de la Dialéctica Materialista, se presenta un análisis en relación con el concepto e interpretación de los Factores de Riesgo.A analysis on the concept and interpretation of risk factors is presented based on the philosophical foundation of the concepts of materialist dialectics.

  9. Brain derived neurotrophic factor

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Gede, Lene

    2014-01-01

    Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies are curre......Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies...

  10. Factors Impacting Knowledge Sharing

    DEFF Research Database (Denmark)

    Schulzmann, David; Slepniov, Dmitrij

    The purpose of this paper is to examine various factors affecting knowledge sharing at the R&D center of a Western MNE in China. The paper employs qualitative methodology and is based on the action research and case study research techniques. The findings of the paper advance our understanding...... about factors that affect knowledge sharing. The main emphasis is given to the discussion on how to improve knowledge sharing in global R&D organizations....

  11. FGF growth factor analogs

    Science.gov (United States)

    Zamora, Paul O [Gaithersburg, MD; Pena, Louis A [Poquott, NY; Lin, Xinhua [Plainview, NY; Takahashi, Kazuyuki [Germantown, MD

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  12. Factorization and pion form factor in QCD

    International Nuclear Information System (INIS)

    Efremov, A.V.; Radyushkin, A.V.

    1979-01-01

    The behaviour of the pion electromagnetic form factor (EMFF) in the framework of quantum chromodynamics (QCD) is discussed. Pion is considered to be a quark-antiquark bound state. It is proposed to use an OPE description of the bound state structure by matrix elements of certain local gauge-invariant operators. Short-distance quark interactions is proved using a direct analysis of perturbation theory in the α-parametric representation of the Feynman diagrams. It is shown that the short-distance parton picture privides a self-consistent description of the large Q 2 momentum behaviour of the pion EMFF in QCD. Pion EMFF asymptotics is expressed in terms of fu fundamental constants of the theory

  13. Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development

    KAUST Repository

    Park, Myoungryoul

    2010-09-28

    The R2R3-type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub-clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT-HAP transcription factors. Regulatory sub-clusters have different combinations of MYB-like, GCC-box-like, ERD1-box-like, ABRE-like, G-box-like, as1/ocs/TGA-like, AuxRE-like, gibberellic acid response element (GARE)-like and JAre-like cis-elements. Cold-dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co-regulators including nuclear factor-Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra-optimal expression causes misexpression of alternative targets with costly trade-offs to panicle development. © 2010 Blackwell Publishing Ltd.

  14. Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development.

    Science.gov (United States)

    Park, Myoung-Ryoul; Yun, Kil-Young; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Wijaya, Edward; Bajic, Vladimir B; Yun, Song-Joong; De Los Reyes, Benildo G

    2010-12-01

    The R2R3-type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub-clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT-HAP transcription factors. Regulatory sub-clusters have different combinations of MYB-like, GCC-box-like, ERD1-box-like, ABRE-like, G-box-like, as1/ocs/TGA-like, AuxRE-like, gibberellic acid response element (GARE)-like and JAre-like cis-elements. Cold-dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co-regulators including nuclear factor-Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra-optimal expression causes misexpression of alternative targets with costly trade-offs to panicle development. © 2010 Blackwell Publishing Ltd.

  15. [Pathological gambling: risk factors].

    Science.gov (United States)

    Bouju, G; Grall-Bronnec, M; Landreat-Guillou, M; Venisse, J-L

    2011-09-01

    In France, consumption of gambling games increased by 148% between 1960 and 2005. In 2004, gamblers lost approximately 0.9% of household income, compared to 0.4% in 1960. This represents approximately 134 Euros per year and per head. In spite of this important increase, the level remains lower than the European average (1%). However, gambling practices may continue to escalate in France in the next few years, particularly with the recent announce of the legalisation of online games and sports betting. With the spread of legalised gambling, pathological gambling rates may increase in France in the next years, in response to more widely available and more attractive gambling opportunities. In this context, there is a need for better understanding of the risk factors that are implicated in the development and maintenance of pathological gambling. This paper briefly describes the major risk factors for pathological gambling by examining the recent published literature available during the first quarter of 2008. This documentary basis was collected by Inserm for the collective expert report procedure on Gambling (contexts and addictions). Seventy-two articles focusing on risk factors for pathological gambling were considered in this review. Only 47 of them were taken into account for analysis. The selection of these 47 publications was based on the guide on literature analysis established by the French National Agency for Accreditation and Assessment in Health (ANAES, 2000). Some publications from more recent literature have also been added, mostly about Internet gambling. We identify three major types of risk factors implicated in gambling problems: some of them are related to the subject (individual factors), others are related to the object of the addiction, here the gambling activity by itself (structural factors), and the last are related to environment (contextual or situational factors). Thus, the development and maintenance of pathological gambling seems to be

  16. Clinical studies of cerebral blood flows using single photon emission computed tomography (SPECT), 1; The remote effects of tumors and the adverse effects of radiochemotherapy in the non-affected brain of patients with intracranial tumors

    Energy Technology Data Exchange (ETDEWEB)

    Araki, Yuzo (Gifu Univ. (Japan). Faculty of Medicine)

    1991-01-01

    To examine remote effects of tumors on cerebral blood flow (CBF) and adverse effects of radiochemotherapy on cerebral and cerebellar blood flow (CeBF), mean CBF (mCBF) and mean CeBF (mCeBF) have been studied by single photon emission computed tomography (SPECT) with Xe-133. The subjects were 78 patients with brain tumor, whose ages ranged from 9 to 74 years. Forty normal volunteers served as controls. In the control group, both mCBF and mCeBF were significantly decreased with advancing age. Both ipsilateral and contralateral mCeBFs were significantly decreased in adult patients with bilateral cerebral tumor, as compared with the control group, which was dependent on tumor volume. mCeBF was significantly decreased on the contralataral side than on the ipsilataral side. Similarly, ipsilateral mCBF was significantly lower than that in the control group. Crossed cerebellar diaschisis occurred frequently associated with extensive involvement of tumor into the frontal, parietal, and temporal lobes. In adult patients, a decreased mCBF on the non-affected side before surgery was improved postoperatively. One month after irradiation, it transiently increased and decreased again. Three months after irradiation, mCBF was significantly decreased, as compared with that in the control group. The degree of atrophy and tumor volume influenced mCBF on the non-affected side. These factors were responsible for mCBF in younger patients for the adult group, and in older patients for the child group. For adult patients, radiation dose was also a contributing factor for mCBF. In the group given chemotherapy, mCBF was significantly decreased, as compared with the group without chemotherapy. (N.K.) 102 refs.

  17. Regional cerebral blood flow measurements by a noninvasive microsphere method using 123I-IMP. Comparison with the modified fractional uptake method and the continuous arterial blood sampling method

    International Nuclear Information System (INIS)

    Nakano, Seigo; Matsuda, Hiroshi; Tanizaki, Hiroshi; Ogawa, Masafumi; Miyazaki, Yoshiharu; Yonekura, Yoshiharu

    1998-01-01

    A noninvasive microsphere method using N-isopropyl-p-( 123 I)iodoamphetamine ( 123 I-IMP), developed by Yonekura et al., was performed in 10 patients with neurological diseases to quantify regional cerebral blood flow (rCBF). Regional CBF values by this method were compared with rCBF values simultaneously estimated from both the modified fractional uptake (FU) method using cardiac output developed by Miyazaki et al. and the conventional method with continuous arterial blood sampling. In comparison, we designated the factor which converted raw SPECT voxel counts to rCBF values as a CBF factor. A highly significant correlation (r=0.962, p<0.001) was obtained in the CBF factors between the present method and the continuous arterial blood sampling method. The CBF factors by the present method were only 2.7% higher on the average than those by the continuous arterial blood sampling method. There were significant correlation (r=0.811 and r=O.798, p<0.001) in the CBF factor between modified FU method (threshold for estimating total brain SPECT counts; 10% and 30% respectively) and the continuous arterial blood sampling method. However, the CBF factors of the modified FU method showed 31.4% and 62.3% higher on the average (threshold; 10% and 30% respectively) than those by the continuous arterial blood sampling method. In conclusion, this newly developed method for rCBF measurements was considered to be useful for routine clinical studies without any blood sampling. (author)

  18. Generalised Batho correction factor

    International Nuclear Information System (INIS)

    Siddon, R.L.

    1984-01-01

    There are various approximate algorithms available to calculate the radiation dose in the presence of a heterogeneous medium. The Webb and Fox product over layers formulation of the generalised Batho correction factor requires determination of the number of layers and the layer densities for each ray path. It has been shown that the Webb and Fox expression is inefficient for the heterogeneous medium which is expressed as regions of inhomogeneity rather than layers. The inefficiency of the layer formulation is identified as the repeated problem of determining for each ray path which inhomogeneity region corresponds to a particular layer. It has been shown that the formulation of the Batho correction factor as a product over inhomogeneity regions avoids that topological problem entirely. The formulation in terms of a product over regions simplifies the computer code and reduces the time required to calculate the Batho correction factor for the general heterogeneous medium. (U.K.)

  19. factores psicosociales asociados

    Directory of Open Access Journals (Sweden)

    María Teresa Varela Arévalo

    2007-01-01

    Full Text Available El objetivo de este trabajo fue describir el consumo de sustancias psicoactivas [SPA] ilegales en jóvenes y los factores psicosociales de riesgo y de protección asociados. Participaron 763 estudiantes (46,5% hombres y 52,4% mujeres de una universidad privada de Cali, quienes diligenciaron el cuestionario de factores de riesgo y protección para el consumo de drogas. Los resultados muestran que la marihuana fue la droga de mayor consumo; y que existe una fuerte asociación entre el consumo de las cuatro SPA ilegales (marihuana, opiáceos, cocaína y éxtasis y los factores psicosociales de riesgo y/o protección, principalmente, las habilidades de autocontrol, los preconceptos y valoración de las SPA, la relación con personas consumidoras y los comportamientos perturbadores.

  20. Multi-factor authentication

    Science.gov (United States)

    Hamlet, Jason R; Pierson, Lyndon G

    2014-10-21

    Detection and deterrence of spoofing of user authentication may be achieved by including a cryptographic fingerprint unit within a hardware device for authenticating a user of the hardware device. The cryptographic fingerprint unit includes an internal physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a PUF value. Combining logic is coupled to receive the PUF value, combines the PUF value with one or more other authentication factors to generate a multi-factor authentication value. A key generator is coupled to generate a private key and a public key based on the multi-factor authentication value while a decryptor is coupled to receive an authentication challenge posed to the hardware device and encrypted with the public key and coupled to output a response to the authentication challenge decrypted with the private key.

  1. Human factors guides

    International Nuclear Information System (INIS)

    Penington, J.

    1995-10-01

    This document presents human factors guides, which have been developed in order to provide licensees of the AECB with advice as to how to address human factors issues within the design and assessment process. This documents presents the results of a three part study undertaken to develop three guides which are enclosed in this document as Parts B, C and D. As part of the study human factors standards, guidelines, handbooks and other texts were researched, to define those which would be most useful to the users of the guides and for the production of the guides themselves. Detailed specifications were then produced to outline the proposed contents and format of the three guides. (author). 100 refs., 3 tabs., 11 figs

  2. Human factors guides

    Energy Technology Data Exchange (ETDEWEB)

    Penington, J [PHF Services Inc., (Canada)

    1995-10-01

    This document presents human factors guides, which have been developed in order to provide licensees of the AECB with advice as to how to address human factors issues within the design and assessment process. This documents presents the results of a three part study undertaken to develop three guides which are enclosed in this document as Parts B, C and D. As part of the study human factors standards, guidelines, handbooks and other texts were researched, to define those which would be most useful to the users of the guides and for the production of the guides themselves. Detailed specifications were then produced to outline the proposed contents and format of the three guides. (author). 100 refs., 3 tabs., 11 figs.

  3. The focus factor

    DEFF Research Database (Denmark)

    Nicolaisen, Jeppe; Frandsen, Tove Faber

    2015-01-01

    Introduction. We present a new bibliometric indicator to measure journal specialisation over time, named the focus factor. This new indicator is based on bibliographic coupling and counts the percentage of re-citations given in subsequent years. Method. The applicability of the new indicator....... To validate re-citations as caused by specialisation, other possible causes were measured and correlated (obsolescence, journal self-citations and number of references). Results. The results indicate that the focus factor is capable of distinguishing between general and specialised journals and thus...... effectively measures the intended phenomenon (i.e., journal specialisation). Only weak correlations were found between journal re-citations and obsolescence, journal self-citations, and number of references. Conclusions. The focus factor successfully measures journal specialisation over time. Measures based...

  4. WRKY transcription factors

    Science.gov (United States)

    Bakshi, Madhunita; Oelmüller, Ralf

    2014-01-01

    WRKY transcription factors are one of the largest families of transcriptional regulators found exclusively in plants. They have diverse biological functions in plant disease resistance, abiotic stress responses, nutrient deprivation, senescence, seed and trichome development, embryogenesis, as well as additional developmental and hormone-controlled processes. WRKYs can act as transcriptional activators or repressors, in various homo- and heterodimer combinations. Here we review recent progress on the function of WRKY transcription factors in Arabidopsis and other plant species such as rice, potato, and parsley, with a special focus on abiotic, developmental, and hormone-regulated processes. PMID:24492469

  5. On braid monodromy factorizations

    International Nuclear Information System (INIS)

    Kharlamov, V M; Kulikov, Vik S

    2003-01-01

    We introduce and develop a language of semigroups over the braid groups to study the braid monodromy factorizations (bmf's) of plane algebraic curves and other related objects. As an application, we give a new proof of Orevkov's theorem on the realization of bmf's over a disc by algebraic curves and show that the complexity of such a realization cannot be bounded in terms of the types of factors of the bmf. We also prove that the type of a bmf distinguishes Hurwitz curves with singularities of inseparable type up to H-isotopy and J-holomorphic cuspidal curves in CP 2 up to symplectic isotopy

  6. Dose conversion factors

    International Nuclear Information System (INIS)

    Kocher, D.C.; Eckerman, K.F.

    1992-01-01

    The following is discussed in this report: concepts and quantities used in calculating radiation dose from internal and external exposure. Tabulations of dose conversion factor for internal and external exposure to radionuclides. Dose conversion factors give dose per unit intake (internal) or dose per unit concentration in environment (external). Intakes of radionuclides for internal exposure and concentrations of radionuclides in environment for external exposure are assumed to be known. Intakes and concentrations are obtained, e.g., from analyses of environmental transport and exposure pathways. differences between dosimetry methods for radionuclides and hazardous chemicals are highlighted

  7. Factors stimulating content marketing

    Directory of Open Access Journals (Sweden)

    Naser Azad

    2016-02-01

    Full Text Available This paper presents an empirical investigation to determine factors influencing on content marketing in banking industry. The study designs a questionnaire consists of 40 questions in Likert scale and distributes it among 550 randomly selected regular customers of Bank Mellat in city of Tehran, Iran and 400 properly filled questionnaires are collected. Cronbach alphas for all components of the survey are well above desirable level. Using principle component analysis with Varimax rotation, the study has determined six factors influencing the most on content marketing including organization, details, having new ideas, quality, sensitivity and power while the last component contains only two subcomponents and is removed from the study.

  8. STEREOTYPICAL FACTORS IN TOURISM

    Directory of Open Access Journals (Sweden)

    Cristina-Elena ALBU

    2013-06-01

    Full Text Available International tourism has grown rapidly nowdays, contributing to the growth of the global economy. The purpose of this essay is to identify and analyze stereotypical factors in the development of strategies concerning the offer for the tourism industry: the image of a tourist destination, brand, country of origin and customer behaviour. Documentary study was the research method used: representative articles were analysed, as recent as possible, to determine the factors mentioned above. Professionals in the industry of tourism need to understand cultural differences between tourists, as well as those of the host country, to be able to create tourist reception offers that live up to the standards expected by clients.

  9. Factor analysis and scintigraphy

    International Nuclear Information System (INIS)

    Di Paola, R.; Penel, C.; Bazin, J.P.; Berche, C.

    1976-01-01

    The goal of factor analysis is usually to achieve reduction of a large set of data, extracting essential features without previous hypothesis. Due to the development of computerized systems, the use of largest sampling, the possibility of sequential data acquisition and the increase of dynamic studies, the problem of data compression can be encountered now in routine. Thus, results obtained for compression of scintigraphic images were first presented. Then possibilities given by factor analysis for scan processing were discussed. At last, use of this analysis for multidimensional studies and specially dynamic studies were considered for compression and processing [fr

  10. The Transcription Factor Encyclopedia

    DEFF Research Database (Denmark)

    Yusuf, Dimas; Butland, Stefanie L; Swanson, Magdalena I

    2012-01-01

    mini review articles on pertinent human, mouse and rat TFs. Notable features of the TFe website include a high-quality PDF generator and web API for programmatic data retrieval. TFe aims to rapidly educate scientists about the TFs they encounter through the delivery of succinct summaries written......ABSTRACT: Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130...

  11. Factorizations and physical representations

    International Nuclear Information System (INIS)

    Revzen, M; Khanna, F C; Mann, A; Zak, J

    2006-01-01

    A Hilbert space in M dimensions is shown explicitly to accommodate representations that reflect the decomposition of M into prime numbers. Representations that exhibit the factorization of M into two relatively prime numbers: the kq representation (Zak J 1970 Phys. Today 23 51), and related representations termed q 1 q 2 representations (together with their conjugates) are analysed, as well as a representation that exhibits the complete factorization of M. In this latter representation each quantum number varies in a subspace that is associated with one of the prime numbers that make up M

  12. Model Correction Factor Method

    DEFF Research Database (Denmark)

    Christensen, Claus; Randrup-Thomsen, Søren; Morsing Johannesen, Johannes

    1997-01-01

    The model correction factor method is proposed as an alternative to traditional polynomial based response surface techniques in structural reliability considering a computationally time consuming limit state procedure as a 'black box'. The class of polynomial functions is replaced by a limit...... of the model correction factor method, is that in simpler form not using gradient information on the original limit state function or only using this information once, a drastic reduction of the number of limit state evaluation is obtained together with good approximations on the reliability. Methods...

  13. [Natural factors influencing sleep].

    Science.gov (United States)

    Jurkowski, Marek K; Bobek-Billewicz, Barbara

    2007-01-01

    Sleep is a universal phenomenon of human and animal lives, although the importance of sleep for homeo-stasis is still unknown. Sleep disturbances influence many behavioral and physiologic processes, leading to health complications including death. On the other hand, sleep improvement can beneficially influence the course of healing of many disorders and can be a prognostic of health recovery. The factors influencing sleep have different biological and chemical origins. They are classical hormones, hypothalamic releasing and inhibitory hormones, neuropeptides, peptides and others as cytokines, prostaglandins, oleamid, adenosine, nitric oxide. These factors regulate most physiologic processes and are likely elements integrating sleep with physiology and physiology with sleep in health and disorders.

  14. Cerebral blood flow and brain shrinkage seen on CT during ACTH therapy

    International Nuclear Information System (INIS)

    Futagi, Yasuyuki; Abe, Jiro; Kawahigashi, Kenji

    1986-01-01

    By means of the Doppler ultrasound method, the cerebral blood flow (CBF) was assessed in 21 children with epilepsy undergoing treatment with adrenocorticotrophic hormone (ACTH). The maximum reduction in the internal carotid velocity, as an index of CBF during therapy, was about 35 percent compared with the values before therapy. Furthermore, sequential computed tomography (CT) examinations of the same subjects were performed to evaluate the change in the area of the intracranial brain parenchyma during therapy. The maximum reduction in the parenchymal area during therapy was about 10 percent. This corresponds to a 20 percent reduction in CBF according to Poiseuille's law, however, the remaining reduction in CBF demonstrated by velocity measurement cannot be explained only by that mechanical vascular factor. From these findings, it is concluded that in order to elucidate the mechanism of the CBF reduction, physiological factors such as changes in metabolism during therapy should also be evaluated in addition to the mechanical and physical causes. (author)

  15. Environmental factors and leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, L

    1985-01-01

    Investigations on the association between environmental hazards and the development of various types of leukaemia are reviewed. Regarding acute non-lymphocytic leukaemia (ANLL) exposure to ionizing radiation is a well-documented risk factor. According to several recent studies exposure to strong electromagnetic fields may be suspected to be of etiologic importance for ANLL. There is evidence that occupational handling of benzene is a risk factor and other organic solvents may also be leukaemogenic. Occupational exposure to petrol products has been proposed to be a risk factor although the hazardous substances have not yet been defined. Results of cytogenetic studies in ANLL suggest that exposure to certain environmental agents may be associated with relatively specific clonal chromosome aberrations. Exposure in utero to ionizing radiation has been proposed to be a risk factor for acute lymphocytic leukaemia (ALL) in children. Unlike ANLL there seems at present to be little evidence that ALL is related to exposure to some chemicals. Chronic myeloid leukaemia (CML) may follow exposure to high doses of ionizing radiation whereas such exposure seems to be of insignificant importance for the development of chronic lymphocytic leukaemia (CLL). According to some studies an abnormally high incidence of CLL may be found among farmers in the USA. These results have not been confirmed in Scandinavian studies. There seems to be little evidence that CML or CLL are related to occupational handling of some chemicals. 35 references.

  16. Hyperglycemia: a prothrombotic factor?

    NARCIS (Netherlands)

    Lemkes, B. A.; Hermanides, J.; DeVries, J. H.; Holleman, F.; Meijers, J. C. M.; Hoekstra, J. B. L.

    2010-01-01

    Diabetes mellitus is characterized by a high risk of atherothrombotic events. What is more, venous thrombosis has also been found to occur more frequently in this patient group. This prothrombotic condition in diabetes is underpinned by laboratory findings of elevated coagulation factors and

  17. Thermal disadvantage factor

    International Nuclear Information System (INIS)

    Abdullah, K.M.S.; Loyalka, S.K.

    1990-01-01

    A method is described where reactor cell flux and the disadvantage factor are calculated by using diffusion theory in the moderator and integral transport in the fuel. The method is efficient (noniterative) and provides results that agree well with Monte Carlo, P 5 and ABH results

  18. Threshold factorization redux

    Science.gov (United States)

    Chay, Junegone; Kim, Chul

    2018-05-01

    We reanalyze the factorization theorems for the Drell-Yan process and for deep inelastic scattering near threshold, as constructed in the framework of the soft-collinear effective theory (SCET), from a new, consistent perspective. In order to formulate the factorization near threshold in SCET, we should include an additional degree of freedom with small energy, collinear to the beam direction. The corresponding collinear-soft mode is included to describe the parton distribution function (PDF) near threshold. The soft function is modified by subtracting the contribution of the collinear-soft modes in order to avoid double counting on the overlap region. As a result, the proper soft function becomes infrared finite, and all the factorized parts are free of rapidity divergence. Furthermore, the separation of the relevant scales in each factorized part becomes manifest. We apply the same idea to the dihadron production in e+e- annihilation near threshold, and show that the resultant soft function is also free of infrared and rapidity divergences.

  19. Fibroblast growth factor 23

    African Journals Online (AJOL)

    Dr Olaleye

    Systemic phosphate homeostasis is maintained through several hormonal mechanisms which involve fibroblast growth factor 23 (FGF-23), α-klotho, vitamin D and parathyroid hormone. FGF-23 is known to be the major regulator of phosphate balance (Mirams et al., 2004). FGF-23 is a phosphaturic hormone, which is.

  20. Human factors information system

    International Nuclear Information System (INIS)

    Goodman, P.C.; DiPalo, C.A.

    1991-01-01

    Nuclear power plant safety is dependent upon human performance related to plant operations. To provide improvements in human performance, data collection and assessment play key roles. This paper reports on the Human factors Information System (HFIS) which is designed to meet the needs of the human factors specialists of the United States Nuclear Regulatory Commission. These specialists identify personnel errors and provide guidance designed to prevent such errors. HFIS is a simple and modular system designed for use on a personal computer. It is designed to contain four separate modules that provide information indicative of program or function effectiveness as well as safety-related human performance based on programmatic and performance data. These modules include the Human Factors Status module; the Regulatory Programs module; the Licensee Event Report module; and the Operator Requalification Performance module. Information form these modules can either be used separately or can be combined due to the integrated nature of the system. HFIS has the capability, therefore, to provide insights into those areas of human factors that can reduce the probability of events caused by personnel error at nuclear power plants and promote the health and safety of the public. This information system concept can be applied to other industries as well as the nuclear industry

  1. PATTERNS AND FACTORS INVOLVED

    African Journals Online (AJOL)

    Between 1*' of July 1996 and 30'h of June 2000 a total of 3583 patients were registered at the accident and emergency unit of Nnamdi. Azikiwe ... The case files of these were reviewed with a view to ascertaining the causes and factors involved in the deaths of these patients. The .... H.I.V/AIDS related complications 23 6.8.

  2. Introduction to human factors

    International Nuclear Information System (INIS)

    Winters, J.M.

    1988-03-01

    Some background is given on the field of human factors. The nature of problems with current human/computer interfaces is discussed, some costs are identified, ideal attributes of graceful system interfaces are outlined, and some reasons are indicated why it's not easy to fix the problems

  3. Prognostic factors in oligodendrogliomas

    DEFF Research Database (Denmark)

    Westergaard, L; Gjerris, F; Klinken, L

    1997-01-01

    An outcome analysis was performed on 96 patients with pure cerebral oligodendrogliomas operated in the 30-year period 1962 to 1991. The most important predictive prognostic factors were youth and no neurological deficit, demonstrated as a median survival for the group younger than 20 years of 17...

  4. Factors affecting mining costs

    International Nuclear Information System (INIS)

    Lowell, A.F.

    1977-01-01

    The subject is discussed under the following headings: investment decision-making, unit cost factors (declining ore grade, low-price contracts, ore grade/output relationship, above average cost increases). Economic, environmental, sociological and political aspects are considered. (U.K.)

  5. Quantitative measurement of regional cerebral blood flow using {sup 99m}Tc-HM-PAO SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Hisashi; Nakamura, Yusaku; Yagi, Yuji; Miura, Kosuke; Takahashi, Mitsuo [Kinki Univ., Osaka-Sayama, Osaka (Japan)

    1994-10-01

    This study examined a simple method for measuring the regional cerebral blood flow (rCBF) using {sup 99m}Tc-HM-PAO SPECT. The mean CBF (mCBF) was determined by the Patlack plot method and rCBF was calculated with Lassen`s correction algorithm, as reported by Matsuda et al. The cerebral hemisphere was employed as the reference region for Lassen`s correction. The reference RI count rate was calculated from the left cerebral hemisphere at the basal ganglia level and the correction factor {alpha} was fixed at 2.0. As a result, rCBF could be measured more easily than by Matsuda`s method. The contribution of age, laterality and gender to the CBF of normal subjects were studied. The mCBF value of 26 normal subjects was 53.8{+-}6.4 ml/100 g/min and showed a significant correlation with advancing age (R=0.644, p=0.0004, n=26). The mean values for rCBF of the cerebellum, frontal area, temporal area, occipital area and parietal area were 77.3{+-}6.6 ml/100 g/min, 70.2{+-}9.1 ml/100 g/min, 72.3{+-}7.5 ml/100 g/min, 71.8{+-}6.2 ml/100 g/min and 73.8{+-}8.6 ml/100 g/min, respectively. There were no gender or laterality differences in the mCBF or respective rCBF values. Each of the above listed regions, except for the occipital area, demonstrated a significant correlation with advancing age. The most remarkable decrease in rCBF with age was noted in the frontal area (R=0.757, p=0.001, n=26). (author).

  6. Quantitative measurement of regional cerebral blood flow using 99mTc-HM-PAO SPECT

    International Nuclear Information System (INIS)

    Tanaka, Hisashi; Nakamura, Yusaku; Yagi, Yuji; Miura, Kosuke; Takahashi, Mitsuo

    1994-01-01

    This study examined a simple method for measuring the regional cerebral blood flow (rCBF) using 99m Tc-HM-PAO SPECT. The mean CBF (mCBF) was determined by the Patlack plot method and rCBF was calculated with Lassen's correction algorithm, as reported by Matsuda et al. The cerebral hemisphere was employed as the reference region for Lassen's correction. The reference RI count rate was calculated from the left cerebral hemisphere at the basal ganglia level and the correction factor α was fixed at 2.0. As a result, rCBF could be measured more easily than by Matsuda's method. The contribution of age, laterality and gender to the CBF of normal subjects were studied. The mCBF value of 26 normal subjects was 53.8±6.4 ml/100 g/min and showed a significant correlation with advancing age (R=0.644, p=0.0004, n=26). The mean values for rCBF of the cerebellum, frontal area, temporal area, occipital area and parietal area were 77.3±6.6 ml/100 g/min, 70.2±9.1 ml/100 g/min, 72.3±7.5 ml/100 g/min, 71.8±6.2 ml/100 g/min and 73.8±8.6 ml/100 g/min, respectively. There were no gender or laterality differences in the mCBF or respective rCBF values. Each of the above listed regions, except for the occipital area, demonstrated a significant correlation with advancing age. The most remarkable decrease in rCBF with age was noted in the frontal area (R=0.757, p=0.001, n=26). (author)

  7. Combining glial cell line-derived neurotrophic factor gene delivery (AdGDNF) with L-arginine decreases contusion size but not behavioral deficits after traumatic brain injury.

    Science.gov (United States)

    Degeorge, M L; Marlowe, D; Werner, E; Soderstrom, K E; Stock, M; Mueller, A; Bohn, M C; Kozlowski, D A

    2011-07-27

    Our laboratory has previously demonstrated that viral administration of glial cell line-derived neurotrophic factor (AdGDNF), one week prior to a controlled cortical impact (CCI) over the forelimb sensorimotor cortex of the rat (FL-SMC) is neuroprotective, but does not significantly enhance recovery of sensorimotor function. One possible explanation for this discrepancy is that although protected, neurons may not have been functional due to enduring metabolic deficiencies. Additionally, metabolic events following TBI may interfere with expression of therapeutic proteins administered to the injured brain via gene therapy. The current study focused on enhancing the metabolic function of the brain by increasing cerebral blood flow (CBF) with l-arginine in conjunction with administration of AdGDNF immediately following CCI. An adenoviral vector harboring human GDNF was injected unilaterally into FL-SMC of the rat immediately following a unilateral CCI over the FL-SMC. Within 30min of the CCI and AdGDNF injections, some animals were injected with l-arginine (i.v.). Tests of forelimb function and asymmetry were administered for 4weeks post-injury. Animals were sacrificed and contusion size and GDNF protein expression measured. This study demonstrated that rats treated with AdGDNF and l-arginine post-CCI had a significantly smaller contusion than injured rats who did not receive any treatment, or injured rats treated with either AdGDNF or l-arginine alone. Nevertheless, no amelioration of behavioral deficits was seen. These findings suggest that AdGDNF alone following a CCI was not therapeutic and although combining it with l-arginine decreased contusion size, it did not enhance behavioral recovery. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Human factors in network security

    OpenAIRE

    Jones, Francis B.

    1991-01-01

    Human factors, such as ethics and education, are important factors in network information security. This thesis determines which human factors have significant influence on network security. Those factors are examined in relation to current security devices and procedures. Methods are introduced to evaluate security effectiveness by incorporating the appropriate human factors into network security controls

  9. Electromagnetic form factors

    International Nuclear Information System (INIS)

    Desplanques, B.

    1987-01-01

    Electromagnetic form factors, in first approximation, are sensitive to spatial distribution of nucleons and to their current. In second approximation, more precise effects are concerned, whose role is increasing with momentum transfer and participating essentially of short range nuclei description. They concern of course the nucleon-nucleon interaction while approaching each other and keeping their free-state identity, but also mutually polarizing one the other. In this last effect, radial and orbital excitations of nucleon, the nucleon mesonic cloud modification and the nucleon antinucleon pair excitation are included. In this paper, these contributions are discussed while trying to find the important elements for a good description of form factors. Current questions are also discussed. Light nuclei are essentially concerned [fr

  10. Researching organizational factors

    International Nuclear Information System (INIS)

    Coffman, F.

    1991-01-01

    This paper discusses feedback and insights from experience (both successful and unsuccessful) with the past and the ongoing organizational factors research. That experience suggests a leading set of ingredients that appear proper for performing regulatory research on organizational processes. By keeping focused upon these proper ingredients, the research will contribute to the regulatory assessments of utility management through the use of improved methods and measures in investigations, inspections, diagnostics, performance indicators, and PRA insights. This paper is organized into (1) an introductory description of what the agency is doing to assess organizational effectiveness, (2) some insights from past and ongoing research, (3) an opinion on a leading set of ingredients to properly research organizational factors, and (4) a summary

  11. On braid monodromy factorizations

    Energy Technology Data Exchange (ETDEWEB)

    Kharlamov, V M [Institut de Recherche Matematique Avanee Universite Louis Pasteur et CNRS 7 rue Rene Descartes (France); Kulikov, Vik S [Steklov Mathematical Institute, Russian Academy of Sciences (Russian Federation)

    2003-06-30

    We introduce and develop a language of semigroups over the braid groups to study the braid monodromy factorizations (bmf's) of plane algebraic curves and other related objects. As an application, we give a new proof of Orevkov's theorem on the realization of bmf's over a disc by algebraic curves and show that the complexity of such a realization cannot be bounded in terms of the types of factors of the bmf. We also prove that the type of a bmf distinguishes Hurwitz curves with singularities of inseparable type up to H-isotopy and J-holomorphic cuspidal curves in CP{sup 2} up to symplectic isotopy.

  12. Factors in Agile Methods Adoption

    Directory of Open Access Journals (Sweden)

    Samia Abdalhamid

    2017-05-01

    Full Text Available There are many factors that can affect the process of adopting Agile methods during software developing. This paper illustrates the critical factors in Agile methods adoption in software organizations. To present the success and failure factors, an exploratory study is carried out among the critical factors of success and failure from existing studies. Dimensions and Factors are introduced utilizing success and failure dimensions. The mind map was used to clarify these factors.

  13. Factors of academic procrastination

    OpenAIRE

    Kranjec, Eva; Košir, Katja; Komidar, Luka

    2017-01-01

    This study investigated dimensions of perfectionism, anxiety, and depression as factors of academic procrastination. Our main research interest was to examine the role of specific dimensions of perfectionism as moderators in the relationship between anxiety and depression and academic procrastination. Four scales were administered on the sample of 403 students: perfectionism scale FMPS, academic procrastination scale APS-SI, depression scale CESD and anxiety scale STAI-X2. The results showed ...

  14. Concentration factors for fish

    International Nuclear Information System (INIS)

    Feldt, W.; Lauer, R.; Melzer, M.; Siebert, W.

    1978-01-01

    Concentration factors are defined as operators allowing to calculate the specific activity of fish meat from a given concentration of an element in the water. This parameter depends among others from the content of stable isotopes and homologues in the different waters. If this parameter is reasonably to be used for model calculations it must be referred to water with all of its content substances, these calculations also being based on this type of 'water'. (orig.) [de

  15. Prognostic factors for medulloblastoma

    International Nuclear Information System (INIS)

    Jenkin, Derek; Al Shabanah, Mohamed; Al Shail, Essam; Gray, Alan; Hassounah, Maher; Khafaga, Yasser; Kofide, Amani; Mustafa, Mahmoud; Schultz, Henrik

    2000-01-01

    Purpose: To evaluate prognostic factors for medulloblastoma. Methods and Materials: One hundred and seventy-three consecutive patients with medulloblastoma, treated at King Faisal Specialist Hospital (KFSH) from 1988-1997, were reviewed. Eighty-four percent were children less than 15 years old. From 1988-1994, treatment was at the discretion of the investigator. From 1994-1998, patients entered a single-arm best practice protocol in which, in staged patients, the surgical intent was total resection, standard radiation treatment was defined, and adjuvant chemotherapy was given to a 'high-risk' subset. Results: For 150 patients who completed surgical and radiation treatment, the 5-year survival rate was 58%, compared with 0% for 16 patients who were unable to start or complete radiation treatment. For staged patients, the 5-year survival was M0 + M1, 78% and M2 + M3, 21% (p 14 years and gross cystic/necrotic features in the primary tumor. The size of the primary tumor, the degree of hydrocephalus at diagnosis, the presence of residual tumor in the post-operative CT/MRI, and the functional status of the patient prior to radiation treatment were not significant factors. Conclusions: Stage M0 + M1 was the most powerful favorable prognostic factor. In Saudi Arabia more patients present with advanced disseminated disease, 41% M2 + M3, than in the West, and this impacts adversely on overall survival. Total resection and standard radiation treatment were not sensitive prognostic factors in a treatment environment in which 78% of patients underwent at least 90% tumor resection and 60% received standard radiation treatment. In order to improve the proportion of patients able to complete radiation treatment, consideration should be given to limiting resection when the attainment of total resection is likely to be morbid, and to delaying rather than omitting radiation treatment in the patient severely compromised postoperatively

  16. Risk factors for cancer

    International Nuclear Information System (INIS)

    Lyman, G.H.

    1992-01-01

    It is no longer reasonable to divide cancers into those that are genetic in origin and those that are environmental in origin. With rare exception, carcinogenesis involves environmental factors that directly or indirectly exert a change in the cell's genome. Virtually all causes of cancer are multifactorial, sometimes involving an inherited predisposition to the carcinogenic effects of environmental factors, which include chemicals, ionizing radiation, and oncogenic virus. Carcinogenesis is a multistep process including induction, promotion, and progression. Initiation requires an irreversible change in the cellular genome, whereas promotion is commonly associated with prolonged and reversible exposure. Tumor progression results in genotypic and phenotypic changes associated with tumor growth, invasion, and metastasis. Most information on human cancer risk is based on epidemiologic studies involving both exposed and unexposed individuals. The quality of such studies depends on their ability to assess the strength of any association of exposure and disease and careful attention to any potential bias. Few cancers are inherited in a Mendelian fashion. Several preneoplastic conditions, however, are clearly inherited and several malignancies demonstrate weak familial patterns. Environmental factors may exert their effect on DNA in a random fashion, but certain consistent changes, including specific translocations of genetic information, are often found. Currently, there is great interest in the close proximity of certain oncogenes governing growth control to the consistent chromosomal changes observed. Such changes may represent a final common pathway of action for environmental carcinogens. Sufficient laboratory and epidemiologic evidence exists to establish a causal association of several chemical agents with cancer

  17. Human factoring administrative procedures

    International Nuclear Information System (INIS)

    Grider, D.A.; Sturdivant, M.H.

    1991-01-01

    In nonnuclear business, administrative procedures bring to mind such mundane topics as filing correspondence and scheduling vacation time. In the nuclear industry, on the other hand, administrative procedures play a vital role in assuring the safe operation of a facility. For some time now, industry focus has been on improving technical procedures. Significant efforts are under way to produce technical procedure requires that a validated technical, regulatory, and administrative basis be developed and that the technical process be established for each procedure. Producing usable technical procedures requires that procedure presentation be engineered to the same human factors principles used in control room design. The vital safety role of administrative procedures requires that they be just as sound, just a rigorously formulated, and documented as technical procedures. Procedure programs at the Tennessee Valley Authority and at Boston Edison's Pilgrim Station demonstrate that human factors engineering techniques can be applied effectively to technical procedures. With a few modifications, those same techniques can be used to produce more effective administrative procedures. Efforts are under way at the US Department of Energy Nuclear Weapons Complex and at some utilities (Boston Edison, for instance) to apply human factors engineering to administrative procedures: The techniques being adapted include the following

  18. Human Factors Review Plan

    International Nuclear Information System (INIS)

    Paramore, B.; Peterson, L.R.

    1985-12-01

    ''Human Factors'' is concerned with the incorporation of human user considerations into a system in order to maximize human reliability and reduce errors. This Review Plan is intended to assist in the assessment of human factors conditions in existing DOE facilities. In addition to specifying assessment methodologies, the plan describes techniques for improving conditions which are found to not adequately support reliable human performance. The following topics are addressed: (1) selection of areas for review describes techniques for needs assessment to assist in selecting and prioritizing areas for review; (2) human factors engineering review is concerned with optimizing the interfaces between people and equipment and people and their work environment; (3) procedures review evaluates completeness and accuracy of procedures, as well as their usability and management; (4) organizational interface review is concerned with communication and coordination between all levels of an organization; and (5) training review evaluates training program criteria such as those involving: trainee selection, qualification of training staff, content and conduct of training, requalification training, and program management

  19. Human Factors Review Plan

    Energy Technology Data Exchange (ETDEWEB)

    Paramore, B.; Peterson, L.R. (eds.)

    1985-12-01

    ''Human Factors'' is concerned with the incorporation of human user considerations into a system in order to maximize human reliability and reduce errors. This Review Plan is intended to assist in the assessment of human factors conditions in existing DOE facilities. In addition to specifying assessment methodologies, the plan describes techniques for improving conditions which are found to not adequately support reliable human performance. The following topics are addressed: (1) selection of areas for review describes techniques for needs assessment to assist in selecting and prioritizing areas for review; (2) human factors engineering review is concerned with optimizing the interfaces between people and equipment and people and their work environment; (3) procedures review evaluates completeness and accuracy of procedures, as well as their usability and management; (4) organizational interface review is concerned with communication and coordination between all levels of an organization; and (5) training review evaluates training program criteria such as those involving: trainee selection, qualification of training staff, content and conduct of training, requalification training, and program management.

  20. Human and Organizational Factors

    International Nuclear Information System (INIS)

    Eshiett, P.B.S.

    2016-01-01

    The Human and Organizational Factors Approach to Industrial Safety (HOFS) consists of identifying and putting in place conditions which encourage a positive contribution from operators (individually and in a team) with regards to industrial safety. The knowledge offered by the HOFS approach makes it possible better to understand what conditions human activity and to act on the design of occupational situations and the organization, in the aim of creating the conditions for safe work. Efforts made in this area can also lead to an improvement in results in terms of the quality of production or occupational safety (incidence and seriousness rates) (Daniellou, F., et al., 2011). Research on industrial accidents shows that they rarely happen as a result of a single event, but rather emerge from the accumulation of several, often seemingly trivial, malfunctions, misunderstandings, incorrect assumptions and other issues. The nuclear community has established rigorous international safety standards and concepts to ensure the protection of people and the environment from harmful effects of ionizing radiation (IAEA, 2014). A review of major human induced disasters in a number of countries and in different industries yields insights into several of the human and organizational factors involved in their occurrence. Some of these factors relate to failures in: • Design or technology; • Training; • Decision making; • Communication; • Preparation for the unexpected; • Understanding of organizational interdependencies

  1. Molecular factors in migraine

    Science.gov (United States)

    Kowalska, Marta; Prendecki, Michał; Kozubski, Wojciech; Lianeri, Margarita; Dorszewska, Jolanta

    2016-01-01

    Migraine is a common neurological disorder that affects 11% of adults worldwide. This disease most likely has a neurovascular origin. Migraine with aura (MA) and more common form - migraine without aura (MO) – are the two main clinical subtypes of disease. The exact pathomechanism of migraine is still unknown, but it is thought that both genetic and environmental factors are involved in this pathological process. The first genetic studies of migraine were focused on the rare subtype of MA: familial hemiplegic migraine (FHM). The genes analysed in familial and sporadic migraine are: MTHFR, KCNK18, HCRTR1, SLC6A4, STX1A, GRIA1 and GRIA3. It is possible that migraine is a multifactorial disease with polygenic influence. Recent studies have shown that the pathomechanisms of migraine involves both factors responsible for immune response and oxidative stress such as: cytokines, tyrosine metabolism, homocysteine; and factors associated with pain transmission and emotions e.g.: serotonin, hypocretin-1, calcitonin gene-related peptide, glutamate. The correlations between genetic variants of the HCRTR1 gene, the polymorphism 5-HTTLPR and hypocretin-1, and serotonin were observed. It is known that serotonin inhibits the activity of hypocretin neurons and may affect the appearance of the aura during migraine attack. The understanding of the molecular mechanisms of migraine, including genotype-phenotype correlations, may contribute to finding markers important for the diagnosis and treatment of this disease. PMID:27191890

  2. Structuring factoring business: accounting aspects

    Directory of Open Access Journals (Sweden)

    I.M. Vygivska

    2017-08-01

    Full Text Available The article theoretically substantiates the fact that factoring belongs to the main operational activity of a factoring company, and this allowed structuring the factoring business by types of activity. The lack of a unified approach to the classification of factoring (factoring services made it possible to systematize and refine their classification as a basis for developing accounting and analytical support for risk management of factoring business. The authors single out such classification signs as: the right of the reverse claim (reverse, irretrievable, a territorial feature (international, internal, the subject of the factoring contract (real, consensual, the availability of notification of the debtor (conventional, confidential. The structuring of factoring business contributes to the identification of the risks of the economic activities of a factoring company depending on the type of factoring, the development of methodological support for the bookkeeping of factoring transactions in a risk environment, the search for risk management practices and the determination of management effectiveness in general.

  3. Effect of hematocrit and systolic blood pressure on cerebral blood flow in newborn infants

    International Nuclear Information System (INIS)

    Younkin, D.P.; Reivich, M.; Jaggi, J.L.; Obrist, W.D.; Delivoria-Papadopoulos, M.

    1987-01-01

    The effects of hematocrit and systolic blood pressure on cerebral blood flow were measured in 15 stable, low birth weight babies. CBF was measured with a modification of the xenon-133 ( 133 Xe) clearance technique, which uses an intravenous bolus of 133 Xe, an external chest detector to estimate arterial 133 Xe concentration, eight external cranial detectors to measure cephalic 133 Xe clearance curves, and a two-compartmental analysis of the cephalic 133 Xe clearance curves to estimate CBF. There was a significant inverse correlation between hematocrit and CBF, presumably due to alterations in arterial oxygen content and blood viscosity. Newborn CBF varied independently of systolic blood pressure between 60 and 84 mm Hg, suggesting an intact cerebrovascular autoregulatory mechanism. These results indicate that at least two of the factors that affect newborn animal CBF are operational in human newborns and may have important clinical implications

  4. Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

    2018-01-01

    Background Positron emission tomography (PET) imaging of anaesthetized pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the distribution of several radiotracers. However, the effect of physiological factors regulating...... and the monitoring parameters. Results No significant statistical correlations were found between CBF and the nine monitoring variables. However, we found that arterial carbon dioxide tension (PaCO2) and body temperature were important predictors of CBF that should be observed and kept constant. In addition, we...... found that long-duration anaesthesia was significantly correlated with high heart rate, low arterial oxygen tension, and high body temperature, but not with CBF. Conclusions The findings indicate that PaCO2 and body temperature are crucial for maintaining stable levels of CBF and thus optimizing PET...

  5. Milestones and Impact Factors

    Directory of Open Access Journals (Sweden)

    Grandjean Philippe

    2010-07-01

    Full Text Available Abstract Environmental Health has just received its first Impact Factor by Thomson ISI. At a level of 2.48, this achievement is quite satisfactory and places Environmental Health in the top 25% of environmental science journals. When the journal was launched in 2002, it was still unclear whether the Open Access publishing model could be made into a viable commercial enterprise within the biomedical field. During the past eight years, Open Access journals have become widely available, although still covering only about 15% of journal titles. Major funding agencies and institutions, including prominent US universities, now require that researchers publish in Open Access journals. Because of the profound role of scientific journals for the sharing of results and communication between researchers, the advent of Open Access may be of as much significance as the transition from handwriting to printing via moveable type. As Environmental Health is an electronic Open Access journal, the numbers of downloads at the journal website can be retrieved. The top-20 list of articles most frequently accessed shows that all of them have been downloaded over 10,000 times. Back in 2002, the first article published was accessed only 49 times during the following month. A year later, the server had over 1,000 downloads per month, and now the total number of monthly downloads approaches 50,000. These statistics complement the Impact Factor and confirm the viability of Open Access in our field of research. The advent of digital media and its decentralized mode of distribution - the internet - have dramatically changed the control and financing of scientific information dissemination, while facilitating peer review, accelerating editorial handling, and supporting much needed transparency. Both the meaning and means of "having an impact" are therefore changing, as will the degree and way in which scientific journals remain "factors" in that impact.

  6. Factor 4 planning

    International Nuclear Information System (INIS)

    Bariol-Mathais, Brigitte; Lavoillotte, Philippine; Gall-Sorrentino, Florence; Malez, Marianne; Sanna, Daniela; Marsauche, Maud; Marquet, Sarah; Debergue, Sophie; Aminu, Olufunmi; Bernard, Helene; Marchand, Jean-Michel; Blin, Frederic; Grange, Jerome; Caillierez, Sophie; Muller, Dania; Clement, Bob; Desire, Jean-Charles; Metais, Benedicte; Lannuzel, Philippe; Pezet-Kuhn, Murielle; Pons, Anne; Rivoire-Meley, Benedicte; Tissot, Heloise

    2015-07-01

    Factor 4 is the goal of cutting our greenhouse gas emissions by 75% by 2050. Achieving this objective will necessitate radical changes in our practices, in particular concerning transport and housing; the measures currently implemented, such as positive-energy buildings, low-impact mobility and eco-neighbourhoods, will not be enough to meet this goal. These measures must be conceived in the framework of broad territorial planning that integrates environmental and energy objectives far upstream. To this end, the French Environment and Energy Management Agency (ADEME) and the French network of Urban Planning Agencies (FNAU), pursuing their missions in their respective areas of competence, have joined forces to make infrastructure and land use planning an integral part of the environmental and energy transition process. In 2013, the two organisations signed a partnership agreement and compiled an inventory of practices that are relevant to Factor 4 planning. This work was led by Epures, Saint-etienne urban planning agency, along with FNAU, drawing upon the expertise of a dozen urban planning agencies in precursor territories. This inventory describes the stakes, resources and strengths for each territory, which have led to cross-sectoral territorial planning exercises with ambitious environmental and energy objectives; the importance of evaluation in attaining these goals is emphasised. Current experience, questions and available methodological tools are summarised in this document, to encourage territories and help them design their planning policies along a trajectory to achieve Factor 4 goals. The compilation also aims to be a contribution to the COP21 climate conference

  7. Accidents and human factors

    International Nuclear Information System (INIS)

    Nishiwaki, Y.; Kawai, H.; Morishima, H.; Terano, T.; Sugeno, M.

    1984-01-01

    When the TMI accident occurred it was 4 a.m., an hour when the error potential of the operators would have been very high. The frequency of car and train accidents in Japan is also highest between 4 a.m. and 6 a.m. The error potential may be classified into five phases corresponding to the electroencephalogramic pattern (EEG). At phase 0, when the delta wave appears, a person is unconscious and in deep sleep; at phase I, when the theta wave appears, he is very tired, sleepy and subnormal; at phase II, when the alpha wave appears, he is normal, relaxed and passive; at phase III, when the beta wave appears, he is normal, clear-minded and active; at phase IV, when the strong beta or epileptic wave appears, he is hypernormal, excited and incapable of normal judgement. Should an accident occur at phase II, the brain condition may jump to phase IV. At this phase the error or accident potential is maximum. The response of the human brain to different types of noises and signals may vary somewhat for different individuals and for different groups of people. Therefore, the possibility that such differences in brain functions may influence the mental structure would be worthy of consideration in human factors and in the design of man-machine systems. Human reliability and performance would be affected by many factors: medical, physiological and psychological, etc. The uncertainty involved in human factors may not necessarily be probabilistic, but fuzzy. Therefore, it would be important to develop a theory by which both non-probabilistic uncertainties, or fuzziness, of human factors and the probabilistic properties of machines can be treated consistently. From the mathematical point of view, probabilistic measure is considered a special case of fuzzy measure. Therefore, fuzzy set theory seems to be an effective tool for analysing man-machine systems. To minimize human error and the possibility of accidents, new safety systems should not only back up man and make up for his

  8. Speeding Fermat's factoring method

    Science.gov (United States)

    McKee, James

    A factoring method is presented which, heuristically, splits composite n in O(n^{1/4+epsilon}) steps. There are two ideas: an integer approximation to sqrt(q/p) provides an O(n^{1/2+epsilon}) algorithm in which n is represented as the difference of two rational squares; observing that if a prime m divides a square, then m^2 divides that square, a heuristic speed-up to O(n^{1/4+epsilon}) steps is achieved. The method is well-suited for use with small computers: the storage required is negligible, and one never needs to work with numbers larger than n itself.

  9. Improved Balanced Incomplete Factorization

    Czech Academy of Sciences Publication Activity Database

    Bru, R.; Marín, J.; Mas, J.; Tůma, Miroslav

    2010-01-01

    Roč. 31, č. 5 (2010), s. 2431-2452 ISSN 0895-4798 R&D Projects: GA AV ČR IAA100300802 Grant - others:GA AV ČR(CZ) M100300902 Institutional research plan: CEZ:AV0Z10300504 Source of funding: I - inštitucionálna podpora na rozvoj VO Keywords : preconditioned iterative methods * sparse matrices * incomplete decompositions * approximate inverses * Sherman-Morrison formula * nonsymmetric matrices Subject RIV: BA - General Mathematics Impact factor: 1.725, year: 2010

  10. Sleep-inducing factors.

    Science.gov (United States)

    García-García, Fabio; Acosta-Peña, Eva; Venebra-Muñoz, Arturo; Murillo-Rodríguez, Eric

    2009-08-01

    Kuniomi Ishimori and Henri Piéron were the first researchers to introduce the concept and experimental evidence for a chemical factor that would presumably accumulate in the brain during waking and eventually induce sleep. This substance was named hypnotoxin. Currently, the variety of substances which have been shown to alter sleep includes peptides, cytokines, neurotransmitters and some substances of lipidic nature, many of which are well known for their involvement in other biological activities. In this chapter, we describe the sleep-inducing properties of the vasoactive intestinal peptide, prolactin, adenosine and anandamide.

  11. "Factor Analysis Using ""R"""

    Directory of Open Access Journals (Sweden)

    A. Alexander Beaujean

    2013-02-01

    Full Text Available R (R Development Core Team, 2011 is a very powerful tool to analyze data, that is gaining in popularity due to its costs (its free and flexibility (its open-source. This article gives a general introduction to using R (i.e., loading the program, using functions, importing data. Then, using data from Canivez, Konold, Collins, and Wilson (2009, this article walks the user through how to use the program to conduct factor analysis, from both an exploratory and confirmatory approach.

  12. Perinatal risk factors for strabismus

    DEFF Research Database (Denmark)

    Torp-Pedersen, Tobias; Boyd, Heather A; Poulsen, Gry

    2010-01-01

    Little is known about the aetiological factors underlying strabismus. We undertook a large cohort study to investigate perinatal risk factors for strabismus, overall and by subtype.......Little is known about the aetiological factors underlying strabismus. We undertook a large cohort study to investigate perinatal risk factors for strabismus, overall and by subtype....

  13. Activation of human factor V by factor Xa and thrombin

    International Nuclear Information System (INIS)

    Monkovic, D.D.; Tracy, P.B.

    1990-01-01

    The activation of human factor V by factor Xa and thrombin was studied by functional assessment of cofactor activity and sodium dodecyl sulfate-polycarylamide gel electrophoresis followed by either autoradiography of 125 I-labeled factor V activation products or Western blot analyses of unlabeled factor V activation products. Cofactor activity was measured by the ability of the factor V/Va peptides to support the activation of prothrombin. The factor Xa catalyzed cleavage of factor V was observed to be time, phospholipid, and calcium ion dependent, yielding a cofactor with activity equal to that of thrombin-activated factor V (factor Va). The cleavage pattern differed markedly from the one observed in the bovine system. The factor Xa activated factor V subunits expressing cofactor activity were isolated and found to consist of peptides of M r 220,000 and 105,000. Although thrombin cleaved the M r 220,000 peptide to yield peptides previously shown to be products of thrombin activation, cofactor activity did not increase. N-Terminal sequence analysis confirmed that both factor Xa and thrombin cleave factor V at the same bond to generate the M r 220,000 peptide. The factor Xa dependent functional assessment of 125 I-labeled factor V coupled with densitometric analyses of the cleavage products indicated that the cofactor activity of factor Xa activated factor V closely paralleled the appearance of the M r 220,000 peptide. The data indicate that factor Xa is as efficient an enzyme toward factor V as thrombin

  14. Organizational factors in Korean NPPs

    International Nuclear Information System (INIS)

    Jang, D. J.; Kim, Y. I.; Jeong, C. H.; Kim, J. W.

    2003-01-01

    Organizational factors are referred to as the factors that influence the achievement of a goal of an organization. Latent problems of an organization could contribute to causing human errors in such stages as design, operation and maintenance, and furthermore, leading to an severe accident. In order to evaluate an organization from the safety viewpoint, it is necessary to identify the organizational factors in a systematic fashion. In this paper, some efforts to identify the organizational factors in Korean NPPs are presented. The study was performed in the following steps: 1) Reviewing the definitions and range of the organizational factors used by the previous 13 researches, 2) Structuring the organizational factors by screening and collating factors, 3) Analysing the organizational factors that is considered to have contributed to the trip events based on the trip report of Korean NPPs, 4) Suggesting a more reliable taxonomy of organizational factors for event analysis by applying the Onion Structure Model to the selected factors

  15. Risk Factors in Pemphigus

    Directory of Open Access Journals (Sweden)

    Gülşen Tükenmez Demirc

    2011-09-01

    Full Text Available Background and Design: There have been reports suggesting the involvement of environmental factors in the disease process of pemphigus. In this study, we aimed to find out the risk factors which could play role in the etiopathogenesis in our pemphigus patients.Material and method: A total of 42 patients (15 male and 27 female who were diagnosed as pemphigus with histopathological and direct immunoflurosence examinations in our clinic between the years 1998-2004, were interviewed for assessment of regarding with the subjects of the demographic properties, occupational groups, educational level, the number of pregnancies, stressfull life events, diet habits, smoking and alcohol consumption before the onset of the disease and the results were compared to 42 age and gender-matched controls with similar socioeconomic circumstances. Results: Working in agriculture and livestock, multi-parity, absence of smoking and stressfull life events were found to be statistically significant in pemphigus patients than in controls. Conclusion: Working in agriculture and livestock, multi-parity, absence of smoking and stressfull life events were assumed to play role in the etiopathogenesis and course of pemphigus.

  16. Clinical evaluation of Parkinson's disease using sup 123 I-IMP SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Hiroko; Odano, Ikuo; Nishihara, Mamiko; Higuchi, Shouichi; Sakai, Kunio [Niigata Univ. (Japan). School of Medicine; Ishikawa, Atsushi

    1989-11-01

    N-isopropyl-p({sup 123}I)iodoamphetamine ({sup 123}I-IMP) SPECT and regional cerebral blood flow (rCBF) studies were performed in 20 patients with Parkinson's disease (PD) and 8 normal subjects. RCBF was measured by the arterial blood sampling method which used the microsphere model. We analized seven factors which might be related to the rCBF in PD, i.e., age, stage, duration of the disease, cerebral atrophy, severity of dementia, laterality of symptoms and motor disability score (MDS; the degree of akinesia, rigidity, tremor, gait disturbance, freezing and pulsion sign). Compared with normal subjects, global CBF (supratentorial mean rCBF) was reduced by 21.8% in PD. In particular, rCBF in the basal ganglia and that of frontal cortex were reduced by 25.3% and 24.8%, respectively. Distribution patterns of rCBF in PD were almost as same as those in normals except for cerebellum. The reduction of both rCBFs in the basal ganglia and parietal cortex significantly correlated with MDS (p<0.05, respectively). Especially, akinesia was closely correlated to the reduction of rCBF in the parietal cortex (p<0.02). Moreover, we observed a significant relationship between cerebral atrophy and reduction of rCBF in each region except for cerebellum. However, there was no significant correlation between the severity of dementia and reduction of rCBF, even in the frontal cortex or parietal cortex. These data show that the severity of dementia in PD may be connected with other factors except for rCBF. {sup 123}I-IMP SPECT study is a useful method for clinical evaluation of PD. (author).

  17. Activation of 125I-Factor IX and 125I-Factor X: Effect of tissue factor and Factor VII, Factor Xsub(a) and thrombin

    International Nuclear Information System (INIS)

    Oesterud, B.; Rapaport, S.I.

    Activation of Factor IX and Factor X was studied by adding 125 I-Factor IX or 125 I-Factor X to reaction mixtures and quantitating cleavage products by reduced sodium dodecylsulfate gel electrophoresis. Thrombin failed to activate Factors IX or X; Factor Xsub(a) produced insignificant amounts of cleavage products of both factors. In contrast, the reaction product of tissue factor and Factor VII cleaved large amounts of both Factor IX and Factor X in purified systems and in plasma. In incubation mixtures of plasma containing added 125 I-Factor IX or 125 I-Factor X, tissue factor and Ca 2+ ions, the percentage of total radioactivity in the heavy chain peak of 125 I-IXsub(a) and the heavy chain of 125 I-Xsub(a) increased at a similar rate. When the tissue factor was diluted, similar curves were obtained for percent cleavage of 125 I-Factor IX and percent cleavage of 125 I-Factor X plotted against tissue factor concentration. These findings support the hypothesis that activation of Factor IX by the tissue factor-Factor VII reaction product represents a physiologically significant step in normal haemostasis. (author)

  18. Psychosomatic factors in pruritus.

    Science.gov (United States)

    Tey, Hong Liang; Wallengren, Joanna; Yosipovitch, Gil

    2013-01-01

    Pruritus and psyche are intricately and reciprocally related, with psychophysiological evidence and psychopathological explanations helping us to understand their complex association. Their interaction may be conceptualized and classified into 3 groups: pruritic diseases with psychiatric sequelae, pruritic diseases aggravated by psychosocial factors, and psychiatric disorders causing pruritus. Management of chronic pruritus is directed at treating the underlying causes and adopting a multidisciplinary approach to address the dermatologic, somatosensory, cognitive, and emotional aspects. Pharmcotherapeutic agents that are useful for chronic pruritus with comorbid depression and/or anxiety comprise selective serotonin reuptake inhibitors, mirtazapine, tricyclic antidepressants (amitriptyline and doxepin), and anticonvulsants (gabapentin, pregabalin); the role of neurokinin receptor-1 antagonists awaits verification. Antipsychotics are required for treating itch and formication associated with schizophrenia and delusion of parasitosis (including Morgellons disease). Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Factorization of Observables

    Science.gov (United States)

    Eliaš, Peter; Frič, Roman

    2017-12-01

    Categorical approach to probability leads to better understanding of basic notions and constructions in generalized (fuzzy, operational, quantum) probability, where observables—dual notions to generalized random variables (statistical maps)—play a major role. First, to avoid inconsistencies, we introduce three categories L, S, and P, the objects and morphisms of which correspond to basic notions of fuzzy probability theory and operational probability theory, and describe their relationships. To illustrate the advantages of categorical approach, we show that two categorical constructions involving observables (related to the representation of generalized random variables via products, or smearing of sharp observables, respectively) can be described as factorizing a morphism into composition of two morphisms having desired properties. We close with a remark concerning products.

  20. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  1. Pion form factor

    Energy Technology Data Exchange (ETDEWEB)

    Ryong Ji, C.; Pang, A.; Szczepaniak, A. [North Carolina State Univ., Raleigh, NC (United States)

    1994-04-01

    It is pointed out that the correct criterion to define the legal PQCD contribution to the exclusive processes in the lightcone perturbative expansion should be based on the large off-shellness of the lightcone energy in the intermediate states. In the lightcone perturbative QCD calculation of the pion form factor, the authors find that the legal PQCD contribution defined by the lightcone energy cut saturates in the smaller Q{sup 2} region compared to that defined by the gluon four-momentum square cut. This is due to the contribution by the highly off-energy-shell gluons in the end point regions of the phase space, indicating that the gluon four-momentum-square cut may have cut too much to define the legal PQCD.

  2. Eukaryotic transcription factors

    DEFF Research Database (Denmark)

    Staby, Lasse; O'Shea, Charlotte; Willemoës, Martin

    2017-01-01

    Gene-specific transcription factors (TFs) are key regulatory components of signaling pathways, controlling, for example, cell growth, development, and stress responses. Their biological functions are determined by their molecular structures, as exemplified by their structured DNA-binding domains...... regions with function-related, short sequence motifs and molecular recognition features with structural propensities. This review focuses on molecular aspects of TFs, which represent paradigms of ID-related features. Through specific examples, we review how the ID-associated flexibility of TFs enables....... It is furthermore emphasized how classic biochemical concepts like allostery, conformational selection, induced fit, and feedback regulation are undergoing a revival with the appreciation of ID. The review also describes the most recent advances based on computational simulations of ID-based interaction mechanisms...

  3. Nucleon Electromagnetic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

    2007-10-01

    There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.

  4. Wave friction factor rediscovered

    Science.gov (United States)

    Le Roux, J. P.

    2012-02-01

    The wave friction factor is commonly expressed as a function of the horizontal water particle semi-excursion ( A wb) at the top of the boundary layer. A wb, in turn, is normally derived from linear wave theory by {{U_{{wb}}/T_{{w}}}}{{2π }} , where U wb is the maximum water particle velocity measured at the top of the boundary layer and T w is the wave period. However, it is shown here that A wb determined in this way deviates drastically from its real value under both linear and non-linear waves. Three equations for smooth, transitional and rough boundary conditions, respectively, are proposed to solve this problem, all three being a function of U wb, T w, and δ, the thickness of the boundary layer. Because these variables can be determined theoretically for any bottom slope and water depth using the deepwater wave conditions, there is no need to physically measure them. Although differing substantially from many modern attempts to define the wave friction factor, the results coincide with equations proposed in the 1960s for either smooth or rough boundary conditions. The findings also confirm that the long-held notion of circular water particle motion down to the bottom in deepwater conditions is erroneous, the motion in fact being circular at the surface and elliptical at depth in both deep and shallow water conditions, with only horizontal motion at the top of the boundary layer. The new equations are incorporated in an updated version (WAVECALC II) of the Excel program published earlier in this journal by Le Roux et al. Geo-Mar Lett 30(5): 549-560, (2010).

  5. [The Steel factor].

    Science.gov (United States)

    Cáceres-Cortés, J R

    1997-01-01

    Mice bearing mutations at either of two loci, dominant White spotting(W) or Steel(Sl), exhibit development defects in hematopoietic, melanocytic and germ cells. Genetics studies have shown that the SI locus encodes the Steel factor (SF), which is the ligand for the tyrosine kinase receptor c-kit, the product of the W locus. SF is synthesized in membrane-bound form and can be processed to produce a soluble form. Cell-cell interaction is important in the production of normal blood cells in vivo and in vitro and in the cellular expansion of leukemic cells. We discuss here how SF decreases the requirements in cell interaction for blast colony formation in acute myeloblastic leukemia (AML) and the presence of membrane-bound SF possibly contributes to the density-dependent growth of the AML blasts. We explain that SF is mainly a survival factor for hematopoietic cells, of little proliferative effect, which maintains CD34+ hematopoietic cells in an undifferentiated state. These properties would potentially allow the maintenance of hematopoietic cells in culture for the purpose of marrow purging or gene therapy. The activation of the c-kit signal transduction pathway may play a significant role in the development of many types of non-hematological malignancies by disrupting normal cell-cell interactions and allowing the growth of cancer cell populations. In summary, the properties of the SF indicate it has a role for survival signals during the process of normal differentiation, AML proliferation and in the maintenance of many c-kit+ tumors.

  6. Neutron quality factor

    International Nuclear Information System (INIS)

    1995-06-01

    Both the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP) have recommended that the radiation quality weighting factor for neutrons (Q n , or the corresponding new modifying factor, w R ) be increased by a value of two for most radiation protection practices. This means an increase in the recommended value for Q n from a nominal value of 10 to a nominal value of 20. This increase may be interpreted to mean that the biological effectiveness of neutrons is two times greater than previously thought. A decision to increase the value of Q n will have a major impact on the regulations and radiation protection programs of Federal agencies responsible for the protection of radiation workers. Therefore, the purposes of this report are: (1) to examine the general concept of open-quotes quality factorclose quotes (Q) in radiation protection and the rationale for the selection of specific values of Q n ; and (2) to make such recommendations to the Federal agencies, as appropriate. This report is not intended to be an exhaustive review of the scientific literature on the biological effects of neutrons, with the aim of defending a particular value for Q n . Rather, the working group examined the technical issues surrounding the current recommendations of scientific advisory bodies on this matter, with the aim of determining if these recommendations should be adopted by the Federal agencies. Ultimately, the group concluded that there was no compelling basis for a change in Q n . The report was prepared by Federal scientists working under the auspices of the Science Panel of the Committee on Interagency Radiation Research and Policy Coordination (CIRRPC)

  7. Factorization and non-factorization in diffractive hard scattering

    International Nuclear Information System (INIS)

    Berera, Arjun

    1997-01-01

    Factorization, in the sense defined for inclusive hard scattering, is discussed for diffractive hard scattering. A factorization theorem similar to its inclusive counterpart is presented for diffractive DIS. For hadron-hadron diffractive hard scattering, in contrast to its inclusive counterpart, the expected breakdown of factorization is discussed. Cross section estimates are given from a simple field theory model for non-factorizing double-pomeron-exchange (DPE) dijet production with and without account for Sudakov suppression

  8. Robust and Sparse Factor Modelling

    DEFF Research Database (Denmark)

    Croux, Christophe; Exterkate, Peter

    Factor construction methods are widely used to summarize a large panel of variables by means of a relatively small number of representative factors. We propose a novel factor construction procedure that enjoys the properties of robustness to outliers and of sparsity; that is, having relatively few...... nonzero factor loadings. Compared to the traditional factor construction method, we find that this procedure leads to a favorable forecasting performance in the presence of outliers and to better interpretable factors. We investigate the performance of the method in a Monte Carlo experiment...

  9. Identifying the important factors in simulation models with many factors

    NARCIS (Netherlands)

    Bettonvil, B.; Kleijnen, J.P.C.

    1994-01-01

    Simulation models may have many parameters and input variables (together called factors), while only a few factors are really important (parsimony principle). For such models this paper presents an effective and efficient screening technique to identify and estimate those important factors. The

  10. External Factors, Internal Factors and Self-Directed Learning Readiness

    Science.gov (United States)

    Ramli, Nurjannah; Muljono, Pudji; Afendi, Farit M.

    2018-01-01

    There are many factors which affect the level of self-directed learning readiness. This study aims to investigate the relationship between external factors, internal factors and self-directed learning readiness. This study was carried out by using a census method for fourth year students of medical program of Tadulako University. Data were…

  11. Electromagnetic Hadronic Form-Factors

    International Nuclear Information System (INIS)

    Edwards, Robert G.

    2005-01-01

    We present a calculation of the nucleon electromagnetic form-factors as well as the pion and rho to pion transition form-factors in a hybrid calculation with domain wall valence quarks and improved staggered (Asqtad) sea quarks

  12. R-Factor for Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The rainfall-runoff erosivity factor (R-Factor) quantifies the effects of raindrop impacts and reflects the amount and rate of runoff associated with the rain. The...

  13. Air Emissions Factors and Quantification

    Science.gov (United States)

    Emissions factors are used in developing air emissions inventories for air quality management decisions and in developing emissions control strategies. This area provides technical information on and support for the use of emissions factors.

  14. Integrated Factors Correlating Undergraduate Academic ...

    African Journals Online (AJOL)

    Integrated Factors Correlating Undergraduate Academic Achievement in Bayelsa State, Nigeria. ... AFRREV IJAH: An International Journal of Arts and Humanities ... Thus, it is study investigated the integrated factors determining academic performance of students in public secondary schools in Bayelsa State, Nigeria.

  15. Human Factors in Training

    Science.gov (United States)

    Barshi, Immanuel; Byrne, Vicky; Arsintescu, Lucia; Connell, Erin

    2010-01-01

    Future space missions will be significantly longer than current shuttle missions and new systems will be more complex than current systems. Increasing communication delays between crews and Earth-based support means that astronauts need to be prepared to handle the unexpected on their own. As crews become more autonomous, their potential span of control and required expertise must grow to match their autonomy. It is not possible to train for every eventuality ahead of time on the ground, or to maintain trained skills across long intervals of disuse. To adequately prepare NASA personnel for these challenges, new training approaches, methodologies, and tools are required. This research project aims at developing these training capabilities. By researching established training principles, examining future needs, and by using current practices in space flight training as test beds, both in Flight Controller and Crew Medical domains, this research project is mitigating program risks and generating templates and requirements to meet future training needs. Training efforts in Fiscal Year 09 (FY09) strongly focused on crew medical training, but also began exploring how Space Flight Resource Management training for Mission Operations Directorate (MOD) Flight Controllers could be integrated with systems training for optimal Mission Control Center (MCC) operations. The Training Task addresses Program risks that lie at the intersection of the following three risks identified by the Project: 1) Risk associated with poor task design; 2) Risk of error due to inadequate information; and 3) Risk associated with reduced safety and efficiency due to poor human factors design.

  16. Self-shielding factors

    International Nuclear Information System (INIS)

    Kaul, D.C.

    1982-01-01

    Throughout the last two decades many efforts have been made to estimate the effect of body self-shielding on organ doses from externally incident neutrons and gamma rays. These began with the use of simple geometry phantoms and have culminated in the use of detailed anthropomorphic phantoms. In a recent effort, adjoint Monte Carlo analysis techniques have been used to determine dose and dose equivalent to the active marrow as a function of energy and angle of neutron fluence externally incident on an anthropomorphic phantom. When combined with fluences from actual nuclear devices, these dose-to-fluence factors result in marrow dose values that demonstrate great sensitivity to variations in device type, range, and body orientation. Under a state-of-the-art radiation transport analysis demonstration program for the Japanese cities, sponsored by the Defense Nuclear Agency at the request of the National Council on Radiation Protection and Measurements, the marrow dose study referred to above is being repeated to obtain spectral distributions within the marrow for externally incident neutrons and gamma rays of arbitrary energy and angle. This is intended to allow radiobiologists and epidemiologists to select and to modify numbers of merit for correlation with health effects and to permit a greater understanding of the relationship between human and laboratory subject dosimetry

  17. Research organizational factors

    International Nuclear Information System (INIS)

    Coffman, F.D. Jr.

    1990-01-01

    Organizational processes at nuclear power plants should be sufficient to prevent accidents and to protect public health and safety upon the occurrence of an accident. The role of regulatory research is to confirm that agency assessments of organization processes are on a firm technical basis and provide for improvements in the NRC [Nuclear Regulatory Commission] programs. A firm technical basis is achieved by reducing uncertainties associated with methods and measures used to assess organization processes. The general objective for regulatory research is to confirm that the agency has a coherent understanding of the organizational processes that are individually necessary and are collectively sufficient for safe operations, methods are available to reliably characterize organizational processes, and measures exist to monitor changes in the key organizational processes. The first specific objective was to develop a method to translate organizational processes into PRAs. The discussion provides feedback and insights from experience with the past and the ongoing organizational factors research. That experience suggests a set of ingredients that appear proper for performing regulatory research on organizational processes. By keeping focused upon these proper ingredients, the research will contribute to the regulatory assessments of utility management through the use of improved methods and measures in investigations, inspections, diagnostics, performance indicators, and PRA insights

  18. Prolonged disturbances of regional cerebral blood flow in transient ischemic attacks

    International Nuclear Information System (INIS)

    Hartmann, A.

    1985-01-01

    Regional cerebral blood flow (rCBF) was measured over both hemispheres in 20 patients with unilateral transient ischemic attacks (TIA) of the territory of the internal carotid artery on the day of the TIA. rCBF was estimated with the nontraumatic Xenon 133-inhalation technique using the initial slope index. 13 patients experienced their first TIA, 7 had several attacks. In 14 patients the first rCBF-measurement was performed during the presentation of clinical symptoms. The 2nd rCBF-measurement was done on day 2, the last one on day 7. Scans of the 15 patients studied with CT were normal. On day 1 mean rCBF of the TIA-side was significantly lower than that of the contralateral hemispheres. 22% of all areas showed a significant reduction of flow compared to mean rCBF. Mean rCBF of both the TIA- and the contralateral side was significantly reduced compared to the bi-hemispheric mean rCBF of a control group with no history of TIA or completed strokes but at least 2 risk factors for cerebrovascular disease. Whereas mean rCBF did not change in the contralateral side it increased significantly (+6.9%) in the TIA-side from day 1 to day 2 but not from there to day 7. This is reflected by the increase of the total number of ROI with normal flow from day 1 to day 2. Considering the actual flow and the flow course of that tissue which was believed to be responsible for the clinical symptoms the following regional patterns were observed: normal rCBF in 6 patients; early return to normal concomitant to the clinical course (n = 4)

  19. Cerebral blood flow in patients with hypertensive intracerebral hemorrhage

    International Nuclear Information System (INIS)

    Sugiyama, Hirotaka

    1984-01-01

    Cerebral blood flow (CBF) is usually decreased in patients with hypertensive intracerebral hemorrhage. A total of 81 regional CBF measurements were performed using an Anger-type dynamic gamma camera with the Xe-133 intracarotid injection technique in 23 patients with thalamic hemorrhage, 18 with small putaminal hemorrhage, and 5 with large putaminal hemorrhage. The results were as follows: Bilateral CBF in thalamic hemorrhages was markedly reduced from 1 week to 2 or 3 weeks after onset; it then showed a tendency to increase from 4 weeks to 3 months. In putaminal hemorrhages, however, CBF in the affected hemisphere did not tend to increase despite increased CBF in the contralateral hemisphere. CBF of the affected hemisphere was plotted against the hematoma volume, and the biphasic curve showed an initial steep and subsequent gentle slope in both putaminal and thalamic hemorrhages. The degree of CBF reduction in the affected hemisphere was more evident in thalamic than in putaminal hemorrhages. However, the flow reduction in the contralateral hemisphere was more obvious in thalamic than in putaminal hemorrhages. Factors such as mean arterial blood pressure, partial pressure of arterial carbon dioxide, cerebrospinal fluid pressure, hematocrit and the degree of involvement of the internal capsule, as shown on CT scan were not directly related to CBF reduction. In conclusion, it is unlikely that the mass effect of the hematoma plays an important role in the discrepancy between CBF reduction in putaminal and thalamic hemorrhages. Rather, the discrepancy may result from the impairment of respective anatomical sites in the thalamic and putaminal regions. It is also suggested that ipsilateral as well as contralateral CBF reduction is probably caused by the decreased cortical metabolic demand. This may be based on the disruption of the transneural fiber pathways, which connect both the thalamus and putamen to the cerebral cortex. (author)

  20. BASIC FACTORS OF MARKET CONCENTRATION

    OpenAIRE

    V. Fyliuk

    2013-01-01

    The paper systemizes factors which reinforce trends towards market concentration in all economic systems. These factors include factors related to the general changes in economic environment such as globalization of the world economy, state structural and taxation policies, cycle of economic development and changes in consumer demand. They also include factors related to competition (intensification of competition, companies’ desire to monopolize market and present market structure) and scien...

  1. Improvements in the Quantitative Assessment of Cerebral Blood Volume and Flow with the Removal of Vessel Voxels from MR Perfusion Images

    Directory of Open Access Journals (Sweden)

    Michael Mu Huo Teng

    2013-01-01

    Full Text Available Objective. To improve the quantitative assessment of cerebral blood volume (CBV and flow (CBF in the brain voxels from MR perfusion images. Materials and Methods. Normal brain parenchyma was automatically segmented with the time-to-peak criteria after cerebrospinal fluid removal and preliminary vessel voxel removal. Two scaling factors were calculated by comparing the relative CBV and CBF of the segmented normal brain parenchyma with the absolute values in the literature. Using the scaling factors, the relative values were converted to the absolute CBV and CBF. Voxels with either CBV > 8 mL/100 g or CBF > 100 mL/100 g/min were characterized as vessel voxels and were excluded from the quantitative measurements. Results. The segmented brain parenchyma with normal perfusion was consistent with the angiographic findings for each patient. We confirmed the necessity of dual thresholds including CBF and CBV for proper removal of vessel voxels. The scaling factors were 0.208 ± 0.041 for CBV, and 0.168 ± 0.037, 0.172 ± 0.037 for CBF calculated using standard and circulant singular value decomposition techniques, respectively. Conclusion. The automatic scaling and vessel removal techniques provide an alternative method for obtaining improved quantitative assessment of CBV and CBF in patients with thromboembolic cerebral arterial disease.

  2. Human Factors in Marine Casualties

    Directory of Open Access Journals (Sweden)

    Jelenko Švetak

    2002-05-01

    Full Text Available Human factors play an important role in the origin of accidents,and it is commonly claimed that between seventy andninety-five percent of industrial and transport accidents involvehuman factors, see Figure 1.Some authorities, however, claim that ultimately, all accidentsinvolve human factors.

  3. Risks factoring business: accounting measurement

    Directory of Open Access Journals (Sweden)

    Z.V. Gutsaylyuk

    2015-06-01

    Full Text Available The paper carried out the identification of risk factors for the development of possible accounting software management. Studied theoretical and methodological aspects of the risk classification of factoring operations in the part of the risk assessment factors. It is proposed to consider the risks factors as the risk that is acceptable controlled by accounting instruments and the risks that can not be taken into account in the accounting records. To minimize the risk factor, accounting-driven tools, a method of self-insurance, which is a factor in the creation of provision for factoring transactions designed to cover unexpected expenses and losses. Provision for factoring factor will establish more stable conditions of financial activity and avoid the fluctuations of profit factor in relation to the writing off of losses on factoring operatsіyam.Developed proposals allow for further research to improve the organizational and methodological basis of accounting and analysis of information as a basis for providing risk management factor, particularly in terms of improving the evaluation questions such risks and their qualitative and quantitative analysis.

  4. Investing in systematic factor premiums

    NARCIS (Netherlands)

    Koedijk, Kees G.; Slager, Alfred M. H.; Stork, P.A.

    In this paper we investigate and evaluate factor investing in the US and Europe for equities and bonds. We show that factor-based portfolios generally produce comparable or better portfolios than market indices. We expand the analysis to other asset classes and factors, work with other optimisation

  5. Sparse and Robust Factor Modelling

    NARCIS (Netherlands)

    C. Croux (Christophe); P. Exterkate (Peter)

    2011-01-01

    textabstractFactor construction methods are widely used to summarize a large panel of variables by means of a relatively small number of representative factors. We propose a novel factor construction procedure that enjoys the properties of robustness to outliers and of sparsity; that is, having

  6. Risk Factor Assessment Branch (RFAB)

    Science.gov (United States)

    The Risk Factor Assessment Branch (RFAB) focuses on the development, evaluation, and dissemination of high-quality risk factor metrics, methods, tools, technologies, and resources for use across the cancer research continuum, and the assessment of cancer-related risk factors in the population.

  7. Geriatic Disability Related Factors

    Directory of Open Access Journals (Sweden)

    Mohsen Adib Hajbagheri

    2008-07-01

    Full Text Available Objectives: Reports are indicating of increasing trend of aging and disability in the developing countries while such disabilities are decreasing within the developed countries. This study designed to evaluate the disability and some of its related factors among the elderly population (65 and older in Kashan, Iran. Methods & Materials: A cross-sectional analytical study was conducted on a multi-stage random sample of 350 elderly people (65 year and older in Kashan. The WHO-DAS-II was used as the generic disability measure. The questionnair had 48 questions. The range of score could be between 0-144. Chi-square, t-test analysis and ANOVA were utilized to check significant differences between subgroups. Results: 61% were men and 12% were living lonely. One fourth had some type of addiction, the majority were ilitrate and two thired had not regular phisycal activity.Twenty percent of the old people had a modereate disability and 4.3% were extremely disabled. A significant relationship was found between the disability and variables such as sex, age, living style, needing help, marriage status, living location, addiction, job, level of physical activity, education, and having multiple diseases. Conclusion: In conclusion, geriatric population in Iran, has a lower levels of disability in compare to those of other developed countries. Need of geriatric cares must be be increasing, since the populationpattern of elderly people is increasing in Iran. Female and ilitrate elders were sufering of more disability. These findings indicated the nessesity to more attention to these voulnarable subgroups of population.

  8. Gut transfer factors

    International Nuclear Information System (INIS)

    1990-01-01

    A Nuclear Energy Agency (NEA) Expert Group has proposed values for the absorbed fractions (f 1 values) of radionuclides ingested in food and drinking water by members of the public. The f 1 values for adults, which are also taken to apply to children from 1 year of age, are increased from those given in ICRP Publication 30 for occupationally exposed adults for 7 elements out of the 31 considered. Since the publication of the NEA report, further information has become available that is relevant to the choice of f 1 values for polonium and thorium. These data suggest that for the present the f 1 value for polonium currently recommended by ICRP (0.1) should be retained, and that for thorium a reasonable f 1 value is 0.0005. With these exceptions, the NRPB endorses the revisions in f 1 values proposed by the NEA Expert Group for adults and children from 1 year of age. Higher f 1 values are proposed by the NEA expert Group for absorption in the first year of life. For adult values of between 0.01 and 0.5, an increase by a factor of two is assumed, and for adult values of 0.001 or less, absorption by infants is taken to be ten times greater. This approach is consistent with, and extends, that applied to the actinides in ICRP Publication 48 and represents a reasonable interpretation of current evidence. The NRPB therefore endorses the approach proposed by the NEA Expert Group for the calculation of doses to infants. (author)

  9. Factors Affecting Medical Service Quality.

    Science.gov (United States)

    Mosadeghrad, Ali Mohammad

    2014-02-01

    A better understanding of factors influencing quality of medical service can pinpoint better strategies for quality assurance in medical services. This study aimed to identify factors affecting the quality of medical services provided by Iranian physicians. Exploratory in-depth individual interviews were conducted with sixty-four physicians working in various medical institutions in Iran. Individual, organizational and environmental factors enhance or inhibit the quality of medical services. Quality of medical services depends on the personal factors of the physician and patient, and factors pertaining to the healthcare setting and the broader environment. Differences in internal and external factors such as availability of resources, patient cooperation and collaboration among providers affect the quality of medical services and patient outcomes. Supportive leadership, proper planning, education and training and effective management of resources and processes improve the quality of medical services. This article contributes to healthcare theory and practice by developing a conceptual framework for understanding factors that influence medical services quality.

  10. Prognostic factors of breast cancer

    International Nuclear Information System (INIS)

    Gonzalez Ortega, Jose Maria; Morales Wong, Mario Miguel; Lopez Cuevas, Zoraida; Diaz Valdez, Marilin

    2011-01-01

    The prognostic factors must to be differentiated of the predictive ones. A prognostic factor is any measurement used at moment of the surgery correlated with the free interval of disease or global survival in the absence of the systemic adjuvant treatment and as result is able to correlate with the natural history of the disease. In contrast, a predictive factor is any measurement associated with the response to a given treatment. Among the prognostic factors of the breast cancer are included the clinical, histological, biological, genetic and psychosocial factors. In present review of psychosocial prognostic factors has been demonstrated that the stress and the depression are negative prognostic factors in patients presenting with breast cancer. It is essential to remember that the assessment of just one prognostic parameter is a help but it is not useful to clinical and therapeutic management of the patient.(author)

  11. The population factor.

    Science.gov (United States)

    Kats, G

    1983-01-01

    Reducing population growth is essentil to Egypt's broader efforts to improve facilities, services, and the phsycial quality of life. Although a family planning program has existed since the mid-1950s, the 2.7% annual rate of population growth has not changed in 30 years. Nasser and the other "free officers" who seized power in 1952 became concerned about the adverse effects of the rapidly growing population, but perhaps out of concern with a possible religious backlash, they confined themselves to launching studies and subsidizing several dozen private family planning clinics. From 1962-72, the number of private clinics grew from 28 to 480, and family planning was introduced in government healthclinics in 1965. Such clinics are mainly located in rural areas and are staffed by doctors and other personnel who are not members of the local community and are not very effective at promoting family planning. Local girls and women called Rayadet were recruited to promote the idea to birth control in local communities. By 1970, 12.6% of Egyptians were using reliable contraception. A national survey 12 years later found 34% using contraception, buth the figure seems high. Approximately 60-65% of eligible couples would need to practice birth control for Egypt to reach a less than 1% annuel increase. The Egyptian government hopes to slow population growth to 1% by the year 2000, but major problems of motivation remain especially among the rural poor. Several factors may lead to success of the family planning effort: 1) financial and technical support from international family planning sources has grown rapidley and is likely to remain high; 2) the mortality rate has dropped from 17.8/1000 in 1952 to about half that level, while the rate of natural increase is about the same, suggesting that future reductions in the birth rate will translate to a reduced rate of natural increase, and that parents will be less reluctant to practice faimly planning if there is a greater chance

  12. A factor analysis to detect factors influencing building national brand

    Directory of Open Access Journals (Sweden)

    Naser Azad

    Full Text Available Developing a national brand is one of the most important issues for development of a brand. In this study, we present factor analysis to detect the most important factors in building a national brand. The proposed study uses factor analysis to extract the most influencing factors and the sample size has been chosen from two major auto makers in Iran called Iran Khodro and Saipa. The questionnaire was designed in Likert scale and distributed among 235 experts. Cronbach alpha is calculated as 84%, which is well above the minimum desirable limit of 0.70. The implementation of factor analysis provides six factors including “cultural image of customers”, “exciting characteristics”, “competitive pricing strategies”, “perception image” and “previous perceptions”.

  13. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Genetic interaction and mapping studies on the leaflet development (lld) mutant in Pisum ... Genetic features of thyroid hormone receptors ... DREB1/CBF transcription factors: their structure, function and role in abiotic stress tolerance in plants.

  14. Risk factors for stress fractures.

    Science.gov (United States)

    Bennell, K; Matheson, G; Meeuwisse, W; Brukner, P

    1999-08-01

    Preventing stress fractures requires knowledge of the risk factors that predispose to this injury. The aetiology of stress fractures is multifactorial, but methodological limitations and expediency often lead to research study designs that evaluate individual risk factors. Intrinsic risk factors include mechanical factors such as bone density, skeletal alignment and body size and composition, physiological factors such as bone turnover rate, flexibility, and muscular strength and endurance, as well as hormonal and nutritional factors. Extrinsic risk factors include mechanical factors such as surface, footwear and external loading as well as physical training parameters. Psychological traits may also play a role in increasing stress fracture risk. Equally important to these types of analyses of individual risk factors is the integration of information to produce a composite picture of risk. The purpose of this paper is to critically appraise the existing literature by evaluating study design and quality, in order to provide a current synopsis of the known scientific information related to stress fracture risk factors. The literature is not fully complete with well conducted studies on this topic, but a great deal of information has accumulated over the past 20 years. Although stress fractures result from repeated loading, the exact contribution of training factors (volume, intensity, surface) has not been clearly established. From what we do know, menstrual disturbances, caloric restriction, lower bone density, muscle weakness and leg length differences are risk factors for stress fracture. Other time-honoured risk factors such as lower extremity alignment have not been shown to be causative even though anecdotal evidence indicates they are likely to play an important role in stress fracture pathogenesis.

  15. Interactive effects of vascular risk burden and advanced age on cerebral blood flow

    Directory of Open Access Journals (Sweden)

    Katherine eBangen

    2014-07-01

    Full Text Available Vascular risk factors and cerebral blood flow (CBF reduction have been linked to increased risk of cognitive impairment and Alzheimer’s disease (AD; however the possible moderating effects of age and vascular risk burden on CBF in late life remain understudied. We examined the relationships among elevated vascular risk burden, age, CBF, and cognition. Seventy-one non-demented older adults completed an arterial spin labeling MR scan, neuropsychological assessment, and medical history interview. Relationships among vascular risk burden, age, and CBF were examined in a priori regions of interest (ROIs previously implicated in aging and AD. Interaction effects indicated that, among older adults with elevated vascular risk burden (i.e., multiple vascular risk factors, advancing age was significantly associated with reduced cortical CBF whereas there was no such relationship for those with low vascular risk burden (i.e., no or one vascular risk factor. This pattern was observed in cortical ROIs including medial temporal (hippocampus, parahippocampal gyrus, uncus, inferior parietal (supramarginal gyrus, inferior parietal lobule, angular gyrus, and frontal (anterior cingulate, middle frontal gyrus, medial frontal gyrus cortices. Furthermore, among those with elevated vascular risk, reduced CBF was associated with poorer cognitive performance. Such findings suggest that older adults with elevated vascular risk burden may be particularly vulnerable to cognitive change as a function of CBF reductions. Findings support the use of CBF as a potential biomarker in preclinical AD and suggest that vascular risk burden and regionally-specific CBF changes may contribute to differential age-related cognitive declines.

  16. The value of rCBF brain SPECT in assessing visual function of patients with honeymoons hemianopia

    International Nuclear Information System (INIS)

    Xie Ruiman; Yao Jingli; Qing Zheng

    1995-01-01

    Comparison of 99m Tc-HMPAO brain SPECT imaging of 8 cases with honeymoons hemianopia (HH) was taken before and after a course of oriented dynamic color photic stimulation (ODCPS). It was suggested that ODCPS in patients with HH was an effective method for increasing visual field and improving visual function. Cerebral metabolic patterns reflected the mechanism of ODCPS effecting the patients with HH. The retinal midbrain-occipital visual path-way may play an important role in mediating the increase of visual field and restoration of visual function. It was also concluded that brain SPECT imaging was an useful method for the studying of brain function

  17. Resting and hypercapnic rCBF in patients with unilateral occlusive disease of the internal carotid artery

    International Nuclear Information System (INIS)

    Keyeux, A.; Laterre, C.; Beckers, C.

    1988-01-01

    Regional cerebral blood flow was measured by the 133 Xe inhalation technique in 15 patients with severe unilateral internal carotid artery stenosis (75%) or occlusion, and in the absence of evidence of any sign of occlusive disease in other main afferent cerebral arteries. A comparison with normal subjects showed that lowered resting flow in both hemispheres was a common finding in all patients. Interhemispheric asymmetry was present only in patients with occlusion and the precentral, posterior temporal, and occipital regions were the most seriously affected. The CO 2 reactivity was substantially reduced in both hemispheres of all stenotic and occluded patients, but occluded patients showed an increased reduction of CO 2 reactivity only in the ipsilateral hemisphere. In addition to an hypothetical age effect, the atherosclerotic involvement of the cerebral vascular system leads to a reduction of flow and loss of CO 2 reactivity in both hemispheres. In this context, the collateral supply capacity is not overloaded in case of a unilateral severe stenosis but fails in case of a unilateral occlusion of the internal carotid artery. A suitable estimate of the blood flow reduction as a result of occlusion is made by the hemispheric and regional laterality indices applied in resting and hypercapnia conditions. These indices could be used as indicators for endarterectomy or bypass surgery as well as a sensitive means for appreciating cerebral blood flow response to treatment

  18. Cyclosporine A, FK506, and NIM811 ameliorate prolonged CBF reduction and impaired neurovascular coupling after cortical spreading depression

    DEFF Research Database (Denmark)

    Hansen, Henning Piilgaard; Witgen, Brent Marvin; Rasmussen, Peter

    2011-01-01

    Cortical spreading depression (CSD) is associated with mitochondrial depolarization, increasing intracellular Ca(2+), and the release of free fatty acids, which favor opening of the mitochondrial permeability transition pore (mPTP) and activation of calcineurin (CaN). Here, we test the hypothesis...

  19. Regional differences in the CBF and BOLD responses to hypercapnia: a combined PET and fMRI study

    DEFF Research Database (Denmark)

    Rostrup, Egill; Law, I; Blinkenberg, M

    2000-01-01

    Previous fMRI studies of the cerebrovascular response to hypercapnia have shown signal change in cerebral gray matter, but not in white matter. Therefore, the objective of the present study was to compare (15)O PET and T *(2)-weighted MRI during a hypercapnic challenge. The measurements were perf...

  20. Determination of the rCBF in the Amygdala and Rhinal Cortex Using a FAIR-TrueFISP Sequence

    International Nuclear Information System (INIS)

    Ludescher, Burkhard; Martirosian, Petros; Klose, Uwe; Naegele, Thomas; Schick, Fritz; Ernemann, Ulrike

    2011-01-01

    Brain perfusion can be assessed non-invasively by modern arterial spin labeling MRI. The FAIR (flow-sensitive alternating inversion recovery)-TrueFISP (true fast imaging in steady precession) technique was applied for regional assessment of cerebral blood flow in brain areas close to the skull base, since this approach provides low sensitivity to magnetic susceptibility effects. The investigation of the rhinal cortex and the amygdala is a potentially important feature for the diagnosis and research on dementia in its early stages. Twenty-three subjects with no structural or psychological impairment were investigated. FAIR-True-FISP quantitative perfusion data were evaluated in the amygdala on both sides and in the pons. A preparation of the radiofrequency FOCI (frequency offset corrected inversion) pulse was used for slice selective inversion. After a time delay of 1.2 sec, data acquisition began. Imaging slice thickness was 5 mm and inversion slab thickness for slice selective inversion was 12.5 mm. Image matrix size for perfusion images was 64 X 64 with a field of view of 256 X 256 mm, resulting in a spatial resolution of 4 X 4 X 5 mm. Repetition time was 4.8 ms; echo time was 2.4 ms. Acquisition time for the 50 sets of FAIR images was 6:56 min. Data were compared with perfusion data from the literature. Perfusion values in the right amygdala, left amygdala and pons were 65.2 (± 18.2) mL/100 g/minute, 64.6 (± 21.0) mL/100 g/minute, and 74.4 (± 19.3) mL/100 g/minute, respectively. These values were higher than formerly published data using continuous arterial spin labeling but similar to 15O-PET (oxygen-15 positron emission tomography) data. The FAIR-TrueFISP approach is feasible for the quantitative assessment of perfusion in the amygdala. Data are comparable with formerly published data from the literature. The applied technique provided excellent image quality, even for brain regions located at the skull base in the vicinity of marked susceptibility steps.

  1. Determination of the rCBF in the Amygdala and Rhinal Cortex Using a FAIR-TrueFISP Sequence

    Energy Technology Data Exchange (ETDEWEB)

    Ludescher, Burkhard; Martirosian, Petros; Klose, Uwe; Naegele, Thomas; Schick, Fritz; Ernemann, Ulrike [Eberhard-Karls-University, Tuebingen (Germany)

    2011-10-15

    Brain perfusion can be assessed non-invasively by modern arterial spin labeling MRI. The FAIR (flow-sensitive alternating inversion recovery)-TrueFISP (true fast imaging in steady precession) technique was applied for regional assessment of cerebral blood flow in brain areas close to the skull base, since this approach provides low sensitivity to magnetic susceptibility effects. The investigation of the rhinal cortex and the amygdala is a potentially important feature for the diagnosis and research on dementia in its early stages. Twenty-three subjects with no structural or psychological impairment were investigated. FAIR-True-FISP quantitative perfusion data were evaluated in the amygdala on both sides and in the pons. A preparation of the radiofrequency FOCI (frequency offset corrected inversion) pulse was used for slice selective inversion. After a time delay of 1.2 sec, data acquisition began. Imaging slice thickness was 5 mm and inversion slab thickness for slice selective inversion was 12.5 mm. Image matrix size for perfusion images was 64 X 64 with a field of view of 256 X 256 mm, resulting in a spatial resolution of 4 X 4 X 5 mm. Repetition time was 4.8 ms; echo time was 2.4 ms. Acquisition time for the 50 sets of FAIR images was 6:56 min. Data were compared with perfusion data from the literature. Perfusion values in the right amygdala, left amygdala and pons were 65.2 ({+-} 18.2) mL/100 g/minute, 64.6 ({+-} 21.0) mL/100 g/minute, and 74.4 ({+-} 19.3) mL/100 g/minute, respectively. These values were higher than formerly published data using continuous arterial spin labeling but similar to 15O-PET (oxygen-15 positron emission tomography) data. The FAIR-TrueFISP approach is feasible for the quantitative assessment of perfusion in the amygdala. Data are comparable with formerly published data from the literature. The applied technique provided excellent image quality, even for brain regions located at the skull base in the vicinity of marked susceptibility steps.

  2. CBF patterns in different types of headache using 99mTc HMPAO and high resolution SPECT

    International Nuclear Information System (INIS)

    Jones, B.E.; Davies, P.G.; Costa, D.C.; Steiner, T.J.; Rose, F.C.; Jewkes, R.F.; Charing Cross Hospital, London

    1988-01-01

    High resolution SPECT studies have been performed using 99m Tc HMPAO on patients suffering from migraine, cluster headache or chronic tension headache. Reduced uptake of tracer in the right parieto-occipital cortex was seen in 6/8 patients suffering from classical or hemiplegic migraine and 2/10 patients suffering from common migraine. A high uptake of tracer was seen in the temporal muscle of some patients with chronic tension headache. Extracerebral uptake of radioactivity was also seen in the tissue surrounding the brain in a case injected with the HMPAO 45 minutes after it had been prepared and in metastatic skull lesions in patients suffering from cancer of the breast. It is therefore important to use high resolution instrumentation to avoid artifacts when using this technique. (orig.)

  3. Measurement of activated rCBF by the 133Xe inhalation technique: a comparison of total versus partial curve analysis

    International Nuclear Information System (INIS)

    Leli, D.A.; Katholi, C.R.; Hazelrig, J.B.; Falgout, J.C.; Hannay, H.J.; Wilson, E.M.; Wills, E.L.; Halsey, J.H. Jr.

    1985-01-01

    An initial assessment of the differential sensitivity of total versus partial curve analysis in estimating task related focal changes in cortical blood flow measured by the 133 Xe inhalation technique was accomplished by comparing the patterns during the performance of two sensorimotor tasks by normal subjects. The validity of these patterns was evaluated by comparing them to the activation patterns expected from activation studies with the intra-arterial technique and the patterns expected from neuropsychological research literature. Subjects were 10 young adult nonsmoking healthy male volunteers. They were administered two tasks having identical sensory and cognitive components but different response requirements (oral versus manual). The regional activation patterns produced by the tasks varied with the method of curve analysis. The activation produced by the two tasks was very similar to that predicted from the research literature only for total curve analysis. To the extent that the predictions are correct, these data suggest that the 133 Xe inhalation technique is more sensitive to regional flow changes when flow parameters are estimated from the total head curve. The utility of the total head curve analysis will be strengthened if similar sensitivity is demonstrated in future studies assessing normal subjects and patients with neurological and psychiatric disorders

  4. Increased rCBF in gray matter heterotopias detected by SPECT using 99mTc hexamethyl-propylenamine oxime

    International Nuclear Information System (INIS)

    Henkes, H.; Klinikum Rudolf Virchow, Berlin; Hosten, N.; Cordes, M.; Neumann, K.; Hansen, M.L.

    1991-01-01

    Imaging findings of morphology and regional cerebral blood flow in two patients suffering from epileptic seizures are presented. CT and MRI revealed heterotopic gray matter as a probable structural correlate, causing the seizure disorder. 99m Tc hexamethyl-propylenamine oxime (HM-PAO) SPECT demonstrated focally increased regional cerebral blood flow in both patients in the areas of their heterotopic lesions. Heterotopic and orthotopic gray matter seem to have similar features in terms of regional perfusion. A focally increased brain perfusion in interictal epileptic patients may indicate an underlying migration anomaly. (orig.)

  5. Evaluation of technical problems in 177 cases using 123I-IMP. Autoradiography method for quantitative rCBF study

    International Nuclear Information System (INIS)

    Hachiya, Takenori; Shoji, Yasuaki; Sugawara, Shigeki; Iida, Hidehiro; Hatazawa, Jun.

    1997-01-01

    Regional cerebral blood flow can be quantified using SPECT with N-isopropyl-p-( 123 I)-iodoamphetamine (IMP) according to the IMP-ARG method. This study was intended to review our 177 studies including the six technical procedures in this technique, such as the blood sampling volume, the blood sampling time, the radioactivity in blood samples, the PaCO 2 in blood, the scanning started time, and correlations between injection dose and radioactivity in the blood samples. The blood sample was obtained at 10 min in most of studies. The blood volume was 0.7-1.0 ml. The blood radioactivity concentration was 300-500 cps/g in our well-type scintillation counter system. The PaC0 2 was around 40 mmHg in most cases. Significant correlation was observed between the injection dose and the radioactivity counts in the blood (r=0.45), but this study did not suggest the use of the injection dose the cariblation of standardized input function. (author)

  6. [Predictive factors of anxiety disorders].

    Science.gov (United States)

    Domschke, K

    2014-10-01

    Anxiety disorders are among the most frequent mental disorders in Europe (12-month prevalence 14%) and impose a high socioeconomic burden. The pathogenesis of anxiety disorders is complex with an interaction of biological, environmental and psychosocial factors contributing to the overall disease risk (diathesis-stress model). In this article, risk factors for anxiety disorders will be presented on several levels, e.g. genetic factors, environmental factors, gene-environment interactions, epigenetic mechanisms, neuronal networks ("brain fear circuit"), psychophysiological factors (e.g. startle response and CO2 sensitivity) and dimensional/subclinical phenotypes of anxiety (e.g. anxiety sensitivity and behavioral inhibition), and critically discussed regarding their potential predictive value. The identification of factors predictive of anxiety disorders will possibly allow for effective preventive measures or early treatment interventions, respectively, and reduce the individual patient's suffering as well as the overall socioeconomic burden of anxiety disorders.

  7. Factor of originality in advertising

    OpenAIRE

    Ešner, Rudolf

    2009-01-01

    The bachelor thesis deals with exploitation of original attitudes in advertising. The thesis solves answers, what role plays the factor of originality in advertising, when and why firms use that factor, how creators work with it, how consumers perceive the factor and what other elements it generally contains. The bachelor thesis qualifies relationship of advertising and originality, describes and probes practical situations, when originality in advertising can be used as a serious competitive...

  8. Risk factors in school shootings.

    Science.gov (United States)

    Verlinden, S; Hersen, M; Thomas, J

    2000-01-01

    Nine incidents of multiple-victim homicide in American secondary schools are examined and common risk factors are identified. The literature dealing with individual, family, social, societal, and situational risk factors for youth violence and aggression is reviewed along with existing risk assessment methods. Checklists of risk factors for serious youth violence and school violence are used in reviewing each school shooting case. Commonalties among the cases and implications for psychologists practicing in clinical and school settings are discussed.

  9. First course in factor analysis

    CERN Document Server

    Comrey, Andrew L

    2013-01-01

    The goal of this book is to foster a basic understanding of factor analytic techniques so that readers can use them in their own research and critically evaluate their use by other researchers. Both the underlying theory and correct application are emphasized. The theory is presented through the mathematical basis of the most common factor analytic models and several methods used in factor analysis. On the application side, considerable attention is given to the extraction problem, the rotation problem, and the interpretation of factor analytic results. Hence, readers are given a background of

  10. Summable series and convergence factors

    CERN Document Server

    Moore, Charles N

    1938-01-01

    Fairly early in the development of the theory of summability of divergent series, the concept of convergence factors was recognized as of fundamental importance in the subject. One of the pioneers in this field was C. N. Moore, the author of the book under review.... Moore classifies convergence factors into two types. In type I he places the factors which have only the property that they preserve convergence for a convergent series or produce convergence for a summable series. In type II he places the factors which not only maintain or produce convergence but have the additional property that

  11. Gene regulation by growth factors

    International Nuclear Information System (INIS)

    Metz, R.; Gorham, J.; Siegfried, Z.; Leonard, D.; Gizang-Ginsberg, E.; Thompson, M.A.; Lawe, D.; Kouzarides, T.; Vosatka, R.; MacGregor, D.; Jamal, S.; Greenberg, M.E.; Ziff, E.B.

    1988-01-01

    To coordinate the proliferation and differentiation of diverse cell types, cells of higher eukaryotes communicate through the release of growth factors. These peptides interact with specific transmembrane receptors of other cells and thereby generate intracellular messengers. The many changes in cellular physiology and activity that can be induced by growth factors imply that growth factor-induced signals can reach the nucleus and control gene activity. Moreover, current evidence also suggests that unregulated signaling along such pathways can induce aberrant proliferation and the formation of tumors. This paper reviews investigations of growth factor regulation of gene expression conducted by the authors' laboratory

  12. Factorization method of quadratic template

    Science.gov (United States)

    Kotyrba, Martin

    2017-07-01

    Multiplication of two numbers is a one-way function in mathematics. Any attempt to distribute the outcome to its roots is called factorization. There are many methods such as Fermat's factorization, Dixońs method or quadratic sieve and GNFS, which use sophisticated techniques fast factorization. All the above methods use the same basic formula differing only in its use. This article discusses a newly designed factorization method. Effective implementation of this method in programs is not important, it only represents and clearly defines its properties.

  13. Social networks and factor markets

    DEFF Research Database (Denmark)

    Abay, Kibrom Araya; Kahsay, Goytom Abraha; Berhane, Guush

    In the absence of well-established factor markets, the role of indigenous institutions and social networks can be substantial for mobilizing factors for agricultural production. We investigate the role of an indigenous social network in Ethiopia, the iddir, in facilitating factor market...... transactions among smallholder farmers. Using detailed longitudinal household survey data and employing a difference-in-differences approach, we find that iddir membership improves households’ access to factor markets. Specifically, we find that joining an iddir network improves households’ access to land...

  14. FACTORING- CREDIT OPPORTUNITIES IN ROMANIA

    Directory of Open Access Journals (Sweden)

    ADELA IONESCU

    2013-05-01

    Full Text Available Capital is the main factor of production, business development becomes virtually impossible without taking into account the financial market and the resources it provides to businesses. Any business, regardless of its degree of development, is involving direct contact with financial markets, namely the institutions that mediate mobilization of capital and the services they provide. Understanding the functioning of the financial system, the specific financial mechanisms through which savings are allocated to support capital investments and the costs and risks involved is essential for the development of a solid base for business. In this context, factoring operations can support economic agents, allowing a transfer of commercial receivables from their holder to a factor who commits to their recovery and guarantee such operations even if temporary or permanent insolvency of the debtor . Thus, factoring is a complex technique in at least two aspects, of the debt and the transfer of credit. . Factoring is a means of financing business, especially export-import transactions, less known in Romania. Maybe because of poor business environment popularize the term is as little known as it was a few years ago the leasing. Present in Romanian legislation since 2002, factoring appears as a contract between one party (called adherent, providing goods or service and a banking company or a financial institution specialized (called factor, which the last one shall finance debts pursuing and preservation against credit risks and adherent gives factor by way of sale, debts arising from the sale of goods or services to third parties. The article is divided into three parts. In the first part we defined the concept of factoring and international factoring, then I presented the advantages and development of factoring in Romania, and the last part conclusions.

  15. Distributed Cerebral Blood Flow estimation using a spatiotemporal hemodynamic response model and a Kalman-like Filter approach

    KAUST Repository

    Belkhatir, Zehor

    2015-11-23

    This paper discusses the estimation of distributed Cerebral Blood Flow (CBF) using spatiotemporal traveling wave model. We consider a damped wave partial differential equation that describes a physiological relationship between the blood mass density and the CBF. The spatiotemporal model is reduced to a finite dimensional system using a cubic b-spline continuous Galerkin method. A Kalman Filter with Unknown Inputs without Direct Feedthrough (KF-UI-WDF) is applied on the obtained reduced differential model to estimate the source term which is the CBF scaled by a factor. Numerical results showing the performances of the adopted estimator are provided.

  16. Activation of factor VII bound to tissue factor: a key early step in the tissue factor pathway of blood coagulation.

    OpenAIRE

    Rao, L V; Rapaport, S I

    1988-01-01

    Whether the factor VII/tissue factor complex that forms in tissue factor-dependent blood coagulation must be activated to factor VIIa/tissue factor before it can activate its substrates, factor X and factor IX, has been a difficult question to answer because the substrates, once activated, back-activate factor VII. Our earlier studies suggested that human factor VII/tissue factor cannot activate factor IX. Studies have now been extended to the activation of factor X. Reaction mixtures were ma...

  17. Activation of factor VII bound to tissue factor: A key early step in the tissue factor pathway of blood coagulation

    International Nuclear Information System (INIS)

    Rao, L.V.M.; Rapaport, S.I.

    1988-01-01

    Whether the factor VII/tissue factor complex that forms in tissue factor-dependent blood coagulation must be activated to factor VIIa/tissue factor before it can activate its substrates, factor X and IX, has been a difficult question to answer because the substrates, once activated, back-activate factor VII. The earlier studies suggested that human factor VII/tissue factor cannot activate factor IX. Studies have now been extended to the activation of factor X. Reaction mixtures were made with purified factor VII, X, and tissue factor; in some experiments antithrombin III and heparin were added to prevent back-activation of factor VII. Factor X was activated at similar rates in reaction mixtures containing either VII or factor VIIa after an initial 30-sec lag with factor VII. In reaction mixtures with factor VII a linear activation of factor X was established several minutes before cleavage of 125 I-labeled factor VII to the two-chain activated molecule was demonstrable on gel profiles. These data suggest that factor VII/tissue factor cannot activate measurable amounts of factor X over several minutes. Overall, the results support the hypothesis that a rapid preferential activation of factor VII bound to tissue factor by trace amounts of factor Xa is a key early step in tissue factor-dependent blood coagulation

  18. Factors of trade in Europe

    Czech Academy of Sciences Publication Activity Database

    Hanousek, Jan; Kočenda, Evžen

    2014-01-01

    Roč. 38, č. 4 (2014), s. 518-535 ISSN 0939-3625 R&D Projects: GA ČR(CZ) GAP403/12/0080 Grant - others:UK(CZ) UNCE 204005/2012 Institutional support: PRVOUK-P23 Keywords : bilateral trade * factors of trade * panel data Subject RIV: AH - Economics Impact factor: 0.649, year: 2014

  19. Quadratic prediction of factor scores

    NARCIS (Netherlands)

    Wansbeek, T

    1999-01-01

    Factor scores are naturally predicted by means of their conditional expectation given the indicators y. Under normality this expectation is linear in y but in general it is an unknown function of y. II is discussed that under nonnormality factor scores can be more precisely predicted by a quadratic

  20. Hidden Risk Factors for Women

    Science.gov (United States)

    ... A.S.T. Quiz Hidden Stroke Risk Factors for Women Updated:Nov 22,2016 Excerpted from "What Women Need To Know About The Hidden Risk Factors ... 2012) This year, more than 100,000 U.S. women under 65 will have a stroke. Stroke is ...

  1. Factor analysis of multivariate data

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A.; Mahadevan, R.

    A brief introduction to factor analysis is presented. A FORTRAN program, which can perform the Q-mode and R-mode factor analysis and the singular value decomposition of a given data matrix is presented in Appendix B. This computer program, uses...

  2. Pineal factors other than melatonin

    NARCIS (Netherlands)

    Ebels, I.

    Some sheep pineal factors other than melatonin are described. A “nonmelatonin” antigonadotropic activity has been detected by application of the inhibition of compensatory ovarian hypertrophy (COH) in unilaterally ovariectomized adult Charles River CD-1 mice. The factor has been extracted from

  3. Stroke Risk Factors and Symptoms

    Science.gov (United States)

    ... » [ pdf, 433 kb ] Order Materials » Stroke Risk Factors and Symptoms Risk Factors for a Stroke Stroke prevention is still ... it. Treatment can delay complications that increase the risk of stroke. Transient ischemic attacks (TIAs). Seek help. ...

  4. Electromagnetic form factors of hadrons

    International Nuclear Information System (INIS)

    Zidell, V.S.

    1976-01-01

    A vector meson dominance model of the electromagnetic form factors of hadrons is developed which is based on the use of unstable particle propagators. Least-square fits are made to the proton, neutron, pion and kaon form factor data in both the space and time-like regions. A good fit to the low-energy nucleon form factor data is obtained using only rho, ω, and phi dominance, and leads to a determination of the vector meson resonance parameters in good agreement with experiment. The nucleon-vector meson coupling constants obey simple sum rules indicating that there exists no hard core contribution to the form factors within theoretical uncertainties. The prediction for the electromagnetic radii of the proton is in reasonable agreement with recent experiments. The pion and kaon charge form factors as deduced from the nucleon form factors assuming vector meson universality are compared to the data. The pion form factor agrees with the data in both the space and time-like regions. The pion charge radius is in agreement with the recent Dubna result, but the isovector P-wave pion-pion phase shift calculated from the theory disagrees with experiment. A possible contribution to the form factors from a heavy rho meson is also evaluated

  5. Shell model and spectroscopic factors

    International Nuclear Information System (INIS)

    Poves, P.

    2007-01-01

    In these lectures, I introduce the notion of spectroscopic factor in the shell model context. A brief review is given of the present status of the large scale applications of the Interacting Shell Model. The spectroscopic factors and the spectroscopic strength are discussed for nuclei in the vicinity of magic closures and for deformed nuclei. (author)

  6. EAMJ Risk Factors 10.indd

    African Journals Online (AJOL)

    2010-02-02

    Feb 2, 2010 ... Several factors have been suggested as independent risk factors for their development. Identification of these ... with age, gender or haematological test. ... A meta-analysis of prospective studies on ..... The marked difference may be because monthly .... and dyslipidemia among patients taking first-line,.

  7. Factors That Shape Design Thinking

    Science.gov (United States)

    Gray, Colin M.

    2013-01-01

    A wide range of design literature discusses the role of the studio and its related pedagogy in the development of design thinking. Scholars in a variety of design disciplines pose a number of factors that potentially affect this development process, but a full understanding of these factors as experienced from a critical pedagogy or student…

  8. Kadison-Kastler stable factors

    DEFF Research Database (Denmark)

    Cameron, Jan; Christensen, Erik; Sinclair, Allan M.

    2014-01-01

    It is proven that a pair of continuous finite von Neumann algebra factors are unitarily equivalent if sufficiently close and one satisfies a certain cohomological condition.......It is proven that a pair of continuous finite von Neumann algebra factors are unitarily equivalent if sufficiently close and one satisfies a certain cohomological condition....

  9. Human factors influencing decision making

    OpenAIRE

    Jacobs, Patricia A.

    1998-01-01

    This report supplies references and comments on literature that identifies human factors influencing decision making, particularly military decision making. The literature has been classified as follows (the classes are not mutually exclusive): features of human information processing; decision making models which are not mathematical models but rather are descriptive; non- personality factors influencing decision making; national characteristics influencing decision makin...

  10. Factoring in Factor VIII With Acute Ischemic Stroke.

    Science.gov (United States)

    Siegler, James E; Samai, Alyana; Albright, Karen C; Boehme, Amelia K; Martin-Schild, Sheryl

    2015-10-01

    There is growing research interest into the etiologies of cryptogenic stroke, in particular as it relates to hypercoagulable states. An elevation in serum levels of the procoagulant factor VIII is recognized as one such culprit of occult cerebral infarctions. It is the objective of the present review to summarize the molecular role of factor VIII in thrombogenesis and its clinical use in the diagnosis and prognosis of acute ischemic stroke. We also discuss the utility of screening for serum factor VIII levels among patients at risk for, or those who have experienced, ischemic stroke. © The Author(s) 2015.

  11. Regional cerebral blood flow in Parkinson's disease measured with N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Odano, Ikuo; Nishihara, Mamiko; Hayashi, Hiroko; Higuchi, Shoichi; Sakai, Kunio [Niigata Univ. (Japan). School of Medicine; Ishikawa, Atsushi; Ibayashi, Katsuhiko

    1992-09-01

    N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) SPECT studies were performed on 21 patients (13 females; 45-73 yrs) with idiopathic Parkinson's disease (PD) and 10 age-matched normal controls (39-69 yrs). Regional cerebral blood flow (rCBF) was quantitatively measured by the arterial blood sampling method. When compared with normal controls, global CBF, and rCBF in the frontal cortex and in the basal ganglia were reduced 22.1% (p<0.01), 25.0% (p<0.05) and 25.6% (p<0.01), respectively. The reduction of rCBF in the basal ganglia was significantly correlated (p<0.05) with symptoms such as gait disturbance, frozen gait and motor disability score. However, no significant correlation was observed between the severity of dementia and any regional reduction of CBF, including the frontal or parietal cortices. These data show that the severity of dementia in PD may be related to other factors but not with CBF. Quantification of rCBF with [sup 123]I-IMP SPECT imaging is useful for evaluation and follow-up of patients with PD. (author).

  12. Using Bayes factors for multi-factor, biometric authentication

    Science.gov (United States)

    Giffin, A.; Skufca, J. D.; Lao, P. A.

    2015-01-01

    Multi-factor/multi-modal authentication systems are becoming the de facto industry standard. Traditional methods typically use rates that are point estimates and lack a good measure of uncertainty. Additionally, multiple factors are typically fused together in an ad hoc manner. To be consistent, as well as to establish and make proper use of uncertainties, we use a Bayesian method that will update our estimates and uncertainties as new information presents itself. Our algorithm compares competing classes (such as genuine vs. imposter) using Bayes Factors (BF). The importance of this approach is that we not only accept or reject one model (class), but compare it to others to make a decision. We show using a Receiver Operating Characteristic (ROC) curve that using BF for determining class will always perform at least as well as the traditional combining of factors, such as a voting algorithm. As the uncertainty decreases, the BF result continues to exceed the traditional methods result.

  13. What factors influence mitigative capacity?

    International Nuclear Information System (INIS)

    Winkler, Harald; Baumert, Kevin; Blanchard, Odile; Burch, Sarah; Robinson, John

    2007-01-01

    This article builds on Yohe's seminal piece on mitigative capacity, which elaborates 'determinants' of mitigative capacity, also reflected in the IPCC's third assessment report. We propose a revised definition, where mitigative capacity is a country's ability to reduce anthropogenic greenhouse gas emissions or enhance natural sinks. By 'ability' we mean skills, competencies, fitness, and proficiencies that a country has attained which can contribute to GHG emissions mitigation. A conceptual framework is proposed, linking mitigative capacity to a country's sustainable development path, and grouping the factors influencing mitigative capacity into three main sets: economic factors, institutional ones, and technology. Both quantitative and qualitative analysis of factors is presented, showing how these factors vary across countries. We suggest that it is the interplay between the three economic factors-income, abatement cost and opportunity cost-that shape mitigative capacity. We find that income is an important economic factor influencing mitigative capacity, while abatement cost is important in turning mitigative capacity into actual mitigation. Technology is a critical mitigative capacity, including the ability to absorb existing climate-friendly technologies or to develop innovative ones. Institutional factors that promote mitigative capacity include the effectiveness of government regulation, clear market rules, a skilled work force and public awareness. We briefly investigate such as high abatement cost or lack of political willingness that prevent mitigative capacity from being translated into mitigation

  14. Corrosion effects on friction factors

    International Nuclear Information System (INIS)

    Magleby, H.L.; Shaffer, S.J.

    1996-01-01

    This paper presents the results of NRC-sponsored material specimen tests that were performed to determine if corrosion increases the friction factors of sliding surfaces of motor-operated gate valves, which could require higher forces to close and open safety-related valves when subjected to their design basis differential pressures. Friction tests were performed with uncorroded specimens and specimens subjected to accelerated corrosion. Preliminary tests at ambient conditions showed that corrosion increased the friction factors, indicating the need for additional tests duplicating valve operating parameters at hot conditions. The additional tests showed friction factors of corroded specimens were 0.1 to 0.2 higher than for uncorroded specimens, and that the friction factors of the corroded specimens were not very dependent on contact stress or corrosion film thickness. The measured values of friction factors for the three corrosion films tested (simulating three operating times) were in the range of 0.3 to 0.4. The friction factor for even the shortest simulated operating time was essentially the same as the others, indicating that the friction factors appear to reach a plateau and that the plateau is reached quickly

  15. Conversion factors and oil statistics

    International Nuclear Information System (INIS)

    Karbuz, Sohbet

    2004-01-01

    World oil statistics, in scope and accuracy, are often far from perfect. They can easily lead to misguided conclusions regarding the state of market fundamentals. Without proper attention directed at statistic caveats, the ensuing interpretation of oil market data opens the door to unnecessary volatility, and can distort perception of market fundamentals. Among the numerous caveats associated with the compilation of oil statistics, conversion factors, used to produce aggregated data, play a significant role. Interestingly enough, little attention is paid to conversion factors, i.e. to the relation between different units of measurement for oil. Additionally, the underlying information regarding the choice of a specific factor when trying to produce measurements of aggregated data remains scant. The aim of this paper is to shed some light on the impact of conversion factors for two commonly encountered issues, mass to volume equivalencies (barrels to tonnes) and for broad energy measures encountered in world oil statistics. This paper will seek to demonstrate how inappropriate and misused conversion factors can yield wildly varying results and ultimately distort oil statistics. Examples will show that while discrepancies in commonly used conversion factors may seem trivial, their impact on the assessment of a world oil balance is far from negligible. A unified and harmonised convention for conversion factors is necessary to achieve accurate comparisons and aggregate oil statistics for the benefit of both end-users and policy makers

  16. Factors Influencing of Social Conflict

    Directory of Open Access Journals (Sweden)

    Suwandi Sumartias

    2013-07-01

    Full Text Available Social conflicts that occur in several areas in Indonesia lately, one of them is caused by the weakness of law certainty. This is feared to threaten the integration of the Republic of Indonesia. This study aims to determine the factors that affect social conflict in Manis Lor village in Kuningan district. The method used the explanatory quantitative methods, the statistical test Path Analysis. The study population was a formal and informal community leaders (village chief, clergy, and youth, and the people who involved in a conflict in Manis Lor village Kuningan regency. The result shows a There is no significant influence between social identity factors with social conflict anarchist. b There is significant influence between socio-economic factors with social conflict anarchists. c There is no significant influence between the credibility factor anarchist leaders with social conflict. d There is no significant influence between the motive factor with anarchist social conflict. e There is significant influence between personality factors/beliefs with anarchist social conflict. f There is significant influence of behavioral factors anarchist communication with social conflict.

  17. Factor concentrates for the treatment of factor XIII deficiency.

    Science.gov (United States)

    Gootenberg, J E

    1998-11-01

    Factor XIII deficiency is a severe autosomal recessive bleeding disorder associated with a characteristic pattern of neonatal hemorrhage and a lifelong bleeding diathesis. Even relatively minor trauma can be followed by prolonged and recurrent bleeding. Intracranial hemorrhage is a frequent complication. With the development of safe and effective factor XIII concentrates, reliable prophylactic treatment is possible. Two plasma-derived, virus-inactivated factor XIII concentrates are currently in production. The first, Fibrogammin P, (Centeon LLC, King of Prussia, PA, USA; and Centeon Pharma GmbH, Marburg, Germany) is marketed in Europe, South America, South Africa, and Japan. It is distributed in the United States under a Food and Drug Administration Investigational New Drug Application. A second factor XIII concentrate (Bio Products Laboratory, Elstree, UK) is available for use only on a "named patient" compassionate basis in the United Kingdom. Patients with factor XIII deficiency who receive appropriately timed periodic infusions of such factor XIII concentrates are able to live normal lives, free from catastrophic bleeding episodes.

  18. Sequence Factorization with Multiple References.

    Directory of Open Access Journals (Sweden)

    Sebastian Wandelt

    Full Text Available The success of high-throughput sequencing has lead to an increasing number of projects which sequence large populations of a species. Storage and analysis of sequence data is a key challenge in these projects, because of the sheer size of the datasets. Compression is one simple technology to deal with this challenge. Referential factorization and compression schemes, which store only the differences between input sequence and a reference sequence, gained lots of interest in this field. Highly-similar sequences, e.g., Human genomes, can be compressed with a compression ratio of 1,000:1 and more, up to two orders of magnitude better than with standard compression techniques. Recently, it was shown that the compression against multiple references from the same species can boost the compression ratio up to 4,000:1. However, a detailed analysis of using multiple references is lacking, e.g., for main memory consumption and optimality. In this paper, we describe one key technique for the referential compression against multiple references: The factorization of sequences. Based on the notion of an optimal factorization, we propose optimization heuristics and identify parameter settings which greatly influence 1 the size of the factorization, 2 the time for factorization, and 3 the required amount of main memory. We evaluate a total of 30 setups with a varying number of references on data from three different species. Our results show a wide range of factorization sizes (optimal to an overhead of up to 300%, factorization speed (0.01 MB/s to more than 600 MB/s, and main memory usage (few dozen MB to dozens of GB. Based on our evaluation, we identify the best configurations for common use cases. Our evaluation shows that multi-reference factorization is much better than single-reference factorization.

  19. Cardiovascular risk factors and dementia.

    Science.gov (United States)

    Fillit, Howard; Nash, David T; Rundek, Tatjana; Zuckerman, Andrea

    2008-06-01

    Dementias, such as Alzheimer's disease (AD) and vascular dementia, are disorders of aging populations and represent a significant economic burden. Evidence is accumulating to suggest that cardiovascular disease (CVD) risk factors may be instrumental in the development of dementia. The goal of this review was to discuss the relationship between specific CVD risk factors and dementia and how current treatment strategies for dementia should focus on reducing CVD risks. We conducted a review of the literature for the simultaneous presence of 2 major topics, cardiovascular risk factors and dementia (eg, AD). Special emphasis was placed on clinical outcome studies examining the effects of treatments of pharmacologically modifiable CVD risk factors on dementia and cognitive impairment. Lifestyle risk factors for CVD, such as obesity, lack of exercise, smoking, and certain psychosocial factors, have been associated with an increased risk of cognitive decline and dementia. Some evidence suggests that effectively managing these factors may prevent cognitive decline/dementia. Randomized, placebo-controlled trials of antihypertensive medications have found that such therapy may reduce the risk of cognitive decline, and limited data suggest a benefit for patients with AD. Some small open-label and randomized clinical trials of statins have observed positive effects on cognitive function; larger studies of statins in patients with AD are ongoing. Although more research is needed, current evidence indicates an association between CVD risk factors--such as hypertension, dyslipidemia, and diabetes mellitus--and cognitive decline/dementia. From a clinical perspective, these data further support the rationale for physicians to provide effective management of CVD risk factors and for patients to be compliant with such recommendations to possibly prevent cognitive decline/dementia.

  20. Improved multivariate polynomial factoring algorithm

    International Nuclear Information System (INIS)

    Wang, P.S.

    1978-01-01

    A new algorithm for factoring multivariate polynomials over the integers based on an algorithm by Wang and Rothschild is described. The new algorithm has improved strategies for dealing with the known problems of the original algorithm, namely, the leading coefficient problem, the bad-zero problem and the occurrence of extraneous factors. It has an algorithm for correctly predetermining leading coefficients of the factors. A new and efficient p-adic algorithm named EEZ is described. Bascially it is a linearly convergent variable-by-variable parallel construction. The improved algorithm is generally faster and requires less store then the original algorithm. Machine examples with comparative timing are included

  1. Quality factors for monoenergetic neutrons

    International Nuclear Information System (INIS)

    Cross, W.G.; Ing, H.

    1984-01-01

    Mean quality factors anti Q(E/sub n/), for the dose resulting from first interactons of monoenergetic neutrons in tissue, have been calculated at energies from thermal to 14.7 MeV. Knowledge of these values, along with kerma factors, allows the calculation of the heavy-particle dose equivalent for any known neutron spectrum in tissue. The partial quality factors for the dose delivered by C, N, and O elastic and inelastic recoils are found to be virtually independent of the scattering angular distributions and are given by simple expressions

  2. Nucleocytoplasmic shuttling of transcription factors

    DEFF Research Database (Denmark)

    Cartwright, P; Helin, K

    2000-01-01

    To elicit the transcriptional response following intra- or extracellular stimuli, the signals need to be transmitted to their site of action within the nucleus. The nucleocytoplasmic shuttling of transcription factors is a mechanism mediating this process. The activation and inactivation...... of the transcriptional response is essential for cells to progress through the cell cycle in a normal manner. The involvement of cytoplasmic and nuclear accessory molecules, and the general nuclear membrane transport components, are essential for this process. Although nuclear import and export for different...... transcription factor families are regulated by similar mechanisms, there are several differences that allow for the specific activation of each transcription factor. This review discusses the general import and export pathways found to be common amongst many different transcription factors, and highlights...

  3. Secreted factors as synaptic organizers.

    Science.gov (United States)

    Johnson-Venkatesh, Erin M; Umemori, Hisashi

    2010-07-01

    A critical step in synaptic development is the differentiation of presynaptic and postsynaptic compartments. This complex process is regulated by a variety of secreted factors that serve as synaptic organizers. Specifically, fibroblast growth factors, Wnts, neurotrophic factors and various other intercellular signaling molecules are proposed to regulate presynaptic and/or postsynaptic differentiation. Many of these factors appear to function at both the neuromuscular junction and in the central nervous system, although the specific function of the molecules differs between the two. Here we review secreted molecules that organize the synaptic compartments and discuss how these molecules shape synaptic development, focusing on mammalian in vivo systems. Their critical role in shaping a functional neural circuit is underscored by their possible link to a wide range of neurological and psychiatric disorders both in animal models and by mutations identified in human patients. © The Authors (2010). Journal Compilation © Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  4. Disadvantage factor for anisotropic scattering

    International Nuclear Information System (INIS)

    Saad, E.A.; Abdel Krim, M.S.; EL-Dimerdash, A.A.

    1990-01-01

    The invariant embedding method is used to solve the problem for a two region reactor with anisotropic scattering and to compute the disadvantage factor necessary for calculating some reactor parameters

  5. Calculation of pion form factor

    International Nuclear Information System (INIS)

    Vahedi, N.; Amirarjomand, S.

    1975-09-01

    The pion form factor is calculated using the structure function Wsub(2), which incorporates kinematical constraints, threshold behaviour and scaling. The Bloom-Gilman sum rule is used and only the two leading Regge trajectories are taken into account

  6. EAMJ Factors Aug.indd

    African Journals Online (AJOL)

    2009-08-01

    Aug 1, 2009 ... Objective: To bridge the existing gaps by examining the factors associated with attrition. Design: ... Results: In this cohort study, 1353 women were enrolled at delivery and 1188 (88%) ... wage earners with poor social support.

  7. HIV: Social and Environmental Factors

    Centers for Disease Control (CDC) Podcasts

    Dr. Kevin Fenton, Director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, discusses how social and environmental factors may put African Americans at greater risk for HIV.

  8. Lithuanian Population Aging Factors Analysis

    Directory of Open Access Journals (Sweden)

    Agnė Garlauskaitė

    2015-05-01

    Full Text Available The aim of this article is to identify the factors that determine aging of Lithuania’s population and to assess the influence of these factors. The article shows Lithuanian population aging factors analysis, which consists of two main parts: the first describes the aging of the population and its characteristics in theoretical terms. Second part is dedicated to the assessment of trends that influence the aging population and demographic factors and also to analyse the determinants of the aging of the population of Lithuania. After analysis it is concluded in the article that the decline in the birth rate and increase in the number of emigrants compared to immigrants have the greatest impact on aging of the population, so in order to show the aging of the population, a lot of attention should be paid to management of these demographic processes.

  9. Environmental risk factors and pressures

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    In this chapter the physical risk factors (as radiation [air contamination, contamination of the environment components and food contamination], radon and its radioactive decay products, radioactive wastes, noise), chemical risk factors [chemical substances, xenobiotics in the food chain the ozone depletion], wastes (waste generation, waste management, municipal waste management, import, export and transit of waste) and natural an technological hazards (water quality deterioration as a result of various accidents and fire risk) in the Slovak Republic in 1997 are reviewed

  10. Factorization-algebraization-path integration

    International Nuclear Information System (INIS)

    Inomata, A.; Wilson, R.

    1986-01-01

    The authors review the method of factorization proposed by Schroedinger of a quantum mechanical second-order linear differential equation into a product of two first-order differential operators, often referred to as ladder operators, as well as the modifications made to Schroedinger's method by Infeld and Hull. They then review the group theoretical treatments proposed by Miller of the Schroedinger-Infeld-Hull factorizations and go on to demonstrate the application of dynamical symmetry to path integral calculations. 30 references

  11. Factors determining UK album success

    OpenAIRE

    Elliott, Caroline; Simmons, Robert

    2011-01-01

    This article uses a recently compiled dataset on the UK album sales to determine which factors contribute to best-selling album sales success. We control for factors including length of time since release, nationality of artist, artist type and album type, testing the increasing returns to information hypothesis. Information on general public online review scores for the albums in the dataset allows for a strong test of the accuracy of online reviews in predicting music sales, as online revie...

  12. Virulence Factors of Streptococcus mutans.

    Science.gov (United States)

    1986-08-01

    763512/715242 Final Report U VIRULENCE FACTORS OF STREPTOCOCCUS MUTANS U Samuel Rosen Department of Oral Biology For the Period April 1, 1983 - June 30...00 FINAL REPORT VIRULENCE FACTORS OF STREPTOCOCCUS MUTANS Sam Rosen, Irving Shklair, E. X. Beck and F. M. Beck Ohio State University Columbus,Oh and...206-212. Johnson CP, Gorss S, Hillman JD (1978). Cariogenic properties of LDH deficient mutants of streptococcus mutans . J Dent Res 57, Special Issue

  13. Power peaking nuclear reliability factors

    International Nuclear Information System (INIS)

    Hassan, H.A.; Pegram, J.W.; Mays, C.W.; Romano, J.J.; Woods, J.J.; Warren, H.D.

    1977-11-01

    The Calculational Nuclear Reliability Factor (CNRF) assigned to the limiting power density calculated in reactor design has been determined. The CNRF is presented as a function of the relative power density of the fuel assembly and its radial local. In addition, the Measurement Nuclear Reliability Factor (MNRF) for the measured peak hot pellet power in the core has been evaluated. This MNRF is also presented as a function of the relative power density and radial local within the fuel assembly

  14. FACTORS INFLUENCING SECOND LANGUAGE ACQUISITION

    Directory of Open Access Journals (Sweden)

    Siti Khasinah

    2014-05-01

    Full Text Available Motivation, attitude, age, intelligence, aptitude, cognitive style, and personality are considered as factors that greatly influence someone in the process of his or her second language acquisition. Experts state that those factors give a more dominant contribution in SLA to learners variedly, depend on who the learners are, their age, how they behave toward the language, their cognitive ability, and also the way they learn.

  15. Clinical Application of Wedge Factor

    International Nuclear Information System (INIS)

    Choi, Dong Rak; Ahn, Yong Chan; Huh, Sueng Jae

    1995-01-01

    Purpose : In general. The wedge factors which are used clinical practices are ignored of dependency on field sizes and depths. In this present, we investigated systematically the depth and field size dependency to determine the absorbed dose more accurately. Methods : The wedge factors for each wedge filter were measured at various depth (depth of Dmax, 5cm, 10cm, and 15cm) and field sizes (5 X 5cm, 10 X 10cm, 15 X 15cm, 20 X 20 cm) by using 4-,6-, and 10-MV X rays. By convention, wedge factors are determined by taking the ratio of the central axis ionization readings when the wedge filter is in place to those of the open field in same field size and measurement depth. In this present work, we determined the wedge factors for 4-, 6-, and 10-MV X rays from Clinac 600C and 2100C linear accelerators (manufactured by Varian Associates, Inc., Palo Alto, CA). To confirm that the wedge was centered., measurements were done with the two possible wedge position and various collimator orientations. Results : The standard deviations of measured values are within 0.3% and the depth dependence of wedge factor is greater for the lower energies. Especially, the variation of wedge factor is no less than 5% for 4- and 6- MV X rays with more than 45 .deg. wedge filter. But there seems to be a small dependence on field size. Conclusion : The results of this study show a dependence on the point of measurement. There also seems to be a small dependence on field size. And so, we should consider the depth and field size dependence in determining the wedge factors. If one wedge factor were to be used for each wedge filter, it seems that the measurement for a 10cm X 10cm field size at a depth of 10cm would be a reasonable choice

  16. Demand, Energy, and Power Factor

    Science.gov (United States)

    1994-08-01

    POWER FACTOR DEFINITION I Basically , power factor (pf) is a measure of how effectively the plant uses the electricity it purchases from the utility. It...not be made available by the plant. U 24 This video is relatively short, less than fifteen-minutes, and covers the basics on demand, block extenders... ratemaking methodology and test period as used in determining the NC-RS rates. Pending final decision by the FERC, the Federal Government would pay a rate as

  17. Effects of smoking on brain aging, 1

    International Nuclear Information System (INIS)

    Kubota, Kazuo; Matsuzawa, Taiju; Yamaguchi, Tatsuo; Fujiwara, Takehiko; Seo, Shinya; Sasaki, Yuichiro.

    1985-01-01

    The chronic effects of smoking on regional cerebral blood flow (CBF), and on serum lipids and lipoprotein levels in neurologically normal subjects from 25 to 85 years old were studied. CBF was studied by the 133-Xenon inhalation method and gray matter flow was calculated following the method of Obrist et al. A hundred and twentyfive subjects who had no abnormalities in neurological examinations nor in CT scan, were divided into two groups smokers (48) and non-smokers (77). Those who had a smoking index (Number of cigarettes/day) x (years of smoking history)>200 were designated as smokers. The mean smoking index of smokers was 697. sixty-five of the 77 subjects in the non-smoking group had never smoked, and the mean smoking index of non-smokers was 16. Increased reduction of CBF with advancing age was clearly observed. In the male, CBF was significantly lower in smokers than in non-smokers (mean CBF 15% lower in smokers, p<0.001). Compared to non-smokers, CBF in smokers was found to be significantly lower than the expected age matched value. Serum high density lipoprotein cholesterol values in smokers were significantly lower, and total cholesterol levels significantly higher than in non-smokers. We concluded that smoking chronically reduced CBF. Age dependent decrease of CBF was deteriorated by chronic smoking. Then, chronic smoking was suggested to be a risk factor for brain aging. Decrease of CBF in smokers was probably due to advanced atherosclerosis which produces vascular narrowing and raised resistance in cerebral blood vessels. (author)

  18. Measurement of cerebral blood flow by single photon emission computed tomography in cases of internal carotid artery occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Sunada, Ichiro [Osaka City Univ. (Japan). Faculty of Medicine

    1989-06-01

    Cerebral blood flow (CBF) was measured with {sup 133}xenon inhalation and single photon emission computed tomography in 33 cases of internal carotid artery occlusion, in the resting state and 25 minutes after acetazolamide administration. The patient population consisted of 24 males and nine females with a mean age of 57 years, who presented with transient ischemic attacks or stroke. Acetazolamide inhibits carbonic anhydrase, and CBF increases as a result of dilatation of cerebral arteries due to CO{sub 2} accumulation. The mean CBF was 46 ml/100 g/min on the affected hemisphere and 56 ml/100 g/min on the unaffected hemisphere. The mean CBF value obtained by the same method in 10 normal volunteers was 55 ml/100 g/min. The average increase in CBF after acetazolamide administration was 9% on the affected side and 17% on the unaffected side. The average increase in 10 normal volunteers was 32%. The reduced cerebral arterial reactivity to acetazolamide administration was bilateral in the patient group, suggesting that the cerebral arteries were dilated so as to maintain normal CBF. Extra-intracranial (EC-IC) bypass surgery was performed in nine patients. Preoperatively, the mean CBF was 48 ml/100 g/min on the affected side and 57 ml/100 g/min on the unaffected side. With postoperative acetazolamide administration, the percent increase in CBF rose from 13% to 22% on the affected side and from 17% to 23% on the unaffected side. The bilateral change toward normal in cerebral arterial reactivity to acetazolamide indicates that the dilated cerebral arteries returned to normal after EC-IC bypass surgery. This suggests that bypass surgery is effective in patients with internal carotid artery occlusion in whom ischemia is caused only by hemodynamic factors, and that measurement of CBF via acetazolamide loading is useful in identifying appropriate candidates for bypass surgery.

  19. Spatial heterogeneity of the relation between resting-state connectivity and blood flow: an important consideration for pharmacological studies.

    Science.gov (United States)

    Khalili-Mahani, Najmeh; van Osch, Matthias J; de Rooij, Mark; Beckmann, Christian F; van Buchem, Mark A; Dahan, Albert; van Gerven, Johannes M; Rombouts, Serge A R B

    2014-03-01

    Resting state fMRI (RSfMRI) and arterial spin labeling (ASL) provide the field of pharmacological Neuroimaging tool for investigating states of brain activity in terms of functional connectivity or cerebral blood flow (CBF). Functional connectivity reflects the degree of synchrony or correlation of spontaneous fluctuations--mostly in the blood oxygen level dependent (BOLD) signal--across brain networks; but CBF reflects mean delivery of arterial blood to the brain tissue over time. The BOLD and CBF signals are linked to common neurovascular and hemodynamic mechanisms that necessitate increased oxygen transportation to the site of neuronal activation; however, the scale and the sources of variation in static CBF and spatiotemporal BOLD correlations are likely different. We tested this hypothesis by examining the relation between CBF and resting-state-network consistency (RSNC)--representing average intranetwork connectivity, determined from dual regression analysis with eight standard networks of interest (NOIs)--in a crossover placebo-controlled study of morphine and alcohol. Overall, we observed spatially heterogeneous relations between RSNC and CBF, and between the experimental factors (drug-by-time, time, drug and physiological rates) and each of these metrics. The drug-by-time effects on CBF were significant in all networks, but significant RSNC changes were limited to the sensorimotor, the executive/salience and the working memory networks. The post-hoc voxel-wise statistics revealed similar dissociations, perhaps suggesting differential sensitivity of RSNC and CBF to neuronal and vascular endpoints of drug actions. The spatial heterogeneity of RSNC/CBF relations encourages further investigation into the role of neuroreceptor distribution and cerebrovascular anatomy in predicting spontaneous fluctuations under drugs. Copyright © 2012 Wiley Periodicals, Inc.

  20. Environmental Factors and Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Omer Faruk Tekbas

    2008-10-01

    Full Text Available Epidemiological and clinical observations have led to the hypothesis that the risk of developing cardiovascular diseases is influenced not only by genetic, lifestyle and major risk factors, but also by environmental factors. Environmental factors are considered key determinants of cardiovascular diseases. Although lifestyle choices such as smoking, diet, and exercise are viewed as major environmental influences, the contribution of pollutants and environmental chemicals is less clear. Accumulating evidence suggests that exposure to physically and chemical pollutants could elevate the risk of cardiovascular diseases. Many epidemiological studies report that exposure to physically, biologically and socio-cultural environmental factors are associated with an increase in cardiovascular mortality. Relationships between environmental factors and coronary arter disease, arhythmias, and cardiomyopathies have been reported. Exposures to arsenic, lead, cadmium, pollutant gases, solvents, and pesticides have also been linked to increased incidence of cardiovascular disease. In this paper, I review that relationships between exposure to physically, chemical, biologically and socio-cultural environmental factors and cardiovascular diseases. [TAF Prev Med Bull 2008; 7(5.000: 435-444

  1. Human factors in resuscitation teaching.

    Science.gov (United States)

    Norris, Elizabeth M; Lockey, Andrew S

    2012-04-01

    There is an increasing interest in human factors within the healthcare environment reflecting the understanding of their impact on safety. The aim of this paper is to explore how human factors might be taught on resuscitation courses, and improve course outcomes in terms of improved mortality and morbidity for patients. The delivery of human factors training is important and this review explores the work that has been delivered already and areas for future research and teaching. Medline was searched using MESH terms Resuscitation as a Major concept and Patient or Leadership as core terms. The abstracts were read and 25 full length articles reviewed. Critical incident reporting has shown four recurring problems: lack of organisation at an arrest, lack of equipment, non functioning equipment, and obstructions preventing good care. Of these, the first relates directly to the concept of human factors. Team dynamics for both team membership and leadership, management of stress, conflict and the role of debriefing are highlighted. Possible strategies for teaching them are discussed. Four strategies for improving human factors training are discussed: team dynamics (including team membership and leadership behaviour), the influence of stress, debriefing, and conflict within teams. This review illustrates how human factor training might be integrated further into life support training without jeopardising the core content and lengthening the courses. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  2. Growth factors and new periodontology

    Directory of Open Access Journals (Sweden)

    Paknejad M

    1999-06-01

    Full Text Available Growth factors are biological mediators that have a key roll in proliferation, chemotaxy and"ndifferentiation by acting on specific receptors on the surface of cells and regulating events in wound"nhealing.They can be considered hormones that are not released in to the blood stream but have one a"nlocal action. Some of these factors can regulate premature change in GO to Gl phase in cell devesion"ncycle and even may stimulate synthesis of DNA in suitable cells, Growth substances, primarily secreted"nby fibroblasts, endothelia! cells, macrophages and platelet, include platelet derived growth factor"n(PDGF, insulin like growth factor (IGF transforming growth factor (TGFa and (3 and bone"nmorphogenetic proteins BMPs that approximately are the most important of them. (BMPs could be"nused to control events during periodontal, craniofacial and implant wound healing through favoring bone"nformation"nAccording toLynch, combination of PGDF and IGF1 would be effective in promoting growth of all the"ncomponents of the periodontium."nThe aim of this study was to characterize growth factor and review the literature to determine the"nmechanism of their function, classification and application in implant and periodontal treatment.

  3. Sexual harassment: identifying risk factors.

    Science.gov (United States)

    O'Hare, E A; O'Donohue, W

    1998-12-01

    A new model of the etiology of sexual harassment, the four-factor model, is presented and compared with several models of sexual harassment including the biological model, the organizational model, the sociocultural model, and the sex role spillover model. A number of risk factors associated with sexually harassing behavior are examined within the framework of the four-factor model of sexual harassment. These include characteristics of the work environment (e.g., sexist attitudes among co-workers, unprofessional work environment, skewed sex ratios in the workplace, knowledge of grievance procedures for sexual harassment incidents) as well as personal characteristics of the subject (e.g., physical attractiveness, job status, sex-role). Subjects were 266 university female faculty, staff, and students who completed the Sexual Experience Questionnaire to assess the experience of sexual harassment and a questionnaire designed to assess the risk factors stated above. Results indicated that the four-factor model is a better predictor of sexual harassment than the alternative models. The risk factors most strongly associated with sexual harassment were an unprofessional environment in the workplace, sexist atmosphere, and lack of knowledge about the organization's formal grievance procedures.

  4. Modifying factors for metabolic parameters

    International Nuclear Information System (INIS)

    Inaba, Jiro

    1990-01-01

    Studies on factors which influence the metabolic parameter for calculation of radiation doses from intakes of radionuclides are very important for estimation of the doses for the general public, because the present procedures recommended by the International Commission on Radiological Protection is for occupationally exposed workers and the underlying metabolic and dosimetric models have been developed from studies on adult man and experiments on adult animals and from observations on radionuclides in physico-chemically simple form. Many factors have been reported to influence the metabolic parameters. Among them, the food-chain involvement of radionuclides and the age-dependence in humans and animals are most significant as environmental and physiological factor, respectively. In connection with the age-dependence of dose calculation, the ICRP started a new programme. They organized a Task Group on Age-Dependent Dose-Factors where relevant information on metabolic and biokinetic parameters are presently being reviewed for development of a set of dose factors for the following age-groups: infant, 1-year-old, 5-year-old, 10-year-old, 15-year-old, and ICRP Reference Man. The first stage of the work is for age-dependent integrated organ and effective dose factors for radioisotopes of the following elements: hydrogen, carbon, iodine, cesium, strontium, plutonium and americium. (author)

  5. Multi-factor authentication using quantum communication

    Science.gov (United States)

    Hughes, Richard John; Peterson, Charles Glen; Thrasher, James T.; Nordholt, Jane E.; Yard, Jon T.; Newell, Raymond Thorson; Somma, Rolando D.

    2018-02-06

    Multi-factor authentication using quantum communication ("QC") includes stages for enrollment and identification. For example, a user enrolls for multi-factor authentication that uses QC with a trusted authority. The trusted authority transmits device factor information associated with a user device (such as a hash function) and user factor information associated with the user (such as an encrypted version of a user password). The user device receives and stores the device factor information and user factor information. For multi-factor authentication that uses QC, the user device retrieves its stored device factor information and user factor information, then transmits the user factor information to the trusted authority, which also retrieves its stored device factor information. The user device and trusted authority use the device factor information and user factor information (more specifically, information such as a user password that is the basis of the user factor information) in multi-factor authentication that uses QC.

  6. Rare coagulation disorders: fibrinogen, factor VII and factor XIII.

    Science.gov (United States)

    de Moerloose, P; Schved, J-F; Nugent, D

    2016-07-01

    Rare coagulation disorders (RCDs) include the inherited deficiencies of fibrinogen, factor (F) II, FV, combined FV and VIII, FVII, FX, combined FVII and X, FXI, FXIII and combined congenital deficiency of vitamin K-dependent factors (VKCFDs). Despite their rarity, a deep comprehension of all these disorders is essential to really understand haemostasis. Indeed, even if they share some common features each RCD has some particularity which makes it unique. In this review, we focus on three disorders: fibrinogen, FVII and FXIII. © 2016 John Wiley & Sons Ltd.

  7. Self-similar factor approximants

    International Nuclear Information System (INIS)

    Gluzman, S.; Yukalov, V.I.; Sornette, D.

    2003-01-01

    The problem of reconstructing functions from their asymptotic expansions in powers of a small variable is addressed by deriving an improved type of approximants. The derivation is based on the self-similar approximation theory, which presents the passage from one approximant to another as the motion realized by a dynamical system with the property of group self-similarity. The derived approximants, because of their form, are called self-similar factor approximants. These complement the obtained earlier self-similar exponential approximants and self-similar root approximants. The specific feature of self-similar factor approximants is that their control functions, providing convergence of the computational algorithm, are completely defined from the accuracy-through-order conditions. These approximants contain the Pade approximants as a particular case, and in some limit they can be reduced to the self-similar exponential approximants previously introduced by two of us. It is proved that the self-similar factor approximants are able to reproduce exactly a wide class of functions, which include a variety of nonalgebraic functions. For other functions, not pertaining to this exactly reproducible class, the factor approximants provide very accurate approximations, whose accuracy surpasses significantly that of the most accurate Pade approximants. This is illustrated by a number of examples showing the generality and accuracy of the factor approximants even when conventional techniques meet serious difficulties

  8. Factors Influencing Healthcare Service Quality

    Directory of Open Access Journals (Sweden)

    Ali Mohammad Mosadeghrad

    2014-07-01

    Full Text Available Background The main purpose of this study was to identify factors that influence healthcare quality in the Iranian context. Methods Exploratory in-depth individual and focus group interviews were conducted with 222 healthcare stakeholders including healthcare providers, managers, policy-makers, and payers to identify factors affecting the quality of healthcare services provided in Iranian healthcare organisations. Results Quality in healthcare is a production of cooperation between the patient and the healthcare provider in a supportive environment. Personal factors of the provider and the patient, and factors pertaining to the healthcare organisation, healthcare system, and the broader environment affect healthcare service quality. Healthcare quality can be improved by supportive visionary leadership, proper planning, education and training, availability of resources, effective management of resources, employees and processes, and collaboration and cooperation among providers. Conclusion This article contributes to healthcare theory and practice by developing a conceptual framework that provides policy-makers and managers a practical understanding of factors that affect healthcare service quality.

  9. TRASYS form factor matrix normalization

    Science.gov (United States)

    Tsuyuki, Glenn T.

    1992-01-01

    A method has been developed for adjusting a TRASYS enclosure form factor matrix to unity. This approach is not limited to closed geometries, and in fact, it is primarily intended for use with open geometries. The purpose of this approach is to prevent optimistic form factors to space. In this method, nodal form factor sums are calculated within 0.05 of unity using TRASYS, although deviations as large as 0.10 may be acceptable, and then, a process is employed to distribute the difference amongst the nodes. A specific example has been analyzed with this method, and a comparison was performed with a standard approach for calculating radiation conductors. In this comparison, hot and cold case temperatures were determined. Exterior nodes exhibited temperature differences as large as 7 C and 3 C for the hot and cold cases, respectively when compared with the standard approach, while interior nodes demonstrated temperature differences from 0 C to 5 C. These results indicate that temperature predictions can be artificially biased if the form factor computation error is lumped into the individual form factors to space.

  10. Peaking-factor of PWR

    International Nuclear Information System (INIS)

    Morioka, Noboru; Kato, Yasuji; Yokoi, M.

    1975-01-01

    Output peaking factor often plays an important role in the safety and operation of nuclear reactors. The meaning of the peaking factor of PWRs is categorized into two features or the peaking factor in core (FQ-core) and the peaking factor on the basis of accident analysis (or FQ-limit). FQ-core is the actual peaking factor realized in nuclear core at the time of normal operation, and FQ-limit should be evaluated from loss of coolant accident and other abnormal conditions. If FQ-core is lower than FQ-limit, the reactor may be operated at full load, but if FQ-core is larger than FQ-limit, reactor output should be controlled lower than FQ-limit. FQ-core has two kinds of values, or the one on the basis of nuclear design, and the other actually measured in reactor operation. The first FQ-core should be named as FQ-core-design and the latter as FQ-core-measured. The numerical evaluation of FQ-core-design is as follows; FQ-core-design of three-dimensions is synthesized with FQ-core horizontal value (X-Y) and FQ-core vertical value, the former one is calculated with ASSY-CORE code, and the latter one with one dimensional diffusion code. For the evaluation of FQ-core-measured, on-site data observation from nuclear reactor instrumentation or off-site data observation is used. (Iwase, T.)

  11. [Risk factors of necrotizing enterocolitis].

    Science.gov (United States)

    Tapia-Rombo, C A; Velasco-Lavín, M R; Nieto-Caldelas, A

    1993-09-01

    The purpose of the present study is to compare risk factors of necrotizing enterocolitis (NEC) between two group: group A, newborns with the disease and group B, newborns with other diseases different from NEC, in order to know if these risk factors are more frequent or not in the first group. We assessed the clinical records of all the patients hospitalized in the Neonatal Intensive Care Unit and Neonatology Service of the La Raza General Hospital between 1987 and 1991 with the diagnosis of NEC. They were compared with 65 clinical records chosen at random of patients hospitalized in the same Unit with other diagnosis at the same time, and who were discharged by improvement or deceased. In all of them were look for known risk factors for NEC generally accepted such as: prematurity, neonatal asphyxia, poliglobulia, cyanotic congenital heart disease, patent ductus arteriosus, respiratory distress syndrome, catheterization of umbilical vessels, early feeding of elevated formula increases, exchange exchange transfusion, hypoxic ischemic encephalopathy, infection, etc. Just 25 records of the possible 50 with the diagnosis of NEC full filled inclusion criteria. There were no statistically significant difference in weight, sex, mortality and known risk factors of NEC between both groups. Were concluded that NEC is a disease of unknown etiology that should be studied more thoroughly. The known risk factors must be avoided because the patient susceptibility probably play an important role.

  12. Epistaxis: Prevailing Factors and Treatment

    Directory of Open Access Journals (Sweden)

    Secchi, Myrian Marajó Dal

    2009-12-01

    Full Text Available Introduction: The epistaxis is one the most frequent otorhinolaryngologic emergencies in the medical practice. It is a benign affection, but the refractory cases require hospital admission. Objective: To evaluate prevailing factors in patients with epistaxis and treatment. Form of study: Retrospective study. Method: 60 patients with diagnosis of epistaxis were evaluated and they needed hospital admission between 2005 and 2006. Results: The main prevailing factors were: Systemic arterial hypertension 36% (n= 22, trauma 16% (n=10 and coagulopathy 5% (n=3. The treatment was the use of nasal splint: anterior 58% (n=35 and antero-posterior 27% (n=16, the electrocauterization of the identified bloody point 7% (n=4, endoscopic arterial bandage 8% (n=5 in severe epistaxis. For the patients with antero-posterior splint with recurrence of bleeding in the first 24 hours (five patients, after clinical stabilization, an arterial bandage was indicated by endoscopic means; four patients had systemic arterial hypertension and in one patient no prevailing factor was identified. Conclusion: The main associated prevailing factors were systemic arterial hypertension, trauma and coagulopathy. The treatment depends on the type, severity and cause of bleeding, initially the anterior and antero-posterior splint for bleeding control. The early endoscopic arterial bandage is indicated in patients with severe epistaxis and prevailing factors, and prolonged admission and morbidities associated with nasal splint should be avoided.

  13. Security Gaps In Authentication Factor Credentials

    Directory of Open Access Journals (Sweden)

    Neeraj A. Sharma

    2015-08-01

    Full Text Available Authentication factors refer to user login credentials that a user supplies to an authentication process for it to decide whether to grant or deny access. While two-factor and three-factor authentication generally provides better security than one-factor authentication the aim of this paper is to review security in individual authentication factor credentials that are in use nowadays. These credentials will be discussed in factor categories knowledge factor possession factor and inherence factor. The paper details current security gaps and some novel approaches to diminish the gaps in these authentication factors. We believe that our recommendations will inspire development of better authentication credentials and systems.

  14. Success factors in technology development

    Science.gov (United States)

    Preston, John T.

    1995-01-01

    Universities in the U.S. have a significant impact on business through the transfer of technology. This paper describes goals and philosophy of the Technology Licensing Office at the Massachusetts Institute of Technology. This paper also relates the critical factors for susscessful technology transfer, particularly relating to new business formation. These critical factors include the quality of the technology, the quality of the management, the quality of the investor, the passion for success, and the image of the company. Descriptions of three different levels of investment are also given and the most successful level of investment for starting a new company is reviewed. Licensing to large companies is also briefly reviewed, as this type of licensing requires some different strategies than that of licensing to start-up companies. High quality critical factors and intelligent investment create rewards for the parties and successful ventures.

  15. Critical factors for EIA implementation

    DEFF Research Database (Denmark)

    Zhang, Jasmine; Kørnøv, Lone; Christensen, Per

    2013-01-01

    After decades of development, the gap between expectations of Environment Impact Assessments (EIA) and their practical performance remains significant. Research has been done to identify the critical factors for an effective implementation of EIA. However, this research, to a large extent, has...... not been cumulated and analysed comprehensively according to the stages of the EIA process. This paper contributes to the critical review of the literature on EIA implementation and effectiveness by cumulating mainly empirical findings in an implementation theoretical perspective. It focuses on the links...... between different critical factors and how they relate to different stages in the EIA and thus influence the decision making process. After reviewing 33 refereed journal articles published between 1999 and 2011, we identified 203 notions of critical factors. Of these, 102 related to different stages...

  16. Factors Driving Business Intelligence Culture

    Directory of Open Access Journals (Sweden)

    Rimvydas Skyrius

    2016-05-01

    Full Text Available The field of business intelligence (BI, despite rapid technology advances, continues to feature inadequate levels of adoption. The attention of researchers is shifting towards hu-man factors of BI adoption. The wide set of human factors influencing BI adoption con-tains elements of what we call BI culture – an overarching concept covering key managerial issues that come up in BI implementation. Research sources provide different sets of features pertaining to BI culture or related concepts – decision-making culture, analytical culture and others. The goal of this paper is to perform the review of research and practical sources to examine driving forces of BI – data-driven approaches, BI agility, maturity and acceptance – to point out culture-related issues that support BI adoption and to suggest an emerging set of factors influencing BI culture.

  17. Factors controlling metal fuel lifetime

    International Nuclear Information System (INIS)

    Porter, D.L.; Hofman, G.L.; Seidel, B.R.; Walters, L.C.

    1986-01-01

    The reliability of metal fuel elements is determined by a fuel burnup at which a statistically predicted number of fuel breaches would occur, the number of breaches determined by the amount of free fission gas which a particular reactor design can tolerate. The reliability is therefore measured using experimentally determined breach statistics, or by modelling fuel element behavior and those factors which contribute to cladding breach. The factors are fuel/cladding mechanical and chemical interactions, fission gas pressure, fuel phase transformations involving volume changes, and fission product effects on cladding integrity. Experimental data for EBR-II fuel elements has shown that the primary, and perhaps the only significant factor affecting metal fuel reliability, is the pressure-induced stresses caused by fission gas release. Other metal fuel/cladding systems may perform similarly

  18. Perinatal risk factors including malformation

    International Nuclear Information System (INIS)

    Brachner, A.; Grosche, B.

    1991-10-01

    The study gives a survey of the factors most frequently mentioned in the literature as factors likely to adversely affect a pregnancy. One essential aspect is the discussion of those factors that can be counted among the causes of malformations, as among others, prenatal radiation exposure. The study prepared within the framework of the research project 'Radiobiological environmental monitoring in Bavaria' is intended to serve as a basis for a retrospective and prospective evaluation of infant mortality, perinatal conditions and occurrence of malformations in Bavaria, with the principal idea of drawing up an environment - related health survey. The study therefore, in addition to ionizing radiation also takes into account other detectable risks within the ecologic context, as e.g. industrial installations, refuse incineration plants or waste dumps, or urbanity. (orig./MG) [de

  19. Self-government’s factoring

    Directory of Open Access Journals (Sweden)

    Maciej Tokarski

    2011-12-01

    Full Text Available Local self-governments are reliable business partners. Such belief, confirmed by long-term experience, results in eager collaboration between financial institutions and these entities. Contrary to its name, local self-governments do not constitute the main beneficiaries of the self-government’s factoring. The enterprises which perform investments commissioned by a local commune, district or province are the principal recipients. Such firms may utilise it independently if they have signed contracts with the proper authority and conduct sale with deferred payment, or they may be forced to utilise factoring when they submit their bids in self-government’s tenders within which a refinance guarantee is required. The main aim of the article is to present the mechanism and features of the self-government’s factoring, as well as the benefits which the entities involved enjoy.

  20. Organizational Factors and Intrapreneurial Competences

    Directory of Open Access Journals (Sweden)

    Suzete Antonieta Lizote

    2013-12-01

    Full Text Available This study analyzes the relationship between organizational factors and entrepreneurial competencies of coordinators of undergraduate courses in two community universities in Santa Catarina, Brazil. The organizational factors studied were: management support, freedom at work, rewards, and time available and organizational limitations. Eight entrepreneurial competencies were considered; five included in an achievement set, and three in a planning set. The method was quantitative and descriptive, adopting a structured questionnaire as the data collection tool. Factor analysis, canonical analysis, and multiple regression analysis were performed. The results revealed a positive relationship between the constructs. The most relevant competencies were organizational limitations or uncertainty about tasks, and freedom at work, which indicates the importance having clarity about rules and decisions that should exist both at the level of performance expected of the coordinator, and the freedom that they must feel in their work.

  1. Prognostic factors in Acanthamoeba keratitis.

    Science.gov (United States)

    Kaiserman, Igor; Bahar, Irit; McAllum, Penny; Srinivasan, Sathish; Elbaz, Uri; Slomovic, Allan R; Rootman, David S

    2012-06-01

    To assess the prognostic factors influencing visual prognosis and length of treatment after acanthamoeba keratitis (AK). Forty-two AK eyes of 41 patients treated between 1999 and 2006 were included. A diagnosis of AK was made on the basis of culture results with a corresponding clinical presentation. We calculated the prognostic effect of the various factors on final visual acuity and the length of treatment. Multivariate regression analysis was used to adjust for the simultaneous effects of the various prognostic factors. Mean follow-up was 19.7 ± 21.0 months. Sixty-four percent of cases had > 1 identified risk factor for AK, the most common risk factor being contact lens wear (92.9% of eyes). At presentation, median best spectacle corrected visual acuity (BCVA) was 20/200 (20/30 to Hand Motion [HM]) that improved after treatment to 20/50 (20/20 to Counting Fingers [CF]). Infection acquired by swimming or related to contact lenses had significantly better final BCVA (p = 0.03 and p = 0.007, respectively). Neuritis and pseudodendrites were also associated with better final BCVA (p = 0.04 and p = 0.05, respectively). Having had an epithelial defect on presentation and having been treated with topical steroid were associated with worse final best spectacle corrected visual acuity (BSCVA) (p = 0.0006 and p = 0.04). Multivariate regression analysis found a good initial visual acuity (p = 0.002), infections related to swimming (p = 0.01), the absence of an epithelial defect (p = 0.03), having been treated with chlorhexidine (p = 0.05), and not having receive steroids (p = 0.003) to significantly forecast a good final BCVA. We identified several prognostic factors that can help clinicians evaluate the expected visual damage of the AK infection and thus tailor treatment accordingly. Copyright © 2012 Canadian Ophthalmological Society. All rights reserved.

  2. The selection of occupancy factors

    International Nuclear Information System (INIS)

    Lakey, J.R.A.

    1977-01-01

    An estimate of the proportion of time that an area is occupied by radiation workers is often used in radiological protection to permit relaxation of exposure rate limits above those for continuous occupation. This proportion is known as an occupancy factor and is used most frequently in X-ray facilities. The strategy for controlling the external exposure of radiation workers must be decided before occupancy factors are selected for the design of the radiation protection facilities. When shielding has to be designed the occupancy factor effects the design objectives and permits increased exposure rates at the shield surface. It is useful to note that the selection of occupancy factors with due regard to the expected spatial variation of the exposure rate can help to reduce the range of the worker's radiation exposure because field gradients are usually steeper close to the shield. When other hazards, such as internal exposure, and other constraints, such as cost of the space consumed, are added, the selection of the optimum set of occupancy factors is more difficult. Two zone occupancy factors are discussed in this paper and proposals are made for a strategy to be used when there is more than one hazard and the designer has to meet constraints imposed by limitations of the facilities available. An important feature of the strategy is the avoidance of high radiation exposure to small groups of workers. The errors involved in assessment of the actual dose received by the radiation worker must be taken into account and in particular the selection of the higher exposure rate limits must be made with attention to the accident potential

  3. Theoretical difference between impact factor and influence factor

    Directory of Open Access Journals (Sweden)

    Đilda Pečarić

    2010-06-01

    Full Text Available Bibliometric constructions of "knowledge maps" and "cognitive structures of science" do not differentiate between impact and influence factors. The difference can be constructedaccording to different meaning and interpretation of the terms reference and citation. Reference is "acknowledgment which one author gives to another", whereas citation is "acknowledgment which one document receives from another". Development of Information Science according to period and subject area is analyzed on the corpus of citation literature retrieved from doctoral dissertations in Information Science from 1978 to 2007 at Croatian universities. The research aim is to indicate the difference between document impact factor and author's influence factor (i.e. reference ability to produce effects on actions, behavior, and opinions of authors of doctoral theses. The influence factor serves to distinguish the key role of cited authors in time and according to the duration of the influence (the average age for cited papers of dominant authors in different periods is between eight and ten years. The difference between linear and interactive communication seems vital for the interpretation of cited half-life, i.e. the attitude of one science community towards used information resources and cognitive heritage. The analyzed corpus of 22,210 citations can be divided into three communication phases according to influence factor criteria: in the phase of dialogue and interactive communication 25% of bibliographic units are cited in the first four years; in the second phase another 25% of units are cited from the fifth to the ninth year; after ten years, in the dominant linear communication phase, approximately 30% of units are cited.

  4. Absorption factor for cylindrical samples

    International Nuclear Information System (INIS)

    Sears, V.F.

    1984-01-01

    The absorption factor for the scattering of X-rays or neutrons in cylindrical samples is calculated by numerical integration for the case in which the absorption coefficients of the incident and scattered beams are not equal. An extensive table of values having an absolute accuracy of 10 -4 is given in a companion report [Sears (1983). Atomic Energy of Canada Limited, Report No. AECL-8176]. In the present paper an asymptotic expression is derived for the absorption factor which can be used with an error of less than 10 -3 for most cases of interest in both neutron inelastic scattering and neutron diffraction in crystals. (Auth.)

  5. General introduction and recovery factors

    Science.gov (United States)

    Verma, Mahendra K.

    2017-07-17

    IntroductionThe U.S. Geological Survey (USGS) compared methods for estimating an incremental recovery factor (RF) for the carbon dioxide enhanced oil recovery (CO2-EOR) process involving the injection of CO2 into oil reservoirs. This chapter first provides some basic information on the RF, including its dependence on various reservoir and operational parameters, and then discusses the three development phases of oil recovery—primary, second­ary, and tertiary (EOR). It ends with a brief discussion of the three approaches for estimating recovery factors, which are detailed in subsequent chapters.

  6. Cardiovascular risk factors in men

    DEFF Research Database (Denmark)

    Gyllenborg, J; Rasmussen, S L; Borch-Johnsen, Knut

    2001-01-01

    Males have higher risk of cardiovascular disease (CVD) than premenopausal females. Gonadal steroids are probably involved in the gender difference in CVD, but previous results have been conflicting. We investigated the associations between CVD risk factors and sex hormones in a cross-sectional de......Males have higher risk of cardiovascular disease (CVD) than premenopausal females. Gonadal steroids are probably involved in the gender difference in CVD, but previous results have been conflicting. We investigated the associations between CVD risk factors and sex hormones in a cross...

  7. Efficiency factors in Mie scattering

    International Nuclear Information System (INIS)

    Nussenzveig, H.M.

    1980-04-01

    Asymptotic approximation to the Mie efficiency factors for extinction, absorption and radiation pressure, derived from complex angular momentum theory and averaged over Δβ approximately π (β = size parameter), are given and compared with the exact results. For complex refractive indices N = n + i kappa with 1.1 -2 - 10 -3 % between β = 10 and β = 1000, and computing time is reduced by a factor of order β, so that the Mie formulae can advantageously by replaced by the asymptotic ones in most applications. (Author) [pt

  8. Output factors and scatter ratios

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, P N; Summers, R E; Samulski, T V; Baird, L C [Allegheny General Hospital, Pittsburgh, PA (USA); Ahuja, A S; Dubuque, G L; Hendee, W R; Chhabra, A S

    1979-07-01

    Reference is made to a previous publication on output factors and scatter ratios for radiotherapy units in which it was suggested that the output factor should be included in the definitions of scatter-air ratio and tissue-maximum ratio. In the present correspondence from other authors and from the authors of the previous publication, the original definitions and the proposed changes are discussed. Radiation scatter from source and collimator degradation of beam energy and calculation of dose in tissue are considered in relation to the objective of accurate dosimetry.

  9. Effectiveness of human factors simulator

    International Nuclear Information System (INIS)

    Moragas, F.

    2015-01-01

    En 2011, ANAV started the exploitation of the Human Factors Simulator installed in TECNATOM Training Center located in L'Hospital de L'Infant Tarragona. AVAN's Strategic Plan includes the Action Plan for the improvement of human behavior. The plan includes improving the efficiency of the efficiency of the human factors simulator. It is proposed to improve the efficiency into two different terms: winning effectiveness in modeling behaviors, and interweaving the activities in the simulator with the actual strategy of promoting Safety culture and human behaviour. (Author)

  10. The gamma contamination food factor

    International Nuclear Information System (INIS)

    Kukoc, A.H.; Anicin, I.V.; Adzic, P.R.

    1992-01-01

    We suggest that radioactive food contamination, as determined solely by a quantitative gamma-ray spectroscopic measurement, may, apart from the total activity per unit mass, be for quick reference conveniently characterized by another single figure which we call the ''Gamma Contamination Food Factor'' (GCFF). This factor may be defined as the ratio of the total specific activity of gamma-ray-emitting radionuclides in the food sample (except that of 40 K) to the specific activity of 40 K either in the sample itself or in an ''average man''. We discuss briefly the meaning and advantages of these definitions. (author)

  11. Age factors in biometric processing

    CERN Document Server

    Fairhurst, Michael

    2013-01-01

    As biometrics-based identification and identity authentication become increasingly widespread in their deployment, it becomes correspondingly important to consider more carefully issues relating to reliability, usability and inclusion. One factor which is particularly important in this context is that of the relationship between the nature of the measurements extracted from a particular biometric modality and the age of the sample donor, and the effect which age has on physiological and behavioural characteristics invoked in a biometric transaction. In Age Factors in Biometric Processing an in

  12. Social networks and factor markets

    DEFF Research Database (Denmark)

    Abay, Kibrom Araya; Kahsay, Goytom Abraha; Berhane, Guush

    2018-01-01

    We investigate the role of an indigenous social network in Ethiopia, the iddir, in facilitating factor market transactions among smallholder farmers. We use a detailed longitudinal household survey data and employ a fixed effects estimation to identify the effect of iddir membership on factor...... market transactions among farmers. We find that joining an iddir network improves households’ access to land, labour and credit transactions. Our findings also hint that iddir networks may crowd-out borrowing from local moneylenders (locally referred as ‘Arata Abedari’), a relatively expensive credit...

  13. Risk factor for febrile seizures

    Directory of Open Access Journals (Sweden)

    Odalović Dragica

    2014-01-01

    Full Text Available Febrile seizures are the most frequent neurological disorder in the childhood. According to American Academy of Pediatrics (AAP, they have been defined as seizures provoked by high temperature in children aged between 6 months and 5 years, without previous history of afebrile seizures, intracranial infections and other possible causes of seizures. Seizures can be typical and atypical, according to the characteristics. Pathogenesis of this disorder has not been clarified yet, and it is believed to be a combination of genetic factors, high body temperature and brain maturation. The risk factors for recurrence of febrile seizures are: age in which seizures appeared for the first time, epilepsy in the first degree relative, febrile seizures in the first degree relative, frequent diseases with fever and low body temperature on the beginning of seizures. The frequency of recurrent seizures The risk for occurrence of epilepsy in children with simple seizures is about 1-1.5%, which is slightly higher compared to general population, while it increases to 4-15% in patients with complex seizures. However, there is no evidence that therapy prevents occurrence of epilepsy. When the prevention of recurrent seizures is considered, it is necessary to separate simple from complex seizures. The aim of this paper was to analyze the most important risk factors for febrile seizures, and to evaluate their impact on occurrence of recurrent seizures. Our study included 125 children with febrile seizures, aged from 6 months to 5 years. The presence of febrile seizures and epilepsy in the first degree relative has been noted in 22% of children. Typical febrile seizures were observed in 76% of cases, and atypical in 24%. Most patients had only one seizure (73.6%. Children, who had seizure earlier in life, had more frequent recurrences. Both risk factors were present in 25% of patients, while 68% of patients had only one risk factor. For the children with febrile disease

  14. Factores de risco em implantologia

    OpenAIRE

    Sousa, Inês Silveira e Luz Nunes de

    2015-01-01

    A Implantologia tem ganho popularidade na medicina dentária pelos resultados previsíveis em reabilitações de áreas edêntulas, permitindo minimizar as consequências funcionais, fonéticas e estéticas que advém da perda de dentes através de uma solução fixa que satizfaz os pacientes. Esta é uma revisão da literatura existente sobre factores de risco, fracassos e complicações inerentes ao tratamento com implantes dentários. Categorizam-se os factores de risco em implantologia co...

  15. Tissue factor-dependent activation of tritium-labeled factor IX and factor X in human plasma

    International Nuclear Information System (INIS)

    Morrison, S.A.; Jesty, J.

    1984-01-01

    A comparism was made of the tissue factor-dependent activation of tritium-labeled factor IX and factor X in a human plasma system and a study was made of the role of proteases known to stimulate factor VII activity. Plasma was defibrinated by heating and depleted of its factors IX and X by passing it through antibody columns. Addition of human brain thromboplastin, Ca2+, and purified 3H-labeled factor X to the plasma resulted, after a short lag, in burst-like activation of the factor X, measured as the release of radiolabeled activation peptide. The progress of activation was slowed by both heparin and a specific inhibitor of factor Xa but factor X activation could not be completely abolished by such inhibitors. In the case of 3H-factor IX activation, the rate also increased for approximately 3 min after addition of thromboplastin, but was not subsequently curtailed. A survey of proteases implicated as activators of factor VII in other settings showed that both factor Xa and factor IXa could accelerate the activation of factor IX. However, factor Xa was unique in obliterating activation when present at concentrations greater than approximately 1 nM. Heparin inhibited the tissue factor-dependent activation of factor IX almost completely, apparently through the effect of antithrombin on the feedback reactions of factors Xa and IXa on factor VII. These results suggest that a very tight, biphasic control of factor VII activity exists in human plasma, which is modulated mainly by factor Xa. At saturation of factor VIIa/tissue factor, factor IX activation was significantly more rapid than was previously found in bovine plasma under similar conditions. The activation of factor X at saturation was slightly more rapid than in bovine plasma, despite the presence of heparin

  16. HUMAN PROSTATE CANCER RISK FACTORS

    Science.gov (United States)

    Prostate cancer has the highest prevalence of any non-skin cancer in the human body, with similar likelihood of neoplastic foci found within the prostates of men around the world regardless of diet, occupation, lifestyle, or other factors. Essentially all men with circulating an...

  17. Risk factors for undescended testis.

    NARCIS (Netherlands)

    Brouwers, M.M.; Bruijne, L.M. de; Gier, R.P.E. de; Zielhuis, G.A.; Feitz, W.F.J.; Roeleveld, N.

    2012-01-01

    OBJECTIVE: To contribute to the understanding of the etiology of undescended testis (UDT), by exploring a wide range of potential risk factors in a case-referent study. PATIENTS AND METHODS: Cases and referents were recruited at five hospitals and included 200 boys with surgically corrected UDT and

  18. Factor VII-activating protease

    DEFF Research Database (Denmark)

    Ramanathan, Ramshanker; Gram, Jørgen B; Sand, Niels Peter R

    2017-01-01

    : Factor VII-activating protease (FSAP) may regulate development of cardiovascular disease (CVD). We evaluated sex differences in FSAP measures and examined the association between FSAP and coronary artery calcification (CAC) in a middle-aged population. Participants were randomly selected citizens...

  19. An innovation resistance factor model

    Directory of Open Access Journals (Sweden)

    Siti Salwa Mohd Ishak

    2016-09-01

    Full Text Available The process and implementation strategy of information technology in construction is generally considered through the limiting prism of theoretical contexts generated from innovation diffusion and acceptance. This research argues that more attention should be given to understanding the positive effects of resistance. The study develops a theoretical framing for the Integrated Resistance Factor Model (IRFM. The framing uses a combination of diffusion of innovation theory, technology acceptance model and social network perspective. The model is tested to identify the most significant resistance factors using Partial Least Square (PLS technique. All constructs proposed in the model are found to be significant, valid and consistent with the theoretical framework. IRFM is shown to be an effective and appropriate model of user resistance factors. The most critical factors to influence technology resistance in the online project information management system (OPIMS context are: support from leaders and peers, complexity of the technology, compatibility with key work practices; and pre-trial of the technology before it is actually deployed. The study provides a new model for further research in technology innovation specific to the construction industry.

  20. Seasonality of cardiovascular risk factors

    DEFF Research Database (Denmark)

    Marti-Soler, Helena; Gubelmann, Cédric; Aeschbacher, Stefanie

    2014-01-01

    OBJECTIVE: To assess the seasonality of cardiovascular risk factors (CVRF) in a large set of population-based studies. METHODS: Cross-sectional data from 24 population-based studies from 15 countries, with a total sample size of 237 979 subjects. CVRFs included Body Mass Index (BMI) and waist...