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Sample records for systematic cyclic block

  1. Random matrix theory for pseudo-Hermitian systems: Cyclic blocks

    Indian Academy of Sciences (India)

    We discuss the relevance of random matrix theory for pseudo-Hermitian systems, and, for Hamiltonians that break parity and time-reversal invariance . In an attempt to understand the random Ising model, we present the treatment of cyclic asymmetric matrices with blocks and show that the nearest-neighbour spacing ...

  2. Random matrix theory for pseudo-Hermitian systems: Cyclic blocks

    Indian Academy of Sciences (India)

    Abstract. We discuss the relevance of random matrix theory for pseudo-Hermitian sys- tems, and, for Hamiltonians that break parity P and time-reversal invariance T. In an attempt to understand the random Ising model, we present the treatment of cyclic asym- metric matrices with blocks and show that the nearest-neighbour ...

  3. Chain elongation suppression of cyclic block copolymers in lamellar microphase-separated bulk

    NARCIS (Netherlands)

    Matsushita, Y; Iwata, H; Asari, T; Uchida, T; ten Brinke, G; Takano, A

    2004-01-01

    Chain elongation suppression of cyclic block copolymers in microphase-separated bulk was determined quantitatively. Solvent-cast and annealed films are confirmed to show alternating lamellar structure and their microdomain spacing D increases with increasing total molecular weight M according to the

  4. Lexical selection in the semantically blocked cyclic naming task: The role of cognitive control and learning

    Directory of Open Access Journals (Sweden)

    Jason E. Crowther

    2014-01-01

    Full Text Available Studies of semantic interference in language production have provided evidence for a role of cognitive control mechanisms in regulating the activation of semantic competitors during naming. The present study investigated the relationship between individual differences in cognitive control abilities, for both younger and older adults, and the degree of semantic interference in a blocked cyclic naming task. We predicted that individuals with lower working memory capacity (as measured by word span, lesser ability to inhibit distracting responses (as measured by Stroop interference, and a lesser ability to resolve proactive interference (as measured by a recent negatives task would show a greater increase in semantic interference in naming, with effects being larger for older adults. Instead, measures of cognitive control were found to relate to specific indices of semantic interference in the naming task, rather than overall degree of semantic interference, and few interactions with age were found, with younger and older adults performing similarly. The increase in naming latencies across naming trials within a cycle were negatively correlated with word span for both related and unrelated conditions, suggesting a strategy of narrowing response alternatives based upon memory for the set of item names. Evidence for a role of inhibition in response selection was obtained, as Stroop interference correlated positively with the change in naming latencies across cycles for the related, but not unrelated, condition. In contrast, recent negatives interference correlated negatively with the change in naming latencies across unrelated cycles, suggesting that individual differences in this tap the degree of strengthening of links in a lexical network based upon prior exposure. Results are discussed in terms of current models of lexical selection and consequences for word retrieval in more naturalistic production.

  5. Adverse effects of iodine thyroid blocking: A systematic review

    International Nuclear Information System (INIS)

    Spallek, L.; Krille, L.; Reiners, C.; Schneider, R.; Yamashita, S.; Zeeb, H.

    2008-01-01

    131 I, when released in a radiological or nuclear accident as happened recently in Fukushima (Japan)), may cause thyroid cancer as a long-term consequence. Iodine thyroid blocking (ITB) is known to reduce the risk of developing thyroid cancer. Potential adverse effects of ITB have not been systematically investigated so far. This article summarises the results of a review on adverse effects of ITB based on a systematic literature search in scientific medical databases. A meta-analysis was not performed as identified studies displayed major heterogeneity. The search resulted in 14 articles relevant to the topic, reporting mostly on surveys, ecological and intervention studies. Only one study from Poland focused on effects (both desired and adverse) of an ITB intervention following the Chernobyl accident. All other studies reported on iodine administration in a different context. Overall, the studies did not reveal severe adverse reactions to potassium iodide in the general public. Since ITB is a protective measure only applied in very specific circumstances, scientifically sound studies of adverse effects are scarce and consequently the evidence base is weak. The assessment of adverse effects of ITB relies on indirect evidence from related areas. This study may contribute to ongoing developments in pharmaco-epidemiology aiming to better quantify adverse effects of medications and health care interventions including ITB. All rights reserved. (authors)

  6. Paravertebral Block for Inguinal Herniorrhaphy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Law, Lawrence Siu-Chun; Tan, Mingjuan; Bai, Yaowu; Miller, Timothy E; Li, Yi-Ju; Gan, Tong-Joo

    2015-08-01

    Paravertebral block (PVB) is a safe and effective anesthetic technique for thoracotomy and mastectomy. However, no systematic review or meta-analysis has focused on PVB for inguinal herniorrhaphy. Our study compares PVB with general anesthesia/systemic analgesia, neuraxial blocks, and other peripheral nerve blocks. We analyzed 14 randomized controlled trials from PubMed, MEDLINE, CENTRAL, EMBASE, and CINAHL up to February 2015, without language restriction, comparing PVB under sedation with general anesthesia/systematic analgesia (135 vs 133 patients), neuraxial blocks (191 vs 186 patients), and other peripheral nerve blocks (119 vs 117 patients). We investigated pain scores, consumption of postoperative analgesia, incidence of postoperative nausea and vomiting (PONV), length of hospital stay, postanesthesia care unit bypassing rate, time to perform blocks, intraoperative hemodynamics, and incidence of urinary retention. Joint hypothesis testing was adopted for pain and analgesics, PONV, and hemodynamic variables. All analyses were performed with RevMan 5.2.11 (Cochrane Collaboration, Copenhagen). Hartung-Knapp-Sidik-Jonkman method was used for post hoc testing. PVB reduced PONV (nausea: risk ratio [RR] = 0.22; 95% confidence interval [CI], 0.05-0.93; numbers needed to treat [NNT] = 4.5; I = 15% and vomiting: RR = 0.15; 95% CI, 0.03-0.76; NNT = 8.3; I = 0%) compared with general anesthesia/systematic analgesia (quality of evidence [QoE]: high). Compared with neuraxial blocks, PVB resulted in less postoperative nausea (RR = 0.34 [95% CI, 0.13-0.91], NNT = 8.3, I = 0%) and urinary retention (RR = 0.14 [95% CI, 0.05-0.42], NNT = 7.4, I = 0%) than neuraxial blocks (QoE: high). More time was needed to perform PVB than neuraxial blocks (standardized mean difference = 1.90 [95% CI, 0.02-3.77], I = 92%; mean difference = 5.33 minutes; QoE: moderate). However, the available data could not reject the null hypothesis of noninferiority on all pain scores and analgesic

  7. Wrong-site nerve blocks: A systematic literature review to guide principles for prevention.

    Science.gov (United States)

    Deutsch, Ellen S; Yonash, Robert A; Martin, Donald E; Atkins, Joshua H; Arnold, Theresa V; Hunt, Christina M

    2018-03-02

    Wrong-site nerve blocks (WSBs) are a significant, though rare, source of perioperative morbidity. WSBs constitute the most common type of perioperative wrong-site procedure reported to the Pennsylvania Patient Safety Authority. This systematic literature review aggregates information about the incidence, patient consequences, and conditions that contribute to WSBs, as well as evidence-based methods to prevent them. A systematic search of English-language publications was performed, using the PRISMA process. Seventy English-language publications were identified. Analysis of four publications reporting on at least 10,000 blocks provides a rate of 0.52 to 5.07 WSB per 10,000 blocks, unilateral blocks, or "at risk" procedures. The most commonly mentioned potential consequence was local anesthetic toxicity. The most commonly mentioned contributory factors were time pressure, personnel factors, and lack of site-mark visibility (including no site mark placed). Components of the block process that were addressed include preoperative nerve-block verification, nerve-block site marking, time-outs, and the healthcare facility's structure and culture of safety. A lack of uniform reporting criteria and divergence in the data and theories presented may reflect the variety of circumstances affecting when and how nerve blocks are performed, as well as the infrequency of a WSB. However, multiple authors suggest three procedural steps that may help to prevent WSBs: (1) verify the nerve-block procedure using multiple sources of information, including the patient; (2) identify the nerve-block site with a visible mark; and (3) perform time-outs immediately prior to injection or instillation of the anesthetic. Hospitals, ambulatory surgical centers, and anesthesiology practices should consider creating site-verification processes with clinician input and support to develop sustainable WSB-prevention practices. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. cAMP control of HCN2 channel Mg2+ block reveals loose coupling between the cyclic nucleotide-gating ring and the pore.

    Directory of Open Access Journals (Sweden)

    Alex K Lyashchenko

    Full Text Available Hyperpolarization-activated cyclic nucleotide-regulated HCN channels underlie the Na+-K+ permeable IH pacemaker current. As with other voltage-gated members of the 6-transmembrane KV channel superfamily, opening of HCN channels involves dilation of a helical bundle formed by the intracellular ends of S6 albeit this is promoted by inward, not outward, displacement of S4. Direct agonist binding to a ring of cyclic nucleotide-binding sites, one of which lies immediately distal to each S6 helix, imparts cAMP sensitivity to HCN channel opening. At depolarized potentials, HCN channels are further modulated by intracellular Mg2+ which blocks the open channel pore and blunts the inhibitory effect of outward K+ flux. Here, we show that cAMP binding to the gating ring enhances not only channel opening but also the kinetics of Mg2+ block. A combination of experimental and simulation studies demonstrates that agonist acceleration of block is mediated via acceleration of the blocking reaction itself rather than as a secondary consequence of the cAMP enhancement of channel opening. These results suggest that the activation status of the gating ring and the open state of the pore are not coupled in an obligate manner (as required by the often invoked Monod-Wyman-Changeux allosteric model but couple more loosely (as envisioned in a modular model of protein activation. Importantly, the emergence of second messenger sensitivity of open channel rectification suggests that loose coupling may have an unexpected consequence: it may endow these erstwhile "slow" channels with an ability to exert voltage and ligand-modulated control over cellular excitability on the fastest of physiologically relevant time scales.

  9. Detecting seasonal and cyclical trends in agricultural runoff water quality-hypothesis tests and block bootstrap power analysis.

    Science.gov (United States)

    Uddameri, Venkatesh; Singaraju, Sreeram; Hernandez, E Annette

    2018-02-21

    Seasonal and cyclic trends in nutrient concentrations at four agricultural drainage ditches were assessed using a dataset generated from a multivariate, multiscale, multiyear water quality monitoring effort in the agriculturally dominant Lower Rio Grande Valley (LRGV) River Watershed in South Texas. An innovative bootstrap sampling-based power analysis procedure was developed to evaluate the ability of Mann-Whitney and Noether tests to discern trends and to guide future monitoring efforts. The Mann-Whitney U test was able to detect significant changes between summer and winter nutrient concentrations at sites with lower depths and unimpeded flows. Pollutant dilution, non-agricultural loadings, and in-channel flow structures (weirs) masked the effects of seasonality. The detection of cyclical trends using the Noether test was highest in the presence of vegetation mainly for total phosphorus and oxidized nitrogen (nitrite + nitrate) compared to dissolved phosphorus and reduced nitrogen (total Kjeldahl nitrogen-TKN). Prospective power analysis indicated that while increased monitoring can lead to higher statistical power, the effect size (i.e., the total number of trend sequences within a time-series) had a greater influence on the Noether test. Both Mann-Whitney and Noether tests provide complementary information on seasonal and cyclic behavior of pollutant concentrations and are affected by different processes. The results from these statistical tests when evaluated in the context of flow, vegetation, and in-channel hydraulic alterations can help guide future data collection and monitoring efforts. The study highlights the need for long-term monitoring of agricultural drainage ditches to properly discern seasonal and cyclical trends.

  10. Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s with functional carbonate building blocks. 1. Chemical synthesis and their structural and physical characterization.

    Science.gov (United States)

    Yang, Jing; Hao, Qinghui; Liu, Xiaoyun; Ba, Chaoyi; Cao, Amin

    2004-01-01

    This study presents chemical synthesis, structural, and physical characterization of novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s P(BS-co-CC) bearing functional carbonate building blocks. First, five kinds of six-membered cyclic carbonate monomers, namely, trimethylene carbonate (TMC), 1-methyl-1,3-trimethylene carbonate (MTMC), 2,2-dimethyl-1,3-trimethylene carbonate (DMTMC), 5-benzyloxytrimethylene carbonate (BTMC), and 5-ethyl-5-benzyloxymethyl trimethylene carbonate (EBTMC), were well prepared from ethyl chloroformate and corresponding diols at 0 degrees C in THF solution with our modified synthetic strategies. Then, a series of new P(BS-co-CC)s were synthesized at 210 degrees C through a simple combination of poly-condensation and ring-opening-polymerization (ROP) of hydroxyl capped PBS macromers and the prepared carbonate monomers, and titanium tetra-isopropoxide Ti(i-OPr)4 was used as a more suitable catalyst of 5 candidate catalysts which could concurrently catalyze poly-condensation and ROP. By means of NMR, GPC, FTIR, and thermal analytical instruments, macromolecular structures and physical properties have been characterized for these aliphatic poly(ester carbonate)s. The experimental results indicated that novel biodegradable P(BS-co-CC)s were successfully synthesized with number average molecular weight Mn ranging from 24.3 to 99.6 KDa and various CC molar contents without any detectable decarboxylation and that the more bulky side group was attached to a cyclic carbonate monomer, the lower reactivity for its copolymerization would be observed. The occurrences of 13C NMR signal splitting of succinyl carbonyl attributed to the BS building blocks could be proposed due to the randomized sequences of BS and CC building blocks. FTIR characterization indicated two distinct absorption bands at 1716 and 1733 approximately 1735 cm(-1), respectively, stemming from carbonyl stretching modes for corresponding BS and CC units. With

  11. Sphenopalatine ganglion: block, radiofrequency ablation and neurostimulation - a systematic review.

    Science.gov (United States)

    Ho, Kwo Wei David; Przkora, Rene; Kumar, Sanjeev

    2017-12-28

    Sphenopalatine ganglion is the largest collection of neurons in the calvarium outside of the brain. Over the past century, it has been a target for interventional treatment of head and facial pain due to its ease of access. Block, radiofrequency ablation, and neurostimulation have all been applied to treat a myriad of painful syndromes. Despite the routine use of these interventions, the literature supporting their use has not been systematically summarized. This systematic review aims to collect and summarize the level of evidence supporting the use of sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Medline, Google Scholar, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were reviewed for studies on sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Studies included in this review were compiled and analyzed for their treated medical conditions, study design, outcomes and procedural details. Studies were graded using Oxford Center for Evidence-Based Medicine for level of evidence. Based on the level of evidence, grades of recommendations are provided for each intervention and its associated medical conditions. Eighty-three publications were included in this review, of which 60 were studies on sphenopalatine ganglion block, 15 were on radiofrequency ablation, and 8 were on neurostimulation. Of all the studies, 23 have evidence level above case series. Of the 23 studies, 19 were on sphenopalatine ganglion block, 1 study on radiofrequency ablation, and 3 studies on neurostimulation. The rest of the available literature was case reports and case series. The strongest evidence lies in using sphenopalatine ganglion block, radiofrequency ablation and neurostimulation for cluster headache. Sphenopalatine ganglion block also has evidence in treating trigeminal neuralgia, migraines, reducing the needs of analgesics after endoscopic sinus surgery and reducing pain associated with nasal packing

  12. Pliocene-Pleistocene (Nukumaruan) lithostratigraphy of the Tangoio block, and origin of sedimentary cyclicity, central Hawke's Bay, new Zealand

    International Nuclear Information System (INIS)

    Haywick, D.W.; Lowe, D.A.; Beu, A.G.; Henderson, R.A.; Carter, R.M.

    1991-01-01

    Eleven formations are defined within the Pliocene-Pleistocene Petane Group in a 450 km 2 uplifted area of central Hawkes Bay (Tangoio block). In ascending order these are: Waipunga Formation (new), Esk Formation, Tutira Formation (new), Aropaoanui Formation (new), Darkys Spur Formation (new), Mairau Formation (new), Tangoio Formation, Te Ngaru Formation, Waipatiki Formation, Devils Elbow Formation, and Kaiwaka Formation. Petane Group strata are cyclothemic and alternate between coarse-grained lithofacies (greywacke gravel, siliciclastic and carbonate sand/sandstone and bioclastic limestone) ascribed to nonmarine and inner shelf depositional environments, and sandy/muddy-silt ('papa') ascribed to mid-shelf deposition. The Petane Group is characterised by remarkable lateral continuity of formations, contrasting with conspicuous vertical changes. This stratigraphic style is consistent with glacio-eustatic sea-level fluctuations as proposed by Vella and Beu and Edwards, whereby coarse-grained lithofacies were deposited during sea-level low stands and fine-grained lithofacies were deposited during sea-level high stands. Foraminifera extracted from low-stand lithofacies display opposite δ 18 O signatures to that predicted for glacio-eustasy, a result of synsedimentary seawater dilution during sea-level low stands, and/or isotopic exchange during meteoric diagenesis. Stratigraphic and sedimentary criteria indicate that the Petane Group was deposited under unique circumstances of rapid basinal subsidence and a high rate of sedimentation. This offers an explanation for the general rarity of cyclothemic successions in the Pliocene-Pleistocene stratigraphic record. (author). 45 refs., 9 figs., 1 tab

  13. Suprascapular and Interscalene Nerve Block for Shoulder Surgery: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Hussain, Nasir; Goldar, Ghazaleh; Ragina, Neli; Banfield, Laura; Laffey, John G; Abdallah, Faraj W

    2017-12-01

    Interscalene block provides optimal shoulder surgery analgesia, but concerns over its associated risks have prompted the search for alternatives. Suprascapular block was recently proposed as an interscalene block alternative, but evidence of its comparative analgesic effect is conflicting. This meta-analysis compares the analgesic effect and safety of suprascapular block versus interscalene block for shoulder surgery. Databases were searched for randomized trials comparing interscalene block with suprascapular block for shoulder surgery. Postoperative 24-h cumulative oral morphine consumption and the difference in the area under curve for pooled rest pain scores were designated as primary outcomes. Analgesic and safety outcomes, particularly block-related and respiratory complications, were evaluated as secondary outcomes. Results were pooled using random-effects modeling. Data from 16 studies (1,152 patients) were analyzed. Interscalene block and suprascapular block were not different in 24-h morphine consumption. The difference in area under the curve of pain scores for the 24-h interval favored interscalene block by 1.1 cm/h, but this difference was not clinically important. Compared with suprascapular block, interscalene block reduced postoperative pain but not opioid consumption during recovery room stay by a weighted mean difference (95% CI) of 1.5 cm (0.6 to 2.5 cm; P shoulder surgery.

  14. The efficacy of greater occipital nerve block for the treatment of migraine: A systematic review and meta-analysis.

    Science.gov (United States)

    Zhang, Hehui; Yang, Xiaokai; Lin, Yijun; Chen, Linglong; Ye, Hua

    2018-02-01

    Greater occipital nerve (GON) block has some potential in treating migraine. We conduct a systematic review and meta-analysis to investigate the impact of GON block on pain management of migraine. We have systematically searched randomized controlled trials (RCTs) assessing the efficacy of GON block versus placebo for migraine in various databases including PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases. The primary outcome is pain intensity. Meta-analysis is performed using the random-effect model. Seven RCTs are included in the meta-analysis. Compared with control intervention in migraine patients, GON block intervention can significantly reduce pain intensity (Mean difference = -1.24; 95% CI = -1.98 to -0.49; P = 0.001) and analgesic medication consumption (Mean difference = -1.10; 95% CI = -2.07 to -0.14; P = 0.02), but has no remarkable impact on head duration (Mean difference = -6.96; 95% CI = -14.09 to 0.18; P = 0.0.06) and adverse events (RR = 0.93; 95% CI = 0.52 to 1.65; P = 0.80). GON block intervention is able to significantly reduce pain intensity and analgesic medication consumption in migraine patients. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Nido-Carborane building-block reagents. 3. Cyclic and open-chain oligomers incorporating -CB4H6C - units. Crown carboranes

    International Nuclear Information System (INIS)

    Boyter, H.A. Jr.; Grimes, R.N.

    1988-01-01

    The open-chain dialkynes EtC≡C(CH 2 ) n C≡CEt (n = 4, 6), the trialkyne HC≡C(CH 2 ) 5 C≡CH, and the cyclic dialkynes CH 2 (CH 2 ) 4 C≡C(CH 2 ) n C≡C (n = 4-6) were treated with B 5 H 9 and (C 2 H 5 ) 3 to give the corresponding nido-carborane oligomers, in which the original -C≡C- units are converted to -CB 4 H 6 C- nido-carborane cages. In each case, all available -C≡C- groups were transformed to carborane moieties. No partially converted products (having both carborane and -C≡C- groups in the chain) were found; when the B 5 H 9 /-C≡C- ratio employed was 2+ and oxidative fusion, forming products incorporating C 4 B 8 cages. The cyclic bis(carborane) CH 2 (CH 2 ) 4 CB 4 H 6 C(CH 2 ) 5 CB 4 H 6 C is an air-stable oil that can be deprotonated but does not under metal-promoted oxidative fusion. All products were characterized by 11 B and 1 H NMR, infrared, visible-uv, and mass spectroscopy, and the 13 C NMR spectra of linear bis(carboranes) are reported. 9 references, 7 figures, 4 tables

  16. Effect of Systematic Hydrogenation on the Phase Behavior and Nanostructural Dimensions of Block Copolymers.

    Science.gov (United States)

    Ashraf, Arman R; Ryan, Justin J; Satkowski, Michael M; Smith, Steven D; Spontak, Richard J

    2018-01-31

    Unsaturated polydienes are frequently hydrogenated to yield polyolefins that are more chemically stable. Here, the effects of partial hydrogenation on the phase behavior and nanostructure of polyisoprene-containing block copolymers are investigated. To ensure access to the order-disorder transition temperature (T ODT ) over a wide temperature range, we examine copolymers with at least one random block. Dynamic rheological and scattering measurements indicate that T ODT increases linearly with increasing hydrogenation. Small-angle scattering reveals that the temperature-dependence of the Flory-Huggins parameter changes and the microdomain period increases, while the interfacial thickness decreases. The influence of hydrogenation becomes less pronounced in more constrained multiblock copolymers.

  17. The performance of anti-cyclic citrullinated peptide assays in diagnosing rheumatoid arthritis: a systematic review and meta-analysis.

    Science.gov (United States)

    Mathsson Alm, Linda; Fountain, Donna L; Cadwell, Kevin K; Madrigal, Ana Maria; Gallo, Gaia; Poorafshar, Maryam

    2018-01-01

    We assessed the ability of anti-cyclic citrullinated peptide (CCP) tests to diagnose rheumatoid arthritis (RA), comparing the effect of manufacturer assay type, study design (single- and two-gated) and duration of disease (early vs. established). We searched seven databases for relevant diagnostic studies containing data on CCP tests in known or suspected RA patients. We used a bivariate model to produce summary estimates for test sensitivity, specificity, and positive and negative likelihood ratios. Summary Receiver Operating Characteristic (sROC) curves were derived to compare early versus established RA. 83 studies were identified and included. For individual manufacturer tests there was considerable variation in both pooled sensitivity (range 67-83%) and specificity (range 90-96%) estimates. This heterogeneity was also observed when grouping studies into two-gated and single-gated designs. Study design and disease duration impacted on sensitivity, with single-gated study designs and early RA patients resulting in lower estimates than two-gated and established disease, respectively. This review highlights the large number of CCP tests that are now commercially available and the considerable variation in their diagnostic performance. This variation, although partly influenced in this analysis by the study design (single-gated vs. two-gated), seems to have different levels of impact depending on the manufacturers. The Thermo Fisher Scientific EliA and Inova Diagnostics Quanta Lite (CCP2) tests showed the least between-study variation in sensitivity and specificity suggesting they have the most consistent diagnostic performance overall.

  18. Method and structure for skewed block-cyclic distribution of lower-dimensional data arrays in higher-dimensional processor grids

    Science.gov (United States)

    Chatterjee, Siddhartha [Yorktown Heights, NY; Gunnels, John A [Brewster, NY

    2011-11-08

    A method and structure of distributing elements of an array of data in a computer memory to a specific processor of a multi-dimensional mesh of parallel processors includes designating a distribution of elements of at least a portion of the array to be executed by specific processors in the multi-dimensional mesh of parallel processors. The pattern of the designating includes a cyclical repetitive pattern of the parallel processor mesh, as modified to have a skew in at least one dimension so that both a row of data in the array and a column of data in the array map to respective contiguous groupings of the processors such that a dimension of the contiguous groupings is greater than one.

  19. Continuous versus cyclic use of combined oral contraceptives for contraception: systematic Cochrane review of randomized controlled trials.

    Science.gov (United States)

    Edelman, A; Gallo, M F; Nichols, M D; Jensen, J T; Schulz, K F; Grimes, D A

    2006-03-01

    With the recent US Food and Drug Administration approval of a combination oral contraceptive that causes a withdrawal bleed every 3 months instead of monthly, avoidance of menstruation through extended or continuous administration (>28 days of active pills) of combined oral contraceptives may become more commonplace for reasons of personal preference rather than limited to treatment of menstrual-associated medical disorders. The review aimed to compare contraceptive efficacy, compliance, continuation, satisfaction, bleeding profiles, and menstrual symptoms of combined oral contraceptives with continuous dosing (>28 days of active pills) versus traditional cyclic dosing (21 days of active pills and 7 days of placebo). We searched five computerized databases as well as reference lists of relevant articles for randomized controlled trials (RCT) using continuous or extended combined oral contraceptives for contraception. Two reviewers independently extracted data from eligible articles. Six RCT met inclusion criteria and were of good quality. Contraceptive efficacy and compliance were similar between groups. Discontinuation overall, and for bleeding problems, was not uniformly higher in either group. When studied, participants reported high satisfaction with both dosing regimens. Five out of the six studies found that bleeding patterns were either equivalent or improved with continuous-dosing regimens. The continuous-dosing group had greater improvement of menstrual-associated symptoms (headaches, genital irritation, tiredness, bloating, and menstrual pain). The variations in pill type and time-interval for continuous dosing make direct comparisons between regimens unfeasible. To allow for comparisons, future studies should choose a previously researched pill and dosing regimen. More attention needs to be directed towards participant satisfaction and menstruation-associated symptoms.

  20. Cyclic Limulus anti-lipopolysaccharide (LPS) factor-derived peptide CLP-19 antagonizes LPS function by blocking binding to LPS binding protein.

    Science.gov (United States)

    Liu, Yao; Ni, Bing; Ren, Jian-dong; Chen, Jian-hong; Tian, Zhi-qiang; Tang, Min; Li, Di; Xia, Peiyuan

    2011-01-01

    Inflammation and septic shock due to endotoxins from Gram-negative bacteria infection continue to pose significant challenges to human healthcare. It is, therefore, necessary to develop therapeutic strategies targeting endotoxins, such as lipopolysaccharide (LPS), to prevent their potentially systemic effects. Pathogenesis due to Gram-negative bacteria involves LPS binding to the host LPS-binding protein (LBP), causing detrimental downstream signaling cascades. Our previous study showed that CLP-19, a synthetic peptide derived from the Limulus anti-LPS factor (LALF), could effectively neutralize LPS toxicity; however, the detailed mechanisms underlying this anti-LPS effect remained unexplained. Thus, we carried out investigations to determine how the CLP-19 neutralizes LPS toxicity. CLP-19 was found to block LPS binding to LBP in a dose-dependent manner, as evidenced by competitive enzyme-linked immunosorbent assay (ELISA). In peripheral blood mononuclear cells, CLP-19 blocked LPS-induced phosphorylation of mitogen activated protein kinase (MAPK) signaling proteins p38, extracellular signal-regulating kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK)1/2. Furthermore, CLP-19 potency in LPS antagonism in vitro and in vivo was directly associated with its ability to block the LPS-LBP interaction. Taken together, the results suggested that CLP-19's inhibitory effect on LPS-LBP binding and on the subsequent MAPK pathway signaling may be responsible for its anti-LPS mechanism. This peptide appears to represent a potential therapeutic agent for clinical treatment of sepsis.

  1. Systematic Identification of Cyclic-di-GMP Binding Proteins in Vibrio cholerae Reveals a Novel Class of Cyclic-di-GMP-Binding ATPases Associated with Type II Secretion Systems

    Science.gov (United States)

    Shang, Xiaoran; Orr, Mona W.; Goodson, Jonathan R.; Galperin, Michael Y.; Yildiz, Fitnat H.; Lee, Vincent T.

    2015-01-01

    Cyclic-di-GMP (c-di-GMP) is a ubiquitous bacterial signaling molecule that regulates a variety of complex processes through a diverse set of c-di-GMP receptor proteins. We have utilized a systematic approach to identify c-di-GMP receptors from the pathogen Vibrio cholerae using the Differential Radial Capillary Action of Ligand Assay (DRaCALA). The DRaCALA screen identified a majority of known c-di-GMP binding proteins in V. cholerae and revealed a novel c-di-GMP binding protein, MshE (VC0405), an ATPase associated with the mannose sensitive hemagglutinin (MSHA) type IV pilus. The known c-di-GMP binding proteins identified by DRaCALA include diguanylate cyclases, phosphodiesterases, PilZ domain proteins and transcription factors VpsT and VpsR, indicating that the DRaCALA-based screen of open reading frame libraries is a feasible approach to uncover novel receptors of small molecule ligands. Since MshE lacks the canonical c-di-GMP-binding motifs, a truncation analysis was utilized to locate the c-di-GMP binding activity to the N-terminal T2SSE_N domain. Alignment of MshE homologs revealed candidate conserved residues responsible for c-di-GMP binding. Site-directed mutagenesis of these candidate residues revealed that the Arg9 residue is required for c-di-GMP binding. The ability of c-di-GMP binding to MshE to regulate MSHA dependent processes was evaluated. The R9A allele, in contrast to the wild type MshE, was unable to complement the ΔmshE mutant for the production of extracellular MshA to the cell surface, reduction in flagella swimming motility, attachment to surfaces and formation of biofilms. Testing homologs of MshE for binding to c-di-GMP identified the type II secretion ATPase of Pseudomonas aeruginosa (PA14_29490) as a c-di-GMP receptor, indicating that type II secretion and type IV pili are both regulated by c-di-GMP. PMID:26506097

  2. Influence of the Twin Block propulsor appliance in the mandibular growth: systematic review of literature

    OpenAIRE

    Olibone, Vivian Lys L. [UNIFESP; Guimaraes, Antonio Sergio [UNIFESP; Atta, Joao Yates

    2006-01-01

    OBJETIVO: avaliar a eficácia do aparelho ortopédico propulsor mandibular Twin Block quanto ao crescimento mandibular. METODOLOGIA: revisão sistemática da literatura a partir de 1970. RESULTADOS E CONCLUSÕES: a maioria dos autores afirmou que houve uma diminuição significativa do ângulo SNA com retroinclinação dos incisivos superiores, o ângulo SNB sofreu aumento com vestibularização dos incisivos inferiores, houve uma resposta tissular positiva nas estruturas da ATM durante o uso do propulsor...

  3. The Effect of Femoral Nerve Block on Quadriceps Strength in Anterior Cruciate Ligament Reconstruction: A Systematic Review.

    Science.gov (United States)

    Swank, Katherine R; DiBartola, Alex C; Everhart, Joshua S; Kaeding, Christopher C; Magnussen, Robert A; Flanigan, David C

    2017-05-01

    To assess the isokinetic, functional, and patient-reported outcomes of femoral nerve block (FNB) compared with traditional multimodal anesthesia for FNB in anterior cruciate ligament (ACL) reconstruction. A systematic search of PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature, Cochrane Reviews, and Google Scholar was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Effects of FNB on quadriceps function were evaluated by isokinetic testing, functional scoring systems, range of motion, and patient self-report questionnaires. Heterogeneous reporting of outcomes precluded a formal meta-analysis. The methodologic merit of all studies included was evaluated by the Coleman Methodology Score. Six studies were identified with outcome measures reported between 7 days and 6 months postoperatively. At 6 months, 2 of 4 studies that reported isokinetic testing found significantly greater deficits among patients who received a nerve block; one of the remaining studies showed a deficit at 6 weeks but not 6 months. Limited data showed no significant differences in functional or patient-reported outcomes at 6 months after reconstruction, and data regarding the impact of FNB on return to sport were inconclusive. The mean Coleman Methodology Score for the included studies was 53, indicating poor overall methodologic quality of the available literature. The limited data available suggest that FNB causes a measurable deficit in quadriceps isokinetic strength during the early postoperative period but has no effect on functional outcomes or return to sport at 6 months after ACL reconstruction. However, current clinical evidence is not sufficient to draw any valid or definitive conclusions regarding the effect of FNB on postoperative outcomes after ACL reconstruction. Level IV, systemic review of Level I through IV studies. Copyright © 2017 Arthroscopy Association of North America. Published by

  4. Clinical safety and effectiveness of transversus abdominis plane (TAP) block in post-operative analgesia: a systematic review and meta-analysis.

    Science.gov (United States)

    Ma, Ning; Duncan, Joanna K; Scarfe, Anje J; Schuhmann, Susanne; Cameron, Alun L

    2017-06-01

    Transversus abdominis plane (TAP) blocks can provide analgesia postoperatively for a range of surgeries. Abundant clinical trials have assessed TAP block showing positive analgesic effects. This systematic review assesses safety and effectiveness outcomes of TAP block in all clinical settings, comparing with both active (standard care) and inactive (placebo) comparators. PubMed, EMBASE, The Cochrane Library and the University of York CRD databases were searched. RCTs were screened for their eligibility and assessed for risk of bias. Meta-analyses were performed on available data. TAP block showed an equivalent safety profile to all comparators in the incidence of nausea (OR = 1.07) and vomiting (OR = 0.81). TAP block was more effective in reducing morphine consumption [MD = 13.05, 95% CI (8.33, 51.23)] and in delaying time to first analgesic request [MD = 123.49, 95% CI (48.59, 198.39)]. Postoperative pain within 24 h was reduced or at least equivalent in TAP block compared to its comparators. Therefore, TAP block is a safe and effective procedure compared to standard care, placebo and other analgesic techniques. Further research is warranted to investigate whether the TAP block technique can be improved by optimizing dose and technique-related factors.

  5. Cyclic Vitalism

    DEFF Research Database (Denmark)

    Halse, Sven

    2014-01-01

    an enthusiastic worshipping of life, one that holds youth, health, strength and beauty as its primary attributes, and which was prevalent in all aspects of cultural life around 1900. But even the post war founders of the Vitalist re-conceptualisation of this era, Wolfdietrich Rasch and Gunter Martens, warned...... that also encompasses notions of destruction, decay and death. “All life symbols in literature around 1900 are at the same time symbols of death”. (Rasch, W. 1967:24) Through the analyses of three poems, this article aims to show concrete examples of how cyclic Vitalist thinking is embedded in poetry...

  6. Cyclic multiverses

    Science.gov (United States)

    Marosek, Konrad; Dąbrowski, Mariusz P.; Balcerzak, Adam

    2016-09-01

    Using the idea of regularization of singularities due to the variability of the fundamental constants in cosmology we study the cyclic universe models. We find two models of oscillating and non-singular mass density and pressure (`non-singular' bounce) regularized by varying gravitational constant G despite the scale factor evolution is oscillating and having sharp turning points (`singular' bounce). Both violating (big-bang) and non-violating (phantom) null energy condition models appear. Then, we extend this idea on to the multiverse containing cyclic individual universes with either growing or decreasing entropy though leaving the net entropy constant. In order to get an insight into the key idea, we consider the doubleverse with the same geometrical evolution of the two `parallel' universes with their physical evolution [physical coupling constants c(t) and G(t)] being different. An interesting point is that there is a possibility to exchange the universes at the point of maximum expansion - the fact which was already noticed in quantum cosmology. Similar scenario is also possible within the framework of Brans-Dicke theory where varying G(t) is replaced by the dynamical Brans-Dicke field φ(t) though these theories are slightly different.

  7. Deep neuromuscular block to optimize surgical space conditions during laparoscopic surgery: a systematic review and meta-analysis.

    Science.gov (United States)

    Bruintjes, M H; van Helden, E V; Braat, A E; Dahan, A; Scheffer, G J; van Laarhoven, C J; Warlé, M C

    2017-06-01

    Neuromuscular block (NMB) is frequently used in abdominal surgery to improve surgical conditions by relaxation of the abdominal wall and prevention of sudden muscle contractions. The evidence supporting routine use of deep NMB is still under debate. We aimed to provide evidence for the superiority of routine use of deep NMB during laparoscopic surgery. We performed a systematic review and meta-analysis of studies comparing the influence of deep vs moderate NMB during laparoscopic procedures on surgical space conditions and clinical outcomes. Trials were identified from Medline, Embase, and Central databases from inception to December 2016. We included randomized trials, crossover studies, and cohort studies. Our search yielded 12 studies on the effect of deep NMB on the surgical space conditions. Deep NMB during laparoscopic surgeries improves the surgical space conditions when compared with moderate NMB, with a mean difference of 0.65 (95% confidence interval (CI): 0.47-0.83) on a scale of 1-5, and it facilitates the use of low-pressure pneumoperitoneum. Furthermore, deep NMB reduces postoperative pain scores in the postanaesthesia care unit, with a mean difference of - 0.52 (95% CI: -0.71 to - 0.32). Deep NMB improves surgical space conditions during laparoscopic surgery and reduces postoperative pain scores in the postanaesthesia care unit. Whether this leads to fewer intraoperative complications, an improved quality of recovery, or both after laparoscopic surgery should be pursued in future studies. The review methodology was specified in advance and registered at Prospero on July 27, 2016, registration number CRD42016042144. © The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Effect of tramadol as an adjuvant to local anesthetics for brachial plexus block: A systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Hye Won Shin

    Full Text Available Tramadol, a 4-phenyl-piperidine analog of codeine, has a unique action in that it has a central opioidergic, noradrenergic, serotonergic analgesic, and peripheral local anesthetic (LA effect. Many studies have reported contradictory findings regarding the peripheral analgesic effect of tramadol as an adjuvant to LA in brachial plexus block (BPB. This meta-analysis aimed to evaluate the effects of tramadol as an adjunct to LA in BPB during shoulder or upper extremity surgery.We searched the PubMed, EMBASE, Cochrane, KoreaMed databases, and Google Scholar for eligible randomized controlled trials (RCTs that compared BPB with LA alone and BPB with LA and tramadol. Primary outcomes were the effects of tramadol as an adjuvant on duration of sensory block, motor block, and analgesia. Secondary outcomes were the effects of tramadol as an adjuvant on time to onset of sensory block and motor block and on adverse effects. We performed the meta-analysis using Review Manager 5.3 software.We identified 16 RCTs with 751 patients. BPB with tramadol prolonged the duration of sensory block (mean difference [MD], -61.5 min; 95% CI, -95.5 to -27.6; P = 0.0004, motor block (MD, -65.6 min; 95% CI, -101.5 to -29.7; P = 0.0003, and analgesia (MD, -125.5 min; 95% CI, -175.8 to -75.3; P < 0.0001 compared with BPB without tramadol. Tramadol also shortened the time to onset of sensory block (MD, 2.1 min; 95% CI, 1.1 to 3.1; P < 0.0001 and motor block (MD, 1.2 min; 95% CI, 0.2 to 2.1; P = 0.010. In subgroup analysis, the duration of sensory block, motor block, and analgesia was prolonged for BPB with tramadol 100 mg (P < 0.05 but not for BPB with tramadol 50 mg. The quality of evidence was high for duration of analgesia according to the GRADE system. Adverse effects were comparable between the studies.In upper extremity surgery performed under BPB, use of tramadol 100 mg as an adjuvant to LA appears to prolong the duration of sensory block, motor block, and analgesia, and

  9. Stability of 2 ',3 ' and 3 ',5 ' cyclic nucleotides in formamide and in water: a theoretical insight into the factors controlling the accumulation of nucleic acid building blocks in a prebiotic pool

    Czech Academy of Sciences Publication Activity Database

    Cassone, Giuseppe; Šponer, Jiří; Saija, F.; Di Mauro, E.; Saitta, A. M.; Šponer, Judit E.

    2017-01-01

    Roč. 19, č. 3 (2017), s. 1817-1825 ISSN 1463-9076 R&D Projects: GA ČR(CZ) GA14-12010S Institutional support: RVO:68081707 Keywords : density-functional theory * liquid formamide * 2,3-cyclic nucleotides * molecular- dynamics Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.123, year: 2016

  10. Cyclic Railway Timetable Optimization

    NARCIS (Netherlands)

    L.W.P. Peeters (Leon)

    2003-01-01

    textabstractCyclic Railway Timetable Optimization describes mathematical models and solution methods for constructing high quality cyclic railway timetables. In a cyclic timetable, a train for a certain destination leaves a certain station at the same time every cycle time, say every half an hour,

  11. Neuromuscular Blocking Agents and Neuromuscular Dysfunction Acquired in Critical Illness: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Price, David R; Mikkelsen, Mark E; Umscheid, Craig A; Armstrong, Ehrin J

    2016-11-01

    The relationship between neuromuscular blocking agents and neuromuscular dysfunction acquired in critical illness remains unclear. We examined the association between neuromuscular blocking agents and ICU-acquired weakness, critical illness polyneuropathy, and critical illness myopathy. PubMed, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, Cumulative Index of Nursing and Allied Health Literature, and bibliographies of included studies were searched from database inception until September 24, 2015. Randomized controlled trials and prospective observational studies examining the association between neuromuscular blocking agents and ICU-acquired weakness, critical illness polyneuropathy, or critical illness myopathy. One author screened titles/abstracts. Two authors independently reviewed full text and extracted data from included studies. Meta-analysis was performed using the DerSimonian-Laird random effects model (OpenMetaAnalyst 10.10 for OS.X). We assessed reporting bias with funnel plots and heterogeneity with the I statistic. Of 2,170 titles/abstracts screened, 99 full texts were selected for review, yielding one randomized controlled trial and 18 prospective observational studies, for a total of 2,254 patients. The randomized controlled trial did not show an association between neuromuscular blocking agents and neuromuscular dysfunction acquired in critical illness (odds ratio, 1.21; 95% CI, 0.67-2.19), but pooled data from all included studies suggested a modest association (odds ratio, 1.25; 95% CI, 1.06-1.48; I = 16%). Funnel plots suggested reporting bias, and sensitivity analyses showed a disproportionate contribution from critical illness polyneuropathy/critical illness myopathy and severe sepsis/septic shock studies. This meta-analysis suggests a modest association between neuromuscular blocking agents and neuromuscular dysfunction acquired in critical illness; limitations include studies with a high risk of bias and a

  12. Diagnostic utility of selective nerve root blocks in the diagnosis of lumbosacral radicular pain: systematic review and update of current evidence.

    Science.gov (United States)

    Datta, Sukdeb; Manchikanti, Laxmaiah; Falco, Frank J E; Calodney, Aaron K; Atluri, Sairam; Benyamin, Ramsin M; Buenaventura, Ricardo M; Cohen, Steven P

    2013-04-01

      Lumbosacral selective nerve root blocks and/ or transforaminal epidural injections are used for diagnosis and treatment of different disorders causing low back and lower extremity pain. A clear consensus on the use of selective nerve root injections as a diagnostic tool does not currently exist. Additionally, the validity of this procedure as a diagnostic tool is not clear. To evaluate and update the accuracy of selective nerve root injections in diagnosing lumbar spinal disorders. A systematic review of selective nerve root blocks for the diagnosis of low back and lower extremity pain. Methodological quality assessment of included studies was performed using the Quality Appraisal of Reliability Studies (QAREL) checklist. Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. Studies scoring less than 50% are presented descriptively and analyzed critically. The level of evidence was classified as good, fair, or limited or poor based on the quality of evidence grading scale developed by the United States Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to September 2012, and manual searches of the bibliographies of known primary and review articles. In this review, we evaluated studies in which controlled local anesthetic blocks were performed using at least 50% pain relief as the reference standard. There is limited evidence for the accuracy of selective nerve root injections as a diagnostic tool for lumbosacral disorders. There is limited evidence for their use in the preoperative evaluation of patients with negative or inconclusive imaging studies. The limitations of this systematic review include a paucity of literature, variations in technique, and variable criterion standards for the diagnosis of lumbar radicular pain. There is limited evidence for selective nerve root injections as a diagnostic tool in

  13. Influência do aparelho propulsor Twin Block no crescimento mandibular: revisão sistemática da literatura Influence of the Twin Block propulsor appliance in the mandibular growth: systematic review of literature

    Directory of Open Access Journals (Sweden)

    Vivian Lys L. Olibone

    2006-02-01

    Full Text Available OBJETIVO: avaliar a eficácia do aparelho ortopédico propulsor mandibular Twin Block quanto ao crescimento mandibular. METODOLOGIA: revisão sistemática da literatura a partir de 1970. RESULTADOS E CONCLUSÕES: a maioria dos autores afirmou que houve uma diminuição significativa do ângulo SNA com retroinclinação dos incisivos superiores, o ângulo SNB sofreu aumento com vestibularização dos incisivos inferiores, houve uma resposta tissular positiva nas estruturas da ATM durante o uso do propulsor. As alterações que ocorreram são uma combinação de modificações do côndilo, da fossa mandibular, do osso basal, além de alterações alvéolo-dentárias. Cada modificação estrutural dependeu de uma multiplicidade de fatores em cada indivíduo, como o padrão morfogenético, a idade, o gênero, o padrão funcional, o controle do aparelho e os hábitos orofaciais, entre outros.OBJECTIVE: to verify the efficiency of the mandibular propulsor orthopedic appliance Twin Block in the mandibular growth. METHODOLOGY: systematic review of literature since 1970. RESULTS AND CONCLUSIONS: the majority of the authors agreed with a significant reduction of the SNA angle with retroclination of the upper incisors, an increase of the SNB angle with proclination of the lower incisors and there was a positive tissue response on the TMJ during the use of the appliance. The alterations were the combination of modifications on the condyle, the mandibular fossa, the basal bone and dentoalveolar alterations. The exact role of the structures depend on a multiplicity of factors in each individual such as morphogenetic pattern, age, gender, functional pattern, control of the appliance and habits, among others.

  14. Identification of rheumatoid arthritis biomarkers based on single nucleotide polymorphisms and haplotype blocks: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Mohamed N. Saad

    2016-01-01

    Full Text Available Genetics of autoimmune diseases represent a growing domain with surpassing biomarker results with rapid progress. The exact cause of Rheumatoid Arthritis (RA is unknown, but it is thought to have both a genetic and an environmental bases. Genetic biomarkers are capable of changing the supervision of RA by allowing not only the detection of susceptible individuals, but also early diagnosis, evaluation of disease severity, selection of therapy, and monitoring of response to therapy. This review is concerned with not only the genetic biomarkers of RA but also the methods of identifying them. Many of the identified genetic biomarkers of RA were identified in populations of European and Asian ancestries. The study of additional human populations may yield novel results. Most of the researchers in the field of identifying RA biomarkers use single nucleotide polymorphism (SNP approaches to express the significance of their results. Although, haplotype block methods are expected to play a complementary role in the future of that field.

  15. Enstatite chondrites EL3 as building blocks for the Earth: The debate over the 146Sm-142Nd systematics

    Science.gov (United States)

    Boyet, M.; Bouvier, A.; Frossard, P.; Hammouda, T.; Garçon, M.; Gannoun, A.

    2018-04-01

    The 146Sm-142Nd extinct decay scheme (146Sm half-life of 103 My) is a powerful tool to trace early Earth silicate differentiation. Differences in 142Nd abundance measured between different chondrite meteorite groups and the modern Earth challenges the interpretation of the 142Nd isotopic variations found in terrestrial samples because the origin of the Earth and the nature of its building blocks is still an ongoing debate. As bulk meteorites, the enstatite chondrites (EC) have isotope signatures that are the closest to the Earth value with an average small deficit of ∼10 ppm in 142Nd relative to modern terrestrial samples. Here we review all the Nd isotope data measured on EC so far, and present the first measurements on an observed meteorite fall Almahata Sitta containing pristine fragments of an unmetamorphosed enstatite chondrite belonging to the EL3 subgroup. Once 142Nd/144Nd ratios are normalized to a common chondritic evolution, samples from the EC group (both EL and EH) have a deficit in 142Nd but the dispersion is important (μ142 Nd = - 10 ± 12 (2SD) ppm). This scatter reflects their unique mineralogy associated to their formation in reduced conditions (low fO2 or high C/O). Rare-earth elements are mainly carried by the sulfide phase oldhamite (CaS) that is more easily altered than silicates by weathering since most of the EC meteorites are desert finds. The EL6 have fractionated rare-earth element patterns with depletion in the most incompatible elements. Deviations in Nd mass independent stable isotope ratios in enstatite chondrites relative to terrestrial standard are not resolved with the level of analytical precision achieved by modern mass spectrometry techniques. Here we show that enstatite chondrites from the EL3 and EL6 subgroups may come from different parent bodies. Samples from the EL3 subgroup have Nd (μ142 Nd = - 0.8 ± 7.0, 2SD) and Ru isotope ratios undistinguishable from that of the Bulk Silicate Earth. EL3 samples have never been

  16. No Arithmetic Cyclic Quadrilaterals

    Science.gov (United States)

    Beauregard, Raymond A.

    2006-01-01

    A quadrilateral is arithmetic if its area is an integer and its sides are integers in an arithmetic progression, and it is cyclic if it can be inscribed in a circle. The author shows that no quadrilateral is both arithmetic and cyclic.

  17. Empirical approach based on centrifuge testing for cyclic deformations of laterally loaded piles in sand

    DEFF Research Database (Denmark)

    Truong, P.; Lehane, B. M.; Zania, Varvara

    2018-01-01

    A systematic study into the response of monopiles to lateral cyclic loading in medium dense and dense sand was performed in beam and drum centrifuge tests. The centrifuge tests were carried out at different cyclic load and magnitude ratios, while the cyclic load sequence was also varied...

  18. Real Topological Cyclic Homology

    DEFF Research Database (Denmark)

    Høgenhaven, Amalie

    The main topics of this thesis are real topological Hochschild homology and real topological cyclic homology. If a ring or a ring spectrum is equipped with an anti-involution, then it induces additional structure on the topological Hochschild homology spectrum. The group O(2) acts on the spectrum......, where O(2) is the semi-direct product of T, the multiplicative group of complex number of modulus 1, by the group G=Gal(C/R). We refer to this O(2)-spectrum as the real topological Hochschild homology. This generalization leads to a G-equivariant version of topological cyclic homology, which we call...... real topological cyclic homology. The first part of the thesis computes the G-equivariant homotopy type of the real topological cyclic homology of spherical group rings at a prime p with anti-involution induced by taking inverses in the group. The second part of the thesis investigates the derived G...

  19. Cyclical innovations and production

    OpenAIRE

    Greiner, Alfred

    1994-01-01

    Cyclical innovations and production : a formal model of the firm reflecting Schumpeterian ideas / Alfred Greiner and Horst Hanusch. - In: Innovation in technology, industries, and institutions / ed. by Yuichi Shionoya ... - Ann Arbor : Univ. of Michigan Press, 1994. - S. 157-169

  20. Cyclic nucleotides and radioresistnace

    International Nuclear Information System (INIS)

    Kulinskij, V.I.; Mikheeva, G.A.; Zel'manovich, B.M.

    1982-01-01

    The addition of glucose to meat-peptone broth does not change the radiosensitizing effect (RSE) of cAMP at the logarithmic phase (LP) and the radioprotective effect (RPE) at the stationary phase (SP), but sensitization, characteristic of cGMP, disappears in SP and turns into RPE in LP. Introduction of glucose into the broth for 20 min eliminates all the effects of both cyclic nucleotides in the cya + strain while cya - mutant exhibits RSE. RSE of both cyclic nucleotides is only manifested on minimal media. These data brought confirmation of the dependence of the influence of cyclic media. These data brought confirmation of the dependence of the influence of cyclic nucleotides on radioresistance upon the metabolic status of the cell [ru

  1. Experimental study on uniaxial cyclic ratcheting behavior of 304 stainless steel at room temperature

    International Nuclear Information System (INIS)

    Yang Xianjie; Gao Qing; Cai Lixun; Liu Yujie

    2004-01-01

    The cyclic tests for 304 stainless steel with solution heat treatment under uni-axial cyclic straining and stressing were carried out systematically. The effects of the cyclic engineering stress amplitude history with constant mean stress, the mean engineering stress history with constant cyclic stress amplitude and the stress amplitude histories with the specific mean stress increment per cycle on the uni-axial ratcheting deformation behavior were investigated. Some significant results are obtained

  2. Generalized Wideband Cyclic MUSIC

    Directory of Open Access Journals (Sweden)

    Zhang-Meng Liu

    2009-01-01

    Full Text Available The method of Spectral Correlation-Signal Subspace Fitting (SC-SSF fails to separate wideband cyclostationary signals with coherent second-order cyclic statistics (SOCS. Averaged Cyclic MUSIC (ACM method made up for the drawback to some degree via temporally averaging the cyclic cross-correlation of the array output. This paper interprets ACM from another perspective and proposes a new DOA estimation method by generalizing ACM for wideband cyclostationary signals. The proposed method successfully makes up for the aforementioned drawback of SC-SSF and obtains a more satisfying performance than ACM. It is also demonstrated that ACM is a simplified form of the proposed method when only a single spectral frequency is exploited, and the integration of the frequencies within the signal bandwidth helps the new method to outperform ACM.

  3. Predictability of blocking

    International Nuclear Information System (INIS)

    Tosi, E.; Ruti, P.; Tibaldi, S.; D'Andrea, F.

    1994-01-01

    Tibaldi and Molteni (1990, hereafter referred to as TM) had previously investigated operational blocking predictability by the ECMWF model and the possible relationships between model systematic error and blocking in the winter season of the Northern Hemisphere, using seven years of ECMWF operational archives of analyses and day 1 to 10 forecasts. They showed that fewer blocking episodes than in the real atmosphere were generally simulated by the model, and that this deficiency increased with increasing forecast time. As a consequence of this, a major contribution to the systematic error in the winter season was shown to derive from the inability of the model to properly forecast blocking. In this study, the analysis performed in TM for the first seven winter seasons of the ECMWF operational model is extended to the subsequent five winters, during which model development, reflecting both resolution increases and parametrisation modifications, continued unabated. In addition the objective blocking index developed by TM has been applied to the observed data to study the natural low frequency variability of blocking. The ability to simulate blocking of some climate models has also been tested

  4. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  5. Cyclic Voltammograms from First Principles

    DEFF Research Database (Denmark)

    Karlberg, Gustav; Jaramillo, Thomas; Skulason, Egill

    2007-01-01

    Cyclic voltammetry is a fundamental experimental tool for characterizing electrochemical surfaces. Whereas cyclic voltammetry is widely used within the field of electrochemistry, a way to quantitatively and directly relate the cyclic voltammogram to ab initio calculations has been lacking, even f...

  6. Inferior alveolar nerve block for the treatment of teeth presenting with irreversible pulpitis: A systematic review of the literature and meta-analysis.

    Science.gov (United States)

    Corbella, Stefano; Taschieri, Silvio; Mannocci, Francesco; Rosen, Eyal; Tsesis, Igor; Del Fabbro, Massimo

    2017-01-01

    The objective of the present systematic review was to evaluate, in patients with irreversible pulpitis affecting mandibular posterior teeth, if premedication with nonsteroidal anti-inflammatory drugs can increase the efficacy of inferior alveolar nerve block (IANB) if compared to placebo administration; if one anesthetic agent is more effective than another; if 1.8 mL injection is more effective than 3.6 mL injection to increase the efficacy of IANB; and if supplementary buccal injection is able to increase the efficacy of IANB as compared to a negative control/placebo group. Randomized controlled clinical trials investigating different aspects (technique, premedication with anti-inflammatory drugs, different anesthetic agents) were searched. Success of IANB, as defined in the studies, was considered as the primary outcome. A meta-analysis was performed evaluating relative risks (RRs). Electronic databases (Medline, Embase, Cochrane Central) were searched after preparation of an appropriate search string. After application of selection criteria, a total of 37 studies were included; 19 of them were considered in the meta-analysis. There was evidence of a difference in favor of the use of premedication with anti-inflammatory drugs (RR, 1.80; CI 95%, 1.50-2.14; P < .0001). There was no evidence of a difference between articaine and lidocaine (RR, 1.05; CI 95%, 0.91-1.21; P = .94). With regard to the volume of anesthetic infiltrated, the computed RR was 1.17 (CI, 0.73-1.88) without any significant difference between the use of one or two cartridges (P = .52). The estimated RR for a supplementary buccal infiltration was 1.56 (CI, 1.00-2.42; P = .05). The use of premedication with anti-inflammatory drugs before IANB can increase the efficacy of the IANB. The type of anesthetic agent, the volume of anesthetic, and the use of a supplemental buccal infiltration do not seem to affect the efficacy of anesthesia.

  7. Dynamics of cyclic machines

    CERN Document Server

    Vulfson, Iosif

    2015-01-01

    This book focuses on modern methods of oscillation analysis in machines, including cyclic action mechanisms (linkages, cams, steppers, etc.). It presents schematization techniques and mathematical descriptions of oscillating systems, taking into account the variability of the parameters and nonlinearities, engineering evaluations of dynamic errors, and oscillation suppression methods. The majority of the book is devoted to the development of new methods of dynamic analysis and synthesis for cyclic machines that form regular oscillatory systems with multiple duplicate modules.  There are also sections examining aspects of general engineering interest (nonlinear dissipative forces, systems with non-stationary constraints, impacts and pseudo-impacts in clearances, etc.)  The examples in the book are based on the widely used results of theoretical and experimental studies as well as engineering calculations carried out in relation to machines used in the textile, light, polygraphic and other industries. Particu...

  8. Synthesis of Chiral Cyclic Carbonates via Kinetic Resolution of Racemic Epoxides and Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Xiao Wu

    2016-01-01

    Full Text Available The catalytic synthesis of cyclic carbonates using carbon dioxide as a C1-building block is a highly active area of research. Here, we review the catalytic production of enantiomerically enriched cyclic carbonates via kinetic resolution of racemic epoxides catalysed by metal-containing catalyst systems.

  9. HOST liner cyclic facilities

    Science.gov (United States)

    Schultz, D.

    1983-01-01

    The HOST Liner Cyclic Program is utilizing two types of test apparatus, rectangular box rigs and a full annular rig. To date two quartz lamp cyclic box rigs have been tested and a third is to begin testing in late October 1983. The box rigs are used to evaluate 5x8 inch rectangular linear samples. A 21 inch diameter outer liner simulator is also being built up for testing beginning in April 1984. All rigs are atmospheric rigs. The first box rig, a three 6-kVA lamp installation, was operated under adverse conditions to determine feasibility of using quartz lamps for cyclic testing. This work was done in December 1981 and looked promising. The second box rig, again using three 6-kVA lamps, was operated to obtain instrumentation durability information and initial data input to a Finite Element Model. This limited test program was conducted in August 1983. Five test plates were run. Instrumentation consisted of strain gages, thermocouples and thermal paint. The strain gages were found to fail at 1200 F as expected though plates were heated to 1700 F. The third box rig, containing four 6-kVA lamps, is in build up for testing to begin in late October 1983. In addition to 33 percent greater power input, this rig has provision for 400 F backside line cooling air and a viewing port suitable for IR camera viewing. The casing is also water cooled for extended durability.

  10. Cyclic approximation to stasis

    Directory of Open Access Journals (Sweden)

    Stewart D. Johnson

    2009-06-01

    Full Text Available Neighborhoods of points in $mathbb{R}^n$ where a positive linear combination of $C^1$ vector fields sum to zero contain, generically, cyclic trajectories that switch between the vector fields. Such points are called stasis points, and the approximating switching cycle can be chosen so that the timing of the switches exactly matches the positive linear weighting. In the case of two vector fields, the stasis points form one-dimensional $C^1$ manifolds containing nearby families of two-cycles. The generic case of two flows in $mathbb{R}^3$ can be diffeomorphed to a standard form with cubic curves as trajectories.

  11. Accelerated cyclic corrosion tests

    Directory of Open Access Journals (Sweden)

    Prošek T.

    2016-06-01

    Full Text Available Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.

  12. Random matrix theory for pseudo-Hermitian systems: Cyclic blocks

    Indian Academy of Sciences (India)

    *Corresponding author. E-mail: ... 1.1 Quantum chaos. One of the first examples in the studies on 'quantum chaology and RMT' where. PT symmetry appeared was the time-independent Schrödinger equation for a point particle in a ..... taken the first step towards this by calculating the nearest-neighbour spacing dis- tribution ...

  13. Ekpyrotic and cyclic cosmology

    International Nuclear Information System (INIS)

    Lehners, Jean-Luc

    2008-01-01

    Ekpyrotic and cyclic cosmologies provide theories of the very early and of the very late universe. In these models, the big bang is described as a collision of branes - and thus the big bang is not the beginning of time. Before the big bang, there is an ekpyrotic phase with equation of state w=P/(ρ) >>1 (where P is the average pressure and ρ the average energy density) during which the universe slowly contracts. This phase resolves the standard cosmological puzzles and generates a nearly scale-invariant spectrum of cosmological perturbations containing a significant non-Gaussian component. At the same time it produces small-amplitude gravitational waves with a blue spectrum. The dark energy dominating the present-day cosmological evolution is reinterpreted as a small attractive force between our brane and a parallel one. This force eventually induces a new ekpyrotic phase and a new brane collision, leading to the idea of a cyclic universe. This review discusses the detailed properties of these models, their embedding in M-theory and their viability, with an emphasis on open issues and observational signatures

  14. Cyclic generalized projection MRI.

    Science.gov (United States)

    Sarty, Gordon E

    2015-04-01

    Progress in the development of portable MRI hinges on the ability to use lightweight magnets that have non-uniform magnetic fields. An image encoding method and mathematical procedure for recovering the image from the NMR signal from non-uniform magnets with closed isomagnetic contours is given. Individual frequencies in an NMR signal from an object in a non-uniform magnetic field give rise to integrals of the object along contours of constant magnetic field: generalized projections. With closed isomagnetic field contours a simple, cyclic, direct reconstruction of the image from the generalized projections is possible when the magnet and RF transmit coil are held fixed relative to the imaged object while the RF receive coil moves. Numerical simulations, using the Shepp and Logan mathematical phantom, were completed to show that the mathematical method works and to illustrate numerical limitations. The method is numerically verified and exact reconstruction demonstrated for discrete mathematical image phantoms. Correct knowledge of the RF receive field is necessary or severe image distortions will result. The cyclic mathematical reconstruction method presented here will be useful for portable MRI schemes that use non-uniform magnets with closed isomagnetic contours along with mechanically or electronically moving the RF receive coils. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Transversus abdominis-plane block versus local anesthetic wound infiltration in lower abdominal surgery: a systematic review and meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Yu, Nanze; Long, Xiao; Lujan-Hernandez, Jorge R; Succar, Julien; Xin, Xin; Wang, Xiaojun

    2014-01-01

    Postoperative pain management is of great importance in perioperative anesthetic care. Transversus abdominis plane (TAP) block has been described as an effective technique to reduce postoperative pain and morphine consumption after open lower abdominal operations. Meanwhile, local anesthetic infiltration (LAI) is also commonly used as a traditional method. However, the effectiveness of these two methods has not been compared before. A meta-analysis of all relevant randomized controlled trials (RCTs) was conducted to compare the efficacy of single shot TAP block with that of single shot LAI for postoperative analgesia in adults. Major medical databases and trial registries were searched for published and unpublished RCTs. The endpoints include postoperative visual analog scale (VAS) pain score, morphine requirement, and rate of postoperative nausea and vomiting (PONV). For continuous data, weighted mean differences (WMDs) were formulated; for dichotomous data, risk ratios (RR) were calculated. Results were derived using a random-/fixed-effects model with 95% confidence interval (CI). Four RCTs, encompassing 96 TAP-block and 100 LAI patients, were included in the final analysis. Patients in the TAP-block group had lower VAS pain scores 24 hours postoperatively compared with the LAI group, both at rest (WMD [95% CI] = -0.67 [p < 0.01] and with movement (WMD = -0.89, p < 0.01). There were no significant between-group differences in 24-hour postoperative morphine requirements, the rates if PONV or VAS pain scores at 2 and 4 h postoperatively. TAP block and LAI provide comparable short-term postoperative analgesia, but TAP block has better long-lasting effect.

  16. Systematic review of the use of the lymphocyte cytokinesis-block micronucleus assay to measure DNA damage induced by exposure to polycyclic aromatic hydrocarbons

    Czech Academy of Sciences Publication Activity Database

    Šrám, Radim; Švecová, Vlasta; Rössnerová, Andrea

    2016-01-01

    Roč. 770, oct - dec (2016), s. 162-169 ISSN 1383-5742 R&D Projects: GA ČR(CZ) GA13-13458S Institutional support: RVO:68378041 Keywords : cytokinesis blocked micronuclei * peripheral blood lymphocytes * polycyclic aromatic hydrocarbons Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 5.500, year: 2016

  17. The arabidopsis cyclic nucleotide interactome

    KAUST Repository

    Donaldson, Lara Elizabeth

    2016-05-11

    Background Cyclic nucleotides have been shown to play important signaling roles in many physiological processes in plants including photosynthesis and defence. Despite this, little is known about cyclic nucleotide-dependent signaling mechanisms in plants since the downstream target proteins remain unknown. This is largely due to the fact that bioinformatics searches fail to identify plant homologs of protein kinases and phosphodiesterases that are the main targets of cyclic nucleotides in animals. Methods An affinity purification technique was used to identify cyclic nucleotide binding proteins in Arabidopsis thaliana. The identified proteins were subjected to a computational analysis that included a sequence, transcriptional co-expression and functional annotation analysis in order to assess their potential role in plant cyclic nucleotide signaling. Results A total of twelve cyclic nucleotide binding proteins were identified experimentally including key enzymes in the Calvin cycle and photorespiration pathway. Importantly, eight of the twelve proteins were shown to contain putative cyclic nucleotide binding domains. Moreover, the identified proteins are post-translationally modified by nitric oxide, transcriptionally co-expressed and annotated to function in hydrogen peroxide signaling and the defence response. The activity of one of these proteins, GLYGOLATE OXIDASE 1, a photorespiratory enzyme that produces hydrogen peroxide in response to Pseudomonas, was shown to be repressed by a combination of cGMP and nitric oxide treatment. Conclusions We propose that the identified proteins function together as points of cross-talk between cyclic nucleotide, nitric oxide and reactive oxygen species signaling during the defence response.

  18. Cyclic transfers in school timetabling

    NARCIS (Netherlands)

    Post, Gerhard F.; Ahmadi, Samad; Geertsema, Frederik

    2012-01-01

    In this paper we propose a neighbourhood structure based on sequential/cyclic moves and a cyclic transfer algorithm for the high school timetabling problem. This method enables execution of complex moves for improving an existing solution, while dealing with the challenge of exploring the

  19. Cyclic transfers in school timetabling

    NARCIS (Netherlands)

    Post, Gerhard F.; Ahmadi, Samad; Geertsema, Frederik

    In this paper we propose a neighbourhood structure based on sequential/cyclic moves and a Cyclic Transfer algorithm for the high school timetabling problem. This method enables execution of complex moves for improving an existing solution, while dealing with the challenge of exploring the

  20. Manual for Cyclic Triaxial Test

    DEFF Research Database (Denmark)

    Shajarati, Amir; Sørensen, Kris Wessel; Nielsen, Søren Kjær

    This manual describes the different steps that is included in the procedure for conducting a cyclic triaxial test at the geotechnical Laboratory at Aalborg University. Furthermore it contains a chapter concerning some of the background theory for the static triaxial tests. The cyclic/dynamic tria......This manual describes the different steps that is included in the procedure for conducting a cyclic triaxial test at the geotechnical Laboratory at Aalborg University. Furthermore it contains a chapter concerning some of the background theory for the static triaxial tests. The cyclic....../dynamic triaxial cell is overall constructed in the same way as the static triaxial cell at Aalborg University, but with the ability to apply any kind of load sequence to the test sample. When conducting cyclic triaxial tests, it is recommended that the manual is followed very tediously since there are many steps...

  1. Ada and cyclic runtime scheduling

    Science.gov (United States)

    Hood, Philip E.

    1986-01-01

    An important issue that must be faced while introducing Ada into the real time world is efficient and prodictable runtime behavior. One of the most effective methods employed during the traditional design of a real time system is the cyclic executive. The role cyclic scheduling might play in an Ada application in terms of currently available implementations and in terms of implementations that might be developed especially to support real time system development is examined. The cyclic executive solves many of the problems faced by real time designers, resulting in a system for which it is relatively easy to achieve approporiate timing behavior. Unfortunately a cyclic executive carries with it a very high maintenance penalty over the lifetime of the software that is schedules. Additionally, these cyclic systems tend to be quite fragil when any aspect of the system changes. The findings are presented of an ongoing SofTech investigation into Ada methods for real time system development. The topics covered include a description of the costs involved in using cyclic schedulers, the sources of these costs, and measures for future systems to avoid these costs without giving up the runtime performance of a cyclic system.

  2. Block Tridiagonal Matrices in Electronic Structure Calculations

    DEFF Research Database (Denmark)

    Petersen, Dan Erik

    is developed and compared to standard Gaussian elimination, where it is shown to be qualitatively quicker for the task of determining the block tridiagonal portion of the Green’s function matrix. The Sweep algorithm is then parallelized via a straightforward approach in order to enable moderate speedup...... and memory distribution. The well known block cyclic reduction algorithm first developed by Gene Golub is then presented and analyzed for further expanding our parallel options, and finally a new hybrid method that combines block cyclic reduction and a form of Schur complement calculation is introduced....... The parallel algorithms are then benchmarked and the new hybrid method is shown to possess promising speedup characteristics for common cases of problems that need to be modeled....

  3. A random search algorithm for cyclic delivery synchronization problem

    Directory of Open Access Journals (Sweden)

    Katarzyna Gdowska

    2017-09-01

    Full Text Available Background: The paper is devoted to the cyclic delivery synchronization problem with vehicles serving fixed routes. Each vehicle is assigned to a fixed route: the series of supplier’s and logistic centers to be visited one after another. For each route the service frequency is fixed and known in advance. A vehicle loads at a supplier’s, then it delivers goods to a logistic center and either loads other goods there and delivers them to the next logistic center along the route or goes to another logistic center. Each logistic center can belong to several routes, so goods are delivered there with one vehicle and then they departure for the further journey with another truck. The objective of this cyclic delivery synchronization problem is to maximize the total number of synchronizations of vehicles arrivals in logistic centers and their load times, so that it is possible to organize their arrivals in repeatable blocks. Methods: Basing on the previously developed mathematical model for the cyclic delivery synchronization problem we built a random search algorithm for cyclic delivery synchronization problem. The random heuristic search utilizes objective-oriented randomizing. In the paper the newly-developed random search algorithm for cyclic delivery synchronization problem is presented. Results: A computational experiment consisted of employing the newly-developed random search algorithm for solving a series of cyclic delivery synchronization problems. Results obtained with the algorithm were compared with solutions computed with the exact method. Conclusions: The newly-developed random search algorithm for cyclic delivery synchronization problem gives results which are considerably close to the ones obtained with mixed-integer programming. The main advantage of the algorithm is reduction of computing time; it is relevant for utilization of this method in practice, especially for large-sized problems.

  4. Prognosis of Cyclic Vomiting Syndrome

    Directory of Open Access Journals (Sweden)

    J. Gordon Millichap

    2016-03-01

    Full Text Available Investigators from Teikyo University School of Medicine, Tokyo, Japan, evaluated the clinical features, prognosis, and prophylaxis of cyclic vomiting syndrome and the relationship between the syndrome and levels of adrenocorticotropic/antidiuretic hormones (ACTH/ADH.

  5. Transcriptional regulation by cyclic AMP.

    Science.gov (United States)

    Montminy, M

    1997-01-01

    A number of hormones and growth factors have been shown to stimulate target cells via second messenger pathways that in turn regulate the phosphorylation of specific nuclear factors. The second messenger cyclic AMP, for example, regulates a striking number of physiologic processes, including intermediary metabolism, cellular proliferation, and neuronal signaling, by altering basic patterns of gene expression. Our understanding of cyclic AMP signaling in the nucleus has expanded considerably over the past decade, owing in large part to the characterization of cyclic AMP-responsive promoter elements, transcription factors that bind them, and signal-dependent coactivators that mediate target gene induction. More importantly, these studies have revealed new insights into biological problems as diverse as biological clocks and long-term memory. The purpose of this review is to describe the components of the cyclic AMP response unit and to analyze how these components cooperate to induce target gene expression in response to hormonal stimulation.

  6. Functionalized linear and cyclic polyolefins

    Science.gov (United States)

    Tuba, Robert; Grubbs, Robert H.

    2018-02-13

    This invention relates to methods and compositions for preparing linear and cyclic polyolefins. More particularly, the invention relates to methods and compositions for preparing functionalized linear and cyclic polyolefins via olefin metathesis reactions. Polymer products produced via the olefin metathesis reactions of the invention may be utilized for a wide range of materials applications. The invention has utility in the fields of polymer and materials chemistry and manufacture.

  7. Systematic review and meta-analysis of the efficacy and safety of existing TNF blocking agents in treatment of rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    Kalle J Aaltonen

    Full Text Available Five-tumour necrosis factor (TNF-blockers (infliximab, etanercept, adalimumab, certolizumab pegol and golimumab are available for treatment of rheumatoid arthritis. Only few clinical trials compare one TNF-blocker to another. Hence, a systematic review is required to indirectly compare the substances. The aim of our study is to estimate the efficacy and the safety of TNF-blockers in the treatment of rheumatoid arthritis (RA and indirectly compare all five currently available blockers by combining the results from included randomized clinical trials (RCT.A systematic literature review was conducted using databases including: MEDLINE, SCOPUS (including EMBASE, Cochrane library and electronic search alerts. Only articles reporting double-blind RCTs of TNF-blockers vs. placebo, with or without concomitant methotrexate (MTX, in treatment of RA were selected. Data collected were information of patients, interventions, controls, outcomes, study methods and eventual sources of bias.Forty-one articles reporting on 26 RCTs were included in the systematic review and meta-analysis. Five RCTs studied infliximab, seven etanercept, eight adalimumab, three golimumab and three certolizumab. TNF-blockers were more efficacious than placebo at all time points but were comparable to MTX. TNF-blocker and MTX combination was superior to either MTX or TNF-blocker alone. Increasing doses did not improve the efficacy. TNF-blockers were relatively safe compared to either MTX or placebo.No single substance clearly rose above others in efficacy, but the results of the safety analyses suggest that etanercept might be the safest alternative. Interestingly, MTX performs nearly identically considering both efficacy and safety aspects with a margin of costs.

  8. Defense gene induction in tobacco by nitric oxide, cyclic GMP, and cyclic ADP-ribose.

    Science.gov (United States)

    Durner, J; Wendehenne, D; Klessig, D F

    1998-08-18

    Reactive oxygen species are believed to perform multiple roles during plant defense responses to microbial attack, acting in the initial defense and possibly as cellular signaling molecules. In animals, nitric oxide (NO) is an important redox-active signaling molecule. Here we show that infection of resistant, but not susceptible, tobacco with tobacco mosaic virus resulted in enhanced NO synthase (NOS) activity. Furthermore, administration of NO donors or recombinant mammalian NOS to tobacco plants or tobacco suspension cells triggered expression of the defense-related genes encoding pathogenesis-related 1 protein and phenylalanine ammonia lyase (PAL). These genes were also induced by cyclic GMP (cGMP) and cyclic ADP-ribose, two molecules that can serve as second messengers for NO signaling in mammals. Consistent with cGMP acting as a second messenger in tobacco, NO treatment induced dramatic and transient increases in endogenous cGMP levels. Furthermore, NO-induced activation of PAL was blocked by 6-anilino-5,8-quinolinedione and 1H-(1,2,4)-oxadiazole[4,3-a]quinoxalin-1-one, two inhibitors of guanylate cyclase. Although 6-anilino-5,8-quinolinedione fully blocked PAL activation, inhibition by 1H-(1,2,4)-oxadiazole[4, 3-a]quinoxalin-1-one was not entirely complete, suggesting the existence of cGMP-independent, as well as cGMP-dependent, NO signaling. We conclude that several critical players of animal NO signaling are also operative in plants.

  9. Liposomal bupivacaine infiltration versus femoral nerve block for pain control in total knee arthroplasty: A systematic review and meta-analysis.

    Science.gov (United States)

    Ma, Jianbing; Zhang, Weijie; Yao, Shuxin

    2016-12-01

    Total knee arthroplasty (TKA) usually results in postoperative pain. The objective of this meta-analysis was to compare the effectiveness and safety of liposomal bupivacaine (LB) infiltration and femoral nerve block (FNB) for pain control in total knee arthroplasty. We systemically searched electronic databases, including Embase (1980-2016.7), MEDLINE (1966-2016.7), PubMed (1966-2016.7), ScienceDirect (1985-2016.7), Web of Science (1950-2016.7) and Cochrane Library for potentially relevant articles. All calculations were conducted using Stata 11.0. One randomized controlled trials (RCTs) and five non-RCTs involving 1289 participants met the inclusion criteria. The result of the meta-analysis revealed that there were no significant differences in terms of postoperative pain scores at POD 0 (SMD = -0.047, 95% CI: -0.276 to 0.182, P = 0.688), POD1 (SMD = -0.038, 95% CI: -0.273 to 0.197, P = 0.749) or POD 2 (SMD = -0.043, 95% CI: -0.192 to 0.107, P = 0.575). Significant differences were found between groups in morphine equivalent consumption at POD 1 (SMD = 0.625, 95% CI: 0.068 to 1.183, P = 0.028) and POD 2 (SMD = 0.410, 95% CI: 0.024 to 0.796, P = 0.037) between groups. There were no significant differences regarding the incidence of adverse effects such as nausea (RD = -0.01, 95% CI: -0.04 to -0.075, P = 0.914) or vomiting (RD = 0.006, 95% CI: -0.049 to 0.062, P = 0.821). Liposomal bupivacaine infiltration provides similar postoperative pain relief to femoral nerve block following total knee arthroplasty. In addition, liposomal bupivacaine infiltration could significantly reduce the consumption of morphine equivalents compared to femoral nerve block without an increased risk of adverse events. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  10. Catalytic enantioselective vinylogous Mukaiyama-Michael addition of 2-silyloxyfurans to cyclic unsaturated oxo esters.

    Science.gov (United States)

    Jusseau, Xavier; Retailleau, Pascal; Chabaud, Laurent; Guillou, Catherine

    2013-03-15

    The copper-catalyzed asymmetric addition of 2-silyloxyfurans to cyclic unsaturated oxo esters is reported. The reaction proceeds with excellent diastereocontrol (usually dr 99:1) and modest to high enantioselectivity, depending on the nature of the ester group and the substitution of the cyclic oxo ester. We have shown that these substrates can be transformed into a variety of building blocks bearing a γ-butenolide or γ-lactone connected to a cycloalkane or cycoalkene moiety.

  11. The prognostic value of a new left bundle branch block in patients with acute myocardial infarction: A systematic review and meta-analysis.

    Science.gov (United States)

    Al Rajoub, Belal; Noureddine, Samar; El Chami, Samer; Haidar, Mohamad Hussein; Itani, Bachir; Zaiter, Aida; Akl, Elie A

    To assess the prognostic value of new left bundle branch block (LBBB) in patients with acute myocardial infarction (AMI). LBBB develops in many cardiac conditions, including AMI. The empirical evidence for the contribution of LBBB to mortality in AMI is not consistent. Medline, PubMed, CINAHL, and EMBASE were searched. Inverse variance meta-analysis was performed with odds ratios as the effect estimates. The I 2 statistic and risk of bias were assessed. Eight studies involving 105,861 participants were eligible. New LBBB was associated with higher mortality at 30 days (OR: 2.10, 95% CI 1.27 to 3.48) and 1-year follow up (OR: 2.81, 95% CI 1.64 to 4.80), and increased heart failure risk (OR: 2.64, 95% CI 1.84 to 3.77). AMI patients with new LBBB are a high risk group and must be treated accordingly. Yet, more research is needed given the limitations of studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Nature of solar cyclicity. I

    Energy Technology Data Exchange (ETDEWEB)

    Romanchuk, P.R.

    1981-01-01

    The report contains a critical survey of work devoted to the study of the nature of solar cyclicity. The inconsistency of the representation of cyclic curves using a frequency spectrum is indicated. The useful contribution of the ideas of Wolf, Newcomb, and Waldmeier to the solution of the problem is noted. Data are cited in favor of the theory of the tidal nature of solar cyclicity developed by the author, which also takes into account the ideas of the above-mentioned authors: the continuous paired and single tidal actions of the planets and the resonance character of this action, thanks to which the approximately 10-year period of action of Jupiter and Saturn is transformed into the 11-year activity cycle.

  13. On Improvements of Cyclic MUSIC

    Directory of Open Access Journals (Sweden)

    H. Howard Fan

    2005-01-01

    Full Text Available Many man-made signals encountered in communications exhibit cyclostationarity. By exploiting cyclostationarity, cyclic MUSIC has been shown to be able to separate signals with different cycle frequencies, thus, to be able to perform signal selective direction of-arrival (DOA estimation. However, as will be shown in this paper, the DOA estimation of cyclic MUSIC is actually biased. We show in this paper that by properly choosing the frequency for evaluating the steering vector, the bias of DOA estimation can be substantially reduced and the performance can be improved. Furthermore, we propose another algorithm exploiting cyclic conjugate correlation to further improve the performance of DOA estimation. Simulation results show the effectiveness of both of our methods.

  14. Benchmarking Block Ciphers for Wireless Sensor Networks

    NARCIS (Netherlands)

    Law, Y.W.; Doumen, J.M.; Hartel, Pieter H.

    2004-01-01

    Choosing the most storage- and energy-efficient block cipher specifically for wireless sensor networks (WSNs) is not as straightforward as it seems. To our knowledge so far, there is no systematic evaluation framework for the purpose. We have identified the candidates of block ciphers suitable for

  15. Design of a cyclic multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Piao Yunsong, E-mail: yspiao@gucas.ac.c [College of Physical Sciences, Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)

    2010-08-09

    Recently, it has been noticed that the amplification of the amplitude of curvature perturbation cycle by cycle can lead to a cyclic multiverse scenario, in which the number of universes increases cycle by cycle. However, this amplification will also inevitably induce either the ultimate end of corresponding cycle, or the resulting spectrum of perturbations inside corresponding universe is not scale invariant, which baffles the existence of observable universes. In this Letter, we propose a design of a cyclic multiverse, in which the observable universe can emerges naturally. The significance of a long period of dark energy before the turnaround of each cycle for this implementing is shown.

  16. The effect of blue-light blocking spectacle lenses on visual performance, macular health and the sleep-wake cycle: a systematic review of the literature.

    Science.gov (United States)

    Lawrenson, John G; Hull, Christopher C; Downie, Laura E

    2017-11-01

    Blue-blocking (BB) spectacle lenses, which attenuate short-wavelength light, are being marketed to alleviate eyestrain and discomfort when using digital devices, improve sleep quality and potentially confer protection from retinal phototoxicity. The aim of this review was to investigate the relative benefits and potential harms of these lenses. We included randomised controlled trials (RCTs), recruiting adults from the general population, which investigated the effect of BB spectacle lenses on visual performance, symptoms of eyestrain or eye fatigue, changes to macular integrity and subjective sleep quality. We searched MEDLINE, EMBASE, the Cochrane Library and clinical trial registers, until 30 April 2017. Risk of bias was assessed using the Cochrane tool. Three studies (with 136 participants) met our inclusion criteria; these had limitations in study design and/or implementation. One study compared the effect of BB lenses with clear lenses on contrast sensitivity (CS) and colour vision (CV) using a pseudo-RCT crossover design; there was no observed difference between lens types (log CS; Mean Difference (MD) = -0.01 [-0.03, 0.01], CV total error score on 100-hue; MD = 1.30 [-7.84, 10.44]). Another study measured critical fusion frequency (CFF), as a proxy for eye fatigue, on wearers of low and high BB lenses, pre- and post- a two-hour computer task. There was no observed difference between low BB and standard lens groups, but there was a less negative change in CFF between the high and low BB groups (MD = 1.81 [0.57, 3.05]). Both studies compared eyestrain symptoms with Likert scales. There was no evidence of inter-group differences for either low BB (MD = 0.00 [-0.22, 0.22]) or high BB lenses (MD = -0.05 [-0.31, 0.21]), nor evidence of a difference in the proportion of participants showing an improvement in symptoms of eyestrain or eye fatigue. One study reported a small improvement in sleep quality in people with self-reported insomnia after wearing

  17. Cyclic Processing for Context Fusion

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun

    2007-01-01

    Many machine-learning techniques use feedback information. However, current context fusion systems do not support this because they constrain processing to be structured as acyclic processing. This paper proposes a generalization which enables the use of cyclic processing in context fusion systems...

  18. Cyclic codes of length 2

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    [X]/〈X2m. − 1〉 are given. Cyclic codes of length 2m over the finite field Fq, of odd characteristic, are defined in terms of their generator polynomials. The exact minimum distance and the dimension of the codes are obtained. Keywords.

  19. Color visualization of cyclic magnitudes

    Science.gov (United States)

    Restrepo, Alfredo; Estupiñán, Viviana

    2014-02-01

    We exploit the perceptual, circular ordering of the hues in a technique for the visualization of cyclic variables. The hue is thus meaningfully used for the indication of variables such as the azimuth and the units of the measurement of time. The cyclic (or circular) variables may be both of the continuous type or the discrete type; among the first there is azimuth and among the last you find the musical notes and the days of the week. A correspondence between the values of a cyclic variable and the chromatic hues, where the natural circular ordering of the variable is respected, is called a color code for the variable. We base such a choice of hues on an assignment of of the unique hues red, yellow, green and blue, or one of the 8 even permutations of this ordered list, to 4 cardinal values of the cyclic variable, suitably ordered; color codes based on only 3 cardinal points are also possible. Color codes, being intuitive, are easy to remember. A possible low accuracy when reading instruments that use this technique is compensated by fast, ludic and intuitive readings; also, the use of a referential frame makes readings precise. An achromatic version of the technique, that can be used by dichromatic people, is proposed.

  20. Cyclic theory of Lie algebroids

    NARCIS (Netherlands)

    Blom, A.

    2017-01-01

    In this thesis we study the cyclic theory of universal enveloping algebras of Lie algebroids. Lie algebroids are geometrical objects that encode infinitesimal symmetries, and the concept encompasses many classical objects from geometry, such as Poisson manifolds, foliations and actions of Lie

  1. Cyclic peptide therapeutics: past, present and future.

    Science.gov (United States)

    Zorzi, Alessandro; Deyle, Kaycie; Heinis, Christian

    2017-06-01

    Cyclic peptides combine several favorable properties such as good binding affinity, target selectivity and low toxicity that make them an attractive modality for the development of therapeutics. Over 40 cyclic peptide drugs are currently in clinical use and around one new cyclic peptide drug enters the market every year on average. The vast majority of clinically approved cyclic peptides are derived from natural products, such as antimicrobials or human peptide hormones. New powerful techniques based on rational design and in vitro evolution have enabled the de novo development of cyclic peptide ligands to targets for which nature does not offer solutions. A look at the cyclic peptides currently under clinical evaluation shows that several have been developed using such techniques. This new source for cyclic peptide ligands introduces a freshness to the field, and it is likely that de novo developed cyclic peptides will be in clinical use in the near future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Deformation mechanisms in cyclic creep and fatigue

    International Nuclear Information System (INIS)

    Laird, C.

    1979-01-01

    Service conditions in which static and cyclic loading occur in conjunction are numerous. It is argued that an understanding of cyclic creep and cyclic deformation are necessary both for design and for understanding creep-fatigue fracture. Accordingly a brief, and selective, review of cyclic creep and cyclic deformation at both low and high strain amplitudes is provided. Cyclic loading in conjunction with static loading can lead to creep retardation if cyclic hardening occurs, or creep acceleration if softening occurs. Low strain amplitude cyclic deformation is understood in terms of dislocation loop patch and persistent slip band behavior, high strain deformation in terms of dislocation cell-shuttling models. While interesting advances in these fields have been made in the last few years, the deformation mechanisms are generally poorly understood

  3. Experimental and theoretical investigations into the stability of cyclic aminals

    Directory of Open Access Journals (Sweden)

    Edgar Sawatzky

    2016-10-01

    Full Text Available Background: Cyclic aminals are core features of natural products, drug molecules and important synthetic intermediates. Despite their relevance, systematic investigations into their stability towards hydrolysis depending on the pH value are lacking.Results: A set of cyclic aminals was synthesized and their stability quantified by kinetic measurements. Steric and electronic effects were investigated by choosing appropriate groups. Both molecular mechanics (MM and density functional theory (DFT based studies were applied to support and explain the results obtained. Rapid decomposition is observed in acidic aqueous media for all cyclic aminals which occurs as a reversible reaction. Electronic effects do not seem relevant with regard to stability, but the magnitude of the conformational energy of the ring system and pKa values of the N-3 nitrogen atom.Conclusion: Cyclic aminals are stable compounds when not exposed to acidic media and their stability is mainly dependent on the conformational energy of the ring system. Therefore, for the preparation and work-up of these valuable synthetic intermediates and natural products, appropriate conditions have to be chosen and for application as drug molecules their sensitivity towards hydrolysis has to be taken into account.

  4. Monopod bucket foundations under cyclic lateral loading

    DEFF Research Database (Denmark)

    Foglia, Aligi; Ibsen, Lars Bo

    on bucket foundations under lateral cyclic loading. The test setup is described in detail and a comprehensive experimental campaign is presented. The foundation is subjected to cyclic overturning moment, cyclic horizontal loading and constant vertical loading, acting on the same plane for thousands...

  5. Cyclic homology and group actions

    Science.gov (United States)

    Ponge, Raphaël

    2018-01-01

    In this paper we present the construction of explicit quasi-isomorphisms that compute the cyclic homology and periodic cyclic homology of crossed-product algebras associated with (discrete) group actions. In the first part we deal with algebraic crossed-products associated with group actions on unital algebras over any ring k ⊃ Q. In the second part, we extend the results to actions on locally convex algebras. We then deal with crossed-products associated with group actions on manifolds and smooth varieties. For the finite order components, the results are expressed in terms of what we call "mixed equivariant cohomology". This "mixed" theory mediates between group homology and de Rham cohomology. It is naturally related to equivariant cohomology, and so we obtain explicit constructions of cyclic cycles out of equivariant characteristic classes. For the infinite order components, we simplify and correct the misidentification of Crainic (1999). An important new homological tool is the notion of "triangular S-module". This is a natural generalization of the cylindrical complexes of Getzler-Jones. It combines the mixed complexes of Burghelea-Kassel and parachain complexes of Getzler-Jones with the S-modules of Kassel-Jones. There are spectral sequences naturally associated with triangular S-modules. In particular, this allows us to recover spectral sequences of Feigin-Tsygan and Getzler-Jones and leads us to a new spectral sequence.

  6. Ring-opening of cyclic ethers with carbon–carbon bond formation by Grignard reagents

    DEFF Research Database (Denmark)

    Christensen, Stig Holden; Holm, Torkil; Madsen, Robert

    2014-01-01

    The ring-opening of cyclic ethers with concomitant C–C bond formation was studied with a number of Grignard reagents. The transformation was performed in a sealed vial by heating to ∼160 °C in an aluminum block or at 180 °C in a microwave oven. Good yields of the product alcohols were obtained...

  7. Efficient synthesis of fluorophosphonylated alkyles by ring-opening reaction of cyclic sulfates.

    Science.gov (United States)

    Diab, Sonia Amel; Sene, Aboubacary; Pfund, Emmanuel; Lequeux, Thierry

    2008-09-04

    Ring-opening reactions of functionalized 1,2-cyclic sulfates and oxetanes with the phosphonodifluoromethyl carbanion are reported. This approach allows an easy access to fluorinated beta-hydroxyphosphonates that are building blocks in the synthesis of acyclic nucleosides. Synthesis of precursors of nucleoside phosphorylase inhibitors from these alcohols is described.

  8. Efficient block-based frequency domain wavelet transform implementations.

    Science.gov (United States)

    Lin, Jianyu; Smith, Mark J T

    2009-08-01

    Subband decompositions for image coding have been explored extensively over the last few decades. The condensed wavelet packet (CWP) transform is one such decomposition that was recently shown to have coding performance advantages over conventional decompositions. A special feature of the CWP is that its design and implementation are performed in the cyclic frequency domain. While performance gains have been reported, efficient implementations of the CWP (or more generally, efficient implementations of cyclic filter banks) have not yet been fully explored. In this paper, we present efficient block-based implementations of cyclic filter banks along with an analysis of the arithmetic complexity. Block-based cyclic filter bank implementations of the CWP coder are compared with conventional subband/wavelet image coders whose filter banks are implemented in the time domain. It is shown that block-based cyclic filter bank implementations can result in CWP coding systems that outperform the popular image coding systems both in terms of arithmetic complexity and coding performance.

  9. Functional Block Copolymers as Compatibilizers for Nanoclays in Polypropylene Nanocomposites

    DEFF Research Database (Denmark)

    Jankova Atanasova, Katja; Daugaard, Anders Egede; Stribeck, Norbert

    2011-01-01

    With the aim of creating tough nanocomposits (NC) [1] based on polypropylene (PP) and nanoclay (NCl) in the framework of the 7th EU program NANOTOUGH we have designed amphiphilic block copolymers utilizing Atom Transfer Radical Polymerization (ATRP) [2]. They consist of a hydrophobic block...... crystallites) is replaced by alien-reinforcement (of the MMT). Furthermore, the results from the impact strength and cyclic test of the prepared PP nanocomposites [3] are promicing....

  10. Cyclic density functional theory: A route to the first principles simulation of bending in nanostructures

    Science.gov (United States)

    Banerjee, Amartya S.; Suryanarayana, Phanish

    2016-11-01

    We formulate and implement Cyclic Density Functional Theory (Cyclic DFT) - a self-consistent first principles simulation method for nanostructures with cyclic symmetries. Using arguments based on Group Representation Theory, we rigorously demonstrate that the Kohn-Sham eigenvalue problem for such systems can be reduced to a fundamental domain (or cyclic unit cell) augmented with cyclic-Bloch boundary conditions. Analogously, the equations of electrostatics appearing in Kohn-Sham theory can be reduced to the fundamental domain augmented with cyclic boundary conditions. By making use of this symmetry cell reduction, we show that the electronic ground-state energy and the Hellmann-Feynman forces on the atoms can be calculated using quantities defined over the fundamental domain. We develop a symmetry-adapted finite-difference discretization scheme to obtain a fully functional numerical realization of the proposed approach. We verify that our formulation and implementation of Cyclic DFT is both accurate and efficient through selected examples. The connection of cyclic symmetries with uniform bending deformations provides an elegant route to the ab-initio study of bending in nanostructures using Cyclic DFT. As a demonstration of this capability, we simulate the uniform bending of a silicene nanoribbon and obtain its energy-curvature relationship from first principles. A self-consistent ab-initio simulation of this nature is unprecedented and well outside the scope of any other systematic first principles method in existence. Our simulations reveal that the bending stiffness of the silicene nanoribbon is intermediate between that of graphene and molybdenum disulphide - a trend which can be ascribed to the variation in effective thickness of these materials. We describe several future avenues and applications of Cyclic DFT, including its extension to the study of non-uniform bending deformations and its possible use in the study of the nanoscale flexoelectric effect.

  11. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  12. Cyclic voltammetry of dental amalgams.

    Science.gov (United States)

    Horasawa, N; Nakajima, H; Ferracane, J L; Takahashi, S; Okabe, T

    1996-05-01

    This study used cyclic voltammetry to examine the effect of the composition of dental amalgams on their electrochemical behavior, including reactions occurring outside of oral conditions. Amalgams (residual mercury 47.5%) were prepared using two low-copper (3 wt% Cu) powders and five high-copper powders (40-80 wt% Ag, 12-30 wt% Cu) with and without zinc (1.5 wt%). Cyclic voltammograms were obtained at 37 degrees C in 1.0% NaCl scanning at 2 mV/s in the potential range from -1.5 V to +0.8 V vs. Ag/AgCl. During the anodic scans, AgCl and Hg2Cl2 films were formed on all amalgams except the one with only 40 wt% Ag. In all high-copper amalgams, a prominent Cu (oxidation) peak was found at -0.1 V, indicating the release of copper during corrosion. Zinc affected the oxidation process for both low- and high-copper amalgams. When zinc was absent, a peak for Sn2+ oxidation appeared at -0.4 V. When zinc was present, a Sn4+ oxidation peak was revealed at -0.6 V. In some amalgams, there was evidence of the selective corrosion (pitting corrosion) of tin and copper. In the lowest silver-content amalgam, no protective films were formed, which is indicative of its poor corrosion resistance. As expected, in all the low-copper amalgams, an extreme increase in current density was recorded immediately at 0 V, due to the release of tin from gamma 2. Cyclic voltammetry is useful for the rapid examination (less than an hour) of the electrochemical behavior of amalgams, specifically to obtain information on the formation of compounds and the sequences of electrochemical reactions.

  13. Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

    Directory of Open Access Journals (Sweden)

    Huixin Jiang

    2015-06-01

    Full Text Available A selection of cyclic and acyclic acetylenic scaffolds bearing two tetrathiafulvalene (TTF units was prepared by different metal-catalyzed coupling reactions. The bridge separating the two TTF units was systematically changed from linearly conjugated ethyne, butadiyne and tetraethynylethene (trans-substituted units to a cross-conjugated tetraethynylethene unit, placed in either acyclic or cyclic arrangements. The cyclic structures correspond to so-called radiaannulenes having both endo- and exocyclic double bonds. Interactions between two redox-active TTF units in these molecules were investigated by cyclic voltammetry, UV–vis–NIR and EPR absorption spectroscopical methods of the electrochemically generated oxidized species. The electron-accepting properties of the acetylenic cores were also investigated electrochemically.

  14. On numerically pluricanonical cyclic coverings

    International Nuclear Information System (INIS)

    Kulikov, V S; Kharlamov, V M

    2014-01-01

    We investigate some properties of cyclic coverings f:Y→X (where X is a complex surface of general type) branched along smooth curves B⊂X that are numerically equivalent to a multiple of the canonical class of X. Our main results concern coverings of surfaces of general type with p g =0 and Miyaoka-Yau surfaces. In particular, such coverings provide new examples of multi-component moduli spaces of surfaces with given Chern numbers and new examples of surfaces that are not deformation equivalent to their complex conjugates

  15. On charge-3 cyclic monopoles

    International Nuclear Information System (INIS)

    Braden, H W; D'Avanzo, Antonella; Enolski, V Z

    2011-01-01

    We determine the spectral curve of charge-3 BPS su(2) monopoles with C 3 cyclic symmetry. The symmetry means that the genus 4 spectral curve covers a (Toda) spectral curve of genus 2. A well adapted homology basis is presented enabling the theta functions and monopole data of the genus 4 curve to be given in terms of genus 2 data. The Richelot correspondence, a generalization of the arithmetic mean, is used to solve for this genus 2 curve. Results of other approaches are compared

  16. A system for cyclical voltametry

    International Nuclear Information System (INIS)

    Silva, R.P. da; Chierice, G.O.

    1974-01-01

    The constrution of a system composed by two instruments, voltametric circuit and potenciostate is depicted. Both instruments junction joined so that the voltametric circuit works as a triangular pulse generator, capable of operating with independent ascendant and descendant slope change, with unique pulse of continuous regime. The circuit of the potenciostate is composed of an amplifier with high entrance impedance and capable of supplying relatively high currents at the exit. The equipment was tested to study the aqueous Pb 2+ system in mercury electrode. this system depicted for the cyclical-voltometry technique set in use at I.E.A., Sao Paulo (Brazil), has very good linearity

  17. Cyclic AMP in rat pancreatic islets

    International Nuclear Information System (INIS)

    Grill, V.; Borglund, E.; Cerasi, E.; Uppsala Univ.

    1977-01-01

    The incorporation of [ 3 H]adenine into cyclic AMP was studied in rat pancreatic islets under varying conditions of labeling. Prolonging the exposure to [ 3 H]adenine progressively augmented the islet cyclic [ 3 H]AMP level. Islets labeled for different periods of time and subsequently incubated (without adenine) in the presence of D-glucose or cholera toxin showed stimulations of intra-islet cyclic [ 3 H]AMP that were proportionate to the levels of radioactive nucleotide present under non-stimulatory conditions. Labeling the islets in a high glucose concentration (27.7 mM) did not modify the nucleotide responses to glucose or cholera toxin. The specific activity of cyclic [ 3 H]AMP, determined by simultaneous assay of cyclic [ 3 H]AMP and total cyclic AMP, was not influenced by glucose or cholera toxin. Glucose had no effect on the specific activity of labeled ATP

  18. The Cyclical Characteristics of Universal Social Insurance

    OpenAIRE

    Richard Hemming

    2013-01-01

    This paper examines how a universal social insurance program proposed for Mexico can respond to cyclical variations in revenue while remaining selffinancing. More specifically, it discusses the issues involved in setting up a stabilization fund that can accumulate surpluses when revenue is cyclically high, which can be drawn down when revenue is cyclically low. Attention is also paid to the options available to create a fund with sufficient resources to respond to revenue shocks early it its ...

  19. Cyclic plasticity and fatigue of metals

    International Nuclear Information System (INIS)

    Mughrabi, H.

    1993-01-01

    This report is a survey of the cyclic deformation and fatigue behaviour of selected engineering steels and alloys. Emphasis is placed on the important roles of the cyclic slip mode and the stability of the microstructure during cyclic stressing and on the conditions of fatigue testing with respect to the failure mechanisms and fatigue life. The examples presented include low-temperature fatigue, high-temperature fatigue in the presence of dynamic strain ageing and thermomechanical fatigue. (orig.)

  20. Cyclic Vomiting Syndrome in Children

    Directory of Open Access Journals (Sweden)

    T.V. Sorokman

    2016-08-01

    Full Text Available Introduction. Cyclic vomiting syndrome (CVS — is a fairly common disease of unknown etiology that affects children of all age groups and sometimes adult population and refers to the functional disorders of the gastrointestinal tract. Objective: to evaluate the effectiveness of the usage of Rehydron Optim for oral rehydration therapy in children. Materials and methods. The treatment of 40 children aged 3 to 11 years with CVS (15 persons and primary acetonemic syndrome (25 persons in the period of acetonemic crisis, including 15 boys and 25 girls, was analyzed. All children were observed in the outpatient department of the Regional children’s hospital of Chernivtsi. Diagnosis was established based on anamnesis, clinical and laboratory data. Patients underwent required clinico-biological tests and instrumental examinations. The dynamics of the following syndromes was investigated: pain, vomiting, dehydration and intoxication. Rehydration therapy in all cases was oral with the usage of Rehydron Optim. Results of the study and their discussion. A cyclical vomiting was observed in children with primary acetonemic syndrome with satisfactory condition in attack-free period. Migraine-like headaches prevailed in 36 patients (80 %, and the age of these patients was older than 7 years. Same children had episodes of paroxysmal autonomic failure. Almost all surveyed children had in their family history the risk factors for CVS development. All children had positive dynamics of the main basic clinical manifestations on the background of oral rehydration therapy using Rehydron Optim. Within the 1st day of oral rehydration therapy with Rehydron Optim in children, we have noted a significant decrease in the incidence of lethargy, vomiting, spastic abdominal pain, smell of acetone in the exhaled air (p < 0.05. In children with the I degree of dehydration, clinical signs of dehydration were not seen before the treatment, and children with the II degree had an

  1. Modeling Cyclic Variation of Intracranial Pressure

    National Research Council Canada - National Science Library

    Daley, M

    2001-01-01

    ...) recording during mechanical ventilation are due to cyclic extravascular compressional modulation primarily of the cerebral venous bed, an established isovolumetric model of cerebrospinal fluid...

  2. Behaviour of Cohesionless Soils During Cyclic Loading

    DEFF Research Database (Denmark)

    Shajarati, Amir; Sørensen, Kris Wessel; Nielsen, Søren Kjær

    Offshore wind turbine foundations are typically subjected to cyclic loading from both wind and waves, which can lead to unacceptable deformations in the soil. However, no generally accepted standardised method is currently available, when accounting for cyclic loading during the design of offshore...... wind turbine foundations. Therefore a literature study is performed in order to investigate existing research treating the behaviour of cohesionless soils, when subjected to cyclic loading. The behaviour of a soil subjected to cyclic loading is found to be dependent on; the relative density, mean...

  3. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

  4. Strain hardening of red blood cells by accumulated cyclic supraphysiological stress

    NARCIS (Netherlands)

    Lee, Sung S.; Antaki, James F.; Kameneva, Marina V.; Dobbe, Johannes G.; Hardeman, Max R.; Ahn, Kyung H.; Lee, Seung J.

    2007-01-01

    The effect of elevated shear stress upon cellular trauma has been studied for many years, but the effect of long-term cyclic stress trauma on hemorheology has never been explored systematically. This study investigated sublytic trauma of red blood cells (RBCs) caused by repeated exposure to shear

  5. Cyclic Multiblock Copolymers via Combination of Iterative Cu(0)-Mediated Radical Polymerization and Cu(I)-Catalyzed Azide-Alkyne Cycloaddition Reaction.

    Science.gov (United States)

    Xiao, Lifen; Zhu, Wen; Chen, Jiqiang; Zhang, Ke

    2017-02-01

    Cyclic multiblock polymers with high-order blocks are synthesized via the combination of single-electron transfer living radical polymerization (SET-LRP) and copper-catalyzed azide-alkyne cycloaddition (CuAAC). The linear α,ω-telechelic multiblock copolymer is prepared via SET-LRP by sequential addition of different monomers. The SET-LRP approach allows well control of the block length and sequence as A-B-C-D-E, etc. The CuAAC is then performed to intramolecularly couple the azide and alkyne end groups of the linear copolymer and produce the corresponding cyclic copolymer. The block sequence and the cyclic topology of the resultant cyclic copolymer are confirmed by the characterization of 1 H nuclear magnetic resonance spectroscopy, gel permeation chromatography, Fourier transform infrared spectroscopy, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Investigating cyclic nucleotide and cyclic dinucleotide binding to HCN channels by surface plasmon resonance.

    Directory of Open Access Journals (Sweden)

    Sebastien Hayoz

    Full Text Available Hyperpolarization-activated cyclic nucleotide-modulated (HCN channels control cardiac and neuronal rhythmicity. HCN channels contain cyclic nucleotide-binding domain (CNBD in their C-terminal region linked to the pore-forming transmembrane segment with a C-linker. The C-linker couples the conformational changes caused by the direct binding of cyclic nucleotides to the HCN pore opening. Recently, cyclic dinucleotides were shown to antagonize the effect of cyclic nucleotides in HCN4 but not in HCN2 channels. Based on the structural analysis and mutational studies it has been proposed that cyclic dinucleotides affect HCN4 channels by binding to the C-linker pocket (CLP. Here, we first show that surface plasmon resonance (SPR can be used to accurately measure cyclic nucleotide binding affinity to the C-linker/CNBD of HCN2 and HCN4 channels. We then used SPR to investigate cyclic dinucleotide binding in HCN channels. To our surprise, we detected no binding of cyclic dinucleotides to the isolated monomeric C-linker/CNBDs of HCN4 channels with SPR. The binding of cyclic dinucleotides was further examined with isothermal calorimetry (ITC, which indicated no binding of cyclic dinucleotides to both monomeric and tetrameric C-linker/CNBDs of HCN4 channels. Taken together, our results suggest that interaction of the C-linker/CNBD with other parts of the channel is necessary for cyclic-dinucleotide binding in HCN4 channels.

  7. Effect of oral premedication on the anaesthetic efficacy of inferior alveolar nerve block in patients with irreversible pulpitis - A systematic review and network meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Pulikkotil, S J; Nagendrababu, V; Veettil, S K; Jinatongthai, P; Setzer, F C

    2018-02-26

    This systematic review (SR; PROSPERO database: CRD42017075160) and network meta-analysis (NMA) identified the most effective oral premedication for anaesthetic success of inferior alveolar nerve blocks (IANB) in cases of irreversible pulpitis. Medline and Ebscohost databases were searched up until 10/2017. Randomized controlled trials (RCT) studying the effect of oral premedication, alone or in combination, on the success of IANB for cases of irreversible pulpitis, compared to placebo or other oral premedications, were included. Quality of the included studies was appraised by the revised Cochrane risk of bias tool for randomized trials. Pairwise analysis, NMA and quality of evidence assessment using GRADE criteria were performed. Nineteen studies (n = 1654 participants) were included. NMA demonstrated that compared to placebo, dexamethasone was most effective in increasing anaesthetic success (RR, 2.92 [95% CI 1.74,4.91]; SUCRA = 0.96), followed by NSAIDs (RR, 1.92 [95% CI 1.63,2.27], SUCRA = 0.738) and Tramadol (RR, 2.03 [95% CI 1.18,3.49], SUCRA = 0.737). Premedication with acetaminophen added to NSAIDs demonstrated similar efficacy as NSAIDs alone (RR, 1.06 [95% CI 0.79,1.43]). Sensitivity analyses proved the superiority of dexamethasone or NSAIDs over any other premedications. Subgroup analyses of specific dosages in comparison with placebo demonstrated that dexamethasone 0.5 mg was most effective, followed by ketorolac 10 mg, piroxicam 20 mg, ibuprofen 400 mg + acetaminophen 500 mg and Tramadol 50 mg. Ibuprofen 400 mg, 600 mg and 800 mg had a significantly improved IANB success, while Ibuprofen 300 mg had no effect. Oral premedication with dexamethasone, NSAIDs or Tramadol significantly increased anaesthetic success. More trials are needed to evaluate the premedication effects of dexamethasone or Tramadol for improved anaesthetic success of IANB when treating irreversible pulpitis. © 2018 International Endodontic Journal. Published by John

  8. Impact of New-Onset Left Bundle Branch Block and Periprocedural Permanent Pacemaker Implantation on Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Regueiro, Ander; Abdul-Jawad Altisent, Omar; Del Trigo, María; Campelo-Parada, Francisco; Puri, Rishi; Urena, Marina; Philippon, François; Rodés-Cabau, Josep

    2016-05-01

    Available data on the clinical impact of new-onset left bundle branch block (LBBB) and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR) remains controversial. We aimed to evaluate the impact of (1) periprocedural new-onset LBBB or PPI post-TAVR on cardiac mortality and all-cause 1-year mortality and (2) new-onset LBBB on the need for PPI at 1-year follow-up. We performed a systematic search from PubMed and EMBASE databases for studies reporting raw data on new-onset LBBB post-TAVR and the need for PPI or mortality at 1-year follow-up, or on 1-year mortality according to the need for periprocedural PPI post-TAVR. Data from 17 studies, including 4756 patients (8 studies) and 7032 patients (11 studies) for the evaluation of the impact of new-onset LBBB and periprocedural PPI post-TAVR were sourced, respectively (with 2 studies used for both outcomes). New-onset LBBB post-TAVR was associated with a higher risk of PPI (risk ratio [RR], 2.18; 95% confidence interval [CI], 1.28-3.70) and cardiac death (RR, 1.39; 95% CI, 1.04-1.86) during follow-up, as well with a tendency toward an increase in all-cause mortality (RR, 1.21; 95% CI, 0.98-1.50). Periprocedural PPI post-TAVR was not associated with any increased risk of all-cause mortality at 1 year (RR, 1.03; 95% CI, 0.9-1.18), yet a tendency toward a protective effect on cardiac death was observed (RR, 0.78; 95% CI, 0.60-1.03). New-onset LBBB post-TAVR is a marker of an increased risk of cardiac death and need for PPI at 1-year follow-up. The need for PPI early post-TAVR did not increase the risk of death. © 2016 American Heart Association, Inc.

  9. The undesirable effects of neuromuscular blocking drugs

    DEFF Research Database (Denmark)

    Claudius, C; Garvey, L H; Viby-Mogensen, J

    2009-01-01

    Neuromuscular blocking drugs are designed to bind to the nicotinic receptor at the neuromuscular junction. However, they also interact with other acetylcholine receptors in the body. Binding to these receptors causes adverse effects that vary with the specificity for the cholinergic receptor...... in question. Moreover, all neuromuscular blocking drugs may cause hypersensitivity reactions. Often the symptoms are mild and self-limiting but massive histamine release can cause systematic reactions with circulatory and respiratory symptoms and signs. At the end of anaesthesia, no residual effect...... of a neuromuscular blocking drug should be present. However, the huge variability in response to neuromuscular blocking drugs makes it impossible to predict which patient will suffer postoperative residual curarization. This article discusses the undesirable effects of the currently available neuromuscular blocking...

  10. Block copolymer structures in nano-pores

    Science.gov (United States)

    Pinna, Marco; Guo, Xiaohu; Zvelindovsky, Andrei

    2010-03-01

    We present results of coarse-grained computer modelling of block copolymer systems in cylindrical and spherical nanopores on Cell Dynamics Simulation. We study both cylindrical and spherical pores and systematically investigate structures formed by lamellar, cylinders and spherical block copolymer systems for various pore radii and affinity of block copolymer blocks to the pore walls. The obtained structures include: standing lamellae and cylinders, ``onions,'' cylinder ``knitting balls,'' ``golf-ball,'' layered spherical, ``virus''-like and mixed morphologies with T-junctions and U-type defects [1]. Kinetics of the structure formation and the differences with planar films are discussed. Our simulations suggest that novel porous nano-containers can be formed by confining block copolymers in pores of different geometries [1,2]. [4pt] [1] M. Pinna, X. Guo, A.V. Zvelindovsky, Polymer 49, 2797 (2008).[0pt] [2] M. Pinna, X. Guo, A.V. Zvelindovsky, J. Chem. Phys. 131, 214902 (2009).

  11. Cyclic nucleotide content of tobacco BY-2 cells.

    Science.gov (United States)

    Richards, Helen; Das, Swadipa; Smith, Christopher J; Pereira, Louisa; Geisbrecht, Alan; Devitt, Nicola J; Games, David E; van Geyschem, Jan; Gareth Brenton, A; Newton, Russell P

    2002-11-01

    The cyclic nucleotide content of cultured tobacco bright yellow-2 (BY-2) cells was determined, after freeze-killing, perchlorate extraction and sequential chromatography, by radioimmunoassay. The identities of the putative cyclic nucleotides, adenosine 3',5'-cyclic monophosphate (cyclic AMP), guanosine 3',5'-cyclic monophosphate (cyclic GMP) and cytidine 3',5'-cyclic monophosphate (cyclic CMP) were unambiguously confirmed by tandem mass spectrometry. The potential of BY-2 cell cultures as a model system for future investigations of cyclic nucleotide function in higher plants is discussed.

  12. Cyclic nucleotide specific phosphodiesterases of Leishmania major

    Directory of Open Access Journals (Sweden)

    Linder Markus

    2006-03-01

    Full Text Available Abstract Background Leishmania represent a complex of important human pathogens that belong to the systematic order of the kinetoplastida. They are transmitted between their human and mammalian hosts by different bloodsucking sandfly vectors. In their hosts, the Leishmania undergo several differentiation steps, and their coordination and optimization crucially depend on numerous interactions between the parasites and the physiological environment presented by the fly and human hosts. Little is still known about the signalling networks involved in these functions. In an attempt to better understand the role of cyclic nucleotide signalling in Leishmania differentiation and host-parasite interaction, we here present an initial study on the cyclic nucleotide-specific phosphodiesterases of Leishmania major. Results This paper presents the identification of three class I cyclic-nucleotide-specific phosphodiesterases (PDEs from L. major, PDEs whose catalytic domains exhibit considerable sequence conservation with, among other, all eleven human PDE families. In contrast to other protozoa such as Dictyostelium, or fungi such as Saccharomyces cerevisiae, Candida ssp or Neurospora, no genes for class II PDEs were found in the Leishmania genomes. LmjPDEA contains a class I catalytic domain at the C-terminus of the polypeptide, with no other discernible functional domains elsewhere. LmjPDEB1 and LmjPDEB2 are coded for by closely related, tandemly linked genes on chromosome 15. Both PDEs contain two GAF domains in their N-terminal region, and their almost identical catalytic domains are located at the C-terminus of the polypeptide. LmjPDEA, LmjPDEB1 and LmjPDEB2 were further characterized by functional complementation in a PDE-deficient S. cerevisiae strain. All three enzymes conferred complementation, demonstrating that all three can hydrolyze cAMP. Recombinant LmjPDEB1 and LmjPDEB2 were shown to be cAMP-specific, with Km values in the low micromolar range

  13. CYCLICAL SUBNORMAL SEPARATION IN A-GROUPS

    African Journals Online (AJOL)

    :-at are split extensions of certain abelian p-groups by a metabelian pi-group, to satisfy the cyclic a1 subnormal separation condition. There is also a result which shows that A-groups with elementary abelian Sylow subgroups are. :icl~cally separated. KEYWORD: A-groups, Cyclical~Subnormal Separation, CS,-groups.

  14. Interactions of Cyclic Hydrocarbons with Biological Membranes

    NARCIS (Netherlands)

    SIKKEMA, J; DEBONT, JAM; POOLMAN, B

    1994-01-01

    Many cyclic hydrocarbons, e.g. aromatics, cycloalkanes, and terpenes, are toxic to microorganisms. The primary site of the toxic action is probably the cytoplasmic membrane, but the mechanism of the toxicity is still poorly understood. The effects of cyclic hydrocarbons were studied in liposomes

  15. Fractional behaviour at cyclic stretch-bending

    NARCIS (Netherlands)

    Emmens, W.C.; van den Boogaard, Antonius H.; Kazantzis, A.V.; de Hosson, J.Th.M.; Kolleck, R

    2010-01-01

    The fractional behaviour at cyclic stretch-bending has been studied by performing tensile tests at long specimens that are cyclically bent at the same time, on mild steel, dual-phase steel, stainless steel, aluminium and brass. Several types of fracture are observed, these are discussed, as are the

  16. Synthesis of cyclic alpha-MSH peptides

    NARCIS (Netherlands)

    Schaaper, W.M.M.; Adan, R.A.H.; Posthuma, T.A.; Oosterom, J.; Gispen, W.H.; Meloen, R.H.

    1998-01-01

    Cyclic lactam analogs of α-melanocyte stimulating hormone (α-MSH) have been shown to be potent agonists in the frog skin bioassay [Al-Obeidi, F. et al., J. Med. Chem., 32 (1989) 2555], demonstrating melanocortin-1 (MC1) receptor activity. We synthesized cyclic α-MSH(1-13) and α-MSH(4-10) lactam

  17. Synthesis of cyclic α-MSH peptides

    NARCIS (Netherlands)

    Gispen, W.H.; Schaaper, W.M.M..; Adan, R.A.H.; Posthuma, T.A.; Oosterom, J.; Meloen, R.H.

    1998-01-01

    Cyclic lactam analogs of -melanocyte stimulating hormone (-MSH) have been shown to be potent agonists in the frog skin bioassay [Al-Obeidi, F. et al., J. Med. Chem., 32 (1989) 2555], demonstrating melanocortin-1 (MC1) receptor activity. We synthesized cyclic -MSH(1-13) and -MSH(4-10) lactam analogs.

  18. Cyclic completion of the anamorphic universe

    Science.gov (United States)

    Ijjas, Anna

    2018-04-01

    Cyclic models of the universe have the advantage of avoiding initial conditions problems related to postulating any sort of beginning in time. To date, the best known viable examples of cyclic models have been ekpyrotic. In this paper, we show that the recently proposed anamorphic scenario can also be made cyclic. The key to the cyclic completion is a classically stable, non-singular bounce. Remarkably, even though the bounce construction was originally developed to connect a period of contraction with a period of expansion both described by Einstein gravity, we show here that it can naturally be modified to connect an ordinary contracting phase described by Einstein gravity with a phase of anamorphic smoothing. The paper will present the basic principles and steps in constructing cyclic anamorphic models.

  19. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    A new 3-parameter family of homogeneous 2-by-2 block shifts is described. These are the first examples of irreducible homogeneous bilateral block shifts of block size larger than 1. Author Affiliations. Adam Korányi1. Department of Mathematics, The Graduate Center, City University of New York, New York, NY 10016, USA ...

  20. A review of cyclic fatigue testing of nickel-titanium rotary instruments.

    Science.gov (United States)

    Plotino, Gianluca; Grande, Nicola M; Cordaro, Massimo; Testarelli, Luca; Gambarini, Gianluca

    2009-11-01

    Fractured rotary nickel-titanium (NiTi) instruments have been classified into those that fail as a result of cyclic flexural fatigue or torsional failure or a combination of both. Clinically, NiTi rotary instruments are subjected to both torsional load and cyclic fatigue, and ongoing research aims to clarify the relative contributions of both factors to instrument separation. To date, there is no specification or international standard to test cyclic fatigue resistance of endodontic rotary instruments. As a consequence, several devices and methods have been used to investigate in vitro cyclic fatigue fracture resistance of NiTi rotary endodontic instruments. In nearly all studies reported in the endodontic literature, the rotating instrument was either confined in a glass or metal tube, in a grooved block-and-rod assembly, or in a sloped metal block. There has been no mention of the "fit" of the instrument in the tube or groove. As the instrument is likely to be fitting loosely, the description of the radius of curvature in those studies is likely to be overstated (ie, the file was actually bent less severely than reported, adding a variability in the amount of flexural stress). This review analyzed several devices that have been used in endodontic literature for cyclic fatigue testing and found that differences in the methodology affected the fatigue behavior of rotary instruments and, consequently, the outcome of these studies. An international standard for cyclic fatigue testing of NiTi rotary instruments is required to ensure uniformity of methodology and comparable results.

  1. Undrained Cyclic Behaviour of Dense Frederikshavn Sand

    DEFF Research Database (Denmark)

    Nielsen, Søren Kjær; Ibsen, Lars Bo; Sørensen, Kris Wessel

    2013-01-01

    of undrained cyclic triaxial tests, which have been performed at the Geotechnical Laboratory at Aalborg University. In order to ensure offshore conditions, the tests were fully saturated and performed with a relative density of 80 %. During cyclic loading, special attention was given to the development of pore......A modified contour diagram is created for the Frederikshavn Sand in the undrained case for a relative density of ID = 80 %. It can be used to estimate the number of cycles to failure for a given combination of pore pressure, average and cyclic load ratio. The diagram is based on a series...

  2. Driving Force Based Design of Cyclic Distillation

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Fjordbak; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2017-01-01

    Driving force based design is adopted from conventional continuous distillation to cyclic distillation. This leads to a definition of the operating line representation for the cyclic distillation process. A possible realization of the driving force design is presented, which implies operation...... with mixed phase feeds. A range of binary test cases, benzene toluene, methanol water, and ethanol water, are evaluated. The advantage of the design approach in cyclic distillation is shown to be analogous to the advantages obtained in conventional continuous distillation, including a minimal utility...

  3. A "catalyst switch" Strategy for the sequential metal-free polymerization of epoxides and cyclic Esters/Carbonate

    KAUST Repository

    Zhao, Junpeng

    2014-06-24

    A "catalyst switch" strategy was used to synthesize well-defined polyether-polyester/polycarbonate block copolymers. Epoxides (ethylene oxide and/or 1,2-butylene oxide) were first polymerized from a monoalcohol in the presence of a strong phosphazene base promoter (t-BuP4). Then an excess of diphenyl phosphate (DPP) was introduced, followed by the addition and polymerization of a cyclic ester (ε-caprolactone or δ-valerolactone) or a cyclic carbonate (trimethylene carbonate), where DPP acted as both the neutralizer of phosphazenium alkoxide (polyether chain end) and the activator of cyclic ester/carbonate. This work has provided a one-pot sequential polymerization method for the metal-free synthesis of block copolymers from monomers which are suited for different types of organic catalysts. © 2014 American Chemical Society.

  4. Cyclic AMP Pathway Activation and Extracellular Zinc Induce Rapid Intracellular Zinc Mobilization in Candida albicans

    Science.gov (United States)

    Kjellerup, Lasse; Winther, Anne-Marie L.; Wilson, Duncan; Fuglsang, Anja T.

    2018-01-01

    Zinc is an essential micronutrient, required for a range of zinc-dependent enzymes and transcription factors. In mammalian cells, zinc serves as a second messenger molecule. However, a role for zinc in signaling has not yet been established in the fungal kingdom. Here, we used the intracellular zinc reporter, zinbo-5, which allowed visualization of zinc in the endoplasmic reticulum and other components of the internal membrane system in Candida albicans. We provide evidence for a link between cyclic AMP/PKA- and zinc-signaling in this major human fungal pathogen. Glucose stimulation, which triggers a cyclic AMP spike in this fungus resulted in rapid intracellular zinc mobilization and this “zinc flux” could be stimulated with phosphodiesterase inhibitors and blocked via inhibition of adenylate cyclase or PKA. A similar mobilization of intracellular zinc was generated by stimulation of cells with extracellular zinc and this effect could be reversed with the chelator EDTA. However, zinc-induced zinc flux was found to be cyclic AMP independent. In summary, we show that activation of the cyclic AMP/PKA pathway triggers intracellular zinc mobilization in a fungus. To our knowledge, this is the first described link between cyclic AMP signaling and zinc homeostasis in a human fungal pathogen. PMID:29619016

  5. Effect of Cyclic Loading on Surface Instability of Silicone Rubber under Compression

    Directory of Open Access Journals (Sweden)

    Zhonglin Li

    2017-04-01

    Full Text Available This work combines experiments and finite element simulations to study the effect of pre-imposed cyclic loading on surface instability of silicon rubber under compression. We first fabricate cuboid blocks of silicon rubber and pinch them cyclicly a few times. Then, an in-house apparatus is set to apply uniaxial compression on the silicon rubber under exact plane strain conditions. Surprisingly, we find multiple creases on the surface of silicone rubber, significantly different from what have been observed on the samples without the cyclic pinching. To reveal the underlying physics for these experimentally observed multiple creases, we perform detailed nanoindentation experiments to measure the material properties at different locations of the silicon rubber. The modulus is found to be nonuniform and varies along the thickness direction after the cyclic pinching. According to these experimental results, three-layer and multilayer finite element models are built with different materials properties informed by experiments. The three-layer finite element model can excellently explain the nucleation and pattern of multiple surface creases on the surface of compressed silicone rubber, in good agreement with experiments. Counterintuitively, the multilayer model with gradient modulus cannot be used to explain the multiple creases observed in our experiments. According to these simulations, the experimentally observed multiple creases should be attributed to a thin and stiff layer formed on the surface of silicon rubber after the pre-imposed cyclic loading.

  6. Parallel patterns determination in solving cyclic flow shop problem with setups

    Directory of Open Access Journals (Sweden)

    Bożejko Wojciech

    2017-06-01

    Full Text Available The subject of this work is the new idea of blocks for the cyclic flow shop problem with setup times, using multiple patterns with different sizes determined for each machine constituting optimal schedule of cities for the traveling salesman problem (TSP. We propose to take advantage of the Intel Xeon Phi parallel computing environment during so-called ’blocks’ determination basing on patterns, in effect significantly improving the quality of obtained results.

  7. Phase-Shift Cyclic-Delay Diversity for MIMO OFDM Systems

    Directory of Open Access Journals (Sweden)

    Young-Han Nam

    2010-01-01

    Full Text Available Phase-shift cyclic-delay diversity (PS CDD scheme and space-frequency-block-code (SFBC PS CDD are developed for multiple-input-multiple-output (MIMO orthogonal frequency division multiplexing (OFDM systems. The proposed PS CDD scheme preserves the diversity advantage of traditional CDD in uncorrelated multiantenna channels, and furthermore removes frequency-selective nulling problem of the traditional CDD in correlated multiantenna channels.

  8. Genetics Home Reference: cyclic vomiting syndrome

    Science.gov (United States)

    ... infections. Other triggers can include periods without eating (fasting), temperature extremes, lack of sleep, overexertion, allergies, ingesting ... include changes in brain function, hormonal abnormalities, and gastrointestinal problems. Many researchers believe that cyclic vomiting syndrome ...

  9. Cyclic hardening in bundled actin networks.

    Science.gov (United States)

    Schmoller, K M; Fernández, P; Arevalo, R C; Blair, D L; Bausch, A R

    2010-01-01

    Nonlinear deformations can irreversibly alter the mechanical properties of materials. Most soft materials, such as rubber and living tissues, display pronounced softening when cyclically deformed. Here we show that, in contrast, reconstituted networks of crosslinked, bundled actin filaments harden when subject to cyclical shear. As a consequence, they exhibit a mechano-memory where a significant stress barrier is generated at the maximum of the cyclic shear strain. This unique response is crucially determined by the network architecture: at lower crosslinker concentrations networks do not harden, but soften showing the classic Mullins effect known from rubber-like materials. By simultaneously performing macrorheology and confocal microscopy, we show that cyclic shearing results in structural reorganization of the network constituents such that the maximum applied strain is encoded into the network architecture.

  10. Anodic selective functionalization of cyclic amine derivatives

    OpenAIRE

    Onomura, Osamu

    2012-01-01

    Anodic reactions are desirable methods from the viewpoint of Green Chemistry, since no toxic oxidants are necessary for the oxidation of organic molecules. This review introduces usefulness of anodic oxidation and successive reaction for selective functionalization of cyclic amine derivatives.

  11. Cyclic voltammetry and reduction mechanistic studies of ...

    African Journals Online (AJOL)

    styrylpyrylium perchlorates have been evaluated using cyclic voltammetry, in comparison to their non-methylated derivatives values. The reduction peak of all studied compounds remained chemically irreversible. The presence of the ...

  12. Mortar constituent of concrete under cyclic compression

    Science.gov (United States)

    Maher, A.; Darwin, D.

    1980-10-01

    The behavior of the mortar constituent of concrete under cyclic compression was studied and a simple analytic model was developed to represent its cyclic behavior. Experimental work consisted of monotonic and cyclic compressive loading of mortar. Two mixes were used, with proportions corresponding to concretes having water cement ratios of 0.5 and 0.6. Forty-four groups of specimens were tested at ages ranging from 5 to 70 days. complete monotonic and cyclic stress strain envelopes were obtained. A number of loading regimes were investigated, including cycles to a constant maximum strain. Major emphasis was placed on tests using relatively high stress cycles. Degradation was shown to be a continuous process and a function of both total strain and load history. No stability or fatigue limit was apparent.

  13. cyclic -perimeter hydrocarbon ruthenium complexes bearing ...

    Indian Academy of Sciences (India)

    - cyclic -perimeter hydrocarbon ruthenium complexes bearing functionalized pyridyl diketones: Isolation of complexes with 2-N∩O and 4-N∩O bonding modes of ligands. Saphidabha L Nongbri Babulal Das Mohan Rao Kollipara.

  14. Survey and Benchmark of Block Ciphers for Wireless Sensor Networks

    NARCIS (Netherlands)

    Law, Y.W.; Doumen, J.M.; Hartel, Pieter H.

    Choosing the most storage- and energy-efficient block cipher specifically for wireless sensor networks (WSNs) is not as straightforward as it seems. To our knowledge so far, there is no systematic evaluation framework for the purpose. In this paper, we have identified the candidates of block ciphers

  15. Benchmarking Block Ciphers for Wireless Sensor Networks (Extended Abstract)

    NARCIS (Netherlands)

    Law, Y.W.; Doumen, J.M.; Hartel, Pieter H.

    2004-01-01

    Choosing the most storage- and energy-efficient block cipher specifically for wireless sensor networks (WSNs) is not as straightforward as it seems. To our knowledge so far, there is no systematic evaluation framework for the purpose. We have identified the candidates of block ciphers suitable for

  16. 3' : 5'-Cyclic AMP-dependent 3'

    NARCIS (Netherlands)

    Mato, José M.; Krens, Frans A.; Haastert, Peter J.M. van; Konijn, Theo M.

    1977-01-01

    Suspensions of 3':5'-cyclic AMP (cAMP)-sensitive cells of Dictyostelium discoideum responded to a cAMP pulse with increased 3':5'-cyclic GMP (cGMP) levels. Under the assay conditions used (2 × 10^8 cells per ml in 10 mM phosphate buffer, pH 6.0) cAMP (5 × 10-8 M final concentration) increased cGMP

  17. Empty Container Management in Cyclic Shipping Routes

    OpenAIRE

    Dong-Ping Song; Jing-Xin Dong

    2008-01-01

    This paper considers the empty container management problem in a cyclic shipping route. The objective is to seek the optimal empty container repositioning policy in a dynamic and stochastic situation by minimising the expected total costs consisting of inventory holding costs, demand lost-sale costs, lifting-on and lifting-off charges, and container transportation costs. A three-phase threshold control policy is developed to reposition empty containers in cyclic routes. The threshold values a...

  18. Blocked Randomization with Randomly Selected Block Sizes

    Directory of Open Access Journals (Sweden)

    Jimmy Efird

    2010-12-01

    Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  19. Blocked randomization with randomly selected block sizes.

    Science.gov (United States)

    Efird, Jimmy

    2011-01-01

    When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  20. 31 CFR 595.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM SANCTIONS REGULATIONS General Definitions § 595.301 Blocked account; blocked property. The terms blocked account and blocked...

  1. Consecutive exotropia following surgically corrected cyclic esotropia.

    Science.gov (United States)

    Post, Joel; Eidsness, Ryan B; Romanchuk, Kenneth G

    2007-01-01

    Cyclic esotropia is a rare form of strabismus consisting of regular intervals of esotropia alternating with periods of orthophoria in a rhythmic/cyclic manner. In the vast majority of cases, surgery appears to permanently correct the esotropia, with no sequelae after years of follow-up. We report a case of consecutive exotropia in a patient five years after bilateral medial rectus recessions for cyclic esotropia. A case report involving review of a clinical chart. A two-year-old male presented with right esotropia and mild amblyopia. He was treated with patching and following resolution of the amblyopia he developed a cyclic esotropia. Surgical correction was performed for the full amount measured on a "manifest" day. Following the surgery, he was orthophoric and demonstrated binocular vision. He remained stable for five years, and then returned with occasional diplopia and an intermittent exotropia. Cyclic esotropia is a rare disorder of ocular motility that spontaneously appears and disappears at regular intervals. After surgical correction, the deviation disappears and recurrence of esotropia is very infrequent. We present the first reported case of consecutive exotropia following surgical correction of a cyclic esotropia.

  2. One-pot synthesis of well-defined polyether/polyester block copolymers and terpolymers by a highly efficient catalyst switch approach

    KAUST Repository

    Alamri, Haleema

    2016-04-20

    A highly efficient methodology, based on a novel catalyst switch approach with rapid crossover characteristics, was developed for the one-pot synthesis of block co/terpolymers of cyclic ethers and esters. This new approach, which takes advantage of one of the best catalysts for epoxide (t-BuP4) and cyclic ester (t-BuP2) polymerization, opens new horizons toward the synthesis of cyclic ether/ester complex macromolecular architectures. © The Royal Society of Chemistry 2016.

  3. Generalized Block Failure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2015-01-01

    Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... shows that no readily available tests with a well-defined substantial eccentricity have been performed. This paper presents theoretical and experimental work leading towards generalized block failure capacity methods. Simple combination of normal force, shear force and moment stress distributions along...

  4. On the equivalence of cyclic and quasi-cyclic codes over finite fields

    Directory of Open Access Journals (Sweden)

    Kenza Guenda

    2017-07-01

    Full Text Available This paper studies the equivalence problem for cyclic codes of length $p^r$ and quasi-cyclic codes of length $p^rl$. In particular, we generalize the results of Huffman, Job, and Pless (J. Combin. Theory. A, 62, 183--215, 1993, who considered the special case $p^2$. This is achieved by explicitly giving the permutations by which two cyclic codes of prime power length are equivalent. This allows us to obtain an algorithm which solves the problem of equivalency for cyclic codes of length $p^r$ in polynomial time. Further, we characterize the set by which two quasi-cyclic codes of length $p^rl$ can be equivalent, and prove that the affine group is one of its subsets.

  5. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Homogeneous bilateral block shifts. ADAM KORÁNYI. Department of Mathematics, The Graduate Center, City University of New York,. New York, NY 10016, USA. E-mail: Adam.Koranyi@lehman.cuny.edu. MS received 18 January 2013. Abstract. A new 3-parameter family of homogeneous 2-by-2 block shifts is described.

  6. Related Drupal Nodes Block

    NARCIS (Netherlands)

    Van der Vegt, Wim

    2010-01-01

    Related Drupal Nodes Block This module exposes a block that uses Latent Semantic Analysis (Lsa) internally to suggest three nodes that are relevant to the node a user is viewing. This module performs three tasks. 1) It periodically indexes a Drupal site and generates a Lsa Term Document Matrix.

  7. Chain dimension of cyclic polymers in solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Yutaka [Department of Applied Chemistry, Nagoya University Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Masuoka, Keisuke [Department of Applied Chemistry, Nagoya University Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Takano, Atsushi [Department of Applied Chemistry, Nagoya University Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Matsushita, Yushu [Department of Applied Chemistry, Nagoya University Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)]. E-mail: yushu@apchem.nagoya-u.ac.jp

    2006-11-15

    Telechelic polystyrenes (PSs) were synthesized and cyclized by end-to-end ring closure reaction under extremely diluted condition. Cyclic PSs were isolated from coupling products by GPC fractionation and precipitational fractionation, and 4 cyclic polymers, whose molecular weights M{sub w} are covering the range 20k=cyclic polymers have high purity (over 95%) by HPLC. Their radii of gyration R{sub g} were determined in benzene-d{sub 6} (good solvent) and cyclohexane-d{sub 12} (theta solvent) by small-angle neutron scattering and light scattering. It was found that R{sub g} of cyclic polymer can be scaled with M{sub w} as R{sub g}{proportional_to}M{sub w}{sup 0.6} in benzene-d{sub 6} and as R{sub g}{proportional_to}M{sub w}{sup 0.5} in cyclohexane-d{sub 12}, both exponents being the same as for linear counterparts. However, experimentally determined contraction ratio, R{sub g(cyclic)}/R{sub g(linear)}, is smaller than the theoretical predictions.

  8. Further studies on cyclic erythropoiesis in mice

    International Nuclear Information System (INIS)

    Gibson, C.M.; Gurney, C.W.; Simmons, E.L.; Gaston, E.O.

    1985-01-01

    When young adult female W/Wv mice are given 0.5 micro+Ci 89 Sr/g body weight intravenously, their hematocrit values oscillate from nadirs of 26% to zeniths of 42% with a periodicity of 16 days. The response of the W/Wv mouse to an assortment of radioactive and hematologic stresses have been examined in an effort to understand better the pathophysiology of cyclic erythropoiesis. When the dose of 89 Sr is increased, the amplitude of cycling increases as nadirs are lowered, but periodicity is unchanged. When the dose of 89 Sr is lowered to 0.3 microCi or less, cyclic erythropoiesis of substantial amplitude is observed only after five or six microoscillations. A single hematopoietic insult of 80 rad x-irradiation coupled with phlebotomy produces a transient form of cyclic erythropoiesis, namely, a series of dampened oscillations prior to recovery. Finally, we report that Wv/Wv mice exhibit a form of cyclic erythropoiesis in response to 0.5 microCi 89 Sr/g body weight, in which the hematocrit values of successive nadirs gradually increase, and stabilize at about 100 days. 89 Sr does not induce cyclic erythropoiesis in the +/+, W/+, or W/v/+ mice, the Hertwig strain of anemic mice, or in normal BDF1 mice

  9. Control rod blocking monitor

    International Nuclear Information System (INIS)

    Suzuki, Shigeru.

    1993-01-01

    The number of times for setting up a control rod blocking monitor of a BWR type power plant is remarkably reduced to mitigate operator's burden. In the control rod blocking monitor, trip levels, as a judging standard upon outputting control rod blocking inhibition signals, are set up stepwise depending on the power level around control rods put to blocking control. The present invention comprises an allowance judging means capable of setting up trip levels for each of power levels corresponding to a plurality of control rods at once if the power levels are within the set up allowable range. With such a constitution, the set up allowable range is determined previously in the allowance judging means. Accordingly, when a gang blocking is conducted to control rods, if power levels around the control rods are increased at once into the set up allowable range, the trip levels for each of the control rods are set up at once. (I.S.)

  10. Control of cell volume in the J774 macrophage by microtubule disassembly and cyclic AMP

    Science.gov (United States)

    Melmed, RN; Karanian, PJ; Berlin, RD

    1981-01-01

    We have explored the possibilities that cell volume is regulated by the status of microtubule assembly and cyclic AMP metabolism and may be coordinated with shape change. Treatment of J774.2 mouse macrophages with colchicine caused rapid microtubule disassembly and was associated with a striking increase (from 15-20 to more than 90 percent) in the proportion of cells with a large protuberance at one pole. This provided a simple experimental system in which shape changes occurred in virtually an entire cell population in suspension. Parallel changes in cell volume could then be quantified by isotope dilution techniques. We found that the shape change caused by colchicine was accompanied by a decrease in cell volume of approximately 20 percent. Nocodozole, but not lumicolchicine, caused identical changes in both cell shape and cell volume. The volume loss was not due to cell lysis nor to inhibition of pinocytosis. The mechanism of volume loss was also examined. Colchicine induced a small but reproducible increase in activity of the ouabain-sensitive Na(+), K(+)-dependent ATPase. However, inhibition of this enzyme/transport system by ouabain did not change cell volume nor did it block the colchicines-induced decrease in volume. One the other hand, SITS (4’acetamido, 4-isothiocyano 2,2’ disulfonic acid stilbene), an inhibitor of anion transport, inhibited the effects of colchicines, thus suggesting a role for an anion transport system in cell volume regulation. Because colchicine is known to activate adenylate cyclase in several systems and because cell shape changes are often induced by hormones that elevate cyclic AMP, we also examined the effects of cyclic AMP on cell volume. Agents that act to increase syclic AMP (cholera toxin, which activates adenylate cyclase; IBMX, and inhibitor of phosphodiesterase; and dibutyryl cyclic AMP) all caused a volume decrease comparable to that of colchicine. To define the effective metabolic pathway, we studied two mutants of J

  11. The error performance analysis over cyclic redundancy check codes

    Science.gov (United States)

    Yoon, Hee B.

    1991-06-01

    The burst error is generated in digital communication networks by various unpredictable conditions, which occur at high error rates, for short durations, and can impact services. To completely describe a burst error one has to know the bit pattern. This is impossible in practice on working systems. Therefore, under the memoryless binary symmetric channel (MBSC) assumptions, the performance evaluation or estimation schemes for digital signal 1 (DS1) transmission systems carrying live traffic is an interesting and important problem. This study will present some analytical methods, leading to efficient detecting algorithms of burst error using cyclic redundancy check (CRC) code. The definition of burst error is introduced using three different models. Among the three burst error models, the mathematical model is used in this study. The probability density function, function(b) of burst error of length b is proposed. The performance of CRC-n codes is evaluated and analyzed using function(b) through the use of a computer simulation model within CRC block burst error. The simulation result shows that the mean block burst error tends to approach the pattern of the burst error which random bit errors generate.

  12. The nature of solar cyclicity. I

    Science.gov (United States)

    Romanchuk, P. R.

    1981-02-01

    The report contains a critical survey of work devoted to the study of the nature of solar cyclicity. The inconsistency of the representation of cyclic curves using a frequency spectrum is indicated. The useful contribution of the ideas of Wolf, Newcomb, and Waldmeier to the solution of the problem is noted. Data are cited in favor of the theory of the tidal nature of solar cyclicity developed by the author, which also takes into account the ideas of the above-mentioned authors: the continuous paired and single tidal actions of the planets and the resonance character of this action, thanks to which the approximately 10-year period of action of Jupiter and Saturn is transformed into the 11-year activity cycle.

  13. HOST liner cyclic facilities: Facility description

    Science.gov (United States)

    Schultz, D.

    1982-01-01

    A quartz lamp box, a quartz lamp annular rig, and a low pressure liner cyclic can rig planned for liner cyclic tests are described. Special test instrumentation includes an IR-TV camera system for measuring liner cold side temperatures, thin film thermocouples for measuring liner hot side temperatures, and laser and high temperature strain gages for obtaining local strain measurements. A plate temperature of 2,000 F was obtained in an initial test of an apparatus with three quartz lamps. Lamp life, however, appeared to be limited for the standard commercial quartz lamps available. The design of vitiated and nonvitiated preheaters required for the quartz lamp annular rig and the cyclic can test rigs is underway.

  14. Cyclic distillation technology - A mini-review

    DEFF Research Database (Denmark)

    Bîldea, Costin Sorin; Pătruţ, Cătălin; Jørgensen, Sten Bay

    2016-01-01

    Process intensification in distillation systems has received much attention during the pastdecades, with the aim of increasing both energy and separation efficiency. Varioustechniques, such as internal heat-integrated distillation, membrane distillation, rotating packedbed, dividing-wall columns...... and reactive distillation were studied and reported in literature. All these techniques employ the conventional continuous counter-current contact of vapor andliquid phases. Cyclic distillation technology is based on an alternative operating mode usingseparate phase movement which leads to key practical...... advantages in both chemical andbiochemical processes. This article provides a mini-review of cyclic distillation technology.The topics covered include the working principle, design and control methods, main benefitsand limitations as well as current industrial applications. Cyclic distillation can...

  15. Cyclic cellular automata in 3D

    International Nuclear Information System (INIS)

    Reiter, Clifford A.

    2011-01-01

    Highlights: → We explore the self-organization of cyclic cellular automata in 3D. → Von Neumann, Moore and two types of intermediate neighborhoods are investigated. → Random neighborhoods self organize through phases into complex nested structures. → Demons are seen to have many alternatives in 3D. - Abstract: Cyclic cellular automata in two dimensions have long been intriguing because they self organize into spirals and that behavior can be analyzed. The form for the patterns that develop is highly dependent upon the form of the neighborhood. We extend this work to three dimensional cyclic cellular automata and observe self organization dependent upon the neighborhood type. This includes neighborhood types intermediate between Von Neumann and Moore neighborhoods. We also observe that the patterns include nested shells with the appropriate forms but that the nesting is far more complex than the spirals that occur in two dimensions.

  16. A comparison of two reciprocating instruments using bending stress and cyclic fatigue tests

    Directory of Open Access Journals (Sweden)

    Pantaleo SCELZA

    2015-01-01

    Full Text Available The aim of this study was to comparatively evaluate the bending resistance at 45º, the static and dynamic cyclic fatigue life, and the fracture type of the WaveOne (Dentsply Maillefer, Ballaigues, Switzerland 25-08 and Reciproc (VDW, Munich, Germany 25-08 instruments. A total of 60 nickel-titanium (NiTi instruments (30 Reciproc and 30 WaveOne from three different lots, each of which was 25 mm in length, were tested. The bending resistance was evaluated through the results of a cantilever-bending test conducted using a universal testing machine. Static and dynamic cyclic fatigue testing was conducted using a custom-made device. For the static and dynamic tests, a cast Ni-Cr-Mo-Ti alloy metal block with an artificial canal measuring 1.77 mm in diameter and 20.00 mm in total length was used. A scanning electron microscope was used to determine the type of fracture. Statistical analyses were performed on the results. The WaveOne instrument was less flexible than the Reciproc (p < 0.05. The Reciproc instrument showed better resistance in the static and dynamic cyclic fatigue tests (p < 0.05. The transverse cross-section and geometry of the instruments were important factors in their resistance to bending and cyclic fracture. Both of the instruments showed ductile-type fracture characteristics. It can be concluded that the Reciproc 25-08 instrument was more resistant to static and dynamic cyclic fatigue than the WaveOne 25-08 instrument, while the WaveOne 25-08 instrument was less flexible. Bending and resistance to cyclic fracture were influenced by the instruments’ geometries and transverse cross-sections. Both of the instruments showed ductile-type fracture characteristics.

  17. Cyclic microplasticity factors of some metals

    Energy Technology Data Exchange (ETDEWEB)

    Puskar, A. (University of Transport and Telecommunications, Zilina (Czechoslovakia))

    1983-11-01

    The measurement of the internal friction and the elasticity modulus defect together with a new approximation for evaluating the plastic deformation amplitude from the total deformation amplitude enable the cyclic deformation curves, the changes in hysteresis loop area on increasing the deformation amplitude and many other important characteristics of cyclic microplasticity to be determined during a push-pull type of loading at a frequency of 23kHz on dumb-bell shaped specimens of titanium, molybdenum, niobium and low carbon unalloyed steel.

  18. SICLOPPS cyclic peptide libraries in drug discovery.

    Science.gov (United States)

    Tavassoli, Ali

    2017-06-01

    Cyclic peptide libraries have demonstrated significant potential when employed against challenging targets such as protein-protein interactions. While a variety of methods for library generation exist, genetically encoded libraries hold several advantages over their chemically synthesized counterparts; they are more readily accessible and allow straightforward hit deconvolution. One method for the intracellular generation of such libraries is split-intein circular ligation of peptides and proteins (SICLOPPS). Here we detail and discuss the deployment of SICLOPPS libraries for the identification of cyclic peptide inhibitors of a variety of targets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Towards Optimization of Cyclic Production Systems

    OpenAIRE

    Chauvet, Fabrice; Herrmann, Jeffrey W.; Proth, Jean-Marie

    1999-01-01

    In this paper, the expression "production systems" refers to flow-shops, job-shops, assembly systems, Kanban systems and, in general, to any Discrete Event System (DES) which transforms raw material and/or components into products and/or components. Such a system is said to be cyclic if it provides indefinitely the same sequence of products. A schedule of a cyclic production system is defined as soon as the starting time of each operation on the related resource is known. It has been showed t...

  20. Building blocks for protein interaction devices

    OpenAIRE

    Gr?nberg, Raik; Ferrar, Tony S.; van der Sloot, Almer M.; Constante, Marco; Serrano, Luis

    2010-01-01

    Here, we propose a framework for the design of synthetic protein networks from modular protein?protein or protein?peptide interactions and provide a starter toolkit of protein building blocks. Our proof of concept experiments outline a general work flow for part?based protein systems engineering. We streamlined the iterative BioBrick cloning protocol and assembled 25 synthetic multidomain proteins each from seven standardized DNA fragments. A systematic screen revealed two main factors contro...

  1. Sr-Nd-Pb isotope systematics of the Permian volcanic rocks in the northern margin of the Alxa Block (the Shalazhashan Belt) and comparisons with the nearby regions: Implications for a Permian rift setting?

    Science.gov (United States)

    Shi, Guanzhong; Wang, Hua; Liu, Entao; Huang, Chuanyan; Zhao, Jianxin; Song, Guangzeng; Liang, Chao

    2018-04-01

    The petrogenesis of the Permian magmatic rocks in the Shalazhashan Belt is helpful for us to understand the tectonic evolution of the Central Asian Orogenic Belt (CAOB) in the northern margin of the Alxa Block. The Permian volcanic rocks in the Shalazhashan Belt include basalts, trachyandesites and trachydacites. Our study shows that two basalt samples have negative εNd(t) values (-5.4 to -1.5) and higher radiogenic Pb values, which are relevant to the ancient subcontinental lithospheric mantle. One basalt sample has positive εNd(t) value (+10) representing mafic juvenile crust and is derived from depleted asthenosphere. The trachyandesites are dated at 284 ± 3 Ma with εNd(t) = +2.7 to +8.0; ISr = 0.7052 to 0.7057, and they are generated by different degrees of mixing between mafic magmas and crustal melts. The trachydacites have high εNd(t) values and slightly higher ISr contents, suggesting the derivation from juvenile sources with crustal contamination. The isotopic comparisons of the Permian magmatic rocks of the Shalazhashan Belt, the Nuru-Langshan Belt (representing the northern margin of the Alxa Block), the Solonker Belt (Mandula area) and the northern margin of the North China Craton (Bayan Obo area) indicate that the radiogenic isotopic compositions have an increasingly evolved trend from the south (the northern margins of the Alxa Block and the North China Craton) to the north (the Shalazhashan Belt and the Solonker Belt). Three end-member components are involved to generate the Permian magmatic rocks: the ancient subcontinental lithospheric mantle, the mafic juvenile crust or newly underplated mafic rocks that were originated from depleted asthenosphere, and the ancient crust. The rocks correlative with the mafic juvenile crust or newly underplated mafic rocks are predominantly distributed along the Shalazhashan Belt and the Solonker Belt, and the rocks derived from ancient, enriched subcontinental lithospheric mantle are mainly distributed along

  2. Accelerated Cyclic Reduction: A Distributed-Memory Fast Solver for Structured Linear Systems

    KAUST Repository

    Chávez, Gustavo

    2017-12-15

    We present Accelerated Cyclic Reduction (ACR), a distributed-memory fast solver for rank-compressible block tridiagonal linear systems arising from the discretization of elliptic operators, developed here for three dimensions. Algorithmic synergies between Cyclic Reduction and hierarchical matrix arithmetic operations result in a solver that has O(kNlogN(logN+k2)) arithmetic complexity and O(k Nlog N) memory footprint, where N is the number of degrees of freedom and k is the rank of a block in the hierarchical approximation, and which exhibits substantial concurrency. We provide a baseline for performance and applicability by comparing with the multifrontal method with and without hierarchical semi-separable matrices, with algebraic multigrid and with the classic cyclic reduction method. Over a set of large-scale elliptic systems with features of nonsymmetry and indefiniteness, the robustness of the direct solvers extends beyond that of the multigrid solver, and relative to the multifrontal approach ACR has lower or comparable execution time and size of the factors, with substantially lower numerical ranks. ACR exhibits good strong and weak scaling in a distributed context and, as with any direct solver, is advantageous for problems that require the solution of multiple right-hand sides. Numerical experiments show that the rank k patterns are of O(1) for the Poisson equation and of O(n) for the indefinite Helmholtz equation. The solver is ideal in situations where low-accuracy solutions are sufficient, or otherwise as a preconditioner within an iterative method.

  3. 31 CFR 594.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY GLOBAL TERRORISM SANCTIONS REGULATIONS General Definitions § 594.301 Blocked account; blocked property. The terms blocked account and...

  4. Bundle Branch Block

    Science.gov (United States)

    ... 2015. Bundle branch block Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  5. Blocked Urethral Valves

    Science.gov (United States)

    ... the penis. Rarely, small membranes form across the urethra in boys early in pregnancy, and they can block the flow of urine out of the bladder. These membranes are called posterior urethral valves and can have life-threatening consequences ...

  6. Optoelectronics using block copolymers.

    Energy Technology Data Exchange (ETDEWEB)

    Botiz, I.; Darling, S. B.; Center for Nanoscale Materials

    2010-05-01

    Block copolymers, either as semiconductors themselves or as structure directors, are emerging as a promising class of materials for understanding and controlling processes associated with both photovoltaic energy conversion and light emitting devices.

  7. Breaking antidunes: Cyclic behavior due to hysteresis

    DEFF Research Database (Denmark)

    Deigaard, Rolf

    2006-01-01

    The cyclic behavior of breaking antidunes (growth, breaking of surface wave, obliteration) is investigated by use of a numerical model. The model includes the transition between supercritical and transcritical flow. As the antidune grows the flow becomes transcritical and a hydraulic jump is form...

  8. Cyclic Plastic Deformation and Welding Simulation

    NARCIS (Netherlands)

    Ten Horn, C.H.L.J.

    2003-01-01

    One of the concerns of a fitness for purpose analysis is the quantification of the relevant material properties. It is known from experiments that the mechanical properties of a material can change due to a monotonic plastic deformation or a cyclic plastic deformation. For a fitness for purpose

  9. Cyclical Variability of Prominences, CMEs and Flares

    Indian Academy of Sciences (India)

    tribpo

    tions of solar activity. For many years, qualitative studies were made about the cyclical behaviour of such phenomena. Nowadays, more quantitative ... phenomenon has been observed in every cycle and is independent of the intensity of the cycle. The characteristic pattern of the polar zone is a "rush to the poles" and the.

  10. Cyclical Variability of Prominences, CMEs and Flares

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Journal of Astrophysics and Astronomy; Volume 21; Issue 3-4. Cyclical Variability of Prominences, CMEs and Flares. J. L. Ballester. Session V – Vector Magnetic Fields, Prominences, CMEs & Flares Volume 21 Issue 3-4 September-December 2000 pp ...

  11. Steady state oxygen reduction and cyclic voltammetry

    DEFF Research Database (Denmark)

    Rossmeisl, Jan; Karlberg, Gustav; Jaramillo, Thomas

    2008-01-01

    The catalytic activity of Pt and Pt3Ni for the oxygen reduction reaction is investigated by applying a Sabatier model based on density functional calculations. We investigate the role of adsorbed OH on the activity, by comparing cyclic voltammetry obtained from theory with previously published...

  12. Cyclic Cratonic Carbonates and Phanerozoic Calcite Seas.

    Science.gov (United States)

    Wilkinson, Bruce H.

    1982-01-01

    Discusses causes of cyclicity in cratonic carbonate sequences and evidence for and potential significance of postulated primary calcite sediment components in past Paleozoic seas, outlining problems, focusing on models explaining existing data, and identifying background. Future sedimentary geologists will need to address these and related areas…

  13. Cyclic olefin copolymer-silica nanocomposites foams

    Czech Academy of Sciences Publication Activity Database

    Pegoretti, A.; Dorigato, A.; Biani, A.; Šlouf, Miroslav

    2016-01-01

    Roč. 51, č. 8 (2016), s. 3907-3916 ISSN 0022-2461 R&D Projects: GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : cyclic olefin copolymer * nanocomposites * silica Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.599, year: 2016

  14. Effects of hypokinesia on cyclic nucleotides and hormonal regulation ...

    African Journals Online (AJOL)

    PTH), calcitonin (CT), cyclic nucleotides (cAMP, cGMP) and calcium in the blood of rats, while in urine - phosphate, calcium and cyclic nucleotides. Design: Laboratory based experiment. Setting: Laboratory in the Department of Biochemistry, ...

  15. Augmentation Quotients for Real Representation Rings of Cyclic ...

    Indian Academy of Sciences (India)

    29

    Augmentation Quotients for Real Representation Rings of Cyclic Groups. Article Type: Reseach Article. Keywords: cyclic group; real representation; augmentation ideal; augmentation quotient. Corresponding Author: Hang Liu, Ph.D. Shaanxi Normal University. Xi'an, Shaanxi CHINA. Corresponding Author Secondary.

  16. Compressed sensing with cyclic-S Hadamard matrix for terahertz imaging applications

    Science.gov (United States)

    Ermeydan, Esra Şengün; ćankaya, Ilyas

    2018-01-01

    Compressed Sensing (CS) with Cyclic-S Hadamard matrix is proposed for single pixel imaging applications in this study. In single pixel imaging scheme, N = r . c samples should be taken for r×c pixel image where . denotes multiplication. CS is a popular technique claiming that the sparse signals can be reconstructed with samples under Nyquist rate. Therefore to solve the slow data acquisition problem in Terahertz (THz) single pixel imaging, CS is a good candidate. However, changing mask for each measurement is a challenging problem since there is no commercial Spatial Light Modulators (SLM) for THz band yet, therefore circular masks are suggested so that for each measurement one or two column shifting will be enough to change the mask. The CS masks are designed using cyclic-S matrices based on Hadamard transform for 9 × 7 and 15 × 17 pixel images within the framework of this study. The %50 compressed images are reconstructed using total variation based TVAL3 algorithm. Matlab simulations demonstrates that cyclic-S matrices can be used for single pixel imaging based on CS. The circular masks have the advantage to reduce the mechanical SLMs to a single sliding strip, whereas the CS helps to reduce acquisition time and energy since it allows to reconstruct the image from fewer samples.

  17. Should we search Chinese biomedical databases when performing systematic reviews?

    NARCIS (Netherlands)

    Cohen, Jérémie F.; Korevaar, Daniël A.; Wang, Junfeng; Spijker, René; Bossuyt, Patrick M.

    2015-01-01

    Chinese biomedical databases contain a large number of publications available to systematic reviewers, but it is unclear whether they are used for synthesizing the available evidence. We report a case of two systematic reviews on the accuracy of anti-cyclic citrullinated peptide for diagnosing

  18. Cyclic Soft Groups and Their Applications on Groups

    Directory of Open Access Journals (Sweden)

    Hacı Aktaş

    2014-01-01

    Full Text Available In crisp environment the notions of order of group and cyclic group are well known due to many applications. In this paper, we introduce order of the soft groups, power of the soft sets, power of the soft groups, and cyclic soft group on a group. We also investigate the relationship between cyclic soft groups and classical groups.

  19. Long-term interference at the semantic level: Evidence from blocked-cyclic picture matching.

    Science.gov (United States)

    Wei, Tao; Schnur, Tatiana T

    2016-01-01

    Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn) from an array of unrelated pictures. Across trials, probes were either semantically related or unrelated. To test the locus of interference, we presented probes as either words or pictures. If semantic interference occurs at the stage common to both tasks, that is, access to semantic representations, then interference should occur in both probe presentation modalities. Results showed clear semantic interference effects independent of presentation modality and lexical frequency, confirming a semantic locus of interference in comprehension. To test the mechanism of interference, we repeated trials across 4 presentation cycles and manipulated the number of unrelated intervening trials (zero vs. two). We found that semantic interference was additive across cycles and survived 2 intervening trials, demonstrating interference to be long-lasting as opposed to short-lived. However, interference was smaller with zero versus 2 intervening trials, which we interpret to suggest that short-lived facilitation counteracted the long-lived interference. We propose that retrieving meanings associated with words/pictures from the same semantic category yields both interference due to long-lasting changes in connection strength between semantic representations (i.e., incremental learning) and facilitation caused by short-lived residual activation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  20. Long-Term Interference at the Semantic Level: Evidence from Blocked-Cyclic Picture Matching

    Science.gov (United States)

    Wei, Tao; Schnur, Tatiana T.

    2016-01-01

    Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn)…

  1. Does segmental overlap help or hurt? Evidence from blocked cyclic naming in spoken and written production.

    Science.gov (United States)

    Breining, Bonnie; Nozari, Nazbanou; Rapp, Brenda

    2016-04-01

    Past research has demonstrated interference effects when words are named in the context of multiple items that share a meaning. This interference has been explained within various incremental learning accounts of word production, which propose that each attempt at mapping semantic features to lexical items induces slight but persistent changes that result in cumulative interference. We examined whether similar interference-generating mechanisms operate during the mapping of lexical items to segments by examining the production of words in the context of others that share segments. Previous research has shown that initial-segment overlap amongst a set of target words produces facilitation, not interference. However, this initial-segment facilitation is likely due to strategic preparation, an external factor that may mask underlying interference. In the present study, we applied a novel manipulation in which the segmental overlap across target items was distributed unpredictably across word positions, in order to reduce strategic response preparation. This manipulation led to interference in both spoken (Exp. 1) and written (Exp. 2) production. We suggest that these findings are consistent with a competitive learning mechanism that applies across stages and modalities of word production.

  2. Right bundle branch block

    DEFF Research Database (Denmark)

    Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse

    2013-01-01

    AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included.......5%/2.3% in women, P Right bundle branch block was associated with significantly...... increased all-cause and cardiovascular mortality in both genders with age-adjusted hazard ratios (HR) of 1.31 [95% confidence interval (CI), 1.11-1.54] and 1.87 (95% CI, 1.48-2.36) in the gender pooled analysis with little attenuation after multiple adjustment. Right bundle branch block was associated...

  3. Variation of cyclic strain parameters regulates development of elastic modulus in fibroblast/substrate constructs.

    Science.gov (United States)

    Joshi, Sagar D; Webb, Ken

    2008-08-01

    Dynamic mechanical culture systems are a widely studied approach for improving the functional mechanical properties of tissue engineering constructs intended for loading-bearing orthopedic applications such as tendon/ligament reconstruction. The design of effective mechanical stimulation regimes requires a fundamental understanding of the effects of cyclic strain parameters on the resulting construct properties. Toward this end, these studies employed a modular cyclic strain bioreactor system and fibroblast-seeded, porous polyurethane substrates to systematically investigate the effect of varying cyclic strain amplitude, rate, frequency, and daily cycle number on construct mechanical properties. Significant differences were observed in response to variation of all four loading parameters tested. In general, the highest values of elastic modulus within each experimental group were observed at low to intermediate values of the experimental variables tested, corresponding to the low to subphysiological range (2.5% strain amplitude, 25%/s strain rate, 0.1-0.5 Hz frequency, and 7,200-28,800 cycles/day). These studies demonstrate that fibroblasts are sensitive and responsive to multiple characteristics of their mechanical environment, and suggest that systematic optimization of dynamic culture conditions may be useful for the acceleration of construct maturation and mechanical function.

  4. Supramolecular self-assembly of nonlinear amphiphilic and double hydrophilic block copolymers in aqueous solutions.

    Science.gov (United States)

    Ge, Zhishen; Liu, Shiyong

    2009-09-17

    Supramolecular self-assembly of block copolymers in aqueous solution has received ever-increasing interest over the past few decades due to diverse biological and technological applications in drug delivery, imaging, sensing and catalysis. In addition to relative block lengths, molecular weights and solution conditions, chain architectures of block copolymers can also dramatically affect their self-assembling properties in selective solvents. This feature article mainly focuses on recent developments in the field of supramolecular self-assembly of amphiphilic and double hydrophilic block copolymers (DHBCs) possessing nonlinear chain topologies, including miktoarm star polymers, dendritic-linear block copolymers, cyclic block copolymers and comb-shaped copolymer brushes. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Cosmic evolution in a cyclic universe

    International Nuclear Information System (INIS)

    Steinhardt, Paul J.; Turok, Neil

    2002-01-01

    Based on concepts drawn from the ekpyrotic scenario and M theory, we elaborate our recent proposal of a cyclic model of the universe. In this model, the universe undergoes an endless sequence of cosmic epochs which begin with the universe expanding from a 'big bang' and end with the universe contracting to a 'big crunch'. Matching from 'big crunch' to 'big bang' is performed according to the prescription recently proposed with Khoury, Ovrut and Seiberg. The expansion part of the cycle includes a period of radiation and matter domination followed by an extended period of cosmic acceleration at low energies. The cosmic acceleration is crucial in establishing the flat and vacuous initial conditions required for ekpyrosis and for removing the entropy, black holes, and other debris produced in the preceding cycle. By restoring the universe to the same vacuum state before each big crunch, the acceleration ensures that the cycle can repeat and that the cyclic solution is an attractor

  6. Strain gradient effects on cyclic plasticity

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Legarth, Brian Nyvang

    2010-01-01

    Size effects on the cyclic shear response are studied numerically using a recent higher order strain gradient visco-plasticity theory accounting for both dissipative and energetic gradient hardening. Numerical investigations of the response under cyclic pure shear and shear of a finite slab between...... rigid platens have been carried out, using the finite element method. It is shown for elastic–perfectly plastic solids how dissipative gradient effects lead to increased yield strength, whereas energetic gradient contributions lead to increased hardening as well as a Bauschinger effect. For linearly...... hardening materials it is quantified how dissipative and energetic gradient effects promote hardening above that of conventional predictions. Usually, increased hardening is attributed to energetic gradient effects, but here it is found that also dissipative gradient effects lead to additional hardening...

  7. A cyclic symmetry principle in physics

    International Nuclear Information System (INIS)

    Green, H.S.; Adelaide Univ., SA

    1994-01-01

    Many areas of modern physics are illuminated by the application of a symmetry principle, requiring the invariance of the relevant laws of physics under a group of transformations. This paper examines the implications and some of the applications of the principle of cyclic symmetry, especially in the areas of statistical mechanics and quantum mechanics, including quantized field theory. This principle requires invariance under the transformations of a finite group, which may be a Sylow π-group, a group of Lie type, or a symmetric group. The utility of the principle of cyclic invariance is demonstrated in finding solutions of the Yang-Baxter equation that include and generalize known solutions. It is shown that the Sylow π-groups have other uses, in providing a basis for a type of generalized quantum statistics, and in parametrising a new generalization of Lie groups, with associated algebras that include quantized algebras. 31 refs

  8. E-Block: A Tangible Programming Tool with Graphical Blocks

    OpenAIRE

    Danli Wang; Yang Zhang; Shengyong Chen

    2013-01-01

    This paper designs a tangible programming tool, E-Block, for children aged 5 to 9 to experience the preliminary understanding of programming by building blocks. With embedded artificial intelligence, the tool defines the programming blocks with the sensors as the input and enables children to write programs to complete the tasks in the computer. The symbol on the programming block's surface is used to help children understanding the function of each block. The sequence information is transfer...

  9. Analysis of cyclic creep and rupture. Part 1: bounding theorems and cyclic reference stresses

    Energy Technology Data Exchange (ETDEWEB)

    Carter, P. [Stress Engineering Services, Inc., Mason, OH 45040 (United States)]. E-mail: peter.carter@ses-oh.com

    2005-01-01

    Cyclic loading on structures can produce failures not readily predicted by conventional static analysis. Ratcheting or incremental distortion leads to structural failure, and complicates the problems of creep and fatigue prediction. Predicting shakedown, ratcheting, accelerated creep and rupture, for cyclic loading, are the objectives of cyclic stress analysis.Limit load, shakedown and ratcheting analyses provide a comprehensive basis to understand static structural behaviour for ductile inelastic materials, subject to variable loading but excluding inertial dynamic effects. From them we can predict the following failure modes:-Plastic collapse.-Failure to shakedown.-Ratcheting.-Accelerated creep and rupture.This is achieved with a generalisation of the reference stress concept. Conventionally, and for steady loading, the limit load reference stress is the lowest yield stress for which the structure does not collapse. For cyclic loading two definitions are available. The more conservative is the lowest yield stress for which the structure shakes down (behaves elastically). The less conservative is the lowest yield stress for which the structure does not ratchet. They have different meanings and uses.Explaining and justifying the use of cyclic reference stresses to bound creep and rupture is the objective of Part 1. Part 2 gives examples illustrating a range of structural behaviours. The methodology of these papers involves so-called approximate methods at one level, that of inferring limiting or conservative time-dependent behaviour from time-independent elastic-plastic cyclic analyses. The elastic-plastic cyclic analyses themselves are straightforward if tedious. Some ideas and a new analysis technique are available to reduce the trial-and-error.

  10. Numerically investigating the emergent cyclic inflation scenario

    International Nuclear Information System (INIS)

    Duhe, William; Biswas, Tirthabir

    2014-01-01

    We provide a comprehensive numerical study of the emergent cyclic inflation scenario. This is a scenario where instead of traditional monotonic slow roll inflation, the universe expands over numerous short asymmetric cycles due to the production of entropy via interactions among different species. This is one of the very few scenarios of inflation that provides a non-singular geodesically complete space-time and does not require any ‘reheating’ mechanism. (paper)

  11. Scale factor duality for conformal cyclic cosmologies

    International Nuclear Information System (INIS)

    Silva, University Camara da; Lima, A.L. Alves; Sotkov, G.M.

    2016-01-01

    The scale factor duality is a symmetry of dilaton gravity which is known to lead to pre-big-bang cosmologies. A conformal time version of the scale factor duality (SFD) was recently implemented as a UV/IR symmetry between decelerated and accelerated phases of the post-big-bang evolution within Einstein gravity coupled to a scalar field. The problem investigated in the present paper concerns the employment of the conformal time SFD methods to the construction of pre-big-bang and cyclic extensions of these models. We demonstrate that each big-bang model gives rise to two qualitatively different pre-big-bang evolutions: a contraction/expansion SFD model and Penrose’s Conformal Cyclic Cosmology (CCC). A few examples of SFD symmetric cyclic universes involving certain gauged Kähler sigma models minimally coupled to Einstein gravity are studied. We also describe the specific SFD features of the thermodynamics and the conditions for validity of the generalized second law in the case of Gauss-Bonnet (GB) extension of these selected CCC models.

  12. Visualization of cyclic nucleotide dynamics in neurons

    Directory of Open Access Journals (Sweden)

    Kirill eGorshkov

    2014-12-01

    Full Text Available The second messengers cAMP and cGMP transduce many neuromodulatory signals from hormones and neurotransmitters into specific functional outputs. Their production, degradation and signaling are spatiotemporally regulated to achieve high specificity in signal transduction. The development of genetically encodable fluorescent biosensors has provided researchers with useful tools to study these versatile second messengers and their downstream effectors with unparalleled spatial and temporal resolution in cultured cells and living animals. In this review, we introduce the general design of these fluorescent biosensors and describe several of them in more detail. Then we discuss a few examples of using cyclic nucleotide fluorescent biosensors to study regulation of neuronal function and finish with a discussion of advances in the field. Although there has been significant progress made in understanding how the specific signaling of cyclic nucleotide second messengers is achieved, the mechanistic details in complex cell types like neurons are only just beginning to surface. Current and future fluorescent protein reporters will be essential to elucidate the role of cyclic nucleotide signaling dynamics in the functions of individual neurons and their networks.

  13. Contaminated soil concrete blocks

    NARCIS (Netherlands)

    de Korte, A.C.J.; Brouwers, Jos; Limbachiya, Mukesh C.; Kew, Hsein Y.

    2009-01-01

    According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In

  14. Making Block Grants Accountable.

    Science.gov (United States)

    Chelimsky, Eleanor

    Methods of accountability are presented in considering the Reagan administration plan to consolidate 84 federal health, education and social service grants into six block grant areas and to cut overall funding. After matching aspects of public criticism with proposal objectives, a rationale is developed for building elements of accountability into…

  15. Linoleum Block Printing Revisited.

    Science.gov (United States)

    Chetelat, Frank J.

    1980-01-01

    The author discusses practical considerations of teaching linoleum block printing in the elementary grades (tool use, materials, motivation) and outlines a sequence of design concepts in this area for the primary, intermediate and junior high grades. A short list of books and audiovisual aids is appended. (SJL)

  16. Effects of Block Scheduling

    Directory of Open Access Journals (Sweden)

    William R. Veal

    1999-09-01

    Full Text Available This study examined the effects of a tri-schedule on the academic achievement of students in a high school. The tri-schedule consists of traditional, 4x4 block, and hybrid schedules running at the same time in the same high school. Effectiveness of the schedules was determined from the state mandated test of basic skills in reading, language, and mathematics. Students who were in a particular schedule their freshman year were tested at the beginning of their sophomore year. A statistical ANCOVA test was performed using the schedule types as independent variables and cognitive skill index and GPA as covariates. For reading and language, there was no statistically significant difference in test results. There was a statistical difference mathematics-computation. Block mathematics is an ideal format for obtaining more credits in mathematics, but the block format does little for mathematics achievement and conceptual understanding. The results have content specific implications for schools, administrations, and school boards who are considering block scheduling adoption.

  17. Coding with Blockly

    CERN Document Server

    Lovett, Amber

    2017-01-01

    "Blockly is a fun, graphical programming language designed to get kids interested in creating their own computer programs. Through simple text written to foster creativity and problem solving, students will the art of innovation. Large, colorful images show students how to complete activities. Additional tools, including a glossary and an index, help students learn new vocabulary and locate information."-- Provided by publisher.

  18. Multiaxial elastoplastic cyclic loading of austenitic 316L steel

    Directory of Open Access Journals (Sweden)

    V. Mazánová

    2017-04-01

    Full Text Available Cyclic stress-strain response and fatigue damage character has been investigated in austenitic stainless steel 316L. Hollow cylindrical specimens have been cyclically deformed in combined tension-compression and torsion under constant strain rate condition and different constant strain and shear strain amplitudes. In-phase and 90° out-of-phase cyclic straining was applied and the stress response has been monitored. Cyclic hardening/softening curves were assessed in both channels. Cyclic softening followed for higher strain amplitudes by long-term cyclic hardening was observed. Cyclic stress-strain curves were determined. Study of the surface damage in fractured specimens revealed the types and directions of principal cracks and the sources of fatigue crack initiation in slip bands.

  19. [Masquerading bundle branch block].

    Science.gov (United States)

    Kukla, Piotr; Baranchuk, Adrian; Jastrzębski, Marek; Bryniarski, Leszek

    2014-01-01

    We here describe a surface 12-lead electrocardiogram (ECG) of a 72-year-old female with a prior history of breast cancer and chemotherapy-induced cardiomyopathy. An echocardiogram revealed left ventricular dysfunction, ejection fraction of 23%, with mild enlarged left ventricle. The 12-lead ECG showed atrial fibrillation with a mean heart rate of about 100 bpm, QRS duration 160 ms, QT interval 400 ms, right bundle branch block (RBBB) and left anterior fascicular block (LAFB). The combination of RBBB features in the precordial leads and LAFB features in the limb leads is known as ''masquerading bundle branch block''. In most cases of RBBB and LAFB, the QRS axis deviation is located between - 80 to -120 degrees. Rarely, when predominant left ventricular forces are present, the QRS axis deviation is near about -90 degrees, turning the pattern into an atypical form. In a situation of RBBB associated with LAFB, the S wave can be absent or very small in lead I. Such a situation is the result of not only purely LAFB but also with left ventricular hypertrophy and/or focal block due to scar (extensive anterior myocardial infarction) or fibrosis (cardiomyopathy). Sometimes, this specific ECG pattern is mistaken for LBBB. RBBB with LAFB may imitate LBBB either in the limb leads (known as 'standard masquerading' - absence of S wave in lead I), or in the precordial leads (called 'precordial masquerading' - absence of S wave in leads V₅ and V₆). Our ECG showed both these types of masquerading bundle branch block - absence of S wave in lead I and in leads V₅ and V₆.

  20. High Resolution Rotational Spectroscopy of a Flexible Cyclic Ether

    Science.gov (United States)

    Gámez, F.; Martínez-Haya, B.; Blanco, S.; López, J. C.; Alonso, J. L.

    2011-06-01

    Crown ethers stand as one cornerstone molecular class inhost-guest Supramolecular Chemistry and constitute building blocks for a broad range of modern materials. We report here the first high resolution rotational study of a crown ether: 1,4,7,10,13-pentaoxacyclopentadecane (15-crown-5 ether,15c5). Molecular beam Fourier transform microwave spectroscopy has been employed. The liquid sample of 15c5 has been vaporized using heating methods. The considerable size of 15c5 and the broad range of conformations allowed by the flexibility of its backbone pose important challenges to spectroscopy approaches. In fact, the ab-initio computational study for isolated 15c5, yields at least six stable conformers with relative free energies within 2 kJ Mol-1 (167 Cm-1). Nevertheless, in this investigation it has been possible to identify and characterize in detail one stable rotamer of the 15c5 molecule and to challenge different quantum methods for the accurate description of this system. The results pave the ground for an extensive description of the conformational landscape of 15c5 and related cyclic ethers in the near term. J. L. Alonso, F. J. Lorenzo, J. C. López, A. Lesarri, S. Mata and H. Dreizler, Chem. Phys., 218, 267 (1997) S. Blanco, J.C López, J.L. Alonso, P. Ottaviani, W. Caminati, J. Chem. Phys. 119, 880 (2003) S.E. Hill, D. Feller, Int. J. Mass Spectrom. 201, 41 (2000)

  1. Preoperative oral nonsteroidal anti-inflammatory drugs for the success of the inferior alveolar nerve block in irreversible pulpitis treatment: a systematic review and meta-analysis based on randomized controlled trials.

    Science.gov (United States)

    Li, Chunjie; Yang, Xianrui; Ma, Xiangyu; Li, Longjiang; Shi, Zongdao

    2012-03-01

    To assess the effect and safety of pre-emptive oral nonsteroidal anti-inflammatory drugs (NSAIDs) for the success of inferior alveolar nerve block (IANB) in irreversible pulpitis treatment. Medline (via OVID, 1948 to July 2011), Cochrane Central Register of Controlled Trials (CENTRAL, Issue 2, 2011), EMBASE (via OVID, 1984 to July 2011), Chinese BioMedical Literature Database (1978 to July 2011), China National Knowledge Infrastructure (1994 to July 2011), and WHO International Clinical Trials Registry Platform were searched electronically. In addition, relevant journals as well as reference lists of included studies were hand searched for randomized clinical trials comparing the effect or safety of NSAIDs in irreversible pulpitis treatment. Risk of bias assessment with the Cochrane collaboration tool and data extraction were independently performed by two reviewers. Meta-analysis was delivered with RevMan 5.1. Seven studies were included. Six of them had low risk of bias, and one had an unclear risk of bias. A dosage of 600 to 800 mg of ibuprofen showed a significant effect in increasing the success rate of IANB (relative risk [RR], 1.52; 95% confidence interval [CI], 1.17 to 1.98; P = .002), and the results were moderately reliable. A dosage of 75 mg of indomethacin had a significant effect compared to a placebo (RR, 1.94; 95% CI, 1.22 to 3.06; P = .005), as did 8 mg of lornoxicam (RR, 2.80; 95% CI, 1.59 to 4.93; P = .0004) and 50 mg of diclofenac potassium (RR, 2.40; 95% CI, 1.34 to 4.31; P = .003). Other NSAIDs such as ketorolac, ibuprofen and acetaminophen together, and acetaminophen alone showed no statistical significance compared to the placebo. No serious adverse events were reported. The clinical evidence suggests that pre-emptive oral NSAIDs might have a good effect and are safe in increasing the success rate of IANB, but more studies are necessary to confirm such outcomes.

  2. Contemporary block tectonics: California and Nevada.

    Science.gov (United States)

    Hill, D.P.

    1982-01-01

    Well-determined fault plane solution and the gross pattern of late-Cenozoic faulting in California and Nevada show a systematic relation between the orientation of fault planes and slip directions. In general, normal faults have N strikes, reverse faults have E strikes, and dextral and sinstral strike slip faults have NW and NE strikes, respectively. Kinematically, this relation is consistent with the response of clusters of fault-bounded crustal blocks to a regional stress field generated by the relative motion between the Pacific and N American plates. In this stress field, the greatest and least principal (compressive) stresses are restricted to N and E striking vertical planes, respectively. Simple arrangements of block clusters mimic the gross kinematic pattern of Quaternary faulting in California and Nevada. Some implications for contemporary tectonics emphasized by this model involve the W displacement of the Sierra Nevada block with respect to the stable interior of the N American plates, oblique thrusting of the Salinian block over the Pacific plate, and a progressive increase in the offset of the San Andreas fault represented by the 'big bend' through the Transverse Ranges. -from Author

  3. SUPERFICIAL CERVICAL PLEXUS BLOCK

    Directory of Open Access Journals (Sweden)

    Komang Mega Puspadisari

    2014-01-01

    Full Text Available Superficial cervical plexus block is one of the regional anesthesia in  neck were limited to thesuperficial fascia. Anesthesia is used to relieve pain caused either during or after the surgery iscompleted. This technique can be done by landmark or with ultrasound guiding. The midpointof posterior border of the Sternocleidomastoid was identified and the prosedure done on thatplace or on the level of cartilage cricoid.

  4. Change Around the Block?

    Science.gov (United States)

    Berlin, Joey

    2017-04-01

    Proponents of a block grant or per-capita cap trumpet them as vehicles for the federal government to give the states a capped amount of funding for Medicaid that legislatures would effectively distribute how they see fit. Questions abound as to what capped Medicaid funding would look like, and what effect it would have on the current Medicaid-eligible population, covered services, and physician payments.

  5. Managing access block.

    Science.gov (United States)

    Cameron, Peter; Scown, Paul; Campbell, Donald

    2002-01-01

    There is pessimism regarding the ability of the Acute Health Sector to manage access block for emergency and elective patients. Melbourne Health suffered an acute bed crisis in 2001 resulting in record ambulance diversions and emergency department (ED) delays. We conducted an observational study to reduce access block for emergency patients whilst maintaining elective throughput at Melbourne Health. This involved a clinician-led taskforce using previously proven principles for organisational change to implement 51 actions to improve patient access over a three-month period. The primary outcome measures were ambulance diversion, emergency patients waiting more than 12 hours for an inpatient bed, elective throughput and theatre cancellations. Despite a reduction in multi-day bed numbers all primary objectives were met, ambulance diversion decreased to minimal levels, 12-hour waits decreased by 40% and elective throughput was maintained. Theatre cancellations were also minimised. We conclude that access block can be improved by clinician-led implementation of proven process improvements over a short time frame. The ability to sustain change over the longer term requires further study.

  6. Experimental Investigation on the Fatigue Mechanical Properties of Intermittently Jointed Rock Models Under Cyclic Uniaxial Compression with Different Loading Parameters

    Science.gov (United States)

    Liu, Yi; Dai, Feng; Dong, Lu; Xu, Nuwen; Feng, Peng

    2018-01-01

    Intermittently jointed rocks, widely existing in many mining and civil engineering structures, are quite susceptible to cyclic loading. Understanding the fatigue mechanism of jointed rocks is vital to the rational design and the long-term stability analysis of rock structures. In this study, the fatigue mechanical properties of synthetic jointed rock models under different cyclic conditions are systematically investigated in the laboratory, including four loading frequencies, four maximum stresses, and four amplitudes. Our experimental results reveal the influence of the three cyclic loading parameters on the mechanical properties of jointed rock models, regarding the fatigue deformation characteristics, the fatigue energy and damage evolution, and the fatigue failure and progressive failure behavior. Under lower loading frequency or higher maximum stress and amplitude, the jointed specimen is characterized by higher fatigue deformation moduli and higher dissipated hysteresis energy, resulting in higher cumulative damage and lower fatigue life. However, the fatigue failure modes of jointed specimens are independent of cyclic loading parameters; all tested jointed specimens exhibit a prominent tensile splitting failure mode. Three different crack coalescence patterns are classified between two adjacent joints. Furthermore, different from the progressive failure under static monotonic loading, the jointed rock specimens under cyclic compression fail more abruptly without evident preceding signs. The tensile cracks on the front surface of jointed specimens always initiate from the joint tips and then propagate at a certain angle with the joints toward the direction of maximum compression.

  7. Nitration Study of Cyclic Ladder Polyphenylsilsesquioxane

    Directory of Open Access Journals (Sweden)

    LIANG Jia-xiang

    2017-05-01

    Full Text Available Several nitration reagents including fuming nitric acid, HNO3-H2SO4, KNO3-H2SO4, HNO3-KNO3, CH3COOH-KNO3, (CH3CO2O-HNO3 were used to nitrate cyclic ladder polyphenylsilsesquioxane (CL-PPSQ in different conditions in order to enhance the compatibility of the CL-PPSQ in polymers, the NO2-PPSQ was obtained. FTIR, element analysis, GPC, TGA and 1H NMR were used to characterize the structures of the nitrated products. The results show that the nitrating abilities of the fuming nitric acid, HNO3-H2SO4 and KNO3-H2SO4 are very strong. Many nitro groups can be linked with phenyl groups in CL-PPSQ, but with low molecular mass, fracture occurs in siloxane segment. However, the Mn of the product NO2-PPSQ sharply drops by 50% compared with that of CL-PPSQ, so the nitration reagents can break the cyclic structure of CL-PPSQ. The nitrating reagents of HNO3-KNO3 and CH3COOH-KNO3 have no nitration effects on CL-PPSQ. At last, NO2-CL-PPSQ was prepared using (CH3CO2O-HNO3 because of the moderate nitration process and ability. The cyclic structure of PPSQ is remained, although the number of —NO2 group is not too much. At the same time, the nitration mechanism using different nitration reagents was analyzed. A certain amount of NO2+, which is a kind of activator owning strong nitration ability, can be found in the fuming nitric acid and H2SO4-HNO3(KNO3 systems. As to the (CH3CO2O-HNO3 system, the main activator is CH3COONO2.

  8. Cyclic creep, mechanical ratchetting and amplitude history dependence of modified 9Cr-1Mo steel and evaluation of unified constitutive models

    International Nuclear Information System (INIS)

    Tanaka, Eiichi; Yamada, Hiroshi

    1993-01-01

    The purpose of the present paper is to elucidate inelastic behavior of modified 9Cr-1Mo steel as a candidate material for the next-generation fast breeder reactor and to provide the information for the formulation of a unified constitutive model. For this purpose, cyclic creep, mechanical ratchetting and amplitude history dependence of cyclic hardening were first examined at 550degC. As a result, systematic cyclic creep and mechanical ratchetting behavior were observed under various loading conditions, and little amplitude history dependence was found. Then these results were simulated by three unified constitutive models, i.e. the Chaboche, Bodner-Partom and modified Chaboche models. The simulated results show that these models cannot describe the cyclic creep and mechanical ratchetting behavior with high accuracy, but succeed in describing the inelastic behavior of amplitude variation experiments. (author)

  9. Cosmological D-instantons and cyclic universes

    International Nuclear Information System (INIS)

    Bergshoeff, E A; Collinucci, A; Roest, D; Russo, J G; Townsend, P K

    2005-01-01

    For models of gravity coupled to hyperbolic sigma models, such as the metric-scalar sector of IIB supergravity, we show how smooth trajectories in the 'augmented target space' connect FLRW cosmologies to non-extremal D-instantons through a cosmological singularity. In particular, we find closed cyclic universes that undergo an endless sequence of big-bang to big-crunch cycles separated by instanton 'phases'. We also find 'big-bounce' universes in which a collapsing closed universe bounces off its cosmological singularity to become an open expanding universe

  10. Numerical Simulation of Cyclic Thermodynamic Processes

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård

    2006-01-01

    This thesis is on numerical simulation of cyclic thermodynamic processes. A modelling approach and a method for finding periodic steady state solutions are described. Examples of applications are given in the form of four research papers. Stirling machines and pulse tube coolers are introduced......, compressible flow in one space dimension is presented. The implementation produces models where all the equations, which are on a form that should be understandable to someone with a background in engineering thermodynamics, can be accessed and modified individually. The implementation was designed to make...

  11. Investigation of Cyclic Deformation and Fatigue of Polycrystalline Cu under Pure Compression Cyclic Loading Conditions

    Science.gov (United States)

    Hsu, Tzu-Yin Jean

    It is commonly accepted that fatigue crack is initiated under tensile fatigue stresses. However, practical examples demonstrate that cracks may also initiate under pure compressive fluctuating loads such as the failures observed in aircraft landing gear frames. However, the mechanism of such failures is rarely investigated. Furthermore, knowledge on cyclic deformation response under pure compressive fatigue condition is also very limited or non-existent. Our recent work already verified that fatigue cracks may nucleate from stress concentration sites under pure compression fatigue, but whether or not a form of stress concentration is always needed to initiate a crack under pure compression fatigue remains uncertain. In this study, compression fatigue tests under different peak stresses were carried out on smooth bars of fully annealed OFHC Copper. The purpose of these tests is to investigate not only the cyclic deformation response but also the possibility of crack nucleation without the stress concentrator. Results showed that overall the cyclic stress-strain response and microstructural evolution of OFHC Copper under pure compression fatigue exhibits rather dissimilar behaviour compared to those under symmetrical fatigue. The specimens hardened rapidly within 10 cycles under pure compression fatigue unlike the gradual cyclic hardening behaviour in symmetrical fatigue with the same peak stress amplitude. Compressive cyclic creep behaviour was also observed under the same testing conditions. Moreover, unlike conventional tension-compression fatigue, only moderate slip activity was detectable on the surface instead of typical PSB features detected from TEM observations. The surface observations has revealed that surface slip bands did not increase in number nor did they become more pronounced in height with increasing number of cycles. In addition, surface roughening by grain boundary extrusion was detected to become more severe as the cycling progressed. Therefore

  12. Crystal structure of cyclic tris(ferrocene-1,1′-diyl

    Directory of Open Access Journals (Sweden)

    Ruslan Shekurov

    2014-09-01

    Full Text Available The molecular structure of the trinuclear title compound, [Fe3(C10H83] {systematic name: tris[μ-(η5:η5-1,1′-bicyclopentadienyl]triiron(II}, consists of three ferrocene subunits (each with an eclipsed conformation that are condensed via C—C bonds of the fulvalene moieties into a cyclic trimer. The angles between the planes of the cyclopentadienyl (Cp rings within the three fulvalene moieties are 76.1 (3, 80.9 (3 and 81.7 (3°. In the crystal, C—H...π interactions between neighbouring molecules lead to the cohesion of the structure.

  13. Paving block study : final report.

    Science.gov (United States)

    1971-10-01

    The Louisiana Department of Highways has conducted field tests with an experimental revetment consisting of cellular concrete revetment blocks used in conjunction with plastic filter cloth and/or vegetation such as grass or vines. The precast blocks ...

  14. Habitat Blocks and Wildlife Corridors

    Data.gov (United States)

    Vermont Center for Geographic Information — Habitat blocks are areas of contiguous forest and other natural habitats that are unfragmented by roads, development, or agriculture. Vermonts habitat blocks are...

  15. Demographic Data - MDC_Block

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — A polygon feature class of Miami-Dade Census 2000 Blocks. Census blocks are areas bounded on all sides by visible and/or invisible features shown on a map prepared...

  16. Effects of Mild Curvature on ANCOVA and Randomized Blocks.

    Science.gov (United States)

    Klockars, Alan J.; Potter, Nina Salcedo

    The type I error control and power of a number of analysis of covariance (ANCOVA) and randomized block (RB) designs with curvilinear data were studied for tests of the additive treatment effect and interaction. For tests of additive effects, the analysis was also conducted using systematic assignment to treatments and using random assignment with…

  17. A cyclically actuated electrolytic drug delivery device

    KAUST Repository

    Yi, Ying

    2015-01-01

    This work, focusing on an implantable drug delivery system, presents the first prototype electrolytic pump that combines a catalytic reformer and a cyclically actuated mode. These features improve the release performance and extend the lifetime of the device. Using our platinum (Pt)-coated carbon fiber mesh that acts as a catalytic reforming element, the cyclical mode is improved because the faster recombination rate allows for a shorter cycling time for drug delivery. Another feature of our device is that it uses a solid-drug-in-reservoir (SDR) approach, which allows small amounts of a solid drug to be dissolved in human fluid, forming a reproducible drug solution for long-term therapies. We have conducted proof-of-principle drug delivery studies using such an electrolytic pump and solvent blue 38 as the drug substitute. These tests demonstrate power-controlled and pulsatile release profiles of the chemical substance, as well as the feasibility of this device. A drug delivery rate of 11.44 ± 0.56 μg min-1 was achieved by using an input power of 4 mW for multiple pulses, which indicates the stability of our system. © The Royal Society of Chemistry 2015.

  18. Effects of Cyclic Loading on Gravel

    Science.gov (United States)

    Modoni, Giuseppe; Dan, Le Quang; Koseki, Junichi; Maqbool, Sajjad

    The effects of a large number of load repetitions on gravel are discussed based on experimental evidences. To this purpose the results of several triaxial tests carried out on a coarse grained soil, artificially reconstituted at different prescribed levels of density, are reported and compared. The tests reproduce a broad variety of possible field conditions, being performed at different mean effective stresses, by applying sequences of load-unload repetitions, different by number of repetitions and amplitudes of cycles. The analysis of the experimental results has been conducted by focusing the attention on the plastic components of strain, calculated by scaling the non negligible elastic components from the measured ones. A theory for the interpretation of monotonic test results is first briefly presented to form the basis of the analysis of the cyclic test results. This last is referred to the evolution of the stress-strain relationships along with load repetitions, and particularly to the accumulation of distortional and volumetric strains and to the effects of previous cyclic loading on subsequent soil response.

  19. Fault diagnosis of rolling bearing based on cyclic spectrum density

    International Nuclear Information System (INIS)

    Shi Qingfeng; Yan Junming; Zhang Yanhong

    2009-01-01

    The paper considered the vibration signals of rotating equipment as cyclo stationary signals through analyzing the features of this kind of signals. Based on the analytic method of cyclic spectrum density, the paper pointed out that the impact frequency could be extracted effectively with the help of scanning cyclic frequency domain. The validity of the method of cyclic spectrum density is proved by simulating signals and the method is applied to the diagnosis of rolling bearings. (authors)

  20. Synthesis of Cyclic Py-Im Polyamide Libraries

    OpenAIRE

    Li, Benjamin C.; Montgomery, David C.; Puckett, James W.; Dervan, Peter B.

    2013-01-01

    Cyclic Py-Im polyamides containing two GABA turn units exhibit enhanced DNA binding affinity, but extensive studies of their biological properties have been hindered due to synthetic inaccessibility. A facile modular approach toward cyclic polyamides has been developed via microwave-assisted solid-phase synthesis of hairpin amino acid oligomer intermediates followed by macrocyclization. A focused library of cyclic polyamides 1–7 targeted to the androgen response element (ARE) and the estrogen...

  1. Cyclical mastalgia: Prevalence and associated determinants in Hamadan City, Iran

    OpenAIRE

    Shobeiri, Fatemeh; Oshvandi, Khodayar; Nazari, Mansour

    2016-01-01

    Objective: To assess prevalence of cyclical mastalgia and its main determinants in women who attended in health centers of Hamadan City, Iran. Methods: This case–control study was conducted on 400 women (case: cyclical mastalgia, n = 240; control: without cyclical mastalgia, n = 160) who attended family planning clinic for routine follow-up in health centers. The cluster sampling was used. Information was collected by interviewing and using a standardized validated questionnaire. Severity ...

  2. Influence of polydispersity on the phase behavior of statistical multiblock copolymers with Schultz-Zimm block molecular weight distributions

    NARCIS (Netherlands)

    Angerman, H.J.; Brinke, G. ten; Slot, J.J.M.

    1999-01-01

    In this paper we investigate in a systematic way the influence of polydispersity in the block lengths on the phase behavior of AB-multiblock copolymer melts. As model system we take a polydisperse multiblock copolymer for which both the A-blocks and the B-blocks satisfy a Schultz-Zimm distribution.

  3. Blocking the Hawking radiation

    DEFF Research Database (Denmark)

    Autzen, M.; Kouvaris, C.

    2014-01-01

    grows after its formation (and eventually destroys the star) instead of evaporating. The fate of the black hole is dictated by the two opposite mechanics, i.e., accretion of nuclear matter from the center of the star and Hawking radiation that tends to decrease the mass of the black hole. We study how...... the assumptions for the accretion rate can in fact affect the critical mass beyond which a black hole always grows. We also study to what extent degenerate nuclear matter can impede Hawking radiation due to the fact that emitted particles can be Pauli blocked at the core of the star....

  4. Cyclic fatigue resistance of 3 different nickel-titanium reciprocating instruments in artificial canals.

    Science.gov (United States)

    Higuera, Oscar; Plotino, Gianluca; Tocci, Luigi; Carrillo, Gabriela; Gambarini, Gianluca; Jaramillo, David E

    2015-06-01

    The purpose of this study was to evaluate the cyclic fatigue resistance of 3 different nickel-titanium reciprocating instruments. A total of 45 nickel-titanium instruments were tested and divided into 3 experimental groups (n = 15): group 1, WaveOne Primary instruments; group 2, Reciproc R25 instruments; and group 3, Twisted File (TF) Adaptive M-L1 instruments. The instruments were then subjected to cyclic fatigue test on a static model consisting of a metal block with a simulated canal with 60° angle of curvature and a 5-mm radius of curvature. WaveOne Primary, Reciproc R25, and TF Adaptive instruments were activated by using their proprietary movements, WaveOne ALL, Reciproc ALL, and TF Adaptive, respectively. All instruments were activated until fracture occurred, and the time to fracture was recorded visually for each file with a 1/100-second chronometer. Mean number of cycles to failure and standard deviations were calculated for each group, and data were statistically analyzed (P < .05). Instruments were also observed through scanning electron microscopy to evaluate type of fracture. Cyclic fatigue resistance of Reciproc R25 and TF Adaptive M-L1 was significantly higher than that of WaveOne Primary (P = .009 and P = .002, respectively). The results showed no statistically significant difference between TF Adaptive M-L1 and Reciproc R25 (P = .686). Analysis of the fractured portion under scanning electron microscopy indicated that all instruments showed morphologic characteristics of ductile fracture that were due to accumulation of metal fatigue. No statistically significant differences were found between the instruments tested except for WaveOne Primary, which showed the lowest resistance to cyclic fatigue. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Does Abutment Collar Length Affect Abutment Screw Loosening After Cyclic Loading?

    Science.gov (United States)

    Siadat, Hakimeh; Pirmoazen, Salma; Beyabanaki, Elaheh; Alikhasi, Marzieh

    2015-07-01

    A significant vertical space that is corrected with vertical ridge augmentation may necessitate selection of longer abutments, which would lead to an increased vertical cantilever. This study investigated the influence of different abutment collar heights on single-unit dental implant screw-loosening after cyclic loading. Fifteen implant-abutment assemblies each consisted of an internal hexagonal implant were randomly assigned to 3 groups: Group1, consisting of 5 abutments with 1.5 mm gingival height (GH); Group2, 5 abutments with 3.5 mm GH; and Group3, 5 abutments with 5.5 mm GH. Each specimen was mounted in transparent auto-polymerizing acrylic resin block, and the abutment screw was tightened to 35 Ncm with an electric torque wrench. After 5 minutes, initial torque loss (ITL) was recorded for all specimens. Metal crowns were fabricated with 45° occlusal surface and were placed on the abutments. A cyclic load of 75 N and frequency of 1 Hz were applied perpendicular to the long axis of each specimen. After 500 000 cycles, secondary torque loss (STL) was recorded. One-way ANOVA analysis was used to evaluate the effects of abutment collar height before and after cyclic loading. One-way ANOVA showed that ITL among the groups was not significantly different (P = .52), while STL was significantly different among the groups (P = .008). Post-hoc Tukey HSD tests showed that STL values were significantly different between the abutments with 1.5 mm GH (Group1) and with 5.5 mm GH (Group3) (P = .007). A paired comparison t-test showed that cyclic loading significantly influenced the STL in comparison with the ITL in each group. Within the limitations of this study, it can be concluded that increase in height of the abutment collar could adversely affect the torque loss of the abutment screw.

  6. Cyclic delivery-scheduling problem with synchronization of vehicles\\' arrivals at logistic centers

    Directory of Open Access Journals (Sweden)

    Katarzyna Zofia Gdowska

    2015-12-01

    Full Text Available Background: In this paper a cyclic delivery-scheduling problem with vehicles serving fixed routes is presented. Each vehicle is assigned to one route to which some manufacturers' warehouses and logistics centers belong. A vehicle is to be loaded at a manufacturer's warehouse, then to deliver goods to a logistics center and may be also loaded there with other goods and to transport them to the next node along the route. One logistic center belongs to several routes, so the goods delivered by one vehicle may continue their journey by another truck. For every route the frequency of the vehicle is fixed and known. The objective here is to obtain such synchronization of vehicles arrivals in logistics centers, so that it is possible to organize their arrivals in repeatable blocks. Methods: In the paper the cyclic delivery-scheduling problem with vehicles serving fixed routes is formulated as a MIP model. Due to the fixed routes and desirable synchronization of vehicles arrivals in shared points this problem seems to be similar to the public transit network timetabling problem. Because of that the model presented here was based on a model dedicated to the public transit network timetabling problem, where optimization criterion was to maximize synchronization of vehicles' arrivals at the shared nodes. Results: Mixed integer programming model was employed for solving several cases of cyclic delivery-scheduling problem with vehicles serving fixed routes. Computational experiments are reported and obtained results are presented. Conclusions: The mixed integer programming model for the cyclic delivery-scheduling problem with synchronization of vehicles arrivals at logistic centers presented in this paper can be utilized for generating schedules for a group of vehicles serving fixed long routes. It may result in reducing total operational cost related to this group of vehicles as well as in reducing the goods travel time from the place of origin to their

  7. Cyclic Mechanical Stretching Induces Autophagic Cell Death in Tenofibroblasts Through Activation of Prostaglandin E2 Production

    Directory of Open Access Journals (Sweden)

    Hua Chen

    2015-04-01

    Full Text Available Background/Aims: Autophagic cell death has recently been implicated in the pathophysiology of tendinopathy. Prostaglandin E2 (PGE2, a known inflammatory mediator of tendinitis, inhibits tenofibroblast proliferation in vitro; however, the underlying mechanism is unclear. The present study investigated the relationship between PGE2 production and autophagic cell death in mechanically loaded human patellar tendon fibroblasts (HPTFs in vitro. Methods: Cultured HPTFs were subjected to exogenous PGE2 treatment or repetitive cyclic mechanical stretching. Cell death was determined by flow cytometry with acridine orange/ethidium bromide staining. Induction of autophagy was assessed by autophagy markers including the formation of autophagosomes and autolysosomes (by electron microscopy, AO staining, and formation of GPF-LC3-labeled vacuoles and the expression of LC3-II and BECN1 (by western blot. Stretching-induced PGE2 release was determined by ELISA. Results: Exogenous PGE2 significantly induced cell death and autophagy in HPTFs in a dose-dependent manner. Blocking autophagy using inhibitors 3-methyladenine and chloroquine, or small interfering RNAs against autophagy genes Becn-1 and Atg-5 prevented PGE2-induced cell death. Cyclic mechanical stretching at 8% and 12% magnitudes for 24 h significantly stimulated PGE2 release by HPTFs in a magnitude-dependent manner. In addition, mechanical stretching induced autophagy and cell death. Blocking PGE2 production using COX inhibitors indomethacin and celecoxib significantly reduced stretching-induced autophagy and cell death. Conclusion: Taken together, cyclic mechanical stretching induces autophagic cell death in tenofibroblasts through activation of PGE2 production.

  8. How Artists Overcome Creative Blocks.

    Science.gov (United States)

    Hirst, Barbara

    1992-01-01

    Six practicing artists were interviewed about how they overcome creative blocks. Their responses indicated that feelings of self-doubt, fear, and depression accompany blocks but that relaxing and working on new directions and playing ideas off a supportive person helped to overcome such blocks. (DB)

  9. Block Scheduling in High Schools.

    Science.gov (United States)

    Irmsher, Karen

    1996-01-01

    Block Scheduling has been considered a cure for a lengthy list of educational problems. This report reviews the literature on block schedules and describes some Oregon high schools that have integrated block scheduling. Major disadvantages included resistance to change and requirements that teachers change their teaching strategies. There is…

  10. Abdominal wall blocks in adults

    DEFF Research Database (Denmark)

    Neimann, Jens Dupont Børglum; Gögenür, Ismail; Bendtsen, Thomas F.

    2016-01-01

    Purpose of review Abdominal wall blocks in adults have evolved much during the last decade; that is, particularly with the introduction of ultrasound-guided (USG) blocks. This review highlights recent advances of block techniques within this field and proposes directions for future research.  Rec...

  11. Cyclic Team Teaching in Ninth-Grade Physical Science

    Science.gov (United States)

    Swainson, Ralph; And Others

    1971-01-01

    Presents the instructional procedures used in a team teaching situation. Identifies advantages and problems encountered in cyclic approach to demonstration, laboratory, programed, and large group activities. (DS)

  12. Electrochemically controlled self-assembly of block copolymer nanostructures

    Science.gov (United States)

    Eitouni, Hany Basam

    Organometallic block copolymers, wherein one block is composed of alternating ferrocene and dialkylsilane units in the main chain, undergo self-assembly to form microphase-separated ordered structures similarly to typical organic block copolymers. The 1,1'-dimethylsilylferrocenophane monomer was synthesized and polymerized anionically with other monomers to make a variety of different organometallic block copolymers. The phase behavior and thermodynamic interactions of anionically synthesized poly(styrene-block-ferrocenyldimethylsilane) (SF) and poly(isoprene-block-ferrocenyldimethylsilane) (IF) copolymers were examined using depolarized light scattering, small angle x-ray and neutron scattering (SAXS and SANS), and transmission electron microscopy. The temperature-dependence of the Flory-Huggins parameter, chi, and the statistical segment lengths of SF and IF copolymers were determined by SAXS and SANS using the random phase approximation. The thermodynamic interactions in poly(ferrocenyldimethylsilane) diblock copolymers were systematically adjusted by oxidizing the ferrocene moieties with silver salts and examined using SAXS and depolarized light scattering. The polymers retained microphase separated ordered structures upon oxidation and showed systematic changes in the location of the order-disorder transition as a function of extent of oxidation. By controlling the redox properties of the ferrocene moiety in the backbone of the polymer, we present a method for controlling the self-assembled microstructure and hence bulk material properties. Using electrochemical techniques, a novel means of controlling the order-disorder transition of block copolymers was discovered. By applying very small electrical potentials to disordered solutions of organometallic block copolymers, oriented ordered grains were formed near one electrode, the result of electrochemical reactions. After reversing the electrical bias on the system, the ordered grains disappeared and new

  13. Amplifying (Im)perfection: The Impact of Crystallinity in Discrete and Disperse Block Co-oligomers.

    Science.gov (United States)

    van Genabeek, Bas; Lamers, Brigitte A G; de Waal, Bas F M; van Son, Martin H C; Palmans, Anja R A; Meijer, E W

    2017-10-25

    Crystallinity is seldomly utilized as part of the microphase segregation process in ultralow-molecular-weight block copolymers. Here, we show the preparation of two types of discrete, semicrystalline block co-oligomers, comprising an amorphous oligodimethylsiloxane block and a crystalline oligo-l-lactic acid or oligomethylene block. The self-assembly of these discrete materials results in lamellar structures with unforeseen uniformity in the domain spacing. A systematic introduction of dispersity reveals the extreme sensitivity of the microphase segregation process toward chain length dispersity in the crystalline block.

  14. Program structure-based blocking

    Science.gov (United States)

    Bertolli, Carlo; Eichenberger, Alexandre E.; O'Brien, John K.; Sura, Zehra N.

    2017-09-26

    Embodiments relate to program structure-based blocking. An aspect includes receiving source code corresponding to a computer program by a compiler of a computer system. Another aspect includes determining a prefetching section in the source code by a marking module of the compiler. Yet another aspect includes performing, by a blocking module of the compiler, blocking of instructions located in the prefetching section into instruction blocks, such that the instruction blocks of the prefetching section only contain instructions that are located in the prefetching section.

  15. Estrous Cyclicity in Mice During Simulated Weightlessness

    Science.gov (United States)

    Moyer, E. L.; Talyansky, Y.; Scott, R. T.; Tash, J. S.; Christenson, L. K.; Alwood, J. S.; Ronca, A. E.

    2017-01-01

    Hindlimb unloading (HU) is a rodent model system used to simulate weightlessness experienced in space. However, some effects of this approach on rodent physiology are under-studied, specifically the effects on ovarian estrogen production which drives the estrous cycle. To resolve this deficiency, we conducted a ground-based validation study using the HU model, while monitoring estrous cycles in 16-weeks-old female C57BL6 mice. Animals were exposed to HU for 12 days following a 3 day HU cage acclimation period, and estrous cycling was analyzed in HU animals (n=22), normally loaded HU Cage Pair-Fed controls (CPF; n=22), and Vivarium controls fed ad libitum (VIV; n=10). Pair feeding was used to control for potential nutritional deficits on ovarian function. Vaginal cells were sampled daily in all mice via saline lavage. Cells were dried and stained with crystal violet, and the smears evaluated using established vaginal cytology techniques by two individuals blinded to the animal treatment group. Estrous cyclicity was disrupted in nearly all HU and CPF mice, while those maintained in VIV had an average normal cycle length of 4.8+/- 0.5 days, with all stages in the cycle visibly observed. CPF and HU animals arrested in the diestrous phase, which precedes the pre-ovulatory estrogen surge. Additionally, infection-like symptoms characterized by vaginal discharge and swelling arose in several HU animals, which we suspect was due to an inability of these mice to properly groom themselves, and/or due to the change in the gravity vector relative to the vaginal opening, which prevented drainage of the lavage solution. Pair-feeding resulted in similar weight gains of HU and CPF (1.5% vs 3.0%, respectively). The current results indicate that pair-feeding controlled weight gain and that the HU cage alone influenced estrous cyclicity. Thus, longer acclimation needs to be tested to determine if and when normal estrous cycling resumes in non-loaded mice in HU cages prior to HU

  16. Estrous Cyclicity of Mice During Simulated Weightlessness

    Science.gov (United States)

    Moyer, Eric; Talyansky, Yuli; Scott, Ryan; Tash, Joseph; Christenson, Lane; Alwood, Joshua; Ronca, April

    2017-01-01

    Hindlimb unloading (HU) is a rodent model system used to simulate weightlessness experienced in space. However, some effects of this approach on rodent physiology are under-studied, specifically the effects on ovarian estrogen production which drives the estrous cycle. To resolve this deficiency, we conducted a ground-based validation study using the HU model, while monitoring estrous cycles in 16-weeks-old female C57BL6 mice. Animals were exposed to HU for 12 days following a 3 day HU cage acclimation period, and estrous cycling was analyzed in HU animals (n22), normally loaded HU Cage Pair-Fed controls (CPF; n22), and Vivarium controls fed ad libitum (VIV; n10). Pair feeding was used to control for potential nutritional deficits on ovarian function. Vaginal cells were sampled daily in all mice via saline lavage. Cells were dried and stained with crystal violet, and the smears evaluated using established vaginal cytology techniques by two individuals blinded to the animal treatment group. Estrous cyclicity was disrupted in nearly all HU and CPF mice, while those maintained in VIV had an average normal cycle length of 4.8 0.5 days, with all stages in the cycle visibly observed. CPF and HU animals arrested in the diestrous phase, which precedes the pre-ovulatory estrogen surge. Additionally, infection-like symptoms characterized by vaginal discharge and swelling arose in several HU animals, which we suspect was due to an inability of these mice to properly groom themselves, andor due to the change in the gravity vector relative to the vaginal opening, which prevented drainage of the lavage solution. Pair-feeding resulted in similar weight gains of HU and CPF (1.5 vs 3.0, respectively). The current results indicate that pair-feeding controlled weight gain and that the HU cage alone influenced estrous cyclicity. Thus, longer acclimation needs to be tested to determine if and when normal estrous cycling resumes in non-loaded mice in HU cages prior to HU testing. Future

  17. Development of Nonelectronic Part Cyclic Failure Rates

    Science.gov (United States)

    1977-12-01

    SUPPLEMENTARY NOTES R.ADC Project Er.gineer: Lester J. Cubbills (RBRT) 19 KEY WORDS (Continue an reverse aide tC necesser and idenr,11 by block tiumher...failure rate model for relays to modify failure rates of established reliability (ER) relays, based on their failure rate level. The only daca collected

  18. Biologic activity of cyclic and caged phosphates: a review.

    Science.gov (United States)

    Lorke, Dietrich E; Stegmeier-Petroianu, Anka; Petroianu, Georg A

    2017-01-01

    The recognition in the early 1960s by Morifusa Eto that tri-o-cresyl phosphate (TOCP) is hydroxylated by the cytochrome P450 system to an intermediate that spontaneously cyclizes to a neurotoxic phosphate (saligenin phosphate ester) ignited the interest in this group of compounds. Only the ortho isomer can cyclize and clinically cause Organo Phosphate Induced Delayed Neurotoxicity (OPIDN); the meta and para isomers of tri-cresyl phosphate are not neuropathic because they are unable to form stable cyclic saligenin phosphate esters. This review identifies the diverse biological effects associated with various cyclic and caged phosphates and phosphonates and their possible use. Cyclic compounds that inhibit acetylcholine esterase (AChE), such as salithion, can be employed as pesticides. Others are neurotoxic, most probably because of inhibition of neuropathy target esterase (NTE). Cyclic phosphates that inhibit lipases, the cyclipostins, possibly represent promising therapeutic avenues for the treatment of type 2 diabetes mellitus and/or microbial infections; those compounds inhibiting β-lactamase may prevent bacterial resistance against β-lactam antibiotics. Naturally occurring cyclic phosphates, such as cyclic AMP, cyclic phosphatidic acid and the ryanodine receptor modulator cyclic adenosine diphosphate ribose, play an important physiological role in signal transduction. Moreover, some cyclic phosphates are GABA-antagonists, while others are an essential component of Molybdenum-containing enzymes. Some cyclic phosphates (cyclophosphamide, ifosfamide) are clinically used in tumor therapy, while the coupling of therapeutic agents with other cyclic phosphates (HepDirect® Technology) allows drugs to be targeted to specific organs. Possible clinical applications of these compounds are considered. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Magnetoelastic Demagnetization of Steel under Cyclic Loading

    Science.gov (United States)

    Muratov, K. R.; Novikov, V. F.; Neradovskii, D. F.; Kazakov, R. Kh.

    2018-01-01

    Magnetoelastic demagnetization of steel samples under cyclic tensile loads has been analyzed. It has been established that values of residual magnetization that correspond to peak loads are characterized by the power-law dependence on the number of loading cycles. In some cases, in the region of high loads, the qualitative transition to exponential dependence has been observed. Coefficients of the power-law approximation of peak magnetization depend on the value of amplitude load and have specific characteristics in the vicinity of characteristic loads. The ratios of approximated slide load coefficients depending on the load are common for the three considered samples, and there is an outburst in the vicinity of the fatigue limit, which can be used as the basis for developing the rapid nondestructive method for determination of this limit.

  20. The cyclic universe: An informal introduction

    International Nuclear Information System (INIS)

    Steinhaxdt, Paul J.; Turok, Neil

    2003-01-01

    The Cyclic Model is a radical, new cosmological scenario which proposes that the Universe undergoes an endless sequence of epochs which begin with a 'big bang' and end in a 'big crunch.' When the Universes bounces from contraction to re-expansion, the temperature and density remain finite. The model does not include a period of rapid inflation, yet it reproduces all of the successful predictions of standard big bang and inflationary cosmology. We point out numerous novel elements that have not been used previously which may open the door to further alternative cosmologies. Although the model is motivated by M-theory, branes and extra dimensions, here we show that the scenario can be described almost entirely in terms of conventional 4d field theory and 4d cosmology

  1. Janus cyclic peptide-polymer nanotubes

    Science.gov (United States)

    Danial, Maarten; My-Nhi Tran, Carmen; Young, Philip G.; Perrier, Sébastien; Jolliffe, Katrina A.

    2013-11-01

    Self-assembled nanotubular structures have numerous potential applications but these are limited by a lack of control over size and functionality. Controlling these features at the molecular level may allow realization of the potential of such structures. Here we report a new generation of self-assembled cyclic peptide-polymer nanotubes with dual functionality in the form of either a Janus or mixed polymeric corona. A ‘relay’ synthetic strategy is used to prepare nanotubes with a demixing or mixing polymeric corona. Nanotube structure is assessed in solution using 1H-1H nuclear Overhauser effect spectroscopy NMR, and in bulk using differential scanning calorimetry. The Janus nanotubes form artificial pores in model phospholipid bilayers. These molecules provide a viable pathway for the development of intriguing nanotubular structures with dual functionality via a demixing or a mixing polymeric corona and may provide new avenues for the creation of synthetic transmembrane protein channel mimics.

  2. Cyclic steps incised on experimental bedrock

    Science.gov (United States)

    Yokokawa, M.; Kyogoku, A.; Kotera, A.; Izumi, N.

    2013-12-01

    In rivers flowing in mountain areas, a series of steps are often observed on bedrock. They are thought to be cyclic steps formed due to erosion of bedrock, which should be driven by abrasion due to bedload sediment transport. We demonstrated a series of flume experiments of the formation of cyclic steps on bedrock by abrasion due to bedload transportation using weak mortar as the model bedrock. We also compared the shapes of the steps reproduced in the experiments with those obtained in the analysis. The experiments were conducted using a 1.5 m long, 2 cm wide, and 20 cm deep flume made of glass in Osaka Institute of Technology. The flume has 10-cm-high weirs at both ends, so that there is a 10-cm-deep reservoir. We put mortar into the reservoir and hardened it. In order to make a highly erodible mortar, we casted the mortar with extremely low amount of cement. The ratio of cement, sand (0.2 mm in diameter), and water is x:150:50 (x ranges 1-3). The flume is tilted by 10 degrees. The water and colored sand is supplied from a head tank to the upstream end of the flume, flows on 'model bedrock' in the flume, and was dropped from the downstream end. We observed morphological changes of the surface of the bedrock by photos. We also used a laser displacement sensor to measure the surface topography of the 'model bedrock' before and after each run. The configuration of steps largely depends on the hardness of model bedrocks. In the case of the softest model bedrock (cement-sand-water ratio is 1:150:50) with small amount of sand, long-drawn potholes tend to be formed. Clear cyclic steps are formed on harder model bedrocks with large cement-sand-water ratios such as 2:150:50 and 3:150:50. When a series of steps are formed on the bed, typical wavelength and wave height are approximately 20 cm, and 2 - 3 cm, respectively. The general shape of a step is characterized by a relatively long downward-inclined slope just upstream of a short upward-inclined slope. The feature of

  3. Protein Misfolding Cyclic Amplification of Infectious Prions.

    Science.gov (United States)

    Moda, Fabio

    2017-01-01

    Transmissible spongiform encephalopathies, or prion diseases, are a group of incurable disorders caused by the accumulation of an abnormally folded prion protein (PrP Sc ) in the brain. According to the "protein-only" hypothesis, PrP Sc is the infectious agent able to propagate the disease by acting as a template for the conversion of the correctly folded prion protein (PrP C ) into the pathological isoform. Recently, the mechanism of PrP C conversion has been mimicked in vitro using an innovative technique named protein misfolding cyclic amplification (PMCA). This technology represents a great tool for studying diverse aspects of prion biology in the field of basic research and diagnosis. Moreover, PMCA can be expanded for the study of the misfolding process associated to other neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and frontotemporal lobar degeneration. © 2017 Elsevier Inc. All rights reserved.

  4. Block copolymer investigations

    Science.gov (United States)

    Yufa, Nataliya A.

    The research presented in this thesis deals with various aspects of block copolymers on the nanoscale: their behavior at a range of temperatures, their use as scaffolds, or for creation of chemically striped surfaces, as well as the behavior of metals on block copolymers under the influence of UV light, and the healing behavior of copolymers. Invented around the time of World War II, copolymers have been used for decades due to their macroscopic properties, such as their ability to be molded without vulcanization, and the fact that, unlike rubber, they can be recycled. In recent years, block copolymers (BCPs) have been used for lithography, as scaffolds for nano-objects, to create a magnetic hard drive, as well as in photonic and other applications. In this work we used primarily atomic force microscopy (AFM) and transmission electron microscopy (TEM), described in Chapter II, to conduct our studies. In Chapter III we demonstrate a new and general method for positioning nanoparticles within nanoscale grooves. This technique is suitable for nanodots, nanocrystals, as well as DNA. We use AFM and TEM to demonstrate selective decoration. In Chapters IV and V we use AFM and TEM to study the structure of polymer surfaces coated with metals and self-assembled monolayers. We describe how the surfaces were created, exhibit their structure on the nanoscale, and prove that their macroscopic wetting properties have been altered compared to the original polymer structures. Finally, Chapters VI and VII report out in-situ AFM studies of BCP at high temperatures, made possible only recently with the invention of air-tight high-temperature AFM imaging cells. We locate the transition between disordered films and cylinders during initial ordering. Fluctuations of existing domains leading to domain coarsening are also described, and are shown to be consistent with reptation and curvature minimization. Chapter VII deals with the healing of PS-b-PMMA following AFM-tip lithography or

  5. Compressive cyclic ratcheting and fatigue of synthetic, soft biomedical polymers in solution.

    Science.gov (United States)

    Miller, Andrew T; Safranski, David L; Smith, Kathryn E; Guldberg, Robert E; Gall, Ken

    2016-02-01

    The use of soft, synthetic materials for the replacement of soft, load-bearing tissues has been largely unsuccessful due to a lack of materials with sufficient fatigue and wear properties, as well as a lack of fundamental understanding on the relationship between material structure and behavior under cyclic loads. In this study, we investigated the response of several soft, biomedical polymers to cyclic compressive stresses under aqueous conditions and utilized dynamic mechanical analysis and differential scanning calorimetry to evaluate the role of thermo-mechanical transitions on such behavior. Studied materials include: polycarbonate urethane, polydimethylsiloxane, four acrylate copolymers with systematically varied thermo-mechanical transitions, as well as bovine meniscal tissue for comparison. Materials showed compressive moduli between 2.3 and 1900MPa, with polycarbonate urethane (27.3MPa) matching closest to meniscal tissue (37.0MPa), and also demonstrated a variety of thermo-mechanical transition behaviors. Cyclic testing resulted in distinct fatigue-life curves, with failure defined as either classic fatigue fracture or a defined increased in maximum strain due to ratcheting. Our study found that polymers with sufficient dissipation mechanisms at the testing temperature, as evidenced by tan delta values, were generally tougher than those with less dissipation and exhibited ratcheting rather than fatigue fracture much like meniscal tissue. Strain recovery tests indicated that, for some toughened polymers, the residual strain following our cyclic loading protocol could be fully recovered. The similarity in ratcheting behavior, and lack of fatigue fracture, between the meniscal tissue and toughened polymers indicates that such polymers may have potential as artificial soft tissue. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Characteristics of turbulent particle transport in human airways under steady and cyclic flows

    International Nuclear Information System (INIS)

    Jedelsky, Jan; Lizal, Frantisek; Jicha, Miroslav

    2012-01-01

    Highlights: ► PDA data allow to estimate PSD of particle velocity fluctuations in realistic model. ► PSD of micron-sized particles is independent of their size up to 700 Hz. ► Such particles follow air flow and turb. diffusion contributes to their deposition. ► Cyclic flow PSDs contain more TKE at high freq. than equivalent steady-flow PSDs. ► Exp. breathing phase differs from insp. phase at high frequency part of the spectra. - Abstract: Motion of monodispersed aerosol particles suspended in air flow has been studied on realistic transparent model of human airways using Phase Doppler Particle Analyser (P/DPA). Time-resolved velocity data for particles in size range 1–8 μm were processed using Fuzzy Slotting Technique to estimate the power spectral density (PSD) of velocity fluctuations. The optimum processing setup for our data was found and recommendations for future experiments to improve PSD quality were suggested. Typical PSD plots at mainstream positions of the trachea and the upper bronchi are documented and differences among (1) steady-flow regimes and equivalent cyclic breathing regimes, (2) inspiration and expiration breathing phase and (3) behaviour of particles of different sizes are described in several positions of the airway model. Systematically higher level of velocity fluctuations in the upper part of the frequency range (30–500 Hz) was found for cyclic flows in comparison with corresponding steady flows. Expiratory flows in both the steady and cyclic cases produce more high-frequency fluctuations compared to inspiratory flows. Negligible differences were found for flow of particles in the inspected size range 1–8 μm at frequencies below 500 Hz. This finding was explained by Stokes number analysis. Implied match of the air and particle flows thereby indicates turbulent diffusion as important deposition mechanism and confirms the capability to use the P/DPA data as the air flow velocity estimate.

  7. Cyclic nucleotides and mitogen-activated protein kinases: regulation of simvastatin in platelet activation

    Directory of Open Access Journals (Sweden)

    Hou Ssu-Yu

    2010-06-01

    Full Text Available Abstract Background 3-Hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA reductase inhibitors (statins have been widely used to reduce cardiovascular risk. These statins (i.e., simvastatin may exert other effects besides from their cholesterol-lowering actions, including inhibition of platelet activation. Platelet activation is relevant to a variety of coronary heart diseases. Although the inhibitory effect of simvastatin in platelet activation has been studied; the detailed signal transductions by which simvastatin inhibit platelet activation has not yet been completely resolved. Methods The aim of this study was to systematically examine the detailed mechanisms of simvastatin in preventing platelet activation. Platelet aggregation, flow cytometric analysis, immunoblotting, and electron spin resonance studies were used to assess the antiplatelet activity of simvastatin. Results Simvastatin (20-50 μM exhibited more-potent activity of inhibiting platelet aggregation stimulated by collagen than other agonists (i.e., thrombin. Simvastatin inhibited collagen-stimulated platelet activation accompanied by [Ca2+]i mobilization, thromboxane A2 (TxA2 formation, and phospholipase C (PLCγ2, protein kinase C (PKC, and mitogen-activated protein kinases (i.e., p38 MAPK, JNKs phosphorylation in washed platelets. Simvastatin obviously increased both cyclic AMP and cyclic GMP levels. Simvastatin markedly increased NO release, vasodilator-stimulated phosphoprotein (VASP phosphorylation, and endothelial nitric oxide synthase (eNOS expression. SQ22536, an inhibitor of adenylate cyclase, markedly reversed the simvastatin-mediated inhibitory effects on platelet aggregation, PLCγ2 and p38 MAPK phosphorylation, and simvastatin-mediated stimulatory effects on VASP and eNOS phosphorylation. Conclusion The most important findings of this study demonstrate for the first time that inhibitory effect of simvastatin in platelet activation may involve activation of the cyclic AMP-eNOS/NO-cyclic

  8. Celiac ganglia block

    Energy Technology Data Exchange (ETDEWEB)

    Akinci, Devrim [Department of Radiology, Hacettepe University School of Medicine, Sihhiye, 06100 Ankara (Turkey); Akhan, Okan [Department of Radiology, Hacettepe University School of Medicine, Sihhiye, 06100 Ankara (Turkey)]. E-mail: oakhan@hacettepe.edu.tr

    2005-09-01

    Pain occurs frequently in patients with advanced cancers. Tumors originating from upper abdominal viscera such as pancreas, stomach, duodenum, proximal small bowel, liver and biliary tract and from compressing enlarged lymph nodes can cause severe abdominal pain, which do not respond satisfactorily to medical treatment or radiotherapy. Percutaneous celiac ganglia block (CGB) can be performed with high success and low complication rates under imaging guidance to obtain pain relief in patients with upper abdominal malignancies. A significant relationship between pain relief and degree of tumoral celiac ganglia invasion according to CT features was described in the literature. Performing the procedure in the early grades of celiac ganglia invasion on CT can increase the effectiveness of the CGB, which is contrary to World Health Organization criteria stating that CGB must be performed in patients with advanced stage cancer. CGB may also be effectively performed in patients with chronic pancreatitis for pain palliation.

  9. Photovoltaic building blocks

    DEFF Research Database (Denmark)

    Hanberg, Peter Jesper; Jørgensen, Anders Michael

    2014-01-01

    efficiency of about 15% for commercial Silicon solar cells there is still much to gain. DTU Danchip provides research facilities, equipment and expertise for the building blocks that comprises fabricating the efficient solar cell. In order to get more of the sun light into the device we provide thin film......Photovoltaics (PV), better known as solar cells, are now a common day sight on many rooftops in Denmark.The installed capacity of PV systems worldwide is growing exponentially1 and is the third most importantrenewable energy source today. The cost of PV is decreasing fast with ~10%/year but to make...... it directcompetitive with fossil energy sources a further reduction is needed. By increasing the efficiency of the solar cells one gain an advantage through the whole chain of cost. So that per produced Watt of power less material is spent, installation costs are lower, less area is used etc. With an average...

  10. Atomic Basic Blocks

    Science.gov (United States)

    Scheler, Fabian; Mitzlaff, Martin; Schröder-Preikschat, Wolfgang

    Die Entscheidung, einen zeit- bzw. ereignisgesteuerten Ansatz für ein Echtzeitsystem zu verwenden, ist schwierig und sehr weitreichend. Weitreichend vor allem deshalb, weil diese beiden Ansätze mit äußerst unterschiedlichen Kontrollflussabstraktionen verknüpft sind, die eine spätere Migration zum anderen Paradigma sehr schwer oder gar unmöglich machen. Wir schlagen daher die Verwendung einer Zwischendarstellung vor, die unabhängig von der jeweils verwendeten Kontrollflussabstraktion ist. Für diesen Zweck verwenden wir auf Basisblöcken basierende Atomic Basic Blocks (ABB) und bauen darauf ein Werkzeug, den Real-Time Systems Compiler (RTSC) auf, der die Migration zwischen zeit- und ereignisgesteuerten Systemen unterstützt.

  11. Celiac ganglia block

    International Nuclear Information System (INIS)

    Akinci, Devrim; Akhan, Okan

    2005-01-01

    Pain occurs frequently in patients with advanced cancers. Tumors originating from upper abdominal viscera such as pancreas, stomach, duodenum, proximal small bowel, liver and biliary tract and from compressing enlarged lymph nodes can cause severe abdominal pain, which do not respond satisfactorily to medical treatment or radiotherapy. Percutaneous celiac ganglia block (CGB) can be performed with high success and low complication rates under imaging guidance to obtain pain relief in patients with upper abdominal malignancies. A significant relationship between pain relief and degree of tumoral celiac ganglia invasion according to CT features was described in the literature. Performing the procedure in the early grades of celiac ganglia invasion on CT can increase the effectiveness of the CGB, which is contrary to World Health Organization criteria stating that CGB must be performed in patients with advanced stage cancer. CGB may also be effectively performed in patients with chronic pancreatitis for pain palliation

  12. Random versus Blocked Practice in Treatment for Childhood Apraxia of Speech

    Science.gov (United States)

    Maas, Edwin; Farinella, Kimberly A.

    2012-01-01

    Purpose: To compare the relative effects of random vs. blocked practice schedules in treatment for childhood apraxia of speech (CAS). Although there have been repeated suggestions in the literature to use random practice in CAS treatment, no systematic studies exist that have directly compared random with blocked practice in this population.…

  13. Multicomponent Synthesis of Cyclic Depsipeptide Mimics by Ugi Reaction Including Cyclic Hemiacetals Derived from Asymmetric Organocatalysis.

    Science.gov (United States)

    de la Torre, Alexander F; Rivera, Daniel G; Concepción, Odette; Echemendia, Radell; Correa, Arlene G; Paixão, Márcio W

    2016-02-05

    The synthesis of novel cyclic depsipeptide mimics by means of an organocatalytic conjugate addition, leading to chiral cyclic hemiacetals, followed by a multicomponent reaction with α-amino acids and isocyanides, is described. The initial organocatalytic step is employed for the asymmetric derivatization of α,β-unsaturated aldehydes to 4,5-disubstituted 2-hydroxytetrahydropyrans, which are next used as chiral bifunctional substrates on the Ugi five-center three-component reaction, giving rise to nine-membered-ring lactones. This sequential approach proved to be suitable for the rapid generation of molecular complexity through the combination of aliphatic, dipeptidic, glucosidic, and lipidic isocyanides with several amino acids, thus giving access to amido-, glyco-, and lipo-depsipeptide scaffolds featuring natural product-like structures.

  14. Cyclic Oxidation Behaviour of Domestic Superalloys at Elevated Temperature

    International Nuclear Information System (INIS)

    Kang, S. C.; Kim, G. M.; Chon, Y. G.

    1991-01-01

    The cyclic oxidation behaviour of commercial superalloys produced in Korea was investigated in air at 1000 .deg. C and 1100 .deg. C. Cyclic oxidation test was carried out by cyclically oxidizing the specimens in an apparatus which periodically removed the specimens from the furnace and reinserted them. The influence of growth stress and thermal stress on the cyclic oxidation was studied by examination of the oxide structures, their morphologies, and EDS line scanning of cross-section of cyclically oxidized specimens. The results showed that Inconel 601 was the best in the cyclic oxidation resistance among the tested alloys, followed by Nimonic 80A, Incoloy 825 and Inconel 718 at 1100 .deg. C. As in the case of the isothermal oxidation, relatively pure Cr 2 O 3 was effective in the beginning of cyclic oxidation experiment. But, later on, other oxidation products as well as Cr 2 O 3 were formed, resulting in the spallation of oxide scales. Especially, Nb and Mo in the alloys were determental to the cyclic oxidation behavior

  15. Classifying spaces with virtually cyclic stabilizers for linear groups

    DEFF Research Database (Denmark)

    Degrijse, Dieter Dries; Köhl, Ralf; Petrosyan, Nansen

    2015-01-01

    We show that every discrete subgroup of GL(n, ℝ) admits a finite-dimensional classifying space with virtually cyclic stabilizers. Applying our methods to SL(3, ℤ), we obtain a four-dimensional classifying space with virtually cyclic stabilizers and a decomposition of the algebraic K-theory of its...

  16. Evaluating cyclic fatigue of sealants during outdoor testing

    Science.gov (United States)

    R. Sam Williams; Steven Lacher; Corey Halpin; Christopher White

    2009-01-01

    A computer-controlled test apparatus (CCTA) and other instrumentation for subjecting sealant specimens to cyclic fatigue during outdoor exposure was developed. The CCTA enables us to use weather-induced conditions to cyclic fatigue specimens and to conduct controlled tests in-situ during the outdoor exposure. Thermally induced dimensional changes of an aluminum bar...

  17. Improvements of cyclic somatic embryogenesis of cassava (Manihot esculenta Crantz).

    NARCIS (Netherlands)

    Raemakers, C.J.J.M.; Schavemaker, C.M.; Jacobsen, E.; Visser, R.G.F.

    1993-01-01

    In cassava a cyclic system of somatic embryogenesis was developed. Primary (torpedo shaped or germinated) embryos, originating from leaf lobes, could only be obtained after culture on solid medium. Cyclic embryos, originating from embryos, could be obtained in both liquid and on solid medium. The

  18. Supplementary Material for: The arabidopsis cyclic nucleotide interactome

    KAUST Repository

    Donaldson, Lara

    2016-01-01

    Abstract Background Cyclic nucleotides have been shown to play important signaling roles in many physiological processes in plants including photosynthesis and defence. Despite this, little is known about cyclic nucleotide-dependent signaling mechanisms in plants since the downstream target proteins remain unknown. This is largely due to the fact that bioinformatics searches fail to identify plant homologs of protein kinases and phosphodiesterases that are the main targets of cyclic nucleotides in animals. Methods An affinity purification technique was used to identify cyclic nucleotide binding proteins in Arabidopsis thaliana. The identified proteins were subjected to a computational analysis that included a sequence, transcriptional co-expression and functional annotation analysis in order to assess their potential role in plant cyclic nucleotide signaling. Results A total of twelve cyclic nucleotide binding proteins were identified experimentally including key enzymes in the Calvin cycle and photorespiration pathway. Importantly, eight of the twelve proteins were shown to contain putative cyclic nucleotide binding domains. Moreover, the identified proteins are post-translationally modified by nitric oxide, transcriptionally co-expressed and annotated to function in hydrogen peroxide signaling and the defence response. The activity of one of these proteins, GLYGOLATE OXIDASE 1, a photorespiratory enzyme that produces hydrogen peroxide in response to Pseudomonas, was shown to be repressed by a combination of cGMP and nitric oxide treatment. Conclusions We propose that the identified proteins function together as points of cross-talk between cyclic nucleotide, nitric oxide and reactive oxygen species signaling during the defence response.

  19. Rank equivalent and rank degenerate skew cyclic codes

    DEFF Research Database (Denmark)

    Martinez Peñas, Umberto

    2017-01-01

    Two skew cyclic codes can be equivalent for the Hamming metric only if they have the same length, and only the zero code is degenerate. The situation is completely different for the rank metric. We study rank equivalences between skew cyclic codes of different lengths and, with the aim of finding...

  20. Structure and stability of spiro-cyclic water clusters

    Indian Academy of Sciences (India)

    Administrator

    donates two protons, resulting in an overall stabili- zation of the spiro-cyclic structure. A close scrutiny. Figure 1. Optimized geometries of different spiro- cyclic water clusters obtained using HF/6-311++G** cal- culation. These clusters are found to be stable without any reorganization during energy minimization at DFT.

  1. Development of Pore Pressure and Material Damping during Cyclic Loading

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    1994-01-01

    The behaviour of sand during cyclic loading can be characterized as "stabilization", "instant stabilization". "pore pressure buildup" and "liquefaction". The terminologies can be defined exactly by a simple mathematical formulation based on the existence of a cyclic stable state. By introducing...

  2. Behaviour of Dense Frederikshavn Sand During Cyclic Loading

    DEFF Research Database (Denmark)

    Nielsen, Søren Kjær; Shajarati, Amir; Sørensen, Kris Wessel

    of Frederikshavn Sand for an arbitrary stress level and cyclic loading condition. It is discovered that the governing parameters regarding the response is dependent on the stress path and insitu conditions; initial pore pressure, stress state and the combination of average and cyclic shear stresses....

  3. Structure and stability of spiro-cyclic water clusters

    Indian Academy of Sciences (India)

    Administrator

    Abstract. The structure and stability of spiro-cyclic water clusters containing up to 32 water molecules have been investigated at different levels of theory. Although there exist minima lower in energy than these spiro-cyclic clusters, calculations at the Hartree–Fock level, density functional theory using B3LYP parametrization ...

  4. Design of mild steel structures under unequal cyclic loads

    International Nuclear Information System (INIS)

    In this paper a method is proposed to investigate the behavior and life of structural components under unequal cyclic loading conditions. Appropriate cyclic moment-curvature relations and life information, in the form of life versus extreme fiber strain, are developed from tests on beams under pure bending conditions. Theoretical predictions of behavior are based on structural geometry and the cyclic moment-curvature relations used in association with the simple curvature-area method. Structural life is also predicted using the life information developed and the theoretical strain history at the critical section in conjunction with a linear damage summation criterion. Theoretical predictions of behavior and life compare reasonably well with the experiments. Based on this study, a design procedure is proposed for mild steel components subjected to unequal cyclic loading conditions. The loads on the tested components were such that they failed due to low cyclic fatigue (i.e., at less than 10 5 cycles)

  5. History-independent cyclic response of nanotwinned metals

    Science.gov (United States)

    Pan, Qingsong; Zhou, Haofei; Lu, Qiuhong; Gao, Huajian; Lu, Lei

    2017-11-01

    Nearly 90 per cent of service failures of metallic components and structures are caused by fatigue at cyclic stress amplitudes much lower than the tensile strength of the materials involved. Metals typically suffer from large amounts of cumulative, irreversible damage to microstructure during cyclic deformation, leading to cyclic responses that are unstable (hardening or softening) and history-dependent. Existing rules for fatigue life prediction, such as the linear cumulative damage rule, cannot account for the effect of loading history, and engineering components are often loaded by complex cyclic stresses with variable amplitudes, mean values and frequencies, such as aircraft wings in turbulent air. It is therefore usually extremely challenging to predict cyclic behaviour and fatigue life under a realistic load spectrum. Here, through both atomistic simulations and variable-strain-amplitude cyclic loading experiments at stress amplitudes lower than the tensile strength of the metal, we report a history-independent and stable cyclic response in bulk copper samples that contain highly oriented nanoscale twins. We demonstrate that this unusual cyclic behaviour is governed by a type of correlated ‘necklace’ dislocation consisting of multiple short component dislocations in adjacent twins, connected like the links of a necklace. Such dislocations are formed in the highly oriented nanotwinned structure under cyclic loading and help to maintain the stability of twin boundaries and the reversible damage, provided that the nanotwins are tilted within about 15 degrees of the loading axis. This cyclic deformation mechanism is distinct from the conventional strain localizing mechanisms associated with irreversible microstructural damage in single-crystal, coarse-grained, ultrafine-grained and nanograined metals.

  6. Dimensional reduction for conformal blocks

    Science.gov (United States)

    Hogervorst, Matthijs

    2016-09-01

    We consider the dimensional reduction of a CFT, breaking multiplets of the d-dimensional conformal group SO( d + 1 , 1) up into multiplets of SO( d, 1). This leads to an expansion of d-dimensional conformal blocks in terms of blocks in d - 1 dimensions. In particular, we obtain a formula for 3 d conformal blocks as an infinite sum over 2 F 1 hypergeometric functions with closed-form coefficients.

  7. A Five Species Cyclically Dominant Evolutionary Game with Fixed Direction: A New Way to Produce Self-Organized Spatial Patterns

    Directory of Open Access Journals (Sweden)

    Yibin Kang

    2016-08-01

    Full Text Available Cyclically dominant systems are hot issues in academia, and they play an important role in explaining biodiversity in Nature. In this paper, we construct a five-strategy cyclically dominant system. Each individual in our system changes its strategy along a fixed direction. The dominant strategy can promote a change in the dominated strategy, and the dominated strategy can block a change in the dominant strategy. We use mean-field theory and cellular automaton simulation to discuss the evolving characters of the system. In the cellular automaton simulation, we find the emergence of spiral waves on spatial patterns without a migration rate, which suggests a new way to produce self-organized spatial patterns.

  8. A cyclic GMP-dependent calcium-activated chloride current in smooth-muscle cells from rat mesenteric resistance arteries

    DEFF Research Database (Denmark)

    Matchkov, Vladimir; Aalkjær, Christian; Nilsson, Holger

    2004-01-01

    M) in the pipette solution. The current was found to be a calcium-activated chloride current with an absolute requirement for cyclic GMP (EC50 6.4 microM). The current could be activated by the constitutively active subunit of PKG. Current activation was blocked by the protein kinase G antagonist Rp-8-Br......We have previously demonstrated the presence of a cyclic GMP (cGMP)-dependent calcium-activated inward current in vascular smooth-muscle cells, and suggested this to be of importance in synchronizing smooth-muscle contraction. Here we demonstrate the characteristics of this current. Using...... conventional patch-clamp technique, whole-cell currents were evoked in freshly isolated smooth-muscle cells from rat mesenteric resistance arteries by elevation of intracellular calcium with either 10 mM caffeine, 1 microM BAY K8644, 0.4 microM ionomycin, or by high calcium concentration (900 n...

  9. Learning Potentials in Number Blocks

    DEFF Research Database (Denmark)

    Majgaard, Gunver; Misfeldt, Morten; Nielsen, Jacob

    2012-01-01

    . The tool is called Number Blocks and it combines physical interaction, learning, and immediate feedback. Number Blocks supports the children's understanding of place value in the sense that it allows them to experiment with creating large numbers. We found the blocks contributed to the learning process...... in several ways. The blocks combined mathematics and play, and they included and supported children at different academic levels. The auditory representation, especially the enhanced rhythmic effects due to using speech synthesis, and the rhythm helped the children to pronounce large numbers. This creates...

  10. Common blocks for ASQS(12

    Directory of Open Access Journals (Sweden)

    Lorenzo Milazzo

    1997-05-01

    Full Text Available An ASQS(v is a particular Steiner system featuring a set of v vertices and two separate families of blocks, B and G, whose elements have a respective cardinality of 4 and 6. It has the property that any three vertices of X belong either to a B-block or to a G-block. The parameter cb is the number of common blocks in two separate ASQSs, both defined on the same set of vertices X . In this paper it is shown that cb ≤ 29 for any pair of ASQSs(12.

  11. 31 CFR 545.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TALIBAN (AFGHANISTAN) SANCTIONS... name of the Taliban or persons whose property or interests in property are blocked pursuant to § 545.201, or in which the Taliban or persons whose property or interests in property are blocked pursuant...

  12. Cyclic and circadian variations in cardiovascular events.

    Science.gov (United States)

    Elliot, W J

    2001-09-01

    The incidence of many biologic phenomena displays a reproducible and cyclic variation. Cardiovascular disease, the most common cause of death in the United States and other developed countries, also has an intrinsic variation in events. These events are more common in winter, at the beginning of each month, on Mondays (in working people), and during the early morning hours of each day. Recent meta-analyses have quantitated the excess risk of cardiovascular events in the hours around and just after awakening. Between 6 AM and noon, there is a 40% higher risk of heart attack, a 29% increased risk of cardiac death, and a 49% increased risk of stroke (compared with what would be expected if these events happened at random and were evenly distributed throughout the day). These observations have major consequences for emergency medical personnel and medical transport systems. The reasons for these observations are less clear. The circadian pattern of blood pressure (BP) and heart rate may be a major contributor, and long-term "hard end-point" studies designed to test specific pharmacologic interventions targeting the early morning rise in BP and heart rate are underway. Individuals who work night shifts and those whose BP has a different circadian pattern have a higher risk of cardiovascular events, but may be less likely to have an increased risk of cardiovascular events in the morning.

  13. A low-power arcjet cyclic lifetest

    Science.gov (United States)

    Curran, Francis M.; Hardy, Terry L.; Haag, Thomas W.

    1987-01-01

    A cyclic lifetest of a low power dc arcjet thruster using a hydrogen/nitrogen propellant mixture simulating hydrazine is currently in progress. Over 300 hr of operation have been accumulated to date in 2 hr duty cycles at a power level of about 1.15 kW, approximating that available on commercial communications satellites. A burn-in period was carried out before consistent operation was attained. After this period, the arcjet operated in a very stable fashion from cycle to cycle. At the beginning of each cycle, there was a brief starting transient followed by a rapid rise to a steady-state voltage. The steady-state voltage increased by about 5 V over the first 95 cycles. After this, it increased by only 1 V through the remainder of the test. Thrust measurements taken before the life test and again after the completion of the 144th cycle showed that both thrust, specific impulse, and arc voltage had increased over this period of operation. No life limiting mechanisms were observed during the course of the testing.

  14. Bucket foundations under lateral cyclic loading

    DEFF Research Database (Denmark)

    Foglia, Aligi

    To enable a prosperous development of offshore wind energy, economically feasible technologies must be developed. The monopod bucket foundation is likely to become a cost-effective sub-structure for offshore wind turbines and has the potential to make offshore wind more cost-competitive in the en......To enable a prosperous development of offshore wind energy, economically feasible technologies must be developed. The monopod bucket foundation is likely to become a cost-effective sub-structure for offshore wind turbines and has the potential to make offshore wind more cost......-competitive in the energy market. This thesis addresses issues concerning monopod bucket foundations in the hope of providing tools and ideas that could be used to optimize the design of this sub-structure. The work is focussed on the behaviour of bucket foundations under lateral cyclic loading. Other related...... and propaedeutic topics, such as bucket foundations under transient lateral loading and under monotonic lateral loading, are also investigated. All the scientific work is fundamentally based on small-scale experimental tests of bucket foundations in dense water-saturated sand. The most important scientific...

  15. Interuniversal entanglement in a cyclic multiverse

    Science.gov (United States)

    Robles-Pérez, Salvador; Balcerzak, Adam; Dąbrowski, Mariusz P.; Krämer, Manuel

    2017-04-01

    We study scenarios of parallel cyclic multiverses which allow for a different evolution of the physical constants, while having the same geometry. These universes are classically disconnected, but quantum-mechanically entangled. Applying the thermodynamics of entanglement, we calculate the temperature and the entropy of entanglement. It emerges that the entropy of entanglement is large at big bang and big crunch singularities of the parallel universes as well as at the maxima of the expansion of these universes. The latter seems to confirm earlier studies that quantum effects are strong at turning points of the evolution of the universe performed in the context of the timeless nature of the Wheeler-DeWitt equation and decoherence. On the other hand, the entropy of entanglement at big rip singularities is going to zero despite its presumably quantum nature. This may be an effect of total dissociation of the universe structures into infinitely separated patches violating the null energy condition. However, the temperature of entanglement is large/infinite at every classically singular point and at maximum expansion and seems to be a better measure of quantumness.

  16. Simulations of Granular Particles Under Cyclic Shear

    Science.gov (United States)

    Royer, John; Chaikin, Paul

    2012-02-01

    We perform molecular dynamics (MD) simulations of spherical grains subjected to cyclic, quasi-static shear in a 3D parallelepiped shear cell. This virtual shear cell is constructed out of rough, bumpy walls in order to minimize wall-induced ordering and has an open top surface to allow the packing to readily dilate or compact. Using a standard routine for MD simulations of frictional grains, we simulate over 1000 shear cycles, measuring grain displacements, the local packing density and changes in the contact network. Varying the shear amplitude and the friction coefficient between grains, we map out a phase diagram for the different types of behavior exhibited by these sheared grains. With low friction and high enough shear, the grains can spontaneously order into densely packed crystals. With low shear and increasing friction the packing remains disordered, yet the grains arrange themselves into configurations which exhibit limit cycles where all grains return to the same position after each full shear cycle. At higher shear and friction there is a transition to a diffusive state, where grains continue rearrange and move throughout the shear cell.

  17. Copper Regulates Cyclic AMP-Dependent Lipolysis

    Science.gov (United States)

    Krishnamoorthy, Lakshmi; Cotruvo, Joseph A.; Chan, Jefferson; Kaluarachchi, Harini; Muchenditsi, Abigael; Pendyala, Venkata S.; Jia, Shang; Aron, Allegra T.; Ackerman, Cheri M.; Vander Wal, Mark N.; Guan, Timothy; Smaga, Lukas P.; Farhi, Samouil L.; New, Elizabeth J.; Lutsenko, Svetlana; Chang, Christopher J.

    2016-01-01

    Cell signaling relies extensively on dynamic pools of redox-inactive metal ions such as sodium, potassium, calcium, and zinc, but their redox-active transition metal counterparts such as copper and iron have been studied primarily as static enzyme cofactors. Here we report that copper is an endogenous regulator of lipolysis, the breakdown of fat, which is an essential process in maintaining the body's weight and energy stores. Utilizing a murine model of genetic copper misregulation, in combination with pharmacological alterations in copper status and imaging studies in a 3T3-L1 white adipocyte model, we demonstrate that copper regulates lipolysis at the level of the second messenger, cyclic AMP (cAMP), by altering the activity of the cAMP-degrading phosphodiesterase PDE3B. Biochemical studies of the copper-PDE3B interaction establish copper-dependent inhibition of enzyme activity and identify a key conserved cysteine residue within a PDE3-specific loop that is essential for the observed copper-dependent lipolytic phenotype. PMID:27272565

  18. Noise-guided evolution within cyclical interactions

    International Nuclear Information System (INIS)

    Perc, Matjaz; Szolnoki, Attila

    2007-01-01

    We study a stochastic predator-prey model on a square lattice, where each of the six species has two superior and two inferior partners. The invasion probabilities between species depend on the predator-prey pair and are supplemented by Gaussian noise. Conditions are identified that warrant the largest impact of noise on the evolutionary process, and the results of Monte Carlo simulations are qualitatively reproduced by a four-point cluster dynamical mean-field approximation. The observed noise-guided evolution is deeply routed in short-range spatial correlations, which is supported by simulations on other host lattice topologies. Our findings are conceptually related to the coherence resonance phenomenon in dynamical systems via the mechanism of threshold duality. We also show that the introduced concept of noise-guided evolution via the exploitation of threshold duality is not limited to predator-prey cyclical interactions, but may apply to models of evolutionary game theory as well, thus indicating its applicability in several different fields of research

  19. Should we search Chinese biomedical databases when performing systematic reviews?

    OpenAIRE

    Cohen, J?r?mie F; Korevaar, Dani?l A; Wang, Junfeng; Spijker, Ren?; Bossuyt, Patrick M

    2015-01-01

    Background Chinese biomedical databases contain a large number of publications available to systematic reviewers, but it is unclear whether they are used for synthesizing the available evidence. Methods We report a case of two systematic reviews on the accuracy of anti-cyclic citrullinated peptide for diagnosing rheumatoid arthritis. In one of these, the authors did not search Chinese databases; in the other, they did. We additionally assessed the extent to which Cochrane reviewers have searc...

  20. High levels of cyclic-di-GMP in plant-associated Pseudomonas correlate with evasion of plant immunity.

    Science.gov (United States)

    Pfeilmeier, Sebastian; Saur, Isabel Marie-Luise; Rathjen, John Paul; Zipfel, Cyril; Malone, Jacob George

    2016-05-01

    The plant innate immune system employs plasma membrane-localized receptors that specifically perceive pathogen/microbe-associated molecular patterns (PAMPs/MAMPs). This induces a defence response called pattern-triggered immunity (PTI) to fend off pathogen attack. Commensal bacteria are also exposed to potential immune recognition and must employ strategies to evade and/or suppress PTI to successfully colonize the plant. During plant infection, the flagellum has an ambiguous role, acting as both a virulence factor and also as a potent immunogen as a result of the recognition of its main building block, flagellin, by the plant pattern recognition receptors (PRRs), including FLAGELLIN SENSING2 (FLS2). Therefore, strict control of flagella synthesis is especially important for plant-associated bacteria. Here, we show that cyclic-di-GMP [bis-(3'-5')-cyclic di-guanosine monophosphate], a central regulator of bacterial lifestyle, is involved in the evasion of PTI. Elevated cyclic-di-GMP levels in the pathogen Pseudomonas syringae pv. tomato (Pto) DC3000, the opportunist P. aeruginosa PAO1 and the commensal P. protegens Pf-5 inhibit flagellin synthesis and help the bacteria to evade FLS2-mediated signalling in Nicotiana benthamiana and Arabidopsis thaliana. Despite this, high cellular cyclic-di-GMP concentrations were shown to drastically reduce the virulence of Pto DC3000 during plant infection. We propose that this is a result of reduced flagellar motility and/or additional pleiotropic effects of cyclic-di-GMP signalling on bacterial behaviour. © 2015 THE AUTHORS MOLECULAR PLANT PATHOLOGY PUBLISHED BY BRITISH SOCIETY FOR PLANT PATHOLOGY AND JOHN WILEY & SONS LTD.

  1. Centrifuge modelling of a laterally cyclic loaded pile

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Leth, Caspar Thrane; Hededal, Ole

    2010-01-01

    A total number of 9 static and 6 cyclic centrifuge tests on laterally loaded piles in very dense, dry sand was erformed. The prototype dimensions of the piles were 1 meter in diameter and penetration depths varying from 6 to 10 meters. The static tests were used to investigate the initial subgrade...... reaction modulus and as a reference for cyclic tests. For the cyclic tests the accumulation of deflections and the change in secant stiffness of the soil from repetitive loading were investigated. From all the tests carried out accumulations of deflections were seen. rom the centrifuge tests it was seen...

  2. Laterally cyclic loading of monopile in dense sand

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Hededal, Ole; Svensson, M.

    2011-01-01

    In order to investigate the response from laterally cyclic loading of monopiles a large centrifuge tests series is ongoing at the Technical University of Denmark (DTU). This paper will present some of the tests carried out with a focus on the influence of accumulation of rotation when changing...... the loading conditions. In these tests the load conditions are controlled by two load characteristics, one controlling the level of the cyclic loading and one controlling the characteristic of the cyclic loading. The centrifuge tests were performed in dense dry sand on a pile with prototype dimensions...

  3. Classical Virasoro irregular conformal block

    Science.gov (United States)

    Rim, Chaiho; Zhang, Hong

    2015-07-01

    Virasoro irregular conformal block with arbitrary rank is obtained for the classical limit or equivalently Nekrasov-Shatashvili limit using the beta-deformed irregular matrix model (Penner-type matrix model for the irregular conformal block). The same result is derived using the generalized Mathieu equation which is equivalent to the loop equation of the irregular matrix model.

  4. Classical Virasoro irregular conformal block

    Energy Technology Data Exchange (ETDEWEB)

    Rim, Chaiho; Zhang, Hong [Department of Physics and Center for Quantum Spacetime (CQUeST), Sogang University,Seoul 121-742 (Korea, Republic of)

    2015-07-30

    Virasoro irregular conformal block with arbitrary rank is obtained for the classical limit or equivalently Nekrasov-Shatashvili limit using the beta-deformed irregular matrix model (Penner-type matrix model for the irregular conformal block). The same result is derived using the generalized Mathieu equation which is equivalent to the loop equation of the irregular matrix model.

  5. Four-block beam collimator

    CERN Document Server

    CERN PhotoLab

    1977-01-01

    The photo shows a four-block collimator installed on a control table for positioning the alignment reference marks. Designed for use with the secondary beams, the collimators operated in vacuum conditions. The blocks were made of steel and had a standard length of 1 m. The maximum aperture had a square coss-section of 144 cm2. (See Annual Report 1976.)

  6. OPAL Various Lead Glass Blocks

    CERN Document Server

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  7. Writing Blocks and Tacit Knowledge.

    Science.gov (United States)

    Boice, Robert

    1993-01-01

    A review of the literature on writing block looks at two kinds: inability to write in a timely, fluent fashion, and reluctance by academicians to assist others in writing. Obstacles to fluent writing are outlined, four historical trends in treating blocks are discussed, and implications are examined. (MSE)

  8. Block storage subsystem performance analysis

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    You feel that your service is slow because of the storage subsystem? But there are too many abstraction layers between your software and the raw block device for you to debug all this pile... Let's dive on the platters and check out how the block storage sees your I/Os! We can even figure out what those patterns are meaning.

  9. Influence of cyclic torsional preloading on cyclic fatigue resistance of nickel - titanium instruments.

    Science.gov (United States)

    Pedullà, E; Lo Savio, F; Boninelli, S; Plotino, G; Grande, N M; Rapisarda, E; La Rosa, G

    2015-11-01

    To evaluate the effect of different torsional preloads on cyclic fatigue resistance of endodontic rotary instruments constructed from conventional nickel-titanium (NiTi), M-Wire or CM-Wire. Eighty new size 25, 0.06 taper Mtwo instruments (Sweden & Martina), size 25, 0.06 taper HyFlex CM (Coltene/Whaledent, Inc) and X2 ProTaper Next (Dentsply Maillefer) were used. The Torque and distortion angles at failure of new instruments (n = 10) were measured, and 0% (n = 10), 25%, 50% and 75% (n = 20) of the mean ultimate torsional strength as preloading condition were applied according to ISO 3630-1 for each brand. The twenty files tested for every extent of preload were subjected to 20 or 40 torsional cycles (n = 10). After torsional preloading, the number of cycles to failure was evaluated in a simulated canal with 60° angle of curvature and 5 mm of radius of curvature. Data were analysed using two-way analysis of variance. The fracture surface of each fragment was examined with a scanning electron microscope (SEM). Data were analysed by two-way analyses of variance. Preload repetitions did not influence the cyclic fatigue of the three brands; however, the 25%, 50% and 75% torsional preloading significantly reduced the fatigue resistance of all instruments tested (P 0.05). Torsional preloads reduced the cyclic fatigue resistance of conventional and treated (M-wire and CM-wire) NiTi rotary instruments except for size 25, 0.06 taper HyFlex CM instruments with a 25% of torsional preloading. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  10. Cyclic response and early damage evolution in multiaxial cyclic loading of 316L austenitic steel

    Czech Academy of Sciences Publication Activity Database

    Mazánová, Veronika; Škorík, Viktor; Kruml, Tomáš; Polák, Jaroslav

    2017-01-01

    Roč. 100, JUL (2017), s. 466-476 ISSN 0142-1123 R&D Projects: GA MŠk LM2015069; GA MŠk(CZ) LQ1601; GA ČR(CZ) GA13-23652S; GA ČR GA15-08826S Institutional support: RVO:68081723 Keywords : 316L steel * Crack initiation * Cyclic plasticity * Damage mechanism * Multiaxial straining Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis Impact factor: 2.899, year: 2016

  11. Opposite effects of different hexachlorocyclohexane (lindane) isomers on cerebellar cyclic GMP: relation of cyclic GMP accumulation to seizure activity

    International Nuclear Information System (INIS)

    Fishman, B.E.; Gianutsos, G.

    1987-01-01

    A number of different depressant and convulsant agents have been shown to alter accumulation of cerebellar cyclic GMP. Since the different hexachlorocyclohexane (HCH) isomers elicit different pharmacological responses in mammals, the authors examined their effects on the accumulation of cerebellar cyclic GMP. Mice received one of the HCH isomers and were sacrificed for determination of cyclic GMP concentrations one hour later. Gamma-HCH increased cyclic GMP while alpha and delta -HCH decreased it. In addition, alpha and delta -HCH prevented the increase in cyclic GMP due to the gamma isomer. Picrotoxin increased cyclic GMP in a manner similar to that of gamma-HCH while strychnine produced only a small increase. All three HCH isomers inhibited the binding of 3 H-TBOB (a ligand for the GABA-A-receptor linked chloride channel) in mouse cerebellum. It is concluded the different HCH isomers can have different effects on cerebellar cyclic GMP accumulation and that these effects may mediated through actions at the GABA-A receptor linked chloride channel. 15 references, 1 figure, 3 tables

  12. The Chemistry of Cyclic All-Nitrogen Molecules

    National Research Council Canada - National Science Library

    Wodtke, Alec M

    2006-01-01

    ..., $474,927, February 15, 2004 - December 31, 2006. During this period, we have extended our preliminary investigations of azide photochemistry, with the aim of demonstrating unambiguously the photochemical production of cyclic-N, and of revealing...

  13. Riboflavin in cyclic vomiting syndrome: efficacy in three children.

    Science.gov (United States)

    Martinez-Esteve Melnikova, Anastasia; Schäppi, Michela G; Korff, Christian

    2016-01-01

    Cyclic vomiting syndrome is an episodic disorder considered to be a migraine variant. Riboflavin is efficient in the prophylactic treatment of migraines in adults. We describe the effectiveness and tolerance of riboflavin treatment in three children with cyclic vomiting syndrome. All of them fulfilled the diagnosis criteria for cyclic vomiting syndrome. They received prophylactic monotherapy with riboflavin for at least 12 months. Excellent response and tolerability was observed. Based on clinical observation in three cases, riboflavin may be an effective and safe prophylactic treatment for children with cyclic vomiting syndrome. CVS is one of the "childhood periodic syndromes" classified as a migraine subtype by the International Headache Society. Riboflavin is currently used as a prophylactic treatment in patients with migraine. Riboflavin may be an effective and safe prophylactic treatment for children with CVS. Increasing doses of riboflavin and long periods of prophylaxis may be needed in some children..

  14. Monotonic and cyclic deformation behaviour of ultrafine-grained aluminium

    International Nuclear Information System (INIS)

    May, J.; Amberger, D.; Dinkel, M.; Hoeppel, H.W.; Goeken, M.

    2008-01-01

    The effect of the enhanced strain-rate sensitivity (SRS) of ultrafine-grained commercially pure aluminium Al 99.5 on the mechanical properties under monotonic as well as under cyclic loading was investigated. Compared with the conventional grain-sized counterpart, for the monotonic tests, a strongly enhanced strength combined with a high ductility was obtained, depending on the strain rate. The enhanced SRS also affects the cyclic deformation behaviour and the fatigue lives. At a lower strain rate shorter fatigue lives and a different cyclic hardening behaviour are observed. Microstructural changes during cyclic deformation are investigated by X-ray diffraction profile analysis. Based on the fatigue behaviour and the X-ray diffraction profile analysis, thermally activated annihilation processes of dislocations are regarded to be the relevant deformation mechanism leading to enhanced SRS and ductility

  15. Cyclical Cohabitation Among Unmarried Parents in Fragile Families.

    Science.gov (United States)

    Nepomnyaschy, Lenna; Teitler, Julien

    2013-10-01

    Building on past research suggesting that cohabitation is an ambiguous family form, the authors examined an understudied residential pattern among unmarried parents: cyclical cohabitation, in which parents have multiple cohabitation spells with each other. Using 9 years of panel data from the Fragile Families and Child Wellbeing Study ( N = 2,084), they found that 10% of all parents with nonmarital births, and nearly a quarter of those living together when the child is 9 years old, are cyclical cohabitors. Cyclically cohabiting mothers reported more material hardships than mothers in most other relationship patterns but also reported more father involvement with children. On all measures of child well-being, except grade retention, children of cyclically cohabiting parents fared no worse than children of stably cohabiting biological parents and did not differ significantly from any other group.

  16. INFLUENCE OF INTERMITTENT CYCLIC LOADING ON REINFORCED CONCRETE RESISTANCE MODEL

    Directory of Open Access Journals (Sweden)

    Vasyl Karpiuk

    2017-01-01

    Full Text Available This article describes the study of reinforced concrete span bending structures under conditions of high-level cyclic loading. Previous studies on the development of physical models of bending reinforced concrete element fatigue resistance, cyclic effect of lateral forces, and methods of calculation, are important and appropriate owing to certain features and the essential specificity of the mentioned loading type. These primarily include the nonlinearity of deformation, damage accumulation in the form of fatigue micro- and macro-cracks, and exhausting destruction of construction materials. In this paper, key expressions determining the endurance limits of concrete, longitudinal reinforcement, and anchoring longitudinal reinforcement, which contribute to endurance throughout the entire construction, are considered. Establishing a link between stresses in the elements and deformations in the element under conditions of cyclic loading action is of equal importance because of the presence of cyclic stress-induced creep deformation.

  17. The Cyclical Relationship Approach in Teaching Basic Accounting Principles.

    Science.gov (United States)

    Golen, Steven

    1981-01-01

    Shows how teachers can provide a more meaningful presentation of various accounting principles by illustrating them through a cyclical relationship approach. Thus, the students see the entire accounting relationship as a result of doing business. (CT)

  18. A Novel Cyclic Catalytic Reformer for Hydrocarbon Fuels, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed Small Business Innovative Research (SBIR) Phase I addresses development of a compact reformer system based on a cyclic partial oxidation (POx)...

  19. Safety Discrete Event Models for Holonic Cyclic Manufacturing Systems

    Science.gov (United States)

    Ciufudean, Calin; Filote, Constantin

    In this paper the expression “holonic cyclic manufacturing systems” refers to complex assembly/disassembly systems or fork/join systems, kanban systems, and in general, to any discrete event system that transforms raw material and/or components into products. Such a system is said to be cyclic if it provides the same sequence of products indefinitely. This paper considers the scheduling of holonic cyclic manufacturing systems and describes a new approach using Petri nets formalism. We propose an approach to frame the optimum schedule of holonic cyclic manufacturing systems in order to maximize the throughput while minimize the work in process. We also propose an algorithm to verify the optimum schedule.

  20. Synthesis and Catalytic Activity of Two New Cyclic Tetraaza Ligands

    Directory of Open Access Journals (Sweden)

    Burkhard König

    2003-05-01

    Full Text Available Two new chiral cyclic tetraaza ligands were synthesized and characterized. Their catalytic activity was tested in the asymmetric addition of diethylzinc to benzaldehyde. The expected secondary alcohol was obtained in moderate yields, but with very low enantioselectivity.

  1. Cyclical mastalgia: Prevalence and associated determinants in Hamadan City, Iran

    Directory of Open Access Journals (Sweden)

    Fatemeh Shobeiri

    2016-03-01

    Conclusions: Most of women with breast discomfort suffered cyclical mastalgia which severity can be determined by advanced age, age of marriage, history of abortion and history of premenstrual syndrome, but inversely by oral contraceptive use and exercise activity.

  2. Association of Marijuana Use and Cyclic Vomiting Syndrome

    Directory of Open Access Journals (Sweden)

    Mithun B. Pattathan

    2012-06-01

    Full Text Available Cannabis use has become one of the most commonly abused drugs in the world. It is estimated that each year 2.6 million individuals in the USA become new users and most are younger than 19 years of age. Reports describe marijuana use as high as 40–50% in male Cyclic Vomiting Syndrome patients. It is this interest in cannabis in the World, coupled with recognition of a cyclic vomiting illness associated with its chronic use that beckons a review of the most current articles, as well as a contribution from our own experiences in this area. The similarities we have demonstrated for both cannibinoid hyperemesis syndrome and cyclic vomiting make the case that cannibinoid hyperemesis syndrome is a subset of patients who have the diagnoses of cyclic vomiting syndrome and the role of marijuana should always be considered in the diagnosis of CVS, particularly in males.

  3. Quantum Codes From Cyclic Codes Over The Ring R 2

    International Nuclear Information System (INIS)

    Altinel, Alev; Güzeltepe, Murat

    2016-01-01

    Let R 2 denotes the ring F 2 + μF 2 + υ 2 + μυ F 2 + wF 2 + μwF 2 + υwF 2 + μυwF 2 . In this study, we construct quantum codes from cyclic codes over the ring R 2 , for arbitrary length n, with the restrictions μ 2 = 0, υ 2 = 0, w 2 = 0, μυ = υμ, μw = wμ, υw = wυ and μ (υw) = (μυ) w. Also, we give a necessary and sufficient condition for cyclic codes over R 2 that contains its dual. As a final point, we obtain the parameters of quantum error-correcting codes from cyclic codes over R 2 and we give an example of quantum error-correcting codes form cyclic codes over R 2 . (paper)

  4. Cyclic viscoelasticity and viscoplasticity of polypropylene/clay nanocomposites

    DEFF Research Database (Denmark)

    Drozdov, Aleksey; Christiansen, Jesper de Claville; Hog Lejre, Anne-Lise

    2012-01-01

    Observations are reported in tensile relaxation tests under stretching and retraction on poly-propylene/clay nanocomposites with various contents of filler. A two-phase constitutive model is developed in cyclic viscoelasticity and viscoplasticity of hybrid nanocomposites. Adjustable parameters...

  5. Criminal Justice Systems. Block I: Law Enforcement. Block II: The Courts. Block III: Corrections. Block IV: Community Relations. Block V: Proficiency Skills. Block VI: Criminalistics. Student Guide.

    Science.gov (United States)

    Florida State Dept. of Education, Tallahassee. Div. of Vocational, Adult, and Community Education.

    This student guide together with an instructor guide comprise a set of curriculum materials on the criminal justice system. The student guide contains self-contained instructional material that students can study at their own pace most of the time. Six major subject areas or blocks, which are further broken down into several units, with some units…

  6. Criminal Justice Systems. Block I: Law Enforcement. Block II: The Courts. Block III: Corrections. Block IV: Community Relations. Block V: Proficiency Skills. Block VI: Criminalistics. Instructor Guide.

    Science.gov (United States)

    Florida State Dept. of Education, Tallahassee. Div. of Vocational, Adult, and Community Education.

    This instructor guide together with a student guide comprise a set of curriculum materials on the criminal justice system. The instructor guide is a resource for planning and managing individualized, competency-based instruction in six major subject areas or blocks, which are further broken down into several units with some units having several…

  7. A cyclic GMP signalling module that regulates gliding motility in a malaria parasite.

    Directory of Open Access Journals (Sweden)

    Robert W Moon

    2009-09-01

    Full Text Available The ookinete is a motile stage in the malaria life cycle which forms in the mosquito blood meal from the zygote. Ookinetes use an acto-myosin motor to glide towards and penetrate the midgut wall to establish infection in the vector. The regulation of gliding motility is poorly understood. Through genetic interaction studies we here describe a signalling module that identifies guanosine 3', 5'-cyclic monophosphate (cGMP as an important second messenger regulating ookinete differentiation and motility. In ookinetes lacking the cyclic nucleotide degrading phosphodiesterase delta (PDEdelta, unregulated signalling through cGMP results in rounding up of the normally banana-shaped cells. This phenotype is suppressed in a double mutant additionally lacking guanylyl cyclase beta (GCbeta, showing that in ookinetes GCbeta is an important source for cGMP, and that PDEdelta is the relevant cGMP degrading enzyme. Inhibition of the cGMP-dependent protein kinase, PKG, blocks gliding, whereas enhanced signalling through cGMP restores normal gliding speed in a mutant lacking calcium dependent protein kinase 3, suggesting at least a partial overlap between calcium and cGMP dependent pathways. These data demonstrate an important function for signalling through cGMP, and most likely PKG, in dynamically regulating ookinete gliding during the transmission of malaria to the mosquito.

  8. Ciguatoxins: Cyclic Polyether Modulators of Voltage-gated Iion Channel Function

    Directory of Open Access Journals (Sweden)

    Richard J. Lewis

    2006-04-01

    Full Text Available Ciguatoxins are cyclic polyether toxins, derived from marine dinoflagellates, which are responsible for the symptoms of ciguatera poisoning. Ingestion of tropical and subtropical fin fish contaminated by ciguatoxins results in an illness characterised by neurological, cardiovascular and gastrointestinal disorders. The pharmacology of ciguatoxins is characterised by their ability to cause persistent activation of voltage-gated sodium channels, to increase neuronal excitability and neurotransmitter release, to impair synaptic vesicle recycling, and to cause cell swelling. It is these effects, in combination with an action to block voltage-gated potassium channels at high doses, which are believed to underlie the complex of symptoms associated with ciguatera. This review examines the sources, structures and pharmacology of ciguatoxins. In particular, attention is placed on their cellular modes of actions to modulate voltage-gated ion channels and other Na+-dependent mechanisms in numerous cell types and to current approaches for detection and treatment of ciguatera.

  9. Ciguatoxins: Cyclic Polyether Modulators of Voltage-gated Iion Channel Function

    Science.gov (United States)

    Nicholson, Graham M.; Lewis, Richard J.

    2006-01-01

    Ciguatoxins are cyclic polyether toxins, derived from marine dinoflagellates, which are responsible for the symptoms of ciguatera poisoning. Ingestion of tropical and subtropical fin fish contaminated by ciguatoxins results in an illness characterised by neurological, cardiovascular and gastrointestinal disorders. The pharmacology of ciguatoxins is characterised by their ability to cause persistent activation of voltage-gated sodium channels, to increase neuronal excitability and neurotransmitter release, to impair synaptic vesicle recycling, and to cause cell swelling. It is these effects, in combination with an action to block voltage-gated potassium channels at high doses, which are believed to underlie the complex of symptoms associated with ciguatera. This review examines the sources, structures and pharmacology of ciguatoxins. In particular, attention is placed on their cellular modes of actions to modulate voltage-gated ion channels and other Na+-dependent mechanisms in numerous cell types and to current approaches for detection and treatment of ciguatera.

  10. Evolution of Akaganeite in Rust Layers Formed on Steel Submitted to Wet/Dry Cyclic Tests

    Directory of Open Access Journals (Sweden)

    Haigang Xiao

    2017-11-01

    Full Text Available The evolution of akaganeite in rust layers strongly impacts the atmospheric corrosion behavior of steel during long-term exposure; however, the factors affecting the evolution of akaganeite and its mechanism of formation are vague. In this work, wet-dry cyclic corrosion tests were conducted to simulate long-term exposure. Quantitative X-ray diffraction analysis was employed to analyze variations in the relative amounts of akaganeite; scanning electron microscopy and electron probe microanalysis were used to study the migration of relevant elements in the rust layer, which could help elucidate the mechanism of akaganeite evolution. The results indicate that the fraction of akaganeite tends to decrease as the corrosion process proceeded, which is a result of the decrease in the amount of soluble chloride available and the ability of the thick rust layer to block the migration of relevant ions. This work also explores the location of akaganeite formation within the rust layer.

  11. Software and Hardware Solutions for Channel Estimation based on Cyclic Golay Sequences

    Directory of Open Access Journals (Sweden)

    B. Csuka

    2016-12-01

    Full Text Available This paper presents channel estimation methods based on cyclic complementary Golay sequences. First, the conventional Golay correlator is investigated, then a frequency domain approach using Discrete Fourier Transform (DFT is provided. A complex valued fast Golay correlator is introduced which can be used for the estimation of complex valued channel impulse response. Furthermore, this paper presents the Recursive DFT (R-DFT, a signal processing architecture which may be beneficial compared to the well-known Fast Fourier Transform (FFT. The R-DFT is able to efficiently calculate a point-by-point block spectra of the input signal, which makes it suitable for hardware implementation. Throughout the paper, the R-DFT is applied and it is compared to the conventional estimation methods. Finally, the efficiency of the proposed schemes is compared through simulations based on the 60 GHz WiGig and the COST 207 standard, applying various channel models.

  12. Paediatric cyclical Cushing's disease due to corticotroph cell hyperplasia.

    LENUS (Irish Health Repository)

    Noctor, E

    2015-06-01

    Cushing\\'s disease is very rare in the paediatric population. Although uncommon, corticotroph hyperplasia causing Cushing\\'s syndrome has been described in the adult population, but appears to be extremely rare in children. Likewise, cyclical cortisol hypersecretion, while accounting for 15 % of adult cases of Cushing\\'s disease, has only rarely been described in the paediatric population. Here, we describe a very rare case of a 13-year old boy with cyclical cortisol hypersecretion secondary to corticotroph cell hyperplasia.

  13. Microgravity changes in heart structure and cyclic-AMP metabolism

    Science.gov (United States)

    Philpott, D. E.; Fine, A.; Kato, K.; Egnor, R.; Cheng, L.

    1985-01-01

    The effects of microgravity on cardiac ultrastructure and cyclic AMP metabolism in tissues of rats flown on Spacelab 3 are reported. Light and electron microscope studies of cell structure, measurements of low and high Km phosphodiesterase activity, cyclic AMP-dependent protein kinase activity, and regulatory subunit compartmentation show significant deviations in flight animals when compared to ground controls. The results indicate that some changes have occurred in cellular responses associated with catecholamine receptor interactions and intracellular signal processing.

  14. Multiaxial elastoplastic cyclic loading of austenitic 316L steel

    Czech Academy of Sciences Publication Activity Database

    Mazánová, Veronika; Polák, Jaroslav; Škorík, Viktor; Kruml, Tomáš

    2017-01-01

    Roč. 11, č. 40 (2017), s. 162-169 ISSN 1971-8993 R&D Projects: GA ČR(CZ) GA13-23652S; GA MŠk LM2015069; GA MŠk(CZ) LQ1601; GA ČR GA15-08826S Institutional support: RVO:68081723 Keywords : 316L steel * Crack initiation * Cyclic stress-strain curve * Multiaxial cyclic loading Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis

  15. Facile and Green Synthesis of Saturated Cyclic Amines.

    Science.gov (United States)

    Hameed, Arruje; Javed, Sadia; Noreen, Razia; Huma, Tayyaba; Iqbal, Sarosh; Umbreen, Huma; Gulzar, Tahsin; Farooq, Tahir

    2017-10-12

    Single-nitrogen containing saturated cyclic amines are an important part of both natural and synthetic bioactive compounds. A number of methodologies have been developed for the synthesis of aziridines, azetidines, pyrrolidines, piperidines, azepanes and azocanes. This review highlights some facile and green synthetic routes for the synthesis of unsubstituted, multisubstituted and highly functionalized saturated cyclic amines including one-pot, microwave assisted, metal-free, solvent-free and in aqueous media.

  16. SYNERGISTIC DEGRADATION OF DENTIN BY CYCLIC STRESS AND BUFFER AGITATION

    OpenAIRE

    Orrego, Santiago; Romberg, Elaine; Arola, Dwayne

    2015-01-01

    Secondary caries and non-carious lesions develop in regions of stress concentrations and oral fluid movement. The objective of this study was to evaluate the influence of cyclic stress and fluid movement on material loss and subsurface degradation of dentin within an acidic environment. Rectangular specimens of radicular dentin were prepared from caries-free unrestored 3rd molars. Two groups were subjected to cyclic cantilever loading within a lactic acid solution (pH=5) to achieve compressiv...

  17. Global optimization of cyclic Kannan nonexpansive mappings in ...

    African Journals Online (AJOL)

    Consider a self-mapping T defined on a union of two subsets A and B of a Banach space such that T(A) ⊆ B and T(B) ⊆ A. In this work we survey the existence of an optimal approximate solution, known as a best proximity point for a class of cyclic mappings, called cyclic Kannan nonexpansive mappings, in Banach spaces ...

  18. Facile and Green Synthesis of Saturated Cyclic Amines

    Directory of Open Access Journals (Sweden)

    Arruje Hameed

    2017-10-01

    Full Text Available Single-nitrogen containing saturated cyclic amines are an important part of both natural and synthetic bioactive compounds. A number of methodologies have been developed for the synthesis of aziridines, azetidines, pyrrolidines, piperidines, azepanes and azocanes. This review highlights some facile and green synthetic routes for the synthesis of unsubstituted, multisubstituted and highly functionalized saturated cyclic amines including one-pot, microwave assisted, metal-free, solvent-free and in aqueous media.

  19. The role of opportunistic migration in cyclic games.

    Directory of Open Access Journals (Sweden)

    Pierre Buesser

    Full Text Available We study cyclic evolutionary games in a spatial diluted grid environment in which agents strategically interact locally but can also opportunistically move to other positions within a given migration radius. We find that opportunistic migration can inverse the cyclic prevalence between the strategies when the frequency of random imitation is large enough compared to the payoff-driven imitation. At the transition the average size of the patterns diverges and this threatens diversity of strategies.

  20. Similarity analysis, synthesis, and bioassay of antibacterial cyclic peptidomimetics

    Directory of Open Access Journals (Sweden)

    Workalemahu M. Berhanu

    2012-07-01

    Full Text Available The chemical similarity of antibacterial cyclic peptides and peptidomimetics was studied in order to identify new promising cyclic scaffolds. A large descriptor space coupled with cluster analysis was employed to digitize known antibacterial structures and to gauge the potential of new peptidomimetic macrocycles, which were conveniently synthesized by acylbenzotriazole methodology. Some of the synthesized compounds were tested against an array of microorganisms and showed antibacterial activity against Bordetella bronchistepica, Micrococcus luteus, and Salmonella typhimurium.

  1. Block by Block: Civic Action in the Battle of Baghdad

    Science.gov (United States)

    2007-11-01

    bedding, and latrine facilities. Additionally, provide milk , baby formula, diapers, 7 Bogart: Block by Block and infant/family care items such as...viable agricultural businesses. The cattle are a cross breed of a “regular” Iraqi cow and a water buffalo. Chicken farms are mostly egg farms, and...a problem. Contractors did not want to work for fear of being shot or kid - napped. For example, four contractors were shot over the duration of

  2. Dual-Level Security based Cyclic18 Steganographic Method and its Application for Secure Transmission of Keyframes during Wireless Capsule Endoscopy.

    Science.gov (United States)

    Muhammad, Khan; Sajjad, Muhammad; Baik, Sung Wook

    2016-05-01

    In this paper, the problem of secure transmission of sensitive contents over the public network Internet is addressed by proposing a novel data hiding method in encrypted images with dual-level security. The secret information is divided into three blocks using a specific pattern, followed by an encryption mechanism based on the three-level encryption algorithm (TLEA). The input image is scrambled using a secret key, and the encrypted sub-message blocks are then embedded in the scrambled image by cyclic18 least significant bit (LSB) substitution method, utilizing LSBs and intermediate LSB planes. Furthermore, the cover image and its planes are rotated at different angles using a secret key prior to embedding, deceiving the attacker during data extraction. The usage of message blocks division, TLEA, image scrambling, and the cyclic18 LSB method results in an advanced security system, maintaining the visual transparency of resultant images and increasing the security of embedded data. In addition, employing various secret keys for image scrambling, data encryption, and data hiding using the cyclic18 LSB method makes the data recovery comparatively more challenging for attackers. Experimental results not only validate the effectiveness of the proposed framework in terms of visual quality and security compared to other state-of-the-art methods, but also suggest its feasibility for secure transmission of diagnostically important keyframes to healthcare centers and gastroenterologists during wireless capsule endoscopy.

  3. Harmony of spinning conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Volker [DESY Hamburg, Theory Group,Notkestraße 85, 22607 Hamburg (Germany); Sobko, Evgeny [Nordita and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Isachenkov, Mikhail [Department of Particle Physics and Astrophysics, Weizmann Institute of Science,Rehovot 7610001 (Israel)

    2017-03-15

    Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

  4. Harmony of spinning conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Sobko, Evgeny [Stockholm Univ. (Sweden); Nordita, Stockholm (Sweden); Isachenkov, Mikhail [Weizmann Institute of Science, Rehovoth (Israel). Dept. of Particle Physics and Astrophysics

    2016-12-07

    Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

  5. Comparison Of INAA Methods (Long Conventional, Cyclic And Pseudo-Cyclic) For The Determination Of Se In Biological Samples

    International Nuclear Information System (INIS)

    Sarheel, A.

    2004-01-01

    Selenium content in serum blood, sample were received from international comparison programme (SABC) has been determined by Cyclic irradiation, pseudo-cyclic irradiation and long irradiation conventional Instrumental neutron activation analysis through the 162 keV gamma ray of the 77m Se nuclide for both cyclic and pseudo-cyclic and 264 keV gamma ray of 75 Se nuclide for conventional (long irradiation). The CINAA involve irradiation of samples for 20 s, decay for 15 s and counting for 20 s, samples recycling four times to improve the precision. The PCINAA involve irradiation of samples for 20 s, decay for 20 s and counting for 30s, samples recycling four times day by day. The Conventional (long irradiation) involve irradiation of samples for 20 hr (1 week), decay for 4 weeks and counting for 20 hr. The accuracy has been evaluated by analyzing the certified reference materials. (Author)

  6. Effect of cyclic torsional preloading on cyclic fatigue resistance of ProTaper Next and Mtwo nickel–titanium instruments

    Directory of Open Access Journals (Sweden)

    Eugenio Pedullà

    2015-06-01

    Conclusions: Torsional preloads reduced the cyclic fatigue resistance of M-wire and conventional (as ProTaper Next and Mtwo NiTi rotary instruments except for Mtwo with 25% or 50% of torsional preloading.

  7. Circulant Arrays on Cyclic Subgroups of Finite Fields: Rank Analysis and Construction of Quasi-Cyclic LDPC Codes

    OpenAIRE

    Zhang, Li; Lin, Shu; Abdel-Ghaffar, Khaled; Ding, Zhi; Zhou, Bo

    2010-01-01

    This paper consists of three parts. The first part presents a large class of new binary quasi-cyclic (QC)-LDPC codes with girth of at least 6 whose parity-check matrices are constructed based on cyclic subgroups of finite fields. Experimental results show that the codes constructed perform well over the binary-input AWGN channel with iterative decoding using the sum-product algorithm (SPA). The second part analyzes the ranks of the p...

  8. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  9. The wild tapered block bootstrap

    DEFF Research Database (Denmark)

    Hounyo, Ulrich

    -based method in terms of asymptotic accuracy of variance estimation and distribution approximation. For stationary time series, the asymptotic validity, and the favorable bias properties of the new bootstrap method are shown in two important cases: smooth functions of means, and M-estimators. The first......-order asymptotic validity of the tapered block bootstrap as well as the wild tapered block bootstrap approximation to the actual distribution of the sample mean is also established when data are assumed to satisfy a near epoch dependent condition. The consistency of the bootstrap variance estimator for the sample......In this paper, a new resampling procedure, called the wild tapered block bootstrap, is introduced as a means of calculating standard errors of estimators and constructing confidence regions for parameters based on dependent heterogeneous data. The method consists in tapering each overlapping block...

  10. Recursion Relations for Conformal Blocks

    CERN Document Server

    Penedones, João; Yamazaki, Masahito

    2016-09-12

    In the context of conformal field theories in general space-time dimension, we find all the possible singularities of the conformal blocks as functions of the scaling dimension $\\Delta$ of the exchanged operator. In particular, we argue, using representation theory of parabolic Verma modules, that in odd spacetime dimension the singularities are only simple poles. We discuss how to use this information to write recursion relations that determine the conformal blocks. We first recover the recursion relation introduced in 1307.6856 for conformal blocks of external scalar operators. We then generalize this recursion relation for the conformal blocks associated to the four point function of three scalar and one vector operator. Finally we specialize to the case in which the vector operator is a conserved current.

  11. Defying gravity using Jenga™ blocks

    Science.gov (United States)

    Tan, Yin-Soo; Yap, Kueh-Chin

    2007-11-01

    This paper describes how Jenga™ blocks can be used to demonstrate the physics of an overhanging tower that appears to defy gravity. We also propose ideas for how this demonstration can be adapted for the A-level physics curriculum.

  12. Effect of Surgical Removal of Endometriomas on Cyclic and Non-cyclic Pelvic Pain

    Directory of Open Access Journals (Sweden)

    Murat Api

    2015-07-01

    Full Text Available Background: Endometriosis is a complex disease with a spectrum of pain symptoms from mild dysmenorrhea to debilitating pelvic pain. There is no concrete evidence in the literature whether endometriotic cyst per se, causes pain spectrum related to the disease. The aim of the present study was to evaluate the effect of surgical removal of endometriomas on pain symptoms. Materials and Methods: In this prospective, observational, before-after study, which was conducted between March 2012 and January 2013 in Training and Research Hospital,Adana, Turkey, a total of 23 patients including 16 sexually active and 7 virgin symptomatic women were questioned for non-cyclic pelvic pain (NCPP, intensity of the NCPP, presence of cyclic dysmenorrhea, and dyspareunia before and after the endometrioma operation. Participants who were sonographically diagnosed and later pathologically confirmed as having endometrioma without sign and symptoms of deep infiltrative endometriosis (DIE were also questioned for pain symptoms before and after the laparoscopic removal of cyst wall. Patients with intraabdominal adhesions, history of pelvic inflammatory disease, and pathological diagnosis other than endometrioma were excluded. No ancillary procedures were applied for pain management, but if pain was present, pelvic peritoneal endometriotic lesions were ablated beside the removal of ovarian endometriotic cysts. Results: Out of 23 cases with endometrioma, 91 and 78% reported to have NCPP and dysmenorrhea, respectively, before the operation, while 60 and 48%, respectively, after the operation (McNemar’s test, P=0.016 for both figures. Among the sexually active cases, 31% (5/16 had dyspareunia before the operation and only 1 case reported the pain relief after the operation (McNemar’s test, P=1. Intensity of NCPP were reported to be none (8.7%, moderate (21.7%, severe (56.5% and unbearable (13% before the operation and decreased to none (43.5%, mild (43.5%, moderate (4

  13. Cyclic, Early Diagenetic Dolomite Formation in Alkaline Lake Van

    Science.gov (United States)

    McCormack, J.; Bontognali, T. R. R.; Immenhauser, A.; Kwiecien, O.

    2017-12-01

    Modern dolomite-forming environments are commonly constrained to evaporitic marine or marginal marine settings such as lagoons and sabkhas. Beside microbial mediation, high temperatures and Mg2+ concentrations in solution are factors considered important in aiding dolomite formation. Accordingly, previous studies associate the presence of dolomite within deep sediments of alkaline Lake Van (Turkey) with periods of enhanced evaporation, low lake levels and high Mg/Ca ratio. We systematically studied dolomite within the sedimentary record of Lake Van by means of XRD, SEM and stable isotope (δ18O and δ13C) mass spectrometry. First, we considered the origin of the dolomite; next, we focused on the wider implication of its presence. SEM imaging documents large dolomite crystals interwoven with clay minerals and individual crystals with different crystallographic orientations grown together, indicating space-limited growth within the sediment. According to recent climatic reconstructions for the same sequence (ICDP PALEOVAN project), the water depth of the coring site - today at 350 m - unlikely fell below 200 m. Consequently, dolomite formed below a thick water column at constantly low temperatures (supported by heavy δ18O signature). Within this environment, variations in Mg/Ca ratio, pH and alkalinity, which are constantly high, have no effect on the episodic nature of dolomite precipitation. These observations call for a re-evaluation of the palaeoenvironments often invoked to interpret intervals rich in dolomite within ancient sedimentary sequences (e.g., periods of enhanced aridity and evaporation). Further, and in contrast to previous interpretations, our dolomite concentration data backed up by ICDP PALEOVAN reconstructions suggest that intervals rich in dolomite coincide with periods of high lake level and increased humidity. High dolomite concentrations (20 - 85 % relative carbonate content) occur cyclically within the last glacial period and coincide with

  14. The Role of Cyclic Nucleotide Signaling Pathways in Cancer: Targets for Prevention and Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Fajardo, Alexandra M.; Piazza, Gary A. [Drug Discovery Research Center, Mitchell Cancer Institute, University of South Alabama, 1660 Springhill Ave, Suite 3029, Mobile, AL 36604 (United States); Tinsley, Heather N., E-mail: htinsley@montevallo.edu [Department of Biology, Chemistry, and Mathematics, University of Montevallo, Station 6480, Montevallo, AL 35115 (United States)

    2014-02-26

    For more than four decades, the cyclic nucleotides cyclic AMP (cAMP) and cyclic GMP (cGMP) have been recognized as important signaling molecules within cells. Under normal physiological conditions, cyclic nucleotides regulate a myriad of biological processes such as cell growth and adhesion, energy homeostasis, neuronal signaling, and muscle relaxation. In addition, altered cyclic nucleotide signaling has been observed in a number of pathophysiological conditions, including cancer. While the distinct molecular alterations responsible for these effects vary depending on the specific cancer type, several studies have demonstrated that activation of cyclic nucleotide signaling through one of three mechanisms—induction of cyclic nucleotide synthesis, inhibition of cyclic nucleotide degradation, or activation of cyclic nucleotide receptors—is sufficient to inhibit proliferation and activate apoptosis in many types of cancer cells. These findings suggest that targeting cyclic nucleotide signaling can provide a strategy for the discovery of novel agents for the prevention and/or treatment of selected cancers.

  15. The Effect of Compressive Cyclic Loading on the Retention of Cast Single Crowns Cemented to Implant Abutments.

    Science.gov (United States)

    Alvarez-Arenal, Angel; Gonzalez-Gonzalez, Ignacio; Pinés-Hueso, Javier; deLlanos-Lanchares, Hector; del Rio Highsmith, Jaime

    2016-01-01

    The aim of this study was to evaluate and compare the retention strength of three cements commonly used in implant-supported prostheses before and after compressive cyclic loading. The working model consisted of five solid abutments, 7 mm in height and with a 6-degree taper, screw retained to five implant analogs secured in a rectangular block of self-curing acrylic. On the abutments, 30 metal Cr-Ni alloy copings were cemented using three luting agents: glass ionomer, resin urethane-based, and compomer cement (n = 10). Two tensile tests were conducted with a universal testing machine, before and after 100,000 cycles of 100 N and 0.72 Hz compressive cyclic loading in a humid environment. Before applying the compressive load, the retention strength of the resin urethane-based cement was slightly higher than that of the compomer cement and 75% greater than the glass-ionomer cement. After compressive loading, the resin urethane-based cement showed the highest percentage of loss of retention (64.45%, compared with 50% for glass-ionomer and compomer cement). However, the glass-ionomer cement showed the lowest mean retentive strength with 50.35 N as opposed to 75.12 N for the compomer cement and 71.25 N for the resin urethane-based. Compressive cyclic loading significantly influences the retention strength of the luting agents tested. All three cements may favor the retrievability of the crowns.

  16. Non-canonical 3'-5' extension of RNA with prebiotically plausible ribonucleoside 2',3'-cyclic phosphates.

    Science.gov (United States)

    Mutschler, Hannes; Holliger, Philipp

    2014-04-09

    Ribonucleoside 2',3'-cyclic phosphates (N>p's) are generated by multiple prebiotically plausible processes and are credible building blocks for the assembly of early RNA oligomers. While N>p's can be polymerized into short RNAs by non-enzymatic processes with variable efficiency and regioselectivity, no enzymatic route for RNA synthesis had been described. Here we report such a non-canonical 3'-5' nucleotidyl transferase activity. We engineered a variant of the hairpin ribozyme to catalyze addition of all four N>p's (2',3'-cyclic A-, G-, U-, and CMP) to the 5'-hydroxyl termini of RNA strands with 5' nucleotide addition enhanced in all cases by eutectic ice phase formation at -7 °C. We also observed 5' addition of 2',3'-cyclic phosphate-activated β-nicotinamide adenine dinucleotide (NAD>p) and ACA>p RNA trinucleotide, and multiple additions of GUCCA>p RNA pentamers. Our results establish a new mode of RNA 3'-5' extension with implications for RNA oligomer synthesis from prebiotic nucleotide pools.

  17. On the Feasibility of Utilizing Allogeneic Bone Blocks for Atrophic Maxillary Augmentation

    Directory of Open Access Journals (Sweden)

    Alberto Monje

    2014-01-01

    Full Text Available Purpose. This systematic review was aimed at assessing the feasibility by means of survival rate, histologic analysis, and causes of failure of allogeneic block grafts for augmenting the atrophic maxilla. Material and Methods. A literature search was conducted by one reviewer in several databases. Articles were included in this systematic review if they were human clinical trials in which outcomes of allogeneic bone block grafts were studied by means of survival rate. In addition other factors were extracted in order to assess their influence upon graft failure. Results. Fifteen articles fulfilled the inclusion criteria and subsequently were analyzed in this systematic review. A total of 361 block grafts could be followed 4 to 9 months after the surgery, of which 9 (2.4% failed within 1 month to 2 months after the surgery. Additionally, a weighed mean 4.79 mm (95% CI: 4.51–5.08 horizontal bone gain was computed from 119 grafted sites in 5 studies. Regarding implant cumulative survival rate, the weighed mean was 96.9% (95% CI: 92.8–98.7%, computed from 228 implants over a mean follow-up period of 23.9 months. Histologic analysis showed that allogeneic block grafts behave differently in the early stages of healing when compared to autogenous block grafts. Conclusion. Atrophied maxillary reconstruction with allogeneic bone block grafts represents a reliable option as shown by low block graft failure rate, minimal resorption, and high implant survival rate.

  18. On the Feasibility of Utilizing Allogeneic Bone Blocks for Atrophic Maxillary Augmentation

    Science.gov (United States)

    Pikos, Michael A.; Chan, Hsun-Liang; Suarez, Fernando; Gargallo-Albiol, Jordi; Hernández-Alfaro, Federico; Galindo-Moreno, Pablo; Wang, Hom-Lay

    2014-01-01

    Purpose. This systematic review was aimed at assessing the feasibility by means of survival rate, histologic analysis, and causes of failure of allogeneic block grafts for augmenting the atrophic maxilla. Material and Methods. A literature search was conducted by one reviewer in several databases. Articles were included in this systematic review if they were human clinical trials in which outcomes of allogeneic bone block grafts were studied by means of survival rate. In addition other factors were extracted in order to assess their influence upon graft failure. Results. Fifteen articles fulfilled the inclusion criteria and subsequently were analyzed in this systematic review. A total of 361 block grafts could be followed 4 to 9 months after the surgery, of which 9 (2.4%) failed within 1 month to 2 months after the surgery. Additionally, a weighed mean 4.79 mm (95% CI: 4.51–5.08) horizontal bone gain was computed from 119 grafted sites in 5 studies. Regarding implant cumulative survival rate, the weighed mean was 96.9% (95% CI: 92.8–98.7%), computed from 228 implants over a mean follow-up period of 23.9 months. Histologic analysis showed that allogeneic block grafts behave differently in the early stages of healing when compared to autogenous block grafts. Conclusion. Atrophied maxillary reconstruction with allogeneic bone block grafts represents a reliable option as shown by low block graft failure rate, minimal resorption, and high implant survival rate. PMID:25535616

  19. Structural Diversity and Biological Activities of Fungal Cyclic Peptides, Excluding Cyclodipeptides

    OpenAIRE

    Xiaohan Wang; Minyi Lin; Dan Xu; Daowan Lai; Ligang Zhou

    2017-01-01

    Cyclic peptides are cyclic compounds formed mainly by the amide bonds between either proteinogenic or non-proteinogenic amino acids. This review highlights the occurrence, structures and biological activities of fungal cyclic peptides (excluding cyclodipeptides, and peptides containing ester bonds in the core ring) reported until August 2017. About 293 cyclic peptides belonging to the groups of cyclic tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca-, undeca-, dodeca-, tetradeca-, and ...

  20. A Novel Indirect Sequence Readout Component in the E. coli Cyclic AMP Receptor Protein Operator

    DEFF Research Database (Denmark)

    Lindemose, Søren; Nielsen, Peter Eigil; Valentin-Hansen, Poul

    2014-01-01

    binding sites in the E. coli genome, but the exact role of the N6 region in CRP interaction has not previously been systematic examined. Here we employ an in vitro selection system based on a randomized N6 spacer region to demonstrate that CRP binding to the lacP1 site may be enhanced up to 14-fold......The cyclic AMP receptor protein (CRP) from Escherichia coli has been extensively studied for several decades. In particular, a detailed characterization of CRP interaction with DNA has been obtained. The CRP dimer recognizes a consensus sequence AANTGTGANNNNNNTCACANTT through direct amino acid...... nucleobase interactions in the major groove of the two operator half-sites. Crystal structure analyses have revealed that the interaction results in two strong kinks at the TG/CA steps closest to the 6-base-pair spacer (N6). This spacer exhibits high sequence variability among the more than 100 natural...

  1. Analysis of Separated Flow over Blocked Surface

    Directory of Open Access Journals (Sweden)

    Onur YEMENİCİ

    2013-04-01

    Full Text Available In this study, the separated flow over flat and blocked surfaces was investigated experimentally. Velocity and turbulence intensity measurements were carried out by a constanttemperature hot wire anemometer and static pressure measurements by a micro-manometer. The flow separations and reattachments were occurred before the first block, on the first block, between blocks and after the last block, and the presence of the blocks significantly increased the turbulent intensity

  2. Cyclic Stretch Alters Vascular Reactivity of Mouse Aortic Segments

    Directory of Open Access Journals (Sweden)

    Arthur Leloup

    2017-10-01

    Full Text Available Large, elastic arteries buffer the pressure wave originating in the left ventricle and are constantly exposed to higher amplitudes of cyclic stretch (10% than muscular arteries (2%. As a crucial factor for endothelial and smooth muscle cell function, cyclic stretch has, however, never been studied in ex vivo aortic segments of mice. To investigate the effects of cyclic stretch on vaso-reactivity of mouse aortic segments, we used the Rodent Oscillatory Tension Set-up to study Arterial Compliance (ROTSAC. The aortic segments were clamped at frequencies of 6–600 bpm between two variable preloads, thereby mimicking dilation as upon left ventricular systole and recoiling as during diastole. The preloads corresponding to different transmural pressures were chosen to correspond to a low, normal or high amplitude of cyclic stretch. At different time intervals, cyclic stretch was interrupted, the segments were afterloaded and isometric contractions by α1-adrenergic stimulation with 2 μM phenylephrine in the absence and presence of 300 μM L-NAME (eNOS inhibitor and/or 35 μM diltiazem (blocker of voltage-gated Ca2+ channels were measured. As compared with static or cyclic stretch at low amplitude (<10 mN or low frequency (0.1 Hz, cyclic stretch at physiological amplitude (>10 mN and frequency (1–10 Hz caused better ex vivo conservation of basal NO release with time after mounting. The relaxation of PE-precontracted segments by addition of ACh to stimulate NO release was unaffected by cyclic stretch. In the absence of basal NO release (hence, presence of L-NAME, physiological in comparison with aberrant cyclic stretch decreased the baseline tension, attenuated the phasic contraction by phenylephrine in the absence of extracellular Ca2+ and shifted the smaller tonic contraction more from a voltage-gated Ca2+ channel-mediated to a non-selective cation channel-mediated. Data highlight the need of sufficient mechanical activation of endothelial and

  3. Systematic review

    DEFF Research Database (Denmark)

    Enggaard, Helle

    Title: Systematic review a method to promote nursing students skills in Evidence Based Practice Background: Department of nursing educate students to practice Evidence Based Practice (EBP), where clinical decisions is based on the best available evidence, patient preference, clinical experience...... and resources available. In order to incorporate evidence in clinical decisions, nursing students need to learn how to transfer knowledge in order to utilize evidence in clinical decisions. The method of systematic review can be one approach to achieve this in nursing education. Method: As an associate lecturer...... I have taken a Comprehensive Systematic Review Training course provide by Center of Clinical Guidelines in Denmark and Jonna Briggs Institute (JBI) and practice in developing a systematic review on how patients with ischemic heart disease experiences peer support. This insight and experience...

  4. Temperature Dependent Cyclic Deformation Mechanisms in Haynes 188 Superalloy

    Science.gov (United States)

    Rao, K. Bhanu Sankara; Castelli, Michael G.; Allen, Gorden P.; Ellis, John R.

    1995-01-01

    The cyclic deformation behavior of a wrought cobalt-base superalloy, Haynes 188, has been investigated over a range of temperatures between 25 and 1000 C under isothermal and in-phase thermomechanical fatigue (TMF) conditions. Constant mechanical strain rates (epsilon-dot) of 10(exp -3)/s and 10(exp -4)/s were examined with a fully reversed strain range of 0.8%. Particular attention was given to the effects of dynamic strain aging (DSA) on the stress-strain response and low cycle fatigue life. A correlation between cyclic deformation behavior and microstructural substructure was made through detailed transmission electron microscopy. Although DSA was found to occur over a wide temperature range between approximately 300 and 750 C the microstructural characteristics and the deformation mechanisms responsible for DSA varied considerably and were dependent upon temperature. In general, the operation of DSA processes led to a maximum of the cyclic stress amplitude at 650 C and was accompanied by pronounced planar slip, relatively high dislocation density, and the generation of stacking faults. DSA was evidenced through a combination of phenomena, including serrated yielding, an inverse dependence of the maximum cyclic hardening with epsilon-dot, and an instantaneous inverse epsilon-dot sensitivity verified by specialized epsilon-dot -change tests. The TMF cyclic hardening behavior of the alloy appeared to be dictated by the substructural changes occuring at the maximum temperature in the TMF cycle.

  5. Degradation forecast for PEMFC cathode-catalysts under cyclic loads

    Science.gov (United States)

    Moein-Jahromi, M.; Kermani, M. J.; Movahed, S.

    2017-08-01

    Degradation of Fuel Cell (FC) components under cyclic loads is one of the biggest bottlenecks in FC commercialization. In this paper, a novel experimental based algorithm is presented to predict the Catalyst Layer (CL) performance loss during cyclic load. The algorithm consists of two models namely Models 1 and 2. The Model 1 calculates the Electro-Chemical Surface Area (ECSA) and agglomerate size (e.g. agglomerate radius, rt,agg) for the catalyst layer under cyclic load. The Model 2 is the already-existing model from our earlier studies that computes catalyst performance with fixed structural parameters. Combinations of these two Models predict the CL performance under an arbitrary cyclic load. A set of parametric/sensitivity studies is performed to investigate the effects of operating parameters on the percentage of Voltage Degradation Rate (VDR%) with rank 1 for the most influential one. Amongst the considered parameters (such as: temperature, relative humidity, pressure, minimum and maximum voltage of the cyclic load), the results show that temperature and pressure have the most and the least influences on the VDR%, respectively. So that, increase of temperature from 60 °C to 80 °C leads to over 20% VDR intensification, the VDR will also reduce 1.41% by increasing pressure from 2 atm to 4 atm.

  6. Structure of a eukaryotic cyclic nucleotide-gated channel

    Science.gov (United States)

    Li, Minghui; Zhou, Xiaoyuan; Wang, Shu; Michailidis, Ioannis; Gong, Ye; Su, Deyuan; Li, Huan; Li, Xueming; Yang, Jian

    2018-01-01

    Summary Cyclic nucleotide-gated (CNG) channels are essential for vision and olfaction. They belong to the voltage-gated ion channel superfamily but their activities are controlled by intracellular cyclic nucleotides instead of transmembrane voltage. Here we report a 3.5 Å-resolution single-particle electron cryomicroscopy structure of a CNG channel from C. elegans in the cGMP-bound open state. The channel has an unusual voltage-sensor-like domain (VSLD), accounting for its deficient voltage dependence. A C-terminal linker connecting S6 and the cyclic nucleotide-binding domain interacts directly with both the VSLD and pore domain, forming a gating ring that couples conformational changes triggered by cyclic nucleotide binding to the gate. The selectivity filter is lined by the carboxylate side chains of a functionally important glutamate and three rings of backbone carbonyls. This structure provides a new framework for understanding mechanisms of ion permeation, gating and channelopathy of CNG channels and cyclic nucleotide modulation of related channels. PMID:28099415

  7. Cyclic creep and anelastic relaxation analysis of an ODS superalloy

    Science.gov (United States)

    Nardone, Vincent C.; Kimmerle, William L.; Tien, John K.

    1986-09-01

    This paper documents the effect of stress and temperature on the cyclic minimum strain rate at two different loading frequencies for the oxide dispersion strengthened (ODS) superalloy, INCONEL* MA 6000. The apparent stress exponent and activation energy for cyclic creep at both frequencies studied are shown to be greater than values observed for static creep. The large values of the stress exponent and activation energy for cyclic creep are proposed to result from anelastic strain storage delaying nonrecoverable creep during the on-load portion of the cyclic creep loading, such that the “effective stress” driving nonrecoverable creep is only a small fraction of the applied stress. In addition, the temperature dependence of the anelastic relaxation that occurs during the off-load portion of the cyclic creep loading is determined. The activation energy found for the relaxation process is equal to about one-half that for self-diffusion in nickel. A mechanism of localized climb of dislocations over the oxide dispersoids present in INCONEL MA 6000 is postulated to account for the observed activation energy of the relaxation process.

  8. Controlled cyclic stretch bioreactor for tissue-engineered heart valves.

    Science.gov (United States)

    Syedain, Zeeshan H; Tranquillo, Robert T

    2009-09-01

    A tissue-engineered heart valve (TEHV) represents the ultimate valve replacement, especially for juvenile patients given its growth potential. To date, most TEHV bioreactors have been developed based on pulsed flow of culture medium through the valve lumen to induce strain in the leaflets. Using a strategy for controlled cyclic stretching of tubular constructs reported previously, we developed a controlled cyclic stretch bioreactor for TEHVs that leads to improved tensile and compositional properties. The TEHV is mounted inside a latex tube, which is then cyclically pressurized with culture medium. The root and leaflets stretch commensurately with the latex, the stretching being dictated by the stiffer latex and thus controllable. Medium is also perfused through the lumen at a slow rate in a flow loop to provide nutrient delivery. Fibrin-based TEHVs prepared with human dermal fibroblasts were subjected to three weeks of cyclic stretching with incrementally increasing strain amplitude. The TEHV possessed the tensile stiffness and stiffness anisotropy of leaflets from sheep pulmonary valves and could withstand cyclic pulmonary pressures with similar distension as for a sheep pulmonary artery.

  9. Evolutive masing model, cyclic plasticity, ageing and memory effects

    International Nuclear Information System (INIS)

    Sidoroff, F.

    1987-01-01

    Many models are proposed for the mechanical description of the cyclic behaviour of metals and used for structure analysis under cyclic loading. Such a model must include two basic features: Dissipative behaviour on each cycle (hysteresis loop); evolution of this behaviour during the material's life (cyclic hardening or softening, aging,...). However, if both aspects are present in most existing models, the balance between them may be quite different. Many metallurgical investigations have been performed about the microstructure and its evolution during cyclic loading, and it is desirable to introduce these informations in phenomenological models. The evolutive Masing model has been proposed to combine: the accuracy of hereditary models for the description of hysteresis on each cycle, the versatility of internal variables for the state description and evolution, a sufficient microstructural basis to make the interaction easier with microstructural investigations. The purpose of the present work is to discuss this model and to compare different evolution assumptions with respect to some memory effects (cyclic hardening and softening, multilevel tests, aging). Attention is limited to uniaxial, rate independent elasto-plastic behaviour

  10. Various semiclassical limits of torus conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Alkalaev, Konstantin [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky ave. 53, Moscow, 119991 (Russian Federation); Department of General and Applied Physics, Moscow Institute of Physics and Technology,Institutskiy per. 7, Dolgoprudnyi, Moscow region, 141700 (Russian Federation); Geiko, Roman [Mathematics Department, National Research University Higher School of Economics,Usacheva str. 6, Moscow, 119048 (Russian Federation); Rappoport, Vladimir [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky ave. 53, Moscow, 119991 (Russian Federation); Department of Quantum Physics, Institute for Information Transmission Problems,Bolshoy Karetny per. 19, Moscow, 127994 (Russian Federation)

    2017-04-12

    We study four types of one-point torus blocks arising in the large central charge regime. There are the global block, the light block, the heavy-light block, and the linearized classical block, according to different regimes of conformal dimensions. It is shown that the blocks are not independent being connected to each other by various links. We find that the global, light, and heavy-light blocks correspond to three different contractions of the Virasoro algebra. Also, we formulate the c-recursive representation of the one-point torus blocks which is relevant in the semiclassical approximation.

  11. Characteristics of turbulent particle transport in human airways under steady and cyclic flows

    Energy Technology Data Exchange (ETDEWEB)

    Jedelsky, Jan, E-mail: jedelsky@fme.vutbr.cz [Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 61669 Brno (Czech Republic); Lizal, Frantisek, E-mail: lizal@fme.vutbr.cz [Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 61669 Brno (Czech Republic); Jicha, Miroslav, E-mail: jicha@fme.vutbr.cz [Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 61669 Brno (Czech Republic)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer PDA data allow to estimate PSD of particle velocity fluctuations in realistic model. Black-Right-Pointing-Pointer PSD of micron-sized particles is independent of their size up to 700 Hz. Black-Right-Pointing-Pointer Such particles follow air flow and turb. diffusion contributes to their deposition. Black-Right-Pointing-Pointer Cyclic flow PSDs contain more TKE at high freq. than equivalent steady-flow PSDs. Black-Right-Pointing-Pointer Exp. breathing phase differs from insp. phase at high frequency part of the spectra. - Abstract: Motion of monodispersed aerosol particles suspended in air flow has been studied on realistic transparent model of human airways using Phase Doppler Particle Analyser (P/DPA). Time-resolved velocity data for particles in size range 1-8 {mu}m were processed using Fuzzy Slotting Technique to estimate the power spectral density (PSD) of velocity fluctuations. The optimum processing setup for our data was found and recommendations for future experiments to improve PSD quality were suggested. Typical PSD plots at mainstream positions of the trachea and the upper bronchi are documented and differences among (1) steady-flow regimes and equivalent cyclic breathing regimes, (2) inspiration and expiration breathing phase and (3) behaviour of particles of different sizes are described in several positions of the airway model. Systematically higher level of velocity fluctuations in the upper part of the frequency range (30-500 Hz) was found for cyclic flows in comparison with corresponding steady flows. Expiratory flows in both the steady and cyclic cases produce more high-frequency fluctuations compared to inspiratory flows. Negligible differences were found for flow of particles in the inspected size range 1-8 {mu}m at frequencies below 500 Hz. This finding was explained by Stokes number analysis. Implied match of the air and particle flows thereby indicates turbulent diffusion as important deposition

  12. How 'cyclic' is the Supercontinental Cycle

    Science.gov (United States)

    Pisarevsky, Sergei

    2017-04-01

    Precambrian paleogeography currently attracts a lot of attention from Earth scientists in various disciplines. This interest is particularly linked to the supercontinental cycle hypothesis and its relationship with global geodynamic processes. Most of the geoscience community accepts this hypothesis as plausible, but its details are still debated for several reasons. First of all, there is no consensus about the definition of a supercontinent. For example - is Gondwana a supercontinent? Depending on the answer, various estimations of the longevity of supercontinent cycle(s) arise. Another concern regards the methodological approach to paleogeographic reconstructions. For instance, some consider that the Precambrian supercontinent Nuna (aka Columbia) was assembled as a result of the widespread 2.0-1.8 Ga orogenies. However, careful consideration of geological, geochronological and paleomagnetic evidence instead suggests that supercontinent building blocks were assembled during this 2.0-1.8 Ga time interval, but that assembly of these building blocks into a supercontinent only occurred about 200 Myr later. There are only two quantitative tools for Precambrian paleogeographic reconstructions - paleomagnetic data and regional mafic dyke swarms geometries. Unfortunately, there are not yet enough high quality Precambrian paleomagnetic data to produce Apparent Polar Wander Paths (APWPs) for most Precambrian continents and to reconstruct their relative position with respect to each other, as was done for Phanerozoic paleogeography. Consequently all published reconstructions of Precambrian supercontinents are suggestive but not definitive. The only way to build a plausible Precambrian paleogeographic reconstruction is to combine paleomagnetic data with geological, geochemical and geochronological evidence. For example, the combination of paleomagnetic data with matching coeval Large Igneous Provinces (LIPs) and their regional dyke swarms, is helpful, but has limitations

  13. Crack shielding degradation in alumina during cyclic fatigue

    Energy Technology Data Exchange (ETDEWEB)

    El Attaoui, H.; Saadaoui, M. [LERSIM, Rabat (Morocco); INSA de Lyon, Villeurbanne (France). GEMPPM; Chevalier, J.; Fantozzi, G. [INSA de Lyon, Villeurbanne (France). GEMPPM

    2002-07-01

    R curve measurements before and after cyclic fatigue were performed on SENB specimens of coarse grain alumina to investigate fatigue effect. A significant drop of the crack growth resistance was observed after cyclic loading which could be associated to a decrease of the shielding effect due to bridging degradation. No variation was observed on the amount of degradation as the number of cycles increased for a maximum applied load, K{sub max} of 50% of the K{sub R} value before cyclic loading, K{sub f}, whereas an increase was observed for K{sub max}/K{sub f} = 0.7, when the critical number of cycles corresponding to failure was approached. (orig.)

  14. Cyclic AMP system in muscle tissue during prolonged hypokinesia

    Science.gov (United States)

    Antipenko, Y. A.; Bubeyev, Y. A.; Korovkin, B. F.; Mikhaleva, N. P.

    1980-01-01

    Components of the cyclic Adenosine-cyclic-35-monophosphate (AMP) system in the muscle tissue of white rats were studied during 70-75 days of hypokinesia, created by placing the animals in small booths which restricted their movements, and during the readaptation period. In the initial period, cyclic AMP levels and the activities of phosphodiesterase and adenylate cyclase in muscle tissue were increased. The values for these indices were roughly equal for controls and experimental animals during the adaptation period, but on the 70th day of the experiment cAMP levels dropped, phosphodiesterase activity increased, and the stimulative effect of epinephrine on the activity of adenylate cyclase decreased. The indices under study normalized during the readaptation period.

  15. Durability of Modified Expanded Polystyrene Concrete after Dynamic Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Wenbo Shi

    2016-01-01

    Full Text Available EPS concrete was produced by mixing the expanded polystyrene spheres (EPS and polymer emulsion and thickener to the matrix concrete, and this concrete had good vibration energy absorption characteristics. Based on the experimental data obtained on EPS volume ratio of 0%, 20%, 30%, and 40% by replacing matrix or coarse aggregate, the two design styles had nearly the same compressive strength. By applying frequency of 5 Hz, 50000 or 100000 times, 40 KN, 50 KN, and 60 KN cyclic loading, it is shown that the higher the inclusion size was, the lower the compressive strength of the EPS concrete would be; the larger the applying dynamic cyclic load was, the more obvious the compressive strength changing would be. Meanwhile, the strength of EPS concrete had no evident change after durability test. The results of this research had practical significance on using EPS concrete in some long-term cyclic dynamic load engineering.

  16. Application Of Shakedown Analysis To Cyclic Creep Damage Limits

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Peter [Stress Engineering Services Inc.; Jetter, Robert I [Consultant; Sham, Sam [ORNL

    2012-01-01

    Shakedown analysis may be used to provide a conservative estimate of local rupture and hence cyclic creep damage for use in a creep-fatigue assessment. The shakedown analysis is based on an elastic-perfectly plastic material with a temperature-dependent pseudo yield stress defined to guarantee that a shakedown solution exists which does not exceed rupture stress and temperature for a defined life. The ratio of design life to the estimated maximum cyclic life is the shakedown creep damage. The methodology does not require stress classification and is also applicable to cycles over the full range of temperature above and below the creep regime. Full cyclic creep and damage analysis is the alternative when shakedown analysis appears to be excessively conservative.

  17. Cyclicity of non-associative products on D-branes

    CERN Document Server

    Herbst, Manfred; Kreuzer, M

    2004-01-01

    The non-commutative geometry of deformation quantization appears in string theory through the effect of a B-field background on the dynamics of D-branes in the topological limit. For arbitrary backgrounds, associativity of the star product is lost, but only cyclicity is necessary for a description of the effective action in terms of a generalized product. In previous work we showed that this property indeed emerges for a non-associative product that we extracted from open string amplitudes in curved background fields. In the present note we extend our investigation through second order in a complete derivative expansion. We establish cyclicity with respect to the Born--Infeld measure and find a logarithmic correction that modifies the Kontsevich formula in an arbitrary background satisfying the generalized Maxwell equation. This equation is the physical equivalent of a divergence-free non-commutative parameter, which is required for cyclicity already in the associative case.

  18. Cyclicality and Firm Size in Private Firm Defaults

    DEFF Research Database (Denmark)

    Jensen, Thais Lærkholm; Lando, David; Medhat, Mamdouh

    2017-01-01

    The Basel II/III and CRD IV Accords reduce capital charges on bank loans to smaller firms by assuming that the default probabilities of smaller firms are less sensitive to macroeconomic cycles. We test this assumption in a default intensity framework using a large sample of bank loans to private...... Danish firms. We find that controlling only for size, the default probabilities of small firms are, in fact, less cyclical than the default probabilities of large firms. However, accounting for firm characteristics other than size, we find that the default probabilities of small firms are equally...... cyclical or even more cyclical than the default probabilities of large firms. These results hold using a multiplicative Cox model as well as an additive Aalen model with time-varying coefficients....

  19. Cyclic Tetrapyrrole Sulfonation, Metals, and Oligomerization in Antiprion Activity▿

    Science.gov (United States)

    Caughey, Winslow S.; Priola, Suzette A.; Kocisko, David A.; Raymond, Lynne D.; Ward, Anne; Caughey, Byron

    2007-01-01

    Cyclic tetrapyrroles are among the most potent compounds with activity against transmissible spongiform encephalopathies (TSEs; or prion diseases). Here the effects of differential sulfonation and metal binding to cyclic tetrapyrroles were investigated. Their potencies in inhibiting disease-associated protease-resistant prion protein were compared in several types of TSE-infected cell cultures. In addition, prophylactic antiscrapie activities were determined in scrapie-infected mice. The activity of phthalocyanine was relatively insensitive to the number of peripheral sulfonate groups but varied with the type of metal bound at the center of the molecule. The tendency of the various phthalocyanine sulfonates to oligomerize (i.e., stack) correlated with anti-TSE activity. Notably, aluminum(III) phthalocyanine tetrasulfonate was both the poorest anti-TSE compound and the least prone to oligomerization in aqueous media. Similar comparisons of iron- and manganese-bound porphyrin sulfonates confirmed that stacking ability correlates with anti-TSE activity among cyclic tetrapyrroles. PMID:17709470

  20. Cyclic tetrapyrrole sulfonation, metals, and oligomerization in antiprion activity.

    Science.gov (United States)

    Caughey, Winslow S; Priola, Suzette A; Kocisko, David A; Raymond, Lynne D; Ward, Anne; Caughey, Byron

    2007-11-01

    Cyclic tetrapyrroles are among the most potent compounds with activity against transmissible spongiform encephalopathies (TSEs; or prion diseases). Here the effects of differential sulfonation and metal binding to cyclic tetrapyrroles were investigated. Their potencies in inhibiting disease-associated protease-resistant prion protein were compared in several types of TSE-infected cell cultures. In addition, prophylactic antiscrapie activities were determined in scrapie-infected mice. The activity of phthalocyanine was relatively insensitive to the number of peripheral sulfonate groups but varied with the type of metal bound at the center of the molecule. The tendency of the various phthalocyanine sulfonates to oligomerize (i.e., stack) correlated with anti-TSE activity. Notably, aluminum(III) phthalocyanine tetrasulfonate was both the poorest anti-TSE compound and the least prone to oligomerization in aqueous media. Similar comparisons of iron- and manganese-bound porphyrin sulfonates confirmed that stacking ability correlates with anti-TSE activity among cyclic tetrapyrroles.

  1. Radial Coordinates for Conformal Blocks

    CERN Document Server

    Hogervorst, Matthijs

    2013-01-01

    We develop the theory of conformal blocks in CFT_d expressing them as power series with Gegenbauer polynomial coefficients. Such series have a clear physical meaning when the conformal block is analyzed in radial quantization: individual terms describe contributions of descendants of a given spin. Convergence of these series can be optimized by a judicious choice of the radial quantization origin. We argue that the best choice is to insert the operators symmetrically. We analyze in detail the resulting "rho-series" and show that it converges much more rapidly than for the commonly used variable z. We discuss how these conformal block representations can be used in the conformal bootstrap. In particular, we use them to derive analytically some bootstrap bounds whose existence was previously found numerically.

  2. Diversity Gain through Antenna Blocking

    Directory of Open Access Journals (Sweden)

    V. Dehghanian

    2012-01-01

    Full Text Available As part of the typical usage mode, interaction between a handheld receiver antenna and the operator's RF absorbing body and nearby objects is known to generate variability in antenna radiation characteristics through blocking and pattern changes. It is counterintuitive that random variations in blocking can result in diversity gain of practical applicability. This diversity gain is quantified from a theoretical and experimental perspective. Measurements carried out at 1947.5 MHz verify the theoretical predictions, and a diversity gain of 3.1 dB was measured through antenna blocking and based on the utilized measurement setup. The diversity gain can be exploited to enhance signal detectability of handheld receivers based on a single antenna in indoor multipath environments.

  3. Cryptanalysis of Selected Block Ciphers

    DEFF Research Database (Denmark)

    Alkhzaimi, Hoda A.

    , pseudorandom number generators, and authenticated encryption designs. For this reason a multitude of initiatives over the years has been established to provide a secure and sound designs for block ciphers as in the calls for Data Encryption Standard (DES) and Advanced Encryption Standard (AES), lightweight...... ciphers initiatives, and the Competition for Authenticated Encryption: Security, Applicability, and Robustness (CAESAR). In this thesis, we first present cryptanalytic results on different ciphers. We propose attack named the Invariant Subspace Attack. It is utilized to break the full block cipher...... on the family of lightweight block cipher SIMON that was published by the U.S National Security Agency (NSA). The ciphers are developed with optimization towards both hardware and software in mind. While the specification paper discusses design requirements and performance of the presented lightweight ciphers...

  4. Climatological features of blocking anticyclones

    International Nuclear Information System (INIS)

    Lupo, A.R.; Smith, P.J.; Oglesby, R.J.

    1994-01-01

    Several climatological studies have been previously performed using large observational data sets (i.e., 10 years or longer) in order to determine the predominant characteristics of blocking anticyclones, including favored development regions, duration, preferred seasonal occurrence, and frequency of occurrence. These studies have shown that blocking anticyclones occur most frequently from October to April over the eastern Atlantic and Pacific oceans downstream from both the North American and Asian continental regions and the storm track regions to the east of these continents. Some studies have also revealed the presence of a third region block formation in western Russia near 40 degrees E which is associated with another storm track region over the Mediterranean and western Asia

  5. Projectors, shadows, and conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Simmons-Duffin, David [Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States)

    2014-04-24

    We introduce a method for computing conformal blocks of operators in arbitrary Lorentz representations in any spacetime dimension, making it possible to apply bootstrap techniques to operators with spin. The key idea is to implement the “shadow formalism' of Ferrara, Gatto, Grillo, and Parisi in a setting where conformal invariance is manifest. Conformal blocks in d-dimensions can be expressed as integrals over the projective null-cone in the “embedding space' ℝ{sup d+1,1}. Taking care with their analytic structure, these integrals can be evaluated in great generality, reducing the computation of conformal blocks to a bookkeeping exercise. To facilitate calculations in four-dimensional CFTs, we introduce techniques for writing down conformally-invariant correlators using auxiliary twistor variables, and demonstrate their use in some simple examples.

  6. Ultrasound and review of evidence for lower extremity peripheral nerve blocks.

    Science.gov (United States)

    Salinas, Francis V

    2010-01-01

    This qualitative systematic review summarizes existing evidence from randomized controlled trials (RCTs) comparing ultrasound (US) to alternative techniques for lower extremity peripheral nerve block. There were 11 RCTs of sufficient quality for inclusion. Jadad scores ranged from 1 to 4 with a median of 3. For femoral nerve blocks, US provided shorter onset and improved quality of sensory and motor block, as well as a decrease in local anesthetic requirements. For sciatic nerve blocks, US resulted in a higher percentage of patients with complete sensory and motor block, as well as decreased local anesthetic requirements. In 2 of the studies for sciatic nerve block, US resulted in a shorter time to successfully complete the procedure. No study was powered to detect a difference in surgical block success. Overall, there was significant heterogeneity in the definitions of successful sensory and motor block. In 2 studies, the optimal peripheral nerve stimulation technique may have not been used, resulting in a potential bias. No RCT reported US as inferior to alternative techniques in any outcome. There is level Ib evidence to make a grade A recommendation that US guidance provides improvements in onset and success of sensory block, a decrease in local anesthetic requirements, and decreased time to perform lower extremity peripheral nerve blocks.

  7. Cyclic operation of power plant; Cyklisk drift av kraftvaermeverk

    Energy Technology Data Exchange (ETDEWEB)

    Storesund, Jan

    2007-12-15

    The great majority of power plants are designed for base load operation with a relatively small number of starts and stops per year. Therefore, there has been no need to consider fatigue at design. Over the last few years operation with more frequent starts and stops exists as a consequence of swinging electricity prices that has become common. This involves significantly higher frequency of damages; not least fatigue relates damages, and the number of severe failures in components that never before have had damage problems may increase as well. In the present work the different types of component that may suffer from cyclic operation related damage are gathered by a literature survey and described as follows: - where and how the damages comes up, - constructions that should be avoided, - non-destructive testing (NDT) for damage that may come up under cyclic operation, - calculation and assessment of integrity of critical components - areas where continued research would be valuable. Recommendations have been put together to be used to prevent cyclic operation related damage and to detect it in time. The target group for this study is i) plant owners of plants where cyclic operation is or may be present, ii) researchers in the area, and, iii) inspectors and NDT-operators. There are quite a number of components where cyclic operation has been found to significantly influence the lift time. Some of these components are described in many papers whereas occasional papers have been found for others. The amount of information that is possible to get for a certain component is likely related to its significance for cyclic operation damage. The most frequently reported problem is ligament cracking of high temperature headers. Other components where extensive studies have been done are: wall panels, creep-fatigue loaded welds and turbine components

  8. An Analytical Model for Simulating Heavy-Oil Recovery by Cyclic Steam Injection Using Horizontal Wells, SUPRI TR-118

    Energy Technology Data Exchange (ETDEWEB)

    Diwan, Utpal; Kovscek, Anthony R.

    1999-08-09

    In this investigation, existing analytical models for cyclic steam injection and oil recovery are reviewed and a new model is proposed that is applicable to horizontal wells. A new flow equation is developed for oil production during cyclic steaming of horizontal wells. The model accounts for the gravity-drainage of oil along the steam-oil interface and through the steam zone. Oil viscosity, effective permeability, geometry of the heated zone, porosity, mobile oil saturation, and thermal diffusivity of the reservoir influence the flow rate of oil in the model. The change in reservoir temperature with time is also modeled, and it results in the expected decline in oil production rate during the production cycle as the reservoir cools. Wherever appropriate, correlations and incorporated to minimize data requirements. A limited comparison to numerical simulation results agrees well, indicating that essential physics are successfully captured. Cyclic steaming appears to be a systematic met hod for heating a cold reservoir provided that a relatively uniform distribution of steam is obtained along the horizontal well during injection. A sensitivity analysis shows that the process is robust over the range of expected physical parameters.

  9. Projectors, Shadows, and Conformal Blocks

    OpenAIRE

    Simmons-Duffin, David

    2012-01-01

    We introduce a method for computing conformal blocks of operators in arbitrary Lorentz representations in any spacetime dimension, making it possible to apply bootstrap techniques to operators with spin. The key idea is to implement the “shadow formalism” of Ferrara, Gatto, Grillo, and Parisi in a setting where conformal invariance is manifest. Conformal blocks in d -dimensions can be expressed as integrals over the projective null-cone in the “embedding space” $ \\mathbb{R} $ d +1,1 . Taking ...

  10. The Cyclic Sieving Phenomenon for Faces of Generalized Cluster Complexes

    OpenAIRE

    Eu, Sen-Peng; Fu, Tung-Shan

    2006-01-01

    The notion of cyclic sieving phenomenon is introduced by Reiner, Stanton, and White as a generalization of Stembridge's $q=-1$ phenomenon. The generalized cluster complexes associated to root systems are given by Fomin and Reading as a generalization of the cluster complexes found by Fomin and Zelevinsky. In this paper, the faces of various dimensions of the generalized cluster complexes in type $A_n$, $B_n$, $D_n$, and $I_2(a)$ are shown to exhibit the cyclic sieving phenomenon under a cycli...

  11. Photoelectron spectra and structures of three cyclic dipeptides

    DEFF Research Database (Denmark)

    Wickrama Arachchilage, A.P.; Wang, F.; Feyer, V.

    2012-01-01

    spectra of all three cyclic dipeptides agree reasonably well with the experimental spectra. The central ring and the side chains act as independent chromophores whose spectra do not influence one another, except for prolyl dipeptides, where the pyrrole ring is fused with the central ring. In this case......We have investigated the electronic structure of three cyclic dipeptides: cyclo(Histidyl-Glycyl) (cHisGly), cyclo(Tyrosyl-Prolyl) (cTyrPro), and cyclo(Phenylalanyl-Phenylalanyl) (cPhePhe) in the vapor phase, by means of photoemission spectroscopy and theoretical modeling. The last compound...

  12. Cyclic Plane Strain Compression Tests on Dense Granular Materials

    Science.gov (United States)

    Koseki, Junichi; Karimi, Job Munene; Tsutsumi, Yukika; Maqbool, Sajjad; Sato, Takeshi

    A series of cyclic plane strain compression tests are performed under drained condition on dense Toyoura sand and compacted Chiba gravel, by using small-scale and large-scale apparatuses, respectively. Comparisons are made with results from monotonic loading tests. Local strain distributions are calculated by conducting image analyses of digital photographs taken at different stages of loading during each test. Based on these results, strain localization properties of dense granular materials are discussed, in particular focusing on possible effects of cyclic loading history.

  13. Determination of silver using cyclic epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Pun, T.H.; Landsberger, S.

    2012-01-01

    A fast pneumatic transfer facility was installed in Nuclear Engineering Teaching Laboratory (NETL) of the University of Texas at Austin for the purpose of cyclic thermal and epithermal neutron activation analysis. In this study efforts were focused on the evaluation of cyclic epithermal neutron activation analysis (CENAA). Various NIST and CANMET certified materials were analyzed by the system. Experiment results showed 110 Ag with its 25 s half-life as one of the isotopes favored by the system. Thus, the system was put into practical application in identifying silver in metallic ores. Comparison of sliver concentrations as determined by CENAA in CANMET certified reference materials gave very good results. (author)

  14. Progressive buckling under both constant axial load and cyclic distortion

    International Nuclear Information System (INIS)

    Clement, G.; Acker, D.; Lebey, J.

    1988-09-01

    Thin structures submitted to compressive loads must be carefully designed to avoid any risk of ruin by buckling. The aim of this paper is, first, to evidence that the critical buckling load may be notably lowered when cyclic strains are added to the compressive load and, secondly, to propose a practical rule of prevention against the ruin due to the progressive buckling phenomenon. This rule is validated by the results of numerous tests related to the entire range of modes of buckling (i.e. from fully plastic to fully elastic). Practical cases of interest for its use could mainly be those where cyclic thermal stresses are involved

  15. Response of monopiles under cyclic lateral loading in sand

    DEFF Research Database (Denmark)

    Nicolai, Giulio; Ibsen, Lars Bo

    2015-01-01

    Currently the main design guidelines propose to reduce the lateral resistance of offshore piles when accounting for cyclic loading. The present work provides results from laboratory tests in which such reduction has not occurred. The experimental investigation is based on testing a small-scale mo......Currently the main design guidelines propose to reduce the lateral resistance of offshore piles when accounting for cyclic loading. The present work provides results from laboratory tests in which such reduction has not occurred. The experimental investigation is based on testing a small...

  16. Cyclic and Long-Term Variation of Sunspot Magnetic Fields

    Science.gov (United States)

    2014-10-15

    AFRL-RV-PS- TP-2014-0009 AFRL-RV-PS- TP-2014-0009 CYCLIC AND LONG-TERM VARIATION OF SUNSPOT MAGNETIC FIELDS Alexei A. Pevtsov, et al. 15...TITLE AND SUBTITLE Cyclic and Long-Term Variation of Sunspot Magnetic Fields 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62601F...from the Mount Wilson Observatory (MWO) were used to study the long-term variations of sunspot field strengths from 1920 to 1958. Following a modified

  17. Apoptotic Cell Localization in Preantral and Antral Follicles in Relation to Non-cyclic and Cyclic Gilts.

    Science.gov (United States)

    Phoophitphong, D; Srisuwatanasagul, S; Koonjaenak, S; Tummaruk, P

    2016-06-01

    The objective of this study was to determine apoptotic cell localization in preantral and antral follicles of porcine ovaries. Additionally, the proportion of cells undergoing apoptosis was also compared between delayed puberty gilts and normal cyclic gilts. Ovarian tissues were obtained from 34 culled gilts with age and weight of 270.1 ± 3.9 days and 143.8 ± 2.4 kg, respectively. The gilts were classified according to their ovarian appearance as 'non-cyclic' (n = 7) and 'cyclic' (n = 27) gilts. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay was used to determine apoptotic cell expression in different compartments of the ovarian tissue sections. All apparent preantral (n = 110) and antral (n = 262) follicles were evaluated using image analysis software. It was found that apoptotic cells were expressed in both granulosa (22.2%) and theca cell layers (21.3%) of the follicles in the porcine ovaries. The proportion of apoptotic cells in the granulosa layer in the follicles was positively correlated with that in the theca layer (r = 0.90, p  0.05) or theca cell layers (28.6% and 26.5%, p > 0.05). The proportion of apoptotic cells in non-cyclic gilts was higher than cyclic gilts in both granulosa (31.7% and 22.6%, p gilts than cyclic gilts. This implied that apoptosis could be used as a biologic marker for follicular development/function and also that apoptosis was significantly associated with anoestrus or delayed puberty in gilts, commonly observed in tropical climates. © 2016 Blackwell Verlag GmbH.

  18. Main-chain supramolecular block copolymers.

    Science.gov (United States)

    Yang, Si Kyung; Ambade, Ashootosh V; Weck, Marcus

    2011-01-01

    Block copolymers are key building blocks for a variety of applications ranging from electronic devices to drug delivery. The material properties of block copolymers can be tuned and potentially improved by introducing noncovalent interactions in place of covalent linkages between polymeric blocks resulting in the formation of supramolecular block copolymers. Such materials combine the microphase separation behavior inherent to block copolymers with the responsiveness of supramolecular materials thereby affording dynamic and reversible materials. This tutorial review covers recent advances in main-chain supramolecular block copolymers and describes the design principles, synthetic approaches, advantages, and potential applications.

  19. Building Blocks for Personal Brands

    Science.gov (United States)

    Thomas, Lisa Carlucci

    2011-01-01

    In this article, the author discusses the four essential building blocks for personal brands: (1) name; (2) message; (3) channels; and (4) bridges. However, outstanding building materials can only take a person so far. The author emphasizes that vision, determination, faith, a sense of humor, and humility are also required.

  20. Control rod removal blocking device

    International Nuclear Information System (INIS)

    Yoshioka, Ritsuo.

    1981-01-01

    Purpose: To prevent excess power increase resulted from erroneous control rod removal during high power operation in BWR type reactor by decreasing the continuous removal enabling distance for the control rods along with increase in the reactor power where the reactor power is greater than a predetermined level. Constitution: When control rod selection signals are supplied from a control unit to a control rod removal blocking device, the blocking device judges whether the reactor core power is greater than a predetermined value A or not, using reactor core power signals outputted from an average power monitor. Where the reactor core power exceeds the predetermined value A and if the reactor core power is relatively low, a large continuous removal enabling distance N 1 is calculated in the blocking device to allow the continuous removal as far as the notch N 1 . The continuous removal enabling distance is shortened as the reactor core power increases and the removal is blocked, for example, at notch N 2 . While on the other hand, if the reactor core power is below the predetermined value A, both of the notchwise removal and the continuous removal are enabled. (Seki, T.)

  1. First Degree Pacemaker Exit Block

    Directory of Open Access Journals (Sweden)

    Johnson Francis

    2016-10-01

    Full Text Available Usually atrial and ventricular depolarizations follow soon after the pacemaker stimulus (spike on the ECG. But there can be an exit block due to fibrosis at the electrode - tissue interface at the lead tip. This can increase the delay between the spike and atrial or ventricular depolarization.

  2. Vagal Blocking for Obesity Control

    DEFF Research Database (Denmark)

    Johannessen, Helene; Revesz, David; Kodama, Yosuke

    2017-01-01

    BACKGROUND: Recently, the US FDA has approved "vagal blocking therapy or vBLoc® therapy" as a new treatment for obesity. The aim of the present study was to study the mechanism-of-action of "VBLOC" in rat models. METHODS: Rats were implanted with VBLOC, an intra-abdominal electrical device...

  3. Thermo-responsive block copolymers

    NARCIS (Netherlands)

    Mocan Cetintas, Merve

    2017-01-01

    Block copolymers (BCPs) are remarkable materials because of their self-assembly behavior into nano-sized regular structures and high tunable properties. BCPs are in used various applications such as surfactants, nanolithography, biomedicine and nanoporous membranes. In these thesis, we aimed to

  4. Scintigraphic visualization of 'Blocking' thyroid

    International Nuclear Information System (INIS)

    Simeonova, A.; Kostadinova, I.

    2006-01-01

    Full text: An important problem in nuclear endocrinology is 'blocking' of thyroid gland, which necessitates postpone of the investigation, adverse clinical effect of stopping medications and a delay of making diagnosis. The aim of the study was to introduce and to determine the clinical value of the scintigraphy with 99mTc-MIBI in patients (Pts) with 'blocked thyroid'. In 365 Pts (aged 38-75 years), indicated for a thyroid scintigraphy after proper preparation, an investigation was performed with 74 MBq 99mTc-pertechnetate, 20 min. p.i. In 14 of them (3.8%), the thyroid was 'blocked' and additional scintigraphy was done with 370-555 MBq 99mTc-MIBI, 15 and 120 min.p.i. It was estimated that in all Pts there was a visualization of thyroid. In 1 of them, a large 'hot' nodule was visualized in the early and late image. Later on a differentiated thyroid carcinoma was proved histologically. In the rest of the patients 'cold' nodules with different size were visualized, eventually as a result of cysts. As a conclusion we consider, that a scintigraphy with 99mTc-MIBI is a useful tool in Pts with 'blocked' thyroid. In addition an evaluation of the thyroid nodule could be done and therefore- a recommendation for therapy

  5. Systematic review

    DEFF Research Database (Denmark)

    Bager, Palle; Chauhan, Usha; Greveson, Kay

    2017-01-01

    OBJECTIVE: Advice lines for patients with inflammatory bowel diseases (IBD) have been introduced internationally. However, only a few publications have described the advice line service and evaluated the efficiency of it with many results presented as conference posters. A systematic synthesis...... of evidence is needed and the aim of this article was to systematically review the evidence of IBD advice lines. MATERIALS AND METHODS: A broad systematic literature search was performed to identify relevant studies addressing the effect of advice lines. The process of selection of the retrieved studies...... congress abstracts were included in the review. The studies were heterogeneous both in scientific quality and in the focus of the study. No rigorous evidence was found to support that advice lines improve disease activity in IBD and correspondingly no studies reported worsening in disease activity. Advice...

  6. Fuel-Mediated Transient Clustering of Colloidal Building Blocks.

    Science.gov (United States)

    van Ravensteijn, Bas G P; Hendriksen, Wouter E; Eelkema, Rienk; van Esch, Jan H; Kegel, Willem K

    2017-07-26

    Fuel-driven assembly operates under the continuous influx of energy and results in superstructures that exist out of equilibrium. Such dissipative processes provide a route toward structures and transient behavior unreachable by conventional equilibrium self-assembly. Although perfected in biological systems like microtubules, this class of assembly is only sparsely used in synthetic or colloidal analogues. Here, we present a novel colloidal system that shows transient clustering driven by a chemical fuel. Addition of fuel causes an increase in hydrophobicity of the building blocks by actively removing surface charges, thereby driving their aggregation. Depletion of fuel causes reappearance of the charged moieties and leads to disassembly of the formed clusters. This reassures that the system returns to its initial, equilibrium state. By taking advantage of the cyclic nature of our system, we show that clustering can be induced several times by simple injection of new fuel. The fuel-mediated assembly of colloidal building blocks presented here opens new avenues to the complex landscape of nonequilibrium colloidal structures, guided by biological design principles.

  7. Nearly Cyclic Pursuit and its Hierarchical variant for Multi-agent Systems

    DEFF Research Database (Denmark)

    Iqbal, Muhammad; Leth, John-Josef; Ngo, Trung Dung

    2015-01-01

    The rendezvous problem for multiple agents under nearly cyclic pursuit and hierarchical nearly cyclic pursuit is discussed in this paper. The control law designed under nearly cyclic pursuit strategy enables the agents to converge at a point dictated by a beacon. A hierarchical version of the nea......The rendezvous problem for multiple agents under nearly cyclic pursuit and hierarchical nearly cyclic pursuit is discussed in this paper. The control law designed under nearly cyclic pursuit strategy enables the agents to converge at a point dictated by a beacon. A hierarchical version...

  8. Experimental study under uniaxial cyclic behavior at room and high temperature of 316L stainless steel

    International Nuclear Information System (INIS)

    Kang Guozheng; Gao Qing; Yang Xianjie; Sun Yafang

    2001-01-01

    An experimental study was carried out of the cyclic properties of 316L stainless steel subjected to uniaxial strain and stress at room and high temperature. The effects of cyclic strain amplitude, temperature and their histories on the cyclic deformation behavior of 316L stainless steel are investigated. And, the influences of stress amplitude, mean stress, temperature and their histories on ratcheting are also analyzed. It is shown that either uniaxial cyclic property under cyclic strain or ratcheting under asymmetric uniaxial cyclic stress depends not only on the current temperature and loading state, but also on the previous temperature and loading history. Some significant results are obtained

  9. Cyclic and heteroclinic flows near general static spherically symmetric black holes: semi-cyclic flows - addendum and corrigendum

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Ainou, Mustapha [Baskent University, Engineering Faculty, Ankara (Turkey)

    2017-01-15

    We present new accretion solutions of a polytropic perfect fluid onto an f(R)-gravity de Sitter-like black hole. We consider two f(R)-gravity models and obtain finite-period cyclic flows oscillating between the event and cosmological horizons as well as semi-cyclic critical flows executing a two-way motion from and back to the same horizon. Besides the generalizations and new solutions presented in this work, a corrigendum to Eur. Phys. J. C (2016) 76:280 is provided. (orig.)

  10. Finite element analysis of the cyclic indentation of bilayer enamel

    Science.gov (United States)

    Jia, Yunfei; Xuan, Fu-zhen; Chen, Xiaoping; Yang, Fuqian

    2014-04-01

    Tooth enamel is often subjected to repeated contact and often experiences contact deformation in daily life. The mechanical strength of the enamel determines the biofunctionality of the tooth. Considering the variation of the rod arrangement in outer and inner enamel, we approximate enamel as a bilayer structure and perform finite element analysis of the cyclic indentation of the bilayer structure, to mimic the repeated contact of enamel during mastication. The dynamic deformation behaviour of both the inner enamel and the bilayer enamel is examined. The material parameters of the inner and outer enamel used in the analysis are obtained by fitting the finite element results with the experimental nanoindentation results. The penetration depth per cycle at the quasi-steady state is used to describe the depth propagation speed, which exhibits a two-stage power-law dependence on the maximum indentation load and the amplitude of the cyclic load, respectively. The continuous penetration of the indenter reflects the propagation of the plastic zone during cyclic indentation, which is related to the energy dissipation. The outer enamel serves as a protective layer due to its great resistance to contact deformation in comparison to the inner enamel. The larger equivalent plastic strain and lower stresses in the inner enamel during cyclic indentation, as calculated from the finite element analysis, indicate better crack/fracture resistance of the inner enamel.

  11. Selective discrimination of cyclodextrin diols using cyclic sulfates

    DEFF Research Database (Denmark)

    Petrillo, Marta; Marinescu, Lavinia; Rousseau, Cyril

    2009-01-01

    A method for selective monofunctionalition of readily available cyclodextrin diols (2(A-F),3(A-F),6(B,C,E,F)-hexadeca-O-benzyl-alpha-cyclodextrin and 2(A-G),3(A-G),6(B,C,E-G)-nonadeca-O-benzyl-beta-cyclodextrin) by regioselective nucleophilic opening of their cyclic sulfates is presented. Althoug...

  12. Topology and symmetry of surface Majorana arcs in cyclic superconductors

    Science.gov (United States)

    Mizushima, Takeshi; Nitta, Muneto

    2018-01-01

    We study the topology and symmetry of surface Majorana arcs in superconductors with nonunitary "cyclic" pairing. Cyclic p -wave pairing may be realized in a cubic or tetrahedral crystal, while it is a candidate for the interior P32 superfluids of neutron stars. The cyclic state is an admixture of full gap and nodal gap with eight Weyl points and the low-energy physics is governed by itinerant Majorana fermions. We here show the evolution of surface states from Majorana cone to Majorana arcs under rotation of surface orientation. The Majorana cone is protected solely by an accidental spin rotation symmetry and fragile against spin-orbit coupling, while the arcs are attributed to two topological invariants: the first Chern number and one-dimensional winding number. Lastly, we discuss how topologically protected surface states inherent to the nonunitary cyclic pairing can be captured from surface probes in candidate compounds, such as U1 -xThxBe13 . We examine tunneling conductance spectra for two competitive scenarios in U1 -xThxBe13 —the degenerate Eu scenario and the accidental scenario.

  13. Mechanical properties of concrete to cyclic uniaxial tensile loading ...

    Indian Academy of Sciences (India)

    The mechanical properties of concrete under cyclic tensile loading using square waveform, sine waveform and ramp waveform are studied. ... College of Civil and Transportation Engineering, Hobai University, Nanjing 210098, China; College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing ...

  14. Characterizing and modelling cyclic behaviour in non-stationary ...

    Indian Academy of Sciences (India)

    to comprise of stochastic fluctuations as well as cyclic variations at different scales. The wavelet transform ... analysis shows that at small time scales, the fluctuations are primarily stochastic in nature; at higher scales the ..... here also to overcome the problem of GP optimization procedure settling down to persistent solutions ...

  15. 21 CFR 862.1230 - Cyclic AMP test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cyclic AMP test system. 862.1230 Section 862.1230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  16. Optimum Design and Operation of Cyclic Storage Systems; Lumped Approach

    Directory of Open Access Journals (Sweden)

    Leila Ostadrahimi

    2007-01-01

    Full Text Available Conjunctive use of surface and groundwater resources is a preferred approach in water resources management. Compared to dam construction, groundwater has certain advantages, among which are less costs, less sedimentation and evaporation, fewer water quality problems, and less social and cultural problems. To reduce the major problems associated with the development of large-scale surface impoundment systems, cyclic storage systems can be used as an alternative. A cyclic storage system (CYCS is an integrated interactive system consisting of two subsystems of surface water storage (reservoir and groundwater; this system together with artificial recharge is able to satisfy the predefined demands with rather high reliability. In order to optimize these systems, one must consider the hydraulic interactions between all the components, but unfortunately it has been neglected in many studies. In this article, a nonlinear optimization model for design and operation of cyclic storage systems has been developed using the lumped approach. In order to evaluate the model, its results have been compared with the results of a model in which distributed approach had been deployed, and so the efficiency of lumped models to solve the problems of cyclic storage systems has been investigated.

  17. Towards Green Cyclic Carbonate Synthesis : Heterogeneous and Homogeneous Catalyst Development

    NARCIS (Netherlands)

    Stewart, J.A.

    2015-01-01

    This PhD research serves to implement both known and novel catalytic systems for the purpose of cyclic carbonate synthesis from biomass-derived substrates. Such products have been earmarked as potential monomers for non-isocyanate polyurethanes (NIPUs), amongst other uses. Particular attention has

  18. METHODOLOGICAL ASPECTS OF ECONOMIC EVENTS CYCLICITY METHOD CONSIDERATION

    Directory of Open Access Journals (Sweden)

    Yaskova Natalia Yur'ievna

    2017-07-01

    Full Text Available The cyclicity of economic phenomena is not only their immanent property but also the subject of economic analysis. The modern way of making managerial decisions requires analysis of a number of cycles that fill any kind of activity. Accounting and reconciliation of construction, design, investment, purchasing, reproduction, leasing and other cycles is important for the investment and construction sector, both from the point of view of the need for their synchronization and from the position of determining trends in sectoral development. The analysis has showed that three main types of development are characteristic for investment and construction activity. Increasing intensity is inherent in a high level of cyclic synchronization. The degradation trend arises as a result of mismatched cycles. The stabilization character is inherent in the regular modes of maintaining the established proportions and cyclical inter-conformity. The study of the cyclical nature of investment and building processes is impossible without understanding their co-ordination. The principles of synchronization and subordination of the cycles should be used not only for the construction of cost-effective systems but also for the development of management tools.

  19. Laboratory experiments of bucket foundations under cyclic loading

    DEFF Research Database (Denmark)

    Foglia, Aligi; Ibsen, Lars Bo

    This report collects information on the experimental campaign concerning bucket foundations under lateral cyclic loading conducted by the authors between 2011 and 2014. The report includes a step by step manual on the test procedures and a number of information and graphs for each experiment...

  20. The comparison of cyclic deformation curve determination for ADI

    Czech Academy of Sciences Publication Activity Database

    Zapletal, J.; Obrtlík, Karel; Věchet, S.

    308 2005, - (2005), s. 305-309 ISSN 1429-6055. [Miedzynarodowe sympozjum /20./. Ustroň-Jaszowiec, 07.12.2005-09.12.2005] R&D Projects: GA ČR(CZ) GA106/03/1265 Institutional research plan: CEZ:AV0Z20410507 Keywords : cyclic stress-strain curve * austempered ductile iron Subject RIV: JG - Metallurgy

  1. Expression and diagnostic utility of anti-cyclic citrullinated peptide ...

    African Journals Online (AJOL)

    Background: Juvenile idiopathic arthritis (JIA) is a clinically heterogeneous group of arthritis occurring in children. Anti-cyclic citrullinated peptide (anti-CCP) antibodies have been recently included in the revised diagnostic criteria for adult onset rheumatoid arthritis. Its diagnostic value in JIA is still debatable. Objective: The ...

  2. Antifungal cyclic peptides from the marine sponge Microscleroderma herdmani

    Science.gov (United States)

    Screening natural product extracts from National Cancer Institute Open Repository for antifungal discovery afforded hits for bioassay-guided fractionation. Upon LC-MS analysis of column fractions with antifungal activities to generate information on chemical structure, two new cyclic hexapeptides, m...

  3. Aeroelastic Vibrations and Stability in Cyclic Symmetric Domains

    Directory of Open Access Journals (Sweden)

    Bernard Lalanne

    2000-01-01

    wing. In this way, aerodynamic forces may be obtained as general as required, depending on successive time derivatives of degrees of freedom in addition to themselves. Finally, some special cases are given and stability is studied for a cyclic periodic blade assembly, even when mistuning between sectors can occur.

  4. Cyclic machine scheduling with tool transportation - additional calculations

    NARCIS (Netherlands)

    Kuijpers, C.M.H.

    2001-01-01

    In the PhD Thesis of Kuijpers a cyclic machine scheduling problem with tool transportation is considered. For the problem with two machines, it is shown that there always exists an optimal schedule with a certain structure. This is done by means of an elaborate case study. For a number of cases some

  5. Skill Retention and Relearning--A Proposed Cyclical Model.

    Science.gov (United States)

    Ginzburg, S.; Dar-El, E. M.

    2000-01-01

    The relationship between relearning and retention was examined during refresher training for 53 Israeli soldiers operating an electronic system. The longer the training interval, the lower the operator's performance level. Partial simulation was suitable for retraining in complex tasks. A cyclical behavior model of learning, forgetting, and…

  6. Cyclic irradiation method for production of radioisotope tracers using ...

    African Journals Online (AJOL)

    Cyclic Irradiation Method (CIM) involving repeated irradiation of samples at regular time intervals to build up activity has been adopted for the production of 82 Br, 72 Ga, 140La, 24 Na and 46 Sc isotopes using the low power Ghana Research Reactor-1. The results indicate that the specific activities of radioisotopes from ...

  7. Retinal Cyclic Nucleotide-Gated Channels: From Pathophysiology to Therapy

    Directory of Open Access Journals (Sweden)

    Stylianos Michalakis

    2018-03-01

    Full Text Available The first step in vision is the absorption of photons by the photopigments in cone and rod photoreceptors. After initial amplification within the phototransduction cascade the signal is translated into an electrical signal by the action of cyclic nucleotide-gated (CNG channels. CNG channels are ligand-gated ion channels that are activated by the binding of cyclic guanosine monophosphate (cGMP or cyclic adenosine monophosphate (cAMP. Retinal CNG channels transduce changes in intracellular concentrations of cGMP into changes of the membrane potential and the Ca2+ concentration. Structurally, the CNG channels belong to the superfamily of pore-loop cation channels and share a common gross structure with hyperpolarization-activated cyclic nucleotide-gated (HCN channels and voltage-gated potassium channels (KCN. In this review, we provide an overview on the molecular properties of CNG channels and describe their physiological role in the phototransduction pathways. We also discuss insights into the pathophysiological role of CNG channel proteins that have emerged from the analysis of CNG channel-deficient animal models and human CNG channelopathies. Finally, we summarize recent gene therapy activities and provide an outlook for future clinical application.

  8. Cyclic antibiotic therapy for diverticular disease: a critical reappraisal.

    Science.gov (United States)

    Zullo, Angelo; Hassan, Cesare; Maconi, Giovanni; Manes, Gianpiero; Tammaro, Gianfranco; De Francesco, Vincenzo; Annibale, Bruno; Ficano, Leonardo; Buri, Luigi; Gatto, Giovanni; Lorenzetti, Roberto; Campo, Salvatore M; Ierardi, Enzo; Pace, Fabio; Morini, Sergio

    2010-09-01

    Different symptoms have been attributed to uncomplicated diverticular disease (DD). Poor absorbable antibiotics are largely used for uncomplicated DD, mainly for symptom treatment and prevention of diverticulitis onset. Controlled trials on cyclic administration of rifaximin in DD patients were evaluated. Four controlled, including 1 double-blind and 3 open-label, randomized studies were available. Following a long-term cyclic therapy, a significant difference emerged in the global symptoms score (range: 0-18) between rifaximin plus fibers (from 6-6.5 to 1-2) and fibers alone (from 6.7 to 2-3.8), although the actual clinically relevance of such a very small difference remains to be ascertained. Moreover, a similar global symptom score reduction (from 6 to 2.4) can be achieved by simply recommending an inexpensive high-fiber diet. Current data suggest that cyclic rifaximin plus fibers significantly reduce the incidence of the first episode of acute diverticulitis as compared to fibers alone (1.03% vs 2.75%), but a cost-efficacy analysis is needed before this treatment can be routinely recommended. The available studies have been hampered by some limitations, and definite conclusions could not be drawn. The cost of a long-life, cyclic rifaximin therapy administered to all symptomatic DD patients would appear prohibitive.

  9. Cyclic flow shop scheduling problem with two-machine cells

    Directory of Open Access Journals (Sweden)

    Bożejko Wojciech

    2017-06-01

    Full Text Available In the paper a variant of cyclic production with setups and two-machine cell is considered. One of the stages of the problem solving consists of assigning each operation to the machine on which it will be carried out. The total number of such assignments is exponential. We propose a polynomial time algorithm finding the optimal operations to machines assignment.

  10. Mechanism of Cyclically Polarity Reversing Solar Magnetic Cycle as ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... We briefly describe historical development of the concept of solar dynamo mechanism that generates electric current and magnetic field by plasma ... The dynamo is the driver of the cyclically polarity reversing solar magnetic cycle. ... Department of Astronomy, University of Tokyo, Tokyo, Japan 113-0033.

  11. Cyclic deformation behaviour of austenitic steels at ambient and ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. The aim of the present investigation is to characterise cyclic deforma- tion behaviour and plasticity-induced martensite formation of metastable austenitic stainless steels at ambient and elevated temperatures, taking into account the influ- ence of the alloying elements titanium and niobium. Titanium and niobium are.

  12. Cyclic deformation behaviour of austenitic steels at ambient and ...

    Indian Academy of Sciences (India)

    Fatigue behaviour of X6CrNiTi1810 (AISI 321), X10CrNiCb189 (AISI 348) and X5CrNi1810 (AISI 304) is characterised by cyclic hardening and softening effects which are strongly influenced by specific loading conditions. Martensite formation varies with the composition, loading conditions, temperature and number of ...

  13. Evolutions of Yang Phase Under Cyclic Condition and Adiabatic Condition

    International Nuclear Information System (INIS)

    Qian Shangwu; Gu Zhiyu

    2005-01-01

    There are three non-integrable phases in literatures: Berry phase, Aharonov-Anandan phase, and Yang phase. This article discusses the evolutions of Yang phase under the cyclic condition and the adiabatic condition for the general time-dependent harmonic oscillator, thus reveals the intimate relations between these three non-integrable phases.

  14. Effect of Color Shading Procedures and Cyclic Loading on the ...

    African Journals Online (AJOL)

    2018-02-07

    Feb 7, 2018 ... How to cite this article: Tuncel I, Turp I, Usumez A. Effect of color shading procedures and cyclic loading on the biaxial flexural strength of zirconia. Niger J Clin Pract 2018;21:7-12. This is an open access article distributed under the terms of the Creative Commons. Attribution-NonCommercial-ShareAlike 3.0 ...

  15. Effect of Color Shading Procedures and Cyclic Loading on the ...

    African Journals Online (AJOL)

    Purpose: Zirconia is the most preferred ceramic restoration in posterior areas because of its flexural strength. The aim of the study is the evaluation of biaxial flexural strength of different colored zirconium oxide core materials after cyclic loading. Material and Methods: Zirconia discs (12 mm diameter and 1.2 mm thickness) ...

  16. A genus six cyclic tetragonal reduction of the Benney equations

    International Nuclear Information System (INIS)

    England, M; Gibbons, J

    2009-01-01

    A reduction of Benney's equations is constructed corresponding to Schwartz-Christoffel maps associated with a family of genus six cyclic tetragonal curves. The mapping function, a second kind Abelian integral on the associated Riemann surface, is constructed explicitly as a rational expression in derivatives of the Kleinian σ-function of the curve.

  17. Computational design of disulfide cyclic peptide as potential ...

    African Journals Online (AJOL)

    Development of genomic and proteomic studies coupled with computational sciences could facilitate the discovery of various target proteins and potential inhibitor to be developed as drugs. Several researches by molecular docking method have been conducted to design disulfide cyclic peptide ligand as potential inhibitors ...

  18. Synergistic degradation of dentin by cyclic stress and buffer agitation.

    Science.gov (United States)

    Orrego, Santiago; Romberg, Elaine; Arola, Dwayne

    2015-04-01

    Secondary caries and non-carious lesions develop in regions of stress concentrations and oral fluid movement. The objective of this study was to evaluate the influence of cyclic stress and fluid movement on material loss and subsurface degradation of dentin within an acidic environment. Rectangular specimens of radicular dentin were prepared from caries-free unrestored 3rd molars. Two groups were subjected to cyclic cantilever loading within a lactic acid solution (pH = 5) to achieve compressive stresses on the inner (pulpal) or outer sides of the specimens. Two additional groups were evaluated in the same solution, one subjected to movement only (no stress) and the second held stagnant (control: no stress or movement). Exterior material loss profiles and subsurface degradation were quantified on the two sides of the specimens. Results showed that under cyclic stress material loss was significantly greater (p ≤ 0.0005) on the pulpal side than on the outer side and significantly greater (p ≤ 0.05) under compression than tension. However, movement only caused significantly greater material loss (p ≤ 0.0005) than cyclic stress. Subsurface degradation was greatest at the location of highest stress, but was not influenced by stress state or movement. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Undrained behaviour of volcanic soils under monotonic and cyclic loading

    Science.gov (United States)

    de Cristofaro, Martina; Brunzo, Antonia; Mottola, Luciano; Netti, Nadia; Olivares, Lucio; Orense, Rolando; Asadi, Sadeq

    2017-04-01

    Undrained behaviour of volcanic soils under monotonic and cyclic loading. In this study, we focus on the undrained behaviour of volcanic deposits under monotonic and cyclic loading in order to define the susceptibility to liquefaction of granular volcanic deposits. We assume that, in the case of saturated granular volcanic deposits susceptible to liquefaction, an undrained unstable behaviour can be responsible for both, the evolution of flowslide due to rainfall and liquefaction under seismic loading. Starting from these considerations we define a complex experimental program to analyze their undrained behaviour through laboratory testing on reconstituted specimens of cohesionless volcanic soils. The first part of the experimental program is devoted to the use of the steady state concept to evaluate the influence of void ratio and effective confining pressure on the undrained behaviour of Cervinara pyroclastic soils (Italy) under monotonic and cyclic loading. The second part of the experimental program is devoted to the analysis of the influence of particles crushing of pumice soils from Rangiriri (New Zeland) in both monotonic and cyclic undrained triaxial tests.

  20. Liquefaction and cyclic mobility model for saturated granular media

    Science.gov (United States)

    López-Querol, S.; Blázquez, R.

    2006-04-01

    A new constitutive law for the behaviour of undrained sand subjected to dynamic loading is presented. The proposed model works for small and large strain ranges and incorporates contractive and dilative properties of the sand into the unified numerical scheme. These features allow to correctly predict liquefaction and cyclic mobility phenomena for different initial relative densities of the soil. The model has been calibrated as an element test, by using cyclic simple shear data reported in the literature. For the contractive sand behaviour a well-known endochronic densification model has been used, whereas a plastic model with a new non-associative flow rule is applied when the sand tends to dilate. Both dilatancy and flow rule are based on a new state parameter, associated to the stiffness degradation of the material as the shaking goes on. Also, the function that represents the rearrangement memory of the soil takes a zero value when the material dilates, in order to easily model the change in the internal structure. Proceeding along this kind of approach, liquefaction and cyclic mobility are modelled with the same constitutive law, within the framework of a bi-dimensional FEM coupled algorithm developed in the paper. For calibration purposes, the behaviour of the soil in a cyclic simple shear test has been simulated, in order to estimate the influence of permeability, frequency of loading, and homogeneity of the shear stress field on the laboratory data.

  1. Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Breum Andersen, Sandra; Johansen, Helle Krogh

    2016-01-01

    method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between –1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58–0.82 V that is unaffected by other redox-active interferents...

  2. Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry

    DEFF Research Database (Denmark)

    Alatraktchi, Fatima AlZahra'a; Andersen, Sandra Breum; Johansen, Helle Krogh

    2016-01-01

    method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between -1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58-0.82 V that is unaffected by other redox-active interferents...

  3. Biosynthesis and regulation of cyclic lipopeptides in Pseudomonas fluorescens

    NARCIS (Netherlands)

    Bruijn, de I.

    2009-01-01

    Cyclic lipopeptides (CLPs) are surfactant and antibiotic metabolites produced by a variety of bacterial
    genera. For the genus Pseudomonas, many structurally different CLPs have been identified. CLPs play an
    important role in surface motility of Pseudomonas strains, but also in virulence

  4. Optimal control of FES-induced cyclical leg movements

    NARCIS (Netherlands)

    Veltink, Petrus H.; Franken, H.M.; Franken, Henry M.; d' Hollosy, Wendy; Burger, G.J.; Burger, Gert-Jan; Boom, H.B.K.

    1991-01-01

    An optimal control strategy for FES-induced cyclical movements is proposed. Optimal stimulation patterns are determined on the basis of a criterium, consisting of desired movement parameters and a dynamic model of the system. Preliminary results of the identification and optimization are shown.

  5. Cyclic Nucleotide Monophosphates and Their Cyclases in Plant Signaling

    KAUST Repository

    Gehring, Christoph A.

    2017-10-04

    The cyclic nucleotide monophosphates (cNMPs), and notably 3′,5′-cyclic guanosine monophosphate (cGMP) and 3′,5′-cyclic adenosine monophosphate (cAMP) are now accepted as key signaling molecules in many processes in plants including growth and differentiation, photosynthesis, and biotic and abiotic defense. At the single molecule level, we are now beginning to understand how cNMPs modify specific target molecules such as cyclic nucleotide-gated channels, while at the systems level, a recent study of the Arabidopsis cNMP interactome has identified novel target molecules with specific cNMP-binding domains. A major advance came with the discovery and characterization of a steadily increasing number of guanylate cyclases (GCs) and adenylate cyclases (ACs). Several of the GCs are receptor kinases and include the brassinosteroid receptor, the phytosulfokine receptor, the Pep receptor, the plant natriuretic peptide receptor as well as a nitric oxide sensor. We foresee that in the near future many more molecular mechanisms and biological roles of GCs and ACs and their catalytic products will be discovered and further establish cNMPs as a key component of plant responses to the environment.

  6. Optical fibre Bragg grating recorded in TOPAS cyclic olefin copolymer

    DEFF Research Database (Denmark)

    Johnson, I.P.; Yuan, Scott Wu; Stefani, Alessio

    2011-01-01

    A report is presented on the inscription of a fibre Bragg grating into a microstructured polymer optical fibre fabricated from TOPAS cyclic olefin copolymer. This material offers two important advantages over poly (methyl methacrylate), which up to now has formed the basis for polymer fibre Bragg...

  7. Cyclic Voltammetry of Biopolymer Heparin at PVC Plasticized Liquid Membrane

    Czech Academy of Sciences Publication Activity Database

    Samec, Zdeněk; Trojánek, Antonín; Langmaier, Jan; Samcová, E.

    2003-01-01

    Roč. 5, - (2003), s. 867-870 ISSN 1388-2481 R&D Projects: GA ČR GA203/04/0424 Institutional research plan: CEZ:AV0Z4040901 Keywords : cyclic voltammetry * PVC plasticized liquit membrane * heparin Subject RIV: CG - Electrochemistry Impact factor: 2.300, year: 2003

  8. A novel hydrogen-bonded cyclic dibromide in an organic ...

    Indian Academy of Sciences (India)

    Unknown

    A novel hydrogen-bonded cyclic dibromide in an organic diammonium salt. #. BIKSHANDARKOIL R SRINIVASAN,1,* ... rangement of anions and cations may be viewed as a typical lamellar structure. The crystal water mole- cules can be ..... layers of organic (dbtmen)2+ cations (dashed lines indi- cate hydrogen bonding).

  9. A theoretical model for predicting neutron fluxes for cyclic Neutron ...

    African Journals Online (AJOL)

    A theoretical model has been developed for prediction of thermal neutron fluxes required for cyclic irradiations of a sample to obtain the same activity previously used for the detection of any radionuclide of interest. The model is suitable for radiotracer production or for long-lived neutron activation products where the ...

  10. Drained Response of Bucket Foundations under Cyclic Lateral Load

    DEFF Research Database (Denmark)

    Foglia, Aligi; Ibsen, Lars Bo

    2013-01-01

    Introduction The monopod bucket foundation is an innovative support structure for offshore wind turbines. It consists of a shallow embedded foundation which penetrates the seabed by means of a suction created within the caisson. The behaviour of bucket foundations against long-term lateral cyclic...

  11. Cyclic AMP response element binding protein and brain-derived ...

    Indian Academy of Sciences (India)

    Madhu

    the role of CREB and BDNF in depression and as targets/mediators of antidepressant action. [Nair A and Vaidya V A 2006 Cyclic AMP response element binding protein and brain-derived neurotrophic factor: Molecules that modulate our mood?; J. Biosci. 31 423–434]. Keywords. Antidepressant; depression; hippocampus ...

  12. Resistance to cyclic loading of teeth restored with posts

    DEFF Research Database (Denmark)

    Sahafi, A; Peutzfeldt, A; Ravnholt, G

    2005-01-01

    This in vitro study evaluated the effect of presence of post, presence of core, and of shape, type, and surface treatment of posts on resistance to cyclic loading of crowned human teeth. For all teeth, crowns designed without ferrule were cast in sterling silver and luted with resin cement (Panavia...

  13. Long-term Cyclic Variations of Prominences, Green and Red ...

    Indian Academy of Sciences (India)

    Abstract. Long-term cyclic variations in the distribution of promi- nences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18-23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the ...

  14. Route and fleet design for cyclic inventory routing

    NARCIS (Netherlands)

    Raa, Birger; Dullaert, Wout

    2017-01-01

    This paper presents a novel solution approach for planning cyclic distribution from a single depot to multiple customers with constant, deterministic demand rates. The objective is to minimize the total cost rate consisting of fleet costs, distribution costs from the depot to the customers and

  15. Reaction of three cyclic thioester ligands with triiron dodecacarbonyl ...

    Indian Academy of Sciences (India)

    Zhiyin Xiao

    2017-09-27

    Sep 27, 2017 ... unknown iron carbonyl product was isolated in addition to complex 1. Although its precise structure was not established due to ... ysis were used to identify some of the isolated products. Possible reaction mechanisms of the cyclic ... duced in dropwise fashion. The color of the mixture turned slowly to yellow.

  16. Are international fund flows pro- or counter-cyclical?

    NARCIS (Netherlands)

    Li, Suxiao; de Haan, Jakob; Scholtens, Bert; Yang, Haizhen

    2015-01-01

    We investigate whether international fund flows are pro-or counter-cyclical by employing a concordance index. International fund flows are investments in bond and equity markets by institutional investors, such as mutual funds, exchange traded funds, closed-end funds and hedge funds. We find that

  17. Methods and systems for the formation of cyclic carbonates

    Science.gov (United States)

    Hatton, Trevor Alan; Jamison, Timothy F; Kozak, Jennifer Aiden; Simeon, Fritz; Wu, Jie

    2014-12-30

    Described herein are inventive methods for synthesis of cyclic carbonates from CO.sub.2 and epoxide. In some embodiments, the methods are carried out in the presence of a catalyst comprising an electrophilic halogen. In some embodiments, the methods are carried out in a flow reactor.

  18. Characterization of cyclical phases in the manufacturing industry in Spain

    Directory of Open Access Journals (Sweden)

    Mercè Sala

    2014-09-01

    Full Text Available 120 Purpose: The purpose of this paper is to characterize the cyclical phases of the manufacturing industry in Spain and detect which industries have more influence on the Spanish business cycle. We assume that economic growth is a priority; we are going to determine which industries have a more/less appropriate cyclical behavior according this priority. We analyze if the industries with better cyclical behavior are the ones that achieve greater co-movement with the business cycle of the Spanish economy, as this means they have a positive influence on economic activity. Design/methodology/approach: We examine the disaggregated quarterly IPI data of 16 manufacturing industries. Our methodology follows three steps. Firstly, we define cycle turning points; we follow the Harding and Pagan (2002 methodology. Secondly, we characterize the cyclical phases of the manufacturing industries in terms of duration, amplitude, deepness and steepness. We also determine the degree of inter-industrial cyclical synchronization and between industries in the cycle of the Spanish economy. This analysis is performed in two ways. On the one hand, we use the concordance index and the correlation coefficient. On the other hand, we work with indicators based on a consistency table. In the Third step, we apply a multi-objective methodology, specifically the compromise programming, to determine which industries have a more/less appropriate cyclical behavior according to the growth priority. Findings and Originality/value: The business cycle of the Spanish economy is positively influenced by high- and medium-tech industries, which have demonstrated their competitive capacity in international markets, and by medium- low-tech industries, with major strengths in R&D, and in survival and consolidation strategies. These results enable manufacturing industries to exert a positive effect on the business cycle that is weakened because many of them show a high correlation between

  19. New insights into neurogenic cyclic motor activity in the isolated guinea-pig colon.

    Science.gov (United States)

    Costa, M; Wiklendt, L; Keightley, L; Brookes, S J H; Dinning, P G; Spencer, N J

    2017-10-01

    The contents of the guinea pig distal colon consist of multiple pellets that move anally in a coordinated manner. This row of pellets results in continued distention of the colon. In this study, we have investigated quantitatively the features of the neurally dependent colonic motor patterns that are evoked by constant distension of the full length of guinea-pig colon. Constant distension was applied to the excised guinea-pig by high-resolution manometry catheters or by a series of hooks. Constant distension elicited regular Cyclic Motor Complexes (CMCs) that originated at multiple different sites along the colon and propagated in an oral or anal direction extending distances of 18.3±10.3 cm. CMCs were blocked by tetrodotoxin (TTX; 0.6 μ mol L -1 ), hexamethonium (100 μ mol L -1 ) or hyoscine (1 μ mol L -1 ). Application of TTX in a localized compartment or cutting the gut circumferentially disrupted the spatial continuity of CMCs. Localized smooth muscle contraction was not required for CMC propagation. Shortening the length of the preparations or disruption of circumferential pathways reduced the integrity and continuity of CMCs. CMCs are a distinctive neurally dependent cyclic motor pattern, that emerge with distension over long lengths of the distal colon. They do not require changes in muscle tension or contractility to entrain the neural activity underlying CMC propagation. CMCs are likely to play an important role interacting with the neuromechanical processes that time the propulsion of multiple natural pellets and may be particularly relevant in conditions of impaction or obstruction, where long segments of colon are simultaneously distended. © 2017 John Wiley & Sons Ltd.

  20. Iminodiacetic acid as bifunctional linker for dimerization of cyclic RGD peptides

    International Nuclear Information System (INIS)

    Xu, Dong; Zhao, Zuo-Quan; Chen, Shu-Ting; Yang, Yong; Fang, Wei; Liu, Shuang

    2017-01-01

    Introduction: In this study, I2P-RGD 2 was used as the example to illustrate a novel approach for dimerization of cyclic RGD peptides. The main objective of this study was to explore the impact of bifunctional linkers (glutamic acid vs. iminodiacetic acid) on tumor-targeting capability and excretion kinetics of the 99m Tc-labeled dimeric cyclic RGD peptides. Methods: HYNIC-I2P-RGD 2 was prepared by reacting I2P-RGD 2 with HYNIC-OSu in the presence of diisopropylethylamine, and was evaluated for its α v β 3 binding affinity against 125 I-echistatin bound to U87MG glioma cells. 99m Tc-I2P-RGD 2 was prepared with high specific activity (~185 GBq/μmol). The athymic nude mice bearing U87MG glioma xenografts were used to evaluate its biodistribution properties and image quality in comparison with those of 99m Tc-3P-RGD 2 . Results: The IC 50 value for HYNIC-I2P-RGD 2 was determined to be 39 ± 6 nM, which was very close to that (IC 50 = 33 ± 5 nM) of HYNIC-3P-RGD 2 . Replacing glutamic acid with iminodiacetic acid had little impact on α v β 3 binding affinity of cyclic RGD peptides. 99m Tc-I2P-RGD 2 and 99m Tc-3P-RGD 2 shared similar tumor uptake values over the 2 h period, and its α v β 3 -specificity was demonstrated by a blocking experiment. The uptake of 99m Tc-I2P-RGD 2 was significantly lower than 99m Tc-3P-RGD 2 in the liver and kidneys. The U87MG glioma tumors were visualized by SPECT with excellent contrast using both 99m Tc-I2P-RGD 2 and 99m Tc-3P-RGD 2 . Conclusion: Iminodiacetic acid is an excellent bifunctional linker for dimerization of cyclic RGD peptides. Bifunctional linkers have significant impact on the excretion kinetics of 99m Tc radiotracers. Because of its lower liver uptake and better tumor/liver ratios, 99m Tc-I2P-RGD 2 may have advantages over 99m Tc-3P-RGD 2 for diagnosis of tumors in chest region. -- Graphical abstract: This report presents novel approach for dimerization of cyclic RGD peptides using iminodiacetic acid as a

  1. Interaction between short fatigue cracks and grain boundaries. Systematic experiments with focussed ion beam microscope and microstructural tomography; Ueber die Wechselwirkung kurzer Ermuedungsrisse mit Korngrenzen. Systematische Experimente mit Focussed Ion Beam Microscope und mikrostruktureller Tomographie

    Energy Technology Data Exchange (ETDEWEB)

    Schaef, Wolfgang

    2011-04-15

    Increasing the microstructural resistance of metallic materials to short fatigue crack growth is a major task of today's materials science. In this regard, grain boundaries and precipitates are well known to decelerate short cracks, but a quantitative understanding of the blocking effect is still missing. This is due to the fact that crack deceleration is influenced by many parameters: cyclic load, crack length, distance to obstacles, orientations of grains and obstacles. Even the examination of a huge number of short cracks would not be sufficient to identify the effect of these parameters independently, especially since fatigue crack growth is a 3D problem and investigations of the sub surface orientation of cracks and grain boundaries are scarce. The Focused Ion Beam Microscope (FIB) offers new methods for systematic experiments and 3D-investigation of short fatigue cracks that will help to quantify the microstructural impact on short fatigue crack growth. The ion beam is used to cut micro notches in selected grains on the surface of samples characterised by Electron Backscatter Diffraction (EBSD). Plane fatigue cracks initiate under cyclic loading in defined distances to the grain boundaries. By this technique it is possible for the first time to present quantitative data to describe the effect of grain boundaries on short fatigue cracks in nickel based superalloys (CMSX-4) as well as in mild steels.

  2. Systematic review

    DEFF Research Database (Denmark)

    Lødrup, Anders Bergh; Reimer, Christina; Bytzer, Peter

    2013-01-01

    in getting off acid-suppressive medication and partly explain the increase in long-term use of PPI. A number of studies addressing this issue have been published recently. The authors aimed to systematically review the existing evidence of clinically relevant symptoms caused by acid rebound following PPI...

  3. Cyclic delivery scheduling to customers with different priorities

    Directory of Open Access Journals (Sweden)

    Katarzyna Zofia Gdowska

    2013-12-01

    Full Text Available Background: In this paper a cyclic delivery scheduling problem for customers with different priorities is presented. Shops, which are provided with deliveries, are occasionally located in places which are crucial for the proper flow of traffic. In such places coordination of deliveries is crucial; therefore it allows to completely eliminate the phenomenon of the simultaneous arrivals of suppliers. Methods: In this paper the cyclic delivery scheduling problem for customers with different priorities was presented. To this theoretical problem a mix integer programming model was developed. Specific approach to the cyclic delivery scheduling problem is inspired by timetabling problem for urban public transport. Results: Mixed integer programming model was employed for solving four cases of cyclic delivery scheduling problem for customers with different priorities. When the value of the synchronization priority assigned to a single customer raised then the total number of synchronizations in the whole network decreased. In order to compare solutions a synchronization rate was utilized. A simple factor was utilized - the proportion of number of synchronizations of deliveries to a given customer to the total number of synchronizations obtained for the whole network. When the value of synchronization priority raised then the value of synchronization rate of this customer improved significantly. Conclusions: The mixed integer programming model for the cyclic delivery scheduling problem for customers with different priorities presented in this paper can be utilized for generating schedules of serving customers located in places where only one delivery can be received and unloaded at one go and where there is no space for other suppliers to wait in a queue. Such a schedule can be very useful for organizing deliveries to small shops united in a franchising network, since they operate in a way that is very similar to the network presented in this paper

  4. Testing and modeling of cyclically loaded rock anchors

    Directory of Open Access Journals (Sweden)

    Joar Tistel

    2017-12-01

    Full Text Available The Norwegian Public Roads Administration (NPRA is planning for an upgrade of the E39 highway route at the westcoast of Norway. Fixed links shall replace ferries at seven fjord crossings. Wide spans and large depths at the crossings combined with challenging subsea topography and environmental loads call for an extension of existing practice. A variety of bridge concepts are evaluated in the feasibility study. The structures will experience significant loads from deadweight, traffic and environment. Anchoring of these forces is thus one of the challenges met in the project. Large-size subsea rock anchors are considered a viable alternative. These can be used for anchoring of floating structures but also with the purpose of increasing capacity of fixed structures. This paper presents first a thorough study of factors affecting rock anchor bond capacity. Laboratory testing of rock anchors subjected to cyclic loading is thereafter presented. Finally, the paper presents a model predicting the capacity of a rock anchor segment, in terms of a ribbed bar, subjected to a cyclic load history. The research assumes a failure mode occurring in the interface between the rock anchor and the surrounding grout. The constitutive behavior of the bonding interface is investigated for anchors subjected to cyclic one-way tensile loads. The model utilizes the static bond capacity curve as a basis, defining the ultimate bond τbu and the slip s1 at τbu. A limited number of input parameters are required to apply the model. The model defines the bond-slip behavior with the belonging rock anchor capacity depending on the cyclic load level (τmax cy/τbu, the cyclic load ratio (R = τmin cy/τmax cy, and the number of load cycles (N. The constitutive model is intended to model short anchor lengths representing an incremental length of a complete rock anchor.

  5. Cyclic mechanical stretch reduces myofibroblast differentiation of primary lung fibroblasts.

    Science.gov (United States)

    Blaauboer, Marjolein E; Smit, Theo H; Hanemaaijer, Roeland; Stoop, Reinout; Everts, Vincent

    2011-01-07

    In lung fibrosis tissue architecture and function is severely hampered by myofibroblasts due to excessive deposition of extracellular matrix and tissue contraction. Myofibroblasts differentiate from fibroblasts under the influence of transforming growth factor (TGF) β(1) but this process is also controlled mechanically by cytoskeletal tension. In healthy lungs, the cytoskeleton of fibroblasts is mechanically strained during breathing. In stiffer fibrotic lung tissue, this mechanical stimulus is reduced, which may influence fibroblast-to-myofibroblast differentiation. Therefore, we investigated the effect of cyclic mechanical stretch on fibroblast-to-myofibroblast differentiation. Primary normal human lung fibroblasts were grown on BioFlex culture plates and stimulated to undergo myofibroblast differentiation by 10 ng/ml TGFβ(1). Cells were either or not subjected to cyclic mechanical stretch (sinusoidal pattern, maximum elongation 10%, 0.2 Hz) for a period of 48 h on a Flexercell apparatus. mRNA expression was analyzed by real-time PCR. Cyclic mechanical loading reduced the mRNA expression of the myofibroblast marker α-smooth muscle actin and the extracellular matrix proteins type-I, type-III, and type-V collagen, and tenascin C. These outcomes indicate that fibroblast-to-myofibroblast differentiation is reduced. Cyclic mechanical loading did not change the expression of the fibronectin ED-A splice variant, but did decrease the paracrine expression of TGFβ(1), thereby suggesting a possible regulation mechanism for the observed effects. The data suggest that cyclic loading experienced by healthy lung cells during breathing may prevent fibroblasts from differentiating towards myofibroblasts. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. 31 CFR 585.216 - Expenses of maintaining blocked property; liquidation into blocked account.

    Science.gov (United States)

    2010-07-01

    ... property; liquidation into blocked account. 585.216 Section 585.216 Money and Finance: Treasury Regulations... blocked property; liquidation into blocked account. (a) Except as otherwise authorized, and... expenses incident to the blocking and maintenance of property blocked pursuant to § 585.201 or § 585.215(a...

  7. On the Eigenvalues and Eigenvectors of Block Triangular Preconditioned Block Matrices

    KAUST Repository

    Pestana, Jennifer

    2014-01-01

    Block lower triangular matrices and block upper triangular matrices are popular preconditioners for 2×2 block matrices. In this note we show that a block lower triangular preconditioner gives the same spectrum as a block upper triangular preconditioner and that the eigenvectors of the two preconditioned matrices are related. © 2014 Society for Industrial and Applied Mathematics.

  8. Adenosine 3':5'-cyclic monophosphate in higher plants: Isolation and characterization of adenosine 3':5'-cyclic monophosphate from Kalanchoe and Agave.

    Science.gov (United States)

    Ashton, A R; Polya, G M

    1977-07-01

    1.3':5'-Cyclic AMP was extensively purified from Kalanchoe daigremontiana and Agave americana by neutral alumina and anion- and cation-exchange column chromatography. Inclusion of 3':5'-cyclic [8-3H]AMP from the point of tissue extraction permitted calculation of yields. The purification procedure removed contaminating material that was shown to interfere with the 3':5'-cyclic AMP estimation and characterization procedures. 2. The partially purified 3':5'-cyclic AMP was quantified by means of a radiochemical saturation assay using an ox heart 3':5'-cyclic AMP-binding protein and by an assay involving activation of a mammalian protein kinase. 3. The plant 3':5'-cyclic AMP co-migrated with 3':5'-cyclic [8-3H]AMP on cellulose chromatography, poly(ethyleneimine)-cellulose chromatography and silica-gel t.l.c. developed with several solvent systems. 4. The plant 3':5'-cyclic AMP was degraded by ox heart 3':5'-cyclic nucleotide phosphodiesterase at the same rates as authentic 3':5'-cyclic AMP. 1-Methyl-3-isobutylxanthine (1 mM), a specific inhibitor of the 3':5'-cyclic nucleotide phosphodieterase, completely inhibited such degradation. 5. The concentrations of 3':5'-cyclic AMP satisfying the above criteria in Kalanchoe and Agave were 2-6 and 1 pmol/g fresh wt. respectively. Possible bacterial contribution to these analyses was estimated to be less than 0.002pmol/g fresh wt. Evidence for the occurrence of 3':5'-cyclic AMP in plants is discussed.

  9. Adenosine 3':5'-cyclic monophosphate in higher plants: Isolation and characterization of adenosine 3':5'-cyclic monophosphate from Kalanchoe and Agave.

    Science.gov (United States)

    Ashton, A R; Polya, G M

    1977-01-01

    1.3':5'-Cyclic AMP was extensively purified from Kalanchoe daigremontiana and Agave americana by neutral alumina and anion- and cation-exchange column chromatography. Inclusion of 3':5'-cyclic [8-3H]AMP from the point of tissue extraction permitted calculation of yields. The purification procedure removed contaminating material that was shown to interfere with the 3':5'-cyclic AMP estimation and characterization procedures. 2. The partially purified 3':5'-cyclic AMP was quantified by means of a radiochemical saturation assay using an ox heart 3':5'-cyclic AMP-binding protein and by an assay involving activation of a mammalian protein kinase. 3. The plant 3':5'-cyclic AMP co-migrated with 3':5'-cyclic [8-3H]AMP on cellulose chromatography, poly(ethyleneimine)-cellulose chromatography and silica-gel t.l.c. developed with several solvent systems. 4. The plant 3':5'-cyclic AMP was degraded by ox heart 3':5'-cyclic nucleotide phosphodiesterase at the same rates as authentic 3':5'-cyclic AMP. 1-Methyl-3-isobutylxanthine (1 mM), a specific inhibitor of the 3':5'-cyclic nucleotide phosphodieterase, completely inhibited such degradation. 5. The concentrations of 3':5'-cyclic AMP satisfying the above criteria in Kalanchoe and Agave were 2-6 and 1 pmol/g fresh wt. respectively. Possible bacterial contribution to these analyses was estimated to be less than 0.002pmol/g fresh wt. Evidence for the occurrence of 3':5'-cyclic AMP in plants is discussed. PMID:196595

  10. Block-Matching Based Multifocus Image Fusion

    Directory of Open Access Journals (Sweden)

    Feng Zhu

    2015-01-01

    Full Text Available A new multifocus image fusion method is proposed. Two image blocks are selected by sliding the window from the two source images at the same position, discrete cosine transform (DCT is implemented, respectively, on these two blocks, and the alternating component (AC energy of these blocks is then calculated to decide which is the well-focused one. In addition, block matching is used to determine a group of image blocks that are all similar to the well-focused reference block. Finally, all the blocks are returned to their original positions through weighted average. The weight is decided with the AC energy of the well-focused block. Experimental results demonstrate that, unlike other spatial methods, the proposed method effectively avoids block artifacts. The proposed method also significantly improves the objective evaluation results, which are obtained by some transform domain methods.

  11. STRUCTURE FORMATION OF HYPOEUTECTOID CONSTRUCTIONS STEELS AT CARBONITRIDING WITH LOCAL INDUCTION CYCLIC HEATING

    Directory of Open Access Journals (Sweden)

    G. A. Tkachenko

    2010-01-01

    Full Text Available Improvement of mechanical characteristics of details of the soil-cultivating car. Structurization at cyclic heating of steels. The reasons of an intensification of diffusion at cyclic heating. Structure crushing, impact strength and hardness increase.

  12. Blocking incidental frustration during bargaining.

    Science.gov (United States)

    Vargas, Maria Esperanza S; Brown, Anna-Leigh; Durkee, Cassandra M; Sim, Hoeun

    2018-02-08

    The current study examined the effects of an intervention aimed at blocking the transfer of frustration from a previous experience (i.e. recall task) to a subsequent and unrelated task (i.e. ultimatum bargaining task). Participants who went through the intervention were more likely to accept unfair offers in the ultimatum bargaining task than those who did not go through the intervention. These results show that participants who were blocked from transferring their feelings of frustration from the recall task to the subsequent bargaining task (no-transfer condition) more likely accepted unfair offers than those who inadvertently transferred their feelings of frustration (transfer condition). The effect of conditions on accept-reject decisions in the ultimatum bargaining was mediated by reported feelings of frustration.

  13. Building blocks for protein interaction devices.

    Science.gov (United States)

    Grünberg, Raik; Ferrar, Tony S; van der Sloot, Almer M; Constante, Marco; Serrano, Luis

    2010-05-01

    Here, we propose a framework for the design of synthetic protein networks from modular protein-protein or protein-peptide interactions and provide a starter toolkit of protein building blocks. Our proof of concept experiments outline a general work flow for part-based protein systems engineering. We streamlined the iterative BioBrick cloning protocol and assembled 25 synthetic multidomain proteins each from seven standardized DNA fragments. A systematic screen revealed two main factors controlling protein expression in Escherichia coli: obstruction of translation initiation by mRNA secondary structure or toxicity of individual domains. Eventually, 13 proteins were purified for further characterization. Starting from well-established biotechnological tools, two general-purpose interaction input and two readout devices were built and characterized in vitro. Constitutive interaction input was achieved with a pair of synthetic leucine zippers. The second interaction was drug-controlled utilizing the rapamycin-induced binding of FRB(T2098L) to FKBP12. The interaction kinetics of both devices were analyzed by surface plasmon resonance. Readout was based on Förster resonance energy transfer between fluorescent proteins and was quantified for various combinations of input and output devices. Our results demonstrate the feasibility of parts-based protein synthetic biology. Additionally, we identify future challenges and limitations of modular design along with approaches to address them.

  14. A coupled soil-pore fluid formulation for modeling soil liquefaction and cyclic mobility in seabed using the finite volume method

    DEFF Research Database (Denmark)

    Tang, Tian; Roenby, Johan; Hededal, Ole

    The stability of offshore structures, such as wind turbine foundations, breakwaters, and immersed tunnels can be strongly affected by the liquefaction and cyclic mobility phenomena in the seabed. Our goal is to develop a numerical code for analysis of these situations. For this purpose, we start...... by formulating the strong interactions between soil skeleton and the pore fluid via a coupled set of partial differential equations. A single bounding surface soil model capable of simulating the accumulations of pore pressures, strains, dilatancy, and strain „softening‟, is then adopted for quantifying...... the cyclic soil constitutive relations. To deal with the high non-linearity in the equations, the finite volume (FV) method is proposed for the numerical simulation. The corresponding discretization strategies and solution algorithms, including the conventional segregated method and the more recent block...

  15. UAV PHOTOGRAMMETRY: BLOCK TRIANGULATION COMPARISONS

    Directory of Open Access Journals (Sweden)

    R. Gini

    2013-08-01

    Full Text Available UAVs systems represent a flexible technology able to collect a big amount of high resolution information, both for metric and interpretation uses. In the frame of experimental tests carried out at Dept. ICA of Politecnico di Milano to validate vector-sensor systems and to assess metric accuracies of images acquired by UAVs, a block of photos taken by a fixed wing system is triangulated with several software. The test field is a rural area included in an Italian Park ("Parco Adda Nord", useful to study flight and imagery performances on buildings, roads, cultivated and uncultivated vegetation. The UAV SenseFly, equipped with a camera Canon Ixus 220HS, flew autonomously over the area at a height of 130 m yielding a block of 49 images divided in 5 strips. Sixteen pre-signalized Ground Control Points, surveyed in the area through GPS (NRTK survey, allowed the referencing of the block and accuracy analyses. Approximate values for exterior orientation parameters (positions and attitudes were recorded by the flight control system. The block was processed with several software: Erdas-LPS, EyeDEA (Univ. of Parma, Agisoft Photoscan, Pix4UAV, in assisted or automatic way. Results comparisons are given in terms of differences among digital surface models, differences in orientation parameters and accuracies, when available. Moreover, image and ground point coordinates obtained by the various software were independently used as initial values in a comparative adjustment made by scientific in-house software, which can apply constraints to evaluate the effectiveness of different methods of point extraction and accuracies on ground check points.

  16. POMzites: a family of zeolitic polyoxometalate frameworks from a minimal building block library

    OpenAIRE

    Boyd, Thomas; Mitchell, Scott G.; Gabb, David; Long, De-Liang; Song, Yu-Fei; Cronin, Leroy

    2017-01-01

    We describe why the cyclic heteropolyanion [P8W48O184]40? (abbreviated as {P8W48}) is an ideal building block for the construction of intrinsically porous framework materials by classifying and analyzing >30 coordination polymers incorporating this polyoxometalate (POM) ligand. This analysis shows that the exocyclic coordination of first-row transition metals (TMs) to {P8W48} typically yields frameworks which extend through {W?O?TM?O?W} bridges in one, two, or three dimensions. However, despi...

  17. Cyclic reduction and FACR methods for piecewise hermite bicubic orthogonal spline collocation

    Science.gov (United States)

    Bialecki, Bernard

    1994-09-01

    Cyclic reduction and Fourier analysis-cyclic reduction (FACR) methods are presented for the solution of the linear systems which arise when orthogonal spline collocation with piecewise Hermite bicubics is applied to boundary value problems for certain separable partial differential equations on a rectangle. On anN×N uniform partition, the cyclic reduction and Fourier analysis-cyclic reduction methods requireO(N2log2N) andO(N2log2log2N) arithmetic operations, respectively.

  18. [THE TECHNOLOGY "CELL BLOCK" IN CYTOLOGICAL PRACTICE].

    Science.gov (United States)

    Volchenko, N N; Borisova, O V; Baranova, I B

    2015-08-01

    The article presents summary information concerning application of "cell block" technology in cytological practice. The possibilities of implementation of various modern techniques (immune cytochemnical analysis. FISH, CISH, polymerase chain reaction) with application of "cell block" method are demonstrated. The original results of study of "cell block" technology made with gelatin, AgarCyto and Shadon Cyoblock set are presented. The diagnostic effectiveness of "cell block" technology and common cytological smear and also immune cytochemical analysis on samples of "cell block" technology and fluid cytology were compared. Actually application of "cell block" technology is necessary for ensuring preservation of cell elements for subsequent immune cytochemical and molecular genetic analysis.

  19. Phase Separation and Elastic Properties of Poly(Trimethylene Terephthalate-block-poly(Ethylene Oxide Copolymers

    Directory of Open Access Journals (Sweden)

    Elżbieta Piesowicz

    2016-06-01

    Full Text Available A series of poly(trimethylene terephthalate-block-poly(ethylene oxide (PTT-b-PEOT copolymers with different compositions of rigid PTT and flexible PEOT segments were synthesized via condensation in the melt. The influence of the block length and the block ratio on the micro-separated phase structure and elastic properties of the synthesized multiblock copolymers was studied. The PEOT segments in these copolymers were kept constant at 1130, 2130 or 3130 g/mol, whereas the PTT content varied from 30 up to 50 wt %. The phase separation was assessed using differential scanning calorimetry (DSC and dynamic mechanical thermal analysis (DMTA. The crystal structure of the synthesised block copolymers and their microstructure on the manometer scale was evaluated by using WAXS and SAXS analysis. Depending on the PTT/PEOT ratio, but also on the rigid and flexible segment length in PTT-b-PEO copolymers, four different domains were observed i.e.,: a crystalline PTT phase, a crystalline PEO phase (which exists for the whole series based on three types of PEOT segments, an amorphous PTT phase (only at 50 wt % content of PTT rigid segments and an amorphous PEO phase. Moreover, the elastic deformability and reversibility of PTT-b-PEOT block copolymers were studied during a cyclic tensile test. Determined values of permanent set resultant from maximum attained stain (100% and 200% for copolymers were used to evaluate their elastic properties.

  20. Cyclic voltammograms for H on Pt(111) and Pt(100) from first principles

    DEFF Research Database (Denmark)

    Karlberg, Gustav; Jaramillo, Thomas; Skulason, Egill

    2007-01-01

    Cyclic voltammetry is a fundamental experimental method for characterizing electrochemical surfaces. Despite its wide use, a way to quantitatively and directly relate cyclic voltammetry to ab initio calculations has been lacking. We derive the cyclic voltammogram for H on Pt(111) and Pt(100), based...

  1. Elevational gradient in the cyclicity of a forest-defoliating insect

    Science.gov (United States)

    Kyle J. Haynes; Andrew M. Liebhold; Derek M. Johnson

    2012-01-01

    Observed changes in the cyclicity of herbivore populations along latitudinal gradients and the hypothesis that shifts in the importance of generalist versus specialist predators explain such gradients has long been a matter of intense interest. In contrast, elevational gradients in population cyclicity are largely unexplored. We quantified the cyclicity of gypsy moth...

  2. Systematic Avocating

    Directory of Open Access Journals (Sweden)

    Jan Green

    2014-12-01

    Full Text Available Feeling obliged to undertake complex research tasks outside core working hours is a common occurrence in academia. Detailed and timely research projects are expected; the creation and defence of sufficient intervals within a crowded working schedule is one concern explored in this short version paper. Merely working longer hours fails to provide a satisfactory solution for individuals experiencing concerns of this nature. Personal effort and drive are utilised and requires the application of mental mustering and systematic procedures. The attitude to research work is treating the task as a hobby conceptualised as avocating. Whilst this provides a personal solution through immersion in the task, this approach should raise concerns for employers. The flexibility of grounded theory is evident and the freedom to draw on various bodies of knowledge provides fresh insight into a problem that occurs in organizations in many sectors experiencing multiple priorities. The application of the core category, systematic avocating, may prove beneficial.

  3. Blocking device especially for circulating pumps

    International Nuclear Information System (INIS)

    Susil, J.; Vychodil, V.; Lorenc, P.

    1976-01-01

    The claim of the invention is a blocking device which blocks reverse flow occurring after the shutdown of circulating pumps, namely in the operation of nuclear power plants or in pumps with a high delivery head. (F.M.)

  4. Demographic Data - MDC_BlockGroup

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — A polygon feature class of Miami-Dade County Census 2000 Block Groups. A census Block Group is a statistical subdivision of a census Tract consisting of a cluster of...

  5. Gas-permeation properties of poly(ethylene oxide) poly(butylene terephthalate block copolymers

    NARCIS (Netherlands)

    Metz, S.J.; Mulder, M.H.V.; Wessling, Matthias

    2004-01-01

    This paper reports the gas-permeation properties of poly(ethylene oxide) (PEO) poly(butylene terephthalate) (PBT) segmented multiblock copolymers. These block copolymers allow a precise structural modification by the amount of PBT and the PEO segment length, enabling a systematic study of the

  6. A secure cyclic steganographic technique for color images using randomization

    International Nuclear Information System (INIS)

    Muhammad, K.; Ahmad, J.; Rehman, N.U.

    2014-01-01

    Information Security is a major concern in today's modern era. Almost all the communicating bodies want the security, confidentiality and integrity of their personal data. But this security goal cannot be achieved easily when we are using an open network like internet. Steganography provides one of the best solutions to this problem. This paper represents a new Cyclic Steganographic Technique (CST) based on Least Significant Bit (LSB) for true color (RGB) images. The proposed method hides the secret data in the LSBs of cover image pixels in a randomized cyclic manner. The proposed technique is evaluated using both subjective and objective analysis using histograms changeability, Peak Signal-to-Noise Ratio (PSNR) and Mean Square Error (MSE). Experimentally it is found that the proposed method gives promising results in terms of security, imperceptibility and robustness as compared to some existent methods and vindicates this new algorithm. (author)

  7. Application of cyclic fluorocarbon/argon discharges to device patterning

    Energy Technology Data Exchange (ETDEWEB)

    Metzler, Dominik, E-mail: dmetzler@umd.edu [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 and Department of Materials Science and Engineering, and Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20740 (United States); Uppireddi, Kishore; Bruce, Robert L.; Miyazoe, Hiroyuki; Zhu, Yu; Price, William; Sikorski, Ed S.; Engelmann, Sebastian U.; Joseph, Eric A. [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Li, Chen [Department of Physics, and Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20740 (United States); Oehrlein, Gottlieb S. [Department of Materials Science and Engineering, and Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20740 (United States)

    2016-01-15

    With increasing demands on device patterning to achieve smaller critical dimensions and pitches for the 5 nm node and beyond, the need for atomic layer etching (ALE) is steadily increasing. In this work, a cyclic fluorocarbon/Ar plasma is successfully used for ALE patterning in a manufacturing scale reactor. Self-limited etching of silicon oxide is observed. The impact of various process parameters on the etch performance is established. The substrate temperature has been shown to play an especially significant role, with lower temperatures leading to higher selectivity and lower etch rates, but worse pattern fidelity. The cyclic ALE approach established with this work is shown to have great potential for small scale device patterning, showing self-limited etching, improved uniformity and resist mask performance.

  8. TideWatch: Fingerprinting the cyclicality of big data workloads

    KAUST Repository

    Williams, Daniel W.

    2014-04-01

    Intrinsic to \\'big data\\' processing workloads (e.g., iterative MapReduce, Pregel, etc.) are cyclical resource utilization patterns that are highly synchronized across different resource types as well as the workers in a cluster. In Infrastructure as a Service settings, cloud providers do not exploit this characteristic to better manage VMs because they view VMs as \\'black boxes.\\' We present TideWatch, a system that automatically identifies cyclicality and similarity in running VMs. TideWatch predicts period lengths of most VMs in Hadoop workloads within 9% of actual iteration boundaries and successfully classifies up to 95% of running VMs as participating in the appropriate Hadoop cluster. Furthermore, we show how TideWatch can be used to improve the timing of VM migrations, reducing both migration time and network impact by over 50% when compared to a random approach. © 2014 IEEE.

  9. Engine cyclic durability by analysis and material testing

    Science.gov (United States)

    Kaufman, A.; Halford, G. R.

    1984-01-01

    The problem of calculating turbine engine component durability is addressed. Nonlinear, finite-element structural analyses, cyclic constitutive behavior models, and an advanced creep-fatigue life prediction method called strainrange partitioning were assessed for their applicability to the solution of durability problems in hot-section components of gas turbine engines. Three different component or subcomponent geometries are examined: a stress concentration in a turbine disk; a louver lip of a half-scale combustor linear; and a squealer tip of a first-stage high-pressure turbine blade. Cyclic structural analyses were performed for all three problems. The computed strain-temperature histories at the critical locations of the combustor linear and turbine blade components were imposed on smooth specimens in uniaxial, strain-controlled, thermomechanical fatigue tests of evaluate the structural and life analysis methods.

  10. Improvements of cyclic somatic embryogenesis of cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Raemakers, C J; Schavemaker, C M; Jacobsen, E; Visser, R G

    1993-02-01

    In cassava a cyclic system of somatic embryogenesis was developed. Primary (torpedo shaped or germinated) embryos, originating from leaf lobes, could only be obtained after culture on solid medium. Cyclic embryos, originating from embryos, could be obtained in both liquid and on solid medium. The production of embryos in liquid medium was distinctly higher, faster and more synchronized than on solid medium. Lower densities and fragmentation of starting embryos improved the production significantly. The highest production found was 32.1 embryos per initial embryo. In all treatments the explants initiated multiple embryos. The production of single embryos was achieved by pressing starting embryos through a fine meshed sieve, indicating that embryos can be produced from a piece of tissue with a restricted number of cells. The shoot conversion rate of embryos from liquid medium was comparable with that of embryos from solid medium.

  11. A compact cyclic plasticity model with parameter evolution

    DEFF Research Database (Denmark)

    Krenk, Steen; Tidemann, L.

    2017-01-01

    by the Armstrong–Frederick model, contained as a special case of the present model for a particular choice of the shape parameter. In contrast to previous work, where shaping the stress-strain loops is derived from multiple internal stress states, this effect is here represented by a single parameter......The paper presents a compact model for cyclic plasticity based on energy in terms of external and internal variables, and plastic yielding described by kinematic hardening and a flow potential with an additive term controlling the nonlinear cyclic hardening. The model is basically described by five...... parameters: external and internal stiffness, a yield stress and a limiting ultimate stress, and finally a parameter controlling the gradual development of plastic deformation. Calibration against numerous experimental results indicates that typically larger plastic strains develop than predicted...

  12. A kinematic model for Bayesian tracking of cyclic human motion

    Science.gov (United States)

    Greif, Thomas; Lienhart, Rainer

    2010-01-01

    We introduce a two-dimensional kinematic model for cyclic motions of humans, which is suitable for the use as temporal prior in any Bayesian tracking framework. This human motion model is solely based on simple kinematic properties: the joint accelerations. Distributions of joint accelerations subject to the cycle progress are learned from training data. We present results obtained by applying the introduced model to the cyclic motion of backstroke swimming in a Kalman filter framework that represents the posterior distribution by a Gaussian. We experimentally evaluate the sensitivity of the motion model with respect to the frequency and noise level of assumed appearance-based pose measurements by simulating various fidelities of the pose measurements using ground truth data.

  13. Low Cycle Fatigue of Steel in Strain Controled Cyclic Bending

    Directory of Open Access Journals (Sweden)

    Kulesa Anna

    2016-03-01

    Full Text Available The paper presents a comparison of the fatigue life curves based on test of 15Mo3 steel under cyclic, pendulum bending and tension-compression. These studies were analyzed in terms of a large and small number of cycles where strain amplitude is dependent on the fatigue life. It has been shown that commonly used Manson-Coffin-Basquin model cannot be used for tests under cyclic bending due to the impossibility of separating elastic and plastic strains. For this purpose, some well-known models of Langer and Kandil and one new model of authors, where strain amplitude is dependent on the number of cycles, were proposed. Comparing the results of bending with tension-compression it was shown that for smaller strain amplitudes the fatigue life for both test methods were similar, for higher strain amplitudes fatigue life for bending tests was greater than for tension-compression.

  14. Kolkata Paise Restaurant Problem and the Cyclically Fair Norm

    Science.gov (United States)

    Banerjee, Priyodorshi; Mitra, Manipushpak; Mukherjee, Conan

    In this paper we revisit the Kolkata Paise Restaurant problem by allowing for a more general (but common) preference of the n customers defined over the set of n restaurants. This generalization allows for the possibility that each pure strategy Nash equilibrium differs from the Pareto efficient allocation. By assuming that n is small and by allowing for mutual interaction across all customers we design strategies to sustain cyclically fair norm as a sub-game perfect equilibrium of the Kolkata Paise Restaurant problem. We have a cyclically fair norm if n strategically different Pareto efficient strategies are sequentially sustained in a way such that each customer gets serviced in all the n restaurants exactly once between periods 1 and n and then again the same process is repeated between periods (n+1) and 2n and so on.

  15. Cyclic mechanical fatigue in ceramic-ceramic composites: an update

    International Nuclear Information System (INIS)

    Lewis, D. III

    1983-01-01

    Attention is given to cyclic mechanical fatigue effects in a number of ceramics and ceramic composites, including several monolithic ceramics in which significant residual stresses should be present as a result of thermal expansion mismatches and anisotropy. Fatigue is also noted in several BN-containing ceramic matrix-particulate composites and in SiC fiber-ceramic matrix composites. These results suggest that fatigue testing is imperative for ceramics and ceramic composites that are to be used in applications subject to cyclic loading. Fatigue process models are proposed which provide a rationale for fatigue effect observations, but do not as yet provide quantitative results. Fiber composite fatigue damage models indicate that design stresses in these materials may have to be maintained below the level at which fiber pullout occurs

  16. STUDY OF ELECTROPOLIMERIZATION PROCESSES OF PYRROLE BY CYCLIC VOLTAMMETRIC TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Adhitasari Suratman

    2010-06-01

    Full Text Available Electropolymerization processes and electrochemical properties of polypyrrole as electroactive polymer have been studied by cyclic voltammetric technique. Pyrrole was electropolymerized to form polypyrrole in water-based solvent containing sodium perchlorate as supporting electrolyte in several pH values. The pH of the solutions were varied by using Britton Robinson buffer. The results showed that oxidation potential limit of electropolymerization processes of pyrrole was 1220 mV vs Ag/AgCl reference electrode. It can be seen that cyclic voltammetric respon of polypyrrole membrane that was prepared by electropolymerization processes of pyrrole at the scanning rate of 100 mV/s was stable. While the processes of pyrrole electropolymerization carried out at the variation of pH showed that the best condition was at the pH range of 2 - 6.   Keywords: polypyrolle, electropolymer, voltammetric technique

  17. Production of isomers by the cyclic activation method

    International Nuclear Information System (INIS)

    Salaita, G.N.; Eapen, P.K.

    1974-01-01

    The isomeric states formation cross sections for 14.8 MeV neutron reactions in Mg, Al, As, Y, In, Hf, Tl, Pb, and Bi were measured using the cyclic activation technique and a high resolution Ge(Li) detector. Isomeric activities originating from the various isotopes of lead and thallium were separated by proper choice of cyclic timing parameters and energy discrimination. Long lived isomeric and ground state activities were investigated through conventional activation method. The isomeric cross section ratios, sigma/sub m//sigma/sub g/ for six elements, were measured and compared to the theoretical predictions of the Huizenga-Vandenbosch method. The half-lives of short-lived activities were determined using a wide range time-to-pulse height converter and a multi-channel analyzer

  18. Structural Diversity and Biological Activities of Cyclic Depsipeptides from Fungi

    Directory of Open Access Journals (Sweden)

    Xiaohan Wang

    2018-01-01

    Full Text Available Cyclic depsipeptides (CDPs are cyclopeptides in which amide groups are replaced by corresponding lactone bonds due to the presence of a hydroxylated carboxylic acid in the peptide structure. These peptides sometimes display additional chemical modifications, including unusual amino acid residues in their structures. This review highlights the occurrence, structures and biological activities of the fungal CDPs reported until October 2017. About 352 fungal CDPs belonging to the groups of cyclic tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca-, and tridecadepsipeptides have been isolated from fungi. These metabolites are mainly reported from the genera Acremonium, Alternaria, Aspergillus, Beauveria, Fusarium, Isaria, Metarhizium, Penicillium, and Rosellina. They are known to exhibit various biological activities such as cytotoxic, phytotoxic, antimicrobial, antiviral, anthelmintic, insecticidal, antimalarial, antitumoral and enzyme-inhibitory activities. Some CDPs (i.e., PF1022A, enniatins and destruxins have been applied as pharmaceuticals and agrochemicals.

  19. Bioactive cyclic peptides from the psychrotolerant fungus Penicillium algidum.

    Science.gov (United States)

    Dalsgaard, Petur W; Larsen, Thomas O; Christophersen, Carsten

    2005-02-01

    A new cyclic nitropeptide, psychrophilin D (1), together with two known cyclic peptides, cycloaspeptide A (2) and cycloaspeptide D (3), were isolated from the psychrotolerant fungus Penicillium algidum using C18 flash chromatography, LH-20 Sephadex and preparative HPLC. The structure of psychrophilin D (1) was derived from mass spectrometric information, 1D and 2D NMR spectra and Marfey's method. The compounds were tested in antimicrobial, antiviral, anticancer and antiplasmodial assays. Psychrophilin D (1) exhibited a moderate activity (ID50 10.1 microg/ml) in the P388 murine leukaemia cell assay. Cycloaspeptide A (2) and D (3) exhibited moderate activity (IC50 3.5 and 4.7 microg/ml, respectively) against Plasmodium falciparum.

  20. Identification of cyclic nucleotide gated channels using regular expressions

    KAUST Repository

    Zelman, Alice K.

    2013-09-03

    Cyclic nucleotide-gated channels (CNGCs) are nonselective cation channels found in plants, animals, and some bacteria. They have a six-transmembrane/one- pore structure, a cytosolic cyclic nucleotide-binding domain, and a cytosolic calmodulin-binding domain. Despite their functional similarities, the plant CNGC family members appear to have different conserved amino acid motifs within corresponding functional domains than animal and bacterial CNGCs do. Here we describe the development and application of methods employing plant CNGC-specific sequence motifs as diagnostic tools to identify novel candidate channels in different plants. These methods are used to evaluate the validity of annotations of putative orthologs of CNGCs from plant genomes. The methods detail how to employ regular expressions of conserved amino acids in functional domains of annotated CNGCs and together with Web tools such as PHI-BLAST and ScanProsite to identify novel candidate CNGCs in species including Physcomitrella patens. © Springer Science+Business Media New York 2013.

  1. Species-specific aggregation factor in sponges. VII. Its effect on cyclic amp and cyclic gmp metabolism in cells of Geodia cydonium.

    Science.gov (United States)

    Müller, W E; Müller, I; Zahn, R K; Kurelec, B

    1978-01-01

    In dissociated single cells from the sponge Geodia cydonium, DNA synthesis is initiated after incubation with a homologous, soluble aggregation factor. During the DNA-initiation phase the cyclic AMP- and cyclic GMP levels vary drastically; the cyclic AMP content drops from 2.2 pmol/10(6) cells to 0.3 pmol/10(6) cells while the cyclic GMP content increases from 0.6 pmol to 3.7 pmol/10(6) cells. The activity of neither the adenylate cyclase nor of the guanylate cyclase isolated from cells which have been incubated for different periods of time with the aggregation factor, is changed. The soluble as well as the particulate enzyme activities were checked in vitro. The cyclic nucleotide receptors have been isolated from the sponge cells and characterized with respect to their molecular weight, dissociation constant for cyclic AMP or cyclic GMP and intracellular concentration. None of these parameters are altered during aggregation factor-mediated DNA initiation. From these data it is concluded that the regulation of cyclic nucleotide levels is a consequence of a changed activity of nucleotide cyclases or of phosphodiesterases, but this is presumably not caused by a changed rate of synthesis of nucleotide cyclases or of cyclic nucleotide receptors.

  2. Micromechanics of intergranular creep failure under cyclic loading

    DEFF Research Database (Denmark)

    van der Giessen, Erik; Tvergaard, Viggo

    1996-01-01

    boundaries are modelled individually. The model incorporates power-law creep of the grains, viscous grain boundary sliding between grains as well as the nucleation and growth of grain boundary cavities until they coalesce and form microcracks. Study of a limiting case with a facet-size microcrack reveals....... The analyses provide some new understanding that helps to explain the sometimes peculiar behaviour under balanced cyclic creep. Copyright (C) 1996 Acta Metallurgica Inc....

  3. Biosynthesis and regulation of cyclic lipopeptides in Pseudomonas fluorescens

    OpenAIRE

    Bruijn, de, I.

    2009-01-01

    Cyclic lipopeptides (CLPs) are surfactant and antibiotic metabolites produced by a variety of bacterial genera. For the genus Pseudomonas, many structurally different CLPs have been identified. CLPs play an important role in surface motility of Pseudomonas strains, but also in virulence and attachment/detachment to and from surfaces. In this Ph.D. thesis project, two new CLP biosynthesis clusters were identified in Pseudomonas fluorescens and fully sequenced. In P. fluorescens strain SBW2...

  4. Cyclic behaviour and fatigue life prediction in welded aluminium joints

    International Nuclear Information System (INIS)

    Kosteas, D.

    1979-01-01

    The paper gives an overall state-of-the-art view of international attempts to find a solution, describes cyclic stress-strain behavior for the different zones of aluminium weldments, as stated above, states results from a recent research program of the Versuchsanstalt Stahl, Holz, und Steine in Karlsruhe and gives a step by step model for the calculation procedure of fatigue life. (orig.) 891 RW/orig. 892 RKD [de

  5. Constraining cyclic peptides to mimic protein structure motifs

    DEFF Research Database (Denmark)

    Hill, Timothy A.; Shepherd, Nicholas E.; Diness, Frederik

    2014-01-01

    Many proteins exert their biological activities through small exposed surface regions called epitopes that are folded peptides of well-defined three-dimensional structures. Short synthetic peptide sequences corresponding to these bioactive protein surfaces do not form thermodynamically stable...... and proteins, and identifies some additional restraints incorporated into natural product cyclic peptides and synthetic macrocyclic pepti-domimetics that refine peptide structure and confer biological properties....

  6. Cyclic spectra for wavelength-routed optical networks.

    Science.gov (United States)

    Corcoran, Bill; Geng, Zihan; Rozental, Valery; Lowery, Arthur J

    2017-03-15

    We propose occupying the guard bands in closely spaced WDM systems with redundant signal spectral components to increase tolerance to frequency misalignment and channel shaping from multiplexing elements. By cyclically repeating the spectrum of a modulated signal, we show improved tolerance to impairments due to add/drop multiplexing with a commercial wavelength selective switch in systems using 5%-20% guard bands on a 50 GHz DWDM grid.

  7. Ring-opening of cyclic ethers by aluminum hydridotriphenylborate.

    Science.gov (United States)

    Mukherjee, Debabrata; Osseili, Hassan; Truong, Khai-Nghi; Spaniol, Thomas P; Okuda, Jun

    2017-03-25

    Molecular aluminum hydride [(L)AlH 2 ] (L = Me 3 TACD) reacted with 2 equiv. of BPh 3 in THF or THP to give the cationic alkoxides [(L)Al(OR)][HBPh 3 ] (R = nBu, nPent) by facile ring-opening of the cyclic ethers. The C α -O bond cleavage which involves the isolable intermediate [(L)AlH][HBPh 3 ] is a result of hydride transfer to C α from [HBPh 3 ] - .

  8. [The metabolites of cyclic peptides from three endophytic mangrove fungi].

    Science.gov (United States)

    Guo, Zhi-yong; Huang, Zhong-jing; Wen, Lu; Wan, Qiao; Liu, Fan; She, Zhi-gang; Lin, Yong-cheng; Zhou, Shi-ning

    2007-12-01

    Nine secondary metaboites of cyclic peptide were isolated from three mangrove endophytic fungi Paecilomyces sp. (treel-7), 4557,ZZF65. They were viscumamide(1),cyclo(Pro-Iso)(2),cyclo(Phe-Gly)(3),cyclo(Phe-Ana)(4),cyclo(Gly-Pro) (5),cyclo(Gly-Leu)(6), cyclo(Trp-Ana)(7),neoechinulin A(8),cyclo(Pro-Thr)(9). The compounds 1,7,8,9 were firstly isolated from marine fungus.

  9. Ultrathin monomolecular films and robust assemblies based on cyclic catechols

    Czech Academy of Sciences Publication Activity Database

    Zieger, M. M.; Pop-Georgievski, Ognen; de los Santos Pereira, Andres; Verveniotis, E.; Preuss, C. M.; Zorn, M.; Reck, B.; Goldmann, A. S.; Rodriguez-Emmenegger, Cesar; Barner-Kowollik, C.

    2017-01-01

    Roč. 33, č. 3 (2017), s. 670-679 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GJ15-09368Y Grant - others:OPPK(XE) CZ.2.16/3.1.00/21545 Program:OPPK Institutional support: RVO:61389013 Keywords : cyclic catechols * ultrathin films * macromolecules monolayers Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.833, year: 2016

  10. Effect of loading history on cyclic stress-strain response

    Czech Academy of Sciences Publication Activity Database

    Kunz, Ludvík; Lukáš, Petr; Weiss, B.; Melisova, D.

    2001-01-01

    Roč. 314, 1/2 (2001), s. 1-6 ISSN 0921-5093. [TMS Annual Meeting. Nashville, 12.03.2000-16.03.2000] R&D Projects: GA AV ČR IBS2041001 Institutional research plan: CEZ:AV0Z2041904 Keywords : cyclic plasticity * loading history * mean stress Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.978, year: 2001

  11. Private and public consumption and counter-cyclical fiscal policy

    OpenAIRE

    Marattin, Luigi

    2007-01-01

    This paper bulds a closed-economy NK-DSGE model with no capital, in which consumers value both private and public consumption and fiscal policy is determined by a feedback rule responding to output gap. We analyse how different degrees of substitutatibility/complementarity between private and public consumption and a pro/counter-cyclical stance of fiscal policy affect equilbrium determinacy and the response of the economy to a wide range of shocks. Results show that determinacy is ensured b...

  12. Cyclical Mackey Glass Model for Oil Bull Seasonal

    OpenAIRE

    Sadek MELHEM; Michel TERRAZA; Mohamed CHIKHI

    2011-01-01

    In this article, we propose an innovative way for modelling oil bull seasonals taking into account seasonal speculations in oil markets. Since oil prices behave very seasonally during two periods of the year (summer and winter), we propose a modification of Mackey Glass equation by taking into account the rhythm of seasonal frequencies. Using monthly data for WTI oil prices, Seasonal Cyclical Mackey Glass estimates indicate that seasonal interactions between heterogeneous speculators...

  13. Pro-cyclical Solow Residuals without Technology Shocks

    OpenAIRE

    Adnrew J. Clarke; Alok Johri

    2008-01-01

    Most Real Business Cycle models have a hard time jointly explaining the twin facts of strongly pro-cyclical Solow residuals and extremely low correlations between wages and hours. We present a model that delivers both these results without using exogenous variation in total factor productivity (technology shocks). The key innovation of the paper is to add learning-by-doing to firms technology. As a result firms optimally vary their prices to control the amount of learning which in turn influe...

  14. Higher Genus Abelian Functions Associated with Cyclic Trigonal Curves

    Directory of Open Access Journals (Sweden)

    Matthew England

    2010-03-01

    Full Text Available We develop the theory of Abelian functions associated with cyclic trigonal curves by considering two new cases. We investigate curves of genus six and seven and consider whether it is the trigonal nature or the genus which dictates certain areas of the theory. We present solutions to the Jacobi inversion problem, sets of relations between the Abelian function, links to the Boussinesq equation and a new addition formula.

  15. A cyclic production problem: an application of max-algebra

    NARCIS (Netherlands)

    Nawijn, W.M.

    1998-01-01

    Given are m identical machines, each of which performs the same N operations Oi, 1 ≤ i ≤ N, cyclically and indefinitely, i.e. a production run on a machine looksO1, O2,…,ON, O1, O2,…,ON, O1…. There are nim to to perform operation Oi. The tools are transported between the machines by means of an

  16. On L ∞-Morphisms of Cyclic Chains

    Science.gov (United States)

    Sergio Cattaneo, Alberto; Felder, Giovanni; Willwacher, Thomas

    2009-12-01

    Recently the first two authors (Cattaneo and Felder in 2008) constructed an L ∞-morphism using the S 1-equivariant version of the Poisson Sigma Model. Its role in the deformation quantization was not entirely clear. We give here a “good” interpretation and show that the resulting formality statement is equivalent to formality on cyclic chains as conjectured by Tsygan and proved recently by several authors (Dolgushev et al. in 2008; Willwacher in 2008).

  17. Structural Diversity and Biological Activities of Cyclic Depsipeptides from Fungi

    OpenAIRE

    Xiaohan Wang; Xiao Gong; Peng Li; Daowan Lai; Ligang Zhou

    2018-01-01

    Cyclic depsipeptides (CDPs) are cyclopeptides in which amide groups are replaced by corresponding lactone bonds due to the presence of a hydroxylated carboxylic acid in the peptide structure. These peptides sometimes display additional chemical modifications, including unusual amino acid residues in their structures. This review highlights the occurrence, structures and biological activities of the fungal CDPs reported until October 2017. About 352 fungal CDPs belonging to the groups of cycli...

  18. A unified computational account of cumulative semantic, semantic blocking, and semantic distractor effects in picture naming.

    Science.gov (United States)

    Roelofs, Ardi

    2018-03-01

    Computational models of lexical selection in spoken word production have been applied to semantic interference effects in picture naming response times obtained with continuous naming, blocked-cyclic naming, and picture-word interference paradigms. However, a unified computational account of the effects in the three paradigms is lacking. Here, I show that the inclusion of conceptual bias in the WEAVER++model (Levelt, Roelofs, & Meyer, 1999) explains cumulative semantic and semantic blocking effects while preserving the model's account of semantic distractor effects. The key assumptions of the account are (1) lexical selection by competition, and (2) a conceptual origin and lexical locus of the semantic effects. I provide a proof of concept of the account by reporting computer simulation results, addressing behavioral and neuroimaging evidence. The assumptions are sufficient for a unified account of semantic effects in the three paradigms, contrary to pessimistic views of this area. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Used, Blocking and Sleeping Patents

    DEFF Research Database (Denmark)

    Torrisi, Salvatore; Gambardella, Alfonso; Giuri, Paola

    2016-01-01

    patents are being utilized. A substantial share of patents is neither used internally nor for market transactions, which confirms the importance of strategic patenting and inefficiency in the management of intellectual property. We investigate different types of unused patents—unused blocking patents...... and sleeping patents. We also examine the association between used and unused patents and their characteristics such as family size, scope, generality and overlapping claims, technology area, type of applicant, and the competitive environment from where these patents originate. We discuss our results...

  20. Large block test status report

    International Nuclear Information System (INIS)

    Wilder, D.G.; Lin, W.; Blair, S.C.

    1997-01-01

    This report is intended to serve as a status report, which essentially transmits the data that have been collected to date on the Large Block Test (LBT). The analyses of data will be performed during FY98, and then a complete report will be prepared. This status report includes introductory material that is not needed merely to transmit data but is available at this time and therefore included. As such, this status report will serve as the template for the future report, and the information is thus preserved