20 results
Effect of repetitive transcranial magnetic stimulation on chronobiological hypothalamic-pituitary-thyroid axis activity in major depression
- F. Duval, M. C. Mokrani, V. Danila, A. Erb, F. Gonzalez Lopera, M. Tomsa
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S250
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Introduction
We previously demonstrated that the difference between 11 PM and 8 AM TSH response to protirelin (TRH) tests on the same day (∆∆TSH test) is an improved measure in detecting hypothalamic-pituitary-thyroid (HPT) axis dysregulation in depression. This chronobiological index is normalized after successful antidepressant treatment.
ObjectivesThe present study aimed at assessing the effects of repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC) on the HPT axis activity in treatment resistant depressed inpatients (TRDs) (defined as having at least 2 treatment failures).
MethodsThe ∆∆TSH test was performed in 13 TRDs and 14 healthy hospitalized control subjects (HCs). To be enrolled in this study, patients had to show reduced ∆∆TSH values (i.e., < 2.5 mU/L) at baseline (BL). After 20 sessions of rTMS (using daily theta-burst stimulation; 100% resting motor threshold; number of pulses/session: 900), the ∆∆TSH test was repeated in all inpatients. The 17-item Hamilton depression rating scale (HAM-D) was used to assess the severity of depression. Remission was defined by a final HAM-D score ≤ 8.
ResultsCompared to BL, HAM-D scores decreased and ∆∆ TSH values increased after 20 sessions of rTMS (both p< 0.05 by T-test). There was a relationship between the reduction in HAM-D scores from BL to endpoint and the increase in ∆∆TSH values (rho = - 0.64; n = 13; p = 0.018). At endpoint, 7 patients showed ∆∆TSH normalization (among them 6 were remitters), while 6 patients did not normalize their ∆∆TSH (all were non-remitters) (p < 0.005 by Fisher Exact test).
ConclusionsOur results suggest that after 20 sessions of rTMS, chronobiological restoration of the HPT axis activity is associated with clinical remission. Further investigation of the specific effects of rTMS on the HPT axis activity in TRDs is warranted.
Disclosure of InterestNone Declared
Patients with psychotic disorders exhibit different audio-visual perceptual decision biases and metacognitive abilities
- L. Franzen, S. Eickhoff, H. Schewe, L. M. Schmitt, J. Erb, S. Borgwardt, C. Andreou, J. Obleser
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S129-S130
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Introduction
In the inherently noisy real world, we can rarely have full certainty about what we have just seen or heard. Thus, making a perceptual decision on sensory information, and simultaneously tracking our varying levels of certainty in these decisions (i.e., metacognitive abilities) are crucial components of everyday life.
Hallucinations, such as confidently reporting a human voice or face when none was present, are a hallmark of psychotic disorders but also occur among the normal population. Particularly in patients with psychotic disorders, these misperceptions are linked to confident beliefs in their actual existence. However, whether patients’ confidence is only increased during such erroneous perceptions and whether perceptual and metacognitive decisions arise from supramodal mechanisms across sensory modalities remains unknown.
ObjectivesIn the laboratory, we tested perceptual and metacognitive decisions under varying levels of sensory certainty in healthy adults and patients with psychotic disorders admitted to a psychiatry ward (Ncon=32, Npat=12; age = 19-49; F2x.x diagnoses).
MethodsSpecifically, participants had to detect human voices or faces against briefly presented noisy backdrops and subsequently rate their confidence in the accuracy of their perceptual decision (Fig 1A,B,C). We further hypothesised that probabilistic cues prior to blocks of trials can bias participants’ choices and hallucination probability (i.e., confident false alarms).
ResultsPatients exhibited higher perceptual sensitivity in the auditory than the visual task, alongside a generally stronger decision bias towards fewer ‘voice/face’ choices (Fig 2A,B). This bias was more pronounced in the visual domain. Decision performance was overall higher on the auditory task but lower for patients (predicted minimum > 55%; Fig 2C). Strong correlations between auditory accuracy and PANSS hallucination scores of patients and LSHS scores of healthy participants suggest an effect of these hallucinatory experiences on accurate perception.
Metacognitive abilities were reduced in patients across both modalities: They exhibited general overconfidence, which was stronger for incorrect trials (Fig 3A). Patients’ confidence ratings were inversely related to the probability of choosing ‘voice/face’. Combining both perceptual and confidence decisions, patients showed higher hallucinations probability in the auditory task, particularly in more difficult trials (i.e., with less informative sensory evidence; Fig 3B).
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ConclusionsIn sum, patients with psychotic disorders exhibit increased decision bias accompanied by increased confidence, and thus a reduced fidelity in their metacognitive abilities. The modality differences are in line with phenomenology and reported hallucination rates. These results suggest stronger priors in psychotic disorders resulting in worse perceptual acuity and assessment of this perception.
Disclosure of InterestNone Declared
12 - Ecology and Behaviour of Odd-Nosed Colobines
- Edited by Ikki Matsuda, Cyril C. Grueter, University of Western Australia, Perth, Julie A. Teichroeb
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- The Colobines
- Published online:
- 08 February 2022
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- 24 February 2022, pp 156-185
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Summary
The odd-nosed monkeys represent a monophyletic group of phenotypically unique primates. They include five species of snub-nosed monkeys (Rhinopithecus), three species of doucs (Pygathrix) as well as simakobu (Simias concolor) and the proboscis monkey (Nasalis larvatus). These species are ecologically diverse and inhabit a gradient of environments in China and southeast Asia, from wet equatorial forests to alpine forests. Odd-nosed monkeys tend to be shy and difficult to habituate, and often range over relatively large areas. Many are also renowned for inhabiting remote areas with rugged terrain and inclement climatic conditions. It is thus not surprising that, until fairly recently, they were among the least studied and most enigmatic extant diurnal primates. However, since the beginning of the new millennium, an expanse of new and exciting research has been conducted on these colobines. In this chapter, we provide an overview of the current knowledge of the ecology and behaviour of odd-nosed monkeys and analyse some of their key behavioural traits and ecological adaptations in light of what is known about other colobines and primates as a whole.
Interindividual variation of cerebral activation during encoding and retrieval of words
- R Heun, F Jessen, U Klose, M Erb, D.O Granath, N Freymann, W Grodd
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- European Psychiatry / Volume 15 / Issue 8 / December 2000
- Published online by Cambridge University Press:
- 16 April 2020, pp. 470-479
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The aim of the present study was to compare the cerebral activation associated with encoding and retrieval in individual subjects with the average activation in the same group of subjects. Twelve volunteers performed two paradigms: 1) intentional encoding of words, and 2) recognition of learned words intermixed with new distracters. Echo-planar magnetic resonance imaging (MRI) of BOLD signal changes was used to compare cerebral activation between active and resting conditions. During encoding, activation of the left precentral gyrus related to the motor response was observed in some subjects. Averaged data showed increased activation of the left precentral gyrus, the supplementary motor area (SMA), the left inferior frontal gyrus and in the left temporo-occipital junction. During recognition, motor response-related activity was found in the precentral cortex and SMA in most subjects. Activation in other brain areas showed considerable interindividual variation. In the entire group, recognition showed activation of the left dorsolateral prefrontal cortex, the precentral gyrus, the SMA, and the temporo-occipital junction. The total amount and the distribution of task-related cerebral activation varies considerably between individuals and might correspond to individual preferences of cognitive strategies. The investigation of these interindividual variations will be an exciting scientific challenge in the near future.
1596 – Chronobiological Thyroid Axis Activity Could Predict Antidepressant Response In Major Depression
- F. Duval, M.-C. Mokrani, F. Gonzalez Lopera, C. Alexa, H. Rabia, X. Proudnikova, A. Erb
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- Journal:
- European Psychiatry / Volume 28 / Issue S1 / 2013
- Published online by Cambridge University Press:
- 15 April 2020, 28-E882
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Background
We previously demonstrated that the difference between 23.00h and 08.00h TSH response to TRH tests on the same day (ΔΔTSH test) is reduced in about 75% of drug-free depressed inpatients. This study sought to determine whether this chronobiological index, at baseline and after 2 weeks of treatment, could predict antidepressant response.
MethodsThe ΔΔTSH test was performed in 50 drug-free DSM-IV euthyroid major depressed inpatients and 50 hospitalized controls. After 2 weeks of antidepressant treatment the ΔΔTSH test was repeated in all inpatients. Antidepressant response was evaluated after 6 weeks of treatment.
ResultsAt baseline, ΔΔTSH values were significantly lower in patients compared to controls (p< 0.000001): 38 patients showed reduced values (i.e. ΔΔTSH ≤ 2.5 mIU/L; sensitivity, 76%; specificity, 98%). After two weeks of treatment, 20 patients showed ΔΔTSH normalization (among them 18 were subsequent remitters), while 18 patients did not normalize their ΔΔTSH (among them 15 were non remitters) (p < 0.00001). Among the 12 patients who had normal ΔΔTSH values at baseline, 8 out 9 who had still normal values after 2 weeks of treatment were remitters, while the 3 with worsening thyroid axis function (i.e. reduced ΔΔTSH value after 2 weeks of treatment) were non-remitters (p< 0.02).
ConclusionOur results suggest that after 2 weeks of antidepressant treatment: 1) an abnormal ΔΔTSH test could predict non-remission, and 2) ΔΔTSH normalization is associated with subsequent remission. Thus, chronobiological restoration of the thyroid axis activity precedes clinical improvement and may predict the therapeutic outcome in major depression.
2566 – Chronobiological Thyroid Axis Activity and Suicidal Behavior in Depressed Patients
- F. Duval, M.-C. Mokrani, F. Gonzalez Lopera, X. Proudnikova, H. Rabia, A. Erb
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- European Psychiatry / Volume 28 / Issue S1 / 2013
- Published online by Cambridge University Press:
- 15 April 2020, 28-E1529
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Objectives:
The aim of this study was to investigate the relationship between suicidal behavior and chronobiological thyroid axis activity in depressed patients.
Methods:The serum levels of TSH, were evaluated before and after 8 AM and 11 PM TRH challenges, on the same day, in 230 medication-free DSM-IV euthyroid major depressed inpatients and 50 healthy hospitalized controls.
Results:Compared to controls: 1) patients with a recent suicide attempt (n = 71) showed lower TSH response to TRH (ΔTSH) at 11 PM, lower ΔΔTSH values (differences between 11PM-ΔTSH and 8AM-ΔTSH) (p < 0.03 and p < 0.00001, respectively), and lower free thyroxine (FT4) levels (p < 0.00001); 2) patients with a past suicide attempt (n = 52) showed no major alteration of the HPT axis activity; 3) patients without a suicide attempt history (n = 107) showed both lower 8 AM-ΔTSH and 11-PM ΔTSH (p < 0.04 and p < 0.000001), and lower ΔΔTSH values (p < 0.000001), but no alteration of circulating thyroid hormone levels.
Conclusions:Our results suggest that in patients without a suicide attempt history increased hypothalamic TRH stimulation (as evidenced by reduced TSH responses to TRH) might be a compensatory mechanism. in patients with a suicide history this compensatory mechanism is not effective. in patients with a recent suicide attempt the evening TSH blunting, associated with reduced FT4 levels, might be indicative of a decreased central TRH activity leading to a reduction in the TSH resynthesis in the thyrotrophs during the day after the morning challenge.
Chapter 15 - Anesthesia for Minimally Invasive Neurosurgery
- Edited by Sulpicio G. Soriano, Craig D. McClain
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- Book:
- Essentials of Pediatric Neuroanesthesia
- Published online:
- 02 November 2018
- Print publication:
- 22 November 2018, pp 120-134
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Targets for high repetition rate laser facilities: needs, challenges and perspectives
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- I. Prencipe, J. Fuchs, S. Pascarelli, D. W. Schumacher, R. B. Stephens, N. B. Alexander, R. Briggs, M. Büscher, M. O. Cernaianu, A. Choukourov, M. De Marco, A. Erbe, J. Fassbender, G. Fiquet, P. Fitzsimmons, C. Gheorghiu, J. Hund, L. G. Huang, M. Harmand, N. J. Hartley, A. Irman, T. Kluge, Z. Konopkova, S. Kraft, D. Kraus, V. Leca, D. Margarone, J. Metzkes, K. Nagai, W. Nazarov, P. Lutoslawski, D. Papp, M. Passoni, A. Pelka, J. P. Perin, J. Schulz, M. Smid, C. Spindloe, S. Steinke, R. Torchio, C. Vass, T. Wiste, R. Zaffino, K. Zeil, T. Tschentscher, U. Schramm, T. E. Cowan
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- Journal:
- High Power Laser Science and Engineering / Volume 5 / 2017
- Published online by Cambridge University Press:
- 24 July 2017, e17
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A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities.
Personality traits and combat exposure as predictors of psychopathology over time
- E. Koffel, M. D. Kramer, P. A. Arbisi, C. R. Erbes, M. Kaler, M. A. Polusny
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- Journal:
- Psychological Medicine / Volume 46 / Issue 1 / January 2016
- Published online by Cambridge University Press:
- 08 September 2015, pp. 209-220
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Background.
Research suggests that personality traits have both direct and indirect effects on the development of psychological symptoms, with indirect effects mediated by stressful or traumatic events. This study models the direct influence of personality traits on residualized changes in internalizing and externalizing symptoms following a stressful and potentially traumatic deployment, as well as the indirect influence of personality on symptom levels mediated by combat exposure.
Method.We utilized structural equation modeling with a longitudinal prospective study of 522 US National Guard soldiers deployed to Iraq. Analyses were based on self-report measures of personality, combat exposure, and internalizing and externalizing symptoms.
Results.Both pre-deployment Disconstraint and externalizing symptoms predicted combat exposure, which in turn predicted internalizing and externalizing symptoms. There was a significant indirect effect for pre-deployment externalizing symptoms on post-deployment externalizing via combat exposure (p < 0.01). Negative Emotionality and pre-deployment internalizing symptoms directly predicted post-deployment internalizing symptoms, but both were unrelated to combat exposure. No direct effects of personality on residualized changes in externalizing symptoms were found.
Conclusions.Baseline symptom dimensions had significant direct and indirect effects on post-deployment symptoms. Controlling for both pre-exposure personality and symptoms, combat experiences remained positively related to both internalizing and externalizing symptoms. Implications for diagnostic classification are discussed.
Factors associated with inconsistency in self-reported mild traumatic brain injury over time among military personnel in Iraq
- Nathaniel W. Nelson, Carolyn R. Anderson, Paul Thuras, Shannon M. Kehle-Forbes, Paul A. Arbisi, Christopher R. Erbes, Melissa A. Polusny
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- Journal:
- The British Journal of Psychiatry / Volume 206 / Issue 3 / March 2015
- Published online by Cambridge University Press:
- 02 January 2018, pp. 237-244
- Print publication:
- March 2015
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Background
Estimates of the prevalence of mild traumatic brain injury (mTBI) among military personnel and combat veterans rely almost exclusively on retrospective self-reports; however, reliability of these reports has received little attention.
AimsTo examine the consistency of reporting of mTBI over time and identify factors associated with inconsistent reporting.
MethodA longitudinal cohort of 948 US National Guard Soldiers deployed to Iraq completed self-report questionnaire screening for mTBI and psychological symptoms while in-theatre 1 month before returning home (time 1, T1) and 1 year later (time 2, T2).
ResultsMost respondents (n = 811, 85.5%) were consistent in their reporting of mTBI across time. Among those who were inconsistent in their reports (n = 137, 14.5%), the majority denied mTBI at T1 and affirmed mTBI at T2 (n = 123, 89.8%). Respondents rarely endorsed mTBI in-theatre and later denied mTBI (n = 14, 10.2% of those with inconsistent reports). Post-deployment post-traumatic stress symptoms and non-specific physical complaints were significantly associated with inconsistent report of mTBI.
ConclusionsMilitary service members' self-reports of mTBI are generally consistent over time; however, inconsistency in retrospective self-reporting of mTBI status is associated with current posttraumatic stress symptoms and non-specific physical health complaints.
Prospective risk factors for new-onset post-traumatic stress disorder in National Guard soldiers deployed to Iraq
- M. A. Polusny, C. R. Erbes, M. Murdoch, P. A. Arbisi, P. Thuras, M. B. Rath
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- Journal:
- Psychological Medicine / Volume 41 / Issue 4 / April 2011
- Published online by Cambridge University Press:
- 10 December 2010, pp. 687-698
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Background
National Guard troops are at increased risk for post-traumatic stress disorder (PTSD); however, little is known about risk and resilience in this population.
MethodThe Readiness and Resilience in National Guard Soldiers Study is a prospective, longitudinal investigation of 522 Army National Guard troops deployed to Iraq from March 2006 to July 2007. Participants completed measures of PTSD symptoms and potential risk/protective factors 1 month before deployment. Of these, 81% (n=424) completed measures of PTSD, deployment stressor exposure and post-deployment outcomes 2–3 months after returning from Iraq. New onset of probable PTSD ‘diagnosis’ was measured by the PTSD Checklist – Military (PCL-M). Independent predictors of new-onset probable PTSD were identified using hierarchical logistic regression analyses.
ResultsAt baseline prior to deployment, 3.7% had probable PTSD. Among soldiers without PTSD symptoms at baseline, 13.8% reported post-deployment new-onset probable PTSD. Hierarchical logistic regression adjusted for gender, age, race/ethnicity and military rank showed that reporting more stressors prior to deployment predicted new-onset probable PTSD [odds ratio (OR) 2.20] as did feeling less prepared for deployment (OR 0.58). After accounting for pre-deployment factors, new-onset probable PTSD was predicted by exposure to combat (OR 2.19) and to combat's aftermath (OR 1.62). Reporting more stressful life events after deployment (OR 1.96) was associated with increased odds of new-onset probable PTSD, while post-deployment social support (OR 0.31) was a significant protective factor in the etiology of PTSD.
ConclusionsCombat exposure may be unavoidable in military service members, but other vulnerability and protective factors also predict PTSD and could be targets for prevention strategies.
Contributors
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- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. Hackett, Getatchew Haile, Douglas John Hall, Nicholas Hammond, Daphne Hampson, Jehu J. Hanciles, Barry Hankins, Jennifer Haraguchi, Stanley S. Harakas, Anthony John Harding, Conrad L. Harkins, J. William Harmless, Marjory Harper, Amir Harrak, Joel F. Harrington, Mark W. Harris, Susan Ashbrook Harvey, Van A. Harvey, R. Chris Hassel, Jione Havea, Daniel Hawk, Diana L. Hayes, Leslie Hayes, Priscilla Hayner, S. Mark Heim, Simo Heininen, Richard P. Heitzenrater, Eila Helander, David Hempton, Scott H. Hendrix, Jan-Olav Henriksen, Gina Hens-Piazza, Carter Heyward, Nicholas J. Higham, David Hilliard, Norman A. Hjelm, Peter C. Hodgson, Arthur Holder, M. Jan Holton, Dwight N. Hopkins, Ronnie Po-chia Hsia, Po-Ho Huang, James Hudnut-Beumler, Jennifer S. Hughes, Leonard M. Hummel, Mary E. Hunt, Laennec Hurbon, Mark Hutchinson, Susan E. Hylen, Mary Beth Ingham, H. Larry Ingle, Dale T. Irvin, Jon Isaak, Paul John Isaak, Ada María Isasi-Díaz, Hans Raun Iversen, Margaret C. Jacob, Arthur James, Maria Jansdotter-Samuelsson, David Jasper, Werner G. Jeanrond, Renée Jeffery, David Lyle Jeffrey, Theodore W. Jennings, David H. Jensen, Robin Margaret Jensen, David Jobling, Dale A. Johnson, Elizabeth A. Johnson, Maxwell E. Johnson, Sarah Johnson, Mark D. Johnston, F. Stanley Jones, James William Jones, John R. Jones, Alissa Jones Nelson, Inge Jonsson, Jan Joosten, Elizabeth Judd, Mulambya Peggy Kabonde, Robert Kaggwa, Sylvester Kahakwa, Isaac Kalimi, Ogbu U. Kalu, Eunice Kamaara, Wayne C. Kannaday, Musimbi Kanyoro, Veli-Matti Kärkkäinen, Frank Kaufmann, Léon Nguapitshi Kayongo, Richard Kearney, Alice A. Keefe, Ralph Keen, Catherine Keller, Anthony J. Kelly, Karen Kennelly, Kathi Lynn Kern, Fergus Kerr, Edward Kessler, George Kilcourse, Heup Young Kim, Kim Sung-Hae, Kim Yong-Bock, Kim Yung Suk, Richard King, Thomas M. King, Robert M. Kingdon, Ross Kinsler, Hans G. Kippenberg, Cheryl A. Kirk-Duggan, Clifton Kirkpatrick, Leonid Kishkovsky, Nadieszda Kizenko, Jeffrey Klaiber, Hans-Josef Klauck, Sidney Knight, Samuel Kobia, Robert Kolb, Karla Ann Koll, Heikki Kotila, Donald Kraybill, Philip D. W. Krey, Yves Krumenacker, Jeffrey Kah-Jin Kuan, Simanga R. Kumalo, Peter Kuzmic, Simon Shui-Man Kwan, Kwok Pui-lan, André LaCocque, Stephen E. Lahey, John Tsz Pang Lai, Emiel Lamberts, Armando Lampe, Craig Lampe, Beverly J. Lanzetta, Eve LaPlante, Lizette Larson-Miller, Ariel Bybee Laughton, Leonard Lawlor, Bentley Layton, Robin A. Leaver, Karen Lebacqz, Archie Chi Chung Lee, Marilyn J. Legge, Hervé LeGrand, D. L. LeMahieu, Raymond Lemieux, Bill J. Leonard, Ellen M. Leonard, Outi Leppä, Jean Lesaulnier, Nantawan Boonprasat Lewis, Henrietta Leyser, Alexei Lidov, Bernard Lightman, Paul Chang-Ha Lim, Carter Lindberg, Mark R. Lindsay, James R. Linville, James C. Livingston, Ann Loades, David Loades, Jean-Claude Loba-Mkole, Lo Lung Kwong, Wati Longchar, Eleazar López, David W. Lotz, Andrew Louth, Robin W. Lovin, William Luis, Frank D. Macchia, Diarmaid N. J. MacCulloch, Kirk R. MacGregor, Marjory A. MacLean, Donald MacLeod, Tomas S. Maddela, Inge Mager, Laurenti Magesa, David G. Maillu, Fortunato Mallimaci, Philip Mamalakis, Kä Mana, Ukachukwu Chris Manus, Herbert Robinson Marbury, Reuel Norman Marigza, Jacqueline Mariña, Antti Marjanen, Luiz C. L. Marques, Madipoane Masenya (ngwan'a Mphahlele), Caleb J. D. Maskell, Steve Mason, Thomas Massaro, Fernando Matamoros Ponce, András Máté-Tóth, Odair Pedroso Mateus, Dinis Matsolo, Fumitaka Matsuoka, John D'Arcy May, Yelena Mazour-Matusevich, Theodore Mbazumutima, John S. McClure, Christian McConnell, Lee Martin McDonald, Gary B. McGee, Thomas McGowan, Alister E. McGrath, Richard J. McGregor, John A. McGuckin, Maud Burnett McInerney, Elsie Anne McKee, Mary B. McKinley, James F. McMillan, Ernan McMullin, Kathleen E. McVey, M. Douglas Meeks, Monica Jyotsna Melanchthon, Ilie Melniciuc-Puica, Everett Mendoza, Raymond A. Mentzer, William W. Menzies, Ina Merdjanova, Franziska Metzger, Constant J. Mews, Marvin Meyer, Carol Meyers, Vasile Mihoc, Gunner Bjerg Mikkelsen, Maria Inêz de Castro Millen, Clyde Lee Miller, Bonnie J. Miller-McLemore, Alexander Mirkovic, Paul Misner, Nozomu Miyahira, R. W. L. Moberly, Gerald Moede, Aloo Osotsi Mojola, Sunanda Mongia, Rebeca Montemayor, James Moore, Roger E. Moore, Craig E. Morrison O.Carm, Jeffry H. Morrison, Keith Morrison, Wilson J. Moses, Tefetso Henry Mothibe, Mokgethi Motlhabi, Fulata Moyo, Henry Mugabe, Jesse Ndwiga Kanyua Mugambi, Peggy Mulambya-Kabonde, Robert Bruce Mullin, Pamela Mullins Reaves, Saskia Murk Jansen, Heleen L. Murre-Van den Berg, Augustine Musopole, Isaac M. T. Mwase, Philomena Mwaura, Cecilia Nahnfeldt, Anne Nasimiyu Wasike, Carmiña Navia Velasco, Thulani Ndlazi, Alexander Negrov, James B. Nelson, David G. Newcombe, Carol Newsom, Helen J. Nicholson, George W. E. Nickelsburg, Tatyana Nikolskaya, Damayanthi M. A. Niles, Bertil Nilsson, Nyambura Njoroge, Fidelis Nkomazana, Mary Beth Norton, Christian Nottmeier, Sonene Nyawo, Anthère Nzabatsinda, Edward T. Oakes, Gerald O'Collins, Daniel O'Connell, David W. Odell-Scott, Mercy Amba Oduyoye, Kathleen O'Grady, Oyeronke Olajubu, Thomas O'Loughlin, Dennis T. Olson, J. Steven O'Malley, Cephas N. Omenyo, Muriel Orevillo-Montenegro, César Augusto Ornellas Ramos, Agbonkhianmeghe E. Orobator, Kenan B. Osborne, Carolyn Osiek, Javier Otaola Montagne, Douglas F. Ottati, Anna May Say Pa, Irina Paert, Jerry G. Pankhurst, Aristotle Papanikolaou, Samuele F. Pardini, Stefano Parenti, Peter Paris, Sung Bae Park, Cristián G. Parker, Raquel Pastor, Joseph Pathrapankal, Daniel Patte, W. Brown Patterson, Clive Pearson, Keith F. Pecklers, Nancy Cardoso Pereira, David Horace Perkins, Pheme Perkins, Edward N. Peters, Rebecca Todd Peters, Bishop Yeznik Petrossian, Raymond Pfister, Peter C. Phan, Isabel Apawo Phiri, William S. F. Pickering, Derrick G. Pitard, William Elvis Plata, Zlatko Plese, John Plummer, James Newton Poling, Ronald Popivchak, Andrew Porter, Ute Possekel, James M. Powell, Enos Das Pradhan, Devadasan Premnath, Jaime Adrían Prieto Valladares, Anne Primavesi, Randall Prior, María Alicia Puente Lutteroth, Eduardo Guzmão Quadros, Albert Rabil, Laurent William Ramambason, Apolonio M. Ranche, Vololona Randriamanantena Andriamitandrina, Lawrence R. Rast, Paul L. Redditt, Adele Reinhartz, Rolf Rendtorff, Pål Repstad, James N. Rhodes, John K. Riches, Joerg Rieger, Sharon H. Ringe, Sandra Rios, Tyler Roberts, David M. Robinson, James M. Robinson, Joanne Maguire Robinson, Richard A. H. Robinson, Roy R. Robson, Jack B. Rogers, Maria Roginska, Sidney Rooy, Rev. Garnett Roper, Maria José Fontelas Rosado-Nunes, Andrew C. Ross, Stefan Rossbach, François Rossier, John D. Roth, John K. Roth, Phillip Rothwell, Richard E. Rubenstein, Rosemary Radford Ruether, Markku Ruotsila, John E. Rybolt, Risto Saarinen, John Saillant, Juan Sanchez, Wagner Lopes Sanchez, Hugo N. Santos, Gerhard Sauter, Gloria L. Schaab, Sandra M. Schneiders, Quentin J. Schultze, Fernando F. Segovia, Turid Karlsen Seim, Carsten Selch Jensen, Alan P. F. Sell, Frank C. Senn, Kent Davis Sensenig, Damían Setton, Bal Krishna Sharma, Carolyn J. Sharp, Thomas Sheehan, N. Gerald Shenk, Christian Sheppard, Charles Sherlock, Tabona Shoko, Walter B. Shurden, Marguerite Shuster, B. Mark Sietsema, Batara Sihombing, Neil Silberman, Clodomiro Siller, Samuel Silva-Gotay, Heikki Silvet, John K. Simmons, Hagith Sivan, James C. Skedros, Abraham Smith, Ashley A. Smith, Ted A. Smith, Daud Soesilo, Pia Søltoft, Choan-Seng (C. S.) Song, Kathryn Spink, Bryan Spinks, Eric O. Springsted, Nicolas Standaert, Brian Stanley, Glen H. Stassen, Karel Steenbrink, Stephen J. Stein, Andrea Sterk, Gregory E. Sterling, Columba Stewart, Jacques Stewart, Robert B. Stewart, Cynthia Stokes Brown, Ken Stone, Anne Stott, Elizabeth Stuart, Monya Stubbs, Marjorie Hewitt Suchocki, David Kwang-sun Suh, Scott W. Sunquist, Keith Suter, Douglas Sweeney, Charles H. Talbert, Shawqi N. Talia, Elsa Tamez, Joseph B. Tamney, Jonathan Y. Tan, Yak-Hwee Tan, Kathryn Tanner, Feiya Tao, Elizabeth S. Tapia, Aquiline Tarimo, Claire Taylor, Mark Lewis Taylor, Bishop Abba Samuel Wolde Tekestebirhan, Eugene TeSelle, M. Thomas Thangaraj, David R. Thomas, Andrew Thornley, Scott Thumma, Marcelo Timotheo da Costa, George E. “Tink” Tinker, Ola Tjørhom, Karen Jo Torjesen, Iain R. Torrance, Fernando Torres-Londoño, Archbishop Demetrios [Trakatellis], Marit Trelstad, Christine Trevett, Phyllis Trible, Johannes Tromp, Paul Turner, Robert G. Tuttle, Archbishop Desmond Tutu, Peter Tyler, Anders Tyrberg, Justin Ukpong, Javier Ulloa, Camillus Umoh, Kristi Upson-Saia, Martina Urban, Monica Uribe, Elochukwu Eugene Uzukwu, Richard Vaggione, Gabriel Vahanian, Paul Valliere, T. J. Van Bavel, Steven Vanderputten, Peter Van der Veer, Huub Van de Sandt, Louis Van Tongeren, Luke A. Veronis, Noel Villalba, Ramón Vinke, Tim Vivian, David Voas, Elena Volkova, Katharina von Kellenbach, Elina Vuola, Timothy Wadkins, Elaine M. Wainwright, Randi Jones Walker, Dewey D. Wallace, Jerry Walls, Michael J. Walsh, Philip Walters, Janet Walton, Jonathan L. Walton, Wang Xiaochao, Patricia A. Ward, David Harrington Watt, Herold D. Weiss, Laurence L. Welborn, Sharon D. Welch, Timothy Wengert, Traci C. West, Merold Westphal, David Wetherell, Barbara Wheeler, Carolinne White, Jean-Paul Wiest, Frans Wijsen, Terry L. Wilder, Felix Wilfred, Rebecca Wilkin, Daniel H. Williams, D. Newell Williams, Michael A. Williams, Vincent L. Wimbush, Gabriele Winkler, Anders Winroth, Lauri Emílio Wirth, James A. Wiseman, Ebba Witt-Brattström, Teofil Wojciechowski, John Wolffe, Kenman L. Wong, Wong Wai Ching, Linda Woodhead, Wendy M. Wright, Rose Wu, Keith E. Yandell, Gale A. Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
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- The Cambridge Dictionary of Christianity
- Published online:
- 05 August 2012
- Print publication:
- 20 September 2010, pp xi-xliv
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Thienopyrazine-based low-bandgap polymers for flexible polymer solar cells
- S. Sensfuss, L. Blankenburg, H. Schache, S. Shokhovets, T. Erb, A. Konkin, A. Herasimovich, S. Scheinert, M. Shahid, S. Sell, E. Klemm
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- Journal:
- The European Physical Journal - Applied Physics / Volume 51 / Issue 3 / September 2010
- Published online by Cambridge University Press:
- 02 September 2010, 33204
- Print publication:
- September 2010
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The optical gaps of the low-bandgap PPVs (PM-20, PM-19, PM-18) are decreased down to 1.6-1.7 eV compared with that of MDMO-PPV (2.2 eV). The best lateral hole mobility was determined to be 2.1 × 10-3 cm2/V s (PM-18) in field effect transistors and exceeds that of MDMO-PPV (poly-[ 2-methoxy-5-(3'.7'-dimethyloctyloxy)-1.4-phenylenevinylene], 8.5 × 10-4 cm2/V s). This allows to reduce the PCBM ([6.6]-phenyl-C$_{61(71)}$-butanoic acid methyl ester) content in solar cell devices down to 1:2 w/w giving a better $\eta_{\rm AM1.5}$ than for MDMO-PPV:[60]-PCBM cells (PM-19:[60]-PCBM 2.32% on ITO-PET, 2.86% on ITO glass). The charge transfer to PCBM as acceptor occurs quite normally and shows an effective charge separation using light-induced spin resonance spectroscopy (LESR). The [70]-PCBM$^{-\bullet}$ signals are shifted to lower field related to those of [60]-PCBM$^{-\bullet}$ and overlap more with the polaron signal of PM-19. The LESR g-factor components of [70]-PCBM$^{-\bullet}$ are reported for the first time. The external quantum efficiency peak values achieve up to 42% at ~350–400 nm and 26% at ~640 nm (PM-19:[60]-PCBM).
IRMf relacionadas con la respuesta de reconocimiento verdadero y falso de palabras
- R. Heun, F. Jessen, U. Klose, M. Erb, D.O. Granath, W. Grodd
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- Journal:
- European Psychiatry (Ed.Española) / Volume 11 / Issue 4 / May 2004
- Published online by Cambridge University Press:
- 12 May 2020, pp. 225-236
- Print publication:
- May 2004
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Objetivo.
Los estudios sobre la relación entre la activación cerebral local y el éxito de la recuperación comparaban por lo general condiciones de rendimiento alto y bajo, y mostraban así la activación relacionada con la actuación de áreas cerebrales diferentes. Sólo algunos estudios compararon directamente las intensidades de señal de categorías de respuesta diferentes durante la recuperación. Durante el reconocimiento verbal, observamos hace poco aumento de la activación parieto-occipital relacionado con las falsas alarmas. El presente estudio pretende replicar y extender esta observación investigando la activación común y diferencial según el reconocimiento verdadero y falso.
Métodos.Quince voluntarios sanos llevaron a cabo un paradigma de reconocimiento verbal utilizando 160 palabras diana aprendidas y 160 palabras distractoras nuevas. Los sujetos tenían que indicar si habían aprendido la palabra antes o no. Se realizaron IRM ecoplanares de los cambios de señal dependientes del nivel de oxígeno en la sangre durante esta tarea de reconocimiento. Las palabras se clasificaron post hoc según las respuestas de los sujetos, es decir, aciertos, falsas alarmas, rechazos correctos y omisiones. Se utilizó el análisis de IRMf relacionadas con la respuesta para comparar la activación asociada con el éxito del reconocimiento de los sujetos, es decir, se comparó las intensidades de la señal relacionadas con la presentación de las palabras según los cuatro tipos de respuesta mencionados más arriba.
Resultados.Durante el reconocimiento, todas las categorías de palabras mostraron un aumento de la activación bilateral del giro frontal inferior, el giro temporal inferior, el lóbulo occipital y el tronco encefálico en comparación con la condición de control. Los aciertos y las falsas alarmas activaron varias áreas, incluida la corteza medial izquierda y la corteza parieto-occipital lateral, en comparación con los elementos desconocidos subjetivamente, es decir, los rechazos correctos y las omisiones. Los aciertos mostraron una activación más pronunciada en la corteza medial y las falsas alarmas, en las partes laterales de la corteza parieto-occipital izquierda.
Conclusiones.El reconocimiento verdadero y falso muestra áreas tanto comunes como diferentes de activación cerebral en el lóbulo parieto-occipital izquierdo: el aumento de activación de la corteza parietal medial por los aciertos puede corresponder al reconocimiento verdadero, el aumento de activación de la corteza parieto-occipital por las falsas alarmas puede corresponder a decisiones de familiaridad. Se necesitan más estudios para investigar las razones para las decisiones falsas en sujetos sanos y pacientes con problemas de memoria.
Assessing Excess Nurse Work Load Generated by Multiresistant Nosocomial Bacteria in Intensive Care
- Fabienne F. Saulnier, Hervé Hubert, Thierry M. Onimus, Sébastien Beague, Saad Nseir, Bruno Grandbastien, Catherine Y. Renault, Myrian Idzik, Martine P. Erb, Alain V. Durocher
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 22 / Issue 5 / May 2001
- Published online by Cambridge University Press:
- 02 January 2015, pp. 273-278
- Print publication:
- May 2001
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Objective:
To compare three methods for assessing the excess nurse work load related to recommended procedures for managing nosocomial infections (NI) due to multiresistant bacteria (MRB): two activity scores, the Omega score and the Projet de Recherche en Nursing (PRN) system, and a specific evaluation based on functional analysis of nursing procedures.
Setting:10 beds in a medical intensive care unit (MICU).
Patients:Patients admitted from November 15,1995, to June 15, 1996, were included and divided in two groups based on presence of MRB colonization or infection (MRB+ and MRB− groups).
Methods:Data were collected regarding length of stay (LOS) in days; Omega score for the entire stay; PRN score for the entire stay and per day; and time required to perform correctly four nursing procedures related to MRB NI, as evaluated specifically by the nursing staff, using a detailed functional analysis document that described all elementary nursing tasks in chronological order and all material needed to carry out those tasks.
Results:The LOS and total Omega and PRN scores were higher in the MRB+ group than in the MRB− group: LOS, 23±20.6 versus 12±15.3 days, (P<.001); Omega score, 164±103.4 versus 123±93.7 points (P<.001); PRN score, 3,606±3,187 versus 1,854±2,356 points (P<.001), respectively. The daily PRN score was also higher in MRB+ group (PRN, 160±25 vs 146±34 points in the MRB− group; P<.028). Four nursing procedures made necessary by MRB acquisition were identified: isolation precautions, with two levels according to whether the risk of contamination was mild-moderate or high; bathing the patient with antiseptic solution;, bedpan management; and microbiological screening. The functional analysis indicated that the time needed to carry out these four procedures correctly was 245 minutes per patient per day, as compared to 85 minutes according to the PRN system.
Conclusions:Our data confirm that MRB NIs are responsible for an increase in nurse work load, as estimated by LOS, Omega, and PRN scores. However, the daily excess nurse work load related directly to recommended procedures for managing MRB NIs in MICUs is underestimated by these activity scores, as compared to a specific functional analysis of nursing tasks. This may be of importance in evaluating potential links between nurse work load and MRB NIs and in determining the number of nurse hours needed to comply with infection control recommendations.
Variación interindividual de la activación cerebral durante la codificación y la recuperación de palabras
- R. Heun, F. Jessen, U. Klose, M. Erb, D.O. Granath, N. Freymann, W. Grodd
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- Journal:
- European Psychiatry (Ed.Española) / Volume 8 / Issue 2 / March 2001
- Published online by Cambridge University Press:
- 12 May 2020, pp. 119-128
- Print publication:
- March 2001
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El propósito del presente estudio era comparar la activación cerebral asociada con la codificación y la recuperación en sujetos individuales con la activación media en el mismo grupo de sujetos. Doce voluntarios realizaron dos paradigmas: 1) codificación intencional de palabras, y 2) reconocimiento de las palabras aprendidas mezcladas con distractores nuevos. Se utilizaron imágeries de resonancia magnética (RM) eco-planares de los cambios de señal BOLD para comparar la activación cerebral entre las condiciones activa y de reposo. Durante la codificación, se observó en algunos sujetos activación de la circunvolución precentral izquierda relacionada con la respuesta motora. Los datos promediados mostraron un aumento de la activación de la circunvolución precentral izquierda, el área motora suplementaria (AMS), la circunvolución frontal inferior izquierda y en la zona de unión témporo-occipital izquierda. Durante el reconocimiento, se encontró actividad relacionada con la respuesta motora en la corteza precentral y el AMS en la mayoría de los sujetos. La activación en otras áreas del cerebro mostró variación interindividual considerable. En el grupo entero, el reconocimiento mostró activación de la corteza prefrontal dorsolateral izquierda, la circunvolución precentral, el AMS y la zona de unión témporo-occipital. La cantidad total de activación cerebral relacionada con la tarea y su distribución varían considerablemente entre los individuos y podrían corresponder a preferencias individuales de estrategias cognitivas. La investigación de estas variaciones interindividuales será un reto científico apasionante en el futuro cercano.
A Grain Boundary Engineering Approach to Materials Reliability
- G. Palumbo, E. M. Lehockey, P. Lin, U. Erb, K. T. Aust
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- Journal:
- MRS Online Proceedings Library Archive / Volume 458 / 1996
- Published online by Cambridge University Press:
- 10 February 2011, 273
- Print publication:
- 1996
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Intergranular degradation processes, (e.g., corrosion, stress corrosion, cracking, creep cracking) are a frequent cause of premature and unpredictable service failure of engineering components. Recent advances in (1) understanding structure-property relationships for grain boundaries, and (2) characterization techniques for grain boundaries in polycrystalline materials, have provided the means for improved component lifetime prediction, and the opportunity to engineer intergranular-degradation resistant microstructures.
In this work, we present our previously developed geometric models for grain boundary structure and grain size effects on intergranular degradation susceptibility. Specific examples are presented of the successful application of the ‘grain boundary engineering’ approach to the prediction and mitigation of intergranular corrosion, stress corrosion cracking, and creep cracking in Ni-based materials.
A Comparison Of The Corrosion Behaviour Of Nanocrystalline And Normal Crystalline Nickel
- R. Rofagha, R. Langer, A. M. El-Sherik, U. Erb, G. Palumbo, K. T. Aust
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- Journal:
- MRS Online Proceedings Library Archive / Volume 238 / 1991
- Published online by Cambridge University Press:
- 25 February 2011, 751
- Print publication:
- 1991
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The effect of grain size on the corrosion behaviour of nickel in 2N sulphuric acid is evaluated by potentiodynamic testing and characterization of the corrosion morphology for grain sizes ranging from 100μ to 32nm. The influence of the grain boundary component on key electrochemical parameters (free corrosion potential, passivation current density and potential, transpassive dissolution rate) is discussed.
Grain Growth Behaviour Of Nanocrystalline Nickel
- A. M. El-Sherik, K. Boylan, U. Erb, G. Palumbo, K. T. Aust
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- Journal:
- MRS Online Proceedings Library Archive / Volume 238 / 1991
- Published online by Cambridge University Press:
- 25 February 2011, 727
- Print publication:
- 1991
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The thermal stability of electrodeposited nanocrystalline Ni-1.2%P and Ni-0.12%S alloys is evaluated by in-situ electron microscopy studies. Isothermal grain size versus annealing time curves at 573K and 623K show an unexpected thermal stabilization in form of a transition from rapid initial grain growth to negligible grain growth. This behaviour is discussed in terms of the various grain boundary drag mechanisms which may be operative in these alloys.
On the Non-Existence of Conjugate Points
- G. J. Butler, L. H. Erbe, R. M. Mathsen
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- Journal:
- Canadian Mathematical Bulletin / Volume 13 / Issue 1 / March 1970
- Published online by Cambridge University Press:
- 20 November 2018, pp. 31-37
- Print publication:
- March 1970
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In this paper we consider the types of pairs of multiple zeros which a solution to the differential equation
can possess on an interval I of the real line. The results obtained generalize those in [2] and (for n = 3) in [3].
I. Let f satisfy the condition
1.1
for all t ∊ I, u0 ≠ 0, and all u1, … un-1.