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Trigger
Kinds of Trigger Terms modified by Trigger Selected AbstractsBruce Graham Trigger (1937,2006)AMERICAN ANTHROPOLOGIST, Issue 1 2008MICHAEL S. BISSON No abstract is available for this article. [source] Gadolinium Is Not the Only Trigger for Nephrogenic Systemic Fibrosis: Insights From Two Cases and Review of the Recent LiteratureAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2007I. M. Wahba Nephrogenic systemic fibrosis (NSF) is an emerging fibrosing disease with serious consequences in patients with acute and chronic kidney disease including solid organ and renal transplant recipients. It has recently been linked to gadolinium exposure. Almost all recently reported cases of NSF were found to be preceded by gadolinium administration, which led the FDA to issue a warning against the use of gadolinium in patients with moderate-to-severe reduction in the glomerular filtration rate. We report two organ transplant recipients who developed NSF and in whom extensive record review failed to document any prior gadolinium exposure. We then critically review the recently published literature linking NSF and gadolinium and we propose other possible triggers. We conclude that gadolinium is not the only trigger for NSF, and that the search for other triggers should be sought. We believe that this information is an important addition to the NSF literature, such that the definitive etiology and pathogenesis of NSF can be researched. [source] Epstein-Barr virus: Trigger for autoimmunity?ANNALS OF NEUROLOGY, Issue 6 2010Henry J. Kaminski MD No abstract is available for this article. [source] An Efficient and Simple Aminobenzannulation Reaction: Pyrrolidine as a Trigger for the Synthesis of 1-Amino-acridines.CHEMINFORM, Issue 37 2005Philippe Belmont Abstract For Abstract see ChemInform Abstract in Full Text. [source] Cyclization of Carbonyl Groups onto Alkynes upon Reaction with IPy2BF4 and Their Trapping with Nucleophiles: A Versatile Trigger for Assembling Oxygen Heterocycles.CHEMINFORM, Issue 46 2003Jose Barluenga Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Boron Trifluoride,Tetrahydrofuran Complex: A Superioor Trigger for the Yamaguchi,Hirao Alkylation of Lithio-acetylides by Epoxides.CHEMINFORM, Issue 52 2001Ann B. Evans Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] B,Z DNA Transition Triggered by a Cationic Comb-Type CopolymerADVANCED FUNCTIONAL MATERIALS, Issue 22 2009Naohiko Shimada Abstract The conformational transition from right-handed B,DNA to left-handed Z,DNA,the B,Z transition,has received increased attention recently because of its potential roles in biological systems and its applicability to bionanotechnology. Though the B,Z transition of poly(dG,dC),·,poly(dG,dC) is inducible under high salt concentration conditions (over 4,M NaCl) or by addition of multivalent cations, such as hexaamminecobalt(III), no cationic polymer were known to induce the transition. In this study, it is shown by circular dichroism and UV spectroscopy that the cationic comb-type copolymer, poly(L -lysine)- graft -dextran, but not poly(L -lysine) homopolymer or a basic peptide, induces the B,Z transition of poly(dG,dC),·,poly(dG,dC). At a cationic amino group concentration of 10,4,M the copolymer stabilizes Z,DNA. The transition pathway from the B to the Z form is different to that observed previously. We speculate that the cationic backbone of the copolymer, which reduces electrostatic repulsion among DNA phosphate groups, and the hydrophilic dextran chains, which reduce activity of water, cooperate to induce the B,Z transition. The copolymer specifically modified the micro-environment around DNA molecules to induce Z,DNA formation through stable and spontaneous inter-polyelectrolyte complex formation. [source] Catalytic Dicyanative 5- exo- and 6- endo -Cyclization Triggered by Cyanopalladation of AlkynesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2010Shigeru Arai Abstract A stereoselective dicyanative 5- exo- and 6- endo -cyclization using various enynes has been investigated. The mode of cyclization is critically controlled by the structure of the substrates. For example, N -allyl derivatives prefer 5- exo -cyclization, while methacryloyl amides are transformed to the corresponding lactams with tetra -substituted carbons at the alpha-position via 6- endo -cyclization. Both reactions include syn -cyanopalladation to carboncarbon triple bonds in the initial step, and sequential cyclization followed by reductive elimination in one operation enables the construction of the highly functionalized nitrogen heterocycles. The scope of suitable substrates and a proposed mechanism are also described. [source] B-Site Order,Disorder Transition in Pb(Mg1/3Nb2/3)O3,Pb(Mg1/2W1/2)O3 Triggered by Mechanical ActivationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2002Xingsen Gao B-site cation order,disorder transition induced by mechanical activation was observed in Pb(Mg1/3Nb2/3)O3,Pb(Mg1/2W1/2)O3 (PMN,PMW) solid solution, which was examined using both XRD diffraction and Raman spectroscopic study. The order,disorder transition is composition dependent. Mechanical activation triggers the B-site disordering, which can be steadily recovered by thermal annealing at elevated temperature, i.e., at temperatures around 600°C. Raman spectroscopy demonstrated that there existed tiny ordered microdomains in 0.4PMN·0.6PMW subjected to up to 20 h of mechanical activation, although they cannot be shown by X-ray diffraction. This is a result of the equilibrium between the mechanical destruction and temperature-facilitated recovering at the collision points during mechanical activation. It is therefore unlikely that a complete disordering can be realized in PMN,PMW by mechanical activation. The disordering in PMN,PMW triggered by mechanical activation occurs simultaneously with the refinement in crystallite size at the initial stage of mechanical activation, suggesting that the fragmentation of crystallites is responsible for the order,disorder transition at least during the initial stage of mechanical activation. [source] Rhodium-Catalyzed Cyclization of 1,6-Enynes Triggered by Addition of Arylboronic Acids.CHEMINFORM, Issue 24 2005Tomoya Miura No abstract is available for this article. [source] Triggers for Late Twentieth Century Reform of Australian Coastal ManagementGEOGRAPHICAL RESEARCH, Issue 3 2000B. G. Thom This paper identifies four triggers that underpinned the late 20th century reform of coastal management in Australia. These have operated across federal, state and local levels of government. The triggers are global environmental change, sustainable development, integrated resource management, and community awareness of management issues and participation in decision making. This reform has been driven by international and national forces. A number of inquiries into coastal management in Australia culminated in the production of a national coastal policy in 1995. This has led to fundamental changes in coastal management and to the recognition of the inevitability of changes in coastal systems. Federal policies and programs are being translated into action at the state and local government levels through a variety of funding mechanisms and programs. These involve capacity building, a memorandum of understanding between all levels of government, an enhanced role for state advisory or co-ordinating bodies, and an increased role for public participation. [source] Eco-hydrological controls on summertime convective rainfall triggersGLOBAL CHANGE BIOLOGY, Issue 4 2007JEHN-YIH JUANG Abstract Triggers of summertime convective rainfall depend on numerous interactions and feedbacks, often compounded by spatial variability in soil moisture and its impacts on vegetation function, vegetation composition, terrain, and all the complex turbulent entrainment processes near the capping inversion. To progress even within the most restricted and idealized framework, many of the governing processes must be simplified and parameterized. In this work, a zeroth-order representation of the dynamical processes that control convective rainfall triggers , namely land surface fluxes of heat and moisture , is proposed and used to develop a semianalytical model to explore how differential sensitivities of various ecosystems to soil moisture states modify convective rainfall triggers. The model is then applied to 4 years (2001,2004) of half-hourly precipitation, soil moisture, environmental, and eddy-covariance surface heat flux data collected at a mixed hardwood forest (HW), a maturing planted loblolly pine forest (PP), and an abandoned old field (OF) experiencing the same climatic and edaphic conditions. We found that the sensitivity of PP to soil moisture deficit enhances the trigger of convective rainfall relative to HW and OF, with enhancements of about 25% and 30% for dry moisture states, and 5% and 15% for moist soil moisture states, respectively. We discuss the broader implications of these findings on potential modulations of convective rainfall triggers induced by projected large-scale changes in timberland composition within the Southeastern United States. [source] Brief Communications: An Analysis of Migraine Triggers in a Clinic-Based PopulationHEADACHE, Issue 8 2010Diane Andress-Rothrock MS Background., Many migraineurs report attack "triggers," but relatively few published data exist regarding the relative prevalences of individual triggers, variations related to gender, duration of migraine or migraine subtype, or the existence of any regional variations in the prevalences and distributions of triggers. Objective., We sought to determine the prevalence and types of migraine triggers in our clinic population, to determine what influence gender, migraine subtype, or duration of migraine might have on the prevalences and types of triggers reported and to compare our findings with data derived from surveys we previously had conducted involving 2 clinic-based populations and 1 general population sample from other regions of the USA. Methods., We evaluated 200 consecutive new migraine patients referred to our clinic. All patients specifically were queried as to whether they had noted any of 7 specific factors to serve consistently as migraine attack triggers and additionally were surveyed as to whether they might have "other" triggers not listed on the intake questionnaire. Among the other data collected and analyzed were age, gender, age at time of migraine onset, and migraine subtype (ie, episodic vs chronic). Actively cycling females who reported menses as a trigger were questioned as to whether their menstrual migraine (MM) attacks differed from their non-menstrual migraines and, if so, how they differed. Results., One hundred and eighty-two patients (91%) reported at least 1 migraine trigger, and 165 (82.5%) reported multiple triggers. The most common trigger reported (59%) was "emotional stress," followed by "too much or little sleep" (53.5%), "odors" (46.5%), and "missing meals" (39%). Females or subjects of either gender with chronic migraine were no more likely than males or subjects with episodic migraine to report triggers or multiple triggers. Similarly, longer exposure to migraine did not correlate with a higher likelihood of reporting a trigger or multiple triggers. Fifty-three (62%) of 85 actively cycling females reported menses as a trigger, and of the 51 with menstrually related migraine, 34 (67%) reported their MM to be more severe, more refractory to symptomatic therapy or of longer duration than their non-menstrual attacks; 13 (24.5%) of the 53 women with apparent MM reported their MM to be at least occasionally manifested as status migrainosus. The prevalence and type of triggers reported by this predominantly white female population were similar to those reported by clinic-based populations in San Diego, California and Mobile, Alabama, and in a population-based sample of Hispanics in San Diego County. Conclusions., A large majority of migraineurs report migraine attack triggers, and the triggers most commonly reported include emotional stress, a disrupted sleep pattern, and various odors. These findings do not appear to vary according to geographic region or race/ethnicity. Among the triggers, MM appears inclined to provoke headache that is more severe, less amenable to treatment, or longer in duration than headaches that occur at other times during the cycle. (Headache 2010;50:1366-1370) [source] Headache Triggers in the US MilitaryHEADACHE, Issue 5 2010Brett J. Theeler MD (Headache 2010;50:790-794) Background., Headaches can be triggered by a variety of factors. Military service members have a high prevalence of headache but the factors triggering headaches in military troops have not been identified. Objective., The objective of this study is to determine headache triggers in soldiers and military beneficiaries seeking specialty care for headaches. Methods., A total of 172 consecutive US Army soldiers and military dependents (civilians) evaluated at the headache clinics of 2 US Army Medical Centers completed a standardized questionnaire about their headache triggers. Results., A total of 150 (87%) patients were active-duty military members and 22 (13%) patients were civilians. In total, 77% of subjects had migraine; 89% of patients reported at least one headache trigger with a mean of 8.3 triggers per patient. A wide variety of headache triggers was seen with the most common categories being environmental factors (74%), stress (67%), consumption-related factors (60%), and fatigue-related factors (57%). The types of headache triggers identified in active-duty service members were similar to those seen in civilians. Stress-related triggers were significantly more common in soldiers. There were no significant differences in trigger types between soldiers with and without a history of head trauma. Conclusion., Headaches in military service members are triggered mostly by the same factors as in civilians with stress being the most common trigger. Knowledge of headache triggers may be useful for developing strategies that reduce headache occurrence in the military. [source] Age- and Genotype-Specific Triggers for Life-Threatening Arrhythmia in the Genotyped Long QT SyndromeJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2008TOMOKO SAKAGUCHI M.D. Introduction: Patients with long QT syndrome (LQTS) become symptomatic in adolescence, but some become at age of ,20 years. Since it remains unknown whether clinical features of symptomatic LQTS patients differ depending on the age of onset, we aimed to examine whether triggers for cardiac events are different depending on the age in genotyped and symptomatic LQTS patients. Methods and Results: We identified 145 symptomatic LQTS patients, divided them into three groups according to the age of first onset of symptoms (young <20, intermediate 20,39, and older ,40 years), and analyzed triggers of cardiac events (ventricular tachycardia, syncope, or cardiac arrest). The triggers were divided into three categories: (1) adrenergically mediated triggers: exercise, emotional stress, loud noise, and arousal; (2) vagally mediated triggers: rest/sleep; and (3) secondary triggers: drugs, hypokalemia, and atrioventricular (AV) block. In the young group, 78% of the cardiac events were initiated by adrenergically mediated triggers and 22% were vagally mediated, but none by secondary triggers. In contrast, the adrenergically mediated triggers were significantly lower in the intermediate group. The percentage of secondary triggers was significantly larger in the older group than in the other two groups (0% in young vs 23% in intermediate vs 72% in older; P < 0.0001). Concerning the subdivision of secondary triggers on the basis of genotype, hypokalemia was only observed in LQT1, drugs mainly in LQT2, and AV block only in LQT2. Conclusion: Arrhythmic triggers in LQTS differ depending on the age of the patients, stressing the importance of age-related therapy for genotyped LQTS patients. [source] An Acute Model for Atrial Fibrillation Arising from a Peripheral Atrial Site: Evidence for Primary and Secondary TriggersJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2008BENJAMIN J. SCHERLAG Ph.D. Background: We previously demonstrated that acetylcholine (Ach) injected into cardiac ganglionated plexi (GP) causes pulmonary vein (PV) ectopy initiating atrial fibrillation (AF). Objective: To determine the effects of Ach applied at non-PV sites. Methods: Overall, 54 dogs were anesthetized with Na-pentobarbital. A right and left thoracotomy allowed the placement of multielectrode catheters to record from the superior PVs, mid portion of the atrium and the atrial appendages (AA). A monophasic action potential (MAP) was recorded from the AA. Ach (1, 10, 100 mM) was applied sequentially to the AA. Results: In 19 of 26 animals, Ach 100 mM on the right (n = 15) or left (n = 4) AA induced focal, sustained AF (,10 minutes) with rapid regular firing (cycle length = 37 ± 7 ms) at the AA. A clamp with teeth placed across the AA caused arrest in the AA. However, AF was sustained only when PV sites adjacent to the GP manifested complex fractionated atrial electrograms (CFAE). Clamping the AA prior to Ach (100 mM) application resulted in focal AF arising at the PVs but not at the AA. When a clamp without teeth was applied prior to Ach application, no AF at either AA or PV site could be induced. Conclusion: Isolation of the focal AF at the AA (primary trigger) by clamping caused cessation of activity in the AA, but AF continued due to secondary triggers arising from PVs. The possible mechanism(s) responsible for these findings are discussed, and various ancillary experiments (n = 28) were added to help elucidate mechanisms. [source] On the Atrial Response to Focal Discharges in ManJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2004HEMANTH RAMANNA M.D. Introduction: Triggers and vulnerability are key factors for the occurrence of atrial fibrillation (AF). The aim of this study was to assess spatial dispersion of atrial refractoriness and vulnerability in response to both focal discharges as well as programmed electrical stimulation in patients undergoing ablation of atrial arrhythmogenic foci. Methods and Results: Twenty-nine patients were studied, and 12 right atrial unipolar electrograms were recorded. Inducibility of AF was assessed by a pacing protocol that started with one extrastimulus, followed by more aggressive pacing until AF was obtained. Mean fibrillatory intervals were used to assess the local refractoriness of each recording site. Spatial dispersion of refractoriness was calculated as the coefficient of dispersion (CD value: standard deviation of the mean of all local mean fibrillatory intervals as a percentage of the overall mean fibrillatory interval). Based on our previous study, a CD value , 3.0 was defined as normal, whereas a CD value >3.0 was considered enhanced spatial dispersion of refractoriness. Fifteen of 29 patients had normal dispersion of refractoriness (mean CD value 1.65 ± 0.43), and AF was inducible with burst pacing only. These patients had focal discharges causing rapid atrial tachycardia with a focal activation pattern. Activation mapping of focal activity was possible in 14 of 15 patients. Focal triggering of AF occurred in only 1 of 15 patients. Fourteen of 29 patients had enhanced dispersion (mean CD value 4.2 ± 0.72). AF was inducible with a single extrastimulus in 11 of 14 patients (P < 0.001). Focal triggering of AF occurred in all 14 patients. Conclusion: Spatial dispersion of atrial refractoriness determines whether focal atrial discharges trigger AF with disorganized activity or, alternatively, only rapid atrial tachycardia. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1-8, June 2004) [source] Catheter Ablation of Chronic Atrial Fibrillation Targeting the Reinitiating TriggersJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2000MICHEL HAÏSSAGUERRE M.D. Trigger Ablation in Chronic AF. Introduction: We assessed the mode of reinitiation of atrial fibrillation (AF) after cardioversion and the efficacy of ablating these foci of reinitiation in patients with chronic AF. Methods and Results: Fifteen patients, 7 with structural heart disease, underwent mapping and catheter ablation of drug-resistant AF documented to he persistent for 5 ± 4 months. In all patients, cardioversion was followed by documentation of P on T atrial ectopy and early recurrence, which allowed mapping of the reinitiating trigger or the source of ectopy. Radiofrequency (RF) ablation was performed at pulmonary vein (PV) ostia using a target temperature of 50°C and a power limit of 30 to 40 W, with the endpoint being interruption of all local muscle conduction. A total of 32 arrhythmogenic PVs and 2 atrial foci (left septum and left appendage) were identified: 1, 2, and 3 or 4 PVs in 5, 3, and 6 patients. RF applications at the ostial perimeter resulted in progressively increasing delay, followed by abolition of PV potentials in 8, but potentials persisted in 6. A single ablation session was performed in 7 patients and 8 underwent two or three sessions because of recurrence of AF; ablation was directed at the same source due to recovery of local PV potential or at a different PV. No PV stenosis was noted either acutely or at repeated follow-up angiograms. Nine patients (60%) were in stable sinus rhythm without antiarrhythmic drugs at follow-up of 11 ± 8 months. Anticoagulants were interrupted in 7 patients. Conclusion: PVs are the dominant triggers reinitiating chronic AF in this patient population. Elimination of PV potentials by ostial RF applications results in stable sinus rhythm in 60%. A larger group and longer follow-up are needed to investigate further the role of trigger ablation in curative therapy for chronic AF. [source] A Study of Triggers of Migraine in IndiaPAIN MEDICINE, Issue 1 2010Rama K. Yadav DM ABSTRACT Objective., To evaluate the migraine triggers in consecutive patients and correlate these with demographic and clinical variables. Design., A prospective study. Setting., Tertiary care teaching hospital. Subject and Methods., A total of 182 patients with migraine were included whose age ranged between 14 to 58 years and 131 were females. Duration of migraine ranged between 6 and 260 months. Endogenous and exogenous migraine triggers were inquired using a questionnaire. Severity of migraine, associated symptoms, and functional disability were recorded. Presence of trigger was correlated with various demographic and clinical variables. Results., Migraine triggers were present in 160 (87.9%) patients and included emotional stress in 70%, fasting in 46.3%, physical exhaustion or traveling in 52.5%, sleep deprivation in 44.4%, menstruation in 12.8%, and weather changes in 10.1% patients. Multiple triggers (>2) were present in 34.4% patients. Conclusion., The triggers in the Indian migraine patients are similar to other populations but for dietary factors. [source] A Phytochrome-like Protein AphC Triggers the cAMP Signaling Induced by Far-red Light in the Cyanobacterium Anabaena sp.PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2004Strain PCC7120 ABSTRACT In the filamentous, nitrogen-fixing cyanobacterium Anabaena sp. PCC7120, red light (630 nm) decreased, whereas far-red light (720 nm) increased cellular adenosine 3,,5,-cyclic monophosphate (cAMP) content. To find a red and far-red light photoreceptor that triggers the cAMP signal cascade, we disrupted 10 open reading frame having putative chromophore-binding GAF domains. The response of the cellluar cAMP concentration to red and far-red light in each open reading frame disruptant was determined. It was found that only the mutant of the gene all2699 failed to respond to far-red light. The open reading frame named as aphC encoded a protein with 920 amino acids including GAF domains similar to those involved in Cph2, a photoreceptor of Synechocystis sp. PCC6803. To determine which adenylate cyclase (AC) is responsible for far-red light signal, we disrupted all AC genes and found that CyaC was the candidate. The enzymatic activity of CyaC might be controlled by a far-red light photoreceptor through the phosphotransfer reaction. The site-specific mutant of the Asp59 residue of the receiver (R1) domain of CyaC lost its light-response capability. It was suggested that the far-red light signal was received by AphC and then transferred to the N-terminal response regulator domain of CyaC. Then its catalytic activity was stimulated, which increased the cellular cAMP concentration and drove the subsequent signal transduction cascade. [source] Identifying Combinations of Cancer Markers for Further Study as Triggers of Early InterventionBIOMETRICS, Issue 4 2000Stuart G. Baker Summary. In many long-term clinical trials or cohort studies, investigators repeatedly collect and store tissue or serum specimens and later test specimens from cancer cases and a random sample of controls for potential markers for cancer. An important question is what combination, if any, of the molecular markers should be studied in a future trial as a trigger for early intervention. To answer this question, we summarized the performance of various combinations using Receiver Operating Characteristic (ROC) curves, which plot true versus false positive rates. To construct the ROC curves, we proposed a new class of nonparametric algorithms which extends the ROC paradigm to multiple tests. We fit various combinations of markers to a training sample and evaluated the performance in a test sample using a target region based on a utility function. We applied the methodology to the following markers for prostate cancer, the last value of total prostate-specific antigen (PSA), the last ratio of total to free PSA, the last slope of total PSA, and the last slope of the ratio. In the test sample, the ROC curve for last total PSA was slightly closer to the target region than the ROC curve for a combination of four markers. In a separate validation sample, the ROC curve for last total PSA intersected the target region in 77% of bootstrap replications, indicating some promise for further study. We also discussed sample size calculations. [source] Epidemiology and stratification of risk for sudden cardiac deathCLINICAL CARDIOLOGY, Issue S1 2005Philip J. Podrid M.D. Abstract Sudden cardiac death (SCD) is a major cause of mortality in the United States. Approximately 65% of cases of SCD occur in patients with underlying acute or chronic ischemic heart disease. The incidence of SCD increases 2- to 4-fold in the presence of coronary disease and 6- to 10-fold in the presence of structural heart disease. Ventricular fibrillation (VF) precipitated by ventricular tachycardia (VT) is a common mechanism of cardiac arrest leading to SCD. Triggers for SCD include electrolyte disturbances, heart failure, and transient ischemia. Although a large percentage of patients with out-of-hospital SCD do not survive, successful resuscitation to hospitalization has improved in recent years. One of the challenges for preventing SCD lies in identifying individuals at highest risk for SCD within a lower-risk population. The progression from conventional risk factors of coronary artery disease to arrhythmogenesis and SCD can be represented as a cascade of changes associated with levels of increasing risk. At the first level is atherogenesis, followed by changes in atherosclerotic plaque anatomy, which may be mediated by inflammatory processes. Disruption of active plaque formed during a transitional state initiates the thrombotic cascade and acute occlusion, after which acute changes in myocardial electrophysiology become the immediate trigger for arrhythmogenesis and SCD. Each level of the cascade offers different opportunities for risk prediction. Among the classes of risk predictors are clinical markers, such as ECG measures and ejection fraction. Transient risk markers, such as inflammatory markers, are potentially useful for identifying triggers for SCD. In the future, genetic profiling is expected to allow better assessment of individual risks for SCD. [source] Clinical characteristics of language regression in childrenDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 8 2003Sy Wilson MD; The spectrum of language regression in childhood is incompletely understood. To describe the features of this disorder more fully, we reviewed the records of 196 consecutive children (143 males and 53 females) with language regression or perceived plateau evaluated between 1988 and 1994 by a child neurologist. Mean age at regression was 21.2 months and the mean interval to referral was 34.8 months. A trigger for the regression was identified in 74 of the children (38%) and was associated with a more rapid regression. Mean age at follow-up was 64 months (SD 55). Seventy per cent of the children became nonverbal, and 75% were cognitively impaired. Language regression was associated with a more global autistic regression in 93% of children. There was a history of seizures in 15% of the children. Some recovery occurred in 61% but only one child recovered fully. Improvement was more likely in the 49% who were entirely developmentally normal before the regression. We conclude that language regression in childhood is a serious disorder with significant long-term morbidity. [source] Enteroviruses and type 1 diabetesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2003Ruben Varela-Calvino Abstract The development of type 1 diabetes mellitus (T1DM) has been linked to exposure to environmental triggers, with Enteroviruses (EV) historically considered the prime suspects. Early serological studies suggested a link between EV infections and the development of T1DM and, though controversial, have been bolstered by more recent studies using more sensitive techniques such as direct detection of the EV genome by RT-PCR in peripheral blood. In this review, we consider the weight of evidence that EV can be considered a candidate trigger of T1DM, using three major criteria: (1) is EV infection associated with clinical T1DM, (2) can EV trigger the development of autoimmunity and (3) what would explain the putative association? Copyright © 2003 John Wiley & Sons, Ltd. [source] Spatial dynamics of supercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on Christmas Island, Indian OceanDIVERSITY AND DISTRIBUTIONS, Issue 1 2006K. L. AbbottArticle first published online: 19 DEC 200 ABSTRACT Key to the management of invasive species is an understanding of the scope of an invasion, the rate of proliferation and the rate at which invaded habitats become degraded. This study examines the spatial dynamics of high-density supercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on Christmas Island, Indian Ocean, and the associated impacts at their boundaries. Since the early 1990s, A. gracilipes supercolonies have occupied over 30% of the 10,000 ha of rainforest on Christmas Island. Thirty-four discrete high-density supercolonies formed between 1989 and 2003, ranging in size across nearly three orders of magnitude from 0.9 to 787 ha. Supercolonies boundaries are diffuse, and ants were observed in low densities in some cases up to 200 m from the main high-density supercolony. The 13 boundaries examined were all dynamic over a 10,20 observation month period: nine boundaries expanded, and the maximum rate of spread was 0.5 m day,1. Across boundary transition zones, between high-density supercolonies and intact rainforest, yellow crazy ants reduced other ant species richness, occupied red crab burrows and killed resident red crabs, which was the trigger for ,invasional meltdown' on Christmas Island. The highly variable and unpredictable nature of A. gracilipes boundaries poses a challenge for incorporation into a predictive framework, as well as for their management. [source] Analysis of historical landslide time series in the Emilia-Romagna region, northern ItalyEARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2010Mauro Rossi Abstract A catalogue of historical landslides, 1951,2002, for three provinces in the Emilia-Romagna region of northern Italy is presented and its statistical properties studied. The catalogue consists of 2255 reported landslides and is based on historical archives and chronicles. We use two measures for the intensity of landsliding over time: (i) the number of reported landslides in a day (DL) and (ii) the number of reported landslides in an event (Sevent), where an event is one or more consecutive days with landsliding. From 1951,2002 in our study area there were 1057 days with 1 , DL ,?45 landslides per day, and 596 events with 1 , Sevent , 129 landslides per event. In the first set of analyses, we find that the probability density of landslide intensities in the time series are power-law distributed over at least two-orders of magnitude, with exponent of about ,2·0. Although our data is a proxy for landsliding built from newspaper reports, it is the first tentative evidence that the frequency-size of triggered landslide events over time (not just the landslides in a given triggered event), like earthquakes, scale as a power-law or other heavy-tailed distributions. If confirmed, this could have important implications for risk assessment and erosion modelling in a given area. In our second set of analyses, we find that for short antecedent rainfall periods, the minimum amount of rainfall necessary to trigger landslides varies considerably with the intensity of the landsliding (DL and Sevent); whereas for long antecedent periods the magnitude is largely independent of the cumulative amount of rainfall, and the largest values of landslide intensity are always preceded by abundant rainfall. Further, the analysis of the rainfall trend suggests that the trigger of landslides in the study area is related to seasonal rainfall. Copyright © 2010 John Wiley & Sons, Ltd. [source] Discussion of landslide self-organized criticality and the initiation of debris flowEARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2007Chen Chien-Yuan Abstract The study contains descriptions of landslides and debris flows in a small upland catchment in Taiwan between 1986 and 2004. This catchment, the Chushui Creek, is situated near the epicentre of the 1999 M7·6 Chi-Chi earthquake. This is an area with high background erosion rate. The Chi-Chi earthquake caused a sharp increase in the rate of mass wasting in the epicentral area, and the data presented in this study illustrates the geomorphic change associated with the earthquake. The measurements of the geometry of the trunk stream of the Chushui catchment also show its change due to the impact of a strong typhoon in 1996. Two channel reaches that were affected by separate debris flows during this event were identified. Each reach has three sections: scour, transfer and deposition. Cross profiles of these sections show a systematic change from V-shaped bedrock channel in the scour areas to flat-floored channel in the transfer and deposition areas. Debris flows also occurred on other occasions in this channel, and their frequency has increased since the 1999 earthquake. In addition, this study contains precise geographic and statistical descriptions of the landslides triggered by three typhoons and an earthquake that affected the catchment since 1996. The total landslide area is measured for different time intervals, and a marked increase in landslide incidence is found after the 1999 earthquake. Frequency,area plots of the 126 landslides in the catchment indicate a power-law scaling with an exponent of about -1·5 of these quantities, as has been observed in other studies. We propose that a link exists between landslide frequency,area distributions and initialization of debris flow in the catchment. It may be classified as a self-organized criticality process with a critical frequency,area distribution for the landslide population. In this case, the landslide frequency,area distribution is useful in quantifying the severity of the trigger and the contribution of landslides to debris flow. Copyright © 2006 John Wiley & Sons, Ltd. [source] Landslide inventories and their statistical propertiesEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2004Bruce D. Malamud Abstract Landslides are generally associated with a trigger, such as an earthquake, a rapid snowmelt or a large storm. The landslide event can include a single landslide or many thousands. The frequency,area (or volume) distribution of a landslide event quanti,es the number of landslides that occur at different sizes. We examine three well-documented landslide events, from Italy, Guatemala and the USA, each with a different triggering mechanism, and ,nd that the landslide areas for all three are well approximated by the same three-parameter inverse-gamma distribution. For small landslide areas this distribution has an exponential ,roll-over' and for medium and large landslide areas decays as a power-law with exponent -2·40. One implication of this landslide distribution is that the mean area of landslides in the distribution is independent of the size of the event. We also introduce a landslide-event magnitude scale mL = log(NLT), with NLT the total number of landslides associated with a trigger. If a landslide-event inventory is incomplete (i.e. smaller landslides are not included), the partial inventory can be compared with our landslide probability distribution, and the corresponding landslide-event magnitude inferred. This technique can be applied to inventories of historical landslides, inferring the total number of landslides that occurred over geologic time, and how many of these have been erased by erosion, vegetation, and human activity. We have also considered three rockfall-dominated inventories, and ,nd that the frequency,size distributions differ substantially from those associated with other landslide types. We suggest that our proposed frequency,size distribution for landslides (excluding rockfalls) will be useful in quantifying the severity of landslide events and the contribution of landslides to erosion. Copyright © 2004 John Wiley & Sons, Ltd. [source] An Evaluation of a Blind Rotational Technique for Selective Mainstem IntubationACADEMIC EMERGENCY MEDICINE, Issue 10 2004Aaron E. Bair MD Abstract Objectives: Although rare, massive hemoptysis and major bronchial disruptions are associated with high mortality. Selective ventilation of the uninvolved lung can increase the likelihood of survival. Specialized devices used for single lung ventilation are often not readily available and can be difficult to place in the emergency department. The authors evaluated a blind rotational technique for selective mainstem intubation using either a standard endotracheal tube (ET) or a directional-tip endotracheal tube (DTET). Methods: This was a prospective, randomized trial on 25 human cadavers. The desired side of mainstem intubation was determined by randomization. Each cadaver was used for four ET, four DTET, and four control intubations. In the ET group, the trachea was intubated. The tube was then rotated 90° in the direction of the desired placement and advanced until resistance was met. In the DTET group, the technique was identical, except the trigger was activated to flex the tip during advancement. In the control group, an ET was advanced in neutral alignment until resistance was met. A bronchoscopist blinded to the desired placement determined tube position. Comparison testing was performed using Pearson's chi-square test. Results: When attempting to intubate the left mainstem, use of the ET with the rotational technique was successful 72.3% of the time (95% confidence interval [95% CI] = 57% to 84%). Intubation of the left mainstem using the DTET was successful 68.5% of the time (95% CI = 54% to 81%; p = 0.67). Attempts to selectively intubate the right mainstem using the rotational technique were highly successful in both groups: 94% for the ET (95% CI = 84% to 99%) versus 97.8% for the DTET (95% CI = 89% to 100%). Among controls, the right mainstem was intubated 93% of the time (95% CI = 86% to 97%). Conclusions: In a cadaveric model, the left mainstem bronchus can be selectively intubated with moderate reliability using this rotational technique. Use of a DTET confers no significant advantage. The ability to generalize these findings to living subjects is unknown. [source] Metalloporphyrin solubility: A trigger for catalyzing reductive dechlorination of tetrachloroethyleneENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2004Ishai Dror Abstract Metalloporphyrins are well known for their electron-transfer roles in many natural redox systems. In addition, several metalloporphyrins and related tetrapyrrole macrocycles complexed with various core metals have been shown to catalyze the reductive dechlorination of certain organic compounds, thus demonstrating the potential for using naturally occurring metalloporphyrins to attenuate toxic and persistent chlorinated organic pollutants in the environment. However, despite the great interest in reductive dechlorination reactions and the wide variety of natural and synthetic porphyrins currently available, only soluble porphyrins, which comprise a small fraction of this particular family of organic macrocycles, have been used as electron-transfer shuttles in these reactions. Results from the present study clearly demonstrate that metalloporphyrin solubility is a key factor in their ability to catalyze the reductive dechlorination of tetrachloroethylene and its daughter compounds. Additionally, we show that certain insoluble and nonreactive metalloporphyrins can be activated as catalysts merely by changing solution conditions to bring about their dissolution. Furthermore, once a metalloporphyrin is fully dissolved and activated, tetrachloroethylene transformation proceeds rapidly, giving nonchlorinated and less toxic alkenes as the major reaction products. Results from the present study suggest that if the right environmental conditions exist or can be created, specific metalloporphyrins may provide a solution for cleaning up sites that are contaminated with chlorinated organic pollutants. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||