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Purpose With the Internet quickly becoming a new arena for social interaction, it has also become a growing venue for bullying among youth. The purpose of the present study was to contrast the prevalence of Internet bullying with physical and verbal bullying among elementary, middle, and high school boys and girls, and to examine whether key predictors of physical and verbal bullying also predicted Internet bullying. Methods As part of an ongoing, statewide bullying prevention initiative in Colorado, 3,339 youth in Grades 5, 8, and 11 completed questionnaires in 78 school sites during the fall of 2005, and another 2,293 youth in that original sample participated in a follow-up survey in 65 school sites in the spring of 2006. Questionnaires included measures of bullying perpetration and victimization, normative beliefs about bullying, perceptions of peer social support, and perceptions of school climate. Results The highest prevalence rates were found for verbal, followed by physical, and then by Internet bullying. Physical and Internet bullying peaked in middle school and declined in high school. Verbal bullying peaked in middle school and remained relatively high during high school. Males were more likely to report physical bullying than females, but no gender differences were found for Internet and verbal bullying. All three types of bullying were significantly related to normative beliefs approving of bullying, negative school climate, and negative peer support. Conclusions Preventive interventions that target school bullying by changing norms about bullying and school context may also impact Internet bullying, given the shared predictors.

Introducción: La heterogenidad de las tasas de desnutrición asociada a la Insuficiencia Renal Crónica (IRC) en Hemodiálisis (HD) implica rendimiento(s) dispar(es) del(los) indicador(es) empleado(s). Objetivos: Identificar aquellos indicadores que mejor describan el estado nutricional y la evolución natural del paciente con IRC en HD. Escenario: Programa de Hemodiálisis, Servicio de Nefrología, Hospital Clínico-Quirúrgico "Hermanos Ameijeiras" (Ciudad La Habana, Cuba). Métodos: Se reclutaron 28 pacientes. Se registraron los ingresos entre diciembre 2001-diciembre 2002. Se registró la condición (Vivo/Fallecido) al año de observación. A cada paciente se le rellenó la Encuesta Subjetiva Global (ESG). El perfil nutricional incluyó: talla, peso, circunferencia del brazo (CB), pliegue cutáneo tricipital (PCT), albúmina y conteo total de linfocitos (CTL). El estado nutricional descrito mediante la albúmina y la CB se correlacionó con la ESG, la ocurrencia de ingresos y la condición final. Resultados: Las tasas de desnutrición fueron: (albúmina < 35 g/L): 42,9%; (CB < punto de corte): 60,7%; [(CB < Punto de corte) y/o (albúmina < 35)]: 71,4%; (ESG = En riesgo/Desnutrido): 42,9%. La ESG fue un predictor independiente de la ocurrencia de ingresos [OR = 14,14; IC 95%: 1,5-137,3] y la mortalidad [OR = 21,0; IC 95%: 2,9-151,4]. La albúmina fue un predictor independiente de la mortalidad [OR = 21,0; IC 95%: 2,9-151,4]. La regla [(CB < punto de corte) y/o (albúmina < 35)] falló en predecir la morbi-mortalidad del paciente. El 77,8% de los pacientes con + 60 años falleció durante el año de observación [OR = 13,2; IC 95%: 1,9-89,5]. Conclusiones: Una mortalidad incrementada con valores disminuidos de la albúmina y la CB justifica las políticas de intervención nutricional orientadas a preservar los tejidos magros.Introduction: Heterogeneity of malnutrition rates associated with End-Stage Renal Disease (ESRD) under Haemodialysis (HD) points towards differing performances of the used indicators. Objectives: To identify those indicators that better describe the nutritional state of the patient with ESRD under HD. Setting: Program of Haemodialysis, Service of Nephrology, "Hermanos Ameijeiras" Hospital (Havana City, Cuba). Methods: Twenty-eight patients were recruited. Hospital admissions between december 2001-december 2002 were recorded. The condition of the patient (alive/deceased) after one year of observation was registered. The Subjective Global Assessment (SGA) form was administered to each patient. The nutritional profile included: height, weight, mid-arm circumference (MAC), triceps skinfold (TSF), albumin and total lymphocyte count (TLC). Nutritional status as described by means of albumin and MAC was correlated with SGA score, the ocurrence of hospital admissions and the final condition of the patient. Results: Malnutrition rates were as follows (albumin < 35 g/L): 42.9%; (MAC < cut-off value): 60.7%; [(MAC < cut-off value) and/or (albumin < 35)]: 71.4%; (SGA score = At Risk/Malnourished): 42.9%. SGA score was an independent predictor of the ocurrence of admissions [OR = 14.14; CI 95%: 1.5-137.3] and mortality [OR = 21.0; CI 95%: 2.9-151.4]. Serum albumin was an independent predictor of the patient's mortality [OR = 21.0; CI 95%: 2.9-151.4]. The [(MAC < Cut-off value) and/or (albumin < 35)] rule failed to predict patient's morbimortality. Seventy-seven point eight percent of patients with +60 years-old died during the year of observation [OR = 13.2; IC 95%: 1.9-89.5]. Conclusions: Increased mortality associated with diminished values of albumin and MAC justifies the fostering of nutritional intervention aimed to preserve lean tissues.

Aims Predictors of recurrence following transcatheter cryoablation for atrioventricular nodal reentrant tachycardia (AVNRT) are currently unknown. Our objective was to explore predictors of recurrence postcryoablation for AVNRT, including the impact of procedural endpoints such as complete elimination of slow pathway conduction vs. persistent dual atrioventricular (AV) nodal physiology with or without echo beats. Methods and results A single center cohort study was performed on patients undergoing a first cryoablation procedure for AVNRT between May 1999 and December 2004. Cryoablation for AVNRT was attempted in 185 consecutive patients (79.2% female), age 43.1 + 15.2 years. Acute success was achieved in 170 (91.9%) patients with 4.4+ 3.5 cryoapplications and a total procedural duration of 2.8+ 0.8 h. Complete elimination of slow pathway conduction was noted in 47.6% of acutely successful interventions, absence of AV nodal echoes despite dual AV nodal physiology in 8.8%, and presence of echoes but no inducible AVNRT on and off isoproterenol in 43.5%. Actuarial recurrence-free survival following acutely successful cryoablation at 1, 3, 6, 12, and 24 months was 94.8, 93.1, 91.7, 90.8, and 90.8%, respectively. Independent predictors of recurrence were younger age (P ¼ 0.0045) and valvular heart disease (P ¼ 0.0186). The achieved procedural endpoint did not modulate recurrence rates. Eight patients (4.3%) experienced transient third degree AV block; none required permanent pacing. Conclusions As a cryoablation procedural outcome for AVNRT, persistent dual AV nodal physiology with or without echo beats is not associated with higher recurrence rates than complete elimination of dual AV nodal physiology if AVNRT remains non-inducible on and off isoproterenol.

Patients with multiple (5-100) colorectal adenomas (MCRAs) often have no germline mutation in known predisposition genes, but probably have a genetic origin. We collected a set of 25 MCRA patients with no detectable germline mutation in APC, MYH/MUTYH or the mismatch repair genes. Extracolonic tumours were absent in these cases. No vertical transmission of the MCRA phenotype was found. Based on the precedent of MYH-associated polyposis (MAP), we searched for a mutational signature in 241 adenomatous polyps from our MCRA cases. Somatic mutation frequencies and spectra at APC, K-ras and BRAF were, however, similar to those in sporadic colorectal adenomas. Our data suggest that the genetic pathway of tumorigenesis in the MCRA patients' tumours is very similar to the classical pathway in sporadic adenomas. In sharp contrast to MAP tumours, we did not find evidence of a specific mutational signature in any individual patient or in the overall set of MCRA cases. These results suggest that hypermutation of APC does not cause our patients' disease and strongly suggests that MAP is not a paradigm for the remaining MCRA patients. Our MCRA patients' colons showed no evidence of microadenomas, unlike in MAP and familial adenomatous polyposis (FAP). However, nuclear beta-catenin expression was significantly greater in MCRA patients' tumours than in sporadic adenomas. We suggest that, at least in some cases, the MCRA phenotype results from germline variation that acts subsequent to tumour initiation, perhaps by causing more rapid or more likely progression from microadenoma to macroadenoma.

We evaluated outcomes with the sirolimus (SRL) and mycophenolate mofetil (MMF) combination regimen (SRL/MMF) in solitary kidney transplant recipients transplanted between 2000 and 2005 reported to the Scientific Registry of Renal Transplant Recipients. Three-and-a-half percent received SRL/MMF (n = 2040). Six-month acute rejection rates were higher with SRL/MMF (SRL/MMF: 16.0% vs. other regimens: 11.2%, p < 0.001). Overall graft survival was significantly lower on SRL/MMF. SRL/MMF was associated with twice the hazard for graft loss (AHR = 2.0, 95% C.I., 1.8, 2.2) relative to TAC/MMF, also consistent in both living donor transplants (AHR = 2.4, 95% C.I., 1.9, 2.9) and expanded criteria donor transplants (AHR = 2.1, 95% C.I., 1.7-2.5). Among deceased donor transplants, DGF rates were higher in the SRL/MMF cohort (47% vs. 27%, p < 0.001). However, adjusted graft survival was also significantly inferior with SRL/MMF in DGF-free patients (AHR = 1.9, 95% C.I., 1.6-2.3). In analyses restricted to patients who remained on the discharge regimen at 6 months posttransplant, conditional graft survival in deceased donor transplants was significantly lower with SRL/MMF compared to patients on TAC/MMF or CsA/MMF regimens at 5 years posttransplant (64%, 78%, 78%, respectively, p = 0.001) and across all patient subgroups. In conclusion, SRL/MMF is associated with inferior renal transplant outcomes compared with other commonly used regimens.

Background: Paralleling the rise in pacemaker and defibrillator implantations, lead extraction procedures are increasingly required. Concerns regarding failure and complications remain. Methods and Results: A total of 200 lead extraction procudures were performed at the Montreal Heart Institute between September 2000 and August 2005. In 23 patients, all leads were removed by traction with a locking stylet. A total of 270 leads were extracted using a laser sheath system (Spectranectics, Colorado Springs, CO, USA) in 177 procedures involving 175 patients (74% male), age 62±16 years. Procedural indications were: infection 88 (50%), dysfunction 54 (30%), upgrade 21 (12%), and other 14 (8%). Overall, 241 leads (89%) were successfully extracted, 7 (3%) were partially extracted (≤4 cm retained), and 22 (8%) were non-extractable. In multivariate analyses, predictors of failed extraction were longer time from implant (OR 1.16 per year, P=0.0001) and history of hypertension (OR 5.2, P=0.0023). Acute complications occurred in 14 of 177 procedures (7.9%): 8 (4.5%) minor and 6 (3.4%) major, with one death. In multivariate analyses, the only predictor of acute complications was laser lead extraction from both right and left sides during the same procedure (OR 9.4, P = 0.0119). In addition, 3 of 10 patients with failed or partially extracted infected systems eventually required open chest explantation because of endocarditis. Conclusion: Most leads not amenable to manual traction may be successfully extracted by a percutaneous laser sheath system. While most complications are minor, major complications including death may occur. Older leads are at higher risk for failed extraction. Endocarditis may ensue if infected leads are incompletely removed.

Introduction: Patients with Brugada syndrome (BrS) are at risk for ventricular arrhythmias (VAs) and sudden death. Identification of high-risk individuals beyond those with syncope or resuscitated SCD remains a major challenge. We sought to assess the value of clinical, electrophysiological, and ECG features of depolarization and repolarization in predicting arrhythmic events and SCD in a Quebec population. Methods: Consecutive patients with BrS diagnosed between 2002 and 2013 were recruited from three major university hospitals in the province of Quebec, Canada. Relevant clinical features were recorded at baseline. Qualifying ECGs with the highest type 1 ST-segment elevations were reviewed and analyzed by two electrophysiologists blinded to clinical history, with the following parameters assessed: S duration in V1, aVR sign, QRS duration in V6, R-J interval in V2, maximal Tp-e, duration, Tp-e dispersion, QRS-f, ST elevation and QTc in V2, and presence of an inferolateral ER pattern. Survival analyses considered a left truncation model to account for potential sampling bias, considering that those who died suddenly before recognition of BrS were necessarily excluded. Results: A total of 105 consecutive patients, 79.8% male, were diagnosed with BrS at a median age of 48 years and were followed for 5.0±1.2 years. Ten (9.5%) had a history of SCD, 37 (35.2%) had syncope, and 7 (6.7%) experienced 20 arrhythmic events during follow-up (7 anti-tachycardia pacing; 13 shocks). In multivariate Cox regression analyses adjusted for left truncation and Firth bias correction, a spontaneous type I ECG pattern (HR 10.80; 95% CI 1.03 to 113.87; p=0.0476)], maximal Tp-e duration ≥100ms (HR 29.73; 95% CI 1.33 to 666.37; p= 0.0325) and QRS duration in V6>110 ms (HR 15.27; 95% CI 1.07 to 217.42; p=0.0443) were independently associated with VAs or aborted SCD. Family history of SCD, AF, and inducible VAs during programmed ventricular stimulation were not associated with the primary endpoint. Conclusion: In a cohort of patients with BrS from the province of Quebec, VAs and SCD were independently associated with standard 12-lead ECG features including a spontaneous type 1 pattern, depolarization (QRS in V6 >110 ms), and repolarization (maximal Tp-e duration) criteria.

Catheter ablation is increasingly used to manage atrial fibrillation, but arrhythmia recurrences are common. Adenosine might identify pulmonary veins at risk of reconnection by unmasking dormant conduction, and thereby guide additional ablation to improve arrhythmia-free survival. We assessed whether adenosine-guided pulmonary vein isolation could prevent arrhythmia recurrence in patients undergoing radiofrequency catheter ablation for paroxysmal atrial fibrillation.We did this randomised trial at 18 hospitals in Australia, Europe, and North America. We enrolled patients aged older than 18 years who had had at least three symptomatic atrial fibrillation episodes in the past 6 months, and for whom treatment with an antiarrhythmic drug failed. After pulmonary vein isolation, intravenous adenosine was administered. If dormant conduction was present, patients were randomly assigned (1:1) to additional adenosine-guided ablation to abolish dormant conduction or to no further ablation. If no dormant conduction was revealed, randomly selected patients were included in a registry. Patients were masked to treatment allocation and outcomes were assessed by a masked adjudicating committee. Patients were followed up for 1 year. The primary outcome was time to symptomatic atrial tachyarrhythmia after a single procedure in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT01058980.Adenosine unmasked dormant pulmonary vein conduction in 284 (53%) of 534 patients. 102 (69·4%) of 147 patients with additional adenosine-guided ablation were free from symptomatic atrial tachyarrhythmia compared with 58 (42·3%) of 137 patients with no further ablation, corresponding to an absolute risk reduction of 27·1% (95% CI 15·9-38·2; p0·0001) and a hazard ratio of 0·44 (95% CI 0·31-0·64; p0·0001). Of 115 patients without dormant pulmonary vein conduction, 64 (55·7%) remained free from symptomatic atrial tachyarrhythmia (p=0·0191 vs dormant conduction with no further ablation). Occurrences of serious adverse events were similar in each group. One death (massive stroke) was deemed probably related to ablation in a patient included in the registry.Adenosine testing to identify and target dormant pulmonary vein conduction during catheter ablation of atrial fibrillation is a safe and highly effective strategy to improve arrhythmia-free survival in patients with paroxysmal atrial fibrillation. This approach should be considered for incorporation into routine clinical practice.Canadian Institutes of Health Research, St Jude Medical, Biosense-Webster, and M Lachapelle (Montreal Heart Institute Foundation).

Background It is well recognized that right ventricular apical pacing can have deleterious effects on ventricular function. We performed a head‐to‐head comparison of the SafeR pacing algorithm versus DDD pacing with a long atrioventricular delay in a heterogeneous population of patients with dual‐chamber pacemakers. Methods and Results In a multicenter prospective double‐blinded randomized trial conducted at 10 centers in Canada, 373 patients, age 71±11 years, with indications for dual chamber DC pacemakers were randomized 1:1 to SafeR or DDD pacing with a long atrioventricular delay (250 ms). The primary objective was twofold: (1) reduction in the proportion of ventricular paced beats at 1 year; and (2) impact on atrial fibrillation burden at 3 years, defined as the ratio between cumulative duration of mode‐switches divided by follow‐up time. Statistical significance of both co‐primary end points was required for the trial to be considered positive. At 1 year of follow‐up, the median proportion of ventricular‐paced beats was 4.0% with DDD versus 0% with SafeR ( P DDD (median 0.00%, interquartile range [0.00% to 0.23%] versus median 0.01%, interquartile range [0.00% to 0.44%], respectively, P =0.178]), despite a persistent reduction in the median proportion of ventricular‐paced beats (10% with DDD compared to 0% with SafeR). Conclusions A ventricular‐paced rate Clinical Trial Registration URL : https://www.clinicaltrials.gov/ Unique identifier: NCT 01219621.

The association between standard parameters from a simple 12-lead ECG (i.e., QRS duration and PR, JT, and QT intervals) and adverse cardiovascular outcomes (cardiovascular mortality, all-cause mortality, arrhythmic mortality, and hospitalizations) in patients with a history of atrial fibrillation (AF) has not been previously studied.A pooled analysis of patient-level data was conducted on 5,436 patients, age 68.2 ± 8.3 years, 34.8% female, with a history of non-permanent AF randomized in AFFIRM and AF-CHF trials. The predictive value of ECG parameters was assessed in AF and sinus rhythm in multivariate Cox regression models. During a follow-up of 40.8 ± 16.3 months, QRS duration120 milliseconds was independently associated with all-cause mortality (hazard ratio [HR] 1.46, 95% confidence interval [CI; 1.21-1.76] in AF, P0.001), cardiovascular mortality (HR 1.75, 95% CI (1.15-2.65) in sinus rhythm, P = 0.009; HR 1.56, 95% CI [1.27-1.93] in AF, P0.001), arrhythmic mortality (HR 1.90, 95% CI [1.09-3.32] in sinus, P = 0.024; HR 1.84, 95% CI [1.35-2.51] in AF, P0.001), any hospitalization (HR 1.15, 95% CI [1.02-1.29] in AF, P = 0.027), and cardiovascular hospitalization (HR 1.21, 95% CI [1.06-1.37] in AF; P = 0.004). Increased PR interval (200 milliseconds) was independently associated with cardiovascular (HR 1.56, 95% CI [1.11-2.21], P = 0.010) and arrhythmic (HR 1.91, 95% CI [1.14-3.18], P = 0.004) mortality. The JT and QTc intervals were not predictive of mortality.Simple parameters from standard ECGs are significantly and independently associated with adverse cardiovascular outcomes in patients with a history of AF.

This study estimates spermatozoa mortality, morphology, motility and intracellular calcium levels in Atlantic salmon Salmo salar milt after prolonged storage. Milt samples were preserved at 4° C for 25 days and then evaluated for mortality. Motility remained high for the first 3 days and the mortality was low during the first 5 days of storage. A decrease of50% in calcium content was observed after 5 days of storage. When spermatozoa were activated, calcium levels increased200% in relative fluorescence units (RFU); this rate of increase was lost when the samples were stored for extended periods of time and was only partially manifested in a zero calcium solution. The results suggest that in vitro storage of S. salar spermatozoa at 4° C for a period of 3 days preserves motility and limits mortality to levels similar to those of fresh spermatozoa. This method also maintains intracellular calcium storage critical for spermatozoa performance.

Background The impact of revascularization on recurrent ventricular arrhythmias (VAs) in patients with coronary artery disease and relatively preserved left ventricular ejection fraction (LVEF) is unknown. Objective The purpose of this study was to determine the impact of revascularization on recurrent VAs or death. Methods A cohort study was conducted on consecutive patients with prior myocardial infarction and LVEF ≥40% presenting with a first clinical sustained VA in the absence of an acute coronary syndrome. The impact of revascularization on recurrent VAs and all-cause mortality was assessed. Results A total of 274 patients (mean age 66.1 ± 9.7 years, 85.4% male, mean LVEF 48.3% ± 7.2%) were included in the study. Eight-eight patients (32.1%) underwent coronary revascularization. During mean follow-up of 6.2 ± 5.1 years, 140 (51.1%) died or had recurrent sustained VAs or appropriate implantable-cardioverter defibrillator therapy. Revascularization was not associated with a significantly lower rate of recurrent VAs or death (multivariable hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.60–1.24, P = .43) regardless of whether it was complete or incomplete (HR 0.65, 95% CI 0.25–1.69, P = .37) or was performed by percutaneous or surgical means (HR 1.02, 95% CI 0.53–1.94, P = .96). An implantable-cardioverter defibrillator was associated with a significant reduction in mortality (HR 0.23, 95% CI 0.09–0.55, P = .001). Conclusion Patients with prior myocardial infarction and LVEF ≥40% who present with sustained VAs in the absence of an acute coronary syndrome remain at high risk for recurrent VAs and all-cause death. Coronary revascularization does not systemically mitigate this risk.

This chapter conceptualizes school-based, peer-to-peer bullying as a coercive relational process, in which bullies instrumentally use aggressive interpersonal tactics to influence, change, or dominate others in order to attain desired outcomes. We explain how this coercive process occurs on multiple levels, both within the bully-victim dyad and within the peer group context. We then discuss how the nature and desired outcomes of bullying change according to school setting and developmental period, drawing on empirical research that highlights the increasingly sexualized nature of bullying during early adolescence. Finally, we link sexual harassment and bullying behaviors during adolescence to risk for involvement in coercive relationships and processes in adulthood, and review the implications of this work for evidence-based bullying prevention programs.

Rate and rhythm control strategies for atrial fibrillation (AF) are not always effective or well tolerated in patients with congestive heart failure (CHF). We assessed reasons for treatment failure, associated characteristics, and effects on survival.A total of 1,376 patients enrolled in the AF-CHF trial were followed for 37 ± 19 months, 206 (15.0%) of whom failed initial therapy leading to crossover. Rhythm control was abandoned more frequently than rate control (21.0% vs. 9.1%, P0.0001). Crossovers from rhythm to rate control were driven by inefficacy, whereas worsening heart failure was the most common reason to crossover from rate to rhythm control. In multivariate analyses, failure of rhythm control was associated with female sex, higher serum creatinine, functional class III or IV symptoms, lack of digoxin, and oral anticoagulation. Factors independently associated with failure of rate control were paroxysmal (vs. persistent) AF, statin therapy, and presence of an implantable cardioverter-defibrillator. Crossovers were not associated with cardiovascular mortality (hazard ratio [HR] 1.11 from rhythm to rate control; 95% confidence interval [95% CI, 0.73-1.73]; P = 0.6069; HR 1.29 from rate to rhythm control; 95% CI, 0.73-2.25; P = 0.3793) or all-cause mortality (HR 1.16 from rhythm to rate control, 95% CI [0.79-1.72], P = 0.4444; HR 1.15 from rate to rhythm control, 95% [0.69, 1.91], P = 0.5873).Rhythm control is abandoned more frequently than rate control in patients with AF and CHF. The most common reasons for treatment failure are inefficacy for rhythm control and worsening heart failure for rate control. Changing strategies does not impact survival.

An elevated resting heart rate has been associated with adverse cardiovascular outcomes. Its prognostic value has not specifically been examined in patients with atrial fibrillation.The purpose of this study was to assess the relationship between resting heart rate measured in sinus rhythm and in atrial fibrillation and subsequent hospitalizations and death.An analysis of individual patient-level data from subjects enrolled in the AFFIRM and AF-CHF trials was conducted to determine the impact of resting heart rate on hospitalizations and mortality. Separate analyses were performed in atrial fibrillation and sinus rhythm. A total of 7159 baseline ECGs (4848 in atrial fibrillation, 2311 in sinus rhythm) were analyzed in 5164 patients (34.8% female, age 68.2 ± 8.3 years).During mean follow-up of 40.8 ± 16.3 months, 1016 patients died (668 cardiovascular deaths), and 3150 required at least 1 hospitalization (2215 cardiovascular). An elevated baseline heart rate in sinus rhythm was associated with increased all-cause mortality [hazard ratio (HR) 1.24 per 10 bpm increase, 95% confidence interval (CI) 1.14-1.36, P.0001]. In contrast, a baseline heart rate in atrial fibrillation was not associated with mortality. However, compared to heart rates 90-114 bpm in atrial fibrillation, a heart rate114 bpm was independently associated with all-cause (HR 1.18, 95% CI 1.06-1.31, P = .0018) and cardiovascular (HR 1.25, 95% CI 1.10-1.42, P = .0005) hospitalizations.In patients with a history of atrial fibrillation, an elevated baseline heart rate in sinus rhythm is independently associated with mortality. In contrast, the baseline heart rate in atrial fibrillation is not associated with mortality but predicts hospitalizations.

Introduction Clinical diversity in systemic sclerosis (SSc) reflects multifaceted pathogenesis and the effect of key growth factors or cytokines operating within a disease-specific microenvironment. Dermal interstitial fluid sampling offers the potential to examine local mechanisms and identify proteins expressed within lesional tissue. We used multiplex cytokine analysis to profile the inflammatory and immune activity in the lesions of SSc patients. Methods Dermal interstitial fluid sample from the involved forearm skin, and synchronous plasma samples were collected from SSc patients (n = 26, diffuse cutaneous SSc (DcSSc) n = 20, limited cutaneous SSc (LcSSc) n = 6), and healthy controls (HC) (n = 10) and profiled by Luminex® array for inflammatory cytokines, chemokines, and growth factors. Results Luminex® profiling of the dermal blister fluid showed increased inflammatory cytokines (median interleukin ( IL)-6 in SSc 39.78 pg/ml, HC 5.51 pg/ml, p = 0.01, median IL-15 in SSc 6.27 pg/ml, HC 4.38 pg/ml, p = 0.03), chemokines (monocyte chemotactic protein (MCP)-3 9.81 pg/ml in SSc, 7.18 pg/ml HC, p = 0.04), and profibrotic growth factors (platelet derived growth factor (PDGF)-AA 10.38 pg/ml versus 6.94 pg/ml in HC, p = 0.03). In general dermal fluid and plasma cytokine levels did not correlate, consistent with predominantly local production of these factors within the dermal lesions, rather than leakage from the serum. In hierarchical clustering and network analysis IL-6 emerged as a key central mediator. Conclusions Our data confirm that an immuno-inflammatory environment and aberrant vascular repair are intimately linked to fibroblast activation in lesional skin in SSc. This non-invasive method could be used to profile disease activity in the clinic, and identifies key inflammatory or pro-fibrotic proteins that might be targeted therapeutically. Distinct subgroups of SSc may be defined that show innate or adaptive immune cytokine signatures.

The stringent response modulators, guanosine tetraphosphate (ppGpp) and protein DksA, bind RNA polymerase (RNAP) and regulate gene expression to adapt bacteria to different environmental conditions. Here, we use Atomic Force Microscopy and in vitro transcription assays to study the effects of these modulators on the conformation and stability of the open promoter complex (RPo) formed at the rrnA P1, rrnB P1, its discriminator (dis) variant and lambda pR promoters. In the absence of modulators, RPo formed at these promoters show different extents of DNA wrapping which correlate with the position of UP elements. Addition of the modulators affects both DNA wrapping and RPo stability in a promoter-dependent manner. Overall, the results obtained under different conditions of ppGpp, DksA and initiating nucleotides (iNTPs) indicate that ppGpp allosterically prevents the conformational changes associated with an extended DNA wrapping that leads to RPo stabilization, while DksA interferes directly with nucleotide positioning into the RNAP active site. At the iNTPs-sensitive rRNA promoters ppGpp and DksA display an independent inhibitory effect, while at the iNTPs-insensitive pR promoter DksA reduces the effect of ppGpp in accordance with their antagonistic role.

The genes for the mitochondrial FAD-dependent glycerol-3-phosphate dehydrogenase were identified in Trypanosoma brucei and Leishmania major genomes. We have expressed the L. major gene in Saccharomyces cerevisiae and confirmed the subcellular localization and activity of the produced enzyme. Using cultured T. brucei procyclic and Leishmania mexicana promastigote cells with a permeabilized plasma membrane and containing intact glycosomes, it was shown that dihydroxyacetone phosphate is converted into pyruvate, and stimulates oxygen consumption, indicating that all components of the glycerol 3-phosphate/dihydoxyacetone phosphate shuttle between glycosomes and mitochondrion are present in these insect stages of both organisms. A computer model has been prepared for the energy and carbohydrate metabolism of these cells. It was used in an elementary mode analysis to get insight into the metabolic role of the shuttle in these insect-stage parasites. Our analysis suggests that the shuttle fulfils important roles for these organisms, albeit different from its well-known function in the T. brucei bloodstream form. It allows (1) a high yield of further metabolizable glycolytic products by decreasing the need to produce a secreted end product of glycosomal metabolism, succinate; (2) the consumption of glycerol and glycerol 3-phosphate derived from lipids; and (3) to keep the redox balance of the glycosome finely tuned due to a highly flexible and redundant system. © 2006 Elsevier B.V. All rights reserved.

Using longitudinal data collected over 2 years on a sample of 2,745 urban elementary school children (1st–6th graders, ages 6–11 years) from economically disadvantaged communities, effects of stressful experiences within 3 contexts (school, family, neighborhood), cumulative stress, and multiple context stress on 3 indices of children’s adjustment (achievement, depression, and aggression) were examined. All 3 stressor contexts were related contemporaneously and longitudinally to negative outcomes across adjustment measures, with differential paths in each predictive model. Cumulative stress was linearly related to increases in adjustment problems but multiple context stress was not related to problematic adjustment beyond effects of cumulative stress alone. The important influence of life events stress on children’s adjustment in disadvantaged communities is discussed. In the present study, we build on and expand previous research examining the stress–adjustment relation among elementary school children growing up in disadvantaged urban communities (Brooks-Gunn, Duncan, & Aber, 1997; Evans & English, 2002; Guerra & Williams, 2005; Roosa et al., 2005; Taylor, Seaton, & Rodriguez, 2002; Yates, Egeland, & Sroufe, 2003). We focus on the role of stress in children’s school achievement, depression, and aggression. These three outcomes represent important components of adjustment (or maladjustment) during the elementary school years. Using longitudinal data from a large developmental study of urban elementary school children, we consider different mechanisms by which stress in three specific contexts (school, family, and neighborhood) can influence these outcomes. We are particularly interested in whether the impact of contextual stress varies as a function of the particular type of stress experienced in a given context, the cumulative amount of stress experienced, or the experience of stress across more than one or multiple contexts.

Background— The risk of systemic thromboemboli associated with transvenous leads in the presence of an intracardiac shunt is currently unknown. Methods and Results— To define this risk, we conducted a multicenter, retrospective cohort study of 202 patients with intracardiac shunts: Sixty-four had transvenous leads (group 1), 56 had epicardial leads (group 2), and 82 had right-to-left shunts but no pacemaker or implantable cardioverter defibrillator leads (group 3). Patient-years were accrued until the occurrence of systemic thromboemboli or study termination. Censoring occurred in the event of complete shunt closure, death, or loss to follow-up. Mean ages for groups 1, 2, and 3 were 33.9±18.0, 22.2±12.6, and 22.9±15.0 years, respectively. Respective oxygen saturations were 91.2±9.1%, 88.1±8.1%, and 79.7±6.7%. During respective median follow-ups of 7.3, 9.3, and 17.0 years, 24 patients had at least 1 systemic thromboembolus: 10 (15.6%), 5 (8.9%), and 9 (11.0%) in groups 1, 2, and 3, respectively. Univariate risk factors were older age (hazard ratio [HR], 1.05; P =0.0001), ongoing phlebotomy (HR, 3.1; P =0.0415), and an transvenous lead (HR, 2.4; P =0.0421). In multivariate, stepwise regression analyses, transvenous leads remained an independent predictor of systemic thromboemboli (HR, 2.6; P =0.0265). In patients with transvenous leads, independent risk factors were older age (HR, 1.05; P =0.0080), atrial fibrillation or flutter (HR, 6.7; P =0.0214), and ongoing phlebotomy (HR, 14.4; P =0.0349). Having had aspirin or warfarin prescribed was not protective. Epicardial leads were, however, associated with higher atrial ( P =0.0407) and ventricular ( P =0.0270) thresholds and shorter generator longevity (HR, 1.9; P =0.0176). Conclusions— Transvenous leads incur a >2-fold increased risk of systemic thromboemboli in patients with intracardiac shunts.

Over the past decades, public concern over youth violence has led to a proliferation of prevention programs as well as a corresponding push to identify programs that "work". A more accurate understanding of effectiveness as well as failure can be found by reframing the questions to ask what works, for whom, and under what conditions.

This paper presents a study developed to obtain several parameters of the small scale fading of the wideband propagation channel applied to the portable and mobile reception of Digital Terrestrial Television (DTV) services in an urban Single Frequency Network (SFN) environment. The study is focused on the calculation of some relevant parameter values related to the multipath behavior of the channel, using field data collected in a real network. Mean values for the Root mean square Delay Spread (RDS) and the frequency domain Level Crossing Rate (LCR) are given, together with an analysis of the influence of the specific environment and network (SFN) features.

Recent advances in understanding the learning, maintenance, prevention, and treatment of problematic social behaviors in childhood and adolescence have emphasized the central role of the child's developing cognitions (Beck, 1999; Boxer & Dubow, 2002; Compton et al., 2004; Crick & Dodge, 1994; Durlak, Rubin, & Kahng, 2001; Eron, 1994; Guerra & Huesmann, 2004; Huesmann, 1998; Lochman & Lenhart, 1995). The developing individual is seen as an active participant in a learning process linking individual (e.g., irritability, impulsivity) and environmental (e.g., community violence, poverty) risk factors to social behavior through cognitive structures, such as beliefs, rules, and schemas, and skills, such as attention, attribution, and problem solving. This cognitive-ecological view posits that problem behaviors emerge through interactions between individual predisposition and contextual socialization and are maintained over time and across situations by cognitive "styles" that are shaped by direct and observational learning experiences. Cognitive styles are learned across multiple contexts and, in turn, influence responding across these contexts. The term "ecological" refers to the nested contexts of child development, providing a stage for social interactions, opportunities for social engagement, and a normative or regulatory structure that includes costs and benefits of distinct courses of action (Guerra & Huesmann).Consider a boy who grows up in an environment laced with harsh and hostile encounters with parents, teachers, and peers. Over time, it is likely that these negative experiences will influence, at least to some degree, his self-perception ("nobody likes me"), perceptions of others ("they have it in for me"), and beliefs about aggression ("it's OK to hit and be mean-everybody does it"). Under these conditions, it is also likely that he will develop characteristic biases in social information processing that are based on the presumption that others act with hostile intent, leading to increased perceptions of vulnerability and anger, and a greater likelihood of aggressive retaliation. For example, Dodge and col leagues (Dodge, Pettit, & Bates, 1997; Dodge, Pettit, Bates, & Valente, 1995) have shown that children who experience harsh parental discipline or are physically abused during their early childhood years are more likely to attribute hostile intent to peers in ambiguous situations and behave more aggressively than their nonexposed peers.If cognitive patterns linked to emotional reactions, such as anger, and behaviors, such as aggression, are learned over time, then it is also the case that they can be "unlearned." In essence, this is a fundamental premise of cognitive-behavioral interventions; that is, modifying dysfunctional cognition will, in turn, lead to positive effects on emotional and behavioral adjustment. However, because the primary emphasis is on the individual's cognitive deficits and distortions and how these can be modified, less attention has focused on the contribution of the child's total developmental ecology to the emergence and maintenance of targeted cognitions (Boxer & Butkus, in press; Durlak et al., 2001).Both clinical and psycho-educational interventions typically are designed to change how children think in response to problematic social situations, with less attention focused on modifying contextual influences on these emerging cognitions. The assumption is that once children correct errors in thinking or reduce deficits in social information-processing skills, they will be better equipped to navigate their social and emotional worlds, resulting in corresponding gains in adjustment. Although cognitive-behavioral interventions also address situational factors that have established or are maintaining specific symptoms or behaviors (e.g., functional analysis; Haynes & O'Brien, 1990), they focus primarily on immediate situational contingencies rather than overarching developmental contexts. …

An increase in the prevalence of both atrial fibrillation and congestive heart failure is occurring in part because of the demographic shift toward an aging population. These two clinical entities often coexist in the same patient, resulting in the worsening of symptoms and prognosis, rendering their management even more challenging. A large clinical trial is currently examining whether a rhythm-control strategy is superior to a rate-control strategy in patients with congestive heart failure. New nonpharmacologic therapies such as pulmonary vein isolation are undergoing clinical investigation and may also alter the management of these patients. At present, therapy for atrial fibrillation in patients with congestive heart failure should aim first at controlling heart rate to provide symptomatic relief; then sinus rhythm should be restored if symptoms persist or if congestive heart failure worsens. For a more definitive approach in managing these patients, the authors await further clinical trial data.

A prototype of a quartz-crystal microbalance-based transducer is proposed for in-situ measurements of very low chloroform activity in a gaseous environment. The sensing element consists of an innovative semicrystalline form of syndiotactic polystyrene sprayed as a thin film on the piezoelectric quartz electrode of the microbalance. Chloroform sorption and desorption in the film give rise to a mass variation, implying a related shift in the resonance frequency of the quartz. Results of static and dynamic metrological characterization of the transducer prototype at varying chloroform concentration and temperature in a gaseous environment are reported. Satisfactory sensitivity, repeatability, and dynamic hysteresis are highlighted.

The WT1 transcription factor regulates SRY expression during the initial steps of the sex determination process in humans, activating a gene cascade leading to testis differentiation. In addition to causing Wilms' tumor, mutations in WT1 are often responsible for urogenital defects in men, while SRY mutations are mainly related to 46,XY pure gonadal dysgenesis. In order to evaluate their role in abnormal testicular organogenesis, we screened for SRY and WT1 gene mutations in 10 children with XY partial gonadal dysgenesis, 2 of whom with a history of Wilms' tumor. The open reading frame and 360 bp of the 5' flanking sequence of the SRY gene, and the ten exons and intron boundaries of the WT1 gene were amplified by PCR of genomic DNA. Single-strand conformation polymorphism was initially used for WT1 mutation screening. Since shifts in fragment migration were only observed for intron/exon 4, the ten WT1 exons from all patients were sequenced manually. No mutations were detected in the SRY 5' untranslated region or within SRY open-reading frame sequences. WT1 sequencing revealed one missense mutation (D396N) in the ninth exon of a patient who also had Wilms' tumor. In addition, two silent point mutations were found in the first exon including one described here for the first time. Some non-coding sequence variations were detected, representing one new (IVS4+85A>G) and two already described (-7ATG T>G, IVS9-49 T>C) single nucleotide polymorphisms. Therefore, mutations in two major genes required for gonadal development, SRY and WT1, are not responsible for XY partial gonadal dysgenesis.

Phosphoglycerate mutase (PGAM) activity in promastigotes of the protozoan parasite Leishmania mexicana is found only in the cytosol. It corresponds to a cofactor-independent PGAM as it is not stimulated by 2,3-bisphosphoglycerate and is susceptible to EDTA and resistant to vanadate. We have cloned and sequenced the gene and developed a convenient bacterial expression system and a high-yield purification protocol. Kinetic properties of the bacterially produced protein have been determined (3-phosphoglycerate: K(m) = 0.27 +/- 0.02 mm, k(cat) = 434 +/- 54 s(-1); 2-phosphoglycerate: K(m) = 0.11 +/- 0.03 mm, k(cat) = 199 +/- 24 s(-1)). The activity is inhibited by phosphate but is resistant to Cl(-) and SO(4) (2-). Inactivation by EDTA is almost fully reversed by incubation with CoCl(2) but not with MnCl(2), FeSO(4), CuSO(4), NiCl(2) or ZnCl(2). Alkylation by diethyl pyrocarbonate resulted in irreversible inhibition, but saturating concentrations of substrate provided full protection. Kinetics of the inhibitory reaction showed the modification of a new group of essential residues only after removal of metal ions by EDTA. The modified residues were identified by MS analysis of peptides generated by trypsin digestion. Two substrate-protected histidines in the proximity of the active site were identified (His136, His467) and, unexpectedly, also a distant one (His160), suggesting a conformational change in its environment. Partial protection of His467 was observed by the addition of 25 micro m CoCl(2) to the EDTA treated enzyme but not of 125 micro m MnCl(2), suggesting that the latter metal ion cannot be accommodated in the active site of Leishmania PGAM.

RESUMOA afirmação que a produção de café de qualidade é mais cara que a produção de café de menor qualidade, também que mercado falha na transmissão de sinais de qualidade para os produtores baixarem a qualidade média do café produzido. Ao usar equações simultâneas em mínimos quadrados de três estágios, descobriu-se que algumas variáveis foram significantes: o tamanho do produtor afeta a parcela de café cherry vendida, a qualidade afeta o preço internacional de café verde do México, e a qualidade da cherry aumenta a parcela vendida de café verde. Mas, não há evidencia que a concentração de poder de mercado afete a parcela de preços do café verde.ABSTRACTThe assumption that the production of quality coffee is more expensive than the production of coffee of less quality, also that market failures in the transmission of quality signals to producer lower the average quality of coffee produced industry. Used its simultaneous equations in three stage lest square we have found that some variable were significant; the size of the producer affects the share of sold cherry, the quality affects the international green coffee price of México and the quality of cherry increases the share of green coffee sold. But there in no evidence that market power concentration affects the share prices of green coffee.RESUMENSe afirma que producir café de calidad es más caro que producir café de peor calidad, y también que el mercado falla en la transmisión de señales de calidad para que los productores disminuyan la calidad media del café producido. Al usar ecuaciones simultáneas en mínimos cuadrados de tres etapas, se descubrió que algunas variables fueron significativas: el tamaño del productor afecta la fracción de café cherry vendida, la calidad afecta el precio internacional del café verde de México y la calidad de la cherry aumenta la fracción vendida de café verde. Pero no hay evidencia de que la concentración de poder de mercado afecte la fracción de precios del café verde.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:49:57Z No. of bitstreams: 1 S0100-69162004000100010.pdf: 183945 bytes, checksum: dde798b25430ebd481fc4881ca6e544f (MD5) Made available in DSpace on 2013-08-22T18:49:57Z (GMT). No. of bitstreams: 1 S0100-69162004000100010.pdf: 183945 bytes, checksum: dde798b25430ebd481fc4881ca6e544f (MD5) Previous issue date: 2004-04-01 Made available in DSpace on 2013-09-30T17:59:32Z (GMT). No. of bitstreams: 2 S0100-69162004000100010.pdf: 183945 bytes, checksum: dde798b25430ebd481fc4881ca6e544f (MD5) S0100-69162004000100010.pdf.txt: 27741 bytes, checksum: 74955553493c93130c9922c2a1a97288 (MD5) Previous issue date: 2004-04-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:14:27Z No. of bitstreams: 2 S0100-69162004000100010.pdf: 183945 bytes, checksum: dde798b25430ebd481fc4881ca6e544f (MD5) S0100-69162004000100010.pdf.txt: 27741 bytes, checksum: 74955553493c93130c9922c2a1a97288 (MD5) Made available in DSpace on 2014-05-20T13:14:27Z (GMT). No. of bitstreams: 2 S0100-69162004000100010.pdf: 183945 bytes, checksum: dde798b25430ebd481fc4881ca6e544f (MD5) S0100-69162004000100010.pdf.txt: 27741 bytes, checksum: 74955553493c93130c9922c2a1a97288 (MD5) Previous issue date: 2004-04-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) O experimento teve por objetivo avaliar a freqüência de fertirrigações com nitrogênio e potássio aplicadas por microaspersão na cultura da bananeira (Musa sp. AAB), cultivar Prata-Anã, durante dois ciclos de cultivo. O experimento foi conduzido na Área Demonstrativa e Experimental de Irrigação do Departamento de Engenharia Rural da FCAV/UNESP, Jaboticabal - SP. Utilizou-se do delineamento em blocos ao acaso, com parcelas subdivididas e cinco repetições, constituídas por quatro modalidades de aplicação de fertilizantes (adubação via solo, fertirrigação mensal, fertirrigação bimestral e fertirrigação trimestral) e duas doses de nitrogênio e potássio, correspondendo a 100% (dose 1) e 50% (dose 2) da dose recomendada de nutrientes. A fertirrigação mensal proporcionou peso de cachos, peso de pencas e produtividades superiores à adubação convencional e menor acidez total titulável dos frutos em relação à fertirrigação trimestral; a redução de 50% das doses de N e K não exerceu efeito sobre a produção e qualidade dos frutos. This study was carried out in order to evaluate the effect of fertigations with nitrogen and potassium applied by microsprinkler system on the plantation of Prata-Anã banana (Musa sp AAB), during two growing seasons, under field conditions. The experiment was carried out in the irrigation area of the Department of Agricultural Engineering, FCAV/UNESP - Jaboticabal, São Paulo State, Brazil. It was used a completely randomized block design in split plot with five replications. The treatments studied were composed of four fertilizer application modalities (side dressing fertilization, monthly fertigation, bimonthly fertigation and three monthly fertigation) combined with two rates of nitrogen and potassium, corresponding to 100% (rate 1) and 50% (rate 2) of the recommended rates based on the soil analysis. Monthly fertigation promoted bunch weight and yield higher than side dressing fertilization and lower acidity of the fruits than three monthly fertigation; reducing 50% the doses of N and K did not affect yield and quality of the banana fruit. EMPARN Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Engenharia Rural Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Solos Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Engenharia Rural Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Solos

In order to evaluate mineral concentrations in leaves and fruits of 'Tommy Atkins' mango (Mangifera indica), grown under irrigated conditions, in three different orchards of Rio Grande do Norte State, Brazil, samples were collected at four phenological stages: vegetative growth, pre-flowering, flowering, and fruit ripening, for leaves, and at fruit ripening for fruits. Soil samples were collected at 0-20 and 20-40 cm depths. Chemical analyses showed that there were differences in macro and micronutrient concentrations in leaves among the three orchards studied. For almost all macronutrients, mainly nitrogen and potassium, the levels decreased with the evolution of plant phenological stages. Except for potassium, the highest nutrient levels were registered in plants from Mossoroense zone orchard, while the lowest levels were registered in plants from Oriental Coast orchard. Except for iron, micronutrients concentrations in leaves varied among the orchards and developmental stages. There was a variation in mineral composition of harvested fruits at ripening stage, being potassium and calcium the nutrients at highest concentrations.

We evaluated the extent to which aggressive victims show unique developmental pathways that are different from those of passive victims, bullies, and uninvolved children. A total of 1,722 children were followed from 4th grade to 6th grade, and the prevalence and stability of each group were assessed. Aggressive victims became less prevalent and passive victims and bullies became more prevalent with age. Although it was common for aggressive victims and bullies to move from one group to the other across time, there was little overlap with the passive victim group. Stability estimates were higher for the bully and aggressive victim groups than for the passive victim group, and patterns of stability were influenced by peer rejection and exposure to violence.

Fibrillary glomerulonephritis (FGN) is a pathological diagnosis that is rarely associated with systemic disorders. In this case report, we describe a woman who presented with FGN of the crescentic type in association with hepatitis C viral infection. The existing literature on the association between these 2 disorders is reviewed, and postulated therapy is presented.

The effects of witnessing community violence on aggressive cognitions and behavior were investigated in an ethnically diverse sample of 4,458 children living in urban neighborhoods. Prior violence exposure had a significant effect in increasing aggression, normative beliefs about aggression, and aggressive fantasy. Although exposure to violence predicted aggressive behavior both in Grades 1 through 3 (ages 5–8) and Grades 4 through 6 (ages 9–12), the effects on social cognition were only evident in the later grades. Furthermore, the effect of violence exposure on aggression in the later grades was partially mediated by its effect on social cognition. These findings suggest that witnessing community violence has an effect on children’s aggressive behavior through both imitation of violence and the development of associated cognitions as children get older. One of the most robust findings in the literature on the etiology of aggression is the statistical continuity of aggression from early childhood into adulthood (Huesmann, Eron, Lefkowitz, & Walder, 1984; Olweus, 1979). Several researchers have argued that one of the mediating factors in maintaining this continuity is the pattern of social cognition the child develops supporting aggression. In other words, aggressive behavior is seen as being increasingly controlled by internal self-regulating processes that become more stable over time (Huesmann & Guerra, 1997). Huesmann (1988, 1998) has emphasized the importance of cognitive schemas used as models of the world, cognitive scripts stored in memory and used as guides for social behavior, and normative beliefs used to evaluate the appropriateness of scripts. The more aggressive child is presumed to have acquired cognitive schemas depicting the world as a more hostile place, to endorse normative beliefs that aggression is more acceptable, and to have encoded in memory more extensive, wellconnected networks of social scripts emphasizing aggressive responses.

This article describes the planning, implementation, and evaluation of school-based Wellness Centers operated by the Riverside Unified School District in Riverside, CA, as part of the Safe Schools/Healthy Students Initiative funded by the Substance Abuse and Mental Health Services Administration (SAMHSA). We describe the program as planned in terms of the theoretical model for the intervention and the evaluation design, and discuss the actual implementation including accomplishments and challenges. The program was designed to promote positive development and wellness for individual students via self- and teacher-referrals for personal and mental health problems handled through a case management and referral process, support groups, and other activities such as after-school programs, mentoring, tutoring, and parent training. An effort was also made to promote wellness at the school level by providing wellness campaigns, information, and compatible policies and procedures designed to enhance healthy development. Our observations are based on a qualitative assessment that was a component of the evaluation. A more detailed evaluation examining the impact of school-wide and student-focused activities on academic and behavioral outcomes is currently underway. However, we do include comments from students suggesting that the Wellness Center concept holds much promise for school-based mental health and violence prevention services. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 473–487, 2003.

Bacterially expressed 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (iPGAM) from Leishmania mexicana with a six-His tag fused at its C-terminus was expressed from plasmid pET28a after IPTG induction in Escherichia coli cells and gave a yield of 20 mg of highly purified iPGAM per litre of cell culture. Crystals of the protein complexed with 3-phosphoglycerate were obtained by the hanging-drop method of vapour diffusion with PEG 4000 as the precipitating agent in the presence of cobalt chloride and diffracted synchrotron radiation to beyond 1.90 Angstrom. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 62.46, b = 72.27, c = 129.68 Angstrom. A model of Bacillus stearothermophilus iPGAM (33% identity) was used to provide an initial molecular-replacement solution. X-ray data to 2.05 Angstrom for the structure of L. mexicana iPGAM complexed with 2-phosphoglycerate have also been collected.

Background— Atrial fibrillation (AF) is frequently encountered in patients with heart failure (HF) and is also a predictor of morbidity and mortality in this population. Recent experimental studies have shown electrical and structural atrial remodeling with increased fibrosis in animals with HF and have suggested a preventive effect of ACE inhibitors (ACEi) on the development of AF. To verify the hypothesis that ACEi prevent the development of AF in patients with HF, we conducted a retrospective analysis of the patients from the Montreal Heart Institute (MHI) included in the Studies Of Left Ventricular Dysfunction (SOLVD). Methods and Results— Clinical charts were reviewed and serial ECGs interpreted by a single cardiologist blinded to drug allocation. Patients with AF or flutter on the baseline ECG were excluded. Baseline characteristics were obtained from the SOLVD databases. The mean follow-up was 2.9±1.0 years. Of the 391 patients randomly assigned at MHI, 374 were in sinus rhythm at the time of random assignment, with 186 taking enalapril and 188 taking placebo. Baseline characteristics were similar in the two groups except for a higher incidence of previous myocardial infarction in the enalapril group. Fifty-five patients had AF during the follow-up: 10 (5.4%) in the enalapril group and 45 (24%) in the placebo group ( P P Conclusions— Treatment with the ACEi enalapril markedly reduces the risk of development of atrial fibrillation in patients with left ventricular dysfunction.

Certain pathogenic trypanosomatids are highly dependent on glycolysis for ATP production, and hence their glycolytic enzymes, including glycerol-3-phosphate dehydrogenase (GPDH), are considered attractive drug targets. The ternary complex structure of Leishmania mexicana GPDH (LmGPDH) with dihydroxyacetone phosphate (DHAP) and NAD(+) was determined to 1.9A resolution as a further step towards understanding this enzyme's mode of action. When compared with the apo and binary complex structures, the ternary complex structure shows an 11 degrees hinge-bending motion of the C-terminal domain with respect to the N-terminal domain. In addition, residues in the C-terminal domain involved in catalysis or substrates binding show significant movements and a previously invisible five-residue loop region becomes well ordered and participates in NAD(+) binding. Unexpectedly, DHAP and NAD(+) appear to form a covalent bond, producing an adduct in the active site of LmGPDH. Modeling a ternary complex glycerol 3-phosphate (G3P) and NAD(+) with LmGPDH identified ten active site residues that are highly conserved among all GPDHs. Two lysine residues, Lys125 and Lys210, that are presumed to be critical in catalysis, were mutated resulting in greatly reduced catalytic activity. Comparison with other structurally related enzymes found by the program DALI suggested Lys210 as a key catalytic residue, which is located on a structurally conserved alpha-helix. From the results of site-directed mutagenesis, molecular modeling and comparison with related dehydrogenases, a catalytic mechanism of LmGPDH and a possible evolutionary scenario of this group of dehydrogenases are proposed.

This paper presents a framework for school-based health promotion and prevention programming that can serve to guide planning and action. Rather than separating specific prevention programs (such as violence prevention, substance abuse prevention, etc.) from more broad-based youth development efforts, this approach provides an integrated framework that: (a) identifies benchmarks of healthy development and strategies to support this development across contexts; (b) specifies additional factors that contribute to identified problems that are not directly linked to healthy development; and (c) provides for matching services to individual needs. Suggestions for application of this framework are discussed, with a particular focus on its application to the development of school-based Wellness Centers.

This work develops a mathematical model for the atrioventricular (AV) node in the human heart, based on recordings of electrical activity in the atria (the upper chambers of the heart) and the ventricles (the lower chambers of the heart). Intracardiac recordings of the atrial and ventricular activities were recorded from one patient with atrial flutter and one with atrial fibrillation. During these arrhythmias, not all beats in the atria are conducted to the ventricles. Some are blocked (concealed). However, the blocked beats can affect the properties of the AV node. The activation times of the atrial events were regarded as inputs to a mathematical model of conduction in the AV node, including a representation of AV nodal concealment. The model output was compared to the recorded ventricular response to search for and identify the best possible parameter combinations of the model. Good agreement between the distribution of interbeat intervals in the model and data for durations of 5 min was achieved. A model of AV nodal behavior during atrial flutter and atrial fibrillation could potentially help to understand the relative roles of atrial input activity and intrinsic AV nodal properties in determining the ventricular response.

This study examined the effects of being victimized by peers on children's behavioral, social, emotional, and academic functioning. We assessed an ethnically diverse sample of 2,064 first, second, and fourth graders and followed them over 2 years, locating 1,469 of the participants at the follow-up. Correlation and partial correlation analyses revealed that prior victimization predicted externalizing, internalizing, and social problems 2 years later for the sample as a whole. However, not all victimized children experienced the same types of outcomes; instead, there was heterogeneity in children's responses to victimization. Using cluster analysis, we identified eight outcome patterns that represented different patterns of functioning. These were labeled as externalizing, internalizing, symptomatic, popular, disliked, absent, low achieving, and high achieving. Discriminant function analyses revealed that the symptomatic, externalizing, and disliked patterns were systematically related to victimization. Moreover, significant gender and age differences in the severity of effects were obtained. The discussion highlights the complexity of victimization effects.

Atrial fibrillation (AF) is the most common cardiac arrhythmia, the prevalence of which is increasing with the aging of the population. Because of its clinical importance and the lack of highly satisfactory management approaches, AF is the subject of active clinical and research efforts. This paper reviews recent and on-going developments in pharmacological and non-drug management of AF. The ideal therapeutic goal for AF is the production and maintenance of sinus rhythm. Comparative studies suggest that available class I and III drugs have comparable and modest efficacy for sinus rhythm maintenance. Amiodarone, with actions of all antiarrhythmic classes, has recently been shown to have clearly superior efficacy compared with other available drugs. Newer agents are in development, but their advantages are as yet unclear and appear limited. A potentially interesting approach is the prescription of drugs upon the occurrence of an attack, rather than on a continuous basis. Recent insights into AF mechanisms may permit therapy to prevent development of the AF substrate. An alternative to sinus rhythm maintenance is a rate control approach, with no attempt to prevent AF. Drugs to effect rate control include digitalis, β-blockers and calcium channel antagonists. Digitalis has limited value for control of exercise heart rate and for paroxysmal AF, but is particularly well suited for patients with concomitant AF and congestive heart failure. AV-nodal ablation and pacing is an effective alternative for rate control but leaves the patient pacemaker dependent. The relative merits of rate versus rhythm control are being evaluated in ongoing trials, preliminary results of which indicate no statistically significant differences in primary endpoints but highlight the risks of rhythm control therapy. In patients requiring pacemakers, physiological pacing (dual chamber devices or atrial pacing) has an advantage over purely ventricular pacemakers in AF prevention. Newer pacing modalities that produce more synchronised atrial activation, as well as pacemakers that prevent excessive atrial rate swings, show promise in AF prevention and may soon see wider use. The usefulness of automatic atrial defibrillators is presently limited by discomfort during shocks. Targeted destruction of pulmonary vein foci by radiofrequency catheter ablation suppresses paroxysmal AF. Efficacy in persistent AF is lower and still under study. Problems include potential recurrence in other veins and a small but non-trivial risk of pulmonary vein stenosis. Surgical division of the atria into zones with limited electrical connection, the MAZE procedure, is highly effective in AF prevention but is a major intervention that is not applicable to most patients. In conclusion, significant advances are being made in the management of patients with AF but much more work remains to be done.

Este artículo se enmarca en el estudio de los estándares de la televisión digital en todo el mundo, en comparativa con el estándar empleado adoptado en Ecuador es el japonés con modificaciones hechas en Brasil (ISDB-Tb). Se abordan temas técnicos como la transmisión jerárquica y los modos de difusión para garantizar una cobertura de buena calidad hacia el televidente. Este estándar cuenta con un middleware llamado Ginga, el cual permite implementar nuevos servicios orientados a muchos sectores sociales públicos o privados. El estudio del middleware incorporado (Ginga), permite diseñar, configurar y generar flujos de transporte con contenido audio visual; este middleware podría ser útil para brindar nuevos servicios públicos o privados en la televisión digital.