Recovery of Smelter-Impacted Peat and Sphagnum Moss: a Microbial Perspective.

Peatlands store approximately one-half of terrestrial soil carbon and one-tenth of non-glacial freshwater. Some of these important ecosystems are located near heavy metal emitting smelters. To improve the understanding of smelter impacts and potential recovery after initial pollution controls in the 1970s (roughly 50 years of potential recovery), we sampled peatlands along a distance gradient of 134 km from a smelter in Sudbury, Ontario, Canada, an area with over a century of nickel (Ni) and copper (Cu) mining activity.

Suppressing peatland methane production by electron snorkeling through pyrogenic carbon in controlled laboratory incubations.

Northern peatlands are experiencing more frequent and severe fire events as a result of changing climate conditions. Recent studies show that such a fire-regime change imposes a direct climate-warming impact by emitting large amounts of carbon into the atmosphere. However, the fires also convert parts of the burnt biomass into pyrogenic carbon.

Peatland Microbial Community Composition Is Driven by a Natural Climate Gradient.

Peatlands are important players in climate change-biosphere feedbacks via long-term net carbon (C) accumulation in soil organic matter and as potential net C sources including the potent greenhouse gas methane (CH). Interactions of climate, site-hydrology, plant community, and groundwater chemical factors influence peatland development and functioning, including C dioxide (CO) and CH fluxes, but the role of microbial community composition is not well understood. To assess microbial functional and taxonomic dissimilarities, we used high throughput sequencing of the small subunit ribosomal DNA (SSU rDNA) to determine bacterial and archaeal community composition in soils from twenty North American peatlands.

Right and left ventricular interaction in pulmonary hypertension: Insight from velocity vector imaging.

Objective: To evaluate whether global peak systolic strain (PSS) and peak systolic strain rate (PSSR) derived from velocity vector imaging (VVI) allow early recognition of regional and global right ventricular (RV) dysfunction and the impact of this on left ventricular (LV) function in patients with pulmonary hypertension (PHT).

Background: RV function is an important determinant of prognosis in patients with heart failure, pulmonary hypertension, heart transplant, and congenital heart diseases. However, evaluation of the right ventricle is often limited by its complex geometry and inadequate visualization of RV free wall.

Nanotechnology and Health.

: Potential adverse health effects associated with exposure to engineered or synthesized nanomaterials have not been reported in humans; however, there is accumulating evidence from animal studies that exposure to some nanomaterials is harmful. While there is uncertainty as to the likelihood, frequency, and intensity of exposures experienced by those working around engineered nanoparticles, the American College of Occupational and Environmental Medicine has developed this guidance document for occupational medicine physicians and their colleagues to offer prudent preventive recommendations on the topics of exposure monitoring, exposure controls, and medical surveillance.

Impact of Left Atrial Appendage Closure During Cardiac Surgery on the Occurrence of Early Postoperative Atrial Fibrillation, Stroke, and Mortality: A Propensity Score-Matched Analysis of 10 633 Patients.

Background: Prophylactic exclusion of the left atrial appendage (LAA) is often performed during cardiac surgery ostensibly to reduce the risk of stroke. However, the clinical impact of LAA closure in humans remains inconclusive.

Methods: Of 10 633 adults who underwent coronary artery bypass grafting and valve surgery between January 2000 and December 2005, 9792 patients with complete baseline characteristics, surgery procedure, and follow-up data were included in this analysis.

Real-time physiologic biomarker for prediction of atrial fibrillation recurrence, stroke, and mortality after electrical cardioversion: A prospective observational study.

Background: Left atrial appendage emptying flow velocity (LAAEV) depends largely on left atrioventricular compliance and may play a role in mediating the perpetuation of atrial fibrillation (AF) and AF-related outcomes.

Methods: We identified 3,251 consecutive patients with sustained AF undergoing first-time successful transesophageal echocardiography (TEE)-guided electrical cardioversion who were enrolled in a prospective registry between May 2000 and March 2012. Left atrial appendage emptying flow velocity was stratified into quartiles: ≤20.

Implications of new-onset atrial fibrillation after cardiac surgery on long-term prognosis: a community-based study.

Background: Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery. Data are lacking on the long-term prognostic implications of POAF. We hypothesized that POAF, which reflects underlying cardiovascular pathophysiologic substrate, is a predictive marker of late AF and long-term mortality.

The mind and liver test: a new approach to the diagnosis of minimal hepatic encephalopathy in resource-poor settings.

Background and Aims. Minimal hepatic encephalopathy (MHE) is diagnosed using neuropsychometric tests or neurophysiological tests that are either inapplicable to illiterate patient population in resource-poor settings or require sophisticated and expensive equipment. The available tests assess discrete domains of mental impairment.

Left atrial anatomy and physiology: echo/Doppler assessment.

Purpose Of Review: This article provides a state-of-the-art perspective of left atrial anatomy and physiology.

Recent Findings: Left atrial structure and function can be used to reflect and quantify the physiologic state of complex disease processes. No single left atrial anatomic, functional, or clinical feature will adequately define a complex system.

Ia diastolic dysfunction: an echocardiographic grade.

Objective: To demonstrate that a distinct group of patients with Grade Ia diastolic dysfunction who do not conform to present ASE/ESE diastolic grading exists.

Method And Results: Echocardiographic and demographic data of the Grade Ia diastolic dysfunction were extracted and compared with that of Grades I and II in 515 patients. The mean of age of the cohort was 75 ± 9 years and body mass index did not differ significantly between the 3 groups (P = 0.

Cardiac evaluation of collegiate student athletes: a medical and legal perspective.

Physicians participate in the screening, routine medical supervision, and disqualification process of collegiate student athletes today. Physicians and universities evaluating collegiate student athletes for athletic participation should understand the meticulous medical process necessary to make eligibility/disqualification decisions and the associated liability issues. It is the responsibility of a team physician to take the lead role in the college sports medical evaluation process.

The ABCs of left ventricular assist device echocardiography: a systematic approach.

Echocardiography is an important imaging modality used to determine the indication of left ventricular assist device (LVAD) implantation for patients with advanced heart failure (HF) and for serial follow-up to make management decisions in patient care post-implant. Continuous axial-flow LVAD therapy provides effective haemodynamic support for the failing left ventricle, improving both the clinical functional status and quality of life. Echocardiographers must develop a systematic approach to echocardiographic assessment of LVAD implantation and post-LVAD implant cardiac morphology and physiology.

March Madness 2011: for whom the bell tolls?

The American Heart Association has developed 12 recommendations for preparticipation screening of high school and college athletes, but the application of these recommendations across the US is inconsistent. A recent clinical study suggests that the incidence and prevalence of sudden athletic death (SAD) is greater than previously believed. Currently, diagnostic screening is considered too expensive and is delivered sporadically.

Left ventricular noncompaction: a 25-year odyssey.

Left ventricular noncompaction (LVNC) is a cardiomyopathy associated with sporadic or familial disease, the latter having an autosomal dominant mode of transmission. The clinical features associated with LVNC vary from asymptomatic to symptomatic patients, with the potential for heart failure, supraventricular and ventricular arrhythmias, thromboembolic events, and sudden cardiac death. Echocardiography is the diagnostic modality of choice, revealing the pathognomonic features of a thick, bilayered myocardium; prominent ventricular trabeculations; and deep intertrabecular recesses.