Peatland-fire interactions: A review of wildland fire feedbacks and interactions in Canadian boreal peatlands.

Boreal peatlands store a disproportionately large quantity of soil carbon (C) and play a critical role within the global C-climate system; however, with climatic warming, these C stores are at risk. Increased wildfire frequency and severity are expected to increase C loss from boreal peatlands, contributing to a shift from C sink to source. Here, we provide a comprehensive review of pre- and post-fire hydrological and ecological interactions that affect the likelihood of peatland burning, address the connections between peatland fires and the C-climate cycle, and provide a conceptual model of peatland processes as they relate to wildland fire, hydro-climate, and ecosystem change. Despite negative ecohydrological feedback mechanisms that may compensate for increased C loss initially, the cumulative effects of climatic warming, anthropogenic peatland fragmentation, and subsequent peatland drying will increase C loss to the atmosphere, driving a positive C feedback cycle. However, the extent to which negative and positive feedbacks will compensate for one another and the timelines for each remains unclear. We suggest that a multi-disciplinary approach of combining process knowledge with remotely sensed data and ecohydrological and wildland fire models is essential for better understanding the role of boreal peatlands and wildland fire in the global climate system.

Severe wildfire exposes remnant peat carbon stocks to increased post-fire drying.

The potential of high severity wildfires to increase global terrestrial carbon emissions and exacerbate future climatic warming is of international concern. Nowhere is this more prevalent than within high latitude regions where peatlands have, over millennia, accumulated legacy carbon stocks comparable to all human CO2 emissions since the beginning of the industrial revolution. Drying increases rates of peat decomposition and associated atmospheric and aquatic carbon emissions. The degree to which severe wildfires enhance drying under future climates and induce instability in peatland ecological communities and carbon stocks is unknown. Here we show that high burn severities increased post-fire evapotranspiration by 410% within a feather moss peatland by burning through the protective capping layer that restricts evaporative drying in response to low severity burns. High burn severities projected under future climates will therefore leave peatlands that dominate dry sub-humid regions across the boreal, on the edge of their climatic envelopes, more vulnerable to intense post-fire drying, inducing high rates of carbon loss to the atmosphere that amplify the direct combustion emissions.

Effects of dietary menhaden oil on growth and reproduction in gilts farrowed by sows that consumed diets containing menhaden oil during gestation and lactation.

In sows, n-3 fatty acids increase litter sizes, however, effects on gilt reproductive development have not been adequately studied. Moreover, not determined are effects of feeding n-3 fatty acids to sows on reproduction in offspring. The objective here was to determine effects of 4% dietary menhaden oil on growth and puberty in gilts farrowed by sows fed menhaden oil. Sows (n = 44) were assigned to: (1) control gestation and lactation diets, or (2) diets including menhaden oil. For primiparous sows only, total litter size and born alive were greater (P < 0.05) in females fed menhaden oil. Conversely, pigs from primiparous controls were heavier (P < 0.05) than pigs from primiparous sows fed menhaden oil (parity by diet interactions, P < 0.01). Diet did not affect (P > 0.20) other sow and litter characteristics. At weaning, 84 gilts from control- or menhaden oil sows were placed three gilts per pen and provided control diets or diets containing menhaden oil. Nursery and grow-finish feed intake and feed efficiency were similar (P > 0.21) for gilts from the different sows and weight gain was similar (P > 0.24) for gilts fed control or menhaden diets. Gilts fed menhaden oil tended to eat less in the nursery (1.18±0.08 kg v. 0.98±0.08 kg; P = 0.09) and overall (1.83±0.04 kg v. 1.72±0.04 kg; P = 0.06). Thus, overall feed to gain was greater (2.52±0.03 v. 2.33±0.03; P < 0.01) and nursery (2.12±0.04 v. 1.80±0.04; P = 0.10) and grow-finish (3.07±0.19 v. 2.58±0.19; P = 0.08) feed to gain tended to be greater, for control gilts. Age at puberty was greater (P = 0.02) for gilts from menhaden oil-fed sows (205.1±3.2 days) compared to gilts from controls (193.9±3.2 days) and tended to be greater (P = 0.09), for controls (203.5±3.2 days) compared to gilts fed menhaden oil (195.5±3.2 days). A tendency existed (P = 0.09) for greater follicular fluid in gilts fed menhaden oil, however, ovulation rate and ovarian, luteal and uterine weights were not affected by sow diet, gilt diet or the interaction (P > 0.23). Feeding gilts menhaden oil enhanced feed efficiency and hastened puberty onset. Gilts from sows consuming menhaden oil exhibited delayed puberty and retaining females from sows fed this feedstuff may be ill advised.

Monitoring ecosystem reclamation recovery using optical remote sensing: Comparison with field measurements and eddy covariance.

Time series remote sensing vegetation indices derived from SPOT 5 data are compared with vegetation structure and eddy covariance flux data at 15 dry to wet reclamation and reference sites within the Oil Sands region of Alberta, Canada. This comprehensive analysis examines the linkages between indicators of ecosystem function and change trajectories observed both at the plot level and within pixels. Using SPOT imagery, we find that higher spatial resolution datasets (e.g. 10 m) improves the relationship between vegetation indices and structural measurements compared with interpolated (lower resolution) pixels. The simple ratio (SR) vegetation index performs best when compared with stem density-based indicators (R2 = 0.65; p < 0.00), while the normalised difference vegetation index (NDVI) and soil adjusted vegetation index (SAVI) are most comparable to foliage indicators (leaf area index (LAI) and canopy cover (R2 = 0.52-0.78; p > 0.02). Fluxes (net ecosystem production (NEP) and gross ecosystem production (GEP)) are most related to NDVI and SAVI when these are interpolated to larger 20 m × 20 m pixels (R2 = 0.44-0.50; p < 0.00). As expected, decreased sensitivity of NDVI is problematic for sites with LAI > 3 m2 m-2, making this index more appropriate for newly regenerating reclamation areas. For sites with LAI < 3 m2 m-2, trajectories of vegetation change can be mapped over time and are within 2.7% and 3.3% of annual measured LAI changes observed at most sites. This study demonstrates the utility of remote sensing in combination with field and eddy covariance data for monitoring and scaling of reclaimed and reference site productivity within and beyond the Oil Sands Region of western Canada.

A painless treatment for patients undergoing Milligan-Morgan haemorrhoidectomy.

BACKGROUND: Postoperative pain associated with Milligan Morgan haemorrhoidectomy (MMH) remains problematic. Most patients complaint a severe pain on defecation and in the 1st postoperative week because of secondary infection and sphincter spasm. We studied the effect of metronidazole, lactulose and glyceryl-trinitrate on pain after MMH. METHOD: Thirty patients were randomly assigned to two groups. The 1st received a treatment with oral laxative (lactulose 66.7%) metronidazole and a topical glyceryl-trinitrate ointment at 0.2% both pre and postoperative; the 2nd received a placebo at the same dosage. The amount of pain in the 1st week and at the time of two defecation, postoperative analgesic requirement and time to return to normal activities were documented. RESULTS: A significant differences in the score pain on 2nd and 3rd day and on the 1st two defecation were observed among group. Analgesic consumption was highest in the placebo group. CONCLUSION: The treatment with lactulose, metronidazole and topic glyceryl-trinitrate in patients undergoing MMH, seems to reduce secondary pain and increase patients satisfaction and earlier return to work with improvement of cost and benefit.

[Milligan-Morgan haemorrhoidectomy with ultrasonic scalpel]. / L'emorroidectomia secondo Milligan-Morgan con bisturi ad ultrasuoni.

INTRODUCTION: Milligan-Morgan haemorrhoidectomy is considered the best treatment for hemorrhoidal disease. Although this, many patients complaint post-operative pain that remain the worse complication. For this reason different are the trials performed in order to reduce his intensity. In this report we want to evaluate if the use of ultrasonic scalpel to perform Milligan-Morgan hemorrhoidectomy, compared with conventional surgery, could reduce post-operative pain. MATERIALS AND METHODS: 30 patients with III and IV degree of haemorrhoids were included in this study and divided in two groups. In the first group Milligan-Morgan haemorrhoidectomy was performed with conventional instruments, while in the second group the some procedure was performed with ultrasonic scalpel. The duration of intervention, time hospitalization, the time to open alvus to stools, the time to return to normal activity, the complications, pain and the amount of analgesic consumption were evaluated. RESULTS: In the II group's patients, it was observed a reduced time to healing with reduced spread of necrosis and inflammatory pattern, associated with reduced post-operative pain and the lower analgesic consumption. CONCLUSIONS: The use of ultrasonic scalpel to perform Milligan-Morgan haemorrhoidectomy, compared with conventional instruments, reduce post-operative pain making a more short time to healing and a precocious time to return to normal activity. For this reason we believe that the use of ultrasonic scalpel, although a more elevated costs, seems to be advantageous.

[Bacterial endocarditis. Unusual complications of acute diverticulitis]. / L'endocardite batterica. Complicanza rara della diverticolite acuta.

BACKGROUND: Colon diverticular disease represents an affection with high prevalence in the western countries. It appears particularly insidious in the elderly population for the presence of concomitant illnesses. CLINICAL CASE: A patient (> 80 years old) is submitted to surgical intervention in emergency sec. Hartman for acute diverticulitis and pelvic abscess. The post-operating time has been complicated for the arising of a fever resistant to the common antibiotic therapy, in absence of abdominal and respiratory objectivity. An accurate clinical examination has set the suspect of bacterial endocarditis, confirmed to the echocardiographic examination. DISCUSSION: The acute complicated diverticulitis therapy variates in according to the clinical presentation, the complications and the experience of the different Authors. A first conservative approach foresees the Total Parenteral Nutrition (TPN) and the wide spectrum antibiotic therapy and the eventual percutaneous drainage. The surgical treatment, realized with "open" or laparoscopic method, foresees the resection of the sick intestinal tract and the packing of a temporary preternatural anus. However, some Authors prefer an intestinal anastomosis performed in single time with the resection. Among all the complications, the most frequent are those affecting the respiratory and cardiovascular apparatus, as well as the sepsis. The bacterial endocarditis is not signalled in most recent international Literature. CONCLUSION: The bacterial endocarditis must be suspected in case of common antibiotic therapy resistant fever, with negative abdominal and pulmonary objectivity, arising after a septic surgical intervention.

Coexistence of mitral valve prolapse in a consecutive group of 528 patients with hypertrophic cardiomyopathy assessed with echocardiography.

Hypertrophic cardiomyopathy and mitral valve prolapse are both conditions that may be genetically transmitted and incur a risk for sudden cardiac death. Although the small left ventricular cavity and distorted geometry characteristic of hypertrophic cardiomyopathy might suggest a predisposition to mitral valve prolapse, the frequency with which these two entities coexist and the potential clinical significance of such an association are not known. To further define the relation of hypertrophic cardiomyopathy and mitral valve prolapse, 528 consecutive patients with hypertrophic cardiomyopathy were studied by echocardiography. Patients ranged in age from 1 to 86 years (mean 45); 335 (63%) were male. Unequivocal echocardiographic evidence of systolic mitral valve prolapse into the left atrium was identified in only 16 (3%) of the 528 patients. The mitral valve excised at operation from three of the patients had morphologic characteristics of a floppy mitral valve, which was judged to be responsible for the echocardiographic findings. Occurrence of clinically evident atrial fibrillation was common in patients with hypertrophic cardiomyopathy and mitral valve prolapse (9 [56%] of 16). Hence, in a large group of patients with hypertrophic cardiomyopathy, the association of echocardiographically documented mitral valve prolapse was uncommon. The coexistence of mitral valve prolapse in patients with hypertrophic cardiomyopathy appears to predispose such patients to atrial fibrillation.

A pseudo-outbreak of Methylobacterium mesophilica isolated from patients undergoing bronchoscopy.

An unusual, slow growing, pink-pigmented gram-negative bacillus was isolated from bronchoscopy specimens of seven patients over a three-month period. The organism was identified as Methylobacter mesophilica. None of the patients were believed to be infected with Methylobacter mesophilica. The results of environmental cultures showed that the organism was present in tap water from the bronchoscopy room.

Utility of continuous wave Doppler echocardiography in the noninvasive assessment of left ventricular outflow tract pressure gradient in patients with hypertrophic cardiomyopathy.

Subaortic obstruction is an important determinant of the clinical presentation of and therapeutic approach to patients with hypertrophic cardiomyopathy. Therefore, assessment of the presence and magnitude of the intraventricular pressure gradient is paramount in the clinical evaluation of these patients. To establish the utility of continuous wave Doppler echocardiography in assessing the pressure gradient in hypertrophic cardiomyopathy, 28 patients representing the wide hemodynamic spectrum of this disease underwent simultaneous determination of the subaortic gradient by continuous wave Doppler ultrasound and cardiac catheterization. With use of the modified Bernoulli equation, the Doppler-estimated gradient showed a strong correlation with the maximal instantaneous pressure difference measured at catheterization, both under basal conditions (r = 0.93; p less than 0.0001) and during provocative maneuvers (r = 0.89; p less than 0.0001). In 26 of the 28 patients, all assessments of the subaortic gradient were in agreement within 15 mm Hg (average difference 5 +/- 3 mm Hg). In the other two patients there were substantial differences between these measurements (under basal conditions in one patient and after provocation in another), although the Doppler technique predicted the presence of marked subaortic obstruction in each. In both patients the erroneous interpretation was due to superimposition of the mitral regurgitation signal on that of left ventricular outflow. Doppler waveforms from the left ventricular outflow tract showed variability in contour among different patients and in individual patients. Hence, continuous wave Doppler echocardiography is a useful noninvasive method for estimating the subaortic gradient in patients with hypertrophic cardiomyopathy. However, technical factors such as contamination of the outflow tract jet with that of mitral regurgitation and variability in waveform configuration may importantly influence such assessments of the subaortic gradient.

A clinical trial of intracavernous vasoactive intestinal peptide to induce penile erection.

A double-blind, placebo-controlled clinical trial of the intracavernous injection of vasoactive intestinal peptide was conducted and studied in 24 men with erectile dysfunction of diabetic, neurogenic and psychogenic etiology. The patients were randomized into 6 groups of 4 subjects each and received either placebo, or 200 or 400 pmol. vasoactive intestinal peptide at each of 3 consecutive weekly visits. An increase in penile length was associated significantly with treatment (F equals 5.10, p equals 0.01), dose-related, and independent of the time and sequence of treatment. An increase in penile diameter was associated significantly with treatment (F equals 8.14, p equals 0.001) and time (F equals 8.14, p equals 0.001), dose-related and independent of the sequence of treatment. Penile rigidity was associated significantly with time (F equals 5.44, p equals 0.008), associated nearly significantly with treatment (F equals 3.11, p equals 0.056) and independent of sequence of treatment. Despite some measurable treatment-related increase none of the patients achieved penile rigidity adequate for intromission.

A review of the non-neoplastic kidney effects of hydrocarbon exposure in humans.

This review has demonstrated that there is a considerable amount of information in the medical literature concerning hydrocarbon-associated kidney effects. The existing data lends itself to a variety of divergent interpretations. Ravnskov has stated that "glomerulonephritis should be recognized legally as an occupational disease," yet there is no mention of hydrocarbon exposure in the differential diagnosis of glomerulonephritis in two standard American textbooks of internal medicine. Two recently published textbooks of occupational medicine state without reservation that "studies have linked hydrocarbon exposure to glomerulonephritis" and base this conclusion on the previously cited studies of Beirne and Brennan, Zimmerman, and Ravnskov. Based on this review, the following conclusions have been reasonably substantiated: 1. Massive exposure to petroleum distillates on rare occasions may cause acute renal failure due to tubular necrosis. This appears to be a reversible lesion which, depending on the level of exposure, the medical care and support available, and pre-existing renal function, may be without chronic sequelae. 2. Case reports linking Goodpasture's syndrome and other types of glomerulonephritis to hydrocarbon exposure are based on circumstantial evidence and cannot be used to establish a causal association. 3. The evidence from the eight case-control studies of hydrocarbon exposure and glomerulonephritis is inconclusive. Six of the eight published case-control studies show a positive association between hydrocarbon exposure and glomerulonephritis, but four of the six studies have methodologic flaws that could explain the observed effect. The findings in the one positive study that is methodologically acceptable were not replicated in a subsequent study utilizing a similar design. 4. Studies of hydrocarbon-exposed occupational cohorts have generally revealed a lower than expected risk of death from renal causes. As with most historical cohorts, the specific exposures, intensities and durations of exposure have been poorly defined. Effects of mortality that may occur among highly exposed subsets of these occupational cohorts may be diluted by a relatively large proportion of workers with minimal or no exposure to the class of hydrocarbons in question. 5. Studies of renal biochemistry and renal function effects have been uniformly negative in groups of workers from several industries with relatively high exposures of long duration to a variety of hydrocarbon solvents. The statistically significant differences in proteinuria and cell excretion observed in one of the studies should not be confused with clinical significance.(ABSTRACT TRUNCATED AT 400 WORDS)

Occupational hydrocarbon exposure and renal histopathology.

A blinded, retrospective study of histological sections from ten hydrocarbon-exposed and twenty unexposed nephrectomized renal cell carcinoma cases was conducted to evaluate the histopathologic features present in the apparently normal kidney parenchyma removed with the tumor. Tissue sections from each of the thirty cases were independently reviewed by three consulting pathologists and scored using well defined criteria. Occupational hydrocarbon exposure indices were developed by a team of industrial hygienists and applied to the detailed occupational history of each exposed case. A positive correlation was observed between age and the total renal pathology score (rs = .40, p less than .03). No correlation was found between indices of occupational hydrocarbon exposure and renal pathology scores among exposed cases. No significant differences in renal pathology scores were noted when exposed cases were matched to unexposed cases by age, sex, and race. These results are limited by the inclusion of only cases with historical hydrocarbon exposures. It is recommended that a follow-up study be conducted, utilizing sensitive quantitative methods, to define what, if any, cytopathologic renal effects occur in conjunction with current occupational exposures to hydrocarbons.