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Networks of narrow linear (∼3–12 m wide) forest disturbances used for petroleum exploration (seismic lines) are common throughout Alberta’s boreal forest. These ‘seismic’ lines have often failed to recover trees decades after their initial disturbance, especially within treed peatland and jack pine ( Pinus banksiana ) forests. This has led to regional increases in forest fragmentation contributing to declines in threatened woodland caribou. Restoration of seismic lines to forests is now a top priority for conservation and recovery of woodland caribou, but are expensive and often ignore the occurrence of wildfires that may destroy restoration investments (planted trees), yet also recruit trees. This is especially relevant to jack pine forests that burn more frequently than other forests and depend on moderate to high intensity fires to release seeds en masse from their serotinous cones. Although much is known about jack pine tree recruitment following fire, little is known about patterns of tree recovery on seismic lines and how this varies with fire severity, line width (forest gap size), and line orientation. Here we examine natural tree recovery across a gradient in fire severity (defined as percent overstory tree mortality) with different seismic line characteristics (forest gap width and orientation), as compared to adjacent forest stands, in jack pine forests 5-years post-fire in northeast Alberta, Canada. Overall, jack pine regeneration was consistently 2-fold higher on seismic lines compared to adjacent burned forests with stem density increasing with fire severity in both sites, especially when fire severity was greater than 40%. We suggest that the observed increases in tree regeneration on seismic lines may be due to (1) removal of biomass and exposure of mineral soils on seismic lines creating more favorable conditions for jack pine seeds and seedlings; and/or (2) increases in available light resulting in better growing conditions and survival for this shade-intolerant species. Finally, we suggest that natural recovery (passive restoration) of seismic lines should be expected post-fire in jack pine stands and thus active restoration of these sites through silviculture and tree planting may not be the wisest use of limited restoration dollars if fires are locally common. [ABSTRACT FROM AUTHOR]

• Seismic lines were 34% more compacted than adjacent aspen-dominated boreal forests. • Despite compaction, tree regeneration was 19% higher on lines than adjacent forests. • Tree regeneration was 65% higher in burnt versus unburnt lines. • 90% of seismic lines were >5,000 stems/ha demonstrating potential natural recovery. Energy exploration has led to fragmentation of habitats worldwide. In boreal forests of Alberta, Canada narrow clear-cut linear disturbances (3–14 m wide) called seismic lines are often the largest local source of forest fragmentation. Many lines have failed to recover decades after their creation leading to changes in forest dynamics and biodiversity. In some cases, these linear features function as habitat and/or corridors for species, while being detrimental in other species, most notably the threatened woodland caribou (Rangifer tarandus caribou). Recently, industry and government have focused on reforestation of these lines using silvicultural treatments and tree planting. However, these applications are expensive (> $12,500/km) and do not account for wildfires that can destroy restoration investments (planted trees), yet also initiate early seral conditions that favor natural recovery. Here, we examined soil compaction (bulk density) and tree regeneration density in burnt and unburnt seismic lines within mesic upland forest types and compared these to adjacent (paired) forest controls. Bulk density on seismic lines increased by 34% compared to undisturbed adjacent forests, but was not severe enough to impede regeneration. Despite increases in compaction, regeneration density was 19% higher on lines than in adjacent forests. Specifically, regeneration density averaged 19,622 stems/ha in burnt lines, 11,870 stems/ha in unburnt lines, 16,739 stems/ha in adjacent burnt forest, and 6,934 stems/ha in adjacent unburnt forest where regeneration rates are expected to be lower. We suggest that leave-for-natural recovery (passive restoration) of seismic lines can be expected post-fire in mesic upland forests with even the majority of unburnt seismic lines recovering to densities above the 5,000 stems/ha guidelines. Active restoration treatments using intensive silviculture treatments should therefore only be considered where recovery is not observed or wildfire likely. [ABSTRACT FROM AUTHOR]

Background. Thromboembolism after Fontan’s operation is attributed to low flow states, stasis in venous pathways, right to left shunts, blind cul-de-sacs, prosthetic materials, atrial arrhythmias, and hypercoagulable states. We assessed the efficacy of a strategy to reduce thromboembolic events including aspirin anticoagulation.Methods. From January 1996 through December 2000, 72 patients underwent Fontan procedures. Management included (1) avoidance of direct caval cannulation and central venous lines, (2) inotropic support for 48 to 72 hours to optimize cardiac output, (3) aortopulmonary anastomosis or suture closure of patent pulmonary valves, and (4) administration of aspirin (81 mg per day) beginning on postoperative day one. No other anticoagulation strategies were used. Surveillance included intraoperative and postoperative transesophageal echo, transthoracic echo at discharge, at first reevaluation, and at 6 month intervals, and catheterization 1 year after surgery.Results. There were no early or late deaths. Follow-up was completed with 2,882 patient-months and a mean of 40 months. There were no documented thromboembolic events; however, all suspicious occurrences were investigated by echo and brain imaging. There were no hemorrhagic events or aspirin-related complications.Conclusions. Low dose aspirin can be used safely in young patients with Fontan connections. At intermediate follow-up, the strategies described appear effective in preventing thromboembolic complications. Routine use of more aggressive anticoagulation regimens seems unwarranted. [Copyright &y& Elsevier]

• Wider lines had greater light and diurnal temperature/humidity fluctuations. • South-facing and west-facing edges were most affected by abiotic edge effects. • Edge effects extended up to 10 m from the edge into the forest. • Regeneration increased by 5.8 times for each 10-fold increase in light intensity. Ecological impacts of linear anthropogenic disturbances may be underestimated due to edge effects extending into adjacent forests. Seismic lines are the most pervasive linear disturbance associated with oil and gas development in the boreal forests of western North America. The width and orientation of seismic lines may influence microclimatic edge effects that could alter biotic responses, including tree recruitment. We examined light intensity, air temperature, relative humidity, and tree regeneration within seismic lines and adjacent forests to: (1) compare abiotic conditions between wide (6–8 m) and narrow (3–4 m) seismic lines; (2) quantify microclimatic edge effects of seismic lines of different widths and orientations; and (3) relate patterns in tree regeneration density to local patterns in the abiotic environment. We sampled interior forests and 24 seismic lines that were wide or narrow and orientated east-west or north-south in poor mesic ecosites of northeast Alberta, Canada. Microclimatic conditions in seismic line centres were generally intermediate between interior forest and well pads, with narrow seismic lines more similar to interior forest and wide seismic lines more similar to well pads. Light intensity on wide seismic line centres was at least 1.5 times higher than on narrow seismic line centres and up to 3.8 times higher than interior forest. Edge effects on light intensity extended up to 10 m into the forest adjacent to wide lines, but were restricted to the forest edge (at the interface) of narrow lines. Compared to interior forest, day temperature was up to 2.8 °C and 0.8 °C higher at edges of wide and narrow seismic lines, respectively. Relative humidity during the day was up to 7.3% and 3% lower at the edges of wide and narrow seismic lines, respectively, as compared to interior forest. At night, wide seismic line centres were up to 1.7 °C cooler and up to 8.2% more humid than narrow seismic line centres. Tree regeneration was highest where light intensity was highest (the centre of wide north-south seismic lines) and a 10-fold increase in light intensity resulted in 5.8 times more regenerating trees. This study reveals that seismic line width and orientation affect abiotic factors within the linear disturbance and up to 10 m into the adjacent forest. Edge effects on the microclimate of seismic lines were most pronounced in wider seismic lines and along north (south-facing) forest edges. These findings provide a better understanding of the abiotic factors influencing biotic responses to linear anthropogenic disturbances. [ABSTRACT FROM AUTHOR]

Abstract: Background: In Italy, vaccination against hepatitis B virus infection was strongly recommended for healthcare workers since 1985. Update findings on vaccination coverage are lacking. Aim: To assess current vaccination coverage against hepatitis B in this job category. Methods: In 2006, 1632 healthcare workers randomly selected in 15 Italian public hospitals completed a self-administered precoded questionnaire. Results: The overall vaccination coverage was 85.3%, a figure higher than the 64.5% observed in 1996. Vaccine coverage showed a significant downtrend (p <0.01) from the Northern (93.1%) to the Southern (77.7%) areas. Logistic regression analysis showed that residence in the North (Odds ratio 4.2; 95% confidence interval 2.6–6.7) and youngest age (Odds ratio 4.5; 95% confidence interval 2.6–7.8), both were independent predictors of vaccine acceptance. Conclusions: Ten years apart, vaccine coverage has markedly increased, closely paralleling the downtrend in the incidence of acute B hepatitis among healthcare workers in Italy. [Copyright &y& Elsevier]

Aim: To investigate the impact of noise-optimised virtual monoenergetic imaging (VMI+) reconstructions on quantitative and qualitative image parameters in patients with malignant lymphoma at dual-energy computed tomography (DECT) examinations of the abdomen.Materials and Methods: Thirty-five consecutive patients (mean age, 53.8±18.6 years; range, 21-82 years) with histologically proven malignant lymphoma of the abdomen were included retrospectively. Images were post-processed with standard linear blending (M_0.6), traditional VMI, and VMI+ technique at energy levels ranging from 40 to 100 keV in 10 keV increments. Signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were objectively measured in lymphoma lesions. Image quality, lesion delineation, and image noise were rated subjectively by three blinded observers using five-point Likert scales.Results: Quantitative image quality parameters peaked at 40-keV VMI+ (SNR, 15.77±7.74; CNR, 18.27±8.04) with significant differences compared to standard linearly blended M_0.6 (SNR, 7.96±3.26; CNR, 13.55±3.47) and all traditional VMI series (p<0.001). Qualitative image quality assessment revealed significantly superior ratings for image quality at 60-keV VMI+ (median, 5) in comparison with all other image series (p<0.001). Assessment of lesion delineation showed the highest rating scores for 40-keV VMI+ series (median, 5), while lowest subjective image noise was found for 100-keV VMI+ reconstructions (median, 5).Conclusion: Low-keV VMI+ reconstructions led to improved image quality and lesion delineation of malignant lymphoma lesions compared to standard image reconstruction and traditional VMI at abdominal DECT examinations. [ABSTRACT FROM AUTHOR]