99 research outputs found
Comparing composition and structure in old-growth and harvested (selection and diameter-limit cuts) northern hardwood stands in Quebec
Single-tree selection cutting is sometimes believed to be similar to the natural gap disturbance regime of hardwood forests, but few studies have specifically compared the compositional and structural characteristics of old-growth hardwood stands, undergoing natural gap dynamics and hardwood stands previously subjected to partial cuts. This study characterized and compared the composition (saplings and trees) and structure (gaps, foliage distribution, tree diameter and density, snags and coarse woody debris) of old-growth stands (OG), 12-year-old selection cuts (SC), and 28-33-year-old diameter-limit cuts (DLC) in sugar maple (Acer saccharum)-dominated northern hardwood stands. Results showed marked structural differences between OG and harvested stands, with stronger differences between DLC and OG than between SC and OG. The synchronized formation of numerous canopy openings in harvested stands induced a massive post-harvest recruitment of advance regeneration in both SC and DLC that created a dense foliage layer in the understory. Large living trees (dbh > 39.1 cm) and defective trees were less numerous in SC than OG, which can have a detrimental impact on species dependent on these structural elements, and on the future availability and characteristics of coarse woody debris. Relatively few compositional differences were noticed among stand types, although a greater proportion of mid-tolerant species was found in the post-harvest recruitment cohorts of harvested stands compared to OG, and a lower proportion of beech (Fagus grandifolia Ehrh.) saplings was observed in DLC compared to OG and SC. We argue that even if selection cutting is closer to the natural disturbance regime of hardwood forests than diameter-limit cutting, and therefore representing progress toward the development and implementation of a natural-disturbance-based management, a recurring application of selection cutting might lead to a homogenization of forest structure and composition, a reduction of key structural features and a reduction in biological diversity at both the stand and landscape scales. Some management recommendations are proposed
Agenda control in EU referendum campaigns : the power of the anti-EU side
European Union (EU) referendums provide unique opportunities to study voters’ attitudes toward a distant level of governance. Scholars have long tried to understand whether EU referendum results reflect domestic (dis-)satisfaction with the incumbent governments or actual attitudes toward the Union. Finding evidence supporting both domestic and European factors, the recent focus has thus turned to referendum campaigns. Recent studies emphasise the importance of the information provided to voters during these campaigns in order to analyse how domestic or European issues become salient in the minds of voters. These studies nonetheless overlook the asymmetrical political advantage in such campaigns. The broader literature on referendums and public opinion suggest that in a referendum, the ‘No’ side typically has the advantage since it can boost the public's fears by linking the proposal to unpopular issues. This article explores whether this dynamic applies to EU treaty ratification referendums. Does the anti-EU treaty campaign have more advantage than the pro-EU treaty campaign in these referendums? Campaign strategies in 11 EU treaty ratification referendums are analysed, providing a clear juxtaposition between pro-treaty (‘Yes’) and anti-treaty (‘No’) campaigns. Based on 140 interviews with campaigners in 11 referendums, a series of indicators on political setting and campaign characteristics, as well as an in-depth case study of the 2012 Irish Fiscal Compact referendum, it is found that the anti-treaty side indeed holds the advantage if it engages the debate. Nonetheless, the findings also show that this advantage is not unconditional. The underlying mechanism rests on the multidimensionality of the issue. The extent to which the referendum debate includes a large variety of ‘No’ campaign arguments correlates strongly with the campaigners’ perceived advantage/disadvantage, and the referendum results. When the ‘No’ side's arguments are limited (either through a single-issue treaty or guarantees from the EU), this provides the ‘Yes’ side with a ‘cleaner’ agenda with which to work. Importantly, the detailed data demonstrate that the availability of arguments is important for the ‘Yes’ side as well. They tend to have the most advantage when they can tap into the economic costs of an anti-EU vote. This analysis has implications for other kinds of EU referendums such as Brexit, non-EU referendums such as independence referendums, and the future of European integration
Intensified dose of cyclophosphamide with G-CSF support versus standard dose combined with platinum in first-line treatment of advanced ovarian cancer a randomised study from the GINECO group
ICON3 trial results have suggested that CAP and carboplatin–taxol regimens as first-line treatment of advanced ovarian cancer (AOC) yield similar survival. We explored the impact of increased dose of cyclophosphamide in a modified CAP regimen on the disease-free survival (DFS) and overall survival (OS) of AOC patients. From February 1994 to June 1997, 164 patients were randomised to receive six cycles every 3 weeks of either standard CEP (S) combining cyclophosphamide (C), 500 mg m−2, epirubicin (E) 50 mg m−2, and cisplatin (P) 75 mg m−2 or intensive CEP (I) with E and P at the same doses, but with (C) 1800 mg m−2 and filgrastim 5 μg kg−1 per day × 10 days. Response was evaluated at second-look surgery. Patient characteristics were well balanced. Except for grade 3–4 neutropaenia (S: 54%, I: 38% of cycles), Arm1 presented a significantly more important toxicity: infection requiring antibiotics, grade 3–4 thrombocytopaenia, anaemia, nausea-vomiting, diarrhoea, mucositis. Median follow-up was 84 months. DFS (15.9 vs 14.8 months) and OS (33 vs 30 months) were not significantly different between S and I (P>0.05). Increasing cyclophosphamide dose by more than 3 times with filgrastim support in the modified CAP regimen CEP induces more toxicity but not better efficacy in AOC
Heparin versus 0.9% sodium chloride intermittent flushing for prevention of occlusion in central venous catheters in adults
Background
Heparin intermittent flushing is a standard practice in the maintenance of patency in central venous catheters. However, we could find no systematic review examining its effectiveness and safety.
Objectives
To assess the effectiveness of intermittent flushing with heparin versus 0.9% sodium chloride (normal saline) solution in adults with central venous catheters in terms of prevention of occlusion and overall benefits versus harms.
Search methods
The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched December 2013) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 11). Searches were also carried out in MEDLINE, EMBASE, CINAHL and clinical trials databases (December 2013).
Selection criteria
Randomised controlled trials (RCTs) in adults 18 years of age and older with a central venous catheter (CVC) in which intermittent flushing with heparin (any dose with or without other drugs) was compared with 0.9% normal saline were included. No restriction on language was applied.
Data collection and analysis
Two review authors independently selected trials, assessed trial quality and extracted data. Trial authors were contacted to retrieve additional information, when necessary.
Main results
Six eligible studies with a total of 1433 participants were included. The heparin concentrations used in these studies were very different (10-5000 IU/mL), and follow-up varied from 20 days to 180 days. The overall risk of bias in the studies was low. The quality of the evidence ranged from very low to moderate for the main outcomes (occlusion of CVC, duration of catheter patency, CVC-related sepsis, mortality and haemorrhage at any site).
Combined findings from three trials in which the unit of analysis was the catheter suggest that heparin was associated with reduced CVC occlusion rates (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.29 to 0.94). However, no clear evidence of a similar effect was found when the results of two studies in which the unit of analysis was the participant were combined (RR 0.21, 95% CI 0.03 to 1.70), nor when findings were derived from one study, which considered total line accesses (RR 1.08, 95% CI 0.84 to 1.40). Furthermore, results for other estimated effects were found to be imprecise and compatible with benefit and harm: catheter duration in days (mean difference (MD) 0.41, 95% CI -1.29 to 2.12), CVC-related thrombosis (RR 1.22, 95% CI 0.74 to 1.99), CVC-related sepsis (RR 1.02, 95% CI 0.34 to 3.03), mortality (RR 0.77, 95% CI 0.45 to 1.32) and haemorrhage at any site (RR 1.37, 95% CI 0.49 to 3.85).
Authors' conclusions
We found no conclusive evidence of important differences when heparin intermittent flushing was compared with 0.9% normal saline flushing for central venous catheter maintenance in terms of efficacy or safety. As heparin is more expensive than normal saline, our findings challenge its continued use in CVC flushing outside the context of clinical trials
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
The Botryosphaeriaceae: genera and species known from culture
In this paper we give an account of the genera and species in the Botryosphaeriaceae. We consider morphological characters alone as inadequate to define genera or identify species, given the confusion it has repeatedly introduced in the past, their variation during development, and inevitable overlap as representation grows. Thus it seems likely that all of the older taxa linked to the Botryosphaeriaceae, and for which cultures or DNA sequence data are not available, cannot be linked to the species in this family that are known from culture. Such older taxa will have to be disregarded for future use unless they are epitypified. We therefore focus this paper on the 17 genera that can now be recognised phylogenetically, which concentrates on the species that are presently known from culture. Included is a historical overview of the family, the morphological features that define the genera and species and detailed descriptions of the 17 genera and 110 species. Keys to the genera and species are also provided. Phylogenetic relationships of the genera are given in a multi-locus tree based on combined SSU, ITS, LSU, EF1-α and β-tubulin sequences. The morphological descriptions are supplemented by phylogenetic trees (ITS alone or ITS + EF1-α) for the species in each genus.We would like to thank the curators of the numerous fungaria and Biological Resource Centres cited in this paper, for making specimens and cultures available for examination over the past 15 yr, without which this study would not have been possible. Part of this work was supported by Fundação para a Ciência e a Tecnologia (Portugal) through grant PEst-OE/BIA/UI0457/2011. Artur Alves and Alan Phillips were supported by the programme Ciência 2008, co-funded by the Human Potential Operational Programme (National Strategic Reference Framework 2007–2013) and the European Social Fund (EU).publishe
A Cognitive Investigation of the Internal Validity of a Management Strategy Simulation Game
This study investigates the internal validity of a management simulation game from a cognitive perspective. The results indicate that game participants were unable to determine (i.e., cognitive insight) the nature of the response functions for the demand-generating variables of the game. The internal validity of such a pedagogical tool, therefore, is open to question
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