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Because of their steep gradients in abiotic and biotic factors, mountains offer an ideal setting to illuminate the mechanisms that underlie patterns of species distributions and community assembly. We compared the composition of taxonomically and functionally diverse fungal communities in soils along five elevational gradients in mountains of the Neo- and Palaeotropics (northern Argentina, southern Brazil, Panama, Malaysian Borneo and Papua New Guinea). Both the richness and composition of soil fungal communities reflect environmental factors, particularly temperature and soil pH, with some shared patterns among neotropical and palaeotropical regions. Community dynamics are characterized by replacement of species along elevation gradients, implying a relatively narrow elevation range for most fungi, which appears to be driven by contrasting environmental preferences among both functional and taxonomic groups. For functional groups dependent on symbioses with plants (especially ectomycorrhizal fungi), the distribution of host plants drives richness and community composition, resulting in important differences in elevational patterns between neotropical and palaeotropical montane communities. The pronounced compositional and functional turnover along elevation gradients implies that tropical montane forest fungi will be sensitive to climate change, resulting in shifts in composition and functionality over time.
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Micobioma , Micorrizas , Biodiversidade , Florestas , Fungos , Micorrizas/genética , Plantas , Solo/química , Microbiologia do SoloRESUMO
Although the functional trait approach can facilitate the understanding of mechanisms that underline community responses to habitat alteration, only a few studies used this way on exploring the structure of insect assemblages compared to taxon-based analyses. We compared the descriptive power of medium-term effects (2014-2018) of forestry treatments in a temperate managed oak-dominated forest on taxon- vs. trait-based descriptors of ground beetle assemblages. The treatments included rotation forestry (partial preparation cutting, clear-cutting, retention-tree group, and mature closed forest as control) and continuous cover forestry (gap cutting) operations. The species composition was only slightly influenced by the treatments; on the ordination biplot, the control, retention tree group, and clear-cutting treatments formed relatively homogeneous groups, well separated from each other, while the others were scattered randomly in the ordination space. Over time, the species richness decreased in all treatments, but it was higher in the retention tree group treatment than in others in 2016 and 2017. The activity density also declined between years, but an immediate mass effect was revealed after the implementation of treatment types especially in the control, gap, and preparation cuts. We found that assemblages in the clear-cutting and retention-tree group had similar characteristics: high functional diversity; more open-habitat, generalist, and omnivore species and fewer carnivore species; while those in the control, gap, and preparation cutting groups had the opposite: lower functional diversity, more forest species, and more carnivorous species. Our findings will demonstrate that the simultaneous use of the two approaches will allow the most articulate understanding of the status of ground beetles assemblages in managed forests.
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Biodiversidade , Besouros , Animais , Besouros/fisiologia , Ecossistema , Agricultura Florestal , Florestas , ÁrvoresRESUMO
In Europe, forest management has controlled forest dynamics to sustain commodity production over multiple centuries. Yet over-regulation for growth and yield diminishes resilience to environmental stress as well as threatens biodiversity, leading to increasing forest susceptibility to an array of disturbances. These trends have stimulated interest in alternative management systems, including natural dynamics silviculture (NDS). NDS aims to emulate natural disturbance dynamics at stand and landscape scales through silvicultural manipulations of forest structure and landscape patterns. We adapted a "Comparability Index" (CI) to assess convergence/divergence between natural disturbances and forest management effects. We extended the original CI concept based on disturbance size and frequency by adding the residual structure of canopy trees after a disturbance as a third dimension. We populated the model by compiling data on natural disturbance dynamics and management from 13 countries in Europe, covering four major forest types (i.e., spruce, beech, oak, and pine-dominated forests). We found that natural disturbances are highly variable in size, frequency, and residual structure, but European forest management fails to encompass this complexity. Silviculture in Europe is skewed toward even-aged systems, used predominately (72.9% of management) across the countries assessed. The residual structure proved crucial in the comparison of natural disturbances and silvicultural systems. CI indicated the highest congruence between uneven-aged silvicultural systems and key natural disturbance attributes. Even so, uneven-aged practices emulated only a portion of the complexity associated with natural disturbance effects. The remaining silvicultural systems perform poorly in terms of retention compared to tree survivorship after natural disturbances. We suggest that NDS can enrich Europe's portfolio of management systems, for example where wood production is not the primary objective. NDS is especially relevant to forests managed for habitat quality, risk reduction, and a variety of ecosystem services. We suggest a holistic approach integrating NDS with more conventional practices.
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Ecossistema , Florestas , Biodiversidade , Conservação dos Recursos Naturais/métodos , Europa (Continente) , Agricultura Florestal/métodos , ÁrvoresRESUMO
A stable below-canopy microclimate of forests is essential for their biodiversity and ecosystem functionality. Forest management necessarily modifies the buffering capacity of woodlands. However, the specific effects of different forestry treatments on site conditions, the temporal recovery after the harvests, and the reason for the contrasts between treatments are still poorly understood. The effects of four different forestry treatments (clear-cutting, retention tree group, preparation cutting, and gap-cutting) on microclimatic variables were studied within a field experiment in a managed oak-dominated stand in Hungary, before (2014) and after (2015-2017) the interventions by complete block design with six replicates. From the first post-treatment year, clear-cuts differed the most from the uncut control due to the increased irradiance and heat load. Means and variability of air and soil temperature increased, air became dryer along with higher soil moisture levels. Retention tree groups could effectively ameliorate the extreme temperatures but not the mean values. Preparation cutting induced slight changes from the original buffered and humid forest microclimate. Despite the substantially more incoming light, gap-cutting could retain the cool and humid air conditions and showed the highest increase in soil moisture after the interventions. For most microclimate variables, we could not observe any obvious trend within 3 yr. However, soil temperature variability decreased with time in clear-cuts, while soil moisture difference continuously increased in gap- and clear-cuts. Based on multivariate analyses, the treatments separated significantly based mainly on the temperature maxima and variability. We found that (1) the effect sizes among treatment levels were consistent throughout the years, (2) the climatic recovery time for variables appears to be far more than 3 yr, and (3) the applied silvicultural methods diverged mainly among the temperature maxima. Based on our study, the spatially heterogeneous and fine-scaled treatments of continuous cover forestry (gap-cutting, selection systems) are recommended. By applying these practices, the essential structural elements creating buffered microclimate could be more successfully maintained. Thus, forestry interventions could induce less pronounced alterations in environmental conditions for forest-dwelling organism groups.
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Microclima , Quercus , Ecossistema , Agricultura Florestal , Florestas , Hungria , ÁrvoresRESUMO
The world is currently facing an unprecedented healthcare crisis caused by a pandemic novel beta coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The pathogen is spread by human-to-human transmission via droplets exposure and contact transfer, causing mild symptoms in the majority of cases, but critical illness, bilateral viral pneumonia, and acute respiratory distress syndrome (ARDS) in a minority. Currently, controlling infection to prevent the spread of SARS-CoV-2 is the primary public healthcare intervention used. The pace of transmission and global scale of SARS-CoV-2 infections has implications for strategic oversight, resource management, and responsiveness in infection control. This article presents a summary of learning points in epidemiological infection control from the SARS epidemic, alongside a review of evidence connecting current understanding of the virologic and environmental contamination properties of SARS-CoV-2. We present suggestions for how personal protective equipment policies relate to the viral pandemic context and how the risk of transmission by and to anaesthetists, intensivists, and other healthcare workers can be minimised.
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Anestesia/métodos , Infecções por Coronavirus/prevenção & controle , Controle de Infecções/métodos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Betacoronavirus , COVID-19 , Humanos , SARS-CoV-2RESUMO
Policies to mitigate climate change and biodiversity loss often assume that protecting carbon-rich forests provides co-benefits in terms of biodiversity, due to the spatial congruence of carbon stocks and biodiversity at biogeographic scales. However, it remains unclear whether this holds at the scales relevant for management, and particularly large knowledge gaps exist for temperate forests and for taxa other than trees. We built a comprehensive dataset of Central European temperate forest structure and multi-taxonomic diversity (beetles, birds, bryophytes, fungi, lichens, and plants) across 352 plots. We used Boosted Regression Trees (BRTs) to assess the relationship between above-ground live carbon stocks and (a) taxon-specific richness, (b) a unified multidiversity index. We used Threshold Indicator Taxa ANalysis to explore individual species' responses to changing above-ground carbon stocks and to detect change-points in species composition along the carbon-stock gradient. Our results reveal an overall weak and highly variable relationship between richness and carbon stock at the stand scale, both for individual taxonomic groups and for multidiversity. Similarly, the proportion of win-win and trade-off species (i.e., species favored or disadvantaged by increasing carbon stock, respectively) varied substantially across taxa. Win-win species gradually replaced trade-off species with increasing carbon, without clear thresholds along the above-ground carbon gradient, suggesting that community-level surrogates (e.g., richness) might fail to detect critical changes in biodiversity. Collectively, our analyses highlight that leveraging co-benefits between carbon and biodiversity in temperate forest may require stand-scale management that prioritizes either biodiversity or carbon in order to maximize co-benefits at broader scales. Importantly, this contrasts with tropical forests, where climate and biodiversity objectives can be integrated at the stand scale, thus highlighting the need for context-specificity when managing for multiple objectives. Accounting for critical change-points of target taxa can help to deal with this specificity, by defining a safe operating space to manipulate carbon while avoiding biodiversity losses.
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Biodiversidade , Carbono/análise , Mudança Climática , Florestas , França , Hungria , ItáliaRESUMO
BACKGROUND: Perioperative fluid strategies influence clinical outcomes following major surgery. Many intravenous fluid preparations are based on simple solutions, such as normal saline, that feature an electrolyte composition that differs from that of physiological plasma. Buffered fluids have a theoretical advantage of containing a substrate that acts to maintain the body's acid-base status - typically a bicarbonate or a bicarbonate precursor such as maleate, gluconate, lactate, or acetate. Buffered fluids also provide additional electrolytes, including potassium, magnesium, and calcium, more closely matching the electrolyte balance of plasma. The putative benefits of buffered fluids have been compared with those of non-buffered fluids in the context of clinical studies conducted during the perioperative period. This review was published in 2012, and was updated in 2017. OBJECTIVES: To review effects of perioperative intravenous administration of buffered versus non-buffered fluids for plasma volume expansion or maintenance, or both, on clinical outcomes in adults undergoing all types of surgery. SEARCH METHODS: We electronically searched the Clinicaltrials.gov major trials registry, the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 6) in the Cochrane Library, MEDLINE (1966 to June 2016), Embase (1980 to June 2016), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to June 2016). We handsearched conference abstracts and, when possible, contacted leaders in the field. We reran the search in May 2017. We added one potential new study of interest to the list of 'Studies awaiting classification' and will incorporate this trial into formal review findings when we prepare the review update. SELECTION CRITERIA: Only randomized controlled trials that compared buffered versus non-buffered intravenous fluids for surgical patients were eligible for inclusion. We excluded other forms of comparison such as crystalloids versus colloids and colloids versus different colloids. DATA COLLECTION AND ANALYSIS: Two review authors screened references for eligibility, extracted data, and assessed risks of bias. We resolved disagreements by discussion and consensus, in collaboration with a third review author. We contacted trial authors to request additional information when appropriate. We presented pooled estimates for dichotomous outcomes as odds ratios (ORs) and for continuous outcomes as mean differences (MDs), with 95% confidence intervals (CIs). We analysed data via Review Manager 5.3 using fixed-effect models, and when heterogeneity was high (I² > 40%), we used random-effects models. MAIN RESULTS: This review includes, in total, 19 publications of 18 randomized controlled trials with a total of 1096 participants. We incorporated five of those 19 studies (330 participants) after the June 2016 update. Outcome measures in the included studies were thematically similar, covering perioperative electrolyte status, renal function, and acid-base status; however, we found significant clinical and statistical heterogeneity among the included studies. We identified variable protocols for fluid administration and total volumes of fluid administered to patients intraoperatively. Trial authors variably reported outcome data at disparate time points and with heterogeneous patient groups. Consequently, many outcome measures are reported in small group sizes, reducing overall confidence in effect size, despite relatively low inherent bias in the included studies. Several studies reported orphan outcome measures. We did not include in the results of this review one large, ongoing study of saline versus Ringer's solution.We found insufficient evidence on effects of fluid therapies on mortality and postoperative organ dysfunction (defined as renal insufficiency leading to renal replacement therapy); confidence intervals were wide and included both clinically relevant benefit and harm: mortality (Peto OR 1.85, 95% CI 0.37 to 9.33; I² = 0%; 3 trials, 6 deaths, 276 participants; low-quality evidence); renal insufficiency (OR 0.82, 95% CI 0.34 to 1.98; I² = 0%; 4 trials, 22 events, 276 participants; low-quality evidence).We noted several metabolic differences, including a difference in postoperative pH measured at end of surgery of 0.05 units - lower in the non-buffered fluid group (12 studies with a total of 720 participants; 95% CI 0.04 to 0.07; I² = 61%). However, this difference was not maintained on postoperative day one. We rated the quality of evidence for this outcome as moderate. We observed a higher postoperative serum chloride level immediately after operation, with use of non-buffered fluids reported in 10 studies with a total of 530 participants (MD 6.77 mmol/L, 95% CI 3.38 to 10.17), and this difference persisted until day one postoperatively (five studies with a total of 258 participants; MD 8.48 mmol/L, 95% CI 1.08 to 15.88). We rated the quality of evidence for this outcome as moderate. AUTHORS' CONCLUSIONS: Current evidence is insufficient to show effects of perioperative administration of buffered versus non-buffered crystalloid fluids on mortality and organ system function in adult patients following surgery. Benefits of buffered fluid were measurable in biochemical terms, particularly a significant reduction in postoperative hyperchloraemia and metabolic acidosis. Small effect sizes for biochemical outcomes and lack of correlated clinical follow-up data mean that robust conclusions on major morbidity and mortality associated with buffered versus non-buffered perioperative fluid choices are still lacking. Larger studies are needed to assess these relevant clinical outcomes.
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Hidratação/métodos , Procedimentos Cirúrgicos Operatórios , Adulto , Soluções Tampão , Soluções Cristaloides , Hidratação/efeitos adversos , Hidratação/mortalidade , Mortalidade Hospitalar , Humanos , Soluções Isotônicas/administração & dosagem , Soluções Isotônicas/efeitos adversos , Assistência Perioperatória/métodos , Substitutos do Plasma/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como Assunto , Soluções para ReidrataçãoRESUMO
BACKGROUND: Post-operative cognitive impairment is common in elderly patients following surgery for hip fracture, with undertreated pain being an important etiological factor. Non-opioid based analgesic techniques, such as nerve blocks, may help reduce the risk of cognitive complications. The aim of this study was to investigate whether receiving a fascia iliaca compartment block (FICB) as part of a pre-operative analgesic regime increased the odds of high post-operative abbreviated mental test scores (AMTS) when compared with conventional analgesia without a nerve block. METHODS: A retrospective data analysis of a cohort of 959 patients, aged ≥ 65 years with a diagnosis of hip fracture and admitted to a single hospital over a two-year period was performed. A standardized analgesic regime was used on all patients, and 541/959 (56.4%) of included patients received a FICB. Provision of the FICB was primarily determined by availability of an anesthetist, rather than by patient status and condition. Post-operative cognitive ordinal outcomes were defined by AMTS severity as high (score of ≥9/10), moderate, (score of 7-8) and low (score of ≤6). A multivariable ordinal logistic regression analysis was performed on patient status and clinical care factors, including admission AMTS, age, gender, source of admission, time to surgery, type of anesthesia and ASA score. RESULTS: Admission FICB was associated with higher adjusted odds for a high AMTS (score of ≥9) relative to lower AMTS (score of ≤8) than conventional analgesia only (OR = 1.80, 95% CI 1.27-2.54; p = 0.001). Increasing age, lower AMTS on admission to hospital, and being admitted from a residential or nursing home were associated with worse cognitive outcomes. Mode of anesthesia or surgery did not significantly influence post-operative AMTS. CONCLUSION: Post-operative AMTS is influenced by pre-operative analgesic regimes in elderly patients with hip fracture. Provision of a FICB to patients on arrival to hospital may improve early post-operative cognitive performance in this population.
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Bupivacaína/análogos & derivados , Disfunção Cognitiva/prevenção & controle , Fraturas do Colo Femoral/cirurgia , Bloqueio Nervoso , Complicações Pós-Operatórias/psicologia , Idoso de 80 Anos ou mais , Anestésicos Locais/farmacologia , Bupivacaína/farmacologia , Feminino , Nervo Femoral/efeitos dos fármacos , Humanos , Testes de Inteligência , Levobupivacaína , Masculino , Estudos RetrospectivosRESUMO
BACKGROUND: Oesophageal cancer surgery represents a high perioperative risk of complications to patients, such as postoperative pulmonary complications (PPCs). Postoperative analgesia may influence these risks, but the most favourable analgesic technique is debated. This review aims to provide an updated evaluation of whether thoracic epidural analgesia (TEA) has benefits compared to other analgesic techniques in patients undergoing oesophagectomy surgery. Our hypothesis is that TEA reduces pain scores and PPCs compared to intravenous opioid analgesia in patients post-oesophagectomy. METHODS: Electronic databases PubMed, Excerpta Medica Database (EMBASE) and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomised trials of analgesic interventions in patients undergoing oesophagectomy surgery. Only trials including thoracic epidural analgesia compared with other analgesic techniques were included. The primary outcome was a composite of respiratory infection, atelectasis and respiratory failure (PPCs), with pain scores at rest and on movement as secondary outcomes. Data was pooled using random effect models and reported as relative risks (RR) or mean differences (MD) with 95% confidence intervals (CIs). RESULTS: Data from a total of 741 patients in 10 randomised controlled trials (RCTs) from 1993 to 2023 were included. Nine trials were open surgery, and one trial was laparoscopic. Relative to intravenous opioids, TEA significantly reduced a composite of PPCs (risk ratio (RR) 3.88; 95% confidence interval (CI) 1.98-7.61; n = 222; 3 RCTs) and pain scores (0-100-mm visual analogue scale or VAS) at rest at 24 h (MD 9.02; 95% CI 5.88-12.17; n = 685; 10 RCTs) and 48 h (MD 8.64; 95% CI 5.91-11.37; n = 685; 10 RCTs) and pain scores on movement at 24 h (MD 14.96; 95% CI 5.46-24.46; n = 275; 4 RCTs) and 48 h (MD 16.60; 95% CI 8.72-24.47; n = 275; 4 RCTs). CONCLUSIONS: Recent trials of analgesic technique in oesophagectomy surgery are restricted by small sample size and variation of outcome measurement. Despite these limitations, current evidence indicates that thoracic epidural analgesia reduces the risk of PPCs and severe pain, compared to intravenous opioids in patients following oesophageal cancer surgery. Future research should include minimally invasive surgery, non-epidural regional techniques and record morbidity, using core outcome measures with standardised endpoints. TRIAL REGISTRATION: Prospectively registered on PROSPERO (CRD42023484720).
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Adoption of electronic health record systems offers an opportunity to collate massive volumes of complex information about patient care. Healthcare data can inform performance management, enable predictive analytics and enhance strategic decision making. A data-driven approach to improving patient care is vital to address the growing burden of morbidity and mortality associated with major surgery. We describe our methodology for transforming and utilising process of care data in an electronic health record system to develop a registry for quality improvement purposes in patients undergoing major surgery at a single UK hospital. We highlight development of our data-driven vision, technical aspects of processing raw data into metrics relevant to clinical decision making, alongside challenges encountered. Finally, we outline how our data infrastructure supports clinical governance, quality improvement and research. In sharing our experiences, we hope to enable others to embed and access the transformative clinical insights that healthcare data can yield.
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Registros Eletrônicos de Saúde , Melhoria de Qualidade , Centros de Atenção Terciária , Humanos , Centros de Atenção Terciária/organização & administração , Londres , Medicina Perioperatória/métodos , Sistema de RegistrosRESUMO
BACKGROUND: Demographics of patients undergoing major abdominal surgery are changing. External validity of relevant RCTs may be limited by participants not resembling patients encountered in clinical practice. We aimed to characterise differences in age, weight, BMI, and ASA grade between participants in perioperative trials in major abdominal surgery and patients in a reference real-world clinical practice sample. The secondary aim was to investigate whether time since trial publication was associated with increasing mismatch between these groups. METHODS: MEDLINE and Embase were searched for multicentre RCTs from inception to September 2022. Studies of perioperative interventions in adults were included. Studies that limited enrolment based on age, weight, BMI, or ASA status were excluded. We compared trial cohort age, weight, BMI, and ASA distribution to those of patients undergoing major abdominal surgery at our tertiary referral hospital during September 2021 to September 2022. We used a local, single-institution reference sample to reflect the reality of clinical practice (i.e. patients treated by a clinician in their own hospital, rather than averaged nationally). Mismatch was defined using comparison of summary characteristics and ad hoc criteria based on differences relevant to predicted mortality risk after surgery. RESULTS: One-hundred and six trials (44,499 participants) were compared to a reference cohort of 2792 clinical practice patients. Trials were published a median (IQR [range]) 13.4 (5-20 [0-35]) years ago. A total of 94.3% of trials were mismatched on at least one characteristic (age, weight, BMI, ASA). Recruitment of ASA 3 + participants in trials increased over time, and recruitment of ASA 1 participants decreased over time (Spearman's Rho 0.58 and - 0.44, respectively). CONCLUSIONS: Patients encountered in our current local clinical practice are significantly different from those in our defined set of perioperative RCTs. Older trials recruit more low-risk than high-risk participants-trials may thus 'expire' over time. These trials may not be generalisable to current patients undergoing major abdominal surgery, and meta-analyses or guidelines incorporating these trials may therefore be similarly non-applicable. Comparison to local, rather than national cohorts, is important for meaningful on-the-ground evidence-based decision-making.
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Forest management integrating nature conservation aspects into timber production focuses increasingly on small-scale interventions. However, the ecological consequences of gap cuttings remain ambiguous in oak-dominated forests. In the Pilis Gap Experiment, we analyze how combinations of different gap shapes (circular and elongated), and gap sizes (150 m2 and 300 m2) affect the microclimate and biota of a mature sessile oak-hornbeam forest in Hungary. We first report the changes in direct and diffuse light, soil moisture, daily air and soil temperatures, and relative air humidity in the experimental cuttings in the vegetation season directly following their implementation. Diffuse light had a central maximum and a concentric pattern. Direct light was distributed along a north-south gradient, with maxima in northern gap parts. Soil moisture was determined by gap shape: it increased significantly in the center of circular gaps, with multiple local maxima in the southern-central parts of large circular gaps. Its pattern was negatively related to direct light, and larger spatial variability was present in circular than in elongated gaps. The daily mean air temperatures at 1.3 m increased in all, especially in large gaps. Soil and ground-level temperatures remained largely unchanged, reflecting on light and soil moisture conditions affecting evaporative cooling. Relative humidity remained unaltered. Even though the opening of experimental gaps changed microclimatic conditions immediately, effect sizes remained moderate. Gap size and gap shape were both important determinants of microclimate responses: gap size markedly affected irradiation increase, gap shape determined soil moisture surplus, while soil and air temperatures, and air humidity depended on both components of the gap design. We conclude that 150-300 m2 sized management-created gaps can essentially maintain forest microclimate while theoretically providing enough light for oak regeneration; and that the manipulation of gap shape and gap size within this range are effective tools of adaptive management.
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Harmonization of timber production and forest conservation is a major challenge of modern silviculture. For the establishment of ecologically sustainable forest management, the management-related environmental drivers of multi-taxon biodiversity should be explored. Our study reveals those environmental variables related to tree species diversity and composition, stand structure, litter and soil conditions, microclimate, landscape, and land-use history that determine species richness and composition of 11 forest-dwelling organism groups. Herbs, woody regeneration, ground-floor and epiphytic bryophytes, epiphytic lichens, terricolous saprotrophic, ectomycorrhizal, and wood-inhabiting macrofungi, spiders, carabid beetles, and birds were sampled in West Hungarian mature mixed forests. The correlations among the diversities and compositions of different organism groups were also evaluated. Drivers of organism groups were principally related to stand structure, tree species diversity and composition, and microclimate, while litter, soil, landscape, and land-use historical variables were less influential. The complex roles of the shrub layer, deadwood, and the size of the trees in determining the diversity and composition of various taxa were revealed. Stands with more tree species sustained higher stand-level species richness of several taxa. Besides, stands with different dominant tree species harbored various species communities of organism groups. Therefore, landscape-scale diversity of dominant tree species may enhance the diversity of forest-dwelling communities at landscape level. The effects of the overstory layer on forest biodiversity manifested in many cases via microclimate conditions. Diversity of organism groups showed weaker relationship with the diversity of other taxa than with environmental variables. According to our results, the most influential drivers of forest biodiversity are under the direct control of the actual silvicultural management. Heterogeneous stand structure and tree species composition promote the different organism groups in various ways. Therefore, the long-term maintenance of the structural and compositional heterogeneity both at stand and landscape scale is an important aspect of ecologically sustainable forest management.
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Biodiversidade , Florestas , Animais , Microclima , Solo , ÁrvoresRESUMO
To secure the ecosystem services forests provide, it is important to understand how different management practices impact various components of these ecosystems. We aimed to uncover how silvicultural treatments affected the ground-dwelling spider communities during the first five years of a forest ecological experiment. In an oak-hornbeam forest stand, five treatments, belonging to clear-cutting, shelterwood and continuous cover forestry systems, were implemented using randomised complete block design. Spiders were sampled by pitfall traps, and detailed vegetation, soil and microclimate data were collected throughout the experiment. In the treatment plots spider abundance and species richness increased marginally. Species composition changes were more pronounced and treatment specific, initially diverging from the control plots, but becoming more similar again by the fifth year. These changes were correlated mostly to treatment-related light intensity and humidity gradients. The patchy implementation of the treatments induced modest increase in both gamma and beta diversity of spiders in the stand. Overall, spiders gave a prompt and species specific response to treatments that was by the fifth year showing signs of relatively quick recovery to pre-treatment state. At the present fine scale of implementation the magnitude of changes was not different among forestry treatments, irrespective of their severity.
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Past and present pressures on forest resources have led to a drastic decrease in the surface area of unmanaged forests in Europe. Changes in forest structure, composition, and dynamics inevitably lead to changes in the biodiversity of forest-dwelling species. The possible biodiversity gains and losses due to forest management (i.e., anthropogenic pressures related to direct forest resource use), however, have never been assessed at a pan-European scale. We used meta-analysis to review 49 published papers containing 120 individual comparisons of species richness between unmanaged and managed forests throughout Europe. We explored the response of different taxonomic groups and the variability of their response with respect to time since abandonment and intensity of forest management. Species richness was slightly higher in unmanaged than in managed forests. Species dependent on forest cover continuity, deadwood, and large trees (bryophytes, lichens, fungi, saproxylic beetles) and carabids were negatively affected by forest management. In contrast, vascular plant species were favored. The response for birds was heterogeneous and probably depended more on factors such as landscape patterns. The global difference in species richness between unmanaged and managed forests increased with time since abandonment and indicated a gradual recovery of biodiversity. Clearcut forests in which the composition of tree species changed had the strongest effect on species richness, but the effects of different types of management on taxa could not be assessed in a robust way because of low numbers of replications in the management-intensity classes. Our results show that some taxa are more affected by forestry than others, but there is a need for research into poorly studied species groups in Europe and in particular locations. Our meta-analysis supports the need for a coordinated European research network to study and monitor the biodiversity of different taxa in managed and unmanaged forests.
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Biodiversidade , Árvores , Europa (Continente)RESUMO
OBJECTIVE: To identify, appraise, and synthesise the best available evidence on the efficacy of perioperative interventions to reduce postoperative pulmonary complications (PPCs) in adult patients undergoing non-cardiac surgery. DESIGN: Systematic review and meta-analysis of randomised controlled trials. DATA SOURCES: Medline, Embase, CINHAL, and CENTRAL from January 1990 to December 2017. ELIGIBILITY CRITERIA: Randomised controlled trials investigating short term, protocolised medical interventions conducted before, during, or after non-cardiac surgery were included. Trials with clinical diagnostic criteria for PPC outcomes were included. Studies of surgical technique or physiological or biochemical outcomes were excluded. DATA EXTRACTION AND SYNTHESIS: Reviewers independently identified studies, extracted data, and assessed the quality of evidence. Meta-analyses were conducted to calculate risk ratios with 95% confidence intervals. Quality of evidence was summarised in accordance with GRADE methods. The primary outcome was the incidence of PPCs. Secondary outcomes were respiratory infection, atelectasis, length of hospital stay, and mortality. Trial sequential analysis was used to investigate the reliability and conclusiveness of available evidence. Adverse effects of interventions were not measured or compared. RESULTS: 117 trials enrolled 21 940 participants, investigating 11 categories of intervention. 95 randomised controlled trials enrolling 18 062 participants were included in meta-analysis; 22 trials were excluded from meta-analysis because the interventions were not sufficiently similar to be pooled. No high quality evidence was found for interventions to reduce the primary outcome (incidence of PPCs). Seven interventions had low or moderate quality evidence with confidence intervals indicating a probable reduction in PPCs: enhanced recovery pathways (risk ratio 0.35, 95% confidence interval 0.21 to 0.58), prophylactic mucolytics (0.40, 0.23 to 0.67), postoperative continuous positive airway pressure ventilation (0.49, 0.24 to 0.99), lung protective intraoperative ventilation (0.52, 0.30 to 0.88), prophylactic respiratory physiotherapy (0.55, 0.32 to 0.93), epidural analgesia (0.77, 0.65 to 0.92), and goal directed haemodynamic therapy (0.87, 0.77 to 0.98). Moderate quality evidence showed no benefit for incentive spirometry in preventing PPCs. Trial sequential analysis adjustment confidently supported a relative risk reduction of 25% in PPCs for prophylactic respiratory physiotherapy, epidural analgesia, enhanced recovery pathways, and goal directed haemodynamic therapies. Insufficient data were available to support or refute equivalent relative risk reductions for other interventions. CONCLUSIONS: Predominantly low quality evidence favours multiple perioperative PPC reduction strategies. Clinicians may choose to reassess their perioperative care pathways, but the results indicate that new trials with a low risk of bias are needed to obtain conclusive evidence of efficacy for many of these interventions. STUDY REGISTRATION: Prospero CRD42016035662.
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Procedimentos Clínicos , Complicações Pós-Operatórias/prevenção & controle , Doenças Respiratórias/prevenção & controle , Analgesia Epidural , Expectorantes/uso terapêutico , Hidratação , Hemodinâmica , Humanos , Cuidados Intraoperatórios , Modalidades de Fisioterapia , Terapia Respiratória , Vasoconstritores/uso terapêuticoRESUMO
Levobupivacaine is a long-acting amide local anaesthetic used in analgesia and anaesthesia. Like other local anaesthetic drugs, levobupivacaine exhibits effects on motor and sensory nerves by inhibiting the opening of voltage-gated sodium channels, and hence propagation of neuronal action potentials. Levobupivacaine is the S(-) stereoisomer of dextrobupivacaine, although both are used commercially in the racemic form bupivacaine. A favourable safety and drug effect profile for levobupivacaine has led to widespread use. Levobupivacaine is generally well tolerated but dose adjustment is important in populations such as paediatrics and the elderly. The pharmacokinetic properties of levobupivacaine are similar to that of bupivacaine; both extensively metabolised in the liver, and excreted in the urine and faeces. In vitro, animal model and human studies confirm a lower risk of cardiac and central nervous system toxicity with levobupivacaine compared with bupivacaine. Clinical trials of relative potency are impaired by the variability in chosen endpoints for sensory and motor function blockade, but clinically significant differences in potency are minor, with most clinical trials showing similar duration and quality of anaesthesia between levo- and racemic bupivacaine. In practice, levobupivacaine is most commonly used in regional anaesthesia, neuraxial anaesthesia and local infiltration analgesia. This review includes an appraisal of evidence from clinical trials of the pharmacokinetic and pharmacodynamic properties of levobupivacaine.
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Anestésicos Locais , Levobupivacaína/farmacocinética , Anestésicos Locais/farmacocinética , Animais , Bupivacaína , Sistema Nervoso Central/efeitos dos fármacos , Coração/efeitos dos fármacos , Humanos , DorRESUMO
Regional anaesthesia techniques are an important adjunct to perioperative care of breast surgery patients. This chapter focuses on the practical application, evidence base and advantages of peripheral nerve block regional anaesthesia in the anaesthetic management of patients undergoing breast surgery. Functional anatomy and fascial plane blocks are discussed alongside paravertebral and paraspinal techniques. Guidance on the performance the range of ultrasound-guided blocks is provided. The role that regional anaesthesia may have in reducing the risk of breast cancer recurrence following mastectomy surgery is explored.
Assuntos
Anestesia por Condução/métodos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Mastectomia/métodos , Ultrassonografia de Intervenção/métodos , Feminino , Humanos , Mastectomia/efeitos adversosRESUMO
BACKGROUND: Fascia iliaca compartment block (FICB) is an increasingly popular analgesic technique in elderly patients with hip fracture. Despite requiring large volumes of local anaesthetic, there are no plasma pharmacokinetic data on FICB in elderly patients. OBJECTIVES: The objective of this study was to determine the pharmacokinetic profile of a levobupivacaine 75 mg (30 mL 0.25%) FICB dose in patients aged ≥ 80 years with fractured femur. METHODS: This was a single-arm descriptive pilot study. Twelve adults aged ≥ 80 years with hip fracture received FICB performed under ultrasound guidance. Venous blood was sampled at 10, 20, 30, 45, 60, 75, 90, 105, 120 and 240 min after injection. Total plasma levobupivacaine concentration was measured by mass spectrometry. The main outcome measures were pharmacokinetic parameters, including maximum observed plasma concentration (Cmax), time to reach Cmax (tmax) and area under the plasma concentration-time curve. RESULTS: The median (interquartile range [IQR]) Cmax was 0.82 µg/mL (0.47-1.03). tmax was 45 min (41:20-60:00). No evidence of toxicity was identified. Plasma levobupivacaine concentrations were below the threshold associated with toxicity in younger, healthy patients (2.6 µg/mL). No association was found between individual patient Cmax and α1-acid glycoprotein, weight or body mass index, although the study was not powered for these outcomes. CONCLUSIONS: Absorption of levobupivacaine was slow and all patients had plasma concentrations below the toxic threshold. This pharmacokinetic analysis concludes that the technique appears to be well-tolerated and efficacious at reducing pain and is associated with systemic plasma concentrations unlikely to be associated with major adverse effects in elderly patients. CLINICAL TRIAL REGISTRATION: ISRCTN27364035 (UK Clinical Trials Gateway).