Natural succession and clearcutting as drivers of environmental heterogeneity and beta diversity in North American boreal forests

<div><p>Clear-cutting alters natural ecosystem processes by reducing landscape heterogeneity. It is the dominant harvesting technique across the boreal zone, yet understanding of how environmental heterogeneity and beta diversity are structured in forest ecosystems and post-clear cut is lacking. We use ground-dwelling arthropods as models to determine how natural succession (progression from deciduous to mixed to coniferous cover types) and clear-cutting change boreal forests, exploring the role of environmental heterogeneity in shaping beta diversity across multiple spatial scales (<i>between-cover types</i> and <i>between-stands of the same cover type</i> (1600 to 8500 m), <i>between-plots</i> (100 to 400 m) and <i>within-plots</i> (20 to 40 m)). We characterise environmental heterogeneity as variability in combined structural, vegetational and soil parameters, and beta diversity, as variability in assemblage composition. Clear-cutting homogenised forest environments across all spatial scales, reducing total environmental heterogeneity by 35%. Arthropod beta diversity reflected these changes at larger scales suggesting that environmental heterogeneity is useful in explaining beta diversity both <i>between-cover types</i> and <i>between-stands</i> of the same cover type. However, at smaller scales, <i>within-</i> and <i>between-plots</i> spider beta diversity reflected the lower environmental heterogeneity in regenerating stands, whereas staphylinid and carabids assemblages were not homogenised 12 years post-harvest. Differences in environmental heterogeneity and staphylinid beta diversity between cover types were also important at small scales. In regenerating stands, we detected a subtle yet notable effect of pre-felling cover type on environmental heterogeneity and arthropods, where pre-felling cover type accounted for a significant amount of variance in beta diversity, indicating that biological legacies (e.g. soil pH reflecting pre-harvest conditions) may have a role in driving beta diversity even 12 years post-harvest. This study highlights the importance of understanding site history when predicting impacts of change in forest ecosystems. Further, to understand drivers of beta diversity we must identify biological legacies shaping community structure.</p></div

Characterisation of cross-flow above a railway bridge equipped with solid windbreaks

The flow field above a two dimensional model of a railway bridge equipped with solid windbreaks is analysed in a wind tunnel. Particle image velocimetry (PIV) is used to measure the flow velocity in planes perpendicular to the bridge span. The mean velocity components, the two-component turbulent kinetic energy, the turbulence intensities of the velocity fluctuation components and the Reynolds shear stress above the bridge deck are presented. The flow patterns based on the streamlines of the average flow field are analysed. The inclusion of a windbreak produces a separation bubble, that is locked to the bridge deck due to presence of the leeward fence. Special attention is paid to the analysis of the flow field characteristics along the vertical profiles above the railway tracks. The inclusion of the windbreak leads both to an increase of the mean velocity and the turbulence intensity around the catenary contact wires. On the other hand, the flow in the region close to the bridge deck is slowed-down. The effect of the size of the final interrogation window used in the PIV analysis is considered, more particularly on the determination of the mean velocity and turbulence intensity. The results show that a decrease of the final interrogation window leads to an increase of the turbulence intensity when there are no wind protection devices installed on the bridge

Realidad Virtual y Aumentada para la mejora del aprendizaje en ingeniería. Aplicación a la aeromecánica de alas rotatorias

Presentamos una experiencia piloto de aprendizaje sobre el uso de Realidad Virtual Inmersiva (VR) y Realidad Aumentada (AR), con el objetivo de facilitar la comprensión de la dinámica compleja de rotores, a estudiantes de Grados en Ingeniería Aeroespacial. Las experiencias en VR/AR permiten visualizar los movimientos de las palas de los rotores (hélices, aerogeneradores y helicópteros) así como los campos vectoriales de las acciones externas (aerodinámicas, inerciales y gravitatorias) que originan esos movimientos. Se consulta a los estudiantes sobre los pros y los contras de la experiencia piloto en comparación con los métodos tradicionales basados en representaciones estáticas de los resultados de la dinámica. La conclusión principal es que las experiencias VR/AR son herramientas valiosas para complementar los métodos tradicionales

On some characteristics of the spatial distribution of turbulence components over the Bolund hill determined in wind tunnel compared to full-scale measurements

A comparison is presented between wind tunnel (WT) and full scale (FS) measurements of spatial distributions of turbulence intensities, IUi = aUiS~1, and their ratios; U4 being the fluctuations of velocity components and S the mean velocity magnitude, over the Bolund hill. The Bolund experiment, conducted by Ris0-DTU during a 3-month period in the winter of 2007-2008, is probably the most relevant test case of flow models oriented to wind energy analysis, in this case, over highly complex terrains, in neutral conditions and non affected by Coriolis forces. The Bolund hill is a small peninsula, with an almost vertical 11 m height escarpment facing westerly winds, and a nearly flat plateau extending towards East. This geometry produces complex flow structures which are a challenge for numerical and wind tunnel simulations. The available results, since the end of the Bolund experiment, have mainly focused on the spatial distribution of the mean velocity magnitude and turbulent kinetic energy. Our interest is now in how the turbulent kinetic energy is distributed among the velocity components (what is relevant for wind turbine response), and to which extend our wind tunnel experiment (1:115 scale, 3CHotWire, 3CHW, and Particle Image Velocimetry, PIV) can reproduce these distributions

A clinical practice guideline for the management of the foot and ankle in rheumatoid arthritis

Rheumatoid arthritis causes progressive joint destruction in the long term, causing a deterioration of the foot and ankle. A clinical practice guideline has been created with the main objective of providing recommendations in the field of podiatry for the conservative management of rheumatoid arthritis. Thus, healthcare professionals involved in foot care of adults with rheumatoid arthritis will be able to follow practical recommendations. A clinical practice guideline was created includ- ing a group of experts (podiatrists, rheumatologists, nurses, an orthopaedic surgeon, a physiotherapist, an occupational therapist and patient with rheumatoid arthritis). Methodological experts using GRADE were tasked with systematically reviewing the available scientific evidence and developing the information which serves as a basis for the expert group to make recommendations. Key findings include the efficacy of chiropody in alleviating hyperkeratotic lesions and improv- ing short-term pain and functionality. Notably, custom and standardized foot orthoses demonstrated significant benefits in reducing foot pain, enhancing physical function, and improving life quality. Therapeutic footwear was identified as crucial for pain reduction and mobility improvement, emphasizing the necessity for custom-made options tailored to individual patient needs. Surgical interventions were recommended for cases which were non-responsive to conservative treatments, aimed at preserving foot functionality and reducing pain. Moreover, self-care strategies and education were underscored as essential components for promoting patient independence and health maintenance. A series of recommendations have been created which will help professionals and patients to manage podiatric pathologies derived from rheumatoid arthritis.Funding for open access publishing: Universidad Málaga/CBU

The ABC130 barrel module prototyping programme for the ATLAS strip tracker

For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector, consisting of silicon pixel, silicon strip and transition radiation sub-detectors, will be replaced with an all new 100 % silicon tracker, composed of a pixel tracker at inner radii and a strip tracker at outer radii. The future ATLAS strip tracker will include 11,000 silicon sensor modules in the central region (barrel) and 7,000 modules in the forward region (end-caps), which are foreseen to be constructed over a period of 3.5 years. The construction of each module consists of a series of assembly and quality control steps, which were engineered to be identical for all production sites. In order to develop the tooling and procedures for assembly and testing of these modules, two series of major prototyping programs were conducted: an early program using readout chips designed using a 250 nm fabrication process (ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm processing (ABC130 and HCC130 chips). This second generation of readout chips was used for an extensive prototyping program that produced around 100 barrel-type modules and contributed significantly to the development of the final module layout. This paper gives an overview of the components used in ABC130 barrel modules, their assembly procedure and findings resulting from their tests.Comment: 82 pages, 66 figure

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries