Recent research has indicated an increase in the likelihood and impact of tree failure. The potential for trees to fail relates to various biomechanical and physical factors. Strikingly, there seems to be an absence of tree risk assessment methods supported by observations, despite an increasing availability of variables and parameters measured by scientists, arborists and practitioners. Current urban tree risk assessments vary due to differences in experience, training, and personal opinions of assessors. This stresses the need for a more objective method to assess the hazardousness of urban trees. The aim of this study is to provide an overview of factors that influence tree failure including stem failure, root failure and branch failure. A systematic literature review according to the PRISMA guidelines has been performed in databases, supported by backward referencing: 161 articles were reviewed revealing 142 different factors which influenced tree failure. A meta-analysis of effect sizes and p-values was executed on those factors which were associated directly with any type of tree failure. Bayes Factor was calculated to assess the likelihood that the selected factors appear in case of tree failure. Publication bias was analysed visually by funnel plots and results by regression tests. The results provide evidence that the factors Height and Stem weight positively relate to stem failure, followed by Age, DBH, DBH squared times H, and Cubed DBH (DBH3) and Tree weight. Stem weight and Tree weight were found to relate positively to root failure. For branch failure no relating factors were found. We recommend that arborists collect further data on these factors. From this review it can further be concluded that there is no commonly shared understanding, model or function available that considers all factors which can explain the different types of tree failure. This complicates risk estimations that include the failure potential of urban trees.
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Post-earthquake structural damage shows that out-of-plane (OOP) wall collapse is one of the most common failure mechanisms in unreinforced masonry (URM) buildings. This issue is particularly critical in Groningen, a province located in the northern part of the Netherlands, where low-intensity induced earthquakes have become an uprising problem in recent years. The majority of buildings in this area are constructed using URM and were not designed to withstand earthquakes, as the area had never been affected by tectonic seismic activity before. OOP failure in URM structures often stems from poor connections between structural elements, resulting in insufficient restraint to the URM walls. Therefore, investigating the mechanical behaviour of these connections is of prime importance for mitigating damages and collapses in URM structures. This paper presents the results of an experimental campaign conducted on timber joist-masonry cavity wall connections. The specimens consisted of timber joists pocketed into masonry wallets. The campaign aimed at providing a better understanding and characterisation of the cyclic axial behaviour of these connections. Both as-built and strengthened conditions were considered, with different variations, including two tie distributions, two pre-compression levels, two different as-built connections, and one strengthening solution. The experimental findings underscored that incorporating retrofitting bars not only restores the system's initial capacity but also guarantees deformation compatibility between the wall and the joist. This effectively enhances the overall deformation capacity and ductility of the timber joist-cavity wall system.
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Biodiversity preservation is often viewed in utilitarian terms that render non-human species as ecosystem services or natural resources. The economic capture approach may be inadequate in addressing biodiversity loss because extinction of some species could conceivably come to pass without jeopardizing the survival of the humans. People might be materially sustained by a technological biora made to yield services and products required for human life. The failure to address biodiversity loss calls for an exploration of alternative paradigms. It is proposed that the failure to address biodiversity loss stems from the fact that ecocentric value holders are politically marginalized and underrepresented in the most powerful strata of society. While anthropocentric concerns with environment and private expressions of biophilia are acceptable in the wider society, the more pronounced publicly expressed deep ecology position is discouraged. “Radical environmentalists” are among the least understood of all contemporary opposition movements, not only in tactical terms, but also ethically. The article argues in favor of the inclusion of deep ecology perspective as an alternative to the current anthropocentric paradigm. https://doi.org/10.1080/1943815X.2012.742914 https://www.linkedin.com/in/helenkopnina/
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This study investigated to what degree lesson-to-lesson variability in teachers' goal clarification and process feedback explains variability in secondary students’ motivational correlates. Students (N=570, 24 classes) completed questionnaires at six occasions. Multilevel regression analyses showed that relations between perceived process feedback and experienced need satisfaction (i.e., competence, autonomy and relatedness) were conditional on perceived goal clarification. No such interaction effects between process feedback and goal clarification were found for need frustration (i.e., experiencing failure, feeling pushed to achieve goals, feeling rejected). In general, when students perceived more process feedback or goal clarification, students experienced more competence, autonomy and relatedness satisfaction. Yet, when perceiving very high levels of process feedback, additional benefits of goal clarification were no longer present (and vice versa). In lessons in which students perceived goals to be less clear, they experienced more need frustration. No associations were found between process feedback and need frustration.
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Post-earthquake structural damage shows that out-of-plane wall collapse is one of the most prevalent failure mechanisms in unreinforced masonry (URM) buildings. This issue is particularly critical in Groningen, a province located in the northern part of the Netherlands, where low-intensity ground shaking has occurred since 1991 due to gas extraction. The majority of buildings in this area are constructed using URM and were not designed to withstand earthquakes, as the area had never been affected by tectonic seismic activity before. Hence, the assessment of URM buildings in the Groningen province has become of high relevance.Out-of-plane failure mechanisms in brick masonry structures often stem from poor wall-to-wall, wall-to-floor or wall-to-roof connections that provide insufficient restraint and boundary conditions. Therefore, studying the mechanical behaviour of such connections is of prime importance for understanding and preventing damages and collapses in URM structures. Specifically, buildings with double-leaf cavity walls constitute a large portion of the building stock in the Groningen area. The connections of the leaves in cavity walls, which consist of metallic ties, are expected to play an important role. Regarding the wall-to-floor connections, the traditional way for URM structures in Dutch construction practice is either a simple masonry pocket connection or a hook anchor as-built connection, which are expected to be vulnerable to out-of-plane excitation. However, until now, little research has been carried out to characterise the seismic behaviour of connections between structural elements in traditional Dutch construction practice.This thesis investigates the seismic behaviour of two types of connections: wall-to-wall connections between cavity wall leaves and wall-to-floor connections between the masonry cavity wall and timber diaphragm, commonly found in traditional houses in the Groningen area. The research is divided into three phases: (1) inventory of existing buildings and connections in the Groningen area, (2) performance of experimental tests, and (3) proposal and validation of numerical and mechanical models. The thesis explores the three phases as follows:(i) An inventory of connections within URM buildings in the Groningen area is established. The inventory includes URM buildings of Groningen based on construction material, lateral load-resisting system, floor system, number of storeys, and connection details. Specific focus is given to the wall-to-wall and wall-to-floor connections in each URM building. The thickness of cavity wall leaves, the air gap between the leaves and the size and spacing of timber joists are key aspects of the inventory.(ii) Experimental tests are performed on the most common connection typologies identified in the inventory. This phase consists of two distinct experimental campaigns:o The first experimental campaign took place at the laboratory of the Delft University of Technology to provide a comprehensive characterisation of the axial behaviour of traditional metal tie connections in cavity walls. The campaign included a wide range of variations, such as two embedment lengths, four pre-compression levels, two different tie geometries, and five different testing protocols, including both monotonic and cyclic loading. The experimental results showed that the capacity of the wall tie connection is strongly influenced by the embedment length and the tie geometry, whereas the applied pre-compression and the loading rate do not have a significant influence.o The second experimental campaign has been carried out at the laboratory of the Hanze University of Applied Sciences to characterise the seismic behaviour of timber joist-masonry cavity wall connections, reproducing both as-built and strengthened conditions. Twenty-two unreinforced masonry wallets were tested, with different configurations, including two tie distributions, two pre-compression levels, two different as-built connections, and two different strengthening solutions. The experimental results highlighted the importance of cohesion and friction between joist and masonry since the type of failure mechanism (sliding of the joist or rocking failure of the masonry wallet) depends on the value of these two parameters. Additionally, the interaction between the joist and the wallet and the uplift of the latter activated due to rocking led to an arching effect that increased friction at the interface between the joist and the masonry. Consequently, the arching effect enhanced the force capacity of the connection.(iii) Mechanical and numerical models are proposed and validated against the performed experiments or other benchmarks. Mechanical and numerical models for the cavity wall tie and mechanical models for the timber joist-masonry connections were developed and verified by the experimental results to predict the failure mode and the strength capacity of the examined connections in URM buildings.o The mechanical model for the cavity wall tie connections considers six possible failures, namely tie failure, cone break-out failure, pull-out failure, buckling failure, piercing failure and punching failure. The mechanical model is able to capture the mean peak force and the failure mode obtained from the tests. After being calibrated against the available experiments, the proposed mechanical model is used to predict the performance of untested configurations by means of parametric analyses, including higher strength of mortar for calcium silicate brick masonry, different cavity depth, different tie embedment depth, and the use of solid bricks in place of perforated clay bricks.o The results of the experimental campaign on cavity wall ties were also utilised to calibrate a hysteretic numerical model representing the cyclic axial response of cavity wall tie connections. The proposed model uses zero-length elements implemented in OpenSees with the Pinching4 constitutive model to account for the compression-tension cyclic behaviour of the ties. The numerical model is able to capture important aspects of the tie response, such as strength degradation, unloading stiffness degradation, and pinching behaviour. The mechanical and numerical modelling approach can be easily adopted by practitioner engineers seeking to model the wall ties more accurately when assessing URM structures against earthquakes.o The mechanical model of timber-masonry connections examines two different failure modes: joist-sliding failure mode, including joist-to-wall interaction and rocking failure mode due to joist movement. Both mechanical models have been validated against the outcomes of the experimental campaigns conducted on the corresponding connections. The mechanical model is able to estimate each contribution of the studied mechanism. Structural engineers can use the mechanical model to predict the capacity of the connection for the studied failure modes.This research study can contribute to a better understanding of typical Groningen houses in terms of identifying the most common connections used at wall-to-wall and wall-to-floor connections in cavity walls, characterising the identified connections and proposing mechanical models for the studied connections.
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What you don’t know can’t hurt you: this seems to be the current approach for responding to disinformation by public regulators across the world. Nobody is able to say with any degree of certainty what is actually going on. This is in no small part because, at present, public regulators don’t have the slightest idea how disinformation actually works in practice. We believe that there are very good reasons for the current state of affairs, which stem from a lack of verifiable data available to public institutions. If an election board or a media regulator wants to know what types of digital content are being shared in their jurisdiction, they have no effective mechanisms for finding this data or ensuring its veracity. While there are many other reasons why governments would want access to this kind of data, the phenomenon of disinformation provides a particularly salient example of the consequences of a lack of access to this data for ensuring free and fair elections and informed democratic participation. This chapter will provide an overview of the main aspects of the problems associated with basing public regulatory decisions on unverified data, before sketching out some ideas of what a solution might look like. In order to do this, the chapter develops the concept of auditing intermediaries. After discussing which problems the concept of auditing intermediaries is designed to solve, it then discusses some of the main challenges associated with access to data, potential misuse of intermediaries, and the general lack of standards for the provision of data by large online platforms. In conclusion, the chapter suggests that there is an urgent need for an auditing mechanism to ensure the accuracy of transparency data provided by large online platform providers about the content on their services. Transparency data that have been audited would be considered verified data in this context. Without such a transparency verification mechanism, existing public debate is based merely on a whim, and digital dominance is likely to only become more pronounced.
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Adopted on the fifteenth anniversary of resolution 1325, Security Council resolution 2242 has recognized for the first time the substantial link between climate change and the “Women, Peace and Security” (WPS) framework. Despite this landmark resolution, the intersections of environmental factors, conflict and violence against women remain largely absent from the Security Council's WPS agenda. Competition over natural resources is generally understood as a driver of conflict. The risk of insecurity and conflict are further increased by environmental degradation and climate change. It is therefore clear that the environment and natural resources must be integrated into the WPS agenda. This should necessarily include a discussion of indigenous rights to land and the gender-related dimensions of environmental factors. Indigenous women are disproportionately affected by environmental degradation, caused by resource extraction and increasingly compounded by climatic changes. This in turn exacerbates other vulnerabilities, including sexual and gender-based violence and other forms of marginalization. This article argues, by reference to the situation in West Papua, that unfettered resource extraction not only amplifies vulnerabilities and exacerbates preexisting inequalities stemming from colonial times, it also gives rise to gendered consequences flowing from the damage wreaked on the natural environment and thus poses a danger to international peace and security. As such, the Security Council's failure to recognize the continuous struggle of women in indigenous and rural communities against extractive economies and climate change impact as a security risk forms a serious lacuna within its WPS agenda. Originally published by Oxford University Press in Global Studies Quarterly, Volume 1, Issue 3, September 2021, ksab018, https://doi.org/10.1093/isagsq/ksab018
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Hematological malignancies and treatment with hematopoietic SCT are known to affect patients’ quality of life. The problem profile and care needs of this patient group need clarification, however. This study aimed to assess distress, problems and care needs after allo- or auto-SCT, and to identify risk factors for distress, problems or care needs. In this cross-sectional study, patients treated with allo-SCT or auto-SCT for hematological malignancies completed the Distress Thermometer and Problem List. Three patient groups were created: 0–1, 1–2.5 and 2.5–5.5 years after transplantation. After allo-SCT, distress and the number of problems tended to be lower with longer follow-up. After auto-SCT, distress was highest at 1–2.5 year(s). Patients mainly reported physical problems, followed by cognitive-emotional and practical problems. A minority reported care needs. Risk factors for distress as well as problems after allo-SCT included younger age, shorter time after transplantation and GVHD. A risk factor for distress as well as problems after auto-SCT was the presence of comorbid diseases. Up to 5 years after auto-SCT or allo-SCT, patients continue to experience distress and problems. Judged by prevalence, physical problems are first priority in supportive care, followed by cognitive-emotional and practical problems.
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Study goal: This study was carried out to answer the following research question: which motivation do healthy volunteers have to participate in phase I clinical trials? - Methods: A literature search was done through Google Scholar and Academic Search Premier, followed by three interviews with volunteers who had recently concluded their participation in a (non-commercial) phase I trial. - Results: Our literature search revealed mainly commercial motives for volunteers to participate in phase I clinical trials. The interviews (with volunteers in a non-commercial trial) showed that other factors may also play a decisive role, such as: (1) wish to support the investigator (2) wish to contribute to science, (3) access to more/better health care (4) sociability: possibility to relax and to communicate with other participants (5) general curiosity. Precondition is that risks and burden are deemed acceptable. - Conclusions: financial remuneration appears to be the predominant motive to participate voluntarily in a clinical trial. Other reasons were also mentioned however, such as general curiosity, the drive to contribute to science and the willingness to help the investigator. In addition, social reasons were given such as possibility to relax and to meet other people. Potential subjects state that they adequately assess the (safety) risks of participating in a trial as part of their decision process.
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Individuals with autism increasingly enroll in universities, but little is known about predictors for their success. This study developed predictive models for the academic success of autistic bachelor students (N=101) in comparison to students with other health conditions (N=2465) and students with no health conditions (N=25,077). We applied propensity score weighting to balance outcomes. The research showed that autistic students’ academic success was predictable, and these predictions were more accurate than predictions of their peers’ success. For first-year success, study choice issues were the most important predictors (parallel program and application timing). Issues with participation in pre-education (missingness of grades in pre-educational records) and delays at the beginning of autistic students’ studies (reflected in age) were the most influential predictors for the second-year success and delays in the second and final year of their bachelor’s program. In addition, academic performance (average grades) was the strongest predictor for degree completion in 3 years. These insights can enable universities to develop tailored support for autistic students. Using early warning signals from administrative data, institutions can lower dropout risk and increase degree completion for autistic students.
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