The role of polymerization in adhesive dentistry Cadenaro, Milena; Maravic, Tatjana; Comba, Allegra ...
Dental materials,
January 2019, 2019-Jan, 2019-01-00, 20190101, Letnik:
35, Številka:
1
Journal Article
Recenzirano
•Factors that influence polymerization of adhesives are described.•Accurate evaporation of the solvents may improve the polymerization of adhesive system.•Prolonged curing time increase the ...performance and stability of adhesive systems.•The effect on curing reaction of molecules added to adhesive formulations to counteract the degradation of the adhesive interface over time has to be clarified.
Adhesive systems are resin-based materials that reach their final mechanical properties through a polymerization process. Previous literature correlated the failure of the adhesive interface to low polymer setting. Adhesives systems are elaborate mixtures of different molecules of both hydrophilic and hydrophobic nature, included in the formulation to adequately infiltrate the complex dental substrate or added to prolong the stability of the adhesive layer over time. Each adhesive component may influence the polymerization reaction of the material. Photopolymerization is a complex reaction that has several clinical implications, and besides the material composition, it is influenced by multiple factors, including the substrate characteristics, the operator technique, and the light cure unit properties. This review is focused on the analysis of factors that have a potential role in the setting of adhesive materials and thus the ultimate characteristics of the adhesive layer and the stability of the resin-dentin interface.
Interactions between humans and wildlife resulting in negative impacts are among the most pressing conservation challenges globally. In regions of smallholder livestock and crop production, ...interactions with wildlife can compromise human well‐being and motivate negative sentiment and retaliation toward wildlife, undermining conservation goals. Although impacts may be unavoidable when human and wildlife land use overlap, scant large‐scale human data exist quantifying the direct costs of wildlife to livelihoods. In a landscape of global importance for wildlife conservation in southern Africa, we quantified costs for people living with wildlife through a fundamental measure of human well‐being, food security, and we tested whether existing livelihood strategies buffer certain households against crop depredation by wildlife, predominantly elephants. To do this, we estimated Bayesian multilevel statistical models based on multicounty household data (n = 711) and interpreted model results in the context of spatial data from participatory land‐use mapping. Reported crop depredation by wildlife was widespread. Over half of the sample households were affected and household food security was reduced significantly (odds ratio 0.37 0.22, 0.63). The most food insecure households relied on gathered food sources and welfare programs. In the event of crop depredation by wildlife, these 2 livelihood sources buffered or reduced harmful effects of depredation. The presence of buffering strategies suggests a targeted compensation strategy could benefit the region's most vulnerable people. Such strategies should be combined with dynamic and spatially explicit land‐use planning that may reduce the frequency of negative human–wildlife impacts. Quantifying and mitigating the human costs from wildlife are necessary steps in working toward human–wildlife coexistence.
Impactos de la Fauna y Medios de Subsistencia Vulnerables en unkl Paisaje de Conservación Transfronteriza
Resumen
Las interacciones entre los humanos y la fauna que resultan en impactos negativos se encuentran entre los desafíos más apremiantes para la conservación a nivel mundial. En las regiones de ganaderos y agricultores minifundistas, las interacciones con la fauna pueden poner en peligro el bienestar humano y motivar sentimientos negativos y represalias hacia la fauna, lo que debilita los objetivos de conservación. Aunque los impactos pueden evitarse cuando el uso de suelo por humanos y fauna se traslapa, existen pocos datos humanos a gran escala que cuantifiquen el costo directo de la fauna para los medios de subsistencia. Cuantificamos el costo para las personas que conviven con animales silvestres en un paisaje de importancia global para la conservación de fauna en el sur de África. La cuantificación fue realizada por medio de una medida fundamental de bienestar humano y seguridad alimentaria, y probamos si las estrategias existentes de subsistencia amortiguan a ciertos hogares ante la depredación de cultivos realizada por animales silvestres, predominantemente los elefantes. Para realizar esto, estimamos algunos modelos estadísticos bayesianos de niveles múltiples basados en los datos de hogares ubicados en múltiples condados (n = 711) e interpretamos los resultados de los modelos en el contexto de los datos espaciales a partir de un mapeo participativo de uso de suelo. La depredación de cultivos por animales silvestres fue reportada de manera generalizada. Más de la mitad de los hogares en la muestra estuvieron afectados y la seguridad alimenticia de los hogares se redujo significativamente (proporción de probabilidades 0.37 0.22, 0.63). Los hogares con la menor seguridad alimentaria dependían de fuentes de recolección de alimentos y programas de bienestar. En el evento de la depredación por fauna de los cultivos, estas dos fuentes de subsistencia amortiguaron o redujeron los efectos dañinos de la depredación. La presencia de las estrategias de amortiguamiento sugiere que una estrategia de compensación enfocada podría beneficiar a las personas más vulnerables de la región. Dichas estrategias deberían estar combinadas con la planeación del uso de suelo dinámica y espacialmente explícita, la cual podría reducir la frecuencia de los impactos negativos entre los humanos y la fauna. La cuantificación y mitificación del costo humano a partir de la fauna son pasos necesarios en el camino hacia la coexistencia entre los humanos y la fauna.
摘要
人类与野生动物之间相互作用造成的负面影响是全球最紧迫的保护挑战之一。在小农畜牧和作物种植地区, 与野生动物的相互作用可能损害人类福祉, 并引发人类对野生动物的负面情绪和报复行为, 进而破坏保护目标。人类和野生动物在土地利用重叠时难免产生相应影响, 但在量化野生动物对人类生计的直接影响成本时仍缺乏大尺度的人类数据。我们在南非一个具有全球重要意义的野生动物保护的景观中, 利用人类福祉和粮食安全的基本指标定量分析了人类与野生动物一起生活的成本, 我们还分析了现有生计策略在防止野生动物 (主要是大象) 掠夺农作物中是否能对一些家庭起到缓冲作用。我们基于多个国家的家庭数据 (n = 711) 进行了贝叶斯多层统计模型估计, 并结合参与式土地利用绘图的空间数据对模型结果做出解释。结果发现, 野生动物对农作物的破坏非常普遍, 样本中一半以上的家庭都受到了影响, 这导致粮食安全显著下降 (优势比为 0.37 0.22, 0.63) 。而最缺乏粮食安全保障的家庭主要依赖于收集的食物和福利计划维持生计。当作物遭到野生动物的破坏时, 这两种生计来源可以缓冲或减少破坏的有害影响。缓冲策略的存在表明, 有针对性的补偿策略可以帮助该地区最弱势的群体。而这些策略应与动态及空间显式土地利用规划相结合, 以减少人类‐野生动物负面影响发生的频率。因此, 量化和减少野生动物对人类造成的损失是努力实现人类与野生动物共存的必要步骤。【翻译: 胡怡思; 审校: 聂永刚】
Article Impact statement: Multicounty household data show livelihood costs from wildlife crop depredation.
High-level policy debates surrounding elephant management often dominate global conservation headlines, yet realities for people living with wildlife are not adequately incorporated into policymaking ...or evident in related discourse.1,2 Human health and livelihoods can be severely impacted by wildlife and indirectly by policy outcomes.3 In landscapes where growing human and elephant (Loxodonta spp. and Elephas maximus) populations compete over limited resources, human-elephant conflict causes crop loss, human injury and death, and retaliatory killing of wildlife.4–6 Across Africa, these problems may be increasingly compounded by climate change, which intensifies resource competition and food insecurity.6–9 Here, we examine how human-wildlife impacts interact with climate change and household food insecurity across the Kavango-Zambezi Transfrontier Conservation Area, the world’s largest terrestrial transboundary conservation area, spanning five African nations. We use hierarchical Bayesian statistical models to analyze multi-country household data together with longitudinal satellite-based climate measures relevant to rainfed agriculture. We find that crop depredation by wildlife, primarily elephants, impacts 58% of sampled households annually and is associated with significant increases in food insecurity. These wildlife impacts compound effects of changing climate on food insecurity, most notably observed as a 5-day shortening of the rainy season per 10 years across the data record (1981–2018). To advance sustainability goals, global conservation policy must better integrate empirical evidence on the challenges of human-wildlife coexistence into longer term strategies at transboundary scales, specifically in the context of climate change.3,9–11
•KAZA households experience diverse factors constraining livelihoods•Marginal agriculture is further limited by recent changes in precipitation patterns•Crop depredation by wildlife is widespread and compounds food insecurity•Inclusive policies conserving wildlife and supporting people are needed
Salerno et al. quantify impacts of changing rainfall and wildlife crop depredation across multiple nation sites in KAZA. Crops lost to wildlife, primarily elephants, cause significant increases in food insecurity, beyond observed impacts from shortened rainy seasons. Findings articulate the need for inclusive policies supporting wildlife and people.
move me on Hilton, Tom; Dawson, Hannah
Teaching history (London),
12/2014
157
Journal Article
Recenzirano
...the students' history diet is increasingly restricted to some kind of note-taking exercise followed by a very predictable but more extended question, with only occasional scope to develop their ...thinking and understanding in more expansive ways.
Community‐based conservation (CBC) is essential to promoting biodiversity protection and livelihood development. Despite significant financial and institutional investment, performance of CBC ...interventions is mixed, with shortcomings especially evident in wildlife‐based CBC in Africa. CBC outcomes are typically evaluated through household livelihood gains, or through policy analysis at higher administrative levels such as the central state. Surprisingly, village or local governance capacity is often missing from project assessment. Through a controlled study, we evaluate CBC interventions at multiple scales in Tanzania. Employing Bayesian multilevel latent trait models, we find that CBC participation predicts stronger village governance institutions. Additionally, compared to control villages, CBC villages have more local civic organizations and small business enterprise, but do not experience greater elite capture of public goods. Together, and in the absence of direct CBC benefits provisioned to households or signs of success at the higher level of multi‐village CBC bodies, these findings point to the possibility that village‐level governance institutions can adapt in beneficial ways to prolonged CBC interventions.
move me on Hilton, Tom; Richards, Helen
Teaching history (London),
09/2010
140
Journal Article
Recenzirano
In his first school, where history was taught within a humanities programme, the Key Stage 3 scheme of work had included detailed lesson plans, essentially intended to support the geography and RE ...specialists teaching outside their own subject. Extract from Rate's first curriculum assignment: a critical analysis of the 2008 National Curriculum for history The designation of 'evidence' as a key process rather than a concept within the National Curriculum has been criticised by those who argue, (convincingly in my opinion) that using evidence effectively to construct knowledge of the past depends on an understanding of the nature of historical evidence and the ways in which it can serve as testimony only in response to the questions that we ask of it.
Publically-funded schools in North America are often scary and dangerous places for gay, lesbian, bisexual, transgendered, and questioning (GBLTQ) youth, and many teens suggest that the adults ...charged with ensuring their safety and learning often do little to promote their acceptance and safety among their peers. Educators need preparation to become more sensitized to GBLTQ teen issues and equipped with the empathy, knowledge, and skills to support and protect these marginalized students in their care. The Faculty of Education at the University of Prince Edward Island has introduced a number of initiatives into its pre-service teacher education programs to help new teachers unpack their own beliefs, attitudes, and personal experiences with gender identity and sexual orientation and prepare them to become advocates for their GBLTQ students. (Contains 11 endnotes.)
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