Electrokinetic Dewatering of Softwood Furnishes

Enormous quantities of water are required in the preparation and formation of paper products. One of the most costly operations in paper manufacture is removal of excess water from the sheet and disposal of by-products from paper production. Currently, high steam energy is necessary in the drying process of paper manufacture. Disposal of a paper by-product, sludge, is also a rising concern due to environmental risks, shrinking landfill space, and rising disposal costs. Both production costs and disposal costs could be reduced with a more effective and efficient process to enhance water removal in paper production and sludge disposal. One possible way to reduce operation and disposal costs while minimizing the environmental impact of industry is electrokinetics. Electrokinetics is an electricity-driven separation process which was used in this thesis to assist water removal in a softwood furnish. A bench scale pressing device capable of pressing a softwood furnish between two charged wire screens was used examine the effect of electrolyte concentration on water removal. Variables in this experiment included ion concentration and freeness. Different levels of alum were added to a softwood furnish and final pad consistency was compared to control runs which excluded current and alum additions. The results indicated that for higher freeness pulps, the addition of alum in the electrokinetic press increased final pad consistency. However, for lower freeness pulps alum seemed to inhibit water removal. Further studies in applying electrokinetics should include the use of different cationic sources

What motivates students to be sustainability change agents in the face of adversity?

The world faces significant challenges that require transformative changes facilitated by Sustainability Change Agents (SCAs). Universities around the world have explicitly taken up the responsibility of developing in students the skills and knowledge (i.e., competencies) necessary to be successful SCAs. While there is clear convergence around planning competencies, intrapersonal and implementation competencies have recently emerged in the literature. These competencies will have to remain effective even in the face of adversity, yet too little is known about sources of motivation for SCAs and how motivation can be maintained despite these inevitable setbacks. Since the needed transformations will be collective processes, motivation to be a SCA needs to be understood in the social and realistic context in which they would be applied. This study sought to gain specific insights into: 1.) What motivates students to be SCAs? 2.) How do these SCAs maintain their motivation in the face of setbacks? 3.) What can higher education institutions (e.g., universities, colleges) do to better support the motivation of SCAs? In order to gain insights into these questions, 83 aspiring SCAs were surveyed and their responses analyzed using qualitative content analysis. For this group of SCAs, the key source of motivation evolved from a focus on nature, learning, and individual behavior to a more social view with a concern for structural change. Moreover, social networks and intrapersonal skills helped to restore students' motivation following setbacks. Despite being university students, the SCAs surveyed had already experienced significant setbacks and, largely without institutional support, learned strategies to overcome them and maintain their motivation. Motivation and the skills, knowledge, and experience of how to maintain the drive for positive change in the face of setbacks is crucial in order for SCAs to be capable of supporting the critically needed transformations, and universities must play their part in fostering the SCAs' capability.PostprintPeer reviewe

Structurally complex farms support high avian functional diversity in tropical montane Ethiopia

Of all feeding guilds, understorey insectivores are thought to be most sensitive to disturbance and forest conversion. We compared the composition of bird feeding guilds in tropical forest fragments with adjacent agro-ecosystems in a montane region of south-west Ethiopia. We used a series of point counts to survey birds in 19 agriculture and 19 forest sites and recorded tree species within each farm across an area of 40 × 35 km. Insectivores (~17 spp. per plot), frugivores (~3 spp. per plot) and omnivores (~5 spp. per plot) maintained species density across habitats, while granivores and nectarivores increased in the agricultural sites by factors of 7 and 3 respectively. Species accumulation curves of each guild were equal or steeper in agriculture, suggesting that agricultural and forest landscapes were equally heterogeneous for all bird guilds. Counter to most published studies, we found no decline in insectivore species richness with forest conversion. However, species composition differed between the two habitats, with certain forest specialists replaced by other species within each feeding guild. We suggest that the lack of difference in insectivorous species numbers between forest and agriculture in this region is due to the benign nature of the agricultural habitat, but also due to a regional species pool which contains many bird species which are adapted to open habitats

Scientific concepts and methods for moving persistence assessments into the 21st century

The evaluation of a chemical substance's persistence is key to understanding its environmental fate, exposure concentration, and, ultimately, environmental risk. Traditional biodegradation test methods were developed many years ago for soluble, nonvolatile, single-constituent test substances, which do not represent the wide range of manufactured chemical substances. In addition, the Organisation for Economic Co-operation and Development (OECD) screening and simulation test methods do not fully reflect the environmental conditions into which substances are released and, therefore, estimates of chemical degradation half-lives can be very uncertain and may misrepresent real environmental processes. In this paper, we address the challenges and limitations facing current test methods and the scientific advances that are helping to both understand and provide solutions to them. Some of these advancements include the following: (1) robust methods that provide a deeper understanding of microbial composition, diversity, and abundance to ensure consistency and/or interpret variability between tests; (2) benchmarking tools and reference substances that aid in persistence evaluations through comparison against substances with well-quantified degradation profiles; (3) analytical methods that allow quantification for parent and metabolites at environmentally relevant concentrations, and inform on test substance bioavailability, biochemical pathways, rates of primary versus overall degradation, and rates of metabolite formation and decay; (4) modeling tools that predict the likelihood of microbial biotransformation, as well as biochemical pathways; and (5) modeling approaches that allow for derivation of more generally applicable biotransformation rate constants, by accounting for physical and/or chemical processes and test system design when evaluating test data. We also identify that, while such advancements could improve the certainty and accuracy of persistence assessments, the mechanisms and processes by which they are translated into regulatory practice and development of new OECD test guidelines need improving and accelerating. Where uncertainty remains, holistic weight of evidence approaches may be required to accurately assess the persistence of chemicals. Integr Environ Assess Manag 2022;18:1454-1487. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Keywords: Bioavailability; Biodegradability; Biodegradation; Degradation half-lives; Persistence assessment

Global Kidney Exchange: Analysis and Background Papers from the Perspective of Medical Anthropology

Global Kidney Exchange (GKE) is a program aimed at facilitating trans-national kidney donation. Although its proponents aim at reducing the unmet demand of kidneys in the United States through the trans-nationalization of kidney exchange programs, the World Health Organization (WHO) and The Transplantation Society (TTS) have expressed concerns about its potential effect on black markets of organs and transnational organ trafficking, as well as on low- or middle-income countries health systems. For GKE to be implemented, it would need to be permitted to operate in at least some low- or middle-income countries. Should a low- or middle-income country allow GKE’s implementation? With the aim of answering this question, the eighteen University of Denver students in the Medical Anthropology course I [Alejandro Cerón] taught in autumn 2017, identified and researched the different aspects that would affect this issue, and delved in a holistic analysis we present in this report. Based on our analysis, health authorities in low- or middle-income countries faced with decisions about GKE need to consider the following aspects: the country’s current and projected needs related to kidney transplant, as well as the capacity for addressing those needs; the country’s current situation related to organ trafficking, transplant tourism and black markets of organs; the current and projected legislation related to both organ donation and human trafficking; the prevailing ethical considerations that inform the practice of all professionals related to organ transplant in the country; analyze end-stage renal failure as a preventable disease needing public health measures; and the sociocultural aspects that surround organ donation in the country. We consider that the concrete configuration of these aspects would influence the effects of implementing GKE. Additionally, we identified some issues of concern that are beyond the level of influence of local authorities: the unmet demand of kidneys in high-income countries is a reality that incentivizes organ trade and transplant tourism, and this is a problem in need of solutions; transnational organ trafficking as well as human trafficking with the purpose of organ donation are problems that need more visibility; for a global exchange of organs to be implemented, it would need to rely on supranational or transnational regulation and oversight; and the global epidemic of chronic kidney disease needs to be addressed through a public health perspective that emphasizes prevention

Scientific concepts and methods for moving persistence assessments into the 21st century

34 páginas.- 2 figuras.- 3 tablas.- 225 referenciasThe evaluation of a chemical substance's persistence is key to understanding its environmental fate, exposure concentration, and, ultimately, environmental risk. Traditional biodegradation test methods were developed many years ago for soluble, nonvolatile, single-constituent test substances, which do not represent the wide range of manufactured chemical substances. In addition, the Organisation for Economic Co-operation and Development (OECD) screening and simulation test methods do not fully reflect the environmental conditions into which substances are released and, therefore, estimates of chemical degradation half-lives can be very uncertain and may misrepresent real environmental processes. In this paper, we address the challenges and limitations facing current test methods and the scientific advances that are helping to both understand and provide solutions to them. Some of these advancements include the following: (1) robust methods that provide a deeper understanding of microbial composition, diversity, and abundance to ensure consistency and/or interpret variability between tests; (2) benchmarking tools and reference substances that aid in persistence evaluations through comparison against substances with well-quantified degradation profiles; (3) analytical methods that allow quantification for parent and metabolites at environmentally relevant concentrations, and inform on test substance bioavailability, biochemical pathways, rates of primary versus overall degradation, and rates of metabolite formation and decay; (4) modeling tools that predict the likelihood of microbial biotransformation, as well as biochemical pathways; and (5) modeling approaches that allow for derivation of more generally applicable biotransformation rate constants, by accounting for physical and/or chemical processes and test system design when evaluating test data. We also identify that, while such advancements could improve the certainty and accuracy of persistence assessments, the mechanisms and processes by which they are translated into regulatory practice and development of new OECD test guidelines need improving and accelerating. Where uncertainty remains, holistic weight of evidence approaches may be required to accurately assess the persistence of chemicals. Integr Environ Assess Manag 2022;1–34. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).Peer reviewe

SNP Discovery and Chromosome Anchoring Provide the First Physically-Anchored Hexaploid Oat Map and Reveal Synteny with Model Species

A physically anchored consensus map is foundational to modern genomics research; however, construction of such a map in oat (Avena sativa L., 2n = 6x = 42) has been hindered by the size and complexity of the genome, the scarcity of robust molecular markers, and the lack of aneuploid stocks. Resources developed in this study include a modified SNP discovery method for complex genomes, a diverse set of oat SNP markers, and a novel chromosome-deficient SNP anchoring strategy. These resources were applied to build the first complete, physically-anchored consensus map of hexaploid oat. Approximately 11,000 high-confidence in silico SNPs were discovered based on nine million inter-varietal sequence reads of genomic and cDNA origin. GoldenGate genotyping of 3,072 SNP assays yielded 1,311 robust markers, of which 985 were mapped in 390 recombinant-inbred lines from six bi-parental mapping populations ranging in size from 49 to 97 progeny. The consensus map included 985 SNPs and 68 previously-published markers, resolving 21 linkage groups with a total map distance of 1,838.8 cM. Consensus linkage groups were assigned to 21 chromosomes using SNP deletion analysis of chromosome-deficient monosomic hybrid stocks. Alignments with sequenced genomes of rice and Brachypodium provide evidence for extensive conservation of genomic regions, and renewed encouragement for orthology-based genomic discovery in this important hexaploid species. These results also provide a framework for high-resolution genetic analysis in oat, and a model for marker development and map construction in other species with complex genomes and limited resources

Ten new insights in climate science 2022

Non-technical summary We summarize what we assess as the past year's most important findings within climate change research: limits to adaptation, vulnerability hotspots, new threats coming from the climate–health nexus, climate (im)mobility and security, sustainable practices for land use and finance, losses and damages, inclusive societal climate decisions and ways to overcome structural barriers to accelerate mitigation and limit global warming to below 2°C. Technical summary We synthesize 10 topics within climate research where there have been significant advances or emerging scientific consensus since January 2021. The selection of these insights was based on input from an international open call with broad disciplinary scope. Findings concern: (1) new aspects of soft and hard limits to adaptation; (2) the emergence of regional vulnerability hotspots from climate impacts and human vulnerability; (3) new threats on the climate–health horizon – some involving plants and animals; (4) climate (im)mobility and the need for anticipatory action; (5) security and climate; (6) sustainable land management as a prerequisite to land-based solutions; (7) sustainable finance practices in the private sector and the need for political guidance; (8) the urgent planetary imperative for addressing losses and damages; (9) inclusive societal choices for climate-resilient development and (10) how to overcome barriers to accelerate mitigation and limit global warming to below 2°C. Social media summary Science has evidence on barriers to mitigation and how to overcome them to avoid limits to adaptation across multiple fields

An Exploration of Bitcoin Mining Practices:Miners’ Trust Challenges and Motivations

Bitcoin blockchain technology is a distributed ledger of nodes authorizing transactions between anonymous parties. Its key actors are miners using computational power to solve mathematical problems for validating transactions. By sharing blockchain's characteristics, mining is a decentralized, transparent and unregulated practice, less explored in HCI, so we know little about miners' motivations and experiences, and how these may impact on different dimensions of trust. This paper reports on interviews with 20 bitcoin miners about their practices and trust challenges. Findings contribute to HCI theories by extending the exploration of blockchain's characteristics relevant to trust with the competitiveness dimension underpinning the social organization of mining. We discuss the risks of collaborative mining due to centralization and dishonest administrators, and conclude with design implications highlighting the need for tools monitoring the distribution of rewards in collaborative mining, tools tracking data centers' authorization and reputation, and tools supporting the development of decentralized pools