414 research outputs found
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Recommendations for life-cycle assessment of recyclable plastics in a circular economy
Technologies that enable plastic circularity offer a path to reducing waste generation, improving environmental quality, and reducing reliance on fossil feedstocks. However, life-cycle assessment (LCA) methods commonly applied to these systems fall far short of capturing the full suite of advantages and tradeoffs. This perspective highlights inconsistencies in both the research questions and methodological choices across the growing body of LCA literature for plastics recycling. We assert that conducting LCAs on the basis of tonnes of waste managed vs. tonnes of recycled plastics yields results with fundamentally different conclusions; in most cases, analyses of recyclable plastics should focus on the unit of recycled product yielded. We also offer straightforward paths to better approach LCAs for recycling processes and plastics in a circular economy by rethinking study design (metrics, functional unit, system boundaries, counterfactual scenarios), upstream assumptions (waste feedstock variability, pre-processing requirements), and downstream assumptions (closed-loop vs. open-loop systems, material substitution). Specifically, we recommend expanding to metrics beyond greenhouse gases by including fossil carbon balances, net diversion of waste from landfill, and quantity of avoided plastic waste leakage to the environment. Furthermore, we highlight the role that plastic waste plays as a problematic contaminant in preventing greater diversion of all wastes to recycling, energy recovery, and composting, suggesting that plastics may hold a shared responsibility for the system-wide greenhouse gas emissions that occur when mixed wastes are landfilled
Too early for early education? Effects on parenting for mothers and fathers
Objective: To estimate the effect of children's age of entry into early childhood education and care (ECEC) on parenting quality of mothers and fathers in a context of universal access to subsidized ECEC following a 1 year paid parental leave. Background: Children entering non-parental care settings in early childhood may have negative consequences for parenting quality. Yet, current evidence supporting this claim is predominantly from the United States, is focused almost exclusively on mothers, and is predominantly based on statistical approaches that are vulnerable to unobserved selection bias. Method: Data are from a Norwegian longitudinal study, including ratings of observed mother–child (n = 901) and father–child (n = 621) interactions, and children's age of entry into ECEC. Multivariate regression models and instrumental variable models were used to estimate the causal effect of age of entry on parenting quality. Results: There was no support for the hypothesis that an earlier age of entry into ECEC negatively affects parenting quality, for either fathers or mothers. This was true for the sample as a whole, and for different sociodemographic subgroups. Conclusion: In a Norwegian context in which families have universal access to subsidized ECEC from the time their child is 1 year of age, and most children enter ECEC in their second year, there is no evidence that an earlier age of entry in ECEC harms parenting quality.info:eu-repo/semantics/publishedVersio
Mitigating adolescent social anxiety symptoms : the effects of social support and social self-efficacy in findings from the Young-HUNT 3 study
Adolescents’ exposure to negative life events (NLEs) and potentially traumatic events is highly prevalent and increases their risk of developing psychological disorders considerably. NLE exposure has also been linked to the development of social anxiety disorder (SAD) among older children and young adolescents. Despite the relatively low treatment efficacy reported for children and adolescents suffering from SAD, few studies have addressed the extent to which resilience factors, such as social support and social self-efficacy, are associated with SAD symptoms. This study examined whether social support and social self-efficacy predict, and buffer against SAD symptoms using a large, population-based sample of adolescents, among whom a large proportion have experienced NLEs. The results reveal that NLEs are significantly associated with SAD symptoms, while social support and social self-efficacy are both negatively associated with SAD symptoms. Only the NLEs × social support interaction significantly predicted SAD symptoms, with social support attenuating the association between NLEs and SAD symptoms. Moreover, increases in both social self-efficacy and social support were associated with reduced SAD symptoms, over and above variance explained by social support alone. Our cumulative results suggest that interventions that can modify both social support and social self-efficacy may help reduce SAD symptoms in at-risk adolescents.publishedVersionUnit Licence Agreemen
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FRACTIONAL CRYSTALLIZATION OF HANFORD SINGLE SHELL TANK (SST) WASTES FROM CONCEPT TO PILOT PLANT
The Hanford site has 149 underground single-shell tanks (SST) storing mostly soluble, multi-salt mixed wastes resulting from Cold War era weapons material production. These wastes must be retrieved and the salts immobilized before the tanks can be closed to comply with an overall site-closure consent order entered into by the US Department of Energy, the Environmental Protection Agency, and the State of Washington. Water will be used to retrieve the wastes and the resulting solution will be pumped to a proposed pretreatment process where a high-curie (primarily {sup 137}Cs) waste fraction will be separated from the other waste constituents. The separated waste streams will then be vitrified to allow for safe storage as an immobilized high-level waste, or low-level waste, borosilicate glass. Fractional crystallization, a common unit operation for production of industrial chemicals and pharmaceuticals, was proposed as the method to separate the salt wastes; it works by evaporating excess water until the solubilities of various species in the solution are exceeded (the solubility of a particular species depends on its concentration, temperature of the solution, and the presence of other ionic species in the solution). By establishing the proper conditions, selected pure salts can be crystallized and separated from the radioactive liquid phase. The aforementioned parameters, along with evaporation rate, proper agitation, and residence time, determine nucleation and growth kinetics and the resulting habit and size distribution of the product crystals. These crystals properties are important considerations for designing the crystallizer and solid/liquid separation equipment. A structured program was developed to (a) demonstrate that fractional crystallization could be used to pre-treat Hanford tank wastes and (b) provide data to develop a pilot plant design
Robot rights? Towards a social-relational justification of moral consideration \ud
Should we grant rights to artificially intelligent robots? Most current and near-future robots do not meet the hard criteria set by deontological and utilitarian theory. Virtue ethics can avoid this problem with its indirect approach. However, both direct and indirect arguments for moral consideration rest on ontological features of entities, an approach which incurs several problems. In response to these difficulties, this paper taps into a different conceptual resource in order to be able to grant some degree of moral consideration to some intelligent social robots: it sketches a novel argument for moral consideration based on social relations. It is shown that to further develop this argument we need to revise our existing ontological and social-political frameworks. It is suggested that we need a social ecology, which may be developed by engaging with Western ecology and Eastern worldviews. Although this relational turn raises many difficult issues and requires more work, this paper provides a rough outline of an alternative approach to moral consideration that can assist us in shaping our relations to intelligent robots and, by extension, to all artificial and biological entities that appear to us as more than instruments for our human purpose
Longitudinal MRI follow-up of rheumatoid arthritis in the temporomandibular joint: importance of synovial proliferation as an early-stage sign
This article describes longitudinal magnetic resonance imaging (MRI) observations in a patient with rheumatoid arthritis of the temporomandibular joint. The characteristic findings included marked synovial proliferation, which was observed before the onset of severe bone destruction. MRI is considered to provide valuable information for the early detection of rheumatoid arthritis of the temporomandibular joint
Updated Poster Presentation Abstract (n = 58) From 2020 Combined Sections Meeting Of The American Physical Therapy Association: How Well Do Clinical Walking Measures Predict Natural Walking Behavior In Parkinson Disease?
Declines in the amount and intensity of natural walking behavior in people with Parkinson disease (PD) may precede declines in motor behavior, gait, and balance. Physical interventions targeting walking behavior in PD may have the greatest impact on slowing the progression of disability. Despite a lack of supporting evidence, however, clinicians may be more likely to rely on quick performance measures of walking speed, capacity, and balance to make inferences about a patient’s walking health, rather than direct measures of natural walking behavior. Our primary purpose, therefore, was to examine the extent to which clinical walking measures might predict natural walking behavior in early to mid-stage PD. Secondarily we sought to explore differences in the predictive capability of clinical measures between relatively less active and more active participants
Highly Selective End-Tagged Antimicrobial Peptides Derived from PRELP
Background: Antimicrobial peptides (AMPs) are receiving increasing attention due to resistance development against conventional antibiotics. Pseudomonas aeruginosa and Staphylococcus aureus are two major pathogens involved in an array of infections such as ocular infections, cystic fibrosis, wound and post-surgery infections, and sepsis. The goal of the study was to design novel AMPs against these pathogens. Methodology and Principal Findings: Antibacterial activity was determined by radial diffusion, viable count, and minimal inhibitory concentration assays, while toxicity was evaluated by hemolysis and effects on human epithelial cells. Liposome and fluorescence studies provided mechanistic information. Protease sensitivity was evaluated after subjection to human leukocyte elastase, staphylococcal aureolysin and V8 proteinase, as well as P. aeruginosa elastase. Highly active peptides were evaluated in ex vivo skin infection models. C-terminal end-tagging by W and F amino acid residues increased antimicrobial potency of the peptide sequences GRRPRPRPRP and RRPRPRPRP, derived from proline arginine-rich and leucine-rich repeat protein (PRELP). The optimized peptides were antimicrobial against a range of Gram-positive S. aureus and Gram-negative P. aeruginosa clinical isolates, also in the presence of human plasma and blood. Simultaneously, they showed low toxicity against mammalian cells. Particularly W-tagged peptides displayed stability against P. aeruginosa elastase, and S. aureus V8 proteinase and aureolysin, and the peptide RRPRPRPRPWWWW-NH2 was effective against various "superbugs'' including vancomycin-resistant enterococci, multi-drug resistant P. aeruginosa, and methicillin-resistant S. aureus, as well as demonstrated efficiency in an ex vivo skin wound model of S. aureus and P. aeruginosa infection. Conclusions/Significance: Hydrophobic C-terminal end-tagging of the cationic sequence RRPRPRPRP generates highly selective AMPs with potent activity against multiresistant bacteria and efficiency in ex vivo wound infection models. A precise "tuning'' of toxicity and proteolytic stability may be achieved by changing tag-length and adding W-or F-amino acid tags
End-Tagging of Ultra-Short Antimicrobial Peptides by W/F Stretches to Facilitate Bacterial Killing
BACKGROUND: Due to increasing resistance development among bacteria, antimicrobial peptides (AMPs), are receiving increased attention. Ideally, AMP should display high bactericidal potency, but low toxicity against (human) eukaryotic cells. Additionally, short and proteolytically stable AMPs are desired to maximize bioavailability and therapeutic versatility. METHODOLOGY AND PRINCIPAL FINDINGS: A facile approach is demonstrated for reaching high potency of ultra-short antimicrobal peptides through end-tagging with W and F stretches. Focusing on a peptide derived from kininogen, KNKGKKNGKH (KNK10) and truncations thereof, end-tagging resulted in enhanced bactericidal effect against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Through end-tagging, potency and salt resistance could be maintained down to 4-7 amino acids in the hydrophilic template peptide. Although tagging resulted in increased eukaryotic cell permeabilization at low ionic strength, the latter was insignificant at physiological ionic strength and in the presence of serum. Quantitatively, the most potent peptides investigated displayed bactericidal effects comparable to, or in excess of, that of the benchmark antimicrobial peptide LL-37. The higher bactericidal potency of the tagged peptides correlated to a higher degree of binding to bacteria, and resulting bacterial wall rupture. Analogously, tagging enhanced peptide-induced rupture of liposomes, particularly anionic ones. Additionally, end-tagging facilitated binding to bacterial lipopolysaccharide, both effects probably contributing to the selectivity displayed by these peptides between bacteria and eukaryotic cells. Importantly, W-tagging resulted in peptides with maintained stability against proteolytic degradation by human leukocyte elastase, as well as staphylococcal aureolysin and V8 proteinase. The biological relevance of these findings was demonstrated ex vivo for pig skin infected by S. aureus and E. coli. CONCLUSIONS/SIGNIFICANCE: End-tagging by hydrophobic amino acid stretches may be employed to enhance bactericidal potency also of ultra-short AMPs at maintained limited toxicity. The approach is of general applicability, and facilitates straightforward synthesis of hydrophobically modified AMPs without the need for post-peptide synthesis modifications
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