The NBS: Processing/Microstructure/Property Relationships in 2024 Aluminum Alloy Plates

As received plates of 2024 aluminum alloy were examined. Topics covered include: solidification segregation studies; microsegregation and macrosegregation in laboratory and commercially cast ingots; C-curves and nondestructive evaluation; time-temperature precipitation diagrams and the relationships between mechanical properties and NDE measurements; transmission electron microscopy studies; the relationship between microstructure and properties; ultrasonic characterization; eddy-current conductivity characterization; the study of aging process by means of dynamic eddy current measurements; and Heat flow-property predictions, property degradations due to improve quench from the solution heat treatment temperature

Designing a Solid Waste Infrastructure Management Model for Integration into a National Infrastructure System-of Systems

Solid waste management is arguably one of the most important municipal services provided by government1. Given the rapid socio-economic changes that are projected to take place in the UK2 it is important that we plan our future waste management capacity to ensure the continuance of this valuable service. The Solid Waste Infrastructure Management System (SWIMS) model was designed to model the current solid waste infrastructure requirements (from collection through treatment and disposal) for an area based on its solid waste arisings. SWIMS allows an area’s waste treatment capacity requirements to be forecast against future socio-economic change to help decision-makers choose the right solid waste infrastructure given their goals, constraints and ideas about future conditions. The modelling of solid waste management systems has been carried out since the 1970s3 and such modelling exercises have been undertaken for numerous different geographical areas around the world4. However, the SWIMS model is unique in that it was designed to also operate within a larger national infrastructure system-of-systems model, including interdependencies with other infrastructure sectors including energy, water and waste water. To achieve such flexibility the SWIMS model was carefully designed using object-oriented programming (OOP) principles. In documenting this model’s design methodology we hope to demonstrate how applying OOP principles enables such models to not only be more flexible and more easily integrated with other modelling efforts, but also more easily understood by system experts and end-users

A New Design of Flicker Photometer for Laboratory Colored Light Photometry

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Environmental and Hunter-Gatherer Responses to the White River Ash East Volcanic Eruption in the Late Holocene Canadian Subarctic

The eastern lobe of the Alaskan White River Ash volcanic event of AD 846 – 848 blanketed portions of Yukon and Northwest Territories, Canada, in 5 to 50 cm of tephra. The eruption has been linked to concurrent changes among hunter- gatherers, including the spread of new technologies and the continent-wide migration of a group of Dene ancestors from Subarctic Canada to the United States. We use published palaeoenvironmental data (primarily pollen and charcoal profiles) as well as studies of modern ash fall ecology and human health hazards associated with eruptions to reconstruct effects of the White River Ash east event on northern hunter-gatherer subsistence. While many components of local ecosystems appear to have rebounded quickly from ash deposition, we deduce a more pronounced impact on the important game species of caribou and salmon, the seasonal migration paths of which were intersected by thick deposits of ash. A trophic model informed by palaeoenvironmental data and ethnohistoric records suggests that negative biological effects of the ash temporarily pushed hunter-gatherer populations to neighbouring and less affected kin groups for up to 100 years. This synthesis contextualises archaeological theories of human responses to ecological disturbance events in circumpolar landscapes.Le lobe occidental du dépôt de cendres volcaniques White River Ash, en Alaska, remontant aux années 846 – 848 A.D., a recouvert certaines parties du Yukon et des Territoires du Nord-Ouest, au Canada, d’une couche de téphra de 5 à 50 cm. Cette éruption a été liée à des changements simultanés chez les chasseurs-cueilleurs, dont l’adoption de nouvelles technologies et la migration à l’échelle du continent d’un groupe d’ancêtres dénés, de la zone subarctique canadienne jusqu’aux États-Unis. Nous avons publié des données paléoenvironnementales (principalement des profils de pollen et de charbon de bois) ainsi que des études d’écologie moderne de chutes de cendres et de dangers pour la santé des êtres humains découlant d’éruptions afin de reconstituer les effets du dépôt occidental White River Ash sur la subsistance des chasseurs-cueilleurs nordiques. Même si de nombreuses composantes des écosystèmes locaux semblent s’être remises rapidement des dépôts de cendres, nous déduisons que les répercussions ont été plus prononcées sur les espèces de gibier de caribou et sur le saumon, dont les voies de migration saisonnière croisaient les épais dépôts de cendres. Un modèle trophique établi à l’aide de données paléoenvironnementales et d’enregistrements ethnohistoriques suggère que les effets biologiques négatifs des cendres ont poussé temporairement les populations de chasseurs-cueilleurs chez des groupes apparentés avoisinants et moins touchés pendant une centaine d’années. Cette synthèse met en contexte les théories archéologiques se rapportant aux réactions humaines vis-à-vis d’événements de perturbation écologique dans les paysages circumpolaires

Histotripsy of Rabbit Renal Tissue in Vivo: Temporal Histologic Trends

Background and Purpose: Histotripsy is defined as noninvasive, nonthermal, mechanical (cavitational) tissue ablation. We previously demonstrated the predictable acute tissue effects of histotripsy in rabbit kidney and other tissues. We sought to characterize the appearance and natural history of renal tissue after histotripsy. Materials and Methods: Following Institutional Animal Care Committee approval, the left kidneys of 29 rabbits were treated with 60,000 750-kHz, 15-cycle bursts of ultrasound energy from an 18-element phased-array transducer at a 1-kHz pulse-repetition frequency. The treated kidneys were harvested at 0, 1, 2, 7, 21, or 60 days; fixed in Formalin; then prepared for microscopic analysis with hematoxylin and eosin and trichrome stains. Results: For kidneys harvested acutely (day 0), a contiguous area of finely disrupted tissue was observed containing no recognizable cells or cellular components. Along the boundary of architectural disruption, a border several tubules wide contained cells that were not visibly disrupted but appeared damaged (pyknotic nuclei). At subsequent time intervals, an inflammatory response developed in association with a steadily decreasing area of cellular and architectural disruption. By day 60, only a small fibrous scar persisted adjacent to a wedge of tubular dilation and fibrosis underlying a surface-contour defect. Conclusions: Histotripsy produces mechanical fractionation of cellular and architectural structures. The resultant acellular material appears to be readily reabsorbed within 60 days in the rabbit. This may prove to be a significant advantage for imaging assessment of residual tumor after ablation of renal malignancy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63123/1/end.2007.9915.pd

Histotripsy Effects on the Bladder Trigone: Functional and Histologic Consequences in the Canine Model

Background: Histotripsy is an extracorporeal therapeutic ultrasound (US) technology, where high-amplitude acoustic energy is applied to targeted tissue. Previous research has demonstrated the feasibility, safety, and effectiveness of histotripsy tissue homogenization and debulking of the prostate in the canine model. Before translating this technology for human use, it is prudent to examine the susceptibility of critical periprostatic structures to cavitation injury in the event of histotripsy mistargeting. In this study, we sought to characterize the tissue effects and biologic response of directly treating the bladder trigone with histotripsy. Materials and Methods: In eight anesthetized canines, 750,000 histotripsy pulses were applied uniformly across a 2?1.5-cm area encompassing the bladder trigone and ureteral orifices. Prostate and bladder trigone were harvested immediately after treatment (2 subjects) or at 14 days (6 subjects). Flexible cystourethroscopy, US imaging, and creatinine levels were obtained at intervals until harvest, 14 days after treatment. In one control subject, harvested at 2 days, the same treatment algorithm was applied to the prostate. Results: Transrectal US imaging revealed a cavitation bubble cloud on the surface of the bladder trigone and progressive development of tissue edema during treatment. Flexible cystourethroscopy immediately after treatment confirmed edema and erythema of the trigone. In the six subjects survived 2 weeks after treatment, one incidence of transient, self-limited ureteral obstruction was noted based on hydronephrosis and creatinine levels. At harvest, ureteral orifices were confirmed patent by passage of a guide wire. Histologic evaluation revealed hemorrhage acutely with mild localized fibrosis at 14 days. Conclusions: In this study, designed along the lines of a worst-case, destructive testing scenario, direct targeting of the bladder trigone with supratherapeutic histotripsy failed to induce significant tissue damage or clinical complication. These results are reassuring and will guide treatment strategy in upcoming human clinical trials of histotripsy treatment for benign prostatic hyperplasia.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140374/1/end.2013.0234.pd

Education and articulation: Laclau and Mouffe’s radical democracy in school

This paper outlines a theory of radical democratic education by addressing a key concept in Laclau and Mouffe’s Hegemony and Socialist Strategy: articulation. Through their concept of articulation, Laclau and Mouffe attempt to liberate Gramsci’s theory of hegemony from Marxist economism, and adapt it to a political sphere inhabited by a plurality of struggles and agents none of which is predominant. However, while for Gramsci the political process of hegemony formation has an explicit educational dimension, Laclau and Mouffe ignore this dimension altogether. My discussion starts with elaborating the concept of articulation and analysing it in terms of three dimensions: performance, connection and transformation. I then address the role of education in Gramsci’s politics, in which the figure of the intellectual is central, and argue that radical democratic education requires renouncing that figure. In the final section, I offer a theory of such education, in which both teacher and students articulate their political differences and identities

The Effects of COVID-19 Restrictions on College Students Physical Activity and Mental Health

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Botulinum toxins for the prevention of migraine in adults

BackgroundMigraine occurs in around 15% of adults and is ranked as the seventh most disabling disease amongst all diseases globally. Despite the available treatments many people suffer prolonged and frequent attacks which have a major impact on their quality of life. Chronic migraine is defined as 15 or more days of headache per month, at least eight of those days being migraine. People with episodic migraine have fewer than 15 headache days per month. Botulinum toxin type A has been licensed in some countries for chronic migraine treatment, due to the results of just two trials.ObjectivesTo assess the effects of botulinum toxins versus placebo or active treatment for the prevention or reduction in frequency of chronic or episodic migraine in adults.Search methodsWe searched CENTRAL, MEDLINE & MEDLINE in Process, Embase, ClinicalTrials.gov and World Health Organization International Clinical Trials Registry (to December 2017). We examined reference lists and carried out citation searches on key publications. We sent correspondence to major manufacturers of botulinum toxin.Selection criteriaRandomised, double‐blind, controlled trials of botulinum toxin (any sero‐type) injections into the head and neck for prophylaxis of chronic or episodic migraine in adults. Eligible comparators were placebo, alternative prophylactic agent or different dose of botulinum toxin.Data collection and analysisTwo review authors independently selected trials and extracted data. For continuous outcomes we used mean change data when available. For dichotomous data we calculated risk ratios (RRs). We used data from the 12‐week post‐treatment follow‐up time point. We assessed the evidence using GRADE and created two 'Summary of findings' tables.Main resultsDescription of trialsWe found 90 articles describing 28 trials (4190 participants), which were eligible for inclusion. The longest treatment duration was three rounds of injections with three months between treatments, so we could not analyse long‐term effects. For the primary analyses, we pooled data from both chronic and episodic participant populations. Where possible, we also separated data into chronic migraine, episodic migraine and ‘mixed group’ classification subgroups. Most trials (21 out of 28) were small (fewer than 50 participants per trial arm). The risk of bias for included trials was low or unclear across most domains, with some trials reporting a high risk of bias for incomplete outcome data and selective outcome reporting.Botulinum toxin versus placeboTwenty‐three trials compared botulinum toxin with placebo. Botulinum toxin may reduce the number of migraine days per month in the chronic migraine population by 3.1 days (95% confidence interval (CI) ‐4.7 to ‐1.4, 4 trials, 1497 participants, low‐quality evidence). This was reduced to ‐2 days (95% CI ‐2.8 to ‐1.1, 2 trials, 1384 participants; moderate‐quality evidence) when we removed small trials.A single trial of people with episodic migraine (N = 418) showed no difference between groups for this outcome measure (P = 0.49).In the chronic migraine population, botulinum toxin reduces the number of headache days per month by 1.9 days (95% CI ‐2.7 to ‐1.0, 2 trials, 1384 participants, high‐quality evidence). We did not find evidence of a difference in the number of migraine attacks for both chronic and episodic migraine participants (6 trials, N = 2004, P = 0.30, low‐quality evidence). For the population of both chronic and episodic migraine participants a reduction in severity of migraine rated during clinical visits, on a 10 cm visual analogue scale (VAS) of 3.3 cm (95% CI ‐4.2 to ‐2.5, very low‐quality evidence) in favour of botulinum toxin treatment came from four small trials (N = 209); better reporting of this outcome measure from the additional eight trials that recorded it may have improved our confidence in the pooled estimate. Global assessment and quality‐of‐life measures were poorly reported and it was not possible to carry out statistical analysis of these outcome measures. Analysis of adverse events showed an increase in the risk ratio with treatment with botulinum toxin over placebo 30% (RR 1.28, 95% CI 1.12 to 1.47, moderate‐quality evidence). For every 100 participants 60 experienced an adverse event in the botulinum toxin group compared with 47 in the placebo group.Botulinum toxin versus other prophylactic agentThree trials studied comparisons with alternative oral prophylactic medications. Meta‐analyses were not possible for number of migraine days, number of headache days or number of migraine attacks due to insufficient data, but individually trials reported no differences between groups for a variety of efficacy measures in the population of both chronic and episodic migraine participants. The global impression of disease measured using Migraine Disability Assessment (MIDAS) scores were reported from two trials that showed no difference between groups. Compared with oral treatments, botulinum toxin showed no between‐group difference in the risk of adverse events (2 trials, N = 114, very low‐quality evidence). The relative risk reduction (RRR) for withdrawing from botulinum toxin due to adverse events compared with the alternative prophylactic agent was 72% (P = 0.02, 2 trials, N = 119).Dosing trialsThere were insufficient data available for the comparison of different doses.Quality of the evidenceThe quality of the evidence assessed using GRADE methods was varied but mostly very low; the quality of the evidence for the placebo and active control comparisons was low and very low, respectively for the primary outcome measure. Small trial size, high risk of bias and unexplained heterogeneity were common reasons for downgrading the quality of the evidence.Authors' conclusionsIn chronic migraine, botulinum toxin type A may reduce the number of migraine days per month by 2 days compared with placebo treatment. Non‐serious adverse events were probably experienced by 60/100 participants in the treated group compared with 47/100 in the placebo group. For people with episodic migraine, we remain uncertain whether or not this treatment is effective because the quality of this limited evidence is very low. Better reporting of outcome measures in published trials would provide a more complete evidence base on which to draw conclusions