718 research outputs found
Seeds as Artifacts of Communities of Practice: The Domestication of Erect Knotweed in Eastern North America
Humans are the ultimate ecosystem engineers, and in transforming ecosystems we also change the selective environment for the plants and animals that live among us. The bodies and behaviors of domesticated plants and animals are thus rich artifacts of traditional ecological knowledge and practice. I study the morphology and behavior of domesticated plants as a proxy for ancient agricultural communities of practice. The transition from food procurement to food production is one of the most significant shifts in human history. I consider this process as the evolution and spread of a knowledge system. Domestication studies are usually focused on differentiating wild from domestic types, but I wanted to investigate variation under cultivation. Normally discussed in the context of contemporary or historical small-scale farming, landraces are plant varieties that have been developed to grow particularly well under local conditions or to suit local preferences. Because landraces need to be maintained across generations of both plants and people, they are reflections of communities of practice, social learning, and Traditional Ecological Knowledge systems. By undertaking a detailed case study of variation within a single crop, I hoped to be able to use seeds in the same way that pottery, lithic tools, or iconography are used: to reveal shared traditions and connections between communities. This dissertation is focused on the lost crops of Eastern North America: a suite of annual seed crops that were cultivated for thousands of years before the introduction of maize and other tropical crops through trade. These crops are referred to as the Eastern Agricultural Complex (EAC). I chose to investigate one of these, erect knotweed (Polygonum erectum L.), which was cultivated for its edible seeds by Indigenous people in Eastern North American for ~2,000 years. My goals were 1) to establish whether or not erect knotweed had been domesticated by ancient farmers; and 2) to document variation under cultivation that might reveal different communities of practice in Eastern North America. This dissertation consists of five chapters: 1) A formal description of the domesticated sub-species of erect knotweed (Polygonum erectum ssp. watsoniae N.G. Muell.) including taxonomic background and a comparative analysis of other species of Polygonum native to the study area/ 2) An overview of domestication syndrome in a desiccated assemblage of erect knotweed from the Whitney Bluff site, Arkansas, and a discussion of its implications for ancient agricultural practice in Eastern North America. 3) The results of field studies and experimental cultivation of erect knotweed over two growing seasons, with a discussion of the hypothesized roles of plasticity and heredity in the domestication of this species. 4) An experimental study of the processes that affect preservation of erect knotweed seeds and fruits, namely: carbonization (burning in anoxic conditions) and taphonomy (physical weathering after deposition). These processes systematically bias the archaeobotanical record and need to be accounted for in domestication studies. 5) A review of the archaeological background, and a comparison of ancient erect knotweed assemblages from 14 archaeological sites spanning 2,000 years. My concluding thoughts place this research in the context of global studies of domestication and food production. I suggest that optimal foraging models used in human behavioral ecology may consistently under-rank the seeds of small seeded annuals, and that plasticity under cultivation may have been one factor that made disturbance adapted plants attractive to ancient foragers. I argue that niche construction, food production, and delayed return strategies are all roughly synonymous terms, and that domestication is a likely, but not predetermined, outcome of such systems and behaviors. The spread of food producing economies was dependent on the spread of complex systems of knowledge through interacting communities of practice and without these systems of traditional ecological knowledge domesticated varieties could not be maintained
What does Twitter say about COVID-19 vaccines?
Background and objectives: Vaccines to reduce the level of hospitalisations and death from COVID-19 became available in certain countries from December 2020. This study aimed to analyse social media content shared on Twitter regarding COVID-19 vaccines on a random day to obtain insights into publicly expressed opinions on these vaccines. Method: English language tweets, regardless of country of origin, were collected through NCapture from a 24-hour time period between 06/11/2022 and 07/11/2022 using the search term âCOVID-19 vaccinesâ. NVivo aided content analysis was conducted on all obtained tweets; tweets unrelated to the study aim were coded as irrelevant and subsequently excluded from analysis. The study was exploratory in nature, without an underlying hypothesis. Results: Overall, 1284 tweets were captured. A total of 67 different codes were created with 50 of those directly relating to opinions and/or information about COVID-19 vaccines; 41.8% of which were negative and 34.3% positive. Positive tweets related to, e.g., encouraging the public to get the vaccine; reductions in COVID-19 related health burdens; and providing links to scientific studies. In contrast, negative tweets warned of potential dangers associated with vaccines, primarily highlighting side effects; and reiterated prevalent conspiracy theories. Conclusion: Overall, opinions on Twitter regarding COVID-19 vaccines showed considerable variation on the day the tweets were captured. Nevertheless, there was a notable number of tweets providing links to reliable studies on COVID-19 vaccines, indicating that many Twitter users may aim to provide reliable information regarding COVID-19 vaccines
An umbrella review and quality assessment of renin-angiotensin system drugs use and Covid-19 outcomes : wat is the quality of the research evidence?
Background: During 2020, an extensive number of reviews were published on the effect of angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin-receptor blockers (ARBs) on COVID-19 outcomes, yet the evidence appeared heterogenous. We conducted a meta-analysis and quality assessment of these reviews. Methods: An umbrella review was conducted. Medline, Embase, Scopus, Cochrane library and medRxiv were searched on 1 February 2021. The AMSTAR 2 Critical Appraisal Tool assessed study quality. The Corrected Cover Area (CCA) calculated the degree of study overlap within the reviews. Results: In 2020/21, 47 reviews on this topic were conducted. The overall confidence in the results was most commonly âcritically lowâ (n=22, 44.9%), followed by âlowâ (n=15, 30.6%) and âmoderateâ (n=10, 21.3%). A minority (n=15, 31.9%) established a review protocol a priori. The CCA value was 9.2 indicating a moderate degree of study overlap, yet this analysis was complicated by three studies not fully reporting included studies. In total, 168 studies were known to have been included within the reviews. Most (n = 99) were included in three or less reviews, yet one study was included within 37 reviews. Collective evidence indicated good quality evidence on the significant association between ACEIs/ARBs use and reduction in death and death/ICU admission, but poor-quality evidence on reducing severe COVID-19 and increasing hospitalisation. Conclusions: The superfluous research activities are likely related to the collective interest in the topic, and limited development of review protocols a-priori. Despite quality concerns, our findings do support not discontinuing ACEIs/ARBs therapy in patients with COVID-19
An umbrella review and meta-analysis of renin-angiotensin system drugs use and COVID-19 outcomes
Abstract: Background: Despite the availability of extensive literature on the effect of angiotensinâconverting enzyme inhibitors (ACEIs)/angiotensinâreceptor blockers (ARBs) on COVIDâ19 outcomes, the evidence is still controversial. We aimed to provide a comprehensive assessment of the effect of ACEIs/ARBs on COVIDâ19ârelated outcomes by summarising the currently available evidence. Methods: An umbrella review was conducted using Medline (OVID), Embase, Scopus, Cochrane library and medRxiv from inception to 1 February 2021. Systematic reviews with metaâanalysis that evaluated the effect of ACEIs/ARBs on COVIDâ19ârelated clinical outcomes were eligible. Studies' quality was appraised using the AMSTAR 2 Critical Appraisal Tool. Data were analysed using the randomâeffects modelling including several subgroup analyses. Heterogenicity was assessed using I2 statistic. The study protocol was registered in PROSPERO (CRD42021233398) and reported using PRISMA guidelines. Results: Overall, 47 reviews were eligible for inclusion. Out of the nine COVIDâ19 outcomes evaluated, there was significant associations between ACEIs/ARBs use and each of death (OR = 0.80, 95%CI = 0.75â0.86; I2 = 51.9%), death/ICU admission as composite outcome (OR = 0.86, 95%CI = 0.80â0.92; I2 = 43.9%), severe COVIDâ19 (OR = 0.86, 95%CI = 0.78â0.95; I2 = 68%) and hospitalisation (OR = 1.23, 95%CI = 1.04â1.46; I2 = 76.4%). The significant reduction in death/ICU admission, however, was higher among studies which presented adjusted measure of effects (OR = 0.63, 95%CI = 0.47â0.84) and were of moderate quality (OR = 0.74, 95%CI = 0.63â0.85). Conclusions: Collective evidence from observational studies indicate a good quality evidence on the significant association between ACEIs/ARBs use and reduction in death and death/ICU admission, but poorâquality evidence on both reducing severe COVIDâ19 and increasing hospitalisation. Our findings further support the current recommendations of not discontinuing ACEIs/ARBs therapy in patients with COVIDâ19
The real-world use of drugs for the management of cancer in pediatric population : a scoping review protocol
Objective: The objective of the forthcoming scoping review is to investigate and describe the actual management of pediatric cancer patients who access various clinical settings. Introduction: The overall cancer management with the aid of drugs is a multifaceted process to treat the diagnosed patients, which is usually along with another treatment modalities. This process also involves controlling the emerged harmful symptoms attributed to cancer or cancer treatment using drugs in an effort to enhance patientsâ experience during treatment course and improve their quality of life, besides avoiding the long-lasting detrimental clinical impact. Inclusion criteria: All observational studies that focus on the use of drugs in cancer patients age
Tailings Dust Emissions
Fugitive dust emissions from the storage and handling of mine tailings presents environmental and safety concerns, which must be addressed to promote the land sustainability and the health and safety of individuals around a tailings storage facility (TSF). The investigated dust control methods were agglomeration, binder slurry injection, and topical spray.
The Dust Busters determined that pelletizing was the most practical method of agglomeration. In order to produce durable pellets from the mine tailings, which consist primarily of silica, a binder must be added. A variety of binders were considered including magnesium and calcium chloride, bentonite, barite, cement, vinyl polymers, acrylic polymers, starch, carboxymethyl cellulose, and a commercial lignosulfonate/bitumen blend. Portland cement proved to be the most effective binder in regards to the pelletâs cost, structural integrity, and longevity. However, due to the abrasive nature of the tailings, pelletizing is not cost effective in comparison to other dust suppression techniques.
Binder slurry injection incorporates a pugmill mixer to inject a binding agent into the tailings slurry. Addition of a binder allows the slurry mixture to form a rigid crust that prevents fugitive dust once dried on the existing tailings dam. While the injected slurry is effective at minimizing dust emissions, it is not economically feasible due to high capital costs.
The most effective, environmentally safe, and economically feasible solution to reduce the dust associated with tailings storage facilities is a topical spray solution consisting of a vinyl copolymer. The vinyl copolymer, at relatively low concentrations, produces a robust yet permeable crust along the surface of the tailings, which is unmatched in comparison to the other binding agents. By applying the binder as topical solution rather than injecting the binder into the slurry, the capital cost for effective dust suppression is reduced by eliminating the additional process equipment required for both pelletizing and binder slurry injection. Treating 400 acres per year with a vinyl copolymer application costs 240,000-130,000-$390,000 per year
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