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1.
J Environ Manage ; 356: 120751, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38531131

RESUMEN

Cost-effective treatment or even valorization of the bauxite residue (red mud) from the alumina industry is in demand to improve their environmental and economic liabilities. This study proposes a strategy that provides a near-complete conversion of bauxite residue to valuable products. The first step involves dilute acid leaching, which allowed the fractionation of raw residues into (1) an aqueous fraction rich in silica and aluminium and (2) a solid residue rich in iron, titanium and rare earth elements. For the proposed process, 91% of the original silicon, 67% of the aluminium, 78% of the scandium and 69% of the cerium were recovered. The initial cost evaluation suggested that this approach is profitable with a gross margin of 167 $US per tonne. This "Residue2Product" approach should be considered for large-scale practices as one of the most economical and sustainable solutions to this environmental and economic liability for the alumina industry.


Asunto(s)
Óxido de Aluminio , Aluminio , Óxido de Aluminio/química , Hierro , Titanio , Agua
2.
Age Ageing ; 53(2)2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-38342752

RESUMEN

BACKGROUND: The impact of the COVID-19 pandemic on long-term care residents remains of wide interest, but most analyses focus on the initial wave of infections. OBJECTIVE: To examine change over time in: (i) The size, duration, classification and pattern of care-home outbreaks of COVID-19 and associated mortality and (ii) characteristics associated with an outbreak. DESIGN: Retrospective observational cohort study using routinely-collected data. SETTING: All adult care-homes in Scotland (1,092 homes, 41,299 places). METHODS: Analysis was undertaken at care-home level, over three periods. Period (P)1 01/03/2020-31/08/2020; P2 01/09/2020-31/05/2021 and P3 01/06/2021-31/10/2021. Outcomes were the presence and characteristics of outbreaks and mortality within the care-home. Cluster analysis was used to compare the pattern of outbreaks. Logistic regression examined care-home characteristics associated with outbreaks. RESULTS: In total 296 (27.1%) care-homes had one outbreak, 220 (20.1%) had two, 91 (8.3%) had three, and 68 (6.2%) had four or more. There were 1,313 outbreaks involving residents: 431 outbreaks in P1, 559 in P2 and 323 in P3. The COVID-19 mortality rate per 1,000 beds fell from 45.8 in P1, to 29.3 in P2, and 3.5 in P3. Larger care-homes were much more likely to have an outbreak, but associations between size and outbreaks were weaker in later periods. CONCLUSIONS: COVID-19 mitigation measures appear to have been beneficial, although the impact on residents remained severe until early 2021. Care-home residents, staff, relatives and providers are critical groups for consideration and involvement in future pandemic planning.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , COVID-19/terapia , Casas de Salud , Estudios Retrospectivos , Pandemias , Web Semántica , Estudios de Cohortes
3.
J Sports Sci ; : 1-12, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38293847

RESUMEN

Ecological approaches in sport consider that athletes adapt to properties of the task and the surrounding environment. Thus, task and environment are key constraints of performance. Yet, the influence of task and environmental constraints on athletes' performance needs empirical examination, especially in sport-specific contexts such as soccer goalkeeping. This study aimed to examine if and how task and environmental constraints influenced goalkeepers (GKs') performances. We monitored performance coefficients of two professional female GKs across 13 training tasks that varied based on 9 constraints, referring to both interactions among athletes and properties of the surrounding landscape. Results showed that constraints explain ~ 47% of the observed variability in GKs' performances. Numerical complexity (i.e., the potential interactions between athletes) showed a major influence on performance, which indicates that number of interactions among athletes may constrain GKs' perceived opportunities for action. Field dimensions and landscape representativity (including elements such as penalty area(s), target goal(s) and constraints for shooting) showed positive relationships with performance, supporting that training designs retaining closer proximity to the game may benefit GKs' performances. Overall, results supported that athlete-environment couplings could be understood as a multifactorial model and hence, a combination of task constraints are necessary for designing effective learning environments.

4.
J Sports Sci ; : 1-10, 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-38095157

RESUMEN

Socio-cultural constraints shape behaviour in complexifying ways. In sport, for example, interconnected constraints play an important role in shaping the way a game is played, coached, and spectated. Here, we contend that player development frameworks in sport cannot be operationalised without careful consideration of the complex ecosystem in which they reside. Concurrently, we highlight issues associated with frameworks designed in isolation from the contexts in which they are introduced for integration, guised as trying to "copy and paste" templates from country to country. As such, there is a need to understand the oft-shrouded socio-cultural dynamics that continuously influence practice in order to maximize the utility of player development frameworks in sport. Ecological dynamics offers a complexity-oriented theoretical lens that supports the evolution of context-dependent player development frameworks. Further, tenets of the Learning in Development Research Framework can show how affordances are not just material invitations but constitute a vital component of a broader socio-cultural form of life. These ideas have the potential to: (1) push against a desire to "copy and paste" what is perceived to be "successful" elsewhere, and (2), guide the integration of player development frameworks by learning to resonate with the nuanced complexities of the broader environment inhabited.

5.
Front Sports Act Living ; 5: 1169531, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37361408

RESUMEN

Underpinned by an ecological dynamics rationale, the Learning in Development Research Framework (LDRF) has been suggested to introduce methodological possibilities to investigate and illuminate: (i) socio-cultural constraints within a sports organization or club, and (ii), a research gap on the need for a more contemporary framework to guide reliable ways of conducting investigations and designing practical applications. To provide a strong justification for the nature of the fieldwork and methods adopted, we present insights from a 3-year and 5-month study at a professional football club in Sweden that adapted the framework as a central feature of their Department of Methodology for player development. A phronetic iterative approach was employed to analyze the data. The findings highlight the nature of constraints acting over varied timescales, transcending contexts to manifest in other contexts (e.g., practice task designs), influencing events and experiences. This indicated a need to dampen (using probes) the influence of the pervasive organizational "control over context" approaches that were acting as "sticky" socio-cultural constraints, shaping the intentions (in session design) and attention (during practice and performance) of players and coaches. A practical implication is that the LDRF does not prescribe a universal solution to player development. Rather that it can guide how researchers, practitioners, clubs and organisations could challenge themselves to adapt strategies to design contemporary athlete development frameworks within their ecosystem.

6.
RSC Adv ; 12(33): 21468-21481, 2022 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-35975085

RESUMEN

Processing spodumene for lithium is challenging as it requires a high temperature transformation of the natural α-monoclinic form to ß-tetragonal form, usually followed by acid baking and digestion. This three-step extraction process requires significant heat energy, acid, process complexity and residence time, leading to both operating and capital costs. An approach which helps to eliminate this challenge will therefore be a milestone in processing spodumene. This study, thus, investigates a direct chlorination of α-spodumene using calcium chloride followed by water leaching of the residue to recover lithium, which reduces the energy requirement and number of unit operations. HSC Chemistry software was used to simulate the process using both phases (α and ß) of the mineral up to 1100 °C prior to experimental investigation. The α-form was the only polymorph identified in residues after leaching, suggesting that the extraction is directly from the α-phase. However, an initial formation of a metastable ß-form followed by a fast synthesis of lithium chloride from it is also suspected. Under optimal conditions of calcium chloride/spodumene molar ratio of 2.0, and 1000 °C treatment for 60 minutes, almost 90 percent lithium chloride was extracted and 85 percent was recovered to the leach solution with the remainder exiting with the off-gas. An apparent activation energy of about 122 ± 6 kJ mol-1 was obtained at temperatures ranging from 800 to 950 °C during the process.

7.
Front Sports Act Living ; 4: 832111, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35669555

RESUMEN

In this paper, we consider how youth sport and (talent) development environments have adapted to, and are constrained by, social and cultural forces. Empirical evidence from an 18-month ethnographic case study highlights how social and cultural constraints influence the skill development and psychological wellbeing of young football players. We utilized novel ways of knowing (i.e., epistemologies) coupled to ecological frameworks (e.g., the theory of ecological dynamics and the skilled intentionality framework). A transdisciplinary inquiry was used to demonstrate that the values which athletes embody in sports are constrained by the character of the social institutions (sport club, governing body) and the social order (culture) in which they live. The constraining character of an athlete (talent) development environment is captured using ethnographic methods that illuminate a sociocultural value-directedness toward individual competition. The discussion highlights how an emphasis on individual competition overshadows opportunities (e.g., shared, and nested affordances) for collective collaboration in football. Conceptually, we argue that these findings characterize how a dominating sociocultural constraint may negatively influence the skill development, in game performance, and psychological wellbeing (via performance anxiety) of young football players in Stockholm. Viewing cultures and performance environments as embedded complex adaptive systems, with human development as ecological, it becomes clear that microenvironments and embedded relations underpinning athlete development in high performance sports organizations are deeply susceptible to broad cultural trends toward neoliberalism and competitive individualism. Weaving transdisciplinary lines of inquiry, it is clarified how a value directedness toward individual competition may overshadow collective collaboration, not only amplifying socio-cognitive related issues (anxiety, depression, emotional disturbances) but simultaneously limiting perceptual learning, skill development, team coordination and performance at all levels in a sport organization.

8.
J Environ Manage ; 316: 115216, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35550960

RESUMEN

In treating mine-impacted waters using sulfate-reducing bacteria (SRB), metal inhibition and substrate selection are important factors affecting the efficiency of the bioprocess. This work investigated the role of the substrate (i.e. lactate, formate, glycerol and glucose) on Ni inhibition to SRB with sulfate-reducing activity tests at initial pH 5, 7 and 9 and 100 mg/L of Ni. Results indicated that the type of substrate was a significant factor affecting Ni inhibition in SRB, which was the most negligible in the lactate system, followed by glycerol, glucose, and formate. Although less significant, Ni inhibition also varied with the pH, leading for instance, to a reduction of 77% in the sulfate reducing activity for the formate system, but only of 28% for lactate at pH 5. The added substrate also influenced the precipitation kinetics and the characteristics of the precipitates, reaching Ni precipitation extents above 95%, except for glucose (83.2%).


Asunto(s)
Desulfovibrio , Glicerol , Formiatos , Glucosa , Lactatos , Sulfatos
9.
Early Interv Psychiatry ; 16(12): 1269-1277, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35393743

RESUMEN

AIM: Population-level profiles of risk for later childhood mental disorders have been identified in patterns of early developmental vulnerabilities using Australian Early Developmental Census. We sought to demonstrate the geographical distribution of these early childhood risk profiles for mental illness, to inform policy decisions for place-sensitive provision of health and allied services. METHODS: Using geographic information system techniques, we mapped the regional percentage of children at highest risk for mental disorders across the state of New South Wales (NSW), according to Local Government Areas, for 82 891 children in the NSW Child Development Study. RESULTS: A high proportion (>10%) of children at risk of later mental disorders were located in regional and socioeconomically disadvantaged areas, with a few metropolitan regions showing similarly high proportions of the population at risk. CONCLUSIONS: These findings highlight the potential to identify place-sensitive needs for early intervention and prevention programs for emerging mental health problems in children.


Asunto(s)
Trastornos Mentales , Niño , Preescolar , Humanos , Australia/epidemiología , Trastornos Mentales/epidemiología , Nueva Gales del Sur/epidemiología , Factores de Riesgo
11.
Materials (Basel) ; 14(23)2021 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-34885577

RESUMEN

Spodumene concentrate from the Pilbara region in Western Australia was characterized by X-ray diffraction (XRD), Scanning Electron Microscope Energy Dispersive Spectroscopy (SEM-EDS) and Mineral Liberation Analysis (MLA) to identify and quantify major minerals in the concentrate. Particle diameters ranged from 10 to 200 microns and the degree of liberation of major minerals was found to be more than 90%. The thermal behavior of spodumene and the concentration of its polymorphs were studied by heat treatments in the range of 900 to 1050 °C. All three polymorphs of the mineral (α, γ and ß) were identified. Full transformation of the α-phase was achieved at 975 °C and 1000 °C after 240 and 60 min treatments, respectively. SEM images of thermally treated concentrate revealed fracturing of spodumene grains, producing minor cracks initially which became more prominent with increasing temperature. Material disintegration, melting and agglomeration with gangue minerals were also observed at higher temperatures. The metastable γ-phase achieved a peak concentration of 23% after 120 min at 975 °C. We suggest 1050 °C to be the threshold temperature for the process where even a short residence time causes appreciable transformation, however, 1000 °C may be the ideal temperature for processing the concentrate due to the degree of material disintegration and α-phase transformation observed. The application of a first-order kinetic model yields kinetic parameters which fit the experimental data well. The resultant apparent activation energies of 655 and 731 kJ mol-1 obtained for α- and γ-decay, respectively, confirm the strong temperature dependence for the spodumene polymorph transformations.

12.
Sports Med Open ; 7(1): 55, 2021 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-34342764

RESUMEN

The promotion of inter- and multidisciplinarity - broadly drawing on other disciplines to help collaboratively answer important questions to the field - has been an important goal for many professional development organisations, universities, and research institutes in sport science. While welcoming collaboration, this opinion piece discusses the value of transdisciplinary research for sports science. The reason for this is that inter- and multidisciplinary research are still bound by disciplinary convention - often leading sport science researchers to study about a phenomenon based on pre-determined disciplinary ways of conceptualising, measuring, and doing. In contrast, transdisciplinary research promotes contextualised study with a phenomenon, like sport, unbound by disciplinary confines. It includes a more narrative and abductive way of performing research, with this abduction likely opening new lines of inquiry for attentive researchers to follow. It is in the weaving of these lines where researchers can encounter new information, growing knowledge in-between, through, and beyond the disciplines to progressively entangle novel and innovative insights related to a phenomenon or topic of interest. To guide innovation and the development of such research programmes in sport science, we lean on the four cornerstones of transdisciplinarity proposed by Alfonso Montuori, exemplifying what they could mean for such research programmes in sport science.

13.
Front Psychol ; 12: 635420, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34305709

RESUMEN

In this manuscript, we extend ecological approaches and suggest ideas for enhancing athlete development by utilizing the Skilled Intentionality Framework. A broad aim is to illustrate the extent to which social, cultural and historical aspects of life are embodied in the way football is played and the skills young footballers develop during learning. Here, we contend that certain aspects of the world (i.e., environmental properties) are "weighted" with social and cultural significance, "standing out" to be more readily perceived and simultaneously acted upon when playing football. To comprehend how patterns of team coordination and athletic skill embody aspects of culture and context we outline the value-directedness of player-environment intentionality. We demonstrate that the values an individual can express are constrained by the character of the social institutions (i.e., football clubs) and the social order (i.e., form of life) in which people live. In particular, we illuminate the extent to which value-directedness can act as a constraint on the skill development of football players "for good or ill." We achieve this goal by outlining key ecological and relational concepts that help illustrate the extent to which affordances are value-realizing and intentionality is value-directed (exemplified, by footballers performing in a rondo). To enhance coaching practice, we offer: (a) insights into markers of skilled intentionality, and (b), the language of skilled intentions, as well as highlighting (c), an additional principle of Non-linear Pedagogy: Shaping skilled intentions, or more precisely shaping the value-directedness of player-environment intentionality. We contend that, if sport practitioners do not skilfully attend to sociocultural constraints and shape the intentions of players within training environments and games, the social, cultural, and historic constraints of their environment will do so: constantly soliciting some affordances over others and directing skill development.

14.
Lancet Public Health ; 6(9): e692-e695, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34310906

RESUMEN

Drowning is a leading killer, particularly of children and young adults, yet has been greatly neglected. Despite accounting for a higher number of deaths than many other substantial public health issues, drowning has not benefitted from the targeted attention it requires, which is particularly tragic because low cost and effective drowning prevention interventions exist. Therefore, the recent UN General Assembly's adoption of a resolution on global drowning prevention is a historic first, and offers an exciting opportunity by providing a comprehensive framework and a practical roadmap that a range of actors and sectors, including governments, can follow to address the challenge of drowning prevention.


Asunto(s)
Ahogamiento/mortalidad , Ahogamiento/prevención & control , Salud Global , Humanos , Salud Pública , Naciones Unidas
15.
Age Ageing ; 50(5): 1482-1492, 2021 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-33963849

RESUMEN

BACKGROUND: understanding care-home outbreaks of COVID-19 is a key public health priority in the ongoing pandemic to help protect vulnerable residents. OBJECTIVE: to describe all outbreaks of COVID-19 infection in Scottish care-homes for older people between 01/03/2020 and 31/03/2020, with follow-up to 30/06/2020. DESIGN AND SETTING: National linked data cohort analysis of Scottish care-homes for older people. METHODS: data linkage was used to identify outbreaks of COVID-19 in care-homes. Care-home characteristics associated with the presence of an outbreak were examined using logistic regression. Size of outbreaks was modelled using negative binomial regression. RESULTS: 334 (41%) Scottish care-homes for older people experienced an outbreak, with heterogeneity in outbreak size (1-63 cases; median = 6) and duration (1-94 days, median = 31.5 days). Four distinct patterns of outbreak were identified: 'typical' (38% of outbreaks, mean 11.2 cases and 48 days duration), severe (11%, mean 29.7 cases and 60 days), contained (37%, mean 3.5 cases and 13 days) and late-onset (14%, mean 5.4 cases and 17 days). Risk of a COVID-19 outbreak increased with increasing care-home size (for ≥90 beds vs <20, adjusted OR = 55.4, 95% CI 15.0-251.7) and rising community prevalence (OR = 1.2 [1.0-1.4] per 100 cases/100,000 population increase). No routinely available care-home characteristic was associated with outbreak size. CONCLUSIONS: reducing community prevalence of COVID-19 infection is essential to protect those living in care-homes. More systematic national data collection to understand care-home residents and the homes in which they live is a priority in ensuring we can respond more effectively in future.


Asunto(s)
COVID-19 , Anciano , Estudios de Cohortes , Brotes de Enfermedades , Humanos , Casas de Salud , SARS-CoV-2 , Escocia/epidemiología , Web Semántica
16.
J Hazard Mater ; 410: 124553, 2021 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-33223312

RESUMEN

Knowledge of the behavior of technologically enhanced naturally occurring radioactive materials derived through the decay of U and its daughter products, and their subsequent fractionation, mobilization and retention, is essential to develop effective mitigation strategies and long-term radiological risk prediction. In the present study, multiple state-of-the-art, spatially resolved micro-analytical characterization techniques were combined to systematically track the liberation and migration of radionuclides (RN) from U-bearing phases in an Olympic Dam Cu flotation concentrate following sulfuric-acid-leach processing. The results highlighted the progressive dissolution of U-bearing minerals (mainly uraninite) leading to the release, disequilibrium and ultimately upgrade of daughter RN from the parent U. This occurred in conjunction with primary Cu-Fe-sulfide minerals undergoing coupled-dissolution reprecipitation to the porous secondary Cu-mineral, covellite. The budget of RN remaining in the leached concentrate was split between RN still hosted in the original U-bearing minerals, and RN that were mobilized and subsequently sorbed/precipitated onto porous covellite and auxiliary gangue mineral phases (e.g. barite). Further grinding of the flotation concentrate prior to sulfuric-acid-leach led to dissolution of U-bearing minerals previously encapsulated within Cu-Fe-sulfide minerals, resulting in increased release and disequilibrium of daughter RN, and causing further RN upgrade. The various processes that affect RN (mobility, sorption, precipitation) and sulfide minerals (coupled-dissolution reprecipitation and associated porosity generation) occur continuously within the hydrometallurgical circuit, and their interplay controls the rapid and highly localized enrichment of RN. The innovative combination of tools developed here reveal the heterogeneous distribution and fractionation of the RN in the ores following hydrometallurgical treatment at nm to cm-scales in exquisite detail. This approach provides an effective blueprint for understanding of the mobility and retention of U and its daughter products in complex anthropogenic and natural processes in the mining and energy industries.

17.
J Hazard Mater ; 402: 123506, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-32712361

RESUMEN

This study evaluated the differences in nickel (Ni) and cobalt (Co) solubility in the presence of sulfate reducing bacteria (SRB) to evaluate the feasibility of selective recovery of both metals from mine-impacted waters. A series of sulfate reducing activity tests with Ni, Co and both metals showed that up to 99 % Ni remained soluble despite the availability of sulfide for precipitation, while Co sulfide precipitation always occurred (over 84.5 %). The characterization of proteins in the liquid phase of the experiments revealed that some proteins were only produced in the experiments where Ni displayed higher solubility, suggesting their involvement in metal complexation. Some functions of these proteins included maintaining Ni homeostasis, acting as metalloenzymes and containing Ni-binding ligands. Desulfomicrobium baculatum, Stenotrophomonas maltophilia, and Desulfovibrio magneticus, were the main responsible species producing these proteins.


Asunto(s)
Cobalto , Níquel , Desulfovibrio , Desulfovibrionales , Sulfatos
18.
Ann Diagn Pathol ; 48: 151585, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32829067

RESUMEN

CD200 is a membrane protein with immunosuppressive function and is expressed in many hematopoietic neoplasms, including acute myeloid leukemia (AML), plasma cell myeloma (PCM), and B-cell lymphoproliferative disorders, but is mostly negative in diffuse large cell lymphoma (DLBCL). CD200 has been shown to be a poor prognostic marker in AML and PCM; in AML, its immunomodulatory effect was linked to its ability to induce FoxP3(+) regulatory T cells (Tregs). Post-transplant lymphoproliferative disorders (PTLDs) arise in the setting of immune dysregulation, and tumor-infiltrating T cells, including Tregs, have been shown to correlate with outcome in these disorders. Because there is no literature data and CD200 is a potentially useful diagnostic and prognostic marker, we studied the expression of CD200 in a series of 38 PTLDs by immunohistochemistry (ICH), and found that 23.7% PTLDs were CD200(+) and showed strong membrane and cytoplasmic positivity in the neoplastic cells. All CD200(+) monomorphic PTLDs were DLBCLs and the median FoxP3(+) Treg count/hpf was higher in CD200(+) than in CD200(-) PTLDs: 22.6 vs. 0.30 (p < 0.001). These results indicated that almost a quarter of PTLDs in our series are CD200(+) by IHC, and CD200 expression correlates with the frequency of immunosuppressive Tregs. This is novel data and supports a pathophysiologic link between CD200 activity and Tregs. In our series, the 5-year overall survival was shorter in CD200(+) PTLDs, compared to CD200(-) patients, although this difference did not reach statistical significance. In addition, we find a higher proportion of CD200(+) monomorphic PTLD-DLBCLs (31.0%), as compared to de novo DLBCLs (7-8%, as found here and in other studies). This may indicate differential expression of CD200 in B-cell lymphomas arising in the setting of immune dysregulation, and raises the possibility of anti-CD200 immunotherapy for these cases.


Asunto(s)
Antígenos CD/metabolismo , Factores de Transcripción Forkhead/metabolismo , Trastornos Linfoproliferativos/patología , Linfocitos T Reguladores/inmunología , Trasplantes/metabolismo , Adulto , Anciano , Antígenos CD/inmunología , Antígenos CD/farmacología , Estudios de Casos y Controles , Diagnóstico Diferencial , Femenino , Humanos , Leucemia Mieloide Aguda/metabolismo , Linfoma de Células B Grandes Difuso/metabolismo , Trastornos Linfoproliferativos/inmunología , Trastornos Linfoproliferativos/terapia , Masculino , Persona de Mediana Edad , Mieloma Múltiple/metabolismo , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia , Trasplantes/inmunología , Trasplantes/patología
19.
Front Psychol ; 10: 2090, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31572271

RESUMEN

The challenge of developing creativity to enhance human potential is conceptualized as a multifaceted wicked problem due to the countless interactions between people and environments that constitute human development, athletic skill, and creative moments. To better comprehend the inter-relatedness of ecologies and human behaviors, there have been increasing calls for transdisciplinary approaches and holistic ecological models. In this paper we explore an ecological dynamics rationale for creativity, highlighting the conceptual adjacency of key concepts from transdisciplinarity, dynamic systems theory, ecological psychology and social-cognitive psychology. Our aim is to extend the scope of ecological dynamics and contextualize the application of non-linear pedagogy in sport. Foregrounding the role of sociocultural constraints on creative behaviors, we characterize the athlete-environment system as an ecological niche that arises from, and simultaneously co-creates, a form of life. We elaborate the notion that creative moments, skill and more generally talent in sport, are not traits possessed by individuals alone, but rather can be conceived as properties of the athlete-environment system shaped by changing constraints. This re-conceptualization supports a pedagogical approach predicated on notions of athletes and sports teams as complex adaptive systems. In such systems, continuous non-linear interactions between system components support the exploration of fluent and flexibly creative performance solutions by athletes and sports teams. The implications for practice suggest that cultivating a constellation of constraints can facilitate adaptive exploration of novel affordances (opportunities/invitation for action), fostering creative moments and supporting creative development in athletes. Future models or frameworks for practice contend that pedagogies should emerge from, and evolve in, interaction with the sociocultural context in which practitioners and athletes are embedded.

20.
J Hazard Mater ; 380: 120725, 2019 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-31279943

RESUMEN

The longest-lived naturally occurring isotope of polonium is polonium-210, one of the daughters of uranium-238 (138 days half-life). As a daughter radionuclide of radon-222, polonium-210 can become enriched in pore fluids in U-bearing rocks, leading to contents in excess of 100 Bq.g-1 in some products from the mineral, coal, oil and gas industries (e.g., anode slimes in copper refinement; sludge from the oil and gas industry). Since 2006, IAEA recommendation limits require polonium and other radionuclides from the U- and Th-series decay to be regulated for products and wastes that contain >1 Bq.g-1, which results in the classification of large amounts of industrial products and waste as radioactive. To develop effective methods for polonium removal and/or control, it is necessary to acquire an understanding of its aqueous chemistry. Based on a review of available experimental data, we developed a self-consistent thermochemical model for polonium in inorganic aqueous solutions. Polonium exists mainly in two oxidation states in aqueous solutions: Po(IV) and Po(II). The importance of Po(II) is unique, as Te(II) or Se(II) complexes do not appear to play a significant role in aqueous solution at room temperature. The model is used to discuss polonium speciation in some environmental and process waters.

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