56228 research outputs found
Sort by
Remedy and accountability a decade after the Marikana massacre
Get PDFAugust 16th, 2022 marked the 10th anniversary of the Marikana Massacre in Rustenburg, South Africa. This was the worst incident of mass killing by police since the Sharpeville Massacre in 1960 in the heyday of the Apartheid regime. In the first days of August 2012, workers at Lonmin plc, a platinum group metals mining company, went on a wildcat strike demanding a minimum salary of 12500 Rand, circa 800 USD, per month and protesting against the poor living conditions they and their families where subjected to in the Marikana vicinity, an area 100 km north of Johannesburg where the mine is located. As days passed, tension escalated leading to the killing of ten people, including three non-striking workers, two security guards, three striking workers, and two police officers. Various attempts to facilitate negotiations with striking workers were turned down by Lonmin management. Instead, Lonmin managers actively engaged in communications with senior political leaders, police officers, and state mining officials to frame the situation as one that required strong and decisive police intervention
The Pope’s Rome at the centre of the sea: the Mediterranean in the horizon of Spain’s National Catholicism (1939-1958)
No full textStudy and optimization of a recycling process for sintered Nd-Fe-B magnets at the end of their useful life.
No full textNowadays the scarcity of rare earths is a problem of significant importance due to the
indispensable role of Nd-Fe-B permanent magnets in numerous technological
applications. The international reliance on rare earth elements and the costly
manufacturing processes involved in producing these magnets pose today both
environmental and economic challenges. As the demand for rare earth permanent magnets
grows, concerns about resource scarcity, energy consumption, and waste accumulation
become more pressing.
Developing new recycling routes for Nd-Fe-B permanent magnets is crucial to address
these challenges. By establishing efficient methods to recover and reuse rare earth
containing elements from discarded or obsolete devices could significantly reduce the
need for mining new resources, helping to mitigate the environmental impact associated
with mining and processing.
For that reason, the problem of permanent magnets underscores the necessity of finding
alternative and sustainable ways to produce, utilize, and recover these crucial materials.
The development of novel recycling routes is a key step towards addressing the challenges
posed by resource scarcity, environmental concerns, and economic fluctuations,
contributing to a more sustainable future, and creating new business opportunities in the
green technology sector.
This PhD thesis aims to study new recycling routes for rare earth magnets, based on the
use of gas atomization technique to melt scrap magnets and produce Nd-Fe-B recycled
powders. This powder can be used to manufacture a new magnet. Gas atomization is a
highly interesting industrial production technique with numerous advantages, including
high productivity and lower cost compared to other production techniques.
The limitation of the gas-atomized powders lies in their low magnetic properties. For that
reason, with the aim to enhance their magnetic properties, different alternatives of heat
treatments and reactions in hydrogen atmosphere such as hydrogen decrepitation (HD)
and the hydrogenation-disproportionation-desorption-recombination (HDDR)
process will be analyzed. Moreover, the effect of some commonly used additives in Nd-
Fe-B permanent magnets, such as Nb and Ga will be analyzed. The ultimate motivation
is to enhance their magnetic properties, transforming them into a useful material to
produce both isotropic and anisotropic bonded magnets.En la actualidad, la escasez de tierras raras es un problema de gran importancia debido al
papel indispensable de los imanes permanentes de Nd-Fe-B en numerosas aplicaciones
tecnológicas. La dependencia internacional en el suministro de tierras raras, así como los
costosos procesos de fabricación involucrados en la producción de estos imanes, plantean
en la actualidad un desafío tanto ambiental como económico. A medida que crece la
demanda de imanes permanentes de tierras raras, la preocupación sobre la escasez de
recursos, el consumo de energía y la acumulación de desechos aumenta.
Desarrollar nuevas rutas de reciclaje para imanes permanentes de Nd-Fe-B es crucial
para abordar estos desafíos de la actualidad. Establecer métodos eficientes para recuperar
y reutilizar imanes que contienen tierras raras de dispositivos descartados y obsoletos
podría reducir significativamente la necesidad de extraer nuevos recursos, ayudando a
mitigar el impacto ambiental asociado con la extracción y procesamiento de estos.
Por esta razón, el problema de los imanes permanentes de tierras raras subraya la
necesidad de encontrar formas alternativas y sostenibles de producir, utilizar y recuperar
estos materiales tan cruciales. El desarrollo de nuevas rutas de reciclaje es un paso clave
para abordar los desafíos planteados por la escasez de recursos, los problemas ambientales
y las fluctuaciones económicas, lo que en última instancia contribuye a un futuro más
sostenible y crea nuevas oportunidades de negocio en el sector de la tecnología verde.
Esta tesis tiene como objetivo estudiar nuevas rutas de reciclaje de imanes de tierras raras,
basadas en el uso de la técnica de producción con atomización con gas para fundir imanes
desechados y obtener polvos reciclados de Nd-Fe-B. Este polvo puede utilizarse para
fabricar de nuevo un imán. La atomización con gas es una técnica de producción muy
interesante con numerosas ventajas, incluyendo una alta productividad y un menor coste
de producción en comparación con otras técnicas.
La limitación de los polvos atomizados con gas son sus bajas propiedades magnéticas.
Por esta razón, se analizarán diferentes alternativas de tratamientos térmicos y reacciones
en atmósfera de hidrógeno cómo la decrepitación en hidrógeno (HD) y el proceso de
hidrogenación-desproporción-desorción-recombinación (HDDR) para mejorar sus
propiedades magnéticas. Además, se analizará el efecto de algunos aleantes comúnmente
usados en los imanes de Nd-Fe-B, tales como el Nb y el Ga. La motivación final es
mejorar sus propiedades magnéticas, convirtiéndolos en un material útil para la
fabricación de imanes ligados isótropos o anisótropos
Mucus‑penetrating and permeation enhancer albumin‑based nanoparticles for oral delivery of macromolecules: Application to bevacizumab
No full textThe oral administration of therapeutic proteins copes with important challenges (mainly degradation and poor absorption)
making their potential therapeutic application extremely difficult. The aim of this study was to design and evaluate the
potential of the combination between mucus-permeating nanoparticles and permeation enhancers as a carrier for the oral
delivery of the monoclonal antibody bevacizumab, used as a model of therapeutic protein. For this purpose, bevacizumab
was encapsulated in PEG-coated albumin nanoparticles as a hydrophobic ion-pairing complex with either sodium deoxycholate (DS) or sodium docusate (DOCU). In both cases, complex formation efficiencies close to 90% were found. The
incorporation of either DS or DOCU in PEG-coated nanoparticles significantly increased their mean size, particularly when
DOCU was used. Moreover, the diffusion in mucus of DOCU-loaded nanoparticles was significantly reduced, compared
with DS ones. In a C. elegans model, DS or DOCU (free or nanoencapsulated) disrupted the intestinal epithelial integrity,
but the overall survival of the worms was not affected. In rats, the relative oral bioavailability of bevacizumab incorporated
in PEG-coated nanoparticles as a complex with DS (B-DS-NP-P) was 3.7%, a 1000-fold increase compared to free bevacizumab encapsulated in nanoparticles (B-NP-P). This important effect of DS may be explained not only by its capability to
transiently disrupt tight junctions but also to their ability to increase the fluidity of membranes and to inhibit cytosolic and
brush border enzymes. In summary, the current strategy may be useful to allow the therapeutic use of orally administered
proteins, including monoclonal antibodies
Do you get what you desire? Consequences of (mis) fit of desired versus actual servant leadership, and the role of context across 10 countries
No full textThis study explores how (in)congruence of desired and actual behaviors of servant leaders shape the outcomes of followers’ work engagement, well-being, and turnover intentions. We underline the significance of cultural context in influencing follower outcomes and, thus, integrate a gender-cultural perspective to highlight the moderating role of gender inequality on a country level. In so doing, we postulate a strong relationship between the effects of actual/desired behaviors of servant leaders upon follower work outcomes, especially in contexts where gender inequality is high. Our results from documenting the perceptions of full-time employees (n = 2,960) across 10 countries using polynomial regression analyses show that followers’ turnover intentions are lower and work engagement is higher when there is a congruence between followers’ perception of servant leadership and desired servant leadership. Moreover, we found that followers’ well-being is higher when actual and desired servant leadership is congruent as opposed to incongruent. In addition, the results show that the beneficial impact of congruence (as opposed to incongruence) is stronger in the cultural context where gender inequality is high. We contribute to the literature by showing the important impacts of (in)congruence between desired and actual servant leadership on followers’ outcomes
Innovation as a practice: Why automation will not kill innovation
No full textAs a result of contemporary culture’s focus on continuous innovation and “change before you have to,” innovation has been identified with economic gains rather than with creating added value for society. At the same time, given current trends related to the automation of business models, workers seem all but destined to be replaced by machines in the labor market. In this context, we attempt to explore whether robots and Artificial Intelligence (AI) will be able to innovate, and the extent to which said activity is exclusively inherent to human nature. Following the need for a more anthropological view of innovation, we make use of MacIntyrean categories to present innovation as a domain-relative practice with creativity and practical wisdom as its corresponding virtues. We explain why innovation can only be understood within a tradition as it implies participating in inquiry about the principle and end of practical life. We conclude that machines and “intelligent” devices do not have the capacity to innovate and they never will. They may replicate the human capacity for creativity, but they squarely lack the necessary conditions to be a locus of virtue or engage with a tradition
Carl Schmitt on the transformations of the people in modernity
Get PDFThis article argues that through the reinterpretation of the old theory of pouvoir constituant proposed by Sieyès, Carl Schmitt shows the impossibility of political modernity being anything other than authoritarian populism, whether by means of democratic or autocratic procedures. It is not that Schmitt's theory is authoritarian populism, but that modern politics, born out of the French Revolution, cannot be anything else. Schmitt's analyses of the idea of the people in political modernity in Dictatorship (1921), The Crises of Parliamentary Democracy (1923), Volksentscheid und Volksbegehren (1927), Constitutional Theory (1928), and State, Movement, People (1933) provide a fine analysis of the populist character of modernity. Something that those alive in the twenty-first century have been able to experience was theorized by Schmitt in an oracular way. Because of his keen insight he is still worth reading
TIM-3 blockade as a therapeutic approach for diffuse intrinsic pontine glioma
No full textDiffuse intrinsic pontine gliomas (DIPG) is an aggressive brain tumor and the leading cause of pediatric death caused by cancer. Despite great strides in understanding this disease, prognosis is dismal, with over 90% of patients dying within two years of diagnosis and a median overall survival time of 9-12 months. These grim statistics underscore that DIPG is an unmet clinical need. In this doctoral thesis, I have evaluated the local administration of an anti-TIM-3 antibody in anti-TIM-3 antibody in syngeneic orthotopic models of DIPG as a therapeutic approach for this disease. Our work uncovered, through in silico studies in patient datasets (whole RNAseq and scRNAseq) and samples (by multiplex IF) that TIM-3 was robustly expressed in tumor cells and tumor microenvironment, mainly in microglia and macrophages, suggesting this molecule as a potential therapeutic target in DIPGs. Mechanistic studies showed that TIM-3 provided intrinsic survival cues to the tumor cell while modulating the tumor microenvironment when expressed in the myeloid compartment. In vivo studies showed that TIM-3 blockade significantly increased the overall survival of DIPG immunocompetent orthotopic models, led to long-term survivors, and showed immune memory. TIM-3 inhibition resulted in an increase in the number and proliferative state of microglia, NK cells, and CD8+ T cells and higher levels of IFN, GrzB, and TNF&945; corresponding to NK and T-cell activate phenotypes. Interestingly, there was a decrease in the Treg population, which caused an increase in the pro-inflammatory CD8/Treg ratio. Chemokine studies demonstrated an augmentation of CCL5, CCL2 chemotactic chemokines, and CXCL10, IL-1;, and IFN- pro-inflammatory cytokines in the tumor microenvironment of treated mice. Additionally, DCs, CD4+, and CD8+ T cells were increased in treated draining lymph nodes and of functional significance, expressed higher amounts of pro-inflammatory cytokines than in control mice. Interestingly, the depletion of NK cells, CD4+, and CD8+ T cells immune populations did not completely abrogate the treatment efficacy. However, microglia and macrophages depletion with an anti-CSF1R resulted in a total loss due to a loss of microglia and CD8 T cells pro-inflammatory populations, chemokines, and cytokines indicating a critical role of these populations in the therapeutic effect of TIM-3 blockade.
This study provides a new and previously unstudied view of DIPG treatment. TIM-3 blockade emerges as an exciting alternative to classical immune checkpoints, such as PD-1, that did not obtain the desired results in DIPG clinical trials. Moreover, the lack of other effective therapies for these devastating pediatric brain tumors makes these pre-clinical results especially promising and offers strong support for initiating a clinical trial with an anti-TIM-3 antibody for the treatment of DIPG