This paper describes the trials and tribulations of drawing on Latour’s work on ontological pluralism (An Inquiry into the Mode of Existence) to make sense of a series of recordings collected by ...participants in a sensorial urban walk focused on bacterial “field marks” that I developed with artist-researcher Louise Mackenzie. I explore the possibility that our inability fully account for the recordings should not be seen as failure but instead could be related to the generative power of compound intersections between modes of ordering. I propose that specific arrangements of mode of existences deploy the confusion that we experienced in listening to the microbial walk recordings. Drawing on Serres’s sensorial philosophy of knowledge, I suggest that caring for “neglected things” might entail attending also to incomplete, confused ways of being.
Increased use of scales in data-driven consumer digital platforms and the management of organisations has led to greater interest in understanding social and psychological measurement expertise and ...techniques as historically constituted ‘technologies of power’ in the making of what
Stark has labelled the ‘scalable subject’. Taking a genealogical approach, and drawing on published and archival data, this article focuses on self-rated health, a scale widely used in population censuses, national health surveys, patient-reported outcome measurement tools, and a variety of digital apps. The article suggests that the first methodological articulation of self-rated health by the investigators of the Cornell Study of Occupational Retirement (1951–58) provides a window into the key epistemic, institutional, and cultural uncertainties about psychological and social measurement, processes of adjustment to ‘old age’, and the capacity of individuals to value their own health. I propose that these uncertainties have become incorporated into extant and operational measurements of health.
Devicing future populations Moreira, Tiago
Social studies of science,
02/2019, Letnik:
49, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Taking as point of departure the claim that, in late modern societies, there has been shift from a focus on producing measures of life and death towards metrics of health and disability, this paper ...investigates how, through what means and processes was this transition achieved. It proposes that such questions can be addressed by analysing the transcripts and sociotechnical network of a meeting held at the United States Senate on July 15th 1983 to assess the validity and sensitivity of life expectancy forecasts. The paper analyses how members of the Hearing transformed a weakly articulated set of differing life expectancy projections into a controversy about the issue of vitality and health in populations. Analysis of the Hearing proceedings suggests that ‘calculative devices’ played a generative role in problematizing the relationship between forms of expertise, calculative procedures, data infrastructures and specific expectations of the effect of technology on health and longevity. The paper details empirically that this re-composition was possible through a collective investigation – an opening up – of key instruments in the management of populations in ‘insurance societies’.
This paper describes and explores how translational research models, embedded in institutions and standards, interact with the epistemic and material practices of cell biologists of ageing, a field ...re-energized by emergent technoscientific promises that hinge on the possibility of eliminating or manipulating senescent cells to tackle age-related diseases. Drawing on a 3-year long lab ethnography, the paper suggests that knowledge making in cell biology of ageing relies on two different epistemic and material cultures, to then argue that these cultures combine in four different types of experimental systems, only one of which can properly be seen as pertaining to translation as usually conceived. The paper further analyses how cell biologists articulate the linear temporality of translational research with the unfolding experimental chains where, by shifting between types of experimental system, cell biologists are able to generatively reconfigure their epistemic objects, and the consequences of this fragile arrangements for the field.
The Covid-19 pandemic led to an important reconfiguration of economic governance in the European Union towards deeper economic integration. This fits uneasily with predictions of an inevitable ...political 'lock-in' stemming from a responsibility-responsiveness dilemma, or an inexorably constraining politicisation. Investigating the evolution in discourses on and policies of economic governance in the EU, the papers in this collection approach the relationship between prevailing notions of responsible and responsive government as socially constructed and critically contingent upon politicisation processes. The special issue explores the reconfiguration of economic governance in the EU through multi-level analysis of politicisation, ranging from citizens' attitudes to conflicts over central banking mandates, using a variety of methodological toolkits. As the collection shows, the shift towards investment, fiscal sharing, and green transition in the new recovery programme followed the emergence of a form of 'responsive responsibility' dating back to the aftermath of the euro crisis and which has led to the incorporation of responsiveness imperatives in prevailing notions of 'responsible government'.
Highlights • The feldspathic and polymer infiltrated ceramics (Enamic) have completely different microstructures. The former present crystals while the latter is amorphous. • The lithium dissilicate ...and the Zirconia-reinforced lithium silicate presented greater susceptibility to stress corrosion than the other ceramics. • The zirconia present in the lithium silicate is tetragonal zirconia.
•Fully crystallized materials presented higher hardness and flexural strength.•The harder microstructure created after firing led to a difficulty in polishing.•After firing, zirconia was dispersed in ...the glass phase and decreased in size.
The aim of this study was to characterize the microstructure of two zirconia-reinforced lithium silicate (ZLS) glass-ceramics and evaluate their mechanical properties before and after the crystallization firing process (CFP).
Field emission-scanning electron microscope (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses were performed for microstructural characterization. To evaluate the pattern of crystallization and the molecular composition of ZLS glass-ceramics, was used X-ray diffraction (XRD). Vickers hardness, fracture toughness by the indentation method, and biaxial flexural strength were also measured. One hundred and forty ceramic discs were produced (diameter=12mm; thickness=1.2mm) and allocated among four groups (n=30): Sfir, Sunf-ZLS Vita Suprinity; and Cfir and Cunf-ZLS Celtra Duo; fired and unfired, respectively. Statistical analysis was performed and Weibull failure probabilities were calculated.
Cfir showed the highest characteristic strength (251.25MPa) and hardness (693.333±10.85GPa). Conversely, Sunf presented the lowest characteristic strength (106.95MPa) and significantly lowest hardness (597.533±33.97GPa). According to Weibull analysis, Sunf had the highest structural reliability (m=7.07), while Sfir presented the lowest (m=5.38). The CFP was necessary to crystallize zirconia in the partially crystallized ZLS glass-ceramics. Sfir had a lower percentage of crystallized zirconia than did Cfir. Fractographic analyses showed that all failures initiated from an inherent critical defect in Sunf and from processing defects in the remaining groups.
The CFP had a direct influence on the flexural strength and microstructural characteristics of both ZLS materials.
Very long chain fatty acids (VLCFAs) are essential building blocks for the synthesis of ceramides and sphingolipids. The first step in the fatty acid elongation cycle is catalyzed by the 3-keto ...acyl-coenzyme A (CoA) synthases (in mammals, ELOVL elongases). Although ELOVLs are implicated in common diseases, including insulin resistance, hepatic steatosis and Parkinson's, their underlying molecular mechanisms are unknown. Here we report the structure of the human ELOVL7 elongase, which comprises an inverted transmembrane barrel surrounding a 35-Å long tunnel containing a covalently attached product analogue. The structure reveals the substrate-binding sites in the narrow tunnel and an active site deep in the membrane. We demonstrate that chain elongation proceeds via an acyl-enzyme intermediate involving the second histidine in the canonical HxxHH motif. The unusual substrate-binding arrangement and chemistry suggest mechanisms for selective ELOVL inhibition, relevant for diseases where VLCFAs accumulate, such as X-linked adrenoleukodystrophy.
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The effect of synthesis medium (ethanol and water) on ZnO/Carbon xerogel photocatalysts was studied in order to increase the efficiency of the photocatalytic degradation of ...4-chlorophenol and bisphenol A. The use of carbon xerogel is justified due to its excellent electrical conductivity, high surface area and porosity. The effect of the carbon content in the composites was also evaluated. The composites were characterized using scanning electron microscopy, transmission electron microscopy, dispersive energy spectrometry, X-ray diffractometry, infrared spectroscopy, nitrogen isotherms, differential scanning calorimetry, thermogravimetry, electrochemical impedance spectroscopy and Raman spectroscopy. All materials present the hexagonal crystalline structure of zinc oxide. Materials without carbon in their composition also presented the zinc hydroxychloride monohydrate phase. X-ray diffractograms and bandgap values obtained confirm the incorporation of carbon in the crystalline structure of zinc oxide. Materials produced in ethanol medium have lower values of crystallite and particle size, as well as higher graphite contents in their composition and higher specific surface area. All materials displayed photocatalytic activity when subjected to visible and solar radiation. Materials produced in ethanol displayed superior performance when compared to those synthesized in aqueous medium. The maximum values found for the degradation of 4-chlorophenol and bisphenol A were 88% and 78%, respectively, after 5 h. The mechanism of photocatalysis is strongly influenced by the generation of hydroxyl radicals and the materials were stable for three cycles of reuse. The electrochemical impedance spectroscopy confirms that the charge separation efficiency was optimized in the presence of the carbon xerogel and when the composite was produced in ethanol medium.
Monocarboxylate transporters (MCTs) are essential for the use of lactate, an energy substrate known to be overproduced in brain during an ischemic episode. The expression of MCT1 and MCT2 was ...investigated at 48 h of reperfusion from focal ischemia induced by unilateral extradural compression in Wistar rats. Increased MCT1 mRNA expression was detected in the injured cortex and hippocampus of compressed animals compared to sham controls. In the contralateral, uncompressed hemisphere, increases in MCT1 mRNA level in the cortex and MCT2 mRNA level in the hippocampus were noted. Interestingly, strong MCT1 and MCT2 protein expression was found in peri-lesional macrophages/microglia and in an isolectin B4+/S100β+ cell population in the corpus callosum. In vitro, MCT1 and MCT2 protein expression was observed in the N11 microglial cell line, whereas an enhancement of MCT1 expression by tumor necrosis factor-α (TNF-α) was shown in these cells. Modulation of MCT expression in microglia suggests that these transporters may help sustain microglial functions during recovery from focal brain ischemia. Overall, our study indicates that changes in MCT expression around and also away from the ischemic area, both at the mRNA and protein levels, are a part of the metabolic adaptations taking place in the brain after ischemia.
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