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Growing cybernetic ears: transduction and performativity in the analogue and digital what have you
At a time when digital technologies have become ubiquitous in music making, and where the majority of research into music technology happens at the computational âcutting edgeâ, this practice-based PhD explores analogue technologies deemed, in the main, obsolete, anachronistic, or as quaint nostalgic throwbacks, and asks how a combination of technological, historical and practice-based research, focused through commitment to artistic outputs in the domain of music technology, might shed new light on the terms analogue and digital, and on the nature of the analogue-digital relationship.
Underlying much contemporary enthusiasm for âthe digitalâ are progress narratives that rely on both a succession logic (old analogue technology gets replaced by new digital technology) and an assumption of isomorphism (the digital technology does all the same things as the replaced technology, though often with âenhancedâ affordances). This thesis questions such assumptions along historical, philosophical and practice-based trajectories.
Key to these research trajectories is the trans-discipline cybernetics, in particular the second-order cybernetics of Gordon Pask, whose self-designation âphilosophical mechanicâ indicates the importance he placed on a cyclical, mutually accommodating thinking-designing-making. Pask presented a powerful practical methodology for the examination and creation of dynamical systems in flux, systems that evolve as a result of participant interaction, systems that can be seen to manifest self-organisation. Second-order cybernetics puts the emphasis on processes in interaction rather than positing pre-existing objects (including concepts) in a world âout thereâ. Cybernetics helps us to explore systems whose complexity and interdependence precludes the separation out into constituent parts, systems where control is shared across multiple mutually interacting dimensions, and where the observer is a committed participant whose actions, interests and biases cannot be divorced from the interactions therein.
Two other key concepts are: (1) transduction, which relates energy, information, patterns of growth, or other dynamical processes across media or between domains; (2) performativity, an interventional act that brings forth a world. Transduction is essential to an understanding of recording studio processes and practices: the microphone, signal processing and recording itself all rely on transduction. When viewed from a performative perspective, actions such as recording are found to be carried out very differently when the final stage of transduction is discrete (the case with the now ubiquitous digital audio workstation) or continuous (such as recording to tape). This difference is primarily due to the hyper-plasticity of digital audio, a taking of sound âout of timeâ. Rather than seeing this as an evolution of âprecursorâ analogue technologies, as most accounts have it, this thesis takes the perspective that this is a difference in kind, rather than one of degree, and explores that difference with a particular focus on emergent and intertwined cultural, embodied and technological systems, rather than on end products.
The second half of the thesis presents the compositional practice, ranging from experimental work on tape music composition and installation, through a series of modular synthesis live performances, to tape-based recording of pop music. The physical, gestural engagement with the resistant materiality of these technologies emphasises a very different cognitive engagement with processes of composition and production to that which happens with supposed âsuccessorâ digital technologies; assumptions of isomorphism, buttressed by skeuomorphic emulation, tend to occlude this cognitive distinction.
This thesis is offered as an act of cybernetic musicking â resolutely practical in orientation, with a wide-ranging, trans-disciplinary theoretical framework, and with the emphasis not on things but on ongoing processes in complex interaction with a world in constant becoming
Iron conservation by reduction of metalloenzyme inventories in the marine diazotroph Crocosphaera watsonii
The marine nitrogen fixing microorganisms (diazotrophs) are a major source of nitrogen to open ocean ecosystems and are predicted to be limited by iron in most marine environments. Here we use global and targeted proteomic analyses on a key unicellular marine diazotroph Crocosphaera watsonii to reveal large scale diel changes in its proteome, including substantial variations in concentrations of iron metalloproteins involved in nitrogen fixation and photosynthesis, as well as nocturnal flavodoxin production. The daily synthesis and degradation of enzymes in coordination with their utilization results in a lowered cellular metalloenzyme inventory that requires ~40% less iron than if these enzymes were maintained throughout the diel cycle. This strategy is energetically expensive, but appears to serve as an important adaptation for confronting the iron scarcity of the open oceans. A global numerical model of ocean circulation, biogeochemistry and ecosystems suggests that Crocosphaeraâs ability to reduce its iron-metalloenzyme inventory provides two advantages: It allows Crocosphaera to inhabit regions lower in iron and allows the same iron supply to support higher Crocosphaera biomass and nitrogen fixation than if they did not have this reduced iron requirement.National Science Foundation (U.S.). Chemical and Biological Oceanography Program (OCE-0452883)National Science Foundation (U.S.). Chemical and Biological Oceanography Program (OCE-0752291)National Science Foundation (U.S.). Chemical and Biological Oceanography Program (OCE-0723667)National Science Foundation (U.S.). Chemical and Biological Oceanography Program (OCE-0928414)National Science Foundation (U.S.). Polar Program (ANT-0732665)United States. Environmental Protection Agency (Star Fellowship)Woods Hole Oceanographic Institution. Ocean Life InstituteCenter for Microbial Oceanography: Research and EducationCenter for Environmental Bioinorganic Chemistr
Proceedings of the XVIIIth Telemac & Mascaret User Club 2011, 19-21 October 2011, EDF R&D, Chatou
Water Qualit
A platform to restore intra-tissue flow in live explant assays
Tissue resection during first-line surgery is a standard strategy in the clinic for several life-threatening diseases, such as cancer. In case of malignancy, despite the benefits from surgery, cancer often becomes treatment-resistant and metastasises, limiting therapeutic options and patient survival. Due to tumour heterogeneity, treatment personalisation can improve patient outcomes, however tools based on native tissue samples, used for patient-specific drug screening remain very limited. This is primarily due to the diffusion-limited mass transport in static culture conditions, where tissue viability is rapidly reduced due to ischemia. Our aim is to develop a platform that restores intra-tissue flow through native tissue specimens to prolong their preservation ex vivo.
Flow of culture media around tissue specimens has been commonly used for sample preservation. However, the efficacy of most currently available platforms has been limited, as ex vivo specimen perfusion is not facilitated in these technologies. As fluid is allowed to travel around specimen periphery, intra-tissue flow is hydraulically disadvantaged and benefits from culture media renewal only affect cells within 200 ÎŒm from explant surface. In this thesis, a novel system is presented that comprises a channel-based device with a suitably-designed constriction to block peri-fusion (i.e. flow around the tissue) and facilitate specimen entrapment and perfusion.
Using a syringe pump, device efficacy to facilitate intra-tissue flow was investigated, showing that the induced perfusion occurred through both the vasculature and the interstitium. The effects of perfusion on specimen maintenance and function were also investigated. It was showed that healthy mouse liver and cancerous mouse and human omental specimens were better preserved under perfused conditions in the developed apparatus for 48h. Intra-tissue flow was also effective to inhibit cell metabolism after a 2h-specimen perfusion with a metabolic poison, suggesting this system may have great potential for predictive, live explant assays.Open Acces
Hydrodynamic behavior of packed-bed reactors on a floating platform : liquid distribution and drainage dynamics
Pour combler l'Ă©cart entre l'augmentation de la demande Ă©nergĂ©tique et l'Ă©puisement de la production d'hydrocarbures onshore, l'exploitation des hydrocarbures offshore est de plus en plus envisagĂ©e, en particulier les gisements de gaz / pĂ©trole dans les eaux plus profondes. En attendant, un grand nombre d'unitĂ©s de traitement dĂ©ployĂ©es pour la production d'hydrocarbures doivent respecter les contraintes environnementales conçues pour la protection maritime. Les systĂšmes tels que les rĂ©acteurs et les Ă©purateurs Ă lit fixe embarquĂ©s deviennent inĂ©vitablement l'une des options les plus prometteuses pour atteindre ces deux objectifs. De nombreux efforts dans la littĂ©rature pour dĂ©voiler l'hydrodynamique de l'Ă©coulement multiphasĂ© dans les lits garnis rĂ©vĂšlent que des dĂ©fis persistent soit dans leur conception / mise Ă l'Ă©chelle, soit dans leurs opĂ©rations. De plus, exposer ces rĂ©acteurs Ă des conditions marines difficiles telles que la convolution de la dynamique des navires et de l'hydrodynamique Ă l'intĂ©rieur des rĂ©acteurs Ă lit fixe conduit Ă des situations encore plus compliquĂ©es pour maintenir des performances de fonctionnement acceptables dans les conditions flottantes. Un grand nombre de preuves issues de la littĂ©rature a jusqu'Ă prĂ©sent mis en Ă©vidence l'Ă©chec des colonnes garnies avec des garnissages alĂ©atoires, des garnissages structurĂ©s ou des mousses Ă alvĂ©oles ouvertes, pour empĂȘcher la maldistribution des liquides dans les lits fixes destinĂ©s Ă fonctionner Ă bord de navires ou de platesformes flottantes. Les efforts de recherche doivent donc se poursuivre dans le but de trouver des composants internes robustes et capables de rĂ©silience contre la maldistribution des liquides dans les rĂ©acteurs / unitĂ©s de sĂ©paration gaz-liquide. Ce projet de doctorat sâest proposĂ© des recherches visant dans un premier temps de tester des internes disponibles commercialement pouvant prĂ©server des performances similaires Ă celles des unitĂ©s terrestres classiques. Au meilleur de notre connaissance, la sensibilitĂ© et la susceptibilitĂ© des rĂ©acteurs monolithes Ă une mauvaise distribution soumis Ă des conditions offshore n'ont pas encore Ă©tĂ© Ă©tudiĂ©es. PlutĂŽt que de se concentrer uniquement sur une Ă©tude des lits monolithiques, le chapitre 1 opte pour une campagne expĂ©rimentale plus large comprenant un garnissage alĂ©atoire et un garnissage en mousse Ă cellules ouvertes pour des comparaisons systĂ©matiques de la distribution des liquides en conditions flottantes. La distribution liquide des colonnes embarquĂ©es garnies de divers garnissages et pour une large plage de dĂ©bit gaz / liquide est systĂ©matiquement comparĂ©e Ă l'aide d'un capteur Ă treillis mĂ©tallique (WMS) et d'un Ă©mulateur hexapode Ă six degrĂ©s de libertĂ©. La vraisemblance de conditions mĂ©tĂ©orologiques extracĂŽtiĂšres rudes pourrait menacer la suretĂ© de l'exploitation des lits fixes, en particulier dans des situations extrĂȘmes telles que des cyclones, des Ă©pisodes d'icebergs, etc. Pour assurer la sĂ©curitĂ© du personnel et des installations, lâopĂ©ration des colonnes garnies Ă bord doit ĂȘtre immĂ©diatement interrompue pour Ă©viter des problĂšmes de sĂ©curitĂ© critiques sous de telles circonstances. Par consĂ©quent, la base de connaissances sur la dynamique de drainage des liquides dans les lits flottants est iv essentielle pour assurer une vidange rapide du liquide. NĂ©anmoins, l'Ă©tude de la dynamique du drainage liquide des lits fixes en conditions flottantes est Ă tout le moins rare. Par consĂ©quent, le chapitre 2 se propose de comparer expĂ©rimentalement le drainage du liquide dans des colonnes garnies dans les conditions marines Ă celui observĂ© dans une colonne statique verticale Ă lâinstar des applications terrestres. En dehors de cela, l'influence des mouvements du navire (par exemple, cavalement, embardĂ©e, pilonnement, roulis, tangage, et lacet) Ă diffĂ©rentes amplitudes et pĂ©riodes d'oscillation sur la dynamique de drainage des liquides est Ă©tudiĂ©e pour approfondir nos connaissances. ParallĂšlement Ă l'Ă©tude expĂ©rimentale, un modĂšle numĂ©rique Euler-Euler transitoire et en trois dimensions est utilisĂ© en complĂ©ment pour tenter de prĂ©dire la dynamique du drainage des liquides dans les lits flottants. D'autres facteurs susceptibles d'affecter la dynamique de drainage sont analysĂ©s par la simulation numĂ©rique. Ainsi, le chapitre 3 met en Ă©vidence l'influence globale des propriĂ©tĂ©s des liquides, de la structure du lit et des types de mouvement associĂ© Ă la sollicitation marine. Par ailleurs, la campagne expĂ©rimentale en fournissant des donnĂ©es mesurables a permis de valider le modĂšle dans les conditions de roulis et de tangage testĂ©es au laboratoire.To fill the gap between increasing energy demand and depletion of onshore hydrocarbon production, offshore hydrocarbon exploitation is increasingly contemplated especially the gas/oil fields in the deeper water. Meantime, large amount of deployed processing units for hydrocarbon productions must comply with the environmental codes designated for maritime protection. Systems such as embarked packed-bed reactors and scrubbers inevitably become one of the most promising options to achieve both purposes. Numerous efforts in literature to unveil the hydrodynamics of multiphase flow in packed beds reveal that challenges persist either in their design/scale-up or during the operations. Moreover, exposing these reactors to harsh marine conditions such as the convolution of ship dynamics and hydrodynamics inside packed-bed reactors leads to even more complex situations to maintain the proper operation performance of packed-bed reactors under floating conditions. A lot of evidence from literature has pointed out the failure of random and structured packings and open-cell foams, to prevent liquid maldistribution in packed beds destined to operate on-board sailing ships and floating platforms. Research efforts must therefore continue in the quest for robust internals capable of resilience against liquid maldistribution in gas-liquid reactors/separation units. The proposed Ph.D. research aims at firstly following a sound path to adapt commercially existing internals being capable of preserving performance similar to landbased packed beds. To the best of literature exploring, the sensitivity and susceptibility of monolith reactors to maldistribution subjected to offshore conditions have yet to be investigated. Rather than focusing on a study of monolith beds alone, Chapter 1 opts for a broader experimental campaign including a random packing and an open-cell foam packing for the sake of systematic comparisons of the liquid distribution under floating conditions. Liquid distribution of embarked columns packed with various internals under wide gas/liquid flow range is systematically compared with the assistance of wire mesh sensor (WMS) and six-degree-of-freedom emulator hexapod. Severe offshore weather conditions threaten the operation safety of floating packed beds especially encountering extreme situations such as cyclone, iceberg episodes and so forth. To ensure the safety of staff and facilities, the onboard packed columns must be immediately shutdown to avoid critical safety concerns under such circumstances. Therefore, knowledgebase of liquid draining dynamics in floating packed beds is the essence to ensure timely discharge of liquid. Nevertheless, the study regarding liquid drainage dynamics of packed beds under floating conditions is scarce to say the least. Then, Chapter 2 compares liquid draining of packed columns embarking on floating platforms with static land-based one experimentally. Other than that, the influence of ship motions (e.g., roll, roll & pitch, heave etc.) with different oscillation amplitudes and periods on liquid draining dynamics is investigated to deepen the insights. vi In parallel with the experimental study, a 3D transient Euler-Euler CFD model is employed as a supplementary analysis to further deepen the understanding of liquid drainage dynamics in floating packed beds. More factors possibly affecting the draining dynamics are exploited by numerical simulation. Consequently, Chapter 3 highlights the comprehensive influence of liquid properties, bed structure and moving types instead of focusing on impact of movements alone. Meanwhile, with sufficient body of experimental campaign, the validity and accuracy of model are strongly endorsed
Aerospace medicine and biology: A continuing bibliography with indexes (supplement 367)
This bibliography lists 205 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System during Aug. 1992. Subject coverage includes the following: aerospace medicine and physiology, life support systems and man/system technology, protective clothing, exobiology and extraterrestrial life, planetary biology, and flight crew behavior and performance
Earth Resources: A continuing bibliography with indexes
This bibliography lists 623 reports, articles, and other documents introduced into the NASA scientific and technical information system between April 1 and June 30, 1983. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis
Estimation de l'évaporation des réservoirs hydroélectriques boréals en contexte de données limitées
De par le monde, la gestion des rĂ©servoirs hydroĂ©lectriques repose largement sur des modĂšles hydrologiques qui simulent les entrĂ©es et les sorties dâeau du systĂšme. LâĂ©vaporation sur ces rĂ©servoirs est typiquement nĂ©gligĂ©e ou calculĂ©e de la mĂȘme façon que lâĂ©vapotranspiration sur lâensemble du bassin versant, bien que les processus rĂ©gissant ces deux phĂ©nomĂšnes diffĂšrent. Une meilleure quantification de lâĂ©vaporation suscite un intĂ©rĂȘt grandissant, dĂ» aux changements climatiques qui provoquent une augmentation des pertes en eau par Ă©vaporation sur les rĂ©servoirs. Cette Ă©tude examine divers modĂšles dâĂ©vaporation, et ce, en tenant compte de la rĂ©alitĂ© dans laquelle les modĂšles hydrologiques sont opĂ©rĂ©s de façon gĂ©nĂ©rale, câest-Ă -dire avec une faible disponibilitĂ© de donnĂ©es dâentrĂ©e. LâĂ©tude se concentre principalement sur deux rĂ©servoirs situĂ©s dans la zone borĂ©ale canadienne, soit Eastmain-1 et Romaine-2. Un jeu de donnĂ©es observĂ©es dâĂ©vaporation obtenues grĂące Ă la technique de covariance des tourbillons, est utilisĂ© comme rĂ©fĂ©rence. De toutes les approches considĂ©rĂ©es, le modĂšle de transfert de masse avec un nombre de Dalton constant de 1,2 x 10â»Âł est le plus performant Ă un pas de temps horaire. Les cumuls journaliers sont Ă©galement estimĂ©s avec une bonne prĂ©cision autant lors du rĂ©chauffement de la masse dâeau que lors de la pĂ©riode de relĂąchement dâĂ©nergie. Des analyses de sensibilitĂ© montrent que lâutilisation de ce modĂšle avec des donnĂ©es limitĂ©es est possible, du moins pour les deux rĂ©servoirs Ă©tudiĂ©s. Ces donnĂ©es limitĂ©es consistent en la tempĂ©rature de lâair et lâhumiditĂ© relative prises sur la terre ferme Ă proximitĂ© du rĂ©servoir, la tempĂ©rature de la surface de lâeau mesurĂ©e in situ et la vitesse du vent Ă une hauteur de 10 m prise depuis la berge du rĂ©servoir face aux vents dominants. Lâapplication du modĂšle sur le lac LĂ©man, situĂ© dans une rĂ©gion plus tempĂ©rĂ©e, donne aussi de bons rĂ©sultats.Hydroelectric reservoirs around the world are managed using hydrological models to calculate water inflows and outflows. Evaporation on these reservoirs is typically neglected or calculated in the same way as evapotranspiration over the entire watershed, although the processes governing the two phenomena are different. A better quantification of evaporation is of growing interest in Quebec and internationally due to climate change, which is causing an increase in water losses by evaporation on reservoirs. This study therefore examines various evaporation models for open water bodies, taking into account the practical context in which hydrological models are generally operated, that is with low availability of input data. The study focuses mainly on two reservoirs with contrasting morphometries and located in the Canadian boreal zone, Eastmain-1 and Romaine-2. For this purpose, a set of observed evaporation data obtained using a direct measurement technique called eddy covariance, is used as a reference. Of all the approaches considered, the mass transfer model with a constant Dalton number of 1.2 x 10â»Âł gives the most accurate estimation of evaporation at hourly time steps. Daily totals are also estimated with good accuracy both during the warming of the water body in spring and during the energy release period in fall. Sensitivity analysis show that the use of this model with limited data is possible, at least for the two reservoirs studied. These limited data consist of air temperature and relative humidity taken on land in the vicinity of the reservoir, water surface temperature measured in situ, and wind speed at a height of 10 m taken from the bank of the reservoir facing the prevailing winds. The application of the model on Lake Leman, located in a more temperate region, also gives good results
Local diffusion in the extracellular space of the brain
The brain extracellular space (ECS) is a vast interstitial reticulum of extreme morphological complexity, composed of narrow gaps separated by local expansions, enabling interconnected highways between neural cells. Constituting on average 20% of brain volume, the ECS is key for intercellular communication, and understanding its diffusional properties is of paramount importance for understanding the brain. Within the ECS, neuroactive substances travel predominantly by diffusion, spreading through the interstitial fluid and the extracellular matrix scaffold after being focally released. The nanoscale dimensions of the ECS render it unresolvable by conventional live tissue compatible imaging methods, and historically diffusion of tracers has been used to indirectly infer its structure. Novel nanoscopic imaging techniques now show that the ECS is a highly dynamic compartment, and that diffusivity in the ECS is more heterogeneous than anticipated, with great variability across brain regions and physiological states. Diffusion is defined primarily by the local ECS geometry, and secondarily by the viscosity of the interstitial fluid, including the obstructive and binding properties of the extracellular matrix. ECS volume fraction and tortuosity both strongly determine diffusivity, and each can be independently regulated e.g. through alterations in glial morphology and the extracellular matrix composition. Here we aim to provide an overview of our current understanding of the ECS and its diffusional properties. We highlight emerging technological advances to respectively interrogate and model diffusion through the ECS, and point out how these may contribute in resolving the remaining enigmas of the ECS.The authors acknowledge funding from the Spanish Ministry of Science and Innovation (PID2020-115896RJ-I00, PID2020-113894RB-I00, PCI2022-135040-2), the Basque Government (GIC21/76, GIU21/048), CIBERNED, Human Frontier Science Program (RGP0036/2020) and Aligning Science Across Parkinson's (ASAP-020505) through the Michael J. Fox Foundation for Parkinson's Research (MJFF)
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