The salience of boundaries :strategies of distinction, boundary reification and knowledge sharing in a nascent field of practice

PhD ThesisThe practice of knowledge sharing across socio-epistemic boundaries is one of the key areas of inquiry in Practice-Based Studies of knowledge and learning. A considerable body of work dedicated to issues of boundary transcendence has been developed by scholars working in this tradition. The main themes of this literature focus on the idea of bridging boundaries and include boundary-spanning practices, boundary spanners and brokers, and boundary objects. Due to its disproportionate reliance on a consensual and harmonious view of the practice of knowledge sharing, this approach has resulted in (implicitly) treating boundaries as structural givens. Such a conceptualization runs contrary to the predominant view of social and symbolic boundaries in social science, where they are commonly acknowledged to be enacted and relational phenomena. This thesis seeks to contribute to the considerably less developed strand of Practice-Based Studies of knowledge and learning that draws upon these insights and explores the themes of boundary salience, distinction, and reification. The empirical foundation for the thesis is a case study of a Regional Innovation Strategy (RIS) project, funded by the European Commission as part of the Lisbon Strategy for Europe and based in one of the New Member States that acceded to the European Union in 2004. The project was a partnership between three European regions and eight organisations. The key premise of the project was the idea of knowledge transfer from regions with experience of developing regional innovation strategies under the EC aegis to the focal New Member State region. As such, the project represented a heterogeneous knowledge-sharing context, where multiple boundaries could be expected to come into play. The main findings of the thesis reveal a far from harmonious nature of the practice of knowledge sharing associated with the project. The most salient boundary was found to be a pragmatic knowledge boundary, which polarised the nascent field of regional innovation development in the focal region. ‘Knowledge sharing’ took the form of a struggle over the definition of competence within the field, and thus over field dominance. The study identifies first-order and second-order strategies of distinction ii deployed by each of the opposing parties: the former included perspective-pushing, exploitation, and opportunity hoarding; the latter were knowledge transfer, consensus building, and collaboration. The study also identifies a set of six paired practices which constituted both the boundary work and the practice work between the two opposing groups. These practices were found to fall into two categories associated with the relative position of power of those practicing them, i.e. strong and weak practices. Eventually, the struggle for field dominance ended in the concession of defeat by one of the parties, which was immediately followed by the euphemization of the relations across the pragmatic boundary

Reduction in wound healing complications and infection rate by lumbar CSF drainage after decompressive hemicraniectomy

Objective: Wound healing disorders and surgical site infections are the most frequently encountered complications after decompressive hemicraniectomy (DHC). Subgaleal CSF accumulation causes additional tension of the scalp flap and increases the risk of wound dehiscence, CSF fistula, and infection. Lumbar CSF drainage might relieve subgaleal CSF accumulation and is often used when a CSF fistula through the surgical wound appears. The aim of this study was to investigate if early prophylactic lumbar drainage might reduce the rate of postoperative wound revisions and infections after DHC. Methods: The authors retrospectively analyzed 104 consecutive patients who underwent DHC from January 2019 to May 2021. Before January 2020, patients did not receive lumbar drainage, whereas after January 2020, patients received lumbar drainage within 3 days after DHC for a median total of 4 (IQR 2-5) days if the first postoperative CT scan confirmed open basal cisterns. The primary endpoint was the rate of severe wound healing complications requiring surgical revision. Secondary endpoints were the rate of subgaleal CSF accumulations and hygromas as well as the rate of purulent wound infections and subdural empyema. Results: A total of 31 patients died during the acute phase; 34 patients with and 39 patients without lumbar drainage were included for the analysis of endpoints. The predominant underlying pathology was malignant hemispheric stroke (58.8% vs 66.7%) followed by traumatic brain injury (20.6% vs 23.1%). The rate of surgical wound revisions was significantly lower in the lumbar drainage group (5 [14.7%] vs 14 [35.9%], p = 0.04). A stepwise linear regression analysis was used to identify potential covariates associated with wound healing disorder and reduced them to lumbar drainage and BMI. One patient was subject to paradoxical herniation. However, the patient's symptoms rapidly resolved after lumbar drainage was discontinued, and he survived with only moderate deficits related to the primary disease. There was no significant difference in the rate of radiological herniation signs. The median lengths of stay in the ICU were similar, with 12 (IQR 9-23) days in the drainage group compared with 13 (IQR 11-23) days in the control group (p = 0.21). Conclusions: In patients after DHC and open basal cisterns on postoperative CT, lumbar drainage appears to be safe and reduces the rate of surgical wound revisions and intracranial infection after DHC while the risk for provoking paradoxical herniation is low early after surgery

Factors of Cortical Plasticity in Brachial Plexus Injury

Cortical plasticity is the brain’s capability of decoding new information through growth and reorganization over our whole life spam. It is the basis for good outcomes after reinnervation and for rehabilitation of adult and obstetric brachial plexus injury. Knowledge about cortical reorganization is crucial to reconstructive surgeons and physiotherapists that aim to give their patients a reasonable prognosis. This chapter intends to present and summarize the current literature on how to detect and quantify cortical plasticity and how research on factors that influence cortical plasticity, mainly in relation to peripheral nerve and more precise brachial plexus injury progresses. Peculiarities of adult and obstetric brachial plexus injuries and their treatment are given. We present techniques that visualize and quantify cortical plasticity with focus on functional imaging like fMRI and nTMS as well as molecular aspects. Future research is needed to understand mechanisms of how molecular changes on a synaptic level of a neuron influence the macroscopic plasticity, to improve rehabilitative resources, to understand the exact prognostic value of nTMS in brachial plexus injury and to investigate the therapeutic capability of rTMS

Results of Polish Adult Leukemia Study Group (PALG) project assessing TP53 mutations with next-generation sequencing technology in relapsed and refractory chronic lymphocytic leukemia patients — an 18-month update

Indtroduction and methods: In chronic lymphocytic leukemia (CLL), molecular and cytogenetic diagnostics are crucial for the determination of accurate prognosis and treatment choice. Among different genetic aberrations, del(17p13) or TP53 mutations constitute high-risk factors, and early identification of such defects is a high priority for CLL patients. While cytogenetic diagnostics is well-established and accessible for the majority of CLL patients in Poland, molecular diagnostics of TP53 mutations is performed only in a few ERIC-certified centers (eight as of September 2020), and only two of these employ next-generation sequencing (NGS) for routine analysis of TP53 status in CLL patients. Here we report the interim results of a project assessing TP53 mutations with NGS technology in relapsed or refractory CLL patients with confirmed negative del(17p13) status. 249 patients from 32 clinical centers were included in the study. Results: NGS analysis revealed TP53 mutations in 42/249 (17%) patients, half of whom (21/249, 8.5%) had subclonal mutations (VAF ≤10%). These results are in line with published data in relapsed/refractory CLL patients. Conclusions: The results of the project demonstrated the feasibility and accuracy of NGS testing in CLL patients despite several initial logistical and technical obstacles. Our study also proved that, with appropriate funding, CLL patients from any hematological center in Poland can have access to state-of-the-art molecular diagnostic

No fue la fiesta de todos: unidad y género bajo la dictadura argentina en La fiesta de todos (1979), Basta de mujeres (1977) y Pelota de trapo (1948)

The World Cup is the best stage for soccer. The Argentinian national soccer team is home to players who have shaped the sport of soccer such as Diego Maradona and Lionel Messi . Additionally, the team is the most recent winner of the Cup at the end of 2022. Soccer, at this level, is not just a way of training and pride in Argentina, but is also highly relevant to political discourse. The first time Argentina won the Cup in 1978, the country was host to this global event, with all eyes on the country for the first time in sports history. During this time, Argentina was under the control of the last military dictatorship, known as la junta, a period between 1976 and 1983, which is known as the Dirty War or El Proceso. The censorship of the arts led to the production of films that were commercial and supported the propaganda of the military junta. The films from the time of the Dirty War represent a false image of Argentina, and do not reflect the violence and crisis that was engulfing the country. The junta was much more concerned with portraying a modern, progressive, united, and strong image on the world stage. They used soccer, even the World Cup, to cover the truths of the country and promote the ideas of Argentine nationalism. Everyone\u27s Party (1979) directed by Sergio Renán, Enough of Women (1977) directed by Hugo Moser, and Pelota de trapo (1948) are representative of the junta\u27s efforts to portray a national image of unity and strength

Perioperative functional analysis with navigated trancranial magnetic stimulation in patients with brain tumors and chronic cerebrovascular insufficiency

Hintergrund Die transkranielle Magnetstimulation(TMS) ist die einzige Methode, die es auf nicht-invasive Weise erlaubt neurophysiologische Vorgänge des Neokortex mittels magnetisch induzierter elektrischer Stimulation analog dem Goldstandard der direkten Kortexstimulation zu untersuchen. Durch den zusätzlichen Einsatz der Neuronavigation (nTMS) sind topographische Messungen nunmehr mit einer hohen räumlichen Auflösung möglich. Hieraus ergibt sich für die nTMS ein hohes Potenzial als nicht invasives Messinstrument zur präoperativen Visualisierung eloquenter Kortexareale sowie Funktionsprüfung neuronaler Netzwerke. Um eloquente Areale bei veränderten anatomischen Verhältnissen sicher detektieren und erkrankungsbedingte Veränderungen von physiologischer Fluktuation sicher unterscheiden zu können, ist eine hohe Ergebnisstabilität über die Zeit sowie zwischen den Untersuchern nötig. So wird In der ersten Publikation die Anwendbarkeit des Verfahrens wie auch Reproduzierbarkeit zwischen zwei Untersuchern und Untersuchungszeitpunkten für die Kartierung des Motorkortex bei Patienten mit perirolandischen Tumoren und gesunden Probanden geprüft. Ziel der zweiten Publikation war es mittels repetitiver nTMS für die Sprachfunktion relevante Kortexareale bei Patienten mit linkshemisphärischen Raumforderungen wie auch einer gesunden Kontrollgruppe zu detektieren und charakterisieren. Abschließend wurde in der letzten Publikation das plastische Potenzial des motorischen Systems am Beispiel von Patienten mit chronischer zerebrovaskulärer Insuffizienz vor und nach einer operativen Revaskularisierung dargestellt. Methoden Zunächst wurde die Inter- und Intra-Untersucher-Variabilität des Systems für die topografische Kartierung des Motorkortex bei gesunden Probanden wie auch Patienten mit perirolandischen Tumoren mittels nTMS Einzelpulsstimulation untersucht. Mittels repetitiver nTMS wurden spracheloquente Areale über beiden Hemisphären bei Probanden wie auch Patienten dargestellt und charakterisiert. In der letzten Studie wurde die Änderung der kortikospinalen Erregbarkeit, das Verhältnis von synaptischer Bahnung und Hemmung, wie auch die Reorganisation motorischer Repräsentation bei Patienten mit einer zerebrovaskulären Insuffizienz sowohl prä- wie auch postoperativ untersucht. Ergebnisse Mit der navigierten transkraniellen Magnetstimulation sind Untersuchungen zur Erregbarkeit sowie Repräsentation funktioneller Kortexareale, sowohl bei gesunden wie auch bei Hirntumorpatienten mit einer hohen Intra- und Interuntersucherreliabilität möglich. Mittels der repetitiven nTMS konnten in beiden Gruppen sprachrelevante Areale dargestellt und zudem bei Patienten eine kompensatorisch erhöhte Beteiligung der rechten Hemisphäre an der Sprachverarbeitung gezeigt werden. Nach Wiederherstellung einer suffizienten Hirnperfusion konnte bei Patienten mit hämodynamischer Insuffizienz eine Rekonstitution der kortikalen Errregbarkeit und der motorischen Repräsentationsfläche parallel zum Rückgang der klinischen Symptome beobachtet werden. Diskussion und Zusammenfassung Die navigierte transkranielle Magnetstimulation ist ein nicht-invasives Messinstrument zur Evaluation des kortikospinalen Erregbarkeitsniveaus und präoperativen Visualisierung eloquenter Kortexareale. Die Darstellung der kompensatorischen Reorganisation der funktionellen Kortexarchitektur, erlaubt nicht nur eine individualisierte Operationsplanung, sondern könnte auch als ein potenzieller Verlaufs- und Prognoseparameter dienen.Background Navigated transcranial magnetic stimulation is the only method to measure neurophysiological changes of the cortex through a magnetically induced stimulus analogous to the gold standard of direct electrical stimulation Due to the additional use of neuronavigation high resolution topographic measurements can be performed. Therefore nTMS has a high value as a non-invasive tool to visualize eloquent cortical areas preoperatively and test the function of neuronal networks In order to detect eloquent areas in altered anatomy and distinguish between disease-induced changes and physiological fluctuations, stable results between investigators and timepoints are needed. The first publication investigates the usefulness of this method as well as reproducibility of results across time and between different examiners for the motor mapping in healthy subjects and patients with brain tumors affecting the motor cortex. The goal of the second publication was to detect and characterize speech eloquent areas by means of repetitive nTMS in patients with left hemispheric brain tumors and healthy subjects. Finally, the last publication describes the plastic potential of the motor system exemplified by patients with occlusive cerebrovascular disease undergoing operative revascularization. Methods At first the system’s intraexaminer and test-retest variability was tested for single pulse nTMS motor mapping in healthy subjects and patients with tumors in the vicinity of the primary motor cortex. By means of repetitive nTMS speech eloquent areas were detected and characterized on both hemispheres in subjects and patients. The last study evaluated the change in corticospinal excitability, the relation to inhibition and facilitation and reorganization of motor representation in patients with occlusive cerebrovascular disease pre- and postoperatively. Results Navigated transcranial magnetic stimulation allows for the evaluation of the excitability and representation of functional cortical areas in healthy subjects and brain tumor patients with a high intra- examiner and test-retest reliability. By means of repetitive nTMS a compensatory increased involvement of the left hemisphere in language processing was detected in patients suffering from a left hemispheric lesion. After reconstitution of the cerebral perfusion corticospinal excitability and motor representation recovered in patients with occlusive cerebrovascular disease parallel to the relieve of clinical symptoms. Conclusion Navigated transcranial magnetic stimulation is a reliable non-invasive tool to evaluate corticospinal excitability and visualize eloquent cortical areas preoperatively. Characterizing the compensatory reorganization of functional cortical architecture might not only enable individualized surgical planning but might also be a potential prognostic and follow-up parameter

NTMS based tractography and segmental diffusion analysis in patients with brainstem gliomas: Risk stratification and clinical potential

Introduction: Surgery on the brainstem level is associated with a high-risk of postoperative morbidity. Recently, we have introduced the combination of navigated transcranial magnetic stimulation (nTMS) and diffusion tensor imaging (DTI) tractography to define functionally relevant motor fibers tracts on the brainstem level to support operative planning and risk stratification in brainstem cavernomas. Research question: Evaluate this method and assess it's clinical impact for the surgery of brainstem gliomas. Material and methods: Patients with brainstem gliomas were examined preoperatively with motor nTMS and DTI tractography. A fractional anisotropy (FA) value of 75% of the individual FA threshold (FAT) was used to track descending corticospinal (CST) and -bulbar tracts (CBT). The distance between the tumor and the somatotopic tracts (hand, leg, face) was measured and diffusion parameters were correlated to the patients’ outcome. Results: 12 patients were enrolled in this study, of which 6 underwent surgical resection, 5 received a stereotactic biopsy and 1 patient received conservative treatment. In all patients nTMS mapping and somatotopic tractography were performed successfully. Low FA values correlated with clinical symptoms revealing tract alteration by the tumor (p = 0.049). A tumor-tract distance (TTD) above 2 mm was the critical limit to achieve a safe complete tumor resection. Discussion and conclusion: nTMS based DTI tractography combined with local diffusion analysis is a valuable tool for preoperative visualization and functional assessment of relevant motor fiber tracts, improving planning of safe entry corridors and perioperative risk stratification in brainstem gliomas tumors. This technique allows for customized treatment strategy to maximize patients’ safety

Physiological variables in association with spreading depolarizations in the late phase of ischemic stroke

Physiological effects of spreading depolarizations (SD) are only well studied in the first hours after experimental stroke. In patients with malignant hemispheric stroke (MHS), monitoring of SDs is restricted to the postoperative ICU stay, typically day 2-7 post-ictus. Therefore, we investigated the role of physiological variables (temperature, intracranial pressure, mean arterial pressure and cerebral perfusion pressure) in relationship to SD during the late phase after MHS in humans. Additionally, an experimental stroke model was used to investigate hemodynamic consequences of SD during this time window. In 60 patients with MHS, the occurrence of 1692 SDs was preceded by a decrease in mean arterial pressure (-1.04 mmHg; p = .02) and cerebral perfusion pressure (-1.04 mmHg; p = .03). Twenty-four hours after middle cerebral artery occlusion in 50 C57Bl6/J mice, hypothermia led to prolonged SD-induced hyperperfusion (+2.8 min; p < .05) whereas hypertension mitigated initial hypoperfusion (-1.4 min and +18.5%Delta rCBF; p < .01). MRI revealed that SDs elicited 24 hours after experimental stroke were associated with lesion progression (15.9 vs. 14.8 mm(3); p < .01). These findings of small but significant effects of physiological variables on SDs in the late phase after ischemia support the hypothesis that the impact of SDs may be modified by adjusting physiological variables

Standard-sampling microdialysis and spreading depolarizations in patients with malignant hemispheric stroke

Spreading depolarizations (SD) occur in high frequency in patients with malignant hemispheric stroke (MHS). Experimentally, SDs cause marked increases in glutamate and lactate, whereas glucose decreases. Here, we studied extracellular brain glutamate, glucose, lactate, pyruvate and the lactate/pyruvate ratio in relationship to SDs after MHS. We inserted two microdialysis probes in peri-infarct tissue at 5 and 15 mm to the infarct in close proximity to a subdural electrode strip. During 2356.6 monitoring hours, electrocorticography (ECoG) revealed 697 SDs in 16 of 18 patients. Ninety-nine SDs in electrically active tissue (spreading depressions, SDd) were single (SDds) and 485 clustered (SDdc), whereas 10 SDs with at least one electrode in electrically inactive tissue (isoelectric SDs, SDi) were single (SDis) and 103 clustered (SDic). More SDs and a significant number of clustered SDs occurred during the first 36 h post-surgery when glutamate was significantly elevated (> 100 mu M). In a grouped analysis, we observed minor glutamate elevations with more than two SDs per hour. Glucose slightly decreased during SDic at 5 mm from the infarct. Directions of SD-related metabolic changes correspond to the experimental setting but the long sampling time of standard microdialysis precludes a more adequate account of the dynamics revealed by ECoG

SDF-1 and NOTCH signaling in myogenic cell differentiation: the role of miRNA10a, 425, and 5100

Abstract Background Skeletal muscle regeneration is a complex process regulated by many cytokines and growth factors. Among the important signaling pathways regulating the myogenic cell identity are these involving SDF-1 and NOTCH. SDF-1 participates in cell mobilization and acts as an important chemoattractant. NOTCH, on the other hand, controls cell activation and myogenic determination of satellite cells. Knowledge about the interaction between SDF-1 and NOTCH signaling is limited. Methods We analyzed two populations of myogenic cells isolated from mouse skeletal muscle, that is, myoblasts derived from satellite cells (SCs) and muscle interstitial progenitor cells (MIPCs). First, microRNA level changes in response to SDF-1 treatment were analyzed with next-generation sequencing (NGS). Second, myogenic cells, i.e., SC-derived myoblasts and MIPCs were transfected with miRNA mimics, selected on the basis of NGS results, or their inhibitors. Transcriptional changes, as well as proliferation, migration, and differentiation abilities of SC-derived myoblasts and MIPCs, were analyzed in vitro. Naive myogenic potential was assessed in vivo, using subcutaneous engrafts and analysis of cell contribution to regeneration of the skeletal muscles. Results SDF-1 treatment led to down-regulation of miR10a, miR151, miR425, and miR5100 in myoblasts. Interestingly, miR10a, miR425, and miR5100 regulated the expression of factors involved in the NOTCH signaling pathway, including Dll1, Jag2, and NICD. Furthermore, miR10a, miR425, and miR5100 down-regulated the expression of factors involved in cell migration: Acta1, MMP12, and FAK, myogenic differentiation: Pax7, Myf5, Myod, Mef2c, Myog, Musk, and Myh3. However, these changes did not significantly affect myogenic cell migration or fusion either in vitro or in vivo, except when miR425 was overexpressed, or miR5100 inhibitor was used. These two molecules increased the fusion of MIPCs and myoblasts, respectively. Furthermore, miR425-transfected MIPC transplantation into injured skeletal muscle resulted in more efficient regeneration, compared to control cell transplantation. However, skeletal muscles that were injected with miR10a transfected myoblasts regenerated less efficiently. Conclusions SDF-1 down-regulates miR10a, miR425, and miR5100, what could affect NOTCH signaling, differentiation of myogenic cells, and their participation in skeletal muscle regeneration