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Cyanobacteria are photoautotrophic microorganisms present in almost all ecologically niches on Earth. They exist as single-cell or filamentous forms and the latter often contain specialized cells for N2 fixation known as heterocysts. Heterocysts arise from photosynthetic active vegetative cells by multiple morphological and physiological rearrangements including the absence of O2 evolution and CO2 fixation. The key function of this cell type is carried out by the metalloprotein complex known as nitrogenase. Additionally, many other important processes in heterocysts also depend on metalloproteins. This leads to a high metal demand exceeding the one of other bacteria in content and concentration during heterocyst development and in mature heterocysts. This review provides an overview on the current knowledge of the transition metals and metalloproteins required by heterocysts in heterocyst-forming cyanobacteria. It discusses the molecular, physiological, and physicochemical properties of metalloproteins involved in N2 fixation, H2 metabolism, electron transport chains, oxidative stress management, storage, energy metabolism, and metabolic networks in the diazotrophic filament. This provides a detailed and comprehensive picture on the heterocyst demands for Fe, Cu, Mo, Ni, Mn, V, and Zn as cofactors for metalloproteins and highlights the importance of such metalloproteins for the biology of cyanobacterial heterocysts.
Pain and pain chronification are incompletely understood and unresolved medical problems that continue to have a high prevalence. It has been accepted that pain is a complex phenomenon. Contemporary methods of computational science can use complex clinical and experimental data to better understand the complexity of pain. Among data science techniques, machine learning is referred to as a set of methods that can automatically detect patterns in data and then use the uncovered patterns to predict or classify future data, to observe structures such as subgroups in the data, or to extract information from the data suitable to derive new knowledge. Together with (bio)statistics, artificial intelligence and machine learning aim at learning from data. ...
Background: To prevent persistent post-surgery pain, early identification of patients at high risk is a clinical need. Supervised machine-learning techniques were used to test how accurately the patients’ performance in a preoperatively performed tonic cold pain test could predict persistent post-surgery pain.
Methods: We analysed 763 patients from a cohort of 900 women who were treated for breast cancer, of whom 61 patients had developed signs of persistent pain during three yr of follow-up. Preoperatively, all patients underwent a cold pain test (immersion of the hand into a water bath at 2–4 °C). The patients rated the pain intensity using a numerical ratings scale (NRS) from 0 to 10. Supervised machine-learning techniques were used to construct a classifier that could predict patients at risk of persistent pain.
Results: Whether or not a patient rated the pain intensity at NRS=10 within less than 45 s during the cold water immersion test provided a negative predictive value of 94.4% to assign a patient to the "persistent pain" group. If NRS=10 was never reached during the cold test, the predictive value for not developing persistent pain was almost 97%. However, a low negative predictive value of 10% implied a high false positive rate.
Conclusions: Results provide a robust exclusion of persistent pain in women with an accuracy of 94.4%. Moreover, results provide further support for the hypothesis that the endogenous pain inhibitory system may play an important role in the process of pain becoming persistent.
Hypoxia-induced miR-210 displays a pro-survival, cytoprotective and pro-angiogenic role in several in vitro systems. In vivo, we previously found that miR-210 inhibition increases ischemic damage. Here we describe the generation of a versatile transgenic mouse model allowing the evaluation of miR-210 therapeutic potential in ischemic cardiovascular diseases. We generated a Tet-On miR-210 transgenic mouse strain (TG-210) by targeted transgenesis in the ROSA26 locus. To functionally validate miR-210 transgenic mice, hindlimb ischemia was induced by femoral artery dissection. Blood perfusion was evaluated by power Doppler while tissue damage and inflammation were assessed by histological evaluation. We found that miR-210 levels were rapidly increased in TG-210 mice upon doxycycline administration. miR-210 overexpression was maintained over time and remained within physiological levels in multiple tissues. When hindlimb ischemia was induced, miR-210 overexpression protected from both muscular and vascular ischemic damage, decreased inflammatory cells density and allowed to maintain a better calf perfusion. In conclusion, we generated and functionally validated a miR-210 transgenic mouse model. Albeit validated in the context of a specific cardiovascular ischemic disease, miR-210 transgenic mice may also represent a useful model to assess the function of miR-210 in other physio-pathological conditions.
Different tissue engineering techniques are used to support rapid vascularisation. A novel technique is the use of platelet-rich fibrin (PRF), an autologous source of growth factors. This study was the first to investigate the influence of PRF matrices, isolated following different centrifugation protocols, on human dermal vascular endothelial cells (ECs) in mono-culture and co-culture with human primary fibroblasts (HFs) as an in vitro model for tissue regeneration. Focus was placed on vascular structure formation and growth factor release. HFs and ECs were cultivated with PRF prepared using a high (710 ×g) or low (44 ×g) relative centrifugation force (RCF) over 14 d. Immunofluorescence staining and immunohistochemistry were used to evaluate the microvascular formation. Cell culture supernatants were collected for evaluation of growth factor release. The results showed a PRF-mediated effect on the induction of angiogenesis in ECs. Microvessel-like structure formation was promoted when ECs were combined with low-RCF PRF as compared to high-RCF PRF or control group. The percentage of vascular lumen area was significantly higher in low-RCF PRF, especially at day 7, which coincided with statistically significantly higher growth factor [vascular endothelial factor (VEGF), transforming growth factor β1 (TGF-β1) and platelet derived growth factor (PDGF)] concentration measured in low-RCF PRF as compared to high-RCF PRF or control group. In conclusion, reducing the RCF according to the low-speed centrifugation concept (LSCC) resulted in increased growth factor release and angiogenic structure formation with EC mono-culture, suggesting that PRF may be a highly beneficial therapeutic tool for tissue engineering applications.
Background: Neonatal manifestation of life-threatening hyperammonemic encephalopathy in urea cycle disorders (UCD) is often misdiagnosed as neonatal sepsis, resulting in significantly delayed start of specific treatment and poor outcome. The major aim of this study was to identify specific initial symptoms or signs to clinically distinguish hyperammonemic encephalopathy in neonates from neonatal sepsis in order to identify affected individuals with UCD and to start metabolic therapy without delay. Furthermore, we evaluated the impact of diagnostic delay, peak plasma ammonium (NH4+) concentration, mode of emergency treatment and transfer to a tertiary referral center on the outcome.
Methods: Detailed information of 17 patients (born between 1994 and 2012) with confirmed diagnosis of UCD and neonatal hyperammonemic encephalopathy were collected from the original medical records.
Results: The initially suspected diagnosis was neonatal sepsis in all patients, but was not confirmed in any of them. Unlike neonatal sepsis and not previously reported blood pressure increased above the 95th percentile in 13 (81%) of UCD patients before emergency treatment was started. Respiratory alkalosis was found in 11 (65%) of UCD patients, and in 14 (81%) plasma NH4+concentrations further increased despite initiation of metabolic therapy.
Conclusion: Detection of high blood pressure could be a valuable parameter for distinguishing neonatal sepsis from neonatal manifestation of UCD. Since high blood pressure is not typical for neonatal sepsis, other reasons such as encephalopathy and especially hyperammonemic encephalopathy (caused by e.g. UCD) should be searched for immediately. However, our result that the majority of newborns with UCD initially present with high blood pressure has to be evaluated in larger patient cohorts.
Background: The number of Mesenchymal Stem/Stromal Cells (MSCs) in the human bone marrow (BM) is small compared to other cell types. BM aspirate concentration (BMAC) may be used to increase numbers of MSCs, but the composition of MSC subpopulations and growth factors after processing are unknown. The purpose of this study was to assess the enrichment of stem/progenitor cells and growth factors in BM aspirate by two different commercial concentration devices versus standard BM aspiration.
Methods: 120 mL of BM was aspirated from the iliac crest of 10 male donors. Each sample was processed simultaneously by either Emcyte GenesisCS® (Emcyte) or Harvest SmartPReP2 BMAC (Harvest) devices and compared to untreated BM aspirate. Samples were analyzed with multicolor flow cytometry for cellular viability and expression of stem/progenitor cells markers. Stem/progenitor cell content was verified by quantification of colony forming unit-fibroblasts (CFU-F). Platelet, red blood cell and total nucleated cell (TNC) content were determined using an automated hematology analyzer. Growth factors contents were analyzed with protein quantification assays. Statistical analyses were performed by ANOVA analysis of variance followed by Tukey’s multiple comparison test or Wilcoxon matched-pairs signed rank test with p < 0.05 for significance.
Results: Cell viability after processing was approximately 90% in all groups. Compared to control, both devices significantly enriched TNCs and platelets, as well as the CD45−CD73+ and CD45−CD73+CD90+ cell populations. Further, Harvest significantly concentrated CD45−CD10+, CD45−CD29+, CD45−CD90+, CD45−CD105+, CD45−CD119+ cells, and CD45dimCD90+CD271+ MSCs, whereas Emcyte significantly enriched CD45dimCD44+CD271+ MSCs. BM concentration also increased the numbers of CFU-F, platelet-derived growth factor, vascular endothelial growth factor, macrophage colony-stimulating factor, interleukin-1b, VCAM-1 and total protein. Neither system concentrated red blood cells, hematopoietic stem cells or bone morphogenetic proteins.
Conclusion: This data could contribute to the development of BMAC quality control assays as both BMAC systems concentrated platelets, growth factors and non-hematopoietic stem cell subpopulations with distinct phenotypes without loss of cell viability when compared to unprocessed BM.
Objective: To determine whether the performance of multiple sclerosis (MS) patients in the sound-induced flash illusion (SiFi), a multisensory perceptual illusion, would reflect their cognitive impairment.
Methods: We performed the SiFi task as well as an extensive neuropsychological testing in 95 subjects [39 patients with relapse-remitting MS (RRMS), 16 subjects with progressive multiple sclerosis (PMS) and 40 healthy control subjects (HC)].
Results: MS patients reported more frequently the multisensory SiFi than HC. In contrast, there were no group differences in the control conditions. Essentially, patients with progressive type of MS continued to perceive the illusion at stimulus onset asynchronies (SOA) that were more than three times longer than the SOA at which the illusion was already disrupted for healthy controls. Furthermore, MS patients' degree of cognitive impairment measured with a broad neuropsychological battery encompassing tests for memory, attention, executive functions, and fluency was predicted by their performance in the SiFi task for the longest SOA of 500 ms.
Conclusions: These findings support the notion that MS patients exhibit an altered multisensory perception in the SiFi task and that their susceptibility to the perceptual illusion is negatively correlated with their neuropsychological test performance. Since MS lesions affect white matter tracts and cortical regions which seem to be involved in the transfer and processing of both crossmodal and cognitive information, this might be one possible explanation for our findings. SiFi might be considered as a brief, non-expensive, language- and education-independent screening test for cognitive deficits in MS patients.
Anaerobic ammonium oxidation (anammox) is a major process in the biogeochemical nitrogen cycle in which nitrite and ammonium are converted to dinitrogen gas and water through the highly reactive intermediate hydrazine. So far, it is unknown how anammox organisms convert the toxic hydrazine into nitrogen and harvest the extremely low potential electrons (−750 mV) released in this process. We report the crystal structure and cryo electron microscopy structures of the responsible enzyme, hydrazine dehydrogenase, which is a 1.7 MDa multiprotein complex containing an extended electron transfer network of 192 heme groups spanning the entire complex. This unique molecular arrangement suggests a way in which the protein stores and releases the electrons obtained from hydrazine conversion, the final step in the globally important anammox process.
Fascial tissues form a ubiquitous network throughout the whole body, which is usually regarded as a passive contributor to biomechanical behavior. We aimed to answer the question, whether fascia may possess the capacity for cellular contraction which, in turn, could play an active role in musculoskeletal mechanics. Human and rat fascial specimens from different body sites were investigated for the presence of myofibroblasts using immunohistochemical staining for α-smooth muscle actin (n = 31 donors, n = 20 animals). In addition, mechanographic force registrations were performed on isolated rat fascial tissues (n = 8 to n = 18), which had been exposed to pharmacological stimulants. The density of myofibroblasts was increased in the human lumbar fascia in comparison to fasciae from the two other regions examined in this study: fascia lata and plantar fascia [H(2) = 14.0, p < 0.01]. Mechanographic force measurements revealed contractions in response to stimulation by fetal bovine serum, the thromboxane A2 analog U46619, TGF-β1, and mepyramine, while challenge by botulinum toxin type C3–used as a Rho kinase inhibitor– provoked relaxation (p < 0.05). In contrast, fascial tissues were insensitive to angiotensin II and caffeine (p < 0.05). A positive correlation between myofibroblast density and contractile response was found (rs = 0.83, p < 0.001). The hypothetical application of the registered forces to human lumbar tissues predicts a potential impact below the threshold for mechanical spinal stability but strong enough to possibly alter motoneuronal coordination in the lumbar region. It is concluded that tension of myofascial tissue is actively regulated by myofibroblasts with the potential to impact active musculoskeletal dynamics.
Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders with significant and often lifelong effects on social, emotional, and cognitive functioning. Influential neurocognitive models of ADHD link behavioral symptoms to altered connections between and within functional brain networks. Here, we investigate whether network-based theories of ADHD can be generalized to understanding variations in ADHD-related behaviors within the normal (i.e., clinically unaffected) adult population. In a large and representative sample, self-rated presence of ADHD symptoms varied widely; only eight out of 291 participants scored in the clinical range. Subject-specific brain-network graphs were modeled from functional MRI resting-state data and revealed significant associations between (non-clinical) ADHD symptoms and region-specific profiles of between-module and within-module connectivity. Effects were located in brain regions associated with multiple neuronal systems including the default-mode network, the salience network, and the central executive system. Our results are consistent with network perspectives of ADHD and provide further evidence for the relevance of an appropriate information transfer between task-negative (default-mode) and task-positive brain regions. More generally, our findings support a dimensional conceptualization of ADHD and contribute to a growing understanding of cognition as an emerging property of functional brain networks.
Mein Beitrag zeichnet im ersten Teil die Theoreme der Soziologie nach. Bis in die siebziger Jahre - die Palette reicht von Talcott Parsons über Erving Goffman bis zu Rollenanalyse als kritische Soziologie, das sich zu Alfred Schütz bekennt, und darüber hinaus - kann man verschiedene Stränge der Argumentation unterscheiden, allesamt bemüht, zu sozialen Rollen bzw. der Rollenhaftigkeit des sozialen Lebens etwas zu sagen, und bei einigen außerdem, die (idealisierende) Typisierung ins Visier zu nehmen. Im zweiten Teil wird der Gang des Theaters in den letzten Jahrzehnten skizziert. Seit es kein Stück und kein Publikum – also keine Rollen – mehr geben soll, sondern ein Skript genügen und eine Performance ausreichen soll, hat sich eine Theaterkultur entwickelt, die mit Blick auf Rollenrepertoire und Aufführungspraxis sich durch Wissenschaft begründet oder selbst eine "angewandte Theaterwissenschaft" sein will. Im dritten Teil wird das Verhältnis zwischen Rollen und Theater angesprochen. Nun wird die Typisierung zum Thema: Denn die Gesellschaft und die Bühne haben gemeinsam, dass eine Typisierung stattfindet, wenn in den sozialen Rollen, die das Leben verkörpern, oder dem Leben, das auf der Bühne nachempfunden oder gelegentlich beschworen wird, zwischen den Protagonisten etwas geschieht. Die Gesellschaft und die Bühne - im Blick auf Typisierung und Theater - kann man unter die Perspektive eines Dritten stellen, das sowohl eine Methode der Wissenschaft als auch ein Vorgang des Alltags ist - das Verstehen.
Während seines Aufenthaltes in Algerien hatte Pierre Bourdieu die eminente Bedeutung des Symbolischen erkannt. In der traditionellen Gesellschaft der Kabylei entdeckte er die relative Unabhängigkeit des Symbolischen (etwa der Ehre) gegenüber dem Ökonomischen. Mit Marx und Weber stimmte er darin überein, dass Sinnbeziehungen auf Machtbeziehungen beruhen. Während Marx in seiner antiidealistischen Haltung das Symbolische als eine bloße Widerspiegelung der ökonomisch- politischen Beziehungen betrachtete, unterstrich Bourdieu die Eigenlogik des Symbolischen, das nicht auf das Ökonomische im engeren Sinn reduziert werden kann. Der Begriff des symbolischen Kapitals wurde dann zu einer zentralen Kategorie des Theoriegebäudes von Bourdieu.
Die symbolische Dimension von Macht- und Herrschaftsverhältnissen galt Pierre Bourdieu als Schlüssel zum Verständnis sozialer Ungleichheit in demokratisch verfassten Gesellschaften. Wenngleich er die Bedeutung materieller Ressourcen nie in Frage stellte, sah er Strukturen sozialer Ungleichheit immer auch als Resultat von alltäglichen Bewertungskämpfen, in denen Klassifikationen und evaluative Praktiken eine zentrale Rolle spielen. Besonders anschaulich beschreibt Bourdieu diese Bewertungskämpfe im Feld der Musik. Denn die vermeintlich harmlosen und trivialen Vorlieben und Aversionen waren für Bourdieu nicht nur Ausdruck klassenspezifisch geprägter Lebensstile, sondern auch ein probates Mittel zur Legitimation und Reproduktion sozialer Herrschaftsverhältnisse.
In der Medien- und Filmwissenschaft, von deren semiologischen Ansätzen sich Pierre Bourdieu scharf abgrenzt, wird sein Konzept der symbolischen Herrschaft vergleichsweise wenig rezipiert. Darin selbst sind einige blinde Flecken, die von Bourdieu nicht reflektiert wurden. Zu den blinden Flecken gehören zum einen die Nichtberücksichtigung der darstellerischen, ästhetischen wie narrativen Eigenlogiken des Films, zum anderen die Nichtberücksichtigung der Eigensinnigkeit der ZuschauerInnen in der Rezeption und Aneignung filmischer Inhalte, zwei Aspekte, die die symbolische Herrschaft des oder im Film unterlaufen können. Da Bourdieu weder Filme inhaltlich analysiert noch Rezeptionsstudien durchführte, wird fälschlicherweise von der Form auf die Schichten der ZuschauerInnen geschlossen. Im Anschluss an die zentrale Thematik der symbolischen Herrschaft (symbolischen Gewalt, symbolischen Macht) lassen sich diese Konzepte allerdings gewinnbringend auf die verschiedensten Dimensionen und Instanzen der medialen Analyse an der Schnittstelle zwischen Medien- und Filmwissenschaft sowie der Filmsoziologie, im Folgenden insbesondere die Soziologie des Films respektive die Soziologie durch Film, anwenden.
Zunächst wird kurz in Bourdieus Konzept der symbolischen Herrschaft eingeführt und dessen Stellung im Kontext seiner Theorie der Praxis verdeutlicht. Da Bourdieu sein Verständnis der symbolischen Reproduktion des Sozialen insbesondere in Bezug auf die Sprache entfaltet, wird in einem zweiten Schritt auf seine sprachsoziologischen Arbeiten eingegangen. Dabei wird das Problem der Betonung der statischen Reproduktion sozialer Ordnungen adressiert. Im dritten Abschnitt erfolgt eine Kritik und Erweiterung von Bourdieus Perspektive im Anschluss an Judith Butler, die in "Haß spricht" eine Theorie zur Resignifikation sozialer Klassifikationen entwickelt hat und sich dabei von Bourdieus Sprachsoziologie abgrenzt. Sie betont im Unterschied zu Bourdieu die Möglichkeit der Verschiebung symbolischer Machtverhältnisse. Im Fazit werden die beiden Positionen vergleichend diskutiert und Ansätze einer Theorie sozialer Iterabilität herausgearbeitet.
Wenn in Frankreich, wie Curtius schreibt, die Literatur zum repräsentativen Ausdruck der Nation geworden war, so hatte das historische Gründe, die auf das Zeitalter der Klassik und der absoluten Monarchie zurückgehen. Im heutigen Frankreich ist in der Tat die Klassik, namentlich das Zeitalter Ludwigs XIV., die entscheidende kulturelle Referenz. Die wichtigen Werke dieser Zeit sind im kulturellen Gedächtnis der Franzosen präsent, bilden einen bedeutenden Teil eines lebendigen Erbes. Der Höhepunkt der politischen Macht unter Ludwig XIV. war gleichzeitig eine kulturelle Blütezeit. Die Kultur war schon seit der Renaissance in das nationale Leben integriert. Dieser Integrationsprozess verdichtete sich indes in der zweiten Hälfte des 17. Jahrhunderts. Peter Burke und Louis Marin haben aufgezeigt, wie alle Künste, die Literatur, die Malerei, die Bildhauerei und die Architektur, dazu beitrugen, die symbolische Macht der absoluten Monarchie zu konstituieren, und zwar im zentralen Bereich der Zeichen und der Imagination, eine Macht, die vor allem in der Re-Präsentation bestand. Man wird sich aber vor der Vorstellung hüten müssen, die Künste seien vom Sonnenkönig nur instrumentalisiert worden. Wegen ihrer Integration in die zentralen Sphären der Gesellschaft erreichten sie gleichzeitig einen bedeutenden sozialen Status. Wenn der König sein Zeitalter immer wieder mit demjenigen von Augustus vergleichen ließ, dann war das gleichzeitig ein Anstoß und eine Verpflichtung zur Förderung der Künste.
Pierre Bourdieu kannte seinen Kant. Er hatte ja auch Philosophie studiert und ein glänzendes Abschluss-Examen in diesem Fach abgelegt - als Bester seines Jahrganges in Frankreich. Er verfügte nach Jacques Bouveresse über eine breitere philosophische Kultur als viele Berufsphilosophen. Er kam immer wieder auf philosophische Fragestellungen zurück, die er aber glaubte mit den Instrumenten der Soziologie, zu der er in Algerien auf autodidaktischem Weg fand, besser beantworten zu können als mit denen einer kontext- und geschichtsvergessenen Philosophie. [...] Der Untertitel seines zentralen Werkes 'La distinction' (1979), 'Critique sociale du jugement' – was ich eher als "soziale Kritik der Urteilskraft" und nicht als "Kritik der gesellschaftlichen Urteilskraft" übersetzen würde -, versteht sich als Antwort auf Kants Kritik der Urteilskraft. Nach Kant beweist derjenige, der zu ästhetischen Urteilen über das Schöne fähig ist, Geschmack. Geschmacksurteile sind aber für ihn subjektiv. "Das Geschmacksurteil ist also kein Erkenntnisurteil, mithin nicht logisch, sondern ästhetisch, worunter man dasjenige versteht, dessen Bestimmungsgrund nicht anders als subjektiv sein kann." Die per se subjektiven Geschmacksurteile beanspruchen aber Allgemeingültigkeit, insofern sie "das Wohlgefallen an einem Gegenstand jedermann ansinnen". Nach Bourdieu sind indes auch Geschmacksurteile weder bloß subjektiv noch universell, sondern sozial bedingt. Gegensatzpaare wie Schönheit und Reiz, Wohlgefallen und Genuss oder Kultur und Zivilisation sublimierten indes diese soziale Bedingtheit, verdrängten die doppelte soziale Beziehung zum Hof (als Ort der der Kultur entgegengesetzten civilisation) und zum Volk (als dem Bereich der Natur und der Sinnlichkeit).