36 research outputs found
Control conditions for randomised trials of behavioural interventions in psychiatry: a decision framework
No full textComputation of the nonlinear energy transfer in a narrow gravity wave spectrum with a method derived by Dungey and Hui
No full textIn this report the method of Dungey and Hui is summarized and extended to include the effect of skewness of the directional distribution. Additional information is given about the derivation and computation of the single integrations mentioned above. The method of Dungey and Hui is applied to a number of theoretical spectra. The results of these computations are compared with the results of exact computations by Sell and Hasselmann (1972) and Hasselmann and Hasselmann (1981). Finally, some comments are made about computational aspects of the method of Dungey and Hui.Hydraulic EngineeringCivil Engineering and Geoscience
Leonardos Bücherliste
No full text„Spera“ schrieb Leonardo da Vinci auf eine Bücherliste. Für welches Buch steht diese Notiz? Warum versuchen Wissenschaftler*innen weltweit, die verlorene Bibliothek Leonardos zu rekonstruieren? Und was erzählt uns die Bibliothek Neues über den berühmten Künstler, Wissenschaftler und Intellektuellen?
Begeben Sie sich mit uns auf eine detektivische Jagd nach den Büchern Leonardo da Vincis, erleben Sie die Explosion kosmologischen Wissens zur Zeit des frühen Buchdrucks und tauchen Sie ein in den geistigen Kosmos Leonardos. Ausgehend von einem kurzen Eintrag in einem seiner Notizbücher vermittelt die Folge „Leonardos Bücherliste“ einen Eindruck vom Reiz und von den Herausforderungen, die die Rekonstruktion von Leonardos Bibliothek darstellen. Sie ermöglicht einen Einblick in die Veränderung, Zirkulation und globale Verbreitung von Wissen zu Leonardos Zeiten und erzählt von Leonardos Kampf mit dem Lateinischen.
Für die Folge haben wir mit Jürgen Renn und Matteo Valleriani vom Max-Planck-Institut für Wissenschaftsgeschichte gesprochen.
Die Podcastfolge erscheint im Kontext der Ausstellung „Leonardos intellektueller Kosmos“, die vom 11. Mai bis 28. Juni 2021 im Dietrich Bonhoeffer-Saal der Staatsbibliothek zu Berlin zu sehen ist. Sie wird vom Max-Planck-Institut für Wissenschaftsgeschichte in Kooperation mit der Staatsbibliothek zu Berlin – Preußischer Kulturbesitz, der NOMIS Foundation, dem Museo Galileo + Istituto e Museo di Storia della Scienza und der Ambasciata d’Italia – Berlino ausgerichtet.Musik:
Kompositionen: Armin Hempel,
Renaissance-Flöte: Anna Fusek.Credits:
„Leonardos Bücherliste“ aus der Reihe „Hinter den Dingen. 5000 Jahre Wissensgeschichte zum Mitnehmen und Nachhören“. Eine Produktion des Projekts „Schauräume des Wissenstransfers“ des DFG-Sonderforschungsbereichs „Episteme in Bewegung“ an der Freien Universität Berlin – das sind: Kristiane Hasselmann, Jan Fusek, Armin Hempel und Katrin Wächter.
Kooperationspartner für diese Folge ist das Max-Planck-Institut für Wissenschaftsgeschichte.
Ein Podcast mit Jürgen Renn, SFB-Mitglied und Direktor des Max-Planck-Instituts für Wissenschaftsgeschichte, und Matteo Valleriani, Forschungsgruppenleiter am Max-Planck-Institut für Wissenschaftsgeschichte.
Stimmen:
Friederike Kroitzsch (Sophie Ruch),
Matthias Dittmer (Leonardo),
Katharina Kwaschik (historische Quellen).
Drehbuch: Jan Fusek;
Ton, Technik, Schnitt: Armin Hempel;
Dramaturgie, Redaktion, Regie: Kristiane Hasselmann, Jan Fusek, Armin Hempel, Katrin Wächter.
Grafik: Martina Hoffmann.
„Hinter den Dingen“ entsteht in Kooperation mit den Staatlichen Museen zu Berlin. Deutschlandfunk Kultur ist Medienpartner.Danke!
Für den Einblick in die spannende detektivische Bücherjagd: Jürgen Renn und Matteo Valleriani.
Für die fachliche Beratung und notwendige Lateinnachhilfe: Helge Wendt und Matthias Grandl.
Für die kollegiale Zusammenarbeit: Lina Schwab, Verena Braun, Stephanie Hood, Teresa Hollerbach, Esther Chen und Sabine Bertram.
Für ihre umfassende Unterstützung in allen Belangen: Stefanie Fröhlich.
An unser Team: Julia Beier, John Damm, Samantha Dittrich und Marie-Theres Wittmann.
Für den guten Sound: André König und Studio Funk
The role of monocyte phenotype and steroid-related gene expression in major depressive disorder
No full textBackground: Inflammation has been associated with major depressive disorder (MDD). Meta-analytic evidence has shown increased levels of circulating pro-inflammatory cytokines in groups of patients with MDD. However, little is known about the cellular source of these inflammatory signals. Recent studies have suggested that innate and adaptive immunity may be differentially affected in MDD. Neuroendocrine pathways tightly regulate cellular inflammation via glucocorticoids, such as cortisol. While some studies have found neuroendocrine disturbances in MDD, it has remained unclear whether impairments in glucocorticoid signalling are cell-specific. Therefore, we interrogated phenotype and glucocorticoid signalling of key innate (monocytes) and adaptive (T cells) immune cell populations in patients with MDD and healthy controls (HC).
Methods: 35 well-characterized antidepressant-free patients with MDD and HC individually matched for age, sex, smoking status and body mass index were enrolled. All participants were free of immunomodulatory medications or significant medical illness and non-pregnant. Immunophenotyping was performed by flow cytometry following established guidelines. Cell-specific steroid signalling was determined by mRNA expression of pre-receptor regulation (11β-hydroxysteroid dehydrogenase type 1 [11β-HSD1]), receptor expression (glucocorticoid [GR] and mineralocorticoid receptor [MR]), and its main downstream target (glucocorticoid-induced leucine-zipper [GILZ]). Salivary cortisol (collected on two consecutive days at 8 a.m. and 10 p.m.) and serum levels of IL-6, IL-1ß and TNF-α were analysed with ELISA.
Paired-samples t-tests were used for continuous variables and McNemar’s Test for dichotomous variables. Repeated-measures ANOVA was used for cortisol values. Effects sizes were calculated as Hedges’ g.
Results: In patients with MDD, we observed a shift in monocyte repertoire towards elevated frequencies of non-classical monocytes (p 0.05). Furthermore, monocytes but not T cells from patients with MDD showed lower expression of GR (p = 0.018; Hedges’g = 0.21) and GILZ (p = 0.045; Hedges’g = 0.39), indicative of steroid resistance. Finally, altered monocyte phenotype and steroid gene expression occurred against the backdrop of unchanged salivary cortisol (p = 0.32) and serum cytokine levels (ps > 0.05).
Conclusion: Our results suggest that in MDD regulatory mechanisms of inflammation are affected in a cell-specific manner. More specifically, we found a shift towards a pro-inflammatory phenotype and gene expression consistent with steroid resistance that was restricted to monocytes and occurred without neuroendocrine alterations. Our results could outline avenues for tailored cell-specific treatments to target aberrant inflammation in MDD.Entzündliche Prozesse stehen mit der Pathophysiologie von Depression (MDD) in Verbindung. Meta-Analysen deuten auf erhöhte Spiegel von zirkulierenden pro-inflammatorischen Zytokinen in Patientengruppen hin. Bisher ist nur wenig über den zellulären Ursprung dieser entzündlichen Signale bekannt. Jüngere Untersuchungen konnten zeigen, dass adaptive und angeborene Immunität bei MDD differentiell beeinträchtigt sein könnte. Glukokortikoide wie Cortisol sind potente neuroendokrine Regulatoren von Inflammation. Eine veränderte neuroendokrine Regulation ist bei Patienten mit MDD beschrieben worden, allerdings ist unklar, ob diese neuroendokrinen Veränderungen zell-spezifisch auftreten. Das Ziel dieser Arbeit ist es, Phänotyp sowie Steroidregulation von Monozyten und T-Zellen, den wichtigsten Zellpopulationen von angeborenem und erworbenem Immunsystem, bei Patienten mit MDD und gesunden Kontrollen (GK) zu untersuchen.
Methoden: 35 Antidepressiva-unmedizierte Patienten mit MDD und 35 GK (individuell parallelisiert nach Alter, Geschlecht, Raucherstatus und Body-Mass-Index) wurden für die Studie rekrutiert. Alle Probanden waren frei von immunmodulatorischer Medikation, ohne signifikante medizinische Begleiterkrankungen und nicht-schwanger.
Immunophänotypisierung wurde mithilfe von Durchflusszytometrie gemäß etablierter Standards durchgeführt. Zell-spezifische Steroidregulation wurde anhand der mRNA-Expression auf Ebene von prä-Rezeptor- (11β-hydroxysteroid dehydrogenase type 1 [11β-HSD1]), Rezeptor- (Glukokortikoid- [GR] und Mineralokortikoidrezeptor [MR]) sowie post-Rezeptor-Ebene (glucocorticoid-induced leucine-zipper [GILZ]) bestimmt. Speichel-Cortisol zweier konsekutiver Tage (8:00 und 22:00 Uhr) sowie IL-6, IL-1ß und TNF-α-Serum-Spiegel wurden mittels ELISA analysiert. Kontinuierliche Variablen wurden mittels des t-Tests für verbundene Stichproben, dichotome Variablen mit McNemar’s Test und Speichel-Cortisol mit einer messwiederholten Varianzanalyse ausgewertet. Hedges’ g wurde als Maß der Effektstärke berechnet.
Ergebnisse: Bei Patienten mit MDD zeigte sich eine signifikante Verschiebung des Monozyten-Repertoire hin zu einer erhöhten Frequenz von nicht-klassischen Monozyten (p 0.05). In Einklang hiermit zeigten nur Monozyten, nicht aber T-Zellen, von Patienten mit MDD geringere mRNA-Level von GR (p = 0.018; Hedges’ g = 0.21) und GILZ (p = 0.045; Hedges’ g = 0.39) als Monozyten von Kontrollen, was auf Steroidresistenz hindeutet. Diese Veränderungen waren unabhängig von Speichel-Cortisol- (p = 0.32) und Serum-Zytokin-Spiegeln (ps > 0.05).
Conclusio: Unsere Ergebnisse deuten darauf hin, dass die Regulation von Inflammation bei Patienten mit MDD auf zell-spezifische Weise beeinträchtigt ist. Es zeigte sich eine Verschiebung hin zu einem pro-inflammatorischen Phänotypen gekoppelt mit einer Monozyten-spezifischen Genexpression, die mit Steroidresistenz konsistent ist. Diese Veränderungen traten bei depressiven Patienten ohne Erhöhung der Speichel-Cortisol-Spiegel auf. Diese Ergebnisse könnten Hinweise für zukünftige zell-spezifische Behandlung von entzündlichen Prozessen im Rahmen von MDD liefern
SWAN SurfBeat-1D
No full textThe Simulating WAves Nearshore (SWAN) model has been extended with an infragravity module to predict the Wave-Group-Forced (WGF) infragravity response to a frequency-directional sea-swell spectrum at a mildly sloping alongshore uniform beach. To that end the SWAN model has been extended with an WGF-infragravity source term denoted Ssb where the subscript denotes surfbeat. The corresponding WGF infragravity energy model has been verified with a set of benchmark tests using the infragravity amplitude model of Reniers et al. (2002). Next the implementation of the energy balance in SWAN has been validated with both prototype-scale laboratory experiments and field observations, showing a good comparison with observations not affected by the nodal structure of the (partially) standing infragravity waves. This suggests that the model is capable of providing improved infragravity boundary conditions in relatively shallow water compared to the typical assumption of equilibrium forcing conditions using for instance Hasselmann's equilibrium theory (Hasselmann, 1962). These infragravity boundary conditions can subsequently can be used by other more sophisticated models to compute runup, overtopping and dune erosion.Environmental Fluid Mechanic
Impact of Free Long Waves on Dune Erosion Predictions in Numerical Modelling
No full textThis report presents the methodology and findings of a study on the impacts of free long waves on dune erosion predictions in XBeach. In this paper a distinction is made between two types of infragravity waves: bound infragravity waves and free infragravity waves. Bound infragravity waves are generated by short-wave group forcings and are bound to the propagation of the wave groups. Conversely, free waves are infragravity waves that are released from the wave-group in the surfzone, reflect at the shoreline, and propagate back out of the surf zone. In a semi-enclosed basin with mild bathymetric changes such as the North Sea, free long waves that reflect off one coast can propagate large distances and impact other coastlines. Modelling the response of a coastline during a storm event requires an offshore boundary condition that represents the incident short and long waves. The boundary condition for the incident infragravity waves is often derived by assuming a local equilibrium between the directionally spread sea-swell waves and bound infragravity waves following the K. Hasselmann (1962) method. This approach has proven to be problematic for two main reasons. First, the method tends to overestimate the incident infragravity wave height by assuming a local equilibrium is achieved at the model boundary; however, observations have shown that the transfer of energy from the short-wave groups to the underlying bound wave is gradual on a sloping bed. Second, by applying the equilibrium K. Hasselmann (1962) method it is implied that only bound infragravity waves are present at the boundary underestimating the total incident infragravity wave energy.An analysis of XBeach in surfbeat mode revealed that the model can confidently predict infragravity wave behaviour on a natural beach slope with two well-developed bars during a storm event by calibrating the roller breaker slope coefficient and wave breaker coefficient. Infragravity wave heights were reasonably accurately predicted in the surfzone, but the model generally overpredicted the most energetic infragravity waves. Further, the study investigated the impact of free infragravity waves on dune erosion predictions by simulating the behaviour of two 1D planar beach slopes to the inclusion of free long waves at the boundary. The study revealed that on a beach with a 1:35 slope the relative increase in dune erosion volume was 44.1% when the bound infragravity energy is equal to the free infragravity energy relative to the case excluding free waves. For the same conditions, a 20.6% increase was observed in the maximum runup. For a milder 1:70 slope a 36.4% and 6.1% increase in dune erosion and maximum runup was observed. The results demonstrate that the dune response of a coastline is sensitive to the inclusion of incident free infragravity waves at the boundary. Moreover, neglecting the presence of free infragravity waves at the boundary may underpredict the dune response during a storm event. <br/
Logbuch Wissensgeschichte
No full textDas Logbuch Wissensgeschichte gibt vielfältige, inter- und transdisziplinäre Einblicke in Untersuchungsverfahren, materiale Forschungsgegenstände sowie begriffliche Instrumentarien des Sonderforschungsbereichs 980 Episteme in Bewegung. Wissenstransfer von der Alten Welt bis in die Frühe Neuzeit. Die hier zusammengeführten Studien und konzeptuellen Überlegungen zu Wissen in vormodernen Kontexten eröffnen in fünf Fokusbereichen – Modi, Material & Medium, Praktiken, Macht, Momentum – unterschiedliche Perspektiven auf ‚Episteme in Bewegung‘ und damit auf zwölf Jahre Verbundforschung. In den Beiträgen werden Begriffe und Konzepte in ihrer Produktivität für konkrete Fallstudien und ihre jeweiligen Forschungsgegenstände navigatorisch erprobt, reflektiert, präzisiert und zugleich in Bewegung gehalten. Das hier entfaltete Forschungsspektrum versteht sich als Ausgangspunkt, um den Leser⋅innen Anregungen für zukünftige Forschungen zu bieten
The directional energy distribution of wind generated waves as inferred from stereophotographic observations of the sea surface
No full textThe objective of the present study is to determine characteristics of the directional energy distribution of wind generated waves on the basis of observations with a relatively high resolution. Approximately 75 observations of the above distribution are studied. They are selected from five spectra which are determined from stereophotographic observations of the sea surface. Three of these spectra were obtained in a so-called ideal generation situation. This is a situation where a homogeneous, stationary wind blows perpendicularly off a straight coast over deep water. The other two spectra were observed in similar situations. The difference with the ideal situation is for one spectrum that the wind was slanting across the coastline and for the other that the coastline was irregular. The observed distributions are compared with the cos²s (?/2)-model introduced by Longuet-Higgins et al. (1963). The differences between the observations and this model can be quantified due to the high resolution of the observations. It is found in the ideal situation that the model agrees well for most practical purposes with the observed distributions. In fact, the model is found to be highly consistent with those observations in the ideal situation for which a consistency analysis was carried out. In the other two situations it is found that the shape of the directional energy distribution is strongly influenced by the geometry of the upwind coastline. Thls suggests a directionally decoupled generation of the waves. The results of a simple parametric wave hindcasting model support this suggestion. The shape of the observed functional relationship between the width parameter s of the cos²s(?/2)-model and the wavenumber agrees fairly well with the shapes suggested by Mitsuyasu et al. (1975) and Hasselmann et al. (1980).Hydraulic EngineeringCivil Engineering and Geoscience
Observations and a model of undertow over the inner continental shelf
No full textAuthor Posting. © American Meteorological Society, 2008. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 38 (2008): 2341-2357, doi:10.1175/2008JPO3986.1.Onshore volume transport (Stokes drift) due to surface gravity waves propagating toward the beach can result in a compensating Eulerian offshore flow in the surf zone referred to as undertow. Observed offshore flows indicate that wave-driven undertow extends well offshore of the surf zone, over the inner shelves of Martha’s Vineyard, Massachusetts, and North Carolina. Theoretical estimates of the wave-driven offshore transport from linear wave theory and observed wave characteristics account for 50% or more of the observed offshore transport variance in water depths between 5 and 12 m, and reproduce the observed dependence on wave height and water depth.
During weak winds, wave-driven cross-shelf velocity profiles over the inner shelf have maximum offshore flow (1–6 cm s−1) and vertical shear near the surface and weak flow and shear in the lower half of the water column. The observed offshore flow profiles do not resemble the parabolic profiles with maximum flow at middepth observed within the surf zone. Instead, the vertical structure is similar to the Stokes drift velocity profile but with the opposite direction. This vertical structure is consistent with a dynamical balance between the Coriolis force associated with the offshore flow and an along-shelf “Hasselmann wave stress” due to the influence of the earth’s rotation on surface gravity waves. The close agreement between the observed and modeled profiles provides compelling evidence for the importance of the Hasselmann wave stress in forcing oceanic flows. Summer profiles are more vertically sheared than either winter profiles or model profiles, for reasons that remain unclear.This research was funded by the
Ocean Sciences Division of the National Science Foundation
under Grants OCE-0241292 and OCE-0548961
The Berlin Treatment Algorithm: recommendations for tailored innovative therapeutic strategies for multiple sclerosis-related fatigue
No full textMore than 80% of multiple sclerosis (MS) patients suffer from fatigue. Despite this, there are few therapeutic options and evidence-based pharmacological treatments are lacking. The associated societal burden is substantial (MS fatigue is a major reason for part-time employment or early retirement), and at least one out of four MS patients view fatigue as the most burdensome symptom of their disease. The mechanisms underlying MS-related fatigue are poorly understood, and objective criteria for distinguishing and evaluating levels of fatigue and tiredness have not yet been developed. A further complication is that both symptoms may also be unspecific indicators of many other diseases (including depression, sleep disorders, anemia, renal failure, liver diseases, chronic obstructive pulmonary disease, drug side effects, recent MS relapses, infections, nocturia, cancer, thyroid hypofunction, lack of physical exercise). This paper reviews current treatment options of MS-related fatigue in order to establish an individualized therapeutic strategy that factors in existing comorbid disorders. To ensure that such a strategy can also be easily and widely implemented, a comprehensive approach is needed, which ideally takes into account all other possible causes and which is moreover cost efficient. Using a diagnostic interview, depressive disorders, sleep disorders and side effects of the medication should be identified and addressed. All MS patients suffering from fatigue should fill out the Modified Fatigue Impact Scale, Epworth Sleepiness Scale, the Beck Depression Inventory (or a similar depression scale), and the Pittsburgh Sleep Quality Index (or the Insomnia Severity Index). In some patients, polygraphic or polysomnographic investigations should be performed. The treatment of underlying sleep disorders, drug therapy with alfacalcidol or fampridine, exercise therapy, and cognitive behavioral therapy-based interventions may be effective against MS-related fatigue. The objectives of this article are to identify the reasons for fatigue in patients suffering from multiple sclerosis and to introduce individually tailored treatment approaches. Moreover, this paper focuses on current knowledge about MS-related fatigue in relation to brain atrophy and lesions, cognition, disease course, and other findings in an attempt to identify future research directions
