Showing papers by "Free University of Berlin published in 2023"

Aerosol optical depth retrieval from the EarthCARE multi-spectral imager: the M-AOT product

Abstract: Abstract. The Earth Explorer mission Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) will not only provide profile information on aerosols but will also deliver a horizontal context to it through measurements by its Multi-Spectral Imager (MSI). The columnar aerosol product relying on these passive signals is called M-AOT. Its main parameters are aerosol optical thickness (AOT) at 670 nm over ocean and, where possible land, and at 865 nm over ocean. Here, the algorithm and assumptions behind it are presented. Further, first examples of product parameters are given based on applying the algorithm to simulated EarthCARE test data and Moderate Resolution Imaging Spectroradiometer (MODIS) Level-1 data. Comparisons to input fields used for simulations, to the official MODIS aerosol product, AErosol RObotic NETwork (AERONET) and to Maritime Aerosol Network (MAN) show an overall reasonable agreement. Over ocean correlations are 0.98 (simulated scenes), 0.96 (compared to MYD04) and 0.9 (compared to MAN). Over land correlations are 0.62 (simulated scenes), 0.87 (compared to MYD04) and 0.77 (compared to AERONET). A concluding discussion will focus on future improvements necessary and envisioned to enhance the product.

Offshore Finance and State Power

Abstract: Abstract Offshore financial centres such as Luxembourg, the Cayman Islands, or the City of London provide non-residents with a legal framework that is strong on property rights and soft on taxation and regulation. Building on a historical-institutionalist comparison of Britain, Germany, Brazil, and Mexico, Offshore Finance and State Power asks how these offshore financial services affect the power of the state to finance its political goals. It looks into the mechanics—how does it work?—and the outcome of this effect—is it enhancing or limiting state power? Combining a concept analysis with empirical data from descriptive banking statistics and qualitative expert interviews, the book finds that economic actors go offshore to create money more than to hide it. Legal offshore banking trumps tax planning or money laundering in its impact on state power. Offshore Finance and State Power also reveals that the outcome of that impact on state power is not straightforward. Offshore finance limits state power by transmitting the volatility of unregulated offshore banking into the domestic economy. Counterintuitively, however, offshore finance can also enhance state power. It provides governments with an extraterritorial vehicle to cover up political conflicts over how to finance the state and mitigate class conflict. To which extent a state can put offshore finances at its own service, depends on a country’s domestic elite constellation and the tax and bank bargains they have forged throughout history.

Empirically identifying and computationally modelling the brain-behaviour relationship for human scene categorization

Abstract: Abstract Humans effortlessly make quick and accurate perceptual decisions about the nature of their immediate visual environment, such as the category of the scene they face. Previous research has revealed a rich set of cortical representations potentially underlying this feat. However, it remains unknown which of these representations are suitably formatted for decision-making. Here, we approached this question empirically and computationally, using neuroimaging and computational modelling. For the empirical part, we collected electroencephalography (EEG) data and reaction times from human participants during a scene categorization task (natural vs. man-made). We then related neural representations to behaviour using a multivariate extension of signal detection theory. We observed a correlation specifically between ∼100 ms and ∼200 ms after stimulus onset, suggesting that the neural scene representations in this time period are suitably formatted for decision-making. For the computational part, we evaluated a recurrent convolutional neural network (RCNN) as a model of brain and behaviour. Unifying our previous observations in an image-computable model, the RCNN predicted well the neural representations, the behavioural scene categorization data, as well as the relationship between them. Our results identify and computationally characterize the neural and behavioural correlates of scene categorization in humans. Significance statement Categorizing scene information is a ubiquitous and crucial task. Here we provide an empirical and computational account of scene categorization. Previous research has identified when scenes are represented in the visual processing hierarchy, but it remains unclear which of these representations are relevant for behaviour. We identified such representations between ∼100 ms and ∼200 ms after stimulus onset. We then showed that scene categorization in humans can be modelled via a recurrent convolutional neural network in a unified manner, i.e., in terms of neural and behavioural correlates, and their relationship. Together this reveals which representations underlie scene categorization behaviour and proposes a computational mechanism that implements such representations.

Effects of dietary zinc chloride hydroxide and zinc methionine on the immune system and blood profile of healthy adult horses and ponies

Abstract: The effects of dietary zinc on the immune function of equines have not been evaluated in detail so far. In the present study, eight healthy adult ponies and two healthy adult horses were fed a diet supplemented with either zinc chloride hydroxide or zinc methionine in six feeding periods of four weeks each (according to maintenance zinc requirement, 120 mg zinc/kg dry matter, and 240 mg zinc/kg dry matter, for both dietary zinc supplements, respectively). All animals received the six diets, with increasing amounts of zinc chloride hydroxide in the feeding periods 1–3, and with increasing amounts of zinc methionine in the feeding periods 4–6. At the end of each feeding period, blood samples were collected for a blood profile and the measurement of selected immune variables. Increasing dietary zinc chloride hydroxide doses increased the glutathione concentrations in the erythrocyte concentrate and the glutathione peroxidase activity in the erythrocyte lysate, decreased the numbers of total leukocytes and granulocytes in the blood, and also decreased the interleukin-2 concentrations in the plasma of the animals. The dietary supplementation of increasing doses of zinc methionine enhanced the mitogen-stimulated proliferative activity of peripheral blood mononuclear cells, and decreased the glutathione concentrations in the erythrocyte concentrate and the glutathione peroxidase activity in the plasma of the animals. The percentage of blood monocytes with oxidative burst after in vitro stimulation with E. coli decreased with increasing dietary zinc concentrations, independently of the zinc compound used. The blood profile demonstrated effects of the zinc supplements on the red blood cells and the bilirubin metabolism of the horses and ponies, which require further investigation. Overall, high doses of dietary zinc modulate the equine immune system, for the most part also depending on the zinc compound used.

Numerical Simulations Reproduce Field Observations Showing Transient Weakening During Shear Zone Formation by Diffusional Hydrogen Influx and H₂O Inflow

Abstract: Exposures on Holsnøy island (Bergen Arcs, Norway) indicate fluid infiltration through fractures into a dry, metastable granulite, which triggered a kinetically delayed eclogitization, a transient weakening during fluid-rock interaction, and formation of shear zones that widened during shearing. It remains unclear whether the effects of grain boundary-assisted aqueous fluid inflow on the duration of granulite hydration were influenced by a diffusional hydrogen influx accompanying the fluid inflow. To better estimate the fluid infiltration efficiencies and the parameter interdependencies, a 1D numerical model of a viscous shear zone is utilized and validated using measured mineral phase abundance distributions and H2O-contents in nominally anhydrous minerals of the original granulite assemblage to constrain the hydration by aqueous fluid inflow and diffusional hydrogen influx, respectively. Both hydrations are described with a diffusion equation and affect the effective viscosity. Shear zone kinematics are constrained by the observed shear strain and thickness. The model fits the phase abundance and H2O-content profiles if the effective hydrogen diffusivity is approximately one order of magnitude higher than the diffusivity for aqueous fluid inflow. The observed shear zone thickness is reproduced if the viscosity ratio between dry granulite and deforming, reequilibrating eclogite is ∼104 and that between dry granulite and hydrated granulite is ∼102. The results suggest shear velocities <10−2 cm/a, hydrogen diffusivities of ∼10−13±1 m2/s, and a shearing duration of <10 years. This study successfully links and validates field data to a shear zone model and highlights the importance of hydrogen diffusion for shear zone widening and eclogitization.

Quantum simulation of thermodynamics in an integrated quantum photonic processor

Abstract: Abstract One of the core questions of quantum physics is how to reconcile the unitary evolution of quantum states, which is information-preserving and time-reversible, with evolution following the second law of thermodynamics, which, in general, is neither. The resolution to this paradox is to recognize that global unitary evolution of a multi-partite quantum state causes the state of local subsystems to evolve towards maximum-entropy states. In this work, we experimentally demonstrate this effect in linear quantum optics by simultaneously showing the convergence of local quantum states to a generalized Gibbs ensemble constituting a maximum-entropy state under precisely controlled conditions, while introducing an efficient certification method to demonstrate that the state retains global purity. Our quantum states are manipulated by a programmable integrated quantum photonic processor, which simulates arbitrary non-interacting Hamiltonians, demonstrating the universality of this phenomenon. Our results show the potential of photonic devices for quantum simulations involving non-Gaussian states.

First virological and pathological study of Göttingen Minipigs with Dippity Pig Syndrome (DPS)

Abstract: Abstract Dippity Pig Syndrome (DPS) is a well-known but rare complex of clinical signs affecting minipigs, which has not been thoroughly investigated yet. Clinically affected animals show acute appearance of red, exudating lesions across the spine. The lesions are painful, evidenced by arching of the back (dipping), and the onset of clinical symptoms is generally sudden. In order to understand the pathogenesis, histological and virological investigations were performed in affected and unaffected Göttingen Minipigs (GöMPs). The following DNA viruses were screened for using PCR-based methods: Porcine cytomegalovirus (PCMV), which is a porcine roseolovirus (PCMV/PRV), porcine lymphotropic herpesviruses (PLHV-1, PLHV-2, PLHV-3), porcine circoviruses (PCV1, PCV2, PCV3, PCV4), porcine parvovirus 1 (PPV1), and Torque Teno sus virus (TTSuV1, TTSuV2). Screening was also performed for integrated porcine endogenous retroviruses (PERV-A, PERV-B, PERV-C) and recombinant PERV-A/C and their expression as well as for the RNA viruses hepatitis E virus (HEV) and SARS-CoV-2. Eight clinically affected and one unaffected GöMPs were analyzed. Additional unaffected minipigs had been analyzed in the past. The analyzed GöMPs contained PERV-A and PERV-B integrated in the genome, which are present in all pigs and PERV-C, which is present in most, but not all pigs. In one affected GöMPs recombinant PERV-A/C was detected in blood. In this animal a very high expression of PERV mRNA was observed. PCMV/PRV was found in three affected animals, PCV1 was found in three animals with DPS and in the healthy minipig, and PCV3 was detected in two animals with DPS and in the unaffected minipig. Most importantly, in one animal only PLHV-3 was detected. It was found in the affected and unaffected skin, and in other organs. Unfortunately, PLHV-3 could not be studied in all other affected minipigs. None of the other viruses were detected and using electron microscopy, no virus particles were found in the affected skin. This data identified some virus infections in GöMPs with DPS and assign a special role to PLHV-3. Since PCMV/PRV, PCV1, PCV3 and PLHV-3 were also found in unaffected animals, a multifactorial cause of DPS is suggested. However, elimination of the viruses from GöMPs may prevent DPS.

Automated Multilingual Detection of Pro-Kremlin Propaganda in Newspapers and Telegram Posts

Abstract: Abstract The full-scale conflict between the Russian Federation and Ukraine generated an unprecedented amount of news articles and social media data reflecting opposing ideologies and narratives. These polarized campaigns have led to mutual accusations of misinformation and fake news, shaping an atmosphere of confusion and mistrust for readers worldwide. This study analyses how the media affected and mirrored public opinion during the first month of the war using news articles and Telegram news channels in Ukrainian, Russian, Romanian, French and English. We propose and compare two methods of multilingual automated pro-Kremlin propaganda identification, based on Transformers and linguistic features. We analyse the advantages and disadvantages of both methods, their adaptability to new genres and languages, and ethical considerations of their usage for content moderation. With this work, we aim to lay the foundation for further development of moderation tools tailored to the current conflict.

Epistemic Intuition in Light of Intuition-Deniers

Abstract: As noted in the previous chapter, several views about intuition – reliabilism, skepticism and perspectival relativism – hold that intuitions play a central role in philosophical theorizing. Reliabilism believes that these intuitions function directly as evidence in philosophical arguments. Not less importantly, skepticism asserts that intuitions are usually thought to play such a role, although this is an inappropriate role for intuitions to play. And perspectival relativism admits that intuitions can be taken as a relative source of evidence. Accordingly, it seems as if contemporary analytic philosophers often use intuition as evidence in their philosophizing. I will refer to this sort of thinking as centrality. Contrary to that, several philosophers have recently raised different objections to this thesis of intuition-based evidence denying the claim that philosophers centrally depend on intuitions as evidence. Thus, intuition-deniers present a serious challenge to the claim of intuition-based evidence in philosophy.

Authenticity and Mask: Critical Self-relations in Else Voigtländer

Abstract: In her text “Über die ‘Art’ eines Menschen und das Erlebnis der Maske” [On a Person’s “Manner” and the Experience of the Mask] (1923), Else Voigtländer uses expressions such as “true essence,” “authentic” and “genuine” as though their meaning were completely self-evident. She develops a differentiated theory of the relationship to the self that is fully aware of the perspectival character of any evaluation of a personality “from the outside” and by no means interprets every form of “mask” as necessarily “inauthentic” or “dissimulation.” She illustrates her theory with some sources on Nietzsche’s personality. Voigtländer’s text can be read as allowing for several equivalent sides of a personality and it does not assume a rigid hierarchy of different layers of personality. In this essay, I will reconstruct Voigtländer’s theses (also their incoherencies) and ask what it means to speak of authenticity and genuineness against the background of her theory of self-feelings. In particular, I will critically examine Voigtländer’s talk of the “core” and “periphery” of the person. In the conclusion, I will contrast her theory in a brief sketch with Heidegger’s alternative conception of authenticity and inauthenticity.

Pyroxene microstructures in eclogite from UHP domains and an interjacent area, Western Gneiss Region, Norway

Abstract: The Western Gneiss Region (WGR) in W Norway exposes ultrahigh pressure (UHP) metamorphic eclogite of Scandian age in domains that are spatially separated from one another for unknown reasons. We studied five eclogites from the two northern UHP domains and the area in between (at the localities &#197;rsetneset, Fj&#248;rtoftvika, Riksheim, Synes, Ulsteinvik) for petrography, mineral chemistry and by Raman spectroscopy. The peak metamorphic mineral assemblages contain garnet, Na-pyroxene (jadeite 0.13&#8211;0.46) and &#8211; depending on the sample &#8211; rutile, ilmenite, quartz, kyanite and/or orthopyroxene. Depending on strain accumulation, the eclogite facies fabric is poikiloblastic or has a foliation formed by elongated grains and grain aggregates of Na-pyroxene and garnet. Secondary processes formed amphibole, biotite and symplectite of plagioclase and diopside. Irrespectively, all samples contain Na-pyroxene with needle-shaped inclusions that are in parallel to the presumed c-axis of the host. These needles are either bi-mineralic (quartz + pargasite) or monomineralic (quartz). Chemically integrated compositions obtained at mineral surfaces with needle exposure using a scanning electron beam yielded lower Ca-Tschermak&#8217;s and higher Ca-Eskola components than the host. The molar ratios of these calculated endmembers are consistent with the needles being formed by the reaction: 2 Ca-Eskola = Ca-Tschermak&#8217;s + 3 quartz. If Ca-Eskola is regarded to be typical for UHP metamorphism, then the spatial distribution of eclogite with quartz needles does not support a separation of the two northern UHP domains by the interjacent area.Garnet has minor compositional zoning with smooth gradients at grain rims. Mineral core compositions of garnet and needle-bearing Na-pyroxene suggest minimum metamorphic conditions after needle formation in the ranges of 700-790 &#176;C and 1.0-1.6 GPa, when the calibrations of the Fe&#8211;Mg geothermometer of Krogh Ravna (2000) and the jadeite + quartz geobarometer of Carswell & Harley (1990) are applied. Subsequent retrogression partially transformed quartz needles into albite needles with irregular outline in two of the samples (Riksheim, Ulsteinvik) at the expense of jadeite in the proximal host. Rare associated needles of cristobalite and an unknown phase with albite chemistry in these two southernly samples, perhaps as a result of retrogression, were not observed in the three northernly samples. Hence, the evolution of the pyroxene microstructures after formation allows to investigate spatial differences in the retrogression history.This work is financially supported by the Norwegian Financial Mechanism 2014-2021 and the Polish National Science Centre, project no. 2020/37/K/ST10/02784.Carswell, D.A. & Harley, S.L. (1990): Mineral barometry and thermometry. In: Carswell, D.A. (ed.) Eclogite Facies Rocks. Glasgow and London: Blackie, 83-110.Krogh Ravna, E. (2000): The garnet&#8211;clinopyroxene Fe2+&#8211;Mg geothermometer: an updated calibration. Journal of Metamorphic Geology 18:211-219.

How high can mechanical stresses be within lithospheric materials?

Abstract: Thanks to plate tectonics, the Earth lithosphere is composed of very different lithologies, most of which consisting of peridotites, usually covered by either oceanic or continental crust. Depending on several parameters including composition, pressure, temperature, and strain rate, lithospheric materials can deform smoothly and silently or generate seismic ruptures. Collision belts and subduction systems, including subducted materials being heated and sheared in the mantle transition zone, are characterized by intense seismicity; in contrast, the bottom of lithospheric plates, known as lithosphere-asthenosphere boundary (LAB), is not associated with any seismicity, giving the impression that oceanic plates have the intrinsic ability to maintain their basal stress at relatively low values. Comparing results from experimental geophysics, field geology, geodynamics modelling and seismology, I discuss the representativity of experimental findings and potential consequences on our understanding of the rheology of the lithosphere.The idea that lithospheric materials at intermediate depths or deeper cannot support high deviatoric stresses is still supported by many studies in geosciences or physics. Plenty of authors start by recalling that brittle failure cannot occur at high pressure, and thus conclude that deep earthquakes and their shallow counterparts should consist of totally different events relying on totally different physical processes. Yet, deep seismicity is characterized by double-couple mechanisms and thus is an actual proof of seismic ruptures at great depths. Here I recall achievements from experiments under synchrotron radiation, suggesting that differential stresses can reach several gigapascals within subducting slabs at intermediate depths (30-300 km). In either peridotites or lawsonite blueschists, high-energy X-rays reveal differential stresses above 2 GPa for confining pressures of 1-1.5 GPa, and reaching &#8776; 3 GPa for confining pressures of 2.5-3.5 GPa. This is further supported by both field geology studies and numerical modelling.While mean stresses in seismogenic zones exhibit severe deviations from lithostatic pressure, the base of lithospheric plates deforms in a way that never triggers seismicity. The coupling between lithospheric plates and the underlying asthenosphere is still a matter of debate. According to global dynamics modelling, a basal shear stress as low as only 10-100 MPa would suffice to allow decoupling at the LAB. While partial melting has recently been favoured as an explanation for plate motion, experimental results on an analogue (germanium peridotite) suggest a solid-state lubrication process, involving grain-boundary disordering,&#160;and would confirm that mechanical stresses do not exceed 200 MPa at the LAB (60-120 km).

The relationship between telework and job characteristics: A latent change score analysis during the COVID‐19 pandemic

Abstract: During the COVID-19 pandemic, a sizable proportion of employees conducted home-based telework to contain virus spreading. This situation made it possible to investigate the relationship between telework and job characteristics. Many positive and negative associations between telework and job characteristics have been proposed in the literature, but most studies relied on cross-sectional data as well as narrow samples (e.g. employees voluntarily choosing to telework). Repeated measures designs investigating the association between telework intensity and job characteristics using less selective samples are currently rare. To address this research gap, we collected data at two time points in Germany during the COVID-19 pandemic (n = 479) and investigated if change in telework intensity was associated with change in 19 job characteristics using structural equation modeling. Our analyses showed that—in contrast to several prior cross-sectional studies—telework intensity had a small to moderate association with only two out of the 19 job characteristics: Work scheduling and decision-making autonomy. Hence, the study challenges the previously assumed manifold positive and negative associations between telework intensity and job characteristics and adds to the debate about the role of telework intensity as an antecedent of work design. Future studies should investigate the generalizability of the findings to non-pandemic work contexts.