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Robinson Crusoe – But on Mars: Investigating Intertextuality in Andy Weir’s The Martian (2014)
No full textSince the publication of Defoe’s novel Robinson Crusoe (1719) a steady
stream of adaptations reproduced, reimagined, and/or subverted key elements of
the genre it set off. Charged with layers of discourse, “each age […] reveals the
robinsonade that best fits its needs” (Fisher 2018. “Innovation and Imitation in the
Eighteenth-Century Robinsonade.” In The Cambridge Companion to Robinson Cru-
soe, edited by J. J. Richetti, 99–111. Cambridge: Cambridge University Press, p. 104).
Consider, for example, Andy Weir’s science-fiction (sf) novel The Martian (2014)
where a high degree of intertextuality to Defoe’s novel is juxtaposed with the absence
of a native other. By treating The Martian as a deliberate revisitation of prior works
(cf. Hutcheon 2006). I aim to investigate marked and unmarked intertextuality ac-
cording to Sanders’s model of complex filtration of cultural narratives (2015). The
Martian invites us to revisit Defoe’s novel as a site of cultural significance for the
present-day concern of what it takes to sustain human life
Neural Correlates of Short-Term BCI Intervention in Chronic Stroke Patients
No full textThe present dissertation investigated the effects of brain-computer interface (BCI) training on neural plasticity and motor recovery in chronic stroke patients, with a particular emphasis on changes in functional connectivity and microstructural integrity. BCIs offer promising avenues for post-stroke motor rehabilitation, yet our Understanding of their neuroplastic mechanisms remains limited. This work aimed at elucidate the functional connectivity and microstructural changes induced by BCI- based interventions in chronic stroke patients and to investigate their relationship with motor recovery. Stroke remains a leading cause of long-term disability worldwide, and many survivors experience persistent hemiparesis despite receiving conventional rehabilitation. Although the early post-stroke period is typically characterized by spontaneous and therapy-induced recovery, the chronic phase often presents a functional plateau in motor improvement. Therefore, novel interventions that can overcome this recovery plateau by engaging neuroplastic mechanisms are urgently needed. BCIs offer a particularly compelling approach by transforming neural intent into real-time feedback, creating a closed-loop sensorimotor system that facilitates motor relearning even in the absence of overt movement.
This dissertation sought to address three key mechanistic questions: 1. Is the default mode network (DMN) in stroke patients malleable to short-term Intensive BCI intervention? 2. Are functional brain network changes associated with improvements in motor Function? 3. What underlying structural changes occur following BCI training? To investigate these questions, a comprehensive multimodal neuroimaging approach combining resting-state functional MRI (rs-fMRI) to examine functional connectivity changes and Multi-Parameter Mapping (MPM) to assess microstructural alterations What employed. The integration of these complementary techniques allowed for Characterization of both functional network dynamics and potential tissue-specific modifications that might underlie recovery.
The rs-fMRI analyses revealed significant alterations in functional connectivity following the BCI intervention. Most notably, increased connectivity between the medial prefrontal cortex (mPFC) of the default mode network and multiple motor- related regions was observed. The interaction analysis between group (BCI vs. control) and time (pre vs. post) demonstrated that the BCI group exhibited enhanced connectivity from the mPFC to the left superior parietal gyrus, ipsilesional inferior parietal gyrus, and ipsilesional precuneus. When examining the pre-post differences of the combined intervention weeks from both groups, increased functional connectivity between the mPFC and contralesional SMA, middle cingulate and paracindulate gyri, ipsilesional paracentral lobule, contralesional rolandic operculum, and contralesional pre-and postcentral gyri was Found. These findings were further supported by ROI-to-ROI connectivity analysis, which identified significant increases in functional connectivity between the mPFC and sensorimotor regions, including the precentral gyrus, postcentral gyrus, and SMA. Importantly, these connectivity changes correlated positively with improvements in motor function, as measured by the UE-FMA. Patients who demonstrated greater increases in connectivity between the mPFC and contralesional pre-and postcentral gyri, ipsilesional superior parietal gyrus, and contralesional precuneus also showed bigger gains in motor scores. This brain-behavior relationship suggests that the Reorganization of functional networks induced by BCI training was directly relevant to functional motor recovery.
In addition to functional changes, our study also revealed microstructural brain changes following the BCI intervention. Using quantitative multi-parameter mapping, alterations in myelin-sensitive parameters, specifically in magnetization transfer saturation (MTsat) and longitudinal relaxation rate (R1) were identified.
Post-intervention measurements showed significant decreases in MTsat in the contralesional primary motor cortex and supplementary motor area, with effects extending into parietal regions associated with sensorimotor integration. Additionally, R1 was significantly increased in the ipsilesional inferior frontal gyrus compared to baseline. The temporal profile of these microstructural changes revealed that MTsat values returned closer to baseline levels in measurements obtained one-week post- intervention, suggesting ongoing plastic reorganization beyond the immediate intervention period. The localization of R1 changes to the ipsilesional inferior frontal gyrus is also noteworthy given this region's involvement in motor planning, action observation networks, and executive function.
These findings complement our functional connectivity results by demonstrating that BCI intervention induces not only network-level changes in brain function but also measurable alterations in tissue microstructure.
In conclusion, this dissertation provides compelling evidence that BCI-based
interventions can induce significant functional connectivity and microstructural
changes in chronic stroke patients, which correlate with improvements in motor
function. These findings underscore the remarkable neuroplastic capacity of the adult
brain even in chronic phases post-stroke and highlight the potential of BCIs for
harnessing and promoting adaptive plasticity. By elucidating the neural mechanisms
underlying BCI-driven recovery, this work contributes to the advancement of
neuroscientifically-informed rehabilitation strategies that may help stroke survivors
overcome motor impairments and improve their quality of life
Observation of ice lollies with the Video In Situ Snowfall Sensor (VISSS)
No full textThis study investigates the microphysical properties of ice lollies, using
data from the Video In Situ Snowfall Sensor (VISSS). Ice lollies are a distinctive ice
crystal type, consisting of a supercooled droplet attached to a pristine ice column.
VISSS data provided several cases, where ice lollies could be observed. Two cases
were analysed: 18 January 2022 in Hyytiälä, Finland and 22 May 2022 in Ny-Ålesund,
Svalbard. A method was developed to differentiate ice lollies from other hydrometeor
types based on their shape. For the cases, ice lollies accounted for 2.5% and 10.1% of
all observed particles in Hyytiälä and Ny-Ålesund, respectively. The analysis revealed
consistencies and differences compared to previous studies, particularly in aspect ratios
and maximum dimension. Sedimentation velocities and fall direction were investigated.
Ice lollies predominantly fell with their columnar part oriented vertically, distinct to
the fall direction of pristine ice columns. Further, the analysis explored the potential
involvement of the Hallet-Mossop (H-M) process in ice lolly formation using in-situ
and remote sensing data. Although conclusive evidence for this process could not be
established, indications of secondary ice production (SIP) were observed.Diese Studie untersucht die mikrophysikalischen Eigenschaften
von Ice Lollies unterVerwendung von Daten des Video In Situ Snowfall Sensors (VISSS).
Ice Lollies sind eine besondere Art von Eiskristallen, die durch die Kollision eines unterkühlten
Tropfen mit einer Eissäule entstehen. Mehrere Fälle von Ice Lollies konnten in
den VISSS-Daten beobachtet werden. Zwei dieser Fälle wurden hier analysiert: der 18.
Januar 2022 in Hyytiälä, Finnland, und der 22. Mai 2022 in Ny-Ålesund, Spitzbergen.
Es wurde eine Methode entwickelt, um Ice Lollies anhand ihrer Form von anderen Hydrometeortypen
zu unterscheiden. Für diese Fälle machten Ice Lollies jeweils 2,5% und
10,1% aller beobachteten Partikel in Hyytiälä und Ny-Ålesund aus. Die Analyse zeigte
Übereinstimmungen und Unterschiede zu früheren Studien, insbesondere in Bezug auf
Verhältnis von maximaler/minimaler Ausdehnung und dem maximalen Durchmesser.
Zudem wurden Sedimentationsgeschwindigkeiten und Fallrichtung untersucht. Ice Lollies
fielen überwiegend mit ihrer säulenförmigen Struktur vertikal ausgerichtet, was sich
von der Fallrichtung von Eissäulen unterscheidet. Darüber hinaus wurde die mögliche
Beteiligung des Hallett-Mossop (H-M)-Prozesses an der Bildung von Ice Lollies anhand
von In-situ- und Fernerkundungsdaten untersucht. Obwohl keine signifikanten Beweise
für diesen Prozess gefunden wurden, zeigten sich Hinweise auf sekundäre Eisbildung
(Secondary Ice Production, SIP)
Hypervalent hydridosilicate in the Na–Si–H system
No full textHydrogenation reactions at gigapascal pressures can yield hydrogen-rich materials with properties relating to superconductivity, ion conductivity, and hydrogen storage. Here, we investigated the ternary Na–Si–H system by computational structure prediction and in situ synchrotron diffraction studies of reaction mixtures NaH–Si–H2 at 5–10 GPa. Structure prediction indicated the existence of various hypervalent hydridosilicate phases with compositions NamSiH(4+m) (m = 1–3) at comparatively low pressures, 0–20 GPa. These ternary Na–Si–H phases share, as a common structural feature, octahedral SiH62− complexes which are condensed into chains for m = 1 and occur as isolated species for m = 2, 3. In situ studies demonstrated the formation of the double salt Na3[SiH6]H (Na3SiH7, m = 3) containing both octahedral SiH62− moieties and hydridic H−. Upon formation at elevated temperatures (>500°C), Na3SiH7 attains a tetragonal structure (P4/mbm, Z = 2) which, during cooling, transforms to an orthorhombic polymorph (Pbam, Z = 4). Upon decompression, Pbam-Na3SiH7 was retained to approx. 4.5 GPa, below which a further transition into a yet unknown polymorph occurred. Na3SiH7 is a new representative of yet elusive hydridosilicate compounds. Its double salt nature and polymorphism are strongly reminiscent of fluorosilicates and germanates
Deep-learning based classification of a tumor marker for prognosis on Hodgkin's disease
No full textPurpose: Hodgkin's disease is a common malignant disorder in adolescent patients.
Although most patients are cured, approximately 10%–15% of patients experience a
relapse or have resistant disease. Furthermore, there are no definitive molecular pre-
dictors for early identification of patients at high risk of treatment failure to first line
therapy. The aim of this study was to evaluate the deep learning-based classifier
model of medical image classification to predict clinical outcome that may help in
appropriate therapeutic decisions.
Methods: Eighty-three FFPE biopsy specimens from patients with Hodgkin's disease
were stratified according to the patient's qPET scores, stained with picrosirius red
dye and digitalized by whole slide image scanning. The resulting whole slide images
were cut into tiles and annotated by two classes based on the collagen fibers' degree
of coloring with picrosirius red. The neural network (YOLOv4) was then trained with
the annotated data. Training was performed with 30 cases. Prognostic power of the
weakly stained picrosirius red fibers was evaluated with 53 cases. The same neural
network was trained with MMP9 stained tissue slides from the same cases and the
quantification results were compared with the variant from the picrosirius red cases.
Results: There was a weak monotonically increasing relationship by parametric
ANOVA between the qPET groups and the percentages of weakly stained fibers
(p = .0185). The qPET-positive cases showed an average of 18% of weakly stained
fibers, and the qPET-negative cases 10%–14%. Detection performance showed an
AUC of 0.79.
Conclusions: Picrosirius red shows distinct associations as a prognostic metric candi-
date of disease progression in Hodgkin's disease cases using whole slide images but
not sufficiently as a prognostic device
Foraging on sand particles: Coatings of soft radular teeth (Paludomidae, Gastropoda, Mollusca)
No full textThe radula is the ingesta-gathering structure in Mollusca. As interface, it has to per-
form various tasks without functional deterioration caused by wear. Wear prevention
is well investigated in mollusks that forage on rocks and that generate high punctual
pressure with their hard teeth, which contain high inorganic contents at their tips. In
mollusks that forage on softer substrate, such as sand surfaces, and have relatively
soft teeth, wear prevention has not been a focus of study before. Here, we studied
the teeth of Limnotrochus thomsoni, which are used for raking algae from sand. For
comparison, we investigated the soft outer teeth of Lavigeria grandis, which are used
in gathering particles after the ingesta is loosed from the rock surface. SEM revealed
scratches on all surfaces of the teeth and suggests that every tooth side interacts
with abrasive particles during foraging. Analysis of stomach content revealed that
sand particles of 10–20 μm diameter are ingested. By EDX/EDS, we studied the
composition of the teeth and determined that high proportions of Ca are present on
all surfaces, which could be an adaptation to reduce abrasion. Finally, we here pre-
sent evidence for the existence of a canal within the teeth, which could potentially
serve as delivery pathway of minerals during tooth maturation and has not been pre-
viously detected in Gastropoda
Nachweis von durch Zecken übertragenen Pathogenen in Waschbären (Procyon lotor Linnaeus 1758) aus Deutschland
No full textDer Waschbär (Procyon lotor) ist ein mittelgroßer Allesfresser, der zur Familie
der Kleinbären (Procyonidae) gehört und ursprünglich aus Mittel- und Nordamerika stammt. Heutzutage hat er sich durch absichtliche oder akzidentelle Freisetzungen in verschiedenen Teilen der Welt angesiedelt und ist in Deutschland als invasiver Neozoon gelistet. Viele zoonotische Erreger kommen weltweit bei Waschbären vor, aber für die meisten Waschbärpopulationen in Deutschland fehlen epidemiologische Daten zu durch Zecken übertragenen Krankheitserregern (tick borne pathogens – TBPs).
Ziel dieser Studie war es, die Prävalenzen von fünf durch Zecken
übertragenen, zoonotischen Pathogenen, namentlich Borrelia burgdorferi s.l., Rickettsia spp., Neoehrlichia mikurensis, Babesia spp. und Bartonella spp. in Waschbären zu bestimmen und Sequenzanalysen für einige der oben genannten Erreger durchzuführen.
Die Proben wurden zwischen 2017-2021 von 485 verkehrstoten,
gefangenen und getöteten oder bei der Jagd erlegten Waschbären entnommen, die aus zehn Bundesländern Deutschlands stammen. Alle Tiere wurden – sofern noch möglich – nach Geschlecht sortiert, gewogen, auf ihre Körperkondition hin untersucht sowie anhand des Gebisses und des Reproduktionsstatus in eine von vier Altersklassen eingestuft (Säugling / juvenil / jungadult / adult). Haut- und Milzproben wurden bei den Autopsien entnommen und bis zur weiteren Analyse bei -20°C eingefroren. Die entnommenen Milz- und Hautproben wurden in jeweils 1 cm3 bzw. 1x1 cm große Stücke zurechtgeschnitten und einzeln in Gefäßen mit jeweils 0,6 g sterilen Stahlkügelchen sowie jeweils 500 µL phosphatgepufferter Kochsalzlösung (PBS) gelagert. Anschließend wurden alle Proben in einem Gewebehomogenisator homogenisiert. Die DNA der Milz- und Hautproben wurde extrahiert und mittels real-time-Polymerase-Kettenreaktion (qPCR) auf B. burgdorferi s.l., Rickettsia spp. und Neoehrlichia mikurensis untersucht. Zum Nachweis von Babesia spp. und Bartonella spp. wurde jeweils eine konventionelle PCR durchgeführt. Die Hautproben wurden
auf B. burgdorferi s.l. und Rickettsia spp. getestet; die Milzproben wurden auf Babesia spp., Bartonella spp. und Neoehrlichia mikurensis hin untersucht. Die Konfidenzintervalle (95 % CI) für die Prävalenz der TBPs bei den untersuchten Waschbären wurden mit der Clopper und Pearson Methode unter Verwendung der GraphPad Prism Software v. 4.0 ermittelt. Der Chi-Quadrat-Test wurde verwendet, um die Prävalenzwerte zwischen Altersgruppen und Geschlecht zu vergleichen. Die Signifikanzgrenze wurde auf p < 0,05 gesetzt.
Insgesamt wurden 811 Waschbärproben (Milz, n = 478; Haut, n = 333) von 485
Tieren entnommen. Bei einigen Tieren war der Zugang zu einem der beiden Organe nicht möglich. Insgesamt wurden 6,2 % der Tiere (n = 50) positiv auf mindestens einen Erreger getestet. Der Erreger mit der höchsten Prävalenz war Rickettsia spp. (7,8 %; n = 26), gefolgt von B. burgdorferi s.l. (6,3 %; n = 21) und Bartonella spp. (0,6 %; n = 3). Bei vier (0,8 %) Tieren wurden Koinfektionen mit zwei oder drei verschiedenen TBPs festgestellt. Ein Tier war dreifach mit Rickettsia spp., B. burgdorferi s.l. und Bartonella spp. infiziert, bei einem Tier wurden
Rickettsia spp. und Bartonella spp. bestätigt und bei zwei Tieren wurden Doppelinfektionen mit Rickettsia spp. und B. burgdorferi s.l. festgestellt. Neoehrlichia mikurensis und Babesia spp. wurden nicht nachgewiesen.
In der vorliegenden Arbeit wurden durch Zecken übertragene, zoonotische Pathogene bei Waschbären in Deutschland nachgewiesen. Aufgrund ihrer hohen Reproduktionsrate und ihrer Fähigkeit, sich an verschiedene Lebensräume anzupassen, vergrößert sich die Waschbärpopulation in Deutschland rasant. Dies erhöht nicht nur das Risiko der Ausbreitung von Krankheitserregern, sondern auch das Risiko der Übertragung zwischen verschiedenen Arten. Es sollten künftig weitere Untersuchungen durchgeführt werden, um festzustellen, ob Waschbären in Deutschland tatsächlich als Reservoir für durch Zecken übertragene, zoonotische Pathogene fungieren.:1 Einleitung 1
2 Literaturübersicht 3
2.1 Der Waschbär (Procyon lotor) 3
2.1.1 Taxonomie und Morphologie 3
2.1.2 Vorkommen, Lebensraum, Populationsdichte in Deutschland 4
2.1.3 Zeckenfauna des Waschbären 6
2.2 Ausgewählte zeckenübertragene Pathogene 6
2.2.1 Borrelia burgdorferi sensu lato 6
2.2.1.1 Taxonomie, Morphologie 6
2.2.1.2 Entwicklungszyklus, Reservoirwirte 7
2.2.1.3 Klinik, Nachweis, Verbreitung 7
2.2.1.4 Waschbären als Wirte 8
2.2.2 Rickettsien 8
2.2.2.1 Taxonomie, Morphologie 8
2.2.2.2 Entwicklungszyklus, Reservoirwirte 9
2.2.2.3 Klinik, Nachweis, Verbreitung 9
2.2.2.4 Waschbären als Wirte 10
2.2.3 Bartonella spp. 11
2.2.3.1 Taxonomie, Morphologie 11
2.2.3.2 Entwicklungszyklus, Reservoirwirte 11
2.2.3.3 Klinik, Nachweis, Verbreitung 12
2.2.3.4 Waschbären als Wirte 14
2.2.4 Babesia spp. 14
2.2.4.1 Taxonomie, Morphologie 14
2.2.4.2 Entwicklungszyklus, Reservoirwirte 15
2.2.4.3 Klinik, Nachweis, Verbreitung 15
2.2.4.4 Waschbären als Wirte 16
2.2.5 Neoehrlichia mikurensis 16
2.2.5.1 Taxonomie, Morphologie 16
2.2.5.2 Entwicklungszyklus, Reservoirwirte 16
2.2.5.3 Klinik, Nachweis, Verbreitung 16
2.2.5.4 Waschbären als Wirte 17
3 Publikation 18
3.1 Stellungnahme zum Eigenanteil an den Arbeiten der Publikation 18
3.2 Publikation 19
4 Diskussion und Schlussfolgerung 29
5 Zusammenfassung 36
6 Summary 38
7 Literaturverzeichnis 40
8 Danksagung 53
9 Lebenslauf 5
An Improved Wake-Up Receiver Based on the Optimization of Low-Frequency Pattern Matchers
No full textWake-up receivers are gaining importance in power-aware wireless sensor networks, as they significantly reduce power consumption during RF reception, enabling asynchronous communication with low latency. However, the performance of wake-up receivers still lags behind that of off-the-shelf RF transceivers. There is a growing demand for higher sensitivity, enhanced reliability, and lower latency while maintaining the lowest power consumption. In this article, our goal is to advance the performance of wake-up receivers based on off-the-shelf components and low-frequency pattern matchers. Through a systematic investigation, we proposed multiple improvements aimed at enhancing wake-up receiver performance and reliability. We introduced an improved passive envelope detector and realized a wake-up receiver for the 868 MHz band, which achieves a power consumption of 5.71 μW and latency of 9.02 ms. Our proposed wake-up receiver is capable of detecting signals down to an average power level of −61.6 dBm. These achievements represent significant advancements compared to the existing state of research on wake-up receivers based on low-frequency pattern matchers. Recent articles have not been able to attain such improved values in signal detection, power consumption, and latency
Optimised use of data fusion and memory-based learning with an Austrian soil library for predictions with infrared data
No full textInfrared spectroscopy in the visible to near-infrared (vis–NIR) and midinfrared
(MIR) regions is a well-established approach for the prediction of soil
properties. Different data fusion and training approaches exist, and the optimal
procedures are yet undefined and may depend on the heterogeneity present in
the set and on the considered scale. The objectives were to test the usefulness
of partial least squares regressions (PLSRs) for soil organic carbon (SOC), total
carbon (Ct), total nitrogen (Nt) and pH using vis–NIR and MIR spectroscopy
for an independent validation after standard calibration (use of a general PLSR
model) or using memory-based learning (MBL) with and without spiking for a
national spectral database. Data fusion approaches were simple concatenation
of spectra, outer product analysis (OPA) and model averaging. In total, 481 soils
from an Austrian forest soil archive were measured in the vis–NIR and MIR
regions, and regressions were calculated. Fivefold calibration-validation
approaches were carried out with a region-related split of spectra to implement
independent validations with n ranging from 47 to 99 soils in different folds.
MIR predictions were generally superior over vis–NIR predictions. For all
properties, optimal predictions were obtained with data fusion, with OPA and
spectra concatenation outperforming model averaging. The greatest robustness
of performance was found for OPA and MBL with spiking with R2 ≥ 0.77 (N),
0.85 (SOC), 0.86 (pH) and 0.88 (Ct) in the validations of all folds. Overall, the
results indicate that the combination of OPA for vis–NIR and MIR spectra with
MBL and spiking has a high potential to accurately estimate properties when
using large-scale soil spectral libraries as reference data. However, the reduction
of cost-effectiveness using two spectrometers needs to be weighed against
the potential increase in accuracy compared to a single MIR spectroscopy
approach