Technische Universität Dresden: Qucosa
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Metallschutzgasschweißen mit vorgelagert vorgewärmtem Heißdraht
No full textDie aktuellen Herausforderungen deutscher Fertigungsunternehmen verdeutlichen die Notwendigkeit, Fügeverfahren kontinuierlich weiterzuentwickeln, um die Wirtschaftlichkeit zu sichern. Ziel dieser Arbeit war die grundlegende wissenschaftliche Untersuchung eines neuartigen MSG-Prozesses mit vorgewärmtem Heißdraht, um dessen gezielte industrielle Anwendung zu ermöglichen. Der Prozess nutzt eine Vorwärmeinheit, die den Zusatzdraht ohne Schmelzbadkontakt erhitzt, wodurch die Blaswirkung auf ein Minimum reduziert werden kann. Grundlage der Untersuchungen bildeten Weiterentwicklungen bestehender Anlagen- und Brennertechnologien sowie die Implementierung neuer Steueralgorithmen zur Verbesserung der Prozessstabilität.
Auf dieser Basis erfolgte die Entwicklung und Validierung von Methoden zur Bestimmung des Energieeintrags und der Nahtgeometrie. Die Charakterisierung des MSG-Heißdrahtprozesses zeigte, dass sich Nahtgeometrie und Materialeintrag bei nahezu konstantem Energieeintrag über Heißdrahtstrom und Vorschub gezielt anpassen lassen. Durch die Analyse der Kühlwasserströme konnten erstmals die Wärmeströme von MSG- und HD-Prozess exakt getrennt und deren Abhängigkeit vom Heißdrahtstrom bestimmt werden.
Es wurde ein breites Parameterfeld nachgewiesen, das auf die Vorwärmung des Drahtes ohne Schmelzbadkontakt und die optimierten Steueralgorithmen zurückzuführen ist. Darüber hinaus wurden ingenieurpraktische Abhängigkeiten definiert, die als Handlungsempfehlung zur Einstellung der Nahteigenschaften dienen. Die Analyse des Verbindungsschweißens, des Auftragschweißens und der additiven Fertigung demonstriert das signifikante Potential des MSG-Heißdrahtprozesses. Diese Schweißaufgaben können produktiver bewältigt werden als durch den Einsatz des konventionellen MSG-Prozesses bzw. MSG-HD-Prozesses. Darüber hinaus konnte eine ausgezeichnete Einstellbarkeit sowie eine hohe mögliche Automatisierbarkeit des Prozesses festgestellt werden
Vollautomatisiertes Fahren: Wie entscheidend sind Ethik, Empathie und wahrgenommene Sicherheit für die Akzeptanz?
No full textFokusgruppeninterviews und Feldbeobachtungen zur Erfassung der barrierefreien Nutzbarkeit geneigter öffentlicher Wege
No full textDie DIN 18040-3 stellt die zentrale Norm für barrierefreies Bauen im öffentlichen Verkehrsraum in Deutschland dar. Sie regelt unter anderem die Gestaltung geneigter Gehwege und Rampen und bildet den Ausgangspunkt des im Auftrag des Bundesministeriums für Digitales und Verkehr, vertreten durch die Bundesanstalt für Straßen- und Verkehrswesen, unter FE 77.0607/2022 laufenden Forschungsvorhabens (siehe www.fops.de) , das barrierefreie die Nutzbarkeit von öffentlichen Wegen mit Längsneigungen zwischen 3 % und 12 % in Relation zur Länge der Strecken und der Lage von Zwischenpodesten untersucht
Validation of the German Glasgow Sensory Questionnaire and replication of sensory processing differences in students with higher and lower Autism-Spectrum Quotient
No full textBackground:
The Glasgow Sensory Questionnaire (GSQ) gives insight into sensory processing differences (hypo- and hyper-sensitivity across modalities), which is a clinically defining characteristic of autism spectrum disorder (ASD). Because there is no validated German version of this instrument, this study aimed at validating the German GSQ. Further, a replication of the GSQ’s sensory processing differences was intended.
Methods:
University students of Technische Universität or Universitätsklinikum in Dresden, Germany, were recruited via email distribution or the university homepage and 297 German-speaking students completed the online survey, comprising the German GSQ, Autism-Spectrum Quotient (AQ) and Symptom-Checklist (SCL-90). For validation of the German GSQ, confirmatory factor analyses followed by exploratory factor analyses were applied.
Results:
The German GSQ has moderate to low validity, good to acceptable reliability, and a different internal structure from the original GSQ. Replicating the sensory processing differences in students with higher and lower AQ was not successful.
Conclusions:
Results indicate that the GSQ, developed especially for individuals with ASD, is less informative for the general population if there are not enough individuals with higher AQ scores in the sample
Combining Earth Observation, Socio-Economic Surveys, and Spatial Modelling to Evaluate Ecosystem Services Bundle in Selected Landscapes of North-Eastern Mountains, Tanzania
No full textThe mountainous environments of NE Tanzania are of international relevance for safeguarding biodiversity, sequestering carbon and delivering important ecosystem services (ES) to local populations. However, these landscapes are also particularly vulnerable to land degradation due to steep slopes, fragile soils, increasing population, severe shortages of pastureland, and climate change. Hence, with population densities as high as 650 people/km2 in the highlands, and with smallholder agriculture as the main income-generating activity finding a nexus between sustainability and ES delivery and the urgent short-term economic needs of households is an important challenge. The overarching goal of this doctoral thesis is to establish a guideline framework for understanding the role of indigenous agroforestry systems in delivering ES bundle aims to enhance their long-term sustainability while finding common ground between conservation efforts and the livelihoods of rural communities. The focus was on four smallholder indigenous agroforestry systems (AGF) in mountainous landscapes in the NE Mountains of Tanzania: Kihamba (Mount Kilimanjaro), Ginger (Pare Mountains), Miraba (West Usambara Mountains) and Mixed spices (East Usambara Mountains). These landscapes form a distinct climate transect, characterised by varying altitudes, rainfall patterns, soil types, and vegetation.
Publications I and II use a simple stratification approach by subdividing mountainous landscapes into equal-size study landscape boxes of 200 km2. In each box, six wards (local administrative units) were selected purposefully to characterize and describe the salient features of most common AGF practices by smallholder farmers along transects. A combination of various approaches and techniques, including earth observation, benefit transfer method (BTM) model, field and socio-economic surveys and individual-based statistical methods for the valuation of ES provision from AGF were employed. Publication III assesses the potential and variability of AGF in sequestering carbon and promoting soil fertility by field soil surveys and laboratory analyses. Publication IV evaluates vulnerable group access (i.e., availability and adequacy) to different ES by socio-economic surveys. In publication V the spatial prediction of ES tradeoffs and synergies potential in the AGF was simulated based on regenerative and degenerative scenarios using a spatial system dynamics model.
Publication I reveal that Mt. Kilimanjaro has the highest delivery of ES. However, a noticeable loss in ES is evident in Mt. Kilimanjaro and the South Pare Mts. agroforestry signalling a decline that can significantly impact the livelihoods of communities that rely on highland landscapes for various ES provisioning. Additionally, the increase in ES from forests has not been sufficient to offset the losses observed in agroforestry. These findings highlight that programs promoting
restoration of agroforestry can be successful yet are not sufficient for increasing overall tree cover in the studied landscapes. Publication II, moreover, highlights that within the AGF systems, the native tree cover has been partly replaced by non-native trees in Kilimanjaro and Pare, while native trees have been severely degraded in the West and East Usambara AGF systems. Concerning smallholder farmers' decision-making process across the four study landscapes, the farmers recognise the intrinsic value of native tree species. Their socioeconomic realities force them to prioritise economically significant ES delivery when selecting trees. Specifically, they tend to favour trees that support cash crops, food production, fuel, timber, fodder, or provide shade for coffee. These findings highlight alarming land use/cover changes and degradation within agroforestry ecosystems, underscoring the urgent need for
frameworks that mitigate the adverse impacts while balancing development and restoration efforts with the provision of economic needs and ecosystem services.
In publication III, the evidence base was built for the potential benefits of native trees for carbon sequestration and soil fertility improvement in AGF, contributing to climate change mitigation and adaptation. The findings show that the highest soil carbon sequestering potential was found in the old Kihamba systems (located on Nitisols) of Mt. Kilimanjaro compared to other systems on Acrisols of the Pare, West and East Usambara Mts. which calls for soil management practices and restoration strategies that have significant potential for optimizing the soil carbon and fertility. Next, publication IV determine who suffered most from losses in ES delivery upon
landscape degradation. Degraded landscapes also become less inclusive and vulnerable groups in society, i.e. single-headed households, including female-headed households and persons living with disabilities, are unequally affected by the observed degradation, as they most of all rely on access to ES closer to their homes.
The underlying drivers of this degradation, which create imbalances between conservation efforts and livelihoods, are the topic of publication V. From the dynamic model analysis applied, it is evident that farmers will require additional support and incentives to maintain native trees in their fields. This support could come from government and NGO campaigns and should be inclusive and tailored to local needs. It reveals a clear dichotomy between sustainably managed and degraded agroforests, with the future of these systems depending on the ability to transition from degeneration to regeneration. The findings of this research provide evidence across landscapes for addressing challenges and generating opportunities for the socio-ecological ecosystem services nexus in AGF in tropical mountains:Declaration of conformity................................................................................ ii
Declaration of Independent Work and Consent ............................................ iii
Thesis at a Glance ........................................................................................ v
Graphical abstract (a) ................................................................................... vii
Graphical abstract (b) ................................................................................... viii
Abstract ......................................................................................................... ix
PART A: SYNTHESIS.......................................................................................1
1. INTRODUCTION .........................................................................................1
1.1 Tropical Mountain Landscapes ..................................................................1
1.2 Ecosystem Services Bundle.......................................................................3
1.3 Agroforestry Systems..................................................................................5
1.3.1.1 The genesis and evolution of indigenous agroforestry systems
(Drawing from the past, adapting to the future) ................................................5
1.3.1.2 Strength through diversity .................................................................... 6
1.3.1.3 Socio-cultural aspects of AGF evolution .............................................. 8
1.3.1.4 Success and setbacks ......................................................................... 9
1.3.1.5 Historical impact and evolution in Sub-Sahara Africa ..........................10
1.4 Research Questions and Objectives ..........................................................15
1.4.1 Degenerative scenario .............................................................................15
1.4.2 Regenerative scenario ............................................................................ 16
2. MATERIAL AND METHODS ........................................................................ 17
2.1. Study area ................................................................................................. 17
2.2 Overview and Critical Reflections of Methods Applied................................ 18
3. SYNTHESIS OF RESULTS AND DISCUSSION .......................................... 22
3.1 Indigenous Agroforestry Systems, Biodiversity Conservation, and Ecosystem
Services Bundle (Publication I, II) ............................................................... 23
3.2 Indigenous Agroforestry Systems on Degradation and Climate-smart Solutions
(Publication III)............................................................................................. 27
3.3 Indigenous Agroforestry Systems and Inclusivity (Publication IV) ............. 31
3.4 A System Dynamics Modelling: A Framework for Evaluating Ecosystem Services
bundle (Publication V)................................................................................. 32
3.4.1 Trade-offs, synergies, and provision potentials in tropical mountain
landscapes................................................................................................32
3.4.2 Trends and behaviours from the system dynamic model ........................ 33
3.4.3 Widening all bottlenecks in the conduit to sustainability........................... 35
4. CONCLUSION AND RECOMMENDATIONS ............................................... 36
5. PERSPECTIVES FOR FURTHER RESEARCH .......................................... 39
REFERENCES ................................................................................................. 40
Acknowledgments ............................................................................................. 55
PART B: PUBLICATIONS ................................................................................. 58
PUBLICATION I ................................................................................................ 60
PUBLICATION II ............................................................................................... 98
PUBLICATION III .............................................................................................. 117
PUBLICATION IV .............................................................................................. 131
PUBLICATION V ............................................................................................... 152
List of Figures
Figure 1: Ecosystem services and their link to human well-being (ES Bundle).... 4
Figure 2: Indiscriminate logging for subsequent coffee cultivation in NE Tanzania during the German colonial period before World War I........................................ 11
Figure 3: Location of the studied NE mountain landscapes of Tanzania............. 18
List of Tables
Table 1: The historical evolution of agroforestry systems in Sub-Saharan Africa...13
Table 2: Historical transformation of Indigenous Agroforestry Systems in mountains regions of NE Tanzania ..........................................................................................1
Programming a synthetic out-of- equilibrium reaction network within proteinosomes
No full textLife's persistence is underpinned by dynamic biological systems operating across a variety of scales and complexities. Central to these systems is the ability of cells to dynamically adapt to external stimuli, fostering complex and coordinated behavior within cellular communities. Such complex behaviors emerge from networks of biochemical reactions that govern information processing both within individual cells and across cell populations. This is a universal trait, manifesting from bacterial quorum sensing to the signalling pathways integral to embryonic development. Unravelling the intricate structure of network-driven population behaviors necessitates an understanding of how the interaction of compartmentalized information processing and intercellular communication influences dynamic systems. In studying dynamic biological systems, methodologies vary widely, encompassing animal models, organoids, cell cultures, and extending to synthetic biology, each representing a step toward less biological complexity and providing unique insights while presenting their own sets of challenges. Synthetic biology, in particular, offers a focused approach to dissecting these complex systems. Initial research in this field has replicated complex cellular behaviours with compartmentalized, non-enzymatic reactions. Yet, there remains an essential goal to develop enzyme-driven dynamic systems that more accurately mirror the cyclical processes of degradation and synthesis seen in living organisms. This study aims to fill this gap by reconstructing a minimal dynamic system to investigate emergent behaviours through enzyme-based reactions. Specifically, it focuses on the compartmentalized processing of chemical information, activated by diffusible small molecules, and examines its influence on complex intercellular network formation. Employing synthetic biology, the study utilizes microfluidic-assembled droplets—termed proteinosomes—to create populations of engineered synthetic cells. DNA reactions are encapsulated within these proteinosomes populations to enable specific biochemical reactions via controlled diffusion of molecules, allowing the creation of interconnected networks of reactions. In this work, these reactions within proteinosomes are primers activated and enzyme-driven isothermal DNA reaction, known as PEN-DNA reactions. This process involves a short oligonucleotide primer initiating replication from a longer DNA template, producing two shorter oligonucleotides that can diffuse in solution or, as in this case, through the proteinosome’s membrane. The compartmentalization of the reactions leads to kinetic behaviors that are not present in buffer solutions. For instance, autocatalytic reactions within the proteinosomes occurred at rates comparable to those in buffer solutions but with significantly less DNA template. Reaction rates were found to be markedly higher in relation to template concentration than those in buffer solution. This can be linked to the proteinosomes' selective containment of template DNA while allowing primer DNA to diffuse away from the reaction site. Thus, the system is well-suited for creating reaction networks that leverage compartmentalized information processing with communication between compartments. The effectiveness of this platform was demonstrated by first establishing a linear communication between two proteinosome populations, each containing distinct DNA reactions. The network's complexity was then enhanced by incorporating a negative feedback loop, resulting in oscillatory behavior between DNA reactions within the proteinosome populations. This work not only presents a reliable method for constructing compartmentalized reaction networks but also allows for the examination of how spatial localization and passive diffusion affect reaction rates. These synthetic cells facilitate the examination of reaction dynamics within compartments, including the establishment of an oscillatory communication network displaying emergent behaviours. The findings suggest that bottom-up methods can be employed to develop synthetic systems that mimic reaction-diffusion across networks, driven by selective compartmentalization and cellular communication.:Contents
1. ACKNOWLEDGEMENTS ............................................................................................ 3
2. ABSTRACT .................................................................................................................. 5
3. ZUSAMMENFASSUNG ............................................................................................... 7
4. RELATED PUBLICATIONS ....................................................................................... 14
5. ABBREVIATION LIST ................................................................................................ 16
7. CHAPTER 1: INTRODUCTION .................................................................................
8. CHAPTER 2: PREPARATION OF PEN-DNA REACTION IN PROTEINOSOMES .. 47
9. CHAPTER 3: LINEAR COMMUNICATION BETWEEN DNA TEMPLATES VIA PEN-
DNA REACTION IN PROTEINOSOMES ....................................................................... 80
10. CHAPTER 4: PREDATOR-PREY PEN-DNA REACTION WITHIN
PROTEINOSOMES POPULATION ............................................................................... 90
11. CHAPTER 5: DISCUSSION ................................................................................. 108
12. CHAPTER 6: ........................................................................................................ 116
13. BIBLIOGRAFY ..................................................................................................... 13
Up-Regulation of PSMA Expression In Vitro as Potential Application in Prostate Cancer Therapy
No full textPossibilities to improve the therapeutic efficacy of Lu-177–PSMA-617 radionuclide therapy by modulation of target expression are being investigated. Knowledge on regulatory factors that promote prostate cancer (PCa) progression may contribute to targeting prostate cancer more effectively. We aimed at the stimulation of PCa cell lines using the substances 5-aza-2′-deoxycitidine (5-aza-dC) and valproic acid (VPA) to achieve increased prostate-specific membrane antigen (PSMA) expression. PC3, PC3-PSMA, and LNCaP cells were incubated with varying concentrations of 5-aza-dC and VPA to investigate the cell-bound activity of Lu-177–PSMA-617. Stimulation effects on both the genetically modified cell line PC3-PSMA and the endogenously PSMA-expressing LNCaP cells were demonstrated by increased cellular uptake of the radioligand. For PC3-PSMA cells, the fraction of cell-bound radioactivity was enhanced by about 20-fold compared to that of the unstimulated cells. Our study reveals an increased radioligand uptake mediated by stimulation for both PC3-PSMA and LNCaP cell lines. In perspective of an enhanced PSMA expression, the present study might contribute to advanced radionuclide therapy approaches that improve the therapeutic efficacy, as well as combined treatment options
Demographic overview of pilonidal sinus carcinoma: updated insights into the incidence
No full textPurpose:
There are only rough estimates of the worldwide incidence of pilonidal sinus carcinoma. The purpose of the study is to explore the demographic characteristics of this disease and to provide more precise information about its incidence.
Methods:
The study included questioning the surgeons and pathologists in Germany in addition to a literature research. The literature investigation included all published articles about pilonidal carcinoma in all languages. The questionnaire included 1050 pathologists and all 834 hospitals with a surgical division in Germany. The outcome measures included the total number of cases, the language of publication, gender, age, country of origin, interval until the diagnosis of carcinoma, and reported incidence based on local studies.
Results:
From 1900 to 2022, we found 140 cases of pilonidal sinus carcinoma in 103 articles. The investigation revealed two additional unpublished cases from Germany. The male-to-female ratio was 7.75:1. The countries with the most cases were the USA (35 cases, 25.0%), Spain (13 cases, 9.3%), and Turkey (11 cases, 7.6%). The average age was 54.0 ± 11.8 years and the interval between the diagnosis of the disease and the development of carcinoma was 20.1 ± 14.1 years. There was a parallel increase in reported cases of pilonidal sinus disease and pilonidal carcinoma over the last century. The reported incidence varied from 0.03% to 5.56%. The worldwide calculated incidence equaled 0.17%.
Conclusion:
Due to underreporting and other causes, the incidence of carcinoma emerging on the background of pilonidal sinus disease is higher than reported
Analysis of the correlation between agile team maturity and standardised key performance indicators in automotive development
No full textThe application of agile development methods in response to increasing market dynamics and product complexity is a key lever in the automotive industry. Agile methods originally come from the software industry and enable fast, flexible and customer-oriented product development. These methods are also increasingly being used in hardware development. However, the evaluation of the benefits of agile methods in the context of automotive development has been primarily subjective. The publication aims to present a first data-based approach to objectify the benefits of agile methods in automotive development by highlighting the effects in the quality of collaboration within teams. A standardised procedure is therefore designed and presented. On the one hand, a model for measuring the agile maturity of teams is described. On the other hand, the quality of collaboration within a team is examined in different aspects using standardised key performance indicators. Based on the proposed procedure, a strong positive correlation was found between the considered key performance indicators of the quality of collaboration and the agile maturity of the development teams within the investigated organisation