Technische Universität Dresden
  • Dresden, Saxony, Germany
Recent publications
This paper offers a systematic literature review of real-time detection and classification of Power Quality Disturbances (PQDs). A particular focus is given to voltage sags and notches, as voltage sags cause huge economic losses while research on voltage notches is still very incipient. A systematic method based on scientometrics, text similarity and the analytic hierarchy process is proposed to structure the review and select the most relevant literature. A bibliometric analysis is then performed on the bibliographic data of the literature to identify relevant statistics such as the evolution of publications over time, top publishing countries, and the distribution by relevant topics. A set of articles is subsequently selected to be critically analyzed. The critical review is structured in steps for real-time detection and classification of PQDs, namely, input data preparation, preprocessing, transformation, feature extraction, feature selection, detection, classification, and characterization. Aspects associated with the type of disturbance(s) addressed in the literature are also explored throughout the review, including the perspectives of those studies aimed at multiple PQDs, or specifically focused on voltage sags or voltage notches. The real-time performance of the reviewed tools is also examined. Finally, unsolved issues are discussed, and prospects are highlighted.
The IEC 61000–2–2 standard defines the compatibility levels to evaluate the conducted disturbances in the low voltage grid for the 2-150 kHz range. For frequencies 9–150 kHz, they are defined in terms of quasi peak values measured according to CISPR 16–1–1 standard, but no clear guidance is given on how to apply this standard to grid measurements. The definition of the method in CISPR 16–1–1 accepts a wide range of different implementations, all of them fulfilling the compliance requirements. The reasons are that the standard does not propose a fixed implementation but a ‘black-box’ approach, and some of the proposed configuration values are non-normative and/or wide tolerances are allowed. In this context, some parameters have a pivotal role in the results provided by the method. The impact of variation of these parameters on the measurement results is addressed in this work. In particular, the accuracy requirements and the reproducibility issues of the standard are studied. For that purpose, a high number of different compliant implementations have been developed and the influence of different features of the CISPR 16–1–1 method on the results of these implementations is identified and analyzed. The results show that the wide tolerances allowed by the CISPR 16 specification impede the comparison of results provided by measuring receivers based on different implementations of the standard. Results of the study also show that reproducibility issues for the same input signal may be relevant and generate inconsistences. Moreover, a fixed specific configuration does not ensure that uncertainty issues are solved, as the technical approach used in the implementation of the damped meter has a strong influence on the outputs. An unambiguous guidance of digital implementation of the standard could fix these issues.
Gender is a vital factor of societal organisation and transformation, and figures prominently in global sustainability agendas. Its social construction and interaction with technological change have been studied extensively. Within the field of sustainability transition (ST) research, however, the complex roles gender plays in socio-technical change are still rarely addressed or conceptualised. Based on a systematic review covering scientific publications from 2010 to 2020 we illustrate this overall gap and explore how gender is operationalised. We draw on Harding's notion of gender as structural, symbolic and behavioural expression to consider implications for understanding regimes, niches, and regime/niche interactions. Our results recognise a variety of conceptual approaches accounting for the diverse implications of gender relations for transition dynamics and their sustainability orientation. In conclusion we recognise the usefulness of the suggested analytical lens for strengthening gender-sensitive inter- and transdisciplinary ST research systematically, and suggest promising avenues for future studies.
In the evolution of structural glass beam elements, the requirements for post-fracture load bearing capacity and safe failure behaviour have led to the development of reinforced and post-tensioned beams. Maximum bending capacity in the post-fracture state is normally associated with extensive yielding of the reinforcement, providing a safe failure mechanism through apparent ductility of the composite beam section. This can be achieved as long as the propagation of primary flexural cracks does not compromise the transfer of shear from the load points to the supports. Although shear failure is typically not critical for the ultimate limit state design of ’normal’ unreinforced glass beams, it may govern the load-bearing and deformation capacity in the post-fracture state for reinforced and post-tensioned glass beams. This paper presents exploratory experiments and initial analysis of the shear failure phenomenon in the post-fracture state of reinforced and post-tensioned glass beams. Potential shear transfer mechanisms are identified based on the critical shear crack theory developed for reinforced concrete members and applied in the analysis of shear failures observed in four-point bending tests of post-tensioned glass beams. The behaviour of fractured laminated glass under mixed-mode (tension+shear) loading is explored on a limited set of small-scale double-notched glass specimens, demonstrating the feasibility of the applied test methodology. Preliminary findings of the present study may serve as a basis for further investigations of shear resistance of glass beams. Typical shear failure kinematics and suitable constitutive laws of the applied materials need further investigation in order to provide design recommendations for the prediction of shear resistance of reinforced and post-tensioned glass beams.
Managing agricultural land to maximize the supply of natural pest control can help reduce pesticide use. Tools that are able to represent the relationship between landscape structure, field management and natural pest control can help in deciding which management practices should be used and where. However, the reliability and the predictive power of generic models of natural pest control is largely unknown. We applied an existing generic model of natural pest control potential based on landscape structure to nine sites in five European countries and tested the resulting values against field measurements of natural pest control. Subsequently, we added information on local level factors to test the possibility of improving model performance and predictive power. The results showed that there is generally little or no evidence of correlation between modeled and field-measured values of natural pest control. Moreover, we found high variability in the results, depending on the associations of crops, pests and biocontrol agents considered (e.g. Oilseed rape-Pollen beetle-Parasitoids) and on the different case studies. Factors at the local level, such as conservation tillage, had an overall positive effect on natural pest control, and their inclusion in the models typically increased their predictive power. Our results underline the importance of developing predictive models of natural pest control which are tailored towards specific associations between crops, pests and biocontrol agents, consider local level factors and are trained using field measurements. They would serve as important tools within farmers' decision making, ultimately supporting the shift toward a low-pesticide agriculture.
Steppes have a long history of grazing, which has affected vegetation and ecosystem functioning to varying degrees depending on local environmental and climatic conditions. While the effects of grazing on plant species' diversity and composition are well documented, effects on plants' functional traits and genetic structures are far less widely studied. Similarly, the effects of climate/land-use interactions on plants’ functional traits or genetic structure have rarely been investigated. We conducted a study on the largest representative example of the Palearctic steppe biome, in Mongolia, using long-term grazing exclusion along a broad climatic gradient. We investigated the influence of grazing on the population genetics and functional traits of the prominent shrub species Artemisia frigida. A total of 187 individuals were sampled from eight locations along the Trans-Mongolian Railway and in the Hustai National Park. Comparisons were made between enclosed (ungrazed) and open (grazed) sites and analyzed using ten microsatellite loci. Grazing had a significant positive effect on genetic diversity but no effect on population genetic differentiation. Climatic and soil variables strongly influenced population genetic structure, with soil nutrient availability being positively associated with genetic diversity. Grazing significantly influenced functional traits (plant height, specific leaf area), however, no relationship was found between genetic diversity and plant functional traits. Overall, given that ungrazed A. frigida populations showed lower genetic diversity, a moderate level of grazing is likely to be beneficial for the species, which may also help stabilize ecosystem functioning in steppes more broadly.
The EU's Forest Law Enforcement, Governance and Trade Action Plan (FLEGT) adopted in 2003 includes bilateral trade agreements known as Voluntary Partnership Agreements (VPAs) signed between the EU and timber-supplying countries. The EU has invested more than 1.5 billion euros in VPAs; however, only one of the seven concerned countries has managed to complete all the necessary requirements to expire FLEGT licences. Since there is no research that comprehensively integrates the scientific evidence regarding the effects of this policy, this study systematically reviews all empirical scientific studies on the effects of VPAs. We found that almost all relevant studies are case reports that use qualitative data and focus on only one country at a time, mainly Ghana, Cameroon, or Indonesia. The evidence suggests that while VPAs have contributed to the establishment of governance structures, tools, and procedures they have not been able to solve social problems (i.e., inequality and injustice) and have potentially harmed the economies of EU timber suppliers. Evidence on the effects of VPAs on illegal logging and trade and the environment remains limited. Thus, future research should focus on more countries; use a greater range of methods, including comparative experimental designs; explore possible intended effects on under-researched categories; and systematically investigate unintended effects on other categories within and outside the forestry sector.
Declines in insect biomass and individual numbers have been demonstrated in many parts of the world, including central European dry grasslands. It is, howver, unclear if biomass data or individual numbers are superior as measures of change in species composition, and in trait composition of insect communities. We revisited a former study of ours demonstrating severe losses in abundance of planthoppers and leafhoppers in Central European grasslands since the 1960s. We performed a series of univariate, multivariate and trait-based tests to investigate the relationship between biodiversity change and environment, and compared the results for number-weighted and biomass-weighted community data. While both individual numbers and biomass declined strongly over time, no changes in species diversity (Jost's D) were observed irrespective of the measure used for weighting. Surprisingly, metrics for trait diversity tended to increase over time in both the number-weighted and biomass-weighted data. For both measures, community composition changed strongly over time for species and trait data, and was also associated with landscape structure and mean annual precipitation. Of the tested traits, we only found associations between an early phenology and time, and a temporal increase of species over-wintering in a nymphal stage, but again there was no major difference between the measure used for weighting. Our study shows that declining assemblage size (regardless of the measure used) does not necessarily translate in concomitant changes in functional diversity or trait diversity. From a methodological perspective, no clear evidence emerged for either biomass or individual number as measure of assemblage size being more sensitive to environmental change. This implies that conversion of widely used data of individual numbers to biomass values is unlikely to bring much additional insights. With respect to the general scarcity of quantitative data on insect communities, the focus should be on using whatever data is available.
Laser-based direct energy deposition (L-DED) with blown powder enables the simultaneous or sequential processing of different powder materials within one component and, thus, offers the possibility of additive multimaterial manufacturing. Therefore, the process allows a spatially resolved material allocation and fabrication of sharp or even graded material transitions. Within this contribution, the latest results from two major research fields in multimaterial L-DED—(I) automation and (II) rapid alloy development of high entropy alloys (HEAs) by in situ synthesis—shall be presented. First, an automated multimaterial deposition process was developed, which enables the automated manufacturing of three-dimensionally graded specimens. For this, a characterization of the deposition system regarding powder feeding dynamics and resulting powder mixtures in the process zone was conducted. The obtained system characteristics were used to achieve a three-dimensional deposition of specified powder mixtures. The fabricated specimens were analyzed by energy-dispersive x-ray spectroscopy, scanning electron microscopy, and micro hardness measurement. The research demonstrates the increasing readiness of L-DED for the fabrication of multimaterial components. Second, the latest results from rapid alloy development for HEAs by DED are presented. By the simultaneous usage of up to four powder feeders, a vast range of alloy compositions within the Al–Ti–Co–Cr–Fe–Ni HEA system was investigated. For this, tailored measurement systems such as an in-house developed powder sensor were beneficially used. The study shows the influence of a variation of Al on the phase formation and resulting mechanical properties and demonstrates the potential of L-DED for reducing development times for new alloys.
Identifying new chemical structures against protein targets of interest represents one of the major challenges in drug discovery. As the major experimental method, high throughput screenings are performed with existing chemical libraries, thus restricting its capability to explore high molecular diversity. Herein, we report the use of high throughput array synthesis technology, in combination with growth algorithm, to discover binders for proinflammatory cytokine TNF-α. After 6 iterations of Library design - Array synthesis - Screening (i-LAS), one identified compound T17 has shown a kd value of 14.8 μM, and can rescue L929 cells from TNF-α mediated cytotoxicity. Further engineering T17 in various forms of oligomers have led to low nM binders. More interestingly, through tuning the multi-valent interaction with TNF-α, the high affinity oligomers can be switched from inhibitors to activators, leading to the hypothesis of an oligomerization-induced receptor activation mechanism. The i-LAS technology has allowed us to discover new binder structures, which can be further engineered into molecules with novel properties.
Pavlovian cues can influence ongoing instrumental behaviour via Pavlovian‐to‐instrumental transfer (PIT) processes. While appetitive Pavlovian cues tend to promote instrumental approach, they are detrimental when avoidance behaviour is required, and vice versa for aversive cues. We recently reported that susceptibility to interference between Pavlovian and instrumental control assessed via a PIT task was associated with risky alcohol use at age 18. We now investigated whether such susceptibility also predicts drinking trajectories until age 24, based on AUDIT (Alcohol Use Disorders Identification Test) consumption and binge drinking (gramme alcohol/drinking occasion) scores. The interference PIT effect, assessed at ages 18 and 21 during fMRI, was characterized by increased error rates (ER) and enhanced neural responses in the ventral striatum (VS), the lateral and dorsomedial prefrontal cortices (dmPFC) during conflict, that is, when an instrumental approach was required in the presence of an aversive Pavlovian cue or vice versa. We found that a stronger VS response during conflict at age 18 was associated with a higher starting point of both drinking trajectories but predicted a decrease in binge drinking. At age 21, high ER and enhanced neural responses in the dmPFC were associated with increasing AUDIT‐C scores over the next 3 years until age 24. Overall, susceptibility to interference between Pavlovian and instrumental control might be viewed as a predisposing mechanism towards hazardous alcohol use during young adulthood, and the identified high‐risk group may profit from targeted interventions. Through cluster analyses of the drinking trajectories, we identified two subgroups: The drinking behaviour of the ‘late risers’ escalated after age 21, whereas the drinking of ‘early peakers’ culminated at this age and then declined. The ‘late risers’ showed enhanced dmPFC responses during conflict and three times higher error rates during conflict between Pavlovian cues and instrumental responses in the PIT paradigm at age 21. Interestingly, this group also exhibited an increased behavioural PIT effect from age 18 to 21.
Introduction The percentage of patients diagnosed with pheochromocytoma and paraganglioma (altogether PPGL) carrying known germline mutations in one of the over fifteen susceptibility genes identified to date has dramatically increased during the last two decades, accounting for up to 35-40% of PPGL patients. Moreover, the application of NGS to the diagnosis of PPGL detects unexpected co-occurrences of pathogenic allelic variants in different susceptibility genes. Methods Herein we uncover several cases with dual mutations in NF1 and other PPGL genes by targeted sequencing. We studied the molecular characteristics of the tumours with co-occurrent mutations, using omic tools to gain insight into the role of these events in tumour development. Results Amongst 23 patients carrying germline NF1 mutations, targeted sequencing revealed additional pathogenic germline variants in DLST (n=1) and MDH2 (n=2), and two somatic mutations in H3-3A and PRKAR1A. Three additional patients, with somatic mutations in NF1 were found carrying germline pathogenic mutations in SDHB or DLST, and a somatic truncating mutation in ATRX. Two of the cases with dual germline mutations showed multiple pheochromocytomas or extra-adrenal paragangliomas - an extremely rare clinical finding in NF1 patients. Transcriptional and methylation profiling and metabolite assessment showed an “intermediate signature” to suggest that both variants had a pathological role in tumour development. Discussion In conclusion, mutations affecting genes involved in different pathways (pseudohypoxic and receptor tyrosine kinase signalling) co-occurring in the same patient could provide a selective advantage for the development of PPGL, and explain the variable expressivity and incomplete penetrance observed in some patients.
Background: Research suggests that Alopecia areata (AA) and Major Depressive Disorder (MDD) show substantial comorbidity. To date, no study has investigated the hypothesis that this is attributable to shared genetic etiology. Objectives: To investigate AA-MDD comorbidity on both the epidemiological and the molecular genetic levels. Methods: First, epidemiological analyses were performed using data from a cohort of adult German health insurance beneficiaries (n=1.855 million) to determine the population-based prevalence of AA-MDD comorbidity. Second, analyses were performed to determine the prevalence of MDD in a clinical AA case-control sample with data on psychiatric phenotypes, stratifying for demographic factors to identify possible contributing factors to AA-MDD comorbidity. Third, the genetic overlap between AA and MDD was investigated using a polygenic risk score (PRS) approach and linkage disequilibrium score (LDSC) regression. For PRS, summary statistics from a large MDD GWAS meta-analysis (PGC-MD2) were used as the training sample, while a Central European AA cohort, including the above-mentioned AA patients, and an independent replication US-AA cohort were used as target samples. LDSC was performed using the summary statistics of the PGC-MD2 and the largest AA meta-analysis to date. Results: High levels of AA-MDD comorbidity were reported in the population-based (MDD in 24% of AA patients), and clinical samples (MDD in 44% of AA patients). MDD-PRS explained a modest proportion of the variance in AA case-control status (R2 =1%). This signal was limited to the major histocompatibility complex (MHC) region on chromosome 6. LDSC regression (excluding MHC) revealed no significant genetic correlation between AA and MDD. Conclusions: As in previous research, AA patients showed an increased prevalence of MDD. The present analyses suggest that genetic overlap may be confined to the MHC region, which is implicated in immune function. More detailed investigation is required to refine understanding of how the MHC is involved in the development of AA and MDD comorbidity.
Mimicry, the spontaneous imitation of an interaction partner, is an important part of everyday communication, as it has been shown to foster relationships and increase closeness. People with affective disorders often have problems in their interpersonal lives. In this review, we pursue the question if these problems are linked to differences in mimicry behavior. First, we summarize existing evidence on mimicry, depression and mood. Then, based on five theories differing in their core assumptions regarding mechanisms and functionality of mimicry, we derive suggestions on how mimicry might affect people suffering from bipolar disorders, dysthymia or depression. Depending on each theory, a different understanding of affective disorders and mimicry arises, and we show how the evidence fit in with the suggested theories. Previous studies on affective disorders have focused on mimicry behavior of participants watching photos, computer-generated images, or short video sequences. This review sheds light on the fact that evidence on mimicry needs to be broadened systematically for people with affective disorders in interactional settings. Mimicry represents a novel and important yet underestimated source for diagnostic, intervention and evaluation processes in affective disorders.
Immune checkpoint inhibitors (ICIs) are revolutionary cancer treatments. However, the mechanisms behind their effectiveness are not yet fully understood. Here, we aimed to investigate the role of the pH-regulatory enzyme carbonic anhydrase IX (CAIX) in ICI success. Consequently, we developed an in silico model of the tumour microenvironment. The hybrid model consists of an agent-based model of tumour–immune cell interactions, coupled with a set of diffusion-reaction equations describing substances in the environment. It is calibrated with data from the literature, enabling the study of its qualitative behaviour. In our model, CAIX-expressing tumours acidified their neighbourhood, thereby reducing immune infiltration by 90% ( p < 0.001) and resulting in a 25% increase in tumour burden ( p < 0.001). Moreover, suppression of CAIX improved the response to anti-PD-1 (23% tumour reduction in CAIX knockouts and 6% in CAIX-expressing tumours, p < 0.001), independently of initial PD-L1 expression. Our simulations suggest that patients with CAIX-expressing tumours could respond favourably to combining ICIs with CAIX suppression, even in the absence of pre-treatment PD-L1 expression. Furthermore, when calibrated with tumour-type-specific data, our model could serve as a high-throughput tool for testing the effectiveness of such a combinatorial approach.
Die Forschung in der Klinischen Psychologie befasst sich mit den Fragen der Häufigkeit, Entstehung, Entwicklung, Aufrechterhaltung, Diagnostik und Behandlung psychischer Störungen. Im Fokus stehen insbesondere die Veränderung psychischen Erlebens sowie die Entstehungsbedingungen und die Frage, welche Maßnahmen dazu beitragen können, die Entwicklung einer Störung zu verhindern bzw. sie zu behandeln. Im folgenden Kapitel werden die wichtigsten Forschungsbereiche und Forschungsmethoden im Bereich der Klinischen Psychologie vorgestellt.
Die Psychotherapie gehört neben der medikamentösen Therapie zu den wichtigsten Methoden, um psychische Störungen zu behandeln. Die bekannteste Definition für Psychotherapie stammt von Stotzka (1975) und beschreibt Psychotherapie als bewussten oder geplanten interaktionellen Prozess zur Beeinflussung von Störungen oder Leiden mittels psychologischer Mittel und lernbarer Techniken auf der Basis einer emotionalen Beziehung. Das folgende Kapitel stellt nach einer Begriffsbestimmung das Verfahren der Kognitiven Verhaltenstherapie näher vor und beschreibt zentrale und klassische Therapiemethoden.
Was sind Kernmerkmale von psychischen Störungen? Was verursacht Ängste, Zwänge oder Schizophrenien? Wie viele Menschen leiden unter einer psychischen Störunge? Das folgende Kapitel beschäftigt sich mit der Symptomatik, Häufigkeit und Ätiologie der häufigsten und wichtigsten psychischen Störungen. Betrachtet werden Schizophrenie, depressive Störungen, Angststörungen, Zwangsstörungen, Posttraumatische Belastungsstörung und Störungen durch Substanzkonsum.
Wir haben in diesem Buch einen Einblick in die Teilbereiche Klinische Psychologie und Psychotherapie gegeben. Dieses Kapitel fasst nocheinmal die zentralen Inhalte und Aufgabengebiete des Fachbereichs und deren Anwendung zusammen und verweißt auf aktuelle Entwicklungen.
Ist es Liebeskummer, nur ein Stimmungstief oder doch eine Depression? Ab wann sprechen wir von einer psychischen Störung? Welche psychischen Störungen gibt es? Wie lassen sich psychische Störungen diagnostizieren und klassifizieren? Mit diesen Kernfragen beschäftigt sich das folgende Kapitel.
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14,411 members
Florian Gunzer
  • Institut für Medizinische Mikrobiologie und Hygiene
Mike O. Karl
  • Center for Regenerative Therapies Dresden
Jens Schade
  • Faculty of Transportation and Traffic Science
Philipp Kanske
  • Department of Psychology
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Address
Helmholtzstraße 10, 01069, Dresden, Saxony, Germany
Head of institution
Prof. Dr Ursula M. Staudinger
Website
http://tu-dresden.de/
Phone
+49 (351) / 463 37044
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