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Redewiedergabeverfahren potenzieren das Moment der sozialen Positionierung in der Interaktion. Charaktere, die zum Beispiel in Erzählungen oder Argumentationen ‚zu Wort kommen‘, werden als Protagonisten und Antagonisten, Täter und Opfer, angeberisch und zurückhaltend konstruiert. Das Bild, das sich Gesprächspartner voneinander machen, wird aber nicht nur durch solche Positionierungen innerhalb der erzählten Welt, sondern auch durch ihre aktuelle Performance als Interaktionsspartner geprägt. All diese Positionierungsaktivitäten stehen in Wechselbeziehung zueinander und können auch aufschlussreiche Spannungsverhältnisse aufweisen.
Ausgehend von einer formalen Beschreibung der verwendeten Mittel zeigt die Analyse narrativ-biographisch geprägter Gespräche unter jungen Erwachsenen, wie in der Interaktion soziale Wirklichkeit ko-konstruiert wird, indem konkret oder stereotyp ‚fremde‘ Kontexte aufgerufen und als Kontrastfolie für die eigene Identitätskonstruktion genutzt werden.
This article examines the works of Adolf Jellinek (1821–1893) on the history of mysticism and the Kabbalah, which were written during his fourteen-year residence in Leipzig. It argues that studying the Spanish Kabbalists allowed Jellinek to work through ideas concerning the development of Jewish theology and the interplay of Jewish and non-Jewish philosophical perspectives. The article briefly describes Jellinek’s early education and attraction to Leipzig; his first writings on Kabbalah; and concludes with an analysis of his larger philological and genealogical projects on the authorship and literary background of the Zohar. Though Jellinek’s later prominence as a rabbi and preacher in Vienna has had the tendency to obscure his years in Leipzig, it was Jellinek’s work in Saxony that laid the groundwork for most of his subsequent scholarship on Jewish mysticism. This article is a brief introduction to this research and one more step toward revealing the still too often forgotten Wissenschaft interest in the history of Jewish mysticism.
Redox modulation of protein activity by thioredoxins (TRXs) plays a key role in cellular regulation. Thioredoxin z (TRX z) and its interaction partner fructokinase-like protein 1 (FLN1) represent subunits of the plastid-encoded RNA polymerase (PEP), suggesting a role of both proteins in redox regulation of chloroplast gene expression. Loss of TRX z or FLN1 expression generates a PEP-deficient phenotype and renders the plants incapable to grow autotrophically. This study shows that PEP function in trx z and fln1 plants can be restored by complementation with redox-inactive TRX z C106S and FLN1 C(105/106)A protein variants, respectively. The complemented plants showed wild-type levels of chloroplast gene expression and were restored in photosynthetic capacity, indicating that redox regulation of PEP through TRX z/FLN1 per se is not essential for autotrophic growth. Promoter-reporter gene studies indicate that TRX z and FLN1 are expressed during early phases of leaf development while expression ceases at maturation. Taken together, our data support a model in which TRX z and FLN1 are essential structural components of the PEP complex and their redox activity might only play a role in the fine tuning of PEP function.
There is increasing evidence that reactive oxygen species (ROS) are mediators in growth factor and cytokine signaling pathways. Mechanisms by which ROS can interfere with signaling cascades may include regulation of protein activities by the modification of essential cysteines. Modification can be performed chemically or enzyme-catalyzed. Enzymes catalyzing a reversible thiol modification within proteins are to be able to react with both, ROS and protein thiols. If hydroperoxides are involved, promising candidates are peroxiredoxins and glutathione peroxidases (GPx), especially the phospholipid hydroperoxide GPx. Interleukin-1, one of the key players in inflammatory response, stimulates the production of ROS itself, but its signaling cascade can also be influenced by ROS and by thiol modifying agents. Targets are located in early, intermediate, and late events in the signaling cascade. We here summarize what is known about the effects of thiol modifying agents, selenium and glutathione peroxidases, on the assembly of the IL-1 receptor signaling complex as an early event, on the activation of NF-kappaB as an intermediate event, and on the expression of cell adhesion molecules as a late event in IL-1 signaling. (C) 2003 Elsevier Inc. All rights reserved
Overnutrition contributes to insulin resistance, obesity and metabolic stress, initiating a loss of functional beta-cells and diabetes development. Whether these damaging effects are amplified in advanced age is barely investigated. Therefore, New Zealand Obese (NZO) mice, a well-established model for the investigation of human obesity-associated type 2 diabetes, were fed a metabolically challenging diet with a high-fat, carbohydrate restricted period followed by a carbohydrate intervention in young as well as advanced age. Interestingly, while young NZO mice developed massive hyperglycemia in response to carbohydrate feeding, leading to beta-cell dysfunction and cell death, aged counterparts compensated the increased insulin demand by persistent beta-cell function and beta-cell mass expansion. Beta-cell loss in young NZO islets was linked to increased expression of thioredoxin-interacting protein (TXNIP), presumably initiating an apoptosis-signaling cascade via caspase-3 activation. In contrast, islets of aged NZOs exhibited a sustained redox balance without changes in TXNIP expression, associated with higher proliferative potential by cell cycle activation. These findings support the relevance of a maintained proliferative potential and redox homeostasis for preserving islet functionality under metabolic stress, with the peculiarity that this adaptive response emerged with advanced age in diabetesprone NZO mice.
Human sulfite oxidase (hSO) was immobilised on SAM-coated silver electrodes under preservation of the native heme pocket structure of the cytochrome b5 (Cyt b5) domain and the functionality of the enzyme. The redox properties and catalytic activity of the entire enzyme were studied by surface enhanced resonance Raman (SERR) spectroscopy and cyclic voltammetry (CV) and compared to the isolated heme domain when possible. It is shown that heterogeneous electron transfer and catalytic activity of hSO sensitively depend on the local environment of the enzyme. Increasing the ionic strength of the buffer solution leads to an increase of the heterogeneous electron transfer rate from 17 s(-1) to 440 s(- 1) for hSO as determined by SERR spectroscopy. CV measurements demonstrate an increase of the apparent turnover rate for the immobilised hSO from 0.85 s(-1) in 100 mM buffer to 5.26 s(-1) in 750 mM buffer. We suggest that both effects originate from the increased mobility of the surface-bound enzyme with increasing ionic strength. In agreement with surface potential calculations we propose that at high ionic strength the enzyme is immobilised via the dimerisation domain to the SAM surface. The flexible loop region connecting the Moco and the Cyt b5 domain allows alternating contact with the Moco interaction site and the SAM surface, thereby promoting the sequential intramolecular and heterogeneous electron transfer from Moco via Cyt b5 to the electrode. At lower ionic strength, the contact time of the Cyt b5 domain with the SAM surface is longer, corresponding to a slower overall electron transfer process.
Occludin is a self-associating transmembrane tight junction protein affected in oxidative stress. However, its function is unknown. The cytosolic C-terminal tail contains a coiled coil-domain forming dimers contributing to the self- association. Studying the hypothesis that the self-association is redox-sensitive, we found that the dimerization of the domain depended on the sulfhydryl concentration of the environment in low-millimolar range. Under physiological conditions, monomers and dimers were detected. Masking the sulfhydryl residues in the domain prevented the dimerization but affected neither its helical structure nor cylindric shape. Incubation of cell extracts containing full-length occludin with sulfhydryl reagents prevented the dimerization; a cysteine/alanine exchange mutant also did not show dimer formation. This demonstrates, for the first time, that disulfide bridge formation of the domain is involved in the occludin dimerization. It is concluded that the redox-dependent dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions.
Redox signalling in plants
(2020)
Once proteins are synthesized, they can additionally be modified by post-translational modifications (PTMs). Proteins containing reactive cysteine thiols, stabilized in their deprotonated form due to their local environment as thiolates (RS-), serve as redox sensors by undergoing a multitude of oxidative PTMs (Ox-PTMs). Ox-PTMs such as S-nitrosylation or formation of inter- or intra-disulfide bridges induce functional changes in these proteins. Proteins containing cysteines, whose thiol oxidation state regulates their functions, belong to the so-called redoxome. Such Ox-PTMs are controlled by site-specific cellular events that play a crucial role in protein regulation, affecting enzyme catalytic sites, ligand binding affinity, protein-protein interactions or protein stability. Reversible protein thiol oxidation is an essential regulatory mechanism of photosynthesis, metabolism, and gene expression in all photosynthetic organisms. Therefore, studying PTMs will remain crucial for understanding plant adaptation to external stimuli like fluctuating light conditions. Optimizing methods suitable for studying plants Ox-PTMs is of high importance for elucidation of the redoxome in plants. This study focusses on thiol modifications occurring in plant and provides novel insight into in vivo redoxome of Arabidopsis thaliana in response to light vs. dark. This was achieved by utilizing a resin-assisted thiol enrichment approach. Furthermore, confirmation of candidates on the single protein level was carried out by a differential labelling approach. The thiols and disulfides were differentially labelled, and the protein levels were detected using immunoblot analysis. Further analysis was focused on light-reduced proteins. By the enrichment approach many well studied redox-regulated proteins were identified. Amongst those were fructose 1,6-bisphosphatase (FBPase) and sedoheptulose-1,7-bisphosphatase (SBPase) which have previously been described as thioredoxin system targeted enzymes. The redox regulated proteins identified in the current study were compared to several published, independent results showing redox regulated proteins in Arabidopsis leaves, root, mitochondria and specifically S-nitrosylated proteins. These proteins were excluded as potential new candidates but remain as a proof-of-concept to the enrichment experiments to be effective. Additionally, CSP41A and CSP41B proteins, which emerged from this study as potential targets of redox-regulation, were analyzed by Ribo-Seq. The active translatome study of csp41a mutant vs. wild-type showed most of the significant changes at end of the night, similarly as csp41b. Yet, in both mutants only several chloroplast-encoded genes were altered. Further studies of CSP41A and CSP41B proteins are needed to reveal their functions and elucidate the role of redox regulation of these proteins.
Post-translational redox-regulation is a well-known mechanism to regulate enzymes of the Calvin cycle, oxidative pentose phosphate cycle, NADPH export and ATP synthesis in response to light. The aim of the present thesis was to investigate whether a similar mechanism is also regulating carbon storage in leaves. Previous studies have shown that the key-regulatory enzyme of starch synthesis, ADPglucose pyrophosphorylase (AGPase) is inactivated by formation of an intermolecular disulfide bridge between the two catalytic subunits (AGPB) of the heterotetrameric holoenzyme in potato tubers, but the relevance of this mechanism to regulate starch synthesis in leaves was not investigated. The work presented in this thesis shows that AGPase is subject to post-translational redox-regulation in leaves of pea, potato and Arabidopsis in response to day night changes. Light was shown to trigger posttranslational redox-regulation of AGPase. AGPB was rapidly converted from a dimer to a monomer when isolated pea chloroplasts were illuminated and from a monomer to a dimer when preilluminated leaves were darkened. Conversion of AGPB from dimer to monomer was accompanied by an increase in activity due to changes in the kinetik properties of the enzyme. Studies with pea chloroplast extracts showed that AGPase redox-activation is mediated by thioredoxins f and m from spinach in-vitro. In a further set of experiments it was shown that sugars provide a second input leading to AGPase redox activation and increased starch synthesis and that they can act as a signal which is independent from light. External feeding of sugars such as sucrose or trehalose to Arabidopsis leaves in the dark led to conversion of AGPB from dimer to monomer and to an increase in the rate of starch synthesis, while there were no significant changes in the level of 3PGA, an allosteric activator of the enyzme, and in the NADPH/NADP+ ratio. Experiments with transgenic Arabidopsis plants with altered levels of trehalose 6-phosphate (T6P), the precursor of trehalose synthesis, provided genetic evidence that T6P rather than trehalose is leading to AGPase redox-activation. Compared to Wt, leaves expressing E.coli trehalose-phosphate synthase (TPS) in the cytosol showed increased activation of AGPase and higher starch level during the day, while trehalose-phosphate phosphatase (TPP) overexpressing leaves showed the opposite. These changes occurred independently of changes in sugar and sugar-phosphate levels and NADPH/NADP+ ratio. External supply of sucrose to Wt and TPS-overexpressing leaves led to monomerisation of AGPB, while this response was attenuated in TPP expressing leaves, indicating that T6P is involved in the sucrose-dependent redox-activation of AGPase. To provide biochemical evidence that T6P promotes redox-activation of AGPase independently of cytosolic elements, T6P was fed to intact isolated chloroplasts for 15 min. incubation with concentrations down to 100 µM of T6P, but not with sucrose 6-phosphate, sucrose, trehalose or Pi as controls, significantly and specifically increased AGPB monomerisation and AGPase activity within 15 minutes, implying T6P as a signal reporting the cytosolic sugar status to the chloroplast. The response to T6P did not involve changes in the NADPH/NADP+ ratio consistent with T6P modulating redox-transfer to AGPase independently of changes in plastidial redox-state. Acetyl-CoA carboxylase (ACCase) is known as key-regulatory enzyme of fatty acid and lipid synthesis in plants. At the start of the present thesis there was mainly in vitro evidence in the literature showing redox-regulation of ACCase by DTT, and thioredoxins f and m. In the present thesis the in-vivo relevance of this mechanism to regulate lipid synthesis in leaves was investigated. ACCase activity measurement in leaf tissue collected at the end of the day and night in Arabidopsis leaves revealed a 3-fold higher activation state of the enzyme in the light than in the dark. Redox-activation was accompanied by change in kinetic properties of ACCase, leading to an increase affinity to its substrate acetyl-CoA . In further experiments, DTT as well as sucrose were fed to leaves, and both treatments led to a stimulation in the rate of lipid synthesis accompanied by redox-activation of ACCase and decrease in acetyl-CoA content. In a final approach, comparison of metabolic and transcript profiling after DTT feeding and after sucrose feeding to leaves provided evidence that redox-modification is an important regulatory mechanism in central metabolic pathways such as TCA cycle and amino acid synthesis, which acts independently of transcript levels.
Occludin is a self-associating transmembrane tight junction protein affected in oxidative stress. However, its function is unknown. The cytosolic C-terminal tail contains a coiled coil-domain forming dimers contributing to the self- association. Studying the hypothesis that the self-association is redox-sensitive, we found that the dimerization of the domain depended on the sulfhydryl concentration of the environment in low-millimolar range. Under physiological conditions, monomers and dimers were detected. Masking the sulfhydryl residues in the domain prevented the dimerization but affected neither its helical structure nor cylindric shape. Incubation of cell extracts containing full-length occludin with sulfhydryl reagents prevented the dimerization; a cysteine/alanine exchange mutant also did not show dimer formation. This demonstrates, for the first time, that disulfide bridge formation of the domain is involved in the occludin dimerization. It is concluded that the redox-dependent dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions.
We investigate the vibrational relaxation of a Morse oscillator, nonlinearly coupled to a finite-dimensional bath of harmonic oscillators at zero temperature, using two different approaches: Reduced dynamics with the help of the Lindblad formalism of reduced density matrix theory in combination with Fermi's Golden Rule, and exact dynamics (within the chosen model). with the multiconfiguration time-dependent Hartree (MCTDH) method. Two different models have been constructed, the situation where the bath spectrum is exactly resonant with the anharmonic oscillator transition frequencies, and the case for which the subsystem is slightly off-resonant with the environment. At short times, reduced dynamics calculations describe the relaxation process qualitatively well but fail to reproduce recurrences observed with MCTDH for longer times. Lifetimes of all the vibrational levels of the Morse oscillator have been calculated, and both Lindblad and MCTDH. results show the same dependence of the lifetimes on the initial vibrational state quantum number. A prediction, which should be generic for adsorbate systems is a striking, sharp increase of lifetimes of the subsystem vibrational levels close to the dissociation This is contradictory with harmonic/linear extrapolation laws, which predict a monotonic decrease of the lifetime with initial vibrational quantum number.
Arctic tundra ecosystems have experienced unprecedented change associated with climate warming over recent decades. Across the Pan-Arctic, vegetation productivity and surface greenness have trended positively over the period of satellite observation. However, since 2011 these trends have slowed considerably, showing signs of browning in many regions. It is unclear what factors are driving this change and which regions/landforms will be most sensitive to future browning. Here we provide evidence linking decadal patterns in arctic greening and browning with regional climate change and local permafrost-driven landscape heterogeneity. We analyzed the spatial variability of decadal-scale trends in surface greenness across the Arctic Coastal Plain of northern Alaska (similar to 60,000 km(2)) using the Landsat archive (1999-2014), in combination with novel 30 m classifications of polygonal tundra and regional watersheds, finding landscape heterogeneity and regional climate change to be the most important factors controlling historical greenness trends. Browning was linked to increased temperature and precipitation, with the exception of young landforms (developed following lake drainage), which will likely continue to green. Spatiotemporal model forecasting suggests carbon uptake potential to be reduced in response to warmer and/or wetter climatic conditions, potentially increasing the net loss of carbon to the atmosphere, at a greater degree than previously expected.
Arctic tundra ecosystems have experienced unprecedented change associated with climate warming over recent decades. Across the Pan-Arctic, vegetation productivity and surface greenness have trended positively over the period of satellite observation. However, since 2011 these trends have slowed considerably, showing signs of browning in many regions. It is unclear what factors are driving this change and which regions/landforms will be most sensitive to future browning. Here we provide evidence linking decadal patterns in arctic greening and browning with regional climate change and local permafrost-driven landscape heterogeneity. We analyzed the spatial variability of decadal-scale trends in surface greenness across the Arctic Coastal Plain of northern Alaska (similar to 60,000 km(2)) using the Landsat archive (1999-2014), in combination with novel 30 m classifications of polygonal tundra and regional watersheds, finding landscape heterogeneity and regional climate change to be the most important factors controlling historical greenness trends. Browning was linked to increased temperature and precipitation, with the exception of young landforms (developed following lake drainage), which will likely continue to green. Spatiotemporal model forecasting suggests carbon uptake potential to be reduced in response to warmer and/or wetter climatic conditions, potentially increasing the net loss of carbon to the atmosphere, at a greater degree than previously expected.
Objective: Emotional problems often co-occur in overweight or obese children. However, questions of whether emotion recognition deficits are present and how they are reflected have only been sparsely investigated to date.
Methods: Therefore, the present study included 33 overweight and obese as well as 33 normal weight elementary school children between six and ten years that were matched for sex, age and socioeconomic status. Participants were shown different emotional faces of a well-validated set of stimuli on a computer screen, which they categorized and then rated on an emotional intensity level. Key measures were categorization performance along with reaction times and emotional intelligence as well as emotional eating questionnaire ratings.
Results: Overweight children exhibited lower categorization accuracy as well as longer reaction times as compared to normal weight children, while no differences in intensity ratings occurred. Reaction time to neutral facial expressions was negatively related to intrapersonal and interpersonal emotional intelligence and emotional eating correlated negatively with accuracy for recognizing sad expressions.
Conclusion: Facial emotion decoding difficulties seem to be of importance in overweight and obese children and deserve further consideration in terms of their exact impact on social functioning as well as on the maintenance of elevated body weight during child development. (C) 2015 Elsevier Inc All rights reserved.
Interannual rainfall variations in equatorial East Africa are tightly linked to the El Nino Southern Oscillation (ENSO), with more rain and flooding during El Nino and droughts in La Nina years, both having severe impacts on human habitation and food security. Here we report evidence from an annually laminated lake sediment record from southeastern Kenya for interannual to centennial-scale changes in ENSO-related rainfall variability during the last three millennia and for reductions in both the mean rate and the variability of rainfall in East Africa during the Last Glacial period. Climate model simulations support forward extrapolation from these lake sediment data that future warming will intensify the interannual variability of East Africa's rainfall.
Reduced Interface-Mediated Recombination for High Open-Circuit Voltages in CH3NH3PbI3 Solar Cells
(2017)
Perovskite solar cells with all-organic transport layers exhibit efficiencies rivaling their counterparts that employ inorganic transport layers, while avoiding high-temperature processing. Herein, it is investigated how the choice of the fullerene derivative employed in the electron-transporting layer of inverted perovskite cells affects the open-circuit voltage (V-OC). It is shown that nonradiative recombination mediated by the electron-transporting layer is the limiting factor for the V-OC in the cells. By inserting an ultrathin layer of an insulating polymer between the active CH3NH3PbI3 perovskite and the fullerene, an external radiative efficiency of up to 0.3%, a V-OC as high as 1.16 V, and a power conversion efficiency of 19.4% are realized. The results show that the reduction of nonradiative recombination due to charge-blocking at the perovskite/organic interface is more important than proper level alignment in the search for ideal selective contacts toward high V-OC and efficiency.
Compulsive behaviors (e.g., addiction) can be viewed as an aberrant decision process where inflexible reactions automatically evoked by stimuli (habit) take control over decision making to the detriment of a more flexible (goal-oriented) behavioral learning system. These behaviors are thought to arise from learning algorithms known as "model-based" and "model-free" reinforcement learning. Gambling disorder, a form of addiction without the confound of neurotoxic effects of drugs, showed impaired goal-directed control but the way in which problem gamblers (PG) orchestrate model-based and model-free strategies has not been evaluated. Forty-nine PG and 33 healthy participants (CP) completed a two-step sequential choice task for which model-based and model-free learning have distinct and identifiable trial-by-trial learning signatures. The influence of common psychopathological comorbidities on those two forms of learning were investigated. PG showed impaired model-based learning, particularly after unrewarded outcomes. In addition, PG exhibited faster reaction times than CP following unrewarded decisions. Troubled mood, higher impulsivity (i.e., positive and negative urgency) and current and chronic stress reported via questionnaires did not account for those results. These findings demonstrate specific reinforcement learning and decision-making deficits in behavioral addiction that advances our understanding and may be important dimensions for designing effective interventions.
Non-alcoholic fatty liver diseases (NAFLD) including the severe form with steatohepatitis (NASH) are highly prevalent ailments to which no approved pharmacological treatment exists. Dietary intervention aiming at 10% weight reduction is efficient but fails due to low compliance. Increase in physical activity is an alternative that improved NAFLD even in the absence of weight reduction. The underlying mechanisms are unclear and cannot be studied in humans. Here, a rat NAFLD model was developed that reproduces many facets of the diet-induced NAFLD in humans. The impact of endurance exercise was studied in this model. Male Wistar rats received control chow or a NASH-inducing diet rich in fat, cholesterol, and fructose. Both diet groups were subdivided into a sedentary and an endurance exercise group. Animals receiving the NASH-inducing diet gained more body weight, got glucose intolerant and developed a liver pathology with steatosis, hepatocyte hypertrophy, inflammation and fibrosis typical of NAFLD or NASH. Contrary to expectations, endurance exercise did not improve the NASH activity score and even enhanced hepatic inflammation. However, endurance exercise attenuated the hepatic cholesterol overload and the ensuing severe oxidative stress. In addition, exercise improved glucose tolerance possibly in part by induction of hepatic FGF21 production.
Non-alcoholic fatty liver diseases (NAFLD) including the severe form with steatohepatitis (NASH) are highly prevalent ailments to which no approved pharmacological treatment exists. Dietary intervention aiming at 10% weight reduction is efficient but fails due to low compliance. Increase in physical activity is an alternative that improved NAFLD even in the absence of weight reduction. The underlying mechanisms are unclear and cannot be studied in humans. Here, a rat NAFLD model was developed that reproduces many facets of the diet-induced NAFLD in humans. The impact of endurance exercise was studied in this model. Male Wistar rats received control chow or a NASH-inducing diet rich in fat, cholesterol, and fructose. Both diet groups were subdivided into a sedentary and an endurance exercise group. Animals receiving the NASH-inducing diet gained more body weight, got glucose intolerant and developed a liver pathology with steatosis, hepatocyte hypertrophy, inflammation and fibrosis typical of NAFLD or NASH. Contrary to expectations, endurance exercise did not improve the NASH activity score and even enhanced hepatic inflammation. However, endurance exercise attenuated the hepatic cholesterol overload and the ensuing severe oxidative stress. In addition, exercise improved glucose tolerance possibly in part by induction of hepatic FGF21 production.
OBJECTIVE: Interoceptive awareness is known to be impaired in eating disorders. To date, it has remained unclear whether this variable is related to the construct of interoceptive sensitivity. Interoceptive sensitivity is considered to be an essential variable in emotional processes. The objective of the study was to elucidate this potential relationship and to clarify whether general interoceptive sensitivity is reduced in anorexia nervosa. METHODS: Using a heartbeat perception task, interoceptive sensitivity was assessed in 28 female patients with anorexia nervosa and 28 matched healthy controls. Questionnaires assessing interoceptive awareness (EDI) and several other variables were also administered. RESULTS: Patients with anorexia nervosa displayed significantly decreased interoceptive sensitivity. They also had more difficulties in interoceptive awareness. CONCLUSIONS: In addition to a decreased ability to recognize certain visceral sensations related to hunger, there is a generally reduced capacity to accurately perceive bodily signals in anorexia nervosa. This highlights the potential importance of interoceptive sensitivity in the pathogenesis of eating disorders.
Background: Neuroenhancement (NE), the use of psychoactive substances in order to enhance a healthy individual's cognitive functioning from a proficient to an even higher level, is prevalent in student populations. According to the strength model of self-control, people fail to self-regulate and fall back on their dominant behavioral response when finite self-control resources are depleted. An experiment was conducted to test the hypothesis that ego-depletion will prevent students who are unfamiliar with NE from trying it.
Findings: 130 undergraduates, who denied having tried NE before (43% female, mean age = 22.76 +/- 4.15 years old), were randomly assigned to either an ego-depletion or a control condition. The dependent variable was taking an "energy-stick" (a legal nutritional supplement, containing low doses of caffeine, taurine and vitamin B), offered as a potential means of enhancing performance on the bogus concentration task that followed. Logistic regression analysis showed that ego-depleted participants were three times less likely to take the substance, OR = 0.37, p = .01.
Conclusion: This experiment found that trying NE for the first time was more likely if an individual's cognitive capacities were not depleted. This means that mental exhaustion is not predictive for NE in students for whom NE is not the dominant response. Trying NE for the first time is therefore more likely to occur as a thoughtful attempt at self-regulation than as an automatic behavioral response in stressful situations. We therefore recommend targeting interventions at this inter-individual difference. Students without previous reinforcing NE experience should be provided with information about the possible negative health outcomes of NE. Reconfiguring structural aspects in the academic environment (e.g. lessening workloads) might help to deter current users.
Background: Neuroenhancement (NE), the use of psychoactive substances in order to enhance a healthy individual's cognitive functioning from a proficient to an even higher level, is prevalent in student populations. According to the strength model of self-control, people fail to self-regulate and fall back on their dominant behavioral response when finite self-control resources are depleted. An experiment was conducted to test the hypothesis that ego-depletion will prevent students who are unfamiliar with NE from trying it.
Findings: 130 undergraduates, who denied having tried NE before (43% female, mean age = 22.76 +/- 4.15 years old), were randomly assigned to either an ego-depletion or a control condition. The dependent variable was taking an "energy-stick" (a legal nutritional supplement, containing low doses of caffeine, taurine and vitamin B), offered as a potential means of enhancing performance on the bogus concentration task that followed. Logistic regression analysis showed that ego-depleted participants were three times less likely to take the substance, OR = 0.37, p = .01.
Conclusion: This experiment found that trying NE for the first time was more likely if an individual's cognitive capacities were not depleted. This means that mental exhaustion is not predictive for NE in students for whom NE is not the dominant response. Trying NE for the first time is therefore more likely to occur as a thoughtful attempt at self-regulation than as an automatic behavioral response in stressful situations. We therefore recommend targeting interventions at this inter-individual difference. Students without previous reinforcing NE experience should be provided with information about the possible negative health outcomes of NE. Reconfiguring structural aspects in the academic environment (e.g. lessening workloads) might help to deter current users.
An Arabidopsis double knock-out mutant lacking cytosolic disproportionating enzyme 2 (DPE2) and the plastidial phosphorylase (PHS1) revealed a dwarf-growth phenotype, reduced starch content, an uneven distribution of starch within the plant rosette, and a reduced number of starch granules per chloroplast under standard growth conditions. In contrast, the wild type contained 5-7 starch granules per chloroplast. Mature and old leaves of the double mutant were essentially starch free and showed plastidial disintegration. Several analyses revealed that the number of starch granules per chloroplast was affected by the dark phase. So far, it was unclear if it was the dark phase per se or starch degradation in the dark that was connected to the observed decrease in the number of starch granules per chloroplast. Therefore, in the background of the double mutant dpe2/phs1, a triple mutant was generated lacking the initial starch degrading enzyme glucan, water dikinase (GWD). The triple mutant showed improved plant growth, a starch-excess phenotype, and a homogeneous starch distribution. Furthermore, the number of starch granules per chloroplast was increased and was similar to wild type. However, starch granule morphology was only slightly affected by the lack of GWD as in the triple mutant and, like in dpe2/phs1, more spherical starch granules were observed. The characterized triple mutant was discussed in the context of the generation of starch granules and the formation of starch granule morphology.
A maximum entropy (MaxEnt) method is developed to predict flow rates or pressure gradients in hydraulic pipe networks without sufficient information to give a closed-form (deterministic) solution. This methodology substantially extends existing deterministic flow network analysis methods. It builds on the MaxEnt framework previously developed by the authors. This study uses a continuous relative entropy defined on a reduced parameter set, here based on the external flow rates. This formulation ensures consistency between different representations of the same network. The relative entropy is maximized subject to observable constraints on the mean values of a subset of flow rates or potential differences, the frictional properties of each pipe, and physical constraints arising from Kirchhoff’s first and second laws. The new method is demonstrated by application to a simple one-loop network and a 1,123-node, 1,140-pipe water distribution network in the suburb of Torrens, Australian Capital Territory, Australia.
Colombia's agriculture, forestry and other land use sector accounts for nearly half of its total greenhouse gas (GHG) emissions. The importance of smallholder deforestation is comparatively high in relation to its regional counterparts, and livestock agriculture represents the largest driver of primary forest depletion. Silvopastoral systems (SPSs) are presented as agroecological solutions that synergistically enhance livestock productivity, improve local farmers' livelihoods and hold the potential to reduce pressure on forest conversion. The department of Caquetá represents Colombia's most important deforestation hotspot. Targeting smallholder livestock farms through survey data, in this work we investigate the GHG mitigation potential of implementing SPSs for smallholder farms in this region. Specifically, we assess whether the carbon sequestration taking place in the soil and biomass of SPSs is sufficient to offset the per-hectare increase in livestock GHG emissions resulting from higher stocking rates. To address these questions we use data on livestock population characteristics and historic land cover changes reported from a survey covering 158 farms and model the carbon sequestration occurring in three different scenarios of progressively-increased SPS complexity using the CO2 fix model. We find that, even with moderate tree planting densities, the implementation of SPSs can reduce GHG emissions by 2.6 Mg CO2e ha−1 yr−1 in relation to current practices, while increasing agriculture productivity and contributing to the restoration of severely degraded landscapes.
Nature-based solutions (NBS) have recently received attention due to their potential ability to sustainably reduce hydro-meteorological risks, providing co-benefits for both ecosystems and affected people. Therefore, pioneering research has dedicated efforts to optimize the design of NBS, to evaluate their wider co-benefits and to understand promoting and/or hampering governance conditions for the uptake of NBS. In this article, we aim to complement this research by conducting a comprehensive literature review of factors shaping people’s perceptions of NBS as a means to reduce hydro-meteorological risks. Based on 102 studies, we identified six topics shaping the current discussion in this field of research: (1) valuation of the co-benefits (including those related to ecosystems and society); (2) evaluation of risk reduction efficacy; (3) stakeholder participation; (4) socio-economic and location-specific conditions; (5) environmental attitude, and (6) uncertainty. Our analysis reveals that concerned empirical insights are diverse and even contradictory, they vary in the depth of the insights generated and are often not comparable for a lack of a sound theoretical-methodological grounding. We, therefore, propose a conceptual model outlining avenues for future research by indicating potential inter-linkages between constructs underlying perceptions of NBS to hydro-meteorological risks.
This study investigates spatial patterns and temporal dynamics of aquifer-river exchange flow at a reach of the River Leith, UK. Observations of sub-channel vertical hydraulic gradients at the field site indicate the dominance of groundwater up-welling into the river and the absence of groundwater recharge from surface water. However, observed hydraulic heads do not provide information on potential surface water infiltration into the top 0-15 cm of the streambed as these depths are not covered by the existing experimental infrastructure. In order to evaluate whether surface water infiltration is likely to occur outside the 'window of detection', i.e. the shallow streambed, a numerical groundwater model is used to simulate hydrological exchanges between the aquifer and the river. Transient simulations of the successfully validated model (Nash and Sutcliff efficiency of 0.91) suggest that surface water infiltration is marginal and that the possibility of significant volumes of surface water infiltrating into non-monitored shallow streambed sediments can be excluded for the simulation period. Furthermore, the simulation results show that with increasing head differences between river and aquifer towards the end of the simulation period, the impact of streambed topography and hydraulic conductivity on spatial patterns of exchange flow rates decreases. A set of peak flow scenarios with altered groundwater-surface water head gradients is simulated in order to quantify the potential for surface water infiltration during characteristic winter flow conditions following the observation period. The results indicate that, particularly at the beginning of peak flow conditions, head gradients are likely to cause substantial increase in surface water infiltration into the streambed. The study highlights the potential for the improvement of process understanding of hyporheic exchange flow patterns at the stream reach scale by simulating aquifer-river exchange fluxes with a standard numerical groundwater model and a simple but robust model structure and parameterization. Copyright
Shrews have very high metabolic rates and are often unintentionally starved in rodent live-traps during capture mark recapture (CMR) studies. Here, we suggest a shrew exit as a modification to rodent traps. To test whether this modification is (1) saving shrews and (2) not jeopardizing results of rodent captures, we compared captures in Ugglan traps with and without shrew exits, studying bank voles (Myodes glareolus) in a spruce forest in central Finland. Numbers of captured bank voles and body size of smallest juvenile bank voles were not affected by the shrew exit, while the number of captured common shrews (Sorex araneus) was reduced from 31 to 0 individuals per 100 trap nights. However, rare larger shrew species (> 8 g body weight) could not escape through the exit. A shrew exit can, therefore, save smaller shrew species in standard live-trapping of vole-sized rodents without affecting CMR data of the rodent.
Text is a ubiquitous entity in our world and daily life. We encounter it nearly everywhere in shops, on the street, or in our flats. Nowadays, more and more text is contained in digital images. These images are either taken using cameras, e.g., smartphone cameras, or taken using scanning devices such as document scanners. The sheer amount of available data, e.g., millions of images taken by Google Streetview, prohibits manual analysis and metadata extraction. Although much progress was made in the area of optical character recognition (OCR) for printed text in documents, broad areas of OCR are still not fully explored and hold many research challenges. With the mainstream usage of machine learning and especially deep learning, one of the most pressing problems is the availability and acquisition of annotated ground truth for the training of machine learning models because obtaining annotated training data using manual annotation mechanisms is time-consuming and costly. In this thesis, we address of how we can reduce the costs of acquiring ground truth annotations for the application of state-of-the-art machine learning methods to optical character recognition pipelines. To this end, we investigate how we can reduce the annotation cost by using only a fraction of the typically required ground truth annotations, e.g., for scene text recognition systems. We also investigate how we can use synthetic data to reduce the need of manual annotation work, e.g., in the area of document analysis for archival material. In the area of scene text recognition, we have developed a novel end-to-end scene text recognition system that can be trained using inexact supervision and shows competitive/state-of-the-art performance on standard benchmark datasets for scene text recognition. Our method consists of two independent neural networks, combined using spatial transformer networks. Both networks learn together to perform text localization and text recognition at the same time while only using annotations for the recognition task. We apply our model to end-to-end scene text recognition (meaning localization and recognition of words) and pure scene text recognition without any changes in the network architecture.
In the second part of this thesis, we introduce novel approaches for using and generating synthetic data to analyze handwriting in archival data. First, we propose a novel preprocessing method to determine whether a given document page contains any handwriting. We propose a novel data synthesis strategy to train a classification model and show that our data synthesis strategy is viable by evaluating the trained model on real images from an archive. Second, we introduce the new analysis task of handwriting classification. Handwriting classification entails classifying a given handwritten word image into classes such as date, word, or number. Such an analysis step allows us to select the best fitting recognition model for subsequent text recognition; it also allows us to reason about the semantic content of a given document page without the need for fine-grained text recognition and further analysis steps, such as Named Entity Recognition. We show that our proposed approaches work well when trained on synthetic data. Further, we propose a flexible metric learning approach to allow zero-shot classification of classes unseen during the network’s training. Last, we propose a novel data synthesis algorithm to train off-the-shelf pixel-wise semantic segmentation networks for documents. Our data synthesis pipeline is based on the famous Style-GAN architecture and can synthesize realistic document images with their corresponding segmentation annotation without the need for any annotated data!
Temporal variation of natural light sources such as airglow limits the ability of night light sensors to detect changes in small sources of artificial light (such as villages). This study presents a method for correcting for this effect globally, using the satellite radiance detected from regions without artificial light emissions. We developed a routine to define an approximate grid of locations worldwide that do not have regular light emission. We apply this method with a 5 degree equally spaced global grid (total of 2016 individual locations), using data from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB). This code could easily be adapted for other future global sensors. The correction reduces the standard deviation of data in the Earth Observation Group monthly DNB composites by almost a factor of two. The code and datasets presented here are available under an open license by GFZ Data Services, and are implemented in the Radiance Light Trends web application.
Temporal variation of natural light sources such as airglow limits the ability of night light sensors to detect changes in small sources of artificial light (such as villages). This study presents a method for correcting for this effect globally, using the satellite radiance detected from regions without artificial light emissions. We developed a routine to define an approximate grid of locations worldwide that do not have regular light emission. We apply this method with a 5 degree equally spaced global grid (total of 2016 individual locations), using data from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB). This code could easily be adapted for other future global sensors. The correction reduces the standard deviation of data in the Earth Observation Group monthly DNB composites by almost a factor of two. The code and datasets presented here are available under an open license by GFZ Data Services, and are implemented in the Radiance Light Trends web application.
High photon energy losses limit the open-circuit voltage (V-OC) and power conversion efficiency of organic solar cells (OSCs). In this work, an optimization route is presented which increases the V-OC by reducing the interfacial area between donor (D) and acceptor (A). This optimization route concerns a cascade device architecture in which the introduction of discontinuous interlayers between alpha-sexithiophene (alpha-6T) (D) and chloroboron subnaphthalocyanine (SubNc) (A) increases the V-OC of an alpha-6T/SubNc/SubPc fullerene-free cascade OSC from 0.98 V to 1.16 V. This increase of 0.18 V is attributed solely to the suppression of nonradiative recombination at the D-A interface. By accurately measuring the optical gap (E-opt) and the energy of the charge-transfer state (E-CT) of the studied OSC, a detailed analysis of the overall voltage losses is performed. E-opt - qV(OC) losses of 0.58 eV, which are among the lowest observed for OSCs, are obtained. Most importantly, for the V-OC-optimized devices, the low-energy (700 nm) external quantum efficiency (EQE) peak remains high at 79%, despite a minimal driving force for charge separation of less than 10 meV. This work shows that low-voltage losses can be combined with a high EQE in organic photovoltaic devices.
The present paper presents FORTRAN programs for reducing eye monitor output to fixations and for mapping these fixations to locations in the stimulus space. Flexible parameters of the fixations program allow for determination of the beginning and end of fixations under different resolution criteria and for indicating loss of accurate measurement. The calibration program is based on a rectangular 9-point fixation grid. Each fixation is rescaled within this grid by solving for a quadratic equation. The rescaled values are output in a flexibly determined rectangular coordinate system that is related to the stimulus space, such as character position on the screen. The programs were developed for the 60-Hz Applied Sciences corneal reflection eye monitor, but they may be used with a number of other systems.
We discuss the influence of the material type in metal wires to the electromagnetic fluctuations in magnetic microtraps close to the surface of an atom chip. We show that significant reduction of the magnetic noise can be achieved by replacing the pure noble metal wires with their dilute alloys. The alloy composition provides an additional degree of freedom which enables a, controlled reduction of both magnetic noise and resistivity if the atom chip is cooled. In addition, we provide a careful re-analysis of the magnetically induced trap loss observed by Yu-Ju Lin et al. [Phys. Rev. Lett. 92 050404 (2004)] and find good agreement with an improved theory
Given an algebra of pseudo-differential operators on a manifold, an elliptic element is said to be a reduction of orders, if it induces isomorphisms of Sobolev spaces with a corresponding shift of smoothness. Reductions of orders on a manifold with boundary refer to boundary value problems. We consider smooth symbols and ellipticity without additional boundary conditions which is the relevant case on a manifold with boundary. Starting from a class of symbols that has been investigated before for integer orders in boundary value problems with the transmission property we study operators of arbitrary real orders that play a similar role for operators without the transmission property. Moreover, we show that order reducing symbols have the Volterra property and are parabolic of anisotropy 1; analogous relations are formulated for arbitrary anisotropies. We finally investigate parameter-dependent operators, apply a kernel cut-off construction with respect to the parameter and show that corresponding holomorphic operator-valued Mellin symbols reduce orders in weighted Sobolev spaces on a cone with boundary.
Given an algebra of pseudo-differential operators on a manifold, an elliptic element is said to be a reduction of orders, if it induces isomorphisms of Sobolev spaces with a corresponding shift of smoothness. Reductions of orders on a manifold with boundary refer to boundary value problems. We employ specific smooth symbols of arbitrary real orders and with parameters, and we show that the associated operators induce isomorphisms between Sobolev spaces on a given manifold with boundary. Such operators for integer orders have the transmission property and belong to the calculus of Boutet de Monvel [1], cf. also [9]. In general, they fit to the algebra of boundary value problems without the transmission property in the sense of [17] and [24]. Order reducing elements of the present kind are useful for constructing parametrices of mixed elliptic problems. We show that order reducing symbols have the Volterra property and are parabolic of anisotropy 1; analogous relations are formulated for arbitrary anisotropies. We then investigate parameter-dependent operators, apply a kernel cut-off construction with respect to the parameter and show that corresponding holomorphic operator-valued Mellin symbols reduce orders in weighted Sobolev spaces on a cone with boundary. We finally construct order reducing operators on a compact manifold with conical singularities and boundary
BACKGROUND: The aim of occupational health care management programs (OHMP) is to improve the health status of employees, increase work ability and reduce absence time. This includes better coping abilities, work-related self-efficacy and self-management which are important abilities that should be trained within OHMPs.
OBJECTIVES: To study the effectiveness of an OHMP including special interventions to enhance self-efficacy and self-management.
PARTICIPANTS: Employees from the German Federal Pension Agency.
METHODS: Effects of an OHMP on sickness absence was studied by comparing an intervention group (N = 159) and two control groups (N = 450). A core feature of the OHMP were group sessions with all members of working teams, focussing on self-efficacy and self management of the individual participant as well as the team as a group (focus groups). Participants in the OHMP were asked for their subjective evaluation of the focus groups. Rates of sickness absence were taken from the routine data of the employer.
RESULTS: Participants of the OHMP indicated that they had learned better ways of coping and communication and that they had generated intentions to make changes in their working situation. The rate of sickness absence in the intervention group decreased from 9.26% in the year before the OHMP to 7.93% in the year after the program, while there was in the same time an increase of 7.9% and 10.7% in the two control groups.
CONCLUSIONS: The data suggest that OHMP with focus on self-efficacy and self management of individuals and teams are helpful in reducing work absenteeism.
The Surface Water and Ocean Topography (SWOT) mission is a next generation satellite mission expected to provide a 2 km-resolution observation of the sea surface height (SSH) on a two-dimensional swath. Processing SWOT data will be challenging because of the large amount of data, the mismatch between a high spatial resolution and a low temporal resolution, and the observation errors. The present paper focuses on the reduction of the spatially structured errors of SWOT SSH data. It investigates a new error reduction method and assesses its performance in an observing system simulation experiment. The proposed error-reduction method first projects the SWOT SSH onto a subspace spanned by the SWOT spatially structured errors. This projection is removed from the SWOT SSH to obtain a detrended SSH. The detrended SSH is then processed within an ensemble data assimilation analysis to retrieve a full SSH field. In the latter step, the detrending is applied to both the SWOT data and an ensemble of model-simulated SSH fields. Numerical experiments are performed with synthetic SWOT observations and an ensemble from a North Atlantic, 1/60 degrees simulation of the ocean circulation (NATL60). The data assimilation analysis is carried out with an ensemble Kalman filter. The results are assessed with root mean square errors, power spectrum density, and spatial coherence. They show that a significant part of the large scale SWOT errors is reduced. The filter analysis also reduces the small scale errors and allows for an accurate recovery of the energy of the signal down to 25 km scales. In addition, using the SWOT nadir data to adjust the SSH detrending further reduces the errors.
Cave animals are widely recognised as model organisms to study regressive evolutionary processes like the reduction of eyes. In this paper, we report on the regressive evolution of species discrimination in the cave molly, Poecilia mexicana, which, unlike other cave fishes, still has functional eyes. This allowed us to examine the response to both visual and non-visual cues involved in species discrimination. When surface-dwelling females were given a chance to associate with either a conspecific or a swordtail (Xiphophorus hellerii) female, they strongly preferred the conspecific female both when multiple cues and when solely visual cues were available to the female. No association preference was observed when only non-visual cues were provided. In contrast, cave-dwelling females showed no preference under all testing conditions, suggesting that species recognition mechanisms have been reduced. We discuss the role of species discrimination in relation to habitat differences.