Showing papers by "Martin Luther University of Halle-Wittenberg published in 2022"

Land use land cover change modeling by integrating artificial neural network with cellular Automata-Markov chain model in Gidabo river basin, main Ethiopian rift

Abstract: • Multi-Layer perceptron uses back propagation algorithm to classify imagery. • Evidence likelihood is the most influential parameter in model sensitivity analysis. • Gidabo river basin experienced significant LULC dynamics which will also be expected. • Environmentally friendly management measures are the key to curb the adverse effect. Modeling land use land cover (LULC) change is crucial to understand its spatiotemporal trends to protect the land resources sustainably. The appraisal of this study was to model LULC change from 1985 to 2050 owing to the business-as-usual scenario (BAU) in Gidabo River Basin (GRB) located in the Main Ethiopian Rift Valley. Different dependent and independent spatial datasets were used viz, 1985, 2003 and 2021 Landsat imagery; topography features, proximity variables, population density and evidence likelihood. Since the future projection requires the historical land use as a baseline, historical land use trends were detected using hybrid image classification procedure in ERDAS Imagine and nine major land cover classes were identified. Multi-Layer Perceptron Neural Network and Cellular Automata-Markov Chain model built-in TerrSet software were implemented to project the 2035 and 2050 LULC. The study depicts, GRB experienced significant LULC dynamics and will also be extended for the coming several years. Agriculture land, settlement and water body showed significant gains at the expense of forest, shrub and grasslands loss. Land use changes beyond land's capability played a significant role in triggering land degradation. To minimize these adverse consequences of land use change, environmentally-friendly management measures must be implemented. The outcome of this study will be helpful in providing the opportunity to develop adequate land and water resource conservation strategy plan for the future.

Frequency multiplication by collective nanoscale spin-wave dynamics

Abstract: Frequency multiplication is a process in modern electronics in which harmonics of the input frequency are generated in nonlinear electronic circuits. Devices based on the propagation and interaction of spin waves are a promising alternative to conventional electronics. The characteristic frequency of these excitations is in the gigahertz (GHz) range and devices are not readily interfaced with conventional electronics. Here, we locally probe the magnetic excitations in a soft magnetic material by optical methods and show that megahertz-range excitation frequencies cause switching effects on the micrometer scale, leading to phase-locked spin-wave emission in the GHz range. Indeed, the frequency multiplication process inside the magnetic medium covers six octaves and opens exciting perspectives for spintronic applications, such as all-magnetic mixers or on-chip GHz sources.

Experimental cross species transmission of a major viral pathogen in bees is predominantly from honeybees to bumblebees

Abstract: Cross-species transmission of a pathogen from a reservoir to a recipient host species, spillover, can have major impacts on biodiversity, domestic species and human health. Deformed wing virus (DWV) is a panzootic RNA virus in honeybees that is causal in their elevated colony losses, and several correlative field studies have suggested spillover of DWV from managed honeybees to wild bee species such as bumblebees. Yet unequivocal demonstration of DWV spillover is lacking, while spillback, the transmission of DWV from a recipient back to the reservoir host, is rarely considered. Here, we show in fully crossed laboratory experiments that the transmission of DWV (genotype A) from honeybees to bumblebees occurs readily, yet we neither detected viral transmission from bumblebees to honeybees nor onward transmission from experimentally infected to uninoculated bumblebees. Our results support the potential for viral spillover from honeybees to other bee species in the field when robbing resources from heterospecific nests or when visiting the same flowers. They also underscore the importance of studies on the virulence of DWV in wild bee species so as to evaluate viral impact on individual and population fitness as well as viral adaption to new host species.

Think globally, measure locally: The MIREN standardized protocol for monitoring plant species distributions along elevation gradients

Abstract: Climate change and other global change drivers threaten plant diversity in mountains worldwide. A widely documented response to such environmental modifications is for plant species to change their elevational ranges. Range shifts are often idiosyncratic and difficult to generalize, partly due to variation in sampling methods. There is thus a need for a standardized monitoring strategy that can be applied across mountain regions to assess distribution changes and community turnover of native and non-native plant species over space and time. Here, we present a conceptually intuitive and standardized protocol developed by the Mountain Invasion Research Network (MIREN) to systematically quantify global patterns of native and non-native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. Usually repeated every five years, surveys consist of 20 sample sites located at equal elevation increments along three replicate roads per sampling region. At each site, three plots extend from the side of a mountain road into surrounding natural vegetation. The protocol has been successfully used in 18 regions worldwide from 2007 to present. Analyses of one point in time already generated some salient results, and revealed region-specific elevational patterns of native plant species richness, but a globally consistent elevational decline in non-native species richness. Non-native plants were also more abundant directly adjacent to road edges, suggesting that disturbed roadsides serve as a vector for invasions into mountains. From the upcoming analyses of time series, even more exciting results can be expected, especially about range shifts. Implementing the protocol in more mountain regions globally would help to generate a more complete picture of how global change alters species distributions. This would inform conservation policy in mountain ecosystems, where some conservation policies remain poorly implemented.

Atomic Scale Control of Spin Current Transmission at Interfaces

Abstract: Ferromagnet/heavy metal bilayers represent a central building block for spintronic devices where the magnetization of the ferromagnet can be controlled by spin currents generated in the heavy metal. The efficiency of spin current generation is paramount. Equally important is the efficient transfer of this spin current across the ferromagnet/heavy metal interface. Here, we show theoretically and experimentally that for Ta as heavy metal the interface only partially transmits the spin current while this effect is absent when Pt is used as heavy metal. This is due to magnetic moment reduction at the interface caused by 3d–5d hybridization effects. We show that this effect can be avoided by atomically thin interlayers. On the basis of our theoretical model we conclude that this is a general effect and occurs for all 5d metals with less than half-filled 5d shell.

Functional traits influence patterns in vegetative and reproductive plant phenology – a multi‐botanical garden study

Abstract: Phenology has emerged as key indicator of the biological impacts of climate change, yet the role of functional traits constraining variation in herbaceous species' phenology has received little attention. Botanical gardens are ideal places in which to investigate large numbers of species growing under common climate conditions. We ask whether interspecific variation in plant phenology is influenced by differences in functional traits. We recorded onset, end, duration and intensity of initial growth, leafing out, leaf senescence, flowering and fruiting for 212 species across five botanical gardens in Germany. We measured functional traits, including plant height, absolute and specific leaf area, leaf dry matter content, leaf carbon and nitrogen content and seed mass and accounted for species' relatedness. Closely related species showed greater similarities in timing of phenological events than expected by chance, but species' traits had a high degree of explanatory power, pointing to paramount importance of species' life-history strategies. Taller plants showed later timing of initial growth, and flowered, fruited and underwent leaf senescence later. Large-leaved species had shorter flowering and fruiting durations. Taller, large-leaved species differ in their phenology and are more competitive than smaller, small-leaved species. We assume climate warming will change plant communities' competitive hierarchies with consequences for biodiversity.

Mineralocorticoid receptors in non‐alcoholic fatty liver disease

Abstract: Liver diseases are the fourth common death in Europe responsible for about 2 million death per year worldwide. Among the known detrimental causes for liver dysfunction are virus infections, intoxications and obesity. The mineralocorticoid receptor (MR) is a ligand-dependent transcription factor activated by aldosterone or glucocorticoids but also by pathological milieu factors. Canonical actions of the MR take place in epithelial cells of kidney, colon and sweat glands and contribute to sodium reabsorption, potassium secretion and extracellular volume homeostasis. The non-canonical functions can be initiated by inflammation or an altered micro-milieu leading to fibrosis, hypertrophy and remodelling in various tissues. This narrative review summarizes the evidence regarding the role of MR in portal hypertension, non-alcoholic fatty liver disease, liver fibrosis and cirrhosis, demonstrating that inhibition of the MR in vivo seems to be beneficial for liver function and not just for volume regulation. Unfortunately, the underlying molecular mechanisms are still not completely understood. LINKED ARTICLES: This article is part of a themed issue on Emerging Fields for Therapeutic Targeting of the Aldosterone-Mineralocorticoid Receptor Signaling Pathway. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.13/issuetoc.

RNA binding proteins Smaug and Cup induce CCR4-NOT-dependent deadenylation of the <i>nanos</i> mRNA in a reconstituted system

Abstract: ABSTRACT Posttranscriptional regulation of the maternal nanos mRNA is essential for the development of the anterior – posterior axis of the Drosophila embryo. The nanos RNA is regulated by the protein Smaug. Binding to Smaug recognition elements (SREs) in the nanos 3’-UTR, Smaug nucleates the assembly of a larger repressor complex including the eIF4E-T paralog Cup and five additional proteins. The Smaug-dependent complex represses translation of nanos and induces its deadenylation by the CCR4-NOT deadenylase. Here we report an in vitro reconstitution of the Drosophila CCR4-NOT complex and Smaug-dependent deadenylation. We find that Smaug by itself is sufficient to cause deadenylation by the Drosophila or human CCR4-NOT complexes in an SRE-dependent manner. CCR4-NOT subunits NOT10 and NOT11 are dispensable, but the NOT module, consisting of NOT2, NOT3 and the C-terminal part of NOT1, is required. Smaug interacts with the C-terminal domain of NOT3. Both catalytic subunits of CCR4-NOT contribute to Smaug-dependent deadenylation. Whereas the CCR4-NOT complex itself acts distributively, Smaug induces a processive behavior. The cytoplasmic poly(A) binding protein (PABPC) has but a minor effect on Smaug-dependent deadenylation. Among the additional constituents of the Smaug-dependent repressor complex, Cup also facilitates CCR4-NOT-dependent deadenylation, both independently and in cooperation with Smaug.

Urban Infill Development: A Strategy for Saving Peri-Urban Areas in Developing Countries (the Case Study of Ardabil, Iran)

Abstract: The overall objective of this study was to investigate urban infill development policies as a good solution to counteract urban sprawl and protect the peri-urban area of Ardabil in Northwestern Iran. In this context, we used a mixed methodology (two quantitative methods). Landsat imagery, including a patchy Landsat ETM+ for the year 2000 and a Landsat 8 for the year 2020, was used to map and assess land use to investigate sprawl and land-use change, and ArcGIS was used to investigate the potential for infill development in this city. The results show that between 2000 and 2020, 967 hectares of peri-urban land was lost to urban expansion. CA-Markov projections also showed that 452 hectares will be lost by 2030. The assessment of the city’s internal capacity for infill development showed that more than 999 hectares of land within the city are suitable to support this strategy and provide the land needed for urban expansion over the next decade. Finally, the study of the city’s master plan, which applies to all Iranian cities, discovered that there is a lack of adequate outlook regarding the amount of land available for future urban development, leading to misuse of urban land and urban sprawl in Iranian cities, suggesting that an infill development strategy could be a good way to address this issue.

Monitoring Antibiotic Consumption in Pediatrics. How Close to Reality Are Days of Therapy and Recommended Daily Dose Methods?

Abstract: Hospitals are advised to monitor antibiotic use. Several approximation methods do exist to perform this task. Adult cohorts can easily be monitored using the defined daily dose method, or its German adaption recommended daily doses (RDD) method, that seems inapplicable in pediatric cohorts due to body weight variations. Guidelines recommend the days of therapy (DOT) method in pediatrics. Still, there is a need for more detailed analysis regarding the performance of both methods.Based on data from 4½ years of our fully computerized patient care data managing system in a combined neonatal and pediatric intensive care unit, we compare the results for DOT and RDD per 100 patient days with exact measurement of antibiotic consumption (individual daily dose per 100 patient days) as internal reference.The DOT method reflected antibiotic consumption in our cohort on the level of total consumption, subgroups, and agents with almost always high accuracy (correlation with individual daily dose between 0.73 and 1.00). The RDD method showed poor correlation on the level of total consumption (r = 0.21) and fluctuating results on more detailed levels (correlation, 0.01-0.94). A detailed analysis of body weight distribution and ordered packaging sizes of single agents revealed that RDD seems to work well when only one package size of the agent was ordered in our pharmacy.The DOT method is superior to RDD for monitoring antibiotic drug consumption in pediatric cohorts. RDD seems to work satisfactory well for selected antibiotic agents that are administered with little variation in packaging size.

Direct Observation of “Elongated” Conformational States in α‐Synuclein upon Liquid‐Liquid Phase Separation

Abstract: α-Synuclein (α-syn) is an intrinsically disordered protein (IDP) that undergoes liquid-liquid phase separation (LLPS), fibrillation, and forms insoluble intracellular Lewy bodies in neurons, which are the hallmark of Parkinson's Disease (PD). Neurotoxicity precedes the formation of aggregates and might be related to α-syn LLPS. The molecular mechanisms underlying the early stages of LLPS are still elusive. To obtain structural insights into α-syn upon LLPS, we take advantage of cross-linking/mass spectrometry (XL–MS) and introduce an innovative approach, termed COMPASS (COMPetitive PAiring StatisticS). In this work, we show that the conformational ensemble of α-syn shifts from a “hairpin-like” structure towards more “elongated” conformational states upon LLPS. We obtain insights into the critical initial stages of LLPS and establish a novel mass spectrometry-based approach that will aid to solve open questions in LLPS structural biology.

Peptide Model of the Mutant Proinsulin Syndrome. II. Nascent Structure and Biological Implications

Abstract: Toxic misfolding of proinsulin variants in β-cells defines a monogenic diabetes syndrome, designated mutant INS-gene induced diabetes of the young (MIDY). In our first study (previous article in this issue), we described a one-disulfide peptide model of a proinsulin folding intermediate and its use to study such variants. The mutations (LeuB15→Pro, LeuA16→Pro, and PheB24→Ser) probe residues conserved among vertebrate insulins. In this companion study, we describe 1H and 1H-13C NMR studies of the peptides; key NMR resonance assignments were verified by synthetic 13C-labeling. Parent spectra retain nativelike features in the neighborhood of the single disulfide bridge (cystine B19-A20), including secondary NMR chemical shifts and nonlocal nuclear Overhauser effects. This partial fold engages wild-type side chains LeuB15, LeuA16 and PheB24 at the nexus of nativelike α-helices α1 and α3 (as defined in native proinsulin) and flanking β-strand (residues B24-B26). The variant peptides exhibit successive structural perturbations in order: parent (most organized) > SerB24 >> ProA16 > ProB15 (least organized). The same order pertains to (a) overall α-helix content as probed by circular dichroism, (b) synthetic yields of corresponding three-disulfide insulin analogs, and (c) ER stress induced in cell culture by corresponding mutant proinsulins. These findings suggest that this and related peptide models will provide a general platform for classification of MIDY mutations based on molecular mechanisms by which nascent disulfide pairing is impaired. We propose that the syndrome's variable phenotypic spectrum-onsets ranging from the neonatal period to later in childhood or adolescence-reflects structural features of respective folding intermediates.

Characterization of the class IIa histone deacetylases substrate specificity

Abstract: Class IIa histone deacetylases (HDACs) play critical roles in vertebrate development and physiology, yet direct evidence of their intrinsic deacetylase activity and on substrate specificity regarding the peptide sequence is still missing. In this study, we designed and synthesized a combinatorial peptide library allowing us to profile class IIa HDACs sequence specificity at positions +3 through -3 from the central lysine modified by the well-accepted trifluoroacetyl function. Our data revealed a strong preference for bulky aromatic acids directly flanking the central trifluoroacetyllysine, while all class IIa HDACs disfavor positively charged residues and proline at the +1/-1 positions. The chemical nature of amino acid residues N-terminally to the central trifluoroacetyllysine has a more profound effect on substrate recognition as compared to residues located C-terminally. These findings were validated by designing selected favored and disfavored peptide sequences, with the favored ones are accepted with catalytic efficacy of 75 000 and 525 000 M-1 s-1 for HDAC7 and HDAC5, respectively. Results reported here could help in developing class IIa HDACs inhibitors and also in the search for new natural class IIa HDACs substrates.

$$H^\infty $$-Calculus for the Surface Stokes Operator and Applications

Abstract: Abstract We consider a smooth, compact and embedded hypersurface $$\Sigma $$ Σ without boundary and show that the corresponding (shifted) surface Stokes operator admits a bounded $$H^\infty $$ H ∞ -calculus with angle smaller than $$\pi /2$$ π / 2 . As an application, we consider critical spaces for the Navier–Stokes equations on the surface $$\Sigma $$ Σ . In case $$\Sigma $$ Σ is two-dimensional, we show that any solution with a divergence-free initial value in $$L_2(\Sigma , \textsf{T}\Sigma )$$ L 2 ( Σ , T Σ ) exists globally and converges exponentially fast to an equilibrium, that is, to a Killing field.

Neophyten im Wald – Das Fallbeispiel der Gewöhnlichen Douglasie

Abstract: ZusammenfassungDieser Beitrag widmet sich dem Invasiven-Arten-Konzept in seiner Anwendung auf Bäume, insb. wirtschaftlich genutzter Bäume am Beispiel der gewöhnlichen Douglasie, die eine der für die deutsche Forstwirtschaft wichtigsten Arten ist. Das für die Humangeografie Relevante an dieser Entwicklung ist, dass das Kriterium der ökologischen ‚Natürlichkeit‘ vollkommen verschwindet und es zu einer bewussten Anwendung einer hybriden Ökologie im Naturschutz kommt. Der daraus entstehende Aushandlungsprozess ist dabei emblematisch für zeitgenössische Konflikte über physische Räume und deren Deutung, da dieser Konflikt zum einen mit zunehmender Härte geführt wird, zum anderen sich in immer neue gesellschaftliche Teilbereiche ausbreitet und darüber hinaus von der bewussten Manipulation der öffentlichen Meinung durch die Einführung eigener Begrifflichkeiten und der Förderung bestimmter Assoziation begleitet ist. Ebenso zeigt dieser Beitrag, dass Argumentation um das Für und Wider der Douglasie als invasive Art von gegenseitigem Unverständnis begleitet wird, das symptomatisch für Postmodernisierungsprozesse ist und langfristig ungewisse Folgen für gesellschaftliche Prozesse haben kann.