Search

Among the natural tetramic acids with a decalinoyl part, signermycin B is unique because it contains a cis‐decalin. In this paper, we demonstrate that the cis‐decalin section of signermycin B can be accessed by an anionic oxy‐Cope rearrangement. The substrate, a tricyclic dienol was prepared by an intramolecular Diels‐Alder reaction of a masked ortho‐benzoquinone, generated by oxidation of an α‐methoxyphenol in presence of cis‐2‐hexenol. After a superfluous bromine on the cycloadduct was removed, reaction of the tricyclic ketone with isopropenylmagnesium bromide led to the tricyclic trienol that underwent the oxy‐Cope rearrangement to a cis‐decalinone. While we could show, that introduction of the 4‐ethyl substituent (signermycin B numbering) is possible by enolate alkylation, the 4‐epi‐isomer was formed. [ABSTRACT FROM AUTHOR]

Linguistic categories can impact visual perception. For instance, learning that two objects have different names can enhance their discriminability. Previous studies have identified a typical pattern of categorical perception, characterized by faster discrimination of stimuli from different categories, a neural mismatch response during early visual processing (100–200 ms), and effects restricted to the right visual field. However, it remains unclear whether language affects perception online or through long‐term changes to mental representations in memory. To address this, we tested the impact of newly learned object categories with and without memory consolidation during sleep. We replicated the canonical pattern of categorical perception for categories that underwent consolidation. Without consolidation, linguistic categories still influenced early visual processing but with distinct neural dynamics. Therefore, we found evidence of both transient and long‐term effects of language on perception and conclude that memory consolidation plays a crucial role in shaping how linguistic categories modulate perception. A one‐page Accessible Summary of this article in nontechnical language is freely available in the Supporting Information online and at https://oasis‐database.org. [ABSTRACT FROM AUTHOR]

Additive manufacturing enables the production of lattice structures, which have been proven to be a superior class of lightweight mechanical metamaterials whose specific stiffness can reach the theoretical limit of the upper Hashin–Shtrikman bound for isotropic cellular materials. To achieve isotropy, complex structures are required, which can be challenging in powder bed additive manufacturing, especially with regard to subsequent powder removal. The present study focuses on the Finite Element Method simulation of 2.5D anisotropic plate lattice metamaterials and the investigation of their lightweight potential. The intentional use of anisotropic structures allows the production of a cell architecture that is easily manufacturable via Laser Powder Bed Fusion (LPBF) while also enabling straightforward optimization for specific load cases. The work demonstrates that the considered anisotropic plate lattices exhibit high weight-specific stiffnesses, superior to those of honeycomb structures, and, simultaneously, a good de-powdering capability. A significant increase in stiffness and the associated surpassing of the upper Hashin–Shtrikman bound due to anisotropy is achievable by optimizing wall thicknesses depending on specific load cases. A stability analysis reveals that, in all lattice structures, plastic deformation is initiated before linear buckling occurs. An analysis of stress concentrations indicates that the introduction of radii at the plate intersections reduces stress peaks and simultaneously increases the weight-specific stiffnesses and thus the lightweight potential. Exemplary samples illustrate the feasibility of manufacturing the analyzed metamaterials within the LPBF process. [ABSTRACT FROM AUTHOR]

Background: Forest liming is a common practice in many German forests, which aims primarily at improving soil chemical properties that have been negatively impacted by acid rain. Effects on physical functions have not yet been studied widely. Aims: The hypothesis of this study is that chemical changes after liming lead to changes in the physical properties of the humus layer and mineral soil. Methods: We studied soil physical characteristics (water retention characteristics, air and water permeabilities, and conductivities) of limed and adjacent control plots of sandy to loamy, acidified soils under spruce and beech‐dominated stands. Results: We found differences between limed and control plots, especially in the humus layer and mineral top soil. Here, air capacity values (representing air‐filled macropores at −6 kPa) have experienced an increase, while available water capacities (representing the sum of dewatered mesopores between −6 and −1500 kPa) were reduced to a variable extent. These changes in pore size distributions affected gas diffusion as well as gas permeability positively. Unsaturated hydraulic conductivity was not affected. Below the top mineral soil, a tendency to a reduced macroporosity and gas permeability was observed, but no clear changes were detected. Conclusions: Small but significant changes of soil physical properties and functions in the humus layer and top mineral soil are discussed to be an indirect effect of forest liming. Liming improves pH and nutrient availability, which in turn should have stimulated activity and abundance of soil fauna, especially earthworms. Where observed, their activity could explain the observed changes in soil physical properties. We believe that effects below the top soil might be due to mobilization and translocation of soil particles and a clogging of pores, but these depths were only studied at three plots. Compared to common liming practices, however, the investigated sites are characterized by significantly higher lime applications. The effects on practice liming areas in forestry praxis are therefore likely to be smaller than in this study. [ABSTRACT FROM AUTHOR]

Two decades of research on RNA interference (RNAi) have transformed a breakthrough discovery in biology into a robust platform for a new class of medicines that modulate mRNA expression. Here we provide an overview of the trajectory of small-interfering RNA (siRNA) drug development, including the first approval in 2018 of a liver-targeted siRNA interference (RNAi) therapeutic in lipid nanoparticles and subsequent approvals of five more RNAi drugs, which used metabolically stable siRNAs combined with N-acetylgalactosamine ligands for conjugate-based liver delivery. We also consider the remaining challenges in the field, such as delivery to muscle, brain and other extrahepatic organs. Today's RNAi therapeutics exhibit high specificity, potency and durability, and are transitioning from applications in rare diseases to widespread, chronic conditions. With six approved drugs, siRNA is now an established therapeutic modality poised for expansion. [ABSTRACT FROM AUTHOR]

Copyright of Revista Espanola de Comunicacion en Salud is the property of Asociacion Espanola de Comunicacion Sanitaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift für Rechtsextremismusforschung is the property of Verlag Barbara Budrich GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High-quality AI-generated portraits ("deepfakes") are becoming increasingly prevalent. Understanding the responses they evoke in perceivers is crucial in assessing their societal implications. Here we investigate the impact of the belief that depicted persons are real or deepfakes on psychological and neural measures of human face perception. Using EEG, we tracked participants' (N = 30) brain responses to real faces showing positive, neutral, and negative expressions, after being informed that they are either real or fake. Smiling faces marked as fake appeared less positive, as reflected in expression ratings, and induced slower evaluations. Whereas presumed real smiles elicited canonical emotion effects with differences relative to neutral faces in the P1 and N170 components (markers of early visual perception) and in the EPN component (indicative of reflexive emotional processing), presumed deepfake smiles showed none of these effects. Additionally, only smiles presumed as fake showed enhanced LPP activity compared to neutral faces, suggesting more effortful evaluation. Negative expressions induced typical emotion effects, whether considered real or fake. Our findings demonstrate a dampening effect on perceptual, emotional, and evaluative processing of presumed deepfake smiles, but not angry expressions, adding new specificity to the debate on the societal impact of AI-generated content. [ABSTRACT FROM AUTHOR]

Due to the rapid microbial degradation, ethylene (ethene; C2H4) detection in most soils is difficult. The knowledge about factors favoring the occurrence of C2H4 is mainly based on laboratory experiments which are not necessarily representative for real field conditions in forest soils. We report results from a total of 24 measuring plots in southwest Germany and more than 50,000 gas samples, including long-term forest monitoring sites and other study sites involving liming, artificial soil compaction, and temporary waterlogging. Many of the patterns and influencing factors identified in the laboratory were confirmed. In well-aerated forest soils, C2H4 was detected in 1.3% of the gas samples. C2H4 detection was higher at oxygen (O2) concentrations below 10% in the soil. The effect was positively correlated with bulk density in compacted soils and CO2, CH4, and N2O concentrations—factors that indicate reduced microbial activity and thus also facilitate the detection of C2H4. It could be detected 3.5 times more often in spruce than in beech stands, indicating that plant species plays a role and was not found to follow any distinct spatial or temporal pattern with the exception of seemingly random spatio-temporal clusters of root-born C2H4 near large roots of spruce trees. The long observation period and large dataset of this field study allowed valuable insights into C2H4 occurrence in forest soils under natural conditions supporting the theory that the plant hormone C2H4 is produced as a warning for anaerobic soil areas that are limiting root growth. [ABSTRACT FROM AUTHOR]

High-quality AI-generated portraits ("deepfakes") are becoming increasingly prevalent. Understanding the responses they evoke in perceivers is crucial in assessing their societal implications. Here we investigate the impact of the belief that depicted persons are real or deepfakes on psychological and neural measures of human face perception. Using EEG, we tracked participants' (N = 30) brain responses to real faces showing positive, neutral, and negative expressions, after being informed that they are either real or fake. Smiling faces marked as fake appeared less positive, as reflected in expression ratings, and induced slower evaluations. Whereas presumed real smiles elicited canonical emotion effects with differences relative to neutral faces in the P1 and N170 components (markers of early visual perception) and in the EPN component (indicative of reflexive emotional processing), presumed deepfake smiles showed none of these effects. Additionally, only smiles presumed as fake showed enhanced LPP activity compared to neutral faces, suggesting more effortful evaluation. Negative expressions induced typical emotion effects, whether considered real or fake. Our findings demonstrate a dampening effect on perceptual, emotional, and evaluative processing of presumed deepfake smiles, but not angry expressions, adding new specificity to the debate on the societal impact of AI-generated content. [ABSTRACT FROM AUTHOR]

A new route to the macrolactone antibiotic berkeleylactone A was developed. As a key step, a ring‐closing alkyne metathesis (RCAM) of an ester substrate featuring 1‐propynyl termini was used. The carboxylic part of the substrate was easily assembled using alkyne chemistry, like carboxylation of a diyne followed by isomerization of the ynoate section to a dienoate and dihydroxylation of the 4,5‐double bond. The synthesis of the alcohol part of the ester started with opening of (R)‐propylene oxide with an acetylide and was followed by two triple bond migrations. After successful RCAM which formed the C8−C9 bond, the triple bond was selectively hydrogenated to the corresponding alkene before the 4,5‐diol was oxidized to the 5‐hydroxy‐4‐oxo derivative. At this stage, the thioether was formed and the 8,9‐double bond reduced. We also prepared the 8,9‐didehydro analog of berkeleylactone A. However, it turned out that its antimicrobial activity was slightly reduced. [ABSTRACT FROM AUTHOR]

Gas transport in soils is usually assumed to be purely diffusive, although several studies have shown that non‐diffusive processes can significantly enhance soil gas transport. These processes include barometric air pressure changes, wind‐induced pressure pumping and static air pressure fields generated by wind interacting with obstacles. The associated pressure gradients in the soil can cause advective gas fluxes that are much larger than diffusive fluxes. However, the contributions of the respective transport processes are difficult to separate. We developed a large chamber system to simulate pressure fields and investigate their influence on soil gas transport. The chamber consists of four subspaces in which pressure is regulated by fans that blow air in or out of the chamber. With this setup, we conducted experiments with oscillating and static pressure fields. CO2 concentrations were measured along two soil profiles beneath the chamber. We found a significant relationship between static lateral pressure gradients and the change in the CO2 profiles (R2 = 0.53; p‐value <2e‐16). Even small pressure gradients between −1 and 1 Pa relative to ambient pressure resulted in an increase or decrease in CO2 concentrations of 8% on average in the upper soil, indicating advective flow of air in the pore space. Positive pressure gradients resulted in decreasing, negative pressure gradients in increasing CO2 concentrations. The concentration changes were probably caused by an advective flow field in the soil beneath the chamber generated by the pressure gradients. No effect of oscillating pressure fields was observed in this study. The results indicate that static lateral pressure gradients have a substantial impact on soil gas transport and therefore are an important driver of gas exchange between soil and atmosphere. Lateral pressure gradients in a comparable range can be induced under windy conditions when wind interacts with terrain features. They can also be caused by chambers used for flux measurements at high wind speed or by fans used for head‐space mixing within the chambers, which yields biased flux estimates. [ABSTRACT FROM AUTHOR]

Azo compounds are efficient electron acceptors. Upon one‐electron reduction they generally isomerize forming the thermodynamically most stable radical anion. Herein we show that the size of the central ring in 1,2‐diazocines and diazonines has a ruling influence on the configuration of the one‐electron reduced species. Markedly, diazonines, which bear a central nine membered heterocycle, show light‐induced E/Z isomerization, but retain the configuration of the diazene N=N moiety upon one‐electron reduction. Accordingly, E/Z isomerization is not induced by reduction. [ABSTRACT FROM AUTHOR]

We developed a route to rhodomyrtone analogs that feature different acyl groups at C7. Since electrophilic substitution reactions on the aryl part of the rhodomyrtone core led to C5 derivatives, the C5 position was blocked by a chlorine. Subsequent Duff type formylation followed by Grignard addition to the aldehyde group and oxidation gave various phenones. The benzyl protecting groups were removed by hydrogenation or boron tribromide. Some derivatives turned out to be quite active against multiple resistant Staphylococcus aureus strains and a rhodomyrtone resistant mutant (RomR). The chlorine at C5 seems to have a beneficial effect on the antibacterial activity. [ABSTRACT FROM AUTHOR]

The first regioselective syntheses of 1,2-thiaselenane-4-amine (TSA4) and 1,2-thiaselenane-5-amine (TSA5) are developed. Both are redox motifs with high value in chemical biology that until now were hindered by tedious synthesis. An aziridine intermediate and a kinetically controlled S-acylation were leveraged for regioselective chalcogen installations. Short, fast sequences were optimised with just one or two chromatographic steps that cheaply deliver these motifs on scale for high throughput inhibitor screening, and thus provide a robust methodology for assembling other selenenyl sulfides. [ABSTRACT FROM AUTHOR]

When two individuals share a task with a common goal, coordinating one's own and the other's actions is pivotal. Inhibition of one's own actions when it is the other's turn to act is assumed to play a crucial role in this process. For instance, in the joint Simon task, two individuals share a two-choice task such that one of them responds to one stimulus type and ignores the stimulus type to which the other responds. Because stimuli can either appear on one's own or on the other's side, stimulus location can conflict with stimulus identity, thus slowing response time. It has previously been shown that such conflict leads to a reduction of the detrimental effects of conflict on immediately upcoming trials both following own responses and even more so following the other's responses. This amplified trial-to-trial adjustment following the other's responses has been assumed to reflect the inhibition of own responses on the other's trials. The present study tested this hypothesis by comparing sequential trial-to-trial adjustments following correct responses and commission errors on which the inhibition of own responses has failed. As expected, adjustments were stronger following the other's correct responses than following own correct responses. Crucially, such amplification of sequential adjustment was not observed following own commission errors on the other's trials. This shows that amplification of sequential adjustments following the other's trials depend on successful inhibition of own responses on these trials and points to a crucial role of response inhibition for behavioral control in joint action. [ABSTRACT FROM AUTHOR]

Vegetable oils are very promising alternatives to fossil lubricants due to their abundance, low cost, excellent performance, and environmental friendliness. Due to its multifunctional structure, castor oil is an excellent precursor in the synthesis of new biolubricants. However, it showed poor thermal‐oxidative stability and a higher pour point. This study used castor oil fatty acids prepared by transesterification (EHRO), epoxidation (TEPO), and oxirane ring opening with the aromatic amines aniline (ANIL) and p‐anisidine (ANIS). The chemical structure of these oils was verified by 1H and 13C NMR analysis, and mass spectrometry. Measurements show that the presence of an aromatic amine increases the viscosity resulting in 172 (ANIL) and 199 (ANIS) cSt at 40°C, but reduces viscosity index to 16 and 1, respectively. In addition, the amine groups can scavenge radicals increasing their thermal and oxidative stability. These products do not oxidize copper, and tribological analysis reveals that ANIS has the lowest torque with wear equivalent to commercial mineral lubricant NH‐140. [ABSTRACT FROM AUTHOR]

The generation of the quaternary stereocenter at the C9 position of salvinorin A precursors by the Claisen rearrangement was investigated. The required allyl alcohol was prepared from a Wieland‐Miescher ketone using a known γ‐hydroxylation, reduction of the enone double bond, cyanohydrin formation, and elimination, yielding an unsaturated nitrile. A two‐step reduction led to the required allyl alcohol. The subsequent Johnson‐Claisen rearrangement provided a mixture of two diastereomeric 1,4‐unsaturated esters in a ratio of around 2.6 : 1. The major isomer could be converted to a key intermediate of the Hagiwara synthesis of salvinorin A. [ABSTRACT FROM AUTHOR]

Soils represent a major global source and sink of greenhouse gases (GHGs). Many studies of GHG fluxes between soil, plant and atmosphere rely on chamber measurements. Different chamber techniques have been developed over the last decades, each characterised by different requirements and limitations. In this manuscript, we focus on the non‐steady‐state technique which is widely used for manual measurements but also in automatic systems. Although the measurement method appears very simple, experience gained over the years shows that there are many details which have to be taken into account to obtain reliable measurement results. This manuscript aims to share lessons learnt and pass on experiences in order to assist the reader with possible questions or unexpected challenges, ranging from the planning of the design of studies and chambers to the practical handling of the chambers and the quality assurance of the gas and data analysis. This concise introduction refers to a more extensive Best Practice Guideline initiated by the Working Group Soil Gases (AG Bodengase) of the German Soil Science Society (Deutsche Bodenkundliche Gesellschaft). The intention was to collect and aggregate the expertise of different working groups in the research field. As a compendium, this Best Practice Guideline is intended to help both beginners and experts to meet the practical and theoretical challenges of measuring soil gas fluxes with non‐steady‐state chamber systems and to improve the quality of the individual flux measurements and thus entire GHG studies by reducing sources of uncertainty and error. [ABSTRACT FROM AUTHOR]

Humans are remarkably reliable in detecting errors in their behavior. Whereas error awareness has been assumed to emerge not until 200–400 ms after an error, the so‐called early error sensations refer to the subjective feeling of having detected an error even before the erroneous response was executed. Here, we collected electroencephalogram (EEG) to track how early error sensations are reflected in neural correlates of performance monitoring. Participants first had to perform a task, and then had to indicate whether an error has occurred and whether this error was detected before or after response execution. EEG results showed that early error sensations were associated with an earlier peak of the error‐related negativity (Ne/ERN), a component of error‐related brain activity that occurs briefly after the error response. This demonstrates that early error‐related activity influences metacognitive judgments on the time course of error awareness, and thus contributes to error awareness. Little is known about neural processes that contribute to how we become aware of self‐committed errors. Here, we show that humans frequently report error awareness even before response execution. This early error sensation was associated with an earlier peak in error‐related neural activity that has previously been assumed to precede error awareness. We propose that subjective timing of error awareness is aligned with the time course of early activity to synchronize actions with metacognitive consequences. [ABSTRACT FROM AUTHOR]

This article presents a novel cloud-based charging management system for electric vehicles (EVs). Two levels of cloud computing, i.e., local and remote clouds, are employed to meet the different latency requirements of the heterogeneous EVs while exploiting the lower-cost computing in remote clouds. Specifically, we consider time-sensitive EVs at highway exit charging stations and EVs with relaxed timing constraints at parking lot charging stations. We propose algorithms for the interplay among EVs, charging stations, system operator, and clouds. Considering the contention-based random access for EVs to a 4G Long-Term Evolution network, and the quality of service metrics (average waiting time and blocking probability), the model is composed of: queuing-based cloud server planning, capacity planning in charging stations, delay analysis, and profit maximization. We propose and analyze a price-incentive method that shifts heavy load from peak to off-peak hours, a capacity expansion method that accommodates the peak demand by purchasing additional electricity, and a hybrid method of price incentives and capacity expansion that balances the immediate charging needs of customers with the alleviation of the peak power grid load through price-incentive based demand control. Numerical results demonstrate the effectiveness of the proposed methods and elucidate the tradeoffs between the methods. [ABSTRACT FROM AUTHOR]

Background: Gas exchange between soil and atmosphere is of great importance for greenhouse gas cycles. As gas transport in soil is generally dominated by diffusion, the soil gas diffusion coefficient (DS) is crucial to understand fluxes between soil and atmosphere. Estimating DS is still a great source of uncertainty when calculating soil gas fluxes such as soil respiration from soil gas profiles. In situ measurement of the effective exchange coefficient (Deff) not only reduces this uncertainty, but also allows to quantify non‐diffusive transport processes in addition to the purely diffusive exchange (DS), which cannot be investigated by laboratory measurements or the application of soil gas diffusivity models. Even though several methods for in situ Deff measurement exist, they often lack in the temporal resolution to identify short‐term effects on Deff or require laborious set‐ups, which makes them unsuitable for a fast and mobile application. Aims: Our objective was to test an improved profile probe for model‐based soil gas flux analyses that allows in situ monitoring of (1) soil CO2 profiles with high temporal resolution, (2) soil gas transport coefficients, including non‐diffusive transport processes, (3) soil–atmosphere CO2 flux, and (4) soil respiration profiles. Methods: We developed a CO2 profile probe with build‐in sensors that can easily be installed in soil to gain continuous CO2 concentration profiles. The probe includes the option to inject CO2 as a tracer gas to estimate Deff. To account for changes in natural CO2 concentrations in the soil, we tested two approaches: firstly, a differential approach using two probes, an injection probe and a reference probe, and secondly, a stand‐alone approach in which changes in natural CO2 concentrations are estimated by a statistical model using its main environmental drivers. The resulting tracer gas profiles were used to fit a finite element gas diffusion model to derive Deff. Using the derived Deff values and the CO2 profiles allowed calculating CO2 fluxes. The approach was tested with controlled laboratory experiments using different mineral substrates to compare the diffusivity estimates of the in situ method with laboratory measurements on soil cores. Additional laboratory experiments included artificial CO2 sources to simulate soil respiration in order to evaluate the gradient‐based estimation of soil respiration profiles. In a second step, both approaches were tested under natural conditions in the field. Results: The derived Deff values agreed well with laboratory measurements of DS and DS‐transfer functions. The artificial CO2 sources could accurately be estimated with the gradient method. In the field under calm conditions, both approaches for the estimation of the changing natural CO2 profile gave comparable results. Under windy conditions, the stand‐alone approach gave unrealistically high values, whereas the differential approach using a reference profile still gave reliable results. We observed a clear relationship between Deff and wind‐induced pressure pumping in the topsoil. The estimated surface CO2 efflux agreed well with chamber measurements. Conclusions: This new set‐up enables monitoring of diffusive and non‐diffusive soil gas exchange and soil respiration in situ with high resolution and relatively low effort. [ABSTRACT FROM AUTHOR]

The cyclic five-membered disulfide 1,2-dithiolane has been widely used in chemical biology and in redox probes. Contradictory reports have described it either as nonspecifically reduced in cells, or else as a highly specific substrate for thioredoxin reductase (TrxR). Here we show that 1,2-dithiolane probes, such as "TRFS" probes, are nonspecifically reduced by thiol reductants and redox-active proteins, and their cellular performance is barely affected by TrxR inhibition or knockout. Therefore, results of cellular imaging or inhibitor screening using 1,2-dithiolanes should not be interpreted as reflecting TrxR activity, and previous studies may need re-evaluation. To understand 1,2-dithiolanes' complex behaviour, probe localisation, environment-dependent fluorescence, reduction-independent ring-opening polymerisation, and thiol-dependent cellular uptake must all be considered; particular caution is needed when co-applying thiophilic inhibitors. We present a general approach controlling against assay misinterpretation with reducible probes, to ensure future TrxR-targeted designs are robustly evaluated for selectivity, and to better orient future research. Cyclic five-membered disulfides (1,2-dithiolanes) have been reported either as nonspecific redox motifs, or as highly specific cellular probes for thioredoxin reductase (TrxR). Here the authors show that 1,2-dithiolane probes are nonspecifically reduced by a range of thiol reductants and are not sensitive to TrxR modulation, thus they are unsuitable as cellular probes for TrxR. [ABSTRACT FROM AUTHOR]

Fish farming is a worldwide growing activity and a large amount of residues is produced in this process. The present work describes a cleaner and sustainable way to produce new lubricants from fish waste oil. Oil extracted from the Nile tilapia (Oreochromis niloticus) viscera was utilized as raw material to produce basic oil for lubricants. The products were synthesized by esterification with polyols, trimethylolpropane (TMP) and pentaerythritol (PE), using p‐toluenesulfonic acid (p‐TSA) as catalyst. The synthesized esters were characterized by infrared (IR) and nuclear magnetic resonance (NMR). Computational methods were used to predict the physical characteristics of the material. In addition, the main physicochemical properties were evaluated, as well as the thermal behavior and toxicity of the products against Artemia salina. The synthesized esters showed high viscosity indexes (VI > 150) and viscosities that fit the degree of application ISO‐46 and 150. Molecular dynamics simulations indicated that at room temperature the lubricants Tilapia fatty acid ‐ trimethylolpropane ester (T‐TMPE) and Tilapia fatty acid ‐ pentaerythritol ester (T‐PEE) are in liquid and gel states, respectively, confirming the experimental data. The products did not present toxicity against A. salina. In this research, we reinforce the potential of using tilapia oil from waste to produce green lubricants as a strategy to reduce damage to the environment, as well as the use of computational methods that collaborate to predict physical properties of lubricants. [ABSTRACT FROM AUTHOR]

High per- and polyfluorinated alkyl substance (PFAS) concentrations have been detected in agricultural soils in Southwest Germany. Discharges of PFAS-contaminated paper sludge and compost are suspected to be the cause of the contamination. Perfluorinated carboxylic acids (PFCAs) have been detected also in groundwater, drinking water, and plants in this area. Recently, previously unknown compounds have been identified by high-resolution mass spectrometry (HRMS). Major contaminants were polyfluorinated dialkylated phosphate esters (diPAPs) and N-ethyl perfluorooctane sulfonamide ethanol–based phosphate diester (diSAmPAP). In this study, HRMS screening for PFAS was applied to 14 soil samples from the contaminated area and 14 impregnated paper samples which were from a similar period than the contamination. The paper samples were characterized by diPAPs (from 4:2/6:2 to 12:2/12:2), fluorotelomer mercapto alkyl phosphates (FTMAPs; 6:2/6:2 to 10:2/10:2), and diSAmPAP. In soil samples, diPAPs and their transformation products (TPs) were the major contaminants, but also FTMAPs, diSAmPAP, and their TPs occurred. The distribution patterns of the carbon chain lengths of the precursor PFAS in soil samples were shown to resemble those in paper samples. This supports the hypothesis that paper sludge is a major source of contamination. The presence of major degradation products like PFCAs, FTSAs, or PFOS and their distribution of carbon chain lengths indicate the activity of biotic or abiotic degradation processes and selective leaching processes from the upper soil horizons. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel dynamic bandwidth allocation (DBA) scheme for future generation passive optical networks (PON) in order to meet the beyond 5G (B5G) and sixth generation (6G) stringent requirements. Our proposed algorithm is a generalized multi-access DBA (GMA-DBA) that exploits both orthogonal and non-orthogonal multi-access (MA) resources, resulting in a radical enhancement in the network performance. The proposed GMA-DBA algorithm is modeled as an optimization problem for which a closed form solution is derived. Results show that the GMA-DBA is capable of accommodating a network throughput higher than 1 Tbps while securing a latency and jitter below 100 µs and 10 µs, respectively. It can also maintain reliability, simplicity and energy efficiency. Therefore, using a non-orthogonal MA layer seems to be inevitable to achieve the stringent performance needed for the B5G and 6G next generation systems. [ABSTRACT FROM AUTHOR]

Remote robotic surgery, one of the most interesting 5G-enabled Tactile Internet applications, requires an ultra-low latency of 1 ms and high reliability of 99.999%. Communication disruptions such as packet loss and delay in remote robotic surgery can prevent messages between the surgeon and patient from arriving within the required deadline. In this paper, we advocate for scalable Gaussian process regression (GPR) to predict the contents of delayed and/or lost messages. Specifically, two kernel versions of the sequential randomized low-rank and sparse matrix factorization method ($\ell _{1}$ -SRLSMF and SRLSMF) are proposed to scale GPR and address the issue of delayed and/or lost data in the training dataset. Given that the standard eigen decomposition for online GPR covariance update is cost-prohibitive, we employ incremental eigen decomposition in $\ell _{1}$ -SRLSMF and SRLSMF GPR methods. Simulations were conducted to evaluate the performance of our proposed $\ell _{1}$ -SRLSMF and SRLSMF GPR methods to compensate for the detrimental impacts of excessive delay and packet loss associated with 5G-enabled Tactile Internet remote robotic surgery. The results demonstrate that our proposed framework can outperform state-of-the-art approaches in terms of haptic data generalization performance. Finally, we assess the proposed framework’s ability to meet the Tactile Internet requirement for remote robotic surgery and discuss future research directions. [ABSTRACT FROM AUTHOR]

Many countries worldwide have developed guidelines for offsetting impacts on nature and landscape. Suitable locations are the prerequisite for the implementation of these measures, and this might lead to conflicts with agriculture. In addition, comprehensive planning is often lacking and potential added values for nature conservation are not exploited. Concepts such as the so-called production-integrated compensation (PIC) have been introduced to give farmers the opportunity to actively participate in the offsetting process and improve cooperation. However, up to now, PIC has only rarely been put into practice. Against this backdrop, we have developed a regional planning tool for the implementation of PIC in practice. Based on geodata such as soil data, agricultural structure, or natural conditions at the field and landscape level, the general suitability, and specific measure-based recommendations for each plot can be verified with the help of a decision support system. These factors are assessed from both a nature and an agricultural perspective. The goal here is to highlight synergy effects and increase the likelihood of the proposed measures being implemented. Our tool facilitates the integrated planning of biodiversity offsets at regional level. In this way, it can promote the bundling and networking of measures. However, on-site analyses should be undertaken to complement the implementation of measures. [ABSTRACT FROM AUTHOR]

There has been a growing interest in adapting blockchain technologies to the specific needs of the Internet of Things (IoT) in order to develop a variety of blockchain-based IoT (BIoT) applications such as smart cities and Industry 4.0, where smart contracts play an important role. After briefly reviewing recent progress on BIoT, we explore the symbiosis of blockchain with other key technologies such as artificial intelligence (AI) and robots, while putting our focus on the emerging Tactile Internet for advanced human-to-machine interaction. Our interest is in exploiting the concept of the decentralized autonomous organization (DAO), which executes smart contracts and requires the involvement from humans to perform certain tasks that autonomous AI based software agents and robots themselves cannot do. In our search for synergies between human-agent-robot teamwork (HART) and the complementary strengths of the DAO, AI, and robots, we decentralize the Tactile Internet by leveraging mobile end-user equipment via partially or fully decentralized multi-access edge computing, and crowdsourcing of human expertise to decrease the completion time of physical tasks in the event of unreliable feedback forecasting of teleoperated robots. Finally, we aim at enhancing the human capabilities of unskilled crowd members by using our proposed nudge contract. [ABSTRACT FROM AUTHOR]

We present a strategy to the core structure of the alkaloid palhinine A passing through a 2,5-difunctionalized cyclohexenone. This enone was prepared by a domino Michael/aldol condensation sequence. An allylation reaction on the cyclohexenone followed by oxy-Cope rearrangement introduced an allyl group at C3. After the generation of an aldehyde function on the terminus of the C5 substituent, an intramolecular aldol reaction led to a bicyclo[2.2.2]octanone. The five-membered ring of the core structure could be established by an intramolecular nitrile oxide-alkene [3+2]-cycloaddition. Prior to this key transformation, the keto function was converted to an alkene and the allyl group to an oxime. [ABSTRACT FROM AUTHOR]

Recent empirical and theoretical approaches have called for an understanding of the processes underpinning ecosystem service provision. Environmental gradients have shown effects on key plant functional traits that subsequently explain ecosystem properties of several systems. However, little is known concerning how associations between plant functional traits, including both below- and aboveground plant components, predict ecosystem properties and independently measured final ecosystem services. Here, we modeled (1) the responses of the leaf and plant economics spectrum, Plant size axis, and root growth to environmental gradients and (2) how associations between plant functional traits explain trade-offs and synergies between multiple ecosystem properties and final services. Forty-four plots were studied in a coastal marsh landscape of the German North Sea Coast. We used a partial least square structural equation model approach to test the hypothesized model. We found (1) a negative covariation between plant traits pertaining to a size axis and traits explaining both plant growth (roots and stems) and the leaf economics spectrum; (2) this trade-off responded significantly to the land use gradient and nutrient availability, which were both strongly driven by the groundwater gradient; (3) this trade-off explained an initial major trade-off between carbon stocks, at one extreme of the axis, and both the habitat value to conserve endangered plants and forage production for meat and dairy products at the other extreme. However, a secondary trade-off between nature conservation value and forage production, explained by a trade-off between leaf economics spectrum and plant growth in response to the land use intensity gradient, was also found. [ABSTRACT FROM AUTHOR]

We investigated approaches to the xanthene part of schweinfurthin B. Starting from an exo‐methylene cyclohexanone, an organocuprate addition led to a cyclohexanone featuring a functionalized benzyl substituent in the 2‐position. Ring‐closing reactions to the tetrahydroxanthene core (formation of the central ring) were possible in moderate yield by attack of a phenolic oxygen function on the keto group. More effective was the cyclization to the xanthene core structure after conversion of the cyclohexanone to the exo‐methylene cyclohexane derivative and Lewis acid mediated addition of the phenolic OH to the double bond. In addition, we tried to form the xanthene ring system in a model study by cycloaddition reaction of a silyl enol ether with an ortho‐quinone methide. [ABSTRACT FROM AUTHOR]

Featured Application: Extensive long-term monitoring of greenhouse gases in soils. The mechanically simple and robust design makes the set-up an efficient, versatile, and reliable tool for soil gas monitoring, especially in forest soils. It can also be included in other routine monitoring networks with limited investment and relatively low additional labor costs. Soils provide many functions as they represent a habitat for flora and fauna, supply water, nutrient, and anchorage for plant growth and more. They can also be considered as large bioreactors in which many processes occur that involve the consumption and production of different gas species. Soils can be a source and sink for greenhouse gases. During the last decades this topic attracted special attention. Most studies on soil-atmosphere gas fluxes used chamber methods or micro-meteorological methods. Soil gas fluxes can also be calculated from vertical soil gas profiles which can provide additional insights into the underlying processes. We present a design for sampling and measuring soil gas concentration profiles that was developed to facilitate long term monitoring. Long term monitoring requires minimization of the impact of repeated measurements on the plot and also minimization of the routine workload while the quality of the measurement needs to be maintained continuously high. We used permanently installed gas wells that allowed passive gas sampling at different depths. Soil gas monitoring set ups were installed on 13 plots at 6 forest sites in South West Germany between 1998 and 2010. Until now, soil gas was sampled monthly and analysed for CO2, N2O, CH4, O2, N2, Ar, and C2H4 using gas chromatography. We present typical time series and profiles of soil gas concentrations and fluxes of a selected site as an example. We discuss the effect of different calculation approaches and conclude that flux estimates of O2, CO2 and CH4 can be considered as highly reliable, whereas N2O flux estimates include a higher uncertainty. We point out the potential of the data and suggest ideas for future research questions for which soil gas monitoring would provide the ideal data basis. Combining and linking the soil gas data with additional environmental data promises new insights and understanding of soil processes. [ABSTRACT FROM AUTHOR]

Future emerging communication technologies are anticipated to fold into our surroundings, helping us get our noses off the smartphone screens and back into our environments. In doing so, they make us more (rather than less) present in the world around us. While 5G was supposed to be about the Internet of Everything, to be transformative 6G might be just about the opposite of Everything, that is, Nothing or, more technically, No Things. Building on the invisible-to-visible technology concept, this article explores how the full potential of multisensory extended reality (XR) experiences may be unleashed in Multiverse cross-reality environments. We exploit the convergence of artificial-intelligence-enhanced multi-access edge computing, intelligent mobile robots, and blockchain technologies to help realize the Internet of No Things as an important stepping stone toward ushering in the 6G post-smartphone era. In our experiments, we consider locally connected human-avatar/robot collectives and investigate our proposed extrasensory perception network, which integrates the three evolutionary mobile computing stages of ubiquitous, pervasive, and persuasive computing. As an illustrative example of advanced XR experiences, we study the delivery of sixth-sense perceptions that transverse the boundary between Multiverse realms in order to mimic the quantum realm. [ABSTRACT FROM AUTHOR]

The use of Hydrus‐1D for modeling soil gas fluxes can be improved by introducing a parameter f obtained by fitting the Millington–Quirk (MQ) tortuosity model to measured gas diffusion coefficients. The approach was tested for data from soil horizons of two sandy forest sites located in Northeast‐Germany. f‐values ranged between 0.41 and 0.54, indicating a more tortuous pore systems than predicted by MQ model (f = 1). The parameter optimization procedure can be carried out by using the statistical software R and the enclosed R‐script. [ABSTRACT FROM AUTHOR]

In order to meet the requirements of services and applications envisioned for post-5G and 6G networks, research efforts are heading towards the convergence of architectures aiming to support the wide variety of new compute-demanding and latency-sensitive applications in the context of Tactile Internet. In this article, we study the resource allocation and association of users with different delay requirements in a shared-backhaul fiber-wireless (FiWi) enhanced Heterogeneous Cloud Radio Access Network (h-cran) with Multi-access Edge Computing (mec) and offloading. As opposed to traditional resource and association management, we propose a decentralized algorithm based on a full dual decomposition of the optimization problem to operate the network. Results show that this approach outperforms the traditional one in terms of average delay and energy consumption, achieving up to 80% average delay improvement in high-load scenarios. [ABSTRACT FROM AUTHOR]

Wireless propagation loss modeling has gained significant attention due to its critical importance in forthcoming dynamic wireless technologies. Stochastic and map-based propagation models require more information (elevation extension, statistical scattering characteristics) than required by empirical models (i.e., operating frequency, distance between transceivers, and height of the antennas), but such information is not always available. Thus, empirical models are still widely used to evaluate coverage, link budget, and received signal strength. The drawback of empirical models is inaccuracy in highly dynamic transmitter and receiver environments. To reduce the error caused by the use of a single environment, we divide a geographical terrain to employ a specific propagation model in each segment of the wireless link. We enhance a deep learning (DL) encoder-decoder architecture to extract semantic information from satellite imagery to divide an environment into three classes. Our DL architecture achieved a segmentation accuracy of 89.41%, 86.47%, and 87.37% in urban, suburban, and rural classes, respectively. Simulation results indicate that estimating propagation loss with our multi-environment model reduced the root mean square deviation (RMSD) with respect to two publicly available wireless tracing datasets, CU-WART and Portland MetroFi, by 3.79dB and 4.09dB, respectively. [ABSTRACT FROM AUTHOR]

Streptosetin A belongs to the 3‐decalinoyltetramic acids. In contrast to most of other known natural products of this type, the decalin part features a β‐hydroxyketone subunit, making an intramolecular cycloaddition approach less suitable. We examined an approach where the decalin part would be fashioned by an intramolecular aldol addition. By using a Diels‐Alder reaction between the Rawal diene and a substituted methacrylate, a cyclohexanone was obtained. An organocuprate addition introduced the ethyl substituent before, the side chain was converted to an enal. However, contrary to our expectations, the aldol reaction led to the condensation product. Other routes to reach the key cyclohexanone were also investigated. [ABSTRACT FROM AUTHOR]

Multi-access edge computing (MEC) is an emerging paradigm to meet the rapidly growing computation demands of mobile applications. This paper investigates the performance gains of cooperative computation offloading for MEC enabled FiWi enhanced HetNets with capacity-limited backhaul links. After presenting the envisioned two-tier MEC architecture for a FiWi based networking infrastructure, we propose a simple but efficient offloading strategy, which relies on the flexible trilateral cooperation between end-device, edge servers, and the remote cloud. We then present an analytical framework to estimate the average response time and energy consumption of mobile users for various offloading scenarios with different wireless access modes (i.e., WiFi and 4G LTE-A). The presented analysis flexibly allows for incorporating both offloaded and conventional human-to-human (H2H) traffic of mobile users as well as fixed (wired) subscribers. Finally, we present our self-organization based mechanism, which enables mobile users to make suitable energy-delay trade-offs by jointly minimizing the average task execution time and energy consumption, using only their local information. The obtained results demonstrate the feasibility of the proposed cooperative self-organizing offloading strategy and its superior performance over schemes with MEC- or cloud-only offloading strategies. [ABSTRACT FROM AUTHOR]

The first total synthesis of the natural herbicide MBH‐001 (1) is reported. Structurally it is a 2‐methyloxazol‐5(2H)‐one with a (1‐hydroxyethyl) substituent at the 2‐position. By relying on cyclic nitrones, a flexible route to MBH‐001 and relevant analogues was developed. Key steps include the reaction of a 2‐hydroxyimino ester with an aldehyde to form a 5‐oxo‐2,5‐dihydrooxazole 3‐oxide. In an aldol‐type reaction, the anion of these cyclic nitrones reacted with an aldehyde at the 2‐position. A final reduction of the nitrone to the corresponding imine using zinc led to the target compounds. The cyclic nitrones are also accessible by reacting an α‐keto acid with an oxime. These two versatile synthetic routes enabled us to prepare the first MBH‐001 analogues for structure activity relationship analysis of the herbicidal efficacy. Thus, furthering our aim of developing new herbicides to tackle the ever‐growing problem of weed resistance. [ABSTRACT FROM AUTHOR]

Small air pressure fluctuations (amplitude <10 Pa, frequency range 0.01–0.1 Hz) were simultaneously measured using an inexpensive differential air pressure sensor system and a significantly more expensive high‐precision absolute air pressure sensor reference. The measured air pressure fluctuations were compared and analysed in the time domain and in the time–frequency domain using the wavelet transform. Our analyses demonstrate that there are no significant differences between the measuring results of the two systems. The inexpensive system measures air pressure fluctuations with the same precision as the reference sensor or even a higher precision. As an application, the pressure pumping co‐efficients were calculated from the air pressure fluctuations recorded by both systems. A comparison again showed that both evaluated air pressure sensors yield very similar results. Therefore, it is concluded that the inexpensive system is suitable for reliable air pressure fluctuation measurements. [ABSTRACT FROM AUTHOR]

With the advent of semi-autonomous robotic assistance systems, their integration into human teams is starting to gain steam as part of the vision of human+machine hybrid activities. Unlike their fully autonomous counterparts, semi-autonomous robotic systems mainly rely on human assistance from time to time via teleoperation when human expertise is needed to accomplish a given task. As these robots will need to request human assistance via teleoperation, mapping these requests to human teleoperators stands as a difficult optimization problem. In this paper, after shedding some light on our envisioned FiWi enhanced network infrastructure and its role in realizing the emerging Tactile Internet, we formulate the problem of joint prioritized scheduling and assignment of delay-constrained teleoperation tasks to human operators with the objective to minimize the average weighted task completion time, maximum tardiness, and average operational expenditure (OPEX) per task. We then propose our context-aware prioritized scheduling and task assignment (CAPSTA) algorithm to achieve suitable trade-offs between the contradicting objectives of the problem. Further, to estimate the end-to-end packet delay of local and non-local teleoperation over FiWi enhanced networks, we develop our analytical framework, which flexibly allows for the coexistence of conventional human-to-human (H2H) and haptic human-to-machine (H2M) traffic. [ABSTRACT FROM AUTHOR]