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Summary Organisms regulate gene expression through changes in the activity of transcription factors (TFs). In yeast, the response of genes to changes in TF activity is generally assumed to be encoded in the promoter. To directly test this assumption, we chose 42 genes and, for each, replaced the promoter with a synthetic inducible promoter and measured how protein expression changes as a function of TF activity. Most genes exhibited gene-specific TF dose-response curves not due to differences in mRNA stability, translation, or protein stability. Instead, most genes have an intrinsic ability to buffer the effects of promoter activity. This can be encoded in the open reading frame and the 3′ end of genes and can be implemented by both autoregulatory feedback and by titration of limiting trans regulators. We show experimentally and computationally that, when misexpression of a gene is deleterious, this buffering insulates cells from fitness defects due to misregulation. [ABSTRACT FROM AUTHOR]

The importance of the plant microbiome for host fitness has led to the concept of the “plant holobiont”. Seeds are reservoirs and vectors for beneficial microbes, which are very intimate partners of higher plants with the potential to connect plant generations. In this study, the endophytic seed microbiota of numerous barley samples, representing different cultivars, geographical sites and harvest years, was investigated. Cultivation-dependent and -independent analyses, microscopy, functional plate assays, greenhouse assays and functional prediction were used, with the aim of assessing the composition, stability and function of the barley seed endophytic bacterial microbiota. Associations were consistently detected in the seed endosphere with Paenibacillus , Pantoea and Pseudomonas spp., which were able to colonize the root with a notable rhizocompetence after seed germination. In greenhouse assays, enrichment with these bacteria promoted barley growth, improved mineral nutrition and induced resistance against the fungal pathogen Blumeria graminis . We demonstrated here that barley, an important crop plant, was consistently associated with beneficial bacteria inside the seeds. The results have relevant implications for plant microbiome ecology and for the holobiont concept, as well as opening up new possibilities for research and application of seed endophytes as bioinoculants in sustainable agriculture. [ABSTRACT FROM AUTHOR]

One natural retardation process to be considered in risk assessment for contaminants in the environment is sorption on mineral surfaces. A realistic geochemical modeling is of high relevance in many application areas such as groundwater protection, environmental remediation, or disposal of hazardous waste. Most often concepts with constant distribution coefficients (K d -values) are applied in geochemical modeling with the advantage to be simple and computationally fast, but not reflecting changes in geochemical conditions. In this paper, we describe an innovative and efficient method, where the smart K d -concept, a mechanistic approach mainly based on surface complexation modeling, is used (and modified for complex geochemical models) to calculate and apply realistic distribution coefficients. Using the geochemical speciation code PHREEQC, multidimensional smart K d -matrices are computed as a function of varying (or uncertain) environmental conditions. On the one hand, sensitivity and uncertainty statements for the distribution coefficients can be derived. On the other hand, smart K d -matrices can be used in reactive transport (or migration) codes (not shown here). This strategy has various benefits: (1) rapid computation of K d -values for large numbers of environmental parameter combinations; (2) variable geochemistry is taken into account more realistically; (3) efficiency in computing time is ensured, and (4) uncertainty and sensitivity analysis are accessible. Results are presented exemplarily for the sorption of uranium(VI) onto a natural sandy aquifer material and are compared to results based on the conventional K d -concept. In general, the sorption behavior of U(VI) in dependence of changing geochemical conditions is described quite well. [ABSTRACT FROM AUTHOR]

We tested cytotoxicity of aminoferrocene-based prodrugs towards human androgen-responsive and unresponsive prostate cancer cell lines LNCaP and DU-145 correspondingly. Two prodrugs were selected, which are both activated at elevated concentrations of ROS with generation of quinone methide (antioxidant system inhibitor) and iron-containing compounds ( N -benzylaminoferrocene (prodrug 1 ) and Fe salts ( 2 )). We observed that only prodrug 1 is active against the selected prostate cancer cells (IC 50 = 11–27 μM) and its activity correlates with the high cell-membrane permeability and increased production of intracellular ROS. [ABSTRACT FROM AUTHOR]

Myocardin-related transcription factor A (MRTF-A/MAL/ MKL1/BSAC) regulates the expression of serum-response factor (SRF)-dependent target genes in response to the Rho-actin signaling pathway. Overexpression or activation of MRTF-A affects shape, migration, and invasion of cells and contributes to human malignancies, including cancer. In this study, we report that inhibition of arginyl transferase 1 (ATE1), an enzyme mediating posttranscriptional protein arginylation, is sufficient to increase MRTF-A activity in MCF-7 human breast carcinoma cells independently of external growth factor stimuli. In addition, silencing or inhibiting ATE1 disrupted E-cadherin-mediated cell-cell contacts, enhanced formation of actin-rich protrusions, and increased the number of focal adhesions, subsequently leading to elevated chemotactic migration. Although arginylated actin did not differentially affect MRTF-A, a rapid loss of E-cadherin and F-actin reorganization preceded MRTF-A activation upon ATE1 inhibition. Conversely, ectopic ATE1 expression was sufficient to render MRTF-A inactive, both in resting cells and in cells with exogenously activated RhoA-actin pathways. In this study, we provide a critical link between protein arginylation and MRTF-A activity and place ATE1 upstream of myocardin-related transcription factor. [ABSTRACT FROM AUTHOR]

Highlights: [•] We examine effects of religious heterogeneity on cooperation behavior in a one-shot Public Goods Game (PGG) in India. [•] We examine the effectiveness of ‘Leading by example’ on cooperativeness in religiously pure and mixed groups. [•] Religious heterogeneity does not reduce cooperation in the baseline PGG. [•] Leadership does not increase cooperation in the two-step PGG. [•] In heterogeneous groups leadership significantly lowers cooperation. [ABSTRACT FROM AUTHOR]

Recent findings show that many human pathogenic bacteria can use multiple host organisms. For example, Salmonella Typhimurium can use plants as alternative hosts to humans and other animals. These bacteria are able to adhere to plant surfaces and actively infect the interior of plants. Similarly to the infection of animal cells, S. Typhimurium suppresses plant defense responses by a type III secretion mechanism, indicating that these bacteria possess a dedicated multi-kingdom infection strategy, raising the question of host specificity. In addition, evidence is accumulating that the interaction of Salmonella with plants is an active process with different levels of specificity, because different Salmonella serovars show variations in pathogenicity, and different plant species reveal various levels of resistance towards these bacteria. [Copyright &y& Elsevier]

The sensing of stress signals and their transduction into appropriate responses is crucial for the adaptation and survival of plants. Kinase cascades of the mitogen-activated protein kinase (MAPK) class play a remarkably important role in plant signalling of a variety of abiotic and biotic stresses. MAPK cascade-mediated signalling is an essential step in the establishment of resistance to pathogens. Here, we describe the most recent insights into MAPK-mediated pathogen defence response regulation with a particular focus on the cascades involving MPK3, MPK4 and MPK6. We also discuss the strategies developed by plant pathogens to circumvent, inactivate or even ‘hijack’ MAPK-mediated defence responses. [Copyright &y& Elsevier]

The 3D diagonal anisotropic effective diffusion coefficient of Na + , D eff =(D xx , D yy , D zz ) , was quantified in a clay material in one single experiment/simulation. That is possible due to the combination of the non-invasive observation of Na + diffusion in Opalinus clay by means of GeoPET method (PET: positron emission tomography) followed by quantitative 3D+t data evaluation by means of the finite element numerical modelling (FEM). The extracted anisotropic effective diffusion coefficient parallel ( || ) and normal ( ⊥ ) to the bedding of the clay rock, D eff =(D || , D ⊥ , D || ) are comparable to those obtained on earlier experimental studies in the same clay material but with different methods. We consider this study as benchmark for the long-standing development of our GeoPET method, that explicitly includes a resolute and physics based attenuation and Compton scatter correction algorithm (Kulenkampff, J., M. Gründig, A. Zakhnini and J. Lippmann-Pipke (2016). "Geoscientific process monitoring with positron emission tomography (GeoPET)." Solid Earth 7: 1217–1231) . We suggest GeoPET based fluid flow transport visualization combined with computer based process simulation henceforth as a qualified way for the quantification of three-dimensional, effective transport parameters in geosciences. [ABSTRACT FROM AUTHOR]

• Presence of MGE in MSS correlates positively with ARG and particular heavy metals. • Size of waste water treatment facility does not correlate with ARG or MGE in MSS. • Pollutants and pathogens should be assessed prior the application of sewage sludge. Municipal sewage sludge (MSS) and other biosolids are of high interest for agriculture. These nutrient-rich organic materials can potentially serve as organic fertilizers. Besides an increase of organic matter in soil, other positive effects were shown after their application. Especially the positive influence on circular economy increased the attention paid to management of MSS in recent years. Unfortunately, the use of sewage sludge has some drawbacks. Biosolids are frequently polluted with heavy metals, xenobiotic organic compounds and industrial chemicals, which may be hazardous for the environment and humans. Here, we investigated the influence of stabilization method and the size of wastewater treatment plant on the structure of microbial communities as well as the abundance of antibiotic resistance genes (ARG) and mobile genetic elements (MGE). All tested ARG and MGE were detectable in almost all of the samples. Interestingly, the presence of MGE as well as particular heavy metals correlated positively with the presence of several ARG. We conclude that the distribution of ARG and MGE in biosolids originated from municipal wastewater treatment plants, cannot be explained by the size of the facility or the applied stabilization method. Moreover, we postulate that the presence of pollutants and long-term impacts should be assessed prior to a possible use of sewage sludge as fertilizer. [ABSTRACT FROM AUTHOR]

Abstract: Two different nonthermal plasma reactors at atmospheric pressure were assessed for the first time for cyanide removal (1 mg L−1) from aqueous solutions (0.025 M NaHCO3/NaOH buffer, pH 11) at laboratory scale. Both devices were dielectric barrier discharge (DBD) reactors; one of them was a conventional batch reactor (R1) and the other one was a coaxial thin falling water film reactor (R2). A first-order degradation kinetics was proposed for both experiments, obtaining k R1 = 0.5553 min−1 and k R2 = 0.7482 min−1. The coaxial reactor R2 yielded a removal of 99% within only 3 min. Energy efficiencies (G) were calculated, yielding 1.74 mg kW−1 h−1 for R1 and 127.9 mg kW−1 h−1 for R2. When the treatment was applied to industrial wastewaters, cyanide elimination was confirmed, although at a lower rate (above 92% removal in 90 min with R2). Therefore, plasma reactors could be a relevant alternative to established advanced oxidation techniques (UV, H2O2, ozonation, etc.) for the removal of cyanide from wastewaters with low organic loads or even drinking waters. [Copyright &y& Elsevier]

Mitogen-activated protein kinase kinase kinases (MAPKKKs) play key roles in intra- and extracellular signaling in eukaryotes. Here we report that the MAPKKK MEKK1 regulates redox homeostasis in Arabidopsis. We show that MEKK1-deficient plants are misregulated in the expression of a number of genes involved in cellular redox control and accumulate reactive oxygen species (ROS). Most strikingly, homozygous mekk1 mutant plants exhibit a lethal phenotype when developing true leaves. MEKK1 kinase activity and protein stability was regulated by H2O2 in a proteasome-dependent manner and mekk1 plants were compromised in ROS-induced MAPK MPK4 activation. Whereas mpk3 and mpk6 knock out plants showed no defects in development or changes in redox control genes, mpk4 null mutant shared several phenotypic and transcript profile features with mekk1 plants. In agreement with the concept that ROS negatively regulates auxin responses in plants, mekk1 and mpk4 mutants show reduced expression of several auxin-inducible marker genes. Overall, our data defines MPK4 as downstream target of MEKK1 and show that MEKK1 functions in integrating ROS homeostasis with plant development and hormone signaling. [ABSTRACT FROM AUTHOR]

Abstract: Transmeatal cochlear laser (TCL) treatment has recently been proposed as a therapeutic procedure for cochlear dysfunction such as chronic cochlear tinnitus or sensorineural hearing loss. The aim of this study was to investigate whether TLC has any influence on the central nervous system using functional MRI with healthy young adults. The laser stimulation device was placed on the tympanic membrane of both ears. A laser stimulation run and a placebo run were performed in random order. The participants were unable to differentiate between verum and placebo stimulation. In the comparison of verum to placebo runs, we observed significant activations within the left superior frontal gyrus, the right middle and medial frontal gyrus, the right superior parietal lobule, the left superior occipital gyrus, the precuneus and cuneus bilaterally, the right anterior and the left and right middle and posterior cingulate gyrus and the left thalamus. This network of brain areas corresponds well to results from previous PET studies of patients with tinnitus. Though TCL seems to have a clinically measurable effect on the central nervous system the neurophysiological mechanism leading to the observed activated neuronal network remains unknown. [Copyright &y& Elsevier]

Two monolayers of CdSe sandwiched by ZnSe layers were grown by molecular-beam epitaxy on a vicinal GaAs surface substrate. Small ensembles of these self-assembled quantum dots (QD) have been studied at low temperatures using micro-photoluminescence spectroscopy. We observe reversible spectral diffusion in individual QD luminescence lines. The energy shift is negligibly small at low optical excitation power and amount to about 0.7 meV under higher excitation (0.6 kW/cm2). Because the energy shift is found to be significantly smaller than the exciton–biexciton splitting of CdSe QDs even under high excitation, the conventional spectral filtering could be used to effectively select the exciton-related emission from these QDs. [Copyright &y& Elsevier]

We report the results of studying the optical properties of cubic GaN thin films with photoluminescence and photoluminescence excitation spectroscopies. The films are deposited by plasma-assisted molecular beam epitaxy on GaAs (001) substrates, with and without intentional doping with carbon atoms (p-type doping). The evolution of the optical spectra of the C-doped samples is consistent with a picture in which carbon enters into N-vacancies at low concentrations, producing a marked improvement in the crystalline properties of the material. At higher concentrations it begins to form complexes, possibly due to interstitial occupation. The temperature dependence on the absorption edge of the doped material is also measured and is analyzed with standard theoretical models. [Copyright &y& Elsevier]

Due to their large oscillator strength, ZnSe microcavities with (Zn,Cd)Se quantum wells are particularly suited to investigate the photon–exciton coupling behaviour in semiconductors. We have observed a strong coupling between the excitonic and photonic mode in a ZnSe microcavity with four (Zn,Cd)Se quantum wells and distributed Bragg-mirrors of ZnS and YF3. A very large Rabi-splitting Ω>40 meV was observed at T=300 K in reflection measurements as well as in photoluminescence investigations. [Copyright &y& Elsevier]

Due to their large oscillator strength ZnSe microcavities with (Zn,Cd)Se quantum wells are particularly suited to investigate the photon–exciton coupling behavior in semiconductors. We have observed a strong coupling between the excitonic and photonic mode in a ZnSe microcavity with four (Zn,Cd)Se quantum wells and distributed Bragg-mirrors of ZnS and YF3. A very large Rabi-splitting Ω>40 meV was observed at T=300 K in reflection measurements as well as in photoluminescence investigations. [Copyright &y& Elsevier]

The electrical resistivity of the Si-donor cubic GaN is investigated theoretically at low temperature. The critical impurity concentration, Nc, for the metal–nonmetal transition is estimated in three different ways: from using the generalized Drude approach (GDA) for the resistivity; from the vanishing of the chemical potential calculated using the dielectric function model with a Lorentz-Lorenz correction; from finding the crossing point between the energy in the insulating and metallic states. The bandgap narrowing (BGN) has been determined theoretically and experimentally above the MNM transition. The experimental data have been obtained with photoluminescence measurements. Theoretical and experimental results are in rough agreement in the range of impurity concentration of interest. [Copyright &y& Elsevier]

Abstract: We have investigated the properties of neutral and charged excitons in single CdSe/ZnSe QD photodiodes by μ-photoluminescence spectroscopy. By applying a bias voltage, we have been able to control the number of electrons in a single QD by shifting the energy levels of the QD with respect to the Fermi level in the back contact. Also the quantum-confined Stark effect was observed as a function of the applied electric field. [Copyright &y& Elsevier]