Regulatory elements located in the upstream region of the Rhizobium leguminosarum rosR global regulator are essential for its transcription and mRNA stability

Rhizobium leguminosarum bv. trifolii is a soil bacterium capable of establishing a symbiotic relationship with clover (Trifolium spp.). Previously, the rosR gene, encoding a global regulatory protein involved in motility, synthesis of cell-surface components, and other cellular processes was identified and characterized in this bacterium. This gene possesses a long upstream region that contains several regulatory motifs, including inverted repeats (IRs) of different lengths. So far, the role of these motifs in the regulation of rosR transcription has not been elucidated in detail. In this study, we performed a functional analysis of these motifs using a set of transcriptional rosR-lacZ fusions that contain mutations in these regions. The levels of rosR transcription for different mutant variants were evaluated in R. leguminosarum using both quantitative real-time PCR and β-galactosidase activity assays. Moreover, the stability of wild type rosR transcripts and those with mutations in the regulatory motifs was determined using an RNA decay assay and plasmids with mutations in different IRs located in the 5′ -untranslated region of the gene. The results show that transcription of rosR undergoes complex regulation, in which several regulatory elements located in the upstream region and some regulatory proteins are engaged. These include an upstream regulatory element, an extension of the -10 element containing three nucleotides TGn (TGn-extended -10 element), several IRs, and PraR repressor related to quorum sensing.Polish National Science Centre DEC-2012/07/B/NZ1/0009

Non-typical fluorescence effects and biological activity in selected 1,3,4-thiadiazole derivatives : spectroscopic and theoretical studies on substituent, molecular aggregation, and pH effects

The below article presents the results of spectroscopic research, theoretical (time-dependent density functional theory (TD-DFT)), microbiological, and antioxidative calculations for three compounds from the group of 1,3,4-thiadiazoles: 2-amino-5-phenyl-1,3,4-thiadiazole (TB), 2-amino-5-(2-hydroxyphenyl)-1,3,4-thiadiazole (TS), 2-amino-5-(2-hydroxy-5-sulfobenzoyl)-1,3,4-thiadiazole (TSF). In the fluorescence emission spectra (TS) of solutions with varying concentrations of hydrogen ions, a particularly interesting effect of dual fluorescence was observed. The aforementioned effect was observed even more clearly in the environment of butan-1-ol, relative to the compound’s concentration. Depending on the modification of the resorcylic substituent (TS and TSF), we observed the emergence of two separate, partially overlapping, fluorescence emission spectra or a single emission spectrum. Interpretation of the obtained spectra using stationary and time-resolved spectroscopy allowed the correlation of the effect’s emergence with the phenomenon of molecular aggregation (of a particular type) as well as, above all, the structure of the substituent system. The overlap of said effects most likely induces the processes related to the phenomenon of charge transfer (in TS) and is responsible for the observed fluorescence effects. Also, the position of the –OH group (in the resorcylic ring) is significant and can facilitate the charge transfer (CT). The determinations of the changes in the dipole moment and TD-DFT calculations further corroborate the above assumption. The following paper presents the analysis (the first for this particular group of analogues) of the fluorescence effects relative to the changes in the structure of the resorcylic group combined with pH effects. The results of biological studies also indicate the highest pharmacological potential of the analogue in the case where the effects of dual fluorescence emission are observed, which predisposes this particular group of fluorophores as effective fluorescence probes or potential pharmaceuticals with antimycotic properties

Painter in the film. Psychological portrait of the artist

Przedmiotem pracy jest analiza sposobu przedstawiania malarzy w filmach. Główny cel stanowi zwrócenie uwagi na związek rożnych dziedzin artystycznych, a także wydobycie cech charakteru artystów, podkreślenie ich indywidualizmu oraz rozpoznawalnego stylu. W każdym rozdziale zostało krótko omówione życie malarza a także poddano analizie sposób, w jaki reżyserzy ukazywali wizerunek twórców. Pokazano także, jaką rolę obrazy spełniały w filmach. W celu sformułowania niezbędnych wniosków przydatne okazały się biografie artystów, które pozwoliły na to, aby lepiej zrozumieć ich twórczość, a także motywy postępowania. Przegląd literatury przedmiotu oraz materiałów dostępnych w Internecie pozwolił uzupełnić psychologiczny wizerunek malarzy.The aim of this thesis is to analyse the ways in which certain painters have been portrayed in films. The main goal is to present different artistic styles, highlight the features of character of different artists, their individuality and their recognizable style. Each chapter contains a short biography of an artist, an analysis of how directors presented them and their paintings in films. In order to draw some conclusions it was necessary to study the artists’ biographies, they allowed me to understand their works better and to learn the causes of their behavior. The thesis would not be complete without psychological analysis of the artists, which was possible due to a thorough study of source literature and the material available in the Internet

Mutation in the pssA Gene Involved in Exopolysaccharide Synthesis Leads to Several Physiological and Symbiotic Defects in Rhizobium leguminosarum bv. trifolii

The symbiotic nitrogen-fixing bacterium Rhizobium leguminosarum bv. trifolii 24.2 secretes large amounts of acidic exopolysaccharide (EPS), which plays a crucial role in establishment of effective symbiosis with clover. The biosynthesis of this heteropolymer is conducted by a multi-enzymatic complex located in the bacterial inner membrane. PssA protein, responsible for the addition of glucose-1-phosphate to a polyprenyl phosphate carrier, is involved in the first step of EPS synthesis. In this work, we characterize R. leguminosarum bv. trifolii strain Rt270 containing a mini-Tn5 transposon insertion located in the 3\u27-end of the pssA gene. It has been established that a mutation in this gene causes a pleiotropic effect in rhizobial cells. This is confirmed by the phenotype of the mutant strain Rt270, which exhibits several physiological and symbiotic defects such as a deficiency in EPS synthesis, decreased motility and utilization of some nutrients, decreased sensitivity to several antibiotics, an altered extracellular protein profile, and failed host plant infection. The data of this study indicate that the protein product of the pssA gene is not only involved in EPS synthesis, but also required for proper functioning of Rhizobium leguminosarum bv. trifolii cells

Oxalic acid degradation by a novel fungal oxalate oxidase from Abortiporus biennis

Oxalate oxidase was identified in mycelial extracts of a basidiomycete Abortiporus biennis strain. Intracellular enzyme activity was detected only after prior lowering of the pH value of the fungal cultures by using oxalic or hydrochloric acids. This enzyme was purified using size exclusion chromatography (Sephadex G-25) and ion-exchange chromatography (DEAE-Sepharose). This enzyme exhibited optimum activity at pH 2 when incubated at 40°C, and the optimum temperature was established at 60°C. Among the tested organic acids, this enzyme exhibited specificity only towards oxalic acid. Molecular mass was calculated as 58 kDa. The values of Km for oxalate and Vmax for the enzyme reaction were 0.015 M and 30 mmol min-1, respectively

Application of Conditional Generative Adversarial Networks to Efficiently Generate Photon Phase Space in Medical Linear Accelerators of Different Primary Beam Parameters

Successful application of external photon beam therapy in oncology requires that the dose delivered by a medical linear accelerator and distributed within the patient’s body is accurately calculated. Monte Carlo simulation is currently the most accurate method for this purpose but is computationally too extensive for routine clinical application. A very elaborate and time-consuming part of such Monte Carlo simulation is generation of the full set (phase space) of ionizing radiation components (mainly photons) to be subsequently used in simulating dose delivery to the patient. We propose a method of generating phase spaces in medical linear accelerators through learning, by artificial intelligence models, the joint multidimensional probability density distribution of the photon properties (their location in space, energy, and momentum). The models are conditioned with respect to the parameters of the primary electron beam (unique to each medical accelerator), which, through Bremsstrahlung, generates the therapeutical beam of ionizing radiation. Two variants of conditional generative adversarial networks are chosen, trained, and compared. We also present the second-best type of deep learning architecture that we studied: a variational autoencoder. Differences between dose distributions obtained in a water phantom, in a test phantom, and in real patients using generative-adversarial-network-based and Monte-Carlo-based phase spaces are very close to each other, as indicated by the values of standard quality assurance tools of radiotherapy. Particle generation with generative adversarial networks is three orders of magnitude faster than with Monte Carlo. The proposed GAN model, together with our earlier machine-learning-based method of tuning the primary electron beam of an MC simulator, delivers a complete solution to the problem of tuning a Monte Carlo simulator against a physical medical accelerator