Accumulation of ambient phosphate into the periplasm of marine bacteria is proton motive force dependent

Bacteria acquire phosphate (Pi) by maintaining a periplasmic concentration below environmental levels. We recently described an extracellular Pi buffer which appears to counteract the gradient required for Pi diffusion. Here, we demonstrate that various treatments to outer membrane (OM) constituents do not affect the buffered Pi because bacteria accumulate Pi in the periplasm, from which it can be removed hypo-osmotically. The periplasmic Pi can be gradually imported into the cytoplasm by ATP-powered transport, however, the proton motive force (PMF) is not required to keep Pi in the periplasm. In contrast, the accumulation of Pi into the periplasm across the OM is PMF-dependent and can be enhanced by light energy. Because the conventional mechanism of Pi-specific transport cannot explain Pi accumulation in the periplasm we propose that periplasmic Pi anions pair with chemiosmotic cations of the PMF and millions of accumulated Pi pairs could influence the periplasmic osmolarity of marine bacteria

Diel rhythmicity in amino acid uptake by Prochlorococcus

The marine cyanobacterium Prochlorococcus, the most abundant phototrophic organism on Earth, numerically dominates the phytoplankton in nitrogen (N)-depleted oceanic gyres. Alongside inorganic N sources such as nitrite and ammonium, natural populations of this genus also acquire organic N, specifically amino acids. Here, we investigated using isotopic tracer and flow cytometric cell sorting techniques whether amino acid uptake by Prochlorococcus is subject to a diel rhythmicity, and if so, whether this was linked to a specific cell cycle stage. We observed, in contrast to diurnally similar methionine uptake rates by Synechococcus cells, obvious diurnal rhythms in methionine uptake by Prochlorococcus cells in the tropical Atlantic. These rhythms were confirmed using reproducible cyclostat experiments with a light synchronised axenic Prochlorococcus (PCC9511 strain) culture and 35S-methionine and 3H-leucine tracers. Cells acquired the tracers at lower rates around dawn and higher rates around dusk despite >104 times higher concentration of ammonium in the medium, presumably because amino acids can be directly incorporated into protein. Leucine uptake rates by cells in the S+G2 cell cycle stage were consistently 2.2 times higher than those of cells at the G1 stage. Furthermore, S+G2 cells up-regulated amino acid uptake 3.5 times from dawn to dusk to boost protein synthesis prior to cell division. Because Prochlorococcus populations can account from 13% at midday, and up to 42% at dusk, of total microbial uptake of methionine and probably of other amino acids in N-depleted oceanic waters, this genus exerts diurnally variable, strong competitive pressure on other bacterioplankton populations

The Influence of Transport Load on Quality of Repair Works of Non-Rigid Pavements with Application by a Jet-Injection Method

Increased traffic intensity and increased axial Load from vehicles on road surfaces contribute to the formation of defects in the form of potholes and cracks. To improve the service Life and traffic safety timely care of the coating is required. Untimely work Leads to a decrease in the service Life of the pavement. The use of a jet-injection method of repair of road surfaces aLLows to perform work quickLy with minimaL cost in reLation to other methods of repair. The articLe considers the process of eLimination of defects on non-rigid road surfaces with the use of bitumen-mineraL mixtures by a jet-injection method. The resuLts of experimentaL studies carried out in the course of repair work on the second technicaL category road with high traffic intensity and increased axiaLLoad from vehicLes are presented. It was found out that the formation of the structure of the bitumen-mineraL mixture in the pothoLe of the road surface occurs over a reLativeLy Long period of time. Under the influence of contact stresses under the tire of the car, there are deformations of the material, the excess of whichLeads to its decompression. It is experimentaLLy proved that in order to increase the serviceLife of the repaired road surface, additionaL compaction of the bitumen-mineraL mixture is necessary. It was found that the excessLoad on the Layer of bitumen-mineraL mixture in the pothoLe coating at the stage of formation of its structure above the tensiLe strength contributes to the formation of pLastic deformations and reduce the required compaction coefficient. To improve the quaLity of repair work, it is necessary to Limit the axiaLLoad of vehicLes on the surface of the pothoLe for 20-30 days during the formation of the structure of the Laid materiaL in the pothoLe of the road surface

“Pomacytosis” — Semi-extracellular phagocytosis of cyanobacteria by the smallest marine algae

The smallest algae, less than 3 μm in diameter, are the most abundant eukaryotes of the World Ocean. Their feeding on planktonic bacteria of similar size is globally important but physically enigmatic. Tiny algal cells, tightly packed with the voluminous chloroplasts, nucleus, and mitochondriaon, appear to have insufficient organelle-free space for prey internalization. Here, we present the first direct observations of how the 1.3- μm algae, which are only 1.6 times bigger in diameter than their prey, hold individual Prochlorococcus cells in their open hemispheric cytostomes. We explain this semi-extracellular phagocytosis by the cell size limitation of the predatory alga, identified as the Braarudosphaera haptophyte with a nitrogen (N2)–-fixing endosymbiont. Because the observed semi-extracellular phagocytosis differs from all other types of protistan phagocytosis, we propose to name it “pomacytosis” (from the Greek πώμα for “plug”)

Loricate choanoflagellates (Acanthoecida) from warm water seas. VI. Pleurasiga Schiller and Parvicorbicula Deflandre

The loricate choanoflagellate genera Pleurasiga and Parvicorbicula are taxonomically ambiguous. Pleurasiga because of the uncertainty that relates to the true identity of the type species, and Parvicorbicula because too many newly described species over time have been dumped here in lack of better options. While all species currently allocated to the genus Pleurasiga (with the exception of the type species) are observed in our samples from the global warm water belt, the genus Parvicorbicula is represented by just a few and mostly infrequently recorded taxa. Two new species, viz. Pl. quadrangiella sp. nov. and Pl. minutissima sp. nov., are described here. While the former is closely related to Pl. echinocostata, the latter is reminiscent of Pl. minima. Core species of Pleurasiga and Parvicorbicula deviate from the vast majority of loricate choanoflagellates in having both the anterior and the mid-lorica transverse costae located exterior to the longitudinal costae. In Pl. quadrangiella there is no mid-lorica transverse costa but rather a small posterior transverse costa located inside the longitudinal costae. In Pl. minutissima the mid-lorica transverse costa has extensive costal strip overlaps which reveal patterns of costal strip junctions that deviate from the norm

Raise the anchor! Synthesis, X-ray and NMR characterization of 1,3,5-triazinanes with an axial tert-butyl group

N-t-Bu-N’,N’’-disulfonamide-1,3,5-triazinanes were synthesized and characterized by X-ray single crystal structure analysis. In the course of the X-ray structure elucidation, the first solid experimental evidence of the axial position of the tert-butyl group in unconstrained hexahydro-1,3,5-triazacyclohexanes was obtained. Dynamic low-temperature NMR analysis allowed to fully investigate a rare case of crystallization-driven unanchoring of the tert-butyl group in the chair conformation of saturated sixmembered cycles. DFT calculations show that the use of explicit solvent molecules is necessary to explain the equatorial position of the t-Bu group in solution. Otherwise, the axial conformer is the thermodynamically stable isomer.Fil: Kletskov, Alexey V.. University of Russia; RusiaFil: Zatykina, Anastasya D.. University of Russia; RusiaFil: Grudova, Mariya V.. University of Russia; RusiaFil: Sinelshchikova, Anna A.. Academy of Sciences; RusiaFil: Grigoriev, Mikhail. Academy of Sciences; RusiaFil: Zaytsev, Vladimir P.. University of Russia; RusiaFil: Gil, Diego Mauricio. Universidad Nacional de Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica; ArgentinaFil: Novikov, Roman A.. Academy of Sciences; RusiaFil: Zubkov, Fedor Ivanovich. University of Russia; RusiaFil: Frontera, Antonio. Universidad de las Islas Baleares; Españ

Synthesis, X-ray characterization and theoretical study of 3 a ,6:7,9 a-diepoxybenzo [de] isoquinoline derivatives: on the importance of F⋯O interactions

The synthesis, X-ray characterization and Hirshfeld surface analysis of a series of tetrahydrodiepoxybenzo[de]isoquinoline derivatives obtained by the tandem [4+2] cycloaddition between perfluorobut-2-yne dienophile (F3C–C≡C–CF3) and a row of N,N-bis(furan-2-ylmethyl)-4-Rbenzenesulfonamides (bis-dienes, R = Me, F, Cl, Br, I) are reported in this manuscript. The implementation of kinetic/thermodynamic control allowed to obtain both “pincer”- and “domino”-types adducts in good/moderate yields. In the solid state, most of the pincer adducts form self-assembled dimers (R = Me, Cl, Br, I) and, contrariwise, the domino adducts form 1D supramolecular chains, which are described in detail herein. Remarkably, in the self-assembled dimers, bifurcated halogen bonds involving one fluorine atom of the CF3 group and both O-atoms of sulfonamide are formed, which have been analyzed using DFT calculations, QTAIM and NCIplot computational tools.Fil: Grudova, Mariya V.. Peoples’ Friendship University; RusiaFil: Gil, Diego Mauricio. Universidad Nacional de Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica; ArgentinaFil: Khrustalev, Victor N.. Peoples’ Friendship University; Rusia. Institute of Organic Chemistry ND. Zelinsky; RusiaFil: Nikitina, Eugeniya V.. Peoples’ Friendship University; RusiaFil: Sinelshchikova, Anna A.. Academy of Sciences. Frumkin Institute of Physical Chemistry and Electrochemistry; RusiaFil: Grigoriev, Mikhail S.. Academy of Sciences. Frumkin Institute of Physical Chemistry and Electrochemistry; RusiaFil: Kletskov, Alexey V.. Peoples’ Friendship University; RusiaFil: Frontera, Antonio. Universidad de las Islas Baleares; EspañaFil: Zubkov, Fedor I.. Peoples’ Friendship University; Rusi

Polarons as stable solitary wave solutions to the Dirac-Coulomb system

We consider solitary wave solutions to the Dirac--Coulomb system both from physical and mathematical points of view. Fermions interacting with gravity in the Newtonian limit are described by the model of Dirac fermions with the Coulomb attraction. This model also appears in certain condensed matter systems with emergent Dirac fermions interacting via optical phonons. In this model, the classical soliton solutions of equations of motion describe the physical objects that may be called polarons, in analogy to the solutions of the Choquard equation. We develop analytical methods for the Dirac--Coulomb system, showing that the no-node gap solitons for sufficiently small values of charge are linearly (spectrally) stable.Comment: Latex, 26 page

Intramolecular sp2-sp3 disequalization of chemically identical sulfonamide nitrogen atoms: single crystal X-Ray diffraction characterization, hirshfeld surface analysis and DFT calculations of N-substituted hexahydro-1,3,5-triazines

In this manuscript, the synthesis and single crystal X-ray diffraction characterization of four N-substituted 1,3,5-triazinanes are reported along with a detailed analysis of the noncovalent interactions observed in the solid state architecture to these compounds, focusing on C–H···π and C–H···O H-bonding interactions. These noncovalent contacts have been characterized energetically by using DFT calculations and also by Hirshfeld surface analysis. In addition, the supramolecular assemblies have been characterized using the quantum theory of “atoms-in-molecules” (QTAIM) and molecular electrostatic potential (MEP) calculations. The XRD analysis revealed a never before observed feature of the crystalline structure of some molecules: symmetrically substituted 1,3,5-triazacyclohexanes possess two chemically identical sulfonamide nitrogen atoms in different sp2 and sp3-hybridizations.Fil: Kletskov, Alexey V.. University of Russia; RusiaFil: Gil, Diego Mauricio. Universidad Nacional de Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biotecnología Farmacéutica y Alimentaria; ArgentinaFil: Frontera, Antonio. Universidad de las Islas Baleares; EspañaFil: Zaytsev, Vladimir P.. University of Russia; RusiaFil: Merkulova, Natalia L.. University of Russia; RusiaFil: Beltsova, Ksenia R.. University of Russia; RusiaFil: Sinelshchikova, Anna A.. University of Russia; RusiaFil: Grigoriev, Mikhail S.. University of Russia; RusiaFil: Grudova, Mariya V.. University of Russia; RusiaFil: Zubkov, Fedor I.. University of Russia; Rusi

DIE BIOETHIK UND ANTHROPOLOGIE

Budući da je i bioetika, kako je već naznačeno i u njezinu imenu, posebna, specijalna etika (sadržana i u koncepciji bioetike kao nove, transdisciplinarne znanosti), prvo je rečeno ono osnovno o etici kao disciplini praktičke filozofije, da bi tako postao razgovjetniji i smisao, zadaća i mogućnosti bioetike kao primijenjene etike na područje života općenito, prvenstveno na čovjekov život i zdravlje. Kako je etika kao refleksija o ispravnom i dobrom ljudskom djelovanju bitno povezana s antropologijom kao filozofijskim i znanstvenim promišljanjem naravi, položaja u svijetu i biti čovjekova bića uopće (prirodnoga, društvenoga i duhovnog), to je u drugom dijelu ovoga konspekta pokazana i »pupčana« sveza bioetike s antropologijom, s posebnim obzirom na suvremene ekološke uvjete života, tj. na prijeteću globalnu i strukturalnu ekološku krizu.Since bioethics, as the name itself indicates, is a special kind of ethics (contained in the concept of bioethics as a new, transdisciplinary science), in the beginning, the basic thing about ethics as a discipline of practical philosophy is said, to make, therefore, more comprehensible the sense, task and possibilities of bioethics as applied ethics in the field of life in general, first of all, in human\u27s life and health. And since ethics as a reflection on right and good human activity is essentially connected with anthropology as philosophical and scientific reflexion on nature, on the position in the world and on the essence of human being in general (natural, social and spiritual) , thus, in the second part of this conspectus, the "umbilical" connection between bioethics and anthropology has been shown, with the special regard to contemporary ecological conditions of life, i.e. to the threatening global and ecological crisis.Da auch die Bioethik wie schon aus ihrem Namen hervorgeht eine besondere spezielle Ethik ist (das ist auch in der Konzeption der Bioethik als einer neuen transdisziplinaren Wisenschaft enthalten), wurde zuerst das Grundlegende über Ethik als einer Disziplin der praktischen Philosophie gesagt, damit so auch der Sinn deutlich wird, die Aufgabe und die Möglichkeiten der Bioethik als einer auf dem Gebiet des Lebens allgemein angewandten Ethik, vor allem angewandt auf das menschliche Leben und Gesundheit. Da die Ethik als eine Reflexion über die gute und richtige Wirkung des Menschen im Wesentlichen mit der Anthropologie als philosophische und wissenschaftliche Überlegung der menschlichen Natur verbunden ist, mit der Stellung in der Welt und dem Kern des menschlichen Wesens (natürlichem, gesellschaftlichem und geistigem), so ist im zweiten Teil dieses Konspekts die "Nabelschnurr" — Verbindung der Bioethik mit der Anthropologie dargelegt, und daß mit besonderer Berücksichtigung der heutigen ökologischen Umweltbediengungen., d.h. der droheneden globalen und strukturalen ökologischen Krise