The annual oscillations of the brightnesses observed at 12 and 25 μm by IRAS near the ecliptic poles are mainly due to the inclination of the symmetry plane (SP) of the interplanetary dust cloud upon the ecliptic, but also, secondarily, to the eccentricity of the earth's orbit.
Comparing the brightnesses at the poles and in the ecliptic (near 90° elongation) allows a retrieval of the inclination i and ascending node Ω SP/ecliptic through an inversion technique, with very little model-dependence. The results (i = 1.5°, Ω = 90°) conflict with some of those previously obtained from the same observations by more model-dependent approaches, but they agree with former optical determinations from D2A satellite and from Tenerife
ground-based data.
The Routh reduction of cyclic variables in the Lagrange function and the Jacobi-Maupertuis principle of constant energy systems are generalized. The article deals with one-dimensional variational integral subject to differential constraints, the Lagrange variational problem, that admits the Lie group of symmetries. Reduction to the orbit space is investigated in the absolute sense relieved of all accidental structures. In particular, the widest possible coordinate-free approach to the underdetermined systems of ordinary differential equations, Poincaré-Cartan forms, variations and extremals is involved for the preparation of the main task. The self-contained exposition differs from the common actual theories and rests only on the most fundamental tools of classical mathematical analysis, however, they are applied in infinite-dimensional spaces. The article may be of a certain interest for nonspecialists since all concepts of the calculus of variations undergo a deep reconstruction.
Some open problems appearing in the primary article on the symmetry reduction are solved. A new and quite simple coordinate-free definition of Poincaré-Cartan forms and the substance of divergence symmetries (quasisymmetries) are clarified. The unbeliavable uniqueness and therefore the global existence of Poincaré-Cartan forms without any uncertain multipliers for the Lagrange variational problems are worth extra mentioning.
Like the classical Gram-Schmidt theorem for symplectic vector spaces, the sheaf-theoretic version (in which the coefficient algebra sheaf $\mathcal A$ is appropriately chosen) shows that symplectic $\mathcal A$-morphisms on free $\mathcal A$-modules of finite rank, defined on a topological space $X$, induce canonical bases (Theorem 1.1), called symplectic bases. Moreover (Theorem 2.1), if $(\mathcal {E}, \phi )$ is an $\mathcal A$-module (with respect to a $\mathbb C$-algebra sheaf $\mathcal A$ without zero divisors) equipped with an orthosymmetric $\mathcal A$-morphism, we show, like in the classical situation, that “componentwise” $\phi $ is either symmetric (the (local) geometry is orthogonal) or skew-symmetric (the (local) geometry is symplectic). Theorem 2.1 reduces to the classical case for any free $\mathcal A$-module of finite rank.
Rye (Secale cereale L.) plants were treated with an ethylene releaser ethephon (2-chloroethylphosphonic acid) in concentration of 4×10-2 M. We studied electron microscopically, if and how chloroplasts interact with well-documented sites of ethylene production/binding, i.e., with endoplasmic reticulum, dictyosomes, mitochondria, plasma membrane, and tonoplast. During the sharp increase of ethylene synthesis in mesophyll cells of rye leaves, the direct local continguity of chloroplast envelope or envelope protrusions with the above mentioned cell compartments was typical. Moreover, a large number and diversity of versatile chloroplast-dictyosome associations were conspicuous, in which both the chloroplast and each cisterna of dictyosome were capable to exo/endocytosis. The dictyosomes were directed towards the chloroplasts, plasma membrane, or tonoplast both with cis-face, trans-face, or with the rim, they could change their direction or shut up the trans-face, developing simultaneously several flexible chains of vesicular dispatches among chloroplasts and some other cell compartments. This reflects interaction of protein/ethylene producing, photosynthesising, DNA containing compartments, and regulated action of lysosomal system. Structural contacts and vesicular transport among compartments of symplastic system equalises concentrations of H+, Ca2+, etc. ions, as well as provide connection with an apoplast. We propose that ethylene functions in plant mesophyll cells are both as intra/intercellular signalling substance and as phytohormone that regulates gene expression in nuclei, chloroplasts, and mitochondria in a complicated synapse-like process and causes programmed death of leaves of the main stalks of rye for the sake of promoted growth of side shoots. and T. Selga, M. Selga.
For companies doing business in mining mineral deposits, ensuring safe work is one of the key tasks (Safety First!). One of the important trends in this area is prevention and endeavour to forestall risk situations. Risks need to be searched, technically described, spatially defined, evaluated and categorized by degree of risk. Complex geological and stability conditions can be one of the sources of persistent and significant risks, which are mainly landslides and rockslides threatening both mining equipment and employees. The problem described in this article and its solution concerns the Most Basin (formerly the North Bohemian Lignite Basin). This is a tertiary basin that was founded in the Oligocene. The main mineral is lignite and mining takes place on the surface. The main excavating machinery in the surface lignite quarries in Europe (Czech Republic, Germany, Poland) is the bucket wheel excavator., Roman Kapica, Dana Vrublová and Martin Vrubel., and Obsahuje bibliografii
Examination of the original literature concerning species of Philometra (Philometridae, Dracunculoidea) parasitic in the abdominal cavity of European cyprinids revealed that P. abdominalis Nybelin, 1928 is a junior synonym of P. ovata (Zeder, 1803), a parasite of cyprinids of the genera Gobio, Phoxinus and Leuciscus. The valid name of the species parasitizing cyprinids of the genera Abramis, Rutilus and Vimba, mostly reported erroneously as P. ovata, is P. cyprinirutili (Creplin, 1825) comb. n.
Based on the original description, the nematode genus Piscinema Gambhir et Ng, 2014 and its type species, P. barakensis [sic] Gambhir et Ng, 2014 (probably a misidentified physalopterid larvae), are removed from the Philometridae, where they were allocated; they are considered a genus inquirendum and incertae sedis and a species inquirenda, respectively. The poorly described nematode Rhabdochona carpiae Nimbalkar, Deolalikar et Kamtikar, 2013 (Rhabdochonidae) appears largely fabricated and is regarded a species dubia.
The Tachyusa coarctata species group is revised. The species group is defined on the basis of the distinctly asperate punctation on elytra, the dense punctation on tergites III-V with interstices between punctures 1.5-2.0 times their diameter, and the dense, subrecumbent pubescence on the abdomen. The T. coarctata species group is composed of twenty three species restricted in occurrence to the Holarctic and Africa, including one new species described from Iran: Tachyusa frischi sp.n. A revised key to the species in this group is provided. An analysis of the phylogeny of the Tachyusa coarctata species group based on cladistic methods is presented and the phylogenetic relationships among species are discussed.