«Нова система землеробства» І.Є. Овсинського: наукові ідеї в історичному вимірі

У статті на основі історико-наукового аналізу показано значення ідей І.Є. Овсинського про безвідвальний обробіток ґрунту, а також їх складний шлях утвердження до сьогодення. Його учні та послідовники продовжили і розвинули це вчення, значно доповнили та удосконалили. Ще наприкінці ХІХ ст. І.Є. Овсинський далекоглядно запропонував не просто нову систему обробітку ґрунту, а систему землеробства, яку сьогодні б назвали самовідновлюваним органічним землеробством. Ці ідеї так чи інакше зустрічаються у системах обробітку ґрунту по всьому світу.В статье на основании историко-научного анализа показано бессмертное значение идей И.Е. Овсинского о безотвальной обработке почвы, а также их сложный путь утверждения до сегодняшнего дня. Его ученики и последователи продолжили и развили это учение, значительно его дополнив и усовершенствовав. Еще в конце ХІХ в. И.Е. Овсинский предложил не просто новую систему обработки почвы, а систему земледеия, которую сегодня бы назвали самовосстанавливающимся органическим земледелием. Эти идеи так или иначе встречаются в системах обработки почвы по всему миру.In the article on the basis of historical and scientific analysis shows immortal value of ideas I.E. Ovsinsky of moldboard tillage, and their difficult path to approval today. His learned and followers continued and developed this theory, it is much updated and improved. In the late nineteenth century. I.E. Ovsinsky offered not just a new system of tillage, and the system of agriculture, which today would be called a resettable organic farming. These ideas are somehow found in soil treatment systems in the whole world

Giant optical anisotropy in a single InAs quantum dot in a very dilute quantum-dot ensemble

We present the experimental evidence of giant optical anisotropy in single InAs quantum dots. Polarization-resolved photoluminescence spectroscopy reveals a linear polarization ratio with huge fluctuations, from one quantum dot to another, in sign and in magnitude with absolute values up to 82%. Systematic measurements on hundreds of quantum dots coming from two different laboratories demonstrate that the giant optical anisotropy is an intrinsic feature of dilute quantum-dot arrays.Comment: submitted to Applied Physics Letter

Cohomological aspects on complex and symplectic manifolds

We discuss how quantitative cohomological informations could provide qualitative properties on complex and symplectic manifolds. In particular we focus on the Bott-Chern and the Aeppli cohomology groups in both cases, since they represent useful tools in studying non K\"ahler geometry. We give an overview on the comparisons among the dimensions of the cohomology groups that can be defined and we show how we reach the $\partial\overline\partial$-lemma in complex geometry and the Hard-Lefschetz condition in symplectic geometry. For more details we refer to [6] and [29].Comment: The present paper is a proceeding written on the occasion of the "INdAM Meeting Complex and Symplectic Geometry" held in Cortona. It is going to be published on the "Springer INdAM Series

HOX gene complement and expression in the planarian Schmidtea mediterranea

Abstract Background Freshwater planarians are well known for their regenerative abilities. Less well known is how planarians maintain spatial patterning in long-lived adult animals or how they re-pattern tissues during regeneration. HOX genes are good candidates to regulate planarian spatial patterning, yet the full complement or genomic clustering of planarian HOX genes has not yet been described, primarily because only a few have been detectable by in situ hybridization, and none have given morphological phenotypes when knocked down by RNAi. Results Because the planarian Schmidtea mediterranea (S. mediterranea) is unsegmented, appendage less, and morphologically simple, it has been proposed that it may have a simplified HOX gene complement. Here, we argue against this hypothesis and show that S. mediterranea has a total of 13 HOX genes, which represent homologs to all major axial categories, and can be detected by whole-mount in situ hybridization using a highly sensitive method. In addition, we show that planarian HOX genes do not cluster in the genome, yet 5/13 have retained aspects of axially restricted expression. Finally, we confirm HOX gene axial expression by RNA deep-sequencing 6 anterior–posterior “zones” of the animal, which we provide as a dataset to the community to discover other axially restricted transcripts. Conclusions Freshwater planarians have an unappreciated HOX gene complexity, with all major axial categories represented. However, we conclude based on adult expression patterns that planarians have a derived body plan and their asexual lifestyle may have allowed for large changes in HOX expression from the last common ancestor between arthropods, flatworms, and vertebrates. Using our in situ method and axial zone RNAseq data, it should be possible to further understand the pathways that pattern the anterior–posterior axis of adult planarians

Webs of Lagrangian Tori in Projective Symplectic Manifolds

For a Lagrangian torus A in a simply-connected projective symplectic manifold M, we prove that M has a hypersurface disjoint from a deformation of A. This implies that a Lagrangian torus in a compact hyperk\"ahler manifold is a fiber of an almost holomorphic Lagrangian fibration, giving an affirmative answer to a question of Beauville's. Our proof employs two different tools: the theory of action-angle variables for algebraically completely integrable Hamiltonian systems and Wielandt's theory of subnormal subgroups.Comment: 18 pages, minor latex problem fixe

Introduction to Arithmetic Mirror Symmetry

We describe how to find period integrals and Picard-Fuchs differential equations for certain one-parameter families of Calabi-Yau manifolds. These families can be seen as varieties over a finite field, in which case we show in an explicit example that the number of points of a generic element can be given in terms of p-adic period integrals. We also discuss several approaches to finding zeta functions of mirror manifolds and their factorizations. These notes are based on lectures given at the Fields Institute during the thematic program on Calabi-Yau Varieties: Arithmetic, Geometry, and Physics

Applying Machine Learning to Catalogue Matching in Astrophysics

We present the results of applying automated machine learning techniques to the problem of matching different object catalogues in astrophysics. In this study we take two partially matched catalogues where one of the two catalogues has a large positional uncertainty. The two catalogues we used here were taken from the HI Parkes All Sky Survey (HIPASS), and SuperCOSMOS optical survey. Previous work had matched 44% (1887 objects) of HIPASS to the SuperCOSMOS catalogue. A supervised learning algorithm was then applied to construct a model of the matched portion of our catalogue. Validation of the model shows that we achieved a good classification performance (99.12% correct). Applying this model, to the unmatched portion of the catalogue found 1209 new matches. This increases the catalogue size from 1887 matched objects to 3096. The combination of these procedures yields a catalogue that is 72% matched.Comment: 8 Pages, 5 Figure

Geometric invariant theory of syzygies, with applications to moduli spaces

We define syzygy points of projective schemes, and introduce a program of studying their GIT stability. Then we describe two cases where we have managed to make some progress in this program, that of polarized K3 surfaces of odd genus, and of genus six canonical curves. Applications of our results include effectivity statements for divisor classes on the moduli space of odd genus K3 surfaces, and a new construction in the Hassett-Keel program for the moduli space of genus six curves.Comment: v1: 23 pages, submitted to the Proceedings of the Abel Symposium 2017, v2: final version, corrects a sign error and resulting divisor class calculations on the moduli space of K3 surfaces in Section 5, other minor changes, In: Christophersen J., Ranestad K. (eds) Geometry of Moduli. Abelsymposium 2017. Abel Symposia, vol 14. Springer, Cha