43 research outputs found
The combinatorics of -fixed points in generalized Calogero-Moser spaces and Hilbert schemes
In this paper we study the combinatorial consequences of the relationship between rational Cherednik algebras of type , cyclic quiver varieties and Hilbert schemes. We classify and explicitly construct -fixed points in cyclic quiver varieties and calculate the corresponding characters of tautological bundles. Furthermore, we give a combinatorial description of the bijections between -fixed points induced by the Etingof-Ginzburg isomorphism and Nakajima reflection functors. We apply our results to obtain a new proof as well as a generalization of the -hook formula
An almost full embedding of the category of graphs into the category of abelian groups
We construct an embedding G of the category of graphs into the category of
abelian groups such that for graphs X and Y we have Hom(GX,GY)=Z[Hom(X,Y)], the
free abelian group whose basis is the set Hom(X,Y). The isomorphism is
functorial in X and Y. The existence of such an embedding implies that,
contrary to a common belief, the category of abelian groups is as complex and
comprehensive as any other concrete category. We use this embedding to settle
an old problem of Isbell whether every full subcategory of the category of
abelian groups, which is closed under limits, is reflective. A positive answer
turns out to be equivalent to weak Vopenka's principle, a large cardinal axiom
which is not provable but believed to be consistent with standard set theory.
Several known constructions in the category of abelian groups are obtained as
quick applications of the embedding. In the revised version we add some
consequences to the Hovey-Palmieri-Stricland problem about existence of
arbitrary localizations in a stable homotopy categoryComment: 20 page
An "almost" full embedding of the category of graphs into the category of groups
We construct a functor from the category of graphs to the category of groups
which is faithful and "almost" full, in the sense that it induces bijections of
the Hom sets up to trivial homomorphisms and conjugation in the category of
groups.
We provide several applications of this construction to localizations (i.e.
idempotent functors) in the category of groups and the homotopy category.Comment: 24 pages; to appear in Adv. Math
Obozowisko łowieckie ludności kultury świderskiej na stanowisku Sulejówek 4, pow. miński, woj. mazowieckie
The paper presents results of an analysis of the assemblage of flint artefacts from the site no. 6 in Sulejówek, Mazovian Voivodeship. The main attention was focused on technological and typological observations. Based on the obtained results, these materials were interpreted as a remnant of a medium-sized hunting camp of the Swiderian community. An important feature of the inventory is the extremely high proportion of relics made of chocolate flint, which was imported from about 150 km.The paper presents results of an analysis of the assemblage of flint artefacts from the site no. 6 in Sulejówek, Mazovian Voivodeship. The main attention was focused on technological and typological observations. Based on the obtained results, these materials were interpreted as a remnant of a medium-sized hunting camp of the Swiderian community. An important feature of the inventory is the extremely high proportion of relics made of chocolate flint, which was imported from about 150 km
Znaczenie dziedzictwa kulturowego I Rzeczypospolitej dla integracji Europy Środkowej i Wschodniej z Zachodem
Rozprawa doktorska na temat znaczenia dziedzictwa kulturowego I Rzeczypospolitej dla integracji Europy Środkowej i Wschodniej z Zachodem.The importance of cultural heritage of the First Commonwealth for the integration between Central and Eastern Europe and the Wes
Podlesie, Site 6 – the First Obsidian Inventory of the Linear Pottery Culture Communities from the Połaniec Basin
The article includes the presentation and preliminary characterisation of the obsidian inventory obtained during the five research seasons (2014–2018) at the site in Podlesie, Staszów district, Świętokrzyskie voievodship. Currently, it is one of the largest collections of artefacts of this raw material related to the Linear Pottery culture (104 examples), and at the same time the first obtained from the Połaniec Basin mesoregion. In the light of the current state of research, it is also one of the few inventories of this culture (outside the Rzeszów settlement cluster), in which the share of obsidian exceeded 4%. Its homogeneous nature and large size, as well as the obtained radiocarbon dates, to a very significant extent supplement the current knowledge about the initial phase of the Neolithic obsidian influx into the Upper Vistula basin area, at the end of the 6th millennium BC
Between East and West. Flint assembblage of the linear pottery culture societies from site 6 in Podlesie, świętokrzyskie oivodeship
Paper presents results of analysis of the assemblage of flint artefacts from the settlement of Linear Pottery culture (LBK) at the site no. 6 in Podlesie, Świętokrzyskie voivodeship. Importance of the site is primarily by its location: on the border of two geographical regions, two geological conditions, two settlement eccentrics of the LBK and two provinces of lithic raw materials. Within the flint assemblage we can distinguish two main classes of lithical artefacts: an internally cohesive collection of 104 obsidian products and a collection of 2069 artefacts made of at least five different types of flint. In the group of siliceous rocks, the most numerous is the Jurassic flint from Cracow area – 53%. Second place in the inventory is occupied by the Światchowski flint, which share reaches the level of 19%. Only slightly smaller are amounts of chocolate flint – 15%.Paper presents results of analysis of the assemblage of flint artefacts from the settlement of Linear Pottery culture (LBK) at the site no. 6 in Podlesie, Świętokrzyskie voivodeship. Importance of the site is primarily by its location: on the border of two geographical regions, two geological conditions, two settlement eccentrics of the LBK and two provinces of lithic raw materials. Within the flint assemblage we can distinguish two main classes of lithical artefacts: an internally cohesive collection of 104 obsidian products and a collection of 2069 artefacts made of at least five different types of flint. In the group of siliceous rocks, the most numerous is the Jurassic flint from Cracow area – 53%. Second place in the inventory is occupied by the Światchowski flint, which share reaches the level of 19%. Only slightly smaller are amounts of chocolate flint – 15%
Can malignant and inflammatory pleural effusions in dogs be distinguished using computed tomography
Computed tomography (CT) is the primary imaging modality used to investigate human patients with suspected malignant or inflammatory pleural effusion, but there is a lack of information about the clinical use of this test in dogs. To identify CT signs that could be used to distinguish pleural malignant neoplasia from pleuritis, a retrospective case‐control study was done based on dogs that had pleural effusion, pre‐ and postcontrast thoracic CT images, and cytological or histopathological diagnosis of malignant or inflammatory pleural effusion. There were 20 dogs with malignant pleural effusion (13 mesothelioma, 6 carcinoma; 1 lymphoma), and 32 dogs with pleuritis (18 pyothorax; 14 chylothorax). Compared to dogs with pleuritis, dogs with malignant pleural effusions were significantly older (median 8.5 years vs. 4.9 years, P = 0.001), more frequently had CT signs of pleural thickening (65% vs.34%, P = 0.05), tended to have thickening of the parietal pleura only (45% vs. 3%, P = 0.002) and had more marked pleural thickening (median 3 mm vs. 0 mm, P = 0.03). Computed tomography signs of thoracic wall invasion were observed only in dogs with malignant pleural effusions (P = 0.05). There were no significant differences in pleural fluid volume, distribution or attenuation, degree of pleural contrast accumulation, amount of pannus, or prevalence of mediastinal adenopathy. Although there was considerable overlap in findings in dogs with malignant pleural effusion and pleuritis, marked thickening affecting the parietal pleural alone and signs of thoracic wall invasion on CT support diagnosis of pleural malignant neoplasia, and may help prioritize further diagnostic testing