149 research outputs found

    Half a century after Ionescu’s work on Romanian Diplura – A faunal contribution based on material collected from karst areas

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    The main publication on the Romanian diplurans belongs to M.A. Ionescu who inventoried 22 species mainly from soil and forest litter from 22 collecting points. The further faunal investigation of two caves (Peştera Izvorul Tăuşoarelor and Peştera Movile) allowed Condé to describe other four new taxa, three species and one subspecies. This paper represents the first study at a national level, half century after Ionescu’s contribution. The faunal data presented, were obtained from over 60 sites, most of them karst areas (including caves) unstudied up to the present. As a result, the faunal list of Diplura known in the Romanian fauna has risen to 28 taxa. A new combination: Litocampa montana Sendra n. comb. is argued. For 16 taxa, the local (based on the UTM grid codes) and general distributions and the redescription of some species are given

    A conservation roadmap for the subterranean biome

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    The 15th UN Convention on Biological Diversity (CBD) (COP15) will be held in Kunming, China in October 2021. Historically, CBDs and other multilateral treaties have either alluded to or entirely overlooked the subterranean biome. A multilateral effort to robustly examine, monitor, and incorporate the subterranean biome into future conservation targets will enable the CBD to further improve the ecological effectiveness of protected areas by including groundwater resources, subterranean ecosystem services, and the profoundly endemic subsurface biodiversity. To this end, we proffer a conservation roadmap that embodies five conceptual areas: (1) science gaps and data management needs; (2) anthropogenic stressors; (3) socioeconomic analysis and conflict resolution; (4) environmental education; and (5) national policies and multilateral agreements

    Euro-Mediterranean fauna of Campodeinae (Campodeidae, Diplura)

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    Campodeinae is the most diverse subfamily of Campodeidae diplurans and inhabits soils and subsurface ecosystems. These are distributed in the Palearctic area, clearly rarifying towards northern latitudes. The major taxonomic characters are chaetotaxy, shape and complexity of pretarsal structures, and secondary sexual characters. This monograph provides a taxonomic revision of the subfamily Campodeinae in the Euro-Mediterrnean region, based on extensive literature review and new material studied. It comprises detailed morphological descriptions and illustrations together with habitat and distribution data of 161 species and 14 subspecies from 10 genera: Campodea Westwood, 1842, Edriocampa Silvestri, 1933, Eutrichocampa Silvestri, 1902, Helladocampa Condé, 1984, Libanocampa Condé, 1955, Litocampa Silvestri, 1933, Oreocampa Condé, 1950, Podocampa Silvestri, 1932, Remycampa Condé 1952, and Spaniocampa Silvestri, 1933. With 116 species Campodea is the most diverse and widely distributed genus in the studied area.info:eu-repo/semantics/publishedVersio

    The world’s deepest subterranean community - Krubera-Voronja Cave (Western Caucasus)

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    Subsurface biota extends over a wide variety of habitats that can be spatially interconnected. The largest communities of this subsurface biota inhabit cavities and are well known mainly in caves where biologists are able to have access. Data about deep subterranean communities and arthropods living under one thousand meters was unknown. An expedition to world’s deepest cave, Krubera-Voronja in Western Caucasus, revealed an interesting subterranean community, living below 2000 meters and represented by more than 12 species of arthropods, including several new species for science. This deep cave biota is composed of troglobionts and also epigean species, that can penetrate until -2140 m. Deep subterranean ecosystems should not be seen only as an evolu- tionary dead end towards the troglomorphic syndrome, but also as a shelter for epigean species populations, especially during long periods of time when surface conditions are severe for their survival. Most of the subsurface biota depends on allochthonous sources of organic carbon coming from: water percolating from the surface, sinking streams that enter caves, and activities of animals mov- ing in and out of caves. The biocoenosis and the vertical distribution of invertebrate fauna of Krubera-Voronja are provided, from its entrance to the remarkable depth of 2140 meters, including the discovery of world’s deepest dwelling arthropod

    Representations and geometrical properties of generalized inverses over fields

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    In this paper, as a generalization of Urquhart’s formulas, we present a full description of the sets of inner inverses and (B, C)-inverses over an arbitrary field. In addition, identifying the matrix vector space with an affine space, we analyze geometrical properties of the main generalized inverse sets. We prove that the set of inner inverses, and the set of (B, C)-inverses, form affine subspaces and we study their dimensions. Furthermore, under some hypotheses, we prove that the set of outer inverses is not an affine subspace but it is an affine algebraic variety. We also provide lower and upper bounds for the dimension of the outer inverse set.Agencia Estatal de InvestigaciónUniversidad de Alcal

    Representations and symbolic computation of generalized inverses over fields

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    This paper investigates representations of outer matrix inverses with prescribed range and/or none space in terms of inner inverses. Further, required inner inverses are computed as solutions of appropriate linear matrix equations (LME). In this way, algorithms for computing outer inverses are derived using solutions of appropriately defined LME. Using symbolic solutions to these matrix equations it is possible to derive corresponding algorithms in appropriate computer algebra systems. In addition, we give sufficient conditions to ensure the proper specialization of the presented representations. As a consequence, we derive algorithms to deal with outer inverses with prescribed range and/or none space and with meromorphic functional entries.Agencia Estatal de investigaciónUniversidad de Alcal

    Els tresors desconeguts

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    Invertebrats endèmics valencian

    Conchoidal transform of two plane curves

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    The conchoid of a plane curve CC is constructed using a fixed circle BB in the affine plane. We generalize the classical definition so that we obtain a conchoid from any pair of curves BB and CC in the projective plane. We present two definitions, one purely algebraic through resultants and a more geometric one using an incidence correspondence in \PP^2 \times \PP^2. We prove, among other things, that the conchoid of a generic curve of fixed degree is irreducible, we determine its singularities and give a formula for its degree and genus. In the final section we return to the classical case: for any given curve CC we give a criterion for its conchoid to be irreducible and we give a procedure to determine when a curve is the conchoid of another.Comment: 18 pages Revised version: slight title change, improved exposition, fixed proof of Theorem 5.3 Accepted for publication in Appl. Algebra Eng., Commun. Comput

    On the summability of a class of formal power series

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    The formal power series solutions for some classes of moment differential equations, induced by polynomial moment differential operators, are characterized in terms of their summability properties, and in terms of estimates for recursive expressions involving their coefficients. Of special interest are the particularization of these results to classes of fractional and of ordinary differential equations. The Stokes’ phenomenon can be described in some of these situations. The main results are extended into the framework of q-Gevrey asymptotics and q-difference equations.Agencia Estatal de Investigació
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