We present the results of the first study on the karyotypes of four European species of Roncus: Roncus alpinus L. Koch, 1873, Roncus lubricus L. Koch, 1873, Roncus transsilvanicus Beier, 1928 and Roncus sp. The diploid number was 2n = 23 in Roncus sp., 2n = 43 in R. alpinus and R. transsilvanicus and 2n = 45 in R. lubricus. Telocentric autosomes predominate in species with a high chromosome number and metacentric autosomes in Roncus sp. We assume that the ancestral situation for this genus is a high number of chromosomes. A low number of chromosomes is very likely a consequence of centric fusions, which have possibly played a very important role in karyotype evolution in the genus Roncus. All the species analyzed have the X0 sex chromosome system. The X chromosome is metacentric and is the smallest element in the karyotypes of all the species analyzed., František Šťáhlavský, Jana Christophoryova, Hans Henderickx., and Obsahuje seznam literatury
The karyotypes of pseudoscorpions of three families, Geogarypidae, Garypinidae and Olpiidae (Arachnida: Pseudoscorpiones), were studied for the first time. Three species of the genus Geogarypus from the family Geogarypidae and 10 species belonging to 8 genera from the family Olpiidae were studied. In the genus Geogarypus the diploid chromosome numbers of males range from 15 to 23. In the family Olpiidae the male chromosome numbers vary greatly, from 7 to 23. The male karyotype of single studied member of the family Garypinidae, Garypinus dimidiatus, is composed of 33 chromosomes. It is proposed that the karyotype evolution of the families Geogarypidae and Olpiidae was characterised by a substantial decrease of chromosome numbers. The diploid numbers of some olpiids are the lowest known 2n within pseudoscorpions and even one of the lowest within the class Arachnida. In spite of a considerable reduction of diploid numbers, all species studied possess a X0 sex chromosome system that is widespread and probably ancestral in pseudoscorpions. Moreover, X chromosomes retain conservative metacentric morphology in the majority of species. During the first meiotic division of males, a high number of chiasmata were observed in some species, up to five per bivalent in Indolpium sp. The transient stage between pachytene and diplotene is typically characterised by extensive decondensation of chromatin in males of geogarypids and in Calocheiridius libanoticus, and we interpret this as a diffuse stage. This is recorded in pseudoscorpions for the first time. The relationships between some species belonging to the family Olpiidae are discussed based on the data obtained.
A key to genera of South American Deltocephalini Dallas, 1870 based on adult males is presented. Two new genera, each based on a single new species from Argentina are described and illustrated: Corrientesia gen. n. based on type species C. ochrescens sp. n. and Salnogia gen. n. based on type species S. fletcheri sp. n. A new species of Graminella DeLong, 1936, G. schrocki sp. n. from Argentina is also described and illustrated. Graminella stelliger (Berg, 1884) equals Fusanus acristylus Cheng, 1980, syn. n. A new combination, Limpica pallida (Linnavuori & DeLong, 1979) comb. n., transferred from Reventazonia Linnavuori, 1959, is also proposed. Quaziptus Kramer, 1965, is returned from Paralimnini Distant, 1908 to Deltocephalini Dallas, 1870., Yani Duan, Christopher H. Dietrich., and Obsahuje bibliografii
In this paper, an expert system that performs route planning using dynamic traffic data is introduced. Also an algorithmic approach is introduced to find the shortest path in a three-dimensional. Using both implementations, a comparison is made between the expert system approach and the algorithmic approach. It is concluded that the expert system shows great potential. The expert system indeed finds the best routes, and it outperforms the algorithm approach in computation time, too.
This paper presents a Komlós theorem that extends to the case of the set-valued Henstock-Kurzweil-Pettis integral a result obtained by Balder and Hess (in the integrably bounded case) and also a result of Hess and Ziat (in the Pettis integrability setting). As applications, a solution to a best approximation problem is given, weak compactness results are deduced and, finally, an existence theorem for an integral inclusion involving the Henstock-Kurzweil-Pettis set-valued integral is obtained.
Using the concept of $\mathcal {I}$-convergence we provide a Korovkin type approximation theorem by means of positive linear operators defined on an appropriate weighted space given with any interval of the real line. We also study rates of convergence by means of the modulus of continuity and the elements of the Lipschitz class.
Functioning of plant-aphid-natural enemy interactions may be associated with the structure and composition of withinfield vegetation, neighborhood fields and field borders, and the regional plant community of cropped and noncropped areas. Farmand region-scale vegetation in the wheat-growing area of the North American Great Plains was hypothesized to effect the abundance of two hymenopteran parasitoids, that differ in physiological and behavioral attributes, of the key pest aphid of wheat, Diuraphis noxia (Mordvilko). The parasitoids had greater sensitivity to farm-scale vegetation (wheat strip rotation with or without spring-sown sunflower) than region-scale vegetation (degree of diversification with other crops and wheat fields converted to conservation grasslands). A two-way factorial design of scale (farm- and region-scale) revealed that parasitoid abundance in grass-dominant (homogeneous) areas especially benefited from adding sunflower to the wheat-fallow strip crop rotation. Considerable sensitivity of the analysis was added when adjusting for seasonality of vegetation, revealing that the region-scale effects were most prominent late season. From a management viewpoint, adding sunflower into the wheat production system, especially in relatively homogeneous vegetation regions, tends to promote local parasitoid populations during the summer when spring-sown plants are maturing and wheat is not in cultivation. Contrasting results for A. albipodus and L. testaceipes were consistent with expectations based on behavioral and physiological attributes of the two aphid parasitoid families they represent. Still, the general management interpretation seems robust for the two parasitoids and has relevance to both farm- and region-scale management schemes that are occurring in the wheat production zone of North American Great Plains.