Discontinuous respiration in diapausing pupae of Cecropia silkworms was monitored by means of several electronic methods, including recording changes in haemocoelic pressure, monitoring respiratory movements by strain-gauge sensors and nanorespirographic recording of O2 consumption and CO2 output. It appears that, in contrast to previous concepts of stereotypic discontinuous respiration cycles (DGC) driven by accumulation of gaseous CO2 in the body, the new results indicate that CO2 remains dissolved in liquid carbonate buffers during interburst periods. In other words, there is no accumulation of gaseous CO2 within the air filled tracheal space between the bursts. The bursts of CO2 are caused by homeostatically regulated enzymatic hydration by carbonic anhydrase of metabolically produced carbonic acid. The chemically produced gaseous CO2 was exhaled mainly by a bulk outflow through selectively opened or pulsating spiracles. The output of CO2 was enhanced by actively regulated, unidirectional ventilation. The deep depressions in haemocoelic pressure, caused by permanent closure of all spiracular valves for long periods, appeared to be a specific feature of diapausing saturniid pupae. Physiologically, it has circulatory, not respiratory functions. The original definition of spiracular "fluttering" resulted from a misinterpretation of previously unknown extracardiac pulsations in haemocoelic pressure. The coordinated pulsation of the spiracular valves with extracardiac pulsations produce a very efficient, unidirectional ventilation of the whole tracheal system. According to the new results, the discontinuous respiration cycles of diapausing Cecropia pupae can be briefly described as follows: (1) Spiracular valves are kept permanently closed during the periods of deep depressions, they remain closed for some 99% of the time with occasional snap opening (passive inspirations) during prolonged interburst periods and more than 50% closed during the bursts; (2) During the long interburst periods, CO2 is retained in liquid carbonate buffers, while the relatively high (after the burst) or low (toward the next burst) rate of O2 consumption creates an internal vacuum, which is homeostatically compensated for by the snap-opening of one or just a few spiracular valves (passive suction inspirations); (3) The CO2 gas, produced enzymatically by carbonic anhydrase, enters the air filled tracheal system and leaves the body by diffusion, a bulk outflow, or actively regulated unidirectional ventilation ("fluttering" spiracles). The selective advantage of this actively regulated respiratory system for water retention in pupae is discussed.
A close relationship between the class of totally positive matrices and anti-Monge matrices is used for suggesting a new direction for investigating totally positive matrices. Some questions are posed and a partial answer in the case of Vandermonde-like matrices is given., Miroslav Fiedler., and Obsahuje seznam literatury
Transcellular trafficking in which various molecules are
transported across the interior of a cell, is commonly classified as
transcytosis. However, historically this term has been used
synonymously with transudation. In both cases transcellular
trafficking starts with the internalization of proteins or other
compounds on the basal or basolateral side of a cell and
continues by their transport across the interior to the apical pole
(or vice versa) where they are subsequently released. This allows
a cell to release products which are synthesized elsewhere. Here,
we discuss the common features of both transcytosis and
transudation, and that which differentiates them. It appears that
transcytosis and transudation are identical in terms of vesicular
import and endosomal sorting of cargo, but completely differ in
the re-secretion process. Specialized epithelial cells re-release
substantial quantities of the endocytosed material, and often also
a great variety. Some recent studies indicate that this is achieved
by non-canonical apocrine secretion rather than by the regular
vesicular mechanism of exocytosis, and takes place only on the
apical pole. This massive re-release of endocytosed proteins, and
potentially other compounds via the apocrine mechanism should
be considered as transudation, distinct from transcytosis.
Combinatorial optimization is a discipline of decision making in the case of diserete alternatives. The Genetic Neighborhood Search (GNS) is a hybrid method for these combinatorial optimization problems. The main feature of the approach is iterative use of local search on extended neighborhoods, where the better solution will be the center of a new extended neighborhood. When the center of the neighborhood would be t.he better solution the algorithm will stop. We propose using a genetic algorithm to exi)lore the extended neighborhoods. This GA is characterized by the method of evaluating the fitness of individuals and useing two new operators. Computational experience with the Symmetric TSP shows that this approach is robust with respect to the starting point and that high quality solutions are obtained in a reasonable time.
The use of phytoseiid species in biological plant protection is widespread. However, the techniques used to release them differ. The possible release of Amblyseius andersoni (Chant, 1959) using a new method was tested. High numbers of this mite overwinter in the ground litter in Hungarian orchards. By transferring such ground litter to plots in young orchards, the population density was found to be significantly increased in the release compared to control plots; A. andersoni became the dominant phytoseiid species in the new orchard. Due to the rate at which it spreads, this species was also recorded in the control plots towards the end of the growing season (Aug., Sept.), at which time there was no significant difference in the numbers of this species in the treated and control plots. In the winter following release, A. andersoni was found in the ground litter of the orchard., Árpád Szabó, Béla Pénzes., and Obsahuje seznam literatury
The new family Juraperlidae is erected for the new genus and species Juraperla daohugouensis from the Chinese Middle Jurassic. Its wing venation has strong similarities with that of Mesozoic taxa currently included in the group "Grylloblattodea", but its character "three (or four?)-segmented tarsi" questions its potential inclusion into the same order with the modern Grylloblattodea. This suggests that the systematic assignments of several fossil "grylloblattid" species, mainly based on wing venation, could be very different.
A new mite species Schizocoptes daberti sp. n. (Acariformes: Chirodiscidae) from Chrysochloris stuhlmanni Matsche (Afrosoricida: Chrysochloridae) from the Democratic Republic of the Congo is described. It differs from the closely related species S. conjugatus Lawrence, 1944 in both sexes by distance si-si at least twice longer than si-se (vs these distances are subequal in S. conjugatus); in females by setae cp 30-40 µm long (vs about 65 µm long), and in males by the very weakly sclerotised posterior parts of the hysteronotal shield (vs strongly sclerotised), setae d1 situated anterior to the hysteronotal shield (vs at the hysteronotal shield), and by opened coxal fields III (vs closed). An amended generic diagnosis, including description of immature stages, and a key to named species of Schizocoptes Lawrence, 1944 are provided., Andre V. Bochkov., and Obsahuje bibliografii
The multilayer perceptron model has been suggested as an alternative to conventional approaches, and can accurately forecast time series. Additionally, several novel artificial neural network models have been proposed as alternatives to the multilayer perceptron model, which have used (for example) the generalized- mean, geometric mean, and multiplicative neuron models. Although all of these artificial neural network models can produce successful forecasts, their aggregation functions mean that they are negatively affected by outliers. In this study, we propose a new multilayer, feed forward neural network model, which is a robust model that uses the trimmed mean neuron model. Its aggregation function does not depend on outliers. We trained this multilayer, feed forward neural network using modied particle swarm optimization. We applied the proposed method to three well-known time series, and our results suggest that it produces superior forecasts when compared with similar methods.
Neural networks have shown good results for detecting a certain pattern in a given image. In this paper, faster neural networks for pattern detection are presented. Such processors are designed based on cross correlation in the frequency domain between the input matrix and the input weights of neural networks. This approach is developed to reduce the computation steps required by these faster neural networks for the searching process. The principle of divide and conquer strategy is applied through matrix decomposition. Each matrix is divided into submatrices small in size, and then each one is tested separately by using a single faster neural processor. Furthermore, faster pattern detection is obtained by using parallel processing techniques to test the resulting submatrices at the same time, employing the same number of faster neural networks. In contrast to faster neural networks, the speed-up ratio is increased with the size of the input matrix when using faster neural networks and matrix decomposition. Moreover, the problem of local submatrix normalization in the frequency domain is solved. The effect of matrix normalization on the speed-up ratio of pattern detection is discussed. Simulation results show that local submatrix normalization through weight normalization is faster than submatrix normalization in the spatial domain. The overall speed-up ratio of the detection process is increased as the normalization of weights is done offline.
A new model for propagation of long waves including the coastal area is introduced. This model considers only the motion of the surface of the sea under the condition of preservation of mass and the sea floor is inserted into the model as an obstacle to the motion. Thus we obtain a constrained hyperbolic free-boundary problem which is then solved numerically by a minimizing method called {\em the discrete Morse semi-flow}. The results of the computation in 1D show the adequacy of the proposed model.