Semithin and in particular ultrathin sections of the glandular subdivisions in the oviduct of the terrestrial egg laying, direct developing plethodontid salamanders Bolitoglossa pesruba and Oedipina uniformis revealed remarkable structural differences of secretory products between the two species and in B. pesrubra between the different subdivisions of the duct. In the latter species structure of the secretory granules confirmed the previously described histological differentiation of the glandular portion of the oviduct in four subdivisions. In the first subdivision most secretory granules were moderately electron-dense having a distinct osmiophilic core, in the second these cores are absent, in the third granules revealed a complex inner structure and in the fourth they are more or less homogeneous and electron dense. In O. uniformis, however, secretory granules were differently stained in semithin sections with toluidine blue, but showed a homogeneous moderately electron-dense appearance along the entire oviduct. As oviductal secretions form the generally multi-layered glycoproteinaceous egg jelly enveloping the ovum when passing down the oviduct, our results suggest that in terrestrial breeders considerable differences exist in these secretions even at the structural level and, therefore, very likely in number and nature of egg jelly layers.
Integration between magnetic and gravity data at the Zelten platform, the southeast part of Sirt Basin Libya. Zelten Platform is first discovered oil field in Libya. It shows numerous geological structures of different tectonic events. The methods adopted can assist in locating the hidden subsurface structures. The platform is characterized by the NW-SE trending rift that belongs to the Early Cretaceous age (during the collapse of Sirt Arch). The study aimed to define the structural geology that assisted in the development of future exploration in this area. The analyses utilized several filtering and transformation algorithms to help in structural modeling. For instance, the total horizontal gradient and tilt angle derivative were applied for the edge detection of the tectonic boundaries. The results show NW-SE and NNW-SSE patterns that represents faults that controlled the positions of the troughs and platforms at the Sirt basin. On the other hand, Euler deconvolution and 2D forward modeling were utilized to determine the depth of the basement. The Integrated models deduced revealed that the main faults trends are NW-SE which refer to the rift phases and crustal extension period that occurred during the Mesozoic time (early cretaceous). Also, the basement depth ranges from 6.5 km to 8 km according to the structures that affected the study area., Abdelhakim Eshanibli, Amin Khalil, Abdellatif Younis and Hussin Ghanoush., and Obsahuje bibliografii
In this paper a novel method is proposed for the structural identifiability analysis of nonlinear time delayed systems. It is assumed that all the nonlinearities are analytic functions and the time delays are constant. We consider the joint structural identifiability of models with respect to the ordinary system parameters and time delays by including delays into a unified parameter set. We employ the Volterra series representation of nonlinear dynamical systems and make use of the frequency domain representations of the Volterra kernels, i. e. the Generalized Frequency Response Functions (GFRFs), in order to test the unique computability of the parameters. The advantage of representing nonlinear systems with their GFRFs is that in the frequency domain representation the time delay parameters appear explicitly in the exponents of complex exponential functions from which they can be easily extracted. Since the GFRFs can be symmetrized to be unique, they provide us with an exhaustive summary of the underlying model structure. We use the GFRFs to derive equations for testing structural identifiability. Unique solution of the composed equations with respect to the parameters provides sufficient conditions for structural identifiability. Our method is illustrated on non-linear dynamical system models of different degrees of non-linearities and multiple time delayed terms. Since Volterra series representation can be applied for input-output models, it is also shown that after differential algebraic elimination of unobserved state variables, the proposed method can be suitable for identifiability analysis of a more general class of non-linear time delayed state space models.
Carnap’s reinvention of the Ramsey-sentence approach to scientific theories has been at the center of a new debate in recent years. Following Grover Maxwell, Psillos (2000a) argued that Carnap’s re-invention of the Ramsey-sentence had failed to lead to the desired neutral stance in the realism-instrumentalism debate, and ended, instead, to a form of structural realism which happened to be liable to Newman’s objection to Russell’s version of structural realism. The objection held that without putting suitable restrictions on the range of the variables of the Ramsey-sentence, a Ramsey-sentence approach to theories renders trivial and a priori true all ontological commitments to unobservable entities issued by scientific theories. By arguing that Carnap achieved the neutral stance, Friedman (2011) counter Psillos claim. He denied that any form of realism could be attributed to Carnap. In this paper, I provide a middle ground, where an unorthodox form of structural realism could be attributed to Carnap. I highlight parts of Carnap’s work which deal with the problem of designation of abstract terms and the relation of the language to the facts of the matter (in Carnap 1934; 1950; 1966), to argue that it was Carnap’s view about the practical methodological considerations, being at work in the construction (or choice) of the linguistic systems, which led him to the unorthodox form of structural realism. I also claim that the same practical considerations constitute the nub of a viable Carnapian answer to Newman’s objection., Carnapovo znovuobjevení Ramseyova přístupu k vědeckým teoriím bylo v posledních letech v centru nové debaty. Následovat Grovera Maxwella, Psillos (2000a) dohadoval se o tom Carnap re-vynález Ramsey-věta nedokázala vést k žádoucímu neutrálnímu postoji v realismu-instrumentalism debata, a končil, místo toho, k formě strukturálního realismu, který náhodou byl. náchylný k Newmanově námitce proti Russellově verzi strukturálního realismu. Námitka tvrdila, že bez toho, aby se omezovaly rozsah proměnných Ramseyovy věty, Ramseyův přístup k teoriím činí triviální a a priori pravdivé všechny ontologické závazky vůči nepozorovatelným entitám vydávaným vědeckými teoriemi. Argumentovat, že Carnap dosáhl neutrálního postoje, Friedman (2011) počítadlo Psillos požadavek. On popřel, že nějaká forma realismu mohla být připsána Carnapovi. V tomto příspěvku uvádím střední půdu, kde by mohla být Carnapovi připisována neortodoxní forma strukturálního realismu. Zdůrazňuji části Carnapovy práce, které se zabývají problémem označování abstraktních pojmů a vztahu jazyka ke skutečnostem této věci (v Carnap 1934; 1950; 1966), argumentovat, že to byl Carnapův názor na praktické metodologické úvahy , být v práci v konstrukci (nebo výběr) lingvistických systémů, který vedl jej k neortodoxní formě strukturálního realismu. Také tvrdím, že tytéž praktické úvahy představují podstatu životaschopné karnapské odpovědi na Newmanovu námitku. kde Carnap mohl připisovat neortodoxní formu strukturálního realismu. Zdůrazňuji části Carnapovy práce, které se zabývají problémem označování abstraktních pojmů a vztahu jazyka ke skutečnostem této věci (v Carnap 1934; 1950; 1966), argumentovat, že to byl Carnapův názor na praktické metodologické úvahy , být v práci v konstrukci (nebo výběr) lingvistických systémů, který vedl jej k neortodoxní formě strukturálního realismu. Také tvrdím, že tytéž praktické úvahy představují podstatu životaschopné karnapské odpovědi na Newmanovu námitku. kde Carnap mohl připisovat neortodoxní formu strukturálního realismu. Zdůrazňuji části Carnapovy práce, které se zabývají problémem označování abstraktních pojmů a vztahu jazyka ke skutečnostem této věci (v Carnap 1934; 1950; 1966), argumentovat, že to byl Carnapův názor na praktické metodologické úvahy , být v práci v konstrukci (nebo výběr) lingvistických systémů, který vedl jej k neortodoxní formě strukturálního realismu. Také tvrdím, že tytéž praktické úvahy představují podstatu životaschopné karnapské odpovědi na Newmanovu námitku. argumentovat, že to bylo Carnap pohled na praktické metodologické úvahy, bytí v práci ve stavbě (nebo volba) lingvistických systémů, který vedl jej k neortodoxní formě strukturálního realismu. Také tvrdím, že tytéž praktické úvahy představují podstatu životaschopné karnapské odpovědi na Newmanovu námitku. argumentovat, že to bylo Carnap pohled na praktické metodologické úvahy, bytí v práci ve stavbě (nebo volba) lingvistických systémů, který vedl jej k neortodoxní formě strukturálního realismu. Také tvrdím, že tytéž praktické úvahy představují podstatu životaschopné karnapské odpovědi na Newmanovu námitku., and Maji Davoody Beni
The structural reorganization of pea thylakoid systems in response to osmotic shock in a wide range of temperatures (36-70°C) was studied. At temperatures 40-46°C, the configuration of thylakoid systems changed from a flattened to a nearly round, whereas thylakoids themselves remained compressed. The percentage of thylakoids stacked into grana at 44°C decreased from 71 % in the control to 40 % in experimental samples, reaching 59 % at 48°C. At 44°C and above, thylakoid systems ceased to respond to the osmotic shock by disordering, in contrast to what happened at lower temperatures (36-43°C) and in the control, and retained the configuration inherent in thylakoid systems at these temperatures. At 50°C and above, the packing of thylakoids in grana systems changed, and thylakoids formed extended strands of pseudograna. Simultaneously, single thylakoids formed a network of anastomoses through local fusions. At temperatures of 60-70°C, thylakoid systems appeared as spherical clusters of membrane vesicles with different degree of separation.
Logistic Regression (LR) has become a widely used and accepted method to analyze binary or multiclass outcome variables, since it is a flexible tool that can predict probability for the state of a dichotomous variable. A recently proposed LR method is based on the hybridization of a linear model and Evolutionary Product Unit Neural Network (EPUNN) models for binary classification. This produces a high number of coefficients, so two different methods for simplifying the structure of the final model by reducing the number of initial or PU covariates are presented in this paper, both being based on the Wald test. The first method is a Backtracking Backward Search (BBS) method, and the other is similar, but it is based on the standard Simulated Annealing process for the decision steps (SABBS). In this study, we used aerial imagery taken in mid-May to evaluate the potential of two different combinations of LR and EPUNN (LR using PUs (LRPU), as well as LR using Initial covariates and PUs (LRIPU)) and the two presented methods of structural simplification of the final models (BBS and SABBS) used for discriminating Ridolfia segetum patches (one of the most dominant, competitive and persistent weed in sunflower crops) in a naturally infested field of southern Spain. Then, we compared the performance of these methods to six commonly used classification algorithms; our proposals obtaining a competitive performance and a lower number of coefficients.
In this paper, we have attempted to give a general framework (from bifurcation theory point of view) for understanding the structural stability and bifurcation behavior in following phase synchronized systems: (a) coupled Poincare systems; (b) controlled linear oscillator and (c) ‘predator-prey’ system, on the base of a specifíc version of bifurcational theory (based on the computing first Lyapunov value (not exponent)). Our results suggest that for these three systems soft stability loss take place. and Obsahuje seznam literatury
Th e approach of structuralism came to philosophy from social science. It was also in social science where, in 1950–1970s, in the form of the French structuralism, the approach gained its widest recognition. Since then, however, the approach fell out of favour in social science. Recently, structuralism is gaining currency in the philosophy of mathematics. Aft er ascertai ning that the two structuralisms indeed share a common core, the question stands whether general structuralism could not fi nd its way back into social science. Th e nature of the major objections raised against French structuralism – concerning its alleged ahistoricism, methodological holism and universalism – are reconsidered. While admittedly grounded as far as French structuralism is concerned, these objections do not aff ect general structuralism as such. Th e fate of French structuralism thus does not seem to preclude the return of general structuralism into social science, rather, it provides some hints where the diffi culties may lie. and Strukturalismus přišel do fi losofi e ze společenských věd. Byly to také společenské vědy kde, v letech 1950–1970 v podobě Francouzského strukturalismu, získal strukturalismus nejširší uznání. Od té doby však jeho popularita ve společenských vědách opadla. V nedávné době však začal strukturalismus nabývat na popularitě ve fi losofi i matematiky. Ukazuje se, že tyto dvě formy strukturalismu mají na obecné úrovni mnoho společného. Otázkou pak je, zda neexistuje možnost, aby se obecně chápaný strukturalismus navrátil do společenských věd. Hlavní námitky proti Francouzskému strukturalismu – jeho ahistorismus, metodologický holismus a universalismus – jsou opětovně uváženy. Ačkoliv jsou námitky relevantní, pokud jde o Francouzský strukturalismus, nejedná se o námitky proti obecnému strukturalismu jako takovému. Osud Francouzského strukturalismu se tak nezdá být překážkou pro případný návrat obecného strukturalismu do společenských věd, spíše poskytuje postřehy, kde by se mohly vyskytnout největší obtíže.