Suppose that A is a real symmetric matrix of order n. Denote by m_{A}(0) the nullity of A. For a nonempty subset α of {1, 2,..., n}, let A(α) be the principal submatrix of A obtained from A by deleting the rows and columns indexed by α. When m_{A(\alpha )}(0) = m_{A}(0)+|α|, we call α a P-set of A. It is known that every P-set of A contains at most \left \lfloor n/2 \right \rfloorelements. The graphs of even order for which one can find a matrix attaining this bound are now completely characterized. However, the odd case turned out to be more difficult to tackle. As a first step to the full characterization of these graphs of odd order, we establish some conditions for such graphs G under which there is a real symmetric matrix A whose graph is G and contains a P-set of size (n − 1)/2., Zhibin Du, Carlos M. da Fonseca., and Obsahuje seznam literatury
Although research to date has helped in important ways to shed light on the penetration of Burke’s Enquiry into the German-language area, a comprehensive treatment of this reception as a process distinguished not only by changes over time, but also characterized by regional variations, remains lacking. Based on the lectures on aesthetics by August Gottlieb Meißner (1753–1807) at Prague University in the late eighteenth and early nineteenth centuries, the paper seeks to illuminate this underexposed regional aspect. The first phase of the reception of the Enquiry took place especially in Berlin immediately after its publication in London in 1757. The second phase can be located mainly in the northern maritime centres of German culture, particularly Königsberg, Riga, Hamburg as well as Copenhagen. Christian Garve’s translation, published anonymously by Hartknoch in Riga in 1773, and Kant’s Critique of Judgement (1790) constitute two peaks of north-German interest in Burke’s Enquiry. The intense reception of the Critique of Judgement within German aesthetics around and after 1800 subsequently led to the polemic with the British author becoming a part of Idealist interpretations for the next few decades. Outlining the three centres (and the three corresponding phases) of the German reception of Burke’s Enquiry begs the question which of them should be connected with Meißner’s remarks concerning Burke’s ideas. Leipzig is presented as another important German-language centre disseminating knowledge of Burke’s Enquiry, especially in the first half of the Seventies, moreover the decisive intermediary for the penetration of the Enquiry into the south-German Roman Catholic areas, Prague in particular.
Arthur Prior’s logic was influenced, among others, by logicians from the Lvov-Warsaw school. This paper introduces the impact Leśniewski’s Ontology had on Prior’s logical system. The paper describes the main characteristics of Leśniewski’s Ontology, Prior’s logical system and the manner in which Prior became acquainted with Leśniewski’s logical system. Since Leśniewski was no longer alive when Prior began to develop his logical system and Leśniewski’s papers were not easily available to Prior, this paper also includes Prior’s interpretation of Leśniewski’s logical system which did not always correspond to Leśniewski’s original ideas., Logika Arthura Priora byla ovlivněna mimo jiné i logiky ze školy ve Lvově-Varšavě. Tento článek představuje dopad Leśniewského ontologie na logický systém Prior. Článek popisuje hlavní charakteristiky Leśniewského ontologie, logického systému Prior a způsob, jakým se Prior seznámil s Leśniewského logickým systémem. Vzhledem k tomu, že Leśniewski už nebyl naživu, když Prior začal rozvíjet svůj logický systém a Leśniewskiho dokumenty nebyly Prioritě snadno dostupné, tento dokument zahrnuje také Prorovu interpretaci Leśniewského logického systému, který ne vždy odpovídal Leśniewského původním myšlenkám., and Zuzana Rybaříková
Ornithologists in Finland recorded the autumn migration of the Red Admiral butterfly, Vanessa atalanta (L.). In the best year, 1998, 1240 migrants were counted from a bird tower in September. That is, half a million butterflies migrated over a 100-km front. The butterflies were flying above forests riding on cool northerly winds. Radar indicated that a large proportion migrated at high elevations outside the visible range. These records help to resolve an "evolutionary puzzle" of why migrant butterflies and moths travel to northern latitudes when their offspring have limited possibilities of returning south. Until now, the only butterfly for which a high-elevation return migration on northerly winds is known is the American Monarch Danaus plexippus (L.).
Social magazines contributed to a great extent to the image of South Slavs which was formed in the consciousness of Czech society in the second half of the 19th century. The period after the fall of neo-absolutism (1860), accompanied by relaxation of political rigour, meant a new stage in the development of Czech national life. Czech periodicals of social character come into existence together with the above mentioned development of national life; they were to replace German papers in bourgeoisie circles. They included e.g. Besedy lidu, Čas, Květy, Obzor, Osvěta, Světozor and Zlatá Praha. Slavic subject matter played an important part in the profile of the individual periodicals. The image of South Slavs, which social periodicals in the Czech society were creating by means of fiction, travel stories, historical and ethnographic scientific literature and, last but not least, by means of illustrations production and reproduction of works of visual artists, was in the spirit of Slavic mutual cooperation. Armed conflicts for the sake of gaining national independence, which create the icon of the South Slav as a fearless fighter for freedom, won the heart of the public. Analogously, archaic autochthonous manifestations the Czech society lacked are sought in the folk culture of South Slavs. Czech society thus created a largely idealized and romantic image of the life and culture of South Slavs, into which it projected its own ideals and desires.
In this paper I defend the rejection of fatalism about the past by showing that there are possible circumstances in which it would be rational to attempt to bring about by our decisions and actions a necessary and sufficient condition, other things being equal, for something which we see as favorable to have occurred in the past. The examples I put forward are analogous to our attempts to bring about the occurrence of future events, and demonstrate the symmetry between the past and the future in this respect., V tomto příspěvku hájím odmítnutí fatalismu o minulosti tím, že dokazuji, že existují možné okolnosti, za kterých by bylo rozumné pokusit se o naše rozhodnutí a činy učinit nezbytnou a dostatečnou podmínkou, jiné věci jsou rovnocenné, za něco, co jsme v minulosti bylo příznivé. Příklady, které jsem předložil, jsou analogické s našimi pokusy o nastolení budoucích událostí a v tomto ohledu ukazují symetrii mezi minulostí a budoucností., and Gal Yehezkel
The relations between the patterns of discontinuous gas exchange cycles (DGCs) and water loss were investigated in non-chilled diapausing pupae of the white cabbage butterfly Pieris brassicae kept at room temperature (22-24°C) in Petri dishes. An electrolytic respirometer, combined with an infrared (IR) actographic device was used for the simultaneous recordings of metabolic rate, cyclic release of carbon dioxide (bursts), passive suction inspirations (PSIs) and body movements. The patterns of cyclic gas exchange in four- and five-month-old non-chilled diapausing pupae varied individually to a considerable extent. About 40% of the pupae displayed long DGCs lasting 1-3 h, while the interburst periods were characterised by rare and almost regular large PSIs succeeding at intervals of 1-4 min. Nearly 30% of the pupae exhibited short DGCs lasting 3-5 min, while between the bursts there occurred unclear frequent gas exchange microcycles. Standard metabolic rate (SMR) did not reveal significant differences between long DGCs and short DGCs ranging from 32-56 (mean 47.6 ± 4.6) ml O2 g-1 h-1, and 28-61 (mean 44.95 ± 5.3) ml O2 g-1 h-1, respectively. The mentioned levels of SMR were characteristic of diapausing pupae.
Water loss in pupae with long DGCs was determined gravimetrically to be 0.29 ± 0.1 mg g-1 day1. At the same time, water loss in pupae that showed only short DGCs and irregular microcycles was 1.73 ± 0.31 mg g-1 day-1, which was significantly higher than in individuals characterised by long DGCs. We suggest that water loss in the non-chilled diapausing pupae may depend significantly on the patterns of cyclic gas exchange: long cycles and rare but deep PSIs exerted a marked water conserving effect.
Cíl práce: Lipoperoxidace je dávána do příčinné souvislosti s rozvojem nejdůležitějších rizikových faktorů kardiovaskulárních onemocnění. Lipoperoxidační procesy jsou důsledkem reakcí lipidů s volnými radikály bez ohledu na jejich původ. Vztah mezi triacylglyceroly (TAG) a volnými radikály (VR) není zcela jasný. Může se dokonce stát, že hypertriacylglycerolémie je doprovázena nízkými koncentracemi VR a naopak. Jedno z možných vysvětlení spočívá ve vztahu lipoperoxidace a složení mastných kyselin v molekulách TAG. Cílem této studie bylo analyzovat vztah složení mastných kyselin v TAG a produkci VR u pacientů trpících diabetes mellitus 2. typu. Typ studie: observační s kontrolní skupinou Materiál a metody: Studie zahrnovala 18 normotriacylglycerolemických (NTG) jedinců (M/F 12/6) a 24 hypertriacylglycerolemických (HTG) jedinců (M/F 16/8). Pacienti v obou skupinách byli diabetici 2. typu. Analýzu mastných kyselin v triacylglycerolech plazmy jsme provedli kapilární plynovou chromatografií a koncentrace volných radikálů byly změřeny přímou spektrofotometrií. Statistické analýzy (parametrické i neparametrické) byly provedeny pomocí statistického software STATISTICA pro Windows. Výsledky: Ve skupině HTG jsme pozorovali nižší zastoupení kyseliny myristové (14:0) (1.62 [1.23-2.07] vs. 1.90 [1.72-2.79], p = 0.022, [medián (1.-3. kvartil]) a vyšší poměr alfa-linolenové kyseliny (18:3n-3) (1.51 [1.21-1.86] vs 1.16 [1.02-1.42], p = 0.021). Poměr kyselin arachidonové/eikosapentaenové byl ve skupině HTG nižší (5.54 [3.62-7.98] vs 7.25 [5.98-15.12], p = 0.027). Když jsme HTG skupinu dále rozdělili podle koncentrací VR na tercily, prokázali jsme nižší hodnoty poměru kyseliny arachidonová/eikosapentaenová ve druhém tercilu (4.05 [2.66-4.67] vs 7.64 [5.83-11.00], 1. tercil, a 6.21 [3.20-8.31], 3. tercil p = 0.019). V spojených HTG+NTG skupinách jsme zaznamenali negativní korelaci mezi MA a TAG (r = -0.3153, p = 0.045). V triaclylglycerolech jsme prokázali pozitivní korelace VR a kyseliny stearové (p < 0.001) spolu s negativní korelací některých n-6 vícenenasycených mastných kyselin (18:3n-6, p < 0.05, 22:5n-6, p < 0.01). Závěr: Zastoupení mastných kyselin v molekulách TAG je spojeno s tvorbou VR. Nicméně do tohoto vztahu vstupují i jiné faktory., Objective: The lipoperoxidation plays a causal role in the development of most important risk factors of cardiovascular disease. The lipoperoxidation results from the reaction of lipid molecules with free radicals, regardless of their origin. The relationship between triacylglycerols (TAG) and the free radicals (FR) amount is not clear. Thus, it can turn up that the hypertriacylglyceridaemia is accompanied with the low values of FR, or vice versa. One possible explanation of this phenomenon is that the degree of lipoperoxidation of TAG is dependent on the composition of fatty acids (FA) in their molecule. Therefore, the aim of this study was to analyze FA composition in TAG and its relationship to FR production in type 2 diabetes mellitus. Design: observational study with internal control group Material and Methods: 18 normotriacylglycerolemic (NTG) individuals (12M/6F) and 24 hypertriacylglycerolemic (HTG) patients (16M/8F). Patients in both groups were persons, suffering from type 2 diabetes mellitus. Fatty acid analysis of plasma triacylglycerols was performed by gas chromatography and free radicals were determined by direct spectrophotometric method. Statistical analyses (both parametric and non-parametric) were performed with the statistical software STATISTICA for Windows. Results: We found lower content of myristic acid (14:0) (1.62 [1.23-2.07] vs. 1.90 [1.72-2.79], p = 0.022, [median (1st-3rd quartile)]) and higher content of alpha-linolenic acid (18:3n-3) (1.51 [1.21-1.86] vs. 1.16 [1.02-1.42], p = 0.021) in HTG group. The ratio of arachidonic/eicosapentaenoic acid was in HTG group lower (5.54 [3.62-7.98] vs. 7.25 [5.98-15.12], p = 0.027). When the HTG group was stratified into the tertiles by the FR concentrations, we observed lower values in the second tertile for ratios based on arachidonic acid (20:4n-6) and eicosapentaenoic acid (20:5n-3) (4.05 [2.66-4.67] vs. 7.64 [5.83-11.00], 1st tertile, and 6.21 [3.20-8.31], 3rd tertile, p = 0.019). In pooled groups, we proved negative correlation between MA and TAG (r = -0.3153, p = 0.045) and the link between FR and FA composition of TAG expressed as positive relationship of FR with content of stearic acid (p < 0.001) and negative correlation with some n-6 polyunsaturated fatty acids (18:3n-6, p < 0.05, 22:5n-6, p < 0.01). Conclusion: The composition of FA in TAG molecules has undoubtedly some relationship to the FR generation. However, the other factors seem to play a role, since the relationship is not straightforward within entire FR range., and Vecka M., Tvrzická E., Votruba M.
Objectives. The present study investigated the relative importance of multiple aspects of personal resiliency for the development of externalising and internalising adjustment problems in adolescence. Subjects and setting. The sample comprised 805 adolescents (45.2% boys and 54.8% girls) from seven high schools in Kraljevo, Serbia. The mean age of the adolescents was 16.71 (SD = 1.05; range 15-18 years). The participants filled out questionnaires concerning their personal resiliency and adjustment problems during school hours. Hypotheses. It was hypothesised that sense of mastery and sense of relatedness would be negatively associated with adjustment problems, whereas emotional reactivity would be positively related to externalising and internalising problems. Statistical analyses. Descriptive statistics and correlational and regression analyses were used. Results. The findings indicated that lower levels of sense of mastery and sense of relatedness and higher levels of emotional reactivity were related to antisocial behaviour, anger control problems, emotional distress and negative sense of self. Personal resiliency accounted for a significant amount of the variance (21-37%) in all types of adjustment problems. Further analyses revealed unique relationships between separate qualities of personal resilience and each type of adjustment problem. Study limitations. The present study is limited to one cultural setting and age group. The results were based on cross-sectional and self-reported data., Cíle. Studie zkoumá relativní důležitost aspektů osobní resilience pro vývoj externalizování a internalizování při vyrovnávání se s problémy v adolescenci. Soubor. Soubor zahrnoval 805 adolescentů (45,2 % chlapců a 54,8 % děvčat) ze sedmi středních škol v Kraljevu v Srbsku. Průměrný věk adolescentů byl 16,71 (směrodatná odchylka 1,05, rozpětí 15 až 18 let). Účastníci vyplnili dotazníky zjišťující jejich osobní resilienci a vyrovnávání se s problémy během školních hodin. Hypotézy. Autoři předpokládali, že úroveň dovedností a úroveň vztahů budou negativně asociovány s vyrovnáváním se s problémy, zatímco emoční reaktivita bude v pozitivním vztahu k externalizování a internalizování problémů. Statistická analýza. Byly použity metody deskriptivní statistiky a korelační a regresní analýza. Výsledky. Nižší úroveň dovedností a nižší úroveň vztahů a vyšší úroveň emoční reaktivity jsou ve vztahu k antisociálnímu chování, problémy se zvládáním hněvu, emočním distresem a negativním sebepojetím. Osobní resilience vysvětlila značnou část variance (21-37 %) ve všech typech problémů. Další analýzy ukázaly jedinečné vztahy mezi jednotlivými složkami osobní resilience a všemi typy problémů. Omezení studie. Studie je omezena danou kulturou a věkovou skupinou. Výsledky jsou založeny na transverzální metodě a datech ze subjektivních výpovědí., Vesna Žunić-Pavlović [et al.]., and Obsahuje seznam literatury