Text categorization is based on the idea of content-based texts clustering. An Artificial Neural Network (ANN) or simply Neural Network (NN) classifier for Arabic texts categorization is proposed. The Singular Value Decomposition (SVD) is used as preprocessor with the aim of further reducing data in terms of both size and dimensionality. Indeed, the use of SVD makes data more amenable to classification and the convergence training process faster. Specifically, the effectiveness of the Multilayer Perceptron (MLP) and the Radial Basis Function (RBF) classifiers are implemented. Experiments are conducted using an in-house corpus of Arabic texts. Precision, recall and F-measure are used to quantify categorization effectiveness. The results show that the proposed SVD-Supported MLP/RBF ANN classifier is able to achieve high effectiveness. Experimental results also show that the MLP classifier outperforms the RBF classifier and that the SVD-supported NN classifier is better than the basic NN, as far as Arabic text categorization is concerned.
Closely related species can be used for studying the ecological significance of their traits. The response in terms of survival, clonal growth and vegetative and generative characteristics of three related Myosotis species to competition and soil characteristics were studied in a three year pot experiment. Plants from four populations per species were cultivated in a factorial combination of substrate (nutrient-rich soil and mixtures with sand) and competition (with or without Holcus lanatus) treatments. Survival, clonal growth and the majority of the growth characteristics of all three Myosotis species were reduced by competition. The effect of substrate was less pronounced, and variable for various traits: the soil with sand mixture was more suitable for survival, clonal growth and seed germination whereas in the nutrient-rich soil plants were taller, but this effect was modified by competition. The differences among species corresponded well to expectation based on their known habitat preferences. Myosotis caespitosa, a species typical of short-term habitats such as emerged bottoms of ponds, exhibited the shortest life span and was also the most sensitive to competition: all plants of this species died in the competition treatment before the end of the second season. Nevertheless, the surviving plants (in the no-competition treatment) were able to form several daughter rosettes or stolons; some of them spread clonally till the third year. Myosotis palustris subsp. laxiflora, which inhabits the banks of rivers and brooks often disturbed by torrential floods, survived best and had the highest potential for clonal growth and spreading. Most plants of this species produced rhizomes and stolons and spread the furthest of all the three species. Myosotis nemorosa, which lives mostly in meadows, the most stable habitat of the studied congeners, but also a habitat with a strongly competitive matrix of species, was intermediate in terms of survival, and clonal growth, forming mainly short rhizomes. This species exhibited the highest among-population variability in all recorded characteristics, which might be due to its local adaptation to a wide spectrum of habitats. We argue that the details of prevailing disturbance regime, rather than some general disturbance intensity explain the clonal behaviour of the species compared.
The definition of the performance parameters, especially accuracy, reliability, dependability are presented. Their estimations are developed by using results from the theory of statistical tolerance intervals in the case of random sample from a normal distribution. The proposed approach is illustrated on two examples.
Cíl práce: Upozornit na problematiku apendicitidy v graviditě. Typ práce: kazuistika. Vlastní pozorování: Formou kazuistiky prezentovaný výskyt perforované apendicitidy s difuzní peritonitidou ve 27. týdnu gravidity. Následný porod císařským řezem ve 36. týdnu a komplikované pooperační období a infekční komplikace v šestinedělí. Závěr: Apendicitida v těhotenství je spojována se zvýšenou mateřskou a fetální morbiditou. Perforace apendixu přispívá ke zvýšenému riziku dalších komplikací, které zahrnují např. předčasný porod, abort a mateřské komplikace, zejména infekční. Včasná diagnóza s následnou operací může snížit mateřskou i fetální morbiditu., Objective: To draw attention to the issue of appendicitis in pregnancy. Design: Case report. Case report: We present a case study in the form of a case of occurrence of appendicitis with peritonitis in 27 weeks pregnancy. And describes the birth and childbed, which is complicated by infectious complications. Conslusion: Appendicitis in pregnancy is associated with increased maternal and fetal morbidity and even more in case of peritonitis. Delay surgical intervention correlates with increased risk of perforation, which contributes to the increase of other complications, including premature birth, abortion and maternal complications. Prompt diagnosis and early surgery can reduce maternal and fetal morbidity., and Renáta Hlistová
The purpose of the present study was to define the indirect central effect of hydrogen sulfide (H2S) on baroreflex control of sympathetic outflow. Perfusing the isolated carotid sinus with sodium hydrosulfide (NaHS), a H2S donor, the effect of H2S was measured by recording changes of renal sympathetic nerve activity (RSNA) in anesthetized male rats. Perfusion of isolated carotid sinus with NaHS (25, 50, 100 μmol/l) dose and timedependently inhibited sympathetic outflow. Preconditioning of glibenclamide (20 μmol/l), a ATP-sensitive K+ channels (KATP) blocker, the above effect of NaHS was removed. With 1, 4-dihydro-2, 6-dimethyl-5-nitro-4-(2-[trifluoromethyl] phenyl) pyridine-3-carboxylic acid methyl ester (Bay K8644, 500 nmol/l) pretreatment, which is an agonist of L-calcium channels, the effect of NaHS was eliminated. Perfusion of cystathionine γ-lyase (CSE) inhibitor, DL-propargylglycine (PPG, 200 μmol/l), increased sympathetic outflow. The results show that exogenous H2S in the carotid sinus inhibits sympathetic outflow. The effect of H2S is attributed to opening KATP channels and closing the L-calcium channels., Qi Guo, Yuming Wu, Hongmei Xue, Lin Xiao, Shneg Jin, Ru Wang., and Obsahuje bibliografii
Limited information is available about selection of the threshold for arterial blood pressure in critically ill patients, particularly in sepsis when normal organ blood flow autoregulation may be altered. The present experimental study investigated whether increasing perfusion pressure using norepinephrine in normotensive hyperdynamic porcine bacteremia affects intestinal macro- and microcirculation. Nine pigs received continuous i.v. administration of Pseudomonas aeruginosa (PSAE) to develop hyperdynamic, normotensive (mean arterial pressure [MAP] 65 mm Hg) sepsis. Norepinephrine was used to achieve 10-15 % increase in MAP. Mesenteric arterial blood flow (Qgut), ileal mucosal microvascular perfusion (LDFgut) and ileal-end-tidal PCO2 gap (PCO2 gap) were measured before norepinephrine, after 60 min of norepinephrine infusion and 60 min after norepinephrine infusion had been discontinued. During a 12 h period of PSAE infusion all pigs developed hyperdynamic circulation with significantly decreased MAP. Although the mesenteric blood flow remained unchanged, infusion of PSAE resulted in a gradual fall of ileal microvascular perfusion, which was associated with progressively rising PCO2 gap. Norepinephrine which induced a 10-15 % increase in perfusion pressure (i.e. titrated to attain near baseline values of MAP) affected neither Qgut nor the intestinal blood flow distribution (Qgut/CO). Similarly, norepinephrine did not change either LDFgut or PCO2 gap. In this hyperdynamic, normotensive porcine bacteremia, norepinephrine-induced increase in perfusion pressure exhibited neither beneficial nor deleterious effects on intestinal macrocirculatory blood flow and ileal mucosal microcirculation. The lack of changes suggests that the gut perfusion was within its autoregulatory range.
Pergolide, terguride and N,N'-spacer-linked oligomers of both have been tested for their ability to interact with 5 hydroxytryptamine(HT)2A receptors of rat tail artery. Pergolide was a potent partial agonist (pEC50 7.5, Emax 55 %) and antagonized 5-HT-induced contractions (pKP 7.2). Pergolide dimer 3 with a p-xylene spacer between the indole nitrogens (N-1) displayed somewhat lower agonist potency than pergolide (pEC50 7.0, Emax 55 %, pKP 6.6). The contractile responses to pergolide and dimer 3 were antagonized by the 5-HT2A receptor antagonist ketanserin (pA2 9.4, 9.1). In contrast to pergolide dimer 3, pergolide dimers 5 and 9 with an alkyl and an aralkyl spacer between the piperidine nitrogens (N-6) lacked agonism and displayed low affinity at 5-HT2A receptors (pA2 < 5.5). Terguride behaved as an insurmountable antagonist of 5-HT (pA2 8.4). Oligomers of terguride showed 5 to 50-fold lower affinity. It is concluded that pergolide and terguride show a high affinity for 5-HT2A receptors, but dimerization (oligomerization) of both drugs fails to increase affinity.
Alzheimerova choroba (ACH) se řadí mezi závažná neurodegenerativní onemocnění provázená oxidačním stresem. Produkty radikálových reakcí mohou difundovat z primárních míst a být detekovány v cerebrospinální tekutině (CSF) či krvi. Tyto produkty představují potenciální biochemické markery pro diagnostiku ACH. Nejvíce pozornosti je zaměřeno na analýzu CSF, protože odráží patologické změny v mozkové tkáni u ACH. V CSF byly potvrzeny zvýšené hladiny oxidačních produktů lipidů i proteinů. Hladiny vitaminů jsou snížené, nicméně existují i práce, které nenašly rozdíly oproti kontrolám. Některé studie se zaměřily na detekci produktů oxidačního stresu v krvi u ACH, ale výsledky nejsou konzistentní. Část prací ukazuje na nárůst oxidačních produktů a snížené hladiny antioxidantů v plazmě. Nicméně jiné práce tyto výsledky nepotvrdily. Z hlediska hledání diagnostického biomarkeru pro ACH má význam se zaměřit na specifické produkty peroxidace lipidů, tzv. lipofuscinoidní pigmenty (LFP), v erytrocytech. Na základě fluorescenčních analýz LFP je možné najít specifický produkt v krvi u ACH., Alzheimer´s disease (AD) is a serious neurodegenerative disorder accompanied by oxidative stress. Products of free radical reactions diffuse from primary sites and can be detected in cerebrospinal fluid (CSF) and blood. Such products represent potential biochemical markers for diagnosis of AD. Most studies are focused on CSF since its composition reflects pathological changes in the brain in AD. Increased levels of lipid and protein oxidative products have been found in CSF. Levels of vitamins were reduced in CSF. However, there are studies which show no difference between AD and controls. There is research on free radical products in blood in AD but results are not consistent. Several studies show increased oxidative products and reduced antioxidant in plasma. Nevertheless, others did not confirm it. Considering the investigation of a diagnostic biomarker for AD, specific end-products of lipid peroxidation, so called lipofuscin-like pigments (LFP), in erythrocytes represent an important possibility. A specific product in blood in AD can be found by means of fluorescence analyses of LFP., Skoumalová A., and Literatura 35