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2. Application of infrared spectroscopy and chemometric methods to identification of selected minerals
- Creator:
- Ritz, Michal, Lenka Vaculíková, and Eva Plevová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, minerály, diskriminační analýza, minerals, discriminant analysis, identification, IR spectroscopy, principal component analysis, 7, and 551
- Language:
- English
- Description:
- A new way of identification of minerals was suggested. The identification was based on chemometric analysis of measured IR spectra of selected minerals. IR spectra were collected using diffuse reflectance technique. The discriminant analysis and principal component analysis were used as chemometric methods. Five statistical models were created for separation and identification of clay minerals. Up to 60 samples of various mineral standards (clay minerals, feldspars, carbonates, sulphates and quartz) from different localities were selected for the creation of statistical models. The results of this study confirm that the discriminant analysis of IR spectra of minerals could provide a powerful tool for mineral identification. Even differentiation of muscovite from illite and identification of mixed structures of illite-smectite were achieved., Michal Ritz, Lenka Vaculíková and Eva Plevová., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Carex muricata aggregate in the Czech Republic
- Creator:
- Řepka, Radomír
- Type:
- article and TEXT
- Subject:
- Cyperaceae, discriminant analysis, numerical taxonomy, and principal components analysis
- Language:
- English
- Description:
- Morphological variation of Carex muricata from 232 localities in the Czech Republicwas analysed. The plants were preliminarily classified using qualitative characters into six species: C. contigua, C. muricata, C. pairae, C. chabertii, C. divulsa, and C. leersiana. Of 27 quantitative characters, all were used in a principal components analysis and 25 in a discriminant analysis. Both analyses were done using the data for all the species and then separately for the taxonomically complicated species pairs. In the discriminant analysis, the most useful characters for separating particular species were selected; they included the distance between the first and second lowermost spike of the infructescence, infructescence length, glume length in pistillate flower, achene length, length of perigynium beak and spike size. In the classification discriminant analysis, with the six most important characters, 94.4% of plants were correctly classified to the designated groups. The analysis showed that some species pairs (C. muricata – C. pairae, C. chabertii – C. leersiana) are only partially distinguished by quantitative morphological characters. Some other species (C. contigua, C. divulsa), however, are well differentiated and easily identified.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/
4. Comparison of discriminant analysis and probabilistic expert system in VCG data classification
- Creator:
- Valová, D., Drška, Z., Polánková, M., and Málková, A.
- Type:
- article, model:article, and TEXT
- Subject:
- probabilistic expert system, discriminant analysis, vectorcardiogram, and ischaemic heart disease
- Language:
- English
- Description:
- Our previous studies (Valová et al. 1992) have dealt with the possibilities of expert system utilization for electrocardiologic data interpretation. The results obtained in these studies provided evidence that the selected probabilistic expert system is suitable for the solution of VCG data interpretation problems. The aim of this paper was to compare the results obtained by stepwise discriminant analysis with that obtained by a probabilistic expert system. These classification methods were applied to VCG data measured by Frank's lead system. Five groups of patients were investigated: 76 healthy subjects, 36 patients with angina pectoris, 112 patients with old posterior myocardial infarction, 107 patients with old anterior myocardial infarction and 35 patients with old anteroseptal myocardial infarction. The classification was carried out by the leaving-one-out technique. Results of the classification obtained in five groups by a probabilistic expert system are evidently better than those obtained by stepwise discriminant analysis.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5. elusive Juncus minutulus: a failure to separate tetra- and hexaploid individuals of the Juncus bufonius complex in a morphometric comparison of cytometrically defined groups
- Creator:
- Rooks, Frederick, Jarolímová, Vlasta, Záveská Drábková, Lenka, and Kirschner, Jan
- Type:
- article and TEXT
- Subject:
- chromosomes, discriminant analysis, flow cytometry, Juncus bufonius, J. minutulus, morphometrics, and polyploidy
- Language:
- English
- Description:
- Screening of nuclear genome size was carried out on ca 2400 plants from over 120 mainly Central- European localities of the Juncus bufonius group. Besides the diploid level, corresponding to known diploid species (in this case J. ranarius, J. hybridus and J. sorrentini), two polyploid cytotypes were detected, conforming with the tetraploid and hexaploid levels treated by some authors as separate species: J. minutulus and J. bufonius s. str. The relationship between nuclear DNA content and the number of chromosomes was verified by chromosome counting. Polyploidy, as opposed to agmatoploidy can, therefore, account for the karyological variation. The 2C values of diploid, tetraploid and hexaploid individuals were ca 0.65, 1.18±2.8% and 1.84±1.6% pg 2C DNA, respectively. No other cytotype or statistically significant variation in nuclear genome size was found. To asses the utility of hitherto published morphological characters distinguishing J. minutulus from J. bufonius s. str., measurements of seven floral and three vegetative quantitative characters were obtained (no less than 10 measurements per flower, 30 per plant) for 358 mature plants of known ploidy level from 47 localities. Diverse ordination and clustering techniques did not indicate the presence of any grouping in the dataset. Canonical discriminant analysis and stepwise variable selection indicated that inner tepal length followed by mean capsule width and mean capsule length were the most useful characters for identifying the two ploidy levels; however, the estimated 10-fold cross-validation error rate of a simple k nearest neighbour classification analysis was 0.45. Other analyses corroborated this result. No new morphological character that would allow successful separation of tetraploids from hexaploids was discovered. This provides independent support for the opinion of some previous authors that J. bufonius L. is best treated as a single variable species comprising two cytotypes that are inseparable using hitherto suggested diagnostic characters until convincing proof to the contrary is available.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/
6. Invalidity of three Palaearctic species of Triaenophorus tapeworms (Cestoda: Pseudophyllidea): evidence from morphometric analysis of scolex hooks
- Creator:
- Kuchta, Roman, Vlčková, Romana, Poddubnaya, Larisa G., Gustinelli, Andrea, Dzika, Ewa, and Scholz, Tomáš
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Cestoda, Triaenophorus, scolex hooks, biometry, descriptive statistics, discriminant analysis, and taxonomy
- Language:
- English
- Description:
- A comparative study of the scolex hook morphology of five species of tapeworms of the genus Triaenophorus Rudolphi, 1793 (Cestoda: Pseudophyllidea), parasites of pikes (Esox lucius L. and E. reichertii Dybowski) in the Palaearctic Region, was carried out. Measurements of scolex hooks of 81 plerocercoids and 492 adults from different hosts and regions were compared using basic statistics and forward stepwise linear discriminant analysis. The shape of the scolex and that of tridental hooks were found to be suitable only for differentiation of the taxa with a similar shape of hooks, i.e. Triaenophorus nodulosus (Pallas, 1781) from T. amurensis Kuperman, 1968, and T. crassus Forel, 1868 from T. meridionalis Kuperman, 1968 and T. orientalis Kuperman, 1968, respectively. In contrast, discriminant analysis did not enable reliable separation of specimens of individual taxa of these two morphological groups due to high intraspecific variability and overlaps between species. This was reflected in low classification efficiencies (average 83%) of all species of the T. crassus group, whereas all T. amurensis specimens were misidentified as T. nodulosus. The new data also considerably enlarge (up to twofold) the size range of the species described by Kuperman in 1968, which invalidates suitability of the most important discriminant characteristic, the width of the basal plate, for delimitation of Triaenophorus species. Based on the present data, all Kuperman's taxa are considered to represent only distinct geographical populations of T. nodulosus and T. crassus. As a result, T. amurensis is synonymized with T. nodulosus, whereas T. orientalis is considered to be a synonym of T. crassus. Previous synonymisation of T. meridionalis with T. crassus, first proposed by Dubinina (1987), is also accepted.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
7. Zhodnocení možností odhadu pohlaví autorů paleolitických nástěnných maleb z otisků ruky
- Creator:
- Mik, Patrik, Sosna, Daniel, and Galeta, Patrik
- Type:
- article, model:article, and TEXT
- Subject:
- otisky rukou, odhad pohlaví, paleolit, nástěnné umění, klasifikační funkce, diskriminační analýza, handprints, estimation of sex, Palaeolithic, parietal art, classification functions, and discriminant analysis
- Language:
- Czech
- Description:
- Ačkoliv jsou za autory paleolitického nástěnného umění tradičně považováni muži, otisky rukou, které se v kontextu maleb vyskytují, patří podle většiny recentních studií ženám. Překvapivé výsledky vyvolaly v posledních letech mezi archeology, biologickými a socio-kulturními antropology mezioborovou diskusi, která přesahuje až k chápání rolí mužů a žen v paleolitických společnostech. Cílem této studie je ukázat, že všechny dosavadní studie zabývající se odhadem pohlaví paleolitických otisků jsou metodologicky problematické a neumožňují spolehlivě určit, zda jsou autory otisků muži nebo ženy. Pohlaví paleolitických otisků bylo ve studiích odhadováno na základě morfologických standardů současných populací, které byly chybně aplikovány na paleolitickou populaci s odlišnou morfologií. V textu dále navrhujeme metodologicky vhodnější způsob odhadu pohlaví autorů paleolitických otisků a diskutujeme, do jaké míry je v danou chvíli navrhovaný postup prakticky využitelný. and Even though Palaeolithic cave painters are traditionally regarded as being male, the majority of recent studies have shown that the handprints that occur in the context of paintings belong to women. These surprising results have in recent years given rise to multi-disciplinary discussions among archaeologists, biologists and socio-cultural anthropologists, reaching a better understanding of the role of men and women in Palaeolithic societies. The aim of this study is to demonstrate that all studies to date that focus on the estimation of the sex of cave painters based on handprints are methodologically problematic and do not allow for the reliable estimation of sex. The sex of Palaeolithic painters was revealed in studies on the basis of morphological norms of today’s populations, which were erroneously applied to the Palaeolithic population bearing a different morphology. In the text, the authors propose a methodology more suitable for estimating the sex of Palaeolithic painters based on handprints, and discuss the level to which the proposed procedure is practical in the given moment.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public