Digestive structures in the Middle Ordovician trilobite Prionocheilus Rouault 1847, from the Barrandian area of Czech Republic

Remains of a digestive system from a slightly damaged articulated specimen of the comparatively rare bathycheilid trilobite Prionocheilus vokovicensis (Šnajdr, 1956) are described for the first time. The specimen comes from the Middle Ordovician Šárka Formation of the Prague Basin and contains the midgut region of the digestive system preserved through the axial region of glabella and six anterior thoracic segments. The anterior-most part of the digestive system is unknown as the anterior glabellar lobes are not preserved in the studied specimen. In the cephalic shield, the remains of two pairs of gut diverticulae are seen in the posterior region of the glabella. Remains of five pairs of small cavities developed in the axis of the first six thoracic segments represent the remains of thoracic gut diverticulae. The discussed specimen possess the first undoubted remain of digestive structures established within the family Bathycheilidae (PŘibyl, 1953)

Chemical mistakes in the light of reality - identification and explanation

Tato práce se zabývá rozšířenými misinformacemi a nepravdami s chemickou tematikou. V teoretické části jsou popsány psychologické efekty, které k šíření mýtů vedou, a možnosti vyvracení těchto mýtů. Tato část také popisuje didaktické důvody, které pro středoškolskou práci s misinformacemi existují. Všeobecná praktická část metodami obsahové analýzy na náhodném vzorku Škol- ních vzdělávacích programů prokazuje možnost využití práce s misinformacemi ve vzdělávání. Dále je zde též sestaven přehled organizací a zdrojů užitečných pro vy- vracení mýtů. Specifická praktická část této práce se pak zabývá analýzou vybraných podezře- lých informací, jejich podloženosti a možností didaktického využití. Jde o "léčebné" požívání roztoku oxidu chloričitého, o teorii překyselení organismu a zásadité stravy a o údajnou škodlivost sladidla aspartamu. V podobě, ve které bývají prezentovány, nejsou opodstatněná žádná z těchto tvrzení a ve všech případech bylo nalezeno mezi jejich propagátory množství nepodložených tvrzení.This thesis deals with widespread, chemically-themed misinformation. The the- oretical part describes psychological effects leading to myth spreading. It also descri- bes the debunking possibilities of such myths and the didactic reasons for misinformation- based work on the high school level. General practical part uses methods of content analysis upon random sample of School educational programmes to prove the usability of misinformation-based work in education. It also summarizes the organisations and resources useful for myth debunking. Specific practical part deals with analysis of chosen suspicious information, their credibility and the possibilities of educational work based on them. The chosen in- formation was the "medicinal" usage of chlorine dioxide solution. Rumors of alkaline diet and alleged harmfulness of aspartame, an artificial sweetener, were also chosen. The way they tend to be presented, none of these claims are backed. In all these cases, multiple unsubstantiated claims were found among proponents of these ideas.Katedra učitelství a didaktiky chemieDepartment of teaching and Didactics of ChemistryFaculty of SciencePřírodovědecká fakult

Preparation of 3-phenylpentanoic and 3-phenylpent-2-enoic acid derivatives

Tato bakalářská práce se zabývá přípravou intermediátů analgetika tapentadolu. Zvolená syntetická strategie vyžaduje přípravu vhodných derivátů 3-fenylpentanové a 3-fenylpent-2-enové kyseliny, jejichž syntéza tvoří těžiště této práce. V první části práce je řešena příprava 1-[(3-benzyloxy)fenyl]propan-1-onu, který je potřebným meziproduktem při přípravě v názvu uvedených sloučenin. Na tomto ketonu byly následně studovány adice na karbonylovou skupinu. Druhá část práce se zaměřuje na jednu z těchto adičních reakcí, Reformatského reakci, a zabývá se její optimalizací. Na závěr byly hledány vhodné dehydratace Reformatského aduktů - terciárních alkoholů benzylového typu. Powered by TCPDF (www.tcpdf.org)This Bachelor's thesis deals with preparation of the intermediates of the analgesic tapentadol. The chosen synthetic strategy requires a preparation of appropriate derivatives of 3-phenylpentanoic and 3-phenylpent-2-enoic acid. Synthesis of those derivatives represents the cornerstone of the thesis. In the first part, the thesis describes an effort associated with a preparation of 1-[(3-benzyloxy)phenyl]propan-1-one, a necessary intermediate for the preparation of the titled compounds. Then addition reactions were studied on the aforementioned ketone. The second part of the thesis focuses on one particular addition, a Reformatsky reaction, and deals with further optimization. In addition, the submitted thesis also describes variety of attempts to carry out dehydration of the Reformatsky adducts, namely, benzylic tertiary alcohols. Powered by TCPDF (www.tcpdf.org)Department of Organic ChemistryKatedra organické chemiePřírodovědecká fakultaFaculty of Scienc

Evaluation of data subsystem failure modes

The ALSEP Data Subsystem has been evaluated by an independent contractor to provide added confidence that no allowable sequence of commands can prevent proper operation of the ALSEP System. This report assesses the significance of the failure modes disclosed in this study.prepared by R. Fatka, J. Mansour

An advanced multipole model of the (130) Elektra quadruple system

The Ch-type asteroid (130) Elektra is orbited by three moons, making it the first quadruple system in the main asteroid belt. We aim to characterise the irregular shape of Elektra and construct a complete orbital model of its unique moon system. We applied the All-Data Asteroid Modelling (ADAM) algorithm to 60 light curves of Elektra, including our new measurements, 46 adaptive-optics (AO) images obtained by the VLT/SPHERE and Keck/Nirc2 instruments, and two stellar occultation profiles. For the orbital model, we used an advanced $N$-body integrator, which includes a multipole expansion of the central body (with terms up to the order $\ell = 6$), mutual perturbations, internal tides, as well as the external tide of the Sun acting on the orbits. We fitted the astrometry measured with respect to the central body and also relatively, with respect to the moons themselves. We obtained a revised shape model of Elektra with the volume-equivalent diameter $(201\pm 2)\,{\rm km}$. Out of two pole solutions, $(\lambda, \beta) = (189; -88)\,{\rm deg}$ is preferred, because the other one leads to an incorrect orbital evolution of the moons. We also identified the true orbital period of the third moon S/2014 (130) 2 as $P_2 = (1.642112 \pm 0.000400)\,{\rm d}$, which is in between the other periods, $P_1 \simeq 1.212\,{\rm d}$, $P_3 \simeq 5.300\,{\rm d}$, of S/2014 (130) 1 and S/2003 (130) 1, respectively. The resulting mass of Elektra, $(6.606 \substack{+0.007 \\ -0.013}) \times 10^{18}\,{\rm kg}$, is precisely constrained by all three orbits. Its bulk density is then $(1.536 \pm 0.038)\,{\rm g\,cm}^{-3}$. The expansion with the assumption of homogeneous interior leads to the oblateness $J_2 = -C_{20} \simeq 0.16$. However, the best-fit precession rates indicate a slightly higher value, ${\simeq}\,0.18$.Comment: 19 pages, 23 figure

Révision de la "Tige d'une Cystidée indéterminée" décrite par Barrande (Cambrien, Echinodermata, Eocrinoidea)

Reexamination of the type specimen described by Barrande in 1887 as "Tige d'une Cystidée indéterminée" shows that this unique specimen represents an articulated but incomplete remnant of the gogiid eocrinoid Akadocrinus jani Prokop. The specimen is preserved as an external mould in shale from the mid-Cambrian Jince Formation, and comprises a proximal part of a stem associated with a slightly disarticulated distal portion of a theca, composed of over twenty polygonal plates. With the exception of the basal-most plates, all other preserved thecal plates bear ellipsoidal marginal epispires, and substantiate assignment of this specimen to the epispire-bearing phase in ontogenetic development of Akadocrinus.La réétude du spécimen-type décrit par Barrande en 1887 comme une "tige de Cystidée indéterminée" montre que ce spécimen unique pourrait être attribué à l'espèce d'éocrinoïde gogiidé Akadocrinus jani Prokop. Ce spécimen correspond à une empreinte préservée dans une argilite de la Formation de Jince (Cambrien moyen, République Tchèque). Il présente la partie proximale de la tige articulée à un fragment de thèque distale, composée d'une vingtaine de plaques polygonales. À l'exception des plaques basales, les plaques thécales portent des épispires ellipsoïdales. Cet indice morphologique suggère que ce spécimen pourrait représenter les prémices d'un stade adulte

Rational and non-rational values of trigonometric functions

U radu je izložena primjena Čebiševljevih polinoma prve i druge vrste kod dokazivanja ne-racionalnosti nekih vrijednosti trigonometrijskih funkcija. Odnosno, dat je osvrt na određivanja brojeva koji su racionalni višekratnici broja π, a za koje su vrijednosti sinusa, kosinusa i tangensa racionalni odnosno iracionalni brojevi. Pokazano je, da ako je ( cos alpha ) racionalan broj tada je i ( cos nalpha ) racionalan broj za svaki prirodan broj n, a ako su i ( sin alpha ) i ( cos alpha ) racionalni brojevi, tada je i ( sin nalpha ) racionalan broj. Nadalje, pokazano je, da ako su m, n relativno prosti brojevi i (cos frac{n}{m}pi) racionalan broj, tada je i (cos frac{pi}{m}) racionalan broj, kao i da je za svaki prirodan broj m veći od 3, broj (cos frac{pi}{m}) iracionalan. Razmatrana je također racionalnost i iracionalnost brojeva (tgfrac{2pi }{n}).The paper presents an application of Chebyshev polynomials of the first and second kind in proving the non-rationality of certain values of trigonometric functions. More precisely, we determine those rational multiples of the number π for which the values of sine, cosine and tangent are rational numbers, and for which these values are irrational numbers. We show that if ( cos alpha ) is a rational number, then so is ( cos nalpha ) for every natural number n, and if both ( sin alpha ) and ( cos alpha ) are rational numbers, then so is ( sin nalpha ). Furthermore, it is shown that if m and n are relatively prime numbers and (cos frac{n}{m}pi) is a rational number, then (cos frac{pi}{m}) is also a rational number, while for every natural number m > 3, the number (cos frac{pi}{m}) is irrational. We also discuss rationality and irrationality of numbers (tgfrac{2pi }{n})

Challenges of Clinical Decision Support System Development

One of the high-growing areas in medicine is research and development of advanced IT technologies for clinical decision support. Clinical decision support system (CDSS) must be able to store the necessary clinical data and also to analyze this data, and process and interpret the results for a specialist. This article is focused on interdisciplinary research and development challenges in developing a complex information system for searching and selecting a suitable donor for bone marrow transplantation using an advanced DNA-based donor search model. The particular challenges are summarized and the approaches to tackle them are described