Active space debris removal system

Tato diplomová práce se zabývá návrhem systému aktivního řešení kosmické tříště. Kosmická tříšť, nebo také kosmický odpad, je pojem používaný v kosmonautice k popisu všech antropogenních, neaktivních vesmírných objektů, fragmentů a zbytků všeho, co vzniklo rozpadem kosmické technologie, která byla vypuštěna na oběžnou dráhu člověkem. Kosmická tříšť se vyznačuje nekontrolovaným pohybem celistvých objektů nebo jejich fragmentů s vysokými rychlostmi pohybu a vysokou kinetickou energií. S rozvojem kosmonautiky a její postupnou integrací do běžného lidského života, představuje rostoucí množství kosmického odpadu vážný problém ohrožující budoucnost veškerých kosmických misí. Lidstvo tak v současnosti čelí potenciální hrozbě v podobě zamezení kosmických letů a využívání kosmických technologií po mnoho dalších generací.This diploma thesis focuses on the design of an active space debris removal system. Space debris is a term used in cosmonautics to describe all anthropogenic inactive space objects, fragments, and remnants of everything created by the decay of space technology, which has been launched into orbit by humans. Space debris is characterized by the uncontrolled movement of whole bodies or fragments with high velocities and high kinetic energy. With the development of cosmonautics and its gradual integration into ordinary human life, the increasing amount of space debris poses a serious problem threatening the future of space missions. Thus, humanity is currently facing a potential threat, in the form of the prevention of space flights and the use of space technology for many generations

Frequent Flyer Awards as Taxable Income: Time to Pay the Tax Man

This Comment will argue the Service\u27s position should shift to aggressively collect all applicable taxes on frequent flyer benefits. Part I of this Comment provides a brief overview of the frequent flyer phenomena. Part II analyzes whether frequent flyer benefits are taxable income or excluded from income. Part III proposes a method both to value the benefits earned and to establish the timing of the event. The Conclusion calls for aggressive enforcement of the collection of income taxes on qualifying transactions

Overkilling or Murder with Using Polonium 210

Článek je věnován úkladné vraždě bývalého příslušníka ruské tajné služby (FSB) Alexandra Litviněnka spáchané v listopadu roku 2006. V textu jsou shrnuty základní chemické, fyzikální a toxikologické charakteristiky jedu použitého k jeho zavraždění, jímž byl radioizotop polonium 210. Dále jsou popsány symptomy akutní nemoci z ozáření spolu s detailním popisem Litviněnkovy kazuistiky. Zvláštní důraz byl pak věnován aktuálnímu výzkumu zaměřenému na studium zdravotních rizik, jimž byli v průběhu incidentu vystaveni lidé pobývající na místech spojených s vraždou.Article deals with Alexander Litvinenko assassination in November 2006. Basic chemical, physical and toxicological characteristics of 210 Po are reviewed. Typical symptoms of Acute Radiation Syndrome are explained together with detailed description of Litvinenko case report. Special attention is paid to the actual research on health risk of individuals accidentally exposed to polonium-210 during the incident

Of Vultures and Men

Článek se zabývá masivním vymíráním tří druhů supů (Gyps bengalensis, Gyps indicus, Gyps tenuirostris) v jižní Asii. Drastický pokles početnosti supích populací začal v devadesátých letech minulého století v důsledku zavedení nesteroidního protizánětlivého léčiva s názvem diclofenac do veterinární medicíny. V článku je popsán mechanismus toxického účinku diclofenacu a také jsou zde vysvětleny příčiny kontaminace supí potravy tímto přípravkem. Speciální pozornost je pak věnována diskusi možných následků vymírání supů jako je zvýšení početnosti populací zdivočelých psů, zvýšené riziko onemocnění lidí vzteklinou a vliv na pohřební rituály členů etnika Pársů.The article deals with massive mortality in three vulture species (Gyps bengalensis, Gyps indicus, Gyps tenuirostris) on the South Asian subcontinent, which started in the nineties of the last century. Accidental exposure of scavengers to diclofenac, a non-steroidal anti-inflammatory drug (NSAID), via their food chain is considered to be a scientifically proven reason for the decline of vulture population in India, Pakistan and Nepal. The mechanism of diclofenac toxicity is explained and the sources of diclofenac in vulture food resources are discussed. Special attention is paid to the explanation of possible consequences of vulture extinction as increase in abundance of dog population, increased number of rabies cases in man, effect on the burial customs of Parsi community

Bilješke o kompleksu Phellinus rimosus (Hymenochaetaceae)

In the course of the study of the species of Phellinus with large, coloured spores and complete absence of setae, from various herbaria, we reached the following conclusions: 1. Phellinus badius (Cooke) G. H. Cunningh. This name was based originally on the specimen from North America (Dr. Richardson, No. 6 — K). Some error, however, must have crept in as the fungus evidently came from the tropics. Nevertheless the specimen was the real basis for the original description made by Berkeley. As this type material cannot be identified with any of the Phellinus species known to us, we propose temporarily to restrict the name Phellinus badius to a species which is represented solely by the type material. 2. Phellinus rimosus (Berk) Pil. There is a nomenclatural as well as a taxonomic problem. Originally the name was based on three specimens of which the best one was lost and of the two remaining only one agrees with the common concept (Van Diemen’s land, coll. Lawrence, herb. Berk. No. 2 — K). It is that species with larger spores and pores growing in warm dry regions on various hosts but especially on Robinia, Pistacia and Prosopis. 3. Phellinus robiniae (Murill) A. Ames. This is a characteristic species with smaller spores and pores, distributed in North and Central America, especially common in eastern USA on Robinia preudacacia; it does not occur in Europe. 4. The group of Phellinus with large coloured spores and without setae includes several other species which we have partly studied and reached reliable results in few cases only; we shall publish the new species elsewhere later. There are, however, still further species and we hope that they will become the subject of study by the mycologists who study exclusively or predominantly tropical material.U području Sredozemlja raste rijetka guba iz roda Phellinus, srednje velikih kopitastih plodišta, mikroskopski karakterizirana obojenim spcrama debelih zidova i odsutnošću seta. Različiti autori nazivaju je različito: Phellinus rimosus, Ph. robiniae ili Ph. badius, pri čemu neki smatraju da se radi samo o jednoj vrsti, a drugi o dvije ili više vrsta. Kako je sabrana nekoliko puta na jadranskoj obali u Jugoslaviji, upotrijebili smo tu priliku da je pobliže, proučimo. Ovaj taksonomski i nomenklaturni problem proučavali smo na eksi- katima ne samo iz Evrope, Azije i Afrike nego i iz Sjeverne, Srednje i Južne Amerike i Australije (najviše materijala smo imali iz USA), uključivši i niz tipskih primjeraka. Na osnovi toga došli smo do uvjerenja da u tom kompleksu srodnih i sličnih vrsta postoji najmanje pet koje se mogu vrlo dobro definirati. Od njih su već ranije tri opisane: 1. Phellinus badius (Cooke) G. H. Cunningh. dosad je vrlo slabo poznata vrsta koju zasad moramo ograničiti na tipski materijal. Nije poznato gdje je sabran, ali je očito iz tropskih krajeva. Tipus ne odgovara nijednoj vrsti koju smo imali u rukama; cjevčice su mu krhke a građa plodišta je, čini se, monomitična. 2. Phellinus rimosus (Berk.) Pil. ima veće spore [(5.2 —) 5.8 — 6.8 (—7.2) X (4.1—) 4.8 — 5.5 (—6.0) pm] i veće pore (3 — 5 na 1 mm) koje su prilično tamnosmeđe poput duhana. Raste kao parasit u prvom redu na Robinia, Pistacia i Prosopis, rjeđe također na Acacia, Chilopsis, Juglans i Vitex. Raširen je po mediteranskim krajevima Evrope, Azije i Afrike, zatim u srednjoj Aziji, na indijskom supkontinentu, u istočnoj i južnoj Africi, jugozapadnom dijelu USA, Meksiku i Portoriku. U Jugoslaviji ju je prvi autor sabrao dvaput kod Starigrada blizu Zadra na Pistacia terebinthus, jednom u Budvi na Robinia pseudacacia, a nađena je na Robinia i u Dubrovniku. Herbarski materijal nalazi se u PRM, a duplikat jednog iz Starigrada u ZA. Jahn (1973) spominje da je sabrana i u samom Zadru na Robinia; fragment toga se nalazi u ZA. Ovo bi dakle bili prvi objavljeni lokaliteti za Jugoslaviju. 3. Phellinus robiniae (Murrill) A. Ames ima manje spore [(4.6—) 4.8 — 6.0 (— 6.3) X (3.4 —) 4.0 — 5.0 (— 5.2) pm] i manje pore [(4 —) 5 — 7 (—8) na 1 mm], koje su svijetlorđaste do sivorđaste. Raste kao parasit prvenstveno na Robinia, rjeđe također na Guaiacum i Cedrela. Raširen je samo u Novom svijetu, naročito u istočnom dijelu USA, zatim na Bahamskom otočju, Jamaiki i u Nikaragui. Osim ovih postoji u ovoj grupi roda Phellinus još nekoliko vrsta koje ne rastu u Starom svijetu, a neke će od njih biti opisane kao nove na drugom mjestu

The Montessori method and first language acquisition

Die vorliegende Diplomarbeit beschaeftigt sich mit Maria Montessoris Paedagogik und Erstspracherwerb mit besonderem Augenmerk auf die Anfaenge des Sprechens, Schreibens und Lesens. Im Anhang befinden sich Bilder von Montessori Materialien, die zur Veranschaulichung dienen sollen. Die italienische Aerztin Maria Montessori entwickelte zu Beginn des 20. Jahrhunderts anhand ihrer Erkenntnisse, die sie waehrend empirischer Beobachtungen und wissenschaftlicher Untersuchungen in ihren Kinderhaeusern gewann, eine Erziehungsmethode, die Kinder in ihrem individuellen Entwicklungsprozess begleitend unterstuetzt, und ihnen ermoeglicht, mit Freude und Begeisterung gemaess ihren Interessen selbsttaetig zu lernen. Ziel ihrer Paedagogik ist die Erziehung des Kindes zu einem unabhaengigen, selbstaendigen, verantwortungsbewussten und sozialen Menschen, der selbstbewusst die sich ihm stellenden Anforderungen im Leben meistert. Dieser kindliche Selbstbildungsprozess setzt das Zustandekommen einer tiefen Konzentration beim Kind voraus, die sich nur in einem entspannten Umfeld einstellt, das die sensiblen Phasen in der kindlichen Entwicklung beruecksichtigt. Fuer die verschiedenen akademischen Bereiche, also auch den Spracherwerb, entwickelte Montessori Materialien, mit deren Hilfe sich der Schueler unabhaengig vom Lehrer bilden kann. Dies erfolgt in der sogenannten Freiarbeit, in der das Kind durch das aktive Arbeiten mit konkreten Gegenstaenden abstrakte Lerninhalte begreifen lernt. Im Vergleich mit sprachwissenschaftlichen Theorien zum Spracherwerb, zum Beispiel Noam Chomskys Universal Grammar, wird deutlich, dass Maria Montessori das Lernen von Sprache aus paedagogischer Sicht betrachtet. Andererseits findet man auch interessante Aehnlichkeiten zwischen Chomskys und Montessoris Aufassung davon wie Kinder ihre Muttersprache erlernen. So glauben etwa beide, dass die Faehigkeit Sprache zu erwerben angeboren ist; Chomsky geht sogar soweit zu behaupten, dass Kinder mit Informationen ueber universelle Sprachstrukturen, also mit ‚Universal Grammar’, auf die Welt kommen. Montessori hingegen spricht nur von einem Mechanismus der dem Kind erlaubt Sprache in sich aufzusaugen, den sie ‚absorbent mind’ nennt. Im Gegensatz zu kognitiven Theorien glauben Chomsky und Montessori, dass sich Sprache in einem separaten Teil des Gehirns entwickelt, unabhaengig von der Gesamtintelligenz des Kindes. Beide sprechen von individuellen Teilen oder Modulen im Gehirn, die jeweils fuer die Entwicklung der verschiedenen Faehigkeiten, wie etwa Balance halten, sehen, mathematisch denken usw., zustaendig sind. Im Gegensatz zu Noam Chomsky glaubt Montessori, dass sobald die einzelnen Module fertig entwickelt sind, also auch der Spracherwerbsprozess abgeschlossen ist, diese Teile zusammen die Intelligenz des Menschen bilden. In weiterer Folge wird im zweiten Kapitel analysiert welchen Einfluss die verbale Umgebung und die sensiblen Perioden auf den Spracherwerb haben und welche Phasen Kinder durchlaufen, wenn sie ihre Muttersprache erlernen. Der dritte und letzte Teil der Diplomarbeit befasst sich mit den Anfaengen von Schreiben und Lesen und betrachtet im Detail Maria Montessoris Theorie und Materialien zum Schriftspracherwerb. Zu Beginn des Kapitels werden Aehnlichkeiten und Unterschiede zwischen dem Lautsprach- und Schriftspracherwerb hervorgehoben. Fuer Montessori sind Schreiben und Lesen zwei unterschiedliche Vorgaenge, die nicht zur selben Zeit stattfinden. So geht das Schreiben ihrer Meinung nach dem Lesen voraus. Mit Hilfe der paedagogischen Analyse zerlegt sie die beiden Prozesse in ihre einzelnen Bestandteile. Die Teilfertigkeiten werden mit Materialien getrennt voneinander vorbereitet. Das Lesen, das nach Montessori ein wesentlich abstrakterer Vorgang ist, da es dabei um die Interpretation von graphischen Zeichen geht, muss sich das Kind selbst aneignen. Sinnentnehmendes Lesen kann man nicht lehren, doch man kann das Kind langsam dahin fuehren. In einer Zeit, in der Leistungsdruck und hohe Erwartungen oft zur Ueberforderung werden, stellt Maria Montessoris Methode, Sprache zu erlernen, einen lustvollen und interessanten Weg dar, bei dem das Kind in seiner natuerlichen Entwicklung begleitet wird. Beim Erwerb des Wortschatzes, der Schrift, des Lesens und der Grammatik wird auf die Beduerfnisse und sensiblen Phasen des Kindes Ruecksicht genommen, weshalb das Erlernen des Schreibens und Lesens, das oft als Huerde in der traditionellen Schule angesehen wird, mit Leichtigkeit erfolgt

Quantification of sodium present in dry aggregates and anodes

In aluminum industry, it is important to determine the concentration of contaminants present in anode raw materials as rapidly as possible in order to adjust the anode recipe. Sodium, which is an impurity coming largely from anode butts, significantly influences the anode reactivity, and an increase in its concentration increases the anode consumption. A simple and inexpensive method was developed to quantify the sodium content in dry aggregates and anodes without grinding the samples. The method is based on potentiometric principles using a sodium-ion specific electrode. A sample can be analyzed easily within thirty minutes. In order to prevent the rapid degradation of the specific electrode due to experimental conditions, sodium is extracted from samples by electrophoresis prior to the test. The comparison shows that the measured sodium concentrations obtained are similar to the results determined by other test methods

Obeticholic acid for the treatment of non-alcoholic steatohepatitis: interim analysis from a multicentre, randomised, placebo-controlled phase 3 trial

Background Non-alcoholic steatohepatitis (NASH) is a common type of chronic liver disease that can lead to cirrhosis. Obeticholic acid, a farnesoid X receptor agonist, has been shown to improve the histological features of NASH. Here we report results from a planned interim analysis of an ongoing, phase 3 study of obeticholic acid for NASH. Methods In this multicentre, randomised, double-blind, placebo-controlled study, adult patients with definite NASH,non-alcoholic fatty liver disease (NAFLD) activity score of at least 4, and fibrosis stages F2–F3, or F1 with at least oneaccompanying comorbidity, were randomly assigned using an interactive web response system in a 1:1:1 ratio to receive oral placebo, obeticholic acid 10 mg, or obeticholic acid 25 mg daily. Patients were excluded if cirrhosis, other chronic liver disease, elevated alcohol consumption, or confounding conditions were present. The primary endpointsfor the month-18 interim analysis were fibrosis improvement (≥1 stage) with no worsening of NASH, or NASH resolution with no worsening of fibrosis, with the study considered successful if either primary endpoint was met. Primary analyses were done by intention to treat, in patients with fibrosis stage F2–F3 who received at least one dose of treatment and reached, or would have reached, the month 18 visit by the prespecified interim analysis cutoff date. The study also evaluated other histological and biochemical markers of NASH and fibrosis, and safety. This study is ongoing, and registered with ClinicalTrials.gov, NCT02548351, and EudraCT, 20150-025601-6. Findings Between Dec 9, 2015, and Oct 26, 2018, 1968 patients with stage F1–F3 fibrosis were enrolled and received at least one dose of study treatment; 931 patients with stage F2–F3 fibrosis were included in the primary analysis (311 in the placebo group, 312 in the obeticholic acid 10 mg group, and 308 in the obeticholic acid 25 mg group). The fibrosis improvement endpoint was achieved by 37 (12%) patients in the placebo group, 55 (18%) in the obeticholic acid 10 mg group (p=0·045), and 71 (23%) in the obeticholic acid 25 mg group (p=0·0002). The NASH resolution endpoint was not met (25 [8%] patients in the placebo group, 35 [11%] in the obeticholic acid 10 mg group [p=0·18], and 36 [12%] in the obeticholic acid 25 mg group [p=0·13]). In the safety population (1968 patients with fibrosis stages F1–F3), the most common adverse event was pruritus (123 [19%] in the placebo group, 183 [28%] in the obeticholic acid 10 mg group, and 336 [51%] in the obeticholic acid 25 mg group); incidence was generally mild to moderate in severity. The overall safety profile was similar to that in previous studies, and incidence of serious adverse events was similar across treatment groups (75 [11%] patients in the placebo group, 72 [11%] in the obeticholic acid 10 mg group, and 93 [14%] in the obeticholic acid 25 mg group). Interpretation Obeticholic acid 25 mg significantly improved fibrosis and key components of NASH disease activity among patients with NASH. The results from this planned interim analysis show clinically significant histological improvement that is reasonably likely to predict clinical benefit. This study is ongoing to assess clinical outcomes