The Association for Youth, Science and Technology is a non-governmental, non-profit organization of children and youth. AMAVET brings together 3500 registered active members working in various scientific disciplines. AMAVET plays an important role in conjuction with schools and school institutions, in forming the mindset of young people through informal education, which is becoming a valuable part of a whole life education. The Committee of AMAVET has chosen the ten best student projects on May 6-7, 2008 at the Academy of Sciences of the Czech Republic. and Gabriela Adámková.
Near-isogenic lines of maize varying in their genes for flavonoid biosynthesis were utilized to examine the effects of foliar flavonoids and nutrient deficiency on maximum net photosynthetic rate (PN) and chlorophyll (Chl) fluorescence (Fv/Fm) in response to ultraviolet-B (UV-B) radiation. Plants with deficient (30 to 70 % lower N, K, Mn, Fe, and Zn) and sufficient nutrients were exposed to four irradiation regimes: (1) no UV-B with solar photosynthetically active radiation (PAR), (2) two day shift to ambient artificial UV-B, 8.2-9.5 kJ m-2 d-1 (21-25 mmol m-2 d-1); (3) continuous ambient artificial UV-B; (4) continuous solar UV-B in Hawaii 12-18 kJ m-2 d-1 (32-47 mmol m-2 d-1). The natural ratio of UVB: PAR (0.25-0.40) was maintained in the UV-B treatments. In the adequately fertilized plants, lines b and lc had higher contents of flavonoids and anthocyanins than did lines hi27 and dta. UV-B induced the accumulation of foliar flavonoids in lines hi27 and b, but not in the low flavonoid line dta or in the high flavonoid line lc. In plants grown on deficient relative to adequate nutrients, flavonoid and anthocyanin contents decreased by 30-40 and 40-50 %, respectively, and Chl a and Chl b contents decreased by 30 and 70 %, respectively. The UV-B treatments did not significantly affect PN and Fv/Fm in plants grown on sufficient nutrients, except in the low flavonoid lines dta and hi27 in which PN and Fv/Fm decreased by ∼15 %. PN, Fv/Fm, and stomatal conductance decreased markedly (20-30 %) in all lines exposed to UV-B when grown on low nutrients. The decrease in Fv/Fm was 10 % less in higher flavonoid lines b and lc. The photosynthetic apparatus of maize readily tolerated ambient UV-B in the tropics when plants were adequately fertilized. In contrast, ambient UV-B combined with nutrient deficiency significantly reduced photosynthesis in this C4 plant. Nutrient deficiency increased the susceptibility of maize to UV-B-induced photoinhibition in part by decreasing the contents of photoprotective compounds. and T. S. L. Lau ... [et al.].
Ground concentration of ozone (O3) causes serious threat to plants. In order to protect sensitive plants from O3 pollution, many kinds of antioxidants were assessed in previous studies. In this study, effects of O3 fumigation (a single spike of 120 ± 20 nmol mol-1 for four hours) on an ornamental species (Coleus blumei) was examined in open-top chambers. Before the O3 treatment, plants were sprayed respectively either with a solution of three different antioxidants [Na-ascorbate (NaAsA), kinetin (KIN), and spermidine (Spd)] or with distilled water to compare their protective effects to plants. Our results revealed that O3 fumigation impaired the plasma membrane, decreased chlorophyll (Chl) content, inhibited photosynthesis, induced photoinhibition and photodamage, and caused visible injury. Spraying with KIN, NaAsA or Spd ameliorated the decrease of the Chl content and photosynthetic capability, the impairment of membrane, and visible injury under O3 fumigation. The plants treated with KIN showed the best ability to mitigate the injury caused by O3., L. Zhang, L. L. Jia, J. X. Sui, M. X. Wen, Y. J. Chen., and Obsahuje bibliografii
Salicylic acid (SA) and polyamines (PA) are widely used to overcome various abiotic stresses including salt (NaCl) stress in plants. In the present investigation, co-application efficacies of SA and PA on the salt stress (200 mM NaCl) were evaluated in Lycopersicon esculentum. After transplantation, at 10-d stage, seedlings were exposed to NaCl through soil and then allowed to grow till 30-d stage. At 31-d stage of growth, plants were sprayed with double distilled water (control) or spermidine (1.0 mM) and/or SA (10-5 M). The salt stress significantly reduced the growth, gas-exchange parameters, but increased antioxidant enzymes and proline content in the leaves. Moreover, the loss caused by salt stress was successfully restored by the following treatment of spermidine and SA., Q. Fariduddin, T. A. Khan, M. Yusuf, S. T. Aafaqee, R. R. A. E. Khalil., and Obsahuje bibliografii
In this article, the author traces how the lessons of the Munich Agreement of September 1938 (on the basis of which Czechoslovakia was forced to cede the predominantly ethnic-German Sudetenland to Nazi Germany) were projected into US foreign policy. In Part One of the essay, based on published sources and unpublished documents from American archives, the topic is covered from the late 1930s to the outbreak of the Korean War (which is discussed in Part Two, to be published in the next issue of Soudobé dějiny). The author looks at immediate American reaction to the North Korean attack on South Korea in June 1950, and then returns to autumn 1938 to test his hypothesis that behind the unusual unity of this reaction was the ingrained negative attitude of the United States to the policy of appeasement. He demonstrates that since the late 1930s the terms ‘Munich’ and ‘appeasement’ have remained forever linked in US policy and US public discourse, and he discusses the transformations of the perception of the two concepts during the Second World War, after the war, and at the beginning of the Cold War. The lessons of Munich, he argues, have drawn on the idealistic as well as the pragmatic sources of US policy, because they stem from the conviction that appeasement is immoral and does not pay. Whereas in Roosevelt’s policy the general lesson was not to allow Hitler’s expansion, Harry S. Truman, Roosevelt’s successor in the White House, had to use the lessons, despite his own self-restraint, to try to counter the steps of a wartime ally, Stalin’s Soviet Union. The Communist take-over in Czechoslovakia in February 1948 and the blockade of the western sectors of Berlin beginning in the summer of that year were important events on this path.The author further considers the infl uence of this factor on the US approach taken in the Korean War in the early 1950s. He seeks to demonstrate that the decision of the Truman Administration to substantially intervene in this confl ict was a direct consequence of the negative attitude to the policy of appeasing an aggressor. This attitude was also shared by the American public, regardless of party affi liation and political sympathies. Arguments based on the rejection of appeasement, however, soon began to be used by the Republicans as ammunition in the election campaign against the incumbent Democrats and the choice of strategy also became a matter of dispute in the choice of strategy on the Korean battlefi eld after China entered the war. Whereas the White House wished to avoid an unlimited confl ict with China, the Commander-in-Chief of the United Nation Command in Korea, General Douglas MacArthur (1880–1964), was in favour of an uncompromising approach and in fact ceased to obey President Harry S. Truman (1884-1972). After being relieved of his command by Truman, MacArthur became the chief critic of his policies and a hero of Truman’s Republican opponents. In spring 1951, the Republicans organized a special Senate committee hearing on the circumstances of MacArthur’s suspension. The author looks in detail at this exceptional clash in post-war US domestic politics, which was meant to be triumphantly used against MacArthur, but gradually changed into a debacle in consequence of, among other things, the compelling testimonies of Secretary of State Dean Acheson (1893-1971) and Secretary of Defense George C. Marshall (1880-1959). In his conclusion, the author seeks to demonstrate how other US presidents returned to the ‘lessons of Munich’, and he argues that these lessons became Truman’s lasting political legacy and as such became fi rmly rooted in American political discourse. and Přeložil: Jiří Mareš
V této obsáhlé studii, rozdělené do dvou částí, autor sleduje, jak se do zahraniční politiky Spojených států amerických promítalo poučení z následků Mnichovské dohody ze září 1938, na jejímž základě bylo Československo nuceno odstoupit nacistickému Německu pohraniční území s většinou německého obyvatelstva. V první části studie, založené na publikovaných i nepublikovaných dokumentech z amerických archivů, je téma zpracováno pro období od konce třicátých let do vypuknutí korejského konfliktu (ten je obsahem druhé části, která bude otištěna v příštím čísle časopisu). Autor zachycuje bezprostřední americké reakce na vpád severokorejských vojsk do Jižní Koreje v červnu 1950 a poté se vrací do podzimu 1938, aby verifikoval hypotézu, že za nezvyklou jednotou těchto reakcí byl zažitý odmítavý postoj Spojených států k politice appeasementu. Na americké politice i veřejném diskurzu ukazuje, že od konce třicátých let v nich zůstávaly pojmy Mnichov a appeasement natrvalo spjaty, a přibližuje proměny tohoto vnímání za druhé světové války, po jejím skončení a v počátcích války studené. „Poučení z Mnichova“ se podle autora napájelo z idealistického i pragmatického zdroje americké politiky, neboť vycházelo z přesvědčení, že appeasement je jednak nemravný, jednak se nevyplácí. Zatímco v Rooseveltově politice bylo toto obecné poučení namířeno proti Hitlerově expanzi, jeho nástupce v prezidentském úřadě Harry S. Truman je navzdory vlastní zdrženlivosti musel v konfrontaci se Stalinovými poválečnými kroky začít uplatňovat vůči dosavadnímu válečnému spojenci, Sovětskému svazu. Důležitými událostmi na této cestě byl komunistický převrat v Československu v únoru 1948 a blokáda západních sektorů Berlína od léta téhož roku., In this extensive article, divided into two parts, the author traces how the lessons of the Munich Agreement of September 1938 (on the basis of which Czechoslovakia was forced to cede the predominantly ethnic-German Sudetenland to Nazi Germany) were projected into US foreign policy. In Part One of the essay, based on published sources and unpublished documents from American archives, the topic is covered from the late 1930s to the outbreak of the Korean War (which is discussed in Part Two, to be published in the next issue of Soudobé dějiny). The author looks at immediate American reaction to the North Korean attack on South Korea in June 1950, and then returns to autumn 1938 to test his hypothesis that behind the unusual unity of this reaction was the ingrained negative attitude of the United States to the policy of appeasement. He demonstrates that since the late 1930s the terms ‘Munich’ and ‘appeasement’ have remained forever linked in US policy and US public discourse, and he discusses the transformations of the perception of the two concepts during the Second World War, after the war, and at the beginning of the Cold War. The lessons of Munich, he argues, have drawn on the idealistic as well as the pragmatic sources of US policy, because they stem from the conviction that appeasement is immoral and does not pay. Whereas in Roosevelt’s policy the general lesson was not to allow Hitler’s expansion, Harry S. Truman, Roosevelt’s successor in the White House, had to use the lessons, despite his own self-restraint, to try to counter the steps of a wartime ally, Stalin’s Soviet Union. The Communist take-over in Czechoslovakia in February 1948 and the blockade of the western sectors of Berlin beginning in the summer of that year were important events on this path., and Petr Mareš.
a1_V první části této rozsáhlé studie, která vyšla v minulém dvojčísle Soudobých dějin (roč. 22, č. 1-2/2015, s. 9-29), autor sledoval, jak se poučení z chyb appeasementu, spojovaného s uzavřením Mnichovské dohody na podzim 1938, promítalo v americké zahraniční politice během druhé světové války a na počátku války studené. Ve druhé části na základě poznatků z publikovaných i nepublikovaných amerických pramenů zkoumá vliv daného faktoru na postup Spojených států v korejské válce na počátku padesátých let. Ukazuje, že rozhodnutí Trumanovy administrativy podstatně zasáhnout do tohoto konfliktu bylo přímým důsledkem odmítavého postoje k politice usmiřování agresora, který v té době sdílela v USA politická veřejnost bez ohledu na stranickou příslušnost a politické sympatie. Argumenty založené na odmítání appeasementu však záhy začali využívat republikáni jako munici v předvolebním boji proti vládnoucím demokratům a staly se také předmětem sporu v souvislosti s volbou strategie na korejském bojišti po vstupu čínských jednotek do války. Zatímco Bílý dům se chtěl vyhnout neomezenému konfliktu s Čínou, vrchní velitel vojsk OSN v Koreji generál Douglas MacArthur (1880-1964) zastával nekompromisní postup a fakticky přestal respektovat prezidentovu autoritu. Po svém odvolání z funkce se stal hlavním kritikem Trumanovy politiky a hrdinou republikánské opozice, která na jaře 1951 prosadila slyšení k okolnostem jeho suspendování před zvláštním výborem Senátu., a2_Autor podrobně přibližuje tento mimořádný vnitropolitický střet v poválečných amerických dějinách, který se měl stát triumfem MacArthurovy obžaloby, ale postupně se změnil v její debakl, mimo jiné v důsledku přesvědčivých vystoupení ministrů zahraničí a obrany Deana Achesona (1893-1971) a George C. Marshalla (1880-1959). V závěru autor ukazuje, jak se k „poučení z Mnichova“ vraceli další američtí prezidenti, a konstatuje, že se stalo trvajícím politickým odkazem Harryho S. Trumana (1884-1972) a jako takové pevně zakořenilo v americkém politickém diskurzu., b1_In Part 1 of this article, published in the last issue of Soudobé dějiny (vol. 22, 2015, nos. 1-2, pp. 9-29), the author discusses how the lessons from the mistakes of appeasement, including the signing of the Munich Agreement in autumn 1938, were projected in US foreign policy during the Second World War and at the beginning of the Cold War. In Part 2, based on published and unpublished American sources, he considers the influence of this factor on the US approach taken in the Korean War in the early 1950s. He seeks to demonstrate that the decision of the Truman Administration to substantially intervene in this conflict was a direct consequence of the negative attitude to the policy of appeasing an aggressor. This attitude was also shared by the American public, regardless of party affiliation and political sympathies. Arguments based on the rejection of appeasement, however, soon began to be used by the Republicans as ammunition in the election campaign against the incumbent Democrats and the choice of strategy also became a matter of dispute in the choice of strategy on the Korean battlefield after China entered the war. Whereas the White House wished to avoid an unlimited conflict with China, the Commander-in-Chief of the United Nation Command in Korea, General Douglas MacArthur (1880-1964), was in favour of an uncompromising approach and in fact ceased to obey President Harry S. Truman (1884-1972). After being relieved of his command by Truman, MacArthur became the chief critic of his policies and a hero of Truman’s Republican opponents. In spring 1951, the Republicans organized a special Senate committee hearing on the circumstances of MacArthur’s suspension., b2_The author looks in detail at this exceptional clash in post-war US domestic politics, which was meant to be triumphantly used against MacArthur, but gradually changed into a debacle in consequence of, among other things, the compelling testimonies of Secretary of State Dean Acheson (1893-1971) and Secretary of Defense George C. Marshall (1880-1959). In his conclusion, the author seeks to demonstrate how other US presidents returned to the ‘lessons of Munich’, and he argues that these lessons became Truman’s lasting political legacy and as such became firmly rooted in American political discourse., and Petr Mareš.