194 research outputs found

    Helpful and Harmful Iowa Birds

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    Forty million dollars is the estimated loss annually to the United States on account of weeds, according to Prof. Beal, member of the Department of Agriculture. That a generous share of this loss belongs to Iowa we must all admit, for Iowa is a great agricultural state. Since such is the case it would not seem at all strange if Iowa people should take steps to make this loss as small as possible

    The Crow

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    The crow is the most harmful bird. He feeds on carrion and also carries hog cholera by feeding on the dead hogs. He commences feeding at the ear arid there takes his fill, then flies from one farm to another and so carries the disease. Loss from hog cholera three years ago was ninety-nine thousand and nine hundred and ninety hogs; two years ago it amounted to one hundred forty-seven thousand six hundred and seventy. The crow will carry the foot and mouth disease in the same way and also destroys the newborn sheep in the pasture by picking out their eyes

    How a Tree Grows

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    Professor Ebermeier of Munich, Germany says: When the leaves take carbonic acid from the air they break it up and force its carbon into new chemical compounds which are then stored away as new material in the tree. The forest is the most highly organized portion of the vegetable kingdom. No man can really know the forest without feeling the gentle influence of one of the kindest and strongest parts of nature. It is the most helpful friend of man

    A distinct assembly pathway of the human 39S late pre-mitoribosome

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    Assembly of the mitoribosome is largely enigmatic and involves numerous assembly factors. Little is known about their function and the architectural transitions of the pre-ribosomal intermediates. Here, we solve cryo-EM structures of the human 39S large subunit pre-ribosomes, representing five distinct late states. Besides the MALSU1 complex used as bait for affinity purification, we identify several assembly factors, including the DDX28 helicase, MRM3, GTPBP10 and the NSUN4-mTERF4 complex, all of which keep the 16S rRNA in immature conformations. The late transitions mainly involve rRNA domains IV and V, which form the central protuberance, the intersubunit side and the peptidyltransferase center of the 39S subunit. Unexpectedly, we find deacylated tRNA in the ribosomal E-site, suggesting a role in 39S assembly. Taken together, our study provides an architectural inventory of the distinct late assembly phase of the human 39S mitoribosome

    Lernkulturen und ihre Auswirkung auf die Studienleistungen internationaler Studierender

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    An den deutschen Hochschulen steigt die Zahl internationaler Studierender kontinuierlich, doch ihr Studienerfolg bleibt hinter dem der einheimischen Studierenden signifikant zurück. Trotzdem werden Differenzen in Lehr- und Lernstilen nur selten thematisiert. In diesem Beitrag wird der Versuch unternommen, die schlechtere Studienperformanz internationaler Studierender mit unterschiedlichen Gewohnheiten und Herangehensweisen an Forschen, Lehren und Lernen zu erklären. In einer Lernumgebung, in der sowohl Studierende als auch Lehrende immer häufiger in unterschiedlichen Lern- und Lehrkulturen sozialisiert wurden, kommt es darauf an, die divergierenden Anforderungen und Erwartungen in der Lehre explizit und damit transparent zu machen. Auch Lehrende sollten miteinander über unterschiedliche implizite Orientierungen und Beurteilungskriterien in einen Diskurs treten.The number of international students is continuously increasing in German universities. However their drop out rates are much higher than those of German students. This article will try to explain why international students drop out more than their German counterparts, by focusing on the differences in habits and approaches to research, learning and teaching among them. These reasons have been seldom explored in existing research and literature. In a study environment, in which students and professors are increasingly socialized in different learning and teaching cultures it is important to make differences in learning and teaching among people of different cultures explicit. Discourse among teachers about their own implicit motives, orientations and assessment criteria will also help in decreasing the dropout rates

    Structure of a human translation termination complex

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    In contrast to bacteria that have two release factors, RF1 and RF2, eukaryotes only possess one unrelated release factor eRF1, which recognizes all three stop codons of the mRNA and hydrolyses the peptidyl-tRNA bond. While the molecular basis for bacterial termination has been elucidated, high-resolution structures of eukaryotic termination complexes have been lacking. Here we present a 3.8 angstrom structure of a human translation termination complex with eRF1 decoding a UAA(A) stop codon. The complex was formed using the human cytomegalovirus (hCMV) stalling peptide, which perturbs the peptidyltransferase center (PTC) to silence the hydrolysis activity of eRF1. Moreover, unlike sense codons or bacterial stop codons, the UAA stop codon adopts a U-turn-like conformation within a pocket formed by eRF1 and the ribosome. Inducing the U-turn conformation for stop codon recognition rationalizes how decoding by eRF1 includes monitoring geometry in order to discriminate against sense codons

    Der Spagat zwischen Reproduktion und Ăśberwindung von Klischees: praktische Vermittlung interkultureller Kompetenz fĂĽr angehende Manager an der Hochschule Bremen

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    Jutta Berninghausen stellt mit dem Studiengang Global Management der School of International Business an der Hochschule Bremen ein Modell zur Vermittlung "interkulturellen Wissens" zur Berufsbefähigung bereits nach dem Bachelor-Abschluss vor. Der Vermittlung von social skills wird hier ein Drittel des gesamten Workloads eingeräumt, der in anderen Studiengängen des Fachs größtenteils durch fachliches Wissen bestritten wird.The training of Intercultural competence is given high priority in the study programmes of the School of International Business at the Hochschule Bremen. One third of the curricula of the study cours "International Studies of Global Management" are social skills. To prepare students for their future positions in management, bachelor students in economics first of all need practical knowledge of how to act in an intercultural competent way rather than discussing different approaches of intercultural theories. Intercultural competence is part of a broader social or emotional competence, a skill which is always needed in dealing with people. Emotional intelligence includes affirmative introspective, intercultural literacy, self governance and social architecting. How is it possible to prepare students for their year abroad and educating them to intercultural literacy without reproducing stereotypes and clichés? Although generalizing cultural stereo-types can never fully reflect reality, it might be useful to work with some generalization in the training setting. Only if we know how and why people from other cultures communicate, it is possible to understand their actions and react to it in an appropriate way. It is important to stress that these generalizations are always mere constructs and do not reflect reality. However, we need them to learn and find solutions to antici-pated problems

    Structure of a human translation termination complex

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    In contrast to bacteria that have two release factors, RF1 and RF2, eukaryotes only possess one unrelated release factor eRF1, which recognizes all three stop codons of the mRNA and hydrolyses the peptidyl-tRNA bond. While the molecular basis for bacterial termination has been elucidated, high-resolution structures of eukaryotic termination complexes have been lacking. Here we present a 3.8 angstrom structure of a human translation termination complex with eRF1 decoding a UAA(A) stop codon. The complex was formed using the human cytomegalovirus (hCMV) stalling peptide, which perturbs the peptidyltransferase center (PTC) to silence the hydrolysis activity of eRF1. Moreover, unlike sense codons or bacterial stop codons, the UAA stop codon adopts a U-turn-like conformation within a pocket formed by eRF1 and the ribosome. Inducing the U-turn conformation for stop codon recognition rationalizes how decoding by eRF1 includes monitoring geometry in order to discriminate against sense codons

    Molecular basis of RNA polymerase III transcription repression by Maf1

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    RNA polymerase III (Pol III) transcribes short RNAs required for cell growth. Under stress conditions, the conserved protein Maf1 rapidly represses Pol III transcription. We report the crystal structure of Maf1 and cryo-electron microscopic structures of Pol III, an active Pol III-DNA-RNA complex, and a repressive Pol III-Maf1 complex. Binding of DNA and RNA causes ordering of the Pol III-specific subcomplex C82/34/31 that is required for transcription initiation. Maf1 binds the Pol III clamp and rearranges C82/34/31 at the rim of the active center cleft. This impairs recruitment of Pol III to a complex of promoter DNA with the initiation factors Brf1 and TBP and thus prevents closed complex formation. Maf1 does however not impair binding of a DNA-RNA scaffold and RNA synthesis. These results explain how Maf1 specifically represses transcription initiation from Pol III promoters and indicate that Maf1 also prevents reinitiation by binding Pol III during transcription elongation
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