Shutdown is a component of the Drosophila piRNA biogenesis machinery

In animals, the piRNA pathway preserves the integrity of gametic genomes, guarding them against the activity of mobile genetic elements. This innate immune mechanism relies on distinct genomic loci, termed piRNA clusters, to provide a molecular definition of transposons, enabling their discrimination from genes. piRNA clusters give rise to long, single-stranded precursors, which are processed into primary piRNAs through an unknown mechanism. These can engage in an adaptive amplification loop, the ping-pong cycle, to optimize the content of small RNA populations via the generation of secondary piRNAs.Many proteins have been ascribed functions in either primary biogenesis or the ping-pong cycle, though for the most part the molecular functions of proteins implicated in these pathways remain obscure. Here, we link shutdown (shu), a gene previously shown to be required for fertility in Drosophila, to the piRNA pathway. Analysis of knockdown phenotypes in both the germline and somatic compartments of the ovary demonstrate important roles for shutdown in both primary biogenesis and the ping-pong cycle. shutdown is a member of the FKBP family of immunophilins. Shu contains domains implicated in peptidyl-prolyl cis-trans isomerase activity and in the binding of HSP90-family chaperones, though the relevance of these domains to piRNA biogenesis is unknown. Published by Cold Spring Harbor Laboratory Press. Copyright © 2012 RNA Society

26 Ocena wyników pooperacyjnej radioterapii skojarzonej z 5-fluorouracylem u chorych na raka odbytnicy

Celem pracy była ocena wyników leczenia uzupełniającego z udziałem chemio- i radioterapii chorych po radykalnym zabiegu operacyjnym z powodu raka odbytnicy, ze szczególnym uwzględnieniem tolerancji leczenia. Materiał obejmuje 64 chorych leczonych w Klinice Onkologii i Radioterapii w Iatach1991–1995. Głównymi powikłaniami w czasie leczenia były biegunki (58%), nudności i wymioty (15%), objawy dyżuryczne (6%), leukopenia (33%) i niedokrwistość (5%). Do ostrych powikłań doszło ogółem 43 chorych (66%) w tym u 15 (23%) miały one charakter ciężki (stopień III i IV). Troje chorych nie ukończyło leczenia z powodu znacznego nasilenia objawów niepożądanych leczenia i pogorszenia stanu ogólnego.Późne powikłania, przede wszystkim w obrębie jelit i dróg moczowych, wystąpiły ogółem u 22 chorych (34%) w tym u 6 (9%)- w stopniu ciężkim. Spośród ocenionych 64 chorych dotychczas zmarło 19 (30%). Mediana czasu przeżycia w całej grupie wynosiła 37 miesięcy (11–60 miesięcy). Do wznowy miejscowej doszło u 15 chorych (23%) natomiast przerzuty odległe wystąpiły u 18 chorych (28%). Przedstawione wyniki, wskazujące na wysoki odsetek nawrotów oraz dużą liczbę powikłań popromiennych, skłoniły nas do zmiany techniki napromieniania. Efekty tych modyfikacji będzie można ocenić dopiero za kilka lat

Czech Social Reform/Non-reform: Routes, Actors and Problems

In this contribution, the author first considers the characteristics of the Czechoslovak communist welfare state and its theoretical alternatives. Throughout the reform process, dependency on both corporatist and socialist regimes won out, while residualist efforts were promoted in the beginning, but were later held back. The author then considers the possible actors involved in social reforms. In this respect, when proceeding from a general to a more concrete level, thought should first be devoted to the social classes and their ideologies, and second to political parties and their leaders. The author goes on to summarise the particular problems and traps in individual sections of the Czech social system. While no objection to decent standards of social protection and health care could be raised, the poor efficiency of their achievement should evoke concern. The author concludes by reflecting on the possible specificities of Czech social reform in comparison with the other countries undergoing reform and the EU. The current lethargy of the Czech welfare system corresponds to a “frozen edifice”, just as in most Western countries. However, such stagnation is apparently acceptable to both the politicians (who mask it in reformist rhetoric) and the population (which learned to master taking advantage of the generous welfare state) and thus is basically sustainable in the long run.http://deepblue.lib.umich.edu/bitstream/2027.42/40037/3/wp651.pd

Dipolar ordering in Fe8?

We show that the low-temperature physics of molecular nanomagnets, contrary to the prevailing one-molecule picture, must be determined by the long-range magnetic ordering due to many-body dipolar interactions. The calculations here performed, using Ewald's summation, suggest a ferromagnetic ground state with a Curie temperature of about 130 mK. The energy of this state is quite close to those of an antiferromagnetic state and to a glass of frozen spin chains. The latter may be realized at finite temperature due to its high entropy.Comment: 7 pages, no figures, submitted to EP