505 research outputs found
Formalising the pi-calculus using nominal logic
We formalise the pi-calculus using the nominal datatype package, based on
ideas from the nominal logic by Pitts et al., and demonstrate an implementation
in Isabelle/HOL. The purpose is to derive powerful induction rules for the
semantics in order to conduct machine checkable proofs, closely following the
intuitive arguments found in manual proofs. In this way we have covered many of
the standard theorems of bisimulation equivalence and congruence, both late and
early, and both strong and weak in a uniform manner. We thus provide one of the
most extensive formalisations of a process calculus ever done inside a theorem
prover.
A significant gain in our formulation is that agents are identified up to
alpha-equivalence, thereby greatly reducing the arguments about bound names.
This is a normal strategy for manual proofs about the pi-calculus, but that
kind of hand waving has previously been difficult to incorporate smoothly in an
interactive theorem prover. We show how the nominal logic formalism and its
support in Isabelle accomplishes this and thus significantly reduces the tedium
of conducting completely formal proofs. This improves on previous work using
weak higher order abstract syntax since we do not need extra assumptions to
filter out exotic terms and can keep all arguments within a familiar
first-order logic.Comment: 36 pages, 3 figure
Potential of Radiotelescopes for Atmospheric Line Observations: I. Observation Principles and Transmission Curves for Selected Sites
Existing and planned radiotelescopes working in the millimetre (mm) and
sub-millimetre wavelengths range provide the possibility to be used for
atmospheric line observations. To scrutinize this potential, we outline the
differences and similarities in technical equipment and observing techniques
between ground-based aeronomy mm-wave radiometers and radiotelescopes.
Comprehensive tables summarizing the technical characteristics of existing and
future (sub)-mm radiotelescopes are given. The advantages and disadvantages
using radiotelescopes for atmospheric line observations are discussed. In view
of the importance of exploring the sub-mm and far-infrared wavelengths range
for astronomical observations and atmospheric sciences, we present model
calculations of the atmospheric transmission for selected telescope sites
(DOME-C/Antarctica, ALMA/Chajnantor, JCMT and CSO on Mauna Kea/Hawaii,
KOSMA/Swiss Alpes) for frequencies between 0 and 2000 GHz (150 micron) and
typical atmospheric conditions using the forward model MOLIERE (version~5). For
the DOME-C site, the transmission over a larger range of up to 10 THz (30
micron) is calculated in order to demonstrate the quality of an earth-bound
site for mid-IR observations. All results are available on a dedicated webpage
(http://transmissioncurves.free.fr)Comment: Planetary and Space Science accepted (in press), see also website
http://transmissioncurves.free.f
Another Drop in Water Vapor
In 2000 a sudden severe drop in stratospheric water vapor levels interrupted the supposed long-term increase of this greenhouse gas, an important contributor to global warming and climate variability. Satellite sensors observed a recovery in the following years, hidden behind a large variability. More recently, during 2011 and 2012, measurements revealed another severe drop in stratospheric water vapor concentrations
Role models and trust in socio-political institutions: a case study in Eastern Germany, 1992-96
Die Studie erörtert die Entstehung des Vertrauens in sozio-politische Institutionen unter Jugendlichen in Ostdeutschland im Zeitraum 1992 bis 1996. Dabei berĂŒcksichtigt sie insbesondere Effekte, die entstehen, wenn Jugendliche ihre Eltern (oder Elternteile) als soziale Vorbilder akzeptieren. Die Analyse basiert auf Befragungen von SchĂŒlern aus Regelschulen und Gymnasien, die in einem ausgewĂ€hlten Landkreis in ThĂŒringen durchgefĂŒhrt wurden. Eine Faktorenanalyse von Indikatoren des Vertrauens in mehrere soziale und politische Institutionen ermittelte einen gemeinsamen Faktor des Vertrauens in fĂŒnf sozio-politische Institutionen, die alle zum staatlichen Sektor zu rechnen sind, und die gröĂtenteils eine stark hierarchische Struktur aufweisen: das MilitĂ€r, die Polizei, das Rechtssystem, die öffentliche Verwaltung (unter AusschluĂ der zentralstaatlichen Regierung) und das Parlament. Mehrere multiple Regressionsmodelle (mit unabhĂ€ngigen Variablen zur Vorbildfunktion von Eltern, zu verschiedenen politischen Einstellungen, sowie zur Bewertung der ökonomischen Situation und der sozialen Schichtzugehörigkeit) zeigten, dass positive Bewertungen der staatlichen Vereinigung Deutschlands und die Akzeptanz der Eltern (oder eines Elternteils) als soziale Vorbilder die beiden wichtigsten Determinanten fĂŒr das ermittelte Vertrauen in sozio-politische Institutionen waren. In den frĂŒhen Jahren der Transformation verstĂ€rkte sich der positive Einfluss dieser beiden Variablen auf das Ausmass des Institutionenvertrauens mit zunehmender Distanz vom Zeitpunkt der Wiedervereinigung, wĂ€hrend dieser Einfluss nach 1994 leicht abfiel, aber immer noch oberhalb des 1992er Wertes verblieb. Diese Ergebnisse zeigen, dass Effekte der Sozialisation wichtige ErgĂ€nzungen zum VerstĂ€ndnis des Einflusses von situativen und schichtabhĂ€ngigen Faktoren auf die Entstehung des Vertrauens in sozio-politische Institutionen unter ostdeutschen Jugendlichen sind.This paper discusses the development of trust in socio-political institutions on the part of youth in eastern Germany during the period 1992-96, with special emphasis on the effect of having parents as role model. The analysis is based on surveys of middle and high school students that were conducted by the authors in a county in Thuringia. A factor analysis of trust in a number of social and political institutions yielded a factor comprising five socio-political institutions that belong to the state sector and, for the most part, have a strong hierarchical structure: the military, police, legal system, public administration (but not the government proper), and parliament. Our multiple regression models (including parental role model, various political attitudes, evaluation of the economic situation, and stratification) showed that favorable attitudes towards unification and having parents as role model were the two most important determinants of having trust in socio-political institutions. The positive effects of these two variables on trust became stronger with growing temporal distance from unification during the early years of the transformation; the strength of the effects dropped slightly after 1994 but remained well above the 1992 level. These findings show that socialization variables are an important addition to situational and stratification factors in understanding the development of trust in socio-political institutions among eastern German youth
Integrated systems analysis reveals a molecular network underlying autism spectrum disorders.
Autism is a complex disease whose etiology remains elusive. We integrated previously and newly generated data and developed a systems framework involving the interactome, gene expression and genome sequencing to identify a protein interaction module with members strongly enriched for autism candidate genes. Sequencing of 25 patients confirmed the involvement of this module in autism, which was subsequently validated using an independent cohort of over 500 patients. Expression of this module was dichotomized with a ubiquitously expressed subcomponent and another subcomponent preferentially expressed in the corpus callosum, which was significantly affected by our identified mutations in the network center. RNA-sequencing of the corpus callosum from patients with autism exhibited extensive gene mis-expression in this module, and our immunochemical analysis showed that the human corpus callosum is predominantly populated by oligodendrocyte cells. Analysis of functional genomic data further revealed a significant involvement of this module in the development of oligodendrocyte cells in mouse brain. Our analysis delineates a natural network involved in autism, helps uncover novel candidate genes for this disease and improves our understanding of its molecular pathology
Wird pÀdosexuelles Verhalten in jungen Jahren erlernt? Eine empirische Fall-Kontroll-Studie
'Die Studie testet die These, nach der sexuell befriedigende Beziehungen in ersten Freund- und Partnerschaften unter Kindern und Jugendlichen zur Entstehung und Generalisierung eines paedosexuellen Verhaltensmodells fuehren koennen, welches das Risiko paedosexuell delinquenten Verhaltens im Erwachsenenalter erhoeht. Zum Test dieser Sozialisationsthese standen Daten aus retrospektiven Selbstreports und Gefangenenpersonalakten von inhaftierten maennlichen paedosexuellen Straftaetern (Untersuchungsgruppe) und inhaftierten maennlichen nicht-paedosexuellen Gewaltstraftaetern (Kontrollgruppe) zur Verfuegung. Die Tests wurden mittels asymptotischer und exakter logistischer Regressionsschaetzungen in gematchten Samples mit 1x1-Paaren und mxn-Gruppenpaarungen durchgefuehrt. Die Tests konnten die Sozialisationsthese nicht bestaetigen. Jedoch koennen paedosexuelle Lerneffekte durch Opfer-Taeter-Transitionen entstehen.' (Autorenreferat)'The study explores a socialization thesis of pedosexuality claiming that satisfactory sexual contacts in first peer relationships among children and adolescents can lead to the development and generalization of pedosexual behavioral models increasing the risk of pedosexual delinquent behavior in adulthood. Our statistical tests were based on data from retrospective self-reports and court files of male pedosexual and male non-pedosexual arrested offenders. Logistic regression analysis (with both asymptotic and exact estimators) was applied to matched samples of l x l-paired cases and mxn-paired groups of cases. The tests could not confirm the socialization thesis of pedosexuality. However, there were effects of pedosexual learning caused by victim-to-victimizer transitions.' (author's abstract)
VerÀnderungen von auslÀnderablehnenden Einstellungen in der Adoleszenzphase ostdeutscher Jugendlicher: Ergebnisse einer regionalen 3-Jahres-Panelstudie im Zeitraum von 1994 bis 1996
'Die Studie analysiert die Formierung von Einstellungen der nationalisierenden AuslĂ€nderablehnung in der Adoleszenzphase von Jugendlichen zwischen dem 15ten und 17ten Lebensjahr. Die Analyse basiert auf den Daten einer 3-Wellen-Panelbefragung von Jugendlichen (N=131), die von den Autoren zwischen 1994 und 1996 in einem Landkreis in OstthĂŒringen durchgefĂŒhrt wurde. Die Studie ermittelt bei den befragten Jugendlichen einen Anteil von 25 Prozent mit deutlich bzw. stark ausgeprĂ€gten, manifest nationalisierend-auslĂ€nderablehnenden Einstellungen. Dieser Anteil steigt bis durchschnittlich 50 Prozent an, wenn das Vorhandensein einer rein emotionalen AuslĂ€nderablehnung und nicht die Existenz eines Einstellungssyndroms, das nationalisierende und auslĂ€nderablehnende Kognitionen miteinander verbindet, analysiert wird. Zwei Drittel der Jugendlichen halten an ihrer Meinung zu AuslĂ€ndern zwischen dem 15ten und 17ten Lebensjahr unverĂ€ndert fest, wobei die Einstellungskonstanz von auslĂ€nderakzeptierenden Jugendlichen besonders hoch ist. Von denjenigen Jugendlichen, die ihre Meinung zu AuslĂ€ndern im beobachteten 3-Jahres-Zeitraum Ă€ndern, wechseln mehr Jugendliche zu auslĂ€nderakeptierenden als zu auslĂ€nderablehnenden Positionen. Wenn auslĂ€nderakzeptierende Jugendliche ihre Meinung Ă€ndern, wechseln sie hĂ€ufiger zu mittleren bzw. indifferenten Positionen als zu auslĂ€nderablehnenden Einstellungen, wĂ€hrend Jugendliche, die ihre auslĂ€nderablehnende Haltung aufgeben, eher zu auslĂ€nderakeptierenden als zu indifferenten Positionen wechseln. Mit zunehmendem Alter verlangsamt sich der Trend hin zu auslĂ€nderakzeptierenden Einstellungen, und auch der Anteil von Jugendlichen, die zu auslĂ€nderablehnenden Positionen wechseln, nimmt mit zunehmendem Alter wieder deutlich zu. Die Ergebnisse können mit zwei wichtigen EinschrĂ€nkungen als mikrosoziologische BestĂ€tigung der makrosoziologischen These von der Herausbildung eines neuen MentalitĂ€tstpys junger Ostdeutscher interpretiert werden.' (Autorenreferat)'The study analyzes the formation of attitudes regarding a nationalistic rejection of foreigners among youth between 15 and 17years of age. The analysis is based on data from a three-wave panel survey of youth (N=131) that the authors conducted between 1994 and 1996 in a non-metropolitan county in eastern Thuringia. The study indicated that 25 percent of the respondents had pronounced attitudes against foreigners; these attitudes were clearly nationalistic. This proportion increases to an average of 50 percent, if only the presence of a mere emotional rejection of foreigners is analyzed, and not the existence of an attitudinal syndrome combining the cognition of nationalizing and anti-foreigner cognition. Two-thirds of youth maintain their views towards foreigners between 15 and 17 years of age, with a particularly high stability of attitudes among those youth who accept foreigners. Among youth who change their views towards foreigners during the 3-year period, more youth change to a position of foreigner acceptance than to one of foreigner rejection. When youth who accept foreigners, change their views, they typically shift to neutral positions, rather than to a rejection of foreigners. In contrast, those youth who change from a rejection of foreigners are more likely to shift to a position of acceptance than to a neutral stance. With increasing age, the tendency towards acceptance of foreigners slows down, and a growing proportion of youth exhibits negative attitudes towards foreigners. The findings, albeit with two important qualifications, provide microsociological support for the macro-sociological thesis of the emergence of a new type of young East-Germans.' (author's abstract)
Descent from the polar mesosphere and anomalously high stratopause observed in 8 years of water vapor and temperature satellite observations by the Odin Sub-Millimeter Radiometer
Using newly analyzed mesospheric water vapor and temperature observations from the Sub-Millimeter Radiometer instrument aboard the Odin research satellite over the period 2001-2009, we present evidence for an anomalously strong descent of dry mesospheric air from the lower mesosphere into the upper stratosphere in the winters of 2004, 2006, and 2009. In the three cases, the descent follows the recovery of the upper stratospheric polar vortex from a major midwinter stratospheric sudden warming. It is also accompanied by the rapid formation of an anomalously warm polar mesospheric layer, i.e., an elevated polar stratopause, near 75 km, and its slower descent to prewarming level (near 1 hPa) over 1.5-2 months. These three winters stand out in the current record of Odin/Sub-Millimeter Radiometer observations started in July 2001
PĂ€dosexueller Missbrauch: wenn Opfer zu TĂ€tern werden. Eine empirische Studie
This study reports on statistical analyses of the emergence of pedosexual delinquency. It is based on retrospective self-reports and the court files of 490 offenders, both pedosexual and non-pedosexual, who were arrested. The results of logistic regression analyses (with both asymptotic and exact estimators) show that pedosexually victimized children have an increased risk of becoming child molesters. In addition, the results show that victimized children who behave aggressively in childhood and adolescence have a reduced risk of pedosexual delinquency. Possibly, this aggressive behavior has to be understood as a strategy for coping with the trauma of pedosexual abuse. However, the study did not find any effect on the likelihood of becoming an adult child molester in later years.Die vorliegende Studie berichtet ĂŒber Analysen zur Entstehung pĂ€dosexueller Delinquenz. Als Datengrundlage dienen retrospektive Selbstreports sowie Gefangenenpersonalakten von 490 pĂ€dosexuellen und nichtpĂ€dosexuellen inhaftierten mĂ€nnlichen StraftĂ€tern. Die Ergebnisse von logistischen Regressionsanalysen (mit asymptotischen und exakten SchĂ€tzern) können bestĂ€tigen, dass pĂ€dosexuell viktimisierte Personen eine gesteigerte Chance aufweisen, im Erwachsenenalter ein pĂ€dosexuelles Delikt zu begehen. Des Weiteren gilt, dass pĂ€dosexuell viktimisierte Personen, die in ihrer Kindheit ein besonders aggressives Verhalten aufweisen, im Erwachsenenalter eine reduzierte Chance fĂŒr eine pĂ€dosexuelle Delinquenz haben. Möglicherweise ist das aggressive Verhalten als eine Strategie zu verstehen, das Trauma eines sexuellen Missbrauchs zu bewĂ€ltigen. Im Ăbrigen kann die Studie keinen Effekt der Normalisierung pĂ€dosexueller Viktimisierungserfahrungen auf eine spĂ€tere pĂ€dosexuelle TĂ€terschaft nachweisen
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