84 research outputs found
Halfmann_OpenPracticesDisclosure_rev – Supplemental material for Replicating Roaches: A Preregistered Direct Replication of Zajonc, Heingartner, and Herman’s (1969) Social-Facilitation Study
No full textSupplemental material, Halfmann_OpenPracticesDisclosure_rev for Replicating Roaches: A Preregistered Direct Replication of Zajonc, Heingartner, and Herman’s (1969) Social-
Facilitation Study by Emma Halfmann, Janne Bredehöft and Jan Alexander Häusser in Psychological Science</p
Iulius Alexander in Iulius Iulianus. K prozopografiji 2. stoletja
No full textProzopografska raziskovanja so otežkočena, če imamo o eni osebi mnogo drobnih enkratnih podatkov, ki vsak osvetljuje zgolj drobec iz kariere raziskovane osebe, posebej, četudi imensko ni precizno določena. Imena na spomenikih, posebej polionimnih oseb so često podana reducirano. V takem primeru pomaga morda analiza podatkov, predvsem opravljenih funkcij, ki se ali podajo v časovno enakomerno in administrativno utemeljeno zaporedje, ali pa ne. Analiza mora torej izkristalizirati ali gre pri podatkih v virih za eno ali za več oseb. To je zapleten problem tudi za osebi, navedeni v naslovu, za kateri je predložil avtor kompletno dokumentacijo zgoraj pod št. 1—15. Posamezno navedene funkcije in podatke je podvrgel kronološki in stvarni analizi, preciziral nekaj sumarnih navedb v virih, hkrati zavzel stališča do rezultatov dosedanjih raziskovalcev in prišel do naslednjih zaključkov. T i. Iulius Iulianus Alexander, ki je bil po viru 15 curator operum locorumque publicorum — torej bivši konzul — je istoveten z osebo iz aktov arvalskih bratov (10—14), ter hkrati identičen s provincialnim namestnikom v Arabiji v letih 126 ali 127.3 Slednje mesto je vodilo neposredno v konzulat. Zato je točno datiranje njegovega konzulstva bistveno. Ker so konzuli za leti 127 in 128 vsi dokumentirani, je Julianus to mesto lahko dosegel ali v letu 126 ali 129 (oz. 130). V slednjem prim eru bi moral čakati na dosego konzulata dve ali tri leta, kar bi ustvarilo analogijo s kariero Seksta Julija Maior, ki je bil že 126 (127?) legatus Augusti pro praetore 3. Avguste v Numidiji in konzul morda šele 129/130. Ob tem se postavlja vprašanje o časovnem intervalu med poslednjim provincialnim namestništvom in imenovanjem za konzula. Prozopografske raziskave so pokazale, da je namestništvu v vladarski provinci z legijsko posadko sledilo imenovanje navadno že v zadnjem letu namestništva ali takoj v naslednjem letu (konzulat je opravljal često in absentia; poznanih je tudi nekaj izjem). Drugače je bilo v vladarskih provincah brez legije. Tudi tam je sledilo imenovanje za konzula, vendar navadno z nekajletnim intervalom. Sledi torej, da je bil več kot verjetno tudi Ti. Iulius Iulianus Alexander takoj po namestništvu v Arabiji imenovan za konzula, to je v letu 126. Če to sprejmemo, potem osebe iz napisov 5—7, katere cognomen je tudi Julianus, ne moremo istovetiti s konzulom, pač pa gre pri njej za sufektnega konzula iz ok. 130 in prokonzula Asiae iz leta 145, namreč Ti. Klavdija Julijana. Tudi pod št. 1 omenjeni hypostràtegos Iulius Alexander več kot verjetno ni identičen s Ti. Julijem Julianom Aleksandrom. Če bi namreč bil, bi bil v rangu propretorskega legata ter bi moral kmalu nato doseči imenovanje za konzula. Če bi pa v Juliju Julijanu gledali legijskega legata, bi morali predpostaviti, da je Cassius Dio porabljal eno in isto oznako za dve različni pretorski stopnji; na drugi strani pa bi bil Julianus že pred 116. praetor, in sicer z dokaj dolgim intervalom do konzulata. Vse kaže, da je najbolj prepričljivo istovetiti hyposträtega Julija Aleksandra z Gajem Julijem Aleksandrom Berenicijanom. 2e prej so domnevali, da je Ti. Iulius Iulianus Alexander potomec Tiberija Julija Aleksandra (iz židovske občine v Aleksandriji), ki je dal kot praefectus Aegypti leta 69 vzpodbudo za proklamiranje Vespazijana kot vladarja. Da si je izbral Julianus za glavni cognomen Julianus in ne Alexander, je morda utemeljeno tudi s tem, da ne bi prihajalo do zamenjave s potomcem armenske vladarske hiše Gajem Julijem Aleksandrom in Gajem Julijem Aleksandrom Berenicijanom, ki sta bila njegova generacija. Ti. Iulius Iulianus Alexander je spadal torej v krog oseb iz grškega vzhoda, ki jim je Trajan omogočil vstop v senat, predvsem L. Aemilius Iuncus, Sex. Iulius Maior, L. Flavius Arrianus, Ti. Claudius Iulianus. Njih dostop do vrhunskih pozicij je hkrati seveda omogočil tudi protekcijo za vrsto mladih sonarodnjakov
Identifizierung des Regulons des Zwei-Komponenten Systems CiaRH von Streptococcus pneumoniae
No full textDas Zwei-Komponenten System CiaRH beeinflusst die genetische Kompetenz, das Lyseverhalten, die Virulenz und die Resistenz gegen Cefotaxim von S. pneumoniae. Der entscheidende Einfluss von CiaRH für S. pneumoniae zeigt sich auch darin, dass in mehreren Transkriptomstudien eine große Zahl von Genen identifiziert wurde, die in Abhängigkeit des Zwei-Komponenten Systems transkribiert werden. In dieser Arbeit konnten nun die Gene, deren Transkription direkt durch Bindung des Response Regulators CiaR in ihrem Promotorbereich reguliert wird, eindeutig definiert werden. Durch die Kombination von transkriptionellen Reportergenfusionen in dem neu konstruierten Promoter Probe Plasmid pPP2, Bandshiftassays und Mutageneseexperimenten wurde als Bindestelle von CiaR ein Direct Repeat mit der Sequenz TTTAAG-N5-TTTAAG identifiziert. Für 16 Promotoren mit dieser Bindestelle wurden eine Bindung von CiaR und eine CiaRH abhängige Expression nachgewiesen. Von den 16 Promotoren sind 15 positiv und nur einer negativ reguliert. Insgesamt besteht das CiaRH Regulon aus 30 Genen, wobei 19 Gene in 6 Operons organisiert sind. Zum CiaRH Regulon gehören ciaRH selbst, eine Vielzahl von Genen, die am Zellwandmetabolismus beteiligt sind (lic1 Operon, dlt Operon), die Gene von fünf kleinen nicht-kodierenden RNAs (ccnA-E), die Stressprotease HtrA, das Chromosomensegregationsprotein ParB, die Peptidyl-Prolyl Isomerase PpmA, die Maltoseverwertungsgene malMP, das Phosphotransferasesystem ManLMN und mehrere Gene mit unbekannter Funktion. Die eindeutige Identifizierung der Gene des Regulons des Zwei-Komponenten Systems CiaRH ermöglicht eine detaillierte Analyse der Zusammenhänge mit den cia-vermittelten Phänotypen. In einem zweiten Teil dieser Arbeit wurde darauf eingegangen, welche Rolle die Histidinkinase CiaH spielt und woher das Phosphat für die Phosphorylierung des Response Regulators CiaR stammt. Es wurde durch Einbringen der Mutation D51A in CiaR gezeigt, dass das Aspartat an dieser Stelle des Proteins entscheidend für die Aktivität von CiaR als transkriptionellen Regulator ist. CiaH ist hingegen während des exponentiellen Wachstums in C-Medium für die Aktivität von CiaR verzichtbar. Die Promotoren des CiaRH Regulons zeigten in Abwesenheit der Kinase während dieser Wachstumsphase keine veränderte Aktivität. Die Phosphorylierung von CiaR muss daher auch über einen anderen Weg, beispielsweise über Acetylphosphat, erfolgen können. Deshalb wurde auch der Einfluss der Inaktivierung von spxB, dem Gen für eine Pyruvatoxidase, welche die Synthese eines Großteils des zellulären Acetylphosphats in S. pneumoniae katalysiert, untersucht. Eine entscheidende Rolle wurde für CiaH bei Eintritt in die stationäre Wachstumsphase beobachtet. Es konnte gezeigt werden, dass zu diesem Zeitpunkt nur bei vorhandenem CiaH ein Anstieg der Aktivität der Promotoren des CiaRH Regulons stattfindet. Dies deutet darauf hin, dass die Histidinkinase beim Übergang in die stationäre Phase ein Signal erhält, das die Aktivierung des CiaRH Regulons stimuliert. Möglicherweise können daraus Ansätze zur Identifizierung des bisher unbekannten Signals von CiaH entwickelt werden
Strong quantum interferences in frequency up-conversion towards short vacuum-ultraviolet radiation pulses
No full textReplicating roaches: a preregistered direct replication of Zajonc, Heingartner, and Herman’s (1969) social-facilitation study
No full textFifty years ago, Zajonc, Heingartner, and Herman (1969) conducted a famous experiment on social enhancement and inhibition of performance in cockroaches. A moderating effect of task difficulty on the effect of the presence of an audience, as revealed by impaired performance in complex tasks and enhanced performance in simple tasks, was presented as the major conclusion of this research. However, the researchers did not test this interaction statistically. We conducted a preregistered direct replication using a 2 (audience: present vs. absent) × 2 (task difficulty: runway vs. maze) between-subjects design. Results revealed main effects for task difficulty, with faster running times in the runway than the maze, and for audience, with slower running times when the audience was present than when it was absent. There was no interaction between the presence of an audience and task difficulty. Although we replicated the social-inhibition effect, there was no evidence for a social-facilitation effect
Trapped between goal conflict and availability norm? How users’ mobile messaging behavior during task engagement influences negative self-conscious emotions
No full textAn increasing number of studies indicate that individuals have difficulties in exerting self-control over media use, such as mobile messaging. Specifically, individuals frequently experience that their messenger use conflicts with primary goals (e.g., work tasks), which may cause negative self-conscious emotions such as guilt. At the same time, not checking and answering messages violates a now widely established availability norm, which may trigger negative self-conscious emotions as well. The current study, therefore, tests how goal conflicts and connection cues interact in influencing users’ negative self-conscious emotions about their messenger usage behavior. Drawing on self-control research in conjunction with self-determination theory and theoretical approaches to social norms, we derived hypotheses on the boundary conditions under which the frequency of messenger use causes negative self-conscious emotions. We thereby significantly extend previous research on the self-regulation of mobile media use, which largely assumes that self-control failure results from users’ intrinsic motivation to experience need satisfaction and pleasure and tends to overlook the fact that mediated communication is often extrinsically motivated due to the availability norm. The hypotheses were tested based on a preregistered laboratory experiment
Discovery and characterization of prions in S. cerevisiae
No full textThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis. Vita.Includes bibliographical references.Some protein aggregates can perpetuate themselves in a self-templating protein-misfolding reaction. These aggregates, or prions, are the infectious agents behind diseases like Kuru and mad-cow disease. In yeast, however, prions act as epigenetic elements that confer heritable alternative phenotypes. Prion-forming proteins create bistable molecular systems whose semi-stochastic switching between functional states increases phenotypic diversity within cell populations. My thesis work explores the idea that rather than being detrimental, prions may commonly act to their host's advantage. To broaden the known range of prion phenomena in S. cerevisiae, I, together with a postdoctoral fellow in our lab, systematically surveyed the yeast proteome for prion-forming proteins. Using a combination of computational, cell biological, and biochemical approaches, we ultimately identified 18 novel prion domains capable of driving phenotypic switching, and an additional 6 domains that were highly positive for prion-like aggregation in other assays. These results establish the critical importance of intrinsic amyloid-forming tendencies for prion behavior by Q/N-rich proteins. We further confirmed that one of these proteins, the transcription factor Mot3, forms a novel prion in its endogenous context. An analysis of these findings revealed a strong and unexpected amino acid bias in prionogenic proteins: prions were strongly enriched for asparagine (N), but not the chemically related amino acid glutamine (Q). We validated this finding using molecular simulations and experimental analyses of Q-to-N and N-to-Q variants of prion domains. N-rich sequences had an intrinsic tendency to both nucleate and propagate amyloid conformers. Q-rich proteins tended instead to make structurally non-constrained interactions leading to proteotoxic soluble and non-amyloid aggregated conformers. The appendices include works in progress. Each explores a different aspect of prion biology. Appendix A confirms a theoretical prediction that prions, if functional, should preferentially regulate certain rapidly evolving genes. I demonstrate with the newly discovered prion protein, Mot3, that prions accelerate the appearance of new phenotypes in important traits like mating behavior and cell-adhesion. I further identify naturally occurring prion states of Mot3 and other prion proteins in wild yeast isolates, and show that elimination of these prions has strong phenotypic effects in these strains. Appendix B, work done in collaboration with another lab, establishes that Nup100, a GLFG nucleoporin, is a prion. The conformational flexibility of GLFG nucleoporins is critical for the function of the nuclear pore complex, a molecular sieve that regulates all macromolecular transport between the nucleus and cytoplasm.by Randal A. Halfmann.Ph.D
- …
