Metadynamics with Discriminants: a Tool for Understanding Chemistry

We introduce an extension of a recently published method\cite{Mendels2018} to obtain low-dimensional collective variables for studying multiple states free energy processes in chemical reactions. The only information needed is a collection of simple statistics of the equilibrium properties of the reactants and product states. No information on the reaction mechanism has to be given. The method allows studying a large variety of chemical reactivity problems including multiple reaction pathways, isomerization, stereo- and regiospecificity. We applied the method to two fundamental organic chemical reactions. First we study the \ce{S_N2} nucleophilic substitution reaction of a \ce{Cl} in \ce{CH_2 Cl_2} leading to an understanding of the kinetic origin of the chirality inversion in such processes. Subsequently, we tackle the problem of regioselectivity in the hydrobromination of propene revealing that the nature of empirical observations such as the Markovinikov's rules lies in the chemical kinetics rather than the thermodynamic stability of the products

"Australia’s most evil and repugnant nightspot” Foco Club and transnational politics in Brisbane’s ‘68’

This paper locates Brisbane – traditionally seen as a backwater both politically and culturally – within the transnational flows of people, ideas and actions which constituted global sixties activism. Host to a wide assortment of youth dissidents, Brisbane provided a plethora of streets and spaces in which activists became part of an imagined community of global revolt. Through investigating such locations, ranging from cultural centres such as the disco-cum-movie and poetry spot Foco Club to bookshops like Red and Black, radicals are revealed as engaging in a sophisticated and globally conscious urban politics of occupation and creative transformation – seeking to invent a differentially youthful social geography and everyday life in the face of overt hostility from the establishment. © 2011 The University of Queenslan

Gestione Chirurgica di Cisti e Fistole Cervicali in bambini e adolescenti: uno studio retrospettivo dal 2004 a oggi

la tesi si sviluppa analizzando un numero di pazienti pediatrici pari a circa 160, ricoverati negli ospedali di Cisanello e Anna Meyer per patologie cervicali. vengono analizzate caratteristiche come presentazione clinica, diagnosi, terapia, complicanze e recidive, confrontando tali statistiche con quelle più recenti, mediante una revisione della letteratura

The Secret of the World Remains Hidden: Roberto Bolańo as an Antiliterary Author

The Chilean author Roberto Bolańo cultivated a contentious (and contradictory) attitude to literature, believing that it conceals the fear and self-interest that coordinates its meaningfulness. For Bolańo, great writers should face the abyss of meaninglessness while standing tall, a directive which prohibits drawing conclusions that might ultimately be elevated to the level of fact. Instead, Bolańo commits to a category of truth that cannot be described by inscribing its contingent effects in his writing through what I will call his ‘antiliterature.’ Acknowledging this inaccessible truth, Bolańo’s writing reveals an aversion to all-encompassing literary forms that can be seen in the same light as Jacques Lacan’s term ‘antiphilosophy,’ describing the French psychoanalyst’s position against philosophy. Just as Lacanian antiphilosophy continues to contribute to twenty-first-century philosophical critiques, Bolańo’s antiliterature renders possible novel literary trajectories. Bolańo’s 2009 novel 2666 exemplifies his antiliterary approach, subverting the literary genre of crime fiction by refusing to supply an object to fulfil the reader’s desire for closure and by universalising guilt

A microscopic description of acid-base equilibrium

Acid-base reactions are ubiquitous in nature. Understanding their mechanisms is crucial in many fields, from biochemistry to industrial catalysis. Unfortunately, experiments only give limited information without much insight into the molecular behaviour. Atomistic simulations could complement experiments and shed precious light on microscopic mechanisms. The large free energy barriers connected to proton dissociation however make the use of enhanced sampling methods mandatory. Here we perform an ab initio molecular dynamics (MD) simulation and enhance sampling with the help of methadynamics. This has been made possible by the introduction of novel descriptors or collective variables (CVs) that are based on a conceptually new outlook on acid-base equilibria. We test successfully our approach on three different aqueous solutions of acetic acid, ammonia, and bicarbonate. These are representative of acid, basic, and amphoteric behaviour

Relevant results from the NA48 experiment

We report relevant results from NA48 experiment at CERN SPS. NA48 was proposed in 1990 \cite{proposal} to study direct CP violation in $K^0\to\pi\pi$ to a level of accuracy sufficient to resolve the inconclusive status left by the previous measurements performed by NA31 \cite{NA31} and E731 \cite{E731}. In 2002 NA48 published the final result \cite{NA48epsoeps}. Small modification to the experimental setup have allowed NA48 to go forward with an extensive investigation of $K^0$ rare decays and hyperon decays. Some results are already available and reported here together with the final CP violation measurement.Comment: 3 pages, 1 eps figure, XXIII Physics in collisio

Travel, Politics and the Limits of Liminality During Australia’s Sixties

Victor Turner describes the individual experience of travel as ‘liminal’. Opening new vistas of possibility, it upturns ordinary social conventions and codes, constructing in their place new communities of hope and change. Such utopian moments of encounter are, however, just that—moments that are fleeting and generally inconsequential. This paper seeks to understand and critique Turner’s ideas of liminality, pilgrimage and communitas within the context of Australian social movements in the ‘long’ and ‘global’ 1960s. Though often ignored or marginalised in local and international scholarship, Australia had a much more complex and interesting experience of this period than the paucity of scholarly work would indicate. In fact, a variety of activists in areas ranging from Indigenous rights to the peace and workers movements pushed the boundaries of political discourse during a period marked by stultifying social and cultural climates. Through a focus on three travel narratives—those of Brisbane radical Brian Laver and young Communist Party of Australia (CPA) members to Czechoslovakia and Bulgaria during 1968, Sydney Trotskyite Denis Freney to Algeria in the early 1960s and five Indigenous activists to a Black Power conference in Atlanta, Georgia in 1970—this paper will highlight the importance of global connections to Australian social movements. The notion of liminality will initially be critiqued through a focus on pre-histories to travel: the ideas, rumours and local problems that can be glossed over in work heralding the power of the moment. Such moments of encounter were, however, still transformative for these activists, with their variety of experiences facilitating what Turner called communitas, spontaneous affinities and solidarities across borders of race, culture and understanding. The pilgrims’ return concludes this discussion, with their ‘translation’ of global ideas into new, local contexts giving them the role not just of a missionary, but also a mediator—disrupting travel’s supposed fleetingness and locating its importance to the transnational flow of ideas during the Sixties

Systematic Analysis of Gene Expression Differences between Left and Right Atria in Different Mouse Strains and in Human Atrial Tissue

Background: Normal development of the atria requires left-right differentiation during embryonic development. Reduced expression of Pitx2c (paired-like homeodomain transcription factor 2, isoform c), a key regulator of left-right asymmetry, has recently been linked to atrial fibrillation. We therefore systematically studied the molecular composition of left and right atrial tissue in adult murine and human atria. Methods: We compared left and right atrial gene expression in healthy, adult mice of different strains and ages by employing whole genome array analyses on freshly frozen atrial tissue. Selected genes with enriched expression in either atrium were validated by RT-qPCR and Western blot in further animals and in shock-frozen left and right atrial appendages of patients undergoing open heart surgery. Results: We identified 77 genes with preferential expression in one atrium that were common in all strains and age groups analysed. Independent of strain and age, Pitx2c was the gene with the highest enrichment in left atrium, while Bmp10, a member of the TGFb family, showed highest enrichment in right atrium. These differences were validated by RT-qPCR in murine and human tissue. Western blot showed a 2-fold left-right concentration gradient in PITX2 protein in adult human atria. Several of the genes and gene groups enriched in left atria have a known biological role for maintenance of healthy physiology, specifically the prevention of atrial pathologies involved in atrial fibrillation, including membrane electrophysiology, metabolic cellular function, and regulation of inflammatory processes. Comparison of the array datasets with published array analyses in heterozygous Pitx2c+/2 atria suggested that approximately half of the genes with left-sided enrichment are regulated by Pitx2c. Conclusions: Our study reveals systematic differences between left and right atrial gene expression and supports the hypothesis that Pitx2c has a functional role in maintaining ‘‘leftness’’ in the atrium in adult murine and human hearts