Finite TYCZ expansions and cscK metrics

Let $(M, g)$ be a Kaehler manifold whose associated Kaehler form $\omega$ is integral and let $(L, h)\rightarrow (M, \omega)$ be a quantization hermitian line bundle. In this paper we study those Kaehler manifolds $(M, g)$ admitting a finite TYCZ expansion. We show that if the TYCZ expansion is finite then $T_{mg}$ is indeed a polynomial in $m$ of degree $n$, $n=dim M$, and the log-term of the Szeg\"{o} kernel of the disc bundle $D\subset L^*$ vanishes (where $L^*$ is the dual bundle of $L$). Moreover, we provide a complete classification of the Kaehler manifolds admitting finite TYCZ expansion either when $M$ is a complex curve or when $M$ is a complex surface with a cscK metric which admits a radial Kaehler potential

Dynamic force spectroscopy of DNA hairpins. II. Irreversibility and dissipation

We investigate irreversibility and dissipation in single molecules that cooperatively fold/unfold in a two state manner under the action of mechanical force. We apply path thermodynamics to derive analytical expressions for the average dissipated work and the average hopping number in two state systems. It is shown how these quantities only depend on two parameters that characterize the folding/unfolding kinetics of the molecule: the fragility and the coexistence hopping rate. The latter has to be rescaled to take into account the appropriate experimental setup. Finally we carry out pulling experiments with optical tweezers in a specifically designed DNA hairpin that shows two-state cooperative folding. We then use these experimental results to validate our theoretical predictions.Comment: 28 pages, 12 figure

Applied research by design: an experimental collaborative and interdisciplinary design charrette

This article reports on one experimental case of interdisciplinary collaboration on a design and planning exercise across several scales – local through urban to regional – and sectors – private, public, scholarly, and interest groups. The case is a collaborative and interdisciplinary design charrette on sustainable urbanism for envisioning the future of the Greater Metropolitan Area of Florence in Italy. The experiment entailed the attempt to integrate complex urban conditions via the design charrette in order to create more healthy and sustainable cities. This collaborative work shows how conditions that are at times not addressed comprehensively nor holistically can be combined through doing applied research by design; where design is understood as a process of discovery and creation that results in synthesis. The article details the methodology applied, and provides an initial assessment on the process that the charrette employed. Moreover, it highlights some professional and policy implications of the effort. Finally, it provides a provisional assessment on learning outcomes and addresses opportunities to improve future exercises of this nature

Saudi English-Language Teachers’ Perceptions and Reported Practices of Teacher Leadership

This interpretive study explored how Saudi Arabian nationals employed as English-language teachers within intermediate and secondary Saudi schools understand the concept of teacher leadership, and how they perceive themselves as teacher leaders. The study also explored teachers’ views of current factors that empower or disempower them in being teacher leaders, as well as the roles and support they desire. The research used an exploratory design methodology encompassing three qualitative research methods: focus groups, one-to-one semi-structured interviews and reflective essays. The participants included nine Saudi English-language teachers from intermediate and secondary public schools. Participants were able to define teacher leadership in relation to: practices inside the classroom, practices outside the classroom and teacher knowledge and professionalism. The participants also perceived themselves as teacher leaders with potential professional capital that would allow them to engage and participate professionally in their school community of practice. The data revealed that teacher leadership is not the general practice in Saudi public schools; however, participants reported practices of teacher leadership that they desired and aspired to. The study also reported the many barriers to teacher leadership that currently exist, such as lack of teacher leadership roles, lack of support from the heavily centralised educational hierarchy, insufficient and inadequate pre-service and in-service training, and lack of voice in decision-making processes. Despite these barriers, the participants were eager to act in teacher leadership roles because they believe these roles carry benefits for themselves, their colleagues, headteachers, curricula and students. Based on the data obtained in the research, the study proposed a model for “professional teacher leadership” that supports teacher leaders as professionals who have professional capital to work with professional agency and autonomy in a positive atmosphere of communities of practice. This model could have benefits if applied in the context of Saudi Arabia and would be transferrable to similar contexts globally. The study concluded with some theoretical and practical recommendations for the Ministry of Education and for teachers in regards to teacher leadership within Saudi Arabia. Through teacher perception and reported experiences, TESOL teachers can challenge policy and provide a basis for developing new ways emerging from them in the context, as in-depth perspectives can give a voice to participants. Based on the literature reviewed and the design of the current research with its underpinning theoretical and conceptual frameworks, additional pathways are suggested for future research.Saudi Cultural Bureau in London Saudi Ministry of Educatio

Studio dell’insediamento protostorico in un’area della Sardegna centro-occidentale tramite strumenti GIS ed analisi multivariate

The authors analyze, as a sample-area, the region that includes the municipality of Mogoro, in central-western Sardinia, with the objective to reconstruct, through the study of the settlements and their relationships, some economic and social aspects of the human groups of nuragic culture that inhabited this area between the 18th and the 8th century BC. The territory is located at the foot of Monte Arci, along the Mogoro river that runs through the southern part of the plain of the Campidano of Oristano. The area has been intensively investigated from the half of the past century; an in-depth stratigraphic investigation was carried out since 1994 near the nuragic site of Cuccurada, the main center of an articulated territorial system including a rich network of monuments related to the nuragic civilization. The results are illustrated through various research methods: GIS, with the application of spatial analysis tools, and multivariate analysis (cluster and principal components analysis) that allowed to set out new hypotheses on occupation and populating dynamics and to identify among pre-historical monuments one or more homogeneous and distinguishable groups, resulting from a database in which geomorphological characteristics are recorded. A hierarchical organization and a specific criterion for exploiting and monitoring the landscape have been developed, in which settlement choices depend on functionality criteria, having nuraghi and villages a key role on the strategic control of the territor

Equilibrium and out of equilibrium thermodynamics in supercooled liquids and glasses

We review the inherent structure thermodynamical formalism and the formulation of an equation of state for liquids in equilibrium based on the (volume) derivatives of the statistical properties of the potential energy surface. We also show that, under the hypothesis that during aging the system explores states associated to equilibrium configurations, it is possible to generalize the proposed equation of state to out-of-equilibrium conditions. The proposed formulation is based on the introduction of one additional parameter which, in the chosen thermodynamic formalism, can be chosen as the local minima where the slowly relaxing out-of-equilibrium liquid is trapped.Comment: 7 pages, 4 eps figure

Folding and unfolding of a triple-branch DNA molecule with four conformational states

Single-molecule experiments provide new insights into biological processes hitherto not accessible by measurements performed on bulk systems. We report on a study of the kinetics of a triple-branch DNA molecule with four conformational states by pulling experiments with optical tweezers and theoretical modelling. Three distinct force rips associated with different transitions between the conformational states are observed in the folding and unfolding trajectories. By applying transition rate theory to a free energy model of the molecule, probability distributions for the first rupture forces of the different transitions are calculated. Good agreement of the theoretical predictions with the experimental findings is achieved. Furthermore, due to our specific design of the molecule, we found a useful method to identify permanently frayed molecules by estimating the number of opened basepairs from the measured force jump values.Comment: 17 pages, 12 figure

Vibrational origin of the fast relaxation processes in molecular glass-formers

We study the interaction of the relaxation processes with the density fluctuations by molecular dynamics simulation of a flexible molecule model for o-terphenyl (oTP) in the liquid and supercooled phases. We find evidence, besides the structural relaxation, of a secondary vibrational relaxation whose characteristic time, few ps, is slightly temperature dependent. This i) confirms the result by Monaco et al. [Phys. Rev, E 62, 7595 (2000)] of the vibrational nature of the fast relaxation observed in Brillouin Light Scattering (BLS) experiments in oTP; and ii) poses a caveat on the interpretation of the BLS spectra of molecular systems in terms of a purely center of mass dynamics.Comment: RevTeX, 5 pages, 4 eps figure