The boson peak in structural and orientational glasses of simple alcohols: Specific heat at low temperatures

We review in this work specific-heat experiments, that we have conducted on different hydrogen-bonded glasses during last years. Specifically, we have measured the low-temperature specific heat Cp for a set of glassy alcohols: normal and fully-deuterated ethanol, 1- and 2- propanol, and glycerol. Ethanol exhibits a very interesting polymorphism presenting three different solid phases at low temperature: a fully-ordered (monoclinic) crystal, an orientationally-disordered (cubic) crystal or 'orientational glass', and the ordinary structural glass. By measuring and comparing the low-temperature specific heat of the three phases, in the 'boson peak' range 2-10 K as well as in the tunneling-states range below 1K, we are able to provide a quantitative confirmation that ''glassy behavior'' is not an exclusive property of amorphous solids. On the other hand, propanol is the simplest monoalcohol with two different stereoisomers (1- and 2-propanol), what allows us to study directly the influence of the spatial rearrangement of atoms on the universal properties of glasses. We have measured the specific heat of both isomers, finding a noteworthy quantitative difference between them. Finally, low-temperature specific-heat data of glassy glycerol have also been obtained. Here we propose a simple method based upon the soft-potential model to analyze low-temperature specific-heat measurements, and we use this method for a quantitative comparison of all these data of glassy alcohols and as a stringent test of several universal correlations and scaling laws suggested in the literature. In particular, we find that the interstitialcy model for the boson peak [A. V. Granato, Phys. Rev. Lett. 68 (1992) 974] gives a very good account of the temperature at which the maximum in Cp/T^3 occurs.Comment: 16 pages, 2 figures, Proceedings of the 4th International Discussion Meeting on Relaxations in Complex Systems, Hersonissos (Crete), June 2001. Journal of Non-Crystalline Solids (accepted for publication

Graphical tools for helping firefighters in victim rescues. Assessment during a live fire training program

This study compares three different methods to communicate the features of a building to firefighters, before starting a victim rescue during a live fire training program. Participants in this study did not previously know the hotel used for developing the activities. The effective number of participants was 144, all professional firefighters. One of the exercises in this training program was thoroughly designed not only for training purposes, but also to test different guide versions. The innovative guides were based on two different technologies (simple stapled sheets of paper and digital content displayed on a tablet) and were developed using several graphical tools (conventional pictures, aerial images captured with drone, 3D models, 360° pictures, etc.). With the intention of facilitating firefighters’ activity during a victim rescue, results obtained using these tools were compared with a conventional communication method. The assessment methodology applied in this study included the use of an anonym questionnaire, as well as the analysis of the videos captured with action cameras, attached with a harness to the chest of two of the four firefighters in every team, during the training activities. Thanks to these videos, it was possible to compare the time required for rescuing the victim and to observe followed paths, visited rooms and substantial information about the tested tools, including valuable participants’ comments. For in emergency situations, the tools described in this paper were preferred to the already existent self-protection plans, usually considered too extensive for fast communication, a matter of special importance in victim rescues

Low-temperature specific heat and thermal conductivity of glycerol

We have measured the thermal conductivity of glassy glycerol between 1.5 K and 100 K, as well as the specific heat of both glassy and crystalline phases of glycerol between 0.5 K and 25 K. We discuss both low-temperature properties of this typical molecular glass in terms of the soft-potential model. Our finding of an excellent agreement between its predictions and experimental data for these two independent measurements constitutes a robust proof of the capabilities of the soft-potential model to account for the low-temperature properties of glasses in a wide temperature range.Comment: 4 pages, 3 figures. To be published in Phys. Rev. B (2002

Intimate Partner Violence: perspective of convicts and psychologists of penitentiary institutions. A Qualitative analysis with focus groups

Intimate Partner Violence is a complex process in which individual, relational and contextual variables intervene. The aim of this study was to explore coping strategies and relational dynamics in conflict situations involving people convicted of intimate partner violence with their partners. Focus groups were conducted with convicted intimate partner violence offenders (12 participants) and with psychology professionals (4 participants). The data were explored through thematic analysis following the Nested Ecological Model. The group of convicted perpetrators showed roles of authority and superiority over the woman, a feeling of vulnerability and rejection of the existing legal framework, fear of being arrested for wanting to continue the relationship, the need to control the partner driven by jealousy, justification or denial of responsibility in violent situations or instrumentalization of the children in common. The professionals point out cultural aspects that facilitate violent patterns and roles in the couple's dynamics, communication problems, denial or low awareness of the crime, among other issues. The results are of special interest both for professionals who wish to learn or deepen their knowledge on the subject, as well as for those who work in intervention and/or prevention of intimate partner violence.n. La violencia de género es un proceso complejo en el cual intervienen variables individuales, relacionales y contextuales. El presente estudio tiene como objetivo explorar las estrategias de afrontamiento y dinámicas relacionales en situaciones conflictivas en condenados por violencia de género con sus parejas. Se realizaron grupos focales con condenados por violencia de género (12 participantes) y con profesionales de la psicología (4 participantes). Los datos se exploraron mediante análisis temático siguiendo el Modelo Ecológico Anidado. El grupo de condenados muestra roles de autoridad y superioridad sobre la mujer, sensación de vulnerabilidad y rechazo ante el marco jurídico existente, miedo a sufrir arrestos por querer continuar con la relación, la necesidad de control de la pareja impulsada por lo celos, la justificación o negación de responsabilidad en las situaciones violentas o instrumentalización de los hijos/as en común. Los profesionales señalan aspectos culturales que facilitan esquemas y roles violentos en la dinámica de pareja, problemas de comunicación, negación o baja conciencia del delito, entre otros temas. Los resultados son de especial interés tanto para los profesionales que deseen conocer o profundizar en la temática, como para quienes trabajen en la intervención y/o prevención en violencia de género

Tissue-specific transcriptome profiling of the citrus fruit epidermis and subepidermis using laser capture microdissection

Most studies of the biochemical and regulatory pathways that are associated with, and control, fruit expansion and ripening are based on homogenized bulk tissues, and do not take into consideration the multiplicity of different cell types from which the analytes, be they transcripts, proteins or metabolites, are extracted. Consequently, potentially valuable spatial information is lost and the lower abundance cellular components that are expressed only in certain cell types can be diluted below the level of detection. In this study, laser microdissection (LMD) was used to isolate epidermal and subepidermal cells from green, expanding Citrus clementina fruit and their transcriptomes were compared using a 20k citrus cDNA microarray and quantitative real-time PCR. The results show striking differences in gene expression profiles between the two cell types, revealing specific metabolic pathways that can be related to their respective organelle composition and cell wall specialization. Microscopy provided additional evidence of tissue specialization that could be associated with the transcript profiles with distinct differences in organelle and metabolite accumulation. Subepidermis predominant genes are primarily involved in photosynthesis- and energy-related processes, as well as cell wall biosynthesis and restructuring. By contrast, the most epidermis predominant genes are related to the biosynthesis of the cuticle, flavonoids, and defence responses. Furthermore, the epidermis transcript profile showed a high proportion of genes with no known function, supporting the original hypothesis that analysis at the tissue/cell specific levels can promote gene discovery and lead to a better understanding of the specialized contribution of each tissue to fruit physiology

Rice cv. Bahia mutagenized population: a new resource for rice breeding in the Mediterranean basin

In the Mediterranean basin, the limited availability of rice genetic resources restricts the success of breeding programs. Although mutation induction is a powerful alternative to generate desired novel variations, current rice mutant resources have little relevance in the Mediterranean breeding programs that require well-adapted cultivars for maximum performance. In this work a genome-wide mutation induction has been used on rice cv Bahia, a japonica cultivar well adapted to the Mediterranean climate and cultural practices, to increase its genetic variability and to facilitate the generation and selection of interesting agronomical traits. Bahia mutant collections were generated by irradiating seed batches with either 30 Gy fast neutrons or 250 Gy gamma rays. After initial screening of M2 plants and followed by evaluation of M3 and M4 generations in open field, elite genotypes were selected. The selected lines carried morphological and physiological changes of agronomical interest such as earliness, culm height reduction, yield increase and spontaneous spots appearance in leaves. The mutants are useful as breeding materials for improving varieties in the Mediterranean

Calor específico a bajas temperaturas de alcoholes sólidos vítreos y cristalinos

We present and discuss in this work specific-heat experiments at low temperature that we have conducted on different molecular (hydrogenbonded) glasses and crystals. Specifically, we have measured the low-temperature specific heat Cp(T) for a set of solid alcohols: normal and fully-deuterated ethanol, 1−and 2−propanol, and glycerol. Ethanol exhibits a very interesting polymorphism presenting three different solid phases at low temperature: a fully-ordered (monoclinic) crystal, an orientationally-disordered (cubic) crystal or “orientational glass”, and the canonical (amorphous) structural glass. By measuring and comparing the low-temperature specific heat of the three phases, in the boson peak range, 2−10 K, as well as in the tunneling-states range, below 1K, we are able to provide a quantitative confirmation that “glassy behavior” is not an exclusive property of amorphous solids. On the other hand, propanol is the simplest monoalcohol with two different stereoisomers (1−and 2−propanol), which allows us to study directly the influence of the spatial rearrangement of atoms on the universal properties of glasses. We have measured the specific heat of both isomers, finding a noteworthy quantitative difference between them. Finally, low-temperature specific-heat data of glassy and crystalline glycerol have also been obtained.<br><br>En este trabajo, presentamos y discutimos experimentos de calorimetría a bajas temperaturas que hemos realizado en diferentes vidrios y cristales moleculares (de puentes de hidrógeno). En concreto, hemos medido el calor específico a bajas temperaturas Cp(T) para un conjunto de alcoholes sólidos: etanol normal y completamente deuterado, 1−y 2−propanol, y glicerol. El etanol presenta un muy interesante polimorfismo, con tres fases sólidas diferentes a bajas temperaturas: un cristal estable perfectamente ordenado (monoclínico), un cristal (cúbico) con desorden orientacional o “vidrio orientacional”, y el vidrio estructural canónico (amorfo). Midiendo y comparando el calor específico a bajas temperaturas de las tres fases, en el rango de temperaturas del pico bosónico (2−10 K) así como en el de los estados de tuneleo por debajo de 1K, hemos podido proporcionar una confirmación cuantitativa de que el “comportamiento vítreo” no es una propiedad exclusiva de los sólidos amorfos. Por otra parte, el propanol es el monoalcohol más sencillo que cuenta con dos estereoisómeros (1−y 2−propanol), lo que nos permite estudiar directamente la influencia de la organización espacial de los átomos en las propiedades universales de los vidrios. Hemos medido el calor específico de ambos isómeros, encontrando una notable diferencia cuantitativa entre ellos. Finalmente, también hemos obtenido el calor específico a bajas temperaturas del glicerol en sus fases vítrea y cristalina

The Rise and Fall of Promissory Estoppel or Is Promissory Estoppel Really as Unsuccessful as Scholars Say It Is: A New Look at the Data

This article makes important contributions to the field of empirical promissory estoppel scholarship. First it challenges recent empirical scholarship (by Professors Robert Hillman and Sidney De Long in the 1998 and 1997 Columbia and Wisconsin law reviews). Their scholarship had challenged the view of the vast majority of American Contracts scholarship by proclaiming promissory estoppel to be an unimportant doctrine based on low win rates of tried cases. My article challenges this new orthodoxy based on a comprehensive five year survey of cases. It concludes that it is too soon to announce the death of promissory estoppel and that promissory estoppel is still a vital theory in contract. It argues that if qualitative factors relating to the weakness of a claim are accounted for in the data the win rates are significant. Second, it argues that if such qualitative factors are recognized, promissory estoppel results can be rationalized in efficiency terms. Plaintiffs tend to win claims when a positive result would enhance an efficient outcome and to lose cases in which enforcement would have negative welfare effects. Finally, the Article offers some insights into conducting empirical scholarship. It argues that it may not be possible to draw meaningful conclusions from generalized win/loss ratios without making qualitative judgments about the viability of the underlying claim

ALGEBRAIC VARIETIES FOR THE CHIRAL POTTS MODEL

International audienc