Colossal electroresistance and colossal magnetoresistive step in paramagnetic insulating phase of single crystalline bilayered manganite(La0.4_{0.4}Pr0.6_{0.6})1.2_{1.2}Sr1.8_{1.8}Mn2_{2}O7_{7}

We report a significant decrease in the low-temperature resistance induced by the application of an electric current on the $ab$-plane in the paramagnetic insulating (PMI) state of (La$_{0.4}$Pr$_{0.6}$)$_{1.2}$Sr$_{1.8}$Mn$_{2}$O$_{7}$. A colossal electroresistance effect attaining -95% is observed at lower temperatures. A colossal magnetoresistive step appears near 5T at low temperatures below 10K, accompanied by an ultrasharp width of the insulator-metal transition. Injection of higher currents to the crystal causes a disappearance of the steplike transition. These findings have a close relationship with the presence of the short-range charge-ordered clusters pinned within the PMI matrix of the crystal studied.Comment: 4 pages 3 figure

A cross-sectional study on prevalence and predictors of burnout among a sample of pharmacists employed in pharmacies in Central Italy

Burnout is defined as an occupational phenomenon linked to chronic workplace stress that has not been successfully managed and included among the factors influencing health status or contact with health services. Although several studies were performed for assessing this phenomenon, there is a lack of data on the prevalence of burnout and associated predictors, due to different definitions of the syndrome and heterogeneity of assessment methods. One of the well-known evidences on burnout is related to the highest risk professions, which include policemen, firemen, teachers, psychologists, medical students, nurses, physicians, and other health professionals, such as pharmacists. Objective. The aims of the present study were to (1) assess the occurrence of burnout syndrome among a sample of pharmacists employed in public and private pharmacies located in Rome province (Latium Region; central Italy); (2) evaluate the role of some potential predictors for the development of the syndrome. Materials and Methods. A questionnaire elaborated ad hoc was administered online to 2,000 members of the Association of Professional Pharmacists of Rome and its province and employed in public or private pharmacies. The questionnaire included the 14-item Shirom-Melamed Burnout Measure (SMBM) tool and questions on demographic characteristics and working conditions. Results. Physical exhaustion was the burnout dimension with the highest score; besides, approximately 11% of the studied pharmacists were categorized as having clinically relevant burnout levels (≥4.40). Several of the investigated variables significantly influenced the single burnout dimensions at the univariate analyses; multivariate analyses demonstrated that alcohol consumption and workplace location have a significant independent role on the overall SMBM index, while working time significantly influences clinically relevant burnout level. Conclusions. The results revealed that pharmacists are at risk of burnout, and thus, it is necessary to perform specific preventive intervention for managing this occupational threat

Improving Measurement and Expanding Meta-Analytic Knowledge: Social and Emotional Learning in Elementary and Early Childhood

In the last several decades, the development of student social and emotional skills in educational contexts has received much attention, both domestically and internationally. Whereas previous school-based educational practices had primarily focused on the teaching and testing of cognitive skills, we now recognize that there are constituents of academic success beyond the cognitive skills that are traditionally taught and tested, and the field of social and emotional learning (SEL) has emerged as a result. This two-study dissertation attempted to fill existing gaps in the development of SEL practices by exploring new horizons in both intervention and measurement with preschool and elementary students. Whereas a great amount of meta-analytic evidence exists for K-12 contexts, no previous studies have used meta-analysis to synthesize the literature on preschool SEL interventions. The objective of the first study was to determine the effects of universal and targeted preschool SEL interventions on the development of social and emotional skills and the reduction of problem behaviors. Results showed medium effects for both universal (g = .35) and targeted interventions (g = .48), and meta-regression analyses identified intervention type as accounting for 83% of the heterogeneity found in universal interventions. The objective of the second study was to develop Likert and innovative items (situational judgment test and forced choice) using the Big Five as an assessment framework to measure social and emotional skills in elementary-aged students. This represents several advantages in the field, considering many assessments of student social and emotional skills rely on Likert items alone, and Big Five-based self-report measures for elementary-aged students are rare, albeit the Big Five serving as an empirically supported framework upon which to organize social and emotional skills. Results from a pilot study with these items showed moderate evidence for reliability and validity and also indicated where improvements could be made for future iterations of such items. Together, the two studies make significant contributions to the field - the first by extending meta-analytic evidence to the preschool population, and the second by examining best practices for developing innovative item types for elementary students. Conclusions from the two studies, implications, and future directions for measuring and developing young children’s social and emotional skills are discussed

Local oxidation of silicon surfaces by dynamic force microscopy : nanofabrication and water bridge formation

Local oxidation of siliconsurfaces by atomic force microscopy is a very promising lithographic approach at nanometer scale. Here, we study the reproducibility, voltage dependence, and kinetics when the oxidation is performed by dynamic force microscopy modes. It is demonstrated that during the oxidation, tip and sample are separated by a gap of a few nanometers. The existence of a gap increases considerably the effective tip lifetime for performing lithography. A threshold voltage between the tip and the sample must be applied in order to begin the oxidation. The existence of a threshold voltage is attributed to the formation of a water bridge between tip and sample. It is also found that the oxidation kinetics is independent of the force microscopy mode used (contact or noncontact)

Mechanical detection of carbon nanotube resonator vibrations

Bending-mode vibrations of carbon nanotube resonator devices were mechanically detected in air at atmospheric pressure by means of a novel scanning force microscopy method. The fundamental and higher order bending eigenmodes were imaged at up to 3.1GHz with sub-nanometer resolution in vibration amplitude. The resonance frequency and the eigenmode shape of multi-wall nanotubes are consistent with the elastic beam theory for a doubly clamped beam. For single-wall nanotubes, however, resonance frequencies are significantly shifted, which is attributed to fabrication generating, for example, slack. The effect of slack is studied by pulling down the tube with the tip, which drastically reduces the resonance frequency

Influence of the meteorological record length on the generation of representative weather files

Heat and moisture (HM) transfer simulations of building envelopes and whole building energy simulations require adequate weather files. The common approach is to use weather data of reference years constructed from meteorological records. The weather record affects the capability of representing the real weather of the resulting reference years. In this paper the problem of the influence of the length of the records on the representativeness of the reference years is addressed and its effects are evaluated also for the applicative case of the moisture accumulation risk analysis with the Glaser Method and with DELPHIN 6, confirming that records shorter than 10 years could lead to less representative reference years. On the other hand, it is shown that reference years obtained from longer periods are not representative of the most recent years, which present higher dry-bulb air temperatures due to a short-term climate change effect observed in all the considered weather records. An alternative representative year (Moisture Representative Year) to be used in building energy simulations with a strong dependence on moisture is presented

What Do Grades Mean? Variation in Grading Criteria in American College and University Courses

This study examined differences in the criteria used by college and university instructors in the United States to assign course grades. Two hundred and fifty course syllabi (159 from universities and 91 from four-year colleges) developed by randomly selected instructors from five academic disciplines (education, maths, science, psychology, and English) were examined to determine the extent to which instructors employed different criteria in assigning course grades in introductory-level courses. Sources of variation in grade assignment included the use of product versus process criteria, the prevalence of using performance exams, and the framing criteria for grades. Differences between institution types and among academic disciplines were also investigated. Results revealed significant differences among the five academic disciplines in grading criteria and the use of examinations, with instructors in education and English relying more heavily on process criteria. A significant interaction between institution type and academic discipline in grading criteria was also identified. Theoretical, practical, and policy implications are discussed along with avenues for further research

From an organometallic monolayer to an organic monolayer covered by metal nanoislands: A simple thermal protocol for the fabrication of the top contact electrode in molecular electronic devices

et al.In this contribution, a novel method for practical uses in the fabrication of the top contact electrode in a metal/organic monolayer/metal device is presented. The procedure involves the thermally induced decomposition of an organometallic compound, abbreviated as the TIDOC method. Monolayers incorporating the metal organic compounds (MOCs) [[4-{(4-carboxy)ethynyl}phenyl]ethynyl]-(triphenylphosphine)-gold, 1, or [1-isocyano-4-methoxybenzene]-[4-amino-phenylethynyl]-gold, 2, were annealed at moderate temperatures (1: 150 °C for 2h and 2: 100 °C for 2 h), resulting in cleavage of the Au-P or Au-C bond and reduction of Au(I) to Au(0) as metallic gold nanoparticles (GNPs). These particles are distributed on the surface of the film resulting in formation of metal/molecule/GNP sandwich structures. Electrical properties of these nascent devices were determined by recording I¿V curves with a conductive-AFM. The I¿V curves collected from these metal/organic monolayer/GNPs sandwich structures are typical of metal-molecule-metal junctions, with no low resistance traces characteristic of metallic short circuits observed over a wide range of set-point forces. The TIDOC method is therefore an effective procedure for the fabrication of molecular junctions for the emerging area of molecular electronics.Peer Reviewe

Fabricación del electrodo superior en dispositivos moleculares mediante la formación de enlaces covalentes σ C-Au

Resumen del póster presentado a la 6ª Jornada de Jóvenes Investigadores en Física y Química de Aragón celebrada en Zaragoza el 20 de noviembre de 2014.-- et al.Peer reviewe