Science and environmental stewardship

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A portrait of a school poised for change : bringing governance, time and culture into focus at Chestnut Middle School.

This study presents a portrait of a school poised for change in terms of its governance, time and culture. The purpose of this study is to investigate the major bodies of literature on restructuring, choice and the philosophy supporting the Accelerated Schools Project in order to identify the important, positive elements that are foundational to creating a developmental framework for significant change in education and, in particular, the ongoing restructuring efforts at Chestnut Middle School. This researcher, in the role of participant-observer, describes his observations of the school over a six year period. In doing so he analyzes emergent patterns and themes from the study which are reflected in the literature and describes their application to the restructuring initiative at Chesnut Middle School. Four teachers are interviewed throughout a two year period concerning their descriptions and evaluations of their experiences and reactions to the restructuring process at the school in relation to these same themes. Additionally, the study presents a chronological overview of the Accelerated Schools Project during the first two years at Chestnut Middle School through the analysis of three major areas of focus: governance, time and culture. The study shows that for any substantial, significant change to occur in any school a critical reexamination of the current structure of schools must take place. If anything less than this examination occurs, what follows is nothing more than an adaptive response to the traditional, existing educational paradigm. Further, no restructuring effort can be completely successful without detailed attention to the vital relationships between governance, time and culture. Recommendations for further study include comprehensive examination of the role of central administrative offices in restructuring; more research on the changing role of the principal during a restructuring effort; and research on the implications of the critical elements of school culture, including beliefs, core values and norms of behavior

The dynamics of skills: Technology and business cycles

This article investigates the role of technology, education and wages in shaping the skill structure of employment considering the upswings and downswings of business cycles. We develop an econometric estimation of these relationships and carry out an empirical test at the industry level for manufacturing and services for five European countries (Germany, France, Spain, Italy and United Kingdom) over the period 1999-2011, For the first time, these relationships are separately investigated in the specific contexts of the last upswing of Europe's business cycle (2002-2007) and of the post-crisis downswing (2007-2011) in order to assess the impact of cycles on employment and skill dynamics, and their determinants. Skills are investigated using ISCO professional groups, with a distinction between Managers, Clerks, Craft and Manual workers. We show that patterns of change of such groups are significantly different from one another and are appropriate to account for the evolution of the overall skill structure. Results document the role that different types of technological change, education, wages and demand have on industries' job creation, broken down by professional groups. In manufacturing all professional groups except managers experience job losses that are mainly driven by the introduction of process innovation. In services, a polarised employment structure emerges, mainly driven by the expansion of demand. These relationships, however, do not always hold. During the downswing most established links break down; in particular, product innovation loses its positive impact on jobs while new processes drive the process of restructuring that is taking place, with diverse effects on each professional group

Extremely Metal-Poor Asymptotic Giant Branch Stars

Little is known about the first stars, but hints on this stellar population can be derived from the peculiar chemical composition of the most metal-poor objects in the Milky Way and in resolved stellar populations of nearby galaxies. In this paper, we review the evolution and nucleosynthesis of metal-poor and extremely metal-poor (EMP) stars with low and intermediate masses. In particular, new models of 6 M⊙ with three different levels of metallicity, namely Z=10−4, 10−6 and 10−10, are presented. In addition, we illustrate the results obtained for a 2 M⊙, Z=10−5 model. All these models have been computed by means of the latest version of the FuNS code. We adopted a fully coupled scheme of solutions for the complete set of differential equations describing the evolution of the physical structure and the chemical abundances, as modified by nuclear processes and convective mixing. The scarcity of CNO in the material from which these stars formed significantly affects their evolution, their final fate and their contribution to the chemical pollution of the ISM in primordial galaxies. We show the potential of these models for the interpretation of the composition of EMP stars, with particular emphasis on CEMP stars

Precision medicine and public health interventions: tuberculosis as a model?

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Towards Compact Modeling of Noisy Quantum Computers: A Molecular-Spin-Qubit Case of Study

Classical simulation of Noisy Intermediate Scale Quantum computers is a crucial task for testing the expected performance of real hardware. The standard approach, based on solving Schrödinger and Lindblad equations, is demanding when scaling the number of qubits in terms of both execution time and memory. In this article, attempts in defining compact models for the simulation of quantum hardware are proposed, ensuring results close to those obtained with standard formalism. Molecular Nuclear Magnetic Resonance quantum hardware is the target technology, where three non-ideality phenomena—common to other quantum technologies—are taken into account: decoherence, off-resonance qubit evolution, and undesired qubit-qubit residual interaction. A model for each non-ideality phenomenon is embedded into a MATLAB simulation infrastructure of noisy quantum computers. The accuracy of the models is tested on a benchmark of quantum circuits, in the expected operating ranges of quantum hardware. The corresponding outcomes are compared with those obtained via numeric integration of the Schrödinger equation and the Qiskit’s QASMSimulator. The achieved results give evidence that this work is a step forward towards the definition of compact models able to provide fast results close to those obtained with the traditional physical simulation strategies, thus paving the way for their integration into a classical simulator of quantum computers

Level of Biogenic Amines in Red and White Wines, Dietary Exposure, and Histamine-Mediated Symptoms upon Wine Ingestion

Biogenic amines (BAs) are involved in physiological processes. Foods where typically high levels of BAs occur are fermented food and beverage. This work set out to evaluate the occurrence of BAs in red and white wines, and to also ascertain the dietary exposure to BAs among consumers. Besides, a case report of a probable histamine intoxication upon ingestion of contaminated wine was described. The samples were analyzed through derivatization with dansyl chloride and HPLC-UV detection. Red wines showed higher levels of BAs, especially putrescine (PUT) and histamine (HIS), than white wines (median concentrations of 7.30 and 2.45 mg/L, respectively). However, results of our investigation showed that the dietary exposure to BAs through the consumption of wine (red and white) were lower than the recommended maximum levels for the acute exposure to HIS and tyramine (TYR). In contrast, the levels of BAs in wine on tap were much higher than in bottled wine and close to recommended values. The levels of HIS, TYR, and PUT in tap wine of 9.97, 8.23, and 13.01 mg/L, respectively, were associated with histamine-mediated symptoms in six young individuals after consumption of about three glasses of wine. The overall results and multivariate analysis confirm that red wine shows a higher concentration of BAs than white wine, especially putrescine and histamine. This finding is attributable to the malolactic fermentation that is common for most red wine production. It is also evident that incorrect preservation processes can lead to an increase in BA levels, probably due to the action of bacteria with high decarboxylase activity. The exposure values, although below the toxicity thresholds, could lead to histamine-mediated symptoms in susceptible individuals, also according to the case report discussed in this study

Extended Method for Several Dichotomous Covariates to Estimate the Instantaneous Risk Function of the Aalen Additive Model

The instantaneous risk function of Aalen’s model is estimated considering dichotomous covariates, using parametric accumulated risk functions to smooth cumulative risk of Aalen by grouping the individuals into sets named parcels. This methodology can be used for data with dichotomous covariates