Affect in mathematics education: an introduction

The article presents an introduction to the concept of affect in mathematics education research

Direct Experimental Evidence of Metal-Mediated Etching of Suspended Graphene

Atomic resolution high angle annular dark field imaging of suspended, single-layer graphene, onto which the metals Cr, Ti, Pd, Ni, Al and Au atoms had been deposited was carried out in an aberration corrected scanning transmission electron microscope. In combination with electron energy loss spectroscopy, employed to identify individual impurity atoms, it was shown that nano-scale holes were etched into graphene, initiated at sites where single atoms of all the metal species except for gold come into close contact with the graphene. The e-beam scanning process is instrumental in promoting metal atoms from clusters formed during the original metal deposition process onto the clean graphene surface, where they initiate the hole-forming process. Our observations are discussed in the light of calculations in the literature, predicting a much lowered vacancy formation in graphene when metal ad-atoms are present. The requirement and importance of oxygen atoms in this process, although not predicted by such previous calculations, is also discussed, following our observations of hole formation in pristine graphene in the presence of Si-impurity atoms, supported by new calculations which predict a dramatic decrease of the vacancy formation energy, when SiOx molecules are present.Comment: final version accepted in ACS Nano + supplementary info. 22+6 pages, 4+5 figure

Investment behavior of Canadian Egg Producers: Analyzing the Impacts of Risk Aversion and Variability of Prices and Costs of Production

Animal welfare is a major concern for consumers. This concern has not gone unnoticed by sector stakeholders, especially egg producers. One of the fundamental changes likely to affect egg producers regards modes of production, specifically changes in housing systems, ranging from conventional cages to free range. From farmers’ perspective, changing their mode of production generates a technological and economic/marketing risk. This study documents the level of risk in the Canadian egg sector (conventional and specialty eggs) using data from 2009 to 2011. Our results indicate multiple uncertainty sources (technological, cost of production, price of eggs) that vary according to the types of eggs. We use a quadratic programming approach applied to expected mean-variance models to analyze the impact of risk on decision to invest when the resources must be allocated to different types of production that have different risk levels. Overall our results show how, given risk aversion parameters, producers minimize their risk levels by devoting their resources to the least risky type of eggs. An important result of our study is that supply management, by reducing the perceived risk level, has favored the development of specialty eggs, for the benefit of consumers

Understanding decentralization: deconcentration and devolution processes in the French and Italian cultural sectors

none3noPurpose – Decentralization is a widespread and international phenomenon in public administration. Despite the interest of public management scholars, an in-depth analysis of the interrelationship between two of its forms – deconcentration and devolution – and its impact on policy and management capacities at the local level is seldom investigated. Design/methodology/approach – This article addresses this gap by examining the implementation of deconcentration and devolution processes in France and Italy in the cultural field, combining the analysis of national reform processes with in-depth analyses of two regional cases. The research is the result of document analysis, participatory observation and semi-structured interviews. Findings – The article reconstructs the impacts of devolution and deconcentration processes on the emergence of policy and management capacity in two regions (Rhone-Alpes and Piedmont) in the cultural sector. The article shows that decentralization in the cultural sector in France and Italy is the result of different combinations of devolution and deconcentration processes, that the two processes mutually affect their effectiveness, and that this effectiveness is deeply linked to the previous policy and management capacity of the central state in a specific field/country. Originality/value – The article investigates decentralization as a result of the combination of deconcentration and devolution in comparative terms and in a specific sector of implementation, highlighting the usefulness of this approach also for other sectors/countries.mixedSantagati, Maria Elena; Bonini Baraldi, Sara; Zan, LucaSantagati, Maria Elena; Bonini Baraldi, Sara; Zan, Luc

Analysis of the performance of polarimetric PSI over distributed scatterers with Sentinel-1 data

Sentinel−1 (S1) data enables effective monitoring of displacements using persistent scatterer interferometry (PSI). S1 includes VV and VH polarization channels, allowing us to apply polarimetric techniques to PSI. In short, polarimetric PSI (PolPSI) exploits the available polarization channels to enhance the identification and processing of measurement points including persistent scatterers (PS) and distributed scatterers (DS). Previous works have shown the benefits of using PolPSI for PS points with S1 data, but the corresponding analysis for DS is missing. DS points are processed by finding a neighborhood of statistically homogeneous pixels (SHP) and averaging the phase within that neighborhood. In this work we show how dual-polarimetric data are stricter on the selection of the SHP group than single-polarimetric data. Thanks to the information added by the second channel, different land covers are not mixed in the SHP group. As a result, the number of points in the SHP groups is generally smaller than with VV alone, but they are more reliable. The impact of this strategy on the resulting deformation estimates is also investigated in this work, showing that the deformation areas are fully preserved and the influence of nearby pixels associated with other scene elements is avoided.This work was supported in part by the European Funds for Regional Development and by the Spanish Ministry of Science and Innovation (Agencia Estatal de Investigación, AEI) with Project PID2020-117303GB-C22/AEI/10.13039/501100011033, and in part by the Generalitat Valenciana, Conselleria de Innovacion, Universidades, Ciencia y Sociedad Digital with Project CIAICO/2021/335. The research was also partially performed in the ESA-MOST China DRAGON-5 project ref. 59339

Repetition Legitimizes:Consistent Behavior as a Signal of Reliability, Trustworthiness, and Competence

Appearing consistent across time is a strong motive guiding individual behavior, but why do consistent appearances matter so much to people? Across three studies, we show that people strategically behave more consistently in public to signal their reliability, trustworthiness, and competence. These signals lead to positive social outcomes like increased cooperation and power to persuade others

Repetition Legitimizes:Consistent Behavior as a Signal of Reliability, Trustworthiness, and Competence

Appearing consistent across time is a strong motive guiding individual behavior, but why do consistent appearances matter so much to people? Across three studies, we show that people strategically behave more consistently in public to signal their reliability, trustworthiness, and competence. These signals lead to positive social outcomes like increased cooperation and power to persuade others

A novel polymorphism of resistin gene and its association with meat quality traits in Chinese Bos taurus

Searching for candidate gene polymorphisms and their relationship with meat quality traits is an important issue for Bos taurus industry. In this study, we evaluated polymorphism of resistin (RETN) gene involved in energy metabolism. Using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technology, a novel missense substitution single-nucleotide polymorphism (SNP) g.2528T>C was identified in the exon 2 region of the RETN gene. Allele frequencies, gene heterozygosity, effective allele number and polymorphism information content of the bovine RETN SNP in six populations were investigated and calculated by the χ2 test. The distribution of the polymorphism from the studied six B. taurus breeds was not uniform. Our results suggested that Qinchuan, Luxi and Luxi × Simmental were not in Hardy-Weinberg equilibrium. Moreover, the polymorphism and its association with meat quality traits were analyzed in 369 Qinchuan and 73 Nanyang individuals. The analyzed SNP in the RETN revealed a significant association with marbling and intramuscular fat (p < 0.05). We observed that TT genotype was associated with a heightened marbling score when compared with the TC and CC in Qinchuan and Nanyang breeds. In Qinchuan breed, we also found that TT genotype was associated with an increased intramuscular fat content when compared with the TC. Such associations were not observed on backfat thickness, loin-muscle area and loin-muscle depth. This study showed that polymorphism of the RETN gene is potentially associated with B. taurus meat quality traits.Key words: Bos taurus, meat quality traits, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), resistin gene, single nucleotide polymorphism (SNP)