Decentralized state estimation for the control of network systems

The paper proposes a decentralized state estimation method for the control of network systems, where a cooperative objective has to be achieved. The nodes of the network are partitioned into independent nodes, providing the control inputs, and dependent nodes, controlled by local interaction laws. The proposed state estimation algorithm allows the independent nodes to estimate the state of the dependent nodes in a completely decentralized way. To do that, it is necessary for each independent node of the network to estimate the control input components computed by the other independent nodes, without requiring communication among the independent nodes. The decentralized state estimator, including an input estimator, is developed and the convergence properties are studied. Simulation results show the effectiveness of the proposed approach.     

In the making: constructing in-school pregnancy in Mozambique

This article examines current in-school pregnancy policy in Mozambique, Decree 39/GM/2003, discussing how it discursively constructs in-school pregnancy as a problem, thereby raising the need to regulate its occurrence. Decree 39/GM/2003 indicates that pregnant schoolgirls should be transferred to night courses in order to complete their education. Although progressive in some respects, as it allows pregnant girls to remain in education, the Decree reflects a global tendency to see education and pregnancy as oppositional. As a consequence, the practical implications of transferring pregnant girls to night courses have the perverse effect of encouraging dropout. Stimulated by this contradiction, I reflect on how the policy text produces a deficit view of the pregnant schoolgirl. This Foucauldian process of subjectification results in a strengthening of the opposition between pregnancy and education. As a result, pregnant schoolgirls are ‘thrown out’ of their education, defeating the inclusive aims of the national policy.     

Origins of individual differences in imitation: links with language, pretend play, and socially insightful behavior in two-year-old twins

Imitation, vocabulary, pretend play, and socially insightful behavior were investigated in 5,206 same- and opposite-sex 2-year-old twin pairs in the United Kingdom. Individual differences in imitative ability were due to modest heritability (30%), while environmental factors shared between twins (42%) and unique to each twin (28%) also made significant contributions to the variance. Imitation correlated significantly, although modestly, with vocabulary, pretend play, and socially insightful behavior, and the strongest relationship was with vocabulary. A model that represented the covariance between the variables as being due to correlated latent genetic and environmental factors fitted the data well, with shared environmental factors influencing most of the covariance. Parents who encourage imitation may also tend to foster the development of language, pretence, and socially insightful behavior.     

Bibliography,National Bibliography,and National Union Catalog in Italy*

Abstract

This article analyzes the role of national bibliographies—with particular reference to the Italian National Bibliography—as relevant tools for national bibliographic control. In the first part of the article, the historical and scientific context of international standards is summarized. The second part describes the role played by the Central National Library of Florence (BNCF) in the realization of the bibliographic control of Italian publications. The limits and the potential of the Italian National Bibliography produced by BNCF are highlighted and compared with the Italian National Library Service (SBN), which is the most important national collective catalog among Italian libraries.     

The white colour in Etruscan polychromes on terracotta: Spectroscopic identification of kaolin

The present work reports on a spectroscopic study of white colour samples collected from Etruscan polychromes on terracotta from the Cerveteri area. In particular, both white-on-red potsherds of the Orientalising period and high-value polychromes of the Archaic period were considered. The white pigment, a fundamental element in this class of artworks, was not clearly identified in previous archaeological and analytical studies, although the use of kaolin was tentatively proposed. Therefore, samples from the Monte Sughereto kaolin quarry in the Cerveteri area were also studied. The results of detailed analyses carried out using micro-Raman spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy first show that the quarry material is a high-purity kaolin containing quartz. Raman results strongly suggest that the same kind of kaolin was employed in the polychromes of the Archaic period. As to white-on red potsherds, infrared results have a key role in showing that the white pigment is a kaolin closely corresponding to the quarry material since a particular kaolin polytype (dickite) is dominant in both cases. The present work thus provides the first definitive identification of the white pigment used in Etruscan polychromes on terracotta from the Cerveteri area, and suggests that the source of kaolin might be the Monte Sughereto quarry.     

Climatically Induced Degradation Processes in Conserved Archaeological Wood Studied by Time-lapse Photography

ABSTRACT

Samples of conserved archaeological wood of different ages, origins, and conservation histories were aged in a climate chamber for seven months, while the humidity alternated between 30% RH for 12 hours and 80% RH for 12 hours at a constant temperature of 30°C. Photographs were taken once every hour, which enabled the creation of a time-lapse movie. Some samples degraded visibly, whereas others were unaffected. Most of the samples were robust and would be able to survive well even in a very poor museum climate. Among the sensitive samples, three types of degradation were identified, namely disintegration, pyrite oxidation, and efflorescence of white crystals. Disintegration was ascribed to dimensional changes caused by the RH alternations in very fragile wood. The white efflorescence was interpreted as the recrystallization of an alum-associated substance, possibly mercallite (KHSO₄). The pyrite oxidation was observed as the efflorescence of a thick yellow, grey, and green powder. Characterization of selected samples was performed using X-ray fluorescence spectrometry, X-ray diffraction spectrometry, scanning electron microscopy with energy dispersive X-ray spectroscopy, inductively coupled plasma – optical emission spectroscopy, Fourier transform infrared spectroscopy, ionic conductivity – liquid chromatography, and pyrolysis-gas chromatography-mass spectrometry with in situ silylation using hexamethyldisilazane.     

Helping Improve Dissemination of Research: Toastmasters Is a Novel Mechanism

Competencies for health professionals and students often include the ability to transfer knowledge to different audiences in a variety of ways. Consultation, presentation, teaching, multimedia, and posters are some examples. A recent question on a national listserv about writing, editing, and proofreading services in health sciences libraries prompted this column about a potentially novel way of helping students and faculty in health disciplines to improve their abilities to communicate professionally. In addition to the poster design and review services that one library offers, it is also the host of two Toastmasters International clubs that provide participants a nonthreatening, real-world environment to improve the content, structure, methods, and delivery of their written and spoken messages. A librarian on staff is a member of and serves as liaison to the two clubs.     

Item Response Theory analysis and Differential Item Functioning across age,gender and country of a short form of the Advanced Progressive Matrices

Item Response Theory (IRT) models were applied to investigate the psychometric properties of the Arthur and Day's Advanced Progressive Matrices-Short Form (APM-SF; 1994) [Arthur and Day (1994). Development of a short form for the Raven Advanced Progressive Matrices test. Educational and Psychological Measurement, 54, 395–403] in order to test if the scale is a reliable and valid tool to assess general fluid ability in a short time frame. The APM-SF was administered to 2264 high-school and university students. Once attested the one-factor structure of the scale, unidimensional IRT analyses for dichotomous data were applied to investigate the increases in item difficulty levels, Test Information Function, and Differential Item Functioning across age, gender, and country (comparing Italian and British respondents). Additionally, validity measures were reported. Findings attest that the Arthur and Day's APM-SF is a sound instrument for assessing fluid ability within a short time frame.