When Glass and Metal Corrode Together,V: Sodium Copper Formate

A sodium copper formate, first described in 2002, can also form on copper alloys with sodium originating from soda glass hydrolysis. The frequent occurrence (50% of 250 cases of glass-induced metal corrosion) is due to the presence of formaldehyde emissions in storage and its direct reaction to formate in the alkaline surface films. The compound can be produced without the presence of acetate when chalconatronite or metal coupons immersed in soda solution are exposed to formaldehyde vapours. The crystal structure, derived from X-ray powder diffraction, yielded the sum formula Cu₄Na₄O(HCOO)₈(OH)₂·4H₂O. Except for the absence of acetate in the structure, this is in good agreement with the 2002 publication. To assess which kind of combined glass/metal objects are affected, a number of large museum collections were surveyed. Sodium copper formate was detected as a corrosion product using mainly micro-Raman spectroscopy, for instance, on 18 painted Limoges enamels, eight glass vessels with metal mountings, glass beads on metal wire from 11 bridal crowns, nine Christmas tree balls with wire decoration, 40 pieces of jewellery with glass gems, three daguerreotypes, and one miniature with cover glasses.     

User Experiences with Editorial Control in Online Newspaper Comment Fields

This article investigates user experiences with editorial control in online newspaper comment fields following the public backlash against online comments after the 2011 terror attacks in Norway. We analyze data from a survey of online news consumers focusing on experiences and attitudes towards editorial control set against a spectrum between “interventionist” and “noninterventionist” positions. Results indicate that interventionist respondents rate the quality of online comments as poor, whereas noninterventionist respondents have most often experienced being the target of editorial control measures and feel that editorial control has intensified after the terror attacks. We conclude that newspapers should pay attention to the different needs of participants when devising strategies for editorial control. Media professionals should also consider changes to increase the transparency of moderation practices.     

“Tightening the Knots” of the International Drugs Trade in Brazil

Much academic analysis of media representations of drugs-related violence in Brazil has focused on their role in perpetuating violence and societal divisions. There is less research on how the country’s traditional news media can shape information in order to foster dialogue between people and potentially resolve conflict. This article aims to address this gap by exploring the possibilities and challenges for printed news media to acquire “mediated” social capital. The concept is understood here as a specific resource of power that has the potential to connect people from diverse social, cultural and economic backgrounds. In order to do so, we analyse how a popular Rio newspaper has used its symbolic power to produce social capital with an investigative series about Brazil’s involvement in the international drugs trade. It is argued here that the series paints a complex picture of its causes and consequences and is an important step towards a deliberative process about possible solutions to drugs-related violence in Rio and beyond.     

“I’m Really Confident I Can Find the Exact IKEA Pillow”: A Qualitative Look at the Search Self-Efficacy of Graduating MLIS Students

Abstract

There is limited qualitative research on the information-seeking self-efficacy (SE) of library and information science (LIS) graduate students. This study examines graduating LIS students’ experiences with information seeking, including experiences in the LIS program that led to increased levels of information-seeking SE and specific recollections of moments when SE increased. Many students identified similar factors as key to developing SE, including education-related assignments, library work experience, LIS internships, and specific LIS coursework. Because of the small sample size, further research would help to identify additional factors that promote LIS students’ information-seeking SE.     

Economies of reputation: the case of revenge porn

Revenge porn involves publicly releasing pictures of a person’s sexual activity, along with the means to contact that person, to provoke widespread shaming. This paper analyzes the US-based revenge porn website MyEx.com through discourse, legal, and information network analyses. The paper explores how revenge porn is not only an instance of online sexual violence rooted in abjection but also symptomatic of a new political economy of subjectivity, where both the human-based and the automated, algorithm-based circulation of personal information are at the center of processes through which the self is seen and valued, both socially and economically, by others.     

Boosting multi-label hierarchical text categorization

Hierarchical Text Categorization (HTC) is the task of generating (usually by means of supervised learning algorithms) text classifiers that operate on hierarchically structured classification schemes. Notwithstanding the fact that most large-sized classification schemes for text have a hierarchical structure, so far the attention of text classification researchers has mostly focused on algorithms for “flat” classification, i.e. algorithms that operate on non-hierarchical classification schemes. These algorithms, once applied to a hierarchical classification problem, are not capable of taking advantage of the information inherent in the class hierarchy, and may thus be suboptimal, in terms of efficiency and/or effectiveness. In this paper we propose TreeBoost.MH, a multi-label HTC algorithm consisting of a hierarchical variant of AdaBoost.MH, a very well-known member of the family of “boosting” learning algorithms. TreeBoost.MH embodies several intuitions that had arisen before within HTC: e.g. the intuitions that both feature selection and the selection of negative training examples should be performed “locally”, i.e. by paying attention to the topology of the classification scheme. It also embodies the novel intuition that the weight distribution that boosting algorithms update at every boosting round should likewise be updated “locally”. All these intuitions are embodied within TreeBoost.MH in an elegant and simple way, i.e. by defining TreeBoost.MH as a recursive algorithm that uses AdaBoost.MH as its base step, and that recurs over the tree structure. We present the results of experimenting TreeBoost.MH on three HTC benchmarks, and discuss analytically its computational cost.