Preconditioned fully implicit PDE solvers for monument conservation

Mathematical models for the description, in a quantitative way, of the damages induced on the monuments by the action of specific pollutants are often systems of nonlinear, possibly degenerate, parabolic equations. Although some the asymptotic properties of the solutions are known, for a short window of time, one needs a numerical approximation scheme in order to have a quantitative forecast at any time of interest. In this paper a fully implicit numerical method is proposed, analyzed and numerically tested for parabolic equations of porous media type and on a systems of two PDEs that models the sulfation of marble in monuments. Due to the nonlinear nature of the underlying mathematical model, the use of a fixed point scheme is required and every step implies the solution of large, locally structured, linear systems. A special effort is devoted to the spectral analysis of the relevant matrices and to the design of appropriate iterative or multi-iterative solvers, with special attention to preconditioned Krylov methods and to multigrid procedures. Numerical experiments for the validation of the analysis complement this contribution.Comment: 26 pages, 13 figure

The effect of composition on the mechanism of stress-corrosion cracking of titanium alloys in nitrogen tetroxide, and aqueous and hot- salt environments Annual summary report, 1 May 1967 - 30 Apr. 1968

Stress corrosion data for titanium alloys in aqueous, hot salt, and nitrogen dioxide environment

Pathways to social inequality

Social inequality is now pervasive in human societies, despite the fact that humans lived in relatively egalitarian, small-scale societies across most of our history. Prior literature highlights the importance of environmental conditions, economic defensibility, and wealth transmission for shaping early Holocene origins of social inequality. However, it remains untested whether the mechanisms that drive the evolution of inequality in recent human societies follow a similar trajectory. We conduct the first global analysis of pathways to inequality within modern human societies using structural equation modeling. Our analytical approach demonstrates that environmental conditions, resource intensification, and wealth transmission mechanisms impact various forms of social inequality via a complex web of causality. We further find that subsistence practices have a direct impact on some institutionalized forms of inequality. This work identifies drivers of social inequality in the modern world and demonstrates the application of structural equation modeling methods to investigate complex relationships between elements of human culture

Pathways to social inequality

Social inequality is now pervasive in human societies, despite the fact that humans lived in relatively egalitarian, small-scale societies across most of our history. Prior literature highlights the importance of environmental conditions, economic defensibility, and wealth transmission for shaping early Holocene origins of social inequality. However, it remains untested whether the mechanisms that drive the evolution of inequality in recent human societies follow a similar trajectory. We conduct the first global analysis of pathways to inequality within modern human societies using structural equation modeling. Our analytical approach demonstrates that environmental conditions, resource intensification, and wealth transmission mechanisms impact various forms of social inequality via a complex web of causality. We further find that subsistence practices have a direct impact on some institutionalized forms of inequality. This work identifies drivers of social inequality in the modern world and demonstrates the application of structural equation modeling methods to investigate complex relationships between elements of human culture

The regulatory subunit of PKA-I remains partially structured and undergoes β-aggregation upon thermal denaturation

Background: The regulatory subunit (R) of cAMP-dependent protein kinase (PKA) is a modular flexible protein that responds with large conformational changes to the binding of the effector cAMP. Considering its highly dynamic nature, the protein is rather stable. We studied the thermal denaturation of full-length RIα and a truncated RIα(92-381) that contains the tandem cyclic nucleotide binding (CNB) domains A and B. Methodology/Principal Findings: As revealed by circular dichroism (CD) and differential scanning calorimetry, both RIα proteins contain significant residual structure in the heat-denatured state. As evidenced by CD, the predominantly α-helical spectrum at 25°C with double negative peaks at 209 and 222 nm changes to a spectrum with a single negative peak at 212-216 nm, characteristic of β-structure. A similar α→β transition occurs at higher temperature in the presence of cAMP. Thioflavin T fluorescence and atomic force microscopy studies support the notion that the structural transition is associated with cross-β-intermolecular aggregation and formation of non-fibrillar oligomers. Conclusions/Significance: Thermal denaturation of RIα leads to partial loss of native packing with exposure of aggregation-prone motifs, such as the B' helices in the phosphate-binding cassettes of both CNB domains. The topology of the β-sandwiches in these domains favors inter-molecular β-aggregation, which is suppressed in the ligand-bound states of RIα under physiological conditions. Moreover, our results reveal that the CNB domains persist as structural cores through heat-denaturation. © 2011 Dao et al

Other-Sex Friendships in Late Adolescence: Risky Associations for Substance Use and Sexual Debut?

Adolescents’ friendships with other-sex peers serve important developmental functions, but they may also facilitate engagement in problem behavior. This study examines the unique contributions of other-sex friendships and friends’ behavior to alcohol use, smoking, and initiation of sexual intercourse among late adolescent girls and boys. A total of 320 adolescents (53% girls; 33% racial/ethnic minorities) provided sociometric nominations of friendships annually in grades 10–12. Friendship networks were derived using social network analysis in each grade. Adolescents and their friends also reported on their alcohol use, smoking, and sexual debut at each assessment. After controlling for demographics, previous problem behavior, and friends’ behavior, other-sex friendships in 10th grade were associated with initiation of smoking among girls over the following year, and other-sex friendships in 11th grade were linked with lower levels of subsequent alcohol use among boys. Additionally, friends’ smoking and sexual experience in 10th grade predicted the same behaviors for all adolescents over the following year. Other-sex friendships thus appear to serve as a risk context for adolescent girls’ smoking and a protective context for adolescent boys’ drinking. Promoting mixed-gender activities and friendships among older high school students may be helpful in reducing males’ alcohol use, but may need to incorporate additional components to prevent increases in females’ smoking

Delinquent Behavior of Dutch Rural Adolescents

This article compares Dutch rural and non-rural adolescents’ delinquent behavior and examines two social correlates of rural delinquency: communal social control and traditional rural culture. The analyses are based on cross-sectional data, containing 3,797 participants aged 13–18 (48.7% females). The analyses show that rural adolescents are only slightly less likely to engage in delinquent behavior. Furthermore, while rural adolescents are exposed more often to communal social control, this does not substantially reduce the likelihood that they engage in delinquent behavior. Concerning rural culture, marked differences appeared between rural and non-rural adolescents. First, alcohol use and the frequency of visiting pubs were more related to rural adolescents’ engagement in delinquent behavior. Second, the gender gap in delinquency is larger among rural adolescents: whereas rural boys did not differ significantly from non-rural boys, rural girls were significantly less likely to engage in delinquent behavior than non-rural girls. However, the magnitude of the effects of most indicators was rather low. To better account for the variety of rural spaces and cultures, it is recommended that future research into antisocial and criminal behavior of rural adolescents should adopt alternative measurements of rurality, instead of using an indicator of population density only

Beyond crime statistics: the construction and application of a criminogenity monitor in Amsterdam

Criminologists have devoted a great deal of attention to risk factors - also called criminogenic factors - leading to criminal offending. This paper presents a criminogenity monitor which includes 19 risk factors that underlie crime. These factors do not themselves cause criminal behaviour; rather, they must be seen as signals that crimes may be committed. After discussing how the criminogenity monitor was constructed, we apply the risk factors we examined to the situation in Amsterdam, capital city of the Netherlands. The monitor is intended to function particularly as an instrument to rationalise policy-makers' work in targeting and preventing symptoms of crime at three geographical levels: the entire city, its boroughs and its neighbourhoods. © 2012 The Author(s)

Grambank reveals the importance of genealogical constraints on linguistic diversity and highlights the impact of language loss

While global patterns of human genetic diversity are increasingly well characterized, the diversity of human languages remains less systematically described. Here we outline the Grambank database. With over 400,000 data points and 2,400 languages, Grambank is the largest comparative grammatical database available. The comprehensiveness of Grambank allows us to quantify the relative effects of genealogical inheritance and geographic proximity on the structural diversity of the world's languages, evaluate constraints on linguistic diversity, and identify the world's most unusual languages. An analysis of the consequences of language loss reveals that the reduction in diversity will be strikingly uneven across the major linguistic regions of the world. Without sustained efforts to document and revitalize endangered languages, our linguistic window into human history, cognition and culture will be seriously fragmented.Genealogy versus geography Constraints on grammar Unusual languages Language loss Conclusio