Niemcza diorites and moznodiorites (Sudetes, SW Poland): a record of changing geotectonic setting at ca. 340 Ma

Granites sensu lato in the Sudetes intruded in several episodes during the Variscan orogeny recording different stages of crust and mantle evolution. Correlating precise ages with geochemistry of the Variscan granites provides information on the evolution of these sources within the Variscan orogen. The Variscan intrusive rocks from the Niemcza Zone (Bohemian Massif, Sudetes, SW Poland) include undeformed dioritic to syenitic rocks and magmatically foliated granodiorites. In this study we analysed low SiO2 (48–53 wt.%) monzodioritic rocks from Przedborowa and Koźmice. The monzodiorites contain late-magmatic zircons with ages of 341.8 ± 1.9 Ma for Przedborowa and 335.6 ± 2.3 Ma for Koźmice, interpreted as emplacement ages of the dioritic magmas. Older Przedborowa rocks are lower in K, Mg, Rb and Ni than the Koźmice rocks and similar compositional trend is also observed in the Central Bohemian Plutonic Complex. The implication is that the mantle underlying the Niemcza Zone became more enriched from ca. 342 to ca. 336 Ma, probably following the collision of the Saxothuringian and Moldanubian/Lugian domains. The magmatism related to the collision occurred ca. 12 Ma later than that in the Central Bohemian Plutonic Complex, but was accompanied by a similar change in magma chemistry from high-K (Przedborowa) to shoshonitic (Koźmice, Kośmin enclaves) and probably to ultrapotassic (Wilków Wielki)

Analysis of variability in the burst oscillations of the accreting millisecond pulsar XTE J1814-338

The accreting millisecond pulsar XTE J1814-338 exhibits oscillations at the known spin frequency during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. We present an analysis of the variability of the burst oscillations of this source, focusing on three characteristics: fractional amplitude, harmonic content and frequency. Fractional amplitude and harmonic content constrain the size, shape and position of the emitting region, whilst variations in frequency indicate motion of the emitting region on the neutron star surface. We examine both long-term variability over the course of the outburst, and short-term variability during the bursts. For most of the bursts, fractional amplitude is consistent with that of the accretion pulsations, implying a low degree of fuel spread. There is however a population of bursts whose fractional amplitudes are substantially lower, implying a higher degree of fuel spread, possibly forced by the explosive burning front of a precursor burst. For the first harmonic, substantial differences between the burst and accretion pulsations suggest that hotspot geometry is not the only mechanism giving rise to harmonic content in the latter. Fractional amplitude variability during the bursts is low; we cannot rule out the hypothesis that the fractional amplitude remains constant for bursts that do not exhibit photospheric radius expansion (PRE). There are no significant variations in frequency in any of the bursts except for the one burst that exhibits PRE. This burst exhibits a highly significant but small ($\approx 0.1$Hz) drop in frequency in the burst rise. The timescale of the frequency shift is slower than simple burning layer expansion models predict, suggesting that other mechanisms may be at work.Comment: 20 pages, 20 figures, accepted for publication in ApJ. Uses emulateapj.cl

Social Isolation in Middle Childhood: Variability and Vulnerability

To address debate about risk associated with isolated behaviors during middle childhood, the present study utilized an extreme group approach to examine behavioral characteristics and social functioning of a large sample of children in grades 2-5 who scored 1.5 standard deviations above the classroom mean on an extensively studied, psychometrically sound measure of isolated behavior: the Sensitive-Isolated scale of the Revised Class Play (RCP; Masten, Morison, & Pellegrini, 1985). Children viewed by peers as extremely sensitive-isolated (SI) were first compared to a non-isolated comparison group (COMP) matched one-to-one on classroom, race, and gender, with regard to risk for peer rejection and friendlessness. Risk and/or protective benefits conferred by specific demographic factors (gender, race, grade-level) and behavioral characteristics (academic and athletic competencies) were examined. Regression analyses revealed that SI children were at significantly greater risk for friendlessness and peer rejection relative to COMP peers. There were no main or interactive effects of demographic variables. Main effects of poor academic and athletic abilities were shown for peer rejection and friendlessness; poorer abilities were associated with increased risk for these outcomes. No interactive effects of academic or athletic abilities with group membership were demonstrated. Latent class analyses within the SI group utilizing behavioral data from the RCP revealed the presence of three distinct classes of SI children: SI-Pure (66%), SI-Aggressive (26%), and SI-Prosocial (8%). With regard to relative vulnerability for friendlessness, the SI-Pure class did not demonstrate greater risk for friendlessness relative to the SI-Prosocial class and was less likely than the SI-Aggressive class to be friendless. The SI-Pure class was more likely to be rejected than the SI-Prosocial class. The SI-Prosocial class showed the lowest risk for peer rejection. However, this protective effect was not present for the friendlessness variable. The SI-Aggressive class evidenced significantly relatively greatest risk for friendlessness and peer rejection. Given increased risk for peer rejection and friendlessness associated with SI behaviors in middle childhood, the current study adds more evidence to the literature describing psychosocial difficulties for isolated children, particularly when these behaviors include comorbid aggression, underscoring the need for timely identification and intervention

Evidence that androstadienone, a putative human chemosignal, modulates women’s attributions of men’s attractiveness

Considerable research effort has focused on whether specific compounds found within human body odor influence the behavior or physiology of other individuals. The most intensively studied is 4,16-androstadien-3-one, a chemical which is known to modulate mood and have activational effects in the sympathetic nervous system in a context-dependent manner, but whose action in mate-choice contexts remains largely untested. Here we present evidence that this androgen steroid may modulate women’s judgments of men’sattractiveness in an ecologically valid context. We tested the effects of androstadienone at a speed-dating event in which men and women interacted in a series of brief dyadic encounters. Men were rated more attractive when assessed by women who had been exposed to androstadienone, an effect that was seen in two out of three studies. The results suggest that androstadienone can influence women’s attraction to men, and also that research into the modulatory effects of androstadienone should be made within ecologically valid contexts

Peer Relationships in African American Adolescents: The Role of Cognitive Functioning

Developmental research on social functioning has consistently demonstrated an association between peer reports of a child's social functioning and adjustment in multiple domains. Because peer reports of social functioning have demonstrated stability and predictive power for subsequent behavioral and emotional functioning, there is a strong interest in gaining a better understanding of factors that contribute to variation in peer reports of a child's social behavior and acceptance. The current study examined the relationship between an individual child's cognitive functioning and peer reports of the same child's social functioning for an inner city urban sample of 116 African American adolescents, ages 14 to 17. Cognitive data were obtained utilizing an extensive neuropsychological battery and one-to-one testing. Social functioning data were obtained in classrooms from peers and teachers.A significant association was demonstrated between IQ-Achievement (IQA) and reciprocated friendships, with higher IQA scores associated with a greater number of reciprocated friendships. When specific aspects of cognitive functioning (attention, visual-spatial skills, motor skills, memory, executive functioning) were considered in combination with IQA, only attention was linked to social outcomes; poorer attentional abilities were associated with fewer peer reported popular-leadership behaviors. Two significant IQA interactions also emerged: an interaction between IQA and memory skills for teacher-reported aggressive disruptive behavior, and an interaction between IQA and motor skills for reciprocatedfriendships. All significant findings were of small to medium effect. The absence of significant findings and modest size of the few significant results that were obtained suggests that, in the current sample of African American inner city youth, our measures of neurocognitive functioning were marginally related to peer perceptions of the adolescent's social functioning. While replication is needed, results are discussed considering the role of contextual factors (e.g., age, race, SES), issues related to measurement of cognitive ability, and implications for existing models of social and cognitive development

Survey of leisure time interests and activities of ninth grade boys and girls

Thesis (Ed. M.)--Boston University, 195

Proactive or Reactive? Optimal Management of an Invasive Forest Pest in a Spatial Framework

This paper offers a preliminary investigation into the conditions under which it might be optimal to engage in proactive management of a non-timber forest resource in the presence of an invasive species whose spread is unaffected by management action. Proactive management is defined as treating an uninfected area in order to encourage healthy ecosystem function, given that the arrival of the invasive is inevitable. Inspired by the problem of white pine blister rust in the Rocky Mountain west, the model was solved under varying assumptions concerning the scale of management action, benefit and costs, the discount rate, and uncertainty of spread. Results showed that proactive strategies tended to be optimal when, ceteris paribus, a) more resources are available for treatment; b) the costs of treatment are rapidly increasing in forest health, or conversely, the benefits of healthy and unhealthy stands are relatively similar; and c) the discount rate is low. The introduction of uncertainty did not significantly affect the likelihood of a proactive management strategy being optimal, but did show that the conditional probabilities of infection play important role in the decision of which uninfected stand should be treated if a choice is available to the manager.Crop Production/Industries, Resource /Energy Economics and Policy,

The Power of Play: The Portrayal and Performance of Race in Video Games

Part of the Volume on the Ecology of Games: Connecting Youth, Games, and LearningThe chapter addresses the following question: in what ways do young people's interactions with video games influence how and what they learn about race? We begin by examining one of the most heavily marketed genres in the video games marketplace, what we call "urban/street" games. Specifically, we consider how these games, and the richly detailed and textured urban landscapes they present, establish powerful learning environments that help situate how young gamers understand, perform, and reproduce race and ethnicity. Next, we focus on the aesthetic and narrative properties of one of the most controversial yet successful video games franchises in America, Grand Theft Auto. More precisely, we consider how Grand Theft Auto teaches dominant attitudes and assumptions about race and racial Otherness through racialized pedagogical zones (RPZs). In the final section of the paper we expand the discussion of race and games to include concerns about access to and participation in digital media culture