A new and efficient approach to time-dependent density-functional perturbation theory for optical spectroscopy

Using a super-operator formulation of linearized time-dependent density-functional theory, the dynamical polarizability of a system of interacting electrons is given a matrix continued-fraction representation whose coefficients can be obtained from the non-symmetric block-Lanczos method. The resulting algorithm allows for the calculation of the {\em full spectrum} of a system with a computational workload which is only a few times larger than that needed for {\em static} polarizabilities within time-independent density-functional perturbation theory. The method is demonstrated with the calculation of the spectrum of benzene, and prospects for its application to the large-scale calculation of optical spectra are discussed.Comment: 4 pages, 2 figure

Determination of the charge carrier compensation mechanism in Te-doped GaAs by scanning tunneling microscopy.

We identified the charge carrier compensation mechanism in Te-doped GaAs with atomically resolved scanning tunneling microscopy. Three types of defects were found: tellurium donors (Te-As), Ga vacancies (V-Ga), and Ga vacancy-donor complexes (V-Ga-Te-As). We show quantitatively that the compensation in Te-doped bulk GaAs is exclusively caused by vacancy-donor complexes in contrast to Si-doped GaAs. This is explained with the Fermi-level effect as the universal mechanism leading to Ga vacancy formation in n-doped GaAs, and a Coulomb interaction leading to the formation of the complexes. The quantification of the carrier compensation yields a -3e charge state of V-Ga in bulk GaAs. (C) 2003 American Institute of Physics

Addressing post-harvest losses during traditional banana fermentation for increased food security in Southwest Uganda

Postharvest losses (PHL) destroy 20-60% of the food production in East Africa, exacerbating already severe regional food insecurity. Fermenting perishable foods such as fruits may reduce PHL while providing nutritional enrichment, improving shelf-life and food quality, and addressing seasonality in food supply. Fermented banana products have been refined and diversified in Uganda over generations to make the greatest use of available food resources, but still parts of the raw material are being lost during processing. This study aimed at exploring existing traditional methods and efficiency of fermentation of Musa (AAA-EAHB) 'Mbidde' in southwestern Uganda. The study gathered information through participatory explorations (working with brewers) on banana juice (lightly fermented beer with <1% alcohol content [n=20 brewers]), tonto (turbid beer with ~4% alcohol [n=20]), and amarwa (smoky spirit with ~ 40% alcohol [n=20]). Brewers mentioned several losses of material during harvest and processing. Harvesting bananas requires felling the plant causing ripe fruit damage, particularly during harvest for processing banana juice (loss from fresh bananas=6.4%±8.8%) or amarwa (loss=9.3%±9.5%). Second, losses occur when brewers squeeze juice from the raw banana pulp using stems of Imperata cylindrica, which is then discarded or fed to animals together with the adherent fruit pulp (losses from raw banana juice=50.6%±0.2%; from tonto 39.2%±21.4% and amarwa 47.6%±12.5%). Other causes of PHL during processing are excessive peeling for tonto processing (loss of banana flesh=18.6%±5.8%) and losses of intermediate products during distillation of amarwa (loss=75.9%±1.3%). Total losses of banana products during processing were rare and caused by sabotage (mostly by children), mistakes in the brewing process (e.g. addition of too much water), using bananas of wrong ripening stage, and equipment failure (e.g., burst or leaking drums in distillation equipment). Other non-PHL challenges include Banana Xanthomonas Wilt (BXW) and bad weather (up to 50% losses in the field). Despite the general efficiency of traditional fermentation practices, significant portions of fruit are still lost. Reduction in PHL can complement, both culturally and nutritionally, the role that fermented banana products play in Ugandan food systems and contribute to regional food security. Collaborative mechanisms for PHL reduction should target the cited sources of PHL

Secularization Trends Obscure Developmental Changes in Religiosity

How do people’s religious beliefs and behaviors change over the course of adulthood? Previous research found rapid decreases in religiosity during young adulthood and rebounds in middle and late adulthood. However, secularization trends—if not accounted for—can bias or obscure age-graded changes in religiosity. Using longitudinal data from over 14,000 Dutch participants aged 16 to 101 years, we disentangled secularization trends from developmental changes in religiosity. Controlling for secularization, we found no evidence for age-graded declines in religiosity among young adults but lifelong increases in religiosity. These increases were most pronounced during middle to late adulthood, consistent with theories that emphasize the self-transcendent focus of this life stage. College-educated individuals were generally less religious and experienced less pronounced age-graded increases in their religious beliefs. These findings must be understood in the context of secularization trends as indicated by significant decreases in religiosity among people of all demographic groups

Microscopic identification of native donor Ga-vacancy complexes in Te-doped GaAs

Native vacancies in Te-doped (5×1016–5×1018cm−3) GaAs were investigated by means of positron lifetime and Doppler-broadening coincidence spectroscopy. The experimental data were related to theoretical calculations of the positron lifetime and the annihilation momentum distribution. Monovacancies were observed in all Te-doped GaAs samples under study. It will be shown that they can directly be identified to be Ga-vacancy–TeAs-donor complexes. These complexes are the dominating type of vacancy defects in the doping range under observation.Peer reviewe

Cross-cultural variations in big five relationships with religiosity: a sociocultural motives perspective.

A sociocultural motives perspective (SMP) on Big Five relationships is introduced. According to the SMP, Agreeableness and Conscientiousness elicit assimilation to sociocultural norms, Openness elicits contrast from these norms, and Extraversion and Neuroticism are independent of sociocultural assimilation and contrast. Due to sociocultural assimilation, then, relationships of Agreeableness and Conscientiousness with an outcome wax (become more positive or less negative) with that outcome's increasing sociocultural normativeness. Due to sociocultural contrast, relationships of Openness with an outcome wane (become less positive or more negative) with that outcome's increasing sociocultural normativeness. We tested the SMP using religiosity as our outcome. Study 1 included 4 cross-sectional self-report data sets across 66 countries (N = 1,129,334), 50 U.S. states (N = 1,057,342), 15 German federal states (N = 20,885), and 121 British urban areas (N = 386,315). Study 2 utilized informant-report data across 37 countries (N = 544,512). Study 3 used longitudinal data across 15 German federal states (N = 14,858). Results consistently supported the SMP. Relationships of Agreeableness and Conscientiousness with religiosity were more positive in religious sociocultural contexts than in secular contexts. Relationships of Openness with religiosity were more negative in religious sociocultural contexts than in secular contexts. At a more general level, the SMP offers theory-driven explanations for cross-cultural variations in Big Five relationships with their outcomes.We thankfully acknowledge support from the German Research Foundation (DFG; GE 2515/3-1).This is the accepted manuscript. This article may not exactly replicate the final version published in the APA journal. It is not the copy of record. The final version is available from APA at http://psycnet.apa.org/psycinfo/2014-35855-001/

To Live Among Like-Minded Others: Exploring the Links Between Person-City Personality Fit and Self-Esteem.

Does it matter if your personality fits in with the personalities of the people where you live? The present study explored the links between person-city personality fit and self-esteem. Using data from 543,934 residents of 860 U.S. cities, we examined the extent to which the fit between individuals' Big Five personality traits and the Big Five traits of the city where they live (i.e., the prevalent traits of the city's inhabitants) predicts individuals' self-esteem. To provide a benchmark for these effects, we also estimated the degree to which the fit between person and city religiosity predicts individuals' self-esteem. The results provided a nuanced picture of the effects of person-city personality fit on self-esteem: We found significant but small effects of fit on self-esteem only for openness, agreeableness, and conscientiousness, rather than effects for all Big Five traits. Similar results and effect sizes were observed for religiosity. We conclude with a discussion of the relevance and limitations of this study.This is the author accepted manuscript. The final version is available from SAGE via http://dx.doi.org/10.1177/095679761562713

Cultural norm fulfillment, interpersonal belonging, or getting ahead? A large-scale cross-cultural test of three perspectives on the function of self-esteem.

What is the function of self-esteem? We classified relevant theoretical work into 3 perspectives. The cultural norm-fulfillment perspective regards self-esteem a result of adherence to cultural norms. The interpersonal-belonging perspective regards self-esteem as a sociometer of interpersonal belonging. The getting-ahead perspective regards self-esteem as a sociometer of getting ahead in the social world, while regarding low anxiety/neuroticism as a sociometer of getting along with others. The 3 perspectives make contrasting predictions on the relation between the Big Five personality traits and self-esteem across cultures. We tested these predictions in a self-report study (2,718,838 participants from 106 countries) and an informant-report study (837,655 informants from 64 countries). We obtained some evidence for cultural norm fulfillment, but the effect size was small. Hence, this perspective does not satisfactorily account for self-esteem's function. We found a strong relation between Extraversion and higher self-esteem, but no such relation between Agreeableness and self-esteem. These 2 traits are pillars of interpersonal belonging. Hence, the results do not fit the interpersonal-belonging perspective either. However, the results closely fit the getting-ahead perspective. The relation between Extraversion and higher self-esteem is consistent with this perspective, because Extraversion is the Big Five driver for getting ahead in the social world. The relation between Agreeableness and lower neuroticism is also consistent with this perspective, because Agreeableness is the Big Five driver for getting along with others.We acknowledge support from the German Research Foundation (DFG; Grant GE 2515/2-1).This is the author accepted manuscript. The final version is available from the American Psychological Association via http://dx.doi.org/10.1037/pspp000005

Do Arsenic Interstitials Really Exist in As-Rich GaAs?

To investigate the lattice distortion caused by point defects in As-rich GaAs, we make use of a self-consistent-charge density-functional based tight-binding method. Both relevant defects, the As antisite and the As interstitial, cause significant lattice distortion. In contrast to As interstitials, isolated As antisites lead to lattice strain as well as displacement of nearest neighbor As lattice atoms into the ⟨110⟩ channels, in excellent agreement with experiments. Therefore, our result gives powerful evidence for As antisites being the dominating defect in as-grown As-rich GaAs.Peer reviewe