A high resolution electron energy loss spectroscopy study of the Fermi resonance of CO₂ adsorbed on a Ag(110)/CO₃ layer

The adsorption of CO2 on a Ag(110) surface precovered with a saturated CO3 layer has been studied by high resolution electron energy loss spectroscopy (HREELS). A weakly bound state of CO2 is stabilized by the presence of carbonate. In addition to the losses of the bend (658 cm−1) and the antisymmetric stretch (2343 cm−1) fundamental modes, the presence of two peaks in the frequency region of the symmetric stretch mode have been observed. Such a loss pair is characteristic for the existence of a Fermi resonance, between the overtone of the bend and the symmetric stretch vibration, which had been studied in detail for the gas phase CO2 molecule. By use of three CO2 isotopomers the existence of the Fermi resonance in the adsorbed state has been verified and the Fermi constant and the energy of the unperturbed vibrations have been determined from the isotopic shifts. The character of the CO2 molecule is almost unaffected by the bonding and it adsorbs in a tilted geometry

Improving School Leadership: The Promise of Cohesive Leadership Systems

Describes Wallace grantees' work to create a cohesive leadership system of coordinated policies between states and districts and across state agencies, states' and districts' efforts to forge cohesive policies, and the impact on instructional leadership

Natural occurrence of entomopathogenic nematodes (Rhabditida : Steinernematidae and Heterorhabditidae) in Guadeloupe islands

Des prospections ont été réalisées sur 538 sites en Guadeloupe (Grande Terre, Basse Terre) et dans ses dépendances (Marie-Galante, La Désirade, Petite Terre, Les Saintes, Saint-Barthélémy, Saint-Martin) pour rechercher des nématodes entomopathogènes par la technique du piège à insecte (#FGalleria mellonella$). Sur 35 sites positifs (6$ (97%) et l'un d'eux un #Steinernema$(3$ (88%) et #H. bacteriophora$(12$ appartient sans doute à une nouvelle espèce en cours d'étude. Les nématodes ont été isolés en zone côtière (91,4%), en zone tropicale de basse (5,7%) et de moyenne altitude (2,9%). Aucun nématode n'a été trouvé en zone montagneuse. (Résumé d'auteur

Ethnic Identity and Educational Outcomes of German Immigrants and Their Children

Identity can be an important driving force for educational performance. Immigrants and their children face the challenge of identifying with their host country's culture. This paper examines whether young immigrants and their children who identify stronger with the German culture are more likely to increase their educational outcomes. I use a concept of ethnic identity which is designed to capture Germanness in immigrants' day-to-day routine - based on self-identification, language skills and cultural habits. The research design takes into account the issue of endogeneity of ethnic identity in an educational outcome equation by measuring education and identity at different moments and by using an endogenous latent factor methodology. The paper finds that identification with the German culture has an overall positive effect on educational outcomes and diminishes and renders the educational gap between immigrants and the second generation insignificant. The paper¿s results indicate that the second generation identifies stronger with the German culture than immigrants, no matter whether of German, European, Central European or Turkish background. Apart from the immigrant generation, own low educational attainment and high mother's educational attainment matter for identification with the German culture

Ethnicity, Job Search and Labor Market Reintegration of the Unemployed

This paper is based on recently collected and rich survey data of a representative sample of entrants into unemployment in Germany. Our data include a large number of migration variables, allowing us to adapt a recently developed concept of ethnic identity: the ethnosizer. To shed further light on the native-migrant differences in economic outcomes, we investigate the labor market reintegration, patterns of job search, and reservation wages across unemployed migrants and natives in Germany. Our results indicate that separated migrants have a relatively slow reintegration into the labor market. We explain this finding by arguing that this group exerts a relatively low search effort and that it has reservation wages which are moderate, yet still above the level which would imply similar employment probabilities as other groups of migrants

Correlation dynamics between electrons and ions in the fragmentation of D2_2 molecules by short laser pulses

We studied the recollision dynamics between the electrons and D$_2^+$ ions following the tunneling ionization of D$_2$ molecules in an intense short pulse laser field. The returning electron collisionally excites the D$_2^+$ ion to excited electronic states from there D$_2^+$ can dissociate or be further ionized by the laser field, resulting in D$^+$ + D or D$^+$ + D$^+$, respectively. We modeled the fragmentation dynamics and calculated the resulting kinetic energy spectrum of D$^+$ to compare with recent experiments. Since the recollision time is locked to the tunneling ionization time which occurs only within fraction of an optical cycle, the peaks in the D$^+$ kinetic energy spectra provides a measure of the time when the recollision occurs. This collision dynamics forms the basis of the molecular clock where the clock can be read with attosecond precision, as first proposed by Corkum and coworkers. By analyzing each of the elementary processes leading to the fragmentation quantitatively, we identified how the molecular clock is to be read from the measured kinetic energy spectra of D$^+$ and what laser parameters be used in order to measure the clock more accurately.Comment: 13 pages with 14 figure

SHORT NOTE I back of nucleotide variability in a beetle pest with extreme inbreeding

Abstract The coffee berry borer beetle Hypofhenemus hampei (Ferrari) (Curculionidae: Scolytinae) is the major insect pest of coffee and has spread to most of the coffee-growing countries of the world. This beetle also displays an unusual life cycle, with regular sibling mating. This regular inbreeding and the population bottlenecks occurring on colonization of new regions should lead to low levels of genetic diversity. We were therefore interested in determining the level of nucleotide variation in nuclear and mitochondrial genomes of this beetle worldwide. Here we show that two nuclear loci (Resisfance to dieldrin and ITS2) are completely invariant, whereas some variability is maintained at a mitochondrial locus (COI), probably corresponding to a higher mutation rate in the mitochondrial genome. Phylogenetic analysis of the mitochondrial data shows only two clades of beetle haplotypes outside of Kenya, the proposed origin of the species. These data confirm that inbreeding greatly reduces nucleotide variation and suggest the recent global spread of only two inbreeding lines of this bark beetle

Tools for delivering entomopathogenic fungi to malaria mosquitoes: effects of delivery surfaces on fungal efficacy and persistence.

BACKGROUND\ud \ud Entomopathogenic fungi infection on malaria vectors increases daily mortality rates and thus represents a control measure that could be used in integrated programmes alongside insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS). Before entomopathogenic fungi can be integrated into control programmes, an effective delivery system must be developed.\ud \ud METHODS\ud \ud The efficacy of Metarhizium anisopliae ICIPE-30 and Beauveria bassiana I93-825 (IMI 391510) (2 × 10(10) conidia m(-2)) applied on mud panels (simulating walls of traditional Tanzanian houses), black cotton cloth and polyester netting was evaluated against adult Anopheles gambiae sensu stricto. Mosquitoes were exposed to the treated surfaces 2, 14 and 28 d after conidia were applied. Survival of mosquitoes was monitored daily.\ud \ud RESULTS\ud \ud All fungal treatments caused a significantly increased mortality in the exposed mosquitoes, descending with time since fungal application. Mosquitoes exposed to M. anisopliae conidia on mud panels had a greater daily risk of dying compared to those exposed to conidia on either netting or cotton cloth (p < 0.001). Mosquitoes exposed to B. bassiana conidia on mud panels or cotton cloth had similar daily risk of death (p = 0.14), and a higher risk than those exposed to treated polyester netting (p < 0.001). Residual activity of fungi declined over time; however, conidia remained pathogenic at 28 d post application, and were able to infect and kill 73 - 82% of mosquitoes within 14 d.\ud \ud CONCLUSION\ud \ud Both fungal isolates reduced mosquito survival on immediate exposure and up to 28 d after application. Conidia were more effective when applied on mud panels and cotton cloth compared with polyester netting. Cotton cloth and mud, therefore, represent potential substrates for delivering fungi to mosquitoes in the field

Ethnic diversity and labor market success

The economic potential of ethnic and cultural diversity is often underestimated. This paper summarizes a number of recent studies which show that 'soft' factors such as attitudes, perceptions and identities - and in particular ethnic identities - significantly affect economic outcomes. More specifically, the studies analyze the process of cultural integration over migrant generations as well as the process of job search and labor market reintegration of the unemployed. The economy can thus gain productivity and efficiency by recognizing and incorporating such multi-ethnic factors. Cultural assimilation that goes along with a loss of migrants' own cultural heritage does not appear to be the sole or dominant strategy of an economically successful integration. To tap the full potential of ethnic and cultural diversity, an increased cultural and ethnic open-mindedness of the native population is desirable