Application of external customized waveforms to a commercial quadrupole ion trap

AbstractThe Finnigan LCQ quadrupole ion trap has recently become part of the repertoire of instruments for many analytical laboratories. The LCQ commercial design, while employing complex waveforms to manipulate ions, does not allow the application of many state-of-the-art user-defined waveforms that enable one to perform other complex ion manipulations. The work presented here describes the simple modifications made to the LCQ electronics to allow the application of external customized waveforms. Results show that externally generated waveforms can be applied to the endcap electrodes while still working within the context of the commercial software and hardware. Double resonance, multiple ion isolation, and multiple ion excitation experiments are demonstrated to reveal the effectiveness of these modifications

Eine Längsschnittanalyse der wechselseitigen Beziehungen zwischen schulischem Wohlbefinden und akademischer Leistung

Besides acquisition of academic competencies, well-being is an important educational goal and it has been shown that both outcomes are mutually dependent. However, until now, most studies used cross-sectional designs so that the direction of the relation is not yet fully understood. In the present study we used longitudinal data from students attending grades 5 to 9 who participated in the National Educational Panel Study (NEPS). We analyzed reciprocal relations between different facets of well-being (i.e., physical, cognitive, emotional) and academic achievement. Furthermore, we examined differences between gender and type of school in these reciprocal relations. Results revealed mainly positive reciprocal relations between academic achievement and different indicators of well-being. However, multi-group models did not show differences between gender and type of school. Implications for future research and educational practice are discussed. (DIPF/Orig.)Neben dem Kompetenzerwerb stellt Wohlbefinden ein wichtiges Bildungsziel dar und es konnte gezeigt werden, dass beide Variablen voneinander abhängen. Bis jetzt liegen allerdings im Wesentlichen Befunde aus Querschnittsstudien vor, sodass die Richtung des Zusammenhangs noch nicht vollständig geklärt ist. In der vorliegenden Studie wurden längsschnittliche Daten von Schülerinnen und Schülern der 5. bis zur 9. Klasse genutzt, die an der nationalen Bildungspanelstudie (NEPS) teilgenommen hatten. Untersucht wurden reziproke Zusammenhänge zwischen verschiedenen Facetten von Wohlbefinden (körperlich, kognitiv, emotional) und schulischer Leistung. Weiterhin wurden in Bezug auf diese reziproken Zusammenhänge Unterschiede zwischen Geschlechtern und Schulformen analysiert. Die Ergebnisse zeigten vor allem positive wechselseitige Beziehungen zwischen schulischer Leistung und verschiedenen Indikatoren des Wohlbefindens. Mehrgruppenmodelle ergaben jedoch keine Hinweise auf Unterschiede zwischen Geschlechtern oder Schulformen. Implikationen für Forschung und Bildungspraxis werden diskutiert. (DIPF/Orig.

How do others think about my group? Adolescents’ meta-stereotypes about Turkish- and German-origin students’ subject-related German and general school competence

In Germany, Turkish-origin students face negative competence-related stereotypes held by different groups in society, including teachers at school. While a large body of research has examined stereotypes (i.e., other-stereotypes) about immigrant students, little is known about their own competence-related meta-stereotypes, i.e., beliefs regarding the other-stereotypes that outgroup peers hold about them. The present study addresses this research gap by examining Turkish- and German-origin students’ meta-stereotypes about two dimensions of competencies not yet investigated, namely Turkish- and German-origin students’ subject-related German competence as well as their general school competence using a newly developed instrument combining verbal and non-verbal measures. These assessments are juxtaposed to the evaluations of a group of peers with other immigrant backgrounds (i.e., others’ meta-stereotypes). In line with previous evidence, we found positive meta-stereotypes (as well as other- and others’ meta-stereotypes) towards German-origin students reported by all three groups. However, our study is the first that supports the existence of negative meta-stereotypes (as well as other- and others’ meta-stereotypes) towards Turkish-origin adolescents, again, among all participants. This pattern was particularly pronounced regarding the dimension of subject-related German competence. We discuss the findings’ potential relevance for students’ self-concepts and intergroup interactions in classrooms

Differential patterns of school motivation in students of culturally and linguistically diverse backgrounds

The purpose of this paper was the comparative empirical investigation of school motivation in students of culturally and linguistically diverse backgrounds. Disparities in the levels of multiple adaptive as well as maladaptive dimensions of school motivation between students with and without immigrant backgrounds were investigated. Moreover, the explanatory role of socioeconomic status was examined. Data from 785 students from grade 6, drawn from 36 different German schools were analysed. School motivation was assessed with the eleven translated subscales of the Motivation and Engagement Scale (Martin, 2010). This highly differentiated and integrative instrument does not only take into account adaptive cognitive and behavioural dimensions of school motivation, but also maladaptive cognitive and behavioural dimensions. A multivariate analysis of variance (MANOVA) was performed and effect sizes were calculated. School track was included in the model as a control variable. The results showed no differences in the adaptive motivational dimensions between students with and without immigrant backgrounds. At the same time, students with immigrant backgrounds scored higher on all maladaptive cognitive dimensions while no group differences were observed with regard to the maladaptive behavioural dimensions. After the inclusion of socioeconomic status as a covariate in the model, the reported statistically significant differences between students with and without immigrant backgrounds were no longer identifiable with respect to two of the three maladaptive cognitive dimensions. Implications of the results for research and pedagogical practice in the field of scholastic support for students with immigrant backgrounds are discussed. (DIPF/Orig.

Stereotype threat in learning situations? An investigation among language minority students

Stereotype threat (ST) is a potential explanation for inequalities in language competencies observed between students from different language backgrounds. Language competencies are an important prerequisite for educational success, wherefore the significance for investigation arises. While ST effects on achievement are empirically well documented, little is known about whether ST also impairs learning. Thus, we investigated vocabulary learning in language minority elementary school students, also searching for potential moderators. In a pre-post design, 240 fourth-grade students in Germany who were on average 10 years old (MAge = 9.92, SD = 0.64; 49.8% female) were randomly assigned to one of four experimental conditions: implicit ST, explicit ST without threat removal before posttest, explicit ST with threat removal before posttest, and a control group. Results showed that learning difficult vocabulary from reading two narrative texts was unaffected by ST. Neither students’ identification with their culture of residence and culture of origin nor stereotyped domain of reading were moderators. The findings are discussed with regard to content and methodological aspects such that a motivation effect might have undermined a possible ST effect. Implications for future research include examining the question at what age children become susceptible to ST and whether students have internalized negative stereotypes about their own group, which could increase the likelihood of ST effects occurring. © 2022, The Author(s)

Pine straw yields and economic benefits when added to traditional wood products in loblolly, longleaf and slash pine stands

Paper presented at the 12th North American Agroforesty Conference, which was held June 4-9, 2011 in Athens, Georgia.In Ashton, S. F., S.W. Workman, W.G. Hubbard and D.J. Moorhead, eds. Agroforestry: A Profitable Land Use. Proceedings, 12th North American Agroforestry Conference, Athens, GA, June 4-9, 2011.Many forest landowners have the opportunity to manage their loblolly, longleaf and slash pine stands for pine straw (fresh undecomposed needles; the litter layer) for additional revenues. Pine straw is used primarily as mulch in landscaping and has grown in revenues paid to landowners from $15.5 million in 1999 to$81 million in 2009 in Georgia. Pine straw is typically sold by the acre or by the bale. Selling pine straw by the acre is advantageous for absentee landowners. Selling pine straw by the bale can generate more annual income but bale counts need to be accurate and bale size must be clearly defined. Recent (2005-09) per acre revenues range from $50 to$125/year. Rectangular (13x13x28 inches) bale prices range from $0.25 to$0.40 for loblolly, $0.50 to$1.25 for longleaf, and $0.50 to$0.65 for slash pine in Georgia. Per rake yields from loblolly stands tend to be 15 to 30% greater (150 to 425 bales/acre) than slash (120 to 375 bales/acre) and longleaf pine (100 to 350 bales/acre). Pine straw raking starts at canopy closure continuing to the first thinning, generating from $300/acre to over$1000/acre in new income.E. David Dickens (1), David J. Moorhead (1), Charles T. Bargeron (1),and Bryan C. McElvany (2) ; 1. Warnell School of Forestry & Natural Resources. 2. College of Agriculture & Environmental Sciences, The University of Georgia, Statesboro, Tifton, and Soperton, GA.Includes bibliographical references

Can I dismiss the stereotype – as my teacher did? Influence of stereotype activation and an immigrant teacher on student learning

Lower vocabulary in German is repeatedly reported for students with Turkish migration background attending school in Germany. We investigated whether in students of Turkish descent (a) learning vocabulary is impaired when the teacher activates the negative stereotype that students with Turkish family language learn less well and (b) whether a Turkish-origin teacher, as an ingroup expert model, can mitigate negative effects of the activation of the stereotype. In an experimental study, Turkish- and German-origin students (N = 182) living in Germany worked individually on a tablet on a vocabulary learning task instructed by a teacher in a video tutorial who introduced herself with either a Turkish or German name. Before the task, the teacher either mentioned that students in general (no stereotype activation) or students who speak Turkish in their families (stereotype activation) often have difficulties acquiring new vocabulary. A multiple-group regression analysis showed that Turkish-origin students learned significantly more under stereotype activation with the Turkish-origin teacher than in all other conditions. Results suggest that students are particularly motivated to learn when the teacher represents their ingroup targeted by negative stereotypes and openly addresses potential difficulties students of the stigmatized ingroup may encounter. We discuss the findings in light of the literature on stereotype threat and on the role of ingroup expert models

Gas-phase reactions of carbon cluster ions with isomeric chloropropenes

Sun J, Grützmacher H-F, Lifshitz C. Gas-phase reactions of carbon cluster ions with isomeric chloropropenes. International Journal of Mass Spectrometry and Ion Processes. 1994;138:49-61.Gas-phase ion/molecule reactions of carbon cluster ions (C-n(.+), n = 10-20) with allylchloride (AC) and 2-chloro-propene (CP) were investigated by Fourier transform ion cyclotron resonance spectrometry (FT-ICR). The carbon cluster ions C-n(.+) were generated by electron impact ionization of perchloroarenes and subsequent elimination of all Cl substituents from the molecular ion giving rise to monocyclic C-n(.+). Clear pseudo-first-order reactions were observed for the carbon cluster ions C-n(.+) thus formed without any sign of isomeric clusters of different reactivity. An exception is C-11(.+), for which a small amount of unreactive ions was observed. The reactions of C-n(.+) with AC and CP at low operating pressure (1.2 x 10(-8)-8.0 x 10(-7) mbar) yield product ions Cn+3H5+ by loss of Cl from an intermediate adduct. Rate constants for the reactions with CP are always distinctly larger than with AC in spite of the smaller dissociation energy of the C-Cl bond in AC. Exceptionally large reaction efficiencies are found for C-13(.+) and C-17(.+), corroborating the high reactivity of cyclic anti-aromatic C-n(.+) with n = 4r + 1. The nature of the reaction products depends on the number of carbon atoms in C-n(.+). Secondary reactions of primary product ions Cn+3H5+ were observed only for reactions of odd numbered C-13(.+) and C-17(.+). Further, on collision induced dissociation (CID) the product ions from even C-n(.+) yield exclusively C3H3+, while product ions from odd C-n(.+) generate several fragment ions by loss of H and of C-(2-4)H-2. A reaction model explaining these observations is proposed