5,432 research outputs found
Percussion Ensemble Concert with Guest Artist Bob Becker, Spring 2011
No full textThis is the program for the Spring 2011 Percussion Ensemble concert directed by Dr. Ryan Lewis, and featuring guest artist Bob Becker
Mono- und bifunktionelle Triorganylborane als Bestandteil Frustrierter Lewis-Paare. Synthese und Reaktivitätsstudien
No full textBecker C. Mono- und bifunktionelle Triorganylborane als Bestandteil Frustrierter Lewis-Paare. Synthese und Reaktivitätsstudien. Bielefeld: Universität Bielefeld; 2022
Beyond Lesson Studies and Design Experiments: Using theoretical tools in practice and finding out how they work
No full textThis paper aims to illustrate how fruitful insights into the link between school teaching practice and student learning outcomes can be theoretically grounded by the variation theory from the field of phenomenography; and from this framework demonstrate how a 'pedagogy of awareness' can be implemented in the classroom. In this study, five teachers and 162 students at Primary Four level of school education in Hong Kong participated and the practice of the 'learning study' was adopted. By comparing the results of pre- and posttests, a significant gain was observed in the students learning outcomes.
mAb Das-1 recognizes 3\u27-Sulfated Lewis A/C, which is aberrantly expressed during metaplastic and oncogenic transformation of several gastrointestinal epithelia
No full textINTRODUCTION: Multiple previous studies have shown the monoclonal antibody Das-1 (formerly called 7E12H12) is specifically reactive towards metaplastic and carcinomatous lesions in multiple organs of the gastrointestinal system (e.g. Barrett\u27s esophagus, intestinal-type metaplasia of the stomach, gastric adenocarcinoma, high-grade pancreatic intraepithelial neoplasm, and pancreatic ductal adenocarcinoma) as well as in other organs (bladder and lung carcinomas). Beyond being a useful biomarker in tissue, mAb Das-1 has recently proven to be more accurate than current paradigms for identifying cysts harboring advanced neoplasia. Though this antibody has been used extensively for clinical, basic science, and translational applications for decades, its epitope has remained elusive.
METHODS: In this study, we chemically deglycosylated a standard source of antigen, which resulted in near complete loss of the signal as measured by western blot analysis. The epitope recognized by mAb Das-1 was determined by affinity to a comprehensive glycan array and validated by inhibition of a direct ELISA.
RESULTS: The epitope recognized by mAb Das-1 is 3\u27-Sulfo-Lewis A/C (3\u27-Sulfo-LeA/C). 3\u27-Sulfo-LeA/C is broadly reexpressed across numerous GI epithelia and elsewhere during metaplastic and carcinomatous transformation.
DISCUSSION: 3\u27-Sulfo-LeA/C is a clinically important antigen that can be detected both intracellularly in tissue using immunohistochemistry and extracellularly in cyst fluid and serum by ELISA. The results open new avenues for tumorigenic risk stratification of various gastrointestinal lesions
Frustrated Lewis pair chemistry of hydride sponges
No full textBecker C, Schwabedissen J, Neumann B, Stammler H-G, Mitzel NW. Frustrated Lewis pair chemistry of hydride sponges. Dalton Transactions . 2022.An improved synthesis for 1,8-bis(dimethylboranyl)naphthalene (1, hydride sponge) was developed avoiding the use of tin(IV) reagents. The related 1,2-bis(dimethylboranyl)benzene (2) was prepared. 1 combined with 1,8-bis(dimethylamino)naphthalene (3, proton sponge) is a Frustrated Lewis pair (FLP) that forms adducts [1-EHn-1][3-H] with the protic compounds EHn = H2O, NH3, H2S, PH3, H2Se, HCN. Their structures show the chelation of the deprotonated substrates, except for CN- (binds to one B atom of 1). The mechanisms of formation of [1-EHn-1][3-H] were explored by NMR spectroscopy. Similar reactions took places for the FLP system 2 + 3, but the adducts [2-EHn-1][3-H] are less stable; only the PH3 adduct was isolated and AsH3 forms a chelated adduct [2-NC(CD3)AsH2][3-H]. FLP 1 + 3 does not react with molecular hydrogen, but the formal adduct [1-H][3-H] was isolated via salt metathesis from K[1-H] and [3-H]Cl; it is stable towards water, atmospheric oxygen and up to 100 °C; its thermal decomposition proceeds without formation of H2. The stabilities of both, the mixture 1 + 3 + H2 and the formal adduct [1-H][3-H], allow concluding that hydrogen activation of FLP 1 + 3 is kinetically prevented
para-Chlorotetrafluorophenyl-boranes - syntheses and structures of a series of mono- and bidentate Lewis acids
No full textBecker C, Trapp P, Neumann B, Stammler H-G, Mitzel NW. para-Chlorotetrafluorophenyl-boranes - syntheses and structures of a series of mono- and bidentate Lewis acids. Dalton transactions . 2022.Mono- and bidentate tri-coordinated boron compounds bearing the yet unexplored para-chlorotetrafluorophenyl substituent have been synthesized and structurally investigated. The acidity of tris(para-chlorotetraphenyl)borane (7) was shown to exceed that of the widely used tris(pentafluorophenyl)borane (BCF) according to the Gutmann-Beckett method. Acid-base adducts of 7 with diethyl ether and triethylphosphine oxide were crystallized. Dihydrogen splitting at room temperature was observed with a Frustrated Lewis Pair consisting of 7 and 2,2,6,6-tetramethylpiperidine (TMP). The hydrogen adduct was isolated and characterized by NMR, SC-XRD and elemental analysis. Its solid-state structure contains a H⋯H distance on the verge of dihydrogen bonding (2.28(6) A). Bis(para-chlorotetrafluorophenyl)hydridoborane was prepared in situ and shown to be applicable in hydroboration reactions similarly to Piers' borane
The trade-off between fertility and education : evidence from before the demographic transition
No full textThe trade-off between child quantity and quality is a crucial ingredient of unified growth models that explain the transition from Malthusian stagnation to modern growth. We present first evidence that such a trade-off indeed existed already in the nineteenth century, exploiting a unique census-based dataset of 334 Prussian counties in 1849. Furthermore, we find that causation between fertility and education runs both ways, based on separate instrumental-variable models that instrument fertility by sex ratios and education by landownership inequality and distance to Wittenberg. Education in 1849 also predicts the fertility transition in 1880-1905
A new perspective on the death of Meriwether Lewis
No full textPoster for the 25th Historia Medica lecture.https://digitalcommons.wustl.edu/historyofmedicine_historia_medica_posters/1007/thumbnail.jp
Becker’s Theories of Marriage and the Shrinking Role of Demand and Supply Models
No full textThis paper argues that Gary Becker has been a leader in the economics of marriage not only as a pioneer but also as a leader who influenced the work of other economists who entered this field over at least two decades. A comprehensive survey of economic research on marriage is presented for the years 1970-1993. A distinction is drawn between earlier entrants and later entrants, the dividing line being 1980, coinciding with the publication of Becker’s seminal Treatise on the Family. In his first article on marriage in the JPE in 1973, Becker gave more prominence to Demand & Supply [D&S] models than he later did in the Treatise. It appears that a similar movement away from D&S models is observed among later entrants. This is but one indication of Becker’s leadership in the economics of marriage in the period 1980-1993. Other indications are also discussed.
Demographics and the Anatomy of International Capital Flows
No full textThis thesis is built upon two core arguments. The first is the notion that the demographic transition should be narrated through the perspective of ageing rather than population growth and the second is that ageing on a macroeconomic level represents a strong driver of international capital flows. These two arguments are used to discuss the standard prediction in a life cycle framework that ageing leads to dissaving in the aggregate and thus how old economies should tend towards running current account deficits. Using Japan and Germany as the subjects of analysis, this thesis develops the idea that rapidly ageing societies are not, in the main, characterized by dissaving but rather by the fight against it. Finally, a small empirical exercise acts as a perspectivation on the results to suggest why ageing might lead to a reliance on exports and foreign asset income to achieve growth and what this means in a global context.demographics; international capital flows; life cycle economics,
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