The Curry/Samara Model and The Model Classrooms Project Background and Research Foundations

The Curry/Samara Model(CSM) is an integrated, standards based approach to curriculum development that addresses differentiation from three dimensions (content, process & product). CSM is comprised of strategies related to curriculum, instruction and assessment that helps teachers to: (1) complement factual subject matter with rich, global concepts; (2) foster basic and abstract levels of thinking as related to core content; and (3) engage and assess students through traditional as well as innovative, authentic products

Bacterioplankton drawdown of coral mass-spawned organic matter

Coral reef ecosystems are highly sensitive to microbial activities that result from dissolved organic matter (DOM) enrichment of their surrounding seawater. However, the response to particulate organic matter (POM) enrichment is less studied. In a microcosm experiment, we tested the response of bacterioplankton to a pulse of POM from the mass-spawning of Orbicella franksi coral off the Caribbean coast of Panama. Particulate organic carbon (POC), a proxy measurement for POM, increased by 40-fold in seawater samples collected during spawning; 68% degraded within 66 h. The elevation of multiple hydrolases presumably solubilized the spawn-derived POM into DOM. A carbon budget constructed for the 275 µM of degraded POC showed negligible change to the concentration of dissolved organic carbon (DOC), indicating that the DOM was readily utilized. Fourier transform ion cyclotron resonance mass spectrometry shows that the DOM pool became enriched with heteroatom-containing molecules, a trend that suggests microbial alteration of organic matter. Our sensitivity analysis demonstrates that bacterial carbon demand could have accounted for a large proportion of the POC degradation. Further, using bromodeoxyuridine immunocapture in combination with 454 pyrosequencing of the 16S ribosomal RNA gene, we surmise that actively growing bacterial groups were the primary degraders. We conclude that coral gametes are highly labile to bacteria and that such large capacity for bacterial degradation and alteration of organic matter has implications for coral reef health and coastal marine biogeochemistry

Analogy, concepts and methodology, in mathematics ∗

Motivation for this article is a question put to Ronnie Brown in June 2004 by a young woman, Bree, at a party while he was visiting the Center for Computational Biology in Bozeman, Montana, to give seminars. Bree said that she was studying maths and ‘found proofs neat’. Also she had asked a lecturer why she should study mathematics, and he had said: ‘Becaus

Background and Research Foundations

The Curry/Samara Model(CSM) is an integrated, standards based approach to curriculum development that addresses differentiation from three dimensions (content, process & product). CSM is comprised of strategies related to curriculum, instruction and assessment that helps teachers to: (1) complement factual subject matter with rich, global concepts; (2) foster basic and abstract levels of thinking as related to core content; and (3) engage and assess students through traditional as well as innovative, authentic products. McGehee (2001) supported the belief that teachers must have a well-developed curricular knowledge of the big ideas in a content area. Building on this expectation, Curry and Samara developed the Unit Matrix as the hallmark of their Model. The Matrix provides teachers with a tool for creating units of study that organizes their content to effectively complement basic knowledge with complex ideas, concepts and themes. In addition, within each matrix cell block, objectives related to the specific subject matter must be written at all levels of thinking and with products from all modalities (visual, oral, written, and kinesthetic). Concept-driven unit development helps students learn how to learn (Ornstein, 1997); the Curry/Samara Matrix provides teachers with a format for this development

Synthesis and Degradation of Hexamethylene Triperoxide Diamine (HMTD)

The synthesis and decomposition of hexamethylene triperoxide diamine (HMTD) were studied. Mechanisms were proposed based on isotopic labeling and mass spectral interpretation of both condensed phase products and head-space products. Formation of HMTD from hexamine appeared to proceed from dissociated hexamine as evident from scrambling of the 15N label when synthesis was carried out with equal molar labeled/unlabeled hexamine. Decomposition of HMTD was considered with additives and in the presence and absence of moisture. In addition to mass spectral interpretation, density functional theory (DFT) was used to calculate energy differences of transition states and the entropies of intermediates along different possible decomposition pathways. HMTD is destabilized by water and citric acid making purification following initial synthesis essential in order to avoid unanticipated violent reaction