Theories of Piaget, Who Died this Month, Inspire Growing Band of U.S. Professors

The death of Jean Piaget this month at the age of 84 came at a time when the Swiss psychologist\u27s theories of cognitive development were inspiring a small but growing number of innovative instructional programs in American colleges and universities. Most were started within the past few years and have yet to produce much hard evidence of their effectiveness. But participating faculty members say they are excited about what has been happening in their classrooms. Piagetian-based instruction, they say, offers many potential advantages over traditional methods: It facilitates communication, improves students\u27 reasoning ability and academic achievement, boosts their self-confidence and interest in their work, and provides a practical basis for integrating different subjects in a curriculum through a common emphasis on cognitive skills. Preliminary research findings indicate that students in such programs make significantly greater gains on tests of critical thinking than do their counterparts in other classes. Teachers also report that attendance is up and attrition is down for students in the special classes, which encompass many disciplines in both the sciences and the humanities. It\u27s a movement that is coming in higher education, says one enthusiast. So far about a dozen colleges are conducting formal Piagetian programs, while faculty members at a number of other institutions are believed to be drawing on Piaget independently in their teaching. The formal programs, which range from a single course to a full year of study, have attracted financial support from the federal government and private foundations

Low-Valent Titanium Porphyrin Complexes. Synthesis and Structural Characterization of the First Titanium(II) Porphyrin Complex, (ɳ2-Diphenylacetylene)Oitanium Octaethylporphyrin

The anaerobic reduction of the dlchlorotltanlum( IV) porphyrins (OEP)TICI2 and (TTP)TICI2 (OEP = octaethylporphyrlnato, TTP = meso -tetra-p -tolylporphyrlnato) with LIAIH4 in the presence of diphenylacetylene In toluene produces the 11 -alkyne T~II) aclducts (OEP)TI(172-Phc==cPh) (1) and (TTP)Ti(172-PhC==cPh) (2). The structure of 1 has been determined by single-crystal X-ray diffraction analysis. Complex 1 crystallizes in the centrosymrnetrlc space group C2/c with a= 49.369 (7) A, b = 13.734 (9) A, c = 36.042 (5) A, {3 = 136.62 (1)0 , V = 16784 (9) A3, Z = 16, R = 0.061, and Rw = 0.063. The asymmetric unit of 1 contains two molecules. Alkyne C-C distances and Ti-alkyne distances are 1.30 ( 1) (C27-C28), 2.016 (5) (TI 1-C27), 2.015 (5) (Ti 1-C~8), 1.30 (1) (C81-C62), 2.007 (7) (T12-C61 ), and 2.028 (7) A (Ti2-C62)

Mono- and Dinuclear Complexes of a New Binucleating Porphyrin, α,α-5,15-Bis(ο-(Nicotinoylamino)Phenyl)-2,8,12,18-Tetraethyl-3,7,13,17-Tetramethylporphyrin. Crystal Structures of a Mononuclear Nickel(II) Complex and a Binuclear Copper-Platinum Complex

The synthesis and characterization of a new binucleating porphyrin ligand, a,a-5, 1 5-bis(o-(nicotinoylamido)phenyl)-2,8, 12,18- tetraethyl-3,7,13,17-tetramethylporphyrin, [H2(DPE)]-(pyh is reported. Treatment of [H 2(DPE)]-(pyh with methanol solutions of Ni(II) or Cu(II) leads to the formation of mononuclear metal complexes, [M(DPE)]-(pyh, in which the metal has inserted into the porphyrin core, leaving the pyridine binding site free. Addition of a second metal to form a binuclear complex, [M( DPE)]-(pyhM\u27Cl2, can be accomplished using the reagent M\u27(DMSOhCI2, M\u27 = Pd, Pt, and Zn. [Ni(DPE)]-(pyh and [Cu(DPE)]-(pyhPtCI2 have been characterized by single-crystal X-ray analysis. Crystal data for [Ni(DPE)]-(pyh: Ni02N 8- C56H52·2CHCI3, triclinic, PI, a= 14.306 (4) A, b = 14.719 (5) A, c = 14.296 (5) A, a= 94.86 (3) 0 , {J = 96.38 (3) 0 , -y = 63.45 (2) 0 , Z = 2, R = 0.049, and Rw = 0.064. Crystal data for [Cu(DPE)]-(pyhPtCI2: CuPt02N 8C 56H 52, triclinic, PI, a= 19.333 (1) A, b = 23.74 (I) A, c = 12.984 (5) A, a= 103.28 (4) 0 , fJ = 108.29 (3) 0 , -r = 76.47 (3) 0 , Z = 4, R = 0.073, and Rw = 0.085. Pt-Pt distances between the two molecules in the asymmetric unit are 3.766 (3) A

IHPRPT Steering Committee Meeting - NASA Spacecraft Propulsion Update

The activities and status of NASA Spacecraft Propulsion is presented including recent accomplishments

Receptor-independent metabolism of platelet-activating factor by myelogenous cells

AbstractHuman neutrophils incorporate and metabolize platelet-activating factor (PAF). We dissociated these events from PAF binding to its receptors. Cells were pretreated with either pronase, a PAF antagonist (L652731), or excess PAF. This reduced PAF receptor numbers by 70 to almost 100% but had no comparable effect upon the neutrophil's ability to metabolize PAF. Furthermore, HL-60 cells efficiently metabolized, but did not specifically bind, PAF. Thus, PAF receptor availability did not correlate with PAF metabolic capacity and we conclude that myelogenous tissues can process this bioactive ligand by a receptor-independent pathway