Which Group Dynamics Matter: Social Predictors of Student Achievement in Team-Based Undergraduate Science Classrooms.

While group work in undergraduate science education tends to have overall benefit, less is known about the specific peer-peer dynamics that optimize learning during group interaction. The current study used peer ratings and self-reported data from 436 students enrolled in team-based undergraduate science courses (biology or chemistry) to determine group dynamics that predicted both willingness to work with peers in the future and individual achievement in the course. Results show that greater personal connection and contributions predicted willingness to work with a group member ( = 0.

Who is the Teacher and Who is the Student? The Dual Service- and Engaged-Learning Pedagogical Model of Anatomy Academy.

Anatomy Academy is a simultaneous service-learning experience for preprofessional school undergraduate students and preclinical professional students acting as classroom paraprofessional teachers (Mentors), and engaged-learning experience for fourth to sixth grade elementary school children (Students). Using didactic and kinesthetic active learning teaching strategies in small-group classroom environments, Mentors taught anatomy, physiology, and nutrition concepts to Students. In this study of the program's early years (2012-2014), overall objectives of improving Mentors' pedagogical confidence; and Students' science interest, science knowledge, and exercise self-efficacy were assessed.

Combined use of steady-state fluorescence emission and anisotropy of merocyanine 540 to distinguish crystalline, gel, ripple, and liquid crystalline phases in dipalmitoylphosphatidylcholine bilayers.

The various lamellar phases of dipalmitoylphosphadtidylcholine bilayers with and without cholesterol were used to assess the versatility of the fluorescent probe merocyanine 540 through simultaneous measurements of emission intensity, spectral shape, and steady-state anisotropy. Induction of the crystalline phase (Lc') by pre-incubation at 4°C produced a wavelength dependence of anisotropy which was strong at 15 and 25°C, weak at 38°C, and minimal above the main transition (>~41.5°C) or after returning the temperature from 46 to 25°C.

Kinetic evaluation of cell membrane hydrolysis during apoptosis by human isoforms of secretory phospholipase A2.

Some isoforms of secretory phospholipase A(2) (sPLA(2)) distinguish between healthy and damaged or apoptotic cells. This distinction reflects differences in membrane physical properties. Because various sPLA(2) isoforms respond differently to properties of artificial membranes such as surface charge, they should also behave differently as these properties evolve during a dynamic physiological process such as apoptosis.

Use of fluorescence to determine the effects of cholesterol on lipid behavior in sphingomyelin liposomes and erythrocyte membranes.

The purpose of this study was to generate the equivalent of a cholesterol/temperature phase map for a biological membrane using fluorescence spectroscopy. The pseudo-phase map was created using human erythrocytes treated with various concentrations of methyl-beta-cyclodextrin to remove defined amounts of cholesterol and a trio of fluorescent probes that assess different membrane properties (laurdan, diphenylhexatriene, and merocyanine 540). Parallel experiments with two-photon microscopy suggested that changes in cellular cholesterol content affected the entire membrane rather than being localized to specific macroscopic domains.

Differential detection of phospholipid fluidity, order, and spacing by fluorescence spectroscopy of bis-pyrene, prodan, nystatin, and merocyanine 540.

The properties of liquid-ordered, solid-ordered, and liquid-disordered phases were investigated by steady-state fluorescence spectroscopy in liposomes composed of mixtures of dipalmitoylphosphatidylcholine and cholesterol (0-40 mol %) as a function of temperature (24-51 degrees C). The fluorescent probes used (bis-pyrene, nystatin, prodan, and merocyanine) were chosen because they differ in the location they occupy in the membrane and in the types of properties they sense. Comparison of phase diagrams with contour plots of the fluorescence data suggested that bis-pyrene is sensitive primarily to lipid order.

Mechanisms governing the level of susceptibility of erythrocyte membranes to secretory phospholipase A2.

Although cell membranes normally resist the hydrolytic action of secretory phospholipase A(2) (sPLA(2)), they become susceptible during apoptosis or after cellular trauma. Experimentally, susceptibility to the enzyme can be induced by loading cells with calcium. In human erythrocytes, the ability of the calcium ionophore to cause susceptibility depends on temperature, occurring best above approximately 35 degrees C.

Formation of transient non-protein calcium pores by lysophospholipids in S49 Lymphoma cells.

Palmitoyl-lysophosphatidylcholine promotes a transient calcium influx in lymphoma cells. Previously, it was observed that this influx was accompanied by a temporary increase in propidium iodide permeability that appeared linked to calcium entry. Those studies demonstrated that cobalt or nickel could block the response to lysophosphatidylcholine and raised the question of whether the calcium conductance involved specific channels.