177 research outputs found
Snapshot of KIPP Leadership Practices through 2010 -- 2011
As part of the U.S. Department of Education's Investing in Innovation (i3) grant, the Knowledge Is Power Program (KIPP) Foundation commissioned Mathematica to document leadership practices at KIPP schools. This issue brief summarizes notable findings from the study, which focused on identifying leadership practices across diverse areas: leadership structure and transitions, and the selection, development, and evaluation of leaders. Among other notable findings, KIPP combines a tiered sequence of leadership roles at the local level with national staff development programs to generate a pipeline of school leaders. The study also found that KIPP's Leadership Competency Model defines the skills school leaders need and guides development and evaluation
A leucine-rich repeat peptide derived from the Drosophila Toll receptor forms extended filaments with a β-sheet structure
AbstractLeucine-rich repeats (LRRs) are 22–28 amino acid-long sequence motifs found in a family of cytoplasmic, membrane and extracellular proteins. There is evidence that LRRs function in signal transduction, cellular adhesion and protein-protein interactions. Here we report unusual properties of a synthetic LRR peptide derived from the sequence of the Drosophila membrane receptor Toll. In neutral solution the peptide forms a gel revealed by electron microscopy to consist of extended filaments approximately 8 nm in thickness. As the gel forms, the circular dichroism spectrum of the peptide solution changes from one characteristic of random coil to one associated with β-sheet structures. Molecular modelling suggests that the peptides form an amphipathic structure with a predominantly apolar and charged surface. Based on these results, models for the gross structure of the peptide filaments and a possible molecular mechanism for cellular adhesion are proposed
A leucine-rich repeat peptide derived from the Drosophila Toll receptor forms extended filaments with a β-sheet structure
AbstractLeucine-rich repeats (LRRs) are 22–28 amino acid-long sequence motifs found in a family of cytoplasmic, membrane and extracellular proteins. There is evidence that LRRs function in signal transduction, cellular adhesion and protein-protein interactions. Here we report unusual properties of a synthetic LRR peptide derived from the sequence of the Drosophila membrane receptor Toll. In neutral solution the peptide forms a gel revealed by electron microscopy to consist of extended filaments approximately 8 nm in thickness. As the gel forms, the circular dichroism spectrum of the peptide solution changes from one characteristic of random coil to one associated with β-sheet structures. Molecular modelling suggests that the peptides form an amphipathic structure with a predominantly apolar and charged surface. Based on these results, models for the gross structure of the peptide filaments and a possible molecular mechanism for cellular adhesion are proposed
System size and centrality dependence of the balance function in A+A collisions at sqrt[sNN]=17.2 GeV
Electric charge correlations were studied for p+p, C+C, Si+Si, and centrality selected Pb+Pb collisions at sqrt[sNN]=17.2 GeV with the NA49 large acceptance detector at the CERN SPS. In particular, long-range pseudorapidity correlations of oppositely charged particles were measured using the balance function method. The width of the balance function decreases with increasing system size and centrality of the reactions. This decrease could be related to an increasing delay of hadronization in central Pb+Pb collisions
System size and centrality dependence of the balance function in A + A collisions at sqrt s NN = 17.2 GeV
Electric charge correlations were studied for p+p, C+C, Si+Si and centrality selected Pb+Pb collisions at sqrt s_NN = 17.2$ GeV with the NA49 large acceptance detector at the CERN-SPS. In particular, long range pseudo-rapidity correlations of oppositely charged particles were measured using the Balance Function method. The width of the Balance Function decreases with increasing system size and centrality of the reactions. This decrease could be related to an increasing delay of hadronization in central Pb+Pb collisions
Meteorological and Back Trajectory Modeling for the Rocky Mountain Atmospheric Nitrogen and Sulfur Study II
The Rocky Mountain Atmospheric Nitrogen and Sulfur (RoMANS II) study with field operations during November 2008 through November 2009 was designed to evaluate the composition and sources of reactive nitrogen in Rocky Mountain National Park, Colorado, USA. As part of RoMANS II, a mesoscale meteorological model was utilized to provide input for back trajectory and chemical transport models. Evaluation of the model's ability to capture important transport patterns in this region of complex terrain is discussed. Previous source-receptor studies of nitrogen in this region are also reviewed. Finally, results of several back trajectory analyses for RoMANS II are presented. The trajectory mass balance (TrMB) model, a receptor-based linear regression technique, was used to estimate mean source attributions of airborne ammonia concentrations during RoMANS II. Though ammonia concentrations are usually higher when there is transport from the east, the TrMB model estimates that, on average, areas to the west contribute a larger mean fraction of the ammonia. Possible reasons for this are discussed and include the greater frequency of westerly versus easterly winds, the possibility that ammonia is transported long distances as ammonium nitrate, and the difficulty of correctly modeling the transport winds in this area
Conceptions of the Catastrophe. Discourses on the Past before the Rise of Holocaust Memory
Analysis of early-ypost war institutinonal discourses on the recent past
Strangeness production at SPS energies
We present a summary of measurements of strange particles performed by the
experiment NA49 in central and minimum bias Pb+Pb collisions in the beam energy
range 20A - 158A GeV. New results on Xi production in central Pb+Pb collisions
and on Lambda, Xi production in minimum bias collisions are shown. Transverse
mass spectra and rapidity distributions of strange particles at different
energies are compared. The energy dependence of the particle yields and ratios
is discussed. NA49 measurements of the Lambda and Xi enhancement factors are
shown for the first time.Comment: Submitted to J. Phys. G (Proceedings of the 9th International
Conference on Strangeness in Quark Matter, Los Angeles, USA, March 26-31,
2006). 9 pages, 9 figure
Elevated MicroRNA-33 in Sarcoidosis and a Carbon Nanotube Model of Chronic Granulomatous Disease
We established a murine model of multiwall carbon nanotube (MWCNT)–induced chronic granulomatous disease, which resembles human sarcoidosis pathology. At 60 days after oropharyngeal MWCNT instillation, bronchoalveolar lavage (BAL) cells from wild-type mice exhibit an M1 phenotype with elevated proinflammatory cytokines and reduced peroxisome proliferator–activated receptor γ (PPARγ)—characteristics also present in human sarcoidosis. Based upon MWCNT-associated PPARγ deficiency, we hypothesized that the PPARγ target gene, ATP-binding cassette (ABC) G1, a lipid transporter with antiinflammatory properties, might also be repressed. Results after MWCNT instillation indicated significantly repressed ABCG1, but, surprisingly, lipid transporter ABCA1 was also repressed, suggesting a possible second pathway. Exploration of potential regulators revealed that microRNA (miR)-33, a lipid transporter regulator, was strikingly elevated (13.9 fold) in BAL cells from MWCNT-instilled mice but not sham control mice. Elevated miR-33 was also detected in murine granulomatous lung tissue. In vitro studies confirmed that lentivirus–miR-33 overexpression repressed both ABCA1 and ABCG1 (but not PPARγ) in cultured murine alveolar macrophages. BAL cells of patients with sarcoidosis also displayed elevated miR-33 together with reduced ABCA1 and ABCG1 messenger RNA and protein compared with healthy control subjects. Moreover, miR-33 was elevated within sarcoidosis granulomatous tissue. The findings suggest that alveolar macrophage miR-33 is up-regulated by proinflammatory cytokines and may perpetuate chronic inflammatory granulomatous disease by repressing antiinflammatory functions of ABCA1 and ABCG1 lipid transporters. The results also suggest two possible pathways for transporter dysregulation in granulomatous disease—one associated with intrinsic PPARγ status and the other with miR-33 up-regulation triggered by environmental challenges, such as MWCNT
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