Reconstitution of Munc18-Dependent Mast Cell Degranulation

Mast cells are specialized secretory leukocytes that play diverse roles in the body, mediated by release of histamine and other pharmacologically active substances. Although offering essential protection in innate and adaptive immunity, mast cells are also essential to the progression of inflammatory diseases, including allergy and asthma, (Theoharides et al., 2012). Exocytosis of pro-inflammatory mast cell mediators in response to otherwise innocuous antigens relies on evolutionarily-conserved membrane fusion machinery. These proteins, called SNAREs are regulated by the Sec1/Munc18 (SM) protein family (Axle Lorentz, Baumann, Vitte, & Blank, 2012). Mast cells express three mammalian Munc18 isoforms (a, b, and c), which are linked to SNARE-dependent exocytosis in numerous organisms. However, the exact roles of each of these Munc18 isoforms in mast cell degranulation have not been clearly defined. In this study we investigated the functional relationship between Munc18 and eight sets of degranulation-relevant SNAREs using in vitro reconstitution. We showed that Munc18a was active in stimulating fusion mediated by VAMP2 and VAMP3, but not by VAMP7 and VAMP8. In contrast, Munc18b and Munc18c did not show any stimulatory activity. Further analysis of Munc18a function unraveled a previously unidentified role in the tethering of SNARE complexes prior to fusion, an action that is dependent on the interaction between Munc18a and N-peptide of syntaxin. Inhibition of fusion and trans-SNARE complex formation by soluble VAMP proteins did not interfere with Munc18a-mediated tethering, indicating that Munc18a-mediated tethering occurs prior to trans-SNARE complex formation. This study therefore sheds light on new roles Munc18 proteins might play to regulate mast cell degranulation

Transformation Series as an Ideographic Character Concept

An ideographic concept of character is indispensable to phylogenetic inference. Hennig proposed that characters be conceptualized as “transformation series”, a proposal that is firmly grounded in evolutionary theory and consistent with the method of inferring transformation events as evidence of phylogenetic propinquity. Nevertheless, that concept is usually overlooked or rejected in favor of others based on similarity. Here we explicate Hennig's definition of character as an ideographic concept in the science of phylogenetic systematics. As transformation series, characters are historical individuals akin to species and clades. As such, the related concept of homology refers to a historical identity relation and is not equivalent to or synonymous with synapomorphy. The distinction between primary and secondary homology is dismissed on the grounds that it conflates the concept of homology with the discovery operations used to detect instances of that concept. Although concern for character dependence is generally valid, it is often misplaced, focusing on functional or developmental correlation (both of which are irrelevant in phylogenetic systematics but may be valid in other fields) instead of the historical/transformational independence relevant to phylogenetic inference. As an ideographic science concerned with concrete objects and events (i.e. individuals), intensionally and extensionally defined properties are inconsistent with the individuation of characters for phylogenetic analysis, the utility of properties being limited to communicating results and facilitating future rounds of testing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75671/1/j.1096-0031.2004.00003.x.pd

Ming toy

https://digitalcommons.library.umaine.edu/mmb-vp/3285/thumbnail.jp

An Examination of an Online Tutoring Program\u27s Impact on Low-Achieving Middle School Students\u27 Mathematics Achievement

The purpose of this mixed methods study was to determine the impact of synchronous online tutoring services on struggling middle school students’ mathematics achievement. The online tutoring was provided as a response to intervention (RTI) Tier 3 support (intensive, individualized intervention) in schools implementing a school-wide mathematics program that addresses Tier 1 (high-quality classroom instruction) and Tier 2 (small group interventions). We employed quasi-experimental, within- and between-group designs to examine impacts for 119 students in two schools to measure the tutoring’s impact on mathematics assessment scores. We also conducted qualitative analyses of student and tutor postsession commentary. The findings suggest that the tutoring contributed to statistically significant gains in student assessment scores postintervention. Online tutors’ descriptions of their practice centered on ongoing progress monitoring of student learning, delivery of guided practice to students, the use of multiple explanations and representations of target concepts. Student perceptions of the online tutoring were predominately positive in nature

Ming Toy

Illustration of Asian woman picking flower behind wooden fencehttps://scholarsjunction.msstate.edu/cht-sheet-music/6583/thumbnail.jp

Irrigation and drainage in the new millennium

Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.Verification-based planning is a tool to improve the irrigation system modernization planning process and to effectively monitor the post-project effects on system performance. Modernization of irrigation systems results in waterflow path changes within the system. The planning process for modernization of an irrigation system requires careful documentation and analysis of the pre-project (without-project) condition and quantified prediction of the effects of the planned improvement (with-project). Procedures and strategies for predicting, monitoring and quantifying Targeted Flow Path Changes caused by an irrigation system modernization project for both without- and with-project conditions are presented

catena-Poly[[[bis­(N,N-dimethyl­formamide)iron(II)]-{μ-2,2′-bis­(diphenyl­phosphino­yl)-N,N′-[(1R,2R)-cyclo­hexane-1,2-di­yl]dibenzamide}] bis­(perchlorate) N,N-dimethyl­formamide disolvate]

The title extended solid coordination compound, {[Fe(C44H40N2O4P2)(C3H7NO)2](ClO4)2·2C3H7NO}n, was crystallized un­ex­pectedly from the reaction mixture containing the Trost ligand (1R,2R)-(+)-1,2-diamino­cyclo­hexane-N,N′-bis­(2′-di­phenyl­phosphinobenzo­yl) and Fe(ClO4)2·6H2O in a 1:1 ratio in dimethyl­formamide (DMF) under reflux conditions. The polymeric complex is characterized by FeII metal centers that are coordinated by two oxidized Trost ligands, each coordinated in a bidentate fashion in a square plane, along with two DMF mol­ecules above and below the plane [average Fe—ODMF = 2.086 (4) Å], forming an overall pseudo-octa­hedral geometry. The Trost ligand binds adjacent FeII centers, each FeII being bound through the O atom of one of the phosphine oxides [average Fe—OPPh2 = 2.115 (4) Å] and the carbonyl O atom of the adjacent amide [average Fe—Oamide = 2.192 (3) Å]. Disorder is observed in the co-solvated solvent: there are two DMF mol­ecules per FeII centre, which were modeled as one DMF mol­ecule with complete occupancy and the other being modeled in two positions with equal occupancy. Disorder was also observed with one of the perchlorate anions, which was modeled in two positions with 0.75:0.25 occupancy

MODIS airborne simulator visible and near-infrared calibration, 1991 FIRE-Cirrus field experiment. Calibration version: FIRE King 1.1

Calibration of the visible and near-infrared channels of the MODIS Airborne Simulator (MAS) is derived from observations of a calibrated light source. For the 1991 FIRE-Cirrus field experiment, the calibrated light source was the NASA Goddard 48-inch integrating hemisphere. Laboratory tests during the FIRE Cirrus field experiment were conducted to calibrate the hemisphere and from the hemisphere to the MAS. The purpose of this report is to summarize the FIRE-Cirrus hemisphere calibration, and then describe how the MAS was calibrated from observations of the hemisphere data. All MAS calibration measurements are presented, and determination of the MAS calibration coefficients (raw counts to radiance conversion) is discussed. Thermal sensitivity of the MAS visible and near-infrared calibration is also discussed. Typically, the MAS in-flight is 30 to 60 degrees C colder than the room temperature laboratory calibration. Results from in-flight temperature measurements and tests of the MAS in a cold chamber are given, and from these, equations are derived to adjust the MAS in-flight data to what the value would be at laboratory conditions. For FIRE-Cirrus data, only channels 3 through 6 were found to be temperature sensitive. The final section of this report describes comparisons to an independent MAS (room temperature) calibration by Ames personnel using their 30-inch integrating sphere