ASRM case insulation design and development

This paper describes the achievements made on the Advanced Solid Rocket Motor (ASRM) case insulation design and development program. The ASRM case insulation system described herein protects the metal case and joints from direct radiation and hot gas impingement. Critical failure of solid rocket systems is often traceable to failure of the insulation design. The wide ranging accomplishments included the development of a nonasbestos insulation material for ASRM that replaced the existing Redesigned Solid Rocket Motor (RSRM) asbestos-filled nitrile butadiene rubber (NBR) along with a performance gain of 300 pounds, and improved reliability of all the insulation joint designs, i.e., segmented case joint, case-to-nozzle and case-to-igniter joint. The insulation process development program included the internal stripwinding process. This process advancement allowed Aerojet to match to exceed the capability of other propulsion companies

On G-invariant norms

AbstractA result of R. Mathias and Horn [cf. Linear Algebra Appl. 142 (1990) 63] on the representation of the unitarily invariant norm is extended in the context of Eaton triples and of real semisimple Lie algebras. The representation is related to a function ∥·∥α. Criteria for ∥·∥α being a norm is given in terms of α and the longest element of the underlying finite reflection group. In particular, for the real simple Lie algebras, ∥·∥α is a norm on its Cartan subspace for a given nonzero α if and only if ω0α=−α, where ω0 is the longest element of the Weyl group (this is the case if the Weyl group contains −id). Some related results are obtained

Defective flagellar assembly and length regulation in LF3 null mutants in Chlamydomonas

Four long-flagella (LF) genes are important for flagellar length control in Chlamydomonas reinhardtii. Here, we characterize two new null lf3 mutants whose phenotypes are different from previously identified lf3 mutants. These null mutants have unequal-length flagella that assemble more slowly than wild-type flagella, though their flagella can also reach abnormally long lengths. Prominent bulges are found at the distal ends of short, long, and regenerating flagella of these mutants. Analysis of the flagella by electron and immunofluorescence microscopy and by Western blots revealed that the bulges contain intraflagellar transport complexes, a defect reported previously (for review see Cole, D.G., 2003. Traffic. 4:435–442) in a subset of mutants defective in intraflagellar transport. We have cloned the wild-type LF3 gene and characterized a hypomorphic mutant allele of LF3. LF3p is a novel protein located predominantly in the cell body. It cosediments with the product of the LF1 gene in sucrose density gradients, indicating that these proteins may form a functional complex to regulate flagellar length and assembly

Presenilin-1 mutations associated with familial Alzheimer’s disease do not disrupt protein transport from the endoplasmic reticulum to the Golgi apparatus

AbstractMutations in genes encoding presenilin-1 (PS1) and presenilin-2 (PS2) have been linked to familial forms of Alzheimer’s disease (AD). Cells expressing mutant presenilins produce elevated levels of Aβ42, the major amyloid peptide found in AD plaques. The mechanism whereby this occurs remains unknown, but the localization of presenilins to endoplasmic reticulum (ER) and Golgi compartments has suggested that they may function in intracellular trafficking pathways involved in processing β-amyloid precursor proteins (APP). To test this possibility, we coexpressed PS1(wt), PS1(M146L), or PS1(L286V) in HEK293 cells together with the LDL receptor, a classic glycoprotein marker that undergoes post-translational O-glycosylation in the Golgi compartment. Pulse-chase analysis of the receptor indicated that mutant presenilins had no effect on ER→Golgi transport. Similar results were obtained when the studies were carried out with cells expressing the Swedish variant of APP (SWAPP751) instead of the LDL receptor. Moreover, secretion of the soluble exodomain polypeptide fragments of SWAPP751 that arise from α-secretase and β-secretase cleavage was not markedly affected by the PS1 mutants. Despite the lack of discernible effect of the PS1 mutants on trafficking of proteins through the Golgi apparatus, they caused a substantial increase in the proportion of Aβ42 relative to total Aβ in the culture medium. The results suggest that mutant forms of PS1 cause elevated production of Aβ42 by a mechanism that is independent of a major disruption of exocytic trafficking of APP

Defective flagellar assembly and length regulation in LF3 null mutants in Chlamydomonas

Four long-flagella (LF) genes are important for flagellar length control in Chlamydomonas reinhardtii. Here, we characterize two new null lf3 mutants whose phenotypes are different from previously identified lf3 mutants. These null mutants have unequal-length flagella that assemble more slowly than wild-type flagella, though their flagella can also reach abnormally long lengths. Prominent bulges are found at the distal ends of short, long, and regenerating flagella of these mutants. Analysis of the flagella by electron and immunofluorescence microscopy and by Western blots revealed that the bulges contain intraflagellar transport complexes, a defect reported previously (for review see Cole, D.G., 2003. Traffic. 4:435–442) in a subset of mutants defective in intraflagellar transport. We have cloned the wild-type LF3 gene and characterized a hypomorphic mutant allele of LF3. LF3p is a novel protein located predominantly in the cell body. It cosediments with the product of the LF1 gene in sucrose density gradients, indicating that these proteins may form a functional complex to regulate flagellar length and assembly

StateSim: Lessons Learned from 20 Years of A Country Modeling and Simulation Toolset

A holy grail for military, diplomatic, and intelligence analysis is a valid set of software agent models that act as the desired ethno-political factions so that one can test the effects of alternative courses of action in different countries. This article explains StateSim, a country modeling approach that synthesizes best-of-breed theories from across the social sciences and that has helped numerous organizations over 20 years to study insurgents, gray zone actors, and other societal instabilities. The country modeling literature is summarized (Sect 1.1) and synthetic inquiry is contrasted with scientific inquiry (Sect. 1.2 and 2). Section 2 also explains many fielded StateSim applications and 100s of past acceptability tests and validity assessments. Section 3 then describes how users now construct and run ‘first pass’ country models within hours due to the StateSim Generator, while Section 4 offers two country analyses that illustrate this approach. The conclusions explain lessons learned

Gender dimorphism and age of onset in malignant peripheral nerve sheath tumor preclinical models and human patients.

BackgroundGender-based differences in disease onset in murine models of malignant peripheral nerve sheath tumor (MPNST) and in patients with Neurofibromatosis type-1-(NF-1)-associated or spontaneous MPNST has not been well studied.MethodsForty-three mGFAP-Cre+;Ptenloxp/+;LSL-K-rasG12D/+ mice were observed for tumor development and evaluated for gender disparity in age of MPNST onset. Patient data from the prospectively collected UCLA sarcoma database (1974-2011, n = 113 MPNST patients) and 39 published studies on MPNST patients (n = 916) were analyzed for age of onset differences between sexes and between NF-1 and spontaneous MPNST patients.ResultsOur murine model showed gender-based differences in MPNST onset, with males developing MPNST significantly earlier than females (142 vs. 162 days, p = 0.015). In the UCLA patient population, males also developed MPNST earlier than females (median age 35 vs. 39.5 years, p = 0.048). Patients with NF-1-associated MPNST had significantly earlier age of onset compared to spontaneous MPNST (median age 33 vs. 39 years, p = 0.007). However, expanded analysis of 916 published MPNST cases revealed no significant age difference in MPNST onset between males and females. Similar to the UCLA dataset, patients with NF-1 developed MPNST at a significantly younger age than spontaneous MPNST patients (p < 0.0001, median age 28 vs. 41 years) and this disparity was maintained across North American, European, and Asian populations.ConclusionsAlthough our preclinical model and single-institution patient cohort show gender dimorphism in MPNST onset, no significant gender disparity was detected in the larger MPNST patient meta-dataset. NF-1 patients develop MPNST 13 years earlier than patients with spontaneous MPNST, with little geographical variance

(1S,2S,4R)-7-tert-But­oxy­bicyclo­[2.2.1]hept-5-en-2-yl (2S)-2-(6-meth­oxy­naphthalen-2-yl)propano­ate

In the title mol­ecule, C25H30O4, the napthalene ring system is slightly bowed, with a dihedral angle of 4.37 (13)° between the two benzene rings

3D bioprinting of liver-mimetic construct with alginate/cellulose nanocrystal hybrid bioink

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.bprint.2017.12.001 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/3D bioprinting is a novel platform for engineering complex, three-dimensional (3D) tissues that mimic real ones. The development of hybrid bioinks is a viable strategy that integrates the desirable properties of the constituents. In this work, we present a hybrid bioink composed of alginate and cellulose nanocrystals (CNCs) and explore its suitability for extrusion-based bioprinting. This bioink possesses excellent shear-thinning property, can be easily extruded through the nozzle, and provides good initial shape fidelity. It has been demonstrated that the viscosities during extrusion were at least two orders of magnitude lower than those at small shear rates, enabling the bioinks to be extruded through the nozzle (100µm inner diameter) readily without clogging. This bioink was then used to print a liver-mimetic honeycomb 3D structure containing fibroblast and hepatoma cells. The structures were crosslinked with CaCl2 and incubated and cultured for 3 days. It was found that the bioprinting process resulted in minimal cell damage making the alginate/CNC hybrid bioink an attractive bioprinting material.Natural Sciences and Engineering Research Council (NSERC) of Canada (grant no. RGPIN-2016-04398

tert-Butyl N-hydr­oxy-N-[(1S*,2R*)-2-(1-naphth­yl)cyclo­pent-3-en-1-yl]carbamate

The relative stereochemistry of the title compound, C20H23NO3, was established by X-ray analysis. The asymmetric unit contains two independent mol­ecules. In the crystal structure, each type of mol­ecule forms a centrosymmetric dimer via pairs of inter­molecular O—H⋯O hydrogen bonds, resulting in an R 2 2(10) loop in each case