Prediction of In-Plane Stiffnesses and Thermomechanical Stresses in Cylindrical Composite Cross-Sections

Accurate mechanical analysis of composite structures is necessary for the prediction of laminate behavior. Cylindrical composite tubes are a mainstay in many structural applications. The fundamental design of circular composite cross-sections necessitates the development of a comprehensive composite lamination theory. A new analytical method is developed to characterize the behavior of thin-walled composite cylindrical tubes using a modified plate theory. A generated numerical solver can predict properties such as axial stiffness, bending stiffness, layer stresses, and layer strains in composite tubes subjected to combined mechanical loading and thermal effects. The model accounts for the curvature by transforming and translating the material in-plane lamina properties over a global reference coordinate system. A MATLAB-based solver is used to determine the lamina stiffness and stress outcomes with adjustable parameters, including elastic material properties, thermal coefficients, tubing radius, the orientation of fibers, and the ply stacking sequence. The results are then validated using a FE model developed in ABAQUS using a simple quadrature S4R element type. Parametric case studies confirm the validity of the analytical model by accounting for different ply orientations, stacking sequence, and thermal, mechanical loading

Fluid Power Vehicle Challenge

The FPVC combines mechanical engineering disciplines to design and manufacture a vehicle that utilizes hydraulic power. The FDR covers the final manufacturing process and verification processes developed during the front end of research and analysis built upon the Critical Design Review (CDR) and the PDR (Preliminary Design Review). This report showcases the design decisions and extensive research that supports the continuing efforts by the Team Pump My Ride, to build upon the accomplishments of Cal Poly’s previous team, The Incompressibles. The FDR presents how Team Pump My Ride produced the design changes from the CDR and PDR to achieve improvements to the vehicle’s performance. The FDR is detailed with the procurement methods, validation procedures, results, conclusions, recommendations for next year’s team. In addition, details about the virtual competition are included in this report. Major changes that were made during manufacturing included reconstruction of the rear drive train, installation of the new manifold with soft lines, mounting the controller unit, re-designing the controller software and hardware, installation of new bike tires, and re-orientating the accumulator. Testing that was completed include a full trial run for competition as well as testing different pre-charge pressures. In addition, a user manual was developed in order to aid the next team’s members to operate the bike. This report proceeds to conclude team Pump My Ride’s efforts to improve the vehicle and finish as a high-ranking competitor in the 2020 Fluid Power Vehicle Challenge. Disclaimer: This report is meant to be used as a guide for basic orientation with the 2020 Cal Poly Fluid Powered Vehicle. This is a dangerous machine that can cause grave bodily injury if misused. This report is in no way complete and should not be treated as such. High pressure hydraulics are inherently dangerous, and care should be taken whenever in the vicinity of the vehicle. Likewise, the Li-Po battery used on this project must be fully understood to prevent injury or fires. By using the vehicle, you take full responsibility for your safety and the safety of those around you

Cultural omnivores or culturally homeless? Exploring the shifting cultural identities of the upwardly mobile

The concept of the cultural omnivore has become increasingly influential in cultural sociology. Its proponents argue that it has now become a badge of honour to be eclectic and omnivorous in one’s cultural preferences and explicitly not be seen as an exclusivist cultural ‘snob’. It is even argued that omnivorousness represents a new source of social and cultural capital, enhancing one’s ability to communicate with diverse groups and nurturing greater cultural and political tolerance. Drawing on a large-scale survey of British comedy taste and 24 follow-up interviews, this paper strongly challenges existing representations of the cultural omnivore. Among comedy consumers, I only find omnivorousness among one social group; the upwardly mobile. However, notably, the culture switching of these respondents does not seem to yield the social benefits assumed by other omnivore studies. In contrast, the life histories of these respondents reveals that omnivorousness is more a bi-product of life trajectories - whereby lowbrow comedy taste is established during childhood but then highbrow taste is added as cultural capital resources grow. Significantly, though, this combination of tastes has more negative than positive implications, leaving socially mobile respondents largely uncertain of their cultural identities. While they lack the ‘natural’ confidence to communicate new, more legitimate, tastes as embodied cultural capital, their upwardly mobile trajectory means they are also acutely aware that the tastes of their youth are socially unacceptable and aesthetically inferior. In short, these comedy consumers are more accurately described as culturally homeless, caught with one foot in two different taste cultures

Escherichia coli TatA and TatB Proteins Have N-out, C-in Topology in Intact Cells

The twin arginine protein transport (Tat) system translocates folded proteins across the cytoplasmic membrane of prokaryotes and the thylakoid membrane of chloroplasts. In Escherichia coli, TatA, TatB, and TatC are essential components of the machinery. A complex of TatB and TatC acts as the substrate receptor, whereas TatA is proposed to form the Tat transport channel. TatA and TatB are related proteins that comprise an N-terminal transmembrane helix and an adjacent amphipathic helix. Previous studies addressing the topological organization of TatA have given conflicting results. In this study, we have addressed the topological arrangement of TatA and TatB in intact cells by labeling of engineered cysteine residues with the membrane-impermeable thiol reagent methoxypolyethylene glycol maleimide. Our results show that TatA and TatB share an N-out, C-in topology, with no evidence that the amphipathic helices of either protein are exposed at the periplasmic side of the membrane. We further show that the N-out, C-in topology of TatA is fixed and is not affected by the absence of other Tat components or by the overproduction of a Tat substrate. These data indicate that topological reorganization of TatA is unlikely to accompany Tat-dependent protein transport

Beneficial autoimmunity at body surfaces – immune surveillance and rapid type 2 immunity regulate tissue homeostasis and cancer

Epithelial cells line body surface tissues and provide a physicochemical barrier to the external environment. Frequent microbial and non-microbial challenges such as those imposed by mechanical disruption, injury or exposure to noxious environmental substances including chemicals, carcinogens, ultraviolet-irradiation or toxins cause activation of epithelial cells with release of cytokines and chemokines as well as alterations in the expression of cell surface ligands. Such display of epithelial stress is rapidly sensed by tissue resident immunocytes, which can directly interact with self-moieties on epithelial cells and initiate both local and systemic immune responses. Epithelial cells are thus key drivers of immune surveillance at body surface tissues. However, epithelial cells have a propensity to drive type 2 immunity (rather than type 1) upon non-invasive challenge or stress – a type of immunity whose regulation and function still remain enigmatic. Here we review the induction and possible role of type 2 immunity in epithelial tissues and propose that rapid immune surveillance and type 2 immunity are key regulators of tissue homeostasis and carcinogenesis

Cultural Participation, Trends in

This article focuses on trends in cultural participation. How have the extent and the way in which people consume culture changed? Research shows that participation in highbrow culture remains relatively stable, whereas the consumption of popular, commercial culture has increased since the 1970s. A number of societal developments drive these evolutions in cultural participation. Sociodemographic changes, most notably educational expansion, as well as the rise of the entertainment industry and the Internet boom, greatly affect the field of artistic production, mediation, and consumption. These changes result in the shifting, or, as some argue, the erosion of esthetic boundaries, and the rise of the cultural omnivore – someone who participates in a variety of cultural activities – as provisional endpoints

Cytochrome P450 20A1 in zebrafish: Cloning, regulation and potential involvement in hyperactivity disorders

Cytochrome P450 (CYP) enzymes for which there is no functional information are considered "orphan" CYPs. Previous studies showed that CYP20A1, an orphan, is expressed in human hippocampus and substantia nigra, and in zebrafish (Danio rerio) CYP20A1 maternal transcript occurs in eggs, suggesting involvement in brain and in early development. Moreover, hyperactivity is reported in humans with chromosome 2 microdeletions including CYP20A1. We examined CYP20A1 in zebrafish, including impacts of chemical exposure on expression. Zebrafish CYP20A1 cDNA was cloned, sequenced, and aligned with cloned human CYP20A1 and predicted vertebrate orthologs. CYP20A1s share a highly conserved N-terminal region and unusual sequences in the I-helix and the heme-binding CYP signature motifs. CYP20A1 mRNA expression was observed in adult zebrafish organs including the liver, heart, gonads, spleen and brain, as well as the eye and optic nerve. Putative binding sites in proximal promoter regions of CYP20A1s, and response of zebrafish CYP20A1 to selected nuclear and xenobiotic receptor agonists, point to up-regulation by agents involved in steroid hormone response, cholesterol and lipid metabolism. There also was a dose-dependent reduction of CYP20A1 expression in embryos exposed to environmentally relevant levels of methylmercury. Morpholino knockdown of CYP20A1 in developing zebrafish resulted in behavioral effects, including hyperactivity and a slowing of the optomotor response in larvae. The results suggest that altered expression of CYP20A1 might be part of a mechanism linking methylmercury exposure to neurobehavioral deficits. The expanded information on CYP20A1 brings us closer to "deorphanization" CYP20A1 functions and its roles in health and disease

Functional Genetic Variants in DC-SIGNR Are Associated with Mother-to-Child Transmission of HIV-1

BACKGROUND: Mother-to-child transmission (MTCT) is the main cause of HIV-1 infection in children worldwide. Given that the C-type lectin receptor, dendritic cell-specific ICAM-grabbing non-integrin-related (DC-SIGNR, also known as CD209L or liver/lymph node-specific ICAM-grabbing non-integrin (L-SIGN)), can interact with pathogens including HIV-1 and is expressed at the maternal-fetal interface, we hypothesized that it could influence MTCT of HIV-1. METHODS AND FINDINGS: To investigate the potential role of DC-SIGNR in MTCT of HIV-1, we carried out a genetic association study of DC-SIGNR in a well-characterized cohort of 197 HIV-infected mothers and their infants recruited in Harare, Zimbabwe. Infants harbouring two copies of DC-SIGNR H1 and/or H3 haplotypes (H1-H1, H1-H3, H3-H3) had a 3.6-fold increased risk of in utero (IU) (P = 0.013) HIV-1 infection and a 5.7-fold increased risk of intrapartum (IP) (P = 0.025) HIV-1 infection after adjusting for a number of maternal factors. The implicated H1 and H3 haplotypes share two single nucleotide polymorphisms (SNPs) in promoter region (p-198A) and intron 2 (int2-180A) that were associated with increased risk of both IU (P = 0.045 and P = 0.003, respectively) and IP (P = 0.025, for int2-180A) HIV-1 infection. The promoter variant reduced transcriptional activity in vitro. In homozygous H1 infants bearing both the p-198A and int2-180A mutations, we observed a 4-fold decrease in the level of placental DC-SIGNR transcripts, disproportionately affecting the expression of membrane-bound isoforms compared to infant noncarriers (P = 0.011). CONCLUSION: These results suggest that DC-SIGNR plays a crucial role in MTCT of HIV-1 and that impaired placental DC-SIGNR expression increases risk of transmission