6,045 research outputs found
Complex molecule formation in grain mantles
Context: Complex molecules such as ethanol and dimethyl ether have been
observed in a number of hot molecular cores and hot corinos. Attempts to model
the molecular formation process using gas phase only models have so far been
unsuccessful. Aims : To demonstrate that grain surface processing is a viable
mechanism for complex molecule formation in these environments.
Methods: A variable environment parameter computer model has been constructed
which includes both gas and surface chemistry. This is used to investigate a
variety of cloud collapse scenarios.
Results: Comparison between model results and observation shows that by
combining grain surface processing with gas phase chemistry complex molecules
can be produced in observed abundances in a number of core and corino
scenarios. Differences in abundances are due to the initial atomic and
molecular composition of the core/corino and varying collapse timescales.
Conclusions: Grain surface processing, combined with variation of physical
conditions, can be regarded as a viable method for the formation of complex
molecules in the environment found in the vicinity of a hot core/corino and
produce abundances comparable to those observed.Comment: 28 pages, 192 figures, accepted for publication in A&A
VeloElectric: Creating a Device that Harvests Energy From Bicycles
Long distance mountain bikers, bike-packers, and many bikers in developing countries rely on electrical devices for safety and communication. These specific groups of people operate in areas with little to no electricity, and often times have no power to sustain their devices. The purpose of this Cal Poly senior project, VeloElectric, was to design, build, and test a kinetic energy harvester for bicycles that can be used to charge common mobile devices via USB. This senior project team created a device that attaches directly to a bicycle and uses vibrations to generate energy, which in turn powers a variety of portable devices. The final product will be used by Professor Lynne Slivovsky on a bike ride from Canada to Mexico. This document contains information on the entire project during the 2014-2015 school year. The “Background” section summarizes research and case studies including dynamo chargers and an electromagnetic induction charger called the nPower PEG. The Pedl team used this information to generate initial design ideas such as using piezoelectrics and other kinetic energy harvesting devices. This research was also used to gain a better understanding of the current state of art for this type of product. The end of the background section provides details of the project management plan that was used through the course of the projects focusing heavily on the tasks completed during Spring quarter. Following the “Background” section is an explanation of the development of conceptual designs that lead to the final product. Conceptual designs included decision matrices to decide on a 3D printed exterior casing, Velcro straps for attachment, electromagnetic induction for energy generation, and a battery for energy storage. Diagrams, models and pictures of the end product are displayed and analyzed in the “Description of Final Design” section. This section shows the exterior casing that was created to house the inner casing, battery, and printed circuit board. The “Product Realization” section focuses on how a lathe was used to create the final inner casing, 3D printing for the exterior casing and inner casing caps, and simple soldering for the electrical components. The section also explains how the final prototype cost the team about 45. The “Design Verification” section discusses how the final iteration was tested and includes test descriptions and photos while documenting the results of these tests. Example tests include weight, bike transfer time, USB compatibility, and vibrational tolerance. The document concludes by discussing the progress that was made on the project throughout the year and the recommendations that the design team has for possible future teams assigned to this task
Looking into the puparium: Micro-CT visualization of the internal morphological changes during metamorphosis of the blow fly, Calliphora vicina , with the first quantitative analysis of organ development in cyclorrhaphous dipterans
Uploaded is the initial online version of this Open Access manuscript.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium,
provided the original work is properly cited.
VC 2017 The Authors Journal of Morphology Published by Wiley Periodicals, Inc. This is the published version of the article
Resolving Confusion in the Use of Concepts and Terminology in Intrapuparial Development Studies of Cyclorrhaphous Diptera
This is freely available on the journal website.The attached document is the pre-print/pre-refereeing [Author's original version] version of the article. This article has been accepted for publication in Journal of Medical Entomology, Vol.53(6), 2016, published by Oxford University Press. DOI: http://dx.doi.org/10.1093/jme/tjw0
Comparison of four commercial immunomagnetic separation kits for the detection of Cryptosporidium
Cryptosporidium spp. are protozoan parasites of significant health importance found in environmental waters globally. Four commercially available Cryptosporidium-specific immunomagnetic separation (IMS) kits used in various water sample matrices were analysed and compared. Beads were characterised by flow cytometry and tested for the recovery efficiencies for oocysts spiked into different matrices: river water sediment, clay sample, and filter backwash sample. Results showed that DynabeadsTM Cryptosporidium and Waterborne Crypto-GrabTM kits contained immunoglobulin IgM antibody-coated beads. In contrast, the BioPoint CryptoBead and the TCS Isolate kits contained immunoglobulin IgG antibody-coated beads. BioPoint CryptoBead was significantly coated with more antibodies and were able to capture oocysts more rapidly compared to the other beads. Recovery efficiencies of DynabeadsTM, TCS Isolate® beads, and BioPoint Crypto- Bead ranged from 55 to 93% when tested against different sample matrices, with BioPoint CryptoBead resulting in the highest at 93% in reagent-grade water and DynabeadsTM at 55%, the lowest against clay samples. The Waterborne beads did not perform well on any samples, with recovery efficiencies ranging from 0 to 8%. Fluorescence microscopy analyses showed that both the IMS method and the sample matrix processed affect the quality of the membranes, with the cleanest samples for microscopy examination observed from BioPoint CryptoBead
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Rwanda Cricket Stadium: Seismically stabilised tile vaults
The Rwanda Cricket Stadium, completed in 2017, uses compressed soil-cement tiles, thin-tile vaulting, and geogrid reinforcement for seismic stabilisation in Kigali’'s moderate risk earthquake zone. The vaults follow the natural resolution of forces toward the ground, closely mimicking the parabolic geometry of a bouncing ball and evoking the cherished hilly topography of Rwanda. The masonry vaults in compression allow the use of geogrid embedded within the mortar layers, adding global ductile behaviour to the thin shell composite of low strength tiles. Structural analysis is based on thrust lines, with additional envelope for the thrust lines to leave the profile of the masonry computed from the tensile capacity added by the geogrid (Ramage and Dejong [1]). Construction follows traditional thin-tile techniques adapted for new environments and uses compressed earth tiles as pioneered at the Mapungubwe Interpretive Centre in South Africa (Ramage et al. [2]). Here, the two approaches are combined in a permanent structure, with the largest vault spanning 16 m with a rise of 8 m. The Rwanda Cricket Stadium is a fusion of advanced structural analysis and architectural design with labour intensive, locally-sourced material production offering a much-needed solution to building sustainably in the developing world. Employing air-dried, hand-pressed soil tiles, produced using local labour, this method of construction has proved to be innovative, cost effective and beautiful
Monolithic large-signal transimpedance amplifier for use in multi-gigabit, short-range optoelectronic interconnect applications
Published versio
Widespread association between the ericoid mycorrhizal fungus Rhizoscyphus ericae and a leafy liverwort in the maritime and sub-Antarctic
A recent study identified a fungal isolate from the Antarctic leafy liverwort Cephaloziella varians as the ericoid mycorrhizal associate Rhizoscyphus ericae. However, nothing is known about the wider Antarctic distribution of R. ericae in C. varians, and inoculation experiments confirming the ability of the fungus to form coils in the liverwort are lacking.
Using direct isolation and baiting with Vaccinium macrocarpon seedlings, fungi were isolated from C. varians sampled from eight sites across a 1875-km transect through sub- and maritime Antarctica. The ability of an isolate to form coils in aseptically grown C. varians was also tested.
Fungi with 98–99% sequence identity to R. ericae internal transcribed spacer (ITS) region and partial large subunit ribosomal (r)DNA sequences were frequently isolated from C. varians at all sites sampled. The EF4/Fung5 primer set did not amplify small subunit rDNA from three of five R. ericae isolates, probably accounting for the reported absence of the fungus from C. varians in a previous study. Rhizoscyphus ericae was found to colonize aseptically-grown C. varians intracellularly, forming hyphal coils.
This study shows that the association between R. ericae and C. varians is apparently widespread in Antarctica, and confirms that R. ericae is at least in part responsible for the formation of the coils observed in rhizoids of field-collected C. varians
Discordant inflammatory changes in the apophyseal and sacroiliac joints: serial observations in enthesitis-related arthritis
OBJECTIVE: To determine the extent to which inflammation of the sacroiliac joints (SIJs) and apophyseal joints (AJs) changes concordantly after treatment in enthesitis-related arthritis (ERA). METHODS: A retrospective study was performed with institutional review board approval. 31 young patients with ERA who had been scanned between March 2009 and November 2014 were included. All patients had post-contrast imaging of the SIJs and lumbar spine and short tau inversion-recovery (STIR) images of the SIJs. The severity of sacroiliitis was scored using a modification of an established technique, and inflammation of the AJs was evaluated using a recently described grading system. The changes in SIJ and AJ scores after treatment were classified as either concordant or discordant, and the proportion of scan pairs in these groups was recorded. In addition, the correlation between change in SIJ STIR score (Δnfla) and change in AJ score (ΔAJ) was assessed using Spearman's correlation coefficient. RESULTS: Of a total of 43 scan pairs, the changes in inflammation were concordant in 16 scan pairs and discordant in 27 scan pairs. There was no significant correlation between Δnfla and ΔAJ (R = 0.14, p = 0.37). CONCLUSION: Inflammatory changes in the SIJs and AJs are often discordant. This may be a reason why patients experience ongoing back pain despite apparent improvement in one or the other site. ADVANCES IN KNOWLEDGE: Inflammation may behave differently at different anatomical sites. The SIJs and AJs should both be imaged in patients with ERA with back pain
Expectations of rehabilitation following lower limb amputation: a qualitative study.
To explore the expectations of patients about to undergo prosthetic rehabilitation following a lower limb amputation
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