High-frequency Alfven waves in multi-ion coronal plasma : observational implications

We investigate the effects of high-frequency (of order ion gyrofrequency) Alfvén and ion-cyclotron waves on ion emission lines by studying the dispersion of these waves in a multi-ion coronal plasma. For this purpose we solve the dispersion relation of the linearized multifluid and Vlasov equations in a magnetized multi-ion plasma with coronal abundances of heavy ions. We also calculate the dispersion relation using nonlinear one-dimensional hybrid kinetic simulations of the multi-ion plasma. When heavy ions are present the dispersion relation of parallel propagating Alfvén cyclotron waves exhibits the following branches (in the positive Ω − k quadrant): right-hand polarized nonresonant and left-hand polarized resonant branch for protons and each ion. We calculate the ratio of ion to proton velocities perpendicular to the direction of the magnetic field for each wave modes for typical coronal parameters and find strong enhancement of the heavy ion perpendicular fluid velocity compared with proton perpendicular fluid velocity. The linear multifluid cold plasma results agree with linear warm plasma Vlasov results and with the nonlinear hybrid simulation model results. In view of our findings we discuss how the observed nonthermal line broadening of minor ions in coronal holes may relate to the high-frequency wave motions

Efficacy of Organic Nanocarriers in a 3D Colorectal Cancer In Vitro Model

The thesis addresses two rapidly advancing fields: improvement of drug efficacy using smart targeting and nanotechnology approaches; and testing drug efficacy in clinically relevant in vitro models. The specific aim was to create organic nanoformulations of novel chemotherapeutic agents and test their efficacy in a 3D colorectal cancer in vitro model. The first phase consisted in determining the best candidate for nanoformulations, in cell monolayers, using routine cell and molecular investigations. Different combinations of therapeutic agents were tested on colorectal cancer cells, including inhibitors of the mitogen activated protein kinase (MAPK) pathway, antagonists of the endothelin receptor A (ETAR) and short interfering RNA (siRNA) targeted against key molecules. AZD6244, an inhibitor of the MAPK pathway, produced significant inhibition of proliferation (p<0.05) and was chosen for nanoformulations. AZD6244 was encapsulated in cationic GCPQ micelles and DOPE/DC-Cholesterol liposomes using ultrasonication and extrusion methods, and tested in colorectal cancer cell monolayers. Both nanoparticles exhibited superior inhibitory effects compared to the free drug, shown by proliferation and metabolic activity assays (p<0.05). Additionally, experiments with control nanoparticles and western blot analysis of target proteins suggested that the superior efficacy of the nanoformulations was mainly due to a more efficient delivery of the drug, as opposed to additional toxicity from the nanoparticles. When the nanoformulations were tested in a collagen-based 3D model of colorectal cancer, the superior efficacy of the nanoformulations was reduced, while the efficacy of the free drug increased. Studies performed with fluorescent dye-carrying nanoparticles in these models revealed that nanoparticle efficacy was hindered by poor penetration into the tissue. These results highlight both the potential of organic nanoformulations as therapeutic delivery systems for cancer and the need to include three-dimensional in vitro models in the drug testing process prior to in vivo work

Evaluation of the curvature ductility ratio of a circular cross-section of concrete reinforced with GFRP bars

The present study deals with the use of fiberglass reinforced polymer bars (GFRP) as a replacement for the common steel of a reinforced concrete circular pile, in order to avoid the corrosion of durability of reinforcing bars and thus improve them. The comparative analysis was carried out between a pile reinforced with GFRP and another with steel, where the ductility was evaluated by obtaining moment-curvature diagram. As a result, said idealized moment-curvature diagrams and ductility indices are presented, concluding the ductility of the section reinforced with GFRP in 20% more than that of steel

Detection of cell surface calreticulin as a potential cancer biomarker using near-infrared emitting gold nanoclusters

Calreticulin (CRT) is a cytoplasmic calcium-binding protein. The aim of this study was to investigate CRT presence in cancer with the use of fluorescent gold nanoclusters (AuNCs) and to explore AuNC synthesis using mercaptosuccinic acid (MSA) as a coating agent. MSA-coated AuNCs conferred well-dispersed, bio-stable, water-soluble nanoparticles with bioconjugation capacity and 800-850 nm fluorescence after broad-band excitation. Cell-viability assay revealed good AuNC tolerability. A native CRT amino-terminus corresponding peptide sequence was synthesised and used to generate rabbit site-specific antibodies. Target specificity was demonstrated with antibody blocking in colorectal and breast cancer cell models; human umbilical vein endothelial cells served as controls. We demonstrated a novel route of AuNC/MSA manufacture and CRT presence on colonic and breast cancerous cell surface. AuNCs served as fluorescent bio-probes specifically recognising surface-bound CRT. These results are promising in terms of AuNC application in cancer theranostics and CRT use as surface biomarker in human cancer

Understanding Students' Experiences After Incorporating Indigenous Perspectives in a Postgraduate Science Communication Subject.

Many Australian universities have recently incorporated Indigenous graduate attributes into their programs, and the University of Technology Sydney (UTS) is no exception. This project aimed to investigate students’ perceptions and experiences of learning about Indigenous Knowledge systems and culture while developing science communication skills. Advanced Communication Skills in Science is a core subject in the Master of Science program at UTS. An existing assessment task, a three-minute thesis style oral presentation, was reworked to include the Indigenous Graduate Attribute (IGA) developed for the Faculty of Science. Students researched an aspect of Indigenous Science, an area of emerging interest for cultural and scientific understanding, and a mechanism for empowering Australia’s diverse first nations peoples. They then presented their key message in three minutes using a single PowerPoint slide. This task allowed students to demonstrate an awareness and appreciation of multiple ways of developing understandings of nature while enhancing their ability to understand the role of science communication in the modern world. Students were surveyed at the beginning and end of the semester to establish their Indigenous Science conceptions and reflect on their experiences. Students demonstrated an outstanding ability to integrate appropriate Aboriginal and Torres Strait Islander knowledges, experience, and analysis into a key message. Most students reported greater familiarity with concepts such as Indigenous Science and provided richer definitions of what this means. When asked if understanding Aboriginal and Torres Strait Islander knowledges and cultural practices might impact their practice as a scientist, many felt their perspective had changed and that reflecting on their cultural values and beliefs had improved their cultural capability. Most students responded that this subject challenged (at least to a degree) some firmly held assumptions, ideas, and beliefs

Comprendre l'image de Mérida vue par ses habitants : un lieu et ses représentations

Cette recherche vise à connaître et comprendre la province de Mérida au Venezuela, en analysant l’image que ses habitants construisent de celle-ci à l’aide de photographies de promotion touristique de la province, issues du matériel produit par l’office de tourisme de Mérida, CORMETUR. La recherche est conçue dans une perspective de méthodologie créative. Les participants ont été invités à élaborer –et à commenter- un collage en se servant, à leur guise, des photos fournies pour récréer leur image de leur province. C’est sur la base de ce travail que je cherche à comprendre la manière dont Mérida est perçue par ses habitants. Mon questionnement est théoriquement supporté par la notion d’ « image » ainsi que par le concept de « représentation », entendue dans l’approche constructiviste de Hall (1997), qui me permet ultérieurement d’interpréter les propos des Merideños rencontrés. Dans et à travers les représentations qu’ils construisent, il est possible de comprendre Mérida en tant qu’un « lieu », tel que défendu par Escobar (2001), au sein duquel convergent le « milieu de vie » et le « milieu touristique » qui le composent. De même, il est possible de saisir des enjeux identitaires, tels que Cuche (1996) et Hall (2007) entendent l’ « identité culturelle », dans leurs représentations.This research looks forward to knowing and understanding the state of Mérida – Venezuela through the analysis of the image that its residents build of Mérida. The project proposes to use some promotional touristic photographs taken from promotional material produced by Mérida’s tourism office, CORMETUR. This research is designed based on a creative methodology. The participants were invited to make –and to comment- a collage by using a selection provided of photos, in order to recreate the image they have of their state. My aim is to understand how its residents consider Mérida. This research is theoretically supported by the definition of “image” and by the concept of “representation”, in specific through Hall’s (1997) constructivist approach. This last one particularly allows me to interpret what the participant Merideños express in their collage. The analysis of the representations they construct allows to understand Mérida as a “place” (Escobar, 2001) that is composed by an “everyday-life context” and a “touristic context” that integrate each other. Additionally, it is possible to grasp in their representations a question of “cultural identity”, as Cuche (1997) and Hall (2007) understand it.La presente investigación propone conocer y comprender el estado Mérida - Venezuela à través del análisis de la imagen que sus habitantes construyen de ella mediante fotografías de promoción turística del estado, tomadas del material de promoción producido por la coordinación de turismo de Mérida, CORMETUR. Esta investigación es concebida bajo una perspectiva de metodología creativa. A los participantes se les pidió elaborar –y comentar- un collage utilizando a su gusto una selección de fotos para recrear de esta manera la imagen que tienen de su propio estado. A partir del trabajo que elaboraron, se busca entender la manera como sus habitantes conciben Mérida. La investigación se constituye sobre la base de la noción de “imagen”, pero sobretodo del concepto de “representación”, en su perspectiva constructivista propuesta por Hall (1997), el cual me permite interpretar con mayor profundidad lo que los Merideños entrevistados manifestaron. A través de las representaciones que ellos construyeron, es posible comprender Mérida como un « lugar », entendiéndose este en los términos de Escobar (2001); un lugar en el cual convergen el contexto cotidiano y el contexto turístico que lo componen. Igualmente, se reconoce en sus representaciones una cuestión de “identidad cultural”, tal como la definen Cuche (1996) y Hall (2007)

The Signs of Life Detector (SOLID): An Instrument to Detect Molecular Biosignatures on Mars

The case for life on Mars grows stronger. Investigations at Gale Crater by Curiosity have revealed fine-grained sedimentary rocks inferred to represent an ancient lake environment suited to support life. In addition, Curiosity tentatively found a heterogeneous distribution of organic carbon within these sediments, consistent with the detection of native organic C in Mars meteorites. Furthermore, modern potentially habitable environments have been recognized on Mars including the N. Polar region visited by Phoenix, gully features suggesting modern water flows, and RSLs that occur seasonally suggest liquid processes. The time is ripe for missions to Mars incorporating a search for biochemical evidence of life

The Icebreaker Mission to Search for Life on Mars

The search for evidence of life on Mars is the ultimate motivation for its scientific exploration. The results from the Phoenix mission indicate that the high N. latitude ice-rich regolith at low elevations is likely to be a recently habitable place on Mars [Stoker et al., 2010]. The near-surface ice likely provided adequate water activity during periods of high obliquity, 3 to 10 Myr ago. Carbon dioxide and nitrogen are present in the atmosphere, and nitrates may be present in the soil. Together with iron in basaltic rocks and perchlorate in the soil they provide carbon and energy sources, and oxidative power to drive metabolism. Furthermore, the presence of organics is possible, as thermally reactive perchlorate would have prevented their detection by Viking and Phoenix. The Mars Icebreaker Life mission [McKay et al., 2013] focuses on the following science goals: (1) Search for biomolecular evidence of life; (2) Search for organic matter from either exogeneous or endogeneous sources using methods that are not effected by the presence of perchlorate; (3) Characterize oxidative species that produced reactivity of soils seen by Viking; and 4) Assess the habitability of the ice bearing soils. The Icebreaker Life payload (Figure 1) includes a 1-m rotary percussive drill that brings cuttings samples to the surface where they are delivered to three instruments (Fig. 1), the Signs of Life Detector (SOLID) [Parro et al., 2011] for biomolecular analysis, Laser Desorption Mass Spectrometer (LDMS) [??? 2015]) for broad spectrum organic analysis, and Wet Chemistry Laboratory (WCL) [Hecht et al., 2009] for detecting soluble species of nutrients and reactive oxidants. The Icebreaker payload fits on the Phoenix spacecraft and can land at the well-characterized Phoe-nix landing site in 2020 in a Discovery-class mission

On the magnetic structure and wind parameter profiles of Alfven wave driven winds in late-type supergiant stars

Cool stars at giant and supergiant evolutionary phases present low velocity and high density winds, responsible for the observed high mass-loss rates. Although presenting high luminosities, radiation pressure on dust particles is not sufficient to explain the wind acceleration process. Among the possible solutions to this still unsolved problem, Alfven waves are, probably, the most interesting for their high efficiency in transfering energy and momentum to the wind. Typically, models of Alfven wave driven winds result in high velocity winds if they are not highly damped. In this work we determine self-consistently the magnetic field geometry and solve the momentum, energy and mass conservation equations, to demonstrate that even a low damped Alfven wave flux is able to reproduce the low velocity wind. We show that the magnetic fluxtubes expand with a super-radial factor S>30 near the stellar surface, larger than that used in previous semi-empirical models. The rapid expansion results in a strong spatial dilution of the wave flux. We obtained the wind parameter profiles for a typical supergiant star of 16 M_sun. The wind is accelerated in a narrow region, coincident with the region of high divergence of the magnetic field lines, up to 100 km/s. For the temperature, we obtained a slight decrease near the surface for low damped waves, because the wave heating mechanism is less effective than the radiative losses. The peak temperature occurs at 1.5 r_0 reaching 6000 K. Propagating outwards, the wind cools down mainly due to adiabatic expansion.Comment: to appear in the MNRA

Using meteorological measurements from different sources to evaluate the human comfort in urban area

Climate change affects the thermal and human comfort in urban areas. This is more evident in equatorial towns that have experienced, in the last decades, of an increase of air temperature which, acting together with the increasing of the rain rate, generates a strong deterioration of the human comfort. The characterization of the urban heat island is one of the most important points in the agenda of the Research Centers, as well as of the Weather Services of the Nations located in the equatorial area. The Escuela Superior Politecnica del Litoral (Ecuador), jointly with the Instituto Nacional de Meteorologia e Hidrologia (INAMHI - Ecuador) and with the Politecnico di Torino and the Università di Torino (Italy), started a project devoted to the analysis of the thermal comfort in the Guayaquil urban area. The research is funded by the Secretaria de Educacion Superior, Ciencia, Tecnologia e Innovacion (SENESCYT – Ecuador) in the context of the PROMETEO project. The preliminary results of this research show us how, to better describe the thermal comfort in the urban area, it is important to have available the meteorological parameters measured by a meso-network of Automatic Weather Stations. The elaboration of these measures with the Universal Thermal Climate Indices, like the PMV and the PET, provide a detailed analysis of the thermal comfort and of the related human comfort in the urban area. The results of this analysis are to be evaluated jointly with the aerological measurements and with the remote sensing images to characterize correctly the urban heat island