4,667 research outputs found
MacEwan University Wi-Fi Analysis
MacEwan Unversity has recently upgraded its wireless infrastructure on campus. The goal was to determine whether or not wireless bandwidth speeds were consistent across an area of the school, and if they were not, which areas had the strongest and weakest connections. The results could be taken as a reflection of the new system’s effectiveness and coverage. To assess wireless bandwidth speeds, both the upload and download speeds were measured across regions of the campus library using the mobile app Speedtest.net by Ookla which downloads chunks of data to a mobile device to measure connection speed. To ensure that the samples were representative, speeds were measured through various times of the day and different days of the week. These temporal dimensions were used as blocks in the experimental design. Preliminary data collection also indicated a significant difference in mobile device used, and so the use of either Apple’s iPhone 6 or Samsung’s Galaxy S3 was also selected as a block in order to prevent the age of the device becoming a nuisance factor in the experiment. In the end, the results indicated that wireless speeds were inconsistent across the library. The results provided a heat map which showed that some areas had a significantly higher bandwidth speed than other areas. The results of this study could be used to plan future changes to wireless router layout and influence new infrastructure decisions. In addition, the research methodology could be further developed and extended to any Wi-Fi or cellular service.
*Indicates faculty mento
PRT simulation in an immersive virtual world
Immersive virtual world environments, such as Second LifeTM (SL), have the potential to dramatically improve the process of analyzing usability within technically correct system simulations, long before the system is built. We report our findings with the SL simulation of a Personal Rapid Transit (PRT) system. The SL model and simulation were done according to the original technical specifications. In interacting with this simulation, the system designers were able to identify several usability issues that would have gone unnoticed in a non-immersive simulation environment. Namely: (1) a problem with the design of the offramp to the station; (2) further requirements for the design of the top of the vehicles, so that the suspended track is out of direct sight of the people inside; (3) further safety requirements for dealing with unexpected obstacles along the path. While all of these issues would have been identified upon deployment of the physical prototype, the contribution of our work is to show how usability issues like these can now be identified much earlier, using simulations in a virtual world. Copyright © 2008 ICST
SCREENING FOR IODINE DEFICIENCY – MORE THAN A MEDICAL APPROACH
Working as a team began more and more important in many fields, including medicine. After an era of fragmentation, when the need of deepen the knowledge led to supra-specialization, we witness now the reassembly of these distinct parts, in order to obtain a comprehensive view. This is true not only for research, but also for the clinical practice. We present the building of a team who started with a screening and continued with other evaluations in a city from the eastern part of Romania. The goal of the study was to evaluate the iodine status in a former iodine deficient area. Two parameters were necessary, evaluation of thyroid volume and urinary iodine in a representative group of children. The initial pure endocrinological team increased by adopting new members: medical (nurses, epidemiologist, biochemist) and non-medical (schoolteachers). The results induced new studies and the team had growth and proved the utility of interdisciplinarity
Nanoparticule polimerice în tratamentul maladiilor sistemului nervos central
Background. The main impediment to the absorption of
drugs in the CNS is the blood-brain barrier (BBB). A promising
platform in the successful realization of a treatment,
are the polymeric nanoparticles (PNP). Objective
of the study. Description of PNP as nanosystems capable
of transporting drug molecules through BBB at the level of
CNS. Material and Methods. The main sources of information
regarding the structure, methods of obtaining, functionalization,
and mechanisms involved in transporting PNP
through BBB to therapeutic target (Scopus, Pubmed). Results.
BBB is a mechanical barrier with a very high selective
capacity and allows only the entry of water, nutrients, and
neurotransmitters that govern the maintenance of the CNS
homeostasis. The ability of drugs to cross BBB depends on
drug molecule size, hydrophilicity, degree of ionization and
controllable use of the drug. After absorption, the polymeric
matrix can be triggered to release the drug, resulting in a
protected, prolonged, and targeted therapeutic effect. Conclusion.
Thus, PNPs are a promising nanosystem in the BBB
crossing for an effective treatment of CNS diseases.Introducere. Principalul impediment în absorbția medicamentelor
la nivelul SNC este bariera hematoencefalică
(BHE). O platformă promițătoare în realizarea cu succes
al unui tratament, sunt nanoparticulele polimerice (NPP).
Scopul lucrării. Descrierea NPP ca nanosisteme capabile
să transporte molecule de medicamente prin BHE la nivelul
SNC. Material și Metode. Au fost selectate principalele
surse de informare referitor la structura, metodele de obținere,
funcționalizare, și mecanismele implicate în transportul
NPP prin BHE la ținta terapeutică(Scopus, PubMed).
Rezultate. BHE este o barieră mecanică, cu o capacitate
foarte mare selectivă și permite doar intrarea apei, nutrienților
și neurotransmițătorilor care guvernează întreținerea
homeostaziei SNC. Capacitatea medicamentelor de a traversa
BHE depinde de: mărimea moleculei medicamentului,
hidrofilitatea, gradul de ionizare ș.a. NPP sunt o alegere promițătoare
ca platformă de livrare la țintă a medicamentelor
pentru SNC, datorită arhitecturii lor reglabile (10 până la
1000 nm) și eliberare controlabilă a medicamentului. După
absorbție matricea polimerică poate fi declanșată pentru
a elibera medicamentul, rezultând într-un efect terapeutic
protejat, prelungit și țintit. Concluzie. Astfel, NPP sunt un
nanosistem promițător în traversarea BHE pentru un tratament
eficient al maladiilor SNC
Interplay of Epigenetics with Gynecological Cancer
Recent data on the cell deregulation that occurs during the progression to cancer underlines the cooperation between genetic and epigenetic alterations leading to a malignant phenotype. Unlike genetic alterations, the epigenetic changes do not affect the DNA sequence of the genes, but determine the regulation of gene expression acting upon the genome. Moreover, unlike genetic changes, epigenetic ones are reversible, making them therapeutic targets in various conditions in general and in cancer disease in particular. The term epigenetics includes a series of covalent modifications that regulate the methylation pattern of DNA and posttranslational modifications of histones. Gene expression can also be regulated at the posttranscriptional level by microRNAs (miRNAs), a family of small noncoding RNAs that inhibit the translation of mRNA to protein. miRNAs can act as ‘oncomiRs’, as tumor suppressors, or both. In this chapter, we will (1) summarize the current literature on the key processes responsible for epigenetic regulation: DNA methylation, histone modifications and posttranscriptional gene regulation by miRNAs; (2) evaluate aberrant epigenetic modifications as essential players in cancer progression; (3) establish the roles of microenvironment-mediated epigenetic perturbations in the development of gynecological neoplasia; (4) evaluate epigenetic factors involved in drug resistance
Bound-free pair production from nuclear collisions and the steady-state quench limit of the main dipole magnets of the CERN Large Hadron Collider
During its Run 2 (2015-2018), the Large Hadron Collider (LHC) operated at
almost twice higher energy, and provided Pb-Pb collisions with an order of
magnitude higher luminosity, than in the previous Run 1. In consequence, the
power of the secondary beams emitted from the interaction points by the
bound-free pair production (BFPP) process increased by a factor ~20, while the
propensity of the bending magnets to quench increased with the higher magnetic
field. This beam power is about 35 times greater than that contained in the
luminosity debris from hadronic interactions and is focused on specific
locations that fall naturally inside superconducting magnets. The risk of
quenching these magnets has long been recognized as severe and there are
operational limitations due to the dynamic heat load that must be evacuated by
the cryogenic system. High-luminosity operation was nevertheless possible
thanks to orbit bumps that were introduced in the dispersion suppressors around
the ATLAS and CMS experiments to prevent quenches by displacing and spreading
out these beam losses. Further, in 2015, the BFPP beams were manipulated to
induce a controlled quench, thus providing the first direct measurement of the
steady-state quench level of an LHC dipole magnet. The same experiment
demonstrated the need for new collimators that are being installed around the
ALICE experiment to intercept the secondary beams in the future. This paper
discusses the experience with BFPP at luminosities very close to the future
High Luminosity LHC (HL-LHC) target, gives results on the risk reduction by
orbit bumps and presents a detailed analysis of the controlled quench
experiment.Comment: 16 pages, 11 figure
Correction for fast pseudo-diffusive fluid motion contaminations in diffusion tensor imaging
In this prospective study, we quantified the fast pseudo-diffusion contamination by blood perfusion or cerebrospinal fluid (CSF) intravoxel incoherent movements on the measurement of the diffusion tensor metrics in healthy brain tissue. Diffusion-weighted imaging (TR/TE = 4100 ms/90 ms; b-values: 0, 5, 10, 20, 35, 55, 80, 110, 150, 200, 300, 500, 750, 1000, 1300 s/mm2, 20 diffusion-encoding directions) was performed on a cohort of five healthy volunteers at 3 Tesla. The projections of the diffusion tensor along each diffusion-encoding direction were computed using a two b-value approach (2b), by fitting the signal to a monoexponential curve (mono), and by correcting for fast pseudo-diffusion compartments using the biexponential intravoxel incoherent motion model (IVIM) (bi). Fractional Anisotropy (FA) and Mean Diffusivity (MD) of the diffusion tensor were quantified in regions of interest drawn over white matter areas, gray matter areas, and the ventricles. A significant dependence of the MD from the evaluation method was found in all selected regions. A lower MD was computed when accounting for the fast-diffusion compartments. A larger dependence was found in the nucleus caudatus (bi: median 0.86 10-3 mm2/s, Δ2b: -11.2%, Δmono: -14.4%; p = 0.007), in the anterior horn (bi: median 2.04 10-3 mm2/s, Δ2b: -9.4%, Δmono: -11.5%, p = 0.007) and in the posterior horn of the lateral ventricles (bi: median 2.47 10-3 mm2/s, Δ2b: -5.5%, Δmono: -11.7%; p = 0.007). Also for the FA, the signal modeling affected the computation of the anisotropy metrics. The deviation depended on the evaluated region with significant differences mainly in the nucleus caudatus (bi: median 0.15, Δ2b: +39.3%, Δmono: +14.7%; p = 0.022) and putamen (bi: median 0.19, Δ2b: +3.1%, Δmono: +17.3%; p = 0.015). Fast pseudo-diffusive regimes locally affect diffusion tensor imaging (DTI) metrics in the brain. Here, we propose the use of an IVIM-based method for correction of signal contaminations through CSF or perfusion
- …