3,954 research outputs found
Constraints on Extragalactic Point Source Flux from Diffuse Neutrino Limits
We constrain the maximum flux from extragalactic neutrino point sources by
using diffuse neutrino flux limits. We show that the maximum flux from
extragalactic point sources is E^2(dN/dE) < 1.4 x 10^-9 (L_nu/2x10^43
erg/s)^1/3 GeV cm-^2 s^-1 from individual point sources with average neutrino
luminosity per decade, L_nu. It depends only slightly on factors such as the
inhomogeneous matter density distribution in the local universe, the luminosity
distribution, and the assumed spectral index. The derived constraints are at
least one order of magnitude below the current experimental limits from direct
searches. Significant constraints are also derived on the number density of
neutrino sources and on the total neutrino power density.Comment: 7 pages, 3 figures, and 2 table
Isolation of keratinophilic fungi and aerobic actinomycetes from park soils in Gorgan, North of Iran
Background: Keratinophilic fungi are a group of fungi that colonize in various keratinous substrates and degrade them to the components with low molecular weight. This study was conducted to determine the prevalence of keratinophilic fungi and aerobic Actinomycetes in soil of city parks in Gorgan. Objectives: In this study, we surveyed the city park soils of Gorgan (a northern province of Iran) to determine the identities and diversity of soil aerobic Actinomycetes, keratinophilic and non-keratinophilic fungi. Materials and Methods: A total of 244 soil samples were collected from 22 diferent parks of Gorgan, North of Iran. The samples were collected from the superfcial layer with depth not exceeding than 0-10 cm in sterile polyethylene bags. We used hair bait technique for isolation keratinophilic fungi. The colonies identifed by macroscopic and microscopic characterization after slide culturing. Actinomycetes were isolated by antibiotic dilution methods and detected by using physiological tests such as Lysozyme, Casein, Xanthine, Hypoxanthine, Gelatin, Urea Broth, and modifed acid-fast stain. Results: Totally, 75 isolates of aerobic Actinomycetes were detected that Actinomadura madurae and Nocardia asteroides were the most prevalent strains, with 14.66 and 28% prevalence respectively. Microsporum gypseum was more frequent than other keratinophilic fungi (22.96%) and Aspergillus spp. was the most species of saprophyte fungi (15.92%). Conclusions: This study showed that the collected soil from studied areas was rich of keratinophilic fungi and Actinomycetes, therefore hygiene protocol should be taken to prevent the spread of pathogenic and saprophytes fungi in the environment of susceptible person. © 2013, Ahvaz Jundishapur University of Medical Sciences
Expression levels of vascular endothelial growth factors A and C in patients with peptic ulcers and gastric cancer
Purpose: Vascular endothelial growth factor (VEGF) is one of the most important growth factors for metastatic tumors. To clarify the role of VEGF-A and C in patients with peptic ulcer disease (PUD) or gastric cancer (GC), we evaluated the expression levels of these two molecules. We also analyzed the effect of Helicobacter pylori infection on VEGF-A and C expression levels
Design of Real Time Walsh Transform for Processing of Multiple Digital Signals
This paper presents the design and implementation of multiple digital signals processing using real-time Walsh transforms. The design of real time Walsh transform is done in such a way that it starts producing outputs instantly even before all input data have entered the system. The system consists of Walsh Transform circuit, several Digital Signal Processing (DSP) circuits, and an inverse Walsh transform circuit. The real time Walsh and inverse Walsh transforms are also designed to produce right results for any possible combinations of input data. DSP blocks are able to perform addition, subtraction, and dyadic convolution process of Walsh coefficients of more than one digital signals. Comparisons to the previous methods are briefly presented. It was found that the design of real time Walsh transform structure has better performance than many of the previously reported results in the literature.DOI:http://dx.doi.org/10.11591/ijece.v3i2.196
On UHECR energy estimation algorithms based on the measurement of electromagnetic component parameters in EAS
Model calculations are performed of extensive air shower (EAS) component
energies using a variety of hadronic interaction parameters. A conversion
factor from electromagnetic component energy to the energy of ultra-high energy
cosmic rays (UHECRs) and its model and primary mass dependence is studied. It
is shown that model dependence of the factor minimizes under the necessary
condition of the same maximum position and muon content of simulated showers.Comment: contracted version is accepted for publication in Doklady Physic
Numerical and Physical Modeling of the Effect of Roughness Height on Cavitation Index in Chute Spillways
© 2019, Iran University of Science and Technology. This study presents the results of physical and numerical modeling of the effect of bed roughness height of chute spillways on the cavitation index. A 1:50-scale physical hydraulic model of the chute spillway of Surk Dam was constructed at the hydraulic laboratory of Shahrekord University, Iran. The experiments were conducted for different flow rates and the parameters of pressure, velocity, and flow depth in 26 positions along the chute. Finally, the ANSYS-FLUENT model was calibrated in the chute spillway using the experimental data by assumptions of two-phase volume of fluid and k–ε (RNG) turbulence models. The cavitation index in different sections of the chute spillway was calculated for different values of bed roughness including the roughness heights of 1, 2, and 2.5 mm. Results showed that the minimum values of the cavitation index were 0.2906, 0.2733, and 0.2471 for the roughness heights of 1, 2, and 2.5 mm, respectively. The statistical significance analysis showed that reducing the roughness height from 2.5 to 1 mm would not change significantly the value of the cavitation index at 95% confidence interval
Cosmic Rays at the highest energies
After a century of observations, we still do not know the origin of cosmic
rays. I will review the current state of cosmic ray observations at the highest
energies, and their implications for proposed acceleration models and secondary
astroparticle fluxes. Possible sources have narrowed down with the confirmation
of a GZK-like spectral feature. The anisotropy observed by the Pierre Auger
Observatory may signal the dawn of particle astronomy raising hopes for high
energy neutrino observations. However, composition related measurements point
to a different interpretation. A clear resolution of this mystery calls for
much larger statistics than the reach of current observatories.Comment: 8 pages, 4 figures, in the Proceedings of TAUP 201
Highest Energy Cosmic Rays and results from the HiRes Experiment
The status of the field of ultrahigh energy cosmic rays is summarized, from
the point of view of the latest results of the High Resolution Fly's Eye
(HiRes) Experiment. HiRes results are presented, and compared with those of the
Akeno Giant Air Shower Array (AGASA), plus the Telescope Array and Pierre Auger
experiments. The HiRes measurements of the cosmic ray spectrum, and the
observation of the GZK cutoff are presented. HiRes results on composition,
searches for anisotropy, measurement of the proton-air total cross section, and
shapes of shower profiles are presented.Comment: 31 pages, 18 figures, submitted to Journal of Physics
Ultra High Energy Cosmic Rays: The disappointing model
We develop a model for explaining the data of Pierre Auger Observatory
(Auger) for Ultra High Energy Cosmic Rays (UHECR), in particular, the mass
composition being steadily heavier with increasing energy from 3 EeV to 35 EeV.
The model is based on the proton-dominated composition in the energy range (1 -
3) EeV observed in both Auger and HiRes experiments. Assuming extragalactic
origin of this component, we argue that it must disappear at higher energies
due to a low maximum energy of acceleration, E_p^{\max} \sim (4 - 10) EeV.
Under an assumption of rigidity acceleration mechanism, the maximum
acceleration energy for a nucleus with the charge number Z is ZE_p^{\max}, and
the highest energy in the spectrum, reached by Iron, does not exceed (100 -
200) EeV. The growth of atomic weight with energy, observed in Auger, is
provided by the rigidity mechanism of acceleration, since at each energy
E=ZE_p^{\max} the contribution of nuclei with Z' < Z vanishes. The described
model has disappointing consequences for future observations in UHECR: Since
average energies per nucleon for all nuclei are less than (2 - 4) EeV, (i) pion
photo-production on CMB photons in extragalactic space is absent; (ii) GZK
cutoff in the spectrum does not exist; (iii) cosmogenic neutrinos produced on
CMBR are absent; (iv) fluxes of cosmogenic neutrinos produced on infrared -
optical background radiation are too low for registration by existing detectors
and projects. Due to nuclei deflection in galactic magnetic fields, the
correlation with nearby sources is absent even at highest energies.Comment: Essentially revised version as published in Astropart. Physics 10
pages, 6 figure
Enhancing and assessing group and team learning in architecture and related design contexts
EXECUTIVE SUMMARYTeamwork skills are essential in the design industry where practitioners negotiate often-conflicting design options in multi-disciplinary teams. Indeed, many of the bodies that accredit design courses explicitly list teamwork skills as essential attributes of design graduates e.g., the Australian Institute of Architects (AIA), Royal Institute of British Architects (RIBA), the National Council of Architectural Registration Boards (NCARB) of the United States and the Institution of Engineers, Australia (IEAust). In addition to the need to meet the demands of the accrediting bodies, there are many reasons for the ubiquitous use of teamwork assignments in design schools. For instance, teamwork learning is seen as being representative of work in practice where design is nearly always a collaborative activity. Learning and teaching in teamwork contexts in design education are not without particular challenges. In particular, two broad issues have been identified: first, many students leave academia without having been taught the knowledge and skills of how to design in teams; second, teaching, assessment and assignment design need to be better informed by a clear understanding of what leads to effective teamwork and the learning of teamwork skills. In recognition of the lack of a structured approach to integrating teamwork learning into the curricula of design programs, this project set out to answer three primary research questions: • How do we teach teamwork skills in the context of design? • How do we assess teamwork skills?• How do design students best learn teamwork skills?In addition, four more specific questions were investigated:1. Is there a common range of learning objectives for group-and-team-work in architecture and related design disciplines that will enable the teaching of consistent and measurable outcomes?2. Do group and team formation methods, learning styles and team-role preferences impact students’ academic and course satisfaction outcomes?3. What combinations of group-and-team formation methods, teaching and assessment models significantly improve learning outcomes?4. For design students across different disciplines with different learning styles and cultural origins, are there significant differences in performance, student satisfaction (as measured through questionnaires and unit evaluations), group-and-team working abilities and student participation?To elucidate these questions, a design-based research methodology was followed comprising an iterative series of enquiries: (a) A literature review was completed to investigate: what constitutes effective teamwork, what contributes to effectiveness in teams, what leads to positive design outcomes for teams, and what leads to effective learning in teams. The review encompassed a range of contexts: from work-teams in corporate settings, to professional design teams, to education outside of and within the design disciplines. The review informed a theoretical framework for understanding what factors impact the effectiveness of student design teams. (b) The validity of this multi-factorial Framework of Effectiveness in Student Design Teams was tested via surveys of educators’ teaching practices and attitudes, and of students’ learning experiences. 638 students and 68 teachers completed surveys: two pilot surveys for participants at the four partner institutions, which then informed two national surveys completed by participants from the majority of design schools across Australia. (c) The data collected provided evidence for 22 teamwork factors impacting team effectiveness in student design teams. Pedagogic responses and strategies to these 22 teamwork factors were devised, tested and refined via case studies, focus groups and workshops. (d) In addition, 35 educators from a wide range of design schools and disciplines across Australia attended two National Teaching Symposiums. The first symposium investigated the wider conceptualisation of teamwork within the design disciplines, and the second focused on curriculum level approaches to structuring the teaching of teamwork skills identified in the Framework.The Framework of Effectiveness in Student Design Teams identifies 22 factors impacting effective teamwork, along with teaching responses and strategies that design educators might use to better support student learning. The teamwork factors and teaching strategies are categorised according to three groups of input (Task Characteristics, Individual Level Factors and Team Level Factors), two groups of processes (Teaching Practice & Support Structures and Team Processes), and three categories of output (Task Performance, Teamwork Skills, and Attitudinal Outcomes). Eight of the 22 teamwork factors directly relate to the skills that need to be developed in students, one factor relates to design outputs, and the other thirteen factors inform pedagogies that can be designed for better learning outcomes. In Table 10 of Section 4, we outline which of the 22 teamwork factors pertain to each of five stakeholder groups (curriculum leaders, teachers, students, employers and the professional bodies); thus establishing who will make best use the information and recommendations we make. In the body of this report we summarise the 22 teamwork factors and teaching strategies informed by the Framework of Effectiveness in Student Design Teams, and give succinct recommendations arising from them. This material is covered in depth by the project outputs. For instance, the teaching and assessment strategies will be expanded upon in a projected book on Teaching Teamwork in Design. The strategies are also elucidated by examples of good practice presented in our case studies, and by Manuals on Teamwork for Teachers and Students. Moreover, the project website ( visited by representatives of stakeholder groups in Australia and Canada), is seeding a burgeoning community of practice that promises dissemination, critical evaluation and the subsequent refinement of our materials, tools, strategies and recommendations. The following three primary outputs have been produced by the project in answer to the primary research questions:1. A theoretical Framework of Effectiveness in Student Design Teams;2. Manuals on Teamwork for Teachers and Students (available from the website);3. Case studies of good/innovative practices in teaching and assessing teamwork in design;In addition, five secondary outputs/outcomes have been produced that provide more nuanced responses:4. Detailed recommendations for the professional accrediting bodies and curriculum leaders;5. Online survey data (from over 700 participants), plus Team Effectiveness Scale to determine the factors influencing effective learning and successful outputs for student design teams;6. A community of practice in policy, programs, practice and dialogue;7. A detailed book proposal (with sample chapter), submitted to prospective publishers, on Teaching Teamwork in Design; 8. An annotated bibliography (accessed via the project website) on learning, teaching and assessing teamwork.The project has already had an international impact. As well as papers presented in Canada and New Zealand, the surveys were participated in by six Canadian schools of architecture, whose teaching leaders also provided early feedback on the project aims and objectives during visits made to them by the project leader. In addition, design schools in Vancouver, Canada, and San Diego in the USA have already utilised the Teacher’s Manual, and in February 2014 the project findings were discussed at Tel Aviv University in a forum focusing on the challenges for sustainability in architectural education.</www.teaching-teamwork-in-design.com
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