5,001 research outputs found

    Photon Neutrino Scattering in Non-Commutative Space

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    We extend the non-commutative standard model based on the minimal SU(3)×SU(2)×U(1)SU(3)\times SU(2)\times U(1) gauge group to include the interaction of photon with neutrino. We show that, in the gauge invariant manner, only the right handed neutrino can directly couple to the photon. Consequently, we obtain the Feynman rule for the γννˉ\gamma\nu\bar\nu-vertex which does not exist in the minimal extension of non-commutative standard model (mNCSM). We calculate the amplitude for γνγν\gamma\nu\to\gamma\nu in both the nonminimal non-commutative standard model (nmNCSM) and the extended version of mNCSM. The obtained cross section grows in the center of mass frame, respectively, as (θNC)2MZ4E6(\theta_{NC})^2{M}_Z^{-4}E^6 and (θNC)4E6(\theta_{NC})^4E^6 which can exceed the cross section for γνγγν\gamma\nu\to\gamma\gamma\nu and γνγν\gamma\nu\to\gamma\nu in the high energy limit in the commutative space.Comment: 12 pages, 3 figures, to appear in Phys. Rev.

    Ultrasound - guided access during percutaneous nephrolithotomy: Entering desired calyx with appropriate entry site and angle

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    Objectives: To evaluate the success of ultrasonography directed renal access in entering the target calyx from proper entry site and in the direction of renal pelvis during percutaneous nephrolithotomy (PCNL). Materials and Methods: PCNL cases who were operated on by one fellow from May- June 2014 were included in this study. A vertically placed ultrasound probe on the patient flank in prone position was used to identify the preselected target calyx. Needle was advanced through needle holder and fluoroscopy was used to document the entered calyx, site and angle of entry. Results: Successful entering to the target calyx was achieved in 43 cases (91). Successful entry with appropriate entry site and angle was observed in 34 cases (72). Reasons for failure were minimal hydronephrosis, upper pole access and high lying kidneys. Conclusions: Although it is feasible to access a preselected calyx by ultrasonography guidance during PCNL, but entry to the calyx from the appropriate site and direction is another problem and needs more experience. In cases of minimal hydronephrosis, superior pole access or high lying kidneys, ultrasonography is less successful and should be used with care

    Mutational spectrum of autosomal recessive limb-girdle muscular dystrophies in a cohort of 112 Iranian patients and reporting of a possible founder effect

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    Background: Limb-girdle muscular dystrophies are a group of genetically heterogeneous diseases that are inherited in both autosomal dominant (LGMDD) and autosomal recessive forms (LGMDR), the latter is more common especially in populations with high consanguineous marriages like Iran. In the present study, we aimed to investigate the genetic basis of patients who are suspicious of being affected by LGMDR. DNA samples of 60 families suspected of LGMD were extracted from their whole blood. Four short tandem repeat (STR) markers for each candidate genes related to LGMD R1 (calpain3 related)- R6 (δ-sarcoglycan-related) were selected, and all these 24 STRs were applied in two sets of multiplex PCR. After autozygosity mapping, Sanger sequencing and variant analysis were done. Predicting identified variants' effect was performed using in-silico tools, and they were interpreted according to the American College of Medical Genomics and Genetics (ACMG) guideline. MLPA was used for those patients who had large deletions. Fresh muscle specimens were taken from subjects and were evaluated using the conventional panel of histochemical stains. Results: forty out of sixty families showed homozygote haplotypes in CAPN3, DYSF, SGCA, and SGCB genes. The exons and intron-exon boundaries of the relevant genes were sequenced and totally 38 mutations including CAPN3 (n = 15), DYSF (n = 9), SGCB (n = 11), and SGCA (n = 3) were identified. Five out of them were novel. The most prevalent form of LGMDs in our study was calpainopathy followed by sarcoglycanopathy in which beta-sarcoglycanopathy was the most common form amongst them. Exon 2 deletion in the SGCB gene was the most frequent mutation in this study. We also reported evidence of a possible founder effect in families with mutations in DYSF and SGCB genes. We also detected a large consanguineous family suffered from calpainopathy who showed allelic heterogeneity. Conclusions: This study can expand our knowledge about the genetic spectrum of LGMD in Iran, and also suggest the probable founder effects in some Iranian subpopulations which confirming it with more sample size can facilitate our genetic diagnosis and genetic counseling. © 2020 The Author(s)

    Lessons of 10 years experience on CCHF in Iran

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    International audienceCrimean-Congo Hemorrhagic Fever (CCHF) is a viral zoonotic disease with high mortality rate in humans caused by CCHF virus (CCHFV) belonging to the genus Nairovirus, family Bunyaviridae, and congaing a three segment single-stranded RNA genome. The CCHFV is transmitted to humans by bite of infected ticks, by direct contact with blood or tissues of infected livestock and nosocomially. After Chaharmahal-va-Bakhtiari outbreak in 1999 whose serum samples was sent to South Africa for diagnosis, Arboviruses and Viral Hemorrhagic Fevers Laboratory (As National Reference Lab) was established in 2000 to precise and on time laboratory diagnosis of CCHF in the country. The Lab along with CDC of Iran (national health regulator) and Veterinary organization (control program of tick populations and livestock monitoring) are members of National Expert Committee on Viral Hemorrhagic Fevers (NECVHFs) for surveillance and control of CCHF in Ir

    Impact of compression and small cell deployment on NB-IoT devices’ coverage and energy consumption with a realistic simulation model

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    In the last few years, Low Power Wide Area Networks (LPWAN) technologies have been proposed for Machine-Type Communications (MTC). In this paper we evaluate wireless relay technologies that can improve LPWAN coverage for smart meter communication applications. We provide a realistic coverage analysis using a realistic correlated shadow fading map and path loss calculation for the environment. Our analysis shows significant reductions in the number of MTC devices in outage from by deploying either small cells or Device to Device (D2D) communications. In addition, we analysed the energy consumption of the MTC devices for different data packet sizes and Maximum Coupling Loss (MCL) values. Finally, we study how compression techniques can extend the battery lifetime of MTC devices

    Investigating Ca II emission in the RS CVn binary ER Vulpeculae using the Broadening Function Formalism

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    The synchronously rotating G stars in the detached, short-period (0.7 d), partially eclipsing binary, ER Vul, are the most chromospherically active solar-type stars known. We have monitored activity in the Ca II H & K reversals for almost an entire orbit. Rucinski's Broadening Function Formalism allows the photospheric contribution to be objectively subtracted from the highly blended spectra. The power of the BF technique is also demonstrated by the good agreement of radial velocities with those measured by others from less crowded spectral regions. In addition to strong Ca II emission from the primary and secondary, there appears to be a high-velocity stream flowing onto the secondary where it stimulates a large active region on the surface 30 - 40 degrees in advance of the sub-binary longitude. A model light curve with a spot centered on the same longitude also gives the best fit to the observed light curve. A flare with approximately 13% more power than at other phases was detected in one spectrum. We suggest ER Vul may offer a magnified view of the more subtle chromospheric effects synchronized to planetary revolution seen in certain `51 Peg'-type systems.Comment: Accepted to AJ; 17 pages and 16 figure

    On the impact of using smart boards on improving EFL learners' motivation and learning of phrasal verbs

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    Background and Objective:One of the new developments in educational technology that is currently widely used in classrooms to increase students' learning and motivation is the smart board. Smart board is an educational tool that allows computer images to be displayed using video projector on the board. The teacher can then use his/ her finger as a mouse to directly manipulate and copy items on the board on the screen. The speaker can save the presented content. The smart board's technology capabilities and accompanying software encourage students to immerse themselves deeply in the educational content and to move forward step by step with high motivation with the teacher in order to learn the content of the lesson. Some of the strengths and weaknesses of this tool is understandable and its effectiveness can be revealed by further research.The use of smart boards in teaching English as a foreign language has been of much concern to English language teachers since a couple of years ago. However, the impact of smart boards on learning phrasal verbs and attitudes of Iranian learners of English language has not been appropriately investigated. Methods: The present study aimed at investigating the impact of smart boards on learning phrasal verbs and motivation of language learners for learning a foreign language. In doing so, 30 EFL learners at a high school in Khoramshahr were selected through convenience sampling. They received instruction on phrasal verbs through smart board within 8 weeks. The participants' scores on pretest, posttest, and follow up tests on motivation and phrasal verbs were submitted to two different repeated measures ANOVA. Findings: The results showed that there was a significant difference between the participants' scores on pretest and posttest of both phrasal verbs and motivation test. Therefore, it could be argued that the use of small boards can significantly contribute to the learners' motivation and learning of phrasal verbs. Conclusion: Smart boards as a tool have great potential to increase teachers 'educational performance and learners' educational achievements, and ultimately improve student achievement. However, the claim that the student's success can be automatically increased using this technology may be incorrect. Therefore, teachers need to think carefully about how to use this tool. Due to the spatial limitations of this research, its replication research in other schools may have different results. Therefore, the results may not be generalized to all high school students and other areas. The duration of this study was only eight sessions, which seems to be a limited time. In addition, the participants were high school seniors, and other high school levels were not considered, and only female students were recruited in the study. As a result, choosing a larger sample size consisting both male and female students can increase the validity of the results.   ===================================================================================== COPYRIGHTS  ©2019 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

    The Effects of the Reynolds Number on the Hydrodynamics Characteristics of an AUV

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    The hydrodynamic characteristics of autonomous underwater vehicles (AUVs) play a significant role in the design and analysis of their maneuverability. This paper evaluates the effects of the Reynolds (Re) number on the hydrodynamic characteristics of AUV for various angles of attack (AOA). To estimate the hydrodynamic parameters, a numerical modelling based on computational fluid dynamics (CFD) is employed. Reynolds numbers between 2106 and 150106 were examined at -10º to 10º AOAs. Experimental tests for the same AUV in Re = 2106 in the water tunnel were carried out for CFD validation. A comparison of the results showed an acceptable agreement between the numerical method and the experimental results. The results show that hydrodynamic parameters can be a function of Re and converge on a constant in a limited value when the Re number increases. Results of independent parameters, can be used for full-scale without the establishment of dynamic similarity
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