97 results on '"Mkrtchyan H"'
Search Results
2. Production of 117m Sn and 119m Sn by photonuclear reactions on natural antimony.
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Krmar M, Jovančević N, Medić Ž, Maletić D, Teterev Y, Mitrofanov S, Timoshenko KD, Alexeev SI, Marukyan H, Kerobyan I, Avetisyan R, Dallakyan R, Hakobyan A, Vahradyan L, Mkrtchyan H, Petrosyan A, and Torosyan H
- Abstract
Natural antimony targets were irradiated in a 60 MeV bremsstrahlung beam and gamma spectrometric measurements were performed. The goal was to establish the yield of
117m Sn, a radionuclide with great potential for application in medicine. Considering that117m Sn is predominantly produced through a photonuclear reaction in which an charged particle is emitted (121 Sb(γ,p3n)), the yield of this tin isotope is much lower than the yields of several antimony isotopes produced in (γ,xn) reactions. It has been estimated that photonuclear reactions on natural antimony could produce117m Sn activities needed for therapeutic applications, with accelerators having electron currents of the order of mA. For the used bremsstrahlung energy of 60 MeV, it was estimated how much119m Sn activity can be expected when exposing the antimony target., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)- Published
- 2024
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3. Measured proton electromagnetic structure deviates from theoretical predictions.
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Li R, Sparveris N, Atac H, Jones MK, Paolone M, Akbar Z, Gayoso CA, Berdnikov V, Biswas D, Boer M, Camsonne A, Chen JP, Diefenthaler M, Duran B, Dutta D, Gaskell D, Hansen O, Hauenstein F, Heinrich N, Henry W, Horn T, Huber GM, Jia S, Joosten S, Karki A, Kay SJD, Kumar V, Li X, Li WB, Liyanage AH, Malace S, Markowitz P, McCaughan M, Meziani ZE, Mkrtchyan H, Morean C, Muhoza M, Narayan A, Pasquini B, Rehfuss M, Sawatzky B, Smith GR, Smith A, Trotta R, Yero C, Zheng X, and Zhou J
- Abstract
The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton's bound state. A fundamental property of the proton involves the response of the system to an external electromagnetic field. It is characterized by the electromagnetic polarizabilities
1 that describe how easily the charge and magnetization distributions inside the system are distorted by the electromagnetic field. Moreover, the generalized polarizabilities2 map out the resulting deformation of the densities in a proton subject to an electromagnetic field. They disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents. Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved for two decades2 . Here we report measurements of the proton's electromagnetic generalized polarizabilities at low four-momentum transfer squared. We show evidence of an anomaly to the behaviour of the proton's electric generalized polarizability that contradicts the predictions of nuclear theory and derive its signature in the spatial distribution of the induced polarization in the proton. The reported measurements suggest the presence of a new, not-yet-understood dynamical mechanism in the proton and present notable challenges to the nuclear theory., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)- Published
- 2022
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4. Measures of glucose homeostasis during and after duodenal exclusion using a duodenal-jejunal bypass liner in a normoglycemic, nonobese canine model.
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Paszkiewicz RL, Burch MA, Asare Bediako I, Mkrtchyan H, Piccinini F, Ader M, Bresee C, and Bergman RN
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- Animals, Blood Glucose metabolism, Dogs, Duodenum metabolism, Duodenum surgery, Glucose metabolism, Homeostasis, Humans, Jejunum metabolism, Jejunum surgery, Treatment Outcome, Weight Loss, Bariatric Surgery, Diabetes Mellitus, Type 2 surgery
- Abstract
Background: Discovering the role duodenal exclusion plays in weight loss and resolution of type 2 diabetes (T2D) may help refine the surgical and nonsurgical treatment of obesity and T2D., Objectives: To assess changes in glucose homeostasis due to duodenal exclusion using a duodenal-jejunal bypass liner (DJBL) in a nonobese canine model., Setting: Academic laboratory setting., Methods: An intravenous glucose tolerance test (IVGTT), and a mixed-meal tolerance test (MMTT) at baseline, 1, and 6 weeks post DJBL implantation (I1 and I6, respectively), and 1 and 6 weeks post DJBL removal (R1 and R6, respectively) were done in canines (n = 7) fed a normal chow diet., Results: Placement of the DJBL induced weight loss that was maintained until 4 weeks post removal (R4), despite normal food intake. Total bile acids (TBA) and glucagon-like peptide-1 (GLP-1) during the MMTT were significantly increased at I1 and were associated with increased lactate and free fatty acids. Hypoglycemia counter-regulation was blunted during the IVGTT at I1 and I6, returning to baseline at R1. While there were no changes to insulin sensitivity during the experiment, glucose tolerance was significantly increased following the removal of the DJBL at R1., Conclusion: These data show that in a normoglycemic, nonobese canine model, duodenal exclusion induces energy intake-independent weight loss and negative metabolic effects that are reversed following re-exposure of the small intestine to nutrients., (Copyright © 2022 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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5. Determination of the ^{27}Al Neutron Distribution Radius from a Parity-Violating Electron Scattering Measurement.
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Androić D, Armstrong DS, Bartlett K, Beminiwattha RS, Benesch J, Benmokhtar F, Birchall J, Carlini RD, Cornejo JC, Covrig Dusa S, Dalton MM, Davis CA, Deconinck W, Dowd JF, Dunne JA, Dutta D, Duvall WS, Elaasar M, Falk WR, Finn JM, Forest T, Gal C, Gaskell D, Gericke MTW, Gray VM, Grimm K, Guo F, Hoskins JR, Jones DC, Jones MK, Kargiantoulakis M, King PM, Korkmaz E, Kowalski S, Leacock J, Leckey J, Lee AR, Lee JH, Lee L, MacEwan S, Mack D, Magee JA, Mahurin R, Mammei J, Martin JW, McHugh MJ, Meekins D, Mesick KE, Michaels R, Micherdzinska A, Mkrtchyan A, Mkrtchyan H, Narayan A, Ndukum LZ, Nelyubin V, Nuruzzaman, van Oers WTH, Owen VF, Page SA, Pan J, Paschke KD, Phillips SK, Pitt ML, Radloff RW, Rajotte JF, Ramsay WD, Roche J, Sawatzky B, Seva T, Shabestari MH, Silwal R, Simicevic N, Smith GR, Solvignon P, Spayde DT, Subedi A, Suleiman R, Tadevosyan V, Tobias WA, Tvaskis V, Waidyawansa B, Wang P, Wells SP, Wood SA, Yang S, Zang P, Zhamkochyan S, Christy ME, Horowitz CJ, Fattoyev FJ, and Lin Z
- Abstract
We report the first measurement of the parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al elastic asymmetry is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, and ⟨E_{lab}⟩=1.157 GeV with the Q_{weak} apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the ^{27}Al neutron radius R_{n}=2.89±0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_{n}-R_{p}=-0.04±0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the ^{27}Al weak radius R_{w}=3.00±0.15 fm, and the weak skin thickness R_{wk}-R_{ch}=-0.04±0.15 fm. The weak form factor at this Q^{2} is F_{wk}=0.39±0.04.
- Published
- 2022
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6. Effectiveness and Determinant Variables of Augmentative and Alternative Communication Interventions in Cerebral Palsy Patients with Communication Deficit: a Systematic Review.
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Avagyan A, Mkrtchyan H, Shafa FA, Mathew JA, and Petrosyan T
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- Humans, Case-Control Studies, Communication, Longitudinal Studies, Cerebral Palsy complications
- Abstract
Purpose: Assess the effectiveness of augmentative and alternative communication (AAC) interventions in patients with CP and to reveal determinant variables of main intervention outcomes: receptive and expressive language., Research Strategies: The search was performed in following databases: MEDLINE (Ovid); PubMed (NLM); Embase (Ovid); Cochrane Database of Systematic Reviews; Cumulative Index to Nursing and Allied Health Literature; Database of Abstracts of Reviews of Effects; Cochrane Central Register of Controlled Trials; Health Technology Assessment database and PEDro., Selection Criteria: Full-text and peer-reviewed studies in English studying the effectiveness of AAC in patients with cerebral palsy were included. Studies with patients (<18 years) diagnosed with CP were included., Data Analysis: A narrative analysis was conducted to evaluate the efficacy of AAC methods. A random-effects model meta-analysis was used to assess determinants of AAC intervention outcomes., Results: The online database and manual reference search revealed 445 records. Nine studies investigating a total of 294 subjects with CP met predefined eligibility criteria: 4 studies with single subject, multiple baseline research designs, 3 longitudinal cohort studies, 1 case control study and 1 case series. Results revealed moderate-quality evidence that AAC interventions improve the receptive and expressive communication skills in patients with CP. The random-effects model meta-analysis revealed the power of identified determinant variables affecting the AAC intervention outcomes., Conclusion: Diversity of CP patients requires proper analysis of determinant variables to ensure the efficacy of AAC assessment and intervention. More studies of high methodological and practical quality assessing the efficacy of AAC interventions are needed to clarify the evidence.
- Published
- 2021
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7. The effect of staphylococcal mastitis including resistant strains on serum procalcitonin, neopterin, acute phase response and stress biomarkers in Holstein dairy cows.
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El-Deeb W, Fayez M, Alhumam N, Elsohaby I, Quadri SA, and Mkrtchyan H
- Abstract
Staphylococcal mastitis (SM) is a frequent disease in the dairy cattle that is costly to treat. This study aimed to investigate the alterations in the levels of procalcitonin (PCT), neopterin (NPT), haptoglobin (HP), serum amyloid A (SAA), proinflammatory cytokines (IL-1 β , IL-8, TNF- α , IF- γ ) and oxidative stress (OS) biomarkers in Holstein dairy cows with SM under field conditions. In addition, we also evaluated the role of examined biomarkers in disease pathogenesis and their use as diagnostic biomarkers for the disease in dairy cows. Fifty-three dairy cows with SM, including those with infections caused by Staphylococcus aureus ( n = 42) and methicillin resistant S. aureus (MRSA) ( n = 11) were selected for this study. In addition, 20 healthy dairy cows were enrolled as a control group. Higher serum levels of PCT, NP, IL-1 β , IL-8, TNF- α , IF- γ , HP and SAA and a state of OS was detected in SM group in comparison with the controls. Moreover, the levels of all examined biomarkers in mastitic cows with S. aureus when compared with those infected with MRSA was not significantly different. All examined biomarkers demonstrated a significant degree of discrimination between SM cows and healthy controls (the area under the curve (AUC) ranged from 83.6 for S AA to 100 for PCT). Our study showed that SM in dairy cows was associated with substantial changes in serum PCT, NPT, Acute phase proteins (APPs), proinflammatory cytokines, and OS levels. This study demonstrates that clinical examination in tandem with quantification of PCT, NPT, APPs and cytokines, OS biomarkers could be a useful assessment tool for SM in dairy cows., Competing Interests: The authors declare there are no competing interests., (©2021 El-Deeb et al.)
- Published
- 2021
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8. Ruling out Color Transparency in Quasielastic ^{12}C(e,e^{'}p) up to Q^{2} of 14.2 (GeV/c)^{2}.
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Bhetuwal D, Matter J, Szumila-Vance H, Kabir ML, Dutta D, Ent R, Abrams D, Ahmed Z, Aljawrneh B, Alsalmi S, Ambrose R, Androic D, Armstrong W, Asaturyan A, Assumin-Gyimah K, Ayerbe Gayoso C, Bandari A, Basnet S, Berdnikov V, Bhatt H, Biswas D, Boeglin WU, Bosted P, Brash E, Bukhari MHS, Chen H, Chen JP, Chen M, Christy EM, Covrig S, Craycraft K, Danagoulian S, Day D, Diefenthaler M, Dlamini M, Dunne J, Duran B, Evans R, Fenker H, Fomin N, Fuchey E, Gaskell D, Gautam TN, Gonzalez FA, Hansen JO, Hauenstein F, Hernandez AV, Horn T, Huber GM, Jones MK, Joosten S, Karki A, Keppel C, Khanal A, King PM, Kinney E, Ko HS, Kohl M, Lashley-Colthirst N, Li S, Li WB, Liyanage AH, Mack D, Malace S, Markowitz P, Meekins D, Michaels R, Mkrtchyan A, Mkrtchyan H, Nazeer SJ, Nanda S, Niculescu G, Niculescu I, Nguyen D, Nuruzzaman, Pandey B, Park S, Pooser E, Puckett A, Rehfuss M, Reinhold J, Santiesteban N, Sawatzky B, Smith GR, Sun A, Tadevosyan V, Trotta R, Wood SA, Yero C, and Zhang J
- Abstract
Quasielastic ^{12}C(e,e^{'}p) scattering was measured at spacelike 4-momentum transfer squared Q^{2}=8, 9.4, 11.4, and 14.2 (GeV/c)^{2}, the highest ever achieved to date. Nuclear transparency for this reaction was extracted by comparing the measured yield to that expected from a plane-wave impulse approximation calculation without any final state interactions. The measured transparency was consistent with no Q^{2} dependence, up to proton momenta of 8.5 GeV/c, ruling out the quantum chromodynamics effect of color transparency at the measured Q^{2} scales in exclusive (e,e^{'}p) reactions. These results impose strict constraints on models of color transparency for protons.
- Published
- 2021
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9. Glossary on atmospheric electricity and its effects on biology.
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Fdez-Arroyabe P, Kourtidis K, Haldoupis C, Savoska S, Matthews J, Mir LM, Kassomenos P, Cifra M, Barbosa S, Chen X, Dragovic S, Consoulas C, Hunting ER, Robert D, van der Velde OA, Apollonio F, Odzimek A, Chilingarian A, Royé D, Mkrtchyan H, Price C, Bór J, Oikonomou C, Birsan MV, Crespo-Facorro B, Djordjevic M, Salcines C, López-Jiménez A, Donner RV, Vana M, Pedersen JOP, Vorenhout M, and Rycroft M
- Subjects
- Biology, Electricity
- Abstract
There is an increasing interest to study the interactions between atmospheric electrical parameters and living organisms at multiple scales. So far, relatively few studies have been published that focus on possible biological effects of atmospheric electric and magnetic fields. To foster future work in this area of multidisciplinary research, here we present a glossary of relevant terms. Its main purpose is to facilitate the process of learning and communication among the different scientific disciplines working on this topic. While some definitions come from existing sources, other concepts have been re-defined to better reflect the existing and emerging scientific needs of this multidisciplinary and transdisciplinary area of research.
- Published
- 2021
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10. Probing the Deuteron at Very Large Internal Momenta.
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Yero C, Abrams D, Ahmed Z, Ahmidouch A, Aljawrneh B, Alsalmi S, Ambrose R, Armstrong W, Asaturyan A, Assumin-Gyimah K, Ayerbe Gayoso C, Bandari A, Bane J, Basnet S, Berdnikov VV, Bericic J, Bhatt H, Bhetuwal D, Biswas D, Boeglin WU, Bosted P, Brash E, Bukhari MHS, Chen H, Chen JP, Chen M, Christy ME, Covrig S, Craycraft K, Danagoulian S, Day D, Diefenthaler M, Dlamini M, Dunne J, Duran B, Dutta D, Ent R, Evans R, Fenker H, Fomin N, Fuchey E, Gaskell D, Gautam TN, Gonzalez FA, Hansen JO, Hauenstein F, Hernandez AV, Horn T, Huber GM, Jones MK, Joosten S, Kabir ML, Karki A, Keppel CE, Khanal A, King P, Kinney E, Lashley-Colthirst N, Li S, Li WB, Liyanage AH, Mack DJ, Malace SP, Matter J, Meekins D, Michaels R, Mkrtchyan A, Mkrtchyan H, Nazeer SJ, Nanda S, Niculescu G, Niculescu M, Nguyen D, Nuruzzaman N, Pandey B, Park S, Perdrisat CF, Pooser E, Rehfuss M, Reinhold J, Sawatzky B, Smith GR, Sun A, Szumila-Vance H, Tadevosyan V, Wood SA, and Zhang J
- Abstract
We measure ^{2}H(e,e^{'}p)n cross sections at 4-momentum transfers of Q^{2}=4.5±0.5 (GeV/c)^{2} over a range of neutron recoil momenta p_{r}, reaching up to ∼1.0 GeV/c. We obtain data at fixed neutron recoil angles θ_{nq}=35°, 45°, and 75° with respect to the 3-momentum transfer q[over →]. The new data agree well with previous data, which reached p_{r}∼500 MeV/c. At θ_{nq}=35° and 45°, final state interactions, meson exchange currents, and isobar currents are suppressed and the plane wave impulse approximation provides the dominant cross section contribution. We compare the new data to recent theoretical calculations, where we observe a significant discrepancy for recoil momenta p_{r}>700 MeV/c.
- Published
- 2020
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11. Precision Measurement of the Beam-Normal Single-Spin Asymmetry in Forward-Angle Elastic Electron-Proton Scattering.
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Androić D, Armstrong DS, Asaturyan A, Bartlett K, Beaufait J, Beminiwattha RS, Benesch J, Benmokhtar F, Birchall J, Carlini RD, Cornejo JC, Dusa SC, Dalton MM, Davis CA, Deconinck W, Dowd JF, Dunne JA, Dutta D, Duvall WS, Elaasar M, Falk WR, Finn JM, Forest T, Gal C, Gaskell D, Gericke MTW, Grames J, Gray VM, Grimm K, Guo F, Hoskins JR, Jones D, Jones MK, Jones RT, Kargiantoulakis M, King PM, Korkmaz E, Kowalski S, Leacock J, Leckey JP, Lee AR, Lee JH, Lee L, MacEwan S, Mack D, Magee JA, Mahurin R, Mammei J, Martin JW, McHugh MJ, Meekins D, Mei J, Mesick KE, Michaels R, Micherdzinska A, Mkrtchyan A, Mkrtchyan H, Morgan N, Narayan A, Ndukum LZ, Nelyubin V, Nuruzzaman, van Oers WTH, Owen VF, Page SA, Pan J, Paschke KD, Phillips SK, Pitt ML, Radloff RW, Rajotte JF, Ramsay WD, Roche J, Sawatzky B, Seva T, Shabestari MH, Silwal R, Simicevic N, Smith GR, Solvignon P, Spayde DT, Subedi A, Subedi R, Suleiman R, Tadevosyan V, Tobias WA, Tvaskis V, Waidyawansa B, Wang P, Wells SP, Wood SA, Yang S, Zang P, and Zhamkochyan S
- Abstract
A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θ_{lab}=7.9° and a mean energy of 1.149 GeV. The asymmetry result is B_{n}=-5.194±0.067(stat)±0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (θ_{lab}→0) where they should be most reliable.
- Published
- 2020
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12. Unique Access to u-Channel Physics: Exclusive Backward-Angle Omega Meson Electroproduction.
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Li WB, Huber GM, Blok HP, Gaskell D, Horn T, Semenov-Tian-Shansky K, Pire B, Szymanowski L, Laget JM, Aniol K, Arrington J, Beise EJ, Boeglin W, Brash EJ, Breuer H, Chang CC, Christy ME, Ent R, Gibson EF, Holt RJ, Jin S, Jones MK, Keppel CE, Kim W, King PM, Kovaltchouk V, Liu J, Lolos GJ, Mack DJ, Margaziotis DJ, Markowitz P, Matsumura A, Meekins D, Miyoshi T, Mkrtchyan H, Niculescu I, Okayasu Y, Pentchev L, Perdrisat C, Potterveld D, Punjabi V, Reimer PE, Reinhold J, Roche J, Roos PG, Sarty A, Smith GR, Tadevosyan V, Tang LG, Tvaskis V, Volmer J, Vulcan W, Warren G, Wood SA, Xu C, and Zheng X
- Abstract
Backward-angle meson electroproduction above the resonance region, which was previously ignored, is anticipated to offer unique access to the three quark plus sea component of the nucleon wave function. In this Letter, we present the first complete separation of the four electromagnetic structure functions above the resonance region in exclusive ω electroproduction off the proton, ep→e^{'}pω, at central Q^{2} values of 1.60, 2.45 GeV^{2}, at W=2.21 GeV. The results of our pioneering -u≈-u_{min} study demonstrate the existence of a unanticipated backward-angle cross section peak and the feasibility of full L/T/LT/TT separations in this never explored kinematic territory. At Q^{2}=2.45 GeV^{2}, the observed dominance of σ_{T} over σ_{L}, is qualitatively consistent with the collinear QCD description in the near-backward regime, in which the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes: universal nonperturbative objects only accessible through backward-angle kinematics.
- Published
- 2019
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13. Measurements of Nonsinglet Moments of the Nucleon Structure Functions and Comparison to Predictions from Lattice QCD for Q^{2}=4 GeV^{2}.
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Albayrak I, Mamyan V, Christy ME, Ahmidouch A, Arrington J, Asaturyan A, Bodek A, Bosted P, Bradford R, Brash E, Bruell A, Butuceanu C, Coleman SJ, Commisso M, Connell SH, Dalton MM, Danagoulian S, Daniel A, Day DB, Dhamija S, Dunne J, Dutta D, Ent R, Gaskell D, Gasparian A, Gran R, Horn T, Huang L, Huber GM, Jayalath C, Johnson M, Jones MK, Kalantarians N, Liyanage A, Keppel CE, Kinney E, Li Y, Malace S, Manly S, Markowitz P, Maxwell J, Mbianda NN, McFarland KS, Meziane M, Meziani ZE, Mills GB, Mkrtchyan H, Mkrtchyan A, Mulholland J, Nelson J, Niculescu G, Niculescu I, Pentchev L, Puckett A, Punjabi V, Qattan IA, Reimer PE, Reinhold J, Rodriguez VM, Rondon-Aramayo O, Sakuda M, Sakumoto WK, Segbefia E, Seva T, Sick I, Slifer K, Smith GR, Steinman J, Solvignon P, Tadevosyan V, Tajima S, Tvaskis V, Vulcan WF, Walton T, Wesselmann FR, Wood SA, and Ye Z
- Abstract
We present extractions of the nucleon nonsinglet moments utilizing new precision data on the deuteron F_{2} structure function at large Bjorken-x determined via the Rosenbluth separation technique at Jefferson Lab Experimental Hall C. These new data are combined with a complementary set of data on the proton previously measured in Hall C at similar kinematics and world datasets on the proton and deuteron at lower x measured at SLAC and CERN. The new Jefferson Lab data provide coverage of the upper third of the x range, crucial for precision determination of the higher moments. In contrast to previous extractions, these moments have been corrected for nuclear effects in the deuteron using a new global fit to the deuteron and proton data. The obtained experimental moments represent an order of magnitude improvement in precision over previous extractions using high x data. Moreover, recent exciting developments in lattice QCD calculations provide a first ever comparison of these new experimental results with calculations of moments carried out at the physical pion mass, as well as a new approach that first calculates the quark distributions directly before determining moments.
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- 2019
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14. Catalog of 2017 Thunderstorm Ground Enhancement (TGE) events observed on Aragats.
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Chilingarian A, Mkrtchyan H, Karapetyan G, Chilingaryan S, Sargsyan B, and Arestakesyan A
- Abstract
The natural electron accelerator in the clouds above Aragats high-altitude research station in Armenia operates continuously in 2017 providing more than 100 Thunderstorm Ground enhancements (TGEs). Most important discovery based on analysis of 2017 data is observation and detailed description of the long-lasting TGEs. We present TGE catalog for 2 broad classes according to presence or absence of the high-energy particles. In the catalog was summarized several key parameters of the TGEs and related meteorological and atmospheric discharge observations. The statistical analysis of the data collected in tables reveals the months when TGEs are more frequent, the daytime when TGEs mostly occurred, the mean distance to lightning flash that terminates TGE and many other interesting relations. Separately was discussed the sharp count rate decline and following removal of high-energy particles from the TGE flux after a lightning flash. ADEI multivariate visualization and statistical analysis platform make analytical work on sophisticated problems rather easy; one can try and test many hypotheses very fast and come to a definite conclusion allowing crosscheck and validation.
- Published
- 2019
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15. Revealing Color Forces with Transverse Polarized Electron Scattering.
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Armstrong W, Kang H, Liyanage A, Maxwell J, Mulholland J, Ndukum L, Ahmidouch A, Albayrak I, Asaturyan A, Ates O, Baghdasaryan H, Boeglin W, Bosted P, Brash E, Butuceanu C, Bychkov M, Carter P, Chen C, Chen JP, Choi S, Christy ME, Covrig S, Crabb D, Danagoulian S, Daniel A, Davidenko AM, Davis B, Day D, Deconinck W, Deur A, Dunne J, Dutta D, El Fassi L, Ellis C, Ent R, Flay D, Frlez E, Gaskell D, Geagla O, German J, Gilman R, Gogami T, Gomez J, Goncharenko YM, Hashimoto O, Higinbotham D, Horn T, Huber GM, Jones M, Jones MK, Kalantarians N, Kang HK, Kawama D, Keith C, Keppel C, Khandaker M, Kim Y, King PM, Kohl M, Kovacs K, Kubarovsky V, Li Y, Liyanage N, Luo W, Mack D, Mamyan V, Markowitz P, Maruta T, Meekins D, Melnik YM, Meziani ZE, Mkrtchyan A, Mkrtchyan H, Mochalov VV, Monaghan P, Narayan A, Nakamura SN, Nuruzzaman A, Pentchev L, Pocanic D, Posik M, Puckett A, Qiu X, Reinhold J, Riordan S, Roche J, Rondón OA, Sawatzky B, Shabestari M, Slifer K, Smith G, Soloviev LF, Solvignon P, Tadevosyan V, Tang L, Vasiliev AN, Veilleux M, Walton T, Wesselmann F, Wood S, Yao H, Ye Z, Zhang J, and Zhu L
- Abstract
The Spin Asymmetries of the Nucleon Experiment measured two double spin asymmetries using a polarized proton target and polarized electron beam at two beam energies, 4.7 and 5.9 GeV. A large-acceptance open-configuration detector package identified scattered electrons at 40° and covered a wide range in Bjorken x (0.3
- Published
- 2019
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16. Preliminary Assessment of the Need and Awareness of Augmentative and Alternative Communication Systems in Armenia.
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Petrosyan T, Mkrtchyan H, Harutyunyan Z, and Avagyan A
- Abstract
Competing Interests: Conflict of interest The authors declare that there is no conflict of interests.
- Published
- 2019
17. Polypharmacy, Infectious Diseases, Sexual Behavior, and Psychophysical Health Among Anabolic Steroid-Using Homosexual and Heterosexual Gym Patrons in San Francisco's Castro District.
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Ip EJ, Yadao MA, Shah BM, Doroudgar S, Perry PJ, Tenerowicz MJ, Newsom L, Mann AA, Mkrtchyan H, and Pope HG Jr
- Subjects
- Adult, Alcohol Drinking epidemiology, Cross-Sectional Studies, Humans, Male, Needle Sharing statistics & numerical data, Risk-Taking, San Francisco epidemiology, Self Medication, Seroepidemiologic Studies, Substance-Related Disorders epidemiology, Unsafe Sex statistics & numerical data, Young Adult, Communicable Diseases epidemiology, Heterosexuality psychology, Performance-Enhancing Substances administration & dosage, Polypharmacy, Sexual Behavior psychology, Sexual and Gender Minorities psychology, Testosterone Congeners administration & dosage
- Abstract
Background: Limited studies based in England and Australia reported misuse of anabolic-androgenic steroids (AAS) among homosexual men to enhance body image. Anecdotally, AAS are also being misused by homosexual men in the United States. Since many AAS and certain performance enhancing drugs (PEDs) are administered via injection, this poses a potential vector for the spread of infectious disease in an already at-risk population., Objectives: This study compared and contrasted homosexual and heterosexual male gym clients regarding use of AAS and PEDs, use of alcohol and illicit drugs, seroprevalence of infectious disease, engagement in risky injection practices and sexual behaviors, and presence of psychiatric conditions., Methods: Recruitment and data collection occurred outside four exercise gyms in the San Francisco Castro District area between October 25, 2014 and March 10, 2015. Two hundred and twenty homosexual men and 73 heterosexual men completed the 114-item cross-sectional survey., Results: Ten percent of homosexual men reported lifetime AAS use. Homosexual men had almost four times more sexual partners and were over 14 times more likely to knowingly have unprotected intercourse with a known HIV positive person than heterosexual men. In addition, a quarter of homosexual men who injected drugs admitted to sharing used syringes or needles with another person. Conclusions/Importance: The current study is the first to confirm AAS use among homosexual men in the United States. Homosexual men partook in high-risk sexual behaviors and injection practices which may place them at greater risks for contracting and spreading HIV and other infectious diseases.
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- 2017
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18. Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton.
- Author
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Fanelli C, Cisbani E, Hamilton DJ, Salmé G, Wojtsekhowski B, Ahmidouch A, Annand JR, Baghdasaryan H, Beaufait J, Bosted P, Brash EJ, Butuceanu C, Carter P, Christy E, Chudakov E, Danagoulian S, Day D, Degtyarenko P, Ent R, Fenker H, Fowler M, Frlez E, Gaskell D, Gilman R, Horn T, Huber GM, de Jager CW, Jensen E, Jones MK, Kelleher A, Keppel C, Khandaker M, Kohl M, Kumbartzki G, Lassiter S, Li Y, Lindgren R, Lovelace H, Luo W, Mack D, Mamyan V, Margaziotis DJ, Markowitz P, Maxwell J, Mbianda G, Meekins D, Meziane M, Miller J, Mkrtchyan A, Mkrtchyan H, Mulholland J, Nelyubin V, Pentchev L, Perdrisat CF, Piasetzky E, Prok Y, Puckett AJ, Punjabi V, Shabestari M, Shahinyan A, Slifer K, Smith G, Solvignon P, Subedi R, Wesselmann FR, Wood S, Ye Z, and Zheng X
- Abstract
Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θ_{cm}^{p}=70°. The longitudinal transfer K_{LL}, measured to be 0.645±0.059±0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ~3 times larger than predicted by the generalized-parton-distribution-based calculations, which indicates a significant unknown contribution to the scattering amplitude.
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- 2015
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19. Increase in visceral fat per se does not induce insulin resistance in the canine model.
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Castro AV, Woolcott OO, Iyer MS, Kabir M, Ionut V, Stefanovski D, Kolka CM, Szczepaniak LS, Szczepaniak EW, Asare-Bediako I, Paszkiewicz RL, Broussard JL, Kim SP, Kirkman EL, Rios HC, Mkrtchyan H, Wu Q, Ader M, and Bergman RN
- Subjects
- Animals, Body Composition, Body Weight, Dogs, Glucose Clamp Technique, Intra-Abdominal Fat innervation, Magnetic Resonance Imaging, Male, Models, Animal, Omentum innervation, Organ Size, Subcutaneous Fat, Abdominal anatomy & histology, Subcutaneous Fat, Abdominal innervation, Subcutaneous Fat, Abdominal metabolism, Sympathectomy, Chemical veterinary, Insulin Resistance, Intra-Abdominal Fat anatomy & histology, Intra-Abdominal Fat metabolism
- Abstract
Objectives: To determine whether a selective increase of visceral adipose tissue content will result in insulin resistance., Methods: Sympathetic denervation of the omental fat was performed under general inhalant anesthesia by injecting 6-hydroxydopamine in the omental fat of lean mongrel dogs (n = 11). In the conscious animal, whole-body insulin sensitivity was assessed by the minimal model (SI ) and the euglycemic hyperinsulinemic clamp (SICLAMP ). Changes in abdominal fat were monitored by magnetic resonance. All assessments were determined before (Wk0) and 2 weeks (Wk2) after denervation. Data are medians (upper and lower interquartile)., Results: Denervation of omental fat resulted in increased percentage (and content) of visceral fat [Wk0: 10.2% (8.5-11.4); Wk2: 12.4% (10.4-13.6); P < 0.01]. Abdominal subcutaneous fat remained unchanged. However, no changes were found in SI [Wk0: 4.7 (mU/l)(-1) min(-1) (3.1-8.8); Wk2: 5.3 (mU/l)(-1) min(-1) (4.5-7.2); P = 0.59] or SICLAMP [Wk0: 42.0 × 10(-4) dl kg(-1) min(-1) (mU/l)(-1) (41.0-51.0); Wk2: 40.0 × 10(-4) dl kg(-1) min(-1) (mU/l) (-1) (34.0-52.0); P = 0.67]., Conclusions: Despite a selective increase in visceral adiposity in dogs, insulin sensitivity in vivo did not change, which argues against the concept that accumulation of visceral adipose tissue contributes to insulin resistance., (© 2014 The Obesity Society.)
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- 2015
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20. Hepatic portal vein denervation impairs oral glucose tolerance but not exenatide's effect on glycemia.
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Ionut V, Castro AV, Woolcott OO, Stefanovski D, Iyer MS, Broussard JL, Burch M, Elazary R, Kolka CM, Mkrtchyan H, Bediako IA, and Bergman RN
- Subjects
- Animals, Biomarkers metabolism, Blood Glucose analysis, Crosses, Genetic, Denervation, Exenatide, Glucagon-Like Peptide-1 Receptor, Glucose Clamp Technique, Glucose Intolerance blood, Glucose Intolerance metabolism, Glucose Tolerance Test, Hyperglycemia etiology, Hyperinsulinism etiology, Hyperinsulinism prevention & control, Hypoglycemic Agents administration & dosage, Injections, Subcutaneous, Insulin blood, Insulin metabolism, Insulin Resistance, Insulin Secretion, Islets of Langerhans drug effects, Islets of Langerhans metabolism, Male, Peptides administration & dosage, Portal Vein drug effects, Portal Vein enzymology, Portal Vein surgery, Receptors, Glucagon metabolism, Tyrosine 3-Monooxygenase metabolism, Venoms administration & dosage, Glucose Intolerance drug therapy, Glucose Intolerance physiopathology, Hyperglycemia prevention & control, Hypoglycemic Agents therapeutic use, Peptides therapeutic use, Portal Vein physiopathology, Receptors, Glucagon agonists, Venoms therapeutic use
- Abstract
The hepatoportal area is an important glucohomeostatic metabolic sensor, sensing hypoglycemia, hyperglycemia, and hormones such as glucagon-like peptide-1 (GLP-1). We have reported previously that activation of hepatoportal sensors by intraportal infusion of glucose and GLP-1 or by subcutaneous administration of GLP-1 receptor activator exenatide and of intraportal glucose improved glycemia independent of corresponding changes in pancreatic hormones. It is not clear whether this effect is mediated via the portal vein (PV) or by direct action on the liver itself. To test whether receptors in the PV mediate exenatide's beneficial effect on glucose tolerance, we performed 1) paired oral glucose tolerance tests (OGTT) with and without exenatide and 2) intravenous glucose tolerance tests before and after PV denervation in canines. Denervation of the portal vein affected oral glucose tolerance; post-denervation (POST-DEN) OGTT glucose and insulin AUC were 50% higher than before denervation (P = 0.01). However, portal denervation did not impair exenatide's effect to improve oral glucose tolerance (exenatide effect: 48 ± 12 mmol·l⁻¹·min before vs. 64 ± 26 mmol·l⁻¹·min after, P = 0.67). There were no changes in insulin sensitivity or secretion during IVGTTs. Portal vein sensing might play a role in controlling oral glucose tolerance during physiological conditions but not in pharmacological activation of GLP-1 receptors by exenatide., (Copyright © 2014 the American Physiological Society.)
- Published
- 2014
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21. A yet unreported der(11)t(6;11)(p21;q21) included in a complex karyotype of a refractory anemia with ring sideroblasts and poor prognosis.
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de Souza DC, de Figueiredo AF, Mkrtchyan H, Othman MA, Liehr T, Dobbin J, Silva ML, Abdelhay E, and Fernandez Tde S
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- Anemia, Refractory diagnosis, Chromosomes, Human, Pair 11, Chromosomes, Human, Pair 6, Humans, In Situ Hybridization, Fluorescence, Male, Middle Aged, Prognosis, Anemia, Refractory genetics, Anemia, Refractory pathology, Chromosome Deletion, Karyotype, Translocation, Genetic
- Published
- 2014
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22. Separated response function ratios in exclusive, forward π(±) electroproduction.
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Huber GM, Blok HP, Butuceanu C, Gaskell D, Horn T, Mack DJ, Abbott D, Aniol K, Anklin H, Armstrong C, Arrington J, Assamagan K, Avery S, Baker OK, Barrett B, Beise EJ, Bochna C, Boeglin W, Brash EJ, Breuer H, Chang CC, Chant N, Christy ME, Dunne J, Eden T, Ent R, Fenker H, Gibson EF, Gilman R, Gustafsson K, Hinton W, Holt RJ, Jackson H, Jin S, Jones MK, Keppel CE, Kim PH, Kim W, King PM, Klein A, Koltenuk D, Kovaltchouk V, Liang M, Liu J, Lolos GJ, Lung A, Margaziotis DJ, Markowitz P, Matsumura A, McKee D, Meekins D, Mitchell J, Miyoshi T, Mkrtchyan H, Mueller B, Niculescu G, Niculescu I, Okayasu Y, Pentchev L, Perdrisat C, Pitz D, Potterveld D, Punjabi V, Qin LM, Reimer PE, Reinhold J, Roche J, Roos PG, Sarty A, Shin IK, Smith GR, Stepanyan S, Tang LG, Tadevosyan V, Tvaskis V, van der Meer RL, Vansyoc K, Van Westrum D, Vidakovic S, Volmer J, Vulcan W, Warren G, Wood SA, Xu C, Yan C, Zhao WX, Zheng X, and Zihlmann B
- Abstract
The study of exclusive π(±) electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=σL(π-)/σL(π+) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of RT=σT(π-)/σT(π+) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive π(±) electroproduction on the deuteron at central Q(2) values of 0.6, 1.0, 1.6 GeV(2) at W=1.95 GeV, and Q(2)=2.45 GeV(2) at W=2.22 GeV. Here, we present the L and T cross sections, with emphasis on RL and RT, and compare them with theoretical calculations. Results for the separated ratio RL indicate dominance of the pion-pole diagram at low -t, while results for RT are consistent with a transition between pion knockout and quark knockout mechanisms.
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- 2014
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23. Essentiality of portal vein receptors in hypoglycemic counterregulation: direct proof via denervation in male canines.
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Ionut V, Castro AV, Woolcott OO, Stefanovski D, Iyer MS, Broussard JL, Mkrtchyan H, Burch M, Elazary R, Kirkman E, and Bergman RN
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- Animals, Blood Glucose metabolism, Catecholamines metabolism, Dogs, Epinephrine blood, Glucose metabolism, Glucose Clamp Technique, Homeostasis, Hydrocortisone metabolism, Hypoglycemia metabolism, Hypoglycemia pathology, Insulin metabolism, Male, Norepinephrine blood, Portal Vein metabolism, Time Factors, Denervation methods, Hypoglycemia physiopathology, Hypoglycemic Agents pharmacology, Portal Vein innervation, Portal Vein pathology
- Abstract
A major issue of in the treatment of diabetes is the risk of hypoglycemia. Hypoglycemia is detected both centrally and peripherally in the porto-hepatic area. The portal locus for hypoglycemic detection was originally described using the "local irrigation of the liver" approach in a canine model. Further work using portal vein denervation (DEN) in a rodent model characterized portal hypoglycemic sensing in detail. However, recent controversy about the relevance of rodent findings to large animals and humans prompted us to investigate the effect of portal DEN on the hypoglycemic response in the canine, a species with multiple similarities to human glucose homeostasis. Hypoglycemic hyperinsulinemic clamps were performed in male canines, before (PRE) and after (POST) portal vein DEN or sham surgery (CON, control). Insulin (30 pmol/kg·min) and glucose (variable) were infused to slowly decrease systemic glycemia to 50 mg/dL over 160 minutes. The average plasma glucose during clamp steady state was: 2.9 ± 0.1 mmol DEN-PRE, 2.9 ± 0.2 mmol DEN-POST, 2.9 ± 0.1 mmol CON-PRE, and 2.8 ± 0.0 mmol CON-POST. There were no significant differences in plasma insulin between DEN and CON, PRE and POST experiments. The epinephrine response to hypoglycemia was reduced by 62% in DEN but not in CON. Steady-state cortisol was 46% lower after DEN but not after CON. Our study shows, in a large animal model, that surgical disconnection of the portal vein from the afferent pathway of the hypoglycemic counterregulatory circuitry results in a substantial suppression of the epinephrine response and a significant impact on cortisol response. These findings directly demonstrate an essential role for the portal vein in sensing hypoglycemia and relating glycemic information to the central nervous system.
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- 2014
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24. First detailed reconstruction of the karyotype of Trachypithecus cristatus (Mammalia: Cercopithecidae).
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Xiaobo F, Pinthong K, Mkrtchyan H, Siripiyasing P, Kosyakova N, Supiwong W, Tanomtong A, Chaveerach A, Liehr T, de Bello Cioffi M, and Weise A
- Abstract
Background: The chromosomal homologies of human (Homo sapiens = HSA) and silvered leaf monkey (Trachypithecus cristatus = TCR) have been previously studied by classical chromosome staining and by fluorescence in situ hybridization (FISH) applying chromosome-specific DNA probes of all human chromosomes in the 1980s and 1990s, respectively., Results: However, as the resolution of these techniques is limited we used multicolor banding (MCB) at an ~250-band level, and other selected human DNA probes to establish a detailed chromosomal map of TCR. Therefore it was possible to precisely determine evolutionary conserved breakpoints, orientation of segments and distribution of specific regions in TCR compared to HSA. Overall, 69 evolutionary conserved breakpoints including chromosomal segments, which failed to be resolved in previous reports, were exactly identified and characterized., Conclusions: This work also represents the first molecular cytogenetic one characterizing a multiple sex chromosome system with a male karyotype 44,XY1Y2. The obtained results are compared to other available data for old world monkeys and drawbacks in hominoid evolution are discussed.
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- 2013
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25. First determination of the weak charge of the proton.
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Androic D, Armstrong DS, Asaturyan A, Averett T, Balewski J, Beaufait J, Beminiwattha RS, Benesch J, Benmokhtar F, Birchall J, Carlini RD, Cates GD, Cornejo JC, Covrig S, Dalton MM, Davis CA, Deconinck W, Diefenbach J, Dowd JF, Dunne JA, Dutta D, Duvall WS, Elaasar M, Falk WR, Finn JM, Forest T, Gaskell D, Gericke MT, Grames J, Gray VM, Grimm K, Guo F, Hoskins JR, Johnston K, Jones D, Jones M, Jones R, Kargiantoulakis M, King PM, Korkmaz E, Kowalski S, Leacock J, Leckey J, Lee AR, Lee JH, Lee L, MacEwan S, Mack D, Magee JA, Mahurin R, Mammei J, Martin JW, McHugh MJ, Meekins D, Mei J, Michaels R, Micherdzinska A, Mkrtchyan A, Mkrtchyan H, Morgan N, Myers KE, Narayan A, Ndukum LZ, Nelyubin V, Nuruzzaman, van Oers WT, Opper AK, Page SA, Pan J, Paschke KD, Phillips SK, Pitt ML, Poelker M, Rajotte JF, Ramsay WD, Roche J, Sawatzky B, Seva T, Shabestari MH, Silwal R, Simicevic N, Smith GR, Solvignon P, Spayde DT, Subedi A, Subedi R, Suleiman R, Tadevosyan V, Tobias WA, Tvaskis V, Waidyawansa B, Wang P, Wells SP, Wood SA, Yang S, Young RD, and Zhamkochyan S
- Abstract
The Q(weak) experiment has measured the parity-violating asymmetry in ep elastic scattering at Q(2)=0.025(GeV/c)(2), employing 145 μA of 89% longitudinally polarized electrons on a 34.4 cm long liquid hydrogen target at Jefferson Lab. The results of the experiment's commissioning run, constituting approximately 4% of the data collected in the experiment, are reported here. From these initial results, the measured asymmetry is A(ep)=-279±35 (stat) ± 31 (syst) ppb, which is the smallest and most precise asymmetry ever measured in ep scattering. The small Q(2) of this experiment has made possible the first determination of the weak charge of the proton Q(W)(p) by incorporating earlier parity-violating electron scattering (PVES) data at higher Q(2) to constrain hadronic corrections. The value of Q(W)(p) obtained in this way is Q(W)(p)(PVES)=0.064±0.012, which is in good agreement with the standard model prediction of Q(W)(p)(SM)=0.0710±0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES+APV analysis reveals the neutron's weak charge to be Q(W)(n)(PVES+APV)=-0.975±0.010.
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- 2013
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26. First molecular cytogenetic high resolution characterization of the NIH 3T3 cell line by murine multicolor banding.
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Leibiger C, Kosyakova N, Mkrtchyan H, Glei M, Trifonov V, and Liehr T
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- Animals, Genome, In Situ Hybridization, Fluorescence, Mice, NIH 3T3 Cells, Chromosome Banding, Cytogenetic Analysis
- Abstract
Since being established in 1963, the murine fibroblast cell line NIH 3T3 has been used in thousands of studies. NIH 3T3 immortalized spontaneously and became tetraploid shortly after its establishment. Here we report the first molecular cytogenetic characterization of NIH 3T3 using fluorescence in situ hybridization based multicolor banding (mcb). Overall, a complex rearranged karyotype presenting 16 breakpoints was characterized. Also it was possible to deduce the resulting gains and losses of copy numbers in NIH 3T3. Overall, only 1.8% of the NIH 3T3 genome is disome, 26.2% tri-, 60% tetra-, 10.8% quinta-, and 1.2% hexasome. Strikingly, the cell line gained only 4 derivative chromosomes since its first cytogenetic description in 1989. An attempt to align the observed imbalances of the studied cell line with their homologous regions in humans gave the following surprising result: NIH 3T3 shows imbalances as typically seen in human solid cancers of ectodermal origin.
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- 2013
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27. Heteromorphic variants of chromosome 9.
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Kosyakova N, Grigorian A, Liehr T, Manvelyan M, Simonyan I, Mkrtchyan H, Aroutiounian R, Polityko AD, Kulpanovich AI, Egorova T, Jaroshevich E, Frolova A, Shorokh N, Naumchik IV, Volleth M, Schreyer I, Nelle H, Stumm M, Wegner RD, Reising-Ackermann G, Merkas M, Brecevic L, Martin T, Rodríguez L, Bhatt S, Ziegler M, Kreskowski K, Weise A, Sazci A, Vorsanova S, Cioffi Mde B, and Ergul E
- Abstract
Background: Heterochromatic variants of pericentromere of chromosome 9 are reported and discussed since decades concerning their detailed structure and clinical meaning. However, detailed studies are scarce. Thus, here we provide the largest ever done molecular cytogenetic research based on >300 chromosome 9 heteromorphism carriers., Results: In this study, 334 carriers of heterochromatic variants of chromosome 9 were included, being 192 patients from Western Europe and the remainder from Easter-European origin. A 3-color-fluorescence in situ hybridization (FISH) probe-set directed against for 9p12 to 9q13~21.1 (9het-mix) and 8 different locus-specific probes were applied for their characterization. The 9het-mix enables the characterization of 21 of the yet known 24 chromosome 9 heteromorphic patterns. In this study, 17 different variants were detected including five yet unreported; the most frequent were pericentric inversions (49.4%) followed by 9qh-variants (23.9%), variants of 9ph (11.4%), cenh (8.2%), and dicentric- (3.8%) and duplication-variants (3.3%). For reasons of simplicity, a new short nomenclature for the yet reported 24 heteromorphic patterns of chromosome 9 is suggested. Six breakpoints involved in four of the 24 variants could be narrowed down using locus-specific probes., Conclusions: Based on this largest study ever done in carriers of chromosome 9 heteromorphisms, three of the 24 detailed variants were more frequently observed in Western than in Eastern Europe. Besides, there is no clear evidence that infertility is linked to any of the 24 chromosome 9 heteromorphic variants.
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- 2013
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28. Observation of the (Λ)(7)He hypernucleus by the (e, e'K+) reaction.
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Nakamura SN, Matsumura A, Okayasu Y, Seva T, Rodriguez VM, Baturin P, Yuan L, Acha A, Ahmidouch A, Androic D, Asaturyan A, Asaturyan R, Baker OK, Benmokhtar F, Bosted P, Carlini R, Chen C, Christy M, Cole L, Danagoulian S, Daniel A, Dharmawardane V, Egiyan K, Elaasar M, Ent R, Fenker H, Fujii Y, Furic M, Gan L, Gaskell D, Gasparian A, Gibson EF, Gogami T, Gueye P, Han Y, Hashimoto O, Hiyama E, Honda D, Horn T, Hu B, Hungerford EV, Jayalath C, Jones M, Johnston K, Kalantarians N, Kanda H, Kaneta M, Kato F, Kato S, Kawama D, Keppel C, Lan KJ, Luo W, Mack D, Maeda K, Malace S, Margaryan A, Marikyan G, Markowitz P, Maruta T, Maruyama N, Miyoshi T, Mkrtchyan A, Mkrtchyan H, Nagao S, Navasardyan T, Niculescu G, Niculescu MI, Nomura H, Nonaka K, Ohtani A, Oyamada M, Perez N, Petkovic T, Randeniya S, Reinhold J, Roche J, Sato Y, Segbefia EK, Simicevic N, Smith G, Song Y, Sumihama M, Tadevosyan V, Takahashi T, Tang L, Tsukada K, Tvaskis V, Vulcan W, Wells S, Wood SA, Yan C, and Zhamkochyan S
- Abstract
An experiment with a newly developed high-resolution kaon spectrometer and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab. The ground state of a neutron-rich hypernucleus, (Λ)(7)He, was observed for the first time with the (e, e'K+) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The (Λ)(7)He binding energy supplies the last missing information of the A = 7, T = 1 hypernuclear isotriplet, providing a new input for the charge symmetry breaking effect of the ΛN potential.
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- 2013
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29. An unusual cytogenetic rearrangement originating from two different abnormalities in chromosome 6 in a child with acute promyelocytic leukemia.
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Matos RR, Mkrtchyan H, Amaral BA, Liehr T, de Souza MT, Ney-Garcia DR, Santos N, Marques-Salles TJ, Ribeiro RC, Figueiredo AF, and Silva ML
- Subjects
- Child, Chromosome Banding, Chromosomes, Human, Pair 15, Chromosomes, Human, Pair 17, Humans, In Situ Hybridization, Fluorescence, Male, Chromosomes, Human, Pair 6, Gene Rearrangement, Leukemia, Promyelocytic, Acute genetics, Translocation, Genetic genetics
- Abstract
Acute promyelocytic leukemia (APL) is usually associated with a favorable outcome, but about 10% of patients tend to relapse. The genetic hallmark of APL is a balanced translocation involving chromosomes 15 and 17, and the PML-RARa gene fusion is found in more than 90% of these cases. Other chromosomal abnormalities are commonly found in APL, but their clinical significance has yet to be determined. Here we report a case of childhood APL that was studied by conventional cytogenetics along with molecular cytogenetic techniques. The patient showed a complex karyotype with an unusual cytogenetic rearrangement originating from two different abnormalities in a single chromosome 6. Our case is an exceptional example of a cryptic cytogenetic anomaly in APL and underscores the importance of detailed genetic characterization., (Copyright © 2013 S. Karger AG, Basel.)
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- 2013
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30. Murine multicolor banding.
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Kosyakova N, Trifonov V, Romanenko S, Mkrtchyan H, Graphodatsky A, and Liehr T
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- Animals, Chromosome Banding standards, Chromosome Painting standards, In Situ Hybridization, Fluorescence, Karyotyping, Mice, Chromosome Banding methods, Chromosome Painting methods, Chromosomes, Mammalian
- Abstract
Multicolor banding approach, first introduced for human chromosomes only, was established as an optimal approach for karyotyping of murine chromosomes. Here we present the established mcb probe sets for all murine autosomes and the X-chromosome and review their potential application.
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- 2013
31. Polarization components in π0 photoproduction at photon energies up to 5.6 GeV.
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Luo W, Brash EJ, Gilman R, Jones MK, Meziane M, Pentchev L, Perdrisat CF, Puckett AJ, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Ates O, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy ME, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Kang H, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Markowitz P, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nuruzzaman, Nedev S, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer PE, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Širca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Strakovsky II, Subedi R, Suleiman R, Tomasi-Gustafsson E, Vasiliev A, Veilleux M, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L
- Abstract
We present new data for the polarization observables of the final state proton in the (1)H(γ,p)π(0) reaction. These data can be used to test predictions based on hadron helicity conservation and perturbative QCD. These data have both small statistical and systematic uncertainties and were obtained with beam energies between 1.8 and 5.6 GeV and for π(0) scattering angles larger than 75° in the center-of-mass frame. The data extend the polarization measurements database for neutral pion photoproduction up to E(γ)=5.6 GeV. The results show a nonzero induced polarization above the resonance region. The polarization transfer components vary rapidly with the photon energy and π(0) scattering angle in the center-of-mass frame. This indicates that hadron helicity conservation does not hold and that the perturbative QCD limit is still not reached in the energy regime of this experiment.
- Published
- 2012
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32. Measurement of the parity-violating asymmetry in inclusive electroproduction of π- near the Δ0 resonance.
- Author
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Androić D, Armstrong DS, Arvieux J, Bailey SL, Beck DH, Beise EJ, Benesch J, Benmokhtar F, Bimbot L, Birchall J, Bosted P, Breuer H, Capuano CL, Chao YC, Coppens A, Davis CA, Ellis C, Flores G, Franklin G, Furget C, Gaskell D, Gericke MT, Grames J, Guillard G, Hansknecht J, Horn T, Jones MK, King PM, Korsch W, Kox S, Lee L, Liu J, Lung A, Mammei J, Martin JW, McKeown RD, Micherdzinska A, Mihovilovic M, Mkrtchyan H, Muether M, Page SA, Papavassiliou V, Pate SF, Phillips SK, Pillot P, Pitt ML, Poelker M, Quinn B, Ramsay WD, Real JS, Roche J, Roos P, Schaub J, Seva T, Simicevic N, Smith GR, Spayde DT, Stutzman M, Suleiman R, Tadevosyan V, van Oers WT, Versteegen M, Voutier E, Vulcan W, Wells SP, Williamson SE, and Wood SA
- Abstract
The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the Δ0 resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant d(Δ)- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d(Δ)- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A(γ)-=-5.2 to +5.2 ppm. The measurement performed in this work leads to A(γ)-=-0.36±1.06±0.37±0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V(ud)/V(us). The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form factors using PV electron scattering.
- Published
- 2012
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33. New measurements of high-momentum nucleons and short-range structures in nuclei.
- Author
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Fomin N, Arrington J, Asaturyan R, Benmokhtar F, Boeglin W, Bosted P, Bruell A, Bukhari MH, Christy ME, Chudakov E, Clasie B, Connell SH, Dalton MM, Daniel A, Day DB, Dutta D, Ent R, El Fassi L, Fenker H, Filippone BW, Garrow K, Gaskell D, Hill C, Holt RJ, Horn T, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lindgren R, Lung AF, Malace S, Markowitz P, McKee P, Meekins DG, Mkrtchyan H, Navasardyan T, Niculescu G, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Seely J, Segbefia E, Slifer K, Smith GR, Solvignon P, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wasko C, Wesselmann FR, Wood SA, Wright J, and Zheng X
- Abstract
We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.
- Published
- 2012
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34. Extra Copies of der(21)t(12;21) plus Deletion of ETV6 Gene due to dic(12;18) in B-Cell Precursor ALL with Poor Outcome.
- Author
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Hernandes MA, Marques-Salles Tde J, Mkrtchyan H, Soares-Ventura EM, Leite EP, Muniz MT, Cornélio MT, Liehr T, Santos N, and Silva ML
- Abstract
Acute lymphoblastic leukemia (ALL), CD10+ B-cell precursor, represents the most frequent type of childhood ALL from 3 to 6 years of age. The t(12;21)(p13;q22) occurs in 25% of cases of B-cell precursor ALL, it is rare in children less than 24 months and have been related to good prognosis. Some relapse cases and unfavorable prognosis in ALL CD10+ are associated with t(12;21) bearing additional aberrations as extra copies of chromosome 21 and ETV6 gene loss. This report describes the case of a 15 month-year old girl, who displayed a karyotype with addition on chromosome 12p plus trisomy 10 and tetrasomy of chromosome 21. Molecular cytogenetic studies revealed two extra copies of the der(21) t(12;21), trisomy 10 and deletion of the second ETV6 gene due to the dic(12;18). These findings show the great importance of molecular cytogenetic studies to clarify complex karyotypes, to define prognostic, to carry out risk group stratification and to support correctly disease treatment in childhood acute lymphoblastic leukemia.
- Published
- 2012
- Full Text
- View/download PDF
35. Transverse beam spin asymmetries at backward angles in elastic electron-proton and quasielastic electron-deuteron scattering.
- Author
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Androić D, Armstrong DS, Arvieux J, Bailey SL, Beck DH, Beise EJ, Benesch J, Benmokhtar F, Bimbot L, Birchall J, Bosted P, Breuer H, Capuano CL, Chao YC, Coppens A, Davis CA, Ellis C, Flores G, Franklin G, Furget C, Gaskell D, Gericke MT, Grames J, Guillard G, Hansknecht J, Horn T, Jones MK, King PM, Korsch W, Kox S, Lee L, Liu J, Lung A, Mammei J, Martin JW, McKeown RD, Micherdzinska A, Mihovilovic M, Mkrtchyan H, Muether M, Page SA, Papavassiliou V, Pate SF, Phillips SK, Pillot P, Pitt ML, Poelker M, Quinn B, Ramsay WD, Real JS, Roche J, Roos P, Schaub J, Seva T, Simicevic N, Smith GR, Spayde DT, Stutzman M, Suleiman R, Tadevosyan V, van Oers WT, Versteegen M, Voutier E, Vulcan W, Wells SP, Williamson SE, Wood SA, Pasquini B, and Vanderhaeghen M
- Abstract
We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasielastic scattering on the deuteron, at backward angles (lab scattering angle of 108°) for Q² = 0.22 GeV²/c² and 0.63 GeV²/c² at beam energies of 362 and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single-photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (πN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasistatic deuterium approximation, and is also in agreement with theory.
- Published
- 2011
- Full Text
- View/download PDF
36. Molecular cytogenetics reveals complex karyotype in apparent t(8;13) therapy-related acute myeloid leukemia M2 after fibrosarcoma.
- Author
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Soares-Ventura EM, Mkrtchyan H, de Jesus Marques-Salles T, Silva M, Santos N, de Araujo Silva Amaral B, Liehr T, Abdelhay E, Silva ML, and Muniz MT
- Subjects
- Adolescent, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Bone Neoplasms drug therapy, Bone Neoplasms genetics, Bone Neoplasms pathology, Bone Neoplasms surgery, Chromosome Aberrations, Cytogenetic Analysis, Humans, Karyotyping methods, Lung Neoplasms drug therapy, Lung Neoplasms secondary, Lung Neoplasms surgery, Male, Neoplasms, Second Primary chemically induced, Neoplasms, Second Primary genetics, Osteosarcoma drug therapy, Osteosarcoma genetics, Osteosarcoma pathology, Osteosarcoma surgery, Antineoplastic Combined Chemotherapy Protocols adverse effects, Chromosomes, Human, Pair 13 genetics, Chromosomes, Human, Pair 8 genetics, Leukemia, Myeloid, Acute chemically induced, Leukemia, Myeloid, Acute genetics, Translocation, Genetic
- Published
- 2011
- Full Text
- View/download PDF
37. Search for effects beyond the born approximation in polarization transfer observables in e(over→)p elastic scattering.
- Author
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Meziane M, Brash EJ, Gilman R, Jones MK, Luo W, Pentchev L, Perdrisat CF, Puckett AJ, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Ates O, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy E, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Kang H, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Markowitz P, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nuruzzaman, Nedev S, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer PE, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Širca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Subedi R, Suleiman R, Tomasi-Gustafsson E, Vasiliev A, Vanderhaeghen M, Veilleux M, Wojtsekhowski BB, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L
- Abstract
Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, G(E)/G(M), obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic H(e[over →],e(')p[over →]) reaction for three different beam energies at a Q(2)=2.5 GeV(2), spanning a wide range of the kinematic parameter ε. The ratio R, which equals μ(p)G(E)/G(M) in the Born approximation, is found to be independent of ε at the 1.5% level. The ε dependence of the longitudinal polarization transfer component P(ℓ) shows an enhancement of (2.3±0.6)% relative to the Born approximation at large ε., (© 2011 American Physical Society)
- Published
- 2011
- Full Text
- View/download PDF
38. Secondary abnormalities involving 1q or 13q and poor outcome in high stage Burkitt leukemia/lymphoma cases with 8q24 rearrangement at diagnosis.
- Author
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de Souza MT, Mkrtchyan H, Hassan R, Ney-Garcia DR, de Azevedo AMB, da Costa ES, de Figueiredo AF, Liehr T, Abdelhay E, and Silva MLM
- Subjects
- Burkitt Lymphoma diagnosis, Child, Child, Preschool, Chromosome Breakpoints, Humans, Male, Prognosis, Severity of Illness Index, Burkitt Lymphoma genetics, Chromosomes, Human, Pair 1 genetics, Chromosomes, Human, Pair 13 genetics, Chromosomes, Human, Pair 8 genetics, Gene Duplication, Gene Rearrangement
- Abstract
Classical Burkitt lymphoma/leukemia (BL/L) presenting L3 morphology is found in 1% of childhood ALL. Recently, it has been described that secondary abnormalities could influence the prognosis of these patients. However, little information is available on these cytogenetic abnormalities and their prognostic importance in BL/L. Here, we report four new childhood BL/L cases associated with duplication within 1q or 13q, which exhibited a very unfavorable therapeutic response. We performed both classical and molecular cytogenetic analysis by multicolor chromosome banding of the secondary abnormalities involving the long arms of chromosome 1 or 13. These patients were previously treated with BFM-90 protocol. All of them died during or after the initial treatment. Here, for the first time, the exact breakpoints of the derivative chromosomes involved were determined at the cytogenetic level as 1q21 and 13q33 each.
- Published
- 2011
- Full Text
- View/download PDF
39. Scaling of the F2 structure function in nuclei and quark distributions at x>1.
- Author
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Fomin N, Arrington J, Day DB, Gaskell D, Daniel A, Seely J, Asaturyan R, Benmokhtar F, Boeglin W, Boillat B, Bosted P, Bruell A, Bukhari MH, Christy ME, Chudakov E, Clasie B, Connell SH, Dalton MM, Dutta D, Ent R, El Fassi L, Fenker H, Filippone BW, Garrow K, Hill C, Holt RJ, Horn T, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lindgren R, Lung AF, Malace S, Markowitz P, McKee P, Meekins DG, Miyoshi T, Mkrtchyan H, Navasardyan T, Niculescu G, Okayasu Y, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Segbefia E, Slifer K, Smith GR, Solvignon P, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wasko C, Wesselmann FR, Wood SA, Wright J, and Zheng X
- Abstract
We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.
- Published
- 2010
- Full Text
- View/download PDF
40. Probing quark-gluon interactions with transverse polarized scattering.
- Author
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Slifer K, Rondón OA, Aghalaryan A, Ahmidouch A, Asaturyan R, Bloch F, Boeglin W, Bosted P, Carasco C, Carlini R, Cha J, Chen JP, Christy ME, Cole L, Coman L, Crabb D, Danagoulian S, Day D, Dunne J, Elaasar M, Ent R, Fenker H, Frlez E, Gaskell D, Gan L, Gomez J, Hu B, Jourdan J, Jones MK, Keith C, Keppel CE, Khandaker M, Klein A, Kramer L, Liang Y, Lichtenstadt J, Lindgren R, Mack D, McKee P, McNulty D, Meekins D, Mkrtchyan H, Nasseripour R, Niculescu I, Normand K, Norum B, Pocanic D, Prok Y, Raue B, Reinhold J, Roche J, Kiselev D, Savvinov N, Sawatzky B, Seely M, Sick I, Smith C, Smith G, Stepanyan S, Tang L, Tajima S, Testa G, Vulcan W, Wang K, Warren G, Wesselmann FR, Wood S, Yan C, Yuan L, Yun J, Zeier M, and Zhu H
- Abstract
We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.
- Published
- 2010
- Full Text
- View/download PDF
41. The human genome puzzle - the role of copy number variation in somatic mosaicism.
- Author
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Mkrtchyan H, Gross M, Hinreiner S, Polytiko A, Manvelyan M, Mrasek K, Kosyakova N, Ewers E, Nelle H, Liehr T, Bhatt S, Thoma K, Gebhart E, Wilhelm S, Fahsold R, Volleth M, and Weise A
- Abstract
The discovery of copy number variations (CNV) in the human genome opened new perspectives in the study of the genetic causes of inherited disorders and the etiology of common diseases. Differently patterned instances of somatic mosaicism in CNV regions have been shown to be present in monozygotic twins and throughout different tissues within an individual. A single-cell-level investigation of CNV in different human cell types led us to uncover mitotically derived genomic mosaicism, which is stable in different cell types of one individual. A unique study of immortalized B-lymphoblastoid cell lines obtained with 20 year interval from the same two subjects shows that mitotic changes in CNV regions may happen early during embryonic development and seem to occur only once, as levels of mosaicism remained stable. This finding has the potential to change our concept of dynamic human genome variation. We propose that further genomic studies should focus on the single-cell level, to understand better the etiology and physiology of aging and diseases mediated by somatic variations.
- Published
- 2010
- Full Text
- View/download PDF
42. A rare case of Philadelphia chromosome-positive chronic myelogenous leukemia with inversion in chromosome 9 and t(10;17).
- Author
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Achkar WA, Wafa A, Mkrtchyan H, Moassass F, and Liehr T
- Abstract
The reciprocal translocation t(9;22)(q34;q11), leading to the formation of two fusion genes, BCR/ABL and ABL/BCR, is found in 90-95% of cases with chronic myeloid leukemia (CML). ABL-BCR expression does not correlate with prognosis, as assessed by cytogenetic response, since the ABL/BCR gene is expressed in only a proportion of CML patients. This study examined an exceptional BCR/ABL-positive CML case with inversion in 9q22q34 leading to the absence of ABL/BCR. Moreover, an unbalanced translocation between chromosomes 10 and 17 which caused deletion of the TP53 gene was identified. The TP53 gene plays a potential role in CML progression, and loss of TP53 may be regarded as a poor prognostic factor.
- Published
- 2010
- Full Text
- View/download PDF
43. A unique complex translocation involving six different chromosomes in a case of childhood acute lymphoblastic leukemia with the Philadelphia chromosome and adverse prognosis.
- Author
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Achkar WA, Wafa A, Mkrtchyan H, Moassass F, and Liehr T
- Abstract
Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Approximately 84% of cases of ALL are classified as B-precursor ALL, 14% of cases are T-cell and 2% of cases are B-cell (B-)ALL. About one third of B-ALL cases show an abnormal karyotype. Combining data obtained by immunophenotyping, karyotyping and molecular cytogenetic analyses allows for a better understanding of this heterogeneous disease. This study reports an exceptional B-ALL case with a poor prognosis and unique complex chromosomal aberrations not previously observed, i.e., a translocation involving the six chromosomal regions 1q42, 4q21, 4q24, 4q35 (twice), 8q22 and 10p15.3 besides 9q34 and 22q11.2.
- Published
- 2010
- Full Text
- View/download PDF
44. Unusual childhood biphenotypic acute leukemia with a yet unreported t(3;13)(p25.1;q13).
- Author
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Marques-Salles Tde J, Barros JE, Soares-Ventura EM, Cartaxo Muniz MT, Santos N, Ferreira da Silva E, Silva ML, Liehr T, and Mkrtchyan H
- Subjects
- Adolescent, Humans, Leukemia, Myeloid, Acute drug therapy, Leukemia, Myeloid, Acute genetics, Male, Phenotype, Precursor T-Cell Lymphoblastic Leukemia-Lymphoma drug therapy, Precursor T-Cell Lymphoblastic Leukemia-Lymphoma genetics, Prognosis, Chromosomes, Human, Pair 13 genetics, Chromosomes, Human, Pair 3 genetics, Killer Cells, Natural pathology, Leukemia, Myeloid, Acute pathology, Precursor T-Cell Lymphoblastic Leukemia-Lymphoma pathology, Translocation, Genetic genetics
- Published
- 2010
- Full Text
- View/download PDF
45. Complex karyotype defined by molecular cytogenetic FISH and M-FISH in an infant with acute megakaryoblastic leukemia and neurofibromatosis.
- Author
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Marques-Salles Tde J, Mkrtchyan H, Leite EP, Soares-Ventura EM, Muniz MT, Silva EF, Liehr T, Silva ML, and Santos N
- Subjects
- Female, Genes, p53, Histone-Lysine N-Methyltransferase, Humans, Infant, Karyotyping, Myeloid-Lymphoid Leukemia Protein genetics, In Situ Hybridization, Fluorescence methods, Leukemia, Megakaryoblastic, Acute genetics, Neurofibromatoses genetics
- Abstract
Acute myeloid leukemia in childhood is a heterogeneous group of diseases, and different epidemiologic factors are involved in the etiopathogenesis. Genetic syndromes are one of the predisposing factors of acute myeloid leukemia (AML), including Down syndrome, Bloom syndrome, and neurofibromatosis. Acute megakaryoblastic leukemia (AMKL) is the main subtype in Down syndrome infants, and acquired chromosomal anomalies are closely related to the physiopathology of the illness. The main chromosomal anomalies in AMKL are structural, such as t(1;22); however, complex karyotypes are also common. Here we describe the case of an infant with neurofibromatosis developing AMKL with a complex karyotype including 5q and 17q deletions, TP53 deletion, and an unusual unbalanced chromosomal translocation t(11;19)(q13;p13), leading to three copies of the MLL gene., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
46. Recoil polarization measurements of the proton electromagnetic form factor ratio to Q2 = 8.5 GeV2.
- Author
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Puckett AJ, Brash EJ, Jones MK, Luo W, Meziane M, Pentchev L, Perdrisat CF, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy E, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Gilman R, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nedev S, Nuruzzaman, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer P, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Sirca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Subedi R, Tomasi-Gustafsson E, Vasiliev A, Veilleux M, Wojtsekhowski BB, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L
- Abstract
Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5 GeV2. By extending the range of Q2 for which G(E)(p) is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime.
- Published
- 2010
- Full Text
- View/download PDF
47. A rare case of chronic myeloid leukemia with secondary chromosomal changes including partial trisomy 17q21 to 17qter and partial monosomy of 16p13.3.
- Author
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Al Achkar W, Wafa A, Mkrtchyan H, Moassass F, and Liehr T
- Abstract
Background: The so-called Philadelphia (Ph) chromosome is present in almost all cases with chronic myeloid leukemia (CML). Around 5-10% of these patients show complex translocations involving other chromosomes in addition to and/or besides chromosomes 9 and 22. As nowadays most CML cases are treated with Imatinib, variant rearrangements have in general no specific prognostic significance, though events of therapy resistance remain to be studied., Results: Here we report a Ph chromosome positive patient with hematological typical chronic phase CML. Untypically, an unbalanced complex rearrangement involving chromosomes 16 and 17 leading to a deletion of 16pter and partial trisomy of 17q21 to 17qter, was identified besides a trisomy 8 and an additional Ph chromosome in a part of malignant cells., Conclusion: Here a novel and cytogenetically unique case of a Ph chromosome positive CML clinically in chronic phase is reported, having complex secondary chromosomal aberrations. Thus, CML patients with complex chromosomal changes are nonetheless treatable by Imatinib.
- Published
- 2010
- Full Text
- View/download PDF
48. Early embryonic chromosome instability results in stable mosaic pattern in human tissues.
- Author
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Mkrtchyan H, Gross M, Hinreiner S, Polytiko A, Manvelyan M, Mrasek K, Kosyakova N, Ewers E, Nelle H, Liehr T, Volleth M, and Weise A
- Subjects
- Adult, B-Lymphocytes cytology, Chromosomes, Artificial, Bacterial, Cytogenetic Analysis, Female, Fibroblasts metabolism, Gene Dosage, Genome, Human, Humans, In Situ Hybridization, Fluorescence, Male, Mutation, T-Lymphocytes cytology, Chromosomal Instability, Mosaicism
- Abstract
The discovery of copy number variations (CNV) in the human genome opened new perspectives on the study of the genetic causes of inherited disorders and the aetiology of common diseases. Here, a single-cell-level investigation of CNV in different human tissues led us to uncover the phenomenon of mitotically derived genomic mosaicism, which is stable in different cell types of one individual. The CNV mosaic ratios were different between the 10 individuals studied. However, they were stable in the T lymphocytes, immortalized B lymphoblastoid cells, and skin fibroblasts analyzed in each individual. Because these cell types have a common origin in the connective tissues, we suggest that mitotic changes in CNV regions may happen early during embryonic development and occur only once, after which the stable mosaic ratio is maintained throughout the differentiated tissues. This concept is further supported by a unique study of immortalized B lymphoblastoid cell lines obtained with 20 year difference from two subjects. We provide the first evidence of somatic mosaicism for CNV, with stable variation ratios in different cell types of one individual leading to the hypothesis of early embryonic chromosome instability resulting in stable mosaic pattern in human tissues. This concept has the potential to open new perspectives in personalized genetic diagnostics and can explain genetic phenomena like diminished penetrance in autosomal dominant diseases. We propose that further genomic studies should focus on the single-cell level, to better understand the aetiology of aging and diseases mediated by somatic mutations.
- Published
- 2010
- Full Text
- View/download PDF
49. Purification, characterisation and identification of acidocin LCHV, an antimicrobial peptide produced by Lactobacillus acidophilus n.v. Er 317/402 strain Narine.
- Author
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Mkrtchyan H, Gibbons S, Heidelberger S, Zloh M, and Limaki HK
- Subjects
- Amino Acid Sequence, Antimicrobial Cationic Peptides chemistry, Antimicrobial Cationic Peptides metabolism, Bacteriocins chemistry, Bacteriocins metabolism, Gram-Negative Bacteria drug effects, Gram-Positive Bacteria drug effects, Humans, Hydrogen-Ion Concentration, Lactobacillus acidophilus metabolism, Microbial Viability, Molecular Weight, Peptide Hydrolases metabolism, Protein Stability, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Temperature, Antimicrobial Cationic Peptides isolation & purification, Antimicrobial Cationic Peptides pharmacology, Bacteriocins isolation & purification, Bacteriocins pharmacology, Lactobacillus acidophilus chemistry
- Abstract
In the last two decades, antimicrobial peptides (AMPs) have been gaining attention as antimicrobial alternatives to chemical food preservatives and commonly used antibiotics. Lactobacillus acidophilus n.v. Er 317/402 strain Narine produces a small AMP with a molecular weight of 1.1kDa, designated acidocin LCHV. In this study, the AMP was extremely heat stable (90min at 130 degrees C), was active over a wide pH range and was found to be sensitive to proteolytic enzymes (trypsin, pepsin and proteinase K). Acidocin LCHV has a broad spectrum of activity both against Gram-positive and Gram-negative pathogens, including several that are classified as Especially Dangerous Infections by the World Health Organization as well as meticillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile. Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) was used to determine the molecular mass and sequence of the purified peptide. Complete killing with immediate impact on cells was observed within a very short period of time (10min)., (Copyright 2009 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
50. Molecular cytogenetic studies characterize a near-triploid complex karyotype in a child with acute lymphoblastic leukemia.
- Author
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Mkrtchyan H, Garcia Ney DR, de Ventura ES, Liehr T, Felix GR, Marques-Salles Tde J, Abdelhay E, and Macedo Silva ML
- Subjects
- Child, Female, Humans, Karyotyping, Chromosome Aberrations, Polyploidy, Precursor Cell Lymphoblastic Leukemia-Lymphoma genetics
- Abstract
High hyperdiploidy with modal chromosome numbers between 50 and 65 is common in childhood acute lymphoblastic leukemia (ALL), occurring in 25-30% of the cases. This chromosomal constitution is associated with a very good prognosis. By contrast, near triploidy and tetraploidy are found in <1% of childhood ALL. Given the sparseness of this group, the associated chromosomal abnormalities and their prognostic implications have not yet been studied in detail. Here, we describe clinical and molecular cytogenetic findings in a child with ALL who had a near-triploid complex karyotype, with loss and gain of chromosomes, including extra copies of the same derivative chromosomes. These findings suggest a random nondisjunction mechanism for near triploidy in the present case., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
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